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The evaluation of the ecotoxicity of chemical compounds is often hampered by the scarcity of the literature data on toxicity, biodegradability, and accumulation. In this study additional data on 16 Cl\\/N-containing organic compounds were gathered by laboratory experiments. For assignment to so-called gray or black lists, two different classification schemes were used. According to both schemes 3-nitrotoluene, 1,2- and 1,3-dichlorobenzene,
J. H. Canton; W. Slooff; H. J. Kool; J. Struys; T. J. Pouw; R. C. Wegman; G. J. Piet
The evaluation of the ecotoxicity of chemical compounds is often hampered by the scarcity of the literature data on toxicity, biodegradability, and accumulation. In this study additional data on 16 Cl/N-containing organic compounds were gathered by laboratory experiments. For assignment to so-called gray or black lists, two different classification schemes were used. According to both schemes 3-nitrotoluene, 1,2- and 1,3-dichlorobenzene, the 1-chloro-nitrobenzenes, 2,3-dichloronitrobenzene, 2-chloroaniline, and 2-chloro-4-nitroaniline were marked as black list substances, primarily based on poor biodegradability; 2- and 4-nitrotoluene, nitrobenzene, and 2-methoxyaniline were classified as gray list substances. For 3- and 4-methoxyaniline and 1,4-dichlorobenzene no agreement in classification was obtained. Additionally, water quality criteria are proposed for 2-, 3-, and 4-nitrotoluene and nitrobenzene, based on long-term toxicity data: respectively 0.3, 0.2, 0.4, and 1.0 mg/liter.
Canton, J.H.; Slooff, W.; Kool, H.J.; Struys, J.; Pouw, T.J.; Wegman, R.C.; Piet, G.J.
NASA Technical Reports Server (NTRS)
The successful return of the STARDUST spacecraft provides a unique opportunity to investigate the nature and distribution of organic matter in cometary dust particles collected from Comet 81P/Wild-2. Analysis of individual cometary impact tracks in silica aerogel using the technique of two-step laser mass spectrometry (L2MS) demonstrates the presence of complex aromatic organic matter. While concerns remain as to the organic purity of the aerogel collection medium and the thermal effects associated with hypervelocity capture, the majority of the observed organic species appear indigenous to the impacting particles and are hence of cometary origin. While the aromatic fraction of the total organic matter present is believed to be small, it is notable in that it appears to be N-rich. Spectral analysis in combination with instrumental detection sensitivities suggest that N is incorporated predominantly in the form of aromatic nitriles (R-C N). While organic species in the STARDUST samples do share some similarities with those present in the matrices of carbonaceous chondrites, the closest match is found with stratospherically collected interplanetary dust particles. These findings are consistent with the notion that a fraction of interplanetary dust is of cometary origin. The presence of complex organic N-containing species in comets has astrobiological implications since comets are likely to have contributed to the prebiotic chemical inventory of both the Earth and Mars.
McKay, David S.; Clemett. Simon J.; Sandford, Scott A.; Nakamura-Messenger, Keiko; Hoerz, Fredrich
Organic compounds in meteorites
NASA Technical Reports Server (NTRS)
Recent studies of carbonaceous chondrites provide evidence that certain organic compounds are indigenous and the result of an abiotic, chemical synthesis. The results of several investigators have established the presence of amino acids and precursors, mono- and dicarboxylic acids, N-heterocycles, and hydrocarbons as well as other compounds. For example, studies of the Murchison and Murray meteorites have revealed the presence of at least 40 amino acids with nearly equal abundances of D and L isomers. The population consists of both protein and nonprotein amino acids including a wide variety of linear, cyclic, and polyfunctional types. Results show a trend of decreasing concentration with increasing carbon number, with the most abundant being glycine (41 n Moles/g). These and other results to be reviewed provide persuasive support for the theory of chemical evolution and provide the only natural evidence for the protobiological subset of molecules from which life on earth may have arisen.
Lawless, J. G.
Organic Compounds in Carbonaceous Meteorites
NASA Technical Reports Server (NTRS)
Carbonaceous meteorites are relatively enriched in soluble organic compounds. To date, these compounds provide the only record available to study a range of organic chemical processes in the early Solar System chemistry. The Murchison meteorite is the best-characterized carbonaceous meteorite with respect to organic chemistry. The study of its organic compounds has related principally to aqueous meteorite parent body chemistry and compounds of potential importance for the origin of life. Among the classes of organic compounds found in Murchison are amino acids, amides, carboxylic acids, hydroxy acids, sulfonic acids, phosphonic acids, purines and pyrimidines (Table 1). Compounds such as these were quite likely delivered to the early Earth in asteroids and comets. Until now, polyhydroxylated compounds (polyols), including sugars (polyhydroxy aldehydes or ketones), sugar alcohols, sugar acids, etc., had not been identified in Murchison. Ribose and deoxyribose, five-carbon sugars, are central to the role of contemporary nucleic acids, DNA and RNA. Glycerol, a three-carbon sugar alcohol, is a constituent of all known biological membranes. Due to the relative lability of sugars, some researchers have questioned the lifetime of sugars under the presumed conditions on the early Earth and postulated other (more stable) compounds as constituents of the first replicating molecules. The identification of potential sources and/or formation mechanisms of pre-biotic polyols would add to the understanding of what organic compounds were available, and for what length of time, on the ancient Earth.
Cooper, Grorge
Perfluorinated compounds (PFCs) have gained notoriety in the recent past. Global distribution of PFCs in wildlife, environmental samples and humans has sparked a recent increase in new investigations concerning PFCs. Historically PFCs have been used in a wide variety of consume...
Extraterrestrial Organic Compounds in Meteorites
NASA Technical Reports Server (NTRS)
Many organic compounds or their precursors found in meteorites originated in the interstellar or circumstellar medium and were later incorporated into planetesimals during the formation of the solar system. There they either survived intact or underwent further processing to synthesize secondary products on the meteorite parent body. The most distinct feature of CI and CM carbonaceous chondrites, two types of stony meteorites, is their high carbon content (up to 3% of weight), either in the form of carbonates or of organic compounds. The bulk of the organic carbon consists of an insoluble macromolecular material with a complex structure. Also present is a soluble organic fraction, which has been analyzed by several separation and analytical procedures. Low detection limits can be achieved by derivatization of the organic molecules with reagents that allow for analysis by gas chromatography/mass spectroscopy and high performance liquid chromatography. The CM meteorite Murchison has been found to contain more than 70 extraterrestrial amino acids and several other classes of compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles as well as carbonyl compounds, alcohols, amines and amides. The organic matter was found to be enriched in deuterium, and distinct organic compounds show isotopic enrichments of carbon and nitrogen relative to terrestrial matter.
Botta, Oliver; Bada, Jeffrey L.; Meyer, Michael (Technical Monitor)
Thermochemical data of organic compounds
This reference consists of tables of thermochemical data for many organic compounds. The following topics are covered: standard enthalpies of formation derived from experimental data; prediction of standard enthalpies of formation; group interactions; interpretation of group interactions; prediction of unknown values; and future developments.
J. B. Pedley; R. D. Naylor; S. B. Kirby
Biofiltration of volatile organic compounds.
The removal of volatile organic compounds (VOCs) from contaminated airstreams has become a major air pollution concern. Improvement of the biofiltration process commonly used for the removal of odorous compounds has led to a better control of key parameters, enabling the application of biofiltration to be extended also to the removal of VOCs. Moreover, biofiltration, which is based on the ability of micro-organisms to degrade a large variety of compounds, proves to be economical and environmentally viable. In a biofilter, the waste gas is forced to rise through a layer of packed porous material. Thus, pollutants contained in the gaseous effluent are oxidised or converted into biomass by the action of microorganisms previously fixed on the packing material. The biofiltration process is then based on two principal phenomena: (1) transfer of contaminants from the air to the water phase or support medium, (2) bioconversion of pollutants to biomass, metabolic end-products, or carbon dioxide and water. The diversity of biofiltration mechanisms and their interaction with the microflora mean that the biofilter is defined as a complex and structured ecosystem. As a result, in addition to operating conditions, research into the microbial ecology of biofilters is required in order better to optimise the management of such biological treatment systems. PMID:15803311
Malhautier, Luc; Khammar, Nadia; Bayle, Sandrine; Fanlo, Jean-Louis
Volatile organic compound sensor system
Generally, this invention relates to the development of field monitoring methodology for new substances and sensing chemical warfare agents (CWAs) and terrorist substances. It also relates to a portable test kit which may be utilized to measure concentrations of halogenated volatile organic compounds (VOCs) in the field. Specifically it relates to systems for reliably field sensing the potential presence of such items while also distinguishing them from other elements potentially present. It also relates to overall systems and processes for sensing, reacting, and responding to an indicated presence of such substance, including modifications of existing halogenated sensors and arrayed sensing systems and methods.
Schabron, John F. (Laramie, WY); Rovani, Jr., Joseph F. (Laramie, WY); Bomstad, Theresa M. (Waxahachie, TX); Sorini-Wong, Susan S. (Laramie, WY); Wong, Gregory K. (Laramie, WY)
Low volatile organic compound paints
Increasingly stringent air emission standards in various states has dictated the elimination of engineering finishes which are derived from high volatile organic compound (VOC) paint chemistries. In July 1989, Allied-Signal, Inc., Kansas City Division, Kansas City, Missouri, voluntarily closed its paint facility, due to non-compliance with local air emission standards. The following details the materials selection and evaluations which led to current processing using low VOC paints, which permitted the Allied Signal, Inc., paint facility to achieve compliance and resume operations. 1 tab.
Martinez, F.E.
Organic compounds in carbonaceous meteorites.
The carbonaceous chondrite meteorites are fragments of asteroids that have remained relatively unprocessed since the formation of the solar system 4.6 billion years ago. These carbon-rich objects contain a variety of extraterrestrial organic molecules that constitute a record of chemical evolution prior to the origin of life. Compound classes include aliphatic hydrocarbons, aromatic hydrocarbons, amino acids, carboxylic acids, sulfonic acids, phosphonic acids, alcohols, aldehydes, ketones, sugars, amines, amides, nitrogen heterocycles, sulfur heterocycles and a relatively abundant high molecular weight macromolecular material. Structural and stable isotopic characteristics suggest that a number of environments may have contributed to the organic inventory, including interstellar space, the solar nebula and the asteroidal meteorite parent body. This review covers work published between 1950 and the present day and cites 193 references. PMID:12137279
Sephton, Mark A
Volatile organic compound sensing devices
Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs. 15 figs.
Lancaster, G.D.; Moore, G.A.; Stone, M.L.; Reagen, W.K.
Volatile organic compound sensing devices
Apparatus employing vapochromic materials in the form of inorganic double complex salts which change color reversibly when exposed to volatile organic compound (VOC) vapors is adapted for VOC vapor detection, VOC aqueous matrix detection, and selective VOC vapor detection. The basic VOC vapochromic sensor is incorporated in various devices such as a ground probe sensor, a wristband sensor, a periodic sampling monitor, a soil/water penetrometer, an evaporative purge sensor, and various vacuum-based sensors which are particularly adapted for reversible/reusable detection, remote detection, continuous monitoring, or rapid screening of environmental remediation and waste management sites. The vapochromic sensor is used in combination with various fiber optic arrangements to provide a calibrated qualitative and/or quantitative indication of the presence of VOCs.
Lancaster, Gregory D. (Idaho Falls, ID); Moore, Glenn A. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID); Reagen, William K. (Stillwater, MN)
Microbial removal of hazardous organic compounds
An in-depth evaluation of the potential for microorganisms to remove anthropogenic organic compounds, mainly priority pollutants and related compounds, is presented. The evaluation indicates that use of properly selected populations of microbes, and the maintenance of environmental conditions most conducive to their metabolism, can be an important means of improving biological treatment of organic wastes. One major theme is that
Hester Kobayashi; B. E. Rittman
The results of C┬╣Ōü┤-labeling under neutron irradiation of two ; groups of compounds are reported: (1) naphthalene, phenanthrene, and anthracene ; in an attempt to determine whether or not high energy C┬╣Ōü┤ fragments formed ; by nuclear recoil would favor or discriminate against any particular position in ; product formations; (2) pseudoephedrine, 2-amino-pyrimidine, and 3,6-; dihydroxypyridazine as complex nitrogen-containing compounds.
S. Oae; M. Hamada; Y. Otsuji; N. Furukawa; E. Iwamoto
Alkylation of organic aromatic compounds
Aromatic compounds are alkylated in a catalytic distillation, wherein the catalyst structure also serves as a distillation component by contacting the aromatic compound with a C[sub 2] to C[sub 10] olefin in the catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 80 C to 500 C, using as the catalyst a mole sieve characterized as acidic or an acidic cation exchange resin. For example, ethyl benzene is produced by feeding ethylene below the catalyst bed while benzene is conveniently added through the reflux in molar excess to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene in the bottoms. 1 fig.
Smith, L.A. Jr.
Microwave spectra of some volatile organic compounds
NASA Technical Reports Server (NTRS)
A computer-controlled microwave (MRR) spectrometer was used to catalog reference spectra for chemical analysis. Tables of absorption frequency, peak absorption intensity, and integrated intensity are included for 26 volatile organic compounds, all but one of which contain oxygen.
White, W. F.
A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...
A wide range of perfluorinated organic compounds (PFCs) has been used in a variety of industrial processes and consumer products. The most commonly studied PFCs include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but there are many more compounds in this c...
Volatile organic compounds of Schenella pityophilus
Volatile organic compounds of Schenella pityophilus have been identified via solid-phase microextraction-gas chromatography¢mass spectrometry analysis. Ten compounds have been identified, in which 3-methylthio-1-propene was the most significant component. Some other components were previously identified in Tuber aestivum and Tuber melanosporum.
Maurizio DÆAuria; Rocco Racioppi; Gian Luigi Rana
Volatile organic compounds of Schenella pityophilus.
Volatile organic compounds of Schenella pityophilus have been identified via solid-phase microextraction-gas chromatography-mass spectrometry analysis. Ten compounds have been identified, in which 3-methylthio-1-propene was the most significant component. Some other components were previously identified in Tuber aestivum and Tuber melanosporum. PMID:22236093
D'Auria, Maurizio; Racioppi, Rocco; Rana, Gian Luigi
Volatile organic compounds in ambient aerosols
NASA Astrophysics Data System (ADS)
In order to investigate the concentration levels of volatile organic compounds (VOCs) in ambient aerosols, monocyclic aromatic hydrocarbons (MAHs) and chlorinated hydrocarbons (CHs) in the particulate phase were measured simultaneously with those in the gas phase in the urban atmosphere. Six compounds were detected in the aerosols at concentrations from 0.051 (1,2-dichloroethane) to 1.75 ng m - 3 (benzene). Benzene was detected as the most dominant compound in the aerosols, although toluene was the most dominant compound in the gas phase. The VOCs in the aerosols had concentrations comparable to those reported for some semi-volatile organic compounds (SOCs) in the aerosols. The concentrations of the VOCs in the aerosols were primarily controlled by the aerosol mass loading. Temperature and relative humidity had no significant effect on the gas/particle partitioning of the VOCs. Our results also suggested that the hygroscopic properties of the aerosols should be considered to discuss the partitioning of the VOCs.
Matsumoto, Kiyoshi; Matsumoto, Kumi; Mizuno, Riichi; Igawa, Manabu
Alkylation of organic aromatic compounds
Aromatic compounds are alkylated in a combination reactor/distillation column comprising a vessel suitable for operating between 70 C and 500 C and from 0.5 to 20 atmospheres pressure; an inert distillation packing in the lower one-third of said vessel; solid acidic catalytic material such as zeolites or an acidic cation exchange resin supported in the middle one-third of said vessel; and inert distillation packing in the upper one-third of said vessel. A benzene inlet is located near the upper end of the vessel; an olefin inlet is juxtaposed with said solid acidic catalytic material; a bottoms outlet is positioned near the bottom of said vessel for removing said cumene and ethyl benzene; and an overhead outlet is placed at the top of said vessel for removing any unreacted benzene and olefin.
Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.
Abundance of organic compounds in water
There are currently available 175 lists that give the identities and frequencies of occurrence of organic compounds in water. Some of the environmentally significant questions that arise from examining these lists are presented. A simple, accurate theoretical model is developed to answer these questions and to predict the behavior of trace organics in the aquatic environment. (8 references, 1 tables)
Schaeffer, D.J.; Janardan, K.G.
Possible complex organic compounds on Mars.
It is suggested that primitive Mars had somehow similar environments as primitive Earth. If life was born on the primitive earth using organic compounds which were produced from the early Earth environment, the same types of organic compounds were also formed on primitive Mars. Such organic compounds might have been preserved on Mars still now. We are studying possible organic formation on primitive and present Mars. A gaseous mixture of CO2, CO, N2 and H2O with various mixing ratios were irradiated with high energy protons (major components of cosmic rays). Hydrogen cyanide and formaldehyde were detected among volatile products, and yellow-brown-colored water-soluble non-volatile substances were produced, which gave amino acids after acid-hydrolysis. Major part of "amino acid precursors" were not simple molecules like aminonitriles, but complex compounds which eluted earlier than free amino acids in cation-exchange HPLC. These organic compounds should be major targets in the future Mars mission. Strategy for the detection of the complex organics on Mars will be discussed. PMID:11541335
Kobayashi, K; Sato, T; Kajishima, S; Kaneko, T; Ishikawa, Y; Saito, T
Possible complex organic compounds on Mars
NASA Astrophysics Data System (ADS)
It is suggested that primitive Mars had somehow similar environments as primitive Earth. If life was born on the primitive earth using organic compounds which were produced from the early Earth environment, the same types of organic compounds were also formed on primitive Mars. Such organic compounds might have been preserved on Mars still now. We are studying possible organic formation on primitive and present Mars. A gaseous mixture of CO_2, CO, N_2 and H_2O with various mixing ratios were irradiated with high energy protons (major components of cosmic rays). Hydrogen cyanide and formaldehyde were detected among volatile products, and yellow-brown-colored water-soluble non-volatile substances were produced, which gave amino acids after acid-hydrolysis. Major part of ``amino acid precursors'' were not simple molecules like aminonitriles, but complex compounds which eluted earlier than free amino acids in cation-exchange HPLC. These organic compounds should be major targets in the future Mars mission. Strategy for the detection of the complex organics on Mars will be discussed.
Kobayashi, K.; Sato, T.; Kajishima, S.; Kaneko, T.; Ishikawa, Y.; Saito, T.
Reflectance spectroscopy of organic compounds: 1. Alkanes
Reflectance spectra of the organic compounds comprising the alkane series are presented from the ultraviolet to midinfrared, 0.35 to 15.5 /??m. Alkanes are hydrocarbon molecules containing only single carbon-carbon bonds, and are found naturally on the Earth and in the atmospheres of the giant planets and Saturn's moon, Titan. This paper presents the spectral properties of the alkanes as the first in a series of papers to build a spectral database of organic compounds for use in remote sensing studies. Applications range from mapping the environment on the Earth, to the search for organic molecules and life in the solar system and throughout the. universe. We show that the spectral reflectance properties of organic compounds are rich, with major diagnostic spectral features throughout the spectral range studied. Little to no spectral change was observed as a function of temperature and only small shifts and changes in the width of absorption bands were observed between liquids and solids, making remote detection of spectral properties throughout the solar system simpler. Some high molecular weight organic compounds contain single-bonded carbon chains and have spectra similar to alkanes even ' when they fall into other families. Small spectral differences are often present allowing discrimination among some compounds, further illustrating the need to catalog spectral properties for accurate remote sensing identification with spectroscopy.
Clark, R.N.; Curchin, J.M.; Hoefen, T.M.; Swayze, G.A.
Origin of organic compounds in carbonaceous chondrites
NASA Astrophysics Data System (ADS)
Carbonaceous chondrites, a class of primitive meteorite, have long been known to contain their complement of carbon largely in the form of organic, i.e., hydrocarbon-related, matter. Both discrete organic compounds and an insoluble, macromolecular material are present. Several characteristics of these materials provide evidence for their abiotic origin. The principal formation hypothesis have invoked chemistry occurring either in the solar nebula or on the parent body. However, recent stable isotope analyses of the meteorite carboxylic acids and amino acids indicate that they may be related to interstellar cloud compounds. These results suggest a formation scheme in which interstellar compounds were incorporated into the parent body and subsequently converted to the present suite of meteorite organics by the hydrothermal process believed to have formed the clay minerals of the meteorite matrix.
Cronin, J. R.
Catalyst for Oxidation of Volatile Organic Compounds
NASA Technical Reports Server (NTRS)
Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.
Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)
Ultraviolet radiation absorbing compounds in marine organisms
Studies on the biological effects of solar ultraviolet radiations are becoming increasingly common, in part due to recent interest in the Antarctic ozone hole and in the perceived potential for global climate change. Marine organisms possess many strategies for ameliorating the potentially damaging effects of UV-B (280-320 nm) and the shorter wavelengths of UV-A (320-400nm). One mechanism is the synthesis of bioaccumulation of ultraviolet radiation absorbing compounds. Several investigators have noted the presence of absorbing compounds in spectrophotometer scans of extracts from a variety of marine organisms, particularly algae and coelenterates containing endosymbiotic algae. The absorbing compounds are often mycosporine-like amino acids. Thirteen mycosporine-like amino acids have already been described, and several others have recently been detected. Although, the mycosporine-like amino acids are widely distributed. these compounds are by no means the only type of UV-B absorbing compounds which has been identified. Coumarins from green algae, quinones from sponges, and indoles from a variety of sources are laternative examples which are documented in the natural products literature. When the biological impact of solar ultraviolet radiation is assessed, adequate attention must be devoted to the process of photoadaptation, including the accumulation of ultraviolet radiation absorbing compounds.
Chalker, B.E.; Dunlap, W.C. (Australian Inst. of Marine Science, Queensland (Australia))
Emerging Control Technologies for Volatile Organic Compounds
Environmental problems associated with volatile organic compounds (VOCs) in the atmosphere have provided the driving force for sustained fundamental and applied research in the area of environmental remediation. Conventional methods currently used to treat VOCs include incineration, condensation, adsorption, and absorption. Incineration and condensation are cost-effective only for moderate to high VOC concentrations. Adsorption and absorption do not destroy VOCs
Geeta Rani Parmar; N. N. Rao
Catalytic Destruction Of Toxic Organic Compounds
NASA Technical Reports Server (NTRS)
Proposed process disposes of toxic organic compounds in contaminated soil or carbon beds safely and efficiently. Oxidizes toxic materials without producing such other contaminants as nitrogen oxides. Using air, fuel, catalysts, and steam, system consumes less fuel and energy than decontamination processes currently in use. Similar process regenerates carbon beds used in water-treatment plants.
Voecks, Gerald E.
Azodicarboxylates: synthesis and functionalization of organic compounds
NASA Astrophysics Data System (ADS)
The data on transformations of dialkyl azodicarboxylates and their analogues involving various substrates are generalized. Nucleophilic addition and oxidation, pericyclic reactions and reactions occurring under the Mitsunobu reaction conditions are considered. Ample opportunities for application of these compounds in fine organic synthesis are shown. The bibliography includes 245 references. Dedicated to Academician B A Trofimov on the occasion of his 75th birthday.
Zhirov, A. M.; Aksenov, A. V.
Nonvolatile organic compounds in treated waters.
Over the past decade much information has been published on the analysis of organics extracted from treated water. Certain of these organics have been shown to be by-products of the chlorination disinfection process and to possess harmful effects at high concentrations. This has resulted in increased interest in alternative disinfection processes, particularly ozonation. The data on organics had been largely obtained by using gas chromatography-mass spectrometry, which is only capable of analyzing, at best, 20% of the organics present in treated water. Research in key areas such as mutagenicity testing of water and characterization of chlorination and ozonation by-products has emphasized the need for techniques suitable for analysis of the remaining nonvolatile organics. Several methods for the isolation of nonvolatile organics have been evaluated and, of these, freeze-drying followed by methanol extraction appears the most suitable. Reverse-phase HPLC was used for separation of the methanol extract, but increased resolution for separation of the complex mixtures present is desirable. In this context, high resolution size exclusion chromatography shows promise. Characterization of separated nonvolatiles is possible by the application of state-of-the-art mass spectrometric techniques. Results obtained by these techniques have shown that the nonvolatile organic fraction of chlorinated drinking water consists of many discrete compounds. Among these, some of the chlorinated compounds are almost certainly by-products of disinfection. Studies of the by-products of ozonation of fulvic and humic acids isolated from river waters have indicated a similar proportion of nonvolatile organics. Further, ozonation can result in the release of compounds that are trapped in the macromolecules. PMID:6759110
Watts, C D; Crathorne, B; Fielding, M; Killops, S D
Organic photosensitive devices using subphthalocyanine compounds
An organic photosensitive optoelectronic device, having a donor-acceptor heterojunction of a donor-like material and an acceptor-like material and methods of making such devices is provided. At least one of the donor-like material and the acceptor-like material includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound; and/or the device optionally has at least one of a blocking layer or a charge transport layer, where the blocking layer and/or the charge transport layer includes a subphthalocyanine, a subporphyrin, and/or a subporphyrazine compound.
Rand, Barry (Princeton, NJ); Forrest, Stephen R. (Ann Arbor, MI); Mutolo, Kristin L. (Hollywood, CA); Mayo, Elizabeth (Alhambra, CA); Thompson, Mark E. (Anaheim Hills, CA)
Transport fate of organic compounds with water through landfills
Hazardous organic compounds have previously been identified in landfill leachates. The emissions of the organic compounds with leachates from landfills are dependent, among other processes, on the water transport through the landfill and the sorption of the compounds to the waste. The purpose of this study was to examine the transport of organic compounds with percolating water through a pilot-scale
Cecilia ųman; HÕkan Rosqvist
Toxic organic compounds from energy production
The US Department of Energy's Office of Health and Environmental Research (OHER) has supported work in our laboratory since 1977. The general theme of this program has been the identification of potentially toxic organic compounds associated with various combustion effluents, following the fates of these compounds in the environment, and improving the analytical methodology for making these measurements. The projects currently investigation include: an improved sampler for semi-volatile compounds in the atmosphere; the wet and dry deposition of dioxins and furans from the atmosphere; the photodegradation and mobile sources of dioxins and furans; and the bioaccumulation of PAH by tree bark. These projects are all responsive to OHER's interest in the pathways and mechanisms by which energy-related agents move through and are modified by the atmosphere''. The projects on gas chromatographic and liquid chromatographic tandem mass spectrometry are both responsive to OHER's interest in new and more sensitive technologies for chemical measurements''. 35 refs., 9 figs.
Hites, R.A.
Oxidation of Organic Compounds in the Soil.
, lnspector H. SCHMIDT, D. V. M., Veterinarian SUBSTATION NO. 1: Beeville, Bee County DIVISION OF CHEMISTRY G. S. FRAPS,.~~. D., Chemist in Charge; E. s. BINFORD, B. S.. Superi~tendenf State Chemzst SUBSTATION NO. 2: Troup, Smith County R H RIDGELL B.... After that time the loes on ignition is irregular, and it is difficult to follow the changes in the organic matter bp this .method. In this work, 20 grams excrement was mixed with 500 grams soil. OXIDATION OF ORGANIC COMPOUNDS IN THE SOIL. 7 TABLE 2...
Fraps, G. S. (George Stronach)
Volatile organic compounds (VOCs) in soils
Soils may act as sources or sinks of volatile organic compounds (VOCs). Many of the formed VOCs are produced by microorganisms,\\u000a and it would be a challenge to investigate soil microbial communities by studying their VOC profile. Such ōvolatilomicsö would\\u000a have the advantage of avoiding extraction steps that are often a limit in genomic or proteomic approaches. Abundant literature\\u000a on
Heribert Insam; Martin S. A. Seewald
Metabolic Reactions among Organic Sulfur Compounds
NASA Technical Reports Server (NTRS)
Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.
Schulte, M.; Rogers, K.
Production of volatile organic compounds by mycobacteria.
The need for improved rapid diagnostic tests for tuberculosis disease has prompted interest in the volatile organic compounds (VOCs) emitted by Mycobacterium tuberculosis complex bacteria. We have investigated VOCs emitted by Mycobacterium bovis BCG grown on Lowenstein-Jensen media using selected ion flow tube mass spectrometry and thermal desorption-gas chromatography-mass spectrometry. Compounds observed included dimethyl sulphide, 3-methyl-1-butanol, 2-methyl-1-propanol, butanone, 2-methyl-1-butanol, methyl 2-methylbutanoate, 2-phenylethanol and hydrogen sulphide. Changes in levels of acetaldehyde, methanol and ammonia were also observed. The compounds identified are not unique to M.Ābovis BCG, and further studies are needed to validate their diagnostic value. Investigations using an ultra-rapid gas chromatograph with a surface acoustic wave sensor (zNose) demonstrated the presence of 2-phenylethanol (PEA) in the headspace of cultures of M.Ābovis BCG and Mycobacterium smegmatis, when grown on Lowenstein-Jensen supplemented with glycerol. PEA is a reversible inhibitor of DNA synthesis. It is used during selective isolation of gram-positive bacteria and may also be used to inhibit mycobacterial growth. PEA production was observed to be dependent on growth of mycobacteria. Further study is required to elucidate the metabolic pathways involved and assess whether this compound is produced during in vivo growth of mycobacteria. PMID:22224870
McNerney, Ruth; Mallard, Kim; Okolo, Phyllis Ifeoma; Turner, Claire
40 CFR 60.602 - Standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
...2010-07-01 false Standard for volatile organic compounds. 60.602 Section 60...Standards of Performance for Synthetic Fiber Production Facilities ¦ 60.602 Standard for volatile organic compounds. On and after...
40 CFR 60.602 - Standard for volatile organic compounds.
Code of Federal Regulations, 2011 CFR
...2011-07-01 false Standard for volatile organic compounds. 60.602 Section 60...Standards of Performance for Synthetic Fiber Production Facilities ¦ 60.602 Standard for volatile organic compounds. On and after...
40 CFR 60.742 - Standards for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
...6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.742 Section 60.742 Protection...Supporting Substrates Facilities ¦ 60.742 Standards for volatile organic compounds. (a) Each owner or operator...
40 CFR 60.432 - Standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.432 Section 60.432 Protection...Publication Rotogravure Printing ¦ 60.432 Standard for volatile organic compounds. During the period of the...
Sonochemical processes have been widely used in chemistry and chemical engineering field. Recently, these processes have found new applications in the environmental field, because of advantages in terms of operational simplicity, secondary pollutant formation and safety. Several studies have reported on sonochemical degradation of organic compounds that are toxic in nature. The objective of this review was to identify and
Pankaj Chowdhury; T. Viraraghavan
Organic compounds in meteorites and their origins
NASA Technical Reports Server (NTRS)
The current investigation represents an extensively updated version of a review conducted by Anders et al. (1973). The investigation takes into account the literature through mid-1980. It is pointed out that Type 1 carbonaceous chondrites (C1) contain 6% of their cosmic complement of carbon, mainly in the form of organic matter. Most authors now agree that this material represents primitive prebiotic matter. The principal questions remaining are what abiotic processes formed the organic matter, and to what extent these processes took place in locales other than the solar nebula, such as interstellar clouds or meteorite parent bodes. The problem is approached in three stages. It is attempted to reconstruct the physical conditions during condensation from the clues contained in the inorganic matrix of the meteorite. The condensation behavior of carbon under these conditions is determined on the basis of thermodynamic calculations. Model experiments on the condensation of carbon are performed, and the synthesized compounds are compared with those actually found in meteorites.
Hayatsu, R.; Anders, E.
This research program was conducted to determine the capability of biological treatment and activated carbon adsorption to remove chemical carcinogens and other hazardous organic compounds from water and wastewater. Compounds studied were benzidine, 4-nitrobiphenyl, 3,3'-dichloro...
Static nonrenewal laboratory bioassays were conducted with 26 organic compounds commonly used by industry. The selected compounds represented the five following chemical classes: acids, alcohols, hydrocarbons, ketones and aldehydes, and phenols. Juvenile fathead minnows (Pimephal...
Method and reaction pathway for selectively oxidizing organic compounds
A method of selectively oxidizing an organic compound in a single vessel comprises: a) combining an organic compound, an acid solution in which the organic compound is soluble, a compound containing two oxygen atoms bonded to one another, and a metal ion reducing agent capable of reducing one of such oxygen atoms, and thereby forming a mixture; b) reducing the compound containing the two oxygen atoms by reducing one of such oxygen atoms with the metal ion reducing agent to, 1) oxidize the metal ion reducing agent to a higher valence state, and 2) produce an oxygen containing intermediate capable of oxidizing the organic compound; c) reacting the oxygen containing intermediate with the organic compound to oxidize the organic compound into an oxidized organic intermediate, the oxidized organic intermediate having an oxidized carbon atom; d) reacting the oxidized organic intermediate with the acid counter ion and higher valence state metal ion to bond the acid counter ion to the oxidized carbon atom and thereby produce a quantity of an ester incorporating the organic intermediate and acid counter ion; and e) reacting the oxidized organic intermediate with the higher valence state metal ion and water to produce a quantity of alcohol which is less than the quantity of ester, the acid counter ion incorporated in the ester rendering the carbon atom bonded to the counter ion less reactive with the oxygen containing intermediate in the mixture than is the alcohol with the oxygen containing intermediate.
Camaioni, Donald M. (Richland, WA); Lilga, Michael A. (Richland, WA)
Breath measurements as volatile organic compound biomarkers.
A brief review of the uses of breath analysis in studies of environmental exposure to volatile organic compounds (VOCs) is provided. The U.S. Environmental Protection Agency's large-scale Total Exposure Assessment Methodology Studies have measured concentrations of 32 target VOCs in the exhaled breath of about 800 residents of various U.S. cities. Since the previous 12-hr integrated personal air exposures to the same chemicals were also measured, the relation between exposure and body burden is illuminated. Another major use of the breath measurements has been to detect unmeasured pathways of exposure; the major impact of active smoking on exposure to benzene and styrene was detected in this way. Following the earlier field studies, a series of chamber studies have provided estimates of several important physiological parameters. Among these are the fraction, f, of the inhaled chemical that is exhaled under steady-state conditions and the residence times. tau i in several body compartments, which may be associated with the blood (or liver), organs, muscle, and fat. Most of the targeted VOCs appear to have similar residence times of a few minutes, 30 min, several hours, and several days in the respective tissue groups. Knowledge of these parameters can be helpful in estimating body burden from exposure or vice versa and in planning environmental studies, particularly in setting times to monitor breath in studies of the variation with time of body burden. Improvements in breath methods have made it possible to study short-term peak exposure situations such as filling a gas tank or taking a shower in contaminated water. PMID:8933027
Wallace, L; Buckley, T; Pellizzari, E; Gordon, S
Molecular Models of Volatile Organic Compounds
NSDL National Science Digital Library
This month's Featured Molecules come from the Report from Other Journals column, Nature: Our Atmosphere in the Year of Planet Earth, and the summary found there of the paper by Lelieveld et al. (1, 2) Added to the collection are several volatile organic compounds (VOCs) that are emitted by a variety of plants. The term VOCs is a common one in environmental chemistry, and is interpreted quite broadly, typically referring to any organic molecule with a vapor pressure sufficiently high to allow for part-per-billion levels in the atmosphere. Common VOCs include methane (the most prevalent VOC), benzene and benzene derivatives, chlorinated hydrocarbons, and many others. The source may be natural, as in the case of the plant emissions, or anthropogenic, as in the case of a molecule such as the gasoline additive methyl tert-butyl ether (MTBE).The oxidation of isoprene in the atmosphere has been a source of interest for many years. Several primary oxidation products are included in the molecule collection, although a number of isomeric forms are also possible (3).The area of VOCs provides innumerable topics for students research papers and projects at all levels of the curriculum from high-school chemistry through the undergraduate courses in chemistry and environmental science. Along the way students have the opportunity for exposure to fields such as epidemiology and toxicology, that may be new to them, but are of increasing importance in the environmental sciences. The MTBE story is an interesting one for students to discover, as it once again emphasizes the role that unintended consequences play in life. An exploration of the sources, structures, reactivity, health and environmental effects and ultimate fate of various VOCs reinforces in students minds just how interconnected the chemistry of the environment is, a lesson that bears repeating frequently.
Volatile Organic Compound Emissions by Agricultural Crops
NASA Astrophysics Data System (ADS)
Biogenic Volatile Organic Compounds (BVOCs) participate in ozone and aerosol formation, and comprise a substantial fraction of reactive VOC emission inventories. In the agriculturally intensive Central Valley of California, emissions from crops may substantially influence regional air quality, but emission potentials have not been extensively studied with advanced instrumentation for many important crops. Because crop emissions may vary according to the species, and California emission inventories are constructed via a bottom-up approach, a better knowledge of the emission rate at the species-specific level is critical for reducing uncertainties in emission inventories and evaluating emission model performance. In the present study we identified and quantified the BVOCs released by dominant agricultural crops in California. A screening study to investigate both volatile and semivolatile BVOC fractions (oxygenated VOCs, isoprene, monoterepenes, sesquiterpenes, etc.) was performed for 25 crop species (at least 3 replicates plants each), including branch enclosures of woody species (e.g. peach, mandarin, grape, pistachio) and whole plant enclosures for herbaceous species (e.g. onion, alfalfa, carrot), through a dynamic cuvette system with detection by PTRMS, in-situ GCMS/FID, and collection on carbon-based adsorbents followed by extraction and GCMS analysis. Emission data obtained in this study will allow inclusion of these crops in BVOC emission inventories and air quality simulations.
Ormeno, E.; Farres, S.; Gentner, D.; Park, J.; McKay, M.; Karlik, J.; Goldstein, A.
Volatile organic compound emissions from Siberian larch
NASA Astrophysics Data System (ADS)
We determined hourly emissions of isoprene, monoterpenes and sesquiterpenes from Siberian larch, one of the major tree species in Siberian forests. Summer volatile organic compounds (VOCs) emission from Siberian larch consisted mainly of monoterpenes (about 90%). The monoterpene emission spectrum remained constant during the measurement period, almost half was sabinene and other major monoterpenes were ?3-carene, ?- and ?-pinene. During spring and summer, about 10% of the VOCs were sesquiterpenes, mainly ?-farnesene. The sesquiterpene emissions declined to 3% in the fall. Isoprene, 2-methyl-3-buten-2-ol (MBO) and 1,8-cineole contributed to less than 3% of the VOC emission during the whole period. The diurnal variation of the emissions could be explained using a temperature-dependent parameterization. Emission potentials normalized to 30 ░C were 5.2-21 ?g g dw-1 h -1 (using ?-value of 0.09 ░C -1) for monoterpenes and 0.4-1.8 ?g g dw-1 h -1 (using ?-value of 0.143 ░C -1, mean of determined values) for sesquiterpenes. Normalized monoterpene emission potentials were highest in late summer and elevated again in late fall. Sesquiterpene emission potentials were also highest in late summer, but decreased towards fall.
Ruuskanen, T. M.; Hakola, H.; Kajos, M. K.; Hellķn, H.; Tarvainen, V.; Rinne, J.
Volatile organic compound remedial action project
This Environmental Assessment (EA) reviews a proposed project that is planned to reduce the levels of volatile organic compound (VOC) contaminants present in the Mound domestic water supply. The potable and industrial process water supply for Mound is presently obtained from a shallow aquifer via on-site production wells. The present levels of VOCs in the water supply drawn from the on-site wells are below the maximum contaminant levels (MCLs) permissible for drinking water under Safe Drinking Water Act (SDWA; 40 CFR 141); however, Mound has determined that remedial measures should be taken to further reduce the VOC levels. The proposed project action is the reduction of the VOC levels in the water supply using packed tower aeration (PTA). This document is intended to satisfy the requirements of the National Environmental Policy Act (NEPA) of 1969 and associated Council on Environmental Quality regulations (40 CFR parts 1500 through 1508) as implemented through U.S. Department of Energy (DOE) Order 5440.1D and supporting DOE NEPA Guidelines (52 FR 47662), as amended (54 FR 12474; 55 FR 37174), and as modified by the Secretary of Energy Notice (SEN) 15-90 and associated guidance. As required, this EA provides sufficient information on the probable environmental impacts of the proposed action and alternatives to support a DOE decision either to prepare an Environmental Impact Statement (EIS) or issue a Finding of No Significant Impact (FONSI).
Nitrated Secondary Organic Tracer Compounds in Biomass Burning Smoke
NASA Astrophysics Data System (ADS)
Natural and human-initiated biomass burning releases large amounts of gases and particles into the atmosphere, impacting climate, environment and affecting public health. Several hundreds of compounds are emitted from biomass burning and these compounds largely originate from the pyrolysis of biopolymers such as lignin, cellulose and hemicellulose. Some of compounds are known to be specific to biomass burning and widely recognized as tracer compounds that can be used to identify the presence of biomass burning PM. Detailed chemical analysis of biomass burning influenced PM samples often reveals the presence compounds that correlated well with levoglucosan, a known biomass burning tracer compound. In particular, nitrated aromatic compounds correlated very well with levoglucosan, indicating that biomass burning as a source for this class of compounds. In the present study, we present evidence for the presence of biomass burning originating secondary organic aerosol (BSOA) compounds in biomass burning influenced ambient PM. These BSOA compounds are typically nitrated aromatic compounds that are produced in the oxidation of precursor compounds in the presence of NOx. The precursor identification was performed from a series of aerosol chamber experiments. m-Cresol, which is emitted from biomass burning at significant levels, is found to be a major precursor compounds for nitrated BSOA compounds found in the ambient PM. We estimate that the total concentrations of these compounds in the ambient PM are comparable to biogenic SOA compounds in winter months, indicating the BSOA contributes important amounts to the regional organic aerosol loading.
Iinuma, Y.; B÷ge, O.; Grõfe, R.; Herrmann, H.
The adsorption to sediments and soils of selected organic acid compounds was examined as a function of compound and sediment properties. ntrinsic compound properties examined included the dissociation constant (pKa) and hydrophobic character. roperties of the sediment examined in...
Assessing Transformation Processes of Organic Compounds Using Stable
A S C O N I Swiss Federal Institute of Technology (ETH) Zurich Compound-specific stable isotope analysis signatures Compound-specific stable isotope analysis (CSIA) at natural abundance isotope levels opens newAssessing Transformation Processes of Organic Compounds Using Stable Isotope Fractionation T H O M
Gilli, Adrian
High Arctic Biogenic Volatile Organic Compound emissions
NASA Astrophysics Data System (ADS)
Biogenic volatile organic compounds (BVOCs) emitted from terrestrial vegetation participate in oxidative reactions, affecting the tropospheric ozone concentration and the lifetimes of greenhouse gasses such as methane. Also, they affect the formation of secondary organic aerosols. BVOCs thus provide a strong link between the terrestrial biosphere, the atmosphere and the climate. Global models of BVOC emissions have assumed minimal emissions from the high latitudes due to low temperatures, short growing seasons and sparse vegetation cover. However, measurements from this region of the world are lacking and emissions from the High Arctic have not been published yet. The aim of this study was to obtain the first estimates for BVOC emissions from the High Arctic. Hereby, we wish to add new knowledge to the understanding of global BVOC emissions. Measurements were conducted in NE Greenland (74░30' N, 20░30' W) in four vegetation communities in the study area. These four vegetation communities were dominated by Cassiope tetragona, Salix arctica, Vaccinium uliginosum and Kobresia myosuroides/Dryas octopetela/Salix arctica, respectively. Emissions were measured by enclosure technique and collection of volatiles into adsorbent cartridges in August 2009. The volatiles were analyzed by gas chromatography-mass spectrometry following thermal desorption. Isoprene showed highest emissions in S. arctica-dominated heath, where it was the dominant single BVOC. However, isoprene emission decreased below detection limit in the end of August when the temperature was at or below 10░C. According to a principal component analysis, monoterpene and sesquiterpene emissions were especially associated with C. tetragona-dominated heath. Especially S. arctica and C. tetragona dominated heaths showed distinct patterns of emitted BVOCs. Emissions of BVOC from the studied high arctic heaths were clearly lower than the emissions observed previously in subarctic heaths with more dense vegetation and higher ambient temperature. However, high arctic BVOC emissions are expected to increase in the future as a result of the predicted pronounced climate warming effects in the High Arctic. Therefore, we suggest that further studies should be conducted to investigate the effects of climate changes in the region in order to gain new knowledge and understanding of future global BVOC emissions.
Schollert, Michelle; Buchard, Sebrina; Faubert, Patrick; Michelsen, Anders; Rinnan, Riikka
Thermodynamic Equilibrium and the Inorganic Origin of Organic Compounds
Theoretical and experimental support is presented for the hypothesis that many organic compounds may form under conditions of thermodynamic equilibrium. This possibility must be considered along with special effects of selective catalysts, radiation, and degradation from biological matter, in explaining the origin of organic compounds in carbonaceous chondrites. Similar considerations may apply to solar nebulas and planetary atmospheres. The equilibrium
R. V. Eck; E. R. Lippincott; M. O. Dayhoff; Y. T. Pratt
Presence and Distribution of Organic Wastewater Compounds in Wastewater,
Presence and Distribution of Organic Wastewater Compounds in Wastewater, Surface, Ground.W., Meyer, M.T., and Zaugg, S.D., 2004, Presence and distri- bution of organic wastewater compounds in wastewater, surface, ground, and drinking waters, Minnesota, 2000-02: U.S. Geological Survey Scientific
40 CFR 60.392 - Standards for volatile organic compounds
Code of Federal Regulations, 2010 CFR
...6 2010-07-01 2010-07-01 false Standards for volatile organic compounds 60.392 Section 60.392 Protection...Truck Surface Coating Operations ¦ 60.392 Standards for volatile organic compounds On and after the date on which...
40 CFR 60.622 - Standards for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
...6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.622 Section 60.622 Protection...Performance for Petroleum Dry Cleaners ¦ 60.622 Standards for volatile organic compounds. (a) Each affected petroleum...
40 CFR 60.442 - Standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.442 Section 60.442 Protection...Label Surface Coating Operations ¦ 60.442 Standard for volatile organic compounds. (a) On and after the date on...
40 CFR 60.492 - Standards for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
...6 2010-07-01 2010-07-01 false Standards for volatile organic compounds. 60.492 Section 60.492 Protection...Beverage Can Surface Coating Industry ¦ 60.492 Standards for volatile organic compounds. On or after the date on which...
40 CFR 60.582 - Standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.582 Section 60.582 Protection...and Urethane Coating and Printing ¦ 60.582 Standard for volatile organic compounds. (a) On and after the date on...
40 CFR 60.452 - Standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds. 60.452 Section 60.452 Protection...Surface Coating: Large Appliances ¦ 60.452 Standard for volatile organic compounds. On or after the date on which the...
Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward the goal of developing a portable test kit for screening halogenated VOCs in the field.
John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad
Volatile organic compound sources for Southern Finland
NASA Astrophysics Data System (ADS)
Volatile organic compounds (VOCs) have several sources, both biogenic and anthropogenic. Emissions of biogenic VOCs in a global scale are estimated to be an order of magnitude higher than anthropogenic ones. However, in densely populated areas and during winter time the anthropogenic VOC emissions dominate over the biogenic ones. The aim of this study was to clarify potential local sources and source areas of VOCs in different seasons. Diurnal behaviour in winter and spring were also compared at two different sites in Finland: SMEAR II and III (Station for Measuring Ecosystem - Atmosphere Relations). SMEAR II is a rural site located in Hyytiõlõ in Southern Finland 220 km North-West from Helsinki whereas SMEAR III is background urban site located 5 km from the downtown of Helsinki. The volume mixing ratios of VOCs were measured with a proton-transfer-reaction mass spectrometer (PTR-MS, Ionicon Analytik GmbH, Austria) during years 2006-2011. Other trace gases such as CO, NOXand SO2 were also measured in both sites and used for source analysis. Source areas for long term VOC measurements were investigated with trajectory analysis and sources for local and regional concentrations were determined by Unmix multivariate receptor model. Forest fires affect air quality and the biggest smoke plumes can be seen in satellite images and even hinder visibility in the plume areas. They provide temporally and spatially well-defined sources that can be used to verify source area estimates. During the measurement periods two different forest fire episodes with several hotspots, happened in Russia. Forest fires which showed up in these measurements were in 2006 near the border of Finland in Vyborg area and 2010 in Moscow area. Forest fire episodes were clearly observed in trajectory analysis for benzene, toluene and methanol and also CO and NOX. In addition to event sources continuous source areas were determined. Anthropogenic local sources seemed to be dominant during winter in both sites. However during spring biogenic influence increased. In addition to source analysis this behaviour was visible in enhanced diurnal cycles of VOCs (Patokoski et al., 2014, in press). We will present important sources and source areas for Southern Finland's concentrations. References: Patokoski, J., Ruuskanen, T.M., Hellķn, H., Taipale, R., Gr÷nholm, T., Kajos, M.K., Petõjõ, T., Hakola, H., Kulmala, M. & Rinne, J., 2014. Winter to spring transition and diurnal variation of VOCs in Finland at an urban background site and a rural site. Boreal Env. Res. 19. In press.
Patokoski, Johanna; Ruuskanen, Taina M.; Kajos, Maija K.; Taipale, Risto; Rantala, Pekka; Aalto, Juho; Ryypp÷, Timo; Hakola, Hannele; Rinne, Janne
78 FR 11119 - Air Quality: Revision to Definition of Volatile Organic Compounds-Exclusion of trans
Federal Register 2010, 2011, 2012, 2013
...Definition of Volatile Organic Compounds--Exclusion...definition of volatile organic compounds (VOCs) for...Honeywell under the trade names Solstice TM...small businesses, small organizations, and small governmental...requirements, Volatile organic compounds....
Quantifying commuter exposures to volatile organic compounds
NASA Astrophysics Data System (ADS)
Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the laboratory using standard BTEX gases. The LODs for the Tenax TA sampling tubes (determined with a sample volume of 1,000 standard cubic centimeters which is close to the approximate commuter sample volumes collected) were orders of magnitude lower (0.04 to 0.7 parts per billion (ppb) for individual compounds of BTEX) compared to the PIDs' LODs (9.3 to 15 ppb of a BTEX mixture), which makes the Tenax TA sampling method more suitable to measure BTEX concentrations in the sub-parts per billion (ppb) range. PID and Tenax TA data for commuter exposures were inversely related. The concentrations of VOCs measured by the PID were substantially higher than BTEX concentrations measured by collocated Tenax TA samplers. The inverse trend and the large difference in magnitude between PID responses and Tenax TA BTEX measurements indicates the two methods may have been measuring different air pollutants that are negatively correlated. Drivers in Fort Collins, Colorado with closed windows experienced greater time-weighted average BTEX exposures than cyclists (p: 0.04). Commuter BTEX exposures measured in Fort Collins were lower than commuter exposures measured in prior studies that occurred in larger cities (Boston and Copenhagen). Although route and intake may affect a commuter's BTEX dose, these variables are outside of the scope of this study. Within the limitations of this study (including: small sample size, small representative area of Fort Collins, and respiration rates not taken into account), it appears health risks associated with traffic-induced BTEX exposures may be reduced by commuting via cycling instead of driving with windows closed and living in a less populous area that has less vehicle traffic. Although the PID did not reliably measure low-level commuter BTEX exposures, the Tenax TA sampling method did. The PID measured BTEX concentrations reliably in a controlled environment, at high concentrations (300-800 ppb), and in the absence of other air pollutants. In environments where there could be multiple chemicals present that may produce a PID signal (such a
Kayne, Ashleigh
Enantiomeric and Isotopic Analysis of Organic Compounds in Carbonaceous Meteorites
NASA Technical Reports Server (NTRS)
Carbonaceous meteorites are relatively enriched in soluble organic compounds. The Murchison and Murray meteorites contain numerous compounds of interest in the study of early solar system organic chemistry and organic compounds of potential importance for the origin of life. These include: amino acids, amides, carboxylic acids, and polyols. This talk will focus on the enantiomeric and isotopic analysis of individual meteoritic compounds - primarily polyol acids. The analyses will determine if, in addition to certain amino acids from Murchison, another potentially important class of prebiotic compounds also contains enantiomeric excesses, i.e., excesses that could have contributed to the current homochirality of life. Preliminary enantiomeric and isotopic (C- 13) measurements of Murchison glyceric acid show that it is indeed extraterrestrial. C-13 and D isotope analysis of meteoritic sugar alcohols (glycerol, threitol, ribitol, etc.) has shown that they are also indigenous to the meteorite.
Cooper, George
Organic Compounds Used in Animal Husbandry
Although in general, the same drugs are used by humans as for animal husbandry, some compounds are unique to CAFOs. In raising\\u000a and fattening steers, anabolic steroids are widely used in the US. In the cattle industry, large use is made of the acaricides,\\u000a avermectins, and the cypermethrins as well as juvenile growth hormone inhibitor for fly and tick control
Laurence Shore; Robert Wershaw
Structure of Organic Oxygen Compounds of Sulphur
The nature of the sulphur-oxygen bond, the geometry of molecules of the types XYSO, XYSO2, XSOOH, and XSO2OH, and the character of the intramolecular interactions in these compounds are discussed. Apart from the sigma-bond between sulphur and oxygen, interaction obviously occurs by means of the 3d-orbital of sulphur and the 2p-orbital of oxygen (2p-3d hybridisation). The interaction of a sulphinyl
Yu A. Kolesnik; V. V. Kozlov
High-value organic compounds have been synthesized successfully from linear and cyclic hydrocarbons, by photocatalytic oxidation using a semiconductor material, titanium dioxide (TiO2). Various hydrocarbons were partially oxgenated in both liquid and gaseous phase reactors usi...
Human exposure to volatile organic compounds elicits a variety ofsymptoms, many of which are thought to be mediated by the olfactoryand trigeminal systems. his report describes evidence indicatingthat perceived odor intensity diminishes during prolonged exposure,whearas irritatin...
This research program was conducted to determine the capability of biological and physical-chemical treatment processes to remove chemical carcinogens and other hazardous organic compounds from water and wastewater. Treatment processes investigated included biological degradation...
Innovative and customized monitoring methods for air toxic volatile organic compounds (VOCs) are being developed for applications in exposure and trends monitoring. This task addresses the following applications of specific interest: o Contributions to EPA Regional Monit...
The report gives Level 2 procedures, including results of a laboratory evaluation of detailed methods for analyzing organic chemicals in particular compound categories. The report, supplementing an earlier Level 2 procedures manual, provides an initial experimental data base as a...
Air Oxidation of Organic Compounds in Aqueous Systems.
National Technical Information Service (NTIS)
Wet oxidation is a newer technique for disposal of sludge wastes from sewage or industrial treatment by air oxidation under pressure. The rates of oxidation of several solid organic compounds were studied over a range of conditions. Experiments were condu...
D. W. Sundstrom
Synthesis of fluorinated organic compounds using oxygen difluoride
NASA Technical Reports Server (NTRS)
Oxygen difluoride synthesis is a much simpler, higher-yield procedure than reactions originally followed to synthesize various fluorinated organic compounds. Extreme care is taken in working with oxygen difluoride as its reactions present severe explosion hazard.
Toy, M. S.
Retro-Biosynthesis for the Microbial Production of Organic Compounds.
National Technical Information Service (NTIS)
This project was concerned with the development of a methodology for the specification of novel biosynthetic pathways towards organic compounds. Our overall objective is to expand the potential for biological production of small molecules, especially for ...
K. L. Jones Prather
Improved methods for onsite measurement of multiple volatile organic compounds are needed for process control, monitoring, and remediation. This Phase I SBIR project sets forth an optical measurement method that meets these needs. The proposed approach provides an instantaneous m...
Laboratory, industrial, chemical, or other waste products may have constituents that evolve volatile organic compounds (VOCS) at very high concentrations. hese could pose human health risks during handling, storage, and disposal of the waste through inhalation, dermal exposure, o...
Reduction of Volatile Organic Compound Emissions from Automobile Refinishing,
National Technical Information Service (NTIS)
Automobile refinishing (repainting) is a source of volatile organic compound (VOC) emissions. The study was conducted to evaluate available techniques that can be used to reduce VOC emissions from this source. The document provides information on the step...
C. Athey, C. Hester, M. McLaughlin, R. M. Neulicht, M. B. Turner
The paper discusses the development of a global inventory of anthropogenic volatile organic compound (VOC) emissions. t includes VOC estimates for seven classes of VOCs: paraffins, olefins, aromatics (benzene, toluene, xylene), formaldehyde, other aldehydes, other aromatics, and ...
The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...
Influence of surfactants on microbial degradation of organic compounds
Surfactants have the ability to increase aqueous concentrations of poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. However, both enhancements and inhibitions of biodegradation of organic compounds in the presence of surfactants have been reported. The mechanisms behind these phenomena are not well understood. To better understand the factors
Joseph D. Rouse; David A. Sabatini; Joseph M. Suflita; Jeffrey H. Harwell
The report gives results of the compilation of a data base for concentrations of organic compounds measured indoors. ased on a review of the literature from 1979 through 1990, the data base contains information on over 220 compounds ranging in molecular weight from 30 to 446. he ...
A suite of 27 volatile organic compounds (VOCs) were monitored in personal exposures, indoors and outdoors of participant's residences, and at a central community site during the DEARS summer 2004 monitoring season. The list of VOCs focused on compounds typically associated with ...
Process for reducing organic compounds with calcium, amine, and alcohol
Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about -10.degree. C. to about 30.degree. C. or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.
Benkeser, Robert A. (West Lafayette, IN); Laugal, James A. (Lostant, IL); Rappa, Angela (Baltimore, MD)
Process for reducing organic compounds with calcium, amine, and alcohol
Olefins are produced by contacting an organic compound having at least one benzene ring with calcium metal, ethylenediamine, a low molecular weight aliphatic alcohol, and optionally a low molecular weight aliphatic primary amine, and/or an inert, abrasive particulate substance. The reduction is conducted at temperatures ranging from about [minus]10 C to about 30 C or somewhat higher. Substantially all of the organic compounds are converted to corresponding cyclic olefins, primarily diolefins.
Benkeser, R.A.; Laugal, J.A.; Rappa, A.
Transport, behavior, and fate of volatile organic compounds in streams
Volatile organic compounds (VOCs) are compounds with chemical and physical properties that allow the compounds to move freely between the water and air phases of the environment. VOCs are widespread in the environment because of this mobility. Many VOCs have properties making them suspected or known hazards to the health of humans and aquatic organisms. Consequently, understanding the processes affecting the concentration and distribution VOCs in the environment is necessary. The U.S. Geological Survey selected 55 VOCs for study. This report reviews the characteristics of the various process that could affect the transport, behavior, and fate of these VOCs in streams.
Rathbun, R.E.
Analysis of volatile organic compounds from illicit cocaine samples
Detection of illicit cocaine hydrochloride shipments can be improved if there is a greater understanding of the identity and quantity of volatile compounds present. This study provides preliminary data concerning the volatile organic compounds detected in a limited Set of cocaine hydrochloride samples. In all cases, cocaine was one of the major volatile compounds detected. Other tropeines were detected in almost all samples. Low concentrations of compounds that may be residues of processing solvents were observed in some samples. The equilibrium emissivity of. cocaine from cocaine hydrochloride was investigated and a value of 83 parts-per-trillion was determined.
Robins, W.H.; Wright, B.W.
Adsolubilisation of organic compounds onto collagen fibres.
Adsolubilisation has been defined as the incorporation to solid-water interfaces of molecules that do not adsorb spontaneously to such interfaces, but can be incorporated through an interaction with an adsorbing surfactant molecule. The aim of this work was to study the adsolubilisation of organic molecules with different hydrophobicity on collagen fibres. Hide powder collagen was treated under mild acidic aqueous conditions with an anionic surfactant, sodium dodecylbenzene sulphonate. Thereafter, five different organic molecules, i.e., benzyl alcohol, 2-naphtol, pararosaniline, hexamethylpararosaniline and nonylphenol with 10 mol ethylene oxide were separately applied to the treated collagen in order to study adsolubilisation as a function of their hydrophobicity. It was found that under acidic conditions all molecules were scarcely adsorbed or not adsorbed by the native hide powder collagen. However, all organic molecules, except benzyl alcohol, were adsolubilised if the hide powder collagen was previously treated with the anionic surfactant. The hydrophobicity of the molecules plays an important role in the adsolubilisation phenomenon with the result that the higher the hydrophobicity (nonylphenol with 10 mol ethylene oxide), the higher the adsolubilisation. PMID:20797724
Maldonado, Fernando; Bautista, Elena; Manich, Albert M; Marsal, AgustĒn
A series of fourteen experimental sampling runs were carried out at a field site to collect data from several ambient air monitoring methods for volatile organic compounds (VOCs). Ambient air was drawn through a sampling manifold and was continuously spiked with volatile organic ...
Computational and experimental techniques are combined in order to better understand interactions involving organic compounds and cyclodextrin (CD)-clay systems. CD-clay systems may have great potential in the containment of organic contaminants in the environment. This study w...
Samples of 63 effluent and 22 intake waters were collected from a wide range of chemical manufacturers in areas across the United States. The samples were analyzed for organic compounds in an effort to identify previously unknown and potentially hazardous organic pollutants. Each...
Samples of air and leaves were taken at the University of Nevada-Las Vegas campus and analyzed for volatile organic compounds using vacuum distillation coupled with gas chromatography/mass spectrometry. The data were used to estimate the bioconcentration of volatile organic compo...
Highly stable meteoritic organic compounds as markers of asteroidal delivery
NASA Astrophysics Data System (ADS)
Multiple missions to search for water-soluble organic compounds on the surfaces of Solar System bodies are either current or planned and, if such compounds were found, it would be desirable to determine their origin(s). Asteroid or comet material is likely to have been components of all surface environments throughout Solar System history. To simulate the survival of meteoritic compounds both during impacts with planetary surfaces and under subsequent (possibly) harsh ambient conditions, we subjected known meteoritic compounds to comparatively high impact-shock pressures (>30 GPa) and/or to extremely oxidizing/corrosive acid solution. Consistent with past impact experiments, ?-amino acids survived only at trace levels above ?18 GPa. Polyaromatic hydrocarbons (PAHs) survived at levels of 4-8% at a shock pressure of 36 GPa. Lower molecular weight sulfonic and phosphonic acids (S&P) had the highest degree of impact survival of all tested compounds at higher pressures. Oxidation of compounds was done with a 3:1 mixture of HCl:HNO3, a solution that generates additional strong oxidants such as Cl2 and NOCl. Upon oxidation, keto acids and ?-amino acids were the most labile compounds with proline as a significant exception. Some fraction of the other compounds, including non-? amino acids and dicarboxylic acids, were stable during 16-18 hours of oxidation. However, S&P quantitatively survived several months (at least) under the same conditions. Such results begin to build a profile of the more robust meteoritic compounds: those that may have survived, i.e., may be found in, the more hostile Solar System environments. In the search for organic compounds, one current mission, NASA's Mars Science Laboratory (MSL), will use analytical procedures similar to those of this study and those employed previously on Earth to identify many of the compounds described in this work. The current results may thus prove to be directly relevant to potential findings of MSL and other missions designed for extraterrestrial organic analysis.
Cooper, George; Horz, Friedrich; Spees, Alanna; Chang, Sherwood
Can volatile organic compounds be markers of sea salt?
Sea salt is a handmade food product that is obtained by evaporation of seawater in saltpans. During the crystallisation process, organic compounds from surroundings can be incorporated into sea salt crystals. The aim of this study is to search for potential volatile markers of sea salt. Thus, sea salts from seven north-east Atlantic Ocean locations (France, Portugal, Continental Spain, Canary Islands, and Cape Verde) were analysed by headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry. A total of 165 compounds were detected, ranging from 32 to 71 compounds per salt. The volatile composition revealed the variability and individuality of each salt, and a set of ten compounds were detected in all samples. From these, seven are carotenoid-derived compounds that can be associated with the typical natural surroundings of ocean hypersaline environment. These ten compounds are proposed as potential volatile markers of sea salt. PMID:25236204
Silva, Isabel; Coimbra, Manuel A; Barros, Ant¾nio S; Marriott, Philip J; Rocha, SĒlvia M
On the flux of oxygenated volatile organic compounds from organic aerosol oxidation
On the flux of oxygenated volatile organic compounds from organic aerosol oxidation Alan J. Kwan,1. Avery,4 Cameron S. McNaughton,3 William H. Brune,5 Hanwant B. Singh,6 and Paul O. Wennberg1,7 Received
Clarke, Antony
Geosynthesis of organic compounds: I. Alkylphenols
Methylation, isopropylation, and sec-butylation are proposed as geosynthetic processes to account for the alkylphenol compositions of crude oils with phenol distributions dominated by ortho and para substituted compounds. Phenol distributions in eleven crude oils and four kerogen pyrolysates were analysed using GC-MS (gas chromatography-mass spectrometry). Ten of the crude oils show high relative abundances of ortho and para substituted phenol isomers and some were also enriched in C{sub 3}-C{sub 5} alkylphenols compared to the kerogen pyrolysates. Because the distributions of products obtained from the laboratory alkylation of cresols closely resemble those of phenols in these crude oils, we propose that similar alkylation processes occur in source rocks. Alkylation ratios reflecting the degree of methylation, isopropylation, and sec-butylation, which were based on the relative abundance of the dominant alkylation products compared to their likely precursor ortho-cresol, indicate that high levels of methylation occurred in crude oils over a wide range of maturities, whereas high levels of isopropylation and sec-butylation were observed only in mature samples. Dissolution of the phenols in crude oils by water contact was discounted as an explanation for the observed phenol distributions based on the relative distribution coefficients of phenols between a hydrocarbon phase and water.
Ioppolo-Armanios, M.; Alexander, R.; Kagi, R.I. [Curtin Univ. of Technology, Perth (Australia)] [Curtin Univ. of Technology, Perth (Australia)
Measurements of bromine containing organic compounds at the tropical tropopause
The amount of bromine entering the stratosphere from organic source gases is a primary factor involved in determining the magnitude of bromine catalyzed loss of ozone. Thirty two whole air samples were collected at the tropical tropopause during the NASA STRAT Campaign in Feb., Aug., and Dec., 1996 and were analyzed for brominated organic compounds. Total organic bromine was 17.4+\\/-0.9ppt
S. M. Schauffler; E. L. Atlas; F. Flocke; R. A. Lueb; V. Stroud; W. Travnicek
New Aspects of Zirconium Containing Organic Compounds
NASA Astrophysics Data System (ADS)
Metal carbene complexes have made their way from organometallic curiosities to valuable reagents and catalysts. They offer novel synthetic opportunities in carbon-carbon bond formation based on either carbene-centered reactions or on metal-templated processes which makes them indispensable in modern synthetic methodology. The most prominent metal carbenes are now either commercially available or easy to synthesize and handle with modern laboratory techniques. This volume organized in eight chapters written by the leading scientists in the field illustrates the theoretical background, non-classical nucleophilic and cycloaddition patterns, chromium-templated benzannulation and photo-induced reactions, rhodium-catalyzed carbene transfer as well as the principles and applications of olefin metathesis which has coined the progress in synthetic methodology over the past decade.
Marek, Ilan
Composition and major sources of organic compounds in urban aerosols
NASA Astrophysics Data System (ADS)
Total suspended particles (TSP), collected during June 2002 to July 2003 in Guangzhou, a typical economically developed city in South China, were analyzed for the organic compound compositions using gas chromatography-mass spectrometry (GC/MS). Over 140 organic compounds were detected in the aerosols and grouped into different classes including n-alkanes, hopanoids, polycyclic aromatic hydrocarbons, alkanols, fatty acids, dicarboxylic acids excluding oxalic acid, polyols/polyacids, lignin products, phytosterols, phthalates and water-soluble sugars. The total amounts of the identified organic compounds including unresolved complex mixture (UCM) ranged from 3112 ng/m 3 in spring to 5116 ng/m 3 in winter, comprising on seasonal average 2.8% of TSP. Primary organic compounds peaked in winter although there are no heating systems burning fuels in Guangzhou. The highest saccharide levels occurred in fall due to agricultural activities. This study demonstrated that utilization of fossil fuels, biomass burning, soil resuspension and plastic/refuse burning are the major contributors to the identified organic compounds in the urban atmosphere of South China.
Bi, Xinhui; Simoneit, Bernd R. T.; Sheng, Guoying; Ma, Shexia; Fu, Jiamo
The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. hree compounds (naphthalene, phenathrene, and DDT) that spanned three orders of magnitude in water solubility were used. nstead of humic matter, mole...
The effects of dissolved organic matter (DOM) on the transport of hydrophobic organic compounds in soil columns were investigated. Three compounds (naphthalene, phenanthrene and DDT) that spanned three orders of magnitude in water solubility were used. Instead of humic matter, mo...
Emission, oxidation, and secondary organic aerosol formation of volatile organic compounds, methanol, and MEK measured by other in situ instrumentation. On the other hand these oxidized volatile show these compounds match the oxidation products of isoprene observed in smog chamber studies, and we
Silver, Whendee
Methods of reducing water contaminants: Removal of organic compounds
Much of the recent concern by regulatory agencies about drinking water quality has been directed toward organic contamination in drinking water. Although organic contamination has been thought to primarily affect surface waters, there is a growing awareness and concern over groundwater contamination. What usually occurs is that the groundwaters contain a few organic compounds at high concentrations (microg/L to mg/L levels) while surface water supplies contain many organic compounds at low concentrations (microg/L levels). For example, an EPA research project using the GROB Closed Loop Stripping Method, identified approximately 225 organic compounds during sampling of treated surface water prior to granular activated carbon adsorption at the Cincinnati, Ohio Water Works. Except for the four trihalomethanes (chloroform, dichlorobromomethane, dibromochloromethane, bromoform) all concentrations were in the low part per trillion (microg/L) range. The health significance of these concentrations is unknown. However, one may wonder which is more significant; ingesting a few organics at high concentrations or many organics at low concentrations. The goal of any treatment scheme should be to remove as much contamination as feasible, technologically and economically. Various treatment options are available for removing organic contaminants from drinking water. Three of the treatment options are: granular activated carbon, air stripping, and reverse osmosis.
Lykins, B.W.; Goodrich, J.A.
Production of volatile organic sulfur compounds (VOSCs) by basidiomycetous yeasts
Thirty-seven basidiomycetous yeasts belonging to 30 species of seven genera were grown on media containing l-cysteine or l-methionine as sole nitrogen sources with the objective of evaluating volatile organic sulfur compound (VOSC) production. The headspace of yeast cultures was analyzed by the solid-phase microextraction (SPME) sampling method, and volatile compounds were quantified and identified by GC-MS techniques. Ten strains assimilating
Pietro Buzzini; Sergio Romano; Benedetta Turchetti; Ann Vaughan; Ugo Maria Pagnoni; Paolo Davoli
SDBS: Integrated Spectral Data Base System for Organic Compounds
NSDL National Science Digital Library
Provided by Agency of Industrial Science and Technology of Japan, the Integrated Spectral Data Base System for Organic Compounds is a database of mass spectral, NMR (proton and carbon), and infrared spectra data. As of March 1999, the database contains 19,600 spectra of MS, 11,000 spectra of ^13 C NMR, 13,500 spectra of ^1 H NMR, 2,000 spectra of ESR, 47,500 spectra of IR, 3,500 spectra of Raman, and 30,000 compounds in the Compound Dictionary. A search engine (Frames) for the database allows the following fields to be specified: Compound Name, Molecular Formula, Number of Atoms (Carbon, Hydrogen, Oxygen, and Nitrogen), Molecular Weight, CAS Registry Number, and SDBS Number. Access is free; however, no more than 50 spectra and/or compound files may be downloaded in one day.
Dosimeter for monitoring vapors and aerosols of organic compounds
A dosimeter is provided for collecting and detecting vapors and aerosols of organic compounds. The dosimeter comprises a lightweight, passive device that can be conveniently worn by a person as a badge or placed at a stationary location. The dosimeter includes a sample collector comprising a porous web treated with a chemical for inducing molecular displacement and enhancing phosphorescence. Compounds are collected onto the web by molecular diffusion. The web also serves as the sample medium for detecting the compounds by a room temperature phosphorescence technique. 7 figs.
Vo-Dinh, T.
A gas chromatograph (GC) with a flame ionization detector (FID) is shown to be effective in the determination of water in organic compounds. The ketal, 2,2-dimethoxypropane (DMP), reacts quantitatively with water to yield the products methanol and acetone when an acid catalyst is present. A solid acid catalyst, Nafion, has been effective and is easily separated before sample introduction into the GC. Several organic solvents were analyzed using this indirect method for determining water. The method is effective for determining water from 0.001-3.5% w/w. Solid samples were also analyzed and the water found in additional spikes agreed with the amount added. Simple steam distillation is used for the isolation and concentration of organic compounds from water matrices. Organic compounds are spiked into a flask containing water and the mixture is then boiled. Typical distillation times take less than 25 minutes. The condensate is collected in a small collection tube and a portion is injected into a GC containing a capillary column. The recovery of most compounds with boiling points from 77 to 238{degree}C is better than 90% and a concentration effect of ten is realized. Steam distillation combined with solid phase extraction is shown to be effective in isolating and concentrating compounds from water in the part-per-billion range. A simple interface between the boiling apparatus and resin collection column is presented. Once the organic analytes are boiled and collected on the resin, they are removed with a small amount of ethyl acetate. The ethyl acetate solution is then injected into a GC. Compounds with boiling points above 400{degree}C can be determined by turning off the flow of cold water in the condenser. Recoveries are better than 80% for compounds with boiling points between 132 to 404{degree}C.
Dix, K.D.
The aim of this study was to examine the adsorption capability and mechanism of hexadecyltrimethylammonium modified zeolite, which was synthesized from coal fly ash, for the removal of ionizable phenolic compounds (phenol, p-chlorophenol and bisphenol A, with different pK(a)) and non-ionizable organic compounds (aniline, nitrobenzene, and naphthalene, with different hydrophobicity). The obtained zeolite was identified as type Na-P1 (Na(6)Al(6)Si(10)O(32)Ę12H(2)O, JCPDS code 39-0219), which is classified into the gismondine group with a pore size of 3.1 ┼ ū 4.5 ┼ [100] and 2.8 ┼ ū 4.8 ┼ [101]. The adsorption of the two kinds of organic compounds was due to loaded surfactant bilayer because modified zeolite showed great ability for the removal of organic chemicals while little adsorption by zeolite was observed. The isotherm data of ionizable compounds fitted well to the Langmuir model but those of non-ionizable chemicals followed a linear equation. Uptake of ionizable compounds depended greatly on pH, increasing at alkaline pH conditions. In contrary, adsorption of non-ionizable chemicals was essentially the same at all pH levels studied. The adsorption of both kinds of organic compounds correlated well to k(ow) value, suggesting that more hydrophobic organic contaminants are more easily retained by modified zeolite. Based on the different adsorption behavior, the uptake of non-ionizable pollutants was thought to be a single partitioning process into the surfactant bilayer. For ionizable compounds, however, interaction of the phenol group(s) with the positively charged "head" of surfactant additionally functions. PMID:22771348
Xie, Jie; Meng, Wenna; Wu, Deyi; Zhang, Zhenjia; Kong, Hainan
Chemical reactions of organic compounds on clay surfaces.
Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, and the Br÷nsted or Lewis acidity of clay minerals. PMID:2533556
Soma, Y; Soma, M
Preconcentration and detection of chlorinated organic compounds and benzene.
Remote and automated detection of organic compounds in subsurface aquifers is crucial to superfund monitoring and environmental remediation. Current monitoring techniques use expensive laboratory instruments and trained personnel. The use of a filled tubular preconcentrator combined with a chemicapacitive detector array presents an attractive option for the unattended monitoring of these compounds. Five preconcentrator materials were exposed to common target compounds of subsurface remediation projects (1,1,2-trichloroethane, trichloroethylene, t-1,2-dichloroethylene, benzene, and perchloroethylene). Rapid heating of the tube caused the collected, concentrated effluent to pass over the surface of a chemicapacitive detector array coated with four different sorbent polymers. A system containing a porous ladder polymer and the sensor array was subsequently used to sample the analytes injected onto sand in a laboratory test, simulating a subsurface environment. With extended collection times, effective detection limits of 5 ▒ 3 ppbV for 1,1,2-trichloroethane and 145 ▒ 60 ppbV for benzene were achieved. Effects of the preconcentrator material structure, the collection time, and sensor material on the system performance were observed. The resultant system presents a solution for remote, periodic monitoring of chlorinated organic compounds and other volatile organic compounds in a soil matrix. PMID:22266477
Hobson, Stephen T; Cemalovic, Sabina; Patel, Sanjay V
Key volatile organic compounds emitted from swine nursery house
NASA Astrophysics Data System (ADS)
This study was carried out to quantify the concentration and emission levels of key volatile organic compounds (VOCs) - sulfides, indolics, phenolics and volatile fatty acids (VFA) - emitted from swine nursery house, and assess the effect of microclimate (including temperature, relative humidity and air speed) on the key odorous compounds. Samples were collected from the Experimental Farm of Seoul National University in Suwon, South Korea. And the collection took place for four seasons and the sampling time was fixed at 10:30 in the morning. The application of one-way ANOVA and Bonferroni t analyses revealed that, most of the odorous compound concentrations, such as dimethyl sulfide (DMS), dimethyl disulfide (DMDS), indole, p-cresol and all the volatile fatty acids were lowest during the summer ( P < 0.01). Meanwhile, negative correlations were observed between temperature and odorants, as well as air speed and odorants. A possible reason was that high ventilation transferred most of the odors out of the house during the summer. From the whole year data, non-linear multiple regressions were conducted and the equations were proposed depending upon the relationships between microclimate parameters and odorous compounds. The equations were applied in hope of easily calculating the concentrations of the odorous compounds in the commercial farms. The results obtained in this study should be used for reducing the volatile organic compounds by controlling microclimate parameters and also could be helpful in setting a guideline for good management practices in nursery house.
Yao, H. Q.; Choi, H. L.; Zhu, K.; Lee, J. H.
Analysis of Organic Compounds in Mars Analog Samples
NASA Technical Reports Server (NTRS)
The detailed characterization of organic compounds that might be preserved in rocks, ices, or sedimentary layers on Mars would be a significant step toward resolving the question of the habitability and potential for life on that planet. The fact that the Viking gas chromatograph mass spectrometer (GCMS) did not detect organic compounds should not discourage further investigations since (a) an oxidizing environment in the near surface fines analyzed by Viking is likely to have destroyed many reduced carbon species; (b) there are classes of refractory or partially oxidized species such as carboxylic acids that would not have been detected by the Viking GCMS; and (c) the Viking landing sites are not representative of Mars overall. These factors motivate the development of advanced in situ analytical protocols to carry out a comprehensive survey of organic compounds in martian regolith, ices, and rocks. We combine pyrolysis GCMS for analysis of volatile species, chemical derivatization for transformation of less volatile organics, and laser desorption mass spectrometry (LDMS) for analysis of elements and more refractory, higher-mass organics. To evaluate this approach and enable a comparison with other measurement techniques we analyze organics in Mars simulant samples.
Mahaffy, P. R.; Brinckerhoff, W. B.; Buch, A.; Cabane, M.; Coll, P.; Demick, J.; Glavin, D. P.
Volatile organic compounds in ambient air are usually estimated by trapping them from air or collecting whole air samples and returning them to a laboratory for analysis by gas chromatography using selective detection. ata do not appear for several days, during which sample integ...
The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...
Organic compounds in paper-mill process waters and effluents
Paper-mill effluents are characterized by the presence of color and suspended solids, bad smell, high concentration of nutrients that cause eutrophication of receiving waters, and high toxicity overall. This study attempts to give an overview of organic compounds that contribute to the toxicity of paper-mill waters and effluents, their levels, toxicological characterization and the methodologies used for their analysis. Families
A. Malmqvist; T. Welander
Membrane bioreactor for control of volatile organic compound emissions
A membrane bioreactor system that overcomes many of the limitations of conventional compost biofilters is described. The system utilizes microporous hydrophobic hollow fiber membranes for mass transfer of volatile organic compounds (VOCs) from the gas phase to a microbially active liquid phase. The reactor design provides a high biomass concentration, a method for wasting biomass, and a method for addition
Sarina J. Ergas; Michael S. McGrath
The rejection of specific organic compounds by reverse osmosis membranes
The performance characteristics of two commercially available reverse osmosis (RO) membranes, one cellulose acetate and the other composite polyamide, were investigated with respect to the rejection of different organic compounds, in order to elucidate rejection mechanisms and to investigate correlation with certain solute physical-chemical parameters. Flux and rejection studies were conducted on a series of six alkyl phenols and a
C. Frederik Schutte
Ecological functions of volatile organic compounds in aquatic systems
In terrestrial ecosystems, volatile organic compounds (VOCs) are widely acknowledged as an important group of infochemicals. They play a major role in pollinator attraction by terrestrial plants and as insect pheromones. Furthermore, they are the mediating agent of so-called ætritrophic interactionsÆ. When plants are attacked by herbivorous insects, volatile signal substances are emitted, which act as attractants for parasitoids that
Patrick Fink
Who Took Jerell's iPod? -- An Organic Compound Mystery
NSDL National Science Digital Library
In this activity, students learn how to test for triglycerides, glucose, starch, and protein and then use these tests to solve a mystery. The activity reinforces students understanding of the biological functions and food sources of these different types of organic compounds.
Doherty, Jennifer; Waldron, Ingrid
Process for removing an organic compound from water
A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit
Richard W. Baker; Jurgen Kaschemekat; Johannes G. Wijmans; Henky D. Kamaruddin
Volatile organic compounds in Gulf of Mexico sediments
Volatile organic compounds (VOC), concentrations and compositions were documented for estuarine, coastal, shelf, slope, and deep water sediments from the Gulf of Mexico. VOC were measured (detection limit >0.01 ppb) using a closed-loop stripping apparatus with gas chromatography (GC) and flame ionization, flame photometric, and mass spectrometric detectors. The five primary sources of Gulf of Mexico sediment VOC are: (1)
2 Extracting and trapping biogenic 3 volatile organic compounds stored
, Subcritical water extraction; UAE, Ultrasound-assisted extraction 36 1. Introduction Plants release2 Extracting and trapping biogenic 3 volatile organic compounds stored 4 in plant species 5 Elena are weakly synthesized. These BVOCs can be studied directly through traditional extraction 18 techniques (e
Goldstein, Allen
[Consumption of volatile organic compounds by alcaliphilic microorganisms].
It has been shown that various microbial species used in bioreactors for purification of air from volatile organic compounds can grow at alkaline pH values consuming the xenobiotics as sole carbon sources. The alkali tolerance depends on the carbon source. The alkaline pH of the medium reduces the foreign microbial population restricting the potential of the bioreactor. PMID:17476810
Ulezlo, I V; Bezborodov, A M
During the period June 1 to June 9, 1989, aldehyde and other oxygenated organic compound concentrations were examined at sites 3, 10, and 80 meters northeast of the Vilnius-Kaunas highway in Lithuania, SSR by collecting 120 liter (1 L/min for 120 min) samples on 2,4-dinitrophenyl...
The sorption of ionizable organic compounds to sediments and saturated soils is examined. he sorption of pentachlorophenol to two sediment silt-clay fractions as a function of pH is described. Sorption of both the neutral and the ionic species was shown to occur; results were qua...
Effects of airborne volatile organic compounds on plants
Routine measurements of volatile organic compounds (VOCs) in air have shown that average concentrations are very much smaller than those used in laboratory experiments designed to study the effects of VOCs on plants. However, maximum hourly concentrations of some VOCs can be 100 times larger than the average, even in rural air. Experimental studies have rarely extended for longer than
J. N. Cape
Analysis of organic compounds in returned comet nucleus samples
NASA Technical Reports Server (NTRS)
Techniques for analysis of organic compounds in returned comet nucleus samples are described. Interstellar, chondritic and transitional organic components are discussed. Appropriate sampling procedures will be essential to the success of these analyses. It will be necessary to return samples that represent all the various regimes found in the nucleus, e.g., a complete core, volatile components (deep interior), and crustal components (surface minerals, rocks, processed organics such as macromolecular carbon and polymers). Furthermore, sampling, storage, return, and distribution of samples must be done under conditions that preclude contamination of the samples by terrestrial matter.
Cronin, J. R.
Multilayer adsorption of slightly soluble organic compounds from aqueous solutions
Adsorption isotherms are analyzed for slightly soluble organic components from water for a wide range of reduced concentrations. It is shown that the behavior of these systems can be modeled by an equation of the form a = Ac/[(1 + Bc)(1 {minus} c/c{sub 0}){sup d}] over the range of c/c{sub 0} from about 0.05 to 0.9. Here a is the adsorption amount, c is the concentration of organic compound in the water, c{sub 0} is a solubility limit for the organic compound, and A, B, and d are adjustable parameters. Comparison is made with experimental data for the adsorption of n-caproic acid, n-valeric acid, n-amyl alcohol, n-butyl alcohol, aniline, cyclohexanol, and phenol from aqueous solutions on carbon adsorbents.
Aranovich, G.L.; Donohue, M.D. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemical Engineering] [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemical Engineering
Analysis of Organic Compounds in Returned Comet Nucleus Samples
NASA Astrophysics Data System (ADS)
Comets are generally believed to be primitive bodies that preserve solar system matter in, or nearly in, its primordial state. This expectation has been at least partially borne out by the 1986 flyby missions to Comet Halley which provided data indicating that, with the exception of hydrogen, the light elements (C, N, O, and S) occur in approximately their solar abundances. Although mass spectrometers carried aboard the spacecraft provided much additional data from which to speculate about the molecular forms of these elements a detailed understanding of cometary organic chemistry will ultimately require the laboratory examination of returned samples. Some of the problems that will be encountered in such studies, for example, sensitivity to trace constituents, resolution of numerous isomeric forms, and avoidance of terrestrial contaminants, have already been faced in analyses of the organic compounds from carbonaceous chondrites. Furthermore, there is reason to believe that the progenitors of the carbonaceous chondrites were volatile rich planetesimals similar to those which, at greater radial distances, formed comets. Thus, the organic chemistry of carbonaceous chondrites may represent the outcome of a process of chemical evolution that parallels, although is perhaps further advanced than, that which occurred in comets. These meteorites may then represent not only a useful model for the development and refinement of analytical methods, but also a guide to the types of organic compounds that may be encountered in analyses of cometary matter. In this paper, I have (i) briefly reviewed the results of amino acid analyses of CM chondrites, (ii) discussed the origin of these compounds and the implications for comet organic chemistry, and (iii) described some recent developments in analytical instrumentation for amino acids and their implications for analyses of extraterrestrial materials. Although the emphasis is on amino acids, their general characteristics are common to the other classes of organic compounds in CM chondrites and inferences regarding their origins should be generally relevant.
Cronin, John R.
Biological organisms as volatile compound detectors: a review.
The detection and identification of volatile compounds is essential to the successful undertaking of numerous forensic analyses. Biological olfactory systems possess the extraordinary ability to not only detect many thousands of distinct volatile compounds (odors) but also to discriminate between them. Whole-organism biological sensors, such as detection canines, have been employed in forensic science as volatile compound detectors for many years. A variety of insects including bees, wasps, and moths, which have also been shown to detect volatile compounds of forensic significance, have been investigated for their potential application in field-based detection systems. While the fundamental aim for many developers of portable instruments is to replicate the remarkable ability of biological olfactory systems, such analytical equipment is yet to possess the detection and discriminatory powers achieved by biological sensors. Recent literature reveals an increasing interest in olfactory receptors - the biological components that impart olfactory ability - for detecting volatile compounds associated with forensically significant substances such as explosives and illicit drugs. This paper reviews the literature regarding the current, and potential future, use of biological organisms as sensors for forensic science applications. PMID:24053870
Leitch, Olivia; Anderson, Alisha; Kirkbride, K Paul; Lennard, Chris
Biodiversity of volatile organic compounds from five French ferns.
Five French ferns belonging to different families were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Fifty-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including monoterpenes, sesquiterpenes and carotenoid-type compounds were identified. The main volatile compound of Adiantum capillus-veneris L. (Pteridaceae) was (E)-2-decenal with a plastic or "stink bug" odor. The volatile profiles of Athyrium filix-femina (L.) Roth (Woodsiaceae) and Blechnum spicant (L.) Roth (Blechnaceae) showed similarities, with small amounts of isoprenoids and the same main volatile compounds, i.e., 2-phenylethanal (odor of lilac and hyacinth) and 1-octen-3-ol (mushroom-like odor). The main volatile compound of Dryopteris filix-mas (L.) Schott (Dryopteridaceae) was (E)-nerolidol with a woody or fresh bark note. Polyketides, as acylfilicinic acids, were mainly identified in this fern. Oreopteris limbosperma (Bellardi ex. All.) J. Holub (Thelypteridaceae), well-known for its lemon smell, contained the highest biodiversity of VOC. Eighty percent of the volatiles was issued from the terpenic pathway. The main volatiles were (E)-nerolidol, alpha-terpineol, beta-caryophyllene and other minor monoterpenes (for example, linalool, pinenes, limonene, and gamma-terpinen-7-al). It was also the fern with the highest number of carotenoid-type derivatives, which were identified in large amounts. Our results were of great interest underlying new industrial valorisation for ferns based on their broad spectrum of volatiles. PMID:21121267
Fons, Franńoise; Froissard, Didier; BessiĶre, Jean-Marie; Buatois, Bruno; Rapior, Sylvie
This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (tin, mercury, and lead). Specific emphasis was placed on evaluating key factors that influence interpretation of critical body resid...
Group extraction of organic compounds present in liquid samples
NASA Technical Reports Server (NTRS)
An extraction device is disclosed comprising a tube containing a substantially inert, chemically non-reactive packing material with a large surface area to volume ratio. A sample which consists of organic compounds dissolved in a liquid, is introduced into the tube. As the sample passes through the packing material it spreads over the material's large surface area to form a thin liquid film which is held on the packing material in a stationary state. A particular group or family of compounds is extractable from the sample by passing a particular solvent system consisting of a solvent and selected reagents through the packing material. The reagents cause optimum conditions to exist for the compounds of the particular family to pass through the phase boundary between the sample liquid and the solvent of the solvent system. Thus, the compounds of the particular family are separated from the sample liquid and become dissolved in the solvent of the solvent system. The particular family of compounds dissolved in the solvent, representing an extract, exits the tube together with the solvent through the tube's nozzle, while the rest of the sample remains on the packing material in a stationary state. Subsequently, a different solvent system may be passed through the packing material to extract another family of compounds from the remaining sample on the packing material.
Jahnsen, Vilhelm J. (Inventor)
In present study four newly synthesized organic semiconductor compounds have been used for fabrication of the organic field effect transistors. In all cases p-type channel organic field effect transistors were fabricated. I-V characteristics of the samples were investigated. The highest on\\/off ratio (up to 180) was observed in the case of the organic field effect transistors fabricated using 4-diphenylaminobenzaldehyde N-methyl-N-phenylhydrazone
Rimas GUDAITIS; Juozas Vidas GRA; Ram?nas LYGAITIS; Evaldas BURBULIS; Asta MICHALEVI?I?T?; Vytautas GETAUTIS; Tadas MALINAUSKAS
Natural organic compounds as tracers for biomass combustion in aerosols
Biomass combustion is an important primary source of carbonaceous particles in the global atmosphere. Although various molecular markers have already been proposed for this process, additional specific organic tracers need to be characterized. The injection of natural product organic tracers to smoke occurs primarily by direct volatilization/steam stripping and by thermal alteration based on combustion temperature. The degree of alteration increases as the burn temperature rises and the moisture content of the fuel decreases. Although the molecular composition of organic matter in smoke particles is highly variable, the molecular structures of the tracers are generally source specific. The homologous compound series and biomarkers present in smoke particles are derived directly from plant wax, gum and resin by volatilization and secondarily from pyrolysis of biopolymers, wax, gum and resin. The complexity of the organic components of smoke aerosol is illustrated with examples from controlled burns of temperate and tropical biomass fuels. Burning of biomass from temperate regions (i.e., conifers) yields characteristic tracers from diterpenoids as well as phenolics and other oxygenated species, which are recognizable in urban airsheds. The major organic components of smoke particles from tropical biomass are straight-chain, aliphatic and oxygenated compounds and triterpenoids. The precursor-to-product approach of organic geochemistry can be applied successfully to provide tracers for studying smoke plume chemistry and dispersion.
Simoneit, B.R.T. [Brookhaven National Lab., Upton, NY (United States)]|[Oregon State Univ., Corvallis, OR (United States). Coll. of Oceanic and Atmospheric Sciences; Abas, M.R. bin [Brookhaven National Lab., Upton, NY (United States)]|[Univ. of Malaya, Kuala Lumpur (Malaysia); Cass, G.R. [Brookhaven National Lab., Upton, NY (United States)]|[California Inst. of Tech., Pasadena, CA (United States). Environmental Engineering Science Dept.; Rogge, W.F. [Brookhaven National Lab., Upton, NY (United States)]|[Florida International Univ., University Park, FL (United States). Dept. of Civil and Environmental Engineering; Mazurek, M.A. [Brookhaven National Lab., Upton, NY (United States); Standley, L.J. [Academy of Natural Sciences, Avondale, PA (United States). Stroud Water Research Center; Hildemann, L.M. [Stanford Univ., CA (United States). Dept. of Civil Engineering
Identification and Quantification of Volatile Organic Compounds at a Dairy
NASA Astrophysics Data System (ADS)
Livestock operations in the United States are an escalating environmental concern. The increasing density of livestock within a farm results in an increased emission of odorous gases, which have gained considerable attention by the public in recent years (National Research Council (NRC), 2002). Odorous compounds such as ammonia (NH3), volatile organic compounds (VOC's), and hydrogen sulfide (H2S) were reported to have a major effect on the quality of life of local residents living near livestock facilities (NRC, 2002). There has been little data collected related to identification and quantification of gaseous compounds collected from open stall dairy operations in the United States. The research to be presented identifies and quantifies VOCs produced from a dairy operation that contribute to odor and other air quality problems. Many different VOCs were identified in the air downwind of an open lactating cow stall area and near a waste lagoon at the Washington State University dairy using Gas Chromatography Mass Spectroscopy (GC-MS) analysis techniques. Identified compounds were very diverse and included many alcohols, aldehydes, amines, aromatics, esters, ethers, a fixed gas, halogenated hydrocarbons, hydrocarbons, ketones, other nitrogen containing compounds, sulfur containing compounds, and terpenes. The VOCs directly associated with cattle waste were dependent on ambient temperature, with the highest emissions produced during the summer months. Low to moderate wind speeds were ideal for VOC collection. Concentrations of quantified compounds were mostly below odor detection thresholds found in the literature, however the combined odor magnitude of the large number of compounds detected was most likely above any minimum detection threshold.
Filipy, J.; Mount, G.; Westberg, H.; Rumburg, B.
Identification of volatile organic compounds in flowers of Astragalus lagopoides.
Composition of volatile organic compounds (VOCs) in flowers of Astragalus lagopoides was studied using a hydrodistillation extraction procedure coupled with gas chromatography-mass spectrometry. The analyses allowed the identification of a number of 25 compounds, among which the presence of several bioactive aromatic derivatives such as guaiacol, eugenol, linalool, ?- and 4-terpineol as well as nerol was attention-grabbing. Moreover, some other compounds like cyclohexane, 2-bromoethyl with repellent function also appeared to be present in the flower. As a result, the floral VOCs profile of A. lagopoides might reflect an adaptation to attract specialised pollinator insects. These findings provide important information for advances in understanding the ecological and evolutionary perspectives of pollination biology of the giant genus Astragalus. PMID:21878004
Movafeghi, Ali; Delazar, Abbas; Amini, Majid; Asnaashari, Solmaz
Metamaterial resonator arrays for organic and inorganic compound sensing
NASA Astrophysics Data System (ADS)
In this paper, an electromagnetic metamaterial resonator operating in the terahertz frequency range is presented. By arranging the resonator in a planar array, it is possible to use the structure as a sensing device for organic and inorganic compounds. The sensor is designed to detect the presence of a biological compound by permittivity or absorption measurements. The presence of the biological matter modifies the effective permittivity and, thus, the resonant frequency significantly varies. In addition, biological compounds typically exhibit absorption characteristics that depend on the corresponding molecular structure. Therefore, it is necessary to illuminate the material selectively. We show that by employing the "selective" properties of the metamaterial resonator proposed, it is possible to enhance the sensing performances. The proposed design is suitable to sense the presence of healthy and malignant tissues, with possible applications in food and medical diagnostics. The operation of the sensing device has been demonstrated through proper full-wave simulations.
La Spada, Luigi; Bilotti, Filiberto; Vegni, Lucio
Metamaterial resonator arrays for organic and inorganic compound sensing
NASA Astrophysics Data System (ADS)
In this paper, an electromagnetic metamaterial resonator operating in the terahertz frequency range is presented. By arranging the resonator in a planar array, it is possible to use the structure as a sensing device for organic and inorganic compounds. The sensor is designed to detect the presence of a biological compound by permittivity or absorption measurements. The presence of the biological matter modifies the effective permittivity and, thus, the resonant frequency significantly varies. In addition, biological compounds typically exhibit absorption characteristics that depend on the corresponding molecular structure. Therefore, it is necessary to illuminate the material selectively. We show that by employing the "selective" properties of the metamaterial resonator proposed, it is possible to enhance the sensing performances. The proposed design is suitable to sense the presence of healthy and malignant tissues, with possible applications in food and medical diagnostics. The operation of the sensing device has been demonstrated through proper full-wave simulations.
La Spada, Luigi; Bilotti, Filiberto; Vegni, Lucio
Emission of volatile organic compounds (VOCs) from PVC floor coverings.
In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination. PMID:10431652
Wiglusz, R; Igielska, B; Sitko, E; Nikel, G; Jarnuszkiewicz, I
Sugar-Related Organic Compounds in Carbonaceous Meteorites
NASA Technical Reports Server (NTRS)
Sugars and related polyols are critical components of all organisms and may have been necessary for the origin of life. To date, this class of organic compounds had not been definitively identified in meteorites. This study was undertaken to determine if polyols were present in the early Solar System as constituents of carbonaceous meteorites. Results of analyses of the Murchison and Murray meteorites indicate that formaldehyde and sugar chemistry may be responsible for the presence of a variety of polyols. We conclude that polyols were present on the early Earth through delivery by asteroids and possibly comets.
Cooper, G.; Kimmich, N.; Belisle, W.; Sarinana, J.; Brabham, K.; Garrel, L.; DeVincenzi, Donald L. (Technical Monitor)
Water Pollution: Organic Compounds in the Charles River, Boston
The major lipophilic organic compounds present in water collected during November and December 1971 from the Charles River Basin (Boston) are as follows: normal alkanes (C15 to C31), alkyl naphthalenes, alkyl anthracenes or phenanthrenes, pyrene, fluoranthene, dibutyl phthalate, and di(2-ethylhexyl) phthalate. The concentration of the naphthalenes (determined by liquid chromatography) correlates with the effective storm-water runoff content of the river.
Ronald A. Hites; K. Biemann
DFT derived solvation models for organic compounds in alkane solvents
NASA Astrophysics Data System (ADS)
From a density functional theory (DFT) analysis of solvation and the different components which comprise the free energy of solvation we propose quantitative structure-property relationship (QSPR) models to predict free energy of solvation, ?GS0, of organic compounds in seven alkane solvents ( n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, and n-hexadecane). The data contains 151 structurally different compounds containing diverse organic functions: unbranched and branched alkanes, cycloalkanes, aromatics, alcohols, aldehydes, ketones, esters, ethers, amines, nitriles, pyridines, fluorinated hydrocarbons, thiols, sulfides, carboxylic acids and nitro hydrocarbons; covering a ?GS0 range from about -50 to 0 kJ/mol. The models for the seven n-alkane solvents contain the same two molecular descriptors, one DFT descriptor (softness) and one geometric (molecular surface area). This fact suggests that the physical mechanisms behind the solvation of organic compounds in n-alkane solvents are of the same nature, as expected from the similar physical and chemical properties of alkanes. The models proposed have the merit of predicting free energy of solvation in alkane solvents with fewer descriptors than other QSPR models reported in the literature having similar statistics, allowing in this way a well-defined physical interpretation. The two descriptors have definite physical meaning corresponding to the different components which comprise free energy of solvation. Thus, the models proposed reach the desired compromise among simpleness, physical interpretation and computation time.
Delgado, Eduardo J.; Alderete, Joel B.; Ja±a, Gonzalo A.
Identification and quantification of volatile organic compounds from a dairy
NASA Astrophysics Data System (ADS)
Volatile organic compounds (VOCs) that contribute to odor and air quality problems have been identified from the Washington State University Knott Dairy Farm using gas chromatography-mass spectroscopy (GC-MS). Eighty-two VOCs were identified at a lactating cow open stall and 73 were detected from a slurry wastewater lagoon. These compounds included alcohols, aldehydes, ketones, esters, ethers, aromatic hydrocarbons, halogenated hydrocarbons, terpenes, other hydrocarbons, amines, other nitrogen containing compounds, and sulfur-containing compounds. The concentration of VOCs directly associated with cattle waste increased with ambient air temperature, with the highest concentrations present during the summer months. Concentrations of most detected compounds were below published odor detection thresholds. Emission rates of ethanol (1026▒513 ?g cow -1 s -1) and dimethyl sulfide (DMS) (13.8▒10.3 ?g cow -1 s -1) were measured from the lactating stall area using an atmospheric tracer method and concentrations were plotted using data over a 2-year period. Emission rates of acetone (3.03▒0.85 ng cow -1 s -1), 2-butanone (145▒35 ng cow -1 s -1), methyl isobutyl ketone (3.46▒1.11 ng cow -1 s -1), 2-methyl-3-pentanone (25.1▒8.0 ng cow -1 s -1), DMS (2.19▒0.92 ng cow -1 s -1), and dimethyl disulfide (DMDS) (16.1▒3.9 ng cow -1 s -1) were measured from the slurry waste lagoon using a laboratory emission chamber.
Filipy, Jenny; Rumburg, Brian; Mount, George; Westberg, Hal; Lamb, Brian
Equilibrium isotherms for the simultaneous uptake of binary nonionic organic compounds from water on soil indicated no competitive effect between the two solutes. The observation supports the hypothesis that partition to the soil organic phase is the primary process for sorption ...
NASA Astrophysics Data System (ADS)
The CT (carbon tetrachloride) plume in Hanford site is not large and retardation of the plume is uncertain given that there is no nonreactive tracer applied synchronously with the CT. Unfortunately, direct measurement of sorption distribution coefficients (Kd) for those low Kow (octanol/water partition coefficient) compounds (e.g., CT) on low foc (organic carbon content) sediments is quite challenging using normal batch setup due to the solid/water ratio limitation. One way to solve this problem is to use more hydrophobic compounds (high Kow) as surrogates, where Kd on the target low foc aquifer sediments can be easily measured. With the help of the foc - normalized partition coefficients (Koc = Kd/foc) at different aqueous concentrations (Cw), the Kd values of the target low Kow compounds on the same materials could be estimated. In this study, the nonlinear sorption isotherms of CT and a surrogate compound 1,1,1,3- tetrachlorotetrafluoropropane on selected samples with a wide spectrum of characteristics (from "soft" to "hard" carbon) were simultaneously determined. A relationship of Koc between CT and 1,1,1,3- tetrachlorotetrafluoropropane sorption on the same materials was investigated. Thus, the distribution coefficients (Kd) of the target compound, CT, in Hanford site (Ringold formation) sediments were estimated based on the batch sorption experiments of 1,1,1,3-tetrachlorotetrafluoropropane on the same samples.
Wang, G.; Allen-King, R. M.
Characterisation of polar organic compounds in fog water
NASA Astrophysics Data System (ADS)
In this paper the results of a systematic liquid chromatographic investigation are described to characterise water-soluble organic compounds in fog. A diode array detector is used to record the UV spectrum of the components during separation and a mass spectrometer is applied to obtain information on the ion masses of the constituents. The combination of UV and mass spectra reveal that the organic carbon content of fog water is distributed among a great number of acidic compounds which have polar functional groups and polyconjugated systems absorbing up to 500 nm. Due to the complexity of the organic fraction in fog water an unresolved hump of ions was recorded by the mass spectrometer from m/ z=100-600 the most intense peaks being detected around m/ z=200-250. Tannin and fulvic acid were also examined under the same conditions. In terms of complexity and ion distribution the mass spectrum of the organic fraction was similar to that of a fulvic acid reference material rather than to that of tannin.
Kiss, Gyula; Varga, Bßlint; Gelencsķr, Andrßs; Krivßcsy, Zoltßn; Molnßr, ┴gnes; Alsberg, Tomas; Persson, Linn; Hansson, Hans-Christen; Cristina Facchini, Maria
Reverse osmosis processing of organic model compounds and fermentation broths.
Post-treatment of an anaerobic fermentation broth was evaluated using a 150 gal/day, single cartridge prototype reverse osmosis (RO) system. Baseline tests were conducted at 25 degrees C using six organic model compounds representing key species found in the fermentation broth: ethanol, butanol, acetic acid, oxalic acid, lactic acid, and butyric acid. Correlations of the rejection and recovery efficiencies for these organic species, individually and in simulated mixtures, were obtained as a function of feed pressure with and without recirculation of the retentate. The actual fermentation broth obtained from a continuous-flow biohydrogen process was treated by the RO system under the operating conditions similar to those used in the baseline tests, resulting in greater than 95% removal of total organic carbon. These results are encouraging and useful for further studies on the feasibility of incorporating the RO technology into an integrated and field deployable wastewater management and water recovery system. PMID:16600592
Diltz, Robert A; Marolla, Theodore V; Henley, Michael V; Li, Lixiong
Selective Sorption of Dissolved Organic Carbon Compounds by Temperate Soils
Physico-chemical sorption of dissolved organic carbon (DOC) on soil minerals is one of the major processes of organic carbon (OC) stabilization in soils, especially in deeper layers. The attachment of C on soil solids is related to the reactivity of the soil minerals and the chemistry of the sorbate functional groups, but the sorption studies conducted without controlling microbial activity may overestimate the sorption potential of soil. This study was conducted to examine the sorptive characteristics of a diverse functional groups of simple OC compounds (D-glucose, L-alanine, oxalic acid, salicylic acid, and sinapyl alcohol) on temperate climate soil orders (Mollisols, Ultisols and Alfisols) with and without biological degradative processes. Equilibrium batch experiments were conducted using 0-100 mg C L-1 at a solid-solution ratio of 1:60 for 48 hrs and the sorption parameters were calculated by Langmuir model fitting. The amount of added compounds that remained in the solution phase was detected by high performance liquid chromatography (HPLC) and total organic C (TOC) analysis. Soil sterilization was performed by -irradiation technique and experiments were repeated to determine the contribution of microbial degradation to apparent sorption. Overall, Ultisols did not show a marked preference for apparent sorption of any of the model compounds, as indicated by a narrower range of maximum sorption capacity (Smax) of 173-527 mg kg soil-1 across compounds. Mollisols exhibited a strong preference for apparent sorption of oxalic acid (Smax of 5290 mg kg soil-1) and sinapyl alcohol (Smax of 2031 mg kg soil-1) over the other compounds. The propensity for sorption of oxalic acid is mainly attributed to the precipitation of insoluble Ca-oxalate due to the calcareous nature of most Mollisol subsoils and its preference for sinapyl alcohol could be linked to the polymerization of this lignin monomer on 2:2 mineral dominated soils. The reactivity of Alfisols to DOC was in between that of Ultisols and Mollisols. HPLC results revealed significantly higher sorption of D-glucose and L-alanine than did TOC results, and duplicate experiments with sterilized soils confirmed that glucose and alanine were mineralized leading to higher apparent sorption values via HPLC. This study demonstrated that three common temperate soil orders experienced differential sorption of simple OC compounds, indicating that sorbate chemistry plays a significant role in the sorptive stabilization of DOC.
Jagadamma, Sindhu [ORNL; Mayes, Melanie [ORNL; Phillips, Jana Randolph [ORNL
Multiple microbial activities for volatile organic compounds reduction by biofiltration.
In the northeast of Italy, high volatile organic carbon (VOC) emissions originate from small-medium companies producing furniture. In these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. Among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple VOC degradation potentials used to oxidize these compounds to CO2. Starting from the air emissions of a typical industrial wood-painting plant, a series of experiments studied in vitro microbial degradation of each individual VOC. Isolated strains were then added to a laboratory-scale biofiltration apparatus filled with an organic matrix, and the different VOC behavior demonstrated the potential of single and/or synergic microbial removal actions. When a single substrate was fed, the removal efficiency of a Pseudomonas aeruginosa inoculated reactor was 1.1, 1.17, and 0.33 g m(-3) hr(-1), respectively, for xylene, toluene, and ethoxy propyl acetate. A VOC mixture composed of butyl acetate, ethyl acetate, diacetin alcohol, ethoxy propanol acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene was then fed into a 2-m(3) reactor treating 100 m3 hr(-1) of contaminated air. The reactor was filled with the same mixture of organic matrix, enriched with all of the isolated strains together. During reactor study, different VOC loading rates were used, and the behavior was evaluated continuously. After a short acclimation period, the removal efficiency was > 65% at VOC load of 150-200 g m(-3) hr(-1). Quantification of removal efficiencies and VOC speciation confirmed the relationship among removal efficiencies, compound biodegradability, and the dynamic transport of each mixture component within the organic matrix. Samples of the fixed bed were withdrawn at different intervals and the heterogeneous microbial community evaluated for both total and differential compound counts. PMID:16878585
Civilini, Marcello
Analyses of volatile organic compounds from human skin
Summary Background Human skin emits a variety of volatile metabolites, many of them odorous. Much previous work has focused upon chemical structure and biogenesis of metabolites produced in the axillae (underarms), which are a primary source of human body odour. Nonaxillary skin also harbours volatile metabolites, possibly with different biological origins than axillary odorants. Objectives To take inventory of the volatile organic compounds (VOCs) from the upper back and forearm skin, and assess their relative quantitative variation across 25 healthy subjects. Methods Two complementary sampling techniques were used to obtain comprehensive VOC profiles, viz., solid-phase micro extraction and solvent extraction. Analyses were performed using both gas chromatography/mass spectrometry and gas chromatography with flame photometric detection. Results Nearly 100 compounds were identified, some of which varied with age. The VOC profiles of the upper back and forearm within a subject were, for the most part, similar, although there were notable differences. Conclusions The natural variation in nonaxillary skin odorants described in this study provides a baseline of compounds we have identified from both endogenous and exogenous sources. Although complex, the profiles of volatile constituents suggest that the two body locations share a considerable number of compounds, but both quantitative and qualitative differences are present. In addition, quantitative changes due to ageing are also present. These data may provide future investigators of skin VOCs with a baseline against which any abnormalities can be viewed in searching for biomarkers of skin diseases. PMID:18637798
Gallagher, M.; Wysocki, C.J.; Leyden, J.J.; Spielman, A.I.; Sun, X.; Preti, G.
Volatile organic compounds from a Tuber melanosporum fermentation system.
A total of 59 volatile organic compounds (VOCs) were identified from Tuber melanosporum fermentation: 53 from its fermented mycelia and 32 from the fermentation broth. Alcohol-derived compounds were predominant in both the fermentation mycelia and the broth, although long chain fatty acids and isoprenoids were, for the first time, also found in the mycelia. The intense wine bouquet properties of the broth arose from several specific flavor substances, including sulfur compounds, pyrazines, furans and jasmones. Comparing the VOCs identified in this work with those previously reported, our results are more similar to the composition of the Tuber fruiting-body than previous Tuber fermentations. The composition and accumulation of flavor volatiles (e.g., pyrazines, sulfur compounds, and esters) and major constituents (e.g., 3-methyl-1-butanol and 2-phenylethanol) in this fermentation were significantly influenced by the sucrose concentration in the medium. The obtained information could therefore be useful in applications to convert the flavors of truffle mycelia similar to those of the fruiting-body by optimising the fermentation process. PMID:22980851
Li, Yuan-Yuan; Wang, Guan; Li, Hong-Mei; Zhong, Jian-Jiang; Tang, Ya-Jie
The complexity of the mineral-organic carbon interface may influence the extent of stabilization of organic carbon compounds in soils, which is important for global climate futures. The nanoscale structure of a model interface was examined here by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto a soil mineral analogue (Al2O3). Neutron reflectometry, a technique which provides depth-sensitive insight into the organization of the thin films, indicates that glucose molecules reside in a layer between Al2O3 and stearic acid, a result that was verified by water contact angle measurements. Molecular dynamics simulations reveal the thermodynamic driving force behind glucose partitioning on the mineral interface: The entropic penalty of confining the less mobile glucose on the mineral surface is lower than for stearic acid. The fundamental information obtained here helps rationalize how complex arrangements of organic carbon on soil mineral surfaces may arise. PMID:24328330
Petridis, Loukas; Ambaye, Haile; Jagadamma, Sindhu; Kilbey, S Michael; Lokitz, Bradley S; Lauter, Valeria; Mayes, Melanie A
Fate of Volatile Organic Compounds in Constructed Wastewater Treatment Wetlands
The fate of volatile organic compounds was evaluated in a wastewater-dependent constructed wetland near Phoenix, AZ, using field measurements and solute transport modeling. Numerically based volatilization rates were determined using inverse modeling techniques and hydraulic parameters established by sodium bromide tracer experiments. Theoretical volatilization rates were calculated from the two-film method incorporating physicochemical properties and environmental conditions. Additional analyses were conducted using graphically determined volatilization rates based on field measurements. Transport (with first-order removal) simulations were performed using a range of volatilization rates and were evaluated with respect to field concentrations. The inverse and two-film reactive transport simulations demonstrated excellent agreement with measured concentrations for 1,4-dichlorobenzene, tetrachloroethene, dichloromethane, and trichloromethane and fair agreement for dibromochloromethane, bromo-dichloromethane, and toluene. Wetland removal efficiencies from inlet to outlet ranged from 63% to 87% for target compounds.
Keefe, S. H.; Barber, L. B.; Runkel, R. L.; Ryan, J. N.
The availability of dissolved organic phosphorus compounds to marine phytoplankton
NASA Astrophysics Data System (ADS)
The availability of three dissolved organic phosphorus (DOP) compounds as nutrient sources for experimental culture of three algae was studied. Results indicated that these compounds could be utilized by algae, and that dissolved inorganic phosphorus (DIP) was first to be uptaken when various forms of phosphorus (DIP and DOP) co-existed. Dicrateria zhanjiangensis' uptake of sodium glycerophosphate was faster than that of D-ribose-5-phosphate. The increase of sodium glycerophosphate had little effect on the maximum uptake rate( V max) of Chlorella sp., but increased the semisaturation constant( K s) remarkably; the photosynthesis rates(PR) of Dicrateria zhanjiangensis and Chlorella sp. were rarely affected by using various forms of phosphorus in the culture experiments. The possible DOP pathways utilized by algae are discussed.
Hua-Sheng, Hong; Hai-Li, Wang; Bang-Qin, Huang
Phase Transition Enthalpy Measurements of Organic and Organometallic Compounds. Sublimation, and sublimation are included for organic, organometallic, and a few inorganic compounds. This compendium.1063/1.3309507 Key words: Vaporization enthalpy; fusion enthalpy; sublimation enthalpy; compendium. CONTENTS 1
Chickos, James S.
Federal Register 2010, 2011, 2012, 2013
...Indiana; Volatile Organic Compound Automobile Refinishing Rules for Indiana AGENCY...Plan (SIP) amendments to Indiana's automobile refinishing rule. These rule revisions...approved volatile organic compound (VOC) automobile refinishing rules to all persons...
Federal Register 2010, 2011, 2012, 2013
...Indiana; Volatile Organic Compound Automobile Refinishing Rules for Indiana AGENCY...submitted amendments to Indiana's automobile refinishing rule for approval into its...approved volatile organic compound (VOC) automobile refinishing rules to all persons...
Isotope dilution mass spectrometry (IDMS) can be considered a primary measurement method directly traceable to the International System of Units (SI). This measurement technique is increasingly employed in routine laboratories, owing to its unequalled analytical performance, precision and ease of accreditation. Unfortunately, for the adequate application of IDMS, several isotopically labelled standards, corresponding to the compounds of interest, are required. Additionally, when the enriched isotope is continuously added after a chromatographic separation, and an elemental ion source is used, it allows quantification of the different analytes being eluted from the column without requiring specific standards for each compound (online IDMS). In this article, we discuss how the traditional applicability of online IDMS for elemental speciation can be dramatically expanded by using carbon isotope tracers, oxidation or combustion reactions and a conventional molecular ion source. With such a strategy every carbon-containing compound being eluted from a chromatography system can be quantified without the need for specific standards as long as quantitative combustion/oxidation and complete elution occur. So far, only gas chromatography-combustion-mass spectrometry applications have been described, but recent results indicate the great possibilities of extending this novel approach to the quantification of organic compounds after separation by liquid chromatography. PMID:22009048
DĒaz, Sergio Cueto; Encinar, Jorge Ruiz; Sanz-Medel, Alfredo; Alonso, Josķ Ignacio GarcĒa
Volatile organic compounds in the unsaturated zone from radioactive wastes.
Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0-2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m yr. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere. PMID:22751077
Baker, Ronald J; Andraski, Brian J; Stonestrom, David A; Luo, Wentai
Process for removing an organic compound from water
A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. Apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater.
Baker, Richard W. (Palo Alto, CA); Kaschemekat, Jurgen (Palo Alto, CA); Wijmans, Johannes G. (Menlo Park, CA); Kamaruddin, Henky D. (San Francisco, CA)
Process for removing an organic compound from water
A process for removing organic compounds from water is disclosed. The process involves gas stripping followed by membrane separation treatment of the stripping gas. The stripping step can be carried out using one or multiple gas strippers and using air or any other gas as stripping gas. The membrane separation step can be carried out using a single-stage membrane unit or a multistage unit. The apparatus for carrying out the process is also disclosed. The process is particularly suited for treatment of contaminated groundwater or industrial wastewater. 19 figures.
Baker, R.W.; Kaschemekat, J.; Wijmans, J.G.; Kamaruddin, H.D.
Organic compounds in produced waters from shale gas wells.
A detailed analysis is reported of the organic composition of produced water samples from typical shale gas wells in the Marcellus (PA), Eagle Ford (TX), and Barnett (NM) formations. The quality of shale gas produced (and frac flowback) waters is a current environmental concern and disposal problem for producers. Re-use of produced water for hydraulic fracturing is being encouraged; however, knowledge of the organic impurities is important in determining the method of treatment. The metal content was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Mineral elements are expected depending on the reservoir geology and salts used in hydraulic fracturing; however, significant levels of other transition metals and heavier main group elements are observed. The presence of scaling elements (Ca and Ba) is related to the pH of the water rather than total dissolved solids (TDS). Using gas chromatography mass spectrometry (GC/MS) analysis of the chloroform extracts of the produced water samples, a plethora of organic compounds were identified. In each water sample, the majority of organics are saturated (aliphatic), and only a small fraction comes under aromatic, resin, and asphaltene categories. Unlike coalbed methane produced water it appears that shale oil/gas produced water does not contain significant quantities of polyaromatic hydrocarbons reducing the potential health hazard. Marcellus and Barnett produced waters contain predominantly C6-C16 hydrocarbons, while the Eagle Ford produced water shows the highest concentration in the C17-C30 range. The structures of the saturated hydrocarbons identified generally follows the trend of linear > branched > cyclic. Heterocyclic compounds are identified with the largest fraction being fatty alcohols, esters, and ethers. However, the presence of various fatty acid phthalate esters in the Barnett and Marcellus produced waters can be related to their use in drilling fluids and breaker additives rather than their presence in connate fluids. Halogen containing compounds are found in each of the water samples, and although the fluorocarbon compounds identified are used as tracers, the presence of chlorocarbons and organobromides formed as a consequence of using chlorine containing oxidants (to remove bacteria from source water), suggests that industry should concentrate on non-chemical treatments of frac and produced waters. PMID:25162586
Maguire-Boyle, Samuel J; Barron, Andrew R
NASA Technical Reports Server (NTRS)
Hydrothermal environments are locations of varied geochemistry due to the disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Observations of the organic geochemistry of hydrothermal vent sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols. thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in hydrothermal environments as well as in a variety of biological processes and other abiotic reactions (Wachtershauser, 1990, OLEB 20, 173; Heinen and Lauwers, 1996, OLEB 26, 13 1, Huber and Wachtershauser, 1997, Science 276, 245; Russell et al., 1998, in Thermophiles: The keys to molecular evolution and the origin of life?). The reduction of CO2 to thiols, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power (see Schoonen et al., 1999, OLEB 29, 5). In addition, the enzyme involved in final stage of methanogenesis, coenzyme-M, is itself a thiol. Thus, organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life at high temperatures. Understanding the biochemical processes of microorganisms that can live to temperatures at least as high as 113 C (Blochl et al., 1996, Extremophiles 1, 14) requires knowledge of the properties of the chemical reactions involved. In order to assess the role of aqueous organic sulfur compounds in hydrothermal organic geochemistry, we have been attempting to determine their thermodynamic properties. We have culled the literature to obtain the properties of organic sulfur compounds. We are able to calculate a number of essential properties, such as free energies of formation, from solubility data available in the literature together with standard properties of organic sulfur gases. However, a number of the properties for aqueous organic sulfur compounds have not been experimentally determined. Furthermore, most of thermodynamic data that are available are for 25 C and 1 bar. In order to determine reaction properties to temperatures and pressures appropriate to the hydrothermal conditions in which thermophilic organisms actually live, we use equations of state developed by Helgeson and co-workers (Helgeson et al., 1981, AJS 281, 1249). A key piece of information needed to go up in temperature is the partial molal heat capacity, which is one of the properties for which experimental data are unavailable for nearly all organic sulfur compounds. We have used correlation methods to determine the partial molal heat capacities and volumes of many organic solutes. These estimates allow us to asses the role of organic sulfur compounds during the reduction of carbon in hydrothermal settings. We will present these data, along with examples of the thermodynamic properties of reactions involving aqueous organic sulfur compounds.
Schulte, Mitchell; Rogers, Karyn L.; DeVincenzi, Donald L. (Technical Monitor)
Source apportionment of airborne particulate matter using organic compounds as tracers
A chemical mass balance receptor model based on organic compounds has been developed that relates source contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected
James J. Schauer; Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit
THE OXIDATION OF ORGANIC COMPOUNDS IN THE TROPOSPHERE AND THEIR GLOBAL WARMING POTENTIALS W. J of methane and ozone. The main factors influencing the global warming potentials of the 10 organic compounds pulses of 10 organic compounds were followed in a global 3-D Lagrangian chemistry-transport model
Source apportionment of airborne particulate matter using organic compounds as tracers
A chemical mass balance receptor model based on organic compounds has been developed that relates sours; contributions to airborne fine particle mass concentrations. Source contributions to the concentrations of specific organic compounds are revealed as well. The model is applied to four air quality monitoring sites in southern California using atmospheric organic compound concentration data and source test data collected
Bernd R. T. Simoneit; WOLFGANG F. ROGGE; LYNN M. HILDEMANN; MONICA A. MAZUREK; GLEN R. CASS
Sorption of ethylhexadecyldimethylammonium (EHDDMA+), a large organic cation, and three neutral organic compounds (NOC's) on two low organic carbon aquifer materials was studied using a soil batch equilibration technique. EHDDMA+ competed effectively with metals for exchange site...
Laboratory Studies of Organic Compounds With Reflectance Spectroscopy
NASA Astrophysics Data System (ADS)
In order to properly interpret reflectance spectra of any solar system surface from the earth to the Oort cloud, laboratory spectra of candidate materials for comparative analysis are needed. Although the common cosmochemical species (H2O, CO2, CO, NH3, and CH4) are well represented in the spectroscopic literature, comparatively little reflectance work has been done on organics from room to cryogenic temperatures at visible to near infrared wavelengths. Reflectance spectra not only enhance weak or unseen transmission features, they are also more analogous to spectra obtained by spacecraft that are imaging such bodies as giant planet moons, kuiper belt objects, centaurs, comets and asteroids, as well as remote sensing of the earth. The USGS Spectroscopy Laboratory is measuring reflectance spectra of organic compounds from room to cryogenic temperatures over the spectral range of 0.35 to 15.5 microns. This region encompasses the fundamental absorptions and many overtones and combinations of C, H, O, and N molecular bonds. Because most organic compounds belong to families whose members have similar structure and composition, individual species identification within a narrow wavelength range may be ambiguous. By measuring spectral reflectance of the pure laboratory samples from the visible through the near and mid-infrared, absorption bands unique to each can be observed, cataloged, and compared to planetary reflectance data. We present here spectra of organic compounds belonging to five families: the alkanes, alkenes, alkynes, aromatics, and cyanides. Common to all of these are the deep C-H stretch fundamental absorptions, which shift shortward from 3.35+ microns in alkanes to 3.25+ microns in aromatics, to 3.2+ microns in alkenes, and down to 3.0+ microns in alkynes. Mid-IR absorptions due to C-H bending deformations at 6.8+ and 7.2+ microns are also identified. In the near infrared these stretching and bending fundamentals yield a diagnostic set of combination absorptions at approximately 2.3 microns, as well as the first C-H stretching overtones at 1.6 to 1.7 microns, and even the second stretching overtones at 1.2+ microns. Additionally, the spectral properties of these organic materials have applications to remote sensing of terrestrial environments, including hazardous waste and disaster site characterization.
Curchin, J. M.; Clark, R. N.; Hoefen, T. M.
Identifying organic nitrogen compounds in Rocky Mountain National Park aerosols
NASA Astrophysics Data System (ADS)
Nitrogen deposition is an important issue in Rocky Mountain National Park (RMNP). While inorganic nitrogen contributions to the ecosystems in this area have been studied, the sources of organic nitrogen are still largely unknown. To better understand the potential sources of organic nitrogen, filter samples were collected and analyzed for organic nitrogen species. Samples were collected in RMNP using a Thermo Fisher Scientific TSP (total suspended particulate) high-volume sampler with a PM2.5 impactor plate from April - November of 2008. The samples presented the opportunity to compare two different methods for identification of individual organic nitrogen species. The first type of analysis was performed with a comprehensive two dimensional gas chromatography (GCxGC) system using a nitrogen chemiluminescence detector (NCD). The filter samples were spiked with propanil in dichloromethane to use as an internal standard and were then extracted in water followed by solid phase extraction. The GCxGC system was comprised of a volatility based separation (DB5 column) followed by a polarity based separation (RXI-17 column). A NCD was used to specifically detect nitrogen compounds and remove the complex background matrix. Individual standards were used to identify peaks by comparing retention times. This method has the added benefit of an equimolar response for nitrogen so only a single calibration is needed for all species. In the second analysis, a portion of the same filter samples were extracted in DI water and analyzed with liquid chromatography coupled with mass spectroscopy (LC/MS). The separation was performed using a C18 column and a water-methanol gradient elution. Electrospray ionization into a time of flight mass spectrometer was used for detection. High accuracy mass measurement allowed unambiguous assignments of elemental composition of resulting ions. Positive and negative polarities were used since amines tend to show up in positive mode and nitrates in negative. The differences in the number of species and what species are identified between these two methods are important for planning future analyses of organic nitrogen compounds. In addition, these data provide new insight into the potential source of organic nitrogen in RMNP. Using the GCxGC method, 39 organic nitrogen species were detected and 20 were identified. Identified species include several types of amines and phenols. The LC/MS method identified several types of cresols, amines, and nitrates.
Beem, K. B.; Desyaterik, Y.; Ozel, M. Z.; Hamilton, J. F.; Collett, J. L.
NASA Astrophysics Data System (ADS)
Organic aerosols, as an important fraction of airborne particulate mass, significantly affect the environment, climate, and human health. Compared with inorganic species, characterization of individual organic compounds is much less complete and comprehensive because they number in thousands or more and are diverse in chemical structures. The source contributions of organic aerosols are far from being well understood because they can be emitted from a variety of sources as well as formed from photochemical reactions of numerous precursors. This thesis work aims to improve the characterization of polar organic compounds and source apportionment analysis of fine organic carbon (OC) in Hong Kong, which consists of two parts: (1) An improved analytical method to determine monocarboxylic acids, dicarboxylic acids, ketocarboxylic acids, and dicarbonyls collected on filter substrates has been established. These oxygenated compounds were determined as their butyl ester or butyl acetal derivatives using gas chromatography-mass spectrometry. The new method made improvements over the original Kawamura method by eliminating the water extraction and evaporation steps. Aerosol materials were directly mixed with the BF 3/BuOH derivatization agent and the extracting solvent hexane. This modification improves recoveries for both the more volatile and the less water-soluble compounds. This improved method was applied to study the abundances and sources of these oxygenated compounds in PM2.5 aerosol samples collected in Hong Kong under different synoptic conditions during 2003-2005. These compounds account for on average 5.2% of OC (range: 1.4%-13.6%) on a carbon basis. Oxalic acid was the most abundant species. Six C2 and C3 oxygenated compounds, namely oxalic, malonic, glyoxylic, pyruvic acids, glyoxal, and methylglyoxal, dominated this suite of oxygenated compounds. More efforts are therefore suggested to focus on these small compounds in understanding the role of oxygenated compounds in aerosol chemistry and physics. By reference to tracers for the major organic aerosol sources, it is deduced that the oxygenated compounds are mainly of secondary origin and direct/indirect contribution from biomass burning could also be important. The chemical composition of these oxygenated species in PM2.5 samples in Hong Kong provide useful information to further ambient and model study in the aspects of chemical formation pathways and speciated organic mass distribution. (2) Source apportionment of PM2.5 organic aerosols in Hong Kong were carried out in two studies. In the first study, chemical characterization and source analysis involved samples collected on high particulate matter (PM) days (avg. PM 2.5 >84 mug m-3) at six general stations and one roadside station from October to December in 2003. Analysis of synoptic weather conditions identified three types of high PM episodes: local, regional transport (RT) and long-range transport (LRT). Roadside samples were discussed separately. Using chemical mass balance (CMB) model, contributions of major primary sources (vehicle exhaust, cooking, biomass burning, cigarette smoke, vegetative detritus, and coal combustion) were estimated, which indicate that vehicle exhaust was the most important primary source, followed by cooking and biomass burning. All primary sources except vegetative detritus had the highest contributions at roadside station, in line with its site characteristics. Primary sources dominated roadside and local samples (>64% of fine OC), while un-apportioned OC (i.e., the difference between measured OC and apportioned primary OC) dominated RT and LRT episodes (>60% of fine OC) and un-apportioned OC had characteristics of secondary OC. In the second study, cold front episodes during winter 2004 and 2005 were targeted to investigate the effect of cold front-related LRT on chemical characteristics and organic aerosol sources of PM2.5 in Hong Kong. In comparison with days under influences of mainly local emissions or RT, cold front LRT brought more organic aerosols attributable
Li, Yunchun
Biogenic volatile organic compound emissions from vegetation fires.
The aim of this paper was to provide an overview of the current state of the art on research into the emission of biogenic volatile organic compounds (BVOCs) from vegetation fires. Significant amounts of VOCs are emitted from vegetation fires, including several reactive compounds, the majority belonging to the isoprenoid family, which rapidly disappear in the plume to yield pollutants such as secondary organic aerosol and ozone. This makes determination of fire-induced BVOC emission difficult, particularly in areas where the ratio between VOCs and anthropogenic NOx is favourable to the production of ozone, such as Mediterranean areas and highly anthropic temperate (and fire-prone) regions of the Earth. Fire emissions affecting relatively pristine areas, such as the Amazon and the African savannah, are representative of emissions of undisturbed plant communities. We also examined expected BVOC emissions at different stages of fire development and combustion, from drying to flaming, and from heatwaves coming into contact with unburned vegetation at the edge of fires. We conclude that forest fires may dramatically change emission factors and the profile of emitted BVOCs, thereby influencing the chemistry and physics of the atmosphere, the physiology of plants and the evolution of plant communities within the ecosystem. PMID:24689733
Ciccioli, Paolo; Centritto, Mauro; Loreto, Francesco
Reactive uptake of organic compounds by liquid sulfuric acid.
NASA Astrophysics Data System (ADS)
The uptake of several organic compounds by laboratory surrogates for tropospheric sulfuric acid particles were investigated by mass spectrometry and infrared reflection-absorption spectroscopy. Among the compounds studied were acetone [(CH_3)_2CO], 2,4-hexanedione [CH_3CO(CH_2)_2COCH_3, MBO], and 2-methyl-3-buten-2-ol [CH_2CHC(CH_3)_2OH]. Experiments were carried out on ultrathin sulfuric acid films (ca. 10-100 monolayer equivalents thick) as functions of organic partial pressure, temperature, and acid composition. Acetone uptake is irreversible for acids that contain >70 weight percent (wt. %) H_2SO4, with kinetics that are second-order in concentration of dissolved acetone. Hexanedione and MBO are irreversibly taken for all acid compositions investigated (60-96 wt. %), with first-order uptake kinetics. In all cases, the irreversible uptake is a consequence of sulfuric acid catalyzed reactions that lead to the formation of new C-C bonds. Implications of these results for heterogeneous tropospheric chemistry will be discussed.
Roberts, J.; Michelsen, R.
Evaporation of volatile organic compounds from human skin in vitro.
The specific evaporation rates of 21 volatile organic compounds (VOCs) from either human skin or a glass substrate mounted in modified Franz diffusion cells were determined gravimetrically. The diffusion cells were positioned either on a laboratory bench top or in a controlled position in a fume hood, simulating indoor and outdoor environments, respectively. A data set of 54 observations (34 skin and 20 glass) was assembled and subjected to a correlation analysis employing 5 evaporative mass transfer relationships drawn from the literature. Models developed by Nielsen et al. (Prediction of isothermal evaporation rates of pure volatile organic compounds in occupational environments: a theoretical approach based on laminar boundary layer theory. Ann Occup Hyg 1995;39:497-511.) and the U.S. Environmental Protection Agency (Peress, Estimate evaporative losses from spills. Chem Eng Prog 2003; April: 32-34.) were found to be the most effective at correlating observed and calculated evaporation rates under the various conditions. The U.S. EPA model was selected for further use based on its simplicity. This is a turbulent flow model based only on vapor pressure and molecular weight of the VOC and the effective air flow rate u. Optimum values of u for the two laboratory environments studied were 0.23 m s(-1) (bench top) and 0.92 m s(-1) (fume hood). PMID:23609116
Gajjar, Rachna M; Miller, Matthew A; Kasting, Gerald B
Effectiveness of geomembranes as barriers for organic compounds
Double compartment tests were conducted to evaluate the transport of aqueous organic compounds through high density polyethylene (HDPE), very low density polyethylene (VLDPE), and polyvinyl chloride (PVC) geomembranes, which separated the two compartments. The concentration of methylene chloride (MC), toluene, trichloroethylene (TCE), and m-xylene was monitored in both upstream and downstream compartments over time. Organic compounds were detected in the downstream compartment in 20 to 200 hours for the 0.76, 1.52, and 2.54-mm thick HDPE geomembranes, in 8 hours for the 0.76-mm thick VLDPE, and in 9 hours for the 0.76-mm thick PVC. TCE had the greatest mass flux, followed by toluene, m-xylene and MC while m-xylene had the greatest partition coefficient, followed by toluene, TCE, and MC. A ten-fold increase in the initial aqueous concentration and a four-fold decrease in the geomembrane thickness increased the mass flux by 15 to 19 times. The mass flux increased by 45 to 97% when geomembranes were stretched in one direction by 5 to 8% of their original length.
Park, J.K.; Hoopes, J.A. [Univ. of Wisconsin, Madison, WI (United States); Sakti, J.P.
Suspended material was isolated from water samples from sixteen sites on the Mississippi River and its major tributaries from Minneapolis, Minn., to New Orleans, La., during the summer and fall of 1991 and the spring of 1992. The suspended material was separated into silt and colloid fractions in order to determine the proportion of associated toxic hydrophobic halogenated organic compounds transported on the colloid. The silt fraction (63 {mu}m to 1 {mu}m in diameter) was isolated first by centrifugation, then the colloidal fraction (1 {mu}m to 0.005 {mu}m in diameter) was isolated by tangential-flow ultrafiltration. The colloid averaged about 10 percent by weight of the total suspended material. Organic carbon content of the colloid ranged from 7 to 30 percent by weight. Silt organic carbon content ranged from 2 to 5 percent by weight. The proportion of suspended organic carbon transport in the river associated with the colloids averaged 35 percent of the total suspended organic carbon transport. Toxic halogenated organic compounds associated with both fractions included PCBs, chlordane, DCPA, hexachlorobenzene, and trifluralin. In some cases, transport of these compounds by the colloid fraction in the Mississippi River was greater than by the silt fraction.
Rostad, C.E. [Geological Survey, Arvada, CO (United States)
This paper reviews current knowledge of biogeochemical cycles of pollutant organic chemicals in aquatic ecosystems with a focus on coastal ecosystems. There is a bias toward discussing chemical and geochemical aspects of biogeochemical cycles and an emphasis on hydrophobic organic compounds such as polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and chlorinated organic compounds used as pesticides. The complexity of mixtures of pollutant organic compounds, their various modes of entering ecosystems, and their physical chemical forms are discussed. Important factors that influence bioavailability and disposition (e.g., organism-water partitioning, uptake via food, food web transfer) are reviewed. These factors include solubilities of chemicals; partitioning of chemicals between solid surfaces, colloids, and soluble phases; variables rates of sorption, desorption; and physiological status of organism. It appears that more emphasis on considering food as a source of uptake and bioaccumulation is important in benthic and epibenthic ecosystems when sediment-associated pollutants are a significant source of input to an aquatic ecosystem. Progress with mathematical models for exposure and uptake of contaminant chemicals is discussed briefly. PMID:1904812
Farrington, J W
Chiral Analyses of Organic Compounds in Carbonaceous Meteorites
NASA Technical Reports Server (NTRS)
Contents include the following: 1. Characterization of Tagish Lake organic content. The first two grant years were largely devoted to the molecular and isotopic analyses of Tagish Lake organic composition. This carbonaceous meteorite fell in Canada in the winter of the year 2000, and its exceptional atmospheric entry and subsequent recovery (e. g., the sample was recovered and stored by avoiding hand contact and above freezing temperatures) contributed in providing a rare and pristine extraterrestrial material. 2. Chiral analyses of Murchison and Murray soluble organics. One of the most intriguing finding in regard to soluble meteorite organics is the presence within the amino acid suite of some compounds displaying L-enantiomeric excesses. This configuration is exclusive in the amino acids of terrestrial proteins and the finding has raised speculations of a possible role of amino acids from meteorites in the origin of homochirality on the early Earth. The main objective for this NASA funding was the characterization of enantiomeric excesses in meteorites and we have conducted several studies toward establishing their distribution and indignity.
Pizzarello, Sandra
Cloud processing of organic compounds: Secondary organic aerosol and nitrosamine formation
Cloud processing of atmospheric organic compounds has been investigated through field studies, laboratory experiments, and numerical modeling. Observational cloud chemistry studies were performed in northern Arizona and fog studies in central Pennsylvania. At both locations, the cloud and fogs showed low acidity due to neutralization by soil dust components (Arizona) and ammonia (Pennsylvania). The field observations showed substantial concentrations (20-5500
James W. Hutchings III
Code of Federal Regulations, 2010 CFR
...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings 1 Table 1 to Subpart...Organic Compound Emission Standards for Automobile Refinish Coatings Pt. 59, Subpt...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings Coating...
Code of Federal Regulations, 2013 CFR
...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings 1 Table 1 to Subpart...Organic Compound Emission Standards for Automobile Refinish Coatings Pt. 59, Subpt...Organic Compound (VOC) Content Limits for Automobile Refinish Coatings Coating...
Electrospray ionization high-resolution mass spectrometry (ESI HR-MS) was used to probe molecular structures of oligomers in secondary organic aerosol (SOA) generated in laboratory experiments on isoprene photooxidation at low- and high-NOx conditions. Up to 80-90% of the observed products are oligomers and up to 33% are nitrogen-containing organic compounds (NOC). We observe oligomers with up to 8 monomer units in length. Tandem mass spectrometry (MSn) confirms NOC compounds are organic nitrates and elucidates plausible chemical building blocks contributing to oligomer formation. Most organic nitrates are comprised of methylglyceric acid units. Other important multifunctional C2-C5 monomer units are identified including methylglyoxal, hydroxyacetone, hydroxyacetic acid, glycolaldehyde, and 2-methyltetrols. The majority of the NOC oligomers contain only one nitrate moiety resulting in a low average N:C ratio of 0.019. Average O:C ratios of the detected SOA compounds are 0.54 under the low-NOx conditions and 0.83 under the high-NOx conditions. Our results underscore the importance of isoprene photooxidation as a source of NOC in organic particulate matter.
Nguyen, Tran B.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Serguei
Exposure to volatile organic compounds: Comparison among different transportation modes
NASA Astrophysics Data System (ADS)
The increasing trend of promoting public transportation (bus tram, metro, train) and more environmental friendly and sustainable non fossil-fuel alternatives (walking, cycling etc) as substitutes for auto vehicles brings forward new questions with regard to pollutant levels to which commuters are exposed. In this study, three transportation modes (tram, auto vehicle and bicycle) are studied and concentration levels of 84 volatile organic compounds (VOCs) (hydrocarbons, aromatic hydrocarbons, oxygen containing hydrocarbons, terpenes and halogenated compounds) are measured along a route in the city of Ghent, Belgium. The concentration levels are obtained by active sampling on Tenax TA sorbent tubes followed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) using deuterated toluene as an internal standard. The median total VOC concentrations for the tram mode (33 ?g/m│) is 1.7 times higher than that of the bicycle mode (20 ?g/m│) and 1.5 times higher than for the car mode (22 ?g/m│). It is found that aromatic hydrocarbons account for a significant proportion in the total VOCs concentration (TVOCs) being as high as 41-57%, 59-72% and 58-72% for the tram, car and bicycle respectively. In all transportation modes, there was a high (r > 0.6) degree of correlation between BTEX compounds, isopropylbenzene, n-propylbenzene, 1,3,5-trimethylbenzene and 1,2,4-trimethylbenzene. When comparing time weighed average concentrations along a fixed route in Ghent, it is found that commuters using the tram mode experience the highest TVOCs concentration levels. However, next to the concentration level to which commuters are exposed, the physical activity level involving the mode of transportation is important to assess the exposure to toxic VOCs. It is proven that the commuter using a bicycle (4.3 ▒ 1.5 ?g) inhales seven and nine times more benzene compared to the commuter using the car and tram respectively, when the same route is followed.
Do, Duc Hoai; Van Langenhove, Herman; Chigbo, Stephen Izuchukwu; Amare, Abebech Nuguse; Demeestere, Kristof; Walgraeve, Christophe
Detection of volatile organic compounds using surface enhanced Raman scattering
The authors present the detection of volatile organic compounds directly in their vapor phase by surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. The type of nanopillars is known as the tapered pillars. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of toluene vapor. The results show that SERS signal from a toluene vapor concentration of ppm level can be achieved, and the toluene vapor can be detected within minutes of exposing the SERS substrate to the vapor. A simple adsorption model is developed which gives results matching the experimental data. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors.
Chang, A S; Maiti, A; Ileri, N; Bora, M; Larson, C C; Britten, J A; Bond, T C
In situ bioremediation of petroleum hydrocarbon and other organic compounds
From supertanker oil spills to the leaking underground storage tank at the corner gas station, contamination from petroleum hydrocarbon fuels and other organic compounds is an environmental concern that affects nearly every small hamlet and major metropolis throughout the world. Most petroleum hydrocarbons are amenable to biodegradation, and a considerable body of experience has been built up over the past two decades in applying in situ bioremediation to a variety of contaminants in all media. This volume provides a comprehensive guide to the latest technological breakthroughs in both the laboratory and the field, covering such topics as air sparging, co-metabolic biodegradation, treatment of MTBE, real-time control systems, nutrient addition, rapid biosensor analysis, multiphase extraction, and accelerated bioremediation.
Alleman, B.C.; Leeson, A.
In situ bioremediation of petroleum hydrocarbon and other organic compounds
From supertanker oil spills to the leaking underground storage tank at the corner gas station, contamination from petroleum hydrocarbon fuels and other organic compounds is an environmental concern that affects nearly every small hamlet and major metropolis throughout the world. Most petroleum hydrocarbons are amenable to biodegradation, and a considerable body of experience has been built up over the past two decades in applying in situ bioremediation to a variety of contaminants in all media. This volume provides a comprehensive guide to the latest technological breakthroughs in both the laboratory and the field, covering such topics as air sparging, co-metabolic biodegradation, treatment of MTBE, real-time control systems, nutrient addition, rapid biosensor analysis, multiphase extraction, and accelerated bioremediation.
Alleman, B.C.; Leeson, A.
In situ bioremediation of petroleum hydrocarbon and other organic compounds
From supertanker oil spills to the leaking underground storage tank at the corner gas station, contamination from petroleum hydrocarbon fuels and other organic compounds is an environmental concern that affects nearly every small hamlet and major metropolis throughout the world. Moreover, the world`s rivers, estuaries, and oceans are threatened by contamination from petroleum leaks and spills. Fortunately, most petroleum hydrocarbons are amenable to biodegradation, and a considerable body of experience has been built up over the past two decades in applying in situ bioremediation to a variety of contaminants in all media. Good progress is being made in terms of developing innovative, cost-effective in situ approaches to bioremediation. This volume provides a comprehensive guide to the latest technological breakthroughs in both the laboratory and the field, covering such topics as air sparging, cometabolic biodegradation, treatment of MTBE, real-time control systems, nutrient addition, rapid biosensor analysis, multiphase extraction, and accelerated bioremediation.
Alleman, B.C.; Leeson, A. [eds.
Solid-phase genotoxicity assay for organic compounds in soil
A genotoxicity assay was developed for samples from environments in which toxic organic compounds are largely sorbed. The assay entails measurement of the rate of mutation of a strain of Pseudomonas putida to rifampicin resistance. The ratio of induced to spontaneous mutants was a function of the concentration of a test mutagen in soil. In studies of the utility of the assay in samples amended with 2-aminofluorene as a test mutagen, the ratio of induced to spontaneous mutants declined with time. The decline paralleled the disappearance of extractable 2-aminofluorene from the soil. The ratio of induced to spontaneous mutants also feel in four other soils with dissimilar properties. The authors suggest that this solid-phase assay is more appropriate for the estimation of genotoxicants sorbed in soil than assays involving extractants or suspensions of soil or sediment samples.
Alexander, R.R.; Chung, N.; Alexander, M. [Cornell Univ., Ithaca, NY (United States)
Source apportionment of volatile organic compounds in Tehran, Iran.
Identifying the sources of volatile organic compounds (VOCs) is key issue to reducing ground-level ozone and PAN. A multivariate receptor model (Unmix) was used for the determination of the contributions of VOCs sources in Tehran-Iran. Concentrations of ambient C2-C10 VOCs were measured continuously and online at the center of Tehran city during the winter of 2012. A high correlation coefficient existed between measured and predicted values (R (2) = 0.99), indicating that the data were well modeled. Five possible VOCs source categories were identified and mobile sources such as vehicle exhaust (61 %) and fuel evaporation (12 %) more than half of the total VOC concentration. City gas and CNG sources, biogenic source, and industrial solvent source categories accounted for 17 %, 8 % and 2 % of the total VOC, respectively. Result showed Unmix for VOCs source apportionment can be used to analyze and generate air pollution control strategies and policies. PMID:23283536
Sarkhosh, Maryam; Mahvi, Amir Hossein; Yunesian, Masud; Nabizadeh, Ramin; Borji, Saeedeh Hemmati; Bajgirani, Ali Ghiami
Reactivity of bromine atom complexes with organic compounds
Complexes of bromine atoms with bromo compounds (C{sub 2}H{sub 5}Br{center dot}Br, CH{sub 2}Br{sub 2}{center dot}Br, CHBr{sub 3}{center dot}Br, and CBr{sub 4}{center dot}Br) were produced by pulse radiolysis of the corresponding bromoalkane dissolved in cyclohexane. With benzene as solvent, the complex C{sub 6}H{sub 6}{center dot}Br was produced. These complexes oxidized phenols to phenoxyl radicals and abstract reactive hydrogens from various compounds. Absolute rate constants for these reactions were determined by following the decay of the Br atom complexes (at 370, 390, 425, 480 and 540 nm, respectively) as a function of substrate concentration. The rate constants varied from 10{sup 5} to 10{sup 10} M{sup {minus}1} s{sup {minus}1} and were strongly dependent on the nature of the Br atom complex and of the organic substrate.
Shoute, L.C.T.; Neta, P. (National Institute of Standards and Technology, Gaithersburg, MD (USA))
Indoor carpet as an adsorptive reservoir for volatile organic compounds
Carpet is recognized as a potential source of volatile organic compounds (VOCs) in indoor air. However, carpet systems can also serve as adsorptive sinks with the potential for reductions in peak VOC concentrations and subsequent re-emission of VOCs over prolonged periods of time. A series of experiments involving eight VOCs, and several carpet systems and environmental conditions were completed using a set of parallel chambers to characterize carpet systems as sinks of VOCs. A linear adsorption and desorption model was used to describe interactions between VOCs and carpet. New carpet fibers treated with stain protection generally accounted for only a very small fraction of mass sorbed to carpet. Most of the sorbed mass for carpet systems was accounted for by either the underlying pad or a combination of the pad and structural backing. Methyl-tert-butyl ether (MTBE) was the only compound to exhibit greater sorption to nylon fibers than to other carpet components. Vapor pressure was observed to be one of the properties that can be related to sorption parameters. Variations in relative humidity (RH) had a significant effect on the degree of sorption for a highly soluble VOC (isopropanol). However, RH had no apparent effect on other VOCs. Air exchange rates (0.5, 2.1, 3.2 /hr) and inlet concentrations (2.5, 5, 15 ppm) generally had little effect on sorption.
Won, D.; Corsi, R.L.; Rynes, M.
Semivolatile organic compounds in the ambient air of Denver, Colorado
NASA Astrophysics Data System (ADS)
A filter-polyurethane foam plug high volume air sampler was used to collect the particle (P) and vapor (V) phases of four classes of semivolatile organic compounds (SOC) in Denver, CO: n-alkanes. polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), and organochlorine pesticides. The carbon preference index (CPI) of n-alkanes in the V or P phases alone was skewed by temperature-dependent V/P partitioning; a combined gaseous + particulate CPI was preferred. The CPI suggested that the alkanes in Denver air were predominently petrogenic. Total PCB were calculated as the sum of individual congeners and also as Aroclor equivalents, with good agreement between the two methods. Apparent V/P distributions of these compound classes were expressed as A(TSP)/F, were A and F are the adsorbent- and filter-retained SOC concentrations (ng m -3) and TSP is the total suspended particle concentration (?g m -3). Values of A(TSP)/F were related to the average sampling temperature ( T, K) through: log [ A( TSP)/ F] = m/ T + b. Fitted log A(TSP)/F at 5░C correlated well with pL0 at 5░C, the SOC liquid vapor pressure. No differences were observed in partitioning behavior among the four SOC types.
Foreman, William T.; Bidleman, Terry F.
Volatile organic compounds in fourteen U.S. retail stores.
Retail buildings have a potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. However, little is known about volatile organic compound (VOC) concentrations in the retail sector and influencing factors, such as ventilation, in-store activities, and store type. We measured VOC concentrations and ventilation rates in 14 retail stores in Texas and Pennsylvania. With the exception of formaldehyde and acetaldehyde, VOCs were present in retail stores at concentrations well below health guidelines. Indoor formaldehyde concentrations ranged from 4.6Āppb to 67Āppb. The two mid-sized grocery stores in the sample had the highest levels of ethanol and acetaldehyde, with concentrations up to 2.6Āppm and 92Āppb, respectively, possibly due to the preparation of dough and baking activities. Indoor-to-outdoor concentration ratios indicated that indoor sources were the main contributors to indoor VOC concentrations for the majority of compounds. There was no strong correlation between ventilation and VOC concentrations across all stores. However, increasing the air exchange rates at two stores led to lower indoor VOC concentrations, suggesting that ventilation can be used to reduce concentrations for some specific stores. PMID:24471978
Nirlo, E L; Crain, N; Corsi, R L; Siegel, J A
Constituents of volatile organic compounds of evaporating essential oil
NASA Astrophysics Data System (ADS)
Essential oils containing aromatic compounds can affect air quality when used indoors. Five typical and popular essential oilsŚrose, lemon, rosemary, tea tree and lavenderŚwere investigated in terms of composition, thermal characteristics, volatile organic compound (VOC) constituents, and emission factors. The activation energy was 6.3-8.6 kcal mol -1, the reaction order was in the range of 0.6-0.8, and the frequency factor was 0.01-0.24 min -1. Toluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, n-undecane, p-diethylbenzene and m-diethylbenzene were the predominant VOCs of evaporating gas of essential oils at 40 ░C. In addition, n-undecane, p-diethylbenzene, 1,2,4-trimethylbenzene, m-diethylbenzene, and 1,2,3-trimethylbenzene revealed high emission factors during the thermogravimetric (TG) analysis procedures. The sequence of the emission factors of 52 VOCs (137-173 mg g -1) was rose ? rosemary > tea tree ? lemon ? lavender. The VOC group fraction of the emission factor of aromatics was 62-78%, paraffins were 21-37% and olefins were less than 1.5% during the TG process. Some unhealthy VOCs such as benzene and toluene were measured at low temperature; they reveal the potential effect on indoor air quality and human health.
Chiu, Hua-Hsien; Chiang, Hsiu-Mei; Lo, Cho-Ching; Chen, Ching-Yen; Chiang, Hung-Lung
Effect of water saturation in soil organic matter on the partition of organic compounds
The sorption of benzene, trichloroethylene, and carbon tetrachloride at room temperature from water solution and from vapor on two high-organic-content soils (peat and muck) was determined in order to evaluate the effect of water saturation on the solute partition in soil organic matter (SOM). The uptake of water vapor was similarly determined to define the amounts of water in the saturated soil samples. In such high-organic-content soils the organic vapor sorption and the respective solute sorption from water exhibit linear isotherms over a wide range of relative concentrations. This observation, along with the low BET surface areas of the samples, suggests that partition in the SOM of the samples is the dominant process in the uptake of these liquids. A comparison of the sorption from water solution and from vapor phase shows that water saturation reduces the sorption (partition) efficiency of SOM by ?? 42%; the saturated water content is ??38% by weight of dry SOM. This reduction is relatively small when compared with the almost complete suppression by water of organic compound adsorption on soil minerals. While the effect of water saturation on solute uptake by SOM is much expected in terms of solute partition in SOM, the influence of water on the solubility behavior of polar SOM can be explained only qualitatively by regular solution theory. The results suggest that the major effect of water in a drying-wetting cycle on the organic compound uptake by normal low-organic-content soils (and the associated compound's activity) is the suppression of adsorption by minerals rather than the mitigation of the partition effect in SOM.
Rutherford, D.W.; Chlou, G.T.
From the interfacial tension of organic compounds with water and their contactable surface areas, the aqueous solubility of such compounds can be quantitatively predicted. Vice-versa. when the interfacial tension with water is known for a given organic compound, as well as its aqueous solubility, its contactable surface area can be obtained. From any two of these three data, and the
C. J. van Oss; R. J. Good
This work evaluates the sensitivity of tropospheric ozone and its precursors to the representation of nonmethane volatile organic compounds (NMVOCs) and organic nitrates. A global 3-D tropospheric chemistry\\/transport model (IMPACT) has been exercised initially using the GEOS-Chem chemical reaction mechanism. The model was then extended by adding emissions and photochemical reactions for aromatic and terpenoid hydrocarbons, and by adding explicit
Akinori Ito; Sanford Sillman; Joyce E. Penner
Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were
Ian Cooper Rumsey
Ice Nucleation by High Molecular Weight Organic Compounds
NASA Astrophysics Data System (ADS)
Deep convection in the tropics is frequently associated with biomass burning. Recent work has suggested that the size of ice crystals in the anvils of tropical cumulonimbus clouds may be affected by biomass burning, though the mechanism for such an effect is uncertain (Sherwood, 2002). We will present results of an investigation of the role that high molecular weight organic compounds, known to be produced in biomass burning (Elias et al., 1999), may play in tropical cirrus anvils through heterogeneous nucleation of ice. In particular, we examine the mechanisms underlying heterogeneous nucleation of ice by films of long chain alcohols by studying the interaction of the alcohols and water/ice using temperature controlled, Attenuated Total Reflection - Fourier Transform Infrared spectroscopy. The mechanisms are interpreted in the context of recent criticisms of some aspects of classical nucleation theory (Seeley and Seidler, 2001; Oxtoby, 1998). References V. Elias, B. Simoneit, A. Pereira, J. Cabral, and J. Cardoso, Detection of high molecular weight organic tracers in vegetation smoke samples by high-temperature gas chromatography-mass spectrometry. Environ. Sci. Tecnol., 33, 2369-2376, 1999. D. Oxtoby, Nucleation of first-order phase transitions. Acc. Chem. Res., 31, 91-97, 1998. L. Seeley and G. Seidler, Preactivation in the nucleation of ice by Langmuir films of aliphatic alcohols. J. Chem. Phys., 114, 10464-10470, 2001. S. Sherwood, Aerosols and ice particle size in tropical cumulonimbus. J. Climate, 15, 1051-1063, 2002.
Cantrell, W.
Identification of volatile organic compounds in human cerumen.
We report here the initial examination of volatile organic compounds (VOCs) emanating from human earwax (cerumen). Recent studies link a single nucleotide polymorphism (SNP) in the adenosine triphosphate (ATP) binding cassette, sub-family C, member 11 gene (ABCC11) to the production of different types of axillary odorants and cerumen. ABCC11 encodes an ATP-driven efflux pump protein that plays an important function in ceruminous apocrine glands of the auditory canal and the secretion of axillary odor precursors. The type of cerumen and underarm odor produced by East Asians differ markedly from that produced by non-Asians. In this initial report we find that both groups emit many of the same VOCs but differ significantly in the amounts produced. The principal odorants are volatile organic C2-to-C6 acids. The physical appearance of cerumen from the two groups also matches previously reported ethnic differences, viz., cerumen from East Asians appears dry and white while that from non-Asians is typically wet and yellowish-brown. PMID:24572763
Prokop-Prigge, Katharine A; Thaler, Erica; Wysocki, Charles J; Preti, George
Emission and Chemical Transformation of Biogenic Volatile Organic Compounds (echo)
NASA Astrophysics Data System (ADS)
Forests are complex sources of biogenic volatile organic compounds (VOC) in the planetary boundary layer. The impact of biogenic VOC on tropospheric photochem- istry, air quality, and the formation of secondary products affects our climate on a regional and global scale but is far from being understood. A considerable lack of knowledge exists concerning a forest stand as a net source of reactive trace com- pounds, which are transported directly into the planetary boundary layer (PBL). In particular, little is known about the amounts of VOC which are processed within the canopy. The goal of ECHO, which is presented in this poster, is to investigate these questions and to improve our understanding of biosphere-atmosphere interactions and their effects on the PBL. The investigation of emissions, chemical processing and vertical transport of biogenic VOC will be carried out in and above a mixed forest stand in J³lich, Germany. A large set of trace gases, free radicals and meteorologi- cal parameters will be measured at different heights in and above the canopy, covering concentrations of VOC, CO, O3, organic nitrates und NOx as well as organic aerosols. For the first time concentration profiles of OH, HO2, RO2 und NO3 radicals will be measured as well together with the actinic UV radiation field and photolysis frequen- cies of all relevant radical precursors (O3, NO2, peroxides, oxygenated VOC). The different tasks of the field experiments will be supported by simulation experiments investigating the primary emission and the uptake of VOC by the plants in stirred tank reactors, soil parameters and soil emissions in lysimeter experiments, and the chem- ical processing of the trace gases as observed in and above the forest stand in the atmosphere simulation chamber SAPHIR. The planning and interpretation of the field experiments is supported by simulations of the field site in a wind tunnel.
Koppmann, R.; Hoffmann, T.; Kesselmeier, J.; Schatzmann, M.
Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration
Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.
Farha, Omar K.; Hupp, Joseph T.
Tetratopic phenyl compounds, related metal-organic framework materials and post-assembly elaboration
Disclosed are tetratopic carboxylic acid phenyl for use in metal-organic framework compounds. These compounds are useful in catalysis, gas storage, sensing, biological imaging, drug delivery and gas adsorption separation.
Farha, Omar K; Hupp, Joseph T
Organosulphur compounds constitute a significant fraction of organic matter in both recent and ancient iron-poor marine sediments as well as in petroleum generated in such sediments1,2. Most studies on organosulphur compounds in marine sediments have focused on hydrophobic compounds, for example, thiophenes3-6, sulphur-containing hopanoids7 and volatile compounds. Recently, hydrophilic, organic thiols were found in significant concentrations in anoxic marine sediments8,9.
Appathurai Vairavamurthy; Kenneth Mopper
Constructing Chemical Pathways of Organic Compounds in Titan's Atmosphere
NASA Astrophysics Data System (ADS)
The CURE/Cassini Imaging Project has provided resources in acquiring images of the Saturnian system using the Imaging Science Subsystem Narrow-Angle Camera (ISS NAC) on board Cassini. Twenty eight images of Titan were taken during March 2, 2006, August 10, 2006, September 12, 2006 and May 4, 2007. Titan is the largest satellite of Saturn with a thick atmosphere consisting of 98% N2 and 2% CH4. Studying Titan's atmosphere can provide a better understanding of pre-biotic Earth due to its nitrogen based atmosphere and due to the photochemical interactions of organic compounds occurring within the atmosphere, as well as with Titan's surface features. In studies prior to the arrival of Cassini-Huygens, microphysical models examined particles, referred to as fractal aggregates and tholins, in Titan's atmosphere exhibiting similar optical properties observed during Voyager flybys. Literature research was conducted of Titan's atmosphere in order to map out the expected chemical pathways of the aerosol particles and to figure out the structure and composition of the atmosphere. The formation of haze particle layers is largely caused by the photolysis and polymerization of CH4, and the haze layers obstruct visible and UV light from illuminating surface features of Titan due to its complex scattering and absorption properties. An accurate illustration of the haze formation process is still under development, however, observations show that the main haze is located below the stratosphere (altitude <= 220 km), consisting of end compounds such as polyacetylene (C2H2), polycyclic aromatic hydrocarbons (PAH), and heavy nitriles. A diagram of the chemical reactions in Titan's atmosphere will be presented using the evidence found in the research. Further investigation into developing an accurate representation of the aerosol particle size, composition, and formation mechanism in Titan's atmosphere can be used in conjunction with observational data to create a model of the atmosphere.
Lee, Agustin; Gillam, S.; Bhakta, J.
Geographical variation in the exhaled volatile organic compounds.
Breath-gas analysis has demonstrated that concentration profiles of volatile organic compounds (VOCs) could be used for detecting a variety of diseases, among them gastric cancer (GC) and peptic ulcer disease (PUD). Here, we explore how geographical variation affects the disease-specific changes in the chemical composition of breath samples, as compared to control states (less severe gastric conditions). Alveolar exhaled breath samples from 260Āpatients were collected at two remotely different geographic locations (China and Latvia), following similar breath-collection protocols. Each cohort included 130Āpatients that were matched in terms of diagnosis (37 GC/32 PUD/61 controls), average age, gender ratio and smoking habits. Helicobacter Pylori infection, which is a major cause for GC and PUD, was found in part of the patients, as well as in part of the controls, at both locations. The breath samples were analyzed by gas chromatography/mass spectrometry, using the same equipment and protocol-of-experiment. We observed similar characteristic differences in the chemical composition of the breath samples between the study groups at the two locations, even though the exact composition of the breath samples differed. Both in China and Latvia, the GC patients and controls could be distinguished by differences in the average levels of 6-methyl-5-hepten-2-one; PUD patients were distinguished from controls by the levels of aromatic compounds and alcohols; GC and PUD patients could not be distinguished at either site. This pilot study indicates the limitations of chemical breath-gas analysis alone for identifying gastric diseases based on the concentration profiles of separate VOCs in international patient cohorts. We assume that these limitations would apply to other diseases as well. The presented data could potentially be useful for developing an alternative, universally applicable diagnostic method that relies on the detection of changes in the collective patterns of the disease-specific classes of exhaled VOCs. PMID:24184568
Amal, Haitham; Leja, Marcis; Broza, Yoav Y; Tisch, Ulrike; Funka, Konrads; Liepniece-Karele, Inta; Skapars, Roberts; Xu, Zhen-Qin; Liu, Hu; Haick, Hossam
Screening of ground water samples for volatile organic compounds using a portable gas chromatograph
A portable gas chromatograph was used to screen 32 ground water samples for volatile organic compounds. Seven screened samples were positive; four of the seven samples had volatile organic substances identified by second-column confirmation. Four of the seven positive, screened samples also tested positive in laboratory analyses of duplicate samples. No volatile organic compounds were detected in laboratory analyses of samples that headspace screening indicated to be negative. Samples that contained volatile organic compounds, as identified by laboratory analysis, and that contained a volatile organic compound present in a standard of selected compounds were correctly identified by using the portable gas chromatography. Comparisons of screened-sample data with laboratory data indicate the ability to detect selected volatile organic compounds at concentrations of about 1 microgram per liter in the headspace of water samples by use of a portable gas chromatography. -Author
Buchmiller, R.C.
Compositing water samples for analysis of volatile organic compounds
Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Researchers are able to derive accurate values for the mean concentration of VOCs from a single VOC analysis using established techniques for the collection of representative, discrete water samples. Such samples are then composited with a gas-tight syringe. This methodology can be employed in conjunction with chemical assessment using a conventional laboratory, field-portable equipment, or a mobile laboratory. Estimates of mass loadings in wastewater and urban storm runoff can be generated using values for the flow-weighted mean VOC concentrations. Spatially integrated mean VOC concentrations are useful for the evaluation of drinking waters. Factors that influence the value for the total error are identified.
Lopes, T.J.; Fallon, J.D.; Maluk, T.L.
Reactivity of group IV (100) semiconductor surfaces towards organic compounds
NASA Astrophysics Data System (ADS)
The reactions of simple and multifunctional organic compounds with the clean silicon, germanium, and diamond (100)-2 x 1 semiconductor surfaces have been investigated using a combination of multiple internal reflection infrared spectroscopy and quantum chemistry density functional theory calculations. From these studies, an improved understanding of the atomic level reactivity of these semiconductor surfaces has been obtained, along with insights into how to achieve their selective coupling with organics of desired and varied functionality. In addition to the Si(100) and Ge(100) surfaces, our results show that cycloaddition chemistry can also be extended to the diamond (100) surface. At room temperature, 1,3-butadiene was found to form a Diels-Alder product with the diamond (100) surface, as evidenced by isotopic substitution experiments and comparison of the surface adduct with its direct molecular analogue, cyclohexene. The reactions of other classes of molecules in addition to alkenes on the Si(100) and Ge(100) surfaces, including a series of five-membered cyclic amines, were also examined. For tertiary aliphatic amines on Si(100) and both secondary and tertiary aliphatic amines on Ge(100), a majority of the molecules were observed to become stably trapped in dative-bonded precursor states rather than form energetically favorable dissociation products. For pyrrole, aromaticity was found to play a defining role in its reactivity, and a comparison of its molecular and surface reactivity reveals interesting similarities. To probe the factors controlling the selectivity of organic reactions on clean semiconductor surfaces, the adsorption of acetone and a series of unsaturated ketones was also investigated. The reaction of acetone on Ge(100) was found to be under thermodynamic control at room temperature, resulting in the formation of an "ene" product rather than the kinetically favored [2+2] C=O cycloaddition product previously observed on the Si(100) surface. In contrast to the silicon and diamond surfaces, thermodynamic control on the germanium surface is facilitated by the reversibility of weak adsorption. For the unsaturated ketones, enhanced selectivity on Ge(100) in comparison with Si(100) was observed. The results can be explained by differences between the two surfaces in both thermodynamic and kinetic factors, and suggest that germanium may be a superior material for selective organic functionalization.
Wang, George T.
In this study, a comparison is made of polar organic compounds found in the field with those produced in secondary organic aerosol from laboratory irradiations of natural hydrocarbons and oxides of nitrogen (NOx). The field samples comprised atmospheric particulate matter (PM2.5) collected at Research Triangle Park (RTP), NC, during the summer of 2003, and the laboratory samples originated from the photooxidation of the following monoterpenes: alpha-pinene, beta-pinene, and d-limonene. To determine the structural characteristics of the polar compounds, the filter samples were solvent extracted and derivatized using a technique based on single and multistep derivatizations. The resulting compound derivatives were analyzed by GC-MS in the methane-Cl and El modes. In addition to previously reported biogenic oxidation products (pinic acid, pinonic acid, norpinic acid, nopinone, and pinonaldehyde), seven multifunctional organic compounds were found in both field and laboratory samples. These compounds, which are proposed as possible atmospheric tracers for secondary organic aerosol from monoterpenes, were consistent with the following identifications: 3-isopropyl pentanedioic acid; 3-acetyl pentanedioic acid; 3-carboxy heptanedioic acid; 3-acetyl hexanedioic acid; 2-isopropyl-1,2-dihydroxybutanol; 4-isopropyl-2,4-dihydroxyhexanol; and 3-(2-hydroxy-ethyl)-2,2-dimethyl-cyclobutane carboxylic acid. Initial attempts have been made to quantify the concentrations of these tracer compounds on the basis of surrogate compound calibrations. The occurrence of these compounds in both laboratory and field measurements suggests that secondary organic aerosol originating from biogenic hydrocarbons are contributing to the regional aerosol burden in the southeastern United States. Several of these compounds also appear to contribute to the global aerosol burden in that they have also been identified in Europe and Brazil. PMID:16124301
Jaoui, M; Kleindienst, T E; Lewandowski, M; Offenberg, J H; Edney, E O
On 15 August 2001, a tire fire took place at the Pneu Lavoie Facility in Gatineau, Quebec, in which 4000 to 6000 new and recycled tires were stored along with other potentially hazardous materials. Comprehensive gas chromatography-mass spectrometry (GC-MS) analyses were performed on the tire fire samples to facilitate detailed chemical composition characterization of toxic polycyclic aromatic hydrocarbons (PAHs) and other organic compounds in samples. It is found that significant amounts of PAHs, particularly the high-ring-number PAHs, were generated during the fire. In total, 165 PAH compounds including 13 isomers of molecular weight (MW) 302, 10 isomers of MW 278, 10 isomers of MW 276, 7 isomers of MW 252, 7 isomers of MW 228, and 8 isomers of MW 216 PAHs were positively identified in the tire fire wipe samples for the first time. Numerous S-, O-, and N-containing PAH compounds were also detected. The identification and characterization of the PAH isomers was mainly based on: (1) a positive match of mass spectral data of the PAH isomers with the NIST authentic mass spectra database; (2) a positive match of the GC retention indices (I) of PAHs with authentic standards and with those reported in the literature; (3) agreement of the PAH elution order with the NIST (US National Institute of Standards and Technology) Standard Reference Material 1597 for complex mixture of PAHs from coal tar; (4) a positive match of the distribution patterns of PAH isomers in the SIM mode between the tire fire samples and the NIST Standard Reference Materials and well-characterized reference oils. Quantitation of target PAHs was done on the GC-MS in the selected ion monitoring (SIM) mode using the internal standard method. The relative response factors (RRF) for target PAHs were obtained from analyses of authentic PAH standard compounds. Alkylated PAH homologues were quantitated using straight baseline integration of each level of alkylation. PMID:17112533
Wang, Zhendi; Li, K; Lambert, P; Yang, Chun
The functionalization of porous metal-organic frameworks (Cu{sub 3}(BTC){sub 2}) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N{sub 2} and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius-Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs. - Graphical Abstract: The adsorption behavior of volatile organic compounds in porous metal-organic frameworks functionalized by polyoxometalates has been systematically evaluated. Highlights: > Functionalization of MOFs was achieved by incorporating Keggin-type POMs. > Introduction of POMs improved the thermal stability and adsorption capacity. > Alkali metal ion-exchange modified the inclusion state and also enhanced the adsorption. > Adsorption enthalpies were estimated to study the impact of POMs and alkali metal cations.
Ma Fengji [Key Laboratory of Polyoxometalates Science of the Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); Liu Shuxia, E-mail: firstname.lastname@example.com [Key Laboratory of Polyoxometalates Science of the Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China); Liang Dadong; Ren Guojian; Wei Feng; Chen Yaguang; Su Zhongmin [Key Laboratory of Polyoxometalates Science of the Ministry of Education, College of Chemistry, Northeast Normal University, Changchun 130024 (China)
Volatile organic compounds in ambient air of MumbaiŚIndia
NASA Astrophysics Data System (ADS)
Volatile organic compounds (VOCs) are a major group of air pollutants which play a critical role in atmospheric chemistry. These contribute to toxic oxidants which are harmful to ecosystem, human health and atmosphere. The variability of pollutants is an important factor in determining human exposure to these chemicals. Data on levels of VOCs in developing countries, including India, are lacking. The present work deals with the estimation of target VOCs at 15 locations of five categories in Mumbai. The categories are residential, industrial, commercial, traffic intersections and petrol refueling stations. The monitoring was carried out during peak hours in the morning and evening, once every month, during May 2001 to April 2002. The study focused on target VOCs as defined by USEPA. Concentrations of benzene, at all the locations, were found to be much above the guidelines values prescribed by World Health Organization (WHO) for ambient air quality. All other VOCs were observed to be below the WHO guideline values. The results show that levels of VOCs in Mumbai were high. There is need for a regular monitoring schedule of VOCs in the urban environment. Variability studies are important to assess the exposure potential of pollutants which are an important parameter for health impact studies. This study also presents the variability of VOCs in the urban area of Mumbai. Variability was divided into measurement spatial, temporal and temporal-spatial interaction components. The temporal component along with temporal-spatial interaction component were the major contributors to variability. VOCs associated with mobile source emissions and emissions from marine source were found to be distributed uniformly in the urban atmosphere in Mumbai. the need for continuous monitoring, to capture short term peak concentrations and averages, is evident.
Srivastava, Anjali; Joseph, A. E.; Devotta, S.
Volatile Organic Compounds in the Global Atmosphere (Invited)
NASA Astrophysics Data System (ADS)
The World Meteorological Organization (WMO) - Global Atmospheric Watch (GAW) has been guiding the implementation of a global program for the monitoring of atmospheric volatile organic compounds (VOC). Essential features are 1. regular, in-situ, high temporal resolution measurements of VOC at surface stations, 2. VOC analyses in samples collected within flask sampling networks for wide geographical coverage, and 3. a concerted calibration and data quality control effort. A centerpiece of the flask sampling component builds upon the US NOAA Earth System Research Laboratory - Global Cooperative Air Sampling Network. Nine non-methane hydrocarbon species (NMHC; ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, isoprene, benzene, toluene) are currently analyzed by an automated gas chromatography system at the University of ColoradoÆs Institute of Arctic and Alpine Research (INSTAAR) in pairs of samples collected bi-weekly at 41 global background monitoring sites. Since the implementation of this program in 2004 more than 7000 measurements have been obtained. The obtained data allow elucidating the geographical and seasonal behavior of atmospheric NMHC, as well as interannual variations. Results show a wide dynamic range of mixing ratio changes. Concentration maxima and seasonal cycles are most pronounced in regions of highest emission sources and highest changes in the seasonal OH radical sink, i.e. the northern high and mid-latitudes. Seasonal southern hemisphere (SH) maxima are ~7 times and ~20 times lower for ethane and propane than in the northern hemisphere, which mainly reflects the smaller source strength of these gases in the SH. The richness of information in these data will help constraining the variability in global atmospheric oxidation chemistry and regional budgets of greenhouse gases, such as of methane and CO2, and most certainly stimulate further interests and applications in many fields of atmospheric chemistry and climate research. Global distribution of ethane during 2004-2010 as derived from in ~7000 flask samples collected at 41 remote sites of the NOAA-ESRL network.
Helmig, D.; Bottenheim, J. W.; Galbally, I.; Lewis, A. C.; Masarie, K.; Milton, M.; Penkett, S.; Plass-Duelmer, C.; Reimann, S.; Steinbrecher, R.; Tans, P. P.; Thiel, S.
[Volatile organic compounds (VOCs) emitted from large furniture].
Indoor air pollution by volatile organic compounds (VOCs), which may cause a hazardous influence on human being such as sick building (sick house) syndrome, has become a serious problem. In this study, VOCs emitted from nine pieces of home furniture, three sets of dining tables, three sets of chest of drawers and three sofas, were analyzed as potential sources of indoor air pollution by large chamber test method (JIS A 1911). Based on the emission rates of total VOC (TVOC), the impacts on the indoor TVOC was estimated by the sample model with a volume of 20 m3 and ventilation frequency of 0.5 times/h. The estimated TVOC increment values were exceeded the provisional target value for indoor air (400 microg/m3) in three sets of dining tables, one set of chest of drawer and one sofa. The estimated increment of formaldehyde were exceeded the guideline value (100 microg/m3) in one set of dining table, two sets of chest of drawers and one sofa. These results revealed that VOC emissions from furniture may influence significantly indoor air quality. Also, in this study, to establish the alternative method for large chamber test methods, emission rates from representative three parts of furniture unit were evaluated using the small chamber and emission rate from full-sized furniture was predicted. Emission rates of TVOC and formaldehyde predicted by small chamber test were 3-46% and 6-252% of the data obtained using large chamber test, respectively. PMID:22259846
Tanaka-Kagawa, Toshiko; Furuta, Mitsuko; Shibatsuji, Masayoshi; Jinno, Hideto; Nishimura, Tetsuji
Identification of nonmethane organic compound emissions from grassland vegetation.
Emissions of nonmethane organic compounds (NMOCs) from grassland vegetation were collected in Summa(reg.sign) passivated stainless-steel canisters with a static enclosure technique and were analyzed by high-resolution gas chromatography with flame ionization and ion trap mass spectrometric detectors. Approximately 40 NMOCs with 6-10 carbon atoms were observed in samples analyzed by high-resolution gas chromatography with the flame ionization detector. Nineteen NMOCs in this molecular weight range (6 aliphatic oxygenates; 1 aromatic hydrocarbon; and 4 acyclic, 5 monocyclic, and 3 bicyclic monoterpenoids) were identified by ion trap mass spectrometry. Mass spectrometry was particularly useful for identifying myrcene and cis-3-hexenylacetate, which coeluted on a fused-silica capillary column coated with a 1-{mu}m-thick film of polydimethylsiloxane. An evaluation of the reactivity of the grassland emissions revealed that the aliphatic oxygenates have lifetimes of a few hours with respect to oxidation by OH and O{sub 3} in the atmosphere. This value is similar to the lifetimes of the bicyclic monoterpenoids. The expected lifetimes of the monoterpenoids with respect to oxidation by NO{sub 3} are only several minutes.
Fukui, Y.; Doskey, P. V.; Environmental Research; NASA Ames Research Center
Predicting the emission rate of volatile organic compounds fromvinyl flooring
A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion-controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material-phase (C{sub 0}), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests, and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top side up and bottom side up. With the exception of phenol, and within the limits of experimental precision, the mass of VOCs recovered in the gas phase balances the mass emitted from the material phase. The model parameters (C{sub 0}, K, and D) were measured using procedures that were completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.
Cox, Steven S.; Little, John C.; Hodgson, Alfred T.
Sources of volatile organic compounds in Cairo's ambient air.
The greater Cairo area suffers from extreme levels of gas and particulate phase air pollutants. In order to reduce the levels of ambient pollution, the USAID and the Egyptian Environmental Affairs Agency (EEAA) have supported the Cairo Air Improvement Project (CAIP). As part of this project, two intensive ambient monitoring studies were carried out during the period of February 22 to March 4 and October 27 to November 27, 1999. Volatile organic compounds (VOCs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. During the February/March study, samples were collected daily, while in the October/November study samples were collected every other day. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. High levels of NMHC were observed at all locations. NMHC concentrations ranged from 365 ppb C at Helwan to 1,848 ppb C at El Qualaly during winter, 1999 and from 461 ppb C at Kaha to 2,037 ppb C at El Qualaly during fall, 1999. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The highest mobile source contributions were estimated at this site. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and compressed natural gas. PMID:18843549
Abu-Allaban, M; Lowenthal, D H; Gertler, A W; Labib, M
Advanced heat pump for the recovery of volatile organic compounds
NASA Astrophysics Data System (ADS)
Emissions of Volatile Organic Compounds (VOC) from stationary industrial and commercial sources represent a substantial portion of the total U.S. VOC emissions. The 'Toxic-Release Inventory' of the U.S. Environmental Protection Agency estimates this to be at about 3 billion pounds per year (1987 estimates). The majority of these VOC emissions are from coating processes, cleaning processes, polymer production, fuel production and distribution, foam blowing, refrigerant production, and wood products production. The U.S. Department of Energy's (DOE) interest in the recovery of VOC stems from the energy embodied in the recovered solvents and the energy required to dispose of them in an environmentally acceptable manner. This Phase 1 report documents 3M's work in close working relationship with its subcontractor Nuclear Consulting Services (Nucon) for the preliminary conceptual design of an advanced Brayton cycle heat pump for the recovery of VOC. The Nucon designed Brayton cycle heat pump for the recovery of methyl ethyl ketone and toluene from coating operations at 3M Weatherford, OK, was used as a base line for the work under cooperative agreement between 3M and ODE. See appendix A and reference (4) by Kovach of Nucon. This cooperative agreement report evaluates and compares an advanced Brayton cycle heat pump for solvent recovery with other competing technologies for solvent recovery and reuse. This advanced Brayton cycle heat pump is simple (very few components), highly reliable (off the shelf components), energy efficient, and economically priced.
Personal exposure to volatile organic compounds in the Czech Republic.
Personal exposures to volatile organic compounds (VOCs) were measured in the three industrial cities in the Czech Republic, Ostrava, Karvina and Havirov, while the city of Prague served as a control in a large-scale molecular epidemiological study identifying the impacts of air pollution on human health. Office workers from Ostrava and city policemen from Karvina, Havirov and Prague were monitored in the winter and summer of 2009. Only adult non-smokers participated in the study (N=160). Radiello-diffusive passive samplers were used to measure the exposure to benzene, toluene, ethylbenzene, meta- plus para-xylene and ortho-xylene (BTEX). All participants completed a personal questionnaire and a time-location-activity diary (TLAD). The average personal BTEX exposure levels in both seasons were 7.2/34.3/4.4/16.1??g/m(3), respectively. The benzene levels were highest in winter in Karvina, Ostrava and Prague: 8.5, 7.2 and 5.3??g/m(3), respectively. The personal exposures to BTEX were higher than the corresponding stationary monitoring levels detected in the individual localities (P<0.001; except m,p-xylene in summer). The indoor environment, ETS (environmental tobacco smoke), cooking, a home-heating fireplace or gas stove, automobile use and being in a restaurant were important predictors for benzene personal exposure. Ostrava's outdoor benzene pollution was a significant factor increasing the exposure of the Ostrava study participants in winter (P<0.05). PMID:22669500
Svecova, Vlasta; Topinka, Jan; Solansky, Ivo; Sram, Radim J
Reduction of volatile organic compound emissions from automobile refinishing
Automobile refinishing (repainting) is a source of volatile organic compound (VOC) emissions. The study was conducted to evaluate available techniques that can be used to reduce VOC emissions from this source. The document provides information on the steps involved in the refinishing process which result in emissions, available emission reduction techniques, VOC emission levels, VOC emission reductions, and costs associated with the reduction techniques. Techniques investigated include (1) reduced-VOC cleaners, (2) replacement of lacquers with enamels, (3) replacement of enamels with polyurethanes, (4) replacement of solvent-borne primers with waterborne primers, (5) replacement of conventional clearcoats with higher-solids clearcoats, (6) installation of cleanup solvent recovery systems, (7) replacement of conventional spray guns with higher transfer efficiency equipment, and (8) add-on controls. The primary conclusions from the study are: (1) the use of available techniques could result in VOC emission reductions ranging from 3-50% of the current estimated baseline emissions from typical refinishing shops; and (2) the annualized costs for many of the available techniques are less than the cost of current practices.
Athey, C.; Hester, C.; McLaughlin, M.; Neulicht, R.M.; Turner, M.B.
Evaluation of Volatile Organic Compound Emissions from Megacities and Wildfires
NASA Astrophysics Data System (ADS)
Volatile organic compounds (VOCs) play a critical role in determining air quality through their impact on ozone production and other pollutants. Tropospheric chemistry models use a variety of treatments for the lumping of VOCs in their chemical mechanisms, as a compromise between detailed treatment and computational speed. However, emission inventories are frequently provided for only total VOCs with little or no information on how to split the emissions among the model species, introducing additional uncertainty to the model simulations. Global model simulations using the Model for Ozone and Related Chemical Tracers (MOZART-4) and several different emission inventories are evaluated through detailed comparison to aircraft and surface observations. In particular, correlations between measured VOCs and CO are used to test the emission inventory emission ratios of the modeled VOC species. For example, megacity VOC emissions will be evaluated with surface measurements in Mumbai, Shanghai and Tokyo, as well as aircraft measurements from the NSF/MIRAGE experiment downwind of Mexico City. Wildfire emissions in Siberia, Canada and California will be evaluated using airborne observations of the NASA/ARCTAS experiment.
Emmons, L. K.; Apel, E. C.; Hornbrook, R. S.; Riemer, D. D.; Lamarque, J.; Wiedinmyer, C.; Mirage Science Team; Arctas Science Team
Elimination of volatile organic compounds by biofiltration: a review.
Volatile organic compounds (VOCs) are pollutants that are responsible for the formation of the tropospheric ozone, one of the precursors of smog. VOCs are emitted by various industries including chemical plants, pulp and paper mills, pharmaceuticals, cosmetics, electronics and agri-food industries. Some VOCs cause odor pollution while many of them are harmful to environment and human or animal health. For the removal of VOCs, biofiltration, a biological process, has proved to be reliable when properly operated. This process has therefore been widely applied in Europe and North America. The main advantages associated with the use of biofiltration are related to its set-up, maintenance, and operating costs which are usually lower than those related to other VOCs control technologies and because it is less harmful for the environment than conventional processes like incineration. In the present paper, the main parameters (type, moisture, pH, and temperature of filter bed, microbial population, nutrients concentrations, and VOCs' inlet load) to be controlled during the biofiltration are identified and described in detail. The main phenomena involved in biofiltration are also discussed. For improving the efficiency of VOC control biotechnology, new techniques are now proposed that include the use of membranes, biphasic reactors, UV photolysis, and many others. PMID:18351227
Nikiema, Josiane; Dastous, Paul-Andrķ; Heitz, MichĶle
Remediation of ground water containing volatile organic compounds and tritium
The Trailer 5475 (T-5475) East Taxi Strip Area at Lawrence Livermore National Laboratory (LLNL), Livermore, California was used as a taxi strip by the US Navy to taxi airplanes to the runway from 1942 to 1947. Solvents were used in some unpaved areas adjacent to the East Taxi Strip for cleaning airplanes. From 1953 through 1976, the area was used to store and treat liquid waste. From 1962 to 1976 ponds were constructed and used for evaporation of liquid waste. As a result, the ground water in this area contains volatile organic compounds (VOCs) and tritium. The ground water in this area is also known to contain hexavalent chromium that is probably naturally occurring. Therefore, LLNL has proposed ``pump-and-treat`` technology above grade in a completely closed loop system. The facility will be designed to remove the VOCs and hexavalent chromium, if any, from the ground water, and the treated ground water containing tritium will be reinjected where it will decay naturally in the subsurface. Ground water containing tritium will be reinjected into areas with equal or higher tritium concentrations to comply with California regulations.
Shukla, S.N.; Folsom, E.N.
Intermediate volatility organic compounds (IVOCs) are an important class of secondary organic aerosol (SOA) precursors that have not been traditionally included in chemical transport models. A challenge is that the vast majority of IVOCs cannot be speciated using traditional gas chromatography-based techniques; instead they are classified as an unresolved complex mixture (UCM) that is presumably made up of a complex mixture of branched and cyclic alkanes. To better understand SOA formation from IVOCs, a series of smog chamber experiments was conducted with different alkanes, including cyclic, branched, and linear compounds. The experiments focused on freshly formed SOA from hydroxyl (OH) radical-initiated reactions under high-NO(x) conditions at typical atmospheric organic aerosol concentrations (C(OA)). SOA yields from cyclic alkanes were comparable to yields from linear alkanes three to four carbons larger in size. For alkanes with equivalent carbon numbers, branched alkanes had the lowest SOA mass yields, ranging between 0.05 and 0.08 at a C(OA) of 15 ?g m(-3). The SOA yield of branched alkanes also depends on the methyl branch position on the carbon backbone. High-resolution aerosol mass spectrometer data indicate that the SOA oxygen-to-carbon ratios were largely controlled by the carbon number of the precursor compound. Depending on the precursor size, the mass spectrum of SOA produced from IVOCs is similar to the semivolatile-oxygenated and hydrocarbon-like organic aerosol factors derived from ambient data. Using the new yield data, we estimated SOA formation potential from diesel exhaust and predict the contribution from UCM vapors to be nearly four times larger than the contribution from single-ring aromatics and comparable to that of polycyclic aromatic hydrocarbons after several hours of oxidation at typical atmospheric conditions. Therefore, SOA from IVOCs may be an important contributor to urban OA and should be included in SOA models; the yield data presented in this study are suitable for such use. PMID:22823284
Tkacik, Daniel S; Presto, Albert A; Donahue, Neil M; Robinson, Allen L
In this article, volatile organic compounds in 14 honey samples (rosemary, eucalyptus, orange, thyme, sage, and lavender) were identified. Volatile organic compounds were extracted using a solid phase microextraction method followed by gas chromatography connected with mass spectrometry analysis. The studied honey samples were compared based on their volatile organic compounds composition. In total, more than 180 compounds were detected in the studied samples. The detected compounds belong to various chemical classes such as terpenes, alcohols, acids, aldehydes, ketones, esters, norisoprenoids, benzene and furane derivatives, and organic compounds containing sulfur and nitrogen heteroatom. Ten chiral compounds (linalool, trans-linalool oxide, cis-linalool oxide, 4-terpineol, ?-terpineol, hotrienol, and four stereoisomers of lilac aldehydes) were selected for further chiral separation. Chirality 26:670-674, 2014. ® 2014 Wiley Periodicals, Inc. PMID:25099214
Pa×itnß, Alexandra; D×·rovß, Jana; Spßnik, Ivan
Volatile organic compounds of polyethylene vinyl acetate plastic are toxic to living organisms.
Volatile organic compounds (VOCs) in polyvinyl chloride (PVC) plastic products readily evaporate; as a result, hazardous gases enter the ecosystem, and cause cancer in humans and other animals. Polyethylene vinyl acetate (PEVA) plastic has recently become a popular alternative to PVC since it is chlorine-free. In order to determine whether PEVA is harmful to humans, this research employed the freshwater oligochaete Lumbriculus variegatus as a model to compare their oxygen intakes while they were exposed to the original stock solutions of PEVA, PVC or distilled water at a different length of time for one day, four days or eight days. During the exposure periods, the oxygen intakes in both PEVA and PVC groups were much higher than in the distilled water group, indicating that VOCs in both PEVA and PVC were toxins that stressed L. variegatus. Furthermore, none of the worms fully recovered during the24-hr recovery period. Additionally, the L. variegatus did not clump together tightly after four or eight days' exposure to either of the two types of plastic solutions, which meant that both PEVA and PVC negatively affected the social behaviors of these blackworms. The LD50 tests also supported the observations above. For the first time, our results have shown that PEVA plastic has adverse effects on living organisms, and therefore it is not a safe alternative to PVC. Further studies should identify specific compounds causing the adverse effects, and determine whether toxic effect occurs in more complex organisms, especially humans. PMID:25242410
Meng, Tingzhu Teresa
Effects of polar and nonpolar groups on the solubility of organic compounds in soil organic matter
Vapor sorption capacities on a high-organic-content peat, a model for soil organic matter (SOM), were determined at room temperature for the following liquids: n-hexane, 1,4-dioxane, nitroethane, acetone, acetonitrile, 1-propanol, ethanol, and methanol. The linear organic vapor sorption is in keeping with the dominance of vapor partition in peat SOM. These data and similar results of carbon tetrachloride (CT), trichloroethylene (TCE), benzene, ethylene glycol monoethyl ether (EGME), and water on the same peat from earlier studies are used to evaluate the effect of polarity on the vapor partition in SOM. The extrapolated liquid solubility from the vapor isotherm increases sharply from 3-6 wt % for low-polarity liquids (hexane, CT, and benzene) to 62 wt % for polar methanol and correlates positively with the liquid's component solubility parameters for polar interaction (??P) and hydrogen bonding (??h). The same polarity effect may be expected to influence the relative solubilities of a variety of contaminants in SOM and, therefore, the relative deviations between the SOM-water partition coefficients (Kom) and corresponding octanol-water partition coefficients (Kow) for different classes of compounds. The large solubility disparity in SOM between polar and nonpolar solutes suggests that the accurate prediction of Kom from Kow or Sw (solute water solubility) would be limited to compounds of similar polarity.
Chiou, C. T.; Kile, D. E.
Emission of volatile organic compounds from silage: Compounds, sources, and implications
NASA Astrophysics Data System (ADS)
Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. Through a literature review, we have focused on identifying the most important compounds emitted from corn silage (the most common type of silage in the US) and the sources of these compounds by quantifying their production and emission potential in silage and describing production pathways. We reviewed measurements of VOC emission from silage and assessed the importance of individual silage VOCs through a quantitative analysis of VOC concentrations within silage. Measurements of VOC emission from silage and VOCs present within silage indicated that alcohols generally make the largest contribution to emission from corn silage, in terms of mass emitted and potential ozone formation. Ethanol is the dominant alcohol in corn silage; excluding acids, it makes up more than half of the mean mass of VOCs present. Acids, primarily acetic acid, may be important when emission is high and all VOCs are nearly depleted by emission. Aldehydes and esters, which are more volatile than acids and alcohols, are important when exposure is short, limiting emission of more abundant but less volatile compounds. Variability in silage VOC concentrations is very high; for most alcohols and acids, tolerance intervals indicate that 25% of silages have concentrations a factor of two away from median values, and possibly much further. This observation suggests that management practices can significantly influence VOC concentrations. Variability also makes prediction of emissions difficult. The most important acids, alcohols, and aldehydes present in silage are probably produced by bacteria (and, in the case of ethanol, yeasts) during fermentation and storage of silage. Aldehydes may also be produced aerobically by spoilage microorganisms through the oxidation of alcohols. Abiotic reactions may be important for production of methanol and esters. Although silage additives appear to affect VOC production in individual studies, bacterial inoculants have not shown a consistent effect on ethanol, and effects on other VOCs have not been studied. Production of acetic acid is understood, and production could be minimized, but a decrease could lead to an increase in other, more volatile and more reactive, VOCs. Chemical additives designed for controlling yeasts and undesirable bacteria show promise for reducing ethanol production in corn silage. More work is needed to understand silage VOC production and emission from silage, including: additional measurements of VOC concentrations or production in silage of all types, and an exploration of the causes of variability; accurate on-farm measurements of VOC emission, including an assessment of the importance of individual ensiling stages and practices that could reduce emission of existing VOCs; and work on understanding the sources of silage VOCs and possible approaches for reducing production.
Hafner, Sasha D.; Howard, Cody; Muck, Richard E.; Franco, Roberta B.; Montes, Felipe; Green, Peter G.; Mitloehner, Frank; Trabue, Steven L.; Rotz, C. Alan
NASA Astrophysics Data System (ADS)
Studies concentrating on hydrogen bonding between the base of exobidentate bis(imidazole) derivatives, and 2-aminoheterocyclic compounds, and (▒)-1,10-binaphthalene-2,2'-diol have led to an increased understanding of the role the aromatic N-containing compounds have in binding with (▒)-1,10-binaphthalene-2,2'-diol. Here anhydrous multicomponent adducts of N-containing aromatic bases such as 1,4-bis(N-imidazolyl)butane (L1), 1,3-bis(N-benzimidazolyl)propane (L2), 1,4-bis(N-benzimidazolyl)butane (L3), 1,5-bis(N-benzimidazolyl)-3-oxapentane (L4), 2-amino-4-phenylthiazole (L5), and 2-amino-5,7-dimethyl-1,8-naphthyridine (L6) have been prepared with (▒)-1,10-binaphthalene-2,2'-diol (binol). The six crystalline forms reported are cocrystals of which the crystals and complexes were characterized by X-ray diffraction analysis, IR, mp, and elemental analysis. The inter-ring angles (naphthol/naphthol) in the same binol of the six cocrystals ranged from 70.71░ to 104.2░ as the organic bases varied. In the six cocrystals, the binols exist either as both of the enantiomers of rac-binol or as only of its single enantiomer. All supramolecular architectures of cocrystals 1-6 are stabilized by O-H⋯N hydrogen bonds. In addition other non-conventional interactions (CH-?, CH3-?, NH-?, S-?, and ?-? interactions) play an important role in the solid-state packing of co-crystallization as well. These weak interactions combined, all of the six complexes displayed 3D network structure.
Jin, Shouwen; Dong, Qiong; Wang, Daqi; Zhou, Wei
This paper reviews the tissue residue approach (TRA) for toxicity assessment as it applies to organic chemicals and some organometallic compounds (Sn, Hg, and Pb) in aquatic organisms. Specific emphasis was placed on evaluating key factors that influence interpretation of critical body residue (CBR) toxicity metrics including data quality issues, lipid dynamics, choice of endpoints, processes that alter toxicokinetics and toxicodynamics, phototoxicity, species- and life stage-specific sensitivities, and biotransformation. The vast majority of data available on TRA is derived from laboratory studies of acute lethal responses to organic toxicants exhibiting baseline toxicity. Application of the TRA to various baseline toxicants as well as substances with specific modes of action via receptor-mediated processes, such as chlorinated aromatic hydrocarbons, pesticides, and organometallics is discussed, as is application of TRA concepts in field assessments of tissue residues. In contrast to media-based toxicity relationships, CBR values tend to be less variable and less influenced by factors that control bioavailability and bioaccumulation, and TRA can be used to infer mechanisms of toxic action, evaluate the toxicity of mixtures, and interpret field data on bioaccumulated toxicants. If residue-effects data are not available, body residues can be estimated, as has been done using the target lipid model for baseline toxicants, to derive critical values for risk assessment. One of the primary unresolved issues complicating TRA for organic chemicals is biotransformation. Further work on the influence of biotransformation, a better understanding of contaminant lipid interactions, and an explicit understanding of the time dependency of CBRs and receptor-mediated toxicity are all required to advance this field. Additional residue-effects data on sublethal endpoints, early life stages, and a wider range of legacy and emergent contaminants will be needed to improve the ability to use TRA for organic and organometallic compounds. PMID:21184569
McElroy, Anne E; Barron, Mace G; Beckvar, Nancy; Driscoll, Susan B Kane; Meador, James P; Parkerton, Tom F; Preuss, Thomas G; Steevens, Jeffery A
Gas and fine particulate phase N-nitroso and nitrite organic compounds in the atmosphere
Photochemistry between gas phase organic compounds, NO{sub x} and ozone is expected to result in the formation of nitrogen containing compounds of toxicological importance. Classes of potentially toxic organic compounds which may form include nitro-, N-nitroso- and nitrite-substituted compounds. The compounds are expected to be labile, semi-volatile organic compounds in equilibrium between the gas and particulate phases in the atmosphere. The phase distribution of these potentially toxic semi-volatile organic compounds can be determined using diffusion denuder samplers. The total concentration of N-nitroso compounds in a collected sample is determined using N-nitroso specific denitrosation reactions followed by detection of the NO produced with a chemiluminescence detector. Denitrosation chemistry can also be used to determine nitrite compounds. Differentiation between total N-nitroso- and nitrite-containing compounds is accomplished using sulfamic acid as a nitrite specific reagent. These analytical techniques for the sampling and determination of total N-nitroso and nitrite material have been used for the quantification of these classes of compounds in both fine particles and the gas phase in samples collected in Provo, Utah. The results indicate that the majority of the N-nitroso and nitrite organic compounds present in fine particulate matter in the urban area studied are semi-volatile organic compounds which are lost from particles during sampling. Furthermore, the concentrations of these fine particulate compounds are comparable to the concentrations of gas phase N-nitroso and nitrite organic species. 35 refs., 5 figs., 2 tabs.
Ding, Yiming; Cui, Wenxuan; Lee, M.L.; Eatough, D.J. [Brigham Young Univ., Provo, UT (United States)
An oxygenated organic compound, such as ethanol, is recovered from a dilute aqueous stream thereof by contacting said stream with crosslinked polyvinylpyridine resin or nuclear substituted derivative thereof to effect selective sorption of the compound by said resin. The sorbed compound is thereafter removed from the resin by stripping with an inert gas such as carbon dioxide.
Feldman, J.
Chlorinated and brominated persistent organic compounds in biological samples from the environment
Eleven selected biological samples representing different ecosystems, trophic levels, and areas mainly in Sweden have been analyzed for 31 halogenated organic compounds or compound groups. The multiresidue analytical method provides a good opportunity to compare the concentrations of the different compounds in the investigated samples. By the use of ratios of these concentrations, comparisons can be done between species and
Bo Jansson; Renate Andersson; Lillemor Asplund; K. Litzen; Kerstin Nylund; U. Sellstroem; Ulla-Britt Uvemo; Cajsa Wahlberg; Ulla Wideqvist; T. Odsjoe; Mats Olsson
Model compounds for the determination of organic and total phosphorus dissolved in natural waters
The choice of model compounds for checking the recovery of dissolved organic and total dissolved phosphorus in natural waters is discussed. Ten compounds were compared for their recovery in fresh and seawater. Four different oxidative procedures were used: acidic and alkaline persulfate oxidation, continuous flow UV irradiation and high-temperature combustion (HTC). Certain compounds have been shown to decompose when heated
Roger Kķrouel; Alain Aminot
Mass transfer of nonvolatile organic compounds from porous media
NASA Astrophysics Data System (ADS)
This thesis presents data pertaining to the mass transfer of nonvolatile organic compounds from porous media. Physical properties of porous solids, including surface and pore areas, are studied. Information from these studies, along with dissolution data, are used to develop correlations relating the Sherwood Number to the Peclet Number. The contaminant used in this study is naphthalene; the solids used are Moffett Sand (MS), Borden Sand (BS), Lampblack (LB), and Silica Gel (SG). Surface area results indicate that contamination at 0.1% reduces the area of MS and SG by 48 and 37%, respectively, while contamination at 1.0% reduces the area of MS, BS, and SG by 59, 56, and 40%, respectively. Most of the reduction in area originates in the reduction of pore areas and volumes, where the contaminant precipitates. After long-term storage, surface areas did not recover to their original values due to an "irreversible" fraction of naphthalene. Treatment with heat or solvent or both was necessary to completely remove the contamination. For lampblack, treatment at 100░C decreased areas while treatment at 250░C increased them. Treatment at 250░░C probably opened pores while that at 100░C may have blocked more pores by redistributing the tar-like contaminant characteristic of lampblack. Contaminated MS and SG solids are packed in columns through which water is pumped. The effluent began at a relatively high concentration (ś70% of solubility) for both samples. However, SG column concentrations dropped quickly, never achieving steady state while the MS samples declined more gradually towards steady state. The high pore areas of the SG samples are believed to cause this behavior. The steady state portion of the MS dissolution history is used to develop mass transfer correlations. The correlation in this study differs from previous work in two major ways: (1) the exponent on the Pe is three times larger and (2) the limiting Sh is 106 times smaller. These results suggest that the dissolution mechanism here is different than in other studies, that is, dissolution is occurring from the contaminated pores which are inaccessible to the flowing water. This work can be used to assess the leaching potential of non-volatile organic impacted soils. Also, soil vapor extraction schemes which are hampered by observed long tails can be explained using the data in this thesis.
Khachikian, Crist Simon
The growing demand on water resources has increased interest in wastewater reclamation for potable reuse, in which rejection of organic micropollutants such as disinfection by-products (DBPs), endocrine disrupting compounds (EDCs), and pharmaceutically active compounds (PhACs) is of great concern. The objective of this study was to investigate the rejection of DBPs, EDCs, and PhACs by nanofiltration (NF) and reverse osmosis
Katsuki Kimura; Gary Amy; J÷rg E. Drewes; Thomas Heberer; Tae-Uk Kim; Yoshimasa Watanabe
Sources of Volatile Organic Compounds (VOCs) in the UAE
NASA Astrophysics Data System (ADS)
The gas chromatography-flame ionization detection/mass spectrometry system has been used to identify major volatile organic compounds (VOCs) sources in the UAE (latitude 24.45N; longitude 54.22E). VOCs are emitted from an extensive number of sources in urban environments including fuel production, distribution, and consumption. Transport sources contribute a substantial portion of the VOC burden to the urban atmosphere in developed regions. UAE is located at the edge of the Persian Gulf and is highly affected by emissions from petrochemical industries in neighbouring Saudi Arabia, Qatar, and Iran. VOCs emerging from these industries can be transported to the UAE with jet streams. The analysis of the collected air samples at three locations in Sharjah, UAE during the autumn and winter seasons indicates the presence of more than 100 VOC species. The concentrations of these species vary in magnitudes but the most prominent are: acetylene, ethane, propane, butane, pentane, benzene, and toluene. The possible tracers for various emission sources have also been identified such as 2-methylpentane, 1, 3-butadiene and 2, 2-dimethlybutane for vehicle exhaust, the light hydrocarbons, namely n-butane, trans-2-butene, and n-pentane for gasoline vapor, and n-nonane, n-decane, and n-undecane for diesel vapor and asphalt application processes. As various emission sources are characterized by overlapping VOC species, the ratio of possible VOC tracers are used to quantify the contribution of different sources. Our aim in this paper is to explore and discuss possible impacts of transported emissions on the local VOC emission inventory from various sources for the UAE. This work is partially supported by Office of Development and Alumni Affairs at the American University of Sharjah, U.A.E.
Abbasi, Naveed; Majeed, Tariq; Iqbal, Mazhar; Riemer, Daniel; Apel, Eric; Lootah, Nadia
Volatile organic compound emissions from dry mill fuel ethanol production.
Ethanol fuel production is growing rapidly in the rural Midwest, and this growth presents potential environmental impacts. In 2002, the U.S. Environmental Protection Agency (EPA) and the Minnesota Pollution Control Agency (MPCA) entered into enforcement actions with 12 fuel ethanol plants in Minnesota. The enforcement actions uncovered underreported emissions and resulted in consent decrees that required pollution control equipment be installed. A key component of the consent decrees was a requirement to conduct emissions tests for volatile organic compounds (VOCs) with the goal of improving the characterization and control of emissions. The conventional VOC stack test method was thought to underquantify total VOC emissions from ethanol plants. A hybrid test method was also developed that involved quantification of individual VOC species. The resulting database of total and speciated VOC emissions from 10 fuel ethanol plants is relatively small, but it is the most extensive to date and has been used to develop and gauge compliance with permit limits and to estimate health risks in Minnesota. Emissions were highly variable among facilities and emissions units. In addition to the variability, the small number of samples and the presence of many values below detection limits complicate the analysis of the data. To account for these issues, a nested bootstrap procedure on the Kaplan-Meier method was used to calculate means and upper confidence limits. In general, the fermentation scrubbers and fluid bed coolers emitted the largest mass of VOC emissions. Across most facilities and emissions units ethanol was the pollutant emitted at the highest rate. Acetaldehyde, acetic acid, and ethyl acetate were also important emissions from some units. Emissions of total VOCs, ethanol, and some other species appeared to be a function of the beer feed rate, although the relationship was not reliable enough to develop a production rate-based emissions factor. PMID:17912928
Brady, Daniel; Pratt, Gregory C
Production of volatile organic compounds in cultures of cryptophytes
NASA Astrophysics Data System (ADS)
Volatile organic compounds (VOCs) are known to be produced by macroalgae, phytoplankton and bacteria in the ocean. Some phytoplankton species are known for the production of VOCs such as halomethanes and isoprene in cultures. To discuss the diversity of VOCs production among phytoplankton species, we incubated the strains of cryptophytes and measured concentrations of VOCs and chlorophyll a. Because VOCs productions of cryptophytes were poorly understood, we selected them to cover the lack of data for VOCs production. Phytoplankton cultures were grown in autoclaved f/2-Si medium with GF/F filtered aged seawater. Culture temperature and light conditions were 24.1 ▒ 0.2░C and 78 ▒ 4 ?E m-2 s-1 (1 E = 1 mol of photons) from full-spectrum vita-lite fluorescent lamp (12 h light:12 h dark cycle). VOCs concentrations in the medium were measured using a purge and trap (Tekmar PT 5000J)- gas chromatograph (Agilent 6890N)- mass spectrometer (Agilent 5973N). The concentrations of chlorophyll a was also measured using fluorometer (Turner TD-700). Isoprene concentrations were increased to 290 pmol L-1 during the exponential phase in Rhodomonas salina culture. Isoprene production rate was 0.78 ?mol g chl.a-1 day-1. This value is within the range of isoprene production by other phytoplankton species reported in the previous paper. As for halomethanes, dibromomethane concentrations were increased during the incubation time. Some iodohalomethanes were also increased during the death phase. We are currently examining the production of halomethanes in other strains of Cryptophyta.
Yamakoshi, T.; Kurihara, M.; Hashimoto, S.
Dominant microbial volatile organic compounds in 23 US homes.
Associating Microbial Volatile Organic Compounds (MVOCs) with the species producing them may open the path to more rapid and reliable chemical methods to detect mold problems, especially for mold hidden in wall cavities or small enclosed spaces. This study associated the dominant MVOCs in a convenience sample of 23 homes with the mold species present. Three semi-quantitative predictors of mold growth ("MOW scores") were assessed in the homes through a comparison of basement to main floor areas. MVOC samples were collected and analyzed by GC/MS. Aerotek N-6 samplers were co-located with the MVOC samplers to collect bioaerosols. Concentration and prevalence data for 19 definitive MVOCs were compared with the bioaerosol data. Mold predictor scores were elevated in basement locations as compared with main floor areas. Of the 23 mold genera identified, the predominant genera (ranked occurrences) were Cladosporium, Penicillium, Basidiomycetes, and Aspergilli. The MVOCs 2-octen-1-ol, 3-octenone, 2-heptanone, 1-octen-3-ol, and 1-butanol showed the highest average concentrations (11-37 ?g m(-3)), but no single MVOC was significantly elevated in basement locations as compared with main floor living areas in these non-problematic homes. Using a less conservative one-tail test of significance, average 2-octen-1-ol concentrations in basements were higher (p<0.040), and both 3-octenone and 1-octen-3-ol were elevated (p<0.095). Differences in MVOC occurrence were greatest between homes, with MVOCs found in basement locations typically detected in living areas at similar concentrations and frequencies. Based on these findings, the C(8) MVOCs show promise as gross indicators of fungal growth related to the most frequently found mold genera. PMID:22892356
Ryan, Timothy J; Beaucham, Catherine
NASA Astrophysics Data System (ADS)
A new classification scheme for the speciation of organic compound emissions for use in air quality models is described. The scheme uses 81 organic compound classes to preserve both net gas-phase reactivity and particulate matter (PM) formation potential. Chemical structure, vapor pressure, hydroxyl radical (OH) reactivity, freezing point/boiling point, and solubility data were used to create the 81 compound classes. Volatile, semivolatile, and nonvolatile organic compounds are included. The new classification scheme has been used in conjunction with the Canadian Emissions Processing System (CEPS) to process 1990 gas-phase and particle-phase organic compound emissions data for summer and winter conditions for a domain covering much of eastern North America. A simple postprocessing model was used to analyze the speciated organic emissions in terms of both gas-phase reactivity and potential to form organic PM. Previously unresolved compound classes that may have a significant impact on ozone formation include biogenic high-reactivity esters and internal C6-8 alkene-alcohols and anthropogenic ethanol and propanol. Organic radical production associated with anthropogenic organic compound emissions may be 1 or more orders of magnitude more important than biogenic-associated production in northern United States and Canadian cities, and a factor of 3 more important in southern U.S. cities. Previously unresolved organic compound classes such as low vapour pressure PAHs, anthropogenic diacids, dialkyl phthalates, and high carbon number alkanes may have a significant impact on organic particle formation. Primary organic particles (poorly characterized in national emissions databases) dominate total organic particle concentrations, followed by secondary formation and primary gas-particle partitioning. The influence of the assumed initial aerosol water concentration on subsequent thermodynamic calculations suggests that hydrophobic and hydrophilic compounds may form external mixtures, and that separate treatment for these groups may be required in future air quality model simulations. The post-processing model used here overestimates the organic particle formation relative to measurements, lacks the complexity of a regional air quality model, and is not intended as an alternative to the latter. Results from the post-processing model do, however, provide guidance for the treatment of organic gases and particles in future air quality modeling work. Future air quality model simulations should attempt to speciate primary particulate organic compounds and include more detailed organic compound classes. Future emissions profile measurements should speciate gaseous high-molecular-mass organic compounds and primary organics emitted in particulate form (primary particle emissions are only available as a total particulate mass in currently available emissions data).
Makar, P. A.; Moran, M. D.; Scholtz, M. T.; Taylor, A.
NASA Astrophysics Data System (ADS)
Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs.
Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi
Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs. PMID:25175808
Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi
Ultraviolet (UV) radiation is a ubiquitous energy source for chemical reactions in nature. In particular, UV radiation provides an important pathway for degradation of organic compounds. Although isotopic change in organic compounds exposed to UV radiation may be an indicator for evaluating the extent of degradation, the isotope behavior has not been yet clarified. In this study, stable carbon and
Yasuhiro Oba; Hiroshi Naraoka
Chlorinated Volatile Organic CompoundsŚOld, However, Actual Analytical and Toxicological Problem
The interest in chlorinated volatile organic compounds is not a new task but still draws the attention of scientists. The role they play in human organism, is an important aspect to consider, since the development of analytical techniques and instrumental solutions gives new possibilities of their application in the analytics of volatile compounds and recognition of properties, so far impossible
El?bieta Dobrzy?ska; Ma?gorzata Po?niak; Ma?gorzata Szewczy?ska; Bogus?aw Buszewski
About 100 individual organic compounds were determined in urban aerosols collected at Gent, Belgium. The compounds were identified by gas chromatography-mass spectrometry, and quantitative data were obtained by gas chromatography-flame ionization detection. Measurements of the particulate mass and of organic and elemental carbon mass were also made. Aerosol samples from a winter and a summer campaign were analyzed in order
Alena Kubßtovß; Reinhilde Vermeylen; Magda Claeys; Jan Cafmeyer; Willy Maenhaut
Quantitative Analysis of Organic Compounds: A Simple and Rapid Method for Use in Schools
ERIC Educational Resources Information Center
Describes the procedure for making a quantitative analysis of organic compounds suitable for secondary school chemistry classes. Using the Schoniger procedure, the organic compound, such as PVC, is decomposed in a conical flask with oxygen. The products are absorbed in a suitable liquid and analyzed by titration. (JR)
Schmidt, Hans-Jurgen
We present the conductive-carbon-black filled PDMS (polydimethylsiloxane) composite as the sensing material for the detection of volatile organic compounds (cyclohexane and isopropanol). The sensing composite film is immobilized on the interdigitated gold microelectrode pairs. The resistance change ratios with the organic compounds vapors have been examined. The measurement results show that the outputs of the sensor as a function of
Jian Wang; Bo Feng; Wengang Wu
In-digester reduction of organic sulfur compounds in kraft pulping
This experimental research examines the relationship between the formation of organic sulfur compounds and delignification during kraft wood pulping. A phase transition point (PTP) was discovered below and above which the formation of total organic sulfur compounds, with respect to delignification, changes significantly. The PTP occurs at approximately pulp kappa number 35 for softwoods and 20 for hardwoods. The PTP
S.-H. Yoon; X.-S. Chai; J. Y. Zhu; J. Li; E. W. Malcolm
Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater
Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater: Use in Vulnerability of halogenated volatile organic compounds VOCs were determined by gas chromatography GC with an electron study areas in the United States. In each case, the untreated water sample was used for drinking
Origin of organic compounds on the primitive earth and in meteorites
Summary The role and relative contributions of different forms of energy to the synthesis of amino acids and other organic compounds on the primitive earth, in the parent bodies or carbonaceous chondrites, and in the solar nebula are examined. A single source of energy or a single process would not account for all the organic compounds synthesized in the solar
Stanley L. Miller; Harold C. Urey; J. Or¾
Seasonal changes in the concentration of nutrients and various organic compounds were studied in the waters surrounding mangroves and in the marshy areas of mangroves. Higher amounts of nutrients and organic compounds were observed during low tide. This is due to the remineralisation of plant detritus in this area. High concentration of carbohydrates, proteins, chlorophyll and phosphate were observed during
R. Geetha; N. Chandramohanakumar; L. Mathews
Ventilation Control of Volatile Organic Compounds in New U.S. Homes: Results of a
1 Ventilation Control of Volatile Organic Compounds in New U.S. Homes: Results of a Controlled, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily organic compounds (VOCs) was assessed by measuring air exchange rates and VOC concentrations at three
COMPOSITING WATER SAMPLES FOR ANALYSIS OF VOLATILE ORGANIC COMPOUNDS Thomas J. Lopes1
1 COMPOSITING WATER SAMPLES FOR ANALYSIS OF VOLATILE ORGANIC COMPOUNDS Thomas J. Lopes1 , James D. Fallon2 , Terry L. Maluk3 Abstract: Accurate mean concentrations of volatile organic compounds (VOCs) can, 720 Gracern Road, Columbia, South Carolina, 29210-7651 Any use of trade names is for descriptive
An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road
Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit
An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped diesel trucks, paved road dust,
Wolfgang F. Rogge; Lynn M. Hildemann; Monica A. Mazurek; Glen R. Cass; Bernd R. T. Simoneit
Sorption of organic compounds in the aqueous phase onto tire rubber
Batch sorption tests were conducted to investigate the sorption capacity of organic compounds by ground tire and to assess the effects of the presence of other organic compounds, ionic strength, pH, ground tire particle size, and temperature on sorption. None of the factors were significant under the conditions tested, m-Xylene had the highest partition coefficient, followed by ethylbenzene, toluene, trichloroethylene,
Jae Y. Kim; Jae K. Park; Tuncer B. Edil
40 CFR 60.112 - Standard for volatile organic compounds (VOC).
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.112 Section 60.112...1973, and Prior to May 19, 1978 ¦ 60.112 Standard for volatile organic compounds (VOC). (a) The owner or...
40 CFR 60.312 - Standard for volatile organic compounds (VOC).
Code of Federal Regulations, 2010 CFR
... 6 2010-07-01 2010-07-01 false Standard for volatile organic compounds (VOC). 60.312 Section 60.312...Surface Coating of Metal Furniture ¦ 60.312 Standard for volatile organic compounds (VOC). (a) On and after the date...
40 CFR 60.542a - Alternate standard for volatile organic compounds.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Alternate standard for volatile organic compounds. 60.542a Section 60.542a Protection...Manufacturing Industry ¦ 60.542a Alternate standard for volatile organic compounds. (a) On and after the date...
An improved method of estimating molecular weights of volatile organic compounds from their mass spectra has been developed and evaluated for accuracy. This technique can be implemented with a user friendly expert system on a personal computer. The method is based on a pattern recognition based classifier and empirically derived rules from a set of toxic and related organic compounds.
D Scott
Prevention of marine biofouling using natural compounds from marine organisms
All surfaces that are submerged in the sea rapidly become covered by a biofilm. This process, called biofouling, has substantial economic consequences. Paints containing tri-butyl-tin (TBT) and copper compounds are used to protect marine structures by reducing biofouling. However, these compounds have damaging effects on the marine environment, as they are not biodegradable. It has been noted that many seaweeds
Evelyn Armstrong; Kenneth G. Boyd; J. Grant Burgess
The phenolic compounds and the organic acids composition of the edible beefsteak fungus Fistulina hepatica was determined by HPLC\\/DAD and HPLC\\/UV, respectively. The results showed a profile composed by five phenolic compounds (caffeic, p-coumaric and ellagic acids, hyperoside and quercetin) and six organic acids (oxalic, aconitic, citric, malic, ascorbic and fumaric acids). The quantification of the identified compounds revealed that
Bßrbara Ribeiro; PatrĒcia ValentŃo; Paula Baptista; Rosa M. Seabra; Paula B. Andrade
Cloud processing of organic compounds: Secondary organic aerosol and nitrosamine formation
NASA Astrophysics Data System (ADS)
Cloud processing of atmospheric organic compounds has been investigated through field studies, laboratory experiments, and numerical modeling. Observational cloud chemistry studies were performed in northern Arizona and fog studies in central Pennsylvania. At both locations, the cloud and fogs showed low acidity due to neutralization by soil dust components (Arizona) and ammonia (Pennsylvania). The field observations showed substantial concentrations (20-5500 ngĢL -1) of volatile organic compounds (VOC) in the cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase with half lives of approximately three hours. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction kinetics decreased with increasing organic carbon content, resulting in half lives of approximately 7 hours. The secondary organic aerosol (SUA) mass formation potential of cloud processing of BTEX was evaluated. SOA mass formation by cloud processing of BTEX, while strongly dependent on the atmospheric conditions, could contribute up to 9% of the ambient atmospheric aerosol mass, although typically ś1% appears realistic. Field observations also showed the occurrence of N-nitrosodimethylamine (NDMA), a potent carcinogen, in fogs and clouds (100-340 ngĢL -1). Laboratory studies were conducted to investigate the formation of NDMA from nitrous acid and dimethylamine in the homogeneous aqueous phase within cloud droplets. While NDMA was produced in the cloud droplets, the low yields (<1%) observed could not explain observational concentrations. Therefore heterogeneous or gaseous formation of NDMA with partitioning to droplet must be the source of aqueous NDMA. Box-model calculations tended to demonstrate a predominance of a gas phase formation mechanism followed by partitioning into the cloud droplets. The calculations were consistent with field measurements of gaseous and aqueous NDMA concentrations. Measurements and model calculations showed that while NDMA is eventually photolyzed, it might persist in the atmosphere for hours.
Hutchings, James W., III
A survey of household products for volatile organic compounds
NASA Astrophysics Data System (ADS)
A total of 1159 common household products were analysed for 31 volatile organic compounds as potential sources of indoor air pollution. The products were distributed among 65 product categories within 8 category classes: automotive products (14.4% of the products); household cleaners/polishes (9.6%); paint-related products (39.9%); fabric and leather treatments (7.9%); cleaners for electronic equipment (6.0%); oils, greases and lubricants (9.6%); adhesive-related products (6.6%); and miscellaneous products (6.1%). The study was conducted in two parts. In the first part, or the original study, the products were reanalysed for methylene chloride and five other chlorocarbons using purge-and-trap gas chromatography/mass spectrometry (GC/MS), and a data base containing the analytical results was developed. Because full mass spectra were taken, the original set of GC/MS data also contained information regarding other volatile chemicals in the products. However, this additional data was not reported at that time. In the second part of the study, the GC/MS data were reanalysed to determine the presence and concentrations of an additional 25 volatile chemicals. The 31 chemicals included in both parts of this study were: carbon tetrachloride; methylene chloride; tetrachloroethylene; 1,1,1-trichloroethane; trichlorethylene; 1,1,2-tricholorotrifluoroethane; acetone; benzene; 2-butanone; chlorobenzene; chloroform; cyclohexane; 1,2-dichloroethane; 1,4-dioxane; ethylbenzene; n-hexane; d-limonene; methylcyclohexane; methylcyclopentane; methyl isobutyl ketone; n-nonane; n-octane; ?-pinene; propylene oxide; styrene; 1,1,2,2-tetrachloroethane; tetrahydrofuran; toluene; m-mxylene; o-xylene; and p-xylene. Of the 31 chemicals, toluene, the xylenes and methylene chloride were found to occur most frequentlyŚin over 40% of the products tested. Chemicals that were typically found in relatively high concentrations in the samples (i.e. greater than 20% w/w) included acetone, 2-butanone, hexane, methylene chloride, tetrachloroethylene, toluene, 1,1,1-trichloroethane, trichloroethylene, 1,1,2-trichlorotrifluoroethane and the xylenes. Chlorobenzene, d-limonene, 1,1,2,2-tetrachloroethane, n-nonane and styrene were not found in any of the products at or above the 0.1% level. In all, 935 of the products contained one or more of the target solvents at levels greater than 0.1%. The resulting data base contains information regarding the 1159 products, such as origin, cost, container type, lot number, etc., as well as quantitative information for each of the 31 chemicals. The frequency of occurrence and average concentrations for the target chemicals are summarized for each of the product classes.
Sack, Thomas M.; Steele, David H.; Hammerstrom, Karen; Remmers, Janet
NASA Technical Reports Server (NTRS)
The generally accepted theory for the origin of life on the Earth requires that a large variety of organic compounds be present to form the first living organisms and to provide the energy sources for primitive life either directly or through various fermentation reactions. This can provide a strong constraint on discussions of the formation of the Earth and on the composition of the primitive atmosphere. In order for substantial amounts of organic compounds to have been present on the prebiological Earth, certain conditions must have existed. There is a large body of literature on the prebiotic synthesis of organic compounds in various postulated atmospheres. In this mixture of abiotically synthesized organic compounds, the amino acids are of special interest since they are utilized by modern organisms to synthesize structural materials and a large array of catalytic peptides.
Bada, J. L.; Miller, S. L.
Water and sediment samples were taken from sites adjacent to hazardous waste disposal areas in Niagara Falls, New York. The samples were analyzed by gas chromatography/mass spectrometry. The following compounds were identified: chlorobenzenes, chlorotoluenes, polycyclic aromatic ...
This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves between water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be absorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rate commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence that the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison to concentrations determined during ongoing research. Finally, where sufficient data exist, regional and temporal contamination trends in the United States are discussed.
Smith, James A.; Witkowski, Patrick J.; Fusillo, Thomas V.
This report reviews the occurrence and distribution of manmade organic compounds in the surface waters of the United States. On the basis of their aqueous solubilities, nonionic organic compounds partition themselves among water, dissolved organic matter, particulate organic matter, and the lipid reservoirs of aquatic organisms. Ionized organic compounds can be adsorbed to sediments, thereby reducing their aqueous concentrations. Transformation processes of photolysis, hydrolysis, biodegradation, and volatilization can attenuate organic compounds, and attenuation rates commonly follow a first-order kinetic process. Eight groups of manmade organic compounds are discussed: 1. Polychlorinated biphenyls and organochlorine insecticides, 2. Carbamate and organophosphorus insecticides, 3. Herbicides, 4. Phenols, 5. Halogenated aliphatic and monocyclic aromatic hydrocarbons, 6. Phthalate esters, 7. Polychlorinated dibenzo-p-dioxins, and 8. Polycyclic aromatic hydrocarbons. For each compound group, data pertaining to use, production, and properties are presented and discussed. Processes that influence the environmental fate of each group, as determined primarily through laboratory studies, are reviewed, and important fate processes are identified. Environmental concentrations of compounds from each group in water, biota, and sediment are given to demonstrate representative values for comparison with concentrations determined during ongoing research. Finally, where data are sufficient, regional and temporal contamination trends in the United States are discussed.
Smith, James A.; Witkowski, P.J.; Fusillo, Thomas V.
ERIC Educational Resources Information Center
Segregation and recognition of two unfamiliar concrete organic compounds are achieved through microscale flash chromatography and spectroscopy plus melting point verifications respectively. This inexpensive and harmless microscale experiment for sophomore students ensures exercise in chromatographic and spectroscopic methods.
Feist, Patty L.
Methods and systems for chemoautotrophic production of organic compounds
The present disclosure identifies pathways, mechanisms, systems and methods to confer chemoautotrophic production of carbon-based products of interest, such as sugars, alcohols, chemicals, amino acids, polymers, fatty acids and their derivatives, hydrocarbons, isoprenoids, and intermediates thereof, in organisms such that these organisms efficiently convert inorganic carbon to organic carbon-based products of interest using inorganic energy, such as formate, and in particular the use of organisms for the commercial production of various carbon-based products of interest.
Fischer, Curt R.; Che, Austin J.; Shetty, Reshma P.; Kelly, Jason R.
Extraction techniques for semi-volatile organic compounds from caustic and high ionic strength solutions are presented. It is demonstrated that simple liquid-liquid extraction from a high ionic strength aqueous solution can allow inorganic ions to partition from the aqueous phase into the organic extraction phase. The ability of solid-phase extraction (SPE) adsorbents to separate organic target compounds from a sample, without
J. Ward Hills
Pyrolysis of organic compounds containing long unbranched alkyl groups
Data are presented for the pyrolysis of compounds containing long unbranched alkyl groups at temperature and pressure conditions typical of the petroleum refining process known as delayed coking. The pyrolyzed samples were analyzed by three techniques, all based on gas chromatography. The pyrolysis product interpretation was carried out on the basis of the proposal of Fabuss-Smith-Satterfield (FSS) for the pyrolysis of n-hexadecane, and the FSS behavior predictions were followed for all of the n-alkane compounds. Aromatic substituted alkanes reacted differently, and pyridine and benzene rings greatly enhanced free radical formation. A pyrolysis mechanism consistent with the observed product distribution is proposed for 1-phenyl pentadecane. (BLM)
Hazlett, R.N.; Mushrush, G.W.
Quantum chemical calculations for polymers and organic compounds
NASA Technical Reports Server (NTRS)
The relativistic effects of the orbiting electrons on a model compound were calculated. The computational method used was based on 'Modified Neglect of Differential Overlap' (MNDO). The compound tetracyanoplatinate was used since empirical measurement and calculations along "classical" lines had yielded many known properties. The purpose was to show that for large molecules relativity effects could not be ignored and that these effects could be calculated and yield data in closer agreement to empirical measurements. Both the energy band structure and molecular orbitals are depicted.
Lopez, J.; Yang, C.
Effects of airborne volatile organic compounds on plants.
Routine measurements of volatile organic compounds (VOCs) in air have shown that average concentrations are very much smaller than those used in laboratory experiments designed to study the effects of VOCs on plants. However, maximum hourly concentrations of some VOCs can be 100 times larger than the average, even in rural air. Experimental studies have rarely extended for longer than a few days, so there is little information on potential long-term effects of exposure to small concentrations. This review considers the available evidence for long-term effects, based on laboratory and field data. Previous reviews of the literature from Germany and the USA are cited, prior to an assessment of the effects of individual VOCs. Although hydrocarbons from vehicle exhausts have been implicated in the observed effects on roadside vegetation, the evidence suggests that it is the nitrogen oxides in the exhaust gases that are mostly responsible. There is evidence that aromatic hydrocarbons can be metabolised in plants, although the fate of the metabolites is not known. There is a large literature on the effects of ethylene, because of its role as a plant hormone. Effects have been reported in the field, in response to industrial emissions, and dose-response experiments over several weeks in laboratory studies have clearly identified the potential for effects at ambient concentrations. The main responses are morphological (e.g. epinasty), which may be reversible, and on the development of flowers and fruit. Effects on seed production may be positive or negative, depending on the exposure concentration. Chlorinated hydrocarbons have been identified as potentially harmful to vegetation, but only one long-term experiment has studied dose-response relationships. As for ethylene, the most sensitive indication of effect was on seed production, although long-term accumulation of trichloroacetic acid in tissue may also be a problem. There is little evidence of the direct effects of oxygenated hydrocarbons on plants. Plants are a significant emission source of short-chain alcohols, aldehydes and ketones. Peroxyacetyl nitrate (PAN) has a well-documented history as damaging to vegetation. There have been few long-term experimental studies despite the field evidence for damaging effects. Early studies in California have been followed by more recent data from east Asia, but there is still a dearth of information on the potential for effects of PAN and related peroxyacyl nitrates on vegetation typical of regions around tropical and sub-tropical cities where PAN pollution is increasingly important. The lack of long-term measurements, coupled with the available evidence that effects are not linearly related to 'dose' measured as the product of exposure concentration and time, means that the possibility of adverse effects of VOCs on vegetation cannot be safely rejected, particularly in urban and industrial areas. Although reproductive processes (flowering, seed production) appear to be most sensitive, there have been no experimental studies on subsequent seed viability and the consequences at the ecosystem level of changes to plant phenology. The potential for VOC metabolites to accumulate in plant tissue has been demonstrated, but any subsequent effects on herbivores and phytophagous insects have yet to be investigated. PMID:12535603
Cape, J N
Uneven distribution of volatile organic compounds (VOCs) and biomass, and excess biomass accumulation in some biofilters hinder the application of biofiltration technology. An innovative multilayer rotating drum biofilter (RDB) was developed to correct these problems. The RDB was operated at an empty bed contact time (EBCT) of 30 s and a rotational rate of 1.0 r/min. Diethyl ether was chosen as the model VOC. Performance of the RDB was evaluated at organic loading rates of 32.1, 64.2, 128, and 256 g ether/(m3 x h) (16.06 g ether/(m3 x h) approximately 1.0 kg chemical oxygen demand (COD)/(m3 x d)). The EBCT and organic loading rates were recorded on the basis of the medium volume. Results show that the ether removal efficiency decreased with an increased VOC loading rate. Ether removal efficiencies exceeding 99% were achieved without biomass control even at a high VOC loading rate of 128 g ether/(m3 x h). However, when the VOC loading rate was increased to 256 g ether/(m3 x h), the average removal efficiency dropped to 43%. Nutrient limitation possibly contributed to the drop in ether removal efficiency. High biomass accumulation rate was also observed in the medium at the two higher ether loading rates, and removal of the excess biomass in the media was necessary to maintain stable performance. This work showed that the RDB is effective in the removal of diethyl ether from waste gas streams even at high organic loading rates. The results might help establish criteria for designing and operating RDBs. PMID:18595394
Yang, Chunping; Chen, Hong; Zeng, Guangming; Zhu, Xueqing; Suidan, Makram T
Influence of soil organic matter composition on the partition of organic compounds
The sorption at room temperature of benzene and carbon tetrachloride from water on three high-organic-content soils (muck, peat, and extracted peat) and on cellulose was determined in order to evaluate the effect of sorbent polarity on the solute partition coefficients. The isotherms are highly linear for both solutes on all the organic matter samples, which is consistent with a partition model. For both solutes, the extracted peat shows the greatest sorption capacity while the cellulose shows the lowest capacity; the difference correlates with the polar-to-nonpolar group ratio [(O + N)/C] of the sorbent samples. The relative increase of solute partition coefficient (Kom) with a decrease of sample polar content is similar for both solutes, and the limiting sorption capacity on a given organic matter sample is comparable between the solutes. This observation suggests that one can estimate the polarity effect of a sample of soil organic matter (SOM) on Kom of various nonpolar solutes by determining the partition coefficient of single nonpolar solute when compositional analysis of the SOM is not available. The observed dependence of Kom on sample polarity is used to account for the variation of Kom values of individual compounds on different soils that results from change in the polar group content of SOM. On the assumption that the carbon content of SOM in "ordinary soils" is 53-63%, the calculated variation of Kom is a factor of ???3. This value is in agreement with the limit of variation of most Kom data with soils of relatively high SOM contents.
Rutherford, D.W.; Chiou, C.T.; Klle, D.E.
The primary objective of this study was to evaluate the sorptionand desorption of organic compounds on combustion-generated sootduring the cofiring of hazardous organics with fuel oil in afull-scale boiler. orption of organics was accomplished by firinga watertube package boiler ...
Characteristic properties of organic sulfur compounds containing heteroaromatics and their reactions are described. Applications of these organic sulfur derivatives in organic synthesis, development of several new reactions and their mechanisms are mentioned as follows: 1) simple sulfoxides such as methyl 2-pyridyl sulfoxide are used as efficient phase transfer catalysts in the SN 2 type displacement reactions and alkylations of active
Naomichi Furukawa
Contribution of amino compounds to dissolved organic nitrogen in forest soils
Contribution of amino compounds to dissolved organic nitrogen in forest soils Z. YU, Q. ZHANG, T 2001 Key words: Amino acids, Dissolved organic nitrogen, Nitrogen, Nutrient cycling, Polyphenols, Pro- teins Abstract. Dissolved organic nitrogen (DON) may play an important role in plant nutrition
Zhang, Qi
Green Synthetic Alternatives to Organic Compounds and Nanomaterials
A brief account of reactions involving microwave (MW) exposure of neat reactants or catalyzed by mineral support surfaces, such as alumina, silica, clay, or their ?doped? versions, for the rapid one-pot assembly of heterocyclic compounds from in situ generated reactive intermedia...
Volatile Organic Compounds Produced During Irradiation of Mail
In 2001, Bacillus anthracis spores were delivered through the United States postal system in a series of bioterrorist acts. Controls proposed for this threat included sanitization with high-energy electrons. Solid phase microextraction was used with gas chromatography\\/mass spectrometry for field sampling and analysis of volatile compounds apparently produced from polymeric materials such as cellulose and plastics, immediately following processing of
Philip A. Smith; Michael V. Sheely; Shelly J. Hakspiel; Stephen Miller
Identification of organic compounds on diesel engine soot
Several studies have shown that extracts of soot collected from light-duty diesel engines cause mutations in bacteria and mammalian cells both with and without metabolic activation. To help identify the specific compounds responsible for these biological effects, the detailed chemical composition of one such extract by gas chromatographic mass spectrometry was investigated. The two most mutagenic fractions contain alkylated phenanthrenes,
Ming-Li. Yu; Ronald A. Hites
Multisorbent tubes for collecting volatile organic compounds in spacecraft air
NASA Technical Reports Server (NTRS)
The sampling capability of Tenax-TA tubes, used in the National Aeronautics and Space Administration's solid sorbent air sampler to trap and concentrate contaminants from air aboard spacecraft, was improved by incorporating two sorbents within the tubes. Existing tubes containing only Tenax-TA allowed highly volatile compounds to "break through" during collection of a 1.5 L air sample. First the carbon molecular sieve-type sorbents Carboxen 569 and Carbosieve S-III were tested for their ability to quantitatively trap the highly volatile compounds. Breakthrough volumes were determined with the direct method, whereby low ppm levels of methanol or Freon 12 in nitrogen were flowed through the sorbent tubes at 30 mL/min, and breakthrough was detected by gas chromatography. Breakthrough volumes for methanol were about 9 L/g on Carboxen 569 and 11 L/g on Carbosieve S-III; breakthrough volumes for Freon 12 were about 7 L/g on Carboxen 569 and > 26 L/g on Carbosieve S-III. Next, dual-bed tubes containing either Tenax-TA/Carbosieve S-III, Tenax-TA/Carboxen 569, or Carbotrap/Carboxen 569 to a 10-component gas mixture were exposed, in dry and in humidified air (50% relative humidity), and percentage recoveries of each compound were determined. The Tenax-TA/Carboxen 569 combination gave the best overall recoveries (75-114% for the 10 compounds). Acetaldehyde had the lowest recovery (75%) of the 10 compounds, but this value was still an improvement over either the other two sorbent combinations or the original single-sorbent tubes.
Matney, M. L.; Beck, S. W.; Limero, T. F.; James, J. T.
Much of the recent concern by regulatory agencies about drinking water quality has been directed toward organic contamination in drinking water. lthough organic contamination has been thought to primarily affect surface waters, there is a growing awareness and concern over ground...
The interaction of indoor air pollutants with interior surfaces (i.e., sinks) is a well known, but poorly understood, phenomenon. Studies have shown that re-emissions of adsorbed organic vapours can contribute to elevated concentrations of organics in indoor environments. Researc...
Biogenic volatile organic compound (BVOC) emissions, such as isoprene and terpenes, can be oxidized to form less volatile carbonyls, acids, and multifunctional oxygenated products that may condense to form secondary organic aerosols (SOA). This research was designed to assess the contribution of oxidized BVOC emissions to SOA in coniferous forests by collecting high-volume particulate samples for 6 days and 5
Thomas M. Cahill; Vincent Y. Seaman; M. Judith Charles; Rupert Holzinger; Allen H. Goldstein
originate from anthropogenic sources over East Asia. The temporal variations and chain-length distributionsSpatial distributions of oxygenated organic compounds (dicarboxylic acids, fatty acids, and B. R. T. Simoneit, Spatial distributions of oxygenated organic compounds (dicarboxylic acids, fatty
NASA Astrophysics Data System (ADS)
Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between approximately 500 and 825 Tg yr-1. The volatile olefinic compounds, such as isoprene and the monoterpenes, are thought to constitute the bulk of these emissions. However, it is becoming increasingly clear that a variety of partially oxidized hydrocarbons, principally alcohols, are also emitted. The available information concerning the terrestrial vegetation as sources of volatile organic compounds is reviewed. The biochemical processes associated with these emissions of the compounds and the atmospheric chemistry of the emitted compounds are discussed.
Fehsenfeld, Fred; Calvert, Jack; Fall, Ray; Goldan, Paul; Guenther, Alex B.; Hewitt, C. Nicholas; Lamb, Brian; Liu, Shaw; Trainer, Michael; Westberg, Hal; Zimmerman, Pat
Fate of hazardous waste derived organic compounds in Lake Ontario
Dated sediment cores from Lake Ontario's four sedimentation basins and sedentary fish from tributaries and embayments were analyzed by gas chromatographic, methane-enhanced, negative ion mass spectrometry for a group of fluorinated aromatic compounds. The historical record of these chemicals in Lake Ontario sediments agrees well with the use of the Hyde Park dump in the city of Niagara Falls, NY. These compounds first appeared in sediments in 1958 and rapidly increased until 1970. These dates coincide with the onset of dumping at Hyde Park and remedial action undertaken when this dump was closed, respectively. Chemicals introduced into Lake Ontario by the Niagara River distribute throughout the lake rapidly and uniformly and accumulate in sedentary fish taken from remote locations in the lake. 24 references, 9 figures, 4 tables.
Jaffe, R.; Hites, R.A.
We developed a tunable (220-285-nm) UV and fixed 266-nm laser-induced fluorescence (LIF) system using a spectrometer and a cooled CCD imaging detector to measure the excitation-emission matrix spectra of various compounds in water, including quinine sulfate and plastic compound bisphenol-A. The LIF instrument was used for the fast, nonspecific determination of trace amounts of dissolved organic compounds present in natural
Vasanthi Sivaprakasam; Dennis K. Killinger
Rapid changes of induced volatile organic compounds in Pinus massoniana
Using the thermal-desorption cold trap gas chromatography\\/mass spectrometer (TCT-GC-MS) technique, the composition and relative\\u000a contents of volatile compounds were analyzed in undamaged (control), insect-damaged (ID) and artificially-damaged (AD) leaves\\u000a of Pinus massoniana in field at different times and levels of damage. Results showed that although volatile substances were highly released earlier\\u000a in AD leaves plants, they were significantly less abundant
Qin Ren; Youju Jin; Yongjian Hu; Huajun Chen; Zhenyu Li
Transformations of halogenated organic compounds under denitrification conditions.
Trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dibromoethane, chlorinated benzenes, ethylbenzene, and naphthalene at concentrations commonly found in surface and groundwater were incubated under anoxic conditions to study their transformability in the presence of denitrifying bacteria. None of the aromatic compounds showed significant utilization relative to sterile controls at initial concentrations from 41 to 114 micrograms/liter after 11 weeks of incubation. Of the halogenated aliphatic compounds studied, transformations of carbon tetrachloride and brominated trihalomethanes were observed after 8 weeks in batch denitrification cultures. Carbon from the decomposition of carbon tetrachloride was both assimilated into cell material and mineralized to carbon dioxide. How this was possible remains unexplained, since carbon tetrachloride is transformed to CO2 by hydrolysis and not by oxidation-reduction. Chloroform was detected in bacterial cultures with carbon tetrachloride initially present, indicating that reductive dechlorination had occurred in addition to hydrolysis. The data suggest that transformations of certain halogenated aliphatic compounds are likely to occur under denitrification conditions in the environment. PMID:6859850
Bouwer, E J; McCarty, P L
Numerous volatile organic compounds (VOCs) are under regulatory consideration for inclusion in the National Primary Drinking Water Standards. Adsorption is a cost-effective treatment technology for control of VOCs. Adsorption capacities were determined for fifteen VOCs in distill...
Partitioning of volatile organic compounds (VOCs) into surfactant micelles affects the apparent vapor-liquid equilibrium of VOCs in surfactant solutions. This partitioning will complicate removal of VOCs from surfactant solutions by standard separation processes. Headspace expe...
The open literature, Federal publications, industrial reports, and other sources published between 1975 and 1980 were reviewed for information relevant to personal air samplers potentially useful in sampling organic compounds at ambient levels (50-200 ppt). Seventy one references...
Volatile organic compounds (VOCs) were measured by proton transfer reaction ¢ mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of ...
Fortner, E. C.
Federal Register 2010, 2011, 2012, 2013
...FRL-9245-8] Approval and Promulgation of Implementation Plans; Ohio; Volatile Organic Compound Emission Control Measures for Lithographic and Letterpress Printing in Cleveland AGENCY: Environmental Protection Agency (EPA)....
Several common materials and methods used to collect interstitial water were evaluated to determine their effect on the accuracy and precision of measured concentrations of selected organic compounds and metals. e compared the concentration of pollutants in doses seawater before ...
Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air
Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and ...
Scholten, Elke
Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...
Background: The relationships between levels of volatile organic compounds (VOCs) in blood and air have not been well characterized in the general population where exposure concentrations are generally at ppb levels. Objectives: This study investigates relationships between ...
An automated system for unattended repetitive sampling and analysis of volatile organic compounds has been designed and a prototype constructed. The sampling/analysis scheme involves reduced temperature preconcentration of analytes from whole air with subsequent thermal desorptio...
The prototype computer program SPARC has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC solute-solute physical process models have been developed and tested...
Detection, composition and treatment of volatile organic compounds from waste treatment plants.
Environmental policies at the European and global level support the diversion of wastes from landfills for their treatment in different facilities. Organic waste is mainly treated or valorized through composting, anaerobic digestion or a combination of both treatments. Thus, there are an increasing number of waste treatment plants using this type of biological treatment. During waste handling and biological decomposition steps a number of gaseous compounds are generated or removed from the organic matrix and emitted. Different families of Volatile Organic Compounds (VOC) can be found in these emissions. Many of these compounds are also sources of odor nuisance. In fact, odors are the main source of complaints and social impacts of any waste treatment plant. This work presents a summary of the main types of VOC emitted in organic waste treatment facilities and the methods used to detect and quantify these compounds, together with the treatment methods applied to gaseous emissions commonly used in composting and anaerobic digestion facilities. PMID:22163835
Font, Xavier; Artola, Adriana; Sßnchez, Antoni
A simple batch microcosm had previously been developed to simulate the behavior of volatile organic compounds in unconsolidated subsurface material. The microcosm was evaluated by comparing the behavior of tetrachloroethylene, bromoform, carbon tetrachloride, 1,2-dichlorobenzene,...
Radian Corporation, under contract to the U.S. Environmental Protection Agency, performed site selection, test plan development, and performance tests of catalytic incinerators used for volatile organic compound (VOC) emissions control at industrial sites. VOC emissions are of co...
stormwater, volatile organic compounds, impervious area, atmosphere #12;3 INTRODUCTION Protecting the quality non-point source of VOCs is residue from spills trapped in the pore space of concrete and asphalt
Biogenic emissions of volatile organic compounds (VOC) from forests play an important role in regulating the atmospheric trace gas composition including global tropospheric ozone concentrations. However, more information is needed on VOC emission rates from different forest regio...
Sorption, biodegradation and hydraulic parameters were determined in the laboratory for two candidate soil substrate mixtures for construction of an upflow treatment wetland for volatile organic compounds (VOCs) at a Superfund site. The major parent contaminants in the groundw...
Detection, Composition and Treatment of Volatile Organic Compounds from Waste Treatment Plants
Environmental policies at the European and global level support the diversion of wastes from landfills for their treatment in different facilities. Organic waste is mainly treated or valorized through composting, anaerobic digestion or a combination of both treatments. Thus, there are an increasing number of waste treatment plants using this type of biological treatment. During waste handling and biological decomposition steps a number of gaseous compounds are generated or removed from the organic matrix and emitted. Different families of Volatile Organic Compounds (VOC) can be found in these emissions. Many of these compounds are also sources of odor nuisance. In fact, odors are the main source of complaints and social impacts of any waste treatment plant. This work presents a summary of the main types of VOC emitted in organic waste treatment facilities and the methods used to detect and quantify these compounds, together with the treatment methods applied to gaseous emissions commonly used in composting and anaerobic digestion facilities. PMID:22163835
Font, Xavier; Artola, Adriana; Sanchez, Antoni
The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms...
Five key scientific questions guiding this research were explored. They are given here with results generated from the project. Ā B.1.ĀĀĀĀĀĀĀ How can polar organic compounds be measured in atmospheric fine particulate matter? Is there potential a...
Plant-Associated Bacterial Degradation of Toxic Organic Compounds in Soil
A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review. PMID:19742157
McGuinness, Martina; Dowling, David
A modified clay (organophilic) was utilized to evaluate the potential for chemically stabilizing a waste containing organic compounds. hemical bonding between the binder and the contaminants was indicated. eachate testing also indicated strong binding. Copy available at NTIS as ...
National Technical Information Service (NTIS)
This project was aimed at developing improved and lower-cost alternative experimental procedures for evaluating chemical mechanisms for predicting ozone impacts of volatile organic compounds (VOCs). More precise measurements of effects of VOCs on OH radic...
W. P. L. Carter, I. Malkina
Weathered Diesel oil as a sorptive phase for hydrophobic organic compounds in aquifer materials
The sorptive properties of weathered diesel oil were investigated by conducting miscible displacement experiments with three hydrophobic organic compounds (HOCs), acenapthene, fluorene, and dibenzothiophene, as tracers in columns containing aquifer...
Hudson, Rondall James
The report describes results of an interlaboratory study to estimate repeatability (precision of analyses performed by a single laboratory) and reproducibility (precision analyses performed by different laboratories) of a consumer products volatile organic compound (VOC) measurem...
The computer program SPARC (Sparc Performs Automated Reasoning in Chemistry)has been under development for several years to estimate physical properties and chemical reactivity parameters of organic compounds strictly from molecular structure. SPARC uses computational algorithms ...
Secondary formation of submicron ambient particulate matter occurs when organic and inorganic constituents having sufficiently low volatility condense onto preexisting particles in the atmosphere. The presence of the resulting submicron particles has led to three important env...
The method for the determination of perfluorinated organic compounds (PFCs) in surface water has been developed and applied to natural water. The method shows an adequate sensitivity, precision and accuracy for ten kinds of target compounds. These PFCs were found in most samples...
The chemical mass balance (CMB) receptor model has apportioned volatile organic compounds (VOCs) in more than 20 urban areas, mostly in the United States. These applications differ in terms of the total fraction apportioned, the calculation method, the chemical compounds used ...
In this study, accelerated solid phase dynamic extraction (ASPDE) technique was used to identify biogenic volatile organic compounds (BVOCs) emitted from Norway spruce (Picea abies). Compounds that were determined in tree samples are: tricycylene, ?-pinene, camphene, ?-pinene, myrcene, 3-carene, p-cymene, limonene, cineole, ?-phellandrene, ?-terpinene, ?-terpinene and terpinolene. ASPDE showed a potential for the analysis of environmental samples as well as
Olga Pokorska; Jo Dewulf; Herman Van Langenhove
Volatile organic compounds in snow in the Quebec-Windsor Corridor
Volatile organic compounds (VOC) were determined in snow to investigate the role of the snowpack as an exchange medium for atmospherically active compounds of anthropogenic and biogenic origin. The major question was which VOC species occur in snow and how the species identity and selected concentrations are related to the sampling area and environmental conditions. Samples were collected using a
G. Kos; P. A. Ariya
Solid-phase microextraction (SPME) has shown potential as an in situ passive sampling technique in aqueous environments. The reliability of this method depends upon accurate determination of the partitioning coefficient between the fiber coating and water (Kf) for the compounds of interest. Kf values for poly(dimethylsiloxane) (PDMS) and water spanning 4 orders of magnitude have been reported for hydrophobic organic compounds
E. L. Difilippo; R. P. Eganhouse
Inorganic-organic hybrid compounds exhibiting both magnetic order and non-linear optical properties
NASA Astrophysics Data System (ADS)
Hybrid organic-inorganic framework compounds constitute an important class of materials whose properties, especially paired ones, have not been adequately investigated hitherto. In this communication, we report the non-linear optical properties of hybrid compounds exhibiting interesting magnetic properties.
Ramakrishna Matte, H. S. S.; Cheetham, A. K.; Rao, C. N. R.
Determination of toxic organic compounds in ambient air is a complex task, primarily because of the wide variety of compounds of interest and the lack of standardized sampling and analysis procedures. This compendium of methods has been prepared to provide current, peer-reviewed ...
A novel approach is presented combining semipermeable membranes with the accepted purge and trap gas chromatography-mass spectrometry (GC-MS) technology to produce a method of selectively extracting polar, volatile organic compounds from water, particularly those compounds not am...
The paper discusses the use of flares to destroy volatile organic and toxic compounds. Flares are used to destroy industrial gases from which the heating cannot be economically recovered. Results of an EPA investigation of overall flare combustion efficiency and specific compound...
Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between
Fred Fehsenfeld; Jack Calvert; Ray Fall; Paul Goldan; A. B. Guenther; C. N. Hewitt; Brian Lamb; Shaw Liu; Michael Trainer; Hal Westberg; Pat Zimmerman
Fluorinated organic compounds in an eastern Arctic marine food web.
An eastern Arctic marine food web was analyzed for perfluorooctanesulfonate (PFOS, C8F17SO3-), perfluorooctanoate (PFOA, C7F15COO-), perfluorooctane sulfonamide (PFOSA, C8F17SO2NH2), and N-ethylperfluorooctane sulfonamide (N-EtPFOSA, C8F17SO2NHCH2CH3) to examine the extent of bioaccumulation. PFOS was detected in all species analyzed, and mean concentrations ranged from 0.28 +/- 0.09 ng/g (arithmetic mean +/- 1 standard error, wet wt, whole body) in clams (Mya truncata) to 20.2 +/- 3.9 ng/g (wet wt, liver) in glaucous gulls (Larus hyperboreus). PFOA was detected in approximately 40% of the samples analyzed at concentrations generally smaller than those found for PFOS; the greatest concentrations were observed in zooplankton (2.6 +/- 0.3 ng/g, wet wt). N-EtPFOSA was detected in all species except redfish with mean concentrations ranging from 0.39 +/- 0.07 ng/g (wet wt) in mixed zooplankton to 92.8 +/- 41.9 ng/g (wet wt) in Arctic cod (Boreogadus saida). This is the first report of N-EtPFOSA in Arctic biota. PFOSA was only detected in livers of beluga (Delphinapterus leucas) (20.9 +/- 7.9 ng/g, wet wt) and narwhal (Monodon monoceros) (6.2 +/- 2.3 ng/g, wet wt), suggesting that N-EtPFOSA and other PFOSA-type precursors are likely present but are being biotransformed to PFOSA. A positive linear relationship was found between PFOS concentrations (wet wt) and trophic level (TL), based on delta15N values, (r2 = 0.51, p < 0.0001) resulting in a trophic magnification factor of 3.1. TL-corrected biomagnification factor estimates for PFOS ranged from 0.4 to 9. Both results indicate that PFOS biomagnifies in the Arctic marine food web when liver concentrations of PFOS are used for seabirds and marine mammals. However, transformation of N-EtPFOSA and PFOSA and potential other perfluorinated compounds to PFOS may contribute to PFOS levels in marine mammals and may inflate estimated biomagnification values. None of the other fluorinated compounds (N-EtPFOSA, PFOSA, and PFOA) were found to have a significant relationship with TL, but BMF(TL) values of these compounds were often >1, suggesting potential for these compounds to biomagnify. The presence of perfluorinated compounds in seabirds and mammals provides evidence that trophic transfer is an important exposure route of these chemicals to Arctic biota. PMID:15669302
Tomy, Gregg T; Budakowski, Wes; Halldorson, Thor; Helm, Paul A; Stern, Gary A; Friesen, Ken; Pepper, Karen; Tittlemier, Sheryl A; Fisk, Aaron T
Laboratory and field screening strategies for measuring volatile organic compounds in landfill gas
Distinct patterns often exist in the presence and absence of hazardous contaminants in the environment. These patterns can be used to select efficient screening tools, or groups of compounds that provide the most information on overall occurrences of a larger target group of compounds. By using these screens to indicate whether a sample is contaminated with detectable amounts of the compounds of interest, attention can be focused on those samples considered most likely to contain measurable concentrations of targeted compounds. The cost savings that result from eliminating samples that are most likely uncontaminated can be applied to obtaining additional samples that more accurately characterize the spatial or temporal variability of the environmental problem. In a retrospective application of screening techniques to the State of California's database of volatile organic compounds in landfill gas, two laboratory screening compounds, perchloroethylene and methylene chloride, represent over 95% of the total number of positive detections of a target group of 10 volatile organic compounds. Benzene and vinyl chloride, two field screening compounds that were selected using the characteristics of commercially available colorimetric detector tubes, recorded 74% of the total contaminant detections and a 52% savings in analytical costs as compared to an exhaustive analysis of every sample for all 10 volatile organic compounds. The number of detections recorded could have been improved if more sensitive and less selective field screening devices were available.
Emerson, C.W.
averaged 157 ▒ 118 ng\\/m3 of particulate organic matter while the isoprene oxidation compounds, namely the 2-methyltetrols and 2-methylglyceric acid, accounted for 53 ▒ 19 ng\\/m3. Together, the terpene and isoprene oxidation products represented 36.9% of the identified organic mass of 490 ▒ 95 ng\\/m3 .P M10 organic matter loadings in the region were approximately 2.1 ▒ 1.2 mg\\/m3, so
Thomas M. Cahill; Vincent Y. Seaman; M. Judith Charles; Rupert Holzinger; Allen H. Goldstein
Catalytic combustion of volatile organic compounds on gold\\/cerium oxide catalysts
Catalytic combustion of some representative volatile organic compounds (VOCs) (2-propanol, methanol and toluene) was investigated on gold\\/cerium oxide catalysts prepared by coprecipitation (CP) and deposition¢precipitation (DP). The presence of gold has been found to enhance the activity of cerium oxide towards the oxidation of the selected volatile organic compounds, the extent of this effect depending on the preparation method of
Salvatore ScirĶ; Simona Minic"; Carmelo Crisafulli; Cristina Satriano; Alessandro Pistone
This project investigates the in-situ degradation of semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) using in-well sonication, in-well vapor stripping, and bioremediation. Pretreating groundwaters with sonication techniques in-situ would form VOCs that can be effectively removed by in-well vapor stripping and bioremediation. The mechanistic studies focus on the coupling of megasonics and ultrasonics to ''soften'' (i.e., partially degrade)
Robert W
Reaction of ozone with c5 and c6 biogenic volatile organic compounds
REACTION OF OZONE WITH C5 AND C6 BIOGENIC VOLATILE ORGANIC COMPOUNDS M. O'Connor, M. O'Dwyer, J. Wenger CRAC-Centre for Research into Atmospheric Chemistry, Department of Chemistry, University College Cork, Ireland. firstname.lastname@example.com Biogenic volatile organic compounds (BVOCs) account for around 90% of hydrocarbon emissionsinto the Earth's atmosphere. During the last ten years an increasing number of oxygenated BVOCs have also been
M. O Connor; M. O Dwyer; J. Wenger
'This project investigates the in-situ degradation of semivolatile organic compounds (SVOCs) and volatile organic compounds (VOCs) using in-well sonication, in-well vapor stripping, and bioremediation. Pretreating groundwaters with sonication techniques in-situ would form VOCs that can be effectively removed by in-well vapor stripping and bioremediation. The mechanistic studies focus on the coupling of megasonics and ultrasonics to soften (i.e., partially degrade)
R. W. Peters; J. Manning; M. R. Hoffman; S. Gorelick
Characterization of the solvent extractable organic compounds in PM2.5 aerosols in Hong Kong
The results from a year-long monthly study of the solvent extractable organic compounds (SEOC) in PM2.5 of the ambient aerosols in Hong Kong are reported. A total of 18 samples were analyzed. The extracted organic compounds were separated into four major fractions (n-alkanes, fatty acids, alkanols and PAHs (polycyclic aromatic hydrocarbons)) and identified with GC-MS (gas chromatography¢mass spectrometry). The percentage
Mei Zheng; Ming Fang; Fu Wang; K. L. To
An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80▒17% for benzene and 84▒10% for TCE, respectively in methanol and ethanol. The ?(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of ?(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion. PMID:24360256
Bouchard, Daniel; Hunkeler, Daniel
NASA Astrophysics Data System (ADS)
Gas-phase H2O2, organic peroxides, carbonyl compounds, and carboxylic acids were measured from mid-July to early August 1998 during the Berlin ozone (BERLIOZ) campaign in Pabstthum, Germany. The rural site, located 50 km northwest from Berlin, was chosen to measure the pollutants downwind during a summer smog episode. The hydroperoxides showed pronounced diurnal variations with peak mixing ratios in the early afternoon. The maximum mixing ratios were 1.4 ppbv (H2O2), 0.64 ppbv (methylhydroperoxide), and 0.22 ppbv (hydroxymethyl-hydroperoxide). H2O2 was formed through photochemical activity, but originated also from vertical transport from air residing above the local inversion layer in the morning hours. Sometimes a second maximum was observed in the late afternoon-evening: This H2O2 might be formed from ozonolysis of biogenic alkenes. Ratios of H2O2/HNO3 were used as indicators for the determination of NOx-sensitive versus volatile organic compound (VOC)-sensitive regimes for photochemical production of ozone. Diurnal profiles were measured for alkanals (C2-C10), showing maximum mixing ratios decreased from C2 (0.6 ppbv) to C5 (0.1 ppbv) alkanals, which originate primarily from anthropogenic hydrocarbon degradation processes. However, higher C6, C9, and C10 alkanals show strong fluctuations (0.25, 0.17, and 0.13 ppbv, respectively), showing evidence of biogenic emissions. Both primary unsaturated carbonyl (methyl vinyl ketone, methacrolein) and secondary oxidation products of isoprene (hydroxyacetone and glycolaldehyde, up to 0.16 and 0.20 ppbv, respectively) showed excellent correlation. Diurnal profiles of glyoxal, methylglyoxal, biacetyl, benzaldehyde, and pinonaldehyde were also obtained. Formaldehyde was measured continuously by long-path DOAS and by an instrument based on the "Hantzsch" reaction; however, mixing ratios measured by DOAS (maximum 7.7 ppbv) were systematically larger by a factor of 1.3 on average, but by a factor of 1.7 during high photochemical activity. Homologous series of monocarboxylic acids were determined: Formic and acetic acid varied between 0.6 and 3.0 ppbv. The mixing ratio of the other dropped from 0.1 to 0.2 ppbv for C3 to typical 0.01 to 0.03 ppbv for C6, and from 0.01 to 0.002 ppbv for C7 to C9 monocarboxylic acids.
Grossmann, D.; Moortgat, G. K.; Kibler, M.; Schlomski, S.; BõChmann, K.; Alicke, B.; Geyer, A.; Platt, U.; Hammer, M.-U.; Vogel, B.; Mihelcic, D.; Hofzumahaus, A.; Holland, F.; Volz-Thomas, A.
Organic materials that will not absorb light at wavelengths longer than 295 nanometers (the solar wavelength cutoff) may nevertheless, undergo electron transfer reactions initiated by light. These reactions occur when the organic materials are adsorbed as ligand complexes to the surface of iron oxy-hydroxide (goethite). The adsorbed materials can be either inner or outer coordination sphere complexes. Goethite was chosen as the iron oxyhydroxide surface because it has the highest thermodynamic stability of any of the oxyhydroxides in water and it can be synthesized easily, with high purity.
Goldberg, Marvin C.
The Dissociation Enthalpies of Terminal (N O) Bonds in Organic Compounds
NASA Astrophysics Data System (ADS)
Dissociation enthalpies of terminal (N-O) bonds, DH?(N-O), in amine N-oxides, nitrile N-oxides, pyridine N-oxides, quinoxaline 1,4-dioxides, furoxans, nitrones, azoxy-derivatives, azo-N,N-dioxides, nitro compounds, nitramines, and alkyl nitrates are calculated from published enthalpy of formation, enthalpy of sublimation, and enthalpy of vaporization data. For each class of organic compounds, the calculated DH?(N-O) values are critically evaluated. The derived DH?(N-O) values can be used to estimate enthalpies of formation of other molecules in each of these classes of organic compounds.
Acree, William E.; Pilcher, Geoffrey; Ribeiro da Silva, Maria D. M. C.
Deuterium enrichment by selective photo-induced dissociation of an organic carbonyl compound
A method for producing a deuterium enriched material by photoinduced dissociation which uses as the working material a gas phase photolytically dissociable organic carbonyl compound containing at least one hydrogen atom bonded to an atom which is adjacent to a carbonyl group and consisting of molecules wherein said hydrogen atom is present as deuterium and molecules wherein said hydrogen atom is present as another isotope of hydrogen. The organic carbonyl compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of the deuterium containing species to yield a deuterium enriched stable molecular product. Undissociated carbonyl compound, depleted in deuterium, is preferably redeuterated for reuse.
Marling, John B. (Livermore, CA)
Clean process to destroy arsenic-containing organic compounds with recovery of arsenic
A reduction method is provided for the treatment of arsenic-containing organic compounds with simultaneous recovery of pure arsenic. Arsenic-containing organic compounds include pesticides, herbicides, and chemical warfare agents such as Lewisite. The arsenic-containing compound is decomposed using a reducing agent. Arsine gas may be formed directly by using a hydrogen-rich reducing agent, or a metal arsenide may be formed using a pure metal reducing agent. In the latter case, the arsenide is reacted with an acid to form arsine gas. In either case, the arsine gas is then reduced to elemental arsenic. 1 fig.
Upadhye, R.S.; Wang, F.T.
The primary objective of this research program was to determine whether organotins, contained in heat stabilizers of polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) pipe, and other organics present in pipe sealing cement solvents may leach into potable water su...
Monitoring the toxicity of organic compounds dissolved in Rhine water
Organic concentrates of the River Rhine water were tested for toxicity with a 15 minute test (MicrotoxTM) on luminescent bacteria (Photobacterium phosphoreum, Bacteria). A total number of 18 stations in the Dutch lower Rhine area were sampled five times with an interval of one month (April 1988¢August 1988), whereas two stations located the most apart (Lobith and Maassluis) were sampled
Dick De Zwart; Ariejan Folkerts
NASA Astrophysics Data System (ADS)
Optical spectroscopy based CRDS technology for isotopic analysis of ?D and ?18O directly from liquid water has greatly increased the number and type of liquid samples analyzed. This increase has also revealed a previously unrecognized sample contamination problem. Recently West[1] and Brand[2] identified samples containing ethanol, methanol, plant extracts and other organic compounds analyzed by CRDS and other spectroscopy based techniques as yielding erroneous results for ?D and ?18O (especially ?D) due to spectroscopic interference. Not all organic compounds generate interference. Thus, identifying which samples are contaminated by which organic compounds is of key importance for data credibility and correction. To address this problem a new approach in the form of a software suite, ChemCorrectÖ, has been developed. A chemometrics component uses a spectral library of water isotopologues and interfering organic compounds to best fit the measured spectra. The best fit values provide a quantitative assay of the actual concentrations of the various species and are then evaluated to generate a visual flag indicating samples affected by organic contamination. Laboratory testing of samples spiked with known quantities of interfering organic compounds such as methanol, ethanol, and terpenes was performed. The software correctly flagged and identified type of contamination for all the spiked samples without any false positives. Furthermore the reported values were a linear function of actual concentration with an R^2>0.99 even for samples which contained multiple organic compounds. Further testing was carried out against a range of industrial chemical compounds which can contaminate ground water as well as a variety of plant derived waters and juices which were also analyzed by IRMS. The excellent results obtained give good insight into which organic compounds cause interference and which classes of plants are likely to contain interfering compounds. Finally approaches to minimize the effect of interfering compounds will be discussed including methods to assess the confidence level of an isotopic value obtained from a contaminated sample. [1] Rapid Commun. Mass Spectrom. 2010; 24: 1-7 [2] Rapid Commun. Mass Spectrom. 2009; 23: 1879-1884 Results from laboratory samples, most of which were spiked with interfering organic compounds. Samples are color coded as follows: blue=standard, green=no contamination, yellow=slight contamination, red=heavily contaminated.
Richman, B. A.; Hsiao, G. S.; Rella, C.
NASA Astrophysics Data System (ADS)
The volatile organic compounds of non-irradiated and electron-beam irradiated 'Fuji' apples (Malus domestica Borkh.) at 0, 0.5, and 1 kGy were isolated through simultaneous distillation extractions and analyzed using gas chromatograph-mass spectrometry. A total of 53 volatile organic compounds were characterized in 0 and 1 kGy irradiated samples, whereas two more compounds related to ketone and terpenoid group were identified in 0.5 kGy irradiated samples. The contents of volatile compounds were 24.33, 36.49, and 35.28 mg/kg in 0, 0.5, and 1 kGy irradiated samples, respectively. The major compounds identified were butanol, hexanal, [E]-2-hexenal, and hexanol in all samples. The relative content of alcohol increased after 30 days of storage in all samples, whereas that of aldehyde decreased. Although the contents of some volatile compounds were changed by electron-beam irradiation, the total yield and major flavor compounds of irradiated 'Fuji' apples were similar to, or even greater than, those of the control. Therefore, the application of e-beam irradiation if required for microbial decontamination of 'Fuji' apples is an acceptable method as it does not bring about any major quantitative changes of volatile organic compounds.
Song, Hyun-Pa; Shim, Sung-Lye; Lee, Sun-Im; Kim, Dong-Ho; Kwon, Joong-Ho; Kim, Kyong-Su
Volatile organic compounds from used building materials in a simulated chamber study
Building materials emit volatile organic compounds (VOCs) indoors. They may also adsorb compounds so that an equilibrium with indoor air is reached. Samples were taken from the floor, walls, and ceiling of one room in a seven-year-old preschool building. They were placed in a small climate chamber for a period of 41 days. Samples from the air in the room and the chamber were analysed by gas chromatography and mass spectrometry, and about 60 compounds were identified. The composition of organics in the room air was reestablished in the chamber the first day. Since most of the compounds disappeared within 2 to 23 days, they are believed to have been adsorbed from the room air onto the material surfaces. During the last 10 days, 17 compounds remained at constant concentrations, implying that they are representative of the building material samples.
Berglund, B. (Univ. of Stockholm (Sweden)); Johansson, I.; Lindvall, T. (Karolinska Institute, Stockholm (Sweden))
Compound prioritization methods increase rates of chemical probe discovery in model organisms
SUMMARY Pre-selection of compounds that are more likely to induce a phenotype can increase the efficiency and reduce the costs for model organism screening. To identify such molecules, we screened ~81,000 compounds in S. cerevisiae and identified ~7,500 that inhibit cell growth. Screening these growth-inhibitory molecules across a diverse panel of model organisms resulted in an increased phenotypic hit-rate. This data was used to build a model to predict compounds that inhibit yeast growth. Empirical and in silico application of the model enriched the discovery of bioactive compounds in diverse model organisms. To demonstrate the potential of these molecules as lead chemical probes we used chemogenomic profiling in yeast and identified specific inhibitors of lanosterol synthase and of stearoyl-CoA 9-desaturase. As community resources, the ~7,500 growth-inhibitory molecules has been made commercially available and the computational model and filter used are provided. PMID:22035796
Wallace, Iain M; Urbanus, Malene L; Luciani, Genna M; Burns, Andrew R; Han, Mitchell KL; Wang, Hao; Arora, Kriti; Heisler, Lawrence E; Proctor, Michael; St. Onge, Robert P; Roemer, Terry; Roy, Peter J; Cummins, Carolyn L; Bader, Gary D; Nislow, Corey; Giaever, Guri
Ion-trap detection of volatile organic compounds in alveolar breath
We describe a method for the collection and microanalysis of the volatile organic compounds in human breath. A transportable apparatus supplies subjects with purified air and samples their alveolar breath; the volatile organic compounds are captured in an adsorptive trap containing activated carbon and molecular sieve. The sample is thermally desorbed from the trap in an automated microprocessor-controlled device, concentrated by two-stage cryofocusing, and assayed by gas chromatography with ion-trap detection. Compounds are identified by reference to a computer-based library of mass spectra with subtraction of the background components present in the inspired air. We used this device to study 10 normal subjects and determined the relative abundance of the volatile organic compounds in their alveolar breath. The breath-collecting apparatus was convenient to operate and was well tolerated by human volunteers.
Phillips, M.; Greenberg, J. (Department of Medicine, St. Vincent's Medical Center of Richmond, Staten Island, NY (United States))
Assessment of synthetic organic compounds, and endocrinology and histology of carp in Lake Mead
This study investigated the presence and biologic effects of synthetic organic compounds transported by Las Vegas Wash to Lake Mead National Recreation Area. Water, bottom sediment, and carp (Cyprinus carpio) were analyzed for synthetic organic compounds. Semipermeable membrane devices (SPMDs) were used to sample the water column. Blood samples were collected from Carp for analysis of sex steroid hormones and vitellogenin. Samples of external abnormalities and organs (liver, gill, kidney, small intestine, and gonad) were collected for histologic analysis. Compounds known to affect endocrine systems (PAHs, phthalate esters, PCBs, dioxins and furans) were detected in SPMD, bottom-sediment, and/or carp samples. The number and concentrations of compounds generally were greater in samples from Las Vegas Wash and Bay, than in samples from Callville Bay, a reference site in Lake Mead. High levels of PAHs detected in SPMDs from Callville Bay could indicate the existence of contaminant sources other than Las Vegas Wash.
Bevans, H.; Goodbred, S.; Miesner, J.
Cooperative water-SOM interactions derived from the organic compound effect on SOM hydration
NASA Astrophysics Data System (ADS)
Interactions of water molecules with soil organic matter (SOM) may affect the ability of SOM to participate in multiple physical, chemical and biological processes. Specifically, water-SOM interactions may have a profound effect on interactions of organic compounds with SOM which is often considered as a major natural sorbent controlling the environmental fate of organic pollutants in the soil environment. Quantification of water - SOM interactions may be carried out by using water vapor sorption isotherms. However, water sorption isotherms providing macroscopic thermodynamic data do not allow examining water-SOM interactions on a microenvironment scale. The examination of water-SOM interactions in a local SOM environment may be carried out by determining the response of the SOM hydration to sorption of probe organic compounds. Recently, the model-free approach was proposed which allows quantifying effects of sorbing organic molecules on water - SOM interactions, by using relatively more available data on the effect of water activity on organic compound - SOM interactions. Therefore, this thermodynamic approach was applied to the experimental data describing sorption of organic compounds by SOM, both from the vapor and liquid phases, at various water activities. Hence, the response of water interactions with the model SOM materials such as a humic acid and an organic matter-rich peat soil to the presence of various organic sorbates was evaluated. Depending on a molecular structure of organic sorbates probing various molecular environments in SOM, the SOM-bound water may be driven in or out of the SOM sorbents. Organic compounds containing the atoms of oxygen, nitrogen or sulfur and preferring a relatively "polar" SOM microenvironment demonstrate the distinct enhancing effect on water-SOM interactions. In contrast, the "low-polarity" organic compounds, e.g., hydrocarbons or their halogen-substituted derivatives, produce a weakening effect on water-SOM interactions. Importantly, the changes in water-SOM interactions induced by the presence of organic compounds may demonstrate the cooperative behavior: (1) several water molecules may be involved in an enhanced hydration of SOM, (2) at the presence of an organic sorbate, interactions of water molecules with SOM enhance the uptake of the following water molecules. The proposed cooperative water-SOM interactions may result from a perturbation of the SOM matrix due to a sorption of organic and water molecules where a partial disrupting of molecular contacts in SOM makes easier the following SOM-water interactions thus promoting the enhanced SOM hydration.
Borisover, Mikhail
NASA Astrophysics Data System (ADS)
Hygroscopic behavior of organic compounds, including levoglucosan, 4-hydroxybenzoic acid, and humic acid, as well as their effects on the hygroscopic properties of ammonium sulfate (AS) in internally mixed particles are studied by a hygroscopicity tandem differential mobility analyzer (HTDMA). The organic compounds used represent pyrolysis products of wood that are emitted from biomass burning sources. It is found that humic acid aerosol particles only slightly take up water, starting at RH (relative humidity) above ~70%. This is contrasted by the continuous water absorption of levoglucosan aerosol particles in the range 5-90% RH. However, no hygroscopic growth is observed for 4-hydroxybenzoic acid aerosol particles. Predicted water uptake using the ideal solution theory, the AIOMFAC model and the E-AIM (with UNIFAC) model are consistent with measured hygroscopic growth factors of levoglucosan. However, the use of these models without consideration of crystalline organic phases is not appropriate to describe the hygroscopicity of organics that do not exhibit continuous water uptake, such as 4-hydroxybenzoic acid and humic acid. Mixed aerosol particles consisting of ammonium sulfate and levoglucosan, 4-hydroxybenzoic acid, or humic acid with different organic mass fractions, take up a reduced amount of water above 80% RH (above AS deliquescence) relative to pure ammonium sulfate aerosol particles of the same mass. Hygroscopic growth of mixtures of ammonium sulfate and levoglucosan with different organic mass fractions agree well with the predictions of the thermodynamic models. Use of the Zdanovskii-Stokes-Robinson (ZSR) relation and AIOMFAC model lead to good agreement with measured growth factors of mixtures of ammonium sulfate with 4-hydroxybenzoic acid assuming an insoluble organic phase. Deviations of model predictions from the HTDMA measurement are mainly due to the occurrence of a microscopical solid phase restructuring at increased humidity (morphology effects), which are not considered in the models. Hygroscopic growth factors of mixed particles containing humic acid are well reproduced by the ZSR relation. Lastly, the organic surrogate compounds represent a selection of some of the most abundant pyrolysis products of biomass burning. The hygroscopic growths of mixtures of the organic surrogate compounds with ammonium sulfate with increasing organics mass fraction representing ambient conditions from the wet to the dry seasonal period in the Amazon basin, exhibit significant water uptake prior to the deliquescence of ammonium sulfate. The measured water absorptions of mixtures of several organic surrogate compounds (including levoglucosan) with ammonium sulfate are close to those of binary mixtures of levoglucosan with ammonium sulfate, indicating that levoglucosan constitutes a major contribution to the aerosol water uptake prior to (and beyond) the deliquescence of ammonium sulfate. Hence, certain hygroscopic organic surrogate compounds can substantially affect the deliquescence point of ammonium sulfate and overall particle water uptake.
Lei, T.; Zuend, A.; Wang, W. G.; Zhang, Y. H.; Ge, M. F.
This paper reviews the suspended and surficial sediment fractions and their interactions with manmade organic compounds. The objective of this review is to isolate and describe those contaminant and sediment properties that contribute to the persistence of organic compounds in surface-water systems. Most persistent, nonionic organic contaminants, such as the chlorinated insecticides and polychlorinated biphenyls (PCBs), are characterized by low water solubilities and high octanol-water partition coefficients. Consequently, sorptive interactions are the primary transformation processes that control their environmental behavior. For nonionic organic compounds, sorption is primarily attributed to the partitioning of an organic contaminant between a water phase and an organic phase. Partitioning processes play a central role in the uptake and release of contaminants by sediment organic matter and in the bioconcentration of contaminants by aquatic organisms. Chemically isolated sediment fractions show that organic matter is the primary determinant of the sorptive capacity exhibited by sediment. Humic substances, as dissolved organic matter, contribute a number of functions to the processes cycling organic contaminants. They alter the rate of transformation of contaminants, enhance apparent water solubility, and increase the carrying capacity of the water column beyond the solubility limits of the contaminant. As a component of sediment particles, humic substances, through sorptive interactions, serve as vectors for the hydrodynamic transport of organic contaminants. The capabilities of the humic substances stem in part from their polyfunctional chemical composition and also from their ability to exist in solution as dissolved species, flocculated aggregates, surface coatings, and colloidal organomineral and organometal complexes. The transport properties of manmade organic compounds have been investigated by field studies and laboratory experiments that examine the sorption of contaminants by different sediment size fractions. Field studies indicate that organic contaminants tend to sorb more to fine-grained sediment, and this correlates significantly with sediment organic matter content. Laboratory experiments have extended the field studies to a wider spectrum of natural particulates and anthropogenic compounds. Quantitation of isotherm results allows the comparison of different sediment sorbents as well as the estimation of field partition coefficients from laboratory-measured sediment and contaminant properties. Detailed analyses made on the basis of particle-size classes show that all sediment fractions need to be considered in evaluating the fate and distribution of manmade organic compounds. This conclusion is based on observations from field studies and on the variety of natural organic sorbents that demonstrate sorptive capabilities in laboratory isotherm experiments.
Witkowski, P. J.; Smith, J. A.; Fusillo, T. V.; Chiou, C. T.
Phytoremediation of Loess Soil Contaminated by Organic Compounds
Loess soils extensively cover Central Asia and North China topography where oil fields are widely exploited; thus, organic\\u000a contamination has become a critical environmental issue in these regions. As China faces severe land and eco-environmental\\u000a deterioration, phytoremediation has been considered as a priority remedial alternative for reclamation of contaminated cultivated\\u000a land. This article provides a framework to understand phytore-mediation applications
K. Zhu; H. Chen; Z. Nan
"The disintegration of organic compounds by microorganisms is accompanied by the liberation of
"The disintegration of organic compounds by microorganisms is accompanied by the liberation of electrical energy." M.C. Potter, 1911. It is well known that microorganisms can produce fuels, such as ethanol, methane and hydrogen, from organic matter. It is less well known that microorganisms can also
Lovley, Derek
Catalytic Hydrogenation of Organic Compounds without H2 Supply: An Electrochemical System
ERIC Educational Resources Information Center
An experiment developed for an undergraduate organic chemistry laboratory course that can be used to introduce the catalytic hydrogenation reaction, catalysis electrochemical principles and gas chromatography is presented. The organic compounds hydrogenated by the electrocatalytic hydrogenation (ECH) process were styrene, benzaldehyde andģ
Navarro, Daniela Maria do Amaral Ferraz; Navarro, Marcelo
Particulate organic compounds emitted from motor vehicle exhaust and in the urban atmosphere
The emission rate of particle-phase petroleum biomarkers in vehicular exhaust compared to the concentrations of these biomarkers in ambient air is used to determine the particulate organic compound concentration due to primary particle emissions from motor vehicles in the southern California atmosphere. A material balance on the organic particulate matter emitted from motor vehicle traffic in a Los Angeles highway
Matthew P. Fraser; Glen R. Cass; Bernd R. T. Simoneit
The chemical transformation of organic contaminants in natural groundwater systems is clearly dependent upon local geochemistry which determines the thermodynamically favorable degradation reactions and the nature of local microbial populations. Conversely, groundwater geochemistry may be impacted significantly in terms of pH and redox couple speciation by the chemical transformation of sufficient quantities of organic compounds. Therefore an understanding of the
W. W. Jr. McNab; T. N. Narasimhan
Distributions of brominated organic compounds in the troposphere and lower stratosphere
A comprehensive suite of brominated organic compounds was measured from whole air samples collected during the 1996 NASA Stratospheric Tracers of Atmospheric Transport aircraft campaign and the 1996 NASA Global Tropospheric Experiment Pacific Exploratory Mission-Tropics aircraft campaign. Measurements of individual species and total organic bromine were utilized to describe latitudinal and vertical distributions in the troposphere and lower stratosphere, fractional
S. M. Schauffler; E. L. Atlas; D. R. Blake; F. Flocke; R. A. Lueb; J. M. Lee-Taylor; V. Stroud; W. Travnicek
Stearic acid and albumin dissolved in distilled water, as well as lipoid and amino acid-containing substances dissolved in seawater, interact with carbonate mineral surfaces. In seawater, these compounds represent 14 per cent of the total dissolved organic carbon which is removed from solution by adsorption processes onto carbonate minerals. The mineral surfaces are saturated with organic carbon after adsorbing 0.1
Erwin Suess
The guidance document was originally issued in June 1983. ince then significant changes have occurred in the regulations that cover volatile and semivolatile organic air pollutants. There have also been significant advances in the collection and analysis of organic compounds and ...
Hazardous organic compounds in biogas plant end products--soil burden and risk to food safety.
The end products (digestate, solid fraction of the digestate, liquid fraction of the digestate) of ten biogas production lines in Finland were analyzed for ten hazardous organic compounds or compound groups: polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCB(7)), polyaromatic hydrocarbons (PAH(16)), bis-(2-ethylhexyl) phthalate (DEHP), perfluorinated alkyl compounds (PFCs), linear alkylbenzene sulfonates (LASs), nonylphenols and nonylphenol ethoxylates (NP+NPEOs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA). Biogas plant feedstocks were divided into six groups: municipal sewage sludge, municipal biowaste, fat, food industry by-products, animal manure and others (consisting of milling by-products (husk) and raw former foodstuffs of animal origin from the retail trade). There was no clear connection between the origin of the feedstocks of a plant and the concentrations of hazardous organic compounds in the digestate. For PCDD/Fs and for DEHP, the median soil burden of the compound after a single addition of digestate was similar to the annual atmospheric deposition of the compound or compound group in Finland or other Nordic countries. For PFCs, the median soil burden was somewhat lower than the atmospheric deposition in Finland or Sweden. For NP+NPEOs, the soil burden was somewhat higher than the atmospheric deposition in Denmark. The median soil burden of PBDEs was 400 to 1000 times higher than the PBDE air deposition in Finland or in Sweden. With PBDEs, PFCs and HBCD, the impact of the use of end products should be a focus of further research. Highly persistent compounds, such as PBDE- and PFC-compounds may accumulate in agricultural soil after repeated use of organic fertilizers containing these compounds. For other compounds included in this study, agricultural use of biogas plant end products is unlikely to cause risk to food safety in Finland. PMID:24593894
Suominen, K; Verta, M; Marttinen, S
NASA Astrophysics Data System (ADS)
Reprecipitation is a useful method of preparing organic microcrystals. However, microcrystals of compounds with polar groups are difficult to prepare by this method. A method of preparing microcrystals of organic compounds with polar groups and inorganic salts using isooctane as an organic nonsolvent has been developed. Microcrystals of HMX, NH4NO3 and NH4ClO4 have been successfully prepared. Drop weight impact testing shows that HMX microcrystals of nanoscale size are much less sensitive to impact than HMX bulk crystals.
Zhang, Yongxu; Lv, Chunxu; Liu, Dabin; Guo, Liwei; Fu, Tingming
The effect of organic and conventional agricultural systems on the physicochemical parameters, bioactive compounds content, and sensorial attributes of tomatoes ("Redondo" cultivar) was studied. The influence on phytochemicals distribution among peel, pulp and seeds was also accessed. Organic tomatoes were richer in lycopene (+20%), vitamin C (+30%), total phenolics (+24%) and flavonoids (+21%) and had higher (+6%) in vitro antioxidant activity. In the conventional fruits, lycopene was mainly concentrated in the pulp, whereas in the organic ones, the peel and seeds contained high levels of bioactive compounds. Only the phenolic compounds had a similar distribution among the different fractions of both types of tomatoes. Furthermore, a sensorial analysis indicated that organic farming improved the gustative properties of this tomato cultivar. PMID:24569070
Vinha, Ana F; Barreira, Sķrgio V P; Costa, Anabela S G; Alves, Rita C; Oliveira, M Beatriz P P
NASA Astrophysics Data System (ADS)
A UV Raman instrument holds great promise for future in-situ astrobiology investigations on Mars and elsewhere in the solar system due to its potential for high organic sensitivity, stand-off detection, and detection on unprepared samples. We characterize the fluorescence spectra of a range of organic compounds including amino acids, fatty acids, alkanes, and polycyclic aromatic hydrocarbons (PAHs) at three UV excitations to determine at what Raman excitation fluorescence is minimized. Both Raman and fluorescence measurements indicate that a Raman instrument operating with an excitation of 266 nm will result in less fluorescence compared to an excitation of 355 nm. Raman spectra of organic compounds at a 1% concentration in a silica sand matrix are obtained at an excitation wavelength of 266 nm, and demonstrate either an absence of fluorescence or a reduction of fluorescence to a magnitude on the order of the Raman intensity, increasing the sensitivity of the instrument to organic compounds.
Eshelman, E.; Daly, M. G.; Slater, G.; Dietrich, P.; Gravel, J.-F.
Determination of perfluorinated compounds in aquatic organisms: a review.
Bioaccumulation of PFAS in aquatic organisms is an environmental problem of growing concern around the world. This problem has been tackled by regulatory bodies by proposing EQS for biota in EU water bodies and tolerable daily intake for food. The introduction of regulatory limits requires the availability of harmonised and validated analytical methods of sufficient sensitivity. This paper reviews recent advances in analytical methods for analysis of PFAS in aquatic organisms. The methods available for biota analysis are mostly based on three extraction procedures: ion-pair extraction, solvent liquid extraction, and alkaline digestion. The resulting extracts are then subjected to different clean-up or enrichment steps on solid adsorbents, for example graphitized carbon black, C(18), and WAX phases. All methods reviewed in this work give reliable results but are partially validated only, because of the lack of certified reference materials and regular interlaboratory exercises. The few interlaboratory exercises performed on real unspiked samples did not afford satisfactory results for PFAS other than PFOS, especially for matrices with high lipid content, for example mussels. The reasons for those partially negative results have been identified, and can mainly be attributed to calibration procedures and availability and purity of standards. The urgent need for certified reference materials for this type of analysis is emphasized. PMID:23108980
Valsecchi, Sara; Rusconi, Marianna; Polesello, Stefano
The purpose of this investigation was to remove the organic nitrogen compounds from petroleum-derived diesel fuels. These nitrogen compounds can cause environmental problems, as well as fuel instability problems that can degrade fuels and affect engine performance. Fuels were treated with two different filtering media, activated clay and silica tel. The methylene chloride extracts from both the activated clay and silica gel were subjected to GC/MS analysis. Close to 99% of the total organic nitrogen compounds were removed. About 60% of the nitrogen compounds identified consisted of pyridines, quinolines and tetra-hydroquinolines made up 26%, while indoles and carbazoles about 10% of the total nitrogen compounds. Of the nitrogen heterocyclics identified, indoles and carbazoles were linked to fuel instability reactions. The proposed method was tested on diesels fuels from a variety of countries and found to remove between 97.8 and 99.9% of the N-compounds. The results of this study showed that both of these filtering materials were effective in removing the organic nitrogen compounds and resulted in fuels that exhibited excellent storage stability. These simple filtering methods can be independent of the refining process and do result in an environmentally cleaner burning fuel. PMID:21240705
Mushrush, George W; Quintana, Marian A; Bauserman, Joy W; Willauer, Heather D
This paper presents the results of a numerical study of the kinetics of electrochemical oxidation of different organic substances\\u000a at boron doped diamond (BDD).\\u000a \\u000a It is well established that oxidation of organics at BDD anodes takes place in the potential region of oxygen evolution, through\\u000a reaction steps in which OH radicals are involved: these radicals can react with organic compounds
Michele Mascia; Annalisa Vacca; Simonetta Palmas; Anna Maria Polcaro
Presence and distribution of chlorinated organic compounds in streambed sediments, new jersey
Concentrations of 18 hydrophobic chlorinated organic compounds in streambed sediments from 100 sites throughout New Jersey were examined to determine (1) which compounds were detected most frequently, (2) whether detection frequencies differed among selected drainage basins, and (3) whether concentrations differed significantly among selected drainage basins. Twelve drainage basins across New Jersey that contain a range of land-use patterns and population densities were selected to represent various types and degrees of development. To ensure an adequate number of samples for statistical comparison among drainage basins, the 12 selected basins were consolidated into seven drainage areas on the basis of similarities in land- use patterns and population densities. Additionally, data for three classes of chlorinated organic compounds in streambed sediments from 255 sites throughout New Jersey were examined to determine whether the presence of these compounds in streambed sediments is related to the type and degree of development within the drainage area of each sampling site. Chlorinated organic compounds detected most frequently within the seven representative drainage areas were DDT, DDE, DDD, chlordane, dieldrin, and PCBs. DDT, DDE, and DDD, which were the most widely distributed organic compounds, were detected in about 60 to 100 percent of the samples from all drainage areas hut one (where the detection rate for these compounds was about 20 to 40 percent). Chlordane and dieldrin were detected in about 80 to 100 percent of samples from highly urbanized and populated drainage areas; detection frequencies for these compounds tended to be smaller in less developed and populated areas. PCBs were detected in about 40 to 85 percent of samples from all drainage areas; detection frequencies were highest in the most heavily developed and populated areas. Analysis of variance on rank-transformed organic compound concentrations normalized to sediment organic carbon content was used to evaluate differences in concentrations among the seven representative drainage areas. Chlordane and PCBs were the chlorinated organic compounds with the most highly elevated concentrations in streambed sediments across the State. Median normalized COncentrations of all six of the most frequently detected chlorinated organic compounds were highest in the most heavily urbanized and populated drainage area and lowest in the less populated, predominantly agricultural or forested areas. Concentrations of DDT and DDE, however, did not differ significantly among most of the drainage areas. Concentrations of DDD, chlordane, dieldrin, and PCBs differed significantly among drainage areas. The highest median normalized concentrations were found in samples from the most heavily urbanized and populated areas, and the lowest were in samples from the least developed, most heavily forested area. Logistic regression was used to examine relations between the presence of hydrophobic chlorinated organic compounds in streambed sediments at specified concentrations and variables that characterize the type and degree of development within the drainage areas of 255 sites across New Jersey. The explanatory variables found most useful for predicting the presence of chlorinated organic compounds in streambed sediments include total population and amounts (in square kilometers) of various land-use categories. Logistic regression equations were developed to identify significant relations between population and amounts of specific land-use categories within drainage areas and the probability of detecting chlorinated organic contaminants in streambed sediments. These relations can be used to assist in the identification of geographic regions of primary concern for contamination of bed sediments by chlorinated organic compounds across the State.
Stackelberg, P. E.
NASA Astrophysics Data System (ADS)
This work evaluates the sensitivity of tropospheric ozone and its precursors to the representation of nonmethane volatile organic compounds (NMVOCs) and organic nitrates. A global 3-D tropospheric chemistry/transport model (IMPACT) has been exercised initially using the GEOS-Chem chemical reaction mechanism. The model was then extended by adding emissions and photochemical reactions for aromatic and terpenoid hydrocarbons, and by adding explicit representation of hydroxy alkyl nitrates produced from isoprene. Emissions of methanol, phenol, acetic acid and formic acid associated with biomass burning were also added. Results show that O3 increases by 20% in most of the troposphere, peroxyacetyl nitrate (PAN) increases by 30% over much of the troposphere and OH increases by 10%. NOx (NO + NO2) decreases near source regions and increases in remote locations, reflecting increased transport of NOx away from source regions by organic nitrates. The increase in O3 was driven largely by the increased role of PAN as a transporter of NOx and by the rerelease of NOx from isoprene nitrates. The increased PAN production was associated with increases in methyl glyoxal and hydroxyacetone. Comparison with measured values show reasonable agreement for O3 and PAN, but model measurement agreement does not either improve or degrade in the extended model. The extended model shows improved agreement with measurements for methanol, acetic acid and peroxypropional nitrate (PPN). Results from the extended model were consistent with measured alkyl nitrates and glycolaldehyde, but hydroxyacetone and methyl glyoxal were overestimated. The latter suggests that the effect of the isoprene nitrates is somewhat smaller than estimated here. Although the model measurement comparison does not show specific improvements with the extended model, it provides a more complete description of tropospheric chemistry that we believe is important to include.
Ito, Akinori; Sillman, Sanford; Penner, Joyce E.
Partitioning of Organic Contaminants and Tracer Compounds in a CO2-Brine System at High Salinities
NASA Astrophysics Data System (ADS)
Nonionic chemical species including gases and organic compounds partition between the fluid CO2 phase and the aqueous phase in geologic carbon sequestration systems. The injection and migration of CO2 in geologic carbon sequestration systems covers a wide range of pressure and temperature, so it is important to understand the partitioning of these compounds at various P-T conditions and salinities. Geochemical data is particularly lacking for the partitioning of organic contaminant compounds and tracer compounds between highly saline brines and CO2. Most groundwater is relatively low in organic contaminants; however, groundwater associated with hydrocarbon migration pathways, enhanced oil recovery (EOR), and hydrocarbon storage or extraction can contain high concentrations of known organic contaminants. CO2 injection in these systems may therefore be more likely to result in partitioning of contaminants into the CO2 phase that could, upon migration, represent an important risk to groundwater resources. We present the experimental apparatus and determination of partition coefficients between brine and CO2 for a suite of compounds including benzene, toluene, ethylbenzene, xylene (BTEX), and low molecular weight polynuclear aromatic hydrocarbons (PAHs). In addition, partition coefficients are determined for the important gas phase tracer compounds: SF6 and Krypton covering a P-T envelope consistent with CO2 injection and plume migration to the near surface.
Thomas, B.; Kharaka, Y. K.; Rosenbauer, R. J.; Janesko, D.; Trutna, J.
Solubilities of 17 polar organic compounds in aqueous solutions of Na2SO4, NaCl, NaClO4, and NaSCN at the salt concentrations of up to 1.0-2.0 M were determined and the Setschenow constant, ksalt, values were estimated. It was found that NaClO4 may display both salting-in and salting-out effects depending on the particular compound structure. The Setschenow constant values for all the polar compounds examined in different salt solutions are found to be interrelated. Similar relationships were observed for partition coefficients of nonionic organic compounds in aqueous polyethylene glycol-sodium sulfate two-phase systems in the presence of different salt additives reported previously [Ferreira et al., J. Chromatogr. A, 2011, 1218, 5031], and for the effects of different salts on optical rotation of amino acids reported by Rossi et al. [J. Phys. Chem. B, 2007, 111, 10510]. In order to explain the observed relationships it is suggested that all the effects observed originate as responses of the compounds to the presence of a given ionic environment and its interaction with the compounds by forming direct or solvent-separated ionic pairs. The response is compound-specific and its strength is determined by the compound structure and the type (and concentration) of ions inducing the response. PMID:25260049
Ferreira, L A; Chervenak, A; Placko, S; Kestranek, A; Madeira, P P; Zaslavsky, B Y
Synthetic organic chemistry based on small ring compounds.
Small ring systems are important topics in both organic and inorganic chemistry, and draw considerable attention from both theoretical and preparative perspectives. This review intends to summarize the studies, focusing on the preparative aspects, that have been carried out in our laboratory. Namely, synthesis of (+)- and (-)-alpha-cuparenone, (+)-ipomeamarone, (+)-epiipomeamarone, (-)-ngaione, (-)-alpha-bisabolol, (-)-aplysin, (-)-debromoaplysin, (-)-mesembrine, (-)-filiformin, (-)-debromofiliformin, and (-)-4-deoxyverrucarol via successive asymmetric epoxidation and enantiospecific ring expansion of cyclopropylidenes, (+)-equilenin via successive ring expansion-insertion reaction, estrone, estradiol, chenodeoxycholic acid, 19-norspironolactone, 19-nordeoxycorticosterone, cortisone, adrenosterone, 11-oxoprogesterone, and 1alpha,25-dihydroxyvitamin D3 via intramolecular cycloaddition reaction of o-quinodimethanes. Medicinal chemistry aiming at developing a new type of anti-influenza agent, novel reaction mode of electrocyclic reaction, and substituent effect on that reaction are also discussed. PMID:17603183
Nemoto, Hideo
Organic compounds in the Forest Vale, H4 ordinary chondrite
NASA Astrophysics Data System (ADS)
We have analyzed the H4 ordinary chondrite Forest Vale for polycyclic aromatic hydrocarbons (PAHs) using two-step laser mass spectrometry (L 2MS) and for amino acids using a standard Chromatographic method. Indigenous PAHs were identified in the matrices of freshly cleaved interior faces but could not be detected in pulverized silicates and chondrules. No depth dependence of the PAHs was found in a chipped interior piece. Amino acids, taken from the entire sample, consisted of protein amino acids that were nonracemic, indicating that they are terrestrial contaminants. The presence of indigenous PAHs and absence of indigenous amino acids provides support for the contention that different processes and environments contributed to the synthesis of the organic matter in the solar system.
Zenobi, Renato; Philippoz, Jean-Michel; Zare, Richard N.; Wing, Michael R.; Bada, Jeffrey L.; Marti, Kurt
New unconventional approaches to the development of antimicrobial drugs must target inhibition of infection stages leading to host colonisation or virulence itself, rather than bacterial viability. Amongst the most promising unconventional targets for the development of new antimicrobial drugs is bacterial adherence and biofilm formation as well as their control system, the quorum-sensing (QS) system, a mechanism of communication used to co-ordinate bacterial activities. Here we describe the evaluation of synthetic organic compounds as bacterial biofilm inhibitors against a panel of clinically relevant Gram-positive and Gram-negative bacterial strains. This approach has successfully allowed the identification of five compounds (GEt, GHex, GOctad, G19 and C33) active not only against bacterial biofilms but also displaying potential to be used as antagonists and/or inhibitors of bacterial QS. PMID:24016798
de Lima Pimenta, Andrķa; Chiaradia-Delatorre, Louise Domeneghini; Mascarello, Alessandra; de Oliveira, Karen Andrinķia; Leal, Paulo Cķsar; Yunes, Rosendo Augusto; de Aguiar, Clßudia Beatriz Nedel Mendes; Tasca, Carla InĻs; Nunes, Ricado Josķ; SmŌnia, Artur
DOE's Rocky Flats Site in Colorado is a former nuclear weapons production facility that began operations in the early 1950's. Because of releases of hazardous substances to the environment, the federally owned property and adjacent offsite areas were placed on the CERCLA National Priorities List in 1989. The final remedy was selected in 2006. Engineered components of the remedy include four groundwater treatment systems that were installed before closure as CERCLA-accelerated actions. Two of the systems, the Mound Site Plume Treatment System and the East Trenches Plume Treatment System, remove low levels of volatile organic compounds using zero-valent iron media, thereby reducing the loading of volatile organic compounds in surface water resulting from the groundwater pathway. However, the zero-valent iron treatment does not reliably reduce all volatile organic compounds to consistently meet water quality goals. While adding additional zero-valent iron media capacity could improve volatile organic compound removal capability, installation of a solar powered air-stripper has proven an effective treatment optimization in further reducing volatile organic compound concentrations. A comparison of the air stripper to the alternative of adding additional zero-valent iron capacity to improve Mound Site Plume Treatment System and East Trenches Plume Treatment System treatment based on several key sustainable remediation aspects indicates the air stripper is also more 'environmentally friendly'. These key aspects include air pollutant emissions, water quality, waste management, transportation, and costs. (authors)
Michalski, Casey C.; DiSalvo, Rick; Boylan, John [Stoller LMS Team, 11025 Dover Street, Suite 1000, Westminster, CO 80021 (United States)] [Stoller LMS Team, 11025 Dover Street, Suite 1000, Westminster, CO 80021 (United States)
Compound specific 13C- and 18O-isotope analysis of organic aerosols
NASA Astrophysics Data System (ADS)
The wide ranging environmental and health effects of aerosols are increasingly coming to light. Various studies have further highlighted the complex nature of organic aerosols, particularly oxidised organics with multiple functional groups. Source apportionment studies on aerosols are crucial to successful implementation of mitigation strategies, but this is complicated by their complex nature. Ideally, individual components of aerosols can be tracked from their source to their atmospheric sink. However, chemical alteration and the formation of secondary aerosols in the atmosphere often preclude this direct tracking on a compound specific basis. Compound specific isotope analysis could overcome these problems, as certain processes and sources impose characteristic isotope ratios on products, which may be retained even after chemical alteration in the atmosphere. Progress has been made over the past decades in the separation and identification of individual compounds that contribute to aerosol formation. Compound separation by gas chromatography (GC), coupled to mass spectrometry (MS), has enabled identification of organic compounds of various sources. On the other hand, only few studies have addressed the isotopic composition of these compounds. For successful isotopic analysis of specific compounds, using GC coupled to isotope ratio MS (GC-irMS), several challenges must be faced that go beyond the requirements for GC-MS-based compound identification. Sample extraction and handling techniques must avoid isotope fractionation. This is especially important in the light of sample extraction by e.g. thermal desorption, which may impose a temperature-induced fractionation on complex organics. Furthermore, derivatisation techniques, necessary for adequate GC compound separation, must not lead to exchange reactions of the element of interest, which would alter the measured isotope ratio. So far most studies have dealt with carbon, and other elements have been neglected. Elements other than carbon may provide valuable additional information. Here we report on the development of methods for the analysis of stable carbon and oxygen isotope ratios of organic compounds in aerosols, through GC-combustion-irMS and GC-pyrolysis-irMS. We apply these analyses to environmental aerosol samples and samples of smog-chamber experiments, with the aim of identifying isotopic signatures of sources and pathways. We will pay special attention to derivatisation techniques - notably alternatives to the often-used trimethylsilyl derivatives in GC-pyrolysis-irMS for ?18O analysis - and to compound separation and identification. We present initial data of combined ?13C and ?18O studies on (secondary) organic aerosol samples, and their added value for source apportionment studies.
Blees, Jan; Saurer, Matthias; Siegwolf, Rolf T. W.; Dommen, Josef; Baltensperger, Urs
Neural Network Based on Quantum Chemistry for Predicting Melting Point of Organic Compounds
NASA Astrophysics Data System (ADS)
The melting points of organic compounds were estimated using a combined method that includes a backpropagation neural network and quantitative structure property relationship (QSPR) parameters in quantum chemistry. Eleven descriptors that reflect the intermolecular forces and molecular symmetry were used as input variables. QSPR parameters were calculated using molecular modeling and PM3 semi-empirical molecular orbital theories. A total of 260 compounds were used to train the network, which was developed using MatLab. Then, the melting points of 73 other compounds were predicted and results were compared to experimental data from the literature. The study shows that the chosen artificial neural network and the quantitative structure property relationships method present an excellent alternative for the estimation of the melting point of an organic compound, with average absolute deviation of 5%.
Lazz·s, Juan A.
Biodegradation of organic compounds in vadose zone and aquifer sediments
The microbial processes that occur in the subsurface under a typical Midwest agricultural soil were studied. A 26-m bore was installed in November of 1988 at a site of the Purdue University Agronomy Research Center. Aseptic collections of soil materials were made at 17 different depths. Physical analysis indicated that the site contained up to 14 different strata. The site materials were primarily glacial tills with a high carbonate content. The N,P, and organic C contents of sediments tended to decrease with depth. Ambient water content was generally less than the water content, which corresponds to a -0.3-bar equivalent. No pesticides were detected in slurry incubations of up to 128 days. The sorption of atrazine and metolachlor was correlated with the clay content of the sediments. Microbial biomass (determined by direct microscopic count, viable count, and phospholipid assay) in the tills was lower than in either the surface materials or the aquifer located at 25 m. The biodegradation of glucose and phenol occurred rapidly and without a lag in samples from the aquifer capillary fringe, saturated zone, and surface soils. In contrast, lag periods and smaller biodegradation rates were found in the till samples. Subsurface sediments are rich in microbial numbers and activity. The most active strata appear to be transmissive layers in the saturated zone. This implies that the availability of water may limit activity in the profile.
Konopka, A.; Turco, R. (Purdue Univ., West Lafayette, Indiana (USA))
Biodegradation of organic compounds in vadose zone and aquifer sediments.
The microbial processes that occur in the subsurface under a typical Midwest agricultural soil were studied. A 26-m bore was installed in November of 1988 at a site of the Purdue University Agronomy Research Center. Aseptic collections of soil materials were made at 17 different depths. Physical analysis indicated that the site contained up to 14 different strata. The site materials were primarily glacial tills with a high carbonate content. The N, P, and organic C contents of sediments tended to decrease with depth. Ambient water content was generally less than the water content, which corresponds to a -0.3-bar equivalent. No pesticides were detected in the samples, and degradation of added 14C-labeled pesticides (atrazine and metolachlor) was not detected in slurry incubations of up to 128 days. The sorption of atrazine and metolachlor was correlated with the clay content of the sediments. Microbial biomass (determined by direct microscopic count, viable count, and phospholipid assay) in the tills was lower than in either the surface materials or the aquifer located at 25 m. The biodegradation of glucose and phenol occurred rapidly and without a lag in samples from the aquifer capillary fringe, saturated zone, and surface soils. In contrast, lag periods and smaller biodegradation rates were found in the till samples. Subsurface sediments are rich in microbial numbers and activity. The most active strata appear to be transmissive layers in the saturated zone. This implies that the availability of water may limit activity in the profile. PMID:1768098
Konopka, A; Turco, R
Photosynthesis of organic compounds in the atmosphere of Jupiter
NASA Technical Reports Server (NTRS)
An efficient conversion of CH4 to hydrocarbons and HCN takes place when NH3 is photolysed in the presence of CH4, H2, and He using a 184.9 nm light source. The extent of NH3 decomposition after a 1 hr exposure was determined spectrophotometrically; CH4, N2, and C2 and C3 hydrocarbons were detected and analyzed by mass spectrometry. Photolysis of one molar equivalent of NH3 results in the loss of 0.84 molar equivalent of CH4, which apparently reacts with hot hydrogen atoms produced by photolysis. The 8% of the NH3 which is not converted to N2 probably is converted to organic amines and nitrile derivatives. The results indicate that NH3 photolysis is a highly probable mechanism for the conversion of methane to more complex hydrocarbons in the upper atmosphere of Jupiter, and predict the occurrence of HCN, NH2NH2, and higher hydrocarbons in the Jovian atmosphere above the NH3 clouds.
Ferris, J. P.; Chen, C. T.
On the nature of boron-carbon-nitrogen compounds synthesised from organic precursors
Three compounds were prepared through pyrolysis of organic precursors, namely pyridine-borane, piperazine-borane, poly(acrylonitrile)-BCl3, following the routes proposed in the literature for the synthesis of single-phase boron carbonitrides of various compositions. X-ray diffraction and MAS NMR studies performed on the powders obtained suggest that the resulting compounds are mixtures of amorphous boron and turbostratically distorted hexagonal boron nitride and graphite rather
Yuri G. Andreev; Torsten Lundstr÷m; Robin K. Harris; Se-Woung Oh; David C. Apperley; Derek P. Thompson
In the paper there is presented a methodology of analysis of headspace 52 volatile organic compounds in drinking water by the method of gas chromatography with the use of the chromatograph "Crystal 5000.2" with three detectors and automatic attachment Lab Hut 200N NT-200 for the preparation of the sample water and vapor phase input. The lower limit of detection for all compounds in the 2-10 times lower than that of the corresponding standard value. PMID:25051750
Sotnikov, E E; Zagaynov, V F; Mikhaylova, R I; Milochkin, D A; Ryzhova, I N; Kornilov, I O
The concentrations (C) of several semivolatile organic compounds (SOCs) in Norway spruce needles (N) and in the local humus horizon (O) of 25 remote Austrian forest sites were used to calculate an ecosystem-oriented partition coefficient needles\\/humus horizon (C{sub N}\\/C{sub O}). Between 66 and 78% of the compounds' variation of this quotient could be explained by each of the following physicochemical
Peter Weiss
Seven estrogenic compoundsŚestrone (E1), 17?-estradiol (E2), 17?-ethynylestradiol (EE2), diethylstilbestrol (DES), nonylphenol\\u000a (NP), octylphenol (OP), and bisphenol A (BPA)Śin sediments, surface water, pore water, and organisms were investigated and\\u000a estrogenic activities were estimated by examining estradiol equivalent (EEQ) concentrations in Yundang Lagoon of Xiamen. The\\u000a results showed that estrogenic compounds were present in all matrixes of interest: in surface water, ranging
Xian ZhangYajie; Yajie Gao; Qingzhao Li; Guoxin Li; Qinghai Guo; Changzhou Yan
Distribution of volatile organic compounds in a New Jersey coastal plain aquifer system
Samples for analysis of volatile organic compounds were collected from 315 wells in the Potomac-Raritan-Magothy aquifer system in southwestern New Jersey and a small adjacent area in Pennsylvania during 1980-82. Volatile organic compounds were detected in all three aquifer units of the Potomac-Raritan-Magoth aquifer system in the study area. Most of the contamination appears to be confined to the outcrop area at present. Low levels of contamination, however, were found downdip of the outcrop area in the upper and middle aquifers. Trichloroethylene, tetrachloroethylene, and benzene were the most frequently detected compounds. Differences in the areal distributions of light chlorinated hydrocarbons, such as trichloroethylene, and aromatic hydrocarbons, such as benzene, were noted and are probably due to differences in the uses of the compounds and the distribution patterns of potential contamination sources. The distribution patterns of volatile organic compounds differed greatly among the three aquifer units. The upper aquifer, which crops out mostly in less-developed areas, had the lowest percentage of wells with volatile organic compounds detected (10 percent of wells sampled). The concentrations in most wells in the upper aquifer which had detectable levels were less than 10 ??g/l. In the middle aquifer, which crops out beneath much of the urban and industrial area adjacent to the Delaware River, detectable levels of volatile organic compounds were found in 22 percent of wells sampled, and several wells contained concentrations above 100 ??g/l. The lower aquifer, which is confined beneath much of the outcrop area of the aquifer system, had the highest percentage of wells (28 percent) with detectable levels. This is probably due to (1) vertical leakage of contamination from the middle aquifer, and (2) the high percentage of wells tapping the lower aquifer in the most heavily developed areas of the outcrop.
Fusillo, T.V.; Hochreiter, J.J., Jr.; Lord, D.G.
Few studies were conducted on oxygenated volatile organic compounds (OVOC) because of problems encountered during the sampling/analyzing steps induced by water in sampled air. Consequently, there is a lack of knowledge of their spatial and temporal trends and their origins in ambient air. In this study, an analyzer consisted of a thermal desorber (TD) interfaced with a gas chromatograph (GC) and a flame ionization detector (FID) was developed for online measurements of 18 OVOC in ambient air including 4 alcohols, 6 aldehydes, 3 ketones, 3 ethers, 2 esters and 4 nitriles. The main difficulty was to overcome the humidity effect without loss of compounds. Water amount in the sampled air was reduced by the trap composition (two hydrophobic graphitized carbons-Carbopack B:Carbopack X), the trap temperature (held at 12.5 degrees C), by diluting (50:50) the sample with dry air before the preconcentration step and a trap purge with helium. Humidity management allowed the use of a polar CP-Lowox column in order to separate the polar compounds from the hydrocarbon/aromatic matrix. The safe sampling volume for the dual-sorbent trap 75 mg Carbopack X:5mg Carbopack B was found to 405 mL for ethanol by analyzing a standard mixture at a relative humidity of 80%. Detection limits ranging from 10 ppt for ETBE to 90 ppt for ethanol were obtained for 18 compounds for a sampling volume of 405 mL. Good repeatabilities were obtained at two levels of concentration (relative standard deviation <5%). The calibration (ranging from 0.5 to 10 ppb) was set up at three different levels of relative humidity to test the humidity effect on the response coefficients. Results showed that the response coefficients of all compounds were less affected by humidity except for those of ethanol and acetonitrile (decrease respectively of 30% and 20%). The target compounds analysis shows good reproducibility with response coefficient variability of less then 10% of the mean initial value of calibration for all the compounds. Hourly ambient air measurements were conducted in an urban site in order to test this method. On the basis of these measurements, ethanol, acetone and acetaldehyde have shown the highest concentration levels with an average of 2.10, 1.75 and 1.37 ppb respectively. The daily evolution of some OVOC, namely ethanol and acetaldehyde, was attributed to emissions from motor vehicles while acetone has a different temporal evolution that can be probably associated with remote sources. PMID:19863965
Roukos, J; Plaisance, H; Leonardis, T; Bates, M; Locoge, N
NASA Technical Reports Server (NTRS)
The influence of ammonia on the pyrolysis pattern of selected organic substances sorbed on an inorganic phase was investigated. The thermal degradation products were identified by gas chromatography-mass spectrometry. The feasibility of this technique was tested on a meteoritic sample. All substances examined react with ammonia at the pyrolysis temperature of 500 C, the major products being nitriles and heterocyclic compounds in which nitrogen was incorporated. Based on these results, a model for the non-equilibrium production of organic compounds on Jupiter is discussed. The investigation was performed in connection with the Viking lander molecular analysis. The results obtained indicate that the concentrations of ammonia in the retrorocket fuel exhaust would have been probably too small to produce significant changes in the Martian soil organic compounds if any were found.
Holzer, G.; Oro, J.
Mechanisms of Decomposition of Organic Compounds by Water Plasmas at Atmospheric Pressure
NASA Astrophysics Data System (ADS)
The decomposition of acetone, methanol, and ethanol by water plasmas at atmospheric pressure has been investigated using a direct current (DC) discharge. At torch powers of 910-1050 W and organic compound concentrations of 1-10 mol %, the decomposition rate of methanol was over 99.99%, while those of acetone and/or ethanol was 96-99%. The concentrations of H2 obtained were 65-71% in the effluent gas and the removal efficiencies of 90-95% for total organic carbon (TOC) were achieved in liquid effluent for any compounds by pyrolysis. Over 50 wt % carbon in acetone or ethanol fed as the plasma supporting gas was transformed into soot, while the soot formation was negligible during methanol decomposition. On the basis of the experimental results, the mechanisms of decomposition of organic compounds in water plasmas were proposed and the mechanism of soot formation was clarified for the first time.
Narengerile; Nishioka, Hiroshi; Watanabe, Takayuki
Absorption of organic compounds and organometallics on ceramic substrates for wear reduction
The concept of employing thermally stable compounds (that is, metal oxides) as high temperature vapor phase ceramic lubricants was investigated. A major part of this study was devoted to the development of various calorimetric and tribological techniques that could be used to determine interfacial reactions between thermally stable compounds and ceramic substrates such as zirconia and alumina. This interaction is pivotal in understanding the mechanism of high temperature lubricity. The approach consisted of selecting low sublimation temperature materials and measuring their thermodynamic interactions as vapors with the ceramic substrates. The materials studied included two easily sublimable organic compounds (that is, naphthalene and salicylic acid) and several organometallics (for example, copper phthalocyanine). Thermodynamic data such as heat of adsorption, packing density, and reversibility of the adsorption were obtained on some of these compounds and were related to wear characteristics. All of these compounds provided effective lubrication at room temperature. Copper phthalocyanine was an effective lubricant at temperatures up to 400 C.
Kennedy, P.J.; Agarwala, V.S. [Naval Air Warfare Center, Patuxent River, MD (United States)
Volatile organic compounds detected in the atmosphere of NASA's Biomass Production Chamber
NASA Technical Reports Server (NTRS)
Atmospheres of enclosed environments in which 20 m2 stands of wheat, potato, and lettuce were grown were characterized and quantified by gas chromatography-mass spectrometry. A large number (in excess of 90) of volatile organic compounds (VOCs) were identified in the chambers. Twenty eight VOC's were assumed to be of biogenic origin for these were not found in the chamber atmosphere when air samples were analyzed in the absence of plants. Some of the compounds found were unique to a single crop. For example, only 35% of the biogenic compounds detected in the wheat atmosphere were unique to wheat, while 36% were unique to potato and 26% were unique to lettuce. The number of compounds detected in the wheat (20 compounds) atmosphere was greater than that of potato (11) and lettuce (15) and concentration levels of biogenic and non-biogenic VOC's were similar.
Batten, J. H.; Stutte, G. W.; Wheeler, R. M.
Nucleic acids are useful for biomedical targeting and sensing applications in which the molecular environment is different from that of a dilute aqueous solution. In this study, the influence of various types of mixed solutions of water and water-soluble organic compounds on RNA was investigated by measuring the catalytic activity of the hammerhead ribozyme and the thermodynamic stability of an oligonucleotide duplex. The compounds with a net neutral charge, such as poly(ethylene glycol), small primary alcohols, amide compounds, and aprotic solvent molecules, added at high concentrations changed the ribozyme-catalyzed RNA cleavage rate, with the magnitude of the effect dependent on the NaCl concentration. These compounds also changed the thermodynamic stability of RNA base pairs of an oligonucleotide duplex and its dependence on the NaCl concentration. Specific interactions with RNA molecules and reduced water activity could account for the inhibiting effects on the ribozyme catalysis and destabilizing effects on the duplex stability. The salt concentration dependence data correlated with the dielectric constant, but not with water activity, viscosity, and the size of organic compounds. This observation suggests the significance of the dielectric constant effects on the RNA reactions under molecular crowding conditions created by organic compounds. PMID:25161873
Nakano, Shu-ichi; Kitagawa, Yuichi; Miyoshi, Daisuke; Sugimoto, Naoki
Mechanistic roles of soil humus and soil minerals and their contributions to soil sorption of nonionic organic compounds from aqueous and organic solutions are illustrated. Parathion and lindane are used as model solutes on two soils that differ greatly in their humic and mineral contents. In aqueous systems, observed sorptive characteristics suggest that solute partitioning into the soil-humic phase is the primary mechanism of soil uptake. By contrast, data obtained from organic solutions on dehydrated soil partitioning into humic phase and adsorption by soil minerals is influenced by the soil-moisture content and by the solvent medium from which the solute is sorbed. ?? 1985.
Chiou, C. T.; Shoup, T. D.; Porter, P. E.
Volatile organic compounds (VOCs) commonly detected in urban waters across the United States include gasoline-related compounds (e.g. toluene, xylene) and chlorinated compounds (e.g. chloroform, tetrachloroethane [PCE], trichloroethene [TCE]). Statistical analysis of observational data and results of modeling the partitioning of VOCs between air and water suggest that urban land surfaces are the primary nonpoint source of most VOCs. Urban air is a secondary nonpoint source, but could be an important source of the gasoline oxygenate methyl-tert butyl ether (MTBE). Surface waters in urban areas would most effectively be protected by controlling land-surface sources.
Lopes, T.J.; Bender, D.A.
Sorption capacity of ground tires for vapor-phase volatile organic compounds
Batch sorption tests were conducted to determine the partition coefficient of volatile organic compounds (VOCs) by ground tires. The partition coefficient in the vapor phase was estimated by dividing the partition coefficient in the aqueous phase by Henry`s law constant. Under a diluted condition VOCs are sorbed onto ground tires noncompetitively regardless of the existence of other VOCs. Polar compounds such as methylene chloride were less sorbed onto ground tires than nonpolar compounds. The vapor-phase partition coefficient was found to have a logarithmic relationship with the saturation vapor concentration. VOCs emitted from waste-water treatment facilities can be effectively retarded by the ground tires.
Kim, J.Y.; Park, J.K.; Edil, T.B. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Civil and Environmental Engineering; Jhung, J.K. [Won-Kwang Univ., Iri City (Korea, Republic of). Dept. of Urban Planning Engineering
Liquid-phase adsorption of organic compounds by granular activated carbon (GAC) and activated carbon fibers (ACFs) is investigated. Acetone, isopropyl alcohol (IPA), phenol, and tetrahydrofuran (THF) were employed as the model compounds for the present study. It is observed from the experimental results that adsorption of organic compounds by GAC and ACF is influenced by the BET (Brunauer-Emmett-Teller) surface area of adsorbent and the molecular weight, polarity, and solubility of the adsorbate. The adsorption characteristics of GAC and ACFs were found to differ rather significantly. In terms of the adsorption capacity of organic compounds, the time to reach equilibrium adsorption, and the time for complete desorption, ACFs have been observed to be considerably better than GAC. For the organic compounds tested here, the GAC adsorptions were shown to be represented well by the Langmuir isotherm while the ACF adsorption could be adequately described by the Langmuir or the Freundlich isotherm. Column adsorption tests indicated that the exhausted ACFs can be effectively regenerated by static in situ thermal desorption at 150 C, but the same regeneration conditions do not do as well for the exhausted GAC.
Lin, S.H.; Hsu, F.M. [Yuan Ze Inst. of Tech., Taoyuan (Taiwan, Province of China). Dept. of Chemical Engineering
Organic compounds in hot-water-soluble fractions from water repellent soils
NASA Astrophysics Data System (ADS)
Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes < C20) were extracted through desorption of complex colloids stabilized as micelles in dissolved organic carbon (DOC). Water repellency was completely eliminated by hot water under high pressure. The molecular composition of HWSC can play a critical role in stabilization and destabilization of soil organic matter (SOM), particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds
Atanassova, Irena; Doerr, Stefan
NASA Astrophysics Data System (ADS)
Groundwater pollution remains one of the major environmental and health concerns. A thorough understanding of sources, sinks and transformation processes of groundwater contaminants is needed to improve risk management evaluation, and to design efficient remediation and water treatment strategies. Isotopic tools provide unique information for an in-depth understanding of the fate of organic chemicals in the environment. During the last decades compound specific isotope analysis (CSIA) of complex mixtures, using gas chromatography-isotope ratio mass spectrometry (GC-IRMS), has gained popularity for the characterization and risk assessment of hazardous waste sites and for isotope forensics of organic contaminants. Multi-element isotope fingerprinting of organic substances provides a more robust framework for interpretation than the isotope analysis of only one element. One major challenge for application of CSIA is the analysis of trace levels of organic compounds in environmental matrices. It is necessary to inject 1 nmol carbon or 8 nmol hydrogen on column, to obtain an accurate and precise measurement of the isotope ratios, which is between two and three orders of magnitude larger than the amount of compound needed for conventional analysis of compound concentrations. Therefore, efficient extraction and pre-concentration techniques have to be integrated with GC-IRMS. Further research is urgently needed in this field, to evaluate the potential of novel and environmental-friendly sample pre-treatment techniques for CSIA to lower the detection limits and extending environmental applications. In this study, the novel coupling of a headspace autosampler (HS) with a programmed temperature vaporizer (PTV), allowing large volume injection of headspace samples, is proposed to improve the sensitivity of CSIA. This automatic, fast and solvent free strategy provides a significant increase on the sensitivity of GC-based methods maintaining the simple headspace instrumentation. The method was developed for the multi-element isotope analysis (carbon and hydrogen) of priority volatile organic groundwater pollutants (methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene and o-xylene (BTEX)), and for carbon isotope analysis of chlorinated benzenes and ethenes. The extraction and injection conditions were optimized in terms of maximum sensitivity and minimum isotope effects. During the injection of the headspace sample, the liner is maintained at a low temperature, such that the compounds are retained in a hydrophobic insert packing while the water vapor is eliminated through the split line. With the optimized conditions, it was possible to inject up to 5mL headspace sample with no significant carbon or hydrogen isotopic effects except for the most hydrophobic substance (MTBE), which was subject to a small and reproducible isotope fractionation for hydrogen. The increment on method sensitivity was at least 20 fold in comparison with conventional static headspace analysis. The environmental applicability of the HS-PTV-GC-IRMS method was evaluated by the analysis of groundwater samples from different contaminated field sites, containing BTEX and chlorinated volatile organic contaminants in the low Ąg/L range. The results obtained demonstrate that this pre-concentration technique is highly promising to enhance the limits of detection of current CSIA methods and broaden its possibilities.
Herrero-MartĒn, Sara; Nijenhuis, Ivonne; Schmidt, Marie; Wolfram, Diana; Richnow, Hans. H.; Gehre, Matthias
Thermal engine driven heat pump for recovery of volatile organic compounds
The present invention relates to a method and apparatus for separating volatile organic compounds from a stream of process gas. An internal combustion engine drives a plurality of refrigeration systems, an electrical generator and an air compressor. The exhaust of the internal combustion engine drives an inert gas subsystem and a heater for the gas. A water jacket captures waste heat from the internal combustion engine and drives a second heater for the gas and possibly an additional refrigeration system for the supply of chilled water. The refrigeration systems mechanically driven by the internal combustion engine effect the precipitation of volatile organic compounds from the stream of gas.
Drake, Richard L. (Schenectady, NY)
Deuterium enrichment by selective photoinduced dissociation of a multihalogenated organic compound
A method for deuterium enrichment by photoinduced dissociation which uses as the deuterium source a multihalogenated organic compound selected from the group consisting of a dihalomethane, a trihalomethane, a 1,2-dihaloethene, a trihaloethene, a tetrahaloethane and a pentahaloethane. The multihalogenated organic compound is subjected to intense infrared radiation at a preselected wavelength to selectively excite and thereby induce dissociation of substantially only those molecules containing deuterium to provide a deuterium enriched dissociation product. The deuterium enriched product may be combusted with oxygen to provide deuterium enriched water. The deuterium depleted undissociated molecules may be redeuterated by treatment with a deuterium source such as water.
Marling, John B. (Livermore, CA); Herman, Irving P. (Oakland, CA)
Industrial wastewater survey samples were analyzed for organic compounds not identified by spectrum matching. Analysis of the samples proceeded from an initial packed column GC/MS analysis for Priority Pollutants, through computerized spectrum matching for other compounds, to the...
Semi-volatile compounds present special analytical challenges not met by conventional methods for analysis of ambient particulate matter (PM). Accurate quantification of PM-associated organic compounds requires validation of the laboratory procedures for recovery over a wide v...
The magnitudes, distributions, controlling processes and uncertainties associated with North American natural emissions of oxidant precursors are reviewed. Natural emissions are repsonsible for a major portion of the compounds, including non-methane volatile organic compounds (N...
Unidentified Organic Compounds. For target analytes, standards are purchased, extraction and clean-up procedures are optimized, and mass spectra and retention times for the chromatographic separation are obtained for comparison to the target compounds in environmental sample ...
Long-term extractable compounds screening in surface water to prevent accidental organic pollution.
The organic composition of surface water (a canal network fed by the Rh¶ne river, France) was studied over a period of 3 years. The spatial and temporal evolution of extractable organic compounds was determined by monitoring the water of the principal canal (72 km long) over 3 years and 139 compounds were detected at the ng/l concentration level. Using these data the organic fingerprints were constructed for every sampling point. These fingerprints depend on sampling dates and climatic conditions. Analysed compounds were classified according to two criteria: appearance frequency and average concentrations. Three classes were defined, corresponding to: organic background, occasional component and chronic component. The preponderance of organic background, corresponding to the natural organic fingerprint, indicates the high quality of this surface water. The proportion of some chemical families were calculated in order to assess their anthropogenic impact on the water. This study produced a databank which was useful as a reference for the monitoring and checking of water quality. Any anomaly disturbing organic fingerprints can thus rapidly be detected and identified by comparison with the databank, making better crisis management possible. PMID:9260312
Deroux, J M; Gonzalez, C; Le Cloirec, P; Roumagnac, A
Effects of organic compounds, water content and clay on the water repellency of a model sandy soil
Soil water repellency is related to organic matter and clay, and varies non-linearly with soil water content. The purpose of this study is to assess the combined effects of organic compounds, water content and clays on water repellency of a model sandy soil under wetting and drying processes. Hydrophobic stearic acid and hydrophilic glucomannan were used as the organic compounds,
D. A. L. Leelamanie; Jutaro Karube
A qualitative procedure of purified DNA/RNA co-extraction from complex organic matter, used as biofilter support for removing volatile organic compounds, was set up and applied to detect xylene monooxygenase gene expression by RT-PCR. A DNA/RNA extraction protocol based on a combination of sample lyophilization pre-treatment and CTAB--phenol/chloroform extraction procedure was optimized for the recovery of purified nucleic acids [100-500 ng DNA (10 kb) and 0.5-2 microg of rRNA 16S from 100 mg matrix]. PCR and RT-PCR protocols were established to detect xylene monooxygenase gene expression starting from differentially induced organic matrices obtained by biofiltration technology. This work allowed the microbial degradation activities in heterogeneous organic solid media to be studied and suggests a rapid method to follow specific biological activities during solid and/or semisolid organic substrates biotransformation. PMID:17016674
Tell, Gianluca; Paron, Igor; Civilini, Marcello
High-molecular-weight organic compounds such as humic acids and/or fulvic acids that are naturally mobilized from lignite beds into untreated drinking-water supplies were suggested as one possible cause of Balkan endemic nephropathy (BEN) and cancer of the renal pelvis. A lab investigation was undertaken in order to assess the nephrotoxic potential of such organic compounds using an in vitro tissue culture model. Because of the infeasibility of exposing kidney tissue to low concentrations of organics for years in the lab, tangential flow ultrafiltration was employed to hyperconcentrate samples suitable for discerning effects in the short time frames necessitated by tissue culture systems. Effects on HK-2 kidney cells were measured using two different cell proliferation assays (MTT and alamarBlue). Results demonstrated that exposure of kidney tissue to high-molecular-weight organics produced excess cell death or proliferation depending on concentration and duration of exposure. Copyright ?? Taylor & Francis Group, LLC.
Bunnell, J.E.; Tatu, C.A.; Lerch, H.E.; Orem, W.H.; Pavlovic, N.
At the Hanford Site organic compounds were measured in tank supernate simulant solutions during FY 1995. This solubility information will be used to determine if these organic salts could exist in solid phases (saltcake or sludges) in the waste where they might react violently with the nitrate or nitrite salts present in the tanks. Solubilities of sodium glycolate, succinate, and caproate salts; iron and aluminum and butylphosphate salts; and aluminum oxalate were measured in simulated waste supernate solutions at 25 {degree}C, 30 {degree}C, 40 {degree}C, and 50 {degree}C. The organic compounds were selected because they are expected to exist in relatively high concentrations in the tanks. The solubilities of sodium glycolate, succinate, caproate, and butylphosphate in HLW tank supernate solutions were high over the temperature and sodium hydroxide concentration ranges expected in the tanks. High solubilities will prevent solid sodium salts of these organic acids from precipitating from tank supernate solutions. The total organic carbon concentrations (YOC) of actual tank supernates are generally much lower than the TOC ranges for simulated supernate solutions saturated (at the solubility limit) with the organic salts. This is so even if all the dissolved carbon in a given tank and supernate is due to only one of these eight soluble compounds (an unlikely situation). Metal ion complexes of and butylphosphate and oxalate in supernate solutions were not stable in the presence of the hydroxide concentrations expected in most tanks. Iron and aluminum dibutylphosphate compounds reacted with hydroxide to form soluble sodium dibutylphosphate and precipitated iron and aluminum hydroxides. Aluminum oxalate complexes were also not stable in the basic simulated supernate solutions. Solubilities of all the organic salts decrease with increasing sodium hydroxide concentration because of the common ion effect of Na+. Increasing temperatures raised the solubilities of the organic salts, especially the succinate and caproate salts.
Barney, G.S.
The purposes of this work were to: (1) develop preliminary operating data such as expected concentration endpoints for flow sheet development and evaporator design, and (2) examine the regulatory off-gas emission impacts from the evaporation of relatively organic-rich Hanford Tank 241-AN-107 Envelope C waste simulant containing 14 volatile, semi-volatile and pesticide organic compounds potentially present in actual Hanford RPP waste.
Saito, H.H.
Photocatalytic degradation of nitrogen-containing organic compounds over TiO 2
Economic and environmentally benign technology to remove organic pollutants is highly desired for the sustainable water management to meet the growing clean water demand. This review focuses on the progress of nitrogen-containing organic compounds removal in wastewater by TiO2 photocatalytic degradation during the past 15 years and summarizes the important factors affecting the relevant photocatalytic activity. Photodegradation performance of nitrogen-containing
Jieying Jing; Manhong Liu; Vicki L. Colvin; Wenying Li; William W. Yu
Substrate-induced volatile organic compound emissions from compost-amended soils
The agronomic effects of composts, mineral fertiliser and combinations thereof on chemical, biological and physiological soil\\u000a properties have been studied in an 18-year field experiment. The present study aimed at tracing treatment effects by evaluating\\u000a the volatile organic compound (VOC) emission of the differently treated soils: non-amended control, nitrogen fertilisation\\u000a and composts (produced from organic waste and sewage sludge, respectively)
Martin S. A. Seewald; Wolfgang Singer; Brigitte A. Knapp; Ingrid H. Franke-Whittle; Armin Hansel; Heribert Insam
We undertook a study in Albany, New York, to investigate whether volatile organic compounds (VOCs) were measurable in the blood and in the breathing-zone air of people exposed to gasoline fumes and automotive exhaust. We sampled blood of 40 subjects, placed organic vapor badges on 40 subjects, and obtained personal breathing-zone samples from 24 subjects. We limited this analysis to 19 subjects who wore the organic vapor badges for at least 5 h. VOC levels, as determined by the organic vapor badges, were highly correlated with blood levels of these same compounds. Using detection in blood as the gold standard, we found the badges to be more sensitive than conventional charcoal tube samples in detecting low levels of methyl tert-butyl ether (0.60 vs 0.08), toluene (0.95 vs 0.64), and o-xylene (0.85 vs 0.64). In this study, organic vapor badges provided data on VOC exposure that correlated with blood assay results. These organic vapor badges might provide a convenient means of determining human exposure to VOCs in epidemiologic studies. PMID:7622282
Mannino, D M; Schreiber, J; Aldous, K; Ashley, D; Moolenaar, R; Almaguer, D
An experimental design was applied for the optimization of extraction and clean-up processes of phenolic compounds and organic acids from white ōVinho Verdeö grapes. The developed analytical method consisted in two steps: first a solid¢liquid extraction of both phenolic compounds and organic acids and then a clean-up step using solid-phase extraction (SPE). Afterwards, phenolic compounds and organic acids were determined
M. S. Dopico-GarcĒa; P. ValentŃo; L. Guerra; P. B. Andrade; R. M. Seabra
Carbonaceous meteorites as a source of sugar-related organic compounds for the early Earth.
The much-studied Murchison meteorite is generally used as the standard reference for organic compounds in extraterrestrial material. Amino acids and other organic compounds important in contemporary biochemistry are thought to have been delivered to the early Earth by asteroids and comets, where they may have played a role in the origin of life. Polyhydroxylated compounds (polyols) such as sugars, sugar alcohols and sugar acids are vital to all known lifeforms-they are components of nucleic acids (RNA, DNA), cell membranes and also act as energy sources. But there has hitherto been no conclusive evidence for the existence of polyols in meteorites, leaving a gap in our understanding of the origins of biologically important organic compounds on Earth. Here we report that a variety of polyols are present in, and indigenous to, the Murchison and Murray meteorites in amounts comparable to amino acids. Analyses of water extracts indicate that extraterrestrial processes including photolysis and formaldehyde chemistry could account for the observed compounds. We conclude from this that polyols were present on the early Earth and therefore at least available for incorporation into the first forms of life. PMID:11780054
Cooper, G; Kimmich, N; Belisle, W; Sarinana, J; Brabham, K; Garrel, L
PowerPoint presentation summarizing method development research involving the persistent perfluorinated organic compounds. Review of data indicating widespread distribution of these materials and the potential for toxicity....
PowerPoint presentation summarizing method development research involving the persistent perfluorinated organic compounds. Review of data indicating widespread distribution of these materials and the potential for toxicity....
The Enantiomeric Ratios of Meteoritic Organic Compounds: Their Possible Roles in the Origin of Life
NASA Technical Reports Server (NTRS)
This talk will give an overview of the enantiomer (mirror-image) ratios of organic compounds in meteorites and also describe the results of the present work in my lab. The primary focus will be on sugar derivatives (sugar acids) of carbonaceous meteorites. Our work begins to address questions associated with chirality, i.e., the origins of homochirality. On Earth, biological monomers (amino acids, sugars, etc.) are usually found with one of the enantiomers more abundant than the other. However, biological polymers (proteins, nucleic acids, etc.) are only composed of one enantiomer i.e., they are homochiral. There are hints in meteorites that some organic molecules may also exist in homochiral forms. The talk will address questions such as: did extraterrestrial sources aid in the beginning of this homochirality? Do the increasing size and apparent enantiomer excesses of some meteoritic compounds also extend to larger meteoritic compounds and polymers?
Cooper, George
A solid phase fugacity meter was used to investigate the transport kinetics and steady-state partitioning of semivolatile organic compounds between the gas phase and leaves of Lolium multiflorum (Welsh ray grass). The grass air partition coefficients determined for grass concentrations ranging over several orders of magnitude were in good agreement with each other for each compound. The average partition coefficients correlated well with the octanol/air partition coefficients. The kinetic behavior was described using a two-compartment model consisting of a small surface compartment and a large interior reservoir compartment. The results of this study support the hypothesis that vegetation plays an important role in the fate of lipophilic organic compounds in the terrestrial environment.
Tolls, J.; McLachlan, M.S. [Univ. of Bayreuth (Germany)
Concentrations of 26 volatile organic compounds (VOCs) were measured continuously for 7 days during winter in 96 homes in Quebec City, Canada. Characteristics of the houses and activities of the occupants were documented through detailed questionnaires filled out by one adult per household. VOCs were sampled using passive monitors and analyzed by gas chromatography-mass selective detector (GC-MSD). Results indicate contributions
Marie-╚ve Hķroux; Denis Gauvin; Nicolas L. Gilbert; Mireille Guay; GeneviĶve Dupuis; Michel Legris; BenoŅt Lķvesque
As part of a Superfund Innovative Technology Evaluation (SITE) field program, a Fourier transform infrared (FTIR) spectrometer vas used to make open path measurements of volatile organic compounds in the New Castle, Delaware, area. he SITE program requires that new technologies b...
Recovery of 8 volatile organic compounds (VOCs) from dry soils, each fortified at 800 ng/g soil, was studied in relation to the extraction method and time of extraction. Extraction procedures studied on desiccator-dried soils were modifications of EPA low-and high-level purge-and...
Our objective was to evaluate the stability and extractability of volatile organic compound (VOCs) when fortified on dry soils and stored in sealed ampules. Two desiccator-dried soils were fortified with eight neat VOCs, benzene,toluene,ethylbenzene,o-xylene,1,1,1-trichloroethane...
The emissions from a water wall mass fired municipal waste incinerator and a refuse derived fuel (RDF) fired incinerator were sampled for chlorinated organic compounds and hydrochloric acid (HCl). The sampling was performed to evaluate the extractive sampling methods used to meas...
Two reactions which are important to coal liquefaction include intermolecular transfer and the elimination of two hydrogen atoms. We have designed several model reactions to probe the viability of several hydrogen transfer and elimination pathways. This report described studies on these reactions using organic model compounds.
Suria, S.
Enthalpies of Sublimation of Organic and Organometallic Compounds. James S. Chickosa...
Enthalpies of Sublimation of Organic and Organometallic Compounds. 1910┬Ł2001 James S. Chickosa February 2002; published 7 June 2002 A compendium of sublimation enthalpies, published within the period for the sublimation enthalpies from the temperature of measurement to the standard reference temperature, 298.15 K
Chickos, James S.
Simultaneous microdetermination of iodine and chlorine or iodine and bromine in organic compounds
Summary A micromethod for simultaneous determination of iodine and chlorine or iodine and bromine in organic compounds is described. After combustion in an oxygen-filled separatory funnel containing acidic sodium nitrite, iodine is produced, separated by carbon tetrachloride and oxidised with bromine water to iodate. After removal of carbon tetrachloride and excess bromine, the iodate is determined iodometrically. The aqueous combustion
S. S. M. Hassan; M. B. Elsayes
Simultaneous direct microdetermination of chlorine, bromine and iodine in organic compounds
Summary A new method for the separate microdetermination of chlorine, bromine and iodine present together in an organic compound is described. A 3¢5 mg sample is burnt in an oxygen flask and the products are absorbed in an alkaline solution of hydrazine. Iodide with dichromate and then bromide with permanganate are oxidized to free halogen which is removed, absorbed in
Antonio Campiglio
Most organic compounds are not found in mass spectral libraries and cannot be easily identified from low resolution mass spectra. Ion Composition Elucidation (ICE) utilizes selected ion recording with a double focusing mass spectrometer in a new way to determine exact mas...
The role of boundary layers in the removal of volatile organic compounds from water by pervaporation
Removal of volatile organic compounds (VOCs) from water by pervaporation is dominated by boundary layer effects (concentration polarization). A simple analysis shows these effects to be much more severe in pervaporation than in ultrafiltration and reverse osmosis because of the high VOC enrichment that can be obtained by pervaporation. In pervaporation, the concentration of solute at the membrane surface is
J. G. Wijmans; A. L. Athayde; R. Daniels; J. H. Ly; H. D. Kamaruddin; I. Pinnau
NASA Astrophysics Data System (ADS)
Vibrational (e.g., ATR FTIR and Raman) and nuclear magnetic resonance (NMR) spectroscopies provide excellent information on the bonding and atomic environment of adsorbed organic compounds. However, interpretation of observed spectra collected for organic compounds adsorbed onto mineral surfaces can be complicated by the lack of comparable analogs of known structure and uncertainties about the mineral surface structure. Quantum mechanical calculations provide a method for testing interpretations of observed spectra because models can be built to mimic predicted structures, and the results are independent of experimental parameters (i.e., no fitting to data is necessary). In this talk, methodologies for modeling vibrational frequencies and NMR chemical shifts of adsorbed organic compounds are discussed. Examples included salicylic acid (as an analog for important binding functional groups in humic acids) adsorbed onto aluminum oxides, organic phosphoryl compounds that represent herbicides and bacterial extracellular polymeric substances (EPS), and ofloxacin (a common agricultural antibiotic). The combination of the ability of quantum mechanical calculations to predict structures, spectroscopic parameters and energetics of adsorption with experimental data on these same properties allows for more definitive construction of surface complex models.
Kubicki, J. D.
Effects of selected organic compounds on radionuclide adsorption to sediments in freshwater systems
The roles of selected organic compounds on K/sub d/ (distribution coefficients) values of radionuclides in laboratory sediment-water systems was evaluated. The radionuclides /sup 57/Co, /sup 106/Ru, /sup 137/Cs, and /sup 241/Am were used as tracers in the experiments. Five organic compounds: 1)1-nitroso-2-naphthol; 2)1,10-phenanthroline; 3)acetic acid; 4)salicylic acid; and 5)EDTA were evaluated for their effects on the distribution coefficients of the four radionuclides. The results of the study confirmed that organic compounds can affect sediment-water distribution coefficients of radionuclides, however, the magnitudes and directions of these K/sub d/ effects are functions of both the physico-chemical properties of the radionuclide and the specific interactions of the radionuclide and organic compound within a given sediment-water system. The results emphasize the complex variety of interacting factors that can effect sediment-water distributions of radionuclides. Therefore, it is necessary in any adsorption study to characterize, as fully as possible, the chemical parameters of water and sediment that can contribute to the eventual results in any given system. (JMT)
Clayton, J.R. Jr.; Sibley, T.H.; Schell, W.R.
Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 ĄgCg?1 ...
There are increasing concerns about indoor volatile organic compounds (VOCs) regarding their health effects and frequent occurrence. Adsorption using granular activated carbon (GAC) is a safe methodology for removing VOCs from indoor air. Although GAC has been widely used to remove VOCs from indoor air, the use of activated carbon fiber cloth (ACFC) is a promising substitute to the conventional
Meng Yao; Qiong Zhang; David W. Hand; David Perram; Roy Taylor; Mridul Gautam; Nigel Clark; Thomas Spencer; Daniel Carder; Thomas Balon; Paul Moynihan; Joshua Fu; David Streets; Carey Jang; Jiming Hao; Kebin He; Litao Wang; Qiang Zhang; Jan Paca; Martin Halecky; Mark Fitch; David Williams; William Potter; William Clarkson; Dee Sanders; John Stevens; Hazem El-Zanan; Barbara Zielinska; Lynn Mazzoleni; D. Hansen; Hyun-Sun Kim; Seung-Muk Yi; Eric Edgerton; Gary Casuccio; Rick Saylor; Traci Lersch; Benjamin Hartsell; John Jansen; Roger Wayson; Gregg Fleming; Ralph Iovinelli; Hans Grimm; Delbert Eatough
An extraction technique, involving homogenization of a sediment sample with dichloromethane at dual pH and phase separation by centrifugation, was used in the determination of 51 organic priority pollutants as identified in a standard reference sediment sample. These compounds we...
Volatile organic compound (VOC) abatement regulations in Southern California have driven the development of a vapor processing plant that is suitable for the bunkering barges it serves. A system was required that could be mounted on board existing bunker barges, could be operated by existing tankerman crews and had no need for additional pumps and blowers, which would require additional
Kevin J. Reynolds; Foss Maritime
Regional Analysis of Nonmethane Volatile Organic Compounds in the Lower Troposphere of the Southeast
with winter seasonal values below the level of detection. Isoprene was observed to be the most dominant NMOC of volatile organic compounds VOCs and nitrogen oxides (NOx NO2 NO) as tropospheric O3 precursors have been on the hydrocarbon levels at these rural sites. The data for the sites show similar seasonal patterns for total NMOC
Aneja, Viney P.
Laboratory determined thermal decomposition profiles and kinetic data for a list of 20 selected hazardous organic compounds are reported. All data were obtained in flowing air at mean gas-phase, high-temperature zone residence times ranging from one to six seconds. The extrapolat...
Selecting nitrobenzene as a model compound, the assistance of magnesium cations on ozon ation of refractory organic pollutant was investigated in pure water background. It is interesting to find that the presence of magnesium cations with a level of tens of millimoles per liter can obviously increase the degradation and mineralization efficiency of nitrobenzene compared with the case of ozonation
Ming-Hao Sui; Li Sheng; Jun Ma; Feng Tian; Ke-Xiang Lu
Emissions of oxygenated volatile organic compounds (OVOC) from several plant species were measured in continuously stirred tank reactors (CSTR). High emission pulses of OVOCs were observed when plants were exposed to stress. Absolute emission rates were highly variable ranging up to 10-13 mol Ę cm-2 Ę s-1. The temporal shape of these emissions was described by a formalism similar to
A. C. Heiden; K. Kobel; C. Langebartels; G. Schuh-Thomas; J. Wildt
Ambient air spiked with 1-10 ppbv concentrations of 41 toxic volatile organic compounds (VOCs) listed in U.S. Environmental Protection Agency (EPA) Compendium Method TO-14A was monitored using solid sorbents for sample collection and a Varian Saturn 2000 ion trap mass spectrome...
Concentrations of 53 volatile organic compounds (VOCs) are reported from four locations near the World Trade Center (WTC) (New York, USA) complex for canister samples collected from September 2001 through January 2002. Across the four sampling sites, mean concentrations ranged from 94.5 to 219?gm-3 for total VOCs. The highest mean concentrations for individual VOCs at any site were for ethane
David A. Olson; Gary A. Norris; Robert L. Seila; Matthew S. Landis; Alan F. Vette
Spatial Gradients and Source Apportionment of Volatile Organic Compounds Near Roadways
Concentrations of 55 volatile organic compounds (VOCs) are reported near a highway in Raleigh, NC (traffic volume of approximately 125,000 vehicles/day). Levels of VOCs generally decreased exponentially with perpendicular distance from the roadway 10-100m). The EPA Chemical Mass ...
A study of volatile organic compounds evolved from the decaying human body
Two men were found dead near the island of Samos, Greece, in the Mediterranean sea. The estimated time of death for both victims was 3¢4 weeks. Autopsy revealed no remarkable external injuries or acute poisoning. The exact cause of death remained unclear because the bodies had advanced decomposition. Volatile organic compounds (VOCs) evolved from these two corpses were determined by
M. Statheropoulos; C. Spiliopoulou; A. Agapiou