The instrumental analysis should monitor functional groups of POEA metabolites. MS detection can use functional group-specific neutral loss from the parent ion to identify a chemical's product ion transitions. As class-diagnostic product ions (Prod) or neutral losses (NL) are often created by chemical properties, these approaches allow profiling or screening for discovery analysis. We used this method to find out whether a sample contained any known or new POEA and to improve chromatographic separation. As an example, we have observed that the NL scan of m/z 282.0 and a Prod scan of m/z 400.6 in positive mode detects homologues of a POEA with ten to fourteen EO units by following the fragmentation pattern (Fig. ). Using this technology, we have developed a method for urinary POEA biomarker measurement (Fig. ). We achieved chromatographic separation of all homologues of selected POEA [POE (2), POE (5), and POE (15)] on a Betasil C18 LC column under a under a 10-minute gradient elution with mobile phase A containing 0.1% formic acid in water and mobile phase B containing 0.1% formic acid in acetonitrile (Fig. ). In preliminary studies, we observed a higher detection rate and levels of POE (2) compared to POE with longer chains or glyphosate or its metabolite aminomethylphosphonic acid (AMPA) in urine from a general population sample (Fig ), similar to findings in urine from an animal study. Exposure assessment to POEA is a public health need. Formulation of GBHs varies widely globally and even among those from the same manufacturer; their exact compositions are often unknown. Regulatory posture treats herbicide co-formulants as inert, so their presence in the environment, food, feed, animals and people is not formally monitored. Methods are needed to monitor residues in the food supply, as well as people, cattle, and other animals. In order to make sure that herbicide exposure does not have "unacceptable adverse effects," guideline values are derived from toxicity tests. Usually, the only information provided on product labels is concentration of an active ingredient. Recognizing these differences and figuring out their effect on GBH risk profiles is important. More studies are urgently needed on the potential contribution of co-formulants to GBHs to human exposure and to the toxicity of herbicides.