1 μl of liquid analytes was dissolved in 0.9 ml of acetonitrile. 1.5 mg of solid analytes was dissolved in 1 ml of acetonitrile. Analyses were carried out using Shimadzu GCMS-TQ8040 (Shimadzu). We mixed up to 10 compounds in one solution (partial concentrations are given above), and in those cases where the peak annotation was not absolutely unambiguous, we remeasured solutions of individual compounds. We measured all compounds using three columns with IL (see below), as well as HP-5 (30 m, 0.32 mm×0.25 μm, Agilent) and SH-Stabilwax (30 m, 0.25 mm×0.1 μm, Shimadzu) columns. The numbers in brackets denote the length, inner diameter of the column, and thickness of the SP layer, respectively. Measurements were made for standard polar and non-polar SP in order to obtain spectra for comparison, as well as to verify that the observed RI match the reference ones. 0.5 μl of the liquid solution was injected to the GC-MS instrument; in order to measure n-alkane RI, a mixture of n-alkanes was added to the sample solution.