Trace determination of volatile organic compounds in water by enrichment in ultra-thick-film capillary traps and gas chromatography

The technique by which volatile organic compounds are enriched in coated or uncoated capillaries, and desorbed for qualitative gas chromatographic determination, was adapted for quantitative analysis by using a 1-m length of ultra-thick-film trap (145-μm film thickness) to extract the volatile compounds flowing through the trap at 0°C. The trapped volatiles are thermally desorbed, cryotrapped on an analytical capillary column and determined by gas chromatography with flame ionization detection. It was found that analytes such as dichloromethane and chloroform did not break through when sampling 1 ml of water. With this sampling volume, relative standard deviations well below ca. 2% and ca. 2–4% were obtained for most of the analytes at levels of 1 ppm (v/v) and 1 ppb (v/v), respectively.