Capillary extractors for “negligible depletion” sampling of benzene, toluene, ethylbenzene and xylenes by in-tube solid-phase microextraction

The suitability of “capillary extractors” is demonstrated for the “negligible depletion” extraction of benzene, toluene, ethylbenzene and xylenes in a clean-water matrix. Extraction set-up and major extractor parameters (length, internal diameter, and film thickness) are chosen to allow rugged analysis by GC with flame ionization detection. With the selected negligible extraction conditions, the efficiency for every consecutive extraction is about 2–3% of the dissolved amount.