preparation of carbotrap/silica composite for needle trap field sampling of halogenated volatile organic compounds followed by gas chromatography/mass spectrometry determination

A needle trap device (ntd) was packed with carbotrap/silica composite sorbent and applied for field sampling of halogenated volatile organic compounds (hvocs) followed by gas chromatography/mass spectrometry (gc/ms) separation and determination. carbotrap b, as a highly pure surface sorbent, was prepared using sol-gel method to improve its surface properties for adsorption/desorption of the target analytes. the effects of important experimental variables on the sampling and determination of trichloroethylene (thrce) and tetrachloroethylene (tetce) using the proposed ntd-gc/ms strategy were evaluated and optimized. the results showed that sampling temperature and relative humidity interfered with sampling efficiency of the developed method and peak area responses of the analytes decreased with increasing temperature and relative humidity. the peak areas of the analytes increased with raising desorption temperature from 180 to 250 °c, and increasing desorption time from 1 to 3 min. the carryover experiments showed that the carryover effect disappeared after 3 min of desorption time. the limits of detection (lods) and limits of quantitation (loqs) of the analytes were in the range 0.01–0.03 and 0.05–0.09, respectively. the results indicated that the developed ntd-gc/ms procedure can be used as a technology with high sensitivity for the field sampling and determination of hvocs.