Analysis of Unmetabolized VOCs in Urine by Headspace Solid‐Phase Microcolumn Extraction

Exposure to high concentrations of volatile organic compounds (VOCs) can lead to adverse health effects. Among VOCs, benzene is a haematotoxic substance that can induce acute myleoid leukaemia in occupational exposure, and has been classified as a carcinogen in humans by the International Agency for Research on Cancer. Other VOCs, trihalomethanes (chloroform, bromodichloromethane and dibromochloromethane) were detected in the urine of all persons attending a swimming pool, where the water was treated with chlorine. Tetrachloroethylene in urine of drycleaners has been used as biologic index of low-level exposure. A significant correlation was found between the environmental t r ich loroe thylene concent ra t ion and ur inary trichloroethylene concentration. BTEX (benzene, toluene, ethylbenzene and isomeric xylenes) have attained great relevance as ubiquitous pollutants of outdoor human environments and analysis of urine has been used for the evaluation of environmental exposures to these compounds. Similarly, styrene analysis in urine is a useful biological indicator of exposed workers. Generally, VOCs analyses involve either static or dynamic headspace (HS) sampling, followed by gas chromatographic separation and flame ionization (GCFID) or mass spectrometric detection (GC-MS). In the majority of the newly developed HS sample preparation techniques, the recovery of volatiles is based on sorption in a solid phase . Among them, equilibrium sampling techniques such as HS solid-phase microextraction, HS sorptive extraction , and a non-equilibrium sampling technique, HS solid-phase dynamic extraction, are available. In this study we have used the recently developed sampling technique, solid-phase microcolumn extraction (SPMCE), for the analysis of BTEX, styrene, chloroform, trichloroethylene and tetrachloroethylene in urine using GC-FID.