Solid-phase microextraction and gas chromatography-mass spectrometry for determination of monoaromatic hydrocarbons in blood and urine: Application to people exposed to air pollutants

To assess individual exposure to monoaromatic hydrocarbons (benzene, toluen e, ethylbenzene and xylenes BTEX) in biological fluids, a GC-MS method was developed. Headspace sampling of BTEX was by solid-phase microextraction (S PME) with a 75 mu m Carboxen-polydimethylsiloxane (PDMS) fiber. Linearity w as established for concentrations up to 50 mu g L-1. Detection limits, calc ulated both in human blood and urine, ranged 5-10 ng L-1. Repeatability was in the range 6.5-9.2 % for all compounds. The method was applied to the ev aluation of the internal dose of BTEX in a group of cyclists running for 2 h within city routes. Benzene and toluene in blood, and toluene and xylenes in urine significantly increased after exercise as compared to prerun valu es, such changes being consistent with airborne concentrations. The combina tion of SPME with GC-MS seems to represent an appropriate analytical approa ch to detect changes in the concentration of monoaromatic hydrocarbons in b iological media resulting from exposure to environmental pollution.