Determination of benzene and alkylated benzenes in ambient and exhaled air by microwave desorption coupled with gas chromatography-mass spectrometry

Abstract

A sensitive and rapid method for the determination of benzene, toluene, ethylbenzene and the xylenes (BTX) in ambient and exhaled air is described. After sampling of 1-4 l of ambient or exhaled air on graphitized charcoal tubes, the analytes were thermally desorbed by a microwave device coupled to a gas chromatograph interfaced to a mass spectrometer (GC-MS). The detection limits for benzene, toluene, ethylbenzene m- + p-xylene and o-xylene were 1.6, 3.0, 0.2, 1.4 and 0.4 μg/m 3, respectively, when 1 l of air is sampled. In five smoking households a mean benzene concentration of 13.4 (range: 4.2–18.1) μg/m 3 was measured. In five homes without smokers, the average concentration of benzene was 8.8 (5.5–12.8) μg/m 3. The mean benzene concentrations in the exhalates were 50.2 (19.1–98.0) and 3.9 (0.5–8.8) μg/m 3 for ten smokers and ten non-smokers, respectively. The method was found to be suitable for the determination of environmental BTX exposure in field studies.