Simultaneous determination of 15 BTEX hydroxyl biomarkers in urine by headspace solid-phase microextraction gas chromatography-mass spectrometry

Benzene (B), toluene (T), ethylbenzene (E), o-, m- and p-xylene (o-, m-, p-X) are ubiquitous and frequently exposed to human throughout the environment. Previously published test methods for phenolic biomarkers are not sensitive enough to be detected in most general population groups and require a lot of labor. A simple and convenient headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry method was described for the simultaneous determination of 15 hydroxyl biomarkers of BTEX in urine. Hydroxyl biomarkers in urine were vaporized and adsorbed onto a selected fiber after enzyme hydrolysis with beta-glucuronidaseiarylsulfatase. The optimal HS-SPME conditions were achieved with an 85-mu m-carboxen-polydimethylsiloxane fiber, an extraction temperature of 70 degrees C, a heating time of 30 min, and a pH of 4.0. The desorption was performed for 1 min at 250 degrees C. Under the established conditions, the lowest limits of detection were from 0.02 to 0.15 mu g/L in 5.0 mL of urine, and the intra- and inter-day relative standard deviations were less than 12.7% at 0.5, 2.0, 50, and 200 mu g/L. The calibration curve demonstrated good linearity with greater than r(2) = 0.99 in synthetic urine. This method is convenient, simple, environmentally friendly, and amenable to automation. (C) 2019 Elsevier B.V. All rights reserved.