Toluene itself as the best urinary marker of toluene exposure.
Head-space gas chromatography (GC) and high-performance liquid chromatography (HPLC) (with fluorescence detectors) methods were developed for toluene (TOL-U) and o-cresol (CR-U) in urine, respectively. In order to identify the most sensitive urinary indicator of occupational exposure to toluene vapor (TOL-A) among TOL-U, CR-U, and hippuric acid in urine (HA-U), the two methods together with an HPLC (with untraviolet detectors) method for determination of HA-U were applied in the analysis of end-of-shift urine samples from 115 solvent-exposed workers (exposed to toluene at 4 ppm as geometric mean). Regression analysis showed that TOL-U correlated with TOL-A with a significantly higher correlation coefficient than did HA-U or CR-U. With regard to the TOL-A concentrations at which the exposed subjects could be separated from the nonexposed by the analyte, TOL-U achieved separation at < 10 ppm TOL-A, whereas both HA-U and CR-U did so only when TOL-A was 30 ppm or even higher. The ratio of the analyte concentrations at 50 ppm TOL-A to those at 0 ppm TOL-A was also highest for TOL-U. Overall, the results suggest that TOL-U is a better marker of exposure to toluene vapor than HA-U or CR-U.
Kawai
T
T
Osaka Occupational Health Service Center, Japan.
Mizunuma
K
K
Okada
Y
Y
Horiguchi
S
S
Ikeda
M
M
D015415:Biomarkers / Q000652:urine; D002849:Chromatography, Gas / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003408:Cresols / Q000378:metabolism / Q000652:urine*; D006626:Hippurates / Q000378:metabolism / Q000652:urine*; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D014050:Toluene / Q000378:metabolism / Q000652:urine*
D015415:Biomarkers; D003408:Cresols; D006626:Hippurates; D014050:Toluene; C030514:hippuric acid; C034047:2-cresol