Gas Chromatographic Determination of Urinary o-Cresol for the Monitoring of Toluene Exposure

G. Truchon, R. Tardif, J. Brodeur
1996 Journal of Analytical Toxicology  
I A sensitive and reproducible gas chromatographic procedure for the quantitative determination of urinary o-cresol is described. The first step involves acid hydrolysis (2N HCI, 100~ 10 rain), which yields unconjugated o-cresol. After extraction (methylene chloride, pH 2), the organic layer is concentrated by evaporation and samples are analyzed by gas chromatography-flame ionization detection with a DB-5 column (30 m x 0.25 ram, 0.25 pro). Initial oven temperature is set at 30~ for 12 rain
more » ... then increased 2~ to 93~ 3,4-Dimethylphenol is used as the internal standard. The detection limit of the method is 0.36 I~mol/L (l-pL injection). Additional validation data were obtained by analysis of urine samples collected from volunteers exposed to various concentrations of toluene: 10, 20, 30, 50, and 100 ppm over 7 h. Urinary o-cresol concentrations (0-3, 3-7, 7-24, and 0-24 h) were highly correlated with toluene exposure.
doi:10.1093/jat/20.5.309 pmid:8872240 fatcat:wqaecc4yejgt3ozpa4mts5gmcu