Measurement of toluene and xylene metabolites by gas chromatography

Summary A new method for analyzing urinary hippuric and methyl hippuric acids by gas chromatography was developed. As well the direct analysis of hippuric acids as the determination of their alkaline hydrolytic products, benzoic and toluic acids, are described. Results of the two different methods are compared and discussed. The method was applied to workers occupationally exposed to paints containing mainly toluene and xylene. The urinary hippuric acid concentrations were related to the level of toluene and xylene in blood.