[Biomarkers of occupational and environmental exposure to benzene and styrene determinated by LC-MS/MS].

Based on the studies performed a sensitive and simple method for the determination of benzene and styrene metabolites in urine has been developed. The developed procedure can be used for biological monitoring of occupational and environmental exposure. Urine samples for the determination of styrene metabolites (phenylglyoxylic acid--PGA and mandelic acid--MA) were only acidified with formic acid, while those for the determination of benzene metabolite (S-phenyl-mercapturic acid--S-PMA) were additionally extracted with ethyl acetate. The measurement was performed by high performance liquid chromatography--tandem mass spectrometry (HPLC-MS/MS). The quality of our analysis was verified using internal and external quality control. Limit of detection for S-PMA was 0.33 microg/l, for MA--60 microg/l and for PGA--40 microg/l; precision was 2-3% and recovery 94-98%. The method for the quantification of benzene and styrene metabolites can be used for biological monitoring of occupational and environmental exposure.