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Simultaneous determination of t,t ‐muconic, S ‐phenylmercapturic and S ‐benzylmercapturic acids in urine by a rapid and sensitive liquid chromatography/electrospray tandem mass spectrometry method
Author(s) -
Barbieri Anna,
Sabatini Laura,
Accorsi Antonio,
Roda Aldo,
Violante Francesco Saverio
Publication year - 2004
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1580
Subject(s) - chemistry , chromatography , muconic acid , urine , toluene , mass spectrometry , electrospray ionization , tandem mass spectrometry , liquid chromatography–mass spectrometry , high performance liquid chromatography , analytical chemistry (journal) , organic chemistry , biochemistry
We describe a rapid and sensitive high‐performance liquid chromatography/electrospray tandem mass spectrometry (HPLC/ESI‐MS/MS) method for simultaneous determination of the most relevant metabolites of benzene and toluene, t,t‐ muconic acid ( t,t ‐MA), S ‐phenylmercapturic acid (S‐PMA), and S ‐benzylmercapturic acid (S‐BMA). Urine samples were purified before analysis by solid‐phase microextraction (SPE) on SAX cartridges with 50 mg sorbent mass. The developed method fulfils all the standard requirements of precision and accuracy. Calibration curves were linear within the concentration range of the standards (0–80 μg/L urine for t,t ‐MA, and 0–25 μg/L urine for S‐PMA and S‐BMA), and had correlation coefficients ≥0.997. Limits of detection were 6.0 μg/L for t,t ‐MA, 0.3 μg/L for S‐PMA, and 0.4 μg/L for S‐BMA. The method was used to determine t,t ‐MA, S‐PMA and S‐BMA levels in urine of 31 gasoline‐station workers, with personal monitoring data obtained from radial symmetry passive diffusive samplers. In the context of mean work‐shift exposures of 75.9 μg/m 3 (range 9.4–220.2) for benzene and 331.9 μg/m 3 (78.2–932.1) for toluene, metabolite concentrations in end‐of‐shift urine samples ranged from 23.5–275.3 μg/g creatinine for t,t ‐MA, non‐detectable to 0.9 μg/g creatinine for S‐PMA, and 3.8–74.8 μg/g creatinine for S‐BMA. No significant correlation was found between the environmental concentrations and urinary metabolites ( p > 0.05 for all cases); the ratios of benzene metabolites could be influenced by exposure levels and co‐exposure to xylenes and toluene. The high throughput of this procedure should facilitate exploration of the metabolic effects of benzene‐related co‐exposure to toluene and alkylbenzenes in large populations of subjects exposed to gasoline. Copyright © 2004 John Wiley & Sons, Ltd.