Determination of the major mercapturic acids of 1,3-butadiene in human and rat urine using liquid chromatography with tandem mass spectrometry

The major urinary metabolites of 1,3-butadiene are monohydroxybutenyl-mercapturic acids (MHBMA) and dihydroxy-butyl-mercapturic acid (DHBMA). These metabolites can be used as biomarkers of exposure to this diene. In order to determine, the smoking-related exposure to 1,3-butadiene, we have developed a rapid LC-MS/MS method for the determination of MHBMA and DHBMA in urine of humans and rats. The method requires 2-5 ml of urine which is solid phase extracted prior to LC-MS/MS analysis. Precision for MHBMA is less than or equal to11.2% for human and less than or equal to17% for rat urine. Corresponding values for DHBMA are less than or equal to7.2 and less than or equal to19%, respectively. Recovery rates are approximately 100% for both analytes in human urine and about 115% in rat urine. Limits of detection (LOD) are for humans 0.9 and 23 ng/ml and for rats 1.5 and 33 ng/ml for MHBMA and DHBMA, respectively. Application of the method to urine of humans and rats showed a significant effect of tobacco smoke exposure on the urinary excretion of MHBMA and the metabolic ratio DHBMA/(DHBMA + MHBMA). (C) 2003 Elsevier B.V. All rights reserved.