A column-switching LC-MS/MS method for simultaneous quantification of biomarkers for 1,3-butadiene exposure and oxidative damage in human urine.

1,3-Butadiene (BD) is a ubiquitous environmental pollutant found in tobacco smoke. In vivo, BD is mainly metabolized to form monohydroxybutenylmercapturic acid (MHBMA) and N-acetyl-S-(3, 4-dihydroxybutyl) cysteine (DHBMA). The accurate quantification of MHBMA and DHBMA in urine may provide important insights into the actual internal exposure of the general population to BD. 8-Hydroxy-2-deoxyguanosine (8-OHdG) is the biomarker of oxidative damage. In this study, a column-switching LC-MS/MS method was developed and validated for the simultaneous quantification of MHBMA, DHBMA derived from BD exposure and 8-OHdG in human urine. Urine samples were loaded on a LiChrospher(®) RP-8 ADS (25μm) 25×4mm RAM column for the extraction and clean-up of analytes. The separation was achieved using a SUPELCO(®) LC-18-DB column (75mm×3.0mm, 3μm). The analytes were ionized in negative electrospray ionization mode and analyzed in multiple reaction monitoring mode. Under optimum conditions, recoveries ranged from 78.9% to 101.7%, with relative standard deviations less than 11%. The limits of quantification ranged from 0.15 to 0.27ng/mL, highlighting the high sensitivity of this simple method. The validated method was successfully applied to analysis urine samples from 56 non-smokers and 233 smokers who smoked cigarettes with 3 different tar yields. There was a correlation between urinary MHBMA, DHBMA and 8-OHdG. This method did not require any preparation process and efficiently removed interference from the matrix by using column-switching. The developed method is applicable to epidemiological studies.