IJERPH, Vol. 11, Pages 10902-10914: Ultrasensitive UPLC-MS-MS Method for the Quantitation of Etheno-DNA Adducts in Human Urine (International Journal of Environmental Research and Public Health)

Etheno-DNA adducts are generated from the metabolism of exogenous carcinogens and endogenous lipid peroxidation. We and others have previously reported that 1,N6-ethenodeoxyadenosine (?dA) and 3,N4-ethenodeoxycytidine (?dC) are present in human urine and can be utilized as biomarkers of oxidative stress. In this study, we report a new ultrasensitive UPLC-ESI-MS/MS method for the analysis of ?dA and edC in human urine, capable of detecting 0.5 fmol ?dA and 0.3 fmol ?dC in 1.0 mL of human urine, respectively. For validation of the method, 20 human urine samples were analyzed, and the results revealed that the mean levels of ?dA and ?dC (SD) fmol/µmol creatinine are 5.82 ± 2.11 (range 3.0-9.5) for ?dA and 791.4 ± 328.8 (range 116.7-1264.9) for ?dC in occupational benzene-exposed workers and 2.10 ± 1.32 (range 0.6-4.7) for ?dA and 161.8 ± 200.9 (range 1.8-557.5) for ?dC in non-benzene-exposed workers, respectively. The ultrasensitive detection method is thus suitable for applications in human biomonitoring and molecular epidemiology studies.