www.mdpi.com/journal/ijerph Article Ultrasensitive UPLC-MS-MS Method for the Quantitation of Etheno-DNA Adducts in Human Urine

Abstract: 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 dC in human urine, capable of detecting 0.5 fmol εdA and 0.3 fmol εdC 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 εdA and εdC (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 OPEN ACCESS Int. J. Environ. Res. Public Health 2014, 11 10903 (range 1.8–557.5) for dC in non-benzene-exposed workers, respectively. The ultrasensitiv