Simultaneous determination of four sulfur mustard-DNA adducts in rabbit urine after dermal exposure by isotope-dilution liquid chromatography-tandem mass spectrometry.

•We developed a simultaneous UPLC–MS/MS determination method combining with SPE.•SM–DNAs status directly reveals DNA lesion extent for urine as excretion endpoint.•We found significant dose and time dependent responses of four SM–DNA adducts.•Accumulation abundance follows the order N7-HETEG, Bis-G, N3-HETEA, and O6-HETEG.•Most abundant N7-HETEG still appeared in the end of a month at high dosages.