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

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Analytical technologies in the biomedical and life sciences, 2014-06, Vol.961, p.29-35
• Main Authors: Zhang, Yajiao, Yue, Lijun, Nie, Zhiyong, Chen, Jia, Guo, Lei, Wu, Bidong, Feng, Jianlin, Liu, Qin, Xie, Jianwei
• Format: Article
• Language: English
• Subjects: Animals; Chromatography, High Pressure Liquid - methods; DNA adducts; DNA Adducts - urine; Guanine - analogs & derivatives; Guanine - analysis; Isotope-dilution ultrahigh performance liquid chromatography–tandem mass spectrometry; Metabolism; Mustard Gas - administration & dosage; Mustard Gas - analysis; Mustard Gas - chemistry; Rabbits; Solid-phase extraction; Sulfhydryl Compounds - analysis; Sulfhydryl Compounds - chemistry; Sulfur mustard; Tandem Mass Spectrometry - methods
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2014.04.050

•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. Sulfur mustard (SM) is a classic vesicant agent, which has been greatly employed in several wars or military conflicts. The most lesion mechanism is its strong alkylation of DNAs in vivo. Until now there are four specific DNA adducts of SM identified for further retrospective detection, i.e., N7-(2-hydroxyethylthioethyl)-2′-guanine (N7-HETEG), bis(2-ethyl-N7-guanine)thioether (Bis-G), N3-(2-hydroxyethylthioethyl)-2′-adenine (N3-HETEA) and O6-(2-hydroxyethylthioethyl)-2′-guanine (O6-HETEG), respectively. Here, a novel and sensitive method of isotope-dilution ultrahigh performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) combining with solid phase extraction was reported for the simultaneous determination of four SM–DNA adducts. A lower limit of detection of 2–5ngL−1, and a lower limit of quantitation of 5–10ngL−1 were achieved, respectively, and the recoveries ranged from 87% to 116%. We applied this method in the determination of four SM–DNA adducts in rabbit urine after dermal exposure by SM in three dose levels (2, 5, 15mgkg−1), so as to investigate the related metabolic behavior in vivo. For the first time, in SM exposed rabbit urine, our results revealed the relative accumulation abundance of four SM–DNA adducts, i.e., 67.4% for N7-HETEG, 22.7% for Bis-G, 9.8% for N3-HETEA, 0.1% for O6-HETEG, and significant dose and time dependent responses of these SM–DNA adducts. The four adducts were detectable after 8h, afterwards, their contents continuously increased, achieved maximum in the first two or three days and then gradually decreased till the end of one month. Meanwhile, the amounts of SM–DNA adducts were positively correlated with the exposure doses.