Simultaneous detection of the tetrachloroethylene metabolites S-(122-trichlorovinyl) glutathione S-(122-trichlorovinyl)-L-cysteine and N-acetyl-S-(122-trichlorovinyl)-L-cysteine in multiple mouse tissues via ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry

摘要

Tetrachloroethylene (perchloroethylene; PERC) is a high-production volume chemical and a ubiquitous environmental contaminant that is hazardous to human health. Toxicity of PERC is mediated through oxidative and glutathione conjugation metabolites. The conjugation of PERC by glutathione-s-transferase to generate S-(1,2,2-trichlorovinyl) glutathione (TCVG), which is subsequently metabolized to form S-(1,2,2-trichlorovinyl)-L-cysteine (TCVC) is of special importance to human health. Specifically, TCVC can be metabolized to N-acetyl-S-(1,2,2-trichlorovinyl)-L-cysteine (NAcTCVC) which is excreted through urine, or to electrophilic metabolites that are nephrotoxic and mutagenic. Little is known about toxicokinetics of TCVG, TCVC, and NAcTCVC as analytical methods for simultaneous determination of these metabolites in tissues have not yet been reported. Hence, an ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry-based method was developed for analysis of TCVG, TCVC, and NAcTCVC in liver, kidney, serum, and urine. The method is rapid, sensitive, robust, and selective for detection all three analytes in every tissue examined, with limits of detection ranging from 1.8–68.2 femtomoles on column, depending on the analyte and tissue matrix. This method can be applied to quantify levels of TCVG, TCVC, and NAcTCVC in tissues from mice treated with PERC (10 to 1000 mg/kg, orally) with limits of quantitation of 1–2.5 pmol/g in liver, 1–10 pmol/g in kidney, 1–2.5 pmol/mL in serum, and 2.5–5 pmol/mL in urine. This method is useful for further characterization of the glutathione conjugative pathway of PERC in vivo and improved understanding of PERC toxicity.