A New High Performance Liquid Chromatography Tandem Mass Spectrometric Method for Quantitative Determination of Soman-tyrosine Adduct in Exposed Rat Plasma

Abstract

Towards the urgent need of accurately retrospective analysis of biomedical samples exposed by nerve agent soman( GD),we developed a new quantitative method of GD-tyrosine adduct( GD-Tyr) in exposed rat plasma by liquid chromatography( LC)-tandem mass spectrometry( MS/MS) with high sensitivity and high specificity.After a series of pretreatment procedures including extraction of albumin by affinity chromatography and ultrafiltration,enzymatic hydrolysis by pronase,and solid phase extraction,we qualitatively and quantitatively determined soman-tyrosine adduct by reversed-phase LC-triple quadrupole MS in the positive electrospray ionization and multiple reactions monitoring mode.The monitored transitions were m/z 260/214( GD-Tyr) and m/z 293/247( internal standard).A good linearity was obtained in the range of0.1-500 μg/L for GD-Tyr( R2=0.999) with a limit of detection of 0.02 μg/L and a limit of quantification of 0.05 μg/L.The recovery of GD-Tyr was in the range of 90.1%-103.5%,and the RSD of this method was less than 3%.We then investigated the toxicokinetics of GD-Tyr for GD exposed SD rat( n=5) in an intraperitoneal injection way.An obvious time and dose dependent relationship between GD-Tyr and the dose of soman was observed.We suggest that GD-tyrosine adduct can be used as an exposure biomarker to the retrospective detection of soman after exposure.