Retrospective determination of regenerated nerve agent sarin in human blood by liquid chromatography-mass spectrometry and in vivo implementation in rabbit.

The highly toxic nerve agent sarin (o-isopropyl methyl-phosphonofluoridate, GB) has been used in several armed conflicts and terror attacks in recent decades. Due to its inherent high sensitivity, liquid chromatography-mass spectrometry (LC-MS/MS) has the potential to detect ultratrace levels of fluoride-regenerated G and V agents after appropriate chemical derivatization. A new method for the retrospective determination of exposure to sarin was developed. The method is based on sarin regeneration from blood using the fluoride-induced technique followed by derivatization with 2-[(dimethylamino)methyl]phenol (2-DMAMP) and LC-ESI-MS/MS (MRM) analysis. The validated method presents good linear response in the concentration range of 5-1000 pg/mL with a limit of quantitation (LOQ) of 5 pg/mL, 13.8% accuracy, 16.7% precision and a total recovery of 62% ± 9%. This new analytical approach has several advantages over existing GC/GC-MS-based methods in terms of sensitivity, specificity and simplicity, in addition to a short LC-MS cycle time of 12 min. The method was successfully applied in an in vivo experiment for retrospective determination of sarin in a rabbit exposed to 0.1 LD