Monitoring of hydrolysis products of organophosphorus nerve agents in plant material and soil by liquid chromatography-tandem mass spectrometry.

Nerve agents are organophosphorus compounds of the highest toxicity and danger. The production, transportation and use of these substances are prohibited by the Organization for the Prohibition of Chemical Weapons. Any fact of alleged use of nerve agents is a crime against humanity and must be investigated in detail by the world community. For this purpose, such analysis objects as biological fluids (urine, blood) and environmental objects (water, soil) are well studied. The current study demonstrates the possibility of using plants as a convenient material for retrospective analysis. Methyl phosphonic acid and some of its alkyl esters (ethyl, isopropyl, isobutyl, cyclohexyl, pinacolyl) were chosen as nerve agent metabolites. Hedera Helix growing in soil was used as a carrier of the markers. The selected markers were injected once in the soil and their content in the plant and soil was monitored for 4 weeks. A fast and simple way of sample homogenization with liquid nitrogen followed by ultrasonic liquid extraction was applied. The developed HPLC-MS/MS approach with the use of deuterated internal standards for quantitative analysis was validated. The research discovered that all the studied nerve agent markers could be detected and determined both in the soil and the plant for at least one month. The results indicate the promising use of plants as additional objects of analysis in investigation of incidents involving the use of chemical warfare agents.