Optimization of Methods for Derivatization of Sarin, Soman, and VX Hydrolysis Products in the Process of Analyzing These Compounds Using Gas Chromatography

<ns3:p>The identification and quantification of degradation products of organophosphorus chemical warfare agents (OP-CWAs)are critical for retrospective and forensic analysis or evidence proceedings. Due to their high polarity and low volatility, direct chromatographicanalysis of these hydrolysis products is often ineffective, necessitating derivatization to enhance analytical performance.This study focuses on optimizing the derivatization conditions of sarin, soman and VX hydrolysates – O–alkylmethylphosphonic acids(methylphosphonic (MPA), ethyl methylphosphonic (EMPA), isopropyl methylphosphonic (IMPA), and pinacolyl methylphosphonicacid (PMPA)) using two common reagents: BSTFA for silylation and TMSD for alkylation. For each method, the optimal reagent volumes,reaction times, and temperatures were determined, and the stability of the resulting derivatives was evaluated. All derivatizationreactions proceeded optimally at 80C. Derivatization with BSTFA required 75–120 min to reach optimal analytical signal, whilederivatization with TMSD required 105–135 min. The results confirm that both derivatization strategies are effective in producing thedesired derivatives, although BSTFA silylation proved to be more practical and operationally stable. The findings support the use of derivatizationto improve the detection of OP-CWA degradation products by GC-MS and contribute to the development of more efficientanalytical procedures in the context of chemical weapons.</ns3:p>