Characterization of hydrolysis products and determination of the rate of hydrolysis of Novichok A-234 in different decontaminants

• Complementary analysis methods were used to determine the hydrolysis rate of A-234 • A-234 degradation products formed differed widely and did not favor the hydrolysate • A-234 decomposed in all studied decontaminants • Major degradation products were characterized • Spectroscopic A-234 degradation varied between 6 and 44 hours by decontaminant In this work, studies on the neutralization of Novichok A-234, a member of a class of nerve agents known for their high toxicity, were carried out. Three decontaminants of different composition were used; these were alkaline potassium hydroxide in ethanol, GDS-2000, and Biodecon-83, a deep eutectic solvent. After 24 and 120 hours of exposure to each decontaminant, the degradation products were characterized by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) and UPLC-tandem MS. The rate of hydrolysis of Novichok A-234 in each decontaminant was measured using 31 P nuclear magnetic resonance (NMR) spectroscopy. The three decontaminants showed large variations in the hydrolysis rates of Novichok A-234. The total required decontamination time until Novichok A-234 was no longer observed by 31 P NMR, ranged from 5 to 44 hours. In silico calculations were performed to predict the toxicity of the main decontamination products. All hydrolysis compounds were of lower toxicity than Novichok A-234.