Gas chromatography/mass spectrometry analysis of reaction products of sulfur mustards with phenol

Abstract

Screening of chemicals related to chemical weapons convention including their all possible degradation and reaction products in environmental samples is important in the organization for prohibition of chemical weapons verification process. Sulfur mustards, commonly known as blistering agents, are included in schedule 1 chemicals of chemical weapons convention. Because of the presence of chlorine atoms in sulfur mustards, they are highly reactive and prone to react with other organic molecules such as phenols to produce corresponding reaction products. Thus, it is important to screen for not only the sulfur mustards but also their reaction products for verification process. The sulfur mustards and their degradation products have been routinely analyzed by gas chromatography/mass spectrometry method, however, the methods are yet to establish for the reaction products. In this study, the reaction products of the sulfur mustards with phenol (compounds 1–7) were studied by gas chromatography/mass spectrometry under electron ionization and chemical ionization conditions. The EI spectra of 1–7 displayed molecular ion and characteristic fragments that provided structure information. Mostly the fragment ions were due to homolytic cleavages involving C–O, C–S, and C–C cleavages. The methane or isobutane CI spectra showed M^+., [M + H]⁺, and [M − H]⁺ ions including reagent specific adduct ions. The CI spectra also showed other adduct ions formed by association of analyte molecule with its most abundant fragment ion. The gas chromatography/retention index values were also calculated, which support unambiguous identification of targeted molecules in suspected environmental samples. The method was demonstrated for detection of the targeted molecules spiked in soil samples.