Alkyl methylphosphonic acids, the degradation products of organophosphorous CWA - preparation and direct quantitative GC-FID analysis

Seven alkyl methylphosphonic acids, products of hydrolytic degradation of organophosphorus chemical warfare agents, were obtained with a high purity (mostly above 98%), with the aim of being applyed as future certified reference materials. Ethyl (EMPA), isopropyl (IMPA), pinacolyl (PMPA), butyl (BUMPA), isobutyl (IBUMPA), cyclohexyl (CHMPA) and 2-ethylhexyl (EHMPA) monoesters of MPA were synthesized and characterized by MS EI, FTIR and NMR (H-1, C-13, P-31), TLC, as well as GC and GC-MS after derivatization. The conditions for a direct quantitative GC FID analysis on CP-FFAP CB column of non-derivatized alkyl methylphosphonic acids were developed. This is the first successful attempt of a directed GC analysis of free alkyl phosphonic acids. Their chemical purity was determined and limit of quantification (LOQ) values for some of them were evaluated for the GC-FID method.