Forensic analysis of the deuterium/hydrogen isotopic ratios of the nerve agent sarin, its reaction by-product diisopropyl methylphosphonate and their precursors by 2H SNIF-NMR.

The Deuterium/Hydrogen (D/H) isotope ratios of sarin (5), diisopropyl methylphosphonate (3) and their precursors Isopropanol (1), methylphosphonic acid dichloride (2) and methylphosphonic acid difluoride (4) were measured by the 2H SNIF-NMR technique. The D/H isotope ratios of 1 show a large variation. It is shown, that the formation of 3 by reaction of 1 with 2, the fluorination of 2 to form 4 and the reaction of 4 with 1 to form 5, the D/H isotope ratios of the methyl and isopropyl moieties in 3, 4 and 5 are not significantly changed compared to 1 and 2.