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.

Detection and identification of hydrolysis products of sulfur mustards at trace levels in environmental samples using liquid chromatography solid phase extraction combined with off-line nuclear magnetic resonance analysis.

An LC-UV-SPE NMR method for the analysis of polar hydrolysis products of the chemical warfare agents known as sulfur mustards at low ppm levels in environmental samples is developed. The hydrolysis products thiodiglycol (I), bis(2-hydroxyethylthio)methane (II), 1,2-bis(2-hydroxyethylthio)ethane (III), 1,3-bis(2-hydroxyethylthio)propane (IV), 1,4-bis(2-hydroxyethylthio)butane (V), 1,5-bis(2-hydroxyethylthio)pentane (VI), bis(2-hydroxymethylthioethyl)ether (VII) and bis(2-hydroxyethylthioethyl)ether (VIII) are baseline separated within 11 min by the LC gradient program and trapped post-column on SPE cartridges. After elution in 2mm o.d. NMR tubes (1)H NMR spectra were recorded. Recoveries vary from 43±5 for I to 102±5% for VI and are limited by volume breakthrough. The detection limits of the LC-SPE NMR method vary between 200 ng for V and 450 ng for I. Increasing the injection volume is shown to be more effective than multiple trapping for the analytes I-VIII to increase the amount of material trapped on the SPE cartridges. The applicability of the developed method to the analysis of environmental samples was tested by the analysis of sample 293 provided by the 29th Official OPCW (Organization for the Prohibition of Chemical Weapons) Proficiency Test. The chromatographic and (1)H NMR data obtained by the method are highly reproducible and provide acceptable data for the identification of chemicals related to CWC (Chemical Weapons Convention) in case an off-site analysis for the verification of the CWC or OPCW Proficiency Tests according to the OPCW criteria for the acceptance of chromatographic and (1)H NMR spectral data.

Application of nonselective 1D (1)H-(31)P inverse NMR spectroscopy to the screening of solutions for the presence of organophosphorus compounds related to the chemical weapons convention.

1D nonselective (1)H-(31)P HSQMBC, HSQC, and (31)P decoupled HSQC NMR experiments were applied to the screening of original OPCW proficiency test samples for the presence of organophosphorus (OP) compounds related to the Chemical Weapons Convention. The HSQC and HSQMBC spectra are compared to 1D (1)H NMR spectra with WET solvent suppression and (31)P[(1)H] spectra of the same samples. The 1D nonselective HSQC and HSQMBC experiments are shown to be the most sensitive NMR experiments to selectively screen samples for the presence of organophosphorus(OP) compounds. These experiments are at least three times more sensitive than the (31)P[(1)H] NMR experiment and allow the determination of the number of OP compounds present in the sample and their alkyl group bound to the phosphorus atom. Samples spiked at the 5-10 ppm level can be screened within an hour for the presence of OP compounds, whereas for the (31)P[(1)H] experiments, an overnight acquisition is necessary. The sensitivity of the experiments decreases in the order (31)P decoupled HSQC, HSQMBC, and HSQC. For the different alkyl groups, the sensitivity of these experiments decreases in the order methyl approximately isopropyl > ethyl > propyl.