Technical report | Application of Quantitative Proton Nuclear Magnetic Resonance Spectroscopy to Chemical Warfare Agents

Abstract 

This report outlines the development of a quantitative proton NMR spectroscopy method for determining the purity of CWAs using homogeneous internal standards. The method was validated to an accuracy and precision better than 1% through the use of certified NMR standards. The method is useful for determining the purity of major chemical species at concentrations at or above 25 mM, and for identifying and quantifying minor chemical species at or above 0.06 mM and 0.20 mM, respectively. The method was employed to determine the purity of three chemical warfare agents (HD, GB and VX) and was found to be equal to or better than chromatography in terms of precision, accuracy and analysis turnaround time. As qHNMR simplifies the analysis procedure, exposure of personnel and analytical equipment to CWAs is minimised.

Executive Summary

Proton quantitative Nuclear Magnetic Resonance (qHNMR) Spectroscopy is a non-destructive technique that can be used for quantitation of complex mixtures with absolute errors generally below 2%. This report outlines the development of a qHNMR method for determining the purity of chemical warfare agents (CWAs) using homogeneous internal standards. The method was validated to an accuracy and precision better than 1% through the use of certified NMR standards. The method can be applied to determine the purity of major chemical species at concentrations at or above 25 mM, and to identify and quantify minor chemical species at or above 0.06 mM and 0.20 mM, respectively. The qHNMR method was employed to determine the purity of three chemical warfare agents (HD, GB and VX) and was found to be equal to or better than chromatography in terms of precision, accuracy and analysis turnaround time. The operational simplicity of this method enables quantitative and qualitative information to be rapidly gleaned from a single sample.