Packed capillary liquid chromatography–electrospray ionization (tandem) mass spectrometry of mustard hydrolysis products in soil

Abstract

A packed capillary liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS) method was developed and applied to the identification of mustard hydrolysis products in aqueous extracts of soil. In the first application the LC–ESI-MS/MS method was used to identify thiodiglycol and nine longer chain diols in soil samples taken at different locations and depths from a former mustard storage site as part of an ongoing environmental assessment. Aqueous extracts of the soil samples were analysed by LC–ESI-MS/MS using a quadrupole/time-of-flight tandem mass spectrometer operating with a resolution of 9000. High resolution product mass spectra were acquired for thiodiglycol, the hydrolysis product of mustard and nine other sulfur containing diols, including five longer chain diols that could not be identified during prior LC–ESI-MS analyses. The high resolution LC–ESI-MS/MS method was also incorporated into an analytical approach designed to provide rapid chemical warfare agent identification in cases where the chemical and/or biological warfare agent content of a sample is unknown. A sample handling method involving aqueous extraction of the soil sample in biocontainment level 3 (BL-3), followed by autoclave sterilization of the aqueous extract was developed. Once sterilized, the container and aqueous extract can then be safely manipulated outside of BL-3 in the analytical laboratories and may be analysed for the presence or absence of chemical warfare agents, their hydrolysis products or related compounds by LC–ESI-MS/MS.