Application of Headspace Solid Phase Microextraction and Gas Chromatography/Mass Spectrometry for Rapid Detection of the Chemical Warfare Agent Sulfur Mustard

A field expedient analytical method for detecting the chemical warfare agent (CWA) sulfur mustard as a soil contaminant was developed using solid phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS). Five commercially available SPME fibers were investigated to determine the optimal fiber and extraction conditions. Polyacrylate and carbowax/divinylbenzene fiber coatings gave a statistically indistinguishable and best response compared to the other three types examined in a simple system studied without soil. The polyacrylate fiber coating was selected for study of a system in which sulfur mustard was spiked to an agricultural soil (standard reference material 2709, San Joaquin type). With soil samples, the greatest sensitivity occurred by the addition of deionized water to spiked soil and extraction at ambient temperature for twenty minutes or longer. SPME sampling with GC/MS analyses afforded good reproducibility (relative standard deviation between 2 to 10 %). Analyte concentrations as low as 237 ng g-1 were detected in soil (total ion chromatograms) with this technique. The total time for sampling and analysis was under 1 hour, and the use of organic solvents or special sample introduction equipment was not needed.