Solid phase microextraction sampling and gas chromatography/mass spectrometry for field detection of the chemical warfare agent O-ethyl S-(2-diisopropylaminoethyl) methylphosphono-thiolate (VX)

摘要

A rapid detection method for the chemical warfare nerve agent VX was developed using SPME and gas chromatography/mass spectrometry (GC/MS). Five commercially available SPME fiber coatings were evaluated to determine the optimal fiber coating and conditions for extraction. The use of silanized vials was found to be necessary to limit interaction of the basic tertiary amine component of VX with the acidic silanols present in standard glass vials. The polydimethylsiloxane (PDMS) fiber was ultimately selected for completion of this work with extractions being performed at 50 ℃. Clothing material was spiked in the laboratory with 1 μL of neat VX, placed in a sealed vial, and taken into the field for SPME sampling, using optimized conditions studied. GC/MS analysis was also completed in the field using van-mounted instrumentation. With sampling and analysis completed in less than 20.0 minutes, detection of VX contamination was relatively rapid, especially considering the quality of the resulting data. The use of SPME also provides increased safety for the field analysis of VX since it does not require the handling of solvents for sample preparation and samples are not handled directly by the analyst.