Identification of Nitrogen Mustard Chemical Warfare Agents in Sand by Gas Chromatography–Mass Spectrometry (GC-MS) in a Military Deployable Laboratory

Nitrogen mustards are blistering chemical warfare agents which are considered to be persistent contaminants highly resistant to decontamination. The paper describes the development and optimization of a method for the extraction of nitrogen mustards bis(2-chloroethyl)ethylamine (HN-1), bis(2-chloroethyl)methylamine (HN-2), and tris(2-chloroethyl)amine (HN-3) from sand samples with subsequent identification by gas chromatography–mass spectrometry (GC-MS) in a military deployable laboratory. Common solvents which have been used for various methods in field analysis and are available in deployable laboratories were tested as the extraction reagents—dichloromethane, dichloroethane, hexane, heptane, ethyl acetate, methanol, and acetone. Calibration curves for the determination of nitrogen mustards were created. Methods for the extraction from the sand matrix were developed and optimized. The extraction efficiencies of the tested solvents were compared. Limits of detection of nitrogen mustards in sand samples were determined for all tested extractants. For quantitative purposes, the internal standardization method was used. The extraction efficiencies for the studied solvents varied in the range from 10.8 to 86.4%. The most effective extraction reagents for HN-1, HN-2, and HN-3 extraction were dichloromethane and acetone. Acetone was determined to be the most practical extraction reagent of nitrogen mustards in sand after the consideration of various criteria.