Trace Detection of G-Nerve Agents in Various Environmental Matrices Utilizing Derivatization and LC-MS Analysis

Moran Madmon, Analytical Chemistry, IIBR, Ness Ziona, Israel
Maor Elgarisi, Analytical Chemistry, Iibr, Ness Ziona, Israel
Shai Dagan, Analytical Chemistry, Iibr, Ness Ziona, Israel
Avi Weissberg, Analytical Chemistry, Iibr, Ness Ziona, Israel

A highly sensitive method for the determination of Sarin (GB), Soman (GD) and Cyclosarin (GF) chemical warfare agents in various matrices such as asphalt, concrete, clothing and formica was developed. The method incorporates derivatization of the G-type nerve agent extracts with 2-[(dimethylamino)methyl]phenol (2-DMAMP), followed by LC-ESI(+)-MS/MS analysis. Four extraction solvents were explored for their extraction efficiency and reaction rate with the derivatizing agent while temperature and derivatization-reagent amount were optimized. The optimized procedure included extraction with water by agitation (2 min), followed by the addition of 2-DMAMP directly into an injection vial, stirring 5 min prior to LC-ESI(+)-MS/MS analysis, without any other pretreatment of the complex matrices. The method was applied for the determination of G-nerve agents in real-world samples and showed low detection limits (LODs) at the range of low pg/cm² of the G-nerve agent from all tested matrices. The proposed methodology may be practical for verification and evaluation of contaminated matrices collected in the battlefield or terror scene in forensic investigations.