Identification of G-nerve agents at picogram levels from complex organic samples containing hydrocarbon interferences by aqueous extraction, followed by derivatization and liquid chromatography-mass spectrometry analysis.

The chromatograms obtained from the gas chromatography-electron ionization mass spectrometric (GC-EI-MS) analysis of extracts containing G-nerve agents in the presence of diesel, gasoline, etc., are dominated by hydrocarbon backgrounds that "mask" the G-nerve agents, leading to severe difficulties in identification. This paper presents a practical solution for this challenge by transferring the G-nerve agents from the organic phase into the aqueous phase using liquid-liquid extraction (LLE), followed by derivatization with 2-[(dimethylamino)methyl]phenol (2-DMAMP), allowing ultrasensitive LC-ESI-MS/MS analysis of the G-derivatives. The proposed approach enables rapid identification of trace amounts of G-nerve agents with limits of identification (LOIs) at the pg/mL scale.