Application of microcolumn liquid chromatography and capillary electrophoresis with flame photometric detection for the screening of degradation products of chemical warfare agents in water and soil

Microcolumn liquid chromatography (μLC) and capillary electrophoresis (CE) coupled on-line with flame photometric detection (FPD) have been used for the screening of polar breakdown products of chemical warfare agents in water and soil samples, provided during Official Proficiency Tests organized by the Technical Secretariat of the Organization for the Prohibition of Chemical Weapons. CE–FPD is shown to be a powerful and rapid method for the determination of alkylphosphonic acids, which are the breakdown products of organophosphorus nerve agents. Gradient elution μLC–FPD is more sensitive and robust but less rapid in the determination of these compounds. In addition, μLC–FPD can be applied to screen for hydrolysis products of sulfur mustard and its analogues. Both methods can be applied without prior derivatization and are extremely selective. In order to unambiguously identify the relevant compounds, electrospray ionization (tandem) mass spectrometry, gas chromatography–mass spectrometry and nuclear magnetic resonance spectrometry were applied.