Ultra-Sensitive Analysis of Organophosphorus Compounds by Comparative GC-FPD and GC-ICP-MS: Implications for Chemical Warfare Agent Detection.

Organophosphorus chemical warfare agents such as sarin (GB), soman (GD), and cyclosarin (GF) rank among the most toxic substances known, making trace-level detection critical for public and military safety. In this study, we compared the sensitivity of two analytical techniques for determining these nerve agents: gas chromatography with flame-photometric detection (GC-FPD) and gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS). Diluted samples of sarin, soman, and cyclosarin were prepared under controlled laboratory conditions and then analyzed by both methods. Limits of detection, calibration linearity, and selectivity of the two approaches were evaluated. It was shown that GC-ICP-MS enabled detection of sarin, soman, and cyclosarin at ≈0.12-0.14 ng/mL (LOD), whereas GC-FPD achieved LODs of ≈0.36-0.43 ng/mL. The obtained results confirm that GC-ICP-MS exhibits significantly higher sensitivity than GC-FPD in the analysis of the chemical warfare agents under study. This advantage indicates strong application potential of GC-ICP-MS as a technique for ultra-sensitive detection of trace amounts of chemical warfare agents (CWAs) in environmental samples and in confirmatory testing for compliance with the CWC, while simultaneously employing GC-FPD for rapid preliminary monitoring.