A Modified QuEChERS-DART-MS/MS Technique for High-Throughput Detection of Organophosphate Nerve Agent Hydrolysis Products in Environmental Samples

Organophosphate nerve agents (OPNAs) are lethal chemical weapons (CWs) which hydrolyze rapidly to alkyl phosphate compounds in the environment. The identification of alkyl phosphate compounds in the environment is critical for the verification of OPNAs. Currently, due to the complex sample preparation and long detection process for organophosphate nerve agent hydrolysis products (OPNAHPs), their high-throughput determination is difficult. To simplify sample preparation and detection of OPNAHPs from environmental samples, a quick, easy, cheap, effective, rugged and safe (QuEChERS) method for the simultaneous purification of the five OPNAHPs in environmental samples combined with detection through direct analysis in real-time ionization source coupled with tandem mass spectrometer (DART-MS/MS) was developed. An internal standard method was applied for the quantification. The method exhibited a good linearity (R2 > 0.991) in the range of 1.00 ng/mL-4.00 μg/mL. The limits of detection and limits of quantification were 1.00–7.00 ng/mL and 10.0–20.0 ng/mL, respectively. The recoveries of OPNAHPs in environmental samples were between 65.3% and 107%, with relative standard deviations ranged from 1.6% to 19%. In addition, the sample preparation and analysis process for OPNAHPs could be completed in less than 10 min. The results demonstrated that the modified QuEChERS method could quickly and efficiently remove the matrix of environmental samples. Combined with DART-MS/MS, an accurate and high-throughput detection method of OPNAHPs in environmental samples was provided. The developed method has great potential in the fields of early warning, clinical treatment and environmental decontamination.