Field portable gas chromatography-mass spectrometry, GC-MS, have been established as the ‘gold standard’ of chemical identification and quantification for chemical threats however several chemical warfare agents have been shown to evade required detection limits. This work demonstrates the derivatization of O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX) and N,N-diethyl-2-[methyl(2-methylpropoxy)phosphoryl]sulfanylethanamine (Russian VX, RVX) into VX-G (O-ethyl methylphosphonofluoridate) and RVX-G (O-isobutyl methylphosphonofluoridate) through V-to-G conversion. The G-analogues of VX and RVX are collected on Tenax® TA thermal desorption tubes and are then analyzed by thermal desorption GC-MS. Each thermal desorption tube is loaded with a target-based standard called a focusing agent. Here, we provide relative response factors for the focusing agent diethyl malonate as well as diethyl ethylthiophosphonate that is derivatized into the G-analogue. Our results provide a more reliable and reproducible quantification method for VX (10.4% RSD) and RVX (10.9% RSD) than the bromopentafluorobenzene internal standard (32.9% RSD).

现场便携式气相色谱-质谱联用仪 (GC-MS) 已被确立为化学威胁的化学鉴定和量化的“黄金标准”，但已证明有几种化学战剂可以规避所需的检测限。这项工作证明了 O-乙基 S-(2-二异丙基氨基乙基) 甲基硫代膦酸酯 (VX) 和 N,N-二乙基-2-[甲基(2-甲基丙氧基)磷酰基]硫基乙胺 (俄罗斯 VX, RVX) 衍生化为 VX-G ( O-乙基甲基膦酰氟）和 RVX-G（O-异丁基甲基膦酰氟）通过 V 到 G 的转化。VX 和 RVX 的 G 类似物在 Tenax® TA 热解吸管上收集，然后通过热解吸 GC-MS 进行分析。每个热解吸管都装有一种基于目标的标准，称为聚焦剂。这里，我们提供了聚焦剂丙二酸二乙酯以及衍生为 G 类似物的乙硫代膦酸二乙酯的相对响应因子。我们的结果为 VX (10.4% RSD) 和 RVX (10.9% RSD) 提供了比溴五氟苯内标 (32.9% RSD) 更可靠和可重现的定量方法。