Trace Level Determination of Lewisite in Water by Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry with Selected Ion-Monitoring

A new analytical procedure was developed for the extraction of Lewisite of chemical warfare agents from water and for derivatization prior to analysis by gas chromatography-mass spectrometry (GC-MS) with selected ion-monitoring. Firstly, lewisite and its degradation products 2-chlorovinylarsonous acid (CVAA) or 2-chlorovinylarsenous oxide(CVAO) or 2-chlorovinylarsonic acid (CVAOA) were derivatized with the propane- 1,3-dithiol, then SPME with 100 mum polydimethylsiloxane (PDMS) and analyzed. The experimental results indicated that the recoveries were more than 95%, the lowest detected concentration is 0.0002 mg/L, and the relative standard deviation of seven injections is 3.2%. This method could satisfy the requirements for the destruction of abandoned chemical weapons by Japan in China.