Solid Supported Liquid–Liquid Extraction of Chemical Warfare Agents and Related Chemicals from Water

Trace-level quantification of N-nitrosopiperazine in treated wastewater using supported liquid extraction and hydrophilic interaction chromatography mass spectrometry

Regenerable amine-based solvents used for post-combustion CO2 capture, primarily monoethanolamine and piperazine, are known to undergo degradation and secondary reactions over time forming, amongst other species, N-nitrosamines. These carcinogenic species can eventually make their way from treated wastewater into environmental waters. The United States Environmental Protection Agency (US EPA) recommends that the concentration of N-nitrosamines in surface water not exceed 1.24 μg/L. We have developed a straightforward method to quantify N-nitrosopiperazine in treated wastewater by hydrophilic interaction liquid chromatography – mass spectrometry (HILIC–MS) after sample preparation by supported liquid extraction (SLE). To achieve the best extraction recovery and method limits of quantification (MLOQ), standards were prepared in a high-salt synthetic matrix to mimic the treated wastewater effluent. To further improve the MLOQ, the drying steps after extraction were optimized. HILIC separation of the highly polar analytes was achieved using an ethylene-bridged hybrid amide stationary phase. Detection was achieved using a triple quadrupole mass spectrometer operated in positive electrospray ionisation and multiple reaction monitoring mode, providing a final MLOQ of 0.25 μg/L for N-nitrosopiperazine. Validation of the method was carried out to ensure good confidence in the data obtained for a treated wastewater sample from a post-combustion CO2 capture facility. In addition, N-nitrosopiperazine was quantified with the developed SLE-HILIC–MS method in eight degraded carbon capture samples that had not yet undergone wastewater treatment.

Analysis of the Precursors, Simulants and Degradation Products of Chemical Warfare Agents

Recent advances in analysis of precursors, simulants and degradation products of chemical warfare agents (CWA) are reviewed. Fast and reliable analysis of precursors, simulants and CWA degradation products is extremely important at a time, when more and more terrorist groups and radical non-state organizations use or plan to use chemical weapons to achieve their own psychological, political and military goals. The review covers the open source literature analysis after the time, when the chemical weapons convention had come into force (1997). The authors stated that during last 15 years increased number of laboratories are focused not only on trace analysis of CWA (mostly nerve and blister agents) in environmental and biological samples, but the growing number of research are devoted to instrumental analysis of precursors and degradation products of these substances. The identification of low-level concentration of CWA degradation products is often more important and difficult than the original CWA, because of lower level of concentration and a very large number of compounds present in environmental and biological samples. Many of them are hydrolysis products and are present in samples in the ionic form. For this reason, two or three instrumental methods are used to perform a reliable analysis of these substances.