Lewisite Metabolites in Urine by Solid Phase Extraction—Dual Column Reversed-Phase Liquid Chromatography—Isotope Dilution Tandem Mass Spectrometry

• Published in: Journal of analytical toxicology Vol. 40; no. 6; pp. 419 - 426
• Main Authors: Palcic, Jason D., Donovan, Stephen F., Jones, Janet S., Flagg, E. Lindsay, Salonga, Redentor A., Mock, Walter E., Asirvatham, Victor S.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.07.2016
• Subjects: Arsenicals - analysis; Arsenicals - urine; Chemical Warfare Agents - analysis; Chemical Warfare Agents - metabolism; Chromatography, Liquid; Humans; Solid Phase Extraction; Tandem Mass Spectrometry
• ISSN: 0146-4760; 1945-2403
• DOI: 10.1093/jat/bkw049

Lewisite (2-chlorovinyldichloroarsine) is a chemical warfare agent developed during World War I. A quantitative method using solid phase extraction (SPE) followed by dual column liquid chromatography (LC)—isotope dilution tandem mass spectrometry (MS-MS) was developed for the determination of (2-chlorovinyl)arsonic acid (CVAOA), a metabolite of Lewisite, in human urine. The sample was treated with hydrogen peroxide to oxidize any (2-chlorovinyl)arsonous acid (CVAA) that remained in the trivalent arsenic oxidation state. There was 1.19% (arsenic purity) of bis-(2-chlorovinyl)arsinic acid (BCVAOA), a minor Lewisite metabolite, in the stock CVAA material. The high-throughput method qualitatively assessed BCVAOA simultaneously utilizing normal-phase silica SPE followed by reversed-phase C18 LC for an orthogonal separation. The chromatographic method results in a 5.8-min cycle time with adequate retention (k′ = 2.4) of CVAOA. The mass spectrometer was operated in positive electrospray ionization mode with quantitative m/z 186.9→61.0 and confirmation 186.9→91.0 mass transitions. This selective method demonstrated linearity, accuracy and reproducibility for the clinically relevant calibration range (25–3,200 µg/L as CVAA). The method detection limit was 3.3 µg/L as CVAA from a 10 µL injection. This LC–MS-MS emergency response method has a throughput of >240 samples (2.5 extracted 96-well plates) per day.