MALDI‐TOF Mass Spectrometric Analysis of Chemical Warfare Nerve Agent Simulants

Abstract

To avoid possible danger, simulants of chemical warfare nerve gas agents, such as dimethyl methylphosphonate (DMMP), triethyl phosphate (TEP), di(propylene glycol) monomethyl ether (DPGMME), methyl salicylate, and diethyl phthalate (DEP), are often used for the development of a new detection and analysis method. In the present study, several MALDI matrices were evaluated to determine the optimal matrix for the simultaneous Matrix‐Assisted Laser Desorption/Ionization Time‐of‐Flight Mass Spectrometry (MALDI‐TOF MS) detection of the above‐mentioned five chemical warfare agent (CWA) simulants, and α‐cyanohydroxycinnamic acid (CHCA) was found to be most effective in detecting all of the simulants without interference from strong background matrix peaks. Furthermore, the limits of detection for the five simulants were roughly estimated with the CHCA matrix. This information is expected to be important for the development of future electrowetting‐on‐dielectrics (EWOD)‐based sample preparation methods that can be subjected to subsequent analysis by MALDI‐TOF MS.

The ionization process of chemical warfare agent simulants in low temperature plasma ionization

“…Because of the polarity of hydroxyl (-OH or -OD), hydrogen atom ionization easily generated D þ (H þ ) ( Figure S1), so m/z126.0 appeared in the spectra. Because the ionization took place at atmospheric pressure, the water vapor in the air was ionized to produce water cluster ions (H 2 O) n H þ 26-29 and the proton affinity of DMMP was greater than that of the water cluster ions, so the H þ ions were transferred to DMMP molecule via proton transfer reaction, as shown in reaction (1). This was the reason that the m/z125.0 was witnessed in the spectra while using CD 4 O as the solvent.…”

“…The threat of chemical warfare agents (CWAs) persists till date. For the on-site rapid detection and identification of CWAs, several technologies have been applied, such as mass spectrometry, [1][2][3] ion mobility spectrometry, [4][5][6][7][8] Raman spectroscopy, 9,10 and surface acoustic wave technology. 11 The Organization for the Prohibition of Chemical Weapons adopted solidphase extraction and liquid-liquid extraction coupled with GC-MS to detect CWAs in soil, asphalt, and other substrates.…”