Screening of Nerve Agent Degradation Products by MALDI-TOFMS

Abstract

A novel method for the rapid screening of degradation products derived from nerve agents by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is described. Five standard products were selected as model compounds, including isopropyl methylphosphonic acid (IMPA), pinacolyl methylphosphonic acid (PMPA), ethyl methylphosphonic acid (EMPA), isobutyl methylphosphonic acid (i-BuMPA), and cyclohexyl methylphosphonic acid (CHMPA), which are degradation products of Sarin (GB), Soman (GD), VX, Russian VX (RVX), and GF, respectively. For comparison, CHCA (alpha-cyano-4-hydroxycinnamic acid) and DCCA (7-(diethylamino)coumarin-3-carboxylic acid) were used as the MALDI-matrix when the third harmonic generation (355 nm) of a Nd:YAG laser and a hydrogen Raman laser (multifrequency laser) were used, respectively. The method permitted the five nerve agent degradation products to be screened rapidly and successfully, suggesting that it has the potential for use as a routine monitoring tool.

Development of Spray Deposition/MALDI-TOFMS and Its Application to the Rapid Screening of Hydrolysis Products Derived from Nitrogen Mustards

“…The linear type of time-of-flight mass spectrometer (TOFMS), which was a modified Wiley-McLaren design (R. M. Jordan Co., Grass Valley, CA), laser (355 nm radiation generated from a Nd:YAG laser (Spectraphysics GCR-170, Mountain View, CA)) and the data-acquisition system used were similar to that described previously 17 and are abbreviated herein. A thermal type field emission scanning electron microscope (SEM), JSM-7000F, Japan Electron Optics Laboratory Co., Ltd. (JEOL) was used for surface observation.…”

“…[1][2][3][4][5][6][7][8][9] The analysis of low-mass (m/z < 500) molecules by this method has recently been reported. [10][11][12][13][14][15][16][17] For MALDI-TOFMS to be successful, the ratio of sample to matrix is a critical component. While simply applying a matrix solution and an analyte on a sample plate would appear to be an easy task, many variables influence the final results.…”

“…SEM (scanning electron microscopy) was used to examine differences between matrices prepared using the 2 methods; these data are included in this report. Furthermore, in an extension of our previous research, dealing with the rapid screening of nerve agent degradation products by MALDI-TOFMS, 17 seven hydrolysis products derived from nitrogen mustards were selected as model samples, and their detection was reexamined using the above mentioned technique. Several nations stock-piled large amounts of munitions containing nitrogen mustard gas during World War II, although none were used in combat.…”

Effect of Spacer and the Enzyme-Linked Immunosorbent Assay

“…Current analytical methods using gas and liquid chromatography for the detection of small molecular residues (Mw < 1000) like IMPA are sensitive and reliable 5 . However, they are costly and time-consuming due to the complicated sample preparations and derivatisation steps [6][7][8][9][10] . Therefore, there is a growing demand for more rapid and less costly methods for determining small molecular residues in the environmental sample.…”

An Evaluation of the Spectral Properties of Nerve Agents for Laser Ionization Mass Spectrometry

“…10 The LODs obtained using LC-MS-MS were comparable to those obtained using GC-NICI-MS-MS. 11,12 A technique of matrix-assisted laser desorption ionization/mass spectrometry (MALDI) has been utilized for rapid screening of nerve agent degradation products. 13 A technique involving GC combined with resonance-enhanced multiphoton ionization/time-of-flight mass spectrometry (GC/ REMPI/TOF-MS) has been developed and utilized for the trace analysis of a variety of toxic compounds, including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), [14][15][16][17][18][19][20] polybrominated diphenyl ethers, 21 and pesticides, 22 due to its superior sensitivity and selectivity. However, as can be easily recognized from the chemical structures of the above compounds, the absorption band for a nerve agent is not located in the ultraviolet (UV) region, but appears mainly in the vacuum-ultraviolet (VUV) region.…”