Unambiguous mass spectral characterization of VX and its six other structural isomers using gas chromatography–mass spectrometry

•Seven isomeric VX type nerve agents with molecular weight of 267 were synthesized and their MS spectra were studied under EI- and CI-MS conditions.•This study also focused on calculation of the electrophilicity index of VX and its structural isomers, in order to elucidate their reactive nature.•The results would be valuable during toxic chemical destruction monitoring in support of chemical weapons convention (CWC) and for the verification of state-parties activities, based on CWC context.

VX and its six other isomers which are potentially nerve agents with molecular weight of 267 were synthesized and their EI and CI MS spectra were studied. Although the major ions in the mass spectra for these isomers are similar, these chemicals could be distinguished based on some low abundance characteristic ions. Structures of fragments were assigned using EI-MS analysis of the deuterated analogs. Density functional theory was also applied to show preferred fragmentation pathways. This study is also focused on calculation of the electrophilicity index of VX and its structural isomers, in order to elucidate their reactive nature.

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