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Fragmentation pathways and structural characterization of organophosphorus compounds related to the Chemical Weapons Convention by electron ionization and electrospray ionization tandem mass spectrometry
Author(s) -
Hosseini Seyed Esmaeil,
Saeidian Hamid,
Amozadeh Ali,
Naseri Mohammad Taghi,
Babri Mehran
Publication year - 2016
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7757
Subject(s) - chemistry , electron ionization , electrospray ionization , fragmentation (computing) , tandem mass spectrometry , mass spectrometry , chemical ionization , mass spectrum , collision induced dissociation , ionization , protonation , analytical chemistry (journal) , computational chemistry , chromatography , ion , organic chemistry , computer science , operating system
Rationale For unambiguous identification of Chemical Weapons Convention (CWC)‐related chemicals in environmental samples, the availability of mass spectra, interpretation skills and rapid microsynthesis of suspected chemicals are essential requirements. For the first time, the electron ionization single quadrupole and electrospray ionization tandem mass spectra of a series of O ‐alkyl N ‐[bis(dimethylamino)methylidene]‐ P ‐methylphosphonamidates (Scheme 1, cpd 4 ) were studied for CWC verification purposes. Methods O ‐Alkyl N ‐[bis(dimethylamino)methylidene]‐ P ‐methylphosphonamidates were prepared through a microsynthetic method and were analyzed using electron ionization and electrospray ionization mass spectrometry with gas and liquid chromatography, respectively, as MS‐inlet systems. General EI and ESI fragmentation pathways were proposed and discussed, and collision‐induced dissociation studies of the protonated derivatives of these compounds were performed to confirm proposed fragment ion structures by analyzing mass spectra of deuterated analogs. Results Mass spectrometric studies revealed some interesting fragmentation pathways during the ionization process, such as McLafferty rearrangement, hydrogen rearrangement and a previously unknown intramolecular electrophilic aromatic substitution reaction. Conclusions The EI and ESI fragmentation routes of the synthesized compounds 4 were investigated with the aim of detecting and identifying CWC‐related chemicals during on‐site inspection and/or off‐site analysis and toxic chemical destruction monitoring. Copyright © 2016 John Wiley & Sons, Ltd.