Structural characterization of Chemical Weapons Convention-related phosphonoselenoates by electron ionization and electrospray ionization mass spectrometry.

RATIONALE: Organophosphorus compounds with phosphorus atom bonded to one methyl, ethyl or propyl (normal or iso) group are listed in Schedule 2 of the Chemical Weapons Convention (CWC). Selenophosphorus compounds, listed in Schedule 2.B.4, have very limited representation in mass spectral libraries and the open literature.

METHODS

Members of a new category of selenophosphorus compounds were prepared via microsynthetic protocols and their fragmentation pathways were investigated using electron ionization (EI) and positive electrospray ionization (ESI) mass spectrometry. The EI and ESI fragmentation pathways were suggested and supported by acquired fragment ions of deuterated analogs and density functional theory calculations.

RESULTS

Mass spectrometric investigations showed some interesting fragmentation pathways, such as McLafferty-type, selenono-selenolo rearrangements, intramolecular electrophilic aromatic substitution reaction and α-cleavage.

CONCLUSIONS

Efficient microsynthesis was conducted, and EI-MS spectra and ESI-MS/MS spectra of a series of selenophosphorus compounds were collected and studied with the purpose of identifying CWC-related chemicals during on-site inspection and/or off-site analysis.