title: Microsynthesis and electron ionization mass spectral studies of O(S)-alkyl N,N-dimethyl alkylphosphono(thiolo)thionoamidates for Chemical Weapons Convention verification.
abstract: BACKGROUND
  The availability of mass spectra and interpretation skills are essential for unambiguous identification of the Chemical Weapons Convention (CWC)-related chemicals. The O(S)-alkyl N,N-dimethyl alkylphosphono(thiolo)thionoamidates are included in the list of scheduled CWC-related compounds, but there are very few spectra from these compounds in the literature. This paper examines these spectra and their mass spectral fragmentation routes.
  
  
  METHODS
  The title chemicals were prepared through microsynthetic protocols and were analyzed using electron ionization mass spectrometry with gas chromatography as a MS-inlet system. Structures of fragments were confirmed using analysis of fragment ions of deuterated analogs, tandem mass spectrometry and density functional theory (DFT) calculations.
  
  
  RESULTS
  Mass spectrometric studies revealed some interesting fragmentation pathways during the ionization process, such as alkene and amine elimination and McLafferty-type rearrangements. The most important fragmentation route of the chemicals is the thiono-thiolo rearrangement. DFT calculations are used to support MS results and to reveal relative preference formation of fragment ions. The retention indices (RIs) of all the studied compounds are also reported.
  
  
  CONCLUSIONS
  Mass spectra of the synthesized compounds were investigated with the aim to enrich the Organization for the Prohibition of Chemical Weapons (OPCW) Central Analytical Database (OCAD) which may be used for detection and identification of CWC-related chemicals during on-site inspection and/or off-site analysis such as OPCW proficiency tests.
authors.affiliation: Department of Science, Payame Noor University (PNU), P.O. Box 19395-4697, Tehran, Iran. dcrl@isiran-net.com
authors.forename: Hamdollah
authors.initials: H
authors.lastname: Saeidian
authors.forename: Mehran
authors.initials: M
authors.lastname: Babri
authors.forename: Morteza
authors.initials: M
authors.lastname: Abdoli
authors.forename: Mansour
authors.initials: M
authors.lastname: Sarabadani
authors.forename: Davood
authors.initials: D
authors.lastname: Ashrafi
authors.forename: Mohammad Taghi
authors.initials: MT
authors.lastname: Naseri