Mass spectral study on O,O-dialkyl N,N-dialkyl phosphoramidates under electron impact conditions

Reddy, T. Jagadeshwar; Prabhakar, S.; Saradhi, U.V.R. Vijaya; Rao, V. Jayathirtha; Vairamani, M.

doi:10.1016/j.jasms.2003.12.008

Cited by 16 publications

(17 citation statements)

References 19 publications

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“…However, loss of C 3 H 6 is always more favoured in compounds containing an isopropyl group. A similar type of fragmentation was reported by us previously 33. Typical spectra are shown in Fig.…”

Section: Resultssupporting

confidence: 86%

“…The product ions characteristic of the sulphonate part are not observed. Although the molecular weights of the compounds belonging to the N,N ‐dialkylaminoethylsulphonic acid series match with those of the dialkyl N,N ‐dialkyl phosporamidate series (hydrolysis products of tabun and its possible analogues),33 it is possible to identify the sulphonic acids with the above observed product ions. However, as it is better to have structure‐indicative product ions of the sulphonic acid group, we decided to study the dissociation of the [M+Na] + ions.…”

Section: Resultsmentioning

confidence: 99%

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Electrospray ionization mass spectral studies of N,N‐dialkylaminoethane‐2‐sulphonic acids

Lakshmi

Prabhakar

Murty

et al. 2007

Rapid Comm Mass Spectrometry

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Oxidative reactions of VX type compounds and N,N-dialkylaminoethane-2-thiols that are precursors for VX compounds produce N,N-dialkylaminoethane-2-sulphonic acids, N(R(1))(R(2))-CH(2)-CH(2)SO(3)H (where R(1) and R(2) = methyl, ethyl, n-propyl and isopropyl, 1-10), as the degradation products, and these degradation products are considered as markers for the detection of chemicals listed in the schedules of Chemical Weapons Convention (CWC) chemicals. Off-site detection of such degradation products in aqueous samples is an important task in the verification of CWC-related chemicals. Here we report a simple method involving the direct analysis of aqueous samples using positive and/or negative ion electrospray ionization (ESI) for the screening, detection and identification of N,N-dialkylaminoethane-2-sulphonic acids, avoiding sample preparation and chromatographic steps. The positive ion ESI mass spectra of all the compounds result in abundant [M+Na](+) ions, and the negative ion spectra show abundant [M-H](-) ions to confirm their molecular weight. The collision-induced dissociation spectra of [M+Na](+) and [M-H](-) give characteristic product ions by which it is easy to detect and identify all the studied N,N-dialkylaminoethane-2-sulphonic acids including those of isomeric compounds. The method is successfully applied to detect the spiked chemical, N,N-diisopropylaminoethane-2-sulphonic acid, present in a water sample received in a proficiency test.

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Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Electrospray ionization mass spectral studies of N,N‐dialkylaminoethane‐2‐sulphonic acids

Lakshmi

Prabhakar

Murty

et al. 2007

Rapid Comm Mass Spectrometry

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“…CWA are generally volatile in nature and hence these compounds have been analyzed by employing gas chromatography (GC)‐based techniques in conjunction with element‐specific detectors or mass‐selective detectors under electron ionization (EI) and chemical ionization (CI) mass spectrometric conditions 21–32. The hydrolysis/oxidation of CWA produces polar and non‐volatile compounds that requires an additional derivatization step to enable them to be analyzed by GC‐based techniques.…”

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confidence: 99%

Mass spectral analysis of N‐oxides of Chemical Weapons Convention related aminoethanols under electrospray ionization conditions

Sridhar

Karthikraj

Murty

et al. 2011

Rapid Comm Mass Spectrometry

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N,N'-Dialkylaminoethanols are the hydrolyzed products or precursors of chemical warfare agents such as V-agents and nitrogen mustards, and they are prone to undergo oxidation in environmental matrices or during decontamination processes. Consequently, screening of the oxidized products of aminoethanols in aqueous samples is an important task in the verification of chemical weapons convention-related chemicals. Here we report the successful characterization of the N-oxides of N,N'-dialkylaminoethanols, alkyl diethanolamines, and triethanolamine using positive ion electrospray ionization mass spectrometry. The collision-induced dissociation (CID) spectra of the [M+H](+) and [M+Na](+) ions show diagnostic product ions that enable the unambiguous identification of the studied N-oxides, including those of isomeric compounds. The proposed fragmentation pathways are supported by high-resolution mass spectrometry data and product/precursor ion spectra. The CID spectra of [M+H](+) ions included [MH-CH(4)O(2)](+) as the key product ion, in addition to a distinctive alkene loss that allowed us to recognize the alkyl group attached to the nitrogen. The [M+Na](+) ions show characteristic product ions due to the loss of groups (R) attached to nitrogen either as a radical (R) or as a molecule [R+H or (R-H)] after hydrogen migration.

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“…fragment ion L (m/z 47) is typical of EI-MS of organophosphorus compounds. [13][14][15][16][17][18] It is interesting to note that all possible combinations of H/D were observed for ions J and K in the spectra of deuterated AMPs (entries 1-10 for ions J and K, table 1). It indicates that fragment ions with low mass range undergo extensive hydrogen rearrangement in the EI-MS of these compounds.…”

Section: Resultsmentioning

confidence: 99%

Gas Chromatography Electron Ionization Mass Spectrometric Analysis ofO-Alkyl Methylphosphinates for Verification of Chemical Weapons Convention

Pardasani

Kanaujia

Tak

et al. 2009

Eur J Mass Spectrom (Chichester)

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We describe the gas chromatography/mass spectrometric (GC/MS) analysis of O-alkyl methylphosphinates (AMPs), which are included in schedule 2B4 chemicals in the Chemical Weapons Convention (CWC). GC/MS analysis of variety of AMPs and their deuterated analogues revealed that their fragmentations were determined by alpha-cleavages, McLafferty +1 and hydrogen rearrangements. Based on the obtained electron ionization mass spectra of AMPs the fragmentation routes were rationalized, which were substantiated by the GC/MS analysis of deuterated analogues.

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Mass spectral study on O,O-dialkyl N,N-dialkyl phosphoramidates under electron impact conditions

Cited by 16 publications

References 19 publications

Electrospray ionization mass spectral studies of N,N‐dialkylaminoethane‐2‐sulphonic acids

Electrospray ionization mass spectral studies of N,N‐dialkylaminoethane‐2‐sulphonic acids

Mass spectral analysis of N‐oxides of Chemical Weapons Convention related aminoethanols under electrospray ionization conditions

Gas Chromatography Electron Ionization Mass Spectrometric Analysis ofO-Alkyl Methylphosphinates for Verification of Chemical Weapons Convention

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