Gas chromatographic retention indices in GC/MS identification of alkyl dichlorophosphates, dialkyl chlorophosphates, and their thioanalogues
T16N1
I.G. Zenkevich, V.E. Nosova
Determining the set of analytical parameters for gas chromatographic/ mass spectrometric identification of reactive intermediate products of phosphoryl chloride (POCl3) and thiophosphoryl chrolide (PSCl3) interaction with aliphatic alcohols – O-alkyl dichlorophosphates (I), O,O-dialkyl chlorophosphates (II), O-alkyl dichlorothiophosphates (III), and O,O-dialkyl chlorothiophosphates (IV) is considered. The members of these series are not sufficiently presented in contemporary databases; the exception is the series (I) and (II), which are characterized with EI mass spectra (NIST MS Database, 2017) for 8 and 19 homologues, correspondingly. The set of data includes EI mass spectra and gas chromatographic retention indices (RI) on standard non-polar polydimethylsiloxane stationary phases. Strong differences in mass spectra of homologues of series (I) depending on conditions of their registration are revealed.
Comparing the RI values for alkyl chlorophosphates and -thiophosphates allows evaluating the increments for the hypothetic replacement of oxygen atom in the fragment P=O with sulfur atom (P=S), namely 59 ± 4 и 30 ± 4 for O-alkyl dichloro- and O,O-dialkyl chloroderivatives. Statistical processing of so-called homologous increments of retention indices leads to the average values attributed not to individual homologues, but to the homologous series. Using these values permits us evaluating the molecular weights of homologues containing no reliably detected signals of molecular ions in EI mass spectra.
