Elemental composition determination of organophosphorus compounds using gas chromatography and atomic emission spectrometric detection

The elemental responses for a series of alkylated and arylated phosphates evaluated were measured on an atomic emission spectrometric detector. The signals for carbon, hydrogen, chlorine, phosphorus and oxygen were used to determine the specifity of elemental response ratios to a particular compound structure and the dependence of response ratios on the amounts of the analytes. Variations of the response ratios, as well as the accuracy and variations of the stoichiometric values of the calculated empirical formulae, were evaluated. For this purpose, a test mixture with reference compounds was used. Determination of empirical formulae with acceptable errors of a few percent is possible if the calibrating reference substance is closely related — by structure, elemental composition, molecular weight and amount — to the compounds to be identified. Analyte amounts of at least 30 ng are required for efficient calibration.