Using new structurally related additive schemes in the precalculation of gas chromatographic retention indices of polychlorinated hydroxybiphenyls on HP-5 stationary phase

A new additive scheme is proposed for the precalculation of gas chromatographic retention indices of complex organic compounds. The principal feature of this approach is the absence of previously calculated I increments for any structural fragments or functional groups in the molecule. Instead, arithmetical operations involving I values of simpler structural analogues of target compounds are used directly. I precalculation for polychlorinated hydroxybiphenyls (839 congeners) on the HP-5 stationary phase was chosen as one of the most important applications of the method under discussion. Such a large number of congeners cannot be obtained as reference samples and their gas chromatographic (GC)–mass spectrometric (MS) identification should therefore be based currently on precalculated I values.