Insights into chiral recognition mechanisms in supercritical fluid chromatography. II. Factors contributing to enantiomer separation on tris-(3,5-dimethylphenylcarbamate) of amylose and cellulose stationary phases

In this second part of our work on enantioselective supercritical fluid chromatography (SFC), we investigate the factors participating in the chiral recognition process on tris-(3,5-dimethylphenylcarbamate) of amylose and cellulose chiral stationary phases (CSPs). 135 racemates with diverse structures were analysed under identical SFC conditions on both stationary phases. The possibility of identifying the differential interactions of an enantiomer pair within the chromatographic system is assessed using a modified version of the solvation parameter model and factorial discriminant analysis. It is illustrated that one relationship of intermolecular interactions is insufficient to express the enantioseparation of different groups of racemates. An innovative approach is used in unravelling the interactions taking part in the enantiorecognition process. Different intermolecular interactions participating in the enantiomeric separation are demonstrated between the two stationary phases.