[Evaluation of the retention properties of two cyclodextrin stationary phases with different spacers].

A set of 14 model compounds were selected to evaluate the retention properties of two silica-based cyclodextrin (CD) bonded stationary phases with different spacers (Click Alkyl-CD and Click OEG-CD) under reversed-phase liquid chromatographic (RPLC) mode. The gradient calculation method and CSASS software developed in our group were applied to obtain the retention parameters of the 14 solutes on the two CD bonded stationary phases under 3 gradient conditions. The effect of acetonitrile content in the mobile phase on the retention of both CD stationary phases was studied. It was found that the retention of non-polar and medium polar compounds on the both stationary phases was based on RPLC mode, while the retention of some compounds (such as indazole) on Click OEG-CD was influenced by several kinds of interactions and was not based on RPLC mode. The hydrophobic property of the two CD stationary phases in RPLC mode was studied. High correlation value (R = 0.7) between the retention parameter of Click Alkyl-CD and n-octanol-water partition coefficients of the solutes indicated the high hydrophobicity of Click Alkyl-CD. Nevertheless, the low correlation value (R < 0.3) between the retention parameter of Click OEG-CD and n-octanol-water partition coefficients indicated the presence of influence of other interactions in addition to hydrophobic interaction on the retention in RPLC mode.