SummaryCapillary gas chromatographic enantiomer separation of some polar compounds, including a-phenylethylamine, styrene oxide, pyrethroid insecticides and other carboxylates, was investigated on modified cyclodextrin (CD) chiral stationary phases. The chiral stationary phases studied included permethylated fl-CD (PMBCD), hep-(DNTBCD), the mixture of PMBCD and DBBBCD, and the mixture of PMBCD and DNTBCD. On the mixed chiral stationary phases containing the mixtures ofderivatized cyctodextrins, enantiomer separation was improved significantly for some compounds as compared to the single cyclodextrin derivative chiral stationary phases, and synergistic effects were observed for some compounds on the mixed cyclodextrin derivative chiral stationary phases.

SummarySeparation of the enantiomers of 2-phenylcyclopropanecarboxylate esters has been investigated on derivatized cyclodextrin chiral stationary phases (CD CSPs) to enable direct determination of the enantiomeric purity of the products of enantioselective cyclopropanation. Four stereoisomers of these chiral compounds could be resolved to baseline on permethylated fi-cyclodextrin CSR Some unusual phenomena, iso-enthalpy retention behavior and entropically driven chiral separation, were observed for the enantioseparation of 2-phenylcyclopropanecarboxylates on the CD CSPs. Thermodynamic parameters were evaluated and an enthalp~entropy compensation effect was observed for n-alkyl esters of 2-phenylcyclopropanecarboxylate separated on CD CSPs.