GAS-CHROMATOGRAPHIC SEPARATION OF AMINO-ACID ENANTIOMERS AND THEIR RECOGNITION MECHANISM ON A O-BUTYL-3-O-TRIFLUOROACETYLATED-GAMMA-CYCLODEXTRIN CAPILLARY COLUMN

Some amino acids and 2- and 3-hydroxybutyric acid derivatives were res olved on a chiral capillary column coated with -butyl-3-O-trifluoroace tylated-gamma-cyclodextrin, and their thermodynamic data were obtained from this stationary phase. Obvious differences in Delta(Delta H degr ees) and Delta(Delta S degrees) were observed among these amino acids. The enthalpy-entropy compensation and structural effects were analyse d with consideration of chiral recognition. The results suggested that the induced conformation fit between enantiomers and cyclodextrin der ivatives could be important in chiral recognition. The enantiomers wit h large negative Delta(Delta H degrees) and Delta(Delta S degrees) val ues could form inclusion complexes and the separation of enantiomers w ith small negative Delta(Delta H degrees) and Delta(Delta S degrees) v alues could be due to other types of interactions.