LC Separation of γ-Amino Acid Enantiomers

Three underivatized γ-amino acids were successfully enantioseparated by high-performance liquid chromatography on macrocyclic glycopeptide based chiral stationary phases. The effects of the alcohol modifier in the mobile phase and the column temperature on the enantioseparation were investigated. Apparent thermodynamic parameters were calculated from the plots of ln k or ln α versus 1/T. Some mechanistic aspects of chiral recognition are discussed with respect to the structures of the analytes. It was found that the enantioseparations were enthalpy-driven, the double bond in the analyte exerting a significant influence on the chiral recognition.