CHROMATOGRAPHY, Vol. 28 (2007), No. 3, pp. -125

Extra-thermodynamic study on enantioseparation was carried out with N-carbobenzyloxy-D,L-leucine on amylose tris (3,5-dimethylbenzoate) coated on silica as the chiral stationary phase and a mixture of acetonitrile and phosphate buffer as the mobile phase at different column temperatures. Modification of mobile phase composition had a little impact on separation factor between enantiomers. The van’t Hoff plots of retention factor and separation factor were linear over the temperature range studied. Enthalpy.entropy compensation for enantioseparation was formally established by the methods proposed by Krug et al. Compensation temperature for enantioseparation was calculated to be 69.4 ^oC, indicating nearly-constant values of the difference in Gibbs free energy change over the usable column temperature range.