Original

Thermodynamic Properties of Enantioseparation of Two N.Carbobenzyloxy.D, L.Amino Acids on Cellulose Tris (4.methylbenzoate) Chiral Stationary Phase

Masato Kazusaki*, Toshiya Shoda, Hirofumi Kawabata and Toshikazu Yamaguchi

Department of Chemical Analysis, Pharmaceutical Research Laboratories, Dainippon Pharmaceutical Co., Ltd. 1-5-51 Ebie, Fukushima-ku, Osaka, 553.0001, Japan

Abstract:

The isocratic retention of enantiomers of N.carbobenzyloxy.D, L.tryptophan and N.carbobenzyloxy.D, L.phenylalanine was studied on cellulose tris (4.methylbenzoate) coated on silica as a chiral stationary phase at different temperatures and with different mobile phase compositions in the reversed.phase mode. The thermodynamic parameters were calculated in order to promote an understanding of the relationship between enthalpy and entropy for enantioseparation in this chromatographic system. The separation was enthalpy.controlled with negative entropic contribution in the HPLC condition studied. The enthalpy.entropy relationship indicates that enthalpic gain/loss for enantioseparation from any change of organic modifier content in the mobile phase is almost cancelled out by the entropic loss/gain.

Keywords: cellulose tris (4.methylbanzoate) chiral stationary phase, enantioseparation, enthalpy.entropy compensation

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