The potential of the widely used chiral stationary phase for high-performance liquid chromatography (HPLC) enantioseparations, cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC, sold under the trade name Chiralcel OD) was evaluated under the conditions of nonaqueous capillary electrochromatography (CEC). The effect of the particle size of the silica gel, the loading of CDMPC on the silica gel and nature of the organic solvent, as well as electrolyte salts on the separation characteristics were investigated. This study illustrates the applicability of CDMPC for obtaining highly efficient enantioseparations under the conditions of nonaqueous CEC. Comparative study of enantioseparations in capillary liquid chromatography (CLC) and CEC indicated the significant advantages of CEC such as higher plate number at the similar linear flow rates of the mobile phase as well as better tolerance of higher linear flow rates.

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The effect of the amount of the chiral selector, cellulose tris(3,5-dichlorophenylcarbamate) (CDCPC) on the separation characteristics of enantiomers of some charged and neutral analytes was studied in capillary electrochromatography (CEC). For better understanding of the effect of the loading of the chiral selector on the particles and pore size of the packing material, laser-beam particle size analyzer and scanning electron microscopy (SEM) were used. As shown in this study, CDCPC can be used for CEC enantioseparations of a wide range of chiral charged and neutral analytes with high efficiency. The loading of the polysaccharide derivative on the surface of silica materials even in high amounts does not markedly affect the particle size and porous structure of the packing material. The separation characteristics are strongly affected by the loading of CDCPC onto silica gel in both CEC and capillary liquid chromatography (CLC).

SummaryThe enantioseparation of chiral phenothiazine derivatives has been studied in capillary electrophoresis (CE) using various cyclodextrins (CD) such as native 0~,/?, and y-CD and some of their neutral and charged derivatives. Comparative binding studies were performed using nuclear magnetic resonance (NMR) spectrometry. The advantages and disadvantages of the binding parameters obtained in both techniques (NMR and CE) from the viewpoint of separation optimization are discussed.ques seem to be a promising approach for mechanistic studies and the optimization of enantioseparations in CE.However, before applying the data obtained with one technique for the optimization in another technique the question must be answered how transferable are the data from one technique to another. Previous studies [2, 4, 18 20] described good correlation's between CE and NMR spectrometric data. Both techniques are liquid-phase techniques with a comparable degree of freedom of the chiral selector and the selectand.In this work the interaction between the enantiomers of promethazine (PMZ) and native 13-CD was studied with CE and N M R spectrometry. The data obtained in both techniques were compared from the viewpoint of enantioseparation optimization in CE.

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