Capillary electrochromatographic behaviors of dansyl amino acid enantiomers on a cyclodextrin-immobilized monolithic silica column

We describe the capillary electrochromatographic behaviors of dansyl amino acids on a gamma-cyclodextrin-immobilized monolithic silica column. The changes in the enantio-selectivity and retention behavior, were investigated when organic modifiers, like methanol, actonitrile and tetrahydrofuran were added in the mobile phases. It was found that the enantioselectivity could be manipulated by the addition of moderate organic solvents. The effect of the temperature on the separation behavior was also examined by a thermodynamic analysis. It was shown that a relatively low temperature under enthalpic control benefits the enantio-separation. Further, the relationship between the hydrophobicity of the analytes and the retention behavior was investigated.