Loading Effects and Adsorption Isotherms for Single and Dual Chiral Systems Applying Ligand Exchange Chromatography

The adsorption behavior of five amino acid racemic mixtures applying ligand exchange chromatography for their enantioselelctive separation under the simultaneous interaction of two chiral selectors was investigated. Single and dual chiral systems consisting of a commercially available non-chiral column and a commercially available chiral column using a chiral mobile phase were applied. The adsorption isotherms for three amino acids were determined for both systems only in the linear range due to displacement effects. Additional loading effects investigations reveal decrease of the capacity factors when applying the single chiral system (no base line separation) compared to the dual one. Furthermore, the selectivity for the dual system was always higher than one.