COUPLED COLUMN CHROMATOGRAPHY IN CHIRAL SEPARATIONS - SYSTEMS EMPLOYING BETA-CYCLODEXTRIN PHASES FOR CHIRAL SEPARATION

Two-dimensional chromatographic systems were evaluated which combine a beta-cyclodextrin (beta-CD)-containing column for the optical resolution of enantiomers with a non-chiral column for the preseparation of these enantiomers from other solutes or impurities. beta-CD is used either as a chemically bonded stationary phase or as a mobile phase additive. This multi-column system allows the accurate determination of the enantiomeric composition even in complex samples and improves the significance and reliability of the results. The system was evaluated with respect to peak dilation caused by the carry-over, the maximum carry-over volume up to which severe adverse effects on the resolution can be avoided, and the implications with regard to sensitivity.