DETERMINATION OF EFFECTIVE MOBILITIES AND CHIRAL SEPARATION SELECTIVITIES FROM PARTIALLY SEPARATED ENANTIOMER PEAKS IN A RACEMIC-MIXTURE USING PRESSURE MEDIATED CAPILLARY ELECTROPHORESIS

A new measurement principle has been developed for the rapid determina tion of the effective mobilities of enantiomers from their partially s eparated peaks. The method involves (i) partial separation of the enan tiomers of a racemic sample by electrophoresis, (ii) pressure mobiliza tion of the partially separated band by the detector, (iii) calculatio n of the effective separation distance between the enantiomer centroid s from the observed band width and the extent of theoretical band broa dening, and (iv) calculation of the effective mobilities of the enanti omers (and the separation selectivity) from the effective separation d istance. Experimental conditions that lead to negligible nonideal ioni c contributions to the band width are outlined. The proposed method el iminates the error caused by the changing electroosmotic flow, yields complexation constant and ionic mobility values that are more precise than the conventionally obtained ones, and reduces the measurement tim e by 80-90%. The equations required for the calculations are presented in a simple, ready-to-use spreadsheet format.