Determination of ebrotidine metabolites in overlapping peaks from capillary zone electrophoresis using chemometric methods

This paper illustrates the possibilities of chemometric methods in the reso lution and quantification of various compounds in overlapping peaks from ca pillary electrophoresis. Ebrotidine and most of its metabolites were effici ently separated by capillary zone electrophoresis (CZE) in a fused-silica c apillary. However, the procedure was not suitable for the physical separati on of the three less ionizable metabolites, which comigrated and overlapped with the electroosmotic flow signal. Multivariate curve resolution based o n an alternating least squares procedure was used for their mathematical re solution. For such a purpose, data obtained in the CZE system with a diode array detector, which consisted of UV spectra registered over time, were an alyzed. The ebrotidine metabolites were successfully resolved and quantifie d in synthetic mixtures and urine samples.