Chiral separation of neutral species by capillary electrophoresis - Evaluation of a theoretical model

A theoretical model has been developed for the separation of enantiomers of neutral species by employing a combination of charged and neutral cyclodextrins. A neutral compound (LY213829), an ionizable cyclodextrin (sulfobutylether-cyclodextrin), and three neutral cyclodextrins (beta-cyclodextrin, trimethyl-beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin) were chosen to test the model. The model parameters were obtained by performing two specific sets of experiments. Resolution and selectivity can be readily obtained from these model parameters. The validity of the model has been demonstrated by resolving enantiomers of LY213829 and its four isomeric sulfoxide metabolites, and the model was very successful in predicting the migration times and resolution of the LY213829 enantiomers. Baseline separation was achieved for all the analytes.