Separation of diastereomers by capillary zone electrophoresis with polymer additives: Effect of polymer type and chain length

Diastereomeric derivatives of enantiomers are separated by capillary zone electrophoresis in nonchiral separation systems in the presence of linear polymers. These polymers significantly influence the mobilities of the analytes as well as the stereoselectivity of the system. Three types of linear polymers, poly(vinylpyrrolidone), poly(ethylene glycol), and poly(acrylamide), are investigated to determine their influence on the stereoselective separation of diastereomeric derivatives of ?-amino acids obtained by reaction with optically pure (+)-O,O'-dibenzoyl-L-tartaric anhydride. Differences are found in the strength of the polymer effect and the effected migration order. Polymer chain length had no impact on stereoselectivity