Electrophoretic behaviour of zwitterionic compounds in capillary electrophoresis - Prediction of mobility of several quinolones

A model of electrophoretic behaviour is studied in order to optimize the se paration of zwitterionic substances by capillary electrophoresis. The equat ions derived allow the electrophoretic mobilities of substances at each pH to be predicted and, consequently the resolution between pairs of substance s. The model considers the effect of ionic strength and can be applied to z witterionic substances with very dose pK(a) values. The model is tested to obtain the optimum pH values for the separation of a series of eight quinol ones on the basis of a few initial experiments. (C) 2000 Elsevier Science B .V. All rights reserved.