Separations of chemically different particles by capillary electrophoresis

Fast, well-resolved separations of mixtures of chemically different latex particles (different numbers of attached carboxylate or sulfate groups) have been successfully achieved by capillary electrophoresis. Best experimental conditions of column inside diameter and length, buffer concentration and pH, and applied voltage were identified for the separations. Electrophoretic migration times and mobilities were determined. The separations were characterized as to numbers of theoretical plates, selectivities, and resolution at different pH and applied voltage values. Numbers of theoretical plates ranged from about 400 to 3,000. Selectivities ranged from about 0.1 to 0.4, and resolution values ranged from 0.8 to 2.3. Electrophoretic mobilities varied especially at the higher applied voltages.