Separation and Migration Behavior of Benzophenones in Capillary Zone Electrophoresis

The migration behavior and separation of eight benzophenones selected were investigated by capillary zone electrophoresis in the range of pH 7.5-11.5. The effect of buffer pH, the types of buffer electrolyte, and the concentration of phosphate-borate buffer on the separation and selectivity of benzophenones selected were examined. Better separability can be obtained with phosphate-borate buffer than with phosphate buffer or borate buffer at around pH 9.2. Baseline separation of eight benzophenones could be simultaneously and successfully achieved with an appropriate choice of buffer pH and the concentration of phosphate-borate buffer in capillary zone electrophoresis. The migration order of benzophenones selected could be explained on the basis of the degree of ionization and molecular mass.