Capillary zone electrophoretic separation of β-blockers using citrate buffer at low pH

Abstract

Ten β-blockers were simultaneously separated by capillary zone electrophoresis using citrate buffer as a background electrolyte at low pH. The effects of buffer concentration and buffer pH on the migration behavior and separation of β-blockers were systematically investigated. The results indicate that the resolution of co-migrating analytes improves with increasing buffer concentration at a low pH and that the optimum pH of the buffer decreases with increasing buffer concentration. Complete separation of the β-blockers tested was achieved within a relatively short time with an appropriate concentration of citrate buffer in the range 160–400 m M and a proper pH in the range 3.0-1.8 using a 43 cm×50 μm I.D. fused-silica capillary at 15 kV.