Research And Application Of High Performance Capillary Electrophoresis With Amperometric Detection

High performance capillary electrophoresis (HPCE) has been developed as a powerful separation technique and applied in a wide range of analytical fields since it came out. It possesses many advantages including high performance, high speed, trace analytes and sample consumption. Electrochemical detection (ECD) in combination with HPCE takes advantages of high sensitivity and selectivity, fairly simple instruments compared to other detection modes of CE. This dissertation focuses on the application of CE with end-column amperometric detection described as following. 1. Determination of Propranolol by Capillary Electrophoresis with End-Column Amperometric Detection Amperometric detection of propranolol on carbon fibre electrode (GEE) by capillary zone electrophoresis was described. The electrochemical behavior was observed and the analytical conditions were optimized. The optimum conditions were as following: 40 cm length 25 ~tm i.d. separation capillary; separation voltage 15 kV; electrokinetic injection 3 second at 15 kV; detection potential +1.2 V; pH 7.5 10 mmol/L phosphate buffer solution. Under these conditions, the detection limit (LOD) of propranolol was as low as 5x 1 O8mol/L and the linear range was from 1x106 mol/L to 2xlO4mol/L with the relative coefficient of 0.994. The CFE electrode was stable and reproducible during the experiment. This method was applied to analyze the human urine sample and the recovery was also investigated with satisfactory results. 2. Determination of three 13-blockers by capillary electrophoresis with end column electrochemical detection End-column electrochemical detection of three species of 13-blockers at bare CFE after saparation by CE has shown to be a sensitive, fascinating and rapid technique. The mixture of these three blockers was separated completely within 6 minutes under the optimum conditions. The LOD of propranolol, timolol and acebutolol were 0 .1. 0.01.. 0.05~tmol/L (N/S=3), respectively. The linear response ranges were over ii ABSTRACT three magnitudes, such as 1-1OO~ O.2-15O~ O.2-12O~tmol/L with the linear coefficients over 0.995. The analysis of human urine shows the potential application of this detection mode in clinic.