The Application Of Capillary ElectropHoresis With Electrochemiluminescence Detection For The Analyses Of Amine-containing PHarmaceuticals

Electrochemiluminescence (ECL), which combines the characteristics of electrochemistry and chemiluminescence, is proved to be a powerful analytical tool with advantages of sensitivity, in situ, wide linear range, and good selectivity etc. Capillary electrophoresis (CE) has been greatly evolved since 1980s, now it has been proved to be an effective technique for separation with short analysis time, high resolution and small sample volume. The combination of capillary electrophoresis with tris (2, 2'-bipyridyl) ruthenium (II)-based electrochemiluminescence detection (CE-ECL) shows many advantages, for instance, high selectivity, good efficiency, fast analysis speed, and easy operation, etc. Now, the method has been widely used for the detection of nitrogen-containing compounds, and it has been successfully applyzed to pharmaceuticals, amino acids, narcotics, and environmental samples etc. As a method of analysis, CE-ECL will be more widely use in medical science, environmental science, and life science.This thesis is concentrated on the application of CE-ECL for the analyses of amine-containing pharmaceuticals. Its contents were intruduced as follows:1. A novel and simple pharmacokinetics of Pefloxacin mesylate (PM) in the urine of a healthy adult was developed. The proposed methodology was based on the ECL intensity of ruthenium (II) tris (bipyridine) at a platinum electrode was greatly enhanced by PM. Under the optimal conditions, the calibration curve was linear over the range from 0.05 to 10 mg/L with a detection limit of 0.006 mg/L (σ=3). The relative standard deviation of the peak height was 2.4% (n=6). The recovery in human urine was between 92.9% and 112%. The highest excretion rate was observed during 1.5 h to 2 h after oral administration. The urinary excretion ratio of PM was 13.5% within 48 h.2. Based on electrochemiluminescence (ECL) intensity of ruthenium(II) tris (bipyridine) at a platinum electrode was greatly enhanced by Buflomedil hydrochloride (BUF) and Verapamil hydrochloride (VER), the simultaneous determination of BUF and VER in human plasma has been developed using capillary electrophoresis with ECL. In order to increase the sensitivity, 0.1 mmol/L acetic acid was selected as sample solvent. Under the optimal conditions,the linear ranges were 0.001～3 mg/L for BUF and 0.01～12 mg/L for VER. The detection limits (3σ) for BUF and VER were 0.0007 and 0.0047 mg/L, respectively. The recoveries of the two drugs at different concentrations were between 85% and 92% for BUF and 85% to 93% for VER. Plasma constituents did not interfer with the determination of BUF and VER.3. A novel method for the determination of ephedrine hydrochloride (EP) was proposed. In order to improve the sensitivity, the precolumn derivatization of EP with acetaldehyde was proposed. Under the optimal conditions, the ECL intensity obtained about 50-fold improvement, compared to that wasn't derived. The calibration curve was linear over the range from 0.078 to 11.7 mg/L with a detection limit of 0.002 mg/L (σ=3). All of the values of RSD were lower than 5.9% (n=6), and the recovery was between 93% and 108%. The mothod was applied to the detection of EP extracted from human plasma. The impurities in the plasma didn't interfer with the determination of EP.