Study On The Application Of Capillary Electrophoresis Coupled With Electrochemiluminescence In The Detection Of Medicine

Based on the separation of charged molecules through a small capillary under the influence of an electric field, capillary electrophoresis (CE) has emerged as a powerful analytical separation technique for the determination of numerous analytes and an excellent complement to high-performance liquid chromatography. With advantages including versatility, high speed, small sample consumption, low operational costs, and no-use or use of little organic solvents, CE becomes an attractive tool for rapid analysis of biochemical and pharmaceutical analytes.Electrochemiluminescence (ECL) detection is the combination of electrochemical detection and chemiluminescence detection. It remains the advantages of chemiluminescence such as high sensitivity, wide linear range and simple instrument needed besides its inherently easy manipulation and high selectivity. Ru(bpy)32+, as a kind of high efficient luminescent and good resolvable reagent in both aqueous and nonaqueous solvent, is considered as the most efficient, thoroughly examined, and widely used ECL reagent. It can be oxidized to Ru(bpy)33+ on the working electrode under certain potential. Subsequently, with the aid of tertiary amine group, Ru(bpy)33+ changes to the excited state Ru(bpy)32+?, which can release light by returning to the ground state.The main work of this thesis is summarized as follows:1. A simple but sensitive, selective and green method for the estimation of chlorquine (CQ) and its separation from other pharmaceuticals was proposed. The method was applied to the determination of CQ and its separation from other pharmaceuticals. The system was also used for the study of the interaction between protein and pharmaceuticals. The binding constant and binding sites number of CQ and human serum albumin (HSA) were estimated.2. Capillary electrophoresis electrochemiluminescence (CE-ECL) separation system was employed to detect methadone hydrochloride. This CE-ECL method was further adopted to study the interaction between MD and human serum albumin (HSA). The binding site number n and the binding constant K at 37°C were caculated to be 25.8 and 5.8×10-3 M-1, respectively.3. The Pt electrode with the electrodeposition of nanogold was prepared and applied as the working electrode in CE-ECL system for the detection of difenidol hydrochloride. This method is reproducible and proved to be a sensitive method for the determination of difenidol. Compared to bare Pt electrode, nanogold modified electrode presents a lower LOD and a wider linear range on the determination of difenidol.