The Application Of On-line Concentration To Pharmaceutical Analysis

Since the appearance of capillary electrophoresis (CE) , it has attracted huch attention from analytical researchers because of its celerity and high performance. However, the technique of capillary electrophoresis is hampered by the low concentration sensitivity associated with the limited optical path length for on-capillary photometric detection and the minute volume of sample solution that can be injected. So it is difficult to run trace analysis. On-line concentration techniques is a satisfactory method that could solve this problem. In this thesis, there are five chapters, the development of CE and on-line concentration techniques, the application of CE and on-line concentration techniques to .pharmaceutical analysis and environmental analysis .Chapter one: it is an introduction of the basic theory of capillary electrophoresis and on-line concentration techniques.Chapter two: A new micelle capillary electrophoresis method with on-line sweeping concentration for the determination of trace pheno. o-nitrophenol and p-nitrophenol in industrial waste water was established. Under the optimum condition, 1000-fold concentration of the p-nitrophenol has been attained. By this method, the detection sensitivity of phenol derivatives was greatly increased and the quantitative analysis was accurate. The results showed that the method is precise, simple and effective.Chapter three: an on-line sweeping technique was developed to determinate trace impurity in nateglinide and ciprofloxacin by using SDS buffer solution. The effect of SDS concentration, pH value, running voltage and injection time on the concentration folds were investigated. The result shows that the optimum detection condition of trace impurity in nateglinide and ciprofloxacin were 16 mmol/L NaH2PO4+6 mmol/L Na2B407+60 mmol/L SDS (pH=7.14) and 20 mmol/L NaH2PO4+12 mmol/L Na2B407+60 mmol/L SDS (pH=8.32). Under these conditions, the total trace impurity of nateglinide and ciprofloxacin had been detected, which were 0.56% and 0.26%. The method could be used for the quality control and pharmaceutical analysis.Chapter four and five: Determining method of trace ciprofloxacin and nateglinide in plasma was established by the micelle capillary electrophoresis and on-line sweeping concentration technique. The effect of pH in background solution, the concentration ofSDS, injection time, plasma sample pretreatment method on concentration was investigated. Under the optimal conditions, the plasma sample was directly injected into the column after it was simply de-proteinized with acetonitrile. This condition allowed up to 600-fold concentration of the Ciprofloxacin and 260-fold concentration of e nateglinide. The results obtained above showed that on-line sweeping technique was a good sample concentration approach. The detector responsive signal can be improved significantly. The method could be applied successfully to determine trace drugs in clinical analysis.