The Application Of On-line Concentration To Pharmaceuticals And The Study Of False Peak Phenomena In CE

Since the appearance of capillary electrophoresis (CE), it attracted most of the analytical researchers because of its celerity and high performance. However, CE is restrained by low concentration sensitivity, in a way on-line concentration techniques is a satisfactory method that could discuss this question. In this thesis, five chapters are consisted, the development of CE and on-line concentration techniques, the application of CE and on-line concentration techniques to pharmaceuticals and the studies of false peaks in on-line sweeping concentration techniques have been introduced inspectively.Chapter one: it is an introduction of the basic theory of capillary electrophoresis, on-line concentration techniques and the false peak phenomena of on-line concentrationChapter two: An on-line sweeping technique was developed to determinate trace impurity in bulfomedil hydrochloride by using basic SDS buffer solution. It had been proved that the optimum separation buffer solution of trace impurity in buflomedil hydroloride was 14mmol/L NaH2PO4+15mmol/L Na2B4O7+50mmol/L SDS (Sodium Dodecyl Sulfonate) (pH=9.05) and the optimum injection time was120s. The applied voltage was 16kV and UV detector was set at 214nm. In this method, the detection sensitivity of buflomedil hydroloride was high and the quantitative analysis was accurate. Chapter three: A new MEKC method of on-line Sweeping technique and enantiomeric resolution of trace chlorpheniramine was established using SDS as mecellars and SDC (sodium deoxycholic) additives. The several factors that could influence the chiral separation and limitation of detection had been investigated. In this method, the optimum buffer solution were 50mmol/LSDS, 50mmol/L B -CD, 100mol/LSDC and 30mmol/L Na2B4O7. Under the optimum condition, the LOD (Limitation of Detection) of chlorpheniramine was 4.1 mg/L. The advantage of the method was that it combinedon-line concentration and chiral separation together. At the same time it could be applied the trace analysis of other chiral pharmaceuticals.Chapter four: several kinds of factors that could lead to the appearance of false peak such as the injection time, SDS concentration, pH value of buffer, pH gradient of buffer and so on, were investigated by using on-line sample sweeping technique under different experimental conditions. It proved that pH gradient of buffer is a very importantfactor that could influence the appearance of false peaks. In order to avoid the appearance of false peak, the pH gradient between cathode and anode should be avoided?when sweeping concentration technique is used.Chapter five: A capillary electrophoresis(CE) methods for the chiral separation of synthesized amlodipine intermediate and amlodipine was developed. The effect of pH value of the buffer system, concentration of CD and voltage on the chiral separation was investigated. The experiment had proved that both amlodipine intermediate and amlodipine could gain satisfactory chiral separation while buffer was 30mM phosphate + 50mM CM-β-CD (pH=6.12) under 12kV voltage.