Study On Capillary Electrophoresis With Electrochemical Detection And Its Applications

Capillary Electrophoresis (CE) is one of the most important separation techniques in recent twenty years. Because the theoretical plate number of capillary tube is greatly developed to tens of thousands and even millions per meter, and the volume of sample injection reaches nano liter level in CE analysis, it has been studied and applied to most analytical areas. However, the tiny injected sample volume and very thin capillary bring about difficulties in detection. The commonly used detection methods include ultra-violet (UV), laser induced fluorescence (LIF), mass spectra (MS), etc. Every detection method has some advantages and also suffers from some drawbacks. For example, LIF is very sensitive except that the instrument is very expensive, and some complicated derivation procedures are often needed. Electrochemical detection is usually more sensitive than the commonly used UV detection, and has many advantages when it combines with CE, such as simple instrumentation and operation, low cost, wide linear range, etc. So the method of CE-ED is extensively studied and applied in most analytical fields because of above advantages.The goal of this dissertation is to explore some applications in pharmaceutical analysis, biochemical analysis and food analysis etc. by CE-ED. The contents of this dissertation include seven chapters:1. PrefaceThe characteristics of CE, the separation models, the basic theories of CE, the detectors, the studies and applications of CE-ED are introduced briefly. The goal and significance of this dissertation are also introduced.2. Determination of uric acid in human saliva by capillary electrophoresis with electrochemical detectionCapillary electrophoresis with electrochemical detection (CE-ED) was applied for the determination of UA in human saliva and urine in this work. Under the optimum conditions, uric acid and three coexisting analytes could be well separated within 14 min at the separation voltage of 14 kV in a 80 mmol/L borax running buffer (pH 7.8). Good linear relationship was established between peak current and concentration of analytes over two orders of magnitude with detection limits (S/N=3)...