| Capillary electrophoresis (CE) is a liquid phase separation technology which is developing rapidly, and it is also a powerful and versatile analysis tool.The Variability of CE mainly reflected in the numerous separation modes, which provides the possibility to meet the complex analysis; The powerful of CE due to the characteristics of high efficiency, high speed, ultra-small sample volume, minimal consumption of solvent and ease of clearing up the contaminants. The research of CE method focus in antibiotics, amino acids, phenolic compounds, flavonoids, natural antioxidants, protein, pigment, nucleotides, pesticides,etc for the past two years, and this involves in many areas, such as food chemistry, pharmaceutical chemistry, clinical testing, molecular biology and so on, so it has broad application prospects.In this part, the history of CE development has been retrieved, and the principle, the separation modes, the detection mode, the application fields, the instrumental system, the technological characteristics of CE have been introduced in detail.The second chapter is about a quantitative determination of six neurotransmitter amino acids (NAAs) including Ala, Glu, Asp, Ser, Tau and Gly was performed by capillary zone electrophoresis coupled with amperometric detection (CZE-AD). The CZE-AD method was developed by using two different buffers:borate buffer was in the capillary to separate the six NAAs and NaOH solution was in the detection reservoir for electrochemical detection. The effects of working electrode potential, pH, component and concentration of the running buffer, separation voltage, and injection time on CZE-AD were investigated. Under the optimum conditions the six analytes could be perfectly separated on copper electrode and had good responses at+0.75V (vs SCE) within30min. The linear ranges were from5.0×10-4to5.0×10-6mol·L-1and the detection limits were from10-6to10-7mol-L(S/N=3), respectively. The contents of NAAs in human serum were successfully determined by this CZE-AD method and satisfactory results were obtained. Above results demonstrated that this method was characterized by low volume sampling, simple instrumentation, convenient operation, high repeatability, and rapid determination of practical samples.Analysis of the neutral sugars of Asparagus officinalis Linn. polysaccharide by different methods has yielded inconsistent results. In the work discussed in this paper, capillary zone electrophoresis with amperometric detection (CZE-AD) was used for analysis of neutral sugars in A. officinalis Linn. polysaccharide. The configuration of the wall-jet and the diameter of the copper disk electrode were investigated to achieve optimized detection sensitivity. The separation electrolyte, separation voltage, and injection time were studied for their effects on CZE separation. Under the optimum CZE-AD conditions, seven monosaccharides were separated to baseline by using0.12mol/L NaOH as separation electrolyte. Linear response was excellent and repeatability was satisfactory. It was found that Asparagus polysaccharide was composed of fucose, galactose, glucose, rhamnose, arabinose, fructose, and xylose at a mole ratio of0.2:16.2:5.0:1.0:15.5:0.6:18.8. Analysis of the composition of Asparagus polysaccharide by CZE-AD had the merits of rapidness, accuracy, and low sampling volume.Polyols (alditols) are polyhydric alcohols, they are present in almost every living organism, but their metabolism is not well known and their potential importance in human disease has been investigated only in the last decade. Because some of the polyols are the composition or the metabolites of the organisms, and directly and indirectly involved in the life process, their separation and detection are equally important in clinical applications. According to the literature, seven polyols (erythritol, xylitol, sorbitol, arabinose, alcohol, Adon alcohol, mannitol, galactitol) in urine, which play an important role in human biological fluids were determined by capillary electrophoresis amperometric detection at the first time. The effects of working electrode potential, pH and concentration of running buffer, concentration of the detecting cell solution, separation voltage and injection time on CZE-AD were investigated. The proceeds of the optimum experimental conditions are as follows:detection potential of+0.75V (vs.SCE); running buffer0.07mol/L, pH=9.2borate buffer solution; detection cell solution0.07mol/L NaOH.; Separation voltage17kV, electrokinetic injection time of8s (17kV).Under the optimum conditions, the seven analytes could be perfectly separated The urine samples of a healthy human and DM patients was assayed and the assay results were satisfactory with recoveries in the range of89.6-108.2%and RSDs less than9.1%. |
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