| Capillary electrophoresis (CE) is a separation technique emerging in the 1980's. It has many charming characteristics, such as high separation efficiency, short analytical time, and small requirements for samples, which make CE meet the analytical demands for biomacromolecules in various fields of life sciences. Amperometric detection (AD) is the most common one of all methods hi CE Electrochemical Detection (CEEC). It has a lot of merits, such as high sensitivity, good selectivity and fast response. CE-AD has been applied in many fields of life sciences and clinical medicines.8-hydroxydeoxyguanosine (8-OHdG) has been studied in clinical medicine fields as an important biomarker of oxidative DNA damage. First work of the present thesis is to develop a method for detection of urinary 8-OHdG with end-column amperometric detection coupled to CE and investigate the effects of different conditions for separation and detection on analysis. The optimum method showed a good reproducibility, high sensitivity. The detection limit is 4.3nM, which make the analysis of 8-OHdG in urine into reality. By the optimized method, we measured the urinary 8-OHdG content from smokers and non-smokers and studied the relationship between individual cigarette smoking statuses and DNA oxidative damage degrees. Furthermore, the present study employed the CE-AD method in the investigation of 8-OHdG levels in urine in diabetic nephropathy patients (with different stages) for the first time.The other part of the thesis is to develop a sensitive, reliable CE-AD method for the analysis of curcumin in curcuma and curcuma kwangsiensis. The componentsand concentration of the buffer solution, the time and voltage for injection and the electrochemical behaviors of curcumin were investigated in details. The method showed a good reproducibility, low detection limit (73nM) and wide linear range (0.1μM-100μM). The analytical results for the Chinese traditional medicine agreed well with previous reports. |
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