| High performance capillary electrophoresis (HPCE) has been developed as a kind of separation technique since 1980s. It plays an increasingly important role in life science, drug analysis, environmental science and food safety determination, due to its advantages of high separation efficiency, short analysis time, high sensitivity, extremely small sample volume and low operation cost.In this thesis, HPCE-UV method was used for the separation and determination of five quinolone antibiotics (gatifloxacin, lomefloxacin, ciprofloxacin, enoxacin and ofloxacin), four normal flavonoids (rutin, kaempferol, luteolin and quercetin), and four natural antioxidant (daidzein, genistein, apigenin and catechin), respectively. The effects of buffer system, buffer concentration and pH, running voltage, and injection time on the separation were studied systematically. It has been demonstrated that goog separation is achieved and qualitative analysis can be conducted in the optimal conditions.The baseline separation of five quinolone antibiotics was achieved within 6 min under the optimal conditions and the relative standard deviations of migration time and peak height were 0.78% - 0.87% and 3.03% - 5.67%, respectively. There is a linear relationship between concentration of five quinolone antibiotics and peak height in the range of 1×10-5 - 1×10-4 mol·L-1. The detection limits (S/N = 3) of five quinolone antibiotics were determined: gatifloxacin (4×10-6 mol·L-1), ofloxacin (4×10-6 mol·L-1), lomefloxacin (4×10-6mol·L-1), enoxacin (4×10-6 mol·L-1) and ciprofloxacin (2×10-6 mol·L-1). This method was used to detect the content of the active component in the saled lomefloxacin pills and the recovery rate was found as 109.46%.The baseline separation of four normal flavonoids was achieved within 6 min under the optimal conditions. The relative standard deviations of migration time and peak height were 0.65% - 0.96% and 7.1% - 8.38%, respectively. There is a linear relationship between concentration of four normal flavonoids and peak height in the range of 1×10-5 - 5×10-4 mol·L-1. The detection limits (S/N = 3) of the four normal flavonoids were determined: rutin (2×10-6 mol·L-1), luteolin (2×10-6 mol·L-1), kaempferol (2×10-６ mol·L-1) and quercetin (5×10-６ mol·L-1). Then we detected the contents of thees active components in Cuscuta Chinensis and Zhen Ju antihypertensive tablets, respectively. The contents of rutin, kaempferol and quercetin in Cuscuta Chinensis were 2.15 mg·g-1, 3.75 mg·g-1and 4.32 mg·g-1, respectively, and the content of rutin in Zhen Ju antihypertensive tablets was 65.5 mg·g-1 . The recovery rate of rutin, kaempferol and quercetin in Cuscuta Chinensis were 94.2%, 107.8% and 102.8%, respectively, and the recovery rate of rutin in Zhen Ju antihypertensive was 106.2%.The baseline separation of four normal antioxidants (including impurity) was achieved within 6 min under the optimal conditions. The relative standard deviations of migration time and peak height were 0.7% - 0.8%;and 3.9% - 7.9%, respectively. There is a linear relationship between concentration of the five substances and peak height in the range of 1×10-5 - 2×10-4 mol·L-1 or 2.5×10-5 - 5×10-4 mol·L-1. Detection limits of the five substances were determined: daidzein (2×10-6 mol·L-1), genistein (2×10-6 mol·L-1), apigenin (including impurity, 5×10-6 mol·L-1) and eatechin (5×10-6 mol·L-1). The recovery rate of daidzein, genistein, apigenin, apigenin's impurity and catechin were 95.3%, 106.8%, 102.6%, 97.6% and 104.1%, respectively. This method could be applied to detect practical samples.
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