Methodological And Applied Researches Of Theaflavins And Tea Polyphennols By Capillary Electrophoresis

Tea polyphennols and it's oxide were the most essential quality components in tea and the most beneficial ingredients for health .The optimum analytical conditions for theaflavins and tea polyphennols by the capillary electrophoresis have been described in this paper.The method's applicability also has been researched.There were four parts in this study:1.The first part described the optimum analytical conditions when the theaflavins (TFs) were determined by the capillary electrophoresis. Our electrolyte solution was consisted of 250mmol/L boric acid,10mmol/L potassium dihydrogenphosphate, 0.75mmol/L SDS and 20% (v/v) acetonitrile under pH7.5. The work parameters of the instrument were selected as follows: voltage was 25kV, column temperature was 20℃,and detecting wavelength was 200nm. Dominating four of TFs could be separated each other completely within 10 minutes and each had a good linear relationship between its peak area and corresponding concentration (r=0.9945~0.9990). The mean recoveries of TFs monomers varied from 92.50% to 108.36%. The coefficients of variation were less than 2.67%. Analyzing the black tea was complicated because needing four times extraction,while TFs product can be determined directly.So the method was simple, rapid and accurate for TFs product.2.The optimum analytical conditions for the six catechins to be synchronously determined by the capillary electrophoresis have been described in the second part. The electrolyte solution was consisted of 200mmol/L boric acid(pH7.7), 10mmol/L potassium dihydrogenphosphate, 9mmol/Lβ-CD and 27.5% acetonitrile (v/v). The work parameters of the instrument were selected as follows: voltage was 25kV, column temperature was 30℃,and detecting wavelength was 200nm. These six constituents could be separated from each other completely within 7.5 minutes and each had a good linear relationship between its peak area and corresponding concentration (r=0.9980~0.9998). Furthermore, their detection limits were between from 0.39 to 0.78μg/ml, the mean recoveries varied from 96.60~113.83%.The variation coefficients were less than 3.54%. These results showed that this method was rapid,accurate and convenient .