Abstract: The investigation optimum analytical conditions in the determination of theaflavins(TFs) with capillary electrophoresis was described. The electrolyte solution was consisted of 250βmmol/L H₃BO₄, 10βmmol/L KH₂PO₄, 0.75βmmol/L SDS and 20% (v/v) acetonitrile under pH7.5. The work parameters of the instrument were selected as follows: voltage 25βkV, column temperature 20℃, and detecting wavelength 200βnm. By using this method, the four majors of TF 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 minimum concentration limit was between 0.53~0.64βμg/ml. The mean recoveries of TFs monomers varied from 92.50% to 108.36%. The coefficients of variation were less than 2.67%. Results showed that the method was simple, rapid and accurate for TFs to be determined in black tea and TFs products.

Key words: theaflavins, analytic method, capillary electrophoresis