毛细管电泳法测定淫羊藿甙的pKa值及其在中药淫羊藿中的含量

Abstract：Knowledge of dissociation constants is important for pred iction and un derstanding the migration behavior of analytes in capillary electrophoresis. Icariin is the active com ponent of the Chinese herb medicine Epimedium grandiflorum Morr.. In order t o determine the dissociation constant of icariin and to show many important phar macology activities, a CZE method has been used to determine the ion mobility (μA-) and the pKa value of icariin based on the non -linear relation between　μ_eff and［H⁺］and the linear relation between the reciprocal of effective mobility of the solute (1/μ_eff) and the ［H⁺］of the buffer solution. In addition, the change of pK_a o f icariin with the increase of ethanol concentration in the buffer was also inve stigated. Under the buffer condition of 24 mmol/L phosphate +30% ethanol, the c ontent of the active component icariin in Chinese herb Epimedium grandiflorum Morr. was quantitatively determined. The linear correlation equation was Y =6.96×10^-3+17.0X, and the linear range is 0.032 g/L-0.354 g/L.
Keywords：capillary electrophoresis; icariin; pKa value