Objective: To optimize the electrophoresis condition of determining the content of tetrahydropalmatine and protopine in Corydalis Rhizoma simultaneously by the method of capillary electrophoresis

and to establish the determination method. Method: Single factor method was used to optimize the composition

concentration

pH value

separation voltage and injection time that can influence the buffer solution. And the optimized electrophoresis condition was used to detect the contents of tetrahydropalmatine and protopine simultaneously. Result: The buffer solution was 60 mmol·L-1 of sodium dihydrogen phosphate (pH 7)-methanol (5% THF) (65∶35). The running voltage was set at 17 kV and the voltage of sample injection was at 40 kPa. The time of sample injection was 3 s with temperature of 20 ℃ and detection wavelength of 283 nm. With the optimized condition the complete separation can adopte within 20 min. Conclusion: The electrophoresis condition of determining the two content in Corydalis Rhizoma was established

that is a simple

accurate and reliable method

which provides the basis of determining content with capillary electrophoresis method and also provides a reference for the quality control of Corydalis Rhizoma.