RESUMEN
AIM: To establish an external standard HPLC method for the determination of protocatechuic acid and protocatechualdehyde in Compound Shijiqing Tablets(Folium Ilicis Chinensis, etc.). METHODS:Alltima C 18(5?m, 4.6mm?250mm)was used. The mobile phase was consisted of methanol-1% acetate(18∶82). The flow rate was 1.0mL?min -1. The UV detection wavelength was at 280nm. RESULTS: The two components has good resolution. The liner ranges were in the range of 7.6～127.1?g?mL -1 for protocatechuic acid and in the range of 2.62～43.6?g?mL -1 for protocatechualdehyde with the correlation coefficients 0.9997 and 0.9994, respectively. The average recoveries were 99.9% and 97.5% with RSD 2.1%,2.2%(n=5), respectively CONCLUSION: The method is accurative, reproducible and can be used to control the quality of Compound Sijiqing Tablets.