Simultaneous Determination of Six Components in Yanreqing Tablets by Double-wavelength HPLC

OBJECTIVE To establish a new double-wavelength HPLC method for simultaneous determination of 6 main components in Yanreqing tablets. METHODS The method was performed on an Agilent TC-C₁₈ column (4.6 mm×250 mm, 5 μm). The mobile phase was consisited of methanol-0.2% phosphoric acid by gradient elution at 35℃ column temperature. The flow rate was 1.0 mL·min^-1. The detection wavelength was 254 nm for gentiopicroside, geniposide, mangiferin at 0-20 min, and 280 nm for baicalin, baicalein, wogonin at 20-50 min. RESULTS Gentiopicroside, geniposide, mangiferin, baicalin, baicalein, wogonin showed a good linear relationship in the range of 18.92-189.2 ng (r=0.999 9), 107.44-1 074.4 ng (r=0.999 9), 9.82-98.2 ng (r=0.999 9), 767.68-7 676.8 ng (r=1.000 0), 100.94-1 009.4 ng (r=0.999 9), 49.84-498.4 ng (r=0.999 9), respectively. The average recoveries were 98.31%, 98.35%, 98.40%, 98.03%, 98.46%, 98.24%, the RSD were 0.4%, 0.3%, 0.3%, 0.4%, 0.4%, 0.3%. CONCLUSION The method is sensitive, simple, accurate, and suitable for the quality control of Yanreqing tablets.