Simultaneous Determination of Three Ingredients in Yuxingcao Qinlan Mixtures by HPLC

OBJECTIVE To establish an HPLC method for the simultaneous determination of chlorogenic acid, baicalin and baicalein in Yuxingcao qinlan mixtures. METHODS HPLC conditions included Kromasil-100 C₁₈ (250 mm×4.6 mm, 5 μm) and the mobile phase was a mixture of methanol and 0.1% phosphoric acid for gradient elution. The flow rate was 1.0 mL·min^-1. The wavelength was 322 nm and column temperature was 35 ℃. RESULTS Three ingredients had good linear relationships: in the range of 0.022 4-1.12 μg(R²=0.999 7), baicalin in the range of 0.045 8-2.29 μg(R²=0.999 5) and baicalein in the range of 0.031?8-1.59 μg(R²=0.999 9). Their average recoveries were 99.45%(RSD=1.4%), 99.37%(RSD=2.0%) and 97.90%(RSD=1.7%), respectively. CONCLUSION This method was simple with high precision, good repeatability and stability. It could be used for the determination of the three ingredients and quality control of Yuxingcao qinlan mixtures.