Determination of Isofraxidin in Laomanqing Syrup

OBJECTIVE To determine the quantity of isofraxidin in Laomanqing syrup．METHODS RP-HPLC was used．Chromatographic conditions: Shim-pack VP-ODS C₁₈ column (250 mm×4.6mm, 5 μm), the mobile phase consisted of acetonitrile-0.2% phosphoric acid aqueous solution(19∶81)，the flow rate 1.0 mL·min^-1，the detective wavelength 344 nm and column temperature 30 ℃. RESULTS The calibration curve was linear in the range of 0.214-1.922 μg for the isofraxidin(r=0.999 9)．The average recovery was 99.1% and the RSD was 1.2%(n=9)．CONCLUSION The method is simple and accurate with good repeatability, which may be used for the quality control of Laomanqing syrup.