Objective: To establish a RP-HPLC method to determine the content of loganin in Mingmu Shangqing pill. Method: The analysis was performed on a Kromasil C18 column (4.6 mm×250 mm

5 μm) with tetrahydrofuran-acetonitrile-methanol(1:8: 4)-0.05% phosphoric acid (8: 92) as mobile phase at a flow rate of 1.0 mL·min-1

and at a column temperature of 40 ℃.The detection wavelength was at 236 nm. The content was calculated with external standard method. Result: The linear range of loganin was 40.43-1 213.02 ng(r=1.000 0). The average recovery was 98.2%

and the RSD was 0.8%(n＝6) Conclusion: This method was simple

accurate

reliable and suitable to be applied to the quality control for the preparation.