Objective:To establish the quantitative analysis method for determining the content of gallic acid in Sanguisorba Granule by HPLC so as to provide a scientific basis for development of the drug as well as establishment of its quality standards. Method: Diamonsil C18(2) column (4.6 mm×250 mm

5 μm) was used with methanol-0.05% phosphoric acid (5:95) as the mobile phase; the detection wavelength was 272 nm

the velocity of flow was 1.0mL·min-1

and the column temperature was 20℃. Result: Under the above chromatographic conditions

the injection volume of gallic acid showed a linear relationship with peak area when ranging between 0.009 72-0.097 2 mg·kg-1

the corresponding regression equation being Y=34 347.2X+10.887 (r=0.999 9); the average recovery of gallic acid was 99.83% with corresponding relative standard deviation (RSD) being 2.3% (n=6). Conclusion: The method is simple

accurate

reproducible and can be used for determination of the content of gallic acid in Sanguisorba Granule.