Determination of hydrolyzed Gallic Acid content in Potentilla chinensis Ser by HPLC

Hydrolyzed gallic acid in Potentilla chinensis Ser. was determined by HPLC using Potentilla chinensis Ser. as a model drug with chromatographic conditions as follows: Hypersil C18 column (250 mm × 4.6 mm, 5 μm); mobile phase methanol-0.05% aqueous solution of phosphoric acid (10:90); volume flow 1.0 mL/min; detection wavelength 271 nm; column temperature 25°C; and injection volume 20 μL. Injection amount of gallic acid was in a good linearity with peak area at a range of 36.080~230.912 ng, average recovery was 99.2%, with a RSD of 1.89%. Free gallic acid could hardly be detected in Potentilla chinensis Ser., while gallic acid amount was relatively high after hydrolysis, suggesting that Potentilla chinensis Ser. contained a certain amount of hydrolysable tannins. In conclusion, the indirect control of tannin residual amount in Potentilla chinensis Ser. can be achieved by determining hydrolyzed gallic acid in Potentilla chinensis Ser.