Objective:To establish quantification methods for determination of four types of active constituents in two sorts of Rhei Radix ex Rhizoma by HPLC

including free anthraquinone

anthraquinone glycoside

sennoside

catechin and gallic acid

in order to evaluate the quality of Rhei Radix ex Rhizoma all-around. Method: HPLC was applied on the determination of four types of active constituents with Agilent Zorbax SB-C18 column (4.6 mm×250 mm

5 μm). Mobile phaseⅠwas 0.1% phosphoric acid-methanol by gradient elution

mobile phaseⅡwas THF-water-acetic acid(2∶80∶1.5)-acetonitrile by gradient elution

and mobile phase Ⅲ was 0.5% acetic acid-methanol by gradient elution; the three kinds of flow rate were 1.0

0.8

1.0 mL·min-1; the wavelengths were set at 254

350

270 nm; the column temperature were all set at 25 ℃. Result: Determine of four types of active constituents in two different sorts of Rhei Radix ex Rhizoma. These components were separated completely within 30 minutes under this chromatographic condition. The average recoveries were from 97.09% to 103.2%

its relative standard deviations were from 0.15% to 3.0% (n=6). Conclusion: The methods with good reproducibility are simple and accurate; it can be used as quality control methods for Rhei Radix ex Rhizoma.