Objective: The aim of this study was to establish an HPLC-DAD method for the determination of 2-methy-3-methoxyanthraquinone

2

3-dimethoxy-6-methyanthraquinone in Hedyotidis Herba. Method: The assay was performed on a ZORBAX Extend-C18 column(4.6 mm×250 mm

5 μm) eluted with acetonitrile -0.5% phosphate(48:52).The detection wavelength was 265 nm

the flow rate was 1.0 mL·min-1

and the column temperature was set at 25 ℃. Result: The calibration curves were linear in the ranges of 0.998-9.98 μg(r=0.999 6)for anthraquinone I and 0.675-6.75 μg(r=0.999 9)for anthraquinone II. The average recoveries of anthraquinone I and anthraquinone II were 99.87%(RSD 1.13%)and 99.51%(RSD 0.69%)

respectively. Conclusion: The method is simple and accurate for the quality control of 2-methy-3-methoxyanthraquinone and 2

3-dimethoxy-6-methyanthraquinone in Hedyotidis Herba.