Objective: To establish a sensitive and specific high performance liquid chromatography method (HPLC) for simultaneous determination of five free anthraquinones (2-hydroxyl-3-methyl anthraquinone

2-hydroxy-1-methoxy anthraquinone

1

8-dihydroxy anthraquinone

rubiadin-1-methyl ether and rubiadin) in Morindae Officinalis Radix. Method: The analytic procedure was carried out on a Phenomenex C18 column(4.6 mm×250 mm

5 μm) and detected with an UV detector at the wavelength of 277 nm.Gradient elution was carried out with 0.4% phosphoric acid and acetonitrile at the flow rate of 1.0 mL·min-1. The column temperature was set at 30 ℃. Result: The calibration curves were linear in the range of 0.010-0.250 μg for 2-hydroxyl-3-methyl anthraquinone with r of 0.999 7

0.060-1.500 μg for 2-hydroxy-1-methoxy anthraquinone with r of 0.999 1

0.004-0.100 μg for 1

8-dihydroxy anthraquinone with r of 0.999 6

0.050-1.250 μg for rubiadin-1-methyl ether with r of 0.999 7 and 0.025-0.625 μg for rubiadin with r of 0.999 5

respectively.The average recoveries of these five components were 98.2%

99.6%

97.9%

98.5% and 97.7%

respectively.Relative standard deviations were 1.4%

1.6%

2.2%

1.6% and 1.7%

respectively. Conclusion: The established method is accurate and reliable

and it can be used for the simultaneous determination of these five components

which provides a scientific basis for the quality evaluation of Morindae Officinalis Radix.