Objective: To establish a new RP-HPLC method for simultaneous determination of calycosin

atractylenolide-1

atractylenolide Ⅲ in crude extract of Radix astragali- Atractylodis Macrocephalae herb couple. Method: Analysis was carried out on a Kromasil 100-5C18 (4.6 mm×250 mm) column with acetonitrile-pure water as mobile phases in gradient elution. The flow rate was 1 mL·min-1

and the UV detector was monitored at 220 nm. Result: All calibration curve showed good linear regression in test ranges(r＞0.999 5); and the overall recoveries were in the range of 97%-103%(n=3)with RSD less than 3%. The overall RSD of precision test was less than 3%. Conclusion: The method is rapid

acute

credible and repeatable

and can provide bases for the material basis and compatibility for Radix astragali- Atractylodis Macrocephalae herb couple.