Determination of the osthole and imperatorin in Fructus Cnidii by RP-HPLC

Objective To develop a method for determination of osthole and imperatorin in Fructus Cnidii by RP-HPLC.Methods Chromatography was performed using a Kromasil C 8( 250 mm× 4.6 mm, 5 μm) column with mobile phase of methanol-water (65∶35).The monitoring wavelength was 310 nm.The flow rate was 0.8 mL·min -1 and the column temperature was room temperature.fluocinonide was served as an internal standard.Results A good linearity between peak area ratio of the common peak to the internal standard and the concentration was found in the range of 13～ 208 mg·L -1 for osthole and 8～ 128 mg·L -1 for osthole ( r0.999 8) and imperatorin ( r0.999 9),respectively.The average recoveries were 98.2% (n=9,RSD=1.7%) and 97.5%(n=9,RSD=2.0%) for osthole and imperatorin,respectively.Conclusion The method is simple,rapid and with satisfactory recoveries and good reproducibilities.It can be used to control the quality of Fructus Cnidii.