Simultaneous determination of 4 isoflavones in Radix Astragali and Radix Astragali praeparata cum melle by HPLC

Objective To provide an HPLC method for the content determination of 4 isoflavones in Radix Astragali and Radix Astragali praeparata cum melle.Methods Four iosflavones were successfully analyzed on a kromasil C18 column(250 mm×4.6 mm,5 μm)with methanol(A) and water(B) as the mobile phase in gradient elution.The column temperature was 40 ℃ and the detection wavelength was 251 nm.Results The linear ranges of 4 isoflavones were over 6.3-630 mg·L-1(r=0.999 5),4-400 mg·L-1(r=0.999 5),4.5-450 mg·L-1(r=0.999 6),and 5-500 mg·L-1(r=0.999 7) respectively.The average recoveries(n=6) were more than 96%,and the RSDs were less than 3%.Conclusion The method is simple,accurate,and reliable for the quality evaluation of Radix Astragali and Radix Astragali praeparata cum melle.