Determination of Astragaloside I,II and Acetytastragaloside I in Astragalus Extract by HPLC-ELSD

Objective:To establish an HPLC-ELSD method to determine the content of astragaloside I,II and acetylastragaloside I in Astragalus extract.Method:The HPLC-ELSD system consisted of Welc C18 column(4.6 mm×250 mm,5 μm) with the mobile phase consisting of acetonitrile-water using a gradient elution.The flow rate was 1 mL·min-1 and the column temperature was at 30 ℃.The drift tube temperature of ELSD was 80 ℃ with a carrier gas(air) pressure of 50 psi.Result:The average recoveries of astragaloside I,II and acetylastragaloside I were 101.16%,99.34% and 100.43% respectively,with RSD of 2.76%,2.28%,2.55%.The content of astragaloside I,II and acetylastragaloside I was 4.01%,1.70%,3.67% respectively.Conclusion:It was proved that the newly-established HPLC-ELSD method was simple,reliable,well-separated and precise,which could be used for quantitative analysis of saponins in Astragalus extract.