Simultaneous determination of three sterones in Achyranthis bidentatae Radix by RP-HPLC

An HPLC method was established for the simultaneous determination of β-ecdysterone, R-inokosterone and S-inokosterone in the Achyranthis bidentatae Radix to compare the quality from different habitats. Three phytoecdysones were separated with a Venusil XBP C₁₈ column by isocratic elution using 0. 1% formic acid in water and acetonitrile(84 ∶16)as the mobile phase, while the UV detector wavelength was set at 250 nm. Calibration curves of β-ecdysterone, R-inokosterone and S-inokosterone were linear over the range of 3. 07-1 470. 00, 0. 52-246. 00, and 0. 47-225. 00 μg/mL, respectively. Average recoveries were 101. 4%, 101. 1% and 101. 1%, respectively. The established method will be helpful in the quality control of Achyranthis bidentatae Radix.