Abstract: A HPLC method for the determination of icariin in different particle sizes of Epimedium was developed. Chromatography was performed on a Shimadzu VP-ODS column(150 mm×4.6 mm,5 μm). An acetonitrile-water (V:V=25:75) as the mobile phase was used on the wavelength of 270 nm. The results showed that the calibration curve was linear in the range from 0. 08 to 0.40 mg/mL with r=0.9999. The relative standard deviation was 1.62% and the recovery was from 97.11% to 101.08%. The method was accurate and rapid for the determination of icariin in different particle sizes of Epimedium. And the dissolution amount of icariin was increased with the diminution of particle size. But when the size surpassed 100 meshes, the dissolution amount remained constant.

Key words: high performance liquid chromatography; Epimedium; icariin; dissolution amount