Simultaneous quantitation of five flavonoid glycosides in herba Epimedii by high‐performance liquid chromatography–tandem mass spectrometry

A rapid and accurate reversed‐phase liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) method has been developed and validated for the quantitative determination of five flavonoid glycosides, icariin, epimedin A, epimedin B, epimedin C and hyperin in Herba Epimedii. Chromatographic separations were performed using a C 18 narrow‐bore HPLC column; a mixture of an aqueous solution of ammonium formate (pH 4.0) and acetonitrile was used as the mobile phase, with compounds detected in the positive ion mode with multiple‐reaction monitoring using a triple‐quadrupole mass spectrometer equipped with an electrospray ionisation interface. This method for the determination of the reported flavonoid glycosides was accurate and reproducible, with a lower limit of quantication of 0.5 µg/mL. The standard calibration curves for the above‐mentioned compounds were linear ( r 2 > 0.998) over the concentration range 0.5–10.0 µg/mL. The relative standard deviations for intra‐ and inter‐day precision over the concentration range for the flavonoid glycosides were lower than 7.8% with accuracy between 90.1 and 111.0%. The established method was successfully applied to the quality assessment of samples of Herba Epimedii collected from Korea and China. Copyright © 2007 John Wiley & Sons, Ltd.