Determination of Calycosin and Formononetin in Radix Astragal by High Performance Liquid Chromatography

A method for the determination of calycosin and formononetin in radix astragal was developed with relative chemometrics methods and high performance liquid chromatography.The analytical column was Hypersic ODS column(4.4mm×250mm,5μm).The mobile phase was water containing 0.2%(V/V) acetic acid (A) and acetonitrile containing 0.2% (V/V) acetic acid(B) with a gradient system.The two-way data of HPLC-DAD hyphenated instrument was resolved with heuristic evolving latent projections (HELP) method and the pure chromatogram and spectra of each component were obtained.Then calycosin and formononetin were determined with overall volume integration method.The regression equations and coefficients were y=166.72x+127.8 and 0.9997 for calycosin,y=178.39x+187.2 and 0.9993 for formononetin.The liner ranges were 1.0—116.5μg·mL-1 and 1.2—112.5μg·mL-1 for calycosin and formononetin,respectively.The standard added recoveries were in the range of 96.5%—98.7% and 96.8%—98.5% for calycosin and formononetin,respectively.This method is highly sensitive,selective and reliable,and is used for simultaneous determination of calycosin and formononetin in radix astragal and the quality control of radix astragal.