Spectrophotometric Determination of Total Flavones in Root of Kudzu Vine

A spectrophotometric method for determination of total flavones in root of kudzu vine was proposed. The sample was soaked with ether to remove impurities, and extracted ultrasonically with methanol. Standard curve was prepared with rutin as reference standard, linear relationship between values of absorbance and mass concentration was found in the range of 8.48-28.92 mg·L-1 as measured at the absorption maximum of 510 nm. Detection limit (3S/N) of 0.75 mg ·L-1 was obtained. The proposed method was applied to the determination of total flavones in a sample of root of kudzu vine, giving average content 1.64 mg·g-1 and RSD (n=6) of 1.2%. Recovery was tested by standard addition method, values of recovery were found in the range of 97.2%-101%.