大豆黄素的电化学行为及其循环伏安测定

Electrochemical Behavior of Daidzein and Its Voltammetric Determination

在pH7．5的三羟甲基氨基甲烷一盐酸（Tris-盐酸）缓冲溶液的底液中，采用循环伏安法测定大豆黄素，得到一良好的氧化峰，其峰电位在O．53V处；峰电流与大豆黄素的浓度在1．2×10-7～9．6×10-6mol．L-1叫范围内呈线性关系。该方法的检出限（33／N）为8．0×10-8mol·L-1。用此法测定红车轴草中大豆黄素含量，加标平均回收率为98．0％；对1．6×10-6mol．L-1大豆黄素平行测定8次，进行精密度试验，相对标准偏差为0．81％。根据大豆黄素在玻碳电极上的电化学行为，表明大豆黄素的电极过程具有吸附性和不可逆性。

In a Tris-HCl buffer base solution of pH 7. 5, a well-defined oxidation peak with its peak potential at 0. 53 V （vs. AgCl/Ag） was observed in the cyclic voltammogram of daidzein. Linear relationship was obtained between values of peak current and concentration of daidzein in the range of 1. 2 ×10-7 -- 9. 6×10-6 mol · L-1. Detection limit （3S/N） of 8. 0×10-8mol· L-1 was found for this method. Daidzein content in a sample of trifolium was determined by this method. Using this sample as matrix, recovery test was made by standard addition method, an average recovery of 98. 0% was found. Test for precision was performed with 1.6×10-6mol·L-1 of daidzein, the value of RSD （n=8） found was 0. 81%. It was added that the reaction of daidzein at the glassy carbon electrode was an adsorptive and irreversible process.