在pH 4.6的乙酸-乙酸钠缓冲溶液中,铋(Ⅲ)-芦丁所形成的配合物在-0.28 V(vs.SCE)产生吸附波,加过硫酸钾后该波峰电流增加,其峰电流的二阶导数值与铋(Ⅲ)浓度在1.0×10-8~1.5×10-6mol·L-1范围内呈线性关系,检出限(3S/N)为7.0×10-9mol·L-1。研究了极谱波的性质及增敏的机理,表明该波为配合物吸附催化波。方法用于胶体果胶铋胶囊中铋的测定,测定值与标示值相符。以样品作基体,用标准加入法做回收试验,测得回收率在95.5%~101.1%之间。

In a NaOAc-HOAc buffer solution of pH 4.6, the complex formed between Bi(Ⅲ) and rutin gave an adsorptive polarographic wave at the potential of -0.28 V (vs.SCE), the peak current of which was increased upon the addition of K2S2O8. Values of 2nd derivative of the peak current were found to keep linear relationship with the concentration of Bi(Ⅲ) in the range of 1.0×10-8-1.5×10-6mol·L-1, with its detection limit (3S/N) of 7.0×10-9mol·L-1. The adsorptive and catalytic properties of the polarographic wave were proved by results of electrochemical study. The proposed method was used in the analysis of colloidal bismuth pectin sample for its Bi(Ⅲ) content, giving results in consistency with the labelled value. Tests for recovery were carried out by addition of Bi(Ⅲ) standard solution to the pectin sample as matrix, values of recovery found were ranged from 95.5% to 101.1%.