通过电化学方法使玫瑰红酸(Rh)与镍(Ⅱ)[Ni(Ⅱ)]生成Ni(Ⅱ)-Rh配合物,并聚合、沉积于碳糊电极(CPE)表面,制成Ni(Ⅱ)-Rh修饰的CPE电极[记为Ni(Ⅱ)-Rh-CPE]。试验表明:丹宁酸在此修饰电极上产生电催化氧化反应,在0.1 mol·L-1氢氧化钠溶液中,在电位0.2~0.6 V范围内,扫描速率为0.1 V·s-1的条件下进行伏安测定,丹宁酸的浓度在0.2~1.0 μmol·L-1和1.0~50.0 μmol·L-1两个区间与其阳极峰电流间呈线性关系,检出限(3S/N)为0.14 μmol·L-1。以自来水和河水作基体,用标准加入法对方法的回收率进行试验,测得回收率在95.2%~104%之间。

A coordination complex of Ni(Ⅱ) with sodium rhodizonate (Rh) was formed, polymerized and deposited on the surface of carbon paste electrode (CPE) by electrochemical method, thus to prepare the modified electrode of Ni(Ⅱ)-Rh-CPE. Electrochemical behavior of this modified electrode was studied by CV, showing that electrocatalytic oxidation of tannic acid at the modified electrode was observed. The CV study was performed in 0.1 mol·L-1 NaOH solution with potential range of 0.2-0.6 V and scanning rate of 0.1 V·s-1. Linear relationship between values of the catalytic anodic peak current and concentration of tannic acid was kept in 2 sectional ranges of 0.2-1.0 μmol·L-1 and 1.0-50.0 μmol·L-1, with detection limit (3S/N) of 0.14 μmol·L-1. Using tap water and river water as matrix, test for recovery was made by standard addition method, giving results of recovery in the range of 95.2%-104%.