壳聚糖修饰电极测定碘的研究

Study on Determination of Iodine Ion at Chitosan Modified Glassy Carbon Electrode

应用共价键合法将壳聚糖修饰在玻碳电极表面,研究了I-在该修饰电极上的微分脉冲阳极溶出伏安特性,并对相关机理进行探讨.实验表明,修饰电极在pH为4.0的0.1mol·L-1KH2PO4溶液中,对I 具有良好的吸附性和选择性,电极响应灵敏.其阳极溶出峰电流在2.0×10-6～2.0×10-3mol·L-1I-浓度范围内呈良好线性关系,检出下限达2.0×10-7mol·L-1.该法应用于食用碘盐中总碘量的测定,取得较好的结果.

In this paper, a chitosan modified glassy carbon electrode was prepared by the method of covalent-bond reaction, and the anodic stripping voltammetric characteristics of iodine on the modified electrode was studied. The results showed that the modified electrode has higher adsorption and selectivity for I^-, and the sensitivity for I^- has been much improved in 0.1 mol·L^(-1) KH_2PO_4 solution (pH=4.0). The anodic stripping peak current of I^- on the modified electrode varied linearly with I^- concentration in the range of 2.0×10^(-6)～2.0×10^(-3) mol·L^(-1), and the detection limit reached 2.0×10^(-7) mol·L^(-1).