辛基酚羧基化碳纳米管修饰电极方法测定

Electrochemical determination of diethylstilbestrol with carboxylic carbon nanotube modified electrode

目的建立修饰电极测定辛基酚的新方法。方法通过自组装的方法将羧基化碳纳米管(c-CNT)组装到壳聚糖修饰的玻碳电极表面,构建c-CNT-壳聚糖修饰玻碳电极,在pH 6.0的磷酸盐缓冲溶液中,用循环伏安法和示差脉冲伏安法探讨辛基酚在该修饰电极上的电化学行为及其测定。结果在pH 6.0磷酸盐缓冲溶液中,测定辛基酚的线性范围为8.33×10-8～2.0×10-5mol/L,检测限为3.67×10-8mol/L(S/N=3);采用同一支电极对3.0×10-6mol/L的辛基酚平行测定10次,相对标准偏差为3.6%;对标准样品进行加标回收率实验,回收率为(92.5±0.1)%～(106.5±0.1)%;将修饰电极放置2 d后再次测定,峰电流为最初峰电流的95%;大部分离子如K+、Na+、NH4+、Ca2+、Mg2+、Cl-、NO3-、Ag+、Sr2+、Zn2+、Cd2+、Ni+、F-、Cl-、NO3-、SO24-和PO34-对测定无干扰,50倍量的多巴胺、抗坏血酸、尿酸几乎不干扰辛基酚测定,而10倍的双酚A和壬基酚对辛基酚测定有一定干扰。结论该方法简单、快速,可用于样品中辛基酚含量测定。

Objective To establish a new method for the determination of octylphenol（OP） using modified electrode.Methods c-CNT-chitosan modified electrode was constructed by immobilizing carboxylic carbon nanotubes on the surface of chitosan modified glassy carbon electrode with a self-assembly method.The electrochemical behavior and determination of OP with modified electrode were investigated by cyclic voltammetry and differential pulse voltammetry in pH 6.0 phosphate buffer solution.Results In phosphate buffer solution at pH of 6.0,the calibration curve for OP determination could be obtained with the linear range of 8.33×10-8-2.0×10-5 mol/L and the estimated detection limit of 3.67×10-8 mol/L（S/N=3）.The relative standard deviation was 3.6 % for ten determinations of 3.0×10-6 mol/L OP using the same electrode.The recoveries ranged from 92.5%-106.5%for the samples detected.Conclusion The method is simple and sensivite and could be applied to the determination of OP in samples.