基于表面活性效应下微量镉的电化学测定

Electrochemical Determination of Trace Cd^(2+) in the Presence of Surfactant

报道了在适量表面活性剂的存在下 ,钠型蒙脱石 (SWy - 2 )修饰碳糊电极高灵敏度测定环境体系中微量Cd2 + 的电化学方法 .该电极在HAc-NaAc (pH =5 .0 )溶液中 ,1.0× 10 -4mol/L的溴代十八烷基三甲基铵(STAB)存在下 ,用溶出伏安法测定Cd2 + ,在 - 0 .81V(vs ,SCE)处有灵敏的阳极溶出峰 ,且峰电流与Cd2 + 浓度在 2 .0× 10 -8～ 1.5× 10 -6mol/L的范围内 ,呈良好的线性关系 .该方法用于水样中镉的测定 ,检出限为 2 .0×10 -9mol/L .

In the presence of 1.0×10 -4?mol/L STAB, Carbon paste Electrode was modified by Na-montmorillonite, In 0.1?mol/L HAc-NaAc solution (pH=5.0), a sensitive Oxidation peak of Cd 2+ was observed with anodic tripping voltammetry. The peak potential is -0.81?v(vs,SCE). The peak currents are Linear with the concentrations in the range from 2.0×10 -8?mol/L to 1.5×10 -6?mol/L. The detection limit is 2.0×10 -9?mol/L. The method is applicable to the determination of trace lead iron of water and the results have obtained satisfactorily.