茜素紫修饰碳糊电极阳极溶出伏安法测定痕量银的研究  

Determination of trace Silver by Adsorption Voltammetry at an Alizarin Voilet Modified Carbon Paste Electrode

作　　者：谢红旗[1] 李益恒[2] 

机构地区：[1]衡阳师范学院化学系,湖南衡阳421008 [2]湘潭大学化学系,湖南湘潭411105

出　　处：《湘潭大学自然科学学报》2003年第3期69-71,共3页Natural Science Journal of Xiangtan University

摘　　要：报道了采用茜素紫修饰碳糊电极测定痕量银的阳极溶出伏安法,在0.12mol/L的醋酸盐缓冲溶液中(pH5.2),在0电位下富集3min,Ag(I)和茜素紫形成络合物而富集于电极表面,然后通过介质交换至含Br^-溶出介质中,阴极还原后再进行阳极溶出伏安测定,灵敏度有显著提高.银的阳极溶出峰电流与Ag(I)浓度在6.0×10^(-10)～1.3×10^(-7)mol/L范围内呈良好的线性关系,检出限达2.0×10^(-10)mol/L。同时讨论了电极反应机理及Br^-的增敏作用。A stripping Voltammetric procedure fur determination of trace silver at Alizarin violet(AV) modified carbon paste electrode was developed.In an acetate buffer (pH 5.2) , Silver(I) was accumulated on the electrode surface at 0. 0 V by the formation of the complex of Ag+ - AV, then determined by anodic stripping Vollammetry in 0.05 mol/L H2 SO4 containing 2.0×10 3 mol/L Br after cathodic reduction at - 0.20 V . A well linear relationship between the peak current and the silver(I) concentration was obtained in the range of 6.0×10-10 ~ 1 .3×10~7 mol/L for 3 min accumulation lime , and the detection limit is 2.0× 10-10 mol/L. The enhancement mechanism of Br- has been discussed .The proposed procedure has been satisfactorily applied to the determination of silver in zinc alloys.

关 键 词：银 茜素紫 碳糊修饰电极 阳极溶出伏安法 

分 类 号：O657.4[理学—分析化学]