摘要
首先在玻璃毛细管外化学沉银,然后在银层上电解沉积Ag2S层,制得Ag/Ag2S固膜电极;与毛细管内的Ag/AgCl参比电极组装成复合电极系统。试验表明,该电极对CN-具有良好的能斯特响应,能斯特斜率约为110 mV/pCN-,线性范围为pCN-3~7,检测下限为5×10^-8mol·L^-1。应用此电极分析污水试样的结果与标准光度法的测定结果相符,两者的相对误差小于5.1%。试验了常见离子如S^2-、Ag^＋、Hg^2＋等的干扰及其消除方法。讨论了电极的响应机理。
Ag/Ag2 S crystal membrane electrode was prepared by chemical deposition of a silven layer on the glass capillary and then a layer of Ag2 S was deposited electrolytically onto the silver layer. An electrode system was assembled between the Ag/Ag2S membrane electrode outside the capillary and the Ag/AgC1 reference electrode placed inside the capillary. It was shown by the results of electrochemical study of the composited electrode system, that it was used successfully in the determination of CN^--ion in sewage. Linear Nernst response was obtained in range of 1.00×10^-3-1. 00×10^-7mol · L^-1 of CN^--ion or of pCN^- 3--7, with a detection limit of 5×10^-8mol · L^-1, and the Nernst slope was found to be 110 mV/pCN^-. Analytical results obtained by using this electrode in the analysis of 4 different sewage samples, checked quite well with those obtained by the standard photometric method, giving relative error less than 5. 1%. Interferences and methods of elimination of some commonly co-existing ions （e. g. S^2- , Ag^＋ , Hg^2＋ etc） were tested. Mechanism of the electrode reaction was also discussed briefly.
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2007年第1期45-47,50,共4页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
关键词
离子选择电极
电解沉积
复合电极体系
氰化物
污染水
Crystal membrane ion-selective electrode
Electro-deposition
Composite electrode system
Cyanide ion
Sewage
