EDTA滴定钴(Ⅱ)的示波电位滴定法——用EDTA修饰的铂电极作为指示电极  

Oscillo-Potentiometric Titration of Cobalt(Ⅱ) with EDTA Using EDTA-Modified Platinum Electrode as Indicator Electrode

作　　者：齐同喜[1] 

机构地区：[1]山东理工大学化学工程学院,淄博255049

出　　处：《理化检验（化学分册）》2007年第11期934-936,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：制备了用EDTA修饰的铂电极并用循环伏安法检测了修饰电极的电化学性能,在以钴(Ⅱ)标准溶液滴定EDTA溶液的示波电位滴定中,用两支上述修饰电极作为双指示电极体系。当在阴极示波器的屏幕上观察到荧光点的突然最大位移即可判定滴定终点。取10.00 mg钴(Ⅱ)按此方法连续测定15次,所得终点电位值均在45 mV左右,算得其相对标准偏差(RSD)值为0.01。滴定操作在pH 10~11的氨性缓冲溶液中进行,可按需要加入诸如氟化物、酒石酸盐之类的络合剂。测定质量在1.2~31.2 mg之间的钴(Ⅱ)时,回收率在99.9%~100.3%之间。将此方法应用于陶瓷着色剂中Co2O3的测定,所得结果与已知值相符,测定的RSD值(n=7)小于0.05%。EDTA-modified platinum electrode was prepared and its electrochemical behavior studied by cyclic voltammetry.Two of such modified Pt-electrodes were used as bi-indicator electrode system in the oscillopotentiometric titration of Co(Ⅱ) with EDTA.End point of the titration was determined by an abrupt maximum displacement of the fluorescence spot observed on the screen of the cathodic oscillograph.Repeatability of the modified Pt-electrode was tested for 15 successive determinations using 10.00 mg of Co(Ⅱ),val...

关 键 词：示波电位滴定法 EDTA修饰铂电极 钴(Ⅱ) EDTA滴定 

分 类 号：O657.1[理学—分析化学]