丁二酮肟修饰固体银汞合金电极伏安法测定痕量钴  

Voltammetric Determination of Trace Amount of Cobalt Using Silver Amalgam Solid Electrode Modified with Dimethylglyoxime

作　　者：袁星义 魏小平[2] 李建平[2] 

机构地区：[1]广西地质环境监测总站,桂林541004 [2]桂林理工大学化学与生物工程学院,桂林541004

出　　处：《理化检验（化学分册）》2010年第7期800-802,806,共4页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：广西自然科学基金(桂科自0728214);广西教育厅科研基金(桂教科200508135)项目资助

摘　　要：根据文献[4]采用银粉、丁二酮肟与汞混合制成的汞合金糊涂布在固体石蜡碳糊电极表面，制作修饰汞合金电极，并应用于线性扫描伏安法测定痕量钴。在pH6．0的氯化铵一柠檬酸铵缓冲溶液中，钴（Ⅱ）一丁二酮肟配合物于-1．18V出现灵敏度的还原峰，钴（Ⅱ）的质量浓度在0．10～2．0mg·L^-1范围内与峰高呈线性关系，方法的检出限（3s／k）为0．02mg·L^-1对0．10mg·L^-1钴（Ⅱ）溶液进行11次平行测定，相对标准偏差（n=11）为1．93％。该法已用于2件水样中钴含量的测定，平均回收率分别为98．8％及105．1％。The carbon paste electrode was prepared according to the method described in literature[4], and modified by applying a layer of a paste mixture containing silver powder, dimethylglyoxime and mercury. In the base solution of ammonium citrate and ammonium chloride at pH 6. 0, a coordination complex was formed between the dimethylglyoxime of the modified electrode and Co^2＋ ion, showing a sensitive reduction peak at the potential of -1. 18 V （vs. SCE）, Values of peak height were found to keep linear relationship with mass concentration of Co^2＋ ion in the range of 0. 10-2. 0 mg·L^-1 , with a detection limit （3s/k） of 0. 02 mg·L^-1. Based on these facts, a linear seanning-voltammetric method for determination of traces of cobalt ion in water sample was propose＆ Precision was tested with 0. 10mg·L^-1 Co^2＋ for 11 determination with a same electrode, value of RSD found was 1.93%. Two water samples were analyzed by this method, and using these samples as matrixes, recovery was tested by standard addition method, giving values of average recovery of 98. 8% and 105. 1%.

关 键 词：固体汞合金电极 丁二酮肟 伏安法 钴(Ⅱ) 

分 类 号：O657.14[理学—分析化学]