镉-铝试剂-硫代氨基脲三元络合物吸附波的研究  

Study on the adsorptive polarographic wave of ternary complex of CdⅡ with aluminon and thiosemicarbazide

作　　者：罗登柏[1] 覃擎红[1] 

机构地区：[1]中南民族大学化学与生命科学学院,湖北武汉430074

出　　处：《冶金分析》2005年第4期6-9,共4页Metallurgical Analysis

基　　金：中南民族大学自然科学基金重点项目(YZZ03003)

摘　　要：在pH 4.7的HAc-NaAc缓冲介质中,Cd(Ⅱ)-铝试剂-硫代氨基脲三元络合物在单扫描示波极谱仪上于-0.67 V(vs.SCE)产生一灵敏的络合吸附波.导数波高与Cd(Ⅱ)浓度在1.0×10-8～2.2×10-6mol/L范围内呈线性关系,检出限为5.0×10-9mol/L.机理研究表明,此波是Cd(Ⅱ)-铝试剂-硫代氨基脲络合物(络合比为1:1:1)在电极上吸附,Cd(Ⅱ)在电极上还原而产生.采用适当浓度的Zn2+-乙酰丙酮溶液掩蔽过量铜离子,该法可直接测定废水中痕量Cd(Ⅱ)的含量.A sensitive adsorptive polarographic wave of ternary complex of Cd （Ⅱ） with aluminon and thiosemicarbazide at -0.67 V （vs. SCE）has been observed by using single-sweep polarography in pH 4.7 acetate buffer solution containing 1.1 × 10^-4 mol/L aluminon and 9.0 × 10^-4 mol/L thiosemicarbazide. The peak height is linear with the concentration of cadmium within range of 1.0 × 10^-8—2.2 × 10^-6 mol/ L.The detection limit is 5.0 × 10^-9 mol/L.The results of mechanism study show that the polarographic wave is based on the reduction of Cd（Ⅱ） in the ternary complex adsorbed on the electrode surface. Using a solution of 1.5 × 10^-5 mol/L Zn^2＋ - 3.0 × 10^-3 mol/L acetylacetone to mask the interference of excess copper ion, the method can be applied to the direct determination of trace cadmium in waste water.

关 键 词：Cd(Ⅱ)-铝试剂-硫代氨基脲三元络合物 单扫示渡极谱法 吸附波 

分 类 号：O657.14[理学—分析化学]