铜(Ⅱ)-咪唑络合吸附波的研究

The Adsorptive-Complex Wave of Gopper(Ⅱ)-Imidazole System

本文提出极谱测定微量铜的铜(Ⅱ)-咪唑新体系。以0.2mol/L NaOH为底液,该体系在单扫示波极谱仪上有一灵敏的络合吸附波。波的峰电位为-0.59V(SCE)。波高与浓度在3.1×10^(-8)~1.6×10-6mol/L范围内的铜(Ⅱ)成正比,且选择性校好。应用循环伏安、脉冲极谱等方法研究了该极谱波的性质,结果表明该极谱波属于反应物弱吸附的络合吸附波。

A new system of Cu(Ⅱ)-Imidazole for the determination of trace copper by polarography is proposed.In a supporting electrolyte containing 0.2mol/L NaOH,a sensitive adsorptive-complex wave of this system was obtained by single-sweep polarography.The peak potential of the polarographic wave was -0.59V vs.SCE. The linear relationship between v/ave height and the concentration of coppre held in the range of 3.1×10^(-8)-1.6×10-6mol/L.This method has a better selectivity for it is satisfactory in the determination of trace copper in waste water or surface water.The character of the polarographic wave was studied by cyclic voltammetry, normal pulse polarography and some other methods. The results indicated that the polarographic wave is an adsorptive wave of complex with weakly adsorbed reactant. The .adsorptive species is Cu(Imid)32+, which was inferred from contrast experiment with the. theoretical calculation.