催化动力学荧光法测定铜(Ⅱ)

Catalytic-Kinetic Fluorescence for Detection of the Copper(Ⅱ)

在硫酸介质中,在溴酸钾氧化罗丹明B的反应体系中,加入Cu(Ⅱ),能加速反应的进行,Cu(Ⅱ)对此褪色反应有催化作用,据此建立了测定微量铜的催化动力学荧光法.研究了影响催化褪色反应速度的最佳条件,在最优化条件下,Cu(Ⅱ)浓度在8×10^-8μg/mL^2×10^-6μg/mL范围内与荧光强度呈良好的线性关系,其相关系数为0.9980,方法的检出限为2×10^-8μg/mL.对浓度为1×10^-7μg/mL的Cu(Ⅱ)标准溶液进行11次平行测定,得相对标准偏差(RSD)为1.2%,该法简单、快速、灵敏度高,已应用于自来水、茶叶中Cu(Ⅱ)含量的测定,回收率为96.3%~104.3%,结果令人满意.

Based on the catalytic effect of copper(Ⅱ)on the oxidation of rhodamine B by potassium bromate in sulphuric acid solution,a new catalytic-kinetic fluorometry method was proposed for the determination of trace copper.The optimum conditions affecting the catalytic reaction have been investigated.Under the optimal conditions,the copper(Ⅱ)concentration within a range of 8×10^-8μg/mL^2×10^-6μg/mL has a good linear relation,the linear correlation coefficient is 0.9980,and the detection limit is 2×10^-8μg/mL.The relative standard deviation(RSD)is 1.2%for 1×10^-7μg/mL copper(Ⅱ)solution(n=11).The method has the advantages of simplicity,rapidity and high sensitivity,and has been applied for the detection of copper(Ⅱ)in running water and tea.The recoveries between 96.3%~104.3%are obtained with satisfied results.