【摘要】 在pH 5.0的HAc-NaAc缓冲介质中,用2,2’-联吡啶作活化剂,Cu(Ⅱ)对抗坏血酸还原7-(2,6二-氯苯偶氮)-8-羟基喹啉-5-磺酸具有强烈催化作用且使体系的荧光显著增强,据此建立了催化动力学荧光光度法测定痕量铜的新方法。建立了反应动力学方程,确定此反应对试剂和铜均为一级反应,测得反应速率为2.36×10-6mol.L-1.min-1,求得表观活化能为72.86 kJ/mol。以341 nm为激发波长,443 nm为发射波长,其荧光增强强度与铜量在0.04~7.2μg/L范围呈线性关系,检出限为4×10-8g/L。采用巯基棉富集分离,用于钢样及铝合金中微量铜的测定,相对标准偏差为3.80%~4.40%;与认定值比较,结果相吻合。更多还原

【Abstract】 A new method for determination of trace Cu(Ⅱ) has been established,based on the effect of catalysis and fluorescence enhancement of Cu(Ⅱ) on the reduction reaction of 7-(2,6-dichloride-phenylazo)-8-hydroxyquinoline-5-sulfonic acid and ascorbic acid using 2,2 ′-dipyridyl as activator in pH 5.0 HAcNaAc buffer solution.The catalytic reaction was confirmed as first order one according to the dynamics reaction equation.The reaction rate and apparent activation energy were 2.36×10-6mol·L-1·min-1 and 72.86 kJ/mol,respectively.At λex/λem = 341 nm/443 nm,linear relationship between the fluorescence intensity and concentration of copper(Ⅱ) was 0.04-7.2 μg/L and detection limit was 4×10-8 g/L for copper(Ⅱ),respectively.This method has been used to determine trace amount of Cu(Ⅱ) in aluminum alloy and steel samples with the relative standard deviation of 3.80%-4.40 % and the results were consistent with the certified values.更多还原