In this paper, a novel kinetic spectrophotometric method for the determination of ultra trace Cu(II) was developed. This method was based on catalytic action of Cu(II) on the oxidation of indigo carmine by ammonium persulfate in Na2B4O7-HCl buffer solution (pH = 9.09) and in presence of the surfactant-TritonX-100. Effects of some factors on the reaction speed were investigated in this study. It was observed that the concentration of Cu(II) was linearly correlating to DA in the range of 2.0 × 10-10-1.6 × 10-9 g/mL for Cu(II) in this method. The detecting limit of the proposed method was 1.8 × 10-11 g/mL. This system was a first-order reaction for Cu(II). The apparent rate constant was 3.19 × 10-4 s-1 and the apparent activation energy was 112.5 kJ/mol in this system. Most of the foreign ions did not interfere with the determination and the interferences of Fe(III) and Al(III) could be masked by F–. The proposed method was applied to the determination of ultra trace-level copper(II) in real samples with satisfactory results.
本文开发了一种测定超痕量 Cu(II) 的新型动力学分光光度法。该方法基于在 Na2B4O7-HCl 缓冲溶液(pH = 9.09)和表面活性剂 TritonX-100 存在下,Cu(II) 对过
硫酸铵氧化靛蓝胭脂红的催化作用。本研究探讨了一些因素对反应速度的影响。观察到该方法中 Cu(II) 的浓度与
DA 在 2.0 × 10-10-1.6 × 10-9 g/mL 范围内呈线性相关。该方法的检测限为1.8×10-11 g/mL。该系统是 Cu(II) 的一级反应。该体系的表观速率常数为3.19×10-4 s-1,表观活化能为112.5 kJ/mol。大多数外来离子对测定没有干扰,Fe(III)和Al(III)的干扰可以被F-掩盖。该方法用于实际样品中超痕量
铜(II)的测定,结果满意。