新试剂2-羧基-5-硝基苯基重氮氨基-4-苯基-2-噻唑光度法测定微量铜的研究

Spectrophotometric Determination of Micro Copper with 2-Carboxyl-5-Nitrophenyldiazoamino-4-Phenyl-2-Thiazole

本文研究了新试剂 2 -羧基 - 5 -硝基苯基重氮氨基 - 4 -苯基 - 2 -噻唑 ( CNPDAPT)在 Triton X- 1 0 0的存在下 ,与铜显色反应的适宜条件。结果表明在 p H1 0 .0的 Na2 B4O7- Na OH缓冲介质中 ,铜与试剂形成 1∶ 1红色配合物 ,其最大吸收波长位于 5 1 5 nm,表观摩尔吸光系数 ε=4.5 9× 1 0 4 L· mol- 1· cm- 1 ,铜量在0 - 2 0 μg/ 2 5 m L范围内遵守比耳定律。方法用于水样中微量铜的测定 ,结果满意。

A color reaction of copper (Ⅱ)with 2Carboxyl5nitrophenyldiazoamino4phenyl2thiazole has been studied.In the presence of Triton X100 and at pH10.0 Na_2B_4O_7NaOH buffer,copper(Ⅱ)reacts with the reagent form a red complex with the molar ratio of 1∶1.The complex exhibits maximum absorption at 515nm with a molarabsorptivity of 4.59 x104L·mol^-1·cm^-1.Beer's law is obeyed in therange of 0-20μg/25mL Cu(Ⅱ).The method has been applied to the determination of trace element copper(Ⅱ) in water with satisfactory results.