1-羟基-2-(5-氯-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸与铜的显色反应研究

STUDY OF COLOR REACTION OF COPPER WITH 1-HYDROXY -2-(5-CHLORO-PYRIDYLAZO)-8-AMINO-3, 6-NAPHTHALENE DISULFONIC ACID

研究了新试剂1 羟基 2 (5 氯 2 吡啶偶氮) 8 氨基 3,6 萘二磺酸(5 Cl PAH)与铜(II)的显色反应。结果表明,在pH7.42～8.49的硼砂 盐酸缓冲体系中该试剂与铜(II)可形成1∶1的蓝色配合物,其最大吸收波长位于640nm处,表观摩尔吸光系数为ε640=3.12×104L·moL-1·cm-1,铜(II)浓度在0～12.5μg/10mL的范围内符合比耳定律。将方法用于铝合金样和标准水样中微量铜的测定,结果满意。

The color reaction of copper (II) with reagent 1-hydroxy-2-(5-chloro-pyridylazo)-8-amino-3,6-naphthalene disulfonic acid (5-Cl-PAH) has been investigated.The results showed that in Na_2B_4O_7-HCl buffer at pH 7.42～8.49, Cu (II) reacts with 5-Cl-PAH to form a 1∶1 stable blue complex, its absorbance maximum is measured at 640 nm with the apparent molar absorptive being 3.12×104L·moL^(-1)·cm^(-1) ,and Beer′s law is obeyed in the range of 0～12.5μg/10mL for Cu (II). The method has been applied to the determination of trace Cu (II) in the stander water sample and aluminium alloys with satisfactory results.