镍-对甲氧基苯重氮氨基偶氮苯显色体系的研究——铝合金中微量镍的测定

Spectrophotometric Study on the Colour Reaction of Ni (Ⅱ) with p-Methoxybenzeneaminodiazoazobenzene

本文报告了在硼酸钠介质(pH=10.70～11.60)中,在有Triton X-100和KSCN存在时,对甲氧基苯重氮氨基偶氮苯与镍的反应行为,最大吸收峰位于520nm处,在0～10μg Ni^(2+)/25mL范围内有良好的线性关系,其表观摩尔吸光系数为1.26×10~5L·mol^(-1)·cm^(-1)。实验了46种共存离子,仅Co^(2+)、Cd^(2+)、Pd^(2+)、Fe^(3+)、Ti^(4+)、Cr^(3+)等量干扰。经掩蔽后,可直接用于环境样品及铝合金中镍的测定。

p-Methoxybenzeneaminodiazoazobenzene was first synthesized and employed as a chromogenic agent in the spectrophotometric determination of Ni(Ⅱ). In presence of KSCN and Triton X-100,the maximum absorption of Ni (Ⅱ) complex with the said chromogenic agent is at 520nm,and its apparent molar absorptivity is 1.26× 10~5L·mol^(-1)·cm^(-1). Beer's law is obeyed over the range of 0～10μg/25mL nickel. The composition ratio of Ni(Ⅱ) to p-methoxybenzeneaminodiazoazobenzene in the complex was estimated to be 1:4,and the optimum acid range is found to be pH 10. 70～11. 60. Common ions (Jo not interfere. The recommended procedure has been applied to the determination of Ni (Ⅱ) in environmental samples and aluminium alloys with satisfactory results.