5─Br─PAN─S与镍显色反应及其分析应用的研究

Study on the color reaction of nickel(Ⅱ)with 1-(5-bromo-2-pyridylazo)-2-naphthol-6-sulphonic acid and its application

研究了镍（Ⅱ）与１－（５－溴－２－吡啶偶氮）－２－萘酚－６－磷酸（５－Ｂｒ－ＰＡＮ－Ｓ）的显色反应。在ｐＨ６．０，镍（Ⅱ）与５－Ｂｒ－ＰＡＮ－Ｓ形成１：２的红色配合物，其最大吸收波长在５８０ｎｍ，摩尔吸光系数为５．０×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。镍量在０～２５μｇ／２５ｍＬ范围内符合比尔定律。方法用于铝合金和废水中镍的测定，结果满意。

The color reaction of nickel(Ⅱ) with 1-(5-bromo-2-pyridylazo)-2-naphthonic acid (5-Br-PAN-S)has been studied.At PH 6.0￣8.0,nickel(Ⅱ)reacts with 5-Br-PAN-S to form a stable 1:2 red chelate in aqueous solution.The maximum absorption of this chelate lies at 580urn,its apparent molar absorptivity is 5.0×104L·mol-1·cm-1.Beer's law is obeyed in the range of 0￣25μg/25mL for nickel.The proposed method has been applied to the determination of nickel in aluminium alloy and waste water with satisfactory results.