新显色剂2-[3-羧基-2,4,5-三氮唑]-5-二甲氨基苯甲酸的合成及其与镍的显色反应研究

The synthesis and colour reaction of 2-[3-carboxy-2, 4, 5-triazolyazo ] - 5- dimethylaminobenzoic acid with nickel and its application

合成了２－［３－羧基－２，４，５－三氮唑］－５－二甲氨基苯甲酸（简称ＣＴＺＡＭＢ），并研究了其性质及与镍显色反应的条件。结果表明，在ｐＨ４．０～５．６的缓冲溶液中，ＣＴＺＡＭＢ与镍形成一种稳定的红色配合物，其最大吸收波长位于５４２ｎｍ处，表观摩尔吸光系数为５．３７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，配合物的组成为ｎ（ＣＴＺＡＭＢ）： ｎ（Ｎｉ）＝１： １，Ｎｉ２＋浓度在０～１．２ｍｇ／Ｌ范围内服从比耳定律，在氟化铵和硫脲存在下，可直接用于测定镁和铝合金中的镍，所拟方法已用于标样分析，验证结果与标准样相符，６次平行测定的相对标准偏差为０．８９％～１．２６％。

The synthesis and colour reaction of 2-[3-car- boxy-2, 4, 5-triazolyazo]-5-dimethylamino acid with nickel have been studied. The experimental results show that nickel reacts with CTZAMB to form a stable red complex at pH4. 0-5. 6. The apparent molar absorptivity is 5. 37 × 104L· mol-1· cm-1 in ethanol solution at 542. 0nm. Beer's law is obeyed in the range of 0- 1. 2mg/L for nickel. The ratio of nickel to CTZAMB in the complex is 1: 1. The proposed method has been applied to the spectrophotometric determination of trace nickel in alloys with satisfactory results.