新显色剂3,5-二(4-溴苯氨基重氮基)苯甲酸的合成及其与Ni(Ⅱ)的显色反应研究

Synthesis of a New Chromogenic Reagent 3,5-Bis(4-Bromopenylamino-diazo) Benzoic Acid and Study on Its Color Reaction with Nickel

合成了一种新型的双三氮烯类显色剂3,5-二(4-溴苯氨基重氮基)苯甲酸,并对该试剂与Ni(Ⅱ)的显色反应进行了研究。实验表明,在Triton X-100存在下,pH 10.0的硼砂-氢氧化钠缓冲溶液中,该试剂与Ni(Ⅱ)形成了2:1的红色络合物,其最大吸收波长位于510nm处,表观摩尔吸光系数ε为1.96×10~5L·mol^(-1)·cm^(-1),Ni(Ⅱ)的质量浓度在0一10μg范围内遵守比耳定律。该试剂用于分光光度测定铝合金标样中镍,测定值与认定值相符。

A new Chromogenic reagent 3, 5-bis （4-bromopenylaminodiazo） benzoic acid （BBPAA） has been synthesized and the color reaction conditions of BBPAA with Ni（ II ） have been studied. In the buffer solution of Na2B4O7-NaOH at pH 10.0 and in the presence of TritonX-100,the color reagent reacts with nickel （ II ） to form a red complex （2 ： 1）. The maximum absorption wavelength of the complex is at 510 nm, and the apparent molar absorptivity is 1.96×10^5L·mol^-1·cm^-1. Beer＇s law is obeyed in the range of 0--10μg for nickel （ II ）. This method has been used for the determination of nickel in aluminum alloy samples with RSD of 2.3%-- 3.5%（n=5）.