新显色剂1-(对偶氮苯)-3-(2-吡啶)-三氮烯与镍显色反应的研究

A Study on the Color Reaction of Nickel with a new Chromogenic Reagent 1 ( p azophenyl) 3 (2 Pyridine)Triazene

提出了用新试剂１－（对偶氮苯）－３－（２－吡啶）－三氮烯分光光度法测定镍的方法。研究结果表明，显色反应有很好的选择性，常见离子除镉外，基本上不干扰。显色反应在有一定量非离子表面活性剂存在时，也具有较高的灵敏度，在ｐＨ９．８０～１０．３０范围内，镍与显色剂可形成１∶３的配合物，其最大吸收波长为５３５ｎｍ，配合物的表观摩尔吸光系数为１．４６×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，在０～１２μｇ／２５ｍＬ内符合比耳定律。不经分离可用于铝合金中镍和环境水质标准样品中镍的直接测定，结果较为满意。

hotometric determination of trace amounts of nickel with the new reagent 1 ( p azophenyl) 3 (2 Pyridine) triazene is recommended.It is shown that the new reagent has fairly good selectivity to nickel,the great majonity of common ions do not interfere except cadmium.Nickel forms a stable red complex with APPT in the presence of non ionic surfactant Triton X 100 at pH 9.8～10.30.The maximum absorption of the reagent and complex is at 440nm and 535nm respectively ,the apparent molar absorptivity of the complex is 1.46×10 5L·mol -1 ·cm -1 .Beer's law is obeyed in the range of 0～12μg Ni per 25mL.The ratio of nickel to APPT in the complex is 1∶3.The proposed method has been applied to the determination of nickel in aluminium alloys with satisfactory results.