新显色剂2-羟基-5-磺酸苯基重氮氨基偶氮苯(HSDAA)光度法测定锌合金中的微量镉

SPECTROPHOTOMETRIC DETERMINATION OF MICRO-AMOUNTS OF CADMIUM IN ZINC-BASE ALLOYS WITH A NEW CHROMOGENIC REAGENT HSDAA

报道了２－羟基－５－磺酸苯基重氮氨基偶氮苯（ＨＳＤＡＡ）的合成方法。该试剂与镉在氨性介质中形成３：１的红色配合物，于５２０ｎｍ波长处有最大吸收，摩尔吸光系数为１．８８×１０＾５。镉量在０￣１０μｇ／２５ｍｌ范围内符合比耳定律。在氨水－磺基水杨酸体系中，多种离子不影响测定，可不经分离直接测定锌合金中微量镉。

The synthesis of 2-hydroxy-5-sulfo-benzenediazoaminoazobenzene (HSDAA) is reported in this paper. Cadmium forms with HSDAA in the presence of OP an 1 : 3 complex, which gives a maximum absorption at 520nm with an apparent molar absorptivity of 1. 88×105 in ammoniacal medium and Beer' s Law is obeyed for 0-10μg/25ml. By the addition of sulfosalicylic acid most of metal ions do not interfere with the determination. The method has been applied to the determination of micro amounts of cadmium in zinc-base alloys with satisfactory results.