D－HQADMB分光光度法测定微量镉（Ⅱ）

Spectrophotometric Determination of Cadmium(Ⅱ)with 4,4'-Di[(8-hydroxyquinolyl)azo]-3,3'-dimethylbiphenyl

研究了新显色剂４，４’－二［（８－羟基喹啉）偶氮］－３，３’－二甲基联苯（Ｄ－ＨＱＡＤＭＢ）与Ｃｄ（Ⅱ）的显色反应条件。在吐温－８０存在下的ｐＨ７．８～９．０的缓冲介质中，Ｃｄ（Ⅱ）与Ｄ－ＨＱＡＤＭＢ形成稳定的红色配合物，组成比为Ｃｄ（Ⅱ）＋Ｄ－ＨＱＡＤＭＢ＝１＋２，λｍａｘ＝５３０ｎｍ，表观摩尔吸光系数为７．２０×１０４Ｌ／ｍｏｌ·ｃｍ，Ｃｄ量在０～１．３μｇ／ｍＬ范围内符合比耳定律。用制定的方法测定矿样中的微量镉，结果满意。

The colour reaction of cadmium with a new reagent 4,4'-di[8-hydroxyquinolyl)azo]-3,3'-diniethylbiphenyl has been studied. In the presence of Tween-80 at pH7.8～9.0,cadmium forms a stable red coordination compound with the reagent with a molar ratio of 1+2.The molar absorptivity is 7.20×104L/mol.cm at 530 nm. Beer's law is obeyed in the range of 0～1.3μg/ mL, It has been used satisfactorily for the determination of trace cadmium in mineral samples.