3,5-二溴-2-吡啶重氮氨基偶氮苯的合成及与镉(Ⅱ)的显色反应研究

Colour Reaction of Chromogenic Reagent 3,5-Di-bromine-2-pyridinediazoaminoazobenzene with Cadmium(Ⅱ) and its Application

报道了一种新型三氮烯类偶氮染料的合成方法及其与 Cd( )的显色反应。在 Triton X- 1 0 0存在下的弱碱性介质中 ,该试剂与 Cd( )形成 4∶ 1的红色络合物 ,最大吸收波长位于 52 6nm 处 ;表观摩尔吸收系数为 2 .0 4× 1 0 5L·mol-1·cm-1,镉含量在 0～ 1 5μg/ 2 5m L范围内符合比耳定律。方法可直接用于废水中微量镉的测定。

Synthesis of a new reagent 3,5 di bromine 2 pyridinediazoaminoazobenzene and its chromogenic reaction with cadmium(Ⅱ) ion was repored. In a weak alkaline medium, the reagent reacted with cadmium(Ⅱ) to form a 4∶1 red complex. The absorption maximum of the complex is at 526 nm and the apparent molar absorptivity is 2.04×10 5 L·mol -1 ·cm -1 . Beer′s law is obeyed for cadmium(Ⅱ) in the range of 0～15 μg/25 mL. This method was employed to determine trace amounts of cadmium(Ⅱ) in waste water.