新显色剂4-溴-2-磺酸基苯基重氮氨基偶氮苯的合成及其与镉(Ⅱ)的显色反应

Synthesis of a chromogenic reagent 4-bromo-2-sulfo-benzenediazoaminoazobenzene(BSDAA) and its application to spectrophotometric determination of microamounts of cadmium(Ⅱ)

报道了一种新型的三氮烯类偶氮染料的合成方法及其与Cd(Ⅱ )的显色反应。实验表明 ,在TritonX 1 0 0存在下的弱碱性介质中 ,试剂与镉 (Ⅱ )形成 2∶1的红色络合物 ,摩尔吸收系数为 2 .1× 1 0 5L·mol- 1 ·cm- 1 ;镉含量在 0 μg/2 5mL～ 2 5 μg/2 5mL范围内遵守比耳定律。

The synthesis of a chromogenic reagent 4 bromo 2 sulfobenzene diazoaminoazobenzene(BSDAA) was described. In the pH 10.0～11 0 ammonia ammonium chloride buffer solution a 1∶2 red complex of Cd(Ⅱ) and BSDAA is formed in the presence of TritionX 100, which gave a maximum absorption at 526 nm with an apparent molar absorptivity of 2.1×10 5 L· mol -1 ·cm -1 . The method was used to spectrophotometric determination of cadmium(Ⅱ) in waste water with satisfactory results.