新显色剂2,6-二羟基苯基重氮氨基偶氮苯与镉的显色反应的研究和应用

STUDY ON THE COLOR REACTION OF Cd(Ⅱ) WITH THE NEW REAGENT 2,6- DIHYDROXYPHENYLDIAZOAMINOAZOBENZENE AND ITS APPLICATION

合成了新试剂 2 ,6 二羟基苯基重氮氨基偶氮苯 ,并研究了在TritonX 10 0存在下其与镉的显色反应。在 1mol·L-1氨水中Cd(Ⅱ )与显色剂生成 1∶3的稳定红色配合物 ,最大吸收波长为5 2 0nm ,表观摩尔吸光系数为 1.97× 10 5L·mol-1·cm-1,Cd(Ⅱ )在 0～ 18μg 2 5ml范围内符合比耳定律 ,方法有较高的选择性。用于废水中微量镉的直接测定 。

The synthesis of a new reagent DHDAA and its chromogenic reaction with cadmium(Ⅱ) in the presence of Triton X 100 was studied. In a 1.0mol·L -1 ammonia solution, Cd(Ⅱ) reacts with DHDAA to form a stable red complex with molar ratio of 1∶3. The apparent molar absorptivity is 1.97×10 5L·mol -1 ·cm -1 at the maximum absorption of 520nm. Beer′s law is obeyed over the range of 0～18μg Cd(Ⅱ) in 25ml solution. The method shows higher selectivity and has been applied to determine cadmium derectly in waste water with satisfaction.