显色剂4-氯-2-磺酸基苯基重氮氨基偶氮苯的合成及其与Cd(Ⅱ)显色反应的研究及应用

SYNTHESIS OF A NEW CHROMOGENIC REAGENT 4-CHLORO-2- SULFOBENZENEDIAZOAMINOAZOBENZENE AND STUDY ON ITS COLOR REACTION WITH CADMIUM(Ⅱ)

研究了显色剂 4-氯 - 2 -磺酸基苯基重氮氨基偶氮苯 (CSDAA)的理化性质及其与 Cd( )的高灵敏度显色反应。在 Triton X- 1 0 0存在下 ,于 p H 1 0 .6的氨水 -氯化铵缓冲介质中 ,该试剂与 Cd( )形成 3∶ 1的红色络合物 ,最大吸收波长位于 52 1 nm处 ,Cd( )在 0～ 2 0 μg/2 5ml内符合比耳定律 ,表观摩尔吸光系数为 2 .0× 1 0 5,直接用于废水中微量镉的测定 ,结果满意。

The color reaction of cadmium(Ⅱ) with a new reagent 4 chloro 2 sulfobenzenediazoaminoazo benzene abbreviated as CSDAA was studied and is reported in this paper. In the presence of Triton X 100 the reagent reacts with cadmium(Ⅱ) to form a red complex with a molar ratio of 3∶1 in an ammonical buffer solution of pH 10.6. The maximum absorption of the complex is at 530nm and the apparent molar absorptivity is found to be 2.0×10 5. Beer′s law is obeyed in the rang of 0~20μg of cadmium in 25ml of solution. This mothod has been used to determine trace amounts of cadmium(Ⅱ) in waste water with satisfactory results.