邻羟基苯基重氮氨基偶氮苯的合成及与镉的显色反应

Synthesis of o-Hydroxy-Benzenediazoaminoazobenzene and Its Color Reaction with Cadmium

报道了邻羟基苯基重氮氨基偶氮苯(o-HDAA)的合成及其与镉的显色反应。在TritonX-100存在下,pH10的Na2B4O7-NaOH缓冲溶液中,该试剂与Cd()形成3∶1稳定的红色络合物,其最大吸收波长为516nm,表观摩尔吸光系数为1.88×105L·mol-1·cm-1,Cd()浓度在0—20.0μg/25mL符合朗伯-比耳定律。用拟定方法测定废水中微量镉,结果令人满意。

The o-hydroxy-benzenediazoaminoazobenzene （o-HDAA） was synthesized and its color reacts with cadmium was investigated. In the presence of triton X-100 and in the Na2B4O7-NaOH medium of pH 10,o-HDAA forms a 1 ： 3 red complex with Cd（ Ⅱ）. The apparent molar absorptivity of complex is 1.88 × 10^5L · mol^-1· cm^-1 at 516nm. Beer＇s law is well obeyed in the range of 0-20.0μg/25mL for cadmium. The method has been applied to the direct determination of cadmium in waste water with satisfactory results.