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(4-邻羟基苯基三氮烯)偶氮苯是我们新合成的三氮烯类试剂之一,其结构式为:试剂为棕褐色粉末。难溶于水,易溶于乙醇、三氯甲烷等有机溶剂。与金属离子反应时,结构中处于邻位的羟基参与络合,形成稳定的五元环形结构;羟基同时又是推电子基,可使配位氮原子上的电子云密度增加,从而提高了配位能力,使所形成的配合物的稳定性相应的增加。在非离子表面活性剂 Triton X-100存在下,试剂与镉形成灵敏度很高的胶束增溶配合物,其摩尔吸光系数达1.92×10~5L·mol~(-1)·cm~(-1).25mL 容积中,镉含量为0～9.0μg服从比耳定律。共存元素中 Ni(Ⅱ)、Hg(Ⅱ)等干扰严重,进行试样分析时需采用萃取分离手续。应用本文拟定的分析方法测定茶叶中痕量镉,结果较为满意。
(4-o-hydroxy phenyl triazene) azobenzene is one of our newly synthesized triazene reagents, the formula is: reagents for the tan powder. Hard to dissolve in water, soluble in ethanol, chloroform and other organic solvents. With the reaction of metal ions, the hydroxyl in the ortho-position in the structure participates in the complexation to form a stable five-membered ring structure. At the same time, hydroxyl groups push the electron groups to increase the electron cloud density on the coordinated nitrogen atoms, The ability to form a corresponding increase in the stability of the complex. In the presence of nonionic surfactant Triton X-100, the reagent and the cadmium form a highly sensitive micellar solubilization complex with molar extinction coefficient of 1.92 × 10-5L · mol -1 · cm ~ (- 1) .25mL volume, cadmium content of 0 ~ 9.0μg obey Beer’s law. The coexisting elements of Ni (Ⅱ), Hg (Ⅱ) and other serious interference, the sample analysis required the use of extraction and separation procedures. Application of the analysis method developed in this paper Determination of trace amounts of cadmium in tea, the results are more satisfactory.