【摘要】 合成了试剂 2 - [2 ,3,5-三氮唑偶氮 ]- 5-二甲氨基苯甲酸 (2 - [2 ,3,5- tria-zolylazo]- 5- dimethylaninobenzoic简称 TZAMB) ,并研究了与钴的显色反应。在 p H 8.0 2的水溶液中钴与 TZAMB形成一种稳定的蓝色络合物 ,其最大吸收波长位于 60 9.4nm处 ,表观摩尔吸光系数为 7.37× 1 0 4 L· mol-1·cm-1。络合物的组成为 Co2 +∶TZAMB=1∶ 3,钴的浓度在 0～ 1 .2 mg· L-1范围内服从比耳定律。方法已用于维生素 B注射液和天然水中微量钴的测定。更多还原

【Abstract】 The condition for colour reaction of 2 [2,3,5 triazolylazo] 5 dimethylaninobenzoic acid (TZAMB) with cobalt was studied. The results showed that coblt reacted with TZAMB to form a stable blue complex at pH 8.02. The apparent molar absorptivity is 7.35×10 4 L·mol -1 ·cm -1 in aqueons ethanol solution at 609.4 nm.Beer′s law is obeyed in the range of 0～1.2 mg·L -1 for cobalt. The ratio of cobalt to TZAMB in the complex is 1∶3.The proposed method was applied to spectrophotometric determination of trace cobalt in vitamin B 12 injection and natural waters with satisfactory results.更多还原