钴离子-香兰素缩硫代肼酸苄酯-二乙醇胺多元配合物光谱研究及分析应用

Photometric Determination of Cobalt by the Formation of a Multi-ligand Complex of Co(Ⅱ)-C_(16) H_(16) N_2S_2O_2-DEA

本文合成了一种新的含硫希夫碱 :香兰素缩硫代肼酸苄酯 (HL) ,及其配合物CoL2 DEA ,并通过紫外—可见及红外光谱对该配合物的分子结构进行了研究 ,推断出该三元配合物的配位情况。采用计算机辅助二次回归正交设计 ,系统地研究了该三元配合物在 95%乙醇溶液中的最佳显色条件 (包括反应温度 ,加热时间 ,及各反应物浓度等五个因素 )。根据二次回归方程 ,用步长加速法计算出该体系的最大吸光度及其相应五个因素的最佳显色取值 ,并通过实验验证了计算结果的准确性。试验了干扰离子及其消除方法 ,并将该配合物用于药物华素片及VB12针剂中含钴量的测定 ,获得了满意的结果 ,建立了测定Co(Ⅱ )的新方法。该体系最大吸收波长为 4 0 4 0nm ,ε40 4max=5 2 9× 10 4L·mol-1 ·cm-1 ,检测限为 0～ 2 0 μg·( 2 5mL) -1 ,配合物组成比为 1∶2∶1。

The new ligand vanillin S benzyldithocarbazte(HL) and its complex Co(Ⅱ) C 16 H 16 N 2S 2O 2 DEA was synthesized and characterized by IR,UV Vis.The optimum color conditions of the complex in 95% ethanol solution(including reaction temperature T,heating time t,and the concentrations of the three components)have been studied by quadratic regression orthogonal design method.According to the quadratic regression equation,the maximum absorption intensity and optimum color conditions of the complex were calculated.The results were consistent with those gotten by experiment.The influences of common ions on the determination of cobalt and the methods to eliminate the influence are investigated.The maximum absorption peak of the complex is found at 404 nm and molar absorptivity is 5 29×10 4 L·mol -1 ·cm -1 .Beer′s law is obeyed in the range of 0-20 μg·(25 mL) -1 for Co(Ⅱ).The composition of Co 2+ to HL,and DEA in the complex is 1:2:1.The new method was successfully utilized to the determination of cobalt in VB 12 and medicine.