高灵敏显色剂—meso-四(4-甲基,3-磺基苯)卟啉分光光度法测定痕量钴(Ⅱ)的研究

Studies on the Spectrophotometric Determination of Trace Amounts of Cobalt (Ⅱ) with meso-tetra ( 4-methyI -3-sulfophenyl ) Porphyrin ( TTPS4 )

本文研究了在室温下TTPS_4与钴(Ⅱ)的显色反应。结果表明,在含有镉盐及咪唑的弱碱性介质中,利用Co(Ⅱ)对Cd-TTPS_4的取代反应形成很稳定的灵敏度很高的配合物,其ε436=2.24×10_5L·mol^1·cm^1。钴(Ⅱ)的浓度在0～1.5μg/10ml范围内,符合比尔定律。在掩蔽剂存在下,有一定选择性,可直接测定合成氨触媒、冶炼厂工业废水等样品中钴(Ⅱ),结果满意。

A highly sensitive method for the determination of cobalt(Ⅱ) at ng/g level has been developed by using of TTPS4. The substitution reaction by cobalt(Ⅱ) in the Cd(Ⅱ)-TTPS4 complex has been accelerated in the presence of imidazole at room temperature at pH 8.5. The absorption band of the cobalt(Ⅱ) complex lies at 436nm, which is well separated from that of the reagent blank(at 4l6nml). The apparent molar absorptivity of complex is 2.24×l05L mol-1 cm-1. Beer's law is obeyed for Co(Ⅱ) of 0 to 150ng/g.The method has been applied to the determintion of Co(Ⅱ)in industrial waste water and catalysts with satisfactory results.