微量钴的萃取光度法研究

Determination of Treace Cobalt (Ⅱ) by Organic Solvent Extraction Spectrophotometry

本文研究了TBP-Co(Ⅱ)-SCN三元配位化合物的形成和萃取条件,推荐了一种高灵敏度的快速测定维生素B_(12)中微量Co(Ⅱ)的分析方法.实验表明,在0.09～0.60mol.L^(-1)HCI和0.22mol.L^(-1)KSCN介质溶液中,Co(Ⅱ)和TBP形成TBP-Co(Ⅱ)-SCN三元配合物,其最大吸收波长λ_max为318.0nm.本法不仅可准确测定0～0.15μg·ml^(-1)浓度范围内Co(Ⅱ),原样溶液中的检出限达1.5ng·ml^(-1),1%的吸收灵敏度为2.5ng·ml^-(-1),而且具有灵敏度高、操作简单迅速等优点.

The formation and extraction conditions of TBP-Co(Ⅱ) -SCN-ternary coordination are investigated. A sensitive and rapid method for the determination of Co(Ⅱ) is presented. This method is used in the determination of Co (Ⅱ) in vitamin B_(12). Experiments show that Co(Ⅱ) and TBP are formed as TBP-Co(Ⅱ) -SCN ternary coordination in the solution of 0.09～0.60mol/L HCI and 0. 22mol/L KSCN. The maximum absorption is at 318. 0nm. For Co(Ⅱ) the working curve is linear in 0～0. 15μg/ml and the apparent ε=1.18×10~5L/mol·cm in organic solvent TBP.