新试剂二溴邻硝基偶氮胂光度测定矿石中的钍

Spectrophotometric Determination of Th in Ores with a New Chromogenic Reagent DBNA

本文介绍了用新显色剂二溴邻硝基偶氮胂光度测定矿石中Th的方法。在0.2mol/L HCl介质中,Th与新试剂形成蓝色配合物,在630nm处具有最大吸收,摩尔吸光系数为9.7×10~4L·mol^(-1)·cm^(-1),配合物的组成Th:R=1:2,Th量在0—15μg/25ml范围内符合比耳定律。许多常见的金属离子在几毫克乃至十几毫克时不干扰测定。方法用于矿石中Th的测定能获得满意的结果。

A spectrophotometric method for the determination of thorium in ores with the new chromagenic reagent-DBNA (3-(2-arseaophenylazo) -6- (4,6-dibromo-2-nitrophenylazo)-4,5-dihydroxy-2,7-naphthalene disulfonic acid) is described. In 0.2mol/L HCl medium, thorium forms a blue complex with the reagent with a maxium absorption at 630nm, its molar absorptivitly being 9.7× l04L·mol-1·cm-1. The composition of the complex is found to be Th:R= 1:2. Beer's law is obeyed for 0-15μg of Th in 25ml. Most of the accompanying ions, up to several mg or over l0mg, do not interfere with the determination. The method has been used to determine thorium in ores with satifactory results.