2,4-二硝基苯基重氮氨基偶氮苯测定矿石及煤矸石中痕量镉

Spectrophotometric Determination of Trace Cadmium in Ore and Gangue with 2,4-dinitrobenzenediazoaminoazobenzene

作者合成了新显色剂2,4-二硝基苯基重氮氨基偶氮苯,并研究了试剂性质及其与Cd(Ⅱ) 的显色反应。在Triton X-100存在下,于pH 11.8的Na_2B_4O_7-NaOH缓冲溶液中,显色剂与Cd形成2:1的红色络合物,λ_(max)为525nm,ε=1.68×10~5l·mol^(-1)·cm^(-1),Cd(Ⅱ)含量在0—6μg/25ml范围内遵守比耳定律。将该体系应用于萃取分离-光度法测定矿石及煤矸石样品的痕量镉,结果满意。

The reagent 2,4- dinitrobenzenediazoaminoazobenzene was synthesized and its reaction with Cd investigated. In the presence of Triton X-100 and at pH 11.8 borax buffer, a red complex with a ratio of 2:1 is formed. The molar absorptivity at 525 nm is 1.68 × 105L. mol-1 ·cm·-1. Beer's law is obeyed for cadmium in the range of 0-6μg/25ml. The method has been applied satisfactorily to determination of cadmium in ore and gangue samples with a prior KI-MIBK extraction.