Fundamentals on Development of Low Toxicity Mixed Solvent for Solvent Extraction

点击翻译按钮获取中文摘要

We reported the utility of 1-octanol/benzene mixed solvents for the partition of benzoic acid and the extraction of copper(II) with benzoic acid. As benzene has been pointed out to possess carcinogenic activity, we selected octane as a non-solvating solvent in the place of benzene and investigated the solvent extraction equilibrium for the octane/1-octanol mixed solvent systems.The partition of 8-quinolinol between the octane/1-octanol mixed solvents with the various mixing ratio and water, and the extraction of aluminum, gallium, indium and iron(III) with 8-quinolinol using these mixed solvents were carried out. We found some new and interesting results on the analysis of the extraction equilibrium for these extraction systems. Protonated 8-quinolinol(oxine) cation(H_2O_x+) was found to be extracted by various inorganic anions such as chloride, perchlorate and nitrate in the lower pH regions, and the partition constant of oxine molecule was quantitatively elucidated by the regular solution theory.On the extraction of aluminum, gallium, indium and iron(III) with oxine, the partition constants of M(0_x)_3 complex were successfully determined. The high correlation between the partition constants of oxine and the respective extracted species were found. In addition, the result, which suggests the electrical condensation at the complex formation, was obtained.Extraction of 2-( 2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion was carried out using octane/1-octanol mixed solvents. The extraction equilibrium for the systems was analyzed in detail in order to examine the extraction mechanism. 2-(2-Pyridylazo)-1-naphthol-4-sulfonate was found to be extracted with hydroxonium ion solvated by three 1-octanol molecules as an ion-pair. The extraction and partition constants of the ion-pair of 2-(2-pyridylazo)-1-naphthol-4-sulfonate anion with solvated hydroxonium ion were estimated in the octane/1-octanol mixed solvent systems.