Fundamentals on Development of Low Toxicity Mixed Solvent for Solvent Extraction

本文报道了1-辛醇/苯混合溶剂在苯甲酸的分离和苯甲酸对铜（II）的萃取中的应用。由于苯已被指出具有致癌活性，我们选择辛烷作为非溶剂溶剂代替苯，研究了辛烷/1-辛醇混合溶剂体系的溶剂萃取平衡。研究了不同配比的辛烷/1-辛醇混合溶剂与水对8-喹啉醇的分配，并利用这些混合溶剂对铝、镓、铟和铁（III）进行了萃取。我们对这些萃取体系的萃取平衡进行了分析，发现了一些新的有趣的结果。发现质子化的8-喹啉（氧）阳离子（H_2O_x+）在低pH区可被氯化物、高氯酸盐和硝酸盐等多种无机阴离子萃取，并用正则溶液理论定量地解释了氧分子的分配常数。用氧萃取铝、镓、铟和铁（III），成功地测定了M(0_x)_3配合物的配分常数。结果表明，氧的分配常数与各提取种之间存在较高的相关性。此外，还得到了络合物形成处电缩聚的结果。采用辛烷/辛醇混合溶剂，用溶剂化氢氧离子萃取2-（2-吡啶偶氮）-1-萘酚-4-磺酸盐阴离子。详细分析了体系的萃取平衡，探讨了萃取机理。2-（2-吡啶偶氮）-1-萘酚-4-磺酸盐是用3个1-辛醇分子作为离子对的氢氧根离子溶剂化提取的。测定了辛烷/辛醇混合溶剂体系中2-（2-吡啶偶氮）-1-萘酚-4-磺酸阴离子与溶剂化羟基离子的萃取和配分常数。

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.