The aim of this work is to investigate the quaternary systems which contain (polyethylene glycol/isopropyl alcohol) + ethanol + salt (Na2SO4/Na2CO3) + water to understand their liquid-liquid equilibrium (LLE) and salting-out ability and apply them to definite uses. For this purpose, phase diagrams and liquid-liquid equilibrium (LLE) data of the investigated quaternary systems were experimentally determined at 308.15, 318.15, and 328.15 K. Binodal curves were fitted to three empirical nonlinear equations, whereas tie-lines were fitted to the Setschenow-type equation and another two-parameter equation. All the models were successfully correlated with the experimental data. What is more, factors such as temperature, different organic solvent, and type of salt are studied. It was demonstrated that temperature has no influence in binodal curves and the salting-out ability follows the order Na2CO3 > Na2SO4. Finally, we chose the best system (isopropyl alcohol + ethanol + Na2CO3 + H2O) to find out the extraction efficiency when dealing with vitamin B6. The results show that when the temperature is 308.15 K and pH is 5.02, the extraction efficient can reach a top level. It serves as a theoretical basis for the extraction, separation, and purification.

中文翻译：

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水相两相系统提取维生素B6的研究与机理

这项工作的目的是研究含有（聚乙二醇/异丙醇）+乙醇+盐（Na2SO4/Na2CO3）+水的四元体系，以了解它们的液液平衡（LLE）和盐析能力，并将其应用于确定用途。为此，研究的四元系统的相图和液液平衡 (LLE) 数据在 308.15、318.15 和 328.15 K 下通过实验确定。双节点曲线拟合到三个经验非线性方程，而连接线拟合到Setschnow 型方程和另一个二参数方程。所有模型都成功地与实验数据相关联。此外，还研究了温度、不同的有机溶剂和盐的类型等因素。结果表明，温度对双节点曲线没有影响，盐析能力遵循 Na2CO3 > Na2SO4 的顺序。最后，我们选择了最佳系统（异丙醇 + 乙醇 + Na2CO3 + H2O）来了解处理维生素 B6 时的提取效率。结果表明，当温度为308.15 K，pH为5.02时，提取效率可达到最高水平。它是提取、分离和纯化的理论基础。