Development of high-performance separation methods of inorganic compounds based on aqueous biphasic extraction systems

基于水相双相萃取系统的无机化合物高性能分离方法的开发

基本信息

批准号：
14540563
负责人：
SHIBUKAWA Masami
金额：
$ 2.18万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

Aqueous biphasic systems(ABS) are formed by mixing water, certain inorganic salts and water-soluble polymers and can be efficient for the separation of inorganic compounds as well as of organic compounds. Polyethylene glycols(PEG) are nontoxic, nonflammable and nonvolatile so that the PEG-based ABS can be regarded as environmentally friendly, in contrast to conventional solvent extraction systems utilizing water immiscible organic solvents. A number of investigators have considered that water molecules in ABS should play an important role in separation processes and therefore an understanding of the states of water in the polymer systems is of great importance in the elucidation of the mechanism of separation in ABS. We have thus studied, at first, the states of water in PEG gel as well as poly(vinyl alcohol)(PVA) gels by means of liquid chromatography and differential scanning calorimetry. It was found that the estimated amount of the stationary phase water is in good agreement with the sum of the amount of non-freezing water and that of freezable bound water for most of the PVA gels, while it agrees with the amount of only non-freezing water for the PEG gel. This result can be attributed to the difference in the structure of the gels ; the PVA gels containing PVA at relatively high concentrations have a homogeneous gel phase, whereas the PEG gel have a heterogeneous gel phase consisting hydrated polymer domains and relatively hydrophobic domains.Separation of inorganic anions and metal ions was investigated using high-speed countercurrent chromatography with aqueous biphasic systems consisting of PEG and sodium sulfate. The PEG-rich upper phase was used as the stationary phase and the salt-rich lower phase was used as the mobile phase. Separation of some inorganic anions and that of chromium(III) ion and chromate(VI) ion were easily accomplished by HSCCC with PEG#1000-Na_2SO_4 ABS.

双相系统（ABS）是通过混合水，某些无机盐和水溶性聚合物形成的，并且可以有效地分离无机化合物以及有机化合物。聚乙烯乙二醇（PEG）是无毒的，不可氟的和非易失性的，因此与常规的有机有机溶剂相比，与常规的溶剂提取系统相比，基于PEG的ABS可以被视为环境友好。许多研究人员认为，ABS中的水分子在分离过程中应发挥重要作用，因此对聚合物系统中水状态的理解对于阐明ABS中分离机理的理解至关重要。因此，我们首先通过液相色谱和差异扫描量热法研究了钉凝胶中的水状态以及聚（乙烯基醇）（PVA）凝胶。发现固定相水的估计量与大多数PVA凝胶的非冷冻水和可冻结水的含量和可冻结的水的总和非常吻合，而它仅与非非 - 冻结钉凝胶的水。该结果可以归因于凝胶结构的差异。在相对较高的浓度下含有PVA的PVA凝胶具有均匀的凝胶相，而PEG凝胶的凝胶具有异化的凝胶相，该凝胶相结合了水合聚合物结构域和相对疏水的结构域。使用高速度的异流化学色谱法分别研究了无机阴离子和金属离子。由PEG和硫酸钠组成的双相系统。富含PEG的上相用作固定相，并将富含盐的下相用作流动相。 HSCCC很容易完成某些无机阴离子和铬（III）离子（III）离子（VI）离子的分离。