School of Chemical and Environmental Sciences, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007, China.
J Chromatogr A. 2012 Mar 30;1231:2-7. doi: 10.1016/j.chroma.2012.01.087. Epub 2012 Feb 8.
Partition coefficients of amino acids, including glycine, alanine, 2-aminobutyric acid, valine, leucine, threonine, methinoine, tryptophan and tyrosine, in [C(n)mim]Br (n=4, 6, 8)+K(2)HPO(4) aqueous two-phase systems (ATPSs) have been determined, and the relative hydrophobicity of the equilibrium phases in the ionic liquids-based aqueous two-phase systems has been characterized by the Gibbs energies of transfer for methylene group from the bottom salt-rich phase to the top ionic liquid-rich phase. Based on these results, factors affecting the partitioning behavior of the amino acids have been investigated. It is shown that partition coefficients of the amino acids increase with the increase of hydrophobicity of the amino acids and the ionic liquids, solution pH value, tie-line length of the ATPSs and temperature of the systems. The possible driving forces and the thermodynamic parameters for the partitioning of amino acids in the ionic liquids-based ATPSs have also been discussed.
已测定了[C(n)mim]Br（n=4、6、8）+K2HPO4水两相体系（ATPS）中包括甘氨酸、丙氨酸、2-氨基丁酸、缬氨酸、亮氨酸、苏氨酸、蛋氨酸、色氨酸和酪氨酸在内的氨基酸的分配系数，并通过从底部富盐相到顶部富离子相转移亚甲基基团的吉布斯能量来表征基于离子液体的水两相体系中平衡相的相对疏水性。基于这些结果，研究了影响氨基酸分配行为的因素。结果表明，氨基酸的分配系数随氨基酸和离子液体的疏水性、溶液 pH 值、ATPS 的系带长度和体系温度的增加而增加。还讨论了氨基酸在基于离子液体的 ATPS 中分配的可能驱动力和热力学参数。
