Evaluation of Anion Influence on the Formation and Extraction Capacity of Ionic-Liquid-Based Aqueous Biphasic Systems
Evaluation of Anion Influence on the Formation and Extraction Capacity of Ionic-Liquid-Based Aqueous Biphasic Systems
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DOI：
10.1021/jp903286d
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发表时间：
2009-07-09
影响因子：
3.3
通讯作者：
Coutinho, Joao A. P.
中科院分区：
文献类型：
--
作者：
Ventura, Sonia P. M.;Neves, Catarina M. S. S.;Coutinho, Joao A. P.
使用水性双相系统 (ABS) 的提取发酵是一种很有前景的分离过程，因为它为生物分子提供了非变性环境并提高了细胞的稳定性。由于与常见挥发性有机溶剂相关的环境问题和毒性问题，目前正在研究用于萃取目的的新型非挥发性替代溶剂离子液体 (IL)。在这项工作中，研究了多种基于咪唑鎓的离子液体，旨在获得有关它们形成 ABS 的能力和提取生物分子的能力的新见解。在IL阳离子1-乙基-3-甲基咪唑鎓和1-丁基-3-甲基咪唑鎓的基础上，通过它们与氯化物、溴化物、乙酸盐、硫酸氢盐、甲磺酸盐、甲基硫酸盐、乙基硫酸盐、三氟甲磺酸盐、三氟乙酸盐和二氰胺的组合来评估IL阴离子对ABS形成的影响。测量并报告了由这些亲水性离子液体、水和无机盐 K3PO4 形成的三元相图（以及各自的 tic 线）。结果表明，IL 诱导 ABS 的能力与 IL 阴离子氢键接受强度的降低或氢键酸度的增加密切相关。此外，还通过将其应用于必需氨基酸 L-色氨酸的提取来评估所研究的 ABS 的提取能力。结果表明，IL 和 K3PO4 富水相之间获得的分配系数明显大于通常用聚合物-无机盐或聚合物-多糖水性体系获得的分配系数。
Extractive fermentation using aqueous biphasic systems (ABS) is a promising separation process since it provides a nondenaturing environment for biomolecules and improves the stability of cells. Due to environmental concerns and toxicity issues related with common volatile organic solvents, ionic liquids (ILs), a new class of nonvolatile alternative solvents, are being currently investigated for extraction purposes. In this work, a wide range of imidazolium-based ILs was studied aiming at obtaining new insights regarding their ability toward the formation of ABS and their capacity to the extraction of biomolecules. On the basis of the IL cations 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium, the IL anion influence on ABS formation was assessed through their combination with chloride, bromide, acetate, hydrogensulfate, methanesulfonate, methylsulfate, ethylsulfate, trifluomethanesulfonate, trifluoroacetate, and dicyanamide. Ternary phase diagrams (and respective tic-lines) formed by these hydrophilic ILs, water, and the inorganic salt K3PO4, were measured and are reported. The results indicate that the ability of an IL to induce ABS closely follows the decrease in the hydrogen bond accepting strength or the increase in the hydrogen bond acidity of the IL anion. In addition, the extraction capacity of the studied ABS was evaluated through their application to the extraction of an essential amino acid, L-tryptophan. It is shown that the partition coefficients obtained between the IL and the K3PO4-aqueous rich phases were substantially larger than those typically obtained with polymers-inorganic salts or polymers-polysaccharides aqueous systems.