Kaul Michael J, Mandella Victoria, Dietz Mark L
Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA.
Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, 53211, USA.
Talanta. 2022 Jun 1;243:123373. doi: 10.1016/j.talanta.2022.123373. Epub 2022 Mar 23.
The recent development of hydrophobic deep eutectic solvents (HDESs) has led to growing interest in these reagents as possible environmentally benign replacements for conventional organic media in a host of applications, among them metal ion separations by liquid-liquid extraction. To evaluate the potential utility of these novel solvents in this application, a systematic examination of the facilitated transfer of selected alkali and alkaline earth cations into representative HDESs from aqueous solution in the presence of a macrocyclic polyether (i.e., a crown ether) has been undertaken. Comparison of the results to those obtained for a series of oxygenated, aliphatic solvents (n-alcohols) and for several 1-alkyl-3-methylimidazolium-based ionic liquids (ILs) under the same conditions indicate that despite frequent suggestions that some HDESs resemble ILs, metal ion distribution in HDES-aqueous systems more closely mimics that seen for the alcohols. Metal ion partitioning in these systems appears less dependent on the water content of the organic phase and on structural variations in the solvent than is the case for either alcohols or ionic liquids, however. The implications of these results for the design and application of HDES-based extraction systems for metal ions are described.
疏水性低共熔溶剂（HDESs）的最新进展引发了人们对这些试剂的日益浓厚的兴趣，因为它们有可能在许多应用中作为传统有机介质的环境友好型替代品，其中包括通过液液萃取分离金属离子。为了评估这些新型溶剂在该应用中的潜在效用，我们进行了一项系统研究，考察在大环聚醚（即冠醚）存在下，选定的碱金属和碱土金属阳离子从水溶液中向代表性HDESs的促进转移情况。将这些结果与在相同条件下一系列含氧脂肪族溶剂（正醇）和几种基于1-烷基-3-甲基咪唑鎓的离子液体（ILs）所获得的结果进行比较，结果表明，尽管经常有人认为某些HDESs类似于ILs，但在HDES-水体系中金属离子的分布更类似于在醇类体系中所观察到的情况。然而，与醇类或离子液体相比，这些体系中金属离子的分配似乎对有机相的含水量和溶剂的结构变化不太依赖。本文描述了这些结果对基于HDES的金属离子萃取体系的设计和应用的影响。
