Room temperature ionic liquid as a novel medium for liquid/liquid extraction of metal ions
Room temperature ionic liquid as a novel medium for liquid/liquid extraction of metal ions
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DOI：
10.1016/s0003-2670(03)00660-3
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发表时间：
2003-07-25
影响因子：
6.2
通讯作者：
Chen, CJ
中科院分区：
文献类型：
--
作者：
Wei, GT;Yang, ZS;Chen, CJ
室温离子液体（RTIL）作为一种新型的有机溶剂，在有机合成、溶剂萃取、电化学等领域中被广泛应用，取代了传统的挥发性有机溶剂。某些离子液体的疏水特性和水不溶性允许它们用于疏水性化合物的溶剂萃取。本文以典型的室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐[C（4）mim] [PF 6]为溶剂，研究了液/液萃取重金属离子的性能。以双硫腙为金属螯合剂，与重金属离子形成中性金属-双硫腙络合物，将重金属离子从水溶液中萃取到[C（4）mim][PF 6]中。由于金属络合物在[C（4）mim][PF 6]和水相之间的高分配比，这种萃取是可能的。由于[C（4）mim] [PF 6]和水相之间的金属二硫代唑盐的分配比强烈地依赖于pH，金属络合物的萃取效率可以通过调节萃取体系的pH值来操纵。因此，通过控制萃取体系的pH值，可以实现[C（4）mim][PF 6]-水两相体系对重金属离子的萃取、分离和富集。初步研究结果表明，[C（4）mim][PF 6]作为一种替代溶剂替代传统有机溶剂用于液/液萃取重金属离子是非常有前途的。(C)2003 Elsevier B. V.保留所有权利。
Room temperature ionic liquids (RTILs) have been used as novel solvents to replace traditional volatile organic solvents in organic synthesis, solvent extraction, and electrochemistry. The hydrophobic character and water immiscibility of certain ionic liquids allow their use in solvent extraction of hydrophobic compounds. In this work, a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C(4)mim] [PF6], was used as an alternative solvent to study liquid/liquid extraction of heavy metal ions. Dithizone was employed as a metal chelator to form neutral metal-dithizone complexes with heavy metal ions to extract metal ions from aqueous solution into [C(4)mim][PF6]. This extraction is possible due to the high distribution ratios of the metal complexes between [C(4)mim][PF6] and aqueous phase. Since the distribution ratios of metal dithiozonates between [C(4)mim] [PF6] and aqueous phase are strongly pH dependent, the extraction efficiencies of metal complexes can be manipulated by tailoring the pH value of the extraction system. Hence, the extraction, separation, and preconcentraction of heavy metal ions with the biphasic system of [C(4)mim][PF6] and aqueous phase can be achieved by controlling the pH value of the extraction system. Preliminary results indicate that the use of [C(4)mim][PF6] as an alternate solvent to replace traditional organic solvents in liquid/liquid extraction of heavy metal ions is very promising. (C) 2003 Elsevier B.V. All rights reserved.