@article{oai:kanazawa-u.repo.nii.ac.jp:00010324,
 author = {平山, 直樹},
 issue = {12},
 journal = {分析化学 = Japan analyst},
 month = {Dec},
 note = {Bronsted酸であるキレート試薬(いわゆるキレート抽出剤)を用いてイオン液体相へ金属イオンの抽出を行う「イオン液体キレート抽出系」について,従来の有機溶媒を抽出相とするキレート抽出系との相違点を中心に検討を行った.この系は,カチオン交換によるイオン液体抽出系とは異なり,原理的に金属イオンの逆抽出回収が容易に可能である.2-テノイルトリフルオロアセトンを用いた2価金属イオンの抽出では,金属イオンによって抽出種が異なり,中性配位不飽和(水和)錯体又はアニオン性錯体として抽出された.また,中性種とアニオン性種とでは,抽出相イオン液体を変化させたときの抽出定数の変化に差異が見られた.一方,8-ヒドロキシキノリンを用いた場合には,検討した2価金属イオンはすべて中性錯体として抽出された.更に,8-(トリフルオロメタンスルホンアミド)キノリンを抽出剤として用いた検討の結果から,抽出剤中のトリフルオロメチル基の存在がアニオン性抽出種のイオン液体相内における安定化に一定の寄与を果たしていることが示唆された. An "ionic liquid chelate extraction system", which is a novel liquid-liquid extraction method for the extractive separation of metal cations into the ionic liquid extraction phase with a chelate extractant, was investigated mainly from the point of difference from a normal chelate extraction system using a volatile organic solvent as the extraction phase. In this system, the extracted metals are easily recoverd by using back-extraction into an acidic solution. In the extraction of divalent metal cations (M^<2+>) with 2-thenoyltrifluoroacetone (Htta) (or other β-diketone having trifluoromethyl group), some metals were extracted into the 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] [PF_6]) extraction phase as coordination-unsaturated (hydrated) neutral complexes (M(tta)_2(H_2O)_n), whereas others were extracted as coordination-saturated anionic complexes (M(tta)_3^-) with anion-exchange reactions. The extractability of the former species was reduced by using a more hydrophilic ionic liquid as the extraction phase, whereas that of the latter was enhanced. On the contrary, the use of 8-hydroxyquinoline (Hq) (or its derivative) as the extractant resulted in the extraction of M^<2+> into [bmim] [PF_6] as neutral M(q)_2(H_2O)_n. Furthermore, a comparison of the extraction behavior of M^<2+> with 8-(trifluoromethanesulfonamido) quinoline (H(CF_3)sq) having a trifluoromethyl group with that with 8-(methanesulfonamido) quinoline (H(CH_3)sq) suggested that the existence of a trifluoromethyl group in an chelate extractant contributes to an enhancement of the extractability for an anionic complex into the ionic liquid extraction phase. In addition, a fundamental study was performed on an ionic liquid synergistic cation-exchange extraction system with co-using Htta and 18-crown-6 (18C6) as extractants for the selective extraction of trivalent light lanthanoids, such as lanthanum (La). In this system, La^<3+> was extracted into 1-butyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide as cationic ternary complexes, such as La(tta)_2(18C6)^+ and La (tta) (18C6)^<2+>., 金沢大学自然科学研究科},
 pages = {949--959},
 title = {イオン液体キレート抽出系における金属イオンの抽出挙動(<特集>高度分離へのたゆまぬ挑戦)},
 volume = {57},
 year = {2008}
}