Analytical Sciences


Abstract − Analytical Sciences, 22(2), 199 (2006).

Halogen-Free Water-Immiscible Ionic Liquids Based on Tetraoctylammonium Cation and Dodecylsulfate and Dodecylbenzenesulfonate Anions, and Their Application as Chelate Extraction Solvent
Toshihide TSUKATANI,*1 Hajime KATANO,*2 Hirosuke TATSUMI,*2 Mika DEGUCHI,*3 and Naoki HIRAYAMA*4
*1 General Research Center, Nicca Chemical, Co. Ltd., Bunkyo, Fukui 910-8670, Japan
*2 Department of Bioscience, Fukui Prefectural University, Matsuoka, Fukui 910-1195, Japan
*3 Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
*4 Division of Material Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
The tetraoctylammonium cation forms water-immiscible room temperature ionic liquids with dodecylsulfate and dodecylbenzenesulfonate anions. The ionic liquids are halogen-free and can be considered environmentally friendly solvents. At 25°C, the solubilities of water in tetraoctylammonium dodecylsulfate and tetraoctylammonium dodecylbenzenesulfonate were 2.8 and 4.0%, respectively, and the densities were 0.92 and 0.93 g cm-3. The ionic liquids formed stable interfaces with water at 25°C. The possible use of tetraoctylammonium dodecylsulfate as chelate extraction solvent was evaluated by using 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione as extractant. Tetraoctylammonium dodecylsulfate showed high extraction performance for divalent transition metal cations.