The Partitioning Behavior of Tyramine and 2-Methoxyphenethylamine in a Room Temperature Ionic Liquid–Water System Compared to Traditional Organic–Water System

Ionic liquids have been proposed as replacements for volatile organic solvents (VOSs) by a range of authors, due to their very low vapor pressure, ability to dissolve a range of organic, inorganic, and organometallic compounds, immiscibility with water, and ability to form biphasic systems depending on the choice of cation/ anion combination making up the ionic liquid. In this study the room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] was synthesized and a range of physical properties including the interfacial tension, viscosity, and density determined. The distribution of tyramine and 2-methoxyphenethylamine (MPEA) as a function of pH was determined for the [bmim][PF6] system. This was compared to distribution data obtained for these solutes in conventional organic Received August 26, 2004, Accepted January 9, 2005 Address correspondence to Geoffrey W. Stevens, Department of Chemical and Biomolecular Engineering, The University of Melbourne, VIC 3010, Australia. E-mail: [email protected] Separation Science and Technology, 40: 1555–1566, 2005 Copyright # Taylor & Francis, Inc. ISSN 0149-6395 print/1520-5754 online DOI: 10.1081/SS-200056001