(191v) Partitioning of Synthetic Antibiotics in Ionic-Liquid-Based Aqueous Biphasic Systems

Solvent extraction, due to its effectiveness and economic nature, is by far the most widely used separation technique for antibiotics and biomolecules. Despite economical advantages of extraction using volatile organic solvents, recent stringent environmental and safety regulations have made their applications limited. The use of an ionic liquid, as a green solvent, offers clear advantages over traditional liquid?liquid extractions, in which the use of toxic organic solvents is unavoidable. The tunable nature of the solubility of various compounds, including molecules of pharmaceutical and biological interest, in Room Temperature Ionic Liquids (RTILs), makes extraction with RTILs attractive for many separation and purification processes. In particular, aqueous biphasic systems (ABS) composed of hydrophilic ionic liquids with salting out inorganic salts are particularly promising. In the present work we report the partitioning of model synthetic broad-spectrum antibiotics (fluoroquinolones), using ABS Cholinium and Imidazolium ILs containing systems. The effect of the alkyl side-chain length of the cation, the nature of the anion and also the relative importance of the presence of substituting groups in the cation versus in the anion of the RTILs is explored.