abstract
In addition to the large range of applications proposed in literature, ionic liquids (ILs) have been recently reported to be able to form aqueous biphasic systems (ABS). They could thus be interesting media in biotechnological applications for the separation and purification of vital biomolecules. Therefore, in this work, a systematic study involving a large number of imidazolium-based ILs was conducted to provide new information related to ILs' ABS-promoting capability and extraction ability. For that purpose, the influence of the number of alkyl groups present at the cation, the cation side alkyl chain length, and the presence of double bonds, aromatic rings, and hydroxyl groups on this alkyl chain were evaluated. Ternary phase diagrams of the ABS formed by these ILs and K(3)PO(4) and the respective tie-lines were measured and presented. The ABS here investigated were further characterized for the first time accordingly to their extractive potential for amino acids, where L-tryptophan was selected as a model biomolecule. The partition coefficients here obtained were shown to be substantially larger than those observed in conventional ABS, demonstrating therefore the fine potential of IL-based ABS for biomolecules separation and purification.
keywords
PHASE-DIAGRAM DATA; 2-PHASE SYSTEMS; MUTUAL SOLUBILITIES; POLYETHYLENE-GLYCOL; PARTITIONING BEHAVIOR; PLUS SUCROSE; 298.15 K; WATER; SALT; SEPARATION
subject category
Chemistry
authors
Neves, CMSS; Ventura, SPM; Freire, MG; Marrucho, IM; Coutinho, JAP
our authors
Catarina Maia Seco Seiça Neves
Assistant Researcher
Isabel Maria Delgado Jana Marrucho Ferreira
Full professor
Mara Guadalupe Freire Martins
Coordinating Researcher
Sónia Patrícia Marques Ventura
Assistant ProfessorGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
acknowledgements
The authors are grateful for financial support from Fundacao para a Ciencia e a Tecnologia for the project PTDC/EQU-FT7/65252/2006, Ph.D. grant SFRH/BD/37830/2007 to S.P.M.V., and post-doctoral grant SFRH/BPD/ 41781/2007 to M.G.F. The authors also thank Bernd Schroder for the synthesis of [Cimim]Cl.