abstract
The aim of this work is to test the potential of hydrophobic phosphonium-based ionic liquids for the extraction of caffeine and nicotine from aqueous phases through the determination of the alkaloids' partition coefficients. It was found that the caffeine partitioning for the ionic-liquid-rich phase increases with the ionic liquid hydrogen-bonding accepting capability (or water content), while for nicotine a nearly opposite behavior was observed. In addition, both the influence of the ionic concentration of the aqueous solution (ranging from 0.0 mol . kg(-1) to 3.0 mol . kg(-1)), and the salt nature (with K- and Na-based salts), in the partitioning of caffeine for the ionic-liquid-rich phase were investigated. The influence of the inorganic salt nature in the alkaloid partitioning for the ionic-liquid-rich phase closely follows the Hofmeister series.
keywords
CAPILLARY GAS-CHROMATOGRAPHY; MUTUAL SOLUBILITIES; PHARMACEUTICAL FORMULATIONS; LACTIC-ACID; EXTRACTION; WATER; NICOTINE; CAFFEINE; QUANTIFICATION; PRECIPITATION
subject category
Chemistry; Engineering
authors
Freire, MG; Teles, ARR; Lopes, JNC; Rebelo, LPN; Marrucho, IM; Coutinho, JAP
our authors
Ana Rita Ribeiro Teles
Financial Officer
Isabel Maria Delgado Jana Marrucho Ferreira
Full professor
Mara Guadalupe Freire Martins
Coordinating ResearcherGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
Projects
acknowledgements
The authors would like to acknowledge Cytec Industries for providing all the phosphonium-based ionic liquids used in this work, and the financial support provided by FCT (Portugal) through projects PTDC/QUI/71331/2006, PTDC/QUI/72903/2006, PTDC/QUI/QUI/101794/2008 and PTDC/EQU-EPR/104554/2008, and through the Post-Doctoral grant SFRH/BPD/41781/2007 of Mara G. Freire.