Application of ionic liquid based two-aqueous phase systems in liquid-liquid chromatography
Final Report Abstract
In this project ATPS with IL as a main phase forming compound and as modifier have been studied. ATPS formed with AmmoEng 110 (low cost IL) were too viscous for a use in CPC and the protein partition coefficients were too high. For imidazolium-based ILs it was found that the density difference between the phases is higher than for PEG-based ATPS. The viscosity of ATPS formed with [EMIM]Cl or [BMIM]Cl and phosphate salts is in a similar range as low molecular weight PEG-based ATPS, whereas the viscosity of the IL-rich phase increases drastically for [OMIM]Cl with a longer carbon chain length in the cation. The partition coefficient can be tuned using imidazolium-based IL to some extent; however, all partition coefficients were generally too high for CPC. For the variation of the IL-anion no trend could be observed, since all proteins were exclusively located in the IL-rich phase of the ATPS. The ATPS with IL as a main phase forming compound investigated in this study were not suitable for CPC, but promising for liquid-liquid extraction. Especially their low viscosity and possibility to achieve extraction efficiencies up to 100% are favourable for an application in liquid-liquid extraction, however, the proteins cannot be separated with these ATPS, but remain in the same phase. With a new column cell geometry being launched on the market, it became possible to use PEG-based ATPS in CPC. This column geometry has bigger cells than conventional designs and allows higher flow rates. For the first time, separation of proteins with ATPS and reasonably high flow rates for preparative separations (up to 40 ml min^-1) were shown. Thus, new separation strategies became possible. It was shown that small amounts of IL can be used to tune the partition coefficients of proteins. It was not possible to separate BSA with the ATPS because injecting this protein into the column caused loss of the stationary phase. Proteins with surface activity have to be avoided and cannot be processed with this technique. Using small amounts of IL was shown to be a cost effective tool to tune the protein partition coefficient compared to using IL in larger amounts as a main phase forming compound in ATPS. Furthermore, the injection volume of the feed was successfully increased from 4% to 20% of the column (commonly around 1-5% used in chromatography). The results indicate that even higher injection volumes are likely possible to further increase the productivity.
Publications
- “Evaluation of the applicability of ATPS for protein separations in CPC columns with different cell design” 8th International Conference on Counter-Current Chromatography (CCC2014), Uxbridge, UK, July 23-25, 2014
J. Goll, G. Audo, M. Minceva
- “Potential application of non-conventional aqueous two phase systems in counter-current and centrifugal partition chromatography” 8th International Conference on Counter-Current Chromatography (CCC2014), Uxbridge, UK, July 23-25, 2014
J. Goll, F. Bezold, M. Minceva
- ”Potential application of non-conventional aqueous two phase systems in liquid-liquid partition chromatography” 15th International Symposium on Preparative and Industrial Chromatography and Allied Techniques, SPICA 2014, Basel, Switzerland, October 5-8, 2014
J. Goll, F. Bezold, M. Minceva
- “Aqueous Two-Phase Systems Containing Ionic Liquids for Protein Separations”, Chemie Ingenieur Technik, 2015, 87 (8), 1105
Bezold F., Goll J., Minceva M.
(See online at https://dx.doi.org/10.1002/cite.201550076) - “Aqueous Two-Phase Systems Containing Ionic Liquids for Protein Separations”, Jahrestreffen der ProcessNet-Fachgemeinschaft Fluiddynamik und Trenntechnik, September 9-11, 2015
Bezold F., Goll J., Minceva M.
(See online at https://doi.org/10.1002/cite.201550076) - “Comparison of twin-cell centrifugal partition chromatographic columns with different cell volume”, Journal of Chromatography A, 2015, 1406, 129-135
Goll J., Audo G., Minceva M.
(See online at https://doi.org/10.1016/j.chroma.2015.05.077) - “Study of the applicability of non-conventional aqueous two-phase systems in counter-current and centrifugal partition chromatography”, Journal of Chromatography A, 2015, 1388, 126-132
Bezold F., Goll J., Minceva M.
(See online at https://doi.org/10.1016/j.chroma.2015.02.021) - Protein Separation Using a Centrifugal Partition Extractor” 9th International Conference on Counter-Current Chromatography (CCC2016), Chicago, USA, August 1-3, 2016
Bezold F., Goll J., Minceva M.
