Research Outputs

Now showing 1 - 2 of 2
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    Publication
    Ionic liquids for the selective solvent extraction of lithium from aqueous solutions: a theoretical selection using COSMO-RS
    (Minerals, 2022)
    Olea, Felipe
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    Durán, Guillermo
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    Díaz, Georgina
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    Villarroel, Eduardo
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    Araya López, Claudio
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    Merlet, Gastón
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    Romero, Julio
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    Quijada Maldonado, Esteban
    In this study, the theoretical design of ionic liquids (ILs) for predicting selective extraction of lithium from brines has been conducted using COSMO-RS. A theoretical model for the solvent extraction (SX) of the metal species present in brines was established considering extraction stoichiometry, the distribution of the extractants between aqueous and IL phases, and IL dissociation in the aqueous phase. Theoretical results were validated using experimental extraction percentages from previous works. Results indicate that, in general, the theoretical results for lithium extraction follow experimental trends, except from magnesium extraction. Finally, based on the model, an IL was proposed that was based on the phosphonium cation as the extractant, along with the phase modifier tributylphosphate (TBP) in an organic diluent in order to improve selectivity for lithium ex- traction over sodium. These results provide an insight for the application of ILs in lithium processing, avoiding the long purification times reported in the conventional process.
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    Publication
    Effects of extraction methods on phenolic content, antioxidant and antiplatelet activities of tomato pomace extracts
    (Plants, 2023)
    Plaza, Andrea
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    Rodríguez, Lyanne
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    Concha-Meyer, Anibal
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    Zurob, Elsie
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    Merlet, Gastón
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    Palomo, Iván
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    Fuentes, Eduardo
    Aqueous and ethanolic extracts of tomato pomace were examined with the aim of optimizing the extraction process of compounds with cardioprotective activity. Once the results of the ORAC response variables, total polyphenols, ◦Brix, and antiplatelet activity of the extracts were obtained, a multivariate statistical analysis was performed using the Statgraphics Centurion XIX software. This analysis showed that the most relevant positive effects in the inhibition of platelet aggregation were 83 ± 2% when using the agonist TRAP-6, when the working conditions were the type of tomato pomace conditioning (drum-drying process at 115 ◦C), phase ratio (1/8), type of solvent (ethanol 20%), and type of extraction (ultrasound-assisted solid–liquid extraction). The extracts with the best results were microencapsulated and characterized by HPLC. The presence of chlorogenic acid (0.729 mg/mg of dry sample) was found, a compound that has a potential cardioprotective effect documented in various studies, in addition to rutin (2.747 mg/mg of dry sample) and quercetin (0.255 mg/mg of dry sample). These results show that the extraction efficiency of compounds with cardioprotective activity depends largely on the polarity of the solvent, thus playing an important role in the antioxidant capacity of the extracts of tomato pomace.