Prediction of Selective Extraction of Cresols from Aqueous Solutions by Ionic Liquids Using Theoretical Approach

2011 ◽  
Vol 46 (13) ◽  
pp. 2075-2087 ◽  
Author(s):  
Lalan Kumar ◽  
Tamal Banerjee ◽  
Kaustubha Mohanty
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Theoretical Approach ◽  
Selective Extraction

scholarly journals Chlorophylls Extraction from Spinach Leaves Using Aqueous Solutions of Surface-Active Ionic Liquids

2021 ◽  
Vol 2 (4) ◽  
pp. 764-777
Author(s):  
Ana M. Ferreira ◽  
Ana Cláudia Leite ◽  
João A. P. Coutinho ◽  
Mara G. Freire
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Chlorophyll A ◽  
Cost Effective ◽  
Selective Extraction ◽  
Operating Conditions ◽  
Pure Ethanol ◽  
Pure Compounds ◽  
Surface Active ◽  
Spinach Leaves

Chlorophylls and their derivatives have been extensively studied due to their unique and valuable properties, including their anti-mutagenic and anti-carcinogenic features. Nevertheless, high-purity-level chlorophylls extracted from natural sources are quite expensive because the methods used for their extraction have low selectivity and result in low yields. This study aimed to develop a “greener” and cost-effective technology for the extraction of chlorophylls from biomass using aqueous solutions of ionic liquids (ILs). Several aqueous solutions of ILs, with hydrotropic and surface-active effects were evaluated, demonstrating that aqueous solutions of surface-active ILs are enhanced solvents for the extraction of chlorophylls from spinach leaves. Operating conditions, such as the IL concentration and solid–liquid ratio, were optimized by a response surface methodology. Outstanding extraction yields (0.104 and 0.022 wt.% for chlorophyll a and b, respectively, obtained simultaneously) and selectivity (chlorophyll a/b ratio of 4.79) were obtained with aqueous solutions of hexadecylpyridinium chloride ([C16py]Cl) at moderate conditions of temperature and time. These extraction yields are similar to those obtained with pure ethanol. However, the chlorophyll a/b ratio achieved with the IL aqueous solution is higher than with pure ethanol (3.92), reinforcing the higher selectivity afforded by IL aqueous solutions as viable replacements to volatile organic compounds and allowing the obtainment of more pure compounds. Finally, the recovery and reuse of the solvent were evaluated by using a back-extraction step of chlorophylls using ethyl acetate. The results disclosed here bring new perspectives into the design of new approaches for the selective extraction of chlorophylls from biomass using aqueous solutions of surface-active ILs.

scholarly journals Enhancing Artemisinin Solubility in Aqueous Solutions: Searching for Hydrotropes based on Ionic Liquids

2021 ◽  
Vol 534 ◽  
pp. 112961
Author(s):  
Isabela Sales ◽  
Dinis O. Abranches ◽  
Pedro Costa ◽  
Tânia E. Sintra ◽  
Sónia P.M. Ventura ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions

Adsorption of imidazolium-based ionic liquids with different chemical structures onto various resins from aqueous solutions

RSC Advances ◽  
2015 ◽  
Vol 5 (52) ◽  
pp. 41352-41358 ◽  
Author(s):  
Luyang Li ◽  
Yu Wang ◽  
Xinhua Qi
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Adsorption Behavior ◽  
Chemical Structures

The adsorption behavior of a series of imidazolium-based ionic liquids with different chemical structures onto various resins was investigated.

scholarly journals Valorization of Spent Coffee by Caffeine Extraction Using Aqueous Solutions of Cholinium-Based Ionic Liquids

2021 ◽  
Vol 13 (13) ◽  
pp. 7509
Author(s):  
Ana M. Ferreira ◽  
Hugo M. D. Gomes ◽  
João A. P. Coutinho ◽  
Mara G. Freire
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Pure Water ◽  
Waste Product ◽  
Weight Ratio ◽  
Extraction Yield ◽  
Operational Conditions ◽  
Coffee Grounds ◽  
Extractable Compounds ◽  
Nutraceutical Products

Spent coffee grounds (SCGs) are a waste product with no relevant commercial value. However, SCGs are rich in extractable compounds with biological activity. To add value to this coffee byproduct, water and aqueous solutions of cholinium-based ionic liquids (ILs) were studied to extract caffeine from SCGs. In general, all IL aqueous solutions lead to higher extraction efficiencies of caffeine than pure water, with aqueous solutions of cholinium bicarbonate being the most efficient. A factorial planning was applied to optimize operational conditions. Aqueous solutions of cholinium bicarbonate, at a temperature of 80 °C for 30 min of extraction, a biomass–solvent weight ratio of 0.05 and at an IL concentration of 1.5 M, made it possible to extract 3.29 wt% of caffeine (against 1.50 wt% obtained at the best conditions obtained with pure water). Furthermore, to improve the sustainability of the process, the same IL aqueous solution was consecutively applied to extract caffeine from six samples of fresh biomass, where an increase in the extraction yield from 3.29 to 13.10 wt% was achieved. Finally, the cholinium bicarbonate was converted to cholinium chloride by titration with hydrochloric acid envisioning the direct application of the IL-caffeine extract in food, cosmetic and nutraceutical products. The results obtained prove that aqueous solutions of cholinium-based ILs are improved solvents for the extraction of caffeine from SCGs, paving the way for their use in the valorization of other waste rich in high-value compounds.

The nature of ions organisation in aqueous solutions of ionic liquids based on local anaesthetic drugs and salicylic acid

2021 ◽  
pp. 116673
Author(s):  
Milan Vranes ◽  
Jovana Panic ◽  
Slobodan Gadzuric ◽  
Marija Bester-Rogac ◽  
Aleksandar Tot
Keyword(s):  
Salicylic Acid ◽  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Local Anaesthetic
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