Designer solvent ability of alcohols in aqueous biphasic systems composed of deep eutectic solvents and potassium phosphate

Extraction of some essential amino acids using aqueous two-phase systems made by sugar-based deep eutectic solvents

Aqueous two-phase systems (ATPSs) have long been recognized as versatile and efficient tools for the extraction of biomolecules, including amino acids. Recent advancements in the field have introduced a novel approach by utilizing deep eutectic solvents (DES) to form ATPs. This study aimed to determine the phase diagrams for an ATPS made of polyethylene glycol dimethyl ether 250 and two types of NADESs, namely choline chloride as a hydrogen bond acceptor (HBA), and either sucrose or fructose as a hydrogen bond donor (HBD) with a molar ratio of 1 : 2. The measured tie-line results revealed that the hydrogen bonds of NADES may not be entirely disrupted in aqueous solutions, and thus, these ATPSs act as ternary-like systems. Additionally, the binodal data were fitted using two semi-empirical equations, namely Merchuk and Zafarani-Moattar et al. equations. Furthermore, the ATPSs mentioned above were applied to extract three amino acids, namely l-arginine, l-phenylalanine, and l-tyrosine, and demonstrated good extraction levels. Finally, the Diamond-Hsu equation and its modified version were utilized to correlate the experimental partition coefficients of the amino acids. These advancements pave the way for the development of improved extraction methodologies and the exploration of new applications in the field of biotechnology, pharmaceuticals, and beyond.

Aqueous Two-Phase Systems Based on Ionic Liquids and Deep Eutectic Solvents as a Tool for the Recovery of Non-Protein Bioactive Compounds—A Review

Aqueous two-phase systems (ATPS) based on ionic liquids (IL) and deep eutectic solvents (DES) are ecofriendly choices and can be used to selectively separate compounds of interest, such as bioactive compounds. Bioactive compounds are nutrients and nonnutrients of animal, plant, and microbial origin that benefit the human body in addition to their classic nutritional properties. They can also be used for technical purposes in food and as active components in the chemical and pharmaceutical industries. Because they are usually present in complex matrices and low concentrations, it is necessary to separate them in order to increase their availability and stability, and ATPS is a highlighted technique for this purpose. This review demonstrates the application of ATPS based on IL and DES as a tool for recovering nonprotein bioactive compounds, considering critical factors, results and the most recent advances in this field. In addition, the review emphasizes the perspectives for expanding the use of nonconventional ATPS in purification systems, which consider the use of molecular modelling to predict experimental conditions, the investigation of diverse compounds in phase-forming systems, the establishment of optimal operational parameters, and the verification of bioactivities after the purification process.

A green miniaturized aqueous biphasic system prepared with cholinium chloride and a phosphate salt to extract and preconcentrate personal care products in wastewater samples

A miniaturized extraction/preconcentration method based on an aqueous biphasic system (μ-ABS) was developed with reagents commonly used as food additives: cholinium chloride (ChCl) as main extraction phase, K₂HPO₄ as salting-out agent, and water as the main component (being the sample for analyses). With the aim of obtaining high enrichment factors, miniaturization, and adequate analytical performance, a point in the biphasic region with the lowest amount of ChCl was selected, corresponding to 1.55% (w/w) of ChCl, 59.5% (w/w) of K₂HPO₄, and 38.95% (w/w) of water. The green μ-ABS (attending to its main elements and performance mode) was used in combination with high-performance liquid chromatography with diode-array detection (HPLC-DAD) for the determination of 9 personal care products in wastewater samples. The μ-ABS-HPLC-DAD method showed high enrichment factors (up to 100), and quantitative extraction efficiencies for those compounds containing OH groups in their structure, which can undergo hydrogen bonding with ChCl. Thus, limits of quantification down to 0.8 µg·L^-1 and extraction efficiencies between 66.4 and 108% (concentration levels of 1.3 and 13 µg·L^-1) were reached for the group of parabens and the UV-filter benzophenone-3. The method is characterized by the use of non-harmful reagents and the absence of organic solvents in the entire sample preparation procedure, while being simple, low-cost, easily compatible with HPLC, and highly efficient.

A Review of the Use of Eutectic Solvents, Terpenes and Terpenoids in Liquid–liquid Extraction Processes

Diverse and abundant applications of the eutectic solvents have appeared in the last years. Their promising tunable properties, eco-friendly character and the possibility of being prepared from numerous compounds have led to the publication of numerous papers addressing their use in different areas. Terpenes and terpenoids have been employed in the formulation of eutectic solvents, though they also have been applied as solvents in extraction processes. For their hydrophobic nature, renewable character, low environmental impact, cost and being non-hazardous, they have also been proposed as possible substitutes of conventional solvents in the separation of organic compounds from aqueous streams, similarly to hydrophobic eutectic solvents. The present work reviews the application of eutectic solvents in liquid–liquid extraction and terpenes and terpenoids in extraction processes. It has been made a research in the current state-of-the-art in these fields, describing the proposed applications of the solvents. It has been highlighted the scale-up feasibility, solvent regeneration and reuse procedures and the comparison of the performance of eutectic solvents, terpenes and terpenoids in extraction with conventional organic solvents or ionic liquids. Ultimately, it has been also discussed the employ of predictive methods in extraction, the reliability of thermodynamic models in correlation of liquid–liquid equilibria and simulation of liquid–liquid extraction processes.

Simultaneous extraction of antibiotic and estrogen from animal blood serum using aqueous two-phase systems as predictor of environmental impact

Efficient analytical methods are required for optimizing dosage of veterinary antibiotics and hormones in order to reduce toxicity and antimicrobial resistance in the environment. Thus, the objective of this work was to develop a rapid and low-cost method for determination of hormone estradiol and antibiotic chlortetracycline in bovine and porcine blood serum by aqueous two-phase system (ATPS) extraction and capillary electrophoresis quantification. ATPS based on ionic liquid cholinium alaninate and citrate salt along with mixtures of protic and aprotic polar solvents were evaluated in terms of recovery of extraction (%R). The liquid-liquid equilibrium, phase diagrams, and tie lines are discussed. Antibiotic migrated to solvent-rich phase (R ≈ 89.0%) to all systems. Estradiol migrates to ionic liquid-rich phase; however, addition of 10% methanol changed partition to solvent-rich phase (R ≈ 89.7%). The method has high recovery and cleanliness, is cost-efficient, scalable, and hence is adequate for screening of antibiotics and hormones tested in animal blood serum for dosage optimization and to predict their environment.

Recovery of astaxanthin from shrimp (Penaeus vannamei) waste by ultrasonic-assisted extraction using ionic liquid-in-water microemulsions

In this study, an ultrasonic-assisted extraction using microemulsions was developed for the recovery of natural astaxanthin from shrimp waste. To select applicable solvent systems, the phase equilibrium, microstructure, and physical properties of the microemulsions were investigated. Then the effect of ultrasonic power, ultrasonic time, and microemulsion composition on the extraction efficiency (EEAst) and extraction yield (EAst) of astaxanthin were determined. Compared with organic solvents (ethanol, acetone, and dimethyl sulfoxide), the microemulsion contained tributyloctylphosphonium bromide ([P4448]Br), tributyloctylphosphonium trifluoroacetate ([P4448]CF3COO), or tetrabutylphosphonium trifluoroacetate ([P4444]CF3COO) resulted in significantly enhanced extraction of astaxanthin due to the stronger electrostatic interactions and hydrogen-bonding interactions. When ultrasonic-assisted extraction conditions were 50 W and 60 min, the highest EEAst and EAst reached 32.47 µg·g-1 and 99% by using the IL-in-water microemulsion of [P4448]Br/(TX-100 + n-butanol)/water (0.13:0.25:0.62, w/w), respectively. The IL-based microemulsion is an adequate alternative to conventional methods in the extraction and recovery of astaxanthin from natural bioresources.

Sketching neoteric solvents for boosting drugs bioavailability

Emerging neoteric solvents are being the subject of growing attention due to their lower cost and environmental impact, so they are being applied in a broad spectrum of industries. Among them, the pharmaceutical sector is demanding new environmentally friendly and non-toxic solvents able to enhance drugs solubility and stability. The introduction of ionic liquids turned out to be a breakthrough in the field of Green Chemistry opening up new separation and catalysis opportunities. In this sense, the options represented by Deep Eutectic Solvents make up an attractive alternative due to the low cost of their raw material, simple synthesis, and eco-friendly character. In line with these findings, Therapeutic Deep Eutectic Solvents and Natural Deep Eutectic Solvents are new and promising alternatives to improve the bioavailability of drugs in pharmaceutical formulations. This leading article is focused on providing a general picture of the advantages and drawbacks of these new solvents as well as the main research lines and perspectives to achieve efficient drugs delivery systems.

The antagonist and synergist potential of cholinium-based deep eutectic solvents

The design of environmentally friendlier solvents has gained increasing relevance in the last decade. Deep eutectic solvents (DES) have recently emerged, with advantages like low-cost and putative lower environmental impact. However, information about DES toxicity is still scarce. This work aims to contribute to profiling the ecotoxicity of DES based on cholinium chloride ([Chol]Cl). Six DES were addressed, combining [Chol]Cl (as hydrogen bond acceptor - HBA) with ethylene glycol, glycerol, 1,2-propanediol, propionic acid, 1-propanol, and urea as hydrogen bond donors (HBD), in different molar ratios. The Microtox^® Acute Toxicity Test, was used for assessing their toxicity towards the marine bacteria Allivibrio fischeri . Because the dissociation of DES in water is expected, analysis appraising the mixtures toxicity theory should be considered, which is a step forward in this field. This analysis suggested that [Chol]Cl and all HBD with the exception of propionic acid:[Chol]Cl 1:2 and 4:1 behave antagonistically, which is contrary to what has been suggested previously. The most extreme cases are Urea:[Chol]Cl and 1-Propanol:[Chol]Cl, with EC₅₀ values higher than their starting materials dosed singly, configuring very promising and biocompatible alternative solvents. Toxicity was found to be dependent on DES composition, as well as on molar proportions of the starting materials.

Enantioselective Extraction of Phenylalanine Enantiomers Using Environmentally Friendly Aqueous Two-Phase Systems

(1) Background: The environmentally friendly choline-amino acid ionic liquids (ChAAILs) and deep eutectic solvents (DESs) have been used as excellent alternatives to volatile organic compounds (VOCs) and ionic liquids (ILs) in recent years; (2) Methods: Thus, ChAAILs/salt and DESs/salt aqueous two-phase systems (ATPSs) were developed for the chiral extraction of phenylalanine enantiomers. The optimum ATPS of [Ch][L-Pro]/K3PO4 was chosen, and the influencing parameters were investigated, including ChAAILs concentration, salt concentration, chiral selector concentration, extraction temperature, phenylalanine concentration, and system pH; (3) Results: The phenylalanine enantiomers were mainly extracted into the top phase (ChAAIL-rich phase), meanwhile, the (S)-phenylalanine [(S)-Phe)] was preferentially recognized by the chiral selector in the top phase. The maximum separation factor (α) of 2.05 was obtained under the optimal conditions; and (4) Conclusions: This ATPS that was used for the chiral extraction of enantiomers is much more environmentally friendly, simple, and rapid, and has the potential to be used in the enantioselective extraction of other enantiomers.