Solvent Extraction Research Articles

Microfluidic extensional flow device to study mass transfer dynamics in the polymer microparticle formation process.

Polymer microparticles are often used to encapsulate drugs for sustained drug-release treatments. One of the ways they are manufactured is by using a solvent extraction process, in which the polymer solution is emulsified into an aqueous bulk phase using a surfactant as a stabilizing agent, followed by the removal of the solvent. The radius of a polymer drop decreases as a function of time until the polymer reaches the gelling point, after which it is separated and dried. Among the various operating parameters, the rate of solvent extraction is a critical step that affects the morphology and porosity, and consequently, the kinetics of drug release. But a fundamental mechanistic understanding of the solvent extraction dynamics as a function of shear is still unexplored. In this study, we have developed an experimental mass transfer model to predict the extraction by using the microfluidic extensional flow device (MEFD) to probe the shear and extraction dynamics at the level of a single drop in a linear extensional flow field. We used a computer-controlled feedback algorithm to manipulate the flow field and hydrodynamically trap a Hele-Shaw drop and observe the extraction process. For the polymer solution, we used a biocompatible polymer, poly-lactic-co-glycolic acid (PLGA) with ethyl acetate (EtOAc) as the solvent. Our experiments were conducted by varying the extensional rate (G) in the channel from ∼0.1 s-1 to ∼10 s-1, and using an analytical solution of the flow field, we captured the dissolution process and measured the change in drop radius (R) with time (t). Interestingly, we initially observed a short-time asymptote R ∼ t, and later the long-time asymptote of R = constant; both trends were physically explained. The transport model developed in this work can be used to predict extraction rates and polymer microparticle composition for any polymer-solvent system. This work is also an important contribution to the literature on convective mass transfer in partially miscible emulsions.

Comparison of different green extraction methods used for the extraction of anthocyanin from red onion skin

AbstractGreen extraction primarily emphasizes developing new extraction techniques that consume less energy. It involves using safe, non‐toxic alternative solvents and sustainable natural resources to ensure the production of safe and high‐quality extracts. Red onion skin is an important source of anthocyanins, a subgroup of phenolic compounds. Anthocyanins are an important group of natural pigments that have attracted a lot of attention due to their health benefits. However, the instability and high sensitivity of these pigments have limited their use in food and cosmetics. Therefore, in this study, various modern green extraction methods were used, including solvent extraction, ultrasound‐assisted extraction, subcritical water extraction, microwave‐assisted extraction (MAE), pulsed electric field extraction, supercritical fluid extraction (SFE), and high hydrostatic pressure‐assisted (HHPAE) extraction, to specifically extract and purify anthocyanins. The extraction efficiency, specifically targeting anthocyanins, showed the highest efficiency with HHPAE (81.84%) and the lowest with MAE (40.01%). Measurement of total anthocyanin content revealed that HHPAE and SFE methods yielded the highest anthocyanin concentrations, with 248.49 and 244.98 mg/L, respectively. Identification of anthocyanin by LC–MS revealed that the main anthocyanidins in red onion peel are pelargonidin, cyanidin, delphinidin, and petunidin. These results indicate that innovative green extraction methods, particularly HHPAE and SFE, can effectively replace conventional techniques due to their superior efficiency and enhanced preservation of anthocyanin compounds.

Optimization of Sample Preparation Procedure for Determination of Fat-Soluble Vitamins in Milk and Infant Food by HPLC Technique

Background: The analysis of vitamins in baby food is a challenging task given the complexity of the food matrix, vitamin stability, and strict regulations of the European Union regarding permissible deviations from declared values. Vitamins in food exist in different concentrations and forms and have different stabilities; thus, the preparation of samples for a reliable analysis using the same procedure is not straightforward. Therefore, significant attention has been devoted to optimizing sample preparation in the analysis of vitamins. Methods: This study aims to determine which of the sample preparation and extraction methods is the most efficient for the simultaneous determination of vitamins A, D, E, and K in milk and baby food using high-performance liquid chromatography (HPLC). Different samples of baby food were prepared in seven different ways based on four methods (saponification, enzymatic hydrolysis, solvent extraction, and solid-phase extraction). Results and Conclusion: According to the validation parameters, the optimal preparation method proved to be solid-phase extraction with a C18 stationary phase, with recoveries of 97.4%, 96.1%, 98.3%, and 96.2% for vitamins A, D, E, and K, respectively, and HPLC with a UV–Vis detector was identified as a sufficiently sensitive technique for the identification and quantification of fat-soluble vitamins in milk and baby food.

Suspect screening of per- and polyfluoroalkyl substances in paper by selective and non-selective extraction with UHPLC-Q Orbitrap MS

Non-targeted analysis and suspect screening of per- and polyfluoroalkyl substances (PFAS) in various matrices have gained traction with advancements in accurate mass analytical instruments. This study employed ultra-high performance liquid chromatography coupled to quadrupole orbitrap high-resolution mass spectrometry for PFAS suspect screening of paper grades used in the paper recycling chain. The samples were prepared using two extraction techniques; selective accelerated solvent extraction with weak anionic exchange solid-phase extraction and non-selective ultrasonic-assisted extraction. A suspect screening protocol was established to tentatively identify suspected PFAS against spectral databases using a systematic approach of peak filtering and study-specific thresholds for reporting, linked to a confidence level. The possible prevalence of previously unreported PFAS in several paper materials across the various collection sites in the paper recycling chain was inferred by the common detection of short-chain polyfluoroalkyl ketones and diketones in the paper recycling chain. The suspect screening tentatively identified 41 unique PFAS, with 3 common to both pre-treatment techniques. The detection of unique PFAS by the two sample pre-treatment techniques highlighted the significance of both selective and non-selective extraction in PFAS screening endeavours. Further, it showed the importance of understanding the acquisition mechanisms employed in mass spectrometry where data-dependent acquisition triggered fragmentation in certain identified compounds, and not in others. The tentatively identified PFAS indicated that there were several previously unreported PFAS in the paper recycling chain and that additional studies were required to investigate their abundance, possible persistence, bioaccumulation and toxicity, in relation to their functional groups and carbon chains.

Modeling of microfluidic solvent extraction: Evaluation of different flow regimes and cascade configurations

ABSTRACT Solvent extraction using a microfluidic platform is one of the process intensification tools. It may involve different two-phase flow regimes that have different physical and mass transfer characteristics. Therefore, this study focuses on the selection of a better flow regime, flow conditions and cascade configuration (cross or counter-current) using mathematical modeling for a typical high-throughput application (1000 L/day). The mathematical model is based on a plug flow model. The liquid–liquid system considered is a water–acetone–toluene system. The different flow regimes such as slug flow (SF), slug-droplet flow (SDF) and core-annular flow (CAF) in different cascade configurations are compared on the basis of parameters like specific extraction rate (SER), solvent extraction process effectiveness (SEPE) and modified merit index (MMI). Among the different flow regimes and cases studied, CAF is found to offer lesser parallel paths, total extraction length, total pressure drop and residence time. The best case of CAF has higher SER (3.6 times), SEPE (3.6 times) and MMI (21.8 times) than the best case of SF in both cascades. SDF shows the results between SF and CAF. For a specific flow regime, higher values of parameters are obtained at higher flow rates. Counter-current cascade is found to be better than cross-current cascade.

Systematic study on date palm seeds (Phoenixdactylifera L.) extraction optimisation using natural deep eutectic solvents and ultrasound technique

Natural deep eutectic solvents (NADES) are emerging, environment-friendly solvents that have garnered attention for their application in extracting phenolic compounds. This study investigated the effects of four synthetic NADES on polyphenols extracted from date seeds (DS) using choline chloride (ChCl) as a hydrogen-bond acceptor and lactic acid (La), citric acid (Citri), glycerol (Gly), and fructose (Fruc) as hydrogen-bond donors, in comparison with DS extracts extracted by conventional solvents (water, 70% methanol, and 70% ethanol). The antioxidant activity (DPPH), total phenolic content (TPC) and 6 phenolic compounds were determined using HPLC. The results showed that the ChCl–La and ChCl–Citri systems exhibited a high extraction efficiency regarding TPC, and DPPH in the DS extracts extracted by NADES compare to those DS extracts extracted with conventional solvents (p ˂ 0.001). HPLC results demonstrated that DS extracted by ChCl–La contained all measured phenolic compounds. Also gallic acid and catechin were the major compounds identified in the DS extracts. In addition DS extracted by ChCl–Citri and ChCl–Gly had the highest concentration of catechin. In conclusion, combining NADES is a promising and environment-friendly alternative to the conventional solvent extraction of phenolic compounds from DS.

Investigating the impact of wet rendering (solventless method) on PUFA-rich oil from catfish (Clarias magur) viscera.

Catfish (Clarias magur) is a popular freshwater fish food worldwide. The processing of this fish generates a significant amount of waste, mainly in the form of viscera, which constitutes around 10-12% of the fish's total weight. This study was focused on extracting polyunsaturated fatty acid (PUFA)-rich oil from catfish viscera, aiming to enhance the extraction process and make the production of oil and handling of fish byproducts more cost-effective. The wet reduction method, a solvent-free approach, was used for extraction, with yield optimization done via the Box-Behnken design. The resulting oil was evaluated for its oxidative quality and chemical characteristics. The optimal conditions for the wet rendering process were as follows: viscera to water ratio, 1:0.5 (w/v); temperature, 90℃; and time, 20 min, yielding 12.40 g/100 g of oil. The oil extracted under optimal wet rendering conditions had quality and oxidative stability comparable to solvent extraction and fewer secondary oxidation compounds. This oil had a higher PUFA content, specifically a 4:1 ratio of omega 6 to omega 3. Such oil, derived from catfish viscera, is suitable for the food industry due to its solvent-free extraction method.

Obtention of Suitable Pregnant Leach Solution (PLS) for Copper Solvent Extraction Plants from Copper Concentrate Using Hydrogen Peroxide and Iodine in a Sulfuric Acid–Chloride Medium

Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), enhanced by hydrogen peroxide (H2O2) at room temperature. A significant aspect of this research was optimizing the KI concentration to minimize iodide sublimation into iodine gas (I2). Through the experimental design, the optimal dosages of reagents were determined, leading to maximized copper extraction of approximately 27% in 45 min of testing at room temperature. The results showed that it is possible to obtain a suitable pregnant leach solution (PLS) (i.e., in the range of 3 to 8 g/L of Cu) for treatment in available copper solvent extraction (SX) plants with a cost of less than 4.5 USD/t Cu, according to the economic analysis carried out. The results of this study determine the most effective operational conditions for leaching and ensure a suitable PLS for SX plants in a cost-effective and environmentally friendly manner. This approach could significantly contribute to more sustainable practices in the mining and processing of copper ores.

In Vitro Antioxidant and Anticancer Potential of the Vegetative and Reproductive Organs of Embelia ruminata

ABSTRACT The antioxidant and anticancer potential of solvent extracts of the leaf, stem bark, fruit, and seeds of Embelia ruminata was investigated. The chloroform seed extracts had the highest TAC of 38.50 mg AAE g−1 DW. In the FRAP and DPPH assays, the methanolic seed extracts exhibited the most effective activity (67.63 mg AAE g−1 and IC50 of 3.54 µg mL−1, respectively), compared to the respective standards. In the MTT assays, the hexane seed extracts were the least cytotoxic and had a more pronounced effect on MCF-7 and A549 cell lines (IC50 of 93.1 and 119.5 µg mL−1, respectively) than the control.

Stabilizing Solution–Substrate Interaction of Perovskite Ink on PEDOT:PSS for Scalable Blade Coated Narrow Bandgap Perovskite Solar Modules by Gas Quenching

The development of scalable 1.25 eV mixed Pb–Sn perovskite solar modules by blade coating lags behind Pb‐based perovskites due to limited understanding of solution–substrate interaction of the perovskite ink on PEDOT:PSS and subsequent gas quenching. To address this challenge, the wet film deposition and quenching process to better understand narrow bandgap perovskite film formation on PEDOT:PSS are studied. It is found that the wetting of Pb–Sn perovskite ink on PEDOT:PSS is highly unstable over relevant coating time scales, causing the contact angles to decrease rapidly from 42° to 16° within seconds. This instability leads to localized irregularities in the wet film, resulting in uneven solvent extraction and inhomogeneous nuclei density. As a result, rough perovskite films with voids at the buried interface are obtained. To overcome this problem, a quasistatic wetting process by reducing the blade coating speed is developed, thereby stabilizing the wetting behavior of Pb–Sn perovskite precursor ink on PEDOT:PSS. This optimized process facilitates the deposition of high‐quality, void‐free Pb–Sn perovskite films with uniform thickness over 8 cm of coating length using moderate (1.4 bar) N2 quenching. 20% efficient narrow bandgap perovskite solar cells and minimodules with 15.8% active area efficiency on 15.9 cm2 are achieved.

Botanical corrosion inhibitors in reinforced concrete: material sustainability assessment and analysis - a review

Various methodologies have emerged over the past few decades aimed at controlling and mitigating corrosion. A new field has emerged in controlling corrosion through the use of plant-based corrosion inhibitors. The exploration of botanical extracts’ efficacy marks a significant shift in corrosion science, tapping into the potential and utility offered by green plants. This comprehensive study serves as a review encompassing the spectrum of botanical extracts and their applications in diverse contexts concerning reinforced structures. This research critically assesses the correlation between phytochemical compositions, the methodologies employed in solvent extraction, and the adsorption mechanisms pivotal for enhancing the efficacy of plant extracts in corrosion inhibition. The primary objective lies in uncovering the role of inhibitors in safeguarding embedded steel within concrete structures while aiming to curtail corrosion rates. A focal point of this investigation revolves around the transition from employing toxic inhibitors to environmentally friendly botanical extracts for corrosion mitigation. Furthermore, this study accentuates the range of botanical extracts used as corrosion inhibitors shedding light on the specific phytochemical components responsible for driving the corrosion inhibition process. Notably, it expounds upon the future prospects of corrosion inhibitors, outlining the inherent challenges that must be addressed to facilitate their scalability for widespread commercial utilization.

Enhanced process for efficient extraction of oxygenated monoterpenes from thyme (Thymus vulgaris L.) using subcritical water

Subcritical water extraction (SWE) is a highly effective technique for extracting monoterpenes at elevated pressures and temperatures using only water solvent. This study investigated SWE of monoterpenes, including γ-terpinene, p-cymene, thymol, carvacrol, and thymoquinone, under varying extraction conditions of temperature (110–200 ℃) and time (5–20 min). The extract was qualitatively and quantitatively analyzed by gas chromatography. The maximal extraction conditions of p-cymene (0.11 ± 0.03 mg/g), thymol (0.40 ± 0.02 mg/g), carvacrol (5.28 ± 0.19 mg/g), and thymoquinone (1.28 ± 0.11 mg/g) were obtained at temperature/time of 150 °C/5 min, 200 °C/5 min, 200 °C/5 min, and 110 °C/5 min, respectively. Non-oxygenated monoterpenes, such as γ-terpinene and p-cymene, were either undetected or extracted in small quantities using SWE and were found to be more suited for organic solvent extraction. Oxygenated monoterpenes, such as thymol, carvacrol, and thymoquinone, exhibited optimal extraction when using SWE. By identifying the optimal conditions, SWE can be an efficient technique for selectively extracting target compounds from thyme. The selectivity of SWE could have practical applications in extracting desired compounds from a variety of industrials. SWE technology can be easily implemented on an industrial scale.

Mass balance and economic study of a treatment chain for rare earths, base metals and precious metals recovery from used smartphones

In the present study, a comprehensive hydrometallurgical process was developed for the recovery of several types of metals from used cell phone printed circuit board assemblies. The overall process is divided into four stages of selective leaching of rare earth elements (REE), copper, nickel, silver and finally gold. After solubilization, the metals were purified using precipitation, solvent extraction, electrodeposition, and cementation techniques. Laboratory pilot-scale tests of the complete smart phone printed circuit board processing line showed REE, copper, nickel, silver, and gold recovery efficiencies of 78.0 %, 98.8 %, 81.8 %, 100 % and 96.1 %, respectively. The purity of the products obtained is evaluated at 94.8 % for rare earth oxides (70.0 % Nd2O3, 18.5 % Pr2O3, 2.8 % Dy2O3 and 2.4 % Sm2O3), 99.8 % for elemental copper, 94.3 % for nickel oxide, 93.8 % for silver and 89.3 % for gold. A scenario involving the installation of a plant processing 1 t/h of waste was evaluated using SuperPro Designer software. For a total investment of $53.22 million and an operating cost of $18.23 million per year, the main revenue is $65.77 million per year, with a return on investment of 91.6 % and a payback period of 1.1 years.

Enhancing anthocyanin extraction efficiency in vegetables and fruits: a high-speed shear homogenization technology.

To extract anthocyanins with high efficiency, a hypothesis for high-speed shear homogenization extraction (HSHE) method was established through a combination of solvent and ultrasonic-assisted extractions. The efficacy of this hypothesis was demonstrated by performing qualitative and quantitative analyses of 16 anthocyanins extracted from five northern vegetables, and five berry fruits using ultra-high-performance Q-Exactive Orbitrap tandem mass spectrometry. Single-factor experiments were conducted by varying ethanol concentration, temperature, pH and extraction cycles to determine the optimal conditions for this method. Optimal extraction conditions (ethanol 70-80%, 40-50 °C, pH 3-4, performed twice) were determined using an HSHE (5 min, 10 000 rpm, 25 °C) assisted shaker (60 min) and ultrasonication (40 kHz, 160 W cm-2, 30 min, 25 °C) procedure. Compared to the traditional non-HSHE method, the total anthocyanin content obtained through HSHE extraction showed a significant increase, ranging from 1.0 to 3.9 times higher, with purple cabbage exhibiting the most pronounced enhancement in content. More types of anthocyanins were detected in blueberry (9), black bean (7) and raspberry (5), of which malvidin was the major anthocyanin (0.426 g kg-1) in blueberry, having an amount five times than previously obtained. The established HSHE method has been proven to be a superior technique for anthocyanin extraction, with higher extraction efficiency and concentrations. This technique also provides a new avenue for extracting bioactive compounds from diverse food sources, with potential applications in improving the functional properties of food products. © 2024 Society of Chemical Industry.

GC–MS based metabolomic profiling of Aporosa cardiosperma (Gaertn.) Merr. leaf extracts and evaluating its therapeutic potential

Aporosa cardiosperma is a plant species majorly found in the Indian Western Ghats that belongs to the phyllanthaceae family with ethnobotanical importance. Using a Fourier Transform-Infrared Spectrometer (FT-IR) and Gas Chromatography-Mass Spectrometry (GC–MS) for evaluating leaf extracts of A. cardiosperma, significant functional groups and metabolite constituents were determined, and its total flavonoid, phenol, and tannin content were quantified. Further, its antibacterial efficacy was investigated against microorganisms that cause fish and human disease and are resistant to common antibiotics, including Staphylococcus aureus, Bacillus subtilis, Mycobacterium tuberculosis, Klebsiella pneumoniae, Aeromonas hydrophila, and Pseudomonas aeruginosa. Regarding the outcomes of GC–MS analysis, the primary metabolites in the A. cardiosperma leaf extracts were heneicosane (57.06%), silane (13.60%), 1-heptadecene (10.09%), 3-hexadecene (9.99%), and pentadecane (9.54%). In comparison to other solvents, methanolic extract of A. cardiosperma leaves had increased phenolic, flavonoid, and tannin content; these findings are consistent with in vitro antioxidant potential and obtained that the methanolic extract (100 µg/mL) exhibited the higher percentage of inhibition in DPPH (82.35%), FRAP (86.20%), metal chelating (72.32%), and ABTS (86.06%) antioxidant assays respectively. Similar findings were found regarding the antibacterial efficacy against pathogenic bacteria. Comparatively, to other extracts, methanolic extracts showed more significant antibacterial activity at a lower minimum inhibitory concentration (MIC) value (250 µg/mL), whilst ethyl acetate and hexane solvent extracts of A. cardiosperma leaves had higher MIC values 500 µg/mL and 1000 µg/mL respectively. The antimicrobial potential was validated by investigating bacterial growth through the extracts acquired MICs and sub-MICs range. Bacterial growth was completely inhibited at the determined MIC range. In conclusion, A. cardiosperma leaf extract's phytochemical fingerprint has been determined, and its potent antibacterial and antioxidant activities were discovered. These findings of the current study will pave the way for developing herbal treatments from A. cardiosperma for various fish and human diseases.

Development of an Efficient Process for the Separation of Co(ii), Mn(ii), and Ni(ii) from Chloride Solution by Precipitation

ABSTRACT The demand for nickel, cobalt, and manganese is increasing owing to their critical role in the performance of lithium-ion batteries. Precipitation is simpler to operate than solvent extraction in the separation of metal ions. In this work, precipitation-based procedures were developed to separate Co(II), Mn(II) and Ni(II) from synthetic chloride solutions. Dimethylglyoxime (DMG) was effective in selectively precipitating Ni(II) from the chloride solutions containing Co(II) and Mn(II). Solution pH greatly affected the precipitation of Ni(II) by DMG. In the first procedure, Ni(II) was first precipitated using DMG from solution with initial pH 6 at a DMG/Ni(II) molar ratio of 3, a reaction time of 30 min and then Co(II) was separated from the filtrate by precipitation with Na2S, with optimal conditions being an initial pH of 6, a Na2S/Co(II) molar ratio of 2 and a reaction time of 15 min. In the second procedure, both Ni(II) and Co(II) was simultaneously precipitated with Na2S, leaving Mn(II) in the filtrate. Then the mixed sulfides of Co(II) and Ni(II) were dissolved by using HCl solution containing NaClO as an oxidizing agent. From the leaching solution, Ni(II) was separated by precipitation with DMG. Optimum conditions for the separation conditions were obtained. In both procedures, the separation degree among the three metal ions was higher than 99%. The developed procedures were simple and effective for the separation of the three metal ions compared to solvent extraction.

Advanced and Potential Methods for Extraction of Bioactive Compounds from Avocado Peel—A Review

Extraction techniques are continuously developed by the scientific community. Meanwhile, avocado peel is a by-product of avocado processing and a source of bioactive compounds. The purpose of this review was to summarize the use of advanced techniques for extracting bioactive compounds from avocado peel to help understand which techniques have and have not been applied to avocado peel. Three primary databases were used to collect the information, including Google Scholar, Scopus, and Web of Science, by using the keywords “avocado”, “peel”, and “extraction”. Additional keywords related to the extraction technique were also used, including “Microwave-Assisted Extraction”, “Ultrasound-Assisted Extraction”, “Enzyme-Assisted Extraction”, “Pressurized Liquid Extraction”, “Supercritical Fluid Extraction”, “Natural Deep Eutectic Solvents”, “Three-phase partitioning (TPP)”, “Pulsed-Electric Field”, “High Voltage Electric Discharge Plasma”, “Centrifugal Partition Extraction”, and “Surfactant-Mediated Extraction”. The results show that microwave-assisted extraction, ultrasound-assisted extraction, enzyme-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, TPP, and natural deep eutectic solvent extraction have been used to retrieve bioactive compounds from avocado peel. Other techniques have not yet been applied for the extraction of bioactive compounds from avocado peel. This article is the first review discussing the advanced extraction technique for retrieving bioactive compounds from avocado peel. This article creates a paradigm for future studies.

Understanding Europium and Terbium Speciation and Ion Pairing in Carbonate Complexes Using Advanced Spectroscopy Techniques

Lanthanide (Ln) elements are critical materials that are typically extracted/mined together. Their separation by solvent extraction from acidic media is well known; however, there are few studies in basic media with carbonate anions. We investigated the complexation of Eu(III) and Tb(III) carbonates as solids and solutions in alkaline K2CO3, wherein we sought to access a Tb(IV) carbonate complex through ozonolysis. L3‐edge XANES of Eu and Tb carbonate solids, colorless solutions, and a red‐hued Tb solution (obtained by ozonolysis) all showed Ln(III) cations. The absence of evidence for a Tb(IV) complex was confirmed through XAS and EPR analyses, despite the solution exhibiting a deep red color. For solids and solutions, EXAFS results indicate molecular Ln(III)‐carbonato anions. In terms of the Eu(III) carbonate coordination number, the coordination does not change upon dissolution of the solid sample. Furthermore, EXAFS for the solutions revealed evidence for the association of potassium cations with the Ln(III)‐carbonato anions. This direct observation of contact ion pairing by EXAFS at room temperature is rare. The insights into Ln(III) carbonate complexation and solution speciation afforded by XANES‐EXAFS, FT‐IR, and EPR provides perspectives that serve as benchmarks for future computational and experimental efforts focused on caustic‐side solvent extraction of Ln(III) ions.

Recovery of lithium from the desorption solutions of salt lakes using β-diketone synergistic extraction system

Lithium has become increasingly important because of its irreplaceable role in lithium-ion batteries. Addressing the complex process and high energy consumption of the current adsorption-membrane integrated process for lithium extraction from high Mg/Li ratio salt lake brine, this study put forward an integrated process of adsorption-solvent extraction. Taking the desorption solution of adsorption method as raw material, the process parameters and extraction mechanism of lithium by the novel extraction system were investigated. A novel process of lithium recovery from the desorption solutions of salt lakes by solvent extraction was proposed for the first time. The composition of the extraction system was studied and determined to be HTTA-P113-kerosene. Compared with the previously reported neutral ligands (TOPO, Cyanex923), P113 not only exhibited excellent synergistic extraction ability but also had good miscibility and a green synthesis process. The effects of saponification degree, extraction time, temperature and phase ratio on lithium extraction and βLi/Na were systematically investigated. Through the four-stage countercurrent extraction, more than 99.2 % of lithium could be extracted by the organic phase consisting of 0.4 mol L−1 HTTA, 0.4 mol L−1 P113, saponification degree of 80 % at O/A ratio of 1:1 and equilibrium pH of 6.78. Furthermore, after the scrubbing and stripping process, the lithium-rich solution containing 21.64 g L−1 Li+ and 0.037 g L−1 Na+ was obtained. The Li2CO3 products with a purity of 99.5 % were successfully prepared from the lithium-rich solution by precipitation method. Finally, the extraction mechanism was studied via the slope analysis method and FT-IR spectra. It was indicated that the extracted lithium species were Li(TTA)(P113).

Impact of extraction techniques and process optimization on antioxidant and antibacterial potential of Kalanchoe pinnata leaf extract

ABSTRACT Kalanchoe pinnata (Lam.) Pers. is an ethnomedicinal plant known for its antioxidant, antibacterial, and therapeutic potential. The current study was an effort to explore the impact of extraction technique on the phytochemical, antioxidant, and antibacterial profile of the plant extracts. K. pinnata leaf extracts were prepared using conventional solvent extraction (100% methanol; 50% methanol: 50% water; 100% water), microwave-assisted extraction at 700-W power (3 min; 6 min; 9 min), and supercritical fluid extraction (SFE) (3500 psi; 4500 psi; 5500 psi). Best results were attained from SFE in terms of total phenolic content (240 ± 3 mg GAE/g), total flavonoid content (165.2 ± 0.4 mg QE/g), 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential (91.9 ± 0.4%), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid assay value (8.04 ± 0.03 mMol TE/g) and ferric reducing antioxidant power assay value (471.7 ± 0.8 µg/mL). K. pinnata leaf extracts have been found to be most effective against Yersinia pseudotuberculosis (22.20 ± 0.95 mm) and least effective againstProteus vulgaris (0 ± 0 mm). High-performance liquid chromatography analysis of K. pinnata extract showed that it contains flavanol quercetin (2.0 ± 0.1 mg/g). It is evident from the findings of current study that K. pinnata extract can effectively treat bacterial infections and can cure metabolic disorders by reducing oxidative stress. Application of advance extraction techniques enhances the biological activity of plant extracts.