Optimal Extraction Conditions Research Articles

Lithium recovery from an alumina electrolysis slag leaching solution with strong acidity: Separation of lithium-ion and production of battery grade lithium carbonate

Lithium (Li) with excellent physicochemical properties is widely used in modern industries. However, the shortage and depletion of Li resources has hindered the sustainable economic development. Li recovery from waste resource was an effective approach, in particular, alumina electrolysis slag is exemplified as Li riched solid waste. In this work, separation of Li from alumina electrolysis slag leaching solution (AESLS) via solvent extraction using bis(2-ethylhexyl) hydrogen phosphate (P204) system was explored. Effects of saponification degree, phase ratio, and reaction time on metal ions impurities and Li extraction were investigated. Operational parameters including extraction, scrubbing, saponification and precipitation were optimized. Results showed that the extraction efficiencies of Mg2+, Ca2+, Al3+, Fe3+ and Li+ were 100 %, 100 %, 99.99 %, 100 % and 20.71 %, respectively, under the optimal single extraction conditions. The loss of Li after scrubbing of loaded organic phase using hydrochloric acid was as low as 1.59 %. The P204 extraction process was proved to be a thermodynamic process with spontaneous entropy increase, and the extraction order of metal ions was Al3+ > Fe3+ > Ca2+ > Mg2+ > Li+ according to the extraction driving force (ΔC); The solvent-extracted ligand mechanism was elucidated by infrared spectroscopy and nuclear magnetic resonance. Additionally, battery-grade lithium carbonate was produced. Our study paves a new way for recovery of Li in AESLS.

Polysaccharides from Inonotus obliquus employing subcritical water extraction: Extraction optimization, physiochemical properties and bioactivities analysis

As one of the main components in Inonotus obliquus, polysaccharides was potentially to be developed for the special physiochemical properties and bioactivity. However, the low extraction efficiency of Inonotus obliquus polysaccharides (IOP) significantly hindered the in-depth research and development. To achieve a higher extraction yield of IOP, subcritical water was selected and optimized by Box-Behnken Design (BBD) with a more reasonable yield investigation method in the present study. In addition, for the comparative analysis, the physiochemical properties and bioactivity of the subcritical water extracted polysaccharides (IOP-S), purified polysaccharides (IOP-P) and hot water extracted polysaccharides (IOP-W) were all investigated and analyzed. The results showed that the optimal extraction conditions were 200°C, 13.24 min and 30:1 (mL/g), which corresponded to a polysaccharide yield of 14.14±0.17 %. With simple purified process, the IOP-P with high purity (total sugar content of 87.55 %) was suitable for the further study. Compared to IOP-W, a wider molecular weight range (3.4–98 kDa) of polysaccharide was found in IOP-S, as well as higher sugar and polyphenol content, which might be the main reason for the well antioxidant and digestion enzyme inhibition activity. There were also various differences in the monosaccharide composition, micro-morphology and other physiochemical properties, which all suggested that the subcritical water could efficiently extract a special IOP for the fourthly study and development. In summary, the present study proved that subcritical water extraction could significantly improve the extraction efficiency of IOP, and the basic information in physiochemical properties and bioactivities of IOP would promote the development of IOP in the future.

Natural deep eutectic solvents for efficient recovery of bioactive compounds from by-product of industrial hemp processing: Pretreatment, modeling and optimization

Hempseed hull, an underutilized by-product of the hemp processing industry, is a valuable bio-based material. This study aims to optimize phenolic compound extraction by natural deep eutectic solvents (NADES) with enhanced antioxidant properties (DPPH, FRAP, ABTS). By utilizing a chemometric approach, the research was conducted in three stages: selecting high-extractability NADES, identifying crucial extraction variables via screening, and optimizing conditions using response surface methodology (RSM). Fractional factorial experimental design was employed to identify the important variables, while a face-centered central composite experimental design (CCD) was utilized in combination with response surface methodology (RSM) to determine the optimal extraction conditions. The optimal conditions were found using NADES based on L-proline and lactic acid (1:2 ratio) at 39°C for the liquid-solid ratio, 70°C for temperature, and 135 minutes for extraction time. By optimizing extraction conditions this study contributes to advancing our understanding of hempseed hulls' biochemical composition and its potential as bio-based material.

Extraction of polyphenols from Apocynum venetum leaves using customized deep eutectic solvents: Process optimization and antioxidant evaluation

To encourage the commercial utilization of A. venetum polyphenols as bio-colorant on textile, five different combinations of deep eutectic solvents (DESs) were evaluated using a single-factor approach and the extraction of polyphenols from A. venetum leaves by ultrasound-assisted DESs was optimized. At the same time, the antioxidant activity of polyphenols prepared were investigated. The DESs composed of choline chloride and glycerol with a molar ratio of 1:2 and a water content of 20 % showed higher extraction performance than other DESs and traditional solvents (water, 60 % ethanol and 60 % methanol). With the most effective solvent the maximum yield 8.24 % of polyphenols was obtained under the optimal extraction conditions were as follows: the ratio of liquid volume (mL) to solid mass (g) is 49:1, extraction temperature of 77 ℃, and extraction time of 55 min. In addition, the polyphenols that have been separated and purified from the DESs extract exhibited antioxidant activities in three kinds of assays including 2,2-diphenyl-1-picrylhydrazyl stable free radical (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid free radicals (ABTS) and hydroxyl radical (•OH) scavenging activity. Therefore, this paper demonstrates that DESs are effective and environmentally friendly solvents extraction of antioxidant polyphenols pigments from the leaves of A. venetum.

Optimization and evaluation of biologically active compound with antibacterial and anti-inflammatory properties from peony seed meal

Peony seed meal is produced annually on a large scale in China, resulting in considerable solid residue. Unfortunately, most of this residue is discarded, thereby creating environmental pressure. However, the untapped medicinal value of peony seed meal prompted us to establish an efficient methodology for optimizing the extraction and purification of total alkaloid, followed by a detailed analysis of its biological activities. A single-factor experiment and an orthogonal test were used to identify the optimal extraction parameters. Then, further optimization was performed using the response surface methodology. The extract was enriched using D-101 macroporous adsorption resin. Subsequently, silica gel column chromatography was used for separation, and high-performance liquid chromatography was used for further separation and quantification. Meanwhile, gas chromatography–mass spectrometry (GC–MS) was used to identify alkaloid components. Finally, the antibacterial and anti-inflammatory were evaluated. The optimal extraction conditions substantially improved the yield of alkaloids. A total of 15 alkaloids were separated. GC–MS analysis revealed the presence of Sophoridine, which accounted for 91.88 % of the total alkaloid content. The antibacterial activity of the total alkaloid was tested, and the lowest inhibitory concentrations of E. coli ATCC 25922 and S. aureus ATCC 29213 were 0.04516 and 0.05645 mg/mL, respectively. Additionally, total alkaloid had an inhibitory effect on ear swelling induced by xylene and toe swelling induced by egg white, reducing by 80 % and 24 %, respectively. The current research discovered the antibacterial activity of PSM alkaloid, which has important practical significance for the research and development of new plant-derived antibacterial agents.

Fabrication of a 3D Printer Filamnet Extruder

3D printing, an additive manufacturing process, transforms digital designs into physical objects by layering material. This mechanization adds consecutive layers to build up the complete entity, resulting in a 3D object. It develops objects progressively to formulate the preferred look. Filaments are the main component in a die cast model (FDM) 3D printer, these are thermoplastic substances that are injected through a hot die to form the object. These filaments are available in different types such as PLA, ABS, PETG, HDPE each of which has specific characteristics that offer different applications and material options in 3D printing. This paper depicts about fabricating and developing a design of a 3D filament extruder that can produce 1.75 mm diameter filaments from recycled HDPE material. The extruder consists of a motor, a speed controller, a cylinder, a hopper, band heaters, a thermocouple, a temperature controller, a fan, a nozzle and a winder. This system works in the correct temperature range of 350-370 degrees Celsius for melting thermoplastic materials (recycled HDPE). Extruder function is to feed the material from the nozzle into the hot cylinder. A motor screw pushes the metal into the nozzle, where it becomes the filament. This filament is then injected onto a substrate for later use in 3D printing. The temperature is determined using thermocouples and a temperature controller, which ensures optimal extraction conditions. A fan is designed to quickly cool the removed filament. The objective of this research is to create an economical as well as efficient filament to produce high quality filaments. Extruder performance is evaluated based on filament diameter consistency, material penetration and energy efficiency.

The Testing Results of ACORGA, LIX Extractants and CR60 Crud Mitigation Reagent Influence during SX-EW Copper Extraction

Research analysis reveals factors influencing third-phase crud formation and composition during metal extraction, including solution composition, solid suspensions, organic compounds, colloidal compounds (e.g., silicic acid), and extractant purity. Compositional analysis of copper-containing sulfuric acid solutions (1.25 g/dm3 copper) identifies principal sulfate-forming components. Copper extraction was studied using extractants LIX 984N, ACORGA M5774, and M5640 at different ratios of the organic phase to the aqueous O:A (from 1:2 to 1:10). Suppressive impact of 10 vol.% CR60 additive on third-phase crud formation during copper extraction with LIX 984N, ACORGA M5774, and M5640 is analyzed, with ACORGA M5774 being the most effective. Physicochemical analysis characterizes CR60’s active substance as poly(sodium 4-styrenesulfonate) with steel-suppression properties, and its structural formula is determined. Optimal copper extraction conditions establish ACORGA M5640’s 24% efficiency, followed by ACORGA M5774 at 15%. CR60 reduces crud formation, with 5 cm3 of ACORGA CR60 added to sulfuric acid solution reducing interfacial crud formation by 2–3 times. Optimal extraction parameters include 1:2 O:A ratio, 20 ± 5 °C temperature, 5 cm3 CR60 additive, 5 min process duration, and 1-day settling time. ACORGA M5774 (10 vol.% in kerosene) is recommended as an extractant, with 2–3 stages of countercurrent extraction.

Investigating the potential of aqueous enzymatic extraction of safflower (Carthamus tinctorius L.) seed oil: Process optimization and oil characterization

Safflower seed oil was extracted by aqueous enzymatic extraction (AEE) with a combination of three enzymes: hemicellulase, pectinase, and protease. A Response Surface Methodology (RSM) was performed to optimize the operating conditions: Temperature, pH, and incubation time. Analysis of variance allowed studying the variables' linear, quadratic, and interaction effects. The optimized extraction conditions resulted in 85% oil recovery referring to the conventional Soxhlet extraction (SE). Subsequently, a comparative analysis was conducted to evaluate the quality and composition of oils obtained by SE and AEE. The results revealed that the two oils had similar values of peroxide index, conjugated dienes and trienes, and fatty acid composition. AEE-oil had a lighter yellow color (L* = 31.8 Vs. 24.7) and was richer in polyphenols (147 Vs. 101 mg GAE/Kg of oil), but it was more acidic (2.75% Vs. 1.56% linoleic acid) and less stable (2.86h Vs. 5.66h induction time) with less tocopherol (302 Vs. 409 mg/kg oil) and carotenoid content (0.42 Vs. 0.57 mg/kg oil) than SE-oil. Our findings demonstrated that RSM-based optimization is an efficient and time-saving approach, which significantly improved oil extraction. Finally, we suggested several solutions to further improve the quality and quantity of the obtained AEE-safflower seed oil, paving the path for other future research possibilities.

Optimizing the Extraction of Bioactive Compounds (Polyphenols, Lipids, and Alpha-Tocopherol) from Almond Okara to Unlock Its Potential as Functional Food.

Almond okara, a by-product of almond milk production, is rich in bioactive components, such as polyphenols, lipids, and alpha-tocopherol, making it a valuable functional food ingredient. This work aimed to investigate its composition while exploring two main aspects: (i) the impact of extraction time, solid-to-solvent ratio, ethanol concentration, and temperature on polyphenol recovery, and (ii) the quantification of okara's triglycerides (TG) and alpha-tocopherol contents. The polyphenols' optimal extraction conditions were 90 min, a 1:30 solid-to-solvent ratio (w/v), 50% ethanol, and 60 °C. These conditions achieved a total polyphenol yield of 523 mg GAE, tannin yield of 340 mg GAE, total flavonoid yield of 548 mg CE, and a total antioxidant capacity of 779 mg AAE per 100 g dry okara. The Peleg model effectively described the extraction kinetics. Additionally, TG levels, quantified by UHE/LPSFC-APCI-MS, in okara were comparable to those in almonds, and alpha-tocopherol levels, quantified by LC-UV, were 14,400 µg/100 g in almonds and 15,600 µg/100 g in okara. These findings highlight the potential of okara as a valuable resource, with a straightforward, scalable, and cost-effective solid-liquid extraction (SLE) method for polyphenols and a supercritical fluid extraction method for TG, for use in the functional food, nutraceutical, and cosmetic industries.

Research on the Cell Wall Breaking and Subcritical Extraction of Astaxanthin from Phaffia rhodozyma.

This study focused on developing an effective cell wall-breaking method for Phaffia rhodozyma, followed by utilizing subcritical fluid extraction to isolate, extract, and concentrate astaxanthin from the complex fermentation products of P. rhodozyma. A comprehensive comparison of seven distinct methods for disrupting cell walls, including dimethyl sulfoxide treatment, lactic acid treatment, sodium hydroxide treatment, β-glucanase enzymatic digestion, β-mannanase enzymatic digestion, and a combined enzymatic treatment involving both β-mannanase and β-glucanase was conducted. The results identified the lactic acid method as the most effective in disrupting the cell walls of P. rhodozyma. The software, Design Expert, was used in the process of extracting astaxanthin from cell lysates using a subcritical extraction method. Through fitting analysis and response surface optimization analysis by Design Expert, the optimal extraction conditions were determined as follows: an extraction temperature of 41 °C, extraction frequency of two times, and extraction time of 46 min. These parameters facilitated the efficient extraction, concentration, and enrichment of astaxanthin from P. rhodozyma, resulting in an astaxanthin concentration of 540.00 mg/L. This result can establish the foundation for its high-value applications.

Process Condition Optimization and Structural Feature Analysis of Humic Acid Extraction from Weathered Lignite.

In this study, response surface methodology (RSM) was adopted to investigate the optimization of process conditions for extracting humic acid (HA) from coal, aiming to enhance the yield of humic acid. Additionally, UV-vis spectroscopy, FTIR, XRD, TG-DTG, CP/MAS13CNMR, XPS, and molecular fluorescence were utilized to examine the properties of HAs. The extraction time significantly influenced the yield from Lishi weathered lignite, while the liquid-solid ratio had a significant impact on the yield from Wuhai weathered lignite. The interactive effect between factors did not have a significant effect on the yield. The optimal extraction conditions for Lishi humic acid (LSHA) were determined to be an extraction time of 4.4 h, NaOH concentration of 0.30 mol/L, and liquid-solid ratio of 21 mL/g, while those for Wuhai humic acid (WHHA) were 3.1 h, 0.21 mol/L, and 12 mL/g, respectively. Under these optimal conditions, the true yield values closely matched the predicted value obtained from the model optimization. Comparative analysis of the HAs revealed similarities in their chemical properties, including the degree of aromaticity, molecular weight, and distribution of functional groups. The aromaticity of WHHA was higher compared to that of LSHA. The higher hydrophilic-hydrophobic index of LSHA contributed to its relatively high biological activity compared to that of WHHA. Both humic acids belong to terrestrial humic acids. The results of the study provide a reference for further application of humic acid.

Ultrasound-assisted extraction of withanolides from Tubocapsicum anomalum: Process optimization, isolation and identification, and antiproliferative activity

Tubocapsicum anomalum, a Chinese medicinal plant rich in anti-tumor withanolides, requires efficient extraction methods. In this paper, an HPLC method was first established for the detection of withanolides, and gradient elution was carried out using a methanol–water solvent system. It was found that the content of withanolides was the highest in the leaves of T. anomalum, followed by the stems and fruits, and almost none in the roots. During the actual picking process, the quantity of leaves collected was relatively small, while the number of stems was the highest. Therefore, the Box-Behnken response surface method was used to optimize the ultrasonic-assisted extraction process of withanolides from the stems of T. anomalum. The optimal extraction conditions were determined as follows: the liquid–solid ratio was 20:1, the extraction solvent was 70 % ethanol, the ultrasonic power was 250 W, the ultrasonic time was 40 min, and the ultrasonic temperature was 50 °C. Under these conditions, the average yields of tubocapsenolide A (Te-A) and tubocapsanolide A (Ta-A) can reach 2.87 ± 0.12 mg/g and 1.18 ± 0.05 mg/g, respectively. We further compared extraction rates of two withanolides from different parts of T. anomalum using ultrasonic and traditional extraction methods. Ultrasonic extraction significantly increased rates, with the highest yields from leaves, followed by stems and fruits. The results show that ultrasonic optimization can improve extraction rate, reduce time, lower costs, enhance quality, and increase yield. Therefore, the optimized ultrasonic-assisted extraction process was adopted to extract the aerial parts of T. anomalum and separate the components. After optimization, the extract underwent several chromatographic separations to isolate eight previously undescribed withanolides (1–8) and two artificial withanolides (9–10), in addition to fifteen known compounds (11–25). Their structures were established through extensive spectroscopic data analysis. The compounds were evaluated for their antiproliferative effects against multiple cancer cell lines, including human hepatocellular carcinoma cells (HepG2, Hep3B, and MHCC97-H), human lung cancer cells (A549), human fibro-sarcoma cancer cells (HT1080), human chronic myeloid leukemia cells (K562), and human breast cancer cells (MDA-MB-231 and MCF7). Compounds 1–3, 5, 7, 11, 13, 15–16, and 22 displayed significant activity with IC50 values of 5.14–19.87 μM. The above results indicate that ultrasonic-assisted extraction technology can be used to obtain new withanolides more efficiently from T. anomalum, thereby enhancing the utilization rate of T. anomalum resources.

Theoretical exploration and experimental investigation of acidic deep eutectic solvents as green solvents to separate carbazole from model crude anthracene oil

Carbazole is a highly value-added compound derived from crude anthracene. Deep eutectic solvents (DESs) have been extensively used as promising green solvents for the separation of target compounds from mixture. In this work, 135 acidic DESs, formed by combining 9 quaternary ammonium salts with 15 common acids, were screened based on the conductor-like screening model for real solvents (COSMO-RS) model. The four top-ranked DESs, including tetraethylammonium chloride (TEAC)/2 acetic acid (AA), TEAC/2 propionic acid (PA), tetrapropylammonium chloride (TPAC)/2AA, and TPAC/2PA were identified as suitable extractants for carbazole separation based on their performance index (PI). Among them, TEAC/2AA had the best separation performance for carbazole due to its highest PI value (1448.19). Liquid–liquid extraction experiments were performed, and the results were in good accordance with those predicted by COSMO-RS calculations. Therefore, TEAC/2AA was determined as the most promising DES for the carbazole separation. The extraction conditions of TEAC/2AA were optimized. The extraction efficiency (EE) and selectivity (SE) of carbazole were 97.67 % and 66.64 %, respectively, under the optimal extraction conditions (25 ℃, 5 min of extraction time, DES-oil mass ratio of 1:5, initial carbazole concentration of 5000 ppm). Additionally, the deionized water was employed to regenerate the DES and recovery of carbazole. The recycling performance of promising DES was also investigated. Finally, quantum chemical calculations and Fourier Transform Infrared spectroscopy (FT-IR) analysis were conducted to explore the separation mechanism. The results indicated that the separation of carbazole by DESs were predominantly dominated by hydrogen bonds and van der Waals interaction. This work provided a valuable reference for the selection and design of DES extractants to separate other high value-added components from mixture.

Boric Acid Functionalized Hypercrosslinked Polymers for Selective Extraction of Trace Catecholamines and Their Metabolites in Rat Serum

ABSTRACTAbnormal levels of catecholamine (CA) neurotransmitters and their metabolites in biological fluids can lead to various neurological disorders. Herein, a boric acid‐functionalized hypercrosslinked polymer was prepared and utilized as a sorbent for the dispersive solid‐phase extraction of CAs and their metabolites in rat serum. By combination with a high‐performance liquid chromatography‐fluorescence detector, the extraction parameters for the seven target analytes were optimized. Under the optimal extraction condition, the methodology for the quantitative analysis of CAs and their metabolites in rat serum samples was established. The limits of detection and limits of quantification were found to be in the ranges of 0.010–0.015 and 0.033–0.050 ng/mL, respectively. The results demonstrated satisfactory recoveries, with values ranging from 88.02% to 113.27%, accompanied by relative standard deviations within the range of 2.69%–9.59%. In addition, the method showed good anti‐interference ability (matrix effect ranged from 2.64% to 18.07%). The developed method was validated for the determination of CAs and their metabolites in normal and Alzheimer's disease model rats’ serum, which proved the promising application of the method for CAs neurotransmitter analysis in biological samples.

"Enhancing polyamine enrichment from wheat germs: A study utilizing response surface methodology and liquid chromatography-mass spectrometry"

Wheat germ is one of the richest natural sources of polyamines, especially spermidine. Cell proliferation property of polyamines has given them inductive effects in the reduction of a variety of chronic diseases and fertility enhancement. Preparing a polyamine-rich extract powder from wheat germ for use in supplements is the aim of the present study. For the first time, the effects of three independent variables of clean-up replicate (A), extraction time (B), and solid-to-liquid ratio (C) on the response of total spermidine content (Y) were investigated using a central composite design optimizing polyamine enrichment. The optimal extraction conditions were 7 h, 3 clean-up replicates, and 1:4 solid to liquid ratio. This is the first production report of spermidine-enriched powder for encapsulation purposes. To obtain an acceptable rheological property, the polyamine-enriched extract was spray dried together with a selected group of excipients, among which glucose was evidenced as the best choice based on encapsulation properties.

Flexible and designable metal–organic framework-based electrospun nanofibrous for highly sensitive recognition of polycyclic aromatic hydrocarbons in water samples

In this study, a novel functionalized electrospun nanofibrous material was developed through a straightforward and robust approach that combines polydopamine (PDA) mediation and hydrothermal growth. This material was utilized as a SPME probe for polycyclic aromatic hydrocarbons (PAHs) analysis. Under optimal extraction conditions, the proposed method exhibited higher enrichment factors (1362–4563) and lower detection limits (0.003–0.35 ng mL−1), with relative standard deviations (RSDs) below 6.7 %. Applied to water samples, the stability and reproducibility of the nanofibrous have been validated with the intra- and inter-assay RSD in 2.3–9.8 % and 1.5–9.9 %, respectively. Acceptable recoveries of 87.1–109.2 % were achieved. Furthermore, the developed SPME-GC method was successfully applied to the analysis of PAHs in water samples.

Efficient separation and extraction of guaiacol and its derivatives from bio-oils based on a heterogeneous extraction technique

To fully utilized the high value-added phenolic compounds in biomass pyrolysis bio-oils, a heterogeneous extraction method was developed in this study to separate 4-ethylguaiacol, guaiacol, and eugenol from bio-oil one by one. Based on the high selectivity of coordination intermediates generated between Ca2+ and phenolic compounds with hydroxyl and methoxy groups towards the parent phenol, the reaction intermediate between each of 4-ethylguaiacol, guaiacol, eugenol and Ca2+ was used as the extracting agents. Influencing parameters investigated were the sequence of extracting three phenolic compounds from the model bio-oil, the optimal extraction conditions, and the Ca2+ distribution in the original extracting agents at the end of the reaction. The optimal extraction sequence was determined to be 4-ethylguaiacol, eugenol and guaiacol through the evaluation of multiple experiments changing their addition sequence. Under the conditions of 25 °C reaction temperature, 45 min reaction time, and pH value of 7, the extraction efficiency of 4-ethylguaiacol, eugenol and guaiacol from bio-oil reached 60.6 %, 46.1 % and 60.7 %, respectively. Meanwhile, the purity of these three phenolic compounds achieved 62.4 %, 90.0 % and 89.0 %.

Efficient and selective extraction of gold from acidic leaching solutions using novel guanidinium ionic liquid

As gold is a non-renewable resource, it holds both economic and environmental importance to enhance the recycling of precious metal waste from secondary resources. Herein, a guanidine salt ionic liquid ([DIETMG][NTf2]) with low water solubility and viscosity was synthesized by molecular design of guanidine salt ionic liquid with good biocompatibility and biodegradability, and a solvent-free system of [DIETMG][NTf2]-water was constructed to extract Au(Ⅲ). The findings reveal that the extraction efficiency of Au(Ⅲ) can reach 97.57 % under optimal extraction conditions. Further thermodynamic and kinetic studies revealed that the reaction process is spontaneous and exothermic, with the extraction rate being primarily controlled by interfacial chemical reactions. The system demonstrates remarkable selectivity for Au(Ⅲ) in solutions containing a mix of various metal ions. Finally, ascorbic acid (Vc) was employed as a stripping agent to obtain gold at room temperature. After 8 cycles, [DIETMG][NTf2] still achieved a 90 % extraction efficiency. This study provides a new idea and method for recovery of gold from secondary resources.

A green and sensitive electromembrane extraction (EME) method for the determination of dialkylphosphates in maternal urine and amniotic fluid

Organophosphates compounds are extensively used pesticides, whose metabolites, dialkyl phosphates, are considered as bioindicators of human exposure. Recently, research has indicated that they can affect thyroid endocrine function. Pregnant women are a particularly vulnerable cohort to these effects due to concerns about prenatal exposure to environmental pollutants. For the first time an electromembrane microextraction method is proposed for the simultaneous determination of seven dialkylphosphate metabolites in maternal urine and amniotic fluid, which is compatible with mass spectrometry detection and achieves highly sensitive levels of quantitation. Dialkylphosphates were extracted from a 10 mL donor solution at pH 7 into a 50 µL acceptor solution at pH 12 using 1-octanol as the supported liquid membrane and applying 60 V for 10 min at 600 rpm. The obtained extracts were analysed by ion pair liquid chromatography coupled to a triple quadrupole mass spectrometer, using an Acquity UPLC® BEH C18 column (100 mm × 2.1 mm i.d., 1.7 µm particle size) at 30 °C. Under optimal extraction conditions, the preconcentration factors were achieved were up to 178-fold, allowing for high sensitivity levels, in the order of ng mL−1. The limits of quantitation were within 0.075 ng mL−1 (diethyl thiophosphate) and 1.67 ng mL−1 (dimethyl phosphate) in maternal urine samples and within 0.015 ng mL−1 (diethyl thiophosphate) and 0.5 ng mL−1 (dimethyl dithiophosphate) in amniotic fluid samples. The comparative study revealed a significant improvement in terms of analysis time, sensitivity, greenness, and practicality. Finally, the applicability of the method for the determination of selected dialkylphosphates was demonstrated in paired maternal urine and amniotic fluid samples. These results suggest potential placental transfer to the offspring.

Extraction of polyvinylidene fluoride binder materials for used secondary batteries using supercritical CO2 for an effective battery recycling process

In this study, a polyvinylidene fluoride (PVDF) binder material for secondary batteries was removed using a supercritical CO2 extraction process instead of conventional extraction processes such as leaching and pyrolysis. To determine the optimal process conditions, the phase behavior of the binder in CO2 was studied by measuring the pressure and temperature before the supercritical CO2 extraction. To design an effective extraction process, the extraction time, temperature, and pressure were studied under various experimental conditions using a supercritical extraction system. Various organic cosolvents were used in the experiment to improve the extraction efficiency. According to the experimental result, the optimal extraction conditions were determined to 353.2 K, 10 MPa, and 20 min with dimethylformamide (DMF) cosolvent. Under these process conditions, the removal rate of the binder was 98.8 %. However, there was a significant difference in cell performance such as initial discharge capacity and cycling stability depending on the extraction solvent. Specifically, cycling stability improved in the order of using DMF, NMP, DMSO, and DMAc. The extracted binder material was analyzed by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) to compare the raw and processed materials and evaluate the reusability of the binder material.