97 results on '"back-extraction"'
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2. Dispersive liquid–liquid microextraction with back extraction based on in situ deep eutectic solvent decomposition and air-assisted for determination of some antidepressant drugs in biological samples prior to HPLC-UV.
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Ghane, Mohammad, Mohadesi, Alireza, Ezoddin, Maryam, Ali Karimi, Mohammad, and Abdi, Khosrou
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IN situ processing (Mining) , *VENLAFAXINE , *LIQUID-liquid extraction , *CITALOPRAM , *SERTRALINE , *DETECTION limit , *SOLVENT extraction - Abstract
In this study, a dispersive liquid–liquid microextraction along with a back-extraction step (DLLME-BE) has been developed for the determination of thre antidepressant drugs (citalopram, sertraline, and venlafaxine) in biological samples prior to HPLC-UV. Briefly, the method involved two main steps: first, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide (TBABr as a dispersive agent) and 1-dodecanol (as the extraction solvent) was decomposed in an aqueous phase and led to in situ dispersion of the organic phase and extraction of analytes.. Second, Air-assisted liquid–liquid microextraction (AALLME) was applied to back-extract analytes into 50 µL of an aqueous acceptor phase while many interferences were not able to extract into the acceptor solution. By performing this developed extraction method, a high sample clean-up was achieved. The maximum efficiency of analytes was obtained based on the optimisation of the main parameters. Validation of the method indicated that the limits of detection (LODs) and limits of quantifications (LOQs) were in the range of 0.7–3.9 µg L−1 and 2.1–9.8 µg L−1 respectively. The extraction recoveries and enrichment factors of analytes were obtained to be in the range of 87.1–99.1% and 89–102, respectively. Finally, the method was utilised for extraction of three antidepressant drugs in water, human urine and plasma samples. [ABSTRACT FROM AUTHOR] more...
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- 2024
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3. Eco-friendly dispersive liquid–liquid microextraction procedure based on solidification of floated organic drop coupled with back-extraction for preconcentration of rare earth elements.
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Mortada, Wael I., El-Gamal, Ghada G., Hassanien, Mohamed M., Ibrahim, Amr A., and Abou El-Reash, Yasmeen G.
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INDUCTIVELY coupled plasma atomic emission spectrometry , *MATRIX effect , *STANDARD deviations , *REFERENCE sources , *DETECTION limit - Abstract
In this study, a simple and efficient eco-friendly procedure for preconcentration of trace amounts of Y, Sm, Eu, Gd, Er and Yb was developed prior to determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The extraction process involved two sequential steps. The first is based on ultrasonic-assisted emulsification solidified floating organic drop microextraction using morin and 1-undecanol as complexing and extraction agents, respectively. The analyte in the solidified floated organic drop was then back-extracted into aqueous solution of HNO3 to prevent the relapsing effect of the organic matrix on the performance of ICP-OES. The effect of various experimental parameters on the extraction efficiency was studied and optimised. The limits of detection were in the range of 0.053 (Y) – 0.086 (Sm) µg L−1 with linear dynamic analytical range of 0.3–1000 µg L−1 at the optimal conditions. The relative standard deviations (C = 20 µg L−1, n = 10) ranged from 1.7% (Eu) to 2.5% (Yb). Finally, the approach represented high efficiency in determining the rare earth elements in certified reference material and phosphite rock samples. [ABSTRACT FROM AUTHOR] more...
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- 2024
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4. Efficient preparation of hyperoside and quercitrin from Zanthoxylum bungeanum Maxim leaves using an integrated surfactant-based aqueous two-phase system, back-extraction and adsorption separation.
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Han, Nuan, Chen, Xiaoqi, Wang, Hong, Wang, Nana, Nian, Miaoxiang, and Wang, Dongmei
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TRITON X-100 ,CONTINUOUS processing ,ZANTHOXYLUM ,MICELLES ,FLAVONOIDS - Abstract
Zanthoxylum bungeanum leaves (ZBL) are of great medicinal value for being rich in hyperoside and quercitrin. In this study, a novel, efficient and economical continuous process was established. First, aqueous two-phase system (ATPS) composed of Triton X-100/(NH
4 )2 SO4 was employed to enrich hyperoside and quercitrin from ZBL extracts and the recoveries reached 98.53% and 99.12%. Then back-extraction with dichloromethane-water system was adopted to separate hyperoside and quercitrin from Triton X-100 micelles which were recycled and the recoveries reached 86.58% and 85.19%. Finally, S-8 macroporous resin was used for removing the salt introduced in ATPS and the final recoveries reached 82.38% and 81.81%, much higher than the total flavonoids recovery as 69.08%. Furthermore, scale-up experiment certified that the continuous process was feasible for industrial production. Efficiently and economically, this method achieved a great breakthrough in purity and provided a novel reference for further purification and phase-forming component recycle. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
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5. Analysis of herbicide mixtures in environmental samples with emulsification liquid-liquid microextraction using fatty acids deep eutectic solvents.
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Sazali, Nur Hidayah, Miskam, Mazidatulakmam, Suah, Faiz Bukhari Mohd, and Rahim, Nurul Yani
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ENVIRONMENTAL sampling , *WATER sampling , *FATTY acids , *HYDROGEN bonding , *ACID solutions , *HERBICIDES - Abstract
A method was developed for the simultaneous extraction of herbicides such as 2,4 D, MCPA, ametryn, chlorothalonil, and bromacil in water and vegetable samples by emulsification liquid-liquid microextraction with fatty acids based hydrophobic deep eutectic solvents (DES). The DES were synthesised by mixing several fatty acids ratios that functioned as both the hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). Using the DES as the microextraction solvent, several vital parameters were optimised, including the type and volume of hydrophobic DES, pH of the sample, sonication time, and type and volume of emulsifier. Then, the extracted herbicides were back-extracted into phosphoric acid solution (0.05 M). The detection limits were in the range of 0.01–2.5 ng mL−1, the quantification limits were in the range of 0.03–8.3 ng mL−1, and recoveries were in the range of 73.1–98.8% with RSD <10%. The greenness assessment using Analytical Eco-Scale and AGREE (Analytical GREEnness Metric Approach System) exhibited that the emulsification liquid-liquid microextraction method using DES can be considered as simple, practical, and environmentally friendly. [ABSTRACT FROM AUTHOR] more...
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- 2024
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6. Dispersive Solid Phase Extraction/Back-Extraction Using Carbon Nanotubes as Sorbent for HPLC/UV Determination of Ibuprofen in Human Blood Serum Samples.
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Sheikhian, L. and Zahedinejad, E.
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CARBON nanotubes , *CHEMICAL preconcentration , *BLOOD sampling , *DETECTION limit , *MULTIWALLED carbon nanotubes , *IBUPROFEN , *HIGH performance liquid chromatography , *LIQUID chromatography-mass spectrometry - Abstract
Dispersive solid phase extraction/back–extraction of Ibuprofen using multi-walled carbon nanotubes as sorbent was studied. The effects of some factors on Ibuprofen extraction were investigated. pH of IP solution and temperature were more effective on IP adsorption than other investigated parameters. The obtained preconcentration factor was 11.43. A linear range of 10.31 – 206.28 mg/L (R2 = 0.997) was obtained for the HPLC method. The detection limit and relative standard deviation were 4.93 mg/l and 2.27%, respectively. Extraction and HPLC/UV determination of Ibuprofen in the human blood serum samples was carried out efficiently using the suggested procedure. The obtained results showed satisfactory selectivity and efficiency for the extraction of Ibuprofen molecules from the matrix of the Human blood serum samples. The suggested method is simple, efficient, fast, without usage of organic solvents, and low cost for separation, extraction, and determination of Ibuprofen molecules. [ABSTRACT FROM AUTHOR] more...
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- 2024
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7. Shaker-Assisted Liquid–Liquid Microextraction Followed by Solidification of Floating Organic Droplet and Back-Extraction Procedure besides Partial Least Squares Regression for Simultaneous Spectrophotometric Determination of Benzoic Acid and Sorbic Acid
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Dastyar, Hossein, Ghoreishi, Sayed Mehdi, and Ghani, Milad
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PARTIAL least squares regression , *BENZOIC acid , *SOLIDIFICATION , *ORGANIC solvents , *ALKALINE solutions , *STANDARD deviations - Abstract
A shaker-assisted liquid–liquid microextraction followed by solidification of floating organic droplet and the final back-extraction method (SALLME-SFOD-BE) was introduced for the simultaneous quantification of benzoic acid (BA) and sorbic acid (SA) (as the model analytes) in different kinds of food products. The presented method used partial least squares calibration and UV–Vis detection. Then, the organic solvent was solidified and collected from the solution. Finally, the extracted analytes were back-extracted into an alkaline solution and analyzed by UV–Vis. Under the optimized condition, the calibration graph was linear in the range of 1–200 ng mL−1 and 1–250 ng mL−1 (R2 > 0.995) for BA and SA, respectively. The limits of detection (LODs) of 0.5 ng mL−1 and 0.6 ng mL−1 were determined for BA and SA, respectively. The inter-day relative standard deviations (RSDs) were in the range of 2.9–3.1% and 2.6–2.8% for BA and SA, respectively. The intra-day RSDs were also in the range of 2.6–2.9% and 2.4–2.7%, respectively. The calculated enrichment factor (EF) and percent enrichment recovery (ER%) were within the range of 16.4–16.6 and 98–99 for BA and SA, respectively. The method was used for the determination of selected model analytes in real samples, and satisfactory results were obtained. Since very simple instruments were used, this method is affordable, efficient and convenient for extraction and simultaneous determination of BA and SA in real samples. [ABSTRACT FROM AUTHOR] more...
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- 2023
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8. A critical review of chromatographic methods for analyzing haloacetic acids in water: Advances, uncertainties, and prospects.
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Ma, Wei, Li, Wenyu, Chen, Baiyang, Yang, Yang, and Yang, Jie
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DISINFECTION by-product , *CROSS-entropy method , *ACIDS , *RESEARCH personnel , *DERIVATIZATION - Abstract
Haloacetic acids (HAAs), which are the second largest group of halogenated disinfection byproducts, raise great analytical challenges because of their hydrophilicity, non-volatility, and acidity. To determine HAAs in drinking water, many pretreatment methods (such as extraction and derivatization) have been proposed since 2000. These methods vary significantly in principles and performance, each carrying inherent analytical errors. This review critically compared typical pretreatment, separation, and detection techniques in terms of advantages and disadvantages, aiming to enable an in-depth and comprehensive understanding of HAAs analysis and help researchers meet analytical requirements. Accordingly, we also identified several analytical error sources less considered before, which may alert later method developers. Finally, we proposed several research prospects, such as analyzing trace amounts of multiple HAAs in their native chemical form, especially for iodoacetic acids at ng/L levels, under mild conditions, e.g., free of reagents, ambient temperature, and neutral pH conditions. • HAAs analysis is challenging since they are hydrophilic, non-volatile, and ionic. • Novel GC, LC, IC, and CE methods are developed for HAAs analysis since 2000. • Pretreatment, separation, and detection techniques are necessary for HAAs analysis. • Proper use of each method should first have a good understanding of error sources. • Next-generation HAAs analytical methods should be handy, cheap, and sensitive. [ABSTRACT FROM AUTHOR] more...
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- 2024
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9. Extraction and Back-Extraction Behaviors of La(III), Ce(III), Pr(III), and Nd(III) Single Rare Earth and Mixed Rare Earth by TODGA
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Lina Qiu, Jiandi Li, Weiwei Zhang, Aijun Gong, Xiaotao Yuan, and Yang Liu
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light rare earths ,extraction ,back-extraction ,TODGA ,rate of recovery ,Chemical technology ,TP1-1185 - Abstract
N,N,N′,N′-Tetraoctyl diglycolamide (TODGA), as a new extraction agent, is effective for its excellent performance and low environmental hazard, and it is very welcome for the rare earth separation process. In this paper, by controlling the extraction time, diluent type, acid type and its concentration, rare earth concentration, etc., the optimum extraction and back-extraction effects of TODGA on La(III), Ce(III), Pr(III), and Nd(III) and mixed rare earths were obtained. The experiment showed that 0.10 mol·L−1 TODGA had the best extraction effect on single rare earth under the conditions of using petroleum ether as diluent, 5 mol·L−1 nitric acid, 20 min extraction time, and 0.01 mol·L−1 rare earth. In the mixed rare earth extraction, the percentage concentrations of La(III), Ce(III), Pr(III), and Nd(III) could be achieved from 21.7%, 19.9%, 30.8%, and 22.2% at the initial stage to 90.5%, 37%, 51%, and 62% after extraction, respectively, by controlling the number of back-extraction cycles and the concentrations of hydrochloric acid and nitric acid in the back-extraction system. The TODGA–rare earth carrier system showed the best back-extraction effect when the hydrochloric acid concentration was 1 mol·L−1 and the back-extraction time was 20 min. At the same time, the mixed rare earth liquid system with low initial concentration was selected for extraction and separation of mixed rare earth. The separation effect was better, and the recovery rate was higher than that of mixed rare earth liquid system with a high initial concentration. more...
- Published
- 2021
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10. An efficient sample preparation method based on dispersive liquid–liquid microextraction associated with back extraction for trace determination of acidic pharmaceuticals.
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Ghambarian, Mahnaz, Tajabadi, Fateme, Yamini, Yadollah, Behbahani, Mohammad, Sobhi, Hamid Reza, and Esrafili, Ali
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Reduction of matrix effect seems to be a great challenge for the development of a practical method in bioanalysis. In this regard, a simple and efficient DLLME procedure along with a back-extraction step (DLLME-BE) was developed for the preconcentration of four common non-steroidal anti-inflammatory drugs (NSAIDs) in various biological fluid samples. Briefly, the analytes of interest were initially transferred into the extraction solvent followed by the back-extraction into an immiscible basic methanol (as an acceptor phase) for further preconcentration and clean-up. The main purpose of the work is reducing the matrix effect and sensitive determination of target molecules in the complex matrices. Following on, the separation and determination of the analytes were carried out using GC–MS (in-port derivatization) and HPLC-DAD instrument. The influential parameters affecting the DLLME-BE method were evaluated in detail and the best extraction conditions were established. Under the optimum conditions, low method detection limits in the range of 0.1–1.0 and 0.1–6.0 µg L
−1 were obtained for GC–MS and HPLC-DAD analysis, respectively. Additionally, fair intra-day precisions of 2.7–14.5 and 2.8–7.8% as well as inter-day precisions of 3.9–14.5 and 3.5–8.1% were achieved for the GC–MS and HPLC-DAD analysis, respectively. Finally, the method was successfully applied for the determination of four common NSAIDs in different biological fluid samples. [ABSTRACT FROM AUTHOR] more...- Published
- 2020
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11. Solvent Extraction of Vanadium From Vanadium Slag Leaching Solution by Chloro-1-octyl-3-methylimidazolium Ionic Liquid.
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ZHOU Chao, LI Yong, and XUE Xiangxin
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The solvent extraction and separation of V( V) from a vanadium slag leaching solution using w-pentanol as diluents, chloro-l-octyl-3-methylimidazolium ionic liquid as extractant and ammonium chloride as stripping agent was studied. The effects of extractant concentration, contact time, solution pH and temperature on extraction of V(V),and influences of concentration of back-extraction NH
4 Cl, pH and stripping time on stripping of V(V) were examined. The results show that at the conditions of extractant concentration of 50.0 g/L, contact time of 30 s, temperature of 25.0 °C and solution pH of 8.051, the extraction of V(V) is 96.2%. The extraction process of vanadium is exothermic and spontaneous. The back-extraction of V(V) is 95.84% at the conditions of NH4 Cl concentration of 1.5 mol/L,pH of 8.5, stripping time of 30.0 min. The NH4 VO3 obtained by back-extraction is calcined,the vanadium pentoxide is obtained. [ABSTRACT FROM AUTHOR] more...- Published
- 2019
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12. Recovery of 3-hydroxypropionic acid from organic phases after reactive extraction with amines in an alcohol-type solvent.
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Chemarin, F., Moussa, M., Allais, F., Trelea, I.C., and Athès, V.
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ORGANIC acids , *HEXANE , *AMINES , *DILUTION , *SALTS - Abstract
Highlights • The use of basic salts yields a total recovery in stoichiometric proportions. • Back-extraction much slower than extraction in membrane contactor. • Solvent swing with hexane is efficient but leads to high dilutions. • Temperature swing is the most promising with a recovery up to 78% (volume ratio = 1). Abstract Reactive extraction is a well-known method for the recovery of organic acids from dilute streams. The extraction through complex formation with amines is followed by its back-extraction. Their affinity for amine extractants makes their back-extraction a limiting step. The case of 3-hydroxypropionic acid is addressed here. Three methods were compared: salts additions, diluent swing and temperature swing. Mineral bases led to complete 3-HP recovery but as a salt. Diluent swing was tested using n -hexane as the anti–solvent. Results showed that increasing the n -hexane content led to a great increase of 3-HP recovery. However, high recovery yields are associated with high dilutions. The temperature was varied from 4 to 140 °C and it led to a high decrease of the acid-amine complex formation. Our thermochemical study showed an apparent heat of reaction of −25.3 kJ/mol and, at 140 °C, 78% of 3-HP can be recovered in a single step. [ABSTRACT FROM AUTHOR] more...
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- 2019
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13. Shaker-assisted liquid-liquid microextraction of methylene blue using deep eutectic solvent followed by back-extraction and spectrophotometric determination.
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Ahmadi, Raheleh, Kazemi, Ghasem, Ramezani, Amir M., and Safavi, Afsaneh
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METHYLENE blue , *EUTECTIC reactions , *SOLVENTS , *LIQUID-liquid extraction , *SPECTROPHOTOMETRY - Abstract
Abstract This research describes the spectrophotometric determination of methylene blue (MB) after shaker-assisted liquid-liquid microextraction combined with back-extraction (SALLME-BE). A hydrophobic deep eutectic solvent (DES) was used for extraction of MB from alkaline solutions (0.5 M NaOH). Then, the extracted dye was back-extracted into a hydrochloric acid solution (2 M). Decanoic acid and methyltrioctylammonium bromide were used, respectively as hydrogen bond donor and hydrogen bond acceptor constituents of the hydrophobic DES. The calibration graph was linear in the range of 2–170 ng mL−1. The recovery analysis of wastewater and river water samples verified that this method is practical for environmental monitoring. Highlights • Shaker-assisted liquid-liquid microextraction of methylene blue • Application of deep eutectic solvent as environmentally friendly extraction solvent • Spectrophotometric quantification after back-extraction [ABSTRACT FROM AUTHOR] more...
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- 2019
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14. Facile and Rapid Isolation of Oxypeucedanin Hydrate and Byakangelicin from Angelica dahurica by Using [Bmim]Tf2N Ionic Liquid
- Author
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Alice Nguvoko Kiyonga, Gyeongmin Hong, Hyun Su Kim, Young-Ger Suh, and Kiwon Jung
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ionic liquids ,oxypeucedanin hydrate ,byakangelicin ,A. dahurica ,back-extraction ,enrichment ,Organic chemistry ,QD241-441 - Abstract
Ionic liquids (ILs) have sparked much interest as alternative solvents for plant materials as they provide distinctive properties. Therefore, in this study, the capacity of ILs to extract oxypeucedanin hydrate and byakangelicin from the roots of Angelica dahurica (A. dahurica) was investigated. The back-extraction method was examined to recover target components from the IL solution as well. Herein, [Bmim]Tf2N demonstrated outstanding performance for extracting oxypeucedanin hydrate and byakangelicin. Moreover, factors including solvent/solid ratio, extraction temperature and time were investigated and optimized using a statistical approach. Under optimum extraction conditions (solvent/solid ratio 8:1, temperature 60 °C and time 180 min), the yields of oxypeucedanin hydrate and byakangelicin were 98.06% and 99.52%, respectively. In addition, 0.01 N HCl showed the most significant ability to back-extract target components from the [Bmim]Tf2N solution. The total content of both oxypeucedanin hydrate (36.99%) and byakangelicin (45.12%) in the final product exceeded 80%. Based on the data, the proposed approach demonstrated satisfactory extraction ability, recovery and enrichment of target compounds in record time. Therefore, the developed approach is assumed essential to considerably reduce drawbacks encountered during the separation of oxypeucedanin hydrate and byakangelicin from the roots of A. dahurica. more...
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- 2021
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15. Two-step salting-out extraction of 1,3-propanediol, butyric acid and acetic acid from fermentation broths.
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Li, Zhen, Yan, Ling, Zhou, Jinjie, Wang, Xiaoli, Sun, Yaqin, and Xiu, Zhi-Long
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ORGANIC acids , *ACETIC acid , *ACETOBACTER , *SODIUM bicarbonate , *FERMENTATION - Abstract
Highlights • A novel two-step salting-out extraction was used to separate 1,3-propanediol, butyric acid and acetic acid from fermentation broth. • Butyric acid could be separated from 1,3-propanediol and acetic acid by the salting-out extraction system comprised of acidic inorganic salt and hydrophobic solvent. • Effect of sodium carbonate concentration on the back-extraction of butyric acid was investigated. Abstract The separation of 1,3-propanediol (1,3-PD), butyric acid (BA) and acetic acid (HAc) from the fermentation broth was studied by two-step salting-out extraction. In the first salting-out extraction, the partition coefficient and recovery of BA reached 42.21 and 96.42%, respectively, under the optimal condition of 25 wt% NaH 2 PO 4 /30 wt% n-butyl acetate. Subsequently, 91.28% of BA in the organic phase could be recovered through back-extraction when sodium carbonate solution was mixed with organic phase with initial phase ratio of n-butyl acetate solution to alkaline solution being 2:1, in which the molar ratio of sodium carbonate to organic acids was 3:5. Finally, 50% (v/v) ethanol (95%) was added to the bottom phase for the second step salting-out extraction. And the partition coefficient and recovery of 1,3-PD were 9.40 and 95.50%, and those of HAc were 7.46 and 94.40%, respectively. All the cells and most of the proteins (97.16%) could be removed. Effective separation of 1,3-PD from BA was realized by two-step salting-out extraction, which provides a potential method for separation of 1,3-PD, BA and HAc on an industrial scale. [ABSTRACT FROM AUTHOR] more...
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- 2019
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16. Theme Issue Honoring Professor Robert Verpoorte's 75th Birthday: Past, Current and Future of Natural Products Research.
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Choi, Young Hae, Choi, Young Hae, Dai, Yuntao, Jang, Young Pyo, and Salomé-Abarca, Luis Francisco
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Research & information: general ,13C nuclear magnetic resonance ,1H-NMR ,9-O-angeloyl-retronecine N-oxide ,A. dahurica ,Datura ,Eleutherococcus senticosus ,Ephedra sinica ,GC-FID-MS ,HCT 116 ,LC-MS ,Mexican agastache ,NMR ,Nacobbus aberrans ,NuBBE database ,Ononis diffusa ,Ononis variegata ,PTP-MEG2 ,Psychotria malayana Jack ,RNA interference ,Reseda luteola L. ,Solanaceae ,UHPLC ,alkaloid ,antibacterial assay ,aromatic plants ,back-extraction ,berberine ,bioassay ,botanicals ,byakangelicin ,cell cycle arrest ,centrifugal partition chromatography ,chalcones ,chemical cue ,chemical profiling ,colorectal cancer ,cosmetic industry ,cytotoxic activity ,databases ,dereplication ,direct analysis in real-time mass spectrometry ,docking ,downregulation ,effect-directed analysis ,eleutherosides ,enrichment ,enzyme inhibition assay ,ephedra alkaloids ,ephedrine ,fingerprinting ,flavones ,flax ,fruits ,glucose-uptake ,glycerin ,health food ,herbs ,indole ,inflammation ,ionic liquids ,kairomone ,lignans ,metabolomics ,methylephedrine ,micro-extraction of wool ,molecular docking ,molecular imaging ,molecular structures ,n/a ,natural extract ,natural products ,natural yellow dye ,nematicidal activity ,nutri-pharmacological ,osmotic stress ,oxylipins ,oxypeucedanin hydrate ,phloridzin ,plum brandy ,potentiation ,protein tyrosine phosphatases (PTPs) ,pyrrolidine ,quercetagetin derivatives ,secoisolariciresinol ,signaling ,spectroscopy ,stigmasterol ,structure elucidation ,taxonomy ,telomerase ,telomerase inhibitor ,telomere erosion ,terpenoid ,toronjil ,tropane ,type 2 diabetes ,weld ,α-glucosidase inhibitors ,α-terthienyl ,μ-analysis - Abstract
Summary: This theme issue is to celebrate Professor Robert Verpoorte's 75th birthday. Prof. Verpoorte has been working in Leiden University over 40 years. There is no need to dwell upon the contributions of Dr. Verpoorte to plant-derived natural products research during his whole life. Dr. Verpoorte was a highly productive scientist throughout his academic career, with over 800 scientific publications in the form of research papers, books, and book chapters. His research interests are very diverse, cover- ing numerous topics related to plant-based natural products such as plant cell biotech- nology, biosynthesis, metabolomics, genetic engineering, and green technology, as well as the isolation of new biologically active compounds. He has left indelible footprints in all these fields, and he is widely recognised as a pioneer in the work of the biosynthesis of indole alkaloids, NMR-based metabolomics, and green technology in natural products production. As close friends and colleagues who have been in nearly daily contact with him over the last 20 years viewing all of these remarkable scientific contributions, we felt compelled to recognize this by the publication of a Special Issue of this journal dedicated to him.Thus, this Special Issue has now finally been released with the help of many of his colleagues and former students as a token of our gratitude to his impressive work.The Special Issue covers five main natural products topics: (1) chemical profiling and metabolomics, (2) separation/isolation and identification of plant specialized metabolites, (3) pharmacognosy of natural products to identify bioactive molecules from natural prod- ucts, (4) novel formulation of natural products, and (5) overview of natural products as a source of bioactive molecules. more...
17. Enhanced Am/Eu separation ability of disulfonated diamide N-heterocyclic ligands by adjusting N-, O-donor affinity: A theoretical comparative study.
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Huang, Pin-Wen, Wang, Cong-Zhi, Wu, Qun-Yan, Lan, Jian-Hui, Chai, Zhi-Fang, and Shi, Wei-Qun
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ATOMS in molecules theory , *LIGANDS (Chemistry) , *DENSITY functional theory , *RADIOACTIVE wastes , *WASTE treatment , *RARE earth metals - Abstract
Quantum chemical calculations reveal that adjusting N-, O-donor affinity enhances Am/Eu separation ability of the ligands. [Display omitted] • Am(III), Eu(III) Back-extraction reaction free energy with three disulfonated diamide N-heterocyclic ligands were well modeled by using density functional theory. • The bonds between Am(III) ions and N donor atoms in studied ligands are partial covalence interactions and three disulfonated diamide N-heterocyclic ligands have preference back-extraction ability toward Am(III). • Disulfonated diamide N-heterocyclic ligands' Am(III) preference can be modified by adjusting its N- and O- atoms' affinity. Separation of minor actinides (MAs) from lanthanides (Ln) is a vital and challenging stage in advanced nuclear waste treatment. Development of water-soluble back-extraction ligand is regarded as a feasible alternative method for high efficiency An(III)/Ln(III) separation. Therefore, theoretical investigating on the deep mechanism behind the selective back-extraction of An(III) is very important. In this work, Am- and Eu-complexes with three water-soluble disulfonated N-heterocyclic ligands, disulfonated N,N'-diphenyl-2,9-diamide-1,10-phenanthroline (DS-Ph-DaPhen, L 1), disulfonated N,N'-diphenyl-2,9-diamide-2,2′-Dipyridine (DS-Ph-DADipy, L 2), and disulfonated N,N'-diphenyl-2,9-diamide 5H-cyclopenta[2,1-b:3,4-b']-Dipyridine (DS-Ph-Da-5H-Cyclo-PentaDipy, L 3) were systematically investigated using quasi-relativistic density functional theory (DFT) method. Electrostaic potential (ESP) and restrained electroStatic potential (RESP) atomic charge on donor atoms indicate that N atoms' affinity toward metal ions in L 2 and L 3 was increased by replaceing the phenanthroline ring with dipyridine ring and 5H-Cyclo-PentaDipyridine ring, while the affinity of O atoms seem to decrease from L 1 to L 2 and L 3. Through Wiberg bond indices and quantum theory of atoms in molecule (QTAIM) analyses, three ligands' Am(III) preference may be attributed to the weak but different extend partial covalency in Am-N and Eu-N bonds. Based on the NBO population and PDOS analyses, slightly more overlap of Am-5 f and N/O-2 p orbitals than those between Eu-4 f and N/O-2 p orbitals. Based on the theoretical calculation, the covalency difference between Am-N and Eu-N bonds seems to have inverse correlation with the intensity of M−N bonds. However, all the theoretical results suggest that, by increasing N's affinity and weakening O' affinity at the same time, ligand's Am(III)/Eu(III) separation ability can be improved. This work offers some useful information for changing ligands' An(III)/Ln(III) back-extraction and separation abilities by adjusting the affinity of donor N and O atoms in its central N-heterocyclic skeleton, and may shed light for future designing of more efficient An(III)/Ln(III) back-extraction ligands. [ABSTRACT FROM AUTHOR] more...
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- 2023
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18. Novel Task Specific Ionic Liquids to Remove Heavy Metals from Aqueous Effluents
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Pape Diaba Diabate, Laurent Dupont, Stéphanie Boudesocque, and Aminou Mohamadou
- Subjects
ionic liquids ,metal extraction ,liquid-liquid extraction ,back-extraction ,reusability ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Task Specific Ionic Liquids (ILs) were generated by association between a cationic ester derivative of betaine and coordinating inorganic anions such as dicyanamide (Dca−), chlorosalycilate (ClSal) and saccharinate (sac). Extraction of Cu(II), Ni(II), Co.(II), Pb(II) and Cd(II) from water was performed with these ILs at room temperature. Our results show that ionic liquid with Clsal anions have a high extraction efficiency towards Cu(II), Ni(II), Cd(II), and Pb(II), whereas dicyanamide ionic liquid may extract efficiently Cu(II), Ni(II) Co.(II) and Cd(II). Ionic liquids with saccharinate anions are selective of Cd(II) ions. The extraction mechanism has been studied by the determination of the coextraction of the counter ion of the metal salt. Our results show that the extraction mechanism proceeds via a mixed process involving both cation exchange and ion-pairing. The proportion of which depends on the nature of the cation. The coordination of Cu(II), Ni(II) and Co.(II) in ionic liquid phase was followed by UV-vis spectroscopies. The metal could be back-extracted from the ionic liquid phase with aqueous EDTA solutions. The metal extractability of the ionic liquid after the back-extraction is equivalent to that of the fresh mixture showing that ionic liquid can be reused for several extraction and back-extraction cycles. more...
- Published
- 2018
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19. Salt De-Emulsification Dispersive Liquid-Liquid Microextraction and Back-Extraction Combined with Sweeping Micellar Electrokinetic Capillary Chromatography for Detection of Triazine Herbicides in Honey.
- Author
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Yue, Mei-E, Li, Qian, Xu, Jie, and Jiang, Ting-Fu
- Abstract
A rapid, simple, and sensitive method has been developed for the analysis of triazine herbicides in honey samples by using salt de-emulsification dispersive liquid-liquid microextraction and back-extraction (SD-DLLME-BE) coupled with sweeping in micellar electrokinetic chromatography (MEKC). In the newly developed method, chloroform can be generated by the reaction of chloral hydrate and sodium hydroxide, and the chloroform droplets dispersed into bulk aqueous solution can be swiftly carried to the bottom of the centrifuge tube with the addition of calcium chloride. Then, back-extraction was utilized to extract the analytes into an aqueous solution prior to capillary electrophoresis (CE) analysis. The advantages of the new in situ DLLME lie in dispersive solvent-free and no centrifugation operation compared with the conventional DLLME. Several important parameters influencing the preconcentration and extraction efficiency of SD-DLLME-BE such as sodium dodecyl sulfate (SDS) concentration, pH, chloral hydrate and sodium hydroxide content, extraction time, and calcium chloride content were optimized. Under the optimized conditions, the enrichment factors were achieved in the range from 459 to 636. The proposed method provided a good linearity, low limits of detection (8.56 ng/mL), and good repeatability of the extractions (relative standard deviations (RSDs) below 8.8 %, n = 6). Honey samples were analyzed by the proposed method, and obtained results indicated that the proposed method provides acceptable recoveries and precisions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2016
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20. Multi-magnetic center ionic liquids for dispersive liquid-liquid microextraction coupled with in-situ decomposition based back-extraction for the enrichment of parabens in beverage samples.
- Author
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Qiao, Lizhen, Tao, Yuan, Qin, Honglin, and Niu, Ruiting
- Subjects
- *
IONIC liquids , *MAGNETIC fluids , *PARABENS , *STANDARD deviations - Abstract
• Design and prepare three novel multi-magnetic center magnetic ionic liquids (MMILs). • Establish a MMIL-based DLLME method combined with in-situ decomposition based back-extraction. • Apply the proposed procedure for the enrichment and determination of parabens in beverage samples. In this paper, several new multi-magnetic center magnetic ionic liquids (MMILs) were prepared with paramagnetic component simultaneously contained in both the cation and anion and used as extractants to establish a dispersive liquid-liquid microextraction (DLLME) approach followed by in-situ MMIL decomposition based back-extraction for the enrichment and determination of four parabens in beverages. The appropriate MMIL was selected by investigating the extraction performances of the obtained MMILs combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV), and some other experimental factors were explored. Under the optimized DLLME conditions, the four parabens exhibited coefficients of determination (R2) above 0.9987 in the linear range of 0.1-500 ng·mL−1 for ethylparaben, propylparaben and butylparaben and 0.2-500 ng·mL−1 for methylparaben. The limits of detection (LODs) and limits of quantification (LOQs) were respectively within 0.03-0.06 ng·mL−1 and 0.1-0.2 ng·mL−1, and the relative standard deviations (RSDs) for intra-day and inter-day precision were below 10.8%. Moreover, the application of the developed MMIL-based DLLME method in beverage samples exhibited recoveries within 81.3%-112.1% with RSDs of 0.3%-13.1% at three different spiked levels. [ABSTRACT FROM AUTHOR] more...
- Published
- 2023
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21. Monitoring and investigating reactive extraction of (di–)carboxylic acids using online FTIR – Part II: Reaction equilibria, reaction kinetics and competition within the complex formation between itaconic acid and several amine extractants.
- Author
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Nolte, Lea and Brandenbusch, Christoph
- Subjects
- *
ITACONIC acid , *EQUILIBRIUM reactions , *CHEMICAL kinetics , *FOURIER transform infrared spectroscopy , *CARBOXYLIC acids , *AMINES - Abstract
[Display omitted] • Identifying limiting factors of reactive extraction and back-extraction with online FTIR spectroscopy. • Evaluation of reaction equilibria and reaction kinetics using FTIR spectroscopy. • Investigation on the strength of the acid-extractant complexes. • Optimized amine selection for reactive extraction and back-extraction. • Optimizing downstream concept for (di–)carboxylic acids through mechanistic understanding of complex formation. The downstream processing of biocatalytically produced (di–)carboxylic acids still is a challenging task. One innovative approach, demonstrating industrial applicability, applies an initial reactive extraction (RE) using hydrophobic amine extractants into an organic solvent, followed by a subsequent back-extraction (BE) using water soluble amine extractants into a (fresh) aqueous solution. Although showing promising results in terms of yield and selectivity, state-of-the-art amine extractant selection is only based on trial-and-error screening approaches. Thus, to enable an optimized process design and thereby optimized downstream processing, a deeper understanding of RE and BE on a molecular level is crucial. Within this work, we successfully applied an experimental setup incorporating online Fourier Transform Infrared (FTIR) spectroscopy to elucidate influencing factors on RE and BE as well as to provide a guideline for an optimized selection of amine extractants. Investigations on the kinetics of complex formation between itaconic acid (IA) and tri- n -octylamine (TNOA) in 1-decanol revealed the reaction order to be zero in TNOA, indicating that mass transfer is the rate limiting step in RE. Reaction equilibrium investigations revealed that for all IA - amine extractants combinations in 1-decanol reaction equilibrium was almost completely on the product (complex) side. The strength of the acid-extractant complexes was evaluated using FTIR experiments, providing a novel approach / methodology to efficiently select an optimal combination of amine extractants for RE and BE. Applying the novel online FTIR spectroscopy setup allowed to monitor a complete process sequence of RE and BE of IA with selected amine extractants, validating the proposed guidelines for an optimized selection of amine extractants. The results of this work will facilitate the definition of appropriate RE and BE systems for biocatalytically produced (di–)carboxylic acids. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
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22. Deep eutectic solvents as new media for green extraction of food proteins: Opportunity and challenges.
- Author
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Zhou, Yuhao, Wu, Wei, Zhang, Na, Soladoye, Olugbenga P., Zhang, Yuhao, and Fu, Yu
- Abstract
[Display omitted] • The recent research progress on extraction of food proteins by DES is reviewed. • DES can exhibit high extraction efficiency in the extraction of food proteins. • The structure and activity of extracted proteins can completely be retained by DES-based method. • DES with low viscosity, high selectivity and back-extraction efficiency is needed. The constantly improved quality of life leads to increasing demand for high-quality food proteins. Thus, the high-efficiency extraction methods of food proteins are highly needed. However, the traditional alkali-solution and acid-isolation method employs a large amount of corrosive acid/alkaline solution, which not only pollutes the environment, but also causes denaturation of proteins. Therefore, developing a novel green extraction method is of great significance. Deep eutectic solvents (DES), characterized by good biodegradability, sustainability and low toxicity, have become a green solvent in the past years. Extraction of food proteins by DES can overcome the shortcomings of corrosive solvents (e.g. NaOH, HCl and H 2 SO 4) used in traditional methods, making it a promising novel green extraction method. In this work, the information on DES was firstly recapped. Furthermore, the latest research progress on the extraction of food proteins by DES was emphatically reviewed. In addition, the challenges and future perspectives for DES-assisted extraction were discussed. Overall, the DES-based methods exhibit high extraction efficiency in extracting animal and plant proteins, amino acids, and enzymes, while the extracted proteins were non-denatured. However, DES-based protein extraction method still faces some challenges, such as high viscosity, poor extraction selectivity and inefficient back-extraction method. The present work can provide a theoretical reference for applying DES in the green extraction of food proteins. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
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23. Reduction of Pu(IV) by carbohydrazide in aqueous solutions and in two-phase systems with tributyl phosphate.
- Author
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Alekseenko, V., Dvoeglazov, K., Marchenko, V., Alekseenko, S., Volk, V., and Podrezova, L.
- Subjects
- *
PLUTONIUM isotopes , *HYDRAZIDES , *AQUEOUS solutions , *TRIBUTYL phosphate , *CHEMICAL kinetics , *ACTIVATION energy - Abstract
The possibility of using carbohydrazide as a reducing agent for plutonium in Purex process was examined. Kinetics of the reaction between Pu(IV) and carbohydrazide in HNO aqueous solution was studied spectrophotometrically, the rate law was established, and the rate constant and activation energy values were calculated. Plutonium stripping efficiency by carbohydrazide as defined is higher in the two-phase system: 30 % TBP with Pu(IV) nitric acid aqueous solution, in the presence of glycine. A laboratory scale counter-current experiment performed with the use of simulated WWER-1000 SNF reprocessing solutions demonstrated the possibility of carbohydrazide-glycine mixture using for plutonium concentrating back-extraction process. [ABSTRACT FROM AUTHOR] more...
- Published
- 2015
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24. Facile and Rapid Isolation of Oxypeucedanin Hydrate and Byakangelicin from Angelica dahurica by Using [Bmim]Tf2N Ionic Liquid
- Author
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Young-Ger Suh, Alice Nguvoko Kiyonga, Hyun Su Kim, Kiwon Jung, and Gyeongmin Hong
- Subjects
enrichment ,Time Factors ,back-extraction ,Pharmaceutical Science ,Chemical Fractionation ,oxypeucedanin hydrate ,Article ,Analytical Chemistry ,lcsh:QD241-441 ,ionic liquids ,chemistry.chemical_compound ,Byakangelicin ,lcsh:Organic chemistry ,Furocoumarins ,Drug Discovery ,Physical and Theoretical Chemistry ,Angelica ,Chromatography ,biology ,Chemistry ,Angelica dahurica ,Organic Chemistry ,Extraction (chemistry) ,biology.organism_classification ,A. dahurica ,Solvent ,byakangelicin ,Chemistry (miscellaneous) ,Ionic liquid ,Solvents ,Molecular Medicine ,Hydrate - Abstract
Ionic liquids (ILs) have sparked much interest as alternative solvents for plant materials as they provide distinctive properties. Therefore, in this study, the capacity of ILs to extract oxypeucedanin hydrate and byakangelicin from the roots of Angelica dahurica (A. dahurica) was investigated. The back-extraction method was examined to recover target components from the IL solution as well. Herein, [Bmim]Tf2N demonstrated outstanding performance for extracting oxypeucedanin hydrate and byakangelicin. Moreover, factors including solvent/solid ratio, extraction temperature and time were investigated and optimized using a statistical approach. Under optimum extraction conditions (solvent/solid ratio 8:1, temperature 60 °C and time 180 min), the yields of oxypeucedanin hydrate and byakangelicin were 98.06% and 99.52%, respectively. In addition, 0.01 N HCl showed the most significant ability to back-extract target components from the [Bmim]Tf2N solution. The total content of both oxypeucedanin hydrate (36.99%) and byakangelicin (45.12%) in the final product exceeded 80%. Based on the data, the proposed approach demonstrated satisfactory extraction ability, recovery and enrichment of target compounds in record time. Therefore, the developed approach is assumed essential to considerably reduce drawbacks encountered during the separation of oxypeucedanin hydrate and byakangelicin from the roots of A. dahurica. more...
- Published
- 2021
25. Recovery of clavulanic acid from an aqueous two-phase system by ion-exchange resin.
- Author
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da Silva, C. Sacardo, Barreto, V. O., Bavarotti, E., Rodriguez, G. Youssef, Hokka, C. Osamu, and Barboza, M.
- Subjects
CLAVULANIC acid ,AQUEOUS solutions ,ION exchange resins ,POTASSIUM salts ,PHOSPHATES - Published
- 2009
26. A magnetic ionic liquid based vortex-assisted dispersive liquid-liquid microextraction coupled with back-extraction for the enrichment of fluoroquinolone antibiotics.
- Author
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Qiao, Lizhen, Tao, Yuan, Yao, Wang, Zhao, Jieyu, and Yan, Yang
- Subjects
- *
MAGNETIC fluids , *IONIC liquids , *FLUOROQUINOLONES , *MAGNETIC susceptibility , *SOLVENT extraction , *FORMIC acid , *ANTIBIOTICS - Abstract
In the present work, a magnetic ionic liquid (MIL) ([Co(DMBG) 2 ][Co(hfaca) 3 ]) was designed and synthesized with both the cation and anion respectively containing a paramagnetic component. With the prepared MIL as the extraction solvent, a vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) method was developed and combined with back-extraction for the enrichment of five fluoroquinolone antibiotics (FQs). The MIL can be easily collected and separated from the aqueous phase under an external magnetic field due to the strong magnetic susceptibility and red color. Some experimental factors affecting the extraction efficiency were investigated, and the optimum extraction efficiency was obtained in a basic solution (pH=9) for the extraction process and with 2% (v/v) formic acid as the back-extraction solvent. Under the optimized extraction and back-extraction conditions, the proposed method was validated and exhibited good linearity with coefficients of determination (R2) above 0.9956 in the range of 2.5–800 ng·mL−1 and 5.0–800 ng·mL−1, low limits of detection (LODs) within 0.75–1.5 ng·mL−1 and satisfactory intra-day and inter-day precisions with relative standard deviations (RSDs) respectively less than 10.6% and 8.6%. Finally, the method was applied for the determination of five FQs in four samples of tap water, milk, honey and chicken, and good precision with RSDs of 0.5–9.5% and acceptable recoveries (73.8–114.3%) were obtained. [Display omitted] • A new MIL was prepared with paramagnetic cation and anion. • A vortex-assisted DLLME method coupled with back-extraction was developed. • The method was used for the determination of FQs combined with HPLC-UV. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
27. Selective recovery of thorium and uranium from leach solutions of rare earth concentrates in continuous solvent extraction mode with primary amine N1923.
- Author
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Hung, Nguyen Trong, Thuan, Le Ba, Thanh, Tran Chi, Thuy, Nguyen Thanh, Tra, Doan Thi Thu, Do Van, Khoai, Watanabe, Masayuki, Minh, Pham Quang, Than, Hoang Sy, Vuong, Nguyen Duc, Van Phuc, Dinh, Lee, Jin-Young, Jeon, Jong Hyuk, and Jyothi, Rajesh Kumar more...
- Subjects
- *
SOLVENT extraction , *THORIUM , *RARE earth metals , *URANIUM , *RADIOACTIVE substances , *COUNTERCURRENT processes , *LEACHING , *AMINES - Abstract
A continuous counter-current extraction for the selective recovery of thorium (Th) and uranium (U) from the Yen Phu (Vietnam) rare earth concentrate leach solutions was systematically studied. The primary amine N1923 was used as an extractant which was prepared in the isoparaffin IP-2028 diluent. Thorium and uranium were selectively recovered in a hydrometallurgical circuit established by continuous mixer-settler extraction, scrubbing, and back-extraction at the laboratory scale. The desired purity of Th and U can be achieved by managing the volume ratio of organic to aqueous phase (O/A ratio) in the corresponding steps. Highly pure Th and U were recovered from the pregnant back-extraction liquor and the raffinate, respectively, which have satisfactory properties for further processing of the subsequent nuclear materials. • The continuous countercurrent extraction process was developed for recovery of Th and U. • Primary amine was used to extract the nuclear grade Th and U. • The optimum parameters of the continuous counter-current extraction process were improved. • The individual Th and U of high purity were recovered for nuclear material applications. • The recovered Th and U increase the commercial value of Vietnamese ore concentrate. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
28. Extraction of Metal Ions with Task Specific Ionic Liquids: Influence of a Coordinating Anion.
- Author
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Zhou, Yingsai, Boudesocque, Stéphanie, Mohamadou, Aminou, and Dupont, Laurent
- Subjects
- *
METAL ions , *EXTRACTION (Chemistry) , *IONIC liquids , *COORDINATE covalent bond , *HYDROPHOBIC compounds - Abstract
Hydrophobic ionic liquids (ILs) were generated by association between a cationic ester derivative of betaine and bis(trifluoromethylsulfonyl)imide (Tf2N−) or dicyanamide (Dca−) anions. Extraction of Cu(II), Ni(II), Pb(II), and Cd(II) from water was performed with these ILs at room temperature. The use of Dca−anion greatly enhances the extraction efficiency of IL phase towards metal ions extraction. The metal could be back-extracted from the ionic liquid phase with aqueous EDTA solutions. The metal extractability of the ionic liquid after the back-extraction is equivalent to that of the fresh mixture showing that ionic liquid can be reused for several extraction and back-extraction cycles. [ABSTRACT FROM PUBLISHER] more...
- Published
- 2015
- Full Text
- View/download PDF
29. Transferring of red Monascus pigments from nonionic surfactant to hydrophobic ionic liquid by novel microemulsion extraction.
- Author
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Shen, Lingjie, Zhang, Xuehong, Liu, Mingzhu, and Wang, Zhilong
- Subjects
- *
MONASCUS , *SURFACE active agents , *HYDROPHOBIC compounds , *IONIC liquids , *MICROEMULSIONS , *EXTRACTION (Chemistry) , *AQUEOUS solutions - Abstract
Nonionic surfactant micelle aqueous solution as well as cloud point system is a potential separation/reaction medium. Downstream processing for recovery of product and regeneration of surfactant is indispensable. Adjustment of pH in the dilute phase of cloud point extraction is a common strategy for separation of ionizable organic compound from nonionic surfactant. However, this strategy is no longer suitable for recovery of ionizable organic compound with strong hydrophobicity due to the high solubilization of the ionic state of hydrophobic organic compound in micelles. Setting extractive fermentation of intracellular Monascus pigments in nonionic surfactant micelle aqueous solution to produce high color hue of red Monascus pigments as an example, transferring of hydrophobic Monascus pigments from nonionic surfactant to ionic liquid by novel hydrophobic ionic liquid–nonionic surfactant–water Winsor I microemulsion extraction and then back-extraction of the ionizable Monascus pigments from the ionic liquid by ionic liquid–water two-phase extraction were carried out. Nearly 80% yield was achieved in the complete process for recovery of Monascus pigments. It provides a novel strategy for stripping of hydrophobic ionizable organic compound from nonionic surfactant micelle aqueous solution. [ABSTRACT FROM AUTHOR] more...
- Published
- 2014
- Full Text
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30. Cloud point extraction coupled with back-extraction for speciation of inorganic vanadium in water and determination of total vanadium in food samples by ICP-OES.
- Author
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Mortada, Wael I., El-Defrawy, Mohamed M., Erfan, Eman, and El-Asmy, Hala A.
- Subjects
- *
POINT cloud , *VANADIUM , *MATRIX effect , *HYDROGEN peroxide , *INDUCTIVELY coupled plasma mass spectrometry , *CABBAGE , *WATER analysis , *CHEMICAL speciation - Abstract
[Display omitted] • A CPE-BE procedure was developed for speciation of V4+ and V5+ by ICP-OES. • Deteriorating effect of the organic matrix on the plasma performance was removed by the CPE-BE. • Dynamic linear range from 0.4–750 μg L−1 was achieved. • Validation experiments revealed that the approach is accurate and precise. • The procedure was applied for analysis of water, cabbage, carrots, mint and tomato samples. A preconcentration procedure based on cloud point extraction and back-extraction (CPE-BE) was proposed for speciation of inorganic vanadium (V4+ and V5+) followed by determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Two consecutive steps are used in this technique. The traditional CPE technique was applied as a first step, V5+ reacts with bis(3,4-dihydroxybenzylidene)isophthalohydrazide (DHBIP) forming a hydrophobic complex at pH 7.0. The formed complex is then entrapped in a surfactant-rich phase of Triton X-114, while V4+ kept in the aqueous phase. Following this stage, a back-extraction step was performed to minimize the deteriorating effect of the organic matrix on the plasma performance. For this purpose, the surfactant-rich phase containing the analyte was incubated at 45 °C with 1.0 mL of 1.0 mol L−1 of HNO 3 solution for 15 min. Finally, the analyte in the aqueous phase was determined by ICP-OES. The total vanadium was determined as V5+ after oxidation of V4+ by using hydrogen peroxide. The calibration graph is linear from 0.4–750.0 μg L-1 for V5+ at the optimum conditions (pH 7.0, 10-4 mol L-1 DHBIP, 0.1 % (v/v) Triton X-114 and 45 °C). The detection and quantification limits of V5+ were 0.12 μg L-1and 0.40 μg L-1, respectively, with an enrichment factor of 49.5, and the relative standard deviation was less than 2.5 % (n = 7, c = 10 μg L-1). The method has been used for speciation of inorganic V in water samples and determination of total V in cabbage, carrots, mint, and tomato samples with satisfactory results. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
- Full Text
- View/download PDF
31. Influence of an Alkoxy Group on Bis-Triazinyl-Pyridines for Selective Extraction of Americium(III).
- Author
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Dupont, Carine, Hill, Clément, Suzenet, Franck, and Guillaumet, Gérald
- Subjects
- *
ALKOXY group , *PYRIDINE , *AMERICIUM , *LIQUID-liquid extraction , *SEPARATION (Technology) , *REACTOR fuel reprocessing , *NITRIC acid , *ACTINIDE elements , *RARE earth metals - Abstract
The extraction of americium(III), curium(III), and lanthanides(III) from nitric acid by 2,6-bis-(5,6-dimethyl-[1,2,4]-triazin-3-yl)-pyridine and 2,6-bis-(5,6-dimethyl-[1,2,4]-triazin-3-yl)-4-methoxypyridine was studied. The physico-chemical properties of these ligands, such as the protonation and complexation constants, were also determined to describe the influence of different substituent groups. The selectivity of substituted-BTP was confirmed both in complexation and in solvent extraction experiments. The presence of an alkoxy-group in position 4 of the pyridine decreases the BTP selectivity. Influence of a long alkyl chain on protonation and complexation constants was also studied with 2,6-bis-(5,6-dimethyl-[1,2,4]-triazin-3-yl)-4-dodecyloxypyridine. [ABSTRACT FROM AUTHOR] more...
- Published
- 2013
- Full Text
- View/download PDF
32. Staged Versions of Liquid Membrane Extraction Processes.
- Author
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Kostanian, Artak E.
- Subjects
- *
EXTRACTION (Chemistry) , *LIQUID membranes , *COMPARATIVE studies , *PHYSICAL & theoretical chemistry , *EXTRACTION apparatus , *ACETONE , *WATER - Abstract
The application of the liquid membrane technique to the system consisting of serially connected mixer-settler extractors is suggested and evaluated. A comparative theoretical analysis of various flow schemes of contacting liquids in series of mixer-settler extractors has been performed. It is shown that the scheme of a staged version of supported liquid membrane provides the highest extraction efficiency. One laboratory plant consisting of eight mixer-settler was examined with the standard extraction system water-acetone-toluene using two schemes: with internal (the extractant recycles between each pair of extraction and stripping stages) and external (the extractant first passes through all the stages of extraction, then through all stripping stages) circulation of the extractant. The effectiveness of the first variant (supported liquid membrane scheme) was considerably higher than that of the second scheme. Good agreement between theory and experiment was established. [ABSTRACT FROM AUTHOR] more...
- Published
- 2013
- Full Text
- View/download PDF
33. Recovery of Indium from Scrap TFT-LCDs by Solvent Extraction.
- Author
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Ruan, Jiuli, Guo, Yuwen, and Qiao, Qi
- Subjects
INDIUM tin oxide ,LIQUID crystal displays ,THIN film transistors ,ELECTRONIC waste ,SOLVENT extraction ,LEACHING - Abstract
Abstract: Recovery of indium from scrap LCDs, which contain indium in the form of indium tin oxide (ITO) films, is becoming economically and environmentally justified. Indium is a precious metal and the present study was aimed to recover indium from scrap TFT-LCDs by solvent extraction which was based upon H2SO4 acid leaching–D2EHPA extraction–HCl back extraction. The results showed that indium could be better leached in H2SO4 (1:1, v/v) acid solution in the optimal liquid/solid ratio of 1:1 while other metals’ leaching concentrations were relatively low. Indium could be selectively extracted from its H2SO4 solutions by 30% D2EHPA with O/A ratio of 1:5 within 5min, and be completely stripped by 4M HCl from D2EHPA with A/O ratio of 1:5, the final extraction efficiency achieved more than 97%. [Copyright &y& Elsevier] more...
- Published
- 2012
- Full Text
- View/download PDF
34. Extraction of europium by sodium oleate/pentanol/heptane/NaCl microemulsion system.
- Author
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Wang, W., Yang, Y., Zhao, H., Guo, Q., Lu, W., and Lu, Y.
- Subjects
- *
EXTRACTION techniques , *EUROPIUM , *SODIUM compounds , *PENTANOL , *MICROEMULSIONS , *ANIONIC surfactants , *TEMPERATURE effect - Abstract
The extraction of europium to a W/O microemulsion with an anionic surfactant was studied. In the sodium oleate (NaOL)/pentanol/heptane/NaCl system, the influence of aqueous-microemulsion ratio, concentration of NaOL, extraction temperature, concentration of cosurfactant, pH and salting-out agent on the extraction yield were investigated. Europium was probably extracted into the microemulsion phase in the form of Eu(OL)Cl, and the extraction yield ( E%) was above 99% when R = 8. The enthalpy and entropy of Eu(III) extraction were calculated to be −12.18 kJ/mol and −61.41 J/(mol K), respectively. The back-extraction is conducted by hydrochloric acid (0.8 mol/L), which provided better back-extraction yields (95.15%). [ABSTRACT FROM AUTHOR] more...
- Published
- 2012
- Full Text
- View/download PDF
35. Determination of β-sitosterol and cholesterol in oils after reverse micelles with Triton X-100 coupled with ultrasound-assisted back-extraction by a water/chloroform binary system prior to gas chromatography with flame ionization detection
- Author
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Kardani, Fatemeh, Daneshfar, Ali, and Sahrai, Reza
- Subjects
- *
CHOLESTEROL , *REVERSED micelles , *EXTRACTION (Chemistry) , *CHLOROFORM , *BINARY metallic systems , *GAS chromatography , *IONIZATION (Atomic physics) , *SUNFLOWER seed oil - Abstract
Abstract: Ultrasonic back-extraction of Triton X-100 reverse micelles by a water/chloroform binary system and gas chromatography with flame ionization detection (GC-FID) was developed for extraction and determination of β-sitosterol and cholesterol in soybean and sunflower oil samples. After the homogenization of the oil samples with Triton X-100, an aliquot of 200μL of methanol was added to the samples to form two phases. The clear Triton X-100 extract obtained by centrifugation was treated with a mixture of water (1000μL) and chloroform (300μL) for back-extraction of the analytes into the chloroform phase by ultrasonication. After centrifugation, the sedimented chloroform layer was withdrawn easily by a microsyringe and directly injected into the GC-FID system. The influence of several important parameters on the extraction efficiencies of the analytes was evaluated. Under optimized experimental conditions, the calibration graphs were linear in the range of 1.0–30.0mgL−1 with coefficient of determination more than 0.994 for both analytes. The method detection limit values were in the range of 0.2–0.7mgL−1. The lower limit of quantification values were in the range of 0.7–2.4mgL−1. Intra-day relative standard deviations were in the range of 1.0–2.7%. This procedure was successfully applied with satisfactory results to the determination of β-sitosterol and cholesterol in spiked oil samples. The relative mean recoveries of oil samples ranged from 93.6% to 105.0%. [Copyright &y& Elsevier] more...
- Published
- 2011
- Full Text
- View/download PDF
36. Studies on the Extraction-Simultaneous Back-Extraction of Alkali Metal Picrates Using 1,3 Bis-Benzo-Crown-6-Calix[4] Arene in Hollow-Fiber Contactors.
- Author
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Albaraka, Z., Singh, Suman Kumar, Ghnimi, S., Asfari, Z., and Trebouet, D.
- Subjects
- *
EXTRACTION (Chemistry) , *ALKALI metals , *LIQUID membranes , *DONNAN equilibrium , *MASS transfer , *HOLLOW fibers , *AROMATIC compounds - Abstract
An extraction and simultaneous back-extraction process with two hollow-fiber membrane contactors is evaluated for the continuous recovery of alkali metals and 1,3 bis-benzo-crown-6-calix[4]arene. The results show that this configuration operates as a 'liquid membrane' (permeable only with alkali picrate) and order of the recovery yields is in agreement with the Donnan equilibrium. It is higher for the rubidium (75.8%) than for the cesium (68.1%) while it is only 11% for the potassium. This is a case where the high affinity of cesium picrate for the 1,3 bis-benzo-crown-6-calix[4]arene cannot be neglected and, as a consequence, its release in the back-extraction aqueous phase is more difficult. The effect of the alkali metal and the initial concentration on the system behavior shows that the concentration gradient controls the mass transfer. The kinetics are similar for the cesium and the rubidium whereas the mass-transfer resistance increases for the potassium. A high mass transfer in the first module can slow down the global-transport kinetics. [ABSTRACT FROM AUTHOR] more...
- Published
- 2011
- Full Text
- View/download PDF
37. Copper Extraction Kinetics by Beta-Diketone Derivatives (Acylpyrazolones and Acylisoxazolones) in Water/Chloroform Biphasic System.
- Author
-
Goetz, Geneviève, Arichi, Jaouad, Lakkis, Zeinab, Brunette, Jean-Pierre, and Hébrant, Marc
- Subjects
- *
COPPER , *EXTRACTION (Chemistry) , *DYNAMICS , *KETONES , *CHLOROFORM , *WATER - Abstract
Copper(II) extraction and back-extraction rates were determined in a water/chloroform system using a bell-shaped transport cell. Various 1-phenyl-3-methyl-4-acyl-pyrazol-5-ones (with acyl = benzoyl, 2-thenoyl, octadecanoyl, p-tert-butylbenzoyl, 3-phenyl-propanoyl, and iso-nonanoyl) and 3-phenyl-4-acylisoxazol-5-ones (with acyl = benzoyl and p-tert-butylbenzoyl) were considered. The back-extraction rate is shown to be limited by the diffusion of the complex in the organic unstirred layer, whatever the stirring speed and whatever the ligand considered. At low stirring speed, the extraction rate appears to be limited by the diffusion of either a complex or a ligand species in the unstirred layers, depending on the pH. At high stirring speed, the extraction rate is limited by the interfacial complexation. The extraction rate dependence on side-group variation cannot be correlated with hydrophobicity or acidity of the extractants and may be explained by structural differences of the CO vicinal group of the acyl. [ABSTRACT FROM AUTHOR] more...
- Published
- 2010
- Full Text
- View/download PDF
38. Stripping of nonionic surfactants from the coacervate phase of cloud point system for lipase separation by Winsor II microemulsion extraction with the direct addition of alcohols
- Author
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Pan, Tao, Wang, Zhilong, Xu, Jian-He, Wu, Zhenqiang, and Qi, Hanshi
- Subjects
- *
SURFACE active agents , *SEPARATION (Technology) , *EMULSIONS , *ALCOHOLS (Chemical class) , *LIPASES , *FERMENTATION , *EXTRACTION (Chemistry) , *ORGANIC solvents - Abstract
Abstract: Extractive microbial fermentation of lipase by Serratia marcescens ECU1010 in cloud point system was previously carried out in the cloud point system. The direct addition of different alcohols, including iso-butanol, 2-phenylethanol and 1-octanol, into the coacervate phase of the clear supernatant of the fermentation broth formed microemulsion, where the nonionic surfactants and lipase were unevenly partitioned between the different phases in the microemulsion system. The polarity of alcohols strongly affected the microemulsion type at room temperature condition. The results indicated that the Winsor II microemulsion, formed by the addition of iso-butanol or 2-phenylethanol as the organic solvent, favored the stripping of the nonionic surfactant into the O m phase, whereas the lipase was left in the excess aqueous phase. However, the Winsor I microemulsion, formed by the addition of 1-octanol as the organic solvent, failed to separate the lipase from the nonionic surfactant in the coacervate phase of cloud point system, because the nonionic surfactant and lipase were partitioned into the W m phase at the same time. Moreover, in the Winsor II microemulsion extraction with 2-phenylethanol as the organic solvent, in which case the protein–surfactant complexes were absent at the interface between the O m phase and the excess aqueous phase, the high lipase recovery (above 80%) and good nonionic surfactant removal were achieved. The effect of nonionic surfactants on lipase activity was also presented. [Copyright &y& Elsevier] more...
- Published
- 2010
- Full Text
- View/download PDF
39. 6,6′‐ Bis (5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydro‐benzo[1,2,4]triazin‐3‐yl) [2,2′]bipyridine, an Effective Extracting Agent for the Separation of Americium(III) and Curium(III) from the Lanthanides
- Author
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Geist, Andreas, Hill, Clément, Modolo, Giuseppe, St. J. Foreman, Mark R., Weigl, Michael, Gompper, Klaus, Hudson, Michael J., and Madic, Charles
- Subjects
- *
TRANSPLUTONIUM elements , *AMERICIUM , *NITRIC acid , *INORGANIC acids , *CURIUM , *PARTITION coefficient (Chemistry) , *RARE earth metals , *OCTYL alcohol - Abstract
The extraction of americium(III), curium(III), and the lanthanides(III) from nitric acid by 6,6′‐ bis (5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydro‐benzo[1,2,4]triazin‐3‐yl)‐[2,2′]bipyridine (CyMe 4 ‐BTBP) has been studied. Since the extraction kinetics were slow, N,N′‐dimethyl‐N,N′‐dioctyl‐2‐(2‐hexyloxy‐ethyl)malonamide (DMDOHEMA) was added as a phase transfer reagent. With a mixture of 0.01 M CyMe 4 ‐BTBP+0.25 M DMDOHEMA in n ‐octanol, extraction equilibrium was reached within 5 min of mixing. At a nitric acid concentration of 1 M, an americium(III) distribution ratio of approx. 10 was achieved. Americium(III)/lanthanide(III) separation factors between 50 (dysprosium) and 1500 (lanthanum) were obtained. Whereas americium(III) and curium(III) were extracted as disolvates, the stoichiometries of the lanthanide(III) complexes were not identified unambiguously, owing to the presence of DMDOHEMA. In the absence of DMDOHEMA, both americium(III) and europium(III) were extracted as disolvates. Back‐extraction with 0.1 M nitric acid was thermodynamically possible but rather slow. Using a buffered glycolate solution of pH=4, an americium(III) distribution ratio of 0.01 was obtained within 5 min of mixing. There was no evidence of degradation of the extractant, for example, the extraction performance of CyMe 4 ‐BTBP during hydrolylsis with 1 M nitric acid did not change over a two month contact. [ABSTRACT FROM AUTHOR] more...
- Published
- 2006
- Full Text
- View/download PDF
40. Modelling of the Extraction and Back‐Extraction Equilibria of Zinc from Spent Pickling Solutions.
- Author
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Samaniego, Henar, San Román, M. Fresnedo, and Ortiz, Inmaculada
- Subjects
- *
ZINC , *EXTRACTION (Chemistry) , *INDUSTRIAL chemistry , *CHEMICAL equilibrium , *SOLUTION (Chemistry) , *MATHEMATICAL models - Abstract
This work reports the study of the chemical equilibria of the extraction and back-extraction of zinc from spent pickling solutions. Tributyl phosphate was used as a selective extractant and service water as a back extraction agent. Feed solutions had an average composition of 6.4 M Cl - , 1.2 M Zn +2 , 1.7 M Fe +2 and traces of other heavy metals i.e., Pb, Ni, Cu, Mn. Under the experimental conditions the ion ZnCl 4 2- was the predominant zinc species in feed. A careful experimental design was performed obtaining the equilibria mathematical models and parameters, K EX =0.137 (mol/L) -4 , and K BEX =1.46 [-]. [ABSTRACT FROM AUTHOR] more...
- Published
- 2006
- Full Text
- View/download PDF
41. Interaction between reverse micelles as a key factor governing back-extraction of proteins and its control systems.
- Author
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Lee, Sung-Sik, Hwang, Kyung-Su, Lee, Bong-Kuk, Hong, Dong-Pyo, and Kuboi, Ryoich
- Abstract
The interfacial transport processes of proteins from a reverse micellar phase to an aqueous phase have been investigated focusing on micellar-micellar interaction. The proteins solubilized into reverse micelles were back-extracted to the aqueous phase depending on the concentration of reverse micelles in organic phase. This fact seems to suggest the importance of micellar-micellar interactions in back-extraction processes. The interactions induced by various alcohol addition and temperature change could be evaluated easily and quantitatively by the percolation phenomena in reverse micellar systems (RVMS). The interactions were influenced considerably by the presence of small amount of alcohol and temperature in the RVMS. The addition of alcohols promotes the back-extraction of proteins depending on their species and concentrations. In particular, the alcohols that suppress the cluster formation of reverse micelles, remarkably improve the back-extraction processes. With a small amount of alcohol (20 mM OctOH), Bovine carbonic anhydrase (CAB) can be back-extracted completely from reverse micelles to aqueous solution at the optimal temperature, in which the so high concentration of salt is not necessary. [ABSTRACT FROM AUTHOR] more...
- Published
- 2005
- Full Text
- View/download PDF
42. Back-extraction Of Pu 4 + From 20% Tributyl Phosphate – 20% Mixed Trialkyl Phosphine Oxides/kerosene In The Presence Of.
- Author
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Han, Binbing, Wu, Qiulin, Zhu, Yongjun, and Wickramasinghe, S.R.
- Subjects
- *
EXTRACTION (Chemistry) , *PETROLEUM products , *PHOSPHORUS compounds , *ORGANOPHOSPHORUS compounds , *KEROSENE , *OXALIC acid - Abstract
Back-extraction of Pu 4 + from a mixture of 20% tributyl phosphate (TBP) and 20% mixed trialkyl phosphine oxides (TRPO) in kerosene in the presence of UO 2+ 2 was studied. The back-extractants investigated may be divided into three groups: carboxylic acids and salts, amino polycarboxylates, and phosphonic acid. The distribution coefficients of both Pu 4 + and UO 2+ 2 using a number of different back-extractants were measured and compared. The results obtained suggest that the only practical back-extractants are carboxylic acids. Among the carboxylic acids tested, oxalic acid is suitable when the UO 2+ 2 concentration in the organic phase is less than 2 g/L. For UO 2+ 2 concentrations between 2 and 10 g/L, oxalic acid-nitric acid mixtures may be used. For UO 2+ 2 concentrations greater than 10 g/L, the only practical back-extractant is glycolic acid. The results obtained here may be used to further develop a new process for separation of Pu 4 + and UO 2+ 2 from TBP-TRPO/kerosene mixture. [ABSTRACT FROM AUTHOR] more...
- Published
- 2005
- Full Text
- View/download PDF
43. Comparison of mixed trialkyl phosphine oxides (TRPO) extractants from different sources
- Author
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Han, Binbing, Wu, Qiulin, Zhu, Yongjun, and Wickramasinghe, S.R.
- Subjects
- *
PHOSPHINE , *RADIOISOTOPES - Abstract
Mixed trialkyl phosphine oxides (TRPO) are promising extractants. They may be used to recover radionuclides from highly radioactive liquid wastes. However, since TRPOs contain alkyl chains ranging from C4 to C8, different TRPO may have different characteristics. In this paper, four TRPOs from different sources are compared. The extraction and back-extraction characteristics for UO22+, Pu4+, Am3+, and TcO4− were investigated, and the loading capacities for both of UO22+ and HNO3 were compared. Infrared spectroscopy and pyrolysis gas chromatography were used to analyze the type and composition of the side-group in these TRPOs. The experimental results demonstrate that different TRPOs possess similar extraction and back-extraction characteristics because they have the same type of side-group. However, different TRPOs show different loading capacity for UO22+ and HNO3 due to differences in the alkyl composition of the side-group. [Copyright &y& Elsevier] more...
- Published
- 2003
- Full Text
- View/download PDF
44. The factors affecting the backward-transfer of Bovine Serum Albumin (BSA) from sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micellar solutions.
- Author
-
Rho, Seon-Gyun and Kang, Choon-Hyoung
- Abstract
The factors affecting the back-extraction efficiency of Bovine Serum Albumin (BSA, 65kDa, pI 4.9) solubilized in an AOT reverse micellar solution, prepared by the injection method, to an excess aqueous phase were investigated. In particular, effects of pH, the type of salt and its concentration in the excess aqueous phase were examined. Furthermore, by comparing CD spectra of the back-extracted BSA with the feed BSA, the structural changes of the protein during the extraction process were determined. The addition of 1:1 salt such as KCl or NaCl to the aqueous phase resulted in a 100% recovery of the protein to the aqueous phase at a pH higher than its isoelectric point pI. This high efficiency of the back-extraction might be due to the change in the interactions between the protein and micellar aggregates driven by the added salt. For 1 : 2 salts like MgCl
2 or CaCl2 , BSA was back extracted with lower than 20% extraction efficiency. Maximum efficiencies were achieved at about pH=7 and pH=8 for monovalent and divalent salts, respectively. From the C D spectra of back-extracted BSA, it was observed that denaturation of BSA was not significant during the extraction process. [ABSTRACT FROM AUTHOR] more...- Published
- 2003
- Full Text
- View/download PDF
45. Chemical separation and ICP–AES determination of 22 metallic elements in U and Pu matrices using cyanex-923 extractant and studies on stripping of U and Pu
- Author
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Argekar, A.A., Kulkarni, M.J., Mathur, J.N., and Page, A.G.
- Subjects
- *
URANIUM , *PLUTONIUM , *TRACE elements - Abstract
Comprehensive studies have been carried out on the extraction behavior of uranium and plutonium matrices using cyanex-923 extractant. The near total extraction of U/Pu and quantitative separation of 22 metallic elements at trace levels has been established using inductively coupled plasma–atomic emission spectrometry (ICP–AES). The studies carried out on back extraction of U/Pu from organic phase have established the near total recovery of these matrices into the aqueous phase using 1 M Na2CO3 and saturated oxalic acid, respectively. [Copyright &y& Elsevier] more...
- Published
- 2002
- Full Text
- View/download PDF
46. Extraction and Back-Extraction Behaviors of La(III), Ce(III), Pr(III), and Nd(III) Single Rare Earth and Mixed Rare Earth by TODGA.
- Author
-
Qiu, Lina, Li, Jiandi, Zhang, Weiwei, Gong, Aijun, Yuan, Xiaotao, and Liu, Yang
- Subjects
RARE earth metals ,HYDROCHLORIC acid ,NITRIC acid ,HAZARDS - Abstract
N,N,N′,N′-Tetraoctyl diglycolamide (TODGA), as a new extraction agent, is effective for its excellent performance and low environmental hazard, and it is very welcome for the rare earth separation process. In this paper, by controlling the extraction time, diluent type, acid type and its concentration, rare earth concentration, etc., the optimum extraction and back-extraction effects of TODGA on La(III), Ce(III), Pr(III), and Nd(III) and mixed rare earths were obtained. The experiment showed that 0.10 mol·L
−1 TODGA had the best extraction effect on single rare earth under the conditions of using petroleum ether as diluent, 5 mol·L−1 nitric acid, 20 min extraction time, and 0.01 mol·L−1 rare earth. In the mixed rare earth extraction, the percentage concentrations of La(III), Ce(III), Pr(III), and Nd(III) could be achieved from 21.7%, 19.9%, 30.8%, and 22.2% at the initial stage to 90.5%, 37%, 51%, and 62% after extraction, respectively, by controlling the number of back-extraction cycles and the concentrations of hydrochloric acid and nitric acid in the back-extraction system. The TODGA–rare earth carrier system showed the best back-extraction effect when the hydrochloric acid concentration was 1 mol·L−1 and the back-extraction time was 20 min. At the same time, the mixed rare earth liquid system with low initial concentration was selected for extraction and separation of mixed rare earth. The separation effect was better, and the recovery rate was higher than that of mixed rare earth liquid system with a high initial concentration. [ABSTRACT FROM AUTHOR] more...- Published
- 2021
- Full Text
- View/download PDF
47. Crystallization of erythromycin extracted using novel phase separation 'sugaring-out extraction': A combined modelling and experimental approach.
- Author
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Pawar, Nitin, Moharkar, Sharayu, Agrawal, Shailesh G., Dhamole, Pradip B., and Methekar, Ravi N.
- Subjects
- *
ERYTHROMYCIN , *SALTING out (Chemistry) , *PHASE separation , *CRYSTALLIZATION , *CRYSTALLIZATION kinetics , *CRYSTAL morphology , *EVAPORATIVE cooling - Abstract
• Separation of erythromycin from solvent rich phase of sugaring out extraction. • Combined antisolvent and evaporative crystallization yield was more than 90%. • Mathematical model was developed and validated for EMC crystallization. • Antimicrobial activity of EMC was retained even after crystallization. This paper discusses recovery of erythromycin (EMC) from the solvent rich phase formed after sugaring-out extraction (SOE), a novel two phase separation technique. The conditions for SOE of EMC have already been optimized (glucose 15.6% w/w, temperature 4 °C, pH 8.3, and solvent/broth ratio 1:1). The solvent i.e. acetonitrile (ACN) rich phase was further processed to separate EMC using crystallization. Three different modes of crystallization of EMC were studied for a model system: evaporative, antisolvent (water), and combined antisolvent-evaporative. It was found that EMC degraded during evaporative crystallization, substantially lowering the yield. Antisolvent crystallization at the EMC concentration used did not yield any crystals. The combined antisolvent-evaporative crystallization resulted in the formation of desirable plate like crystals with a yield of 95% and was explored further using simulated fermentation broth (SFB) which resulted in a yield of 92.2% with desired crystal morphology. A mathematical model for EMC crystallization was also developed and the crystallization kinetics was estimated by fitting model predictions with the experimental data. Furthermore, antimicrobial activity of the crystallized EMC was found comparable to the commercial sample, showing that the chosen purification technique did not impact the efficacy of the recovered EMC. [Display omitted] [ABSTRACT FROM AUTHOR] more...
- Published
- 2021
- Full Text
- View/download PDF
48. Method and apparatus for back-extracting metal chelates
- Author
-
Lin, Yuehe [Moscow, IA]
- Published
- 1998
49. Recovery of 3-hydroxypropionic acid from organic phases after reactive extraction with amines in an alcohol-type solvent
- Author
-
Ioan-Cristian Trelea, Florian Chemarin, Marwen Moussa, Florent Allais, Violaine Athès, Centre Européen de Biotechnologies et Bioéconomie (CEBB), Agro-Biotechnologies Industrielles (ABI), AgroParisTech, Génie et Microbiologie des Procédés Alimentaires (GMPA), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Region Grand-Est, Conseil Departemental de la Marne, and Grand Reims more...
- Subjects
Standard enthalpy of reaction ,diluent swing ,Inorganic chemistry ,back-extraction ,temperature swing ,Salt (chemistry) ,Filtration and Separation ,Alcohol ,02 engineering and technology ,3-Hydroxypropionic acid ,Diluent ,Analytical Chemistry ,chemistry.chemical_compound ,[CHIM.GENI]Chemical Sciences/Chemical engineering ,020401 chemical engineering ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,0204 chemical engineering ,chemistry.chemical_classification ,pH swing ,Extraction (chemistry) ,021001 nanoscience & nanotechnology ,6. Clean water ,Solvent ,chemistry ,Amine gas treating ,0210 nano-technology - Abstract
International audience; Reactive extraction is a well-known method for the recovery of organic acids from dilute streams. The extraction through complex formation with amines is followed by its back-extraction. Their affinity for amine extractants makes their back-extraction a limiting step. The case of 3-hydroxypropionic acid is addressed here. Three methods were compared: salts additions, diluent swing and temperature swing. Mineral bases led to complete 3-HP recovery but as a salt. Diluent swing was tested using n-hexane as the anti-solvent. Results showed that increasing the n-hexane content led to a great increase of 3-HP recovery. However, high recovery yields are associated with high dilutions. The temperature was varied from 4 to 140 °C and it led to a high decrease of the acid-amine complex formation. Our thermochemical study showed an apparent heat of reaction of-25.3 kJ/mol and, at 140 °C, 78% of 3-HP can be recovered in a single step. more...
- Published
- 2019
- Full Text
- View/download PDF
50. Novel Task Specific Ionic Liquids to Remove Heavy Metals from Aqueous Effluents
- Author
-
Laurent Dupont, Pape Diaba Diabate, Aminou Mohamadou, Stéphanie Boudesocque, Institut de Chimie Moléculaire de Reims - UMR 7312 (ICMR), SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-SFR CAP Santé (Champagne-Ardenne Picardie Santé), and Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Université de Reims Champagne-Ardenne (URCA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
lcsh:TN1-997 ,liquid-liquid extraction ,Inorganic chemistry ,back-extraction ,Salt (chemistry) ,02 engineering and technology ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,010402 general chemistry ,01 natural sciences ,Metal ,ionic liquids ,chemistry.chemical_compound ,metal extraction ,Liquid–liquid extraction ,[CHIM]Chemical Sciences ,General Materials Science ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Dicyanamide ,ComputingMilieux_MISCELLANEOUS ,lcsh:Mining engineering. Metallurgy ,chemistry.chemical_classification ,Aqueous solution ,Extraction (chemistry) ,Metals and Alloys ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,3. Good health ,chemistry ,visual_art ,Ionic liquid ,visual_art.visual_art_medium ,reusability ,Counterion ,0210 nano-technology - Abstract
Task Specific Ionic Liquids (ILs) were generated by association between a cationic ester derivative of betaine and coordinating inorganic anions such as dicyanamide (Dca&minus, ), chlorosalycilate (ClSal) and saccharinate (sac). Extraction of Cu(II), Ni(II), Co.(II), Pb(II) and Cd(II) from water was performed with these ILs at room temperature. Our results show that ionic liquid with Clsal anions have a high extraction efficiency towards Cu(II), Ni(II), Cd(II), and Pb(II), whereas dicyanamide ionic liquid may extract efficiently Cu(II), Ni(II) Co.(II) and Cd(II). Ionic liquids with saccharinate anions are selective of Cd(II) ions. The extraction mechanism has been studied by the determination of the coextraction of the counter ion of the metal salt. Our results show that the extraction mechanism proceeds via a mixed process involving both cation exchange and ion-pairing. The proportion of which depends on the nature of the cation. The coordination of Cu(II), Ni(II) and Co.(II) in ionic liquid phase was followed by UV-vis spectroscopies. The metal could be back-extracted from the ionic liquid phase with aqueous EDTA solutions. The metal extractability of the ionic liquid after the back-extraction is equivalent to that of the fresh mixture showing that ionic liquid can be reused for several extraction and back-extraction cycles. more...
- Published
- 2018
- Full Text
- View/download PDF
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