High hydrostatic pressure extraction of flavonoids from propolis

A high hydrostatic pressure extraction (HHPE) method is presented for the extraction of flavonoids from propolis. Various experimental conditions of the HHPE process, such as solvents, ethanol concentration (35–95%, v/v), HHPE pressure (100–600 MPa), HHPE time (1–10 min) and solid/liquid ratio (1:5–1:45 g cm^?3), were investigated to optimize the extraction process. The extraction yield with HHPE for 1 min was higher than those using extraction at room temperature for 7 days and heat reflux extraction for 4 h respectively. From the viewpoints of extraction time, the extraction efficiency and the extraction yield of flavonoids, HHPE was more effective than the conventional extraction methods studied. Copyright © 2004 Society of Chemical Industry     

Homogeneous liquid–liquid extraction using perfluorooctanesulfonic acid and calcium and its application to the separation and recovery of vitamin B12

A new phase separation phenomenon was observed in which the perfluorooctanesulfonate ion (PFOS⁻) and calcium ion form an ion‐pair associator and the sedimented liquid phase occurs from the homogeneous aqueous solution. This phenomenon was observed in the neutral pH region at room temperature (25 °C). The optimum concentration conditions for the reagents were [PFOS⁻]_T = 7 × 10⁻³ mol dm^‐3 and [Ca²⁺]_T = 1.1 mol dm^‐3. When these findings were applied to the homogeneous liquid–liquid extraction of vitamin B₁₂, the extraction percentage (E) was 83% and the concentration ratio (ie V_a/V_s, where V_a is the volume of the aqueous phase and V_s is the volume of the sedimented liquid phase) was a maximum of 149. The recovery of vitamin B₁₂ was achieved by adding the propanol–acetone (20 : 80 v/v%) mixed solvent to the sedimented liquid phase; the vitamin B₁₂ precipitated and was filtered. Both the PFOS⁻ and Ca²⁺ were removed by dissolution in the mixed solvent. The recovery percentage of vitamin B₁₂ was 78%. © 1999 Society of Chemical Industry     

Application of thermal ultrasound-assisted liquid–liquid micro-extraction coupled with HPLC-UV for rapid determination of synthetic phenolic antioxidants in edible oils

A simple, fast, and reliable liquid–liquid micro-extraction (LLME) method assisted by thermal ultrasound approach was developed for simultaneous determination of synthetic phenolic antioxidants (SPAs) in edible oils by high-performance liquid chromatography equipped with ultraviolet detector (HPLC-UV). The synthetic antioxidants were propyl gallate (PG), butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), and butylated hydroxyltoluene (BHT). The best extraction conditions were observed were methanol/acetonitrile (1:1, v/v) as the solvent, ultrasound at 4 min, and a temperature of 40°C. The linearity of the calibration curves for the optimum conditions were R² > 0.989 for all of the SPAs in a range from 1–200 μg ml⁻¹. Relative standard deviation (RSD %) for five analysis was in range of 2.83% to 4.21%. Limit of detection (LOD) and limit of quantification (LOQ) were obtained in range of 0.012–0.06 and 0.04–0.2 μg g⁻¹, respectively. With regard to recovery, a range of 91%–116% was calculated for the spiked edible oils.     

Studies on solvent extraction of La(III) using [A336][NO3–] and modeling by statistical analysis and neural network

Solvent extraction of La(III) from acidic nitrate medium has been studied with [A336][NO₃^–] in kerosene. The factors affecting the extraction of La(III) like equilibration time, nitrate ion, extractant and La(III) concentrations, aqueous acidity, O/A ratio variation, nature of diluent, and temperature have been investigated. McCabe-Thiele diagram has been plotted to find out the actual number of theoretical stages needed for complete extraction of lanthanum. The solvent has been successfully regenerated for further use after stripping of the metal. IR studies of [A336][NO₃^–] and La(III) loaded [A336][NO₃^–] have been carried out. Modeling of extraction data has been done using Multiple linear regression analysis and Artificial Neural Network, and the performances have been compared. Error in each case was evaluated in terms of R² and Root mean squared error (RMSE). Maximum extraction of La(III) was 82% when 0.6 M [A336][NO₃^–] was used for extraction. About 98% of the metal has been recovered using 0.2 M HNO₃ as stripping agent. Extractive separation of La(III) and Sm(III) was maximum (β = 65.2) using 0.1 M [A336][NO₃^–]. IR studies revealed formation of lanthanum complex in the extraction process. Artificial Neural Network proved to be better over Multiple linear regression in data prediction.     

Liquid membrane transport and separation of Zn2+ and Cd2+ from sulfate media using organophosphorus acids as mobile carriers

The transport and separation of Zn²⁺ and Cd²⁺ from binary sulfate solutions in a supported liquid membrane using di(2‐ethylhexyl)phosphoric acid (D2EHPA) and 2‐ethylhexylphosphonic acid mono‐2‐ethylhexyl ester (PC88A) as mobile carriers was studied. Batch solvent extraction experiments were conducted to obtain the reaction stoichiometries. Experiments were performed at different metal concentrations (1.4–14.5 mol m^?3), metal concentration ratios (0.4–9.2), pH (2–5), and carrier concentrations (0.1–0.6 mol dm^?3). A mass transfer model was proposed that considers diffusion in the aqueous feed and strip stagnant layers, and within the membrane. The interfacial reactions were assumed to approach equilibrium instantaneously. It was shown that the proposed model was applicable for binary Zn²⁺/Cd²⁺ systems (standard deviation, 5%). The larger separation factors of Zn²⁺ over Cd²⁺ with PC88A than D2EHPA under equilibrium (batch solvent extraction) and non‐equilibrium (liquid membrane) conditions were also evaluated and discussed. Copyright © 2003 Society of Chemical Industry     

Extraction and separation of HCl and Rh(III) with trioctylamine

In this paper the use of trioctylamine (TOA) to extract HCl from Rh(III)-containing solutions generated by a supported liquid membrane (SLM) process is investigated. TOA was found to extract HCl readily (in a single contact of 3 min duration) at a molar ratio [HCl]/[TOA] equal to one. For each mole of HCl extracted an equivalent amount of H₂O was found to be extracted as well. As far as Rh(III) extraction of TOA is concerned this was found to depend on the age of the solution and the Cl⁻ concentration. Prolonged aging (accelerated by heating) or [Cl⁻]⩾3 M was found to completely suppress the extraction of Rh(III) by TOA. The chloride ion concentration effect was attrib-uted to Le Chatelier's principle while the aging effect was attributed to the aquation/conversion of the extractable RhCl₆³⁻ complexes to RhCl₅(H₂O)²⁻. The aquation reaction was studied with UV–Visible spectroscopy in an effort to substantiate the solvent extraction (SX) results. On the basis of the findings of this work a combined SLM/SX process flowsheet is proposed according to which the Rh(III) and HCl co-transported through the supported liquid membrane are co-extracted by TOA and subsequently separated by differential stripping; Rh(III) with 0·5 M HCl/3 M Cl⁻ medium and HCl with NAOH.     

Extraction of Radio-Strontium from Nitric Acid Medium Using Di-tert-Butyl Cyclohexano18-Crown-6 (DTBCH18C6) in Toluene–1-Octanol Diluent Mixture

An alternative extraction system to the SREX solvent using a diluent mixture comprising 4,4′(5′)di-tert-butylcyclohexano-18-crown-6 (DTBCH18C6) in 80% toluene–20% 1-octanol was developed and evaluated for Sr(II) extraction from pressurized heavy water reactor simulated high level waste (PHWR-SHLW). The acid uptake (5.7%) by the present solvent was significantly lower as compared to that by the SREX solvent (21%) which used 100% 1-octanol as the diluent. The extracted species conformed to the ion-pair [Sr(DTBCH18C6)(H₂O)_x]²⁺·2[(NO₃)(H₂O)_y]^?. Studies on Sr(II) extraction as a function of nitric acid concentration indicated more favorable extraction and stripping with the present solvent as compared to the SREX solvent. Loading studies with 0.025 M DTBCH18C6 in the diluent mixture, carried out using the Sr carrier, indicated a decrease in D_Sr from 3.1 with 10 ppm Sr carrier to 1.62 with 100 ppm Sr carrier. Other important physical parameters relevant for the extraction processes such as phase separation time (dispersion number), viscosity, and density were also measured. The radiation stability and reusability of the solvent was also investigated. In sharp contrast to the SREX solvent, with increasing absorbed dose the proposed solvent showed an increase in Sr extraction and an increased acid uptake.     

Mass transfer modeling of membrane carrier system for extraction of Ce(IV) from sulfate media using hollow fiber supported liquid membrane

A theoretical and experimental study on the extraction and stripping of Ce(IV) ions from sulfate media using microporous hydrophobic hollow fiber supported liquid membrane has been performed. The experiments were made in the recycling mode. Tri-n-octylamine (TOA) was used as extractant diluted in kerosene and sodium hydroxide was use as strip solution. The mathematical model focused on the extraction side of a liquid membrane system. The aqueous feed mass transfer coefficient (k_i) and the organic mass transfer coefficient (k_m) which were calculated from the model were 9.47 X 10^-2 and 6.303 cm/s, respectively. Therefore, the rate controlling step is the diffusion of the cerium complex across a liquid membrane. In addition, the mass transfer modeling was performed and the validity of the developed model was evaluated with experimental data and found to tie in well with the theoretical value when the concentration of TOA was higher than 5% (v/v).     

Solvent extraction of uranium from acidic sulfate media by Alamine® 336: computer simulation and optimization of the flow‐sheets

BACKGROUND: A series of nine conventional and non‐conventional flow‐sheets have been considered for the recovery of uranium from acidic sulfate solution by liquid–liquid extraction with 0.146 mol L^?1 Alamine^® 336 in kerosene modified with 5% w/w 1‐tridecanol and stripping with a 199 g L^?1 Na₂CO₃ solution. The reference flow‐sheet was a classical counter‐current configuration with four mixers–settlers in the extraction stage and three mixers–settlers in the stripping stage. The others flow‐sheets possessing a total of eight mixers–settlers are unusual combined solvent extraction flow‐sheets with one or two independent extraction stripping loops and with one or two feed inlets. RESULTS: The configuration of the flow‐sheets strongly influences the extraction performance of the process depending on the working conditions (feed, stripping and solvent flow rates). The presence of two independent extraction–stripping loops may allow the delay of the saturation phenomenon encountered in the conventional flow‐sheet and thus, to operate at higher feed flow rates without loss of performance, as far as the residual fraction in the raffinate and the concentration factor in the stripping solution are concerned. Furthermore, the presence of a modification in the non‐conventional flow‐sheets with two independent extraction–stripping loops and two feed inlets leads to interesting configurations for uranium recovery from less concentrated solutions, such as heap leach solutions. CONCLUSION: The use of non‐conventional flow‐sheets is interesting as it allows the process of uranium (VI) recovery by liquid–liquid extraction to be improved. Copyright © 2009 Society of Chemical Industry     

Extraction of phenolic compounds from spent blackberry pulp by enhanced-fluidity liquid extraction

This research describes an enhance-fluidity liquid extraction process for extracting total phenolic compounds (TPC) from spent blackberry pulp (SBP) using a modified solvent (CO₂–ethanol mixture). Effects of particle size (from 1,400 to 180 μm), pressure (150–300 bar), and cosolvent (ethanol)-to-solid ratio (64, 128, and 192 mL ethanol/32 g solid) on the extraction of TPC at 40°C were investigated. Experimental data was processed using the Sovova's model to obtain the solubility of TPC in the modified solvent. The Peng–Robinson equation of state was used to correlate the solubility of phenolic compounds at high pressures. Results indicated that particle sizes ranging from 600 to 850 μm and pressure of 300 bar allowed obtaining extracts with higher antioxidant activity (94.71% of inhibition) and TPC content (11.59 mg GA/g SBP). High pressure and the modified solvent increased the solubility up to 3.4 × 10⁻⁴ (mol fraction).     

Production of ethanol by continuous fermentation and liquid–liquid extraction

A continuous pilot plant was constructed for fermentation production of ethanol, using liquid–liquid extraction to remove the product and with recycle of the fermented broth raffinate. The plant was operated for up to 18 days with feed glucose concentrations in the range 10·0–45·8% (w/w). The solvent was n-dodecanol and immobilised yeast was used to overcome the problem of emulsification. The concentration of by-products in the fermented broth had no adverse effect on the rate of ethanol production. A mathematical model to predict the time required for achievement of 99% of the steady-state by-products concentrations was shown to be in good agreement with the experimentally determined concentration of the main by-product, glycerol. At a feed glucose concentration of 45·8% (w/w), the aqueous purge was equivalent to 2·8 m³ of effluent per m³ of ethanol produced and represented a 78% reduction in the volume of the aqueous purge compared with using a feed containing 10% (w/w) glucose.     

Separation of Radiogallium from Zinc Using Membrane-Based Liquid-Liquid Extraction in Flow: Experimental and COSMO-RS Studies

ABSTRACT

A switch from batch to continuous manufacturing of gallium-68 (⁶⁸Ga) and ⁶⁸Ga-labeled pharmaceuticals can be advantageous, as it recycles isotopically-enriched zinc-68 (⁶⁸Zn), removes pre- and post-irradiation target manipulations, and provides scalability via dose-on-demand production. Herein we report efficient extraction of radiogallium (^66,67,68Ga = *Ga) from ZnCl₂/HCl solutions in batch and in flow using a membrane-based liquid-liquid separator. From 5.6 M ZnCl₂/3 M HCl, a 1/2 (v/v) diisopropyl ether (ⁱPr₂O)/trifluorotoluene (TFT) solvent extracts 76.3 ± 1.9% of *Ga and 1.9 ± 1.6% of Zn in flow using a single pass through. From 1 M ZnCl₂/6 M HCl, a 1/2 (v/v) n-butyl methyl ether (n-BuOMe)/TFT solvent extracts 95.7 ± 2.0% of *Ga and 0.005 ± 0.003% of Zn in flow. TFT plays a key role in controlling the interfacial tension between the aqueous and the organic phases, ensuring clean membrane-based separation. The process did not extract Cu, Mn, and Co but did extract Fe. Using HGaCl₄ and ZnCl₂ as the extractable species, the COSMO-RS theory predicts the solvation-driven extraction of Ga and Zn with a mean unsigned error of prediction of 4.0% and 3.4% respectively.     

A Rapid Method for Simultaneous Analysis of Lignan and γ‐Tocopherol in Sesame Oil by Using Normal‐Phase Liquid Chromatography

A novel method for rapid and simultaneous analysis of three lignans and γ‐tocopherol in sesame oil has been established based on a one‐step solvent extraction followed by normal‐phase liquid chromatography. The briefness of the experimental procedure, use of 5 mL of n‐hexane/isopropanol (98:2, v/v) for extraction without any further cleanup process, short analysis time (10 min), and excellent sensitivity and selectivity demonstrated the advantages of this practical and efficient method. All the analytes exhibited satisfactory recoveries ranging from 95.4 to 103.4% at three spiked levels, with the relative SD ranging from 1.1 to 4.4%. The limits of quantitation of this method for four analytes were in the range of 0.3–1.0 μg g^?1. The validated method was successfully applied to the coinstantaneous determination of lignan and γ‐tocopherol in five real sesame oil samples. Furthermore, the results of this study were compared with previously reported method and standard method.     

Cloud Point-Dispersive Liquid–Liquid Microextraction for Extraction of Organic Acids from Biological Samples

A new method combining cloud point extraction (CPE) with dispersive liquid–liquid microextraction (DLLME) named “cloud point‐dispersive liquid–liquid microextraction (CP‐DLLME)” was presented in this work for the first time for the determination of organic acids as model compounds in biological samples using high performance liquid chromatography and UV detection (HPLC–UV). Water (disperser solvent) containing tert‐octylphenol ethoxylate (7.5EO) as extraction solvent, was rapidly injected into a warmed sample solution and cloudy state formed immediately. After that, phase separation was performed by centrifugation. The surfactant‐rich phase was diluted with acetonitrile and injected into a HPLC–UV apparatus. The influence of several important parameters on the extraction efficiencies was evaluated. Under optimized experimental conditions, the calibration graphs were linear in the range of 0.06–1,500 µg L^?1 for target analytes. Coefficient of determination (r²) ranged from 0.9985 to 0.9994. The limits of detection were in the range of 0.05–17.1 µg L^?1. The new method was successfully applied with satisfactory results for analysis of target analytes in spiked samples. The relative mean recoveries of the spiked samples ranged from 91.8 to 107.1 % with relative standard deviations in the range of 2.1 to 4.3 %.     

Separation and recovery of vanadium from leached solution of spent residuehydrodesulfurization (RHDS) catalyst using solvent extraction

Leached solution, generated by oxalic acid washing of spent residue hydrodesulfurization (RHDS) catalyst, was used for separation and recovery of vanadium. First of all, solvent extraction, using mixture of 20% (v/v) Alamine-336 and 5% (v/v) tri-butyl phosphate (TBP) as a phase modifier, was conducted to extract molybdenum completely at pH 0.50. Then molybdenum-free solution was used for vanadium extraction at pH 1.25 with 20% Alamine-336 and 5% TBP. Stripping of vanadium from loaded organic solution was performed with 1.5 M H₂SO₄ at O/A phase ratio of 5:1 where more than 99% of vanadium was stripped in two stages. The stripped vanadium solution was further processed by precipitating with ammonium hydroxide to recover ammonium-meta-vanadate which was calcined to obtain vanadium pentoxide. Finally a conceptual process was established for recovery of high purity vanadium pentoxide from oxalic acid leached solution of spent residue hydrodesulfurization (RHDS) catalyst.     

Modeling the Kinetics of Antioxidant Extraction from Origanum vulgare and Brassica nigra

In the present research work, the effect of solvents, particle size, solvent/solid ratio, and temperature on the extraction efficiency of oregano (Origanum vulgare) and mustard (Brassica nigra) were investigated. The extraction process proceeded at a fast rate followed by a slower one. Particle size, solvent type, solvent/solid ratio and temperature had a positive effect on the extraction process, and maximum extraction was achieved by ethanol. Extraction kinetics was determined with a mathematical model derived from Fick's second law. The results were verified with Fick's diffusion model for extraction kinetics in all experiments, which provided the initial rate and extent of solid–liquid extraction. Antioxidant values were determined using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2′-azino-Bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The extracts of O. vulgare and B. nigra prepared using ethanol showed optimal antioxidant activity.     

Micelle-Mediated Extraction and Cloud Point Preconcentration of Chlorophylls from Spinach

A micelle-mediated extraction and cloud point preconcentration of chlorophylls method was developed. Non-ionic surfactant (Genapol X-080) was employed as an alternative and effective extraction solvent. The optimal extraction parameters based on the micelle extraction technique were determined. Under optimal conditions, i.e., 5% Genapol X-080 (v/v), pH 9.0, liquid/solid ratio of 10:1 (mL g^?1), ultrasonic-assisted extraction for 30 min, extraction amount reached the highest value. For the preconcentration of chlorophylls by cloud point extraction (CPE), the solution was incubated at 50° for 30 min, and 0.1 g mL^?1 sodium chloride was added to the solution to facilitate the phase separation. The microstructure of coacervate phase after CPE was explored with transmitting electron microscopy. The preconcentration factor for chlorophylls was about 12.5, the extraction recovery approached 99.2%, and the loading capacity was about 1 mg mL^?1. Thus coupling of ultrasonic-assisted micelle extraction and cloud point extraction could be employed as a new and effective technique for the rapid extraction and preconcentration of chlorophylls from plants such as spinach.     

Extraction and separation of D/L-lactic acid in simulated fermentation broth

The recovery of lactic acid from fermentation broth plays an important part in production of lactic acid. In this case, the extraction of lactic acid from simulated fermentation broth was processed by tri-n-octylamine dissolved in oleyl alcohol. The extraction efficiency was investigated with several variables, and the optimal condition of extraction of lactic acid (10 mg mL⁻¹) from aqueous solution was tri-n-octylamine/oleyl alcohol (30/70, v/v) and solvent phase/ fermentation (1/2, v/v) stirred for 60 min under room temperature. The optimal back extraction of lactic acid was obtained by hot water (∼90 °C) with solvent phase/water (1/4, v/v). The back extracted racemic lactic acid was direct enantiomeric analyzed and separated by chiral ligand chromatography due to strict requirement of absolute configuration in pharmaceutical field and food science. The effect of various parameters on enantioselectivity was discussed and the (L)-phenylalaninamide·HCl (6.0 mmol L⁻¹) and CuSO⁴·5H₂O (3.0 mmol L⁻¹) dissolved in methanol/water (5/95, v/v) at pH=6.0 was the suitable mobile phase for chiral ligand exchange separation of (D, L)-lactic acids. By the investigations, a convenient systemic method was established for extraction and separation of (D, L)-lactic acid.     

Biosynthesis of carbomycin,its extraction,purification and mode of action on Bacillus subtilis NRRL B-543

A fermentation medium containing (g dm^?3)—glucose, 10.0; soyabean meal, 10.0; NaCl, 5.0 and CaCO₃, 1.0 in distilled water—was used in the biosynthesis of the macrolide antibiotic carbomycin. Maximum yield of carbomycin was obtained after 120 h fermentation. Carbomycin was extracted by different organic solvents adjusted to different pH values. Extraction of the antibiotic was possible when the pH of the fermentation broth was neutral (6.5–7.5) with all organic acids used, but the most efficient organic solvent suitable for extraction of carbomycin was chloroform at a pH of 6.5. Further purification was carried out by preparative thin layer chromatography. The most efficient separation into carbomycin A and carbomycin B was obtained using a solvent system of ethanol-hexane-water [90:10:0.15 (v/v)]. Carbomycin inhibited the biosynthesis of the anabolising cellular constituents phosphoprotein, ribonucleic and deoxyribonucleic acids in Bacillus subtilis NRRL B-543.     

Squalene from Fish Livers Extracted by Ultrasound-Assisted Direct In Situ Saponification: Purification and Molecular Characteristics

An ultrasound-assisted direct in situ saponification (U-DS) process was developed to extract unsaponifiable matter (rich in squalene) from the livers of four fish species, sea bass, skipjack tuna, gray bamboo shark, and spot-tail shark. The conventional solvent extraction method was used for comparison. Box–Behnken experimental design (BBD) was adopted to optimize the independent variables including the biomass/methanol ratio (1:3 to 1:9 w/v), 50% KOH volume (1–12 mL), and sonication time (0–30 min) over the unsaponifiable yield. With the conventional process, the yield of squalene was 0.10 ± 0.02 to 5.52 ± 0.06 g (100 g)⁻¹, whereas the U-DS process rendered the yield of 0.13 ± 0.03 to 6.86 ± 0.05 g (100 g)⁻¹, depending on the fish species. After extraction, squalene was further concentrated (purity ≥60%) from all fish species via fractional crystallization (yield of squalene concentrate ranged from 48.35% to 74.49%) and purified using a silica gel column with a maximum recovery up to 98%. For all the fractions, components were examined using thin layer chromatography (TLC). Squalene was qualitatively and quantitatively analyzed using reversed-phase high-performance liquid chromatography (RP-HPLC). Entire extraction processes yielded squalene with a purity of ≥94%. Fourier transform infrared (FTIR) analysis confirmed the native structure of squalene with six nonconjugated bonds, suggesting no degradation of squalene taken place during the U-DS process. Thus, the U-DS process along with fractionation and purification could be used for recovering the squalene from fish livers.