Pressurized Liquid Extraction as a Promising and Economically Feasible Technique for Obtaining Beta-Ecdysone-Rich Extracts from Brazilian Ginseng (Pfaffia glomerata) Roots

Pressurized liquid extraction was used to obtain beta-ecdysone-rich extracts from Brazilian ginseng (Pfaffia glomerata) roots. The effects of temperature, pressure, and solvent on extraction yield, beta-ecdysone content, and antioxidant activity were determined. Extraction yield increased with temperature up to 25% (dry basis) while the selectivity decreased. The use of Ethanol:Water (80:20 v/v) as solvent produced extracts with the highest antioxidant activity. Beta-ecdysone recovery was maximized using pure ethanol. In the first hour of extraction, approximately 70% of the total yield and 74% of the total beta-ecdysone mass is obtained. The cost of manufacturing significantly decrease as the extractor capacity increased.     

Effect of vapor phase ethylenediamine crosslinking of matrimid on alcohol vapor sorption and diffusion

This work examines the sorption, diffusion, and polymer relaxation behavior for water and C1‐C7 alcohol vapors at 30 °C in ethylenediamine vapor‐phase crosslinked Matrimid. Ethylenediamine is sufficiently volatile that crosslinking can occur by exposing the polymeric film to saturated vapor, in contrast to more conventional means of dissolving the crosslinker in a solvent and immersing the polymeric film in the solution. The vapor‐phase exposure method avoids the use of additional solvent and undesired solvent‐induced swelling. Sorption isotherms demonstrate that water and C1‐C5 alcohols do not appreciably differ for unmodified and crosslinked Matrimid; however, an approximate 90% reduction in sorption was determined for hexanol and heptanol. A minor impact on diffusion coefficients for water, methanol, and ethanol was observed, while those of propanol and butanol were reduced over an order of magnitude. Relaxation kinetics were similarly unchanged for water and C1‐C3 alcohols, while being significantly reduced for butanol and higher alcohols. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44771.     

Sensitive Colorimetric Detection of Explosive 2,6‐Bis(picrylamino)pyridine after Preconcentration by Dispersive Liquid‐Liquid Microextraction

An experimental investigation for sensitive spectrophotometric detection of explosive, 2,6‐bis(picrylamino)pyridine (BPAP) using dispersive liquid‐liquid microextraction was carried out. Based on this procedure, which is a dispersive‐solvent‐free technique, the extractant is dispersed in the aqueous sample solution using Aliquat 336 (acted as disperser agent and carrier to extraction solvent) and monitored with microvolume UV/Vis spectrophotometer. The effect of different variables such as pH, concentration of sodium hydroxide, type and volume of extraction solvent, concentration of Aliquat 336 solution and coexisting substances were systematically investigated and optimized. Interference tests showed that the developed method has a good selectivity and could be used conveniently for determination of explosive analyte. The proposed method is capable of determining BPAP over a range of 2.0–150.0 ng mL⁻¹ with a limit of detection 1.0 ng mL⁻¹. Relative standard deviations (RSD) for 20.0 and 80.0 ng mL⁻¹ of BPAP were 3.3 and 1.2 % (n=10), respectively. This colorimetric method was applied to determine BPAP in different water and soil samples.     

Dehydration of light oil by pervaporation using poly(vinyl alcohol)–poly(acrylic acid‐co‐maleic acid) membranes

A new blended membrane was prepared and tested by pervaporation of light oil, a mixture of five alcohols plus water. The blended membrane was synthesized by blending poly(vinyl alcohol) and poly(acrylic acid‐co‐maleic acid) sodium salt in the presence of sulfuric acid to dope the reaction. We tested several membranes in order to choose the adequate composition to have the best permselectivity. The PVA(60)–PAA‐co‐maleic acid(40) membrane was selected as it was found to be highly selective. Sorption experiments were performed using binary and ternary water–alcohol solutions. The influence of temperature and feed composition on the selectivity and flux in pervaporation was investigated for two different binary mixtures (water/ethanol, water/isobutanol) and one ternary system (water/ethanol/isobutanol). This membrane presents good permselective properties, high water flux, and good selectivity and can even be used for high‐water activities The performances of this new membrane were compared to those obtained with the PVA(90)–PAA(10) membrane synthesized recently: The fluxes observed for the water–ethanol separation were of the same order of magnitude but the selectivity was found to be much higher. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1709–1716, 2002     

Liquid–liquid equilibrium extraction of ethanol with mixed solvent for bioethanol concentration

The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process.Furfural and benzaldehyde were selected as extraction solvents,with which the solubility of water is small,expecting large distribution coefficient of ethanol.The liquid–liquid two-phase region was the largest with m-xylene solvent,followed by benzaldehyde and furfural.The region of two liquid–liquid phase became larger with the mixed solvent of m-xylene and furfural than that with furfural solvent.The NRTL model was applied to the ethanol–water–furfural–m-xylene system,and the model could well express the liquid–liquid equilibrium of the system.For any solvent used in this study,the separation selectivity of ethanol relative to water decreased as the distribution coefficient of ethanol increased.The separation selectivity with m-xylene was the largest among the employed solvents,but the distribution coefficient was the smallest.The solvent mixture of furfural and m-xylene showed relatively high distribution coefficient of ethanol and separation selectivity,even in the higher mass fraction of m-xylene in the solvent phase.The ethanol extraction with a countercurrent multistage extractor by a continuous operation was simulated to evaluate the extraction performance.The ethanol content could be concentrated in the extract phase with relatively small number of extraction stages but low yield of ethanol was obtained.     

Ethanol and water capacities of alcohols: A molecular dynamics study

The extended hydrogen bond networks formed by alcohols are good indicators of their capacities to hold water. Results from molecular dynamics simulations on 24 linear alcohol isomers containing 6-12 carbon atoms show the effects of hydroxyl location on bulk hydrogen-bonded structures. Calculated oxygen-oxygen radial distributions obtained from simulations were correlated to experimental liquid-liquid solvent extraction studies involving ternary water/ethanol/alcohol systems. It was found that hydroxyl group location determines the primary structure of the bulk alcohol's hydrogen bond network and that an alcohol's capacity for water correlates directly to the size of this network.     

Optimization of cordycepin extraction from cultured Cordyceps militaris by HPLC‐DAD coupled with uniform design

BACKGROUND: Uniform design was used to optimize the ultrasonic‐assisted extraction of cordycepin from cultured Cordyceps militaris. The peak area of cordycepin identified using high performance liquid chromatography (HPLC) at a detection wavelength of 260 nm was considered the detection index. Three factors, ethanol concentration, extraction time and volume ratio of solvent to sample were studied. Optimal quadric polynomial step by step regression was applied to process the experimental results. RESULTS: Results show that the main factors affecting cordycepin extraction yield were the volume ratio of solvent to sample, extraction time and ethanol concentration, in that order. Cordycepin extraction yield reached a peak with ethanol concentration 20.21%, extraction time 101.88 min, and volume ratio of solvent to sample 33.13 mL g^?1. An extraction model was developed based on the findings. CONCLUSION: A direct, reliable and accurate assay has been developed for the quantification of cordycepin in cultured Cordyceps militaris by a HPLC‐DAD method. The validation procedure confirmed that this method is appropriate for the quality control of cordycepin. Results show that the uniform experimental design approach is useful for finding polynomial functions describing the relationships between variables and responses and to find the best experimental conditions for the extraction of cordycepin in the experimental domain considered. Copyright © 2007 Society of Chemical Industry     

Citrus Essential Oil Deterpenation by Liquid‐Liquid Extraction

The object of the present work is to evaluate the possibility of carrying out the deterpenation of the citrus essential oil by using a mixture of ethanol and water as a solvent for liquid‐liquid extraction. Liquid‐liquid equilibrium has been determined for limonene + linalool + ethanol + water quaternary system at 298.15 K. Partitioning and selectivity of extraction were analyzed. Experimental data were correlated using the UNIQUAC and NRTL equations and the energetic parameters of these models at this temperature are determined.     

Extraction of lipids from Yarrowia Lipolytica

BACKGROUND: Microorganisms have often been considered for the production of oils and fats as an alternative to agricultural and animal resources. Extraction experiments were performed using a strain of the yeast Yarrowia lipolytica (Y. lipolytica), a high‐lipid‐content yeast. Three different methods were tested: Soxhlet extraction, accelerated solvent extraction (ASE) and supercritical carbon dioxide (SCCO₂) extraction using ethanol as a co‐solvent. Also, high pressure solubility measurements in the systems ‘CO₂ + yeast oil’ and ‘CO₂ + ethanol + yeast oil’ were carried out. RESULTS: The solubility experiments determined that, at the conditions of the supercritical extractor (40 °C and 20 MPa), a maximum concentration of 10 mg of yeast oil per g of solvent can be expected in pure CO₂. 10% w/w of ethanol in the solvent mixture increased this value to almost 15 mg of yeast oil per g of solvent. Different pretreatments were necessary to obtain satisfactory yields in the extraction experiments. The Soxhlet and the ASE method were not able to complete the lipid extraction. The ‘SCCO₂ + ethanol’ extraction curves revealed the influence of the different pretreatments on the extraction mechanism. CONCLUSION: Evaluating the effectiveness of a given pretreatment, ASE reduced the amount of material and solvent used compared with Soxhlet. In all three cases, the best total extraction performance was obtained for the ethanol‐macerated yeast (EtM). Addition of ethanol to the solvent mixture enhanced the oil solubility. Oil can be extracted from Y. lipolytica in two different steps: a non‐selective ethanol extraction followed by TAG‐selective SCCO₂ purification. © 2012 Society of Chemical Industry     

Separation of monoglycerides,diglycerides, and triglycerides by liquid-liquid extraction

Summary Ternary-equilibrium data were obtained at 60°C. for mono- and dilaurin, and di- and trilaurin with aqueous alcohols. Distribution between phases and solvent selectivity are shown graphically. Variation of solvent polarity by water addition caused a shift in the phase boundary curve so that either Type 1 or Type 2 diagrams could be obtained. Pure mono-, di-, and trilaurin mixtures, and commercial monoglycerides were studied as quaternary systems for monoglyceride distribution with 50 wt.-% aqueous ethanol. Pure and commercial systems showed similar distribution tendencies even with differences in molecular weight and degree of unsaturation. Solvent selectivity data (β) for quaternary systems were predicted from ternary systems studied with a common solvent. Aqueous ethanol will separate mixtures of mono-, di-, and triglycerides by selective liquid-liquid extraction; however the literature favors more complex systems based on two immiscible solvents. Continuous countercurrent extraction of commercial monoglycerides by 40% aqueous ethanol solution in a four-stage agitated column gave a 15% over-all stage efficiency. Cooling the extract to 0°C. precipitated 96.6% of the extract solids. Flow diagrams were prepared for batch and continuous extraction processes. The findings reported in this paper were included in a thesis submitted by J. A. Monick to the Graduate Division of the College of Engineering of New York University in partial fulfillment of the requirements for the degree of Doctor of Engineering Science. Presented at the fall meeting, American Oil Chemists’ Society, in Philadelphia. Pa., October 10–12, 1955.     

Optimization of Microwave‐Assisted Extraction of Flavonoid from Radix Astragali using Response Surface Methodology

Abstract

Response surface methodology (RSM) was applied to predict optimum conditions for microwave‐assisted extraction (MAE) of flavonoid from Radix Astragali. A central composite design was used to monitor the effect of temperature, extraction time, solvent‐to‐material ratio, and the ethanol concentration on yield of total flavanoid (TFA). Optimum extraction conditions were predicted as 108.2°C, 26.7 min, 23.1 ml/g solvent‐to‐material ratio and 86.2% ethanol. The maximum yield 1.234±0.031 mg/g was close to the yield of Soxhlet and higher than that of ultrasound assisted extraction and heat reflux extraction. MAE was an effective alternative to conventional extraction methods.     

Development of thin layer polymers to concentrate and detect aquatic contaminants

Poly(dimethylsiloxane) (PDMS) and a poly(DMS‐styrene) block copolymer were compared as extraction and optical detection media for hydrophobic compounds in water and water/ethanol solutions. Partitioning to both polymers increased exponentially with increased percent water in ethanol. Partition coefficients to the copolymer were 10–30‐fold higher than to PDMS. Ultraviolet absorbance spectra of pyrene showed a 4‐nm red‐shift in copolymer versus PDMS, providing evidence of π–π interactions, accounting for greater partitioning. The extinction coefficient coefficient of pyrene at 334 nm was twice as high in the copolymer as in PDMS. The combination of higher affinity for polycyclic aromatic hydrocarbons with higher absorbance make poly(DMS‐styrene) copolymers promising material for extraction and in situ detection of hydrophobic aromatic compounds in water. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Investigation of liquid–liquid phase equilibria for reactive extraction of lactic acid with organophosphorus solvents

BACKGROUND: Lactic acid is a versatile commodity chemical with a variety of applications. Synthesis of lactic acid either through fermentation of carbohydrates or through chemical synthesis is state of the art. Separation from dilute aqueous solution is complex and accounts for the major part of production costs. Reactive extraction based on reversible adduct formation is a promising alternative for the separation of lactic acid. RESULTS: Extraction was carried out with the organophosphorus solvents tri‐n‐butyl phosphate, tri‐n‐octylphosphine oxide and Cyanex 923. Shellsol T was used as diluent. Partition coefficients increase with increasing extractant content and decreasing temperature. Cyanex 923 has several advantages compared with tri‐n‐butyl phosphate and tri‐n‐octylphosphine oxide with respect to lactic acid distribution and hydrodynamic properties. Liquid‐liquid phase equilibria for lactic acid extraction with Cyanex 923 were modeled. Selectivity of lactic acid extraction with respect to glycolic acid and formic acid was discussed. CONCLUSION: The organophosphorus extractant Cyanex 923 was found to be an appropriate solvent for lactic acid extraction from aqueous solutions. Experimental data and model data based on the Law of Mass Action showed good agreement. Lactic acid extraction from multi‐acid solution showed good selectivity compared with glycolic acid. Lactic acid selectivity is low with respect to formic acid. © 2012 Society of Chemical Industry     

Highly efficient separation of strongly hydrophilic structurally related compounds by hydrophobic ionic solutions

The selective separation of strongly hydrophilic structurally related compounds in aqueous solutions is a long‐standing challenge due to a trade‐off between separation selectivity and capacity. This work shows a new method to separate strongly hydrophilic structurally related compounds through hydrophobic ionic solution‐based liquid‐liquid extraction, with L‐ascorbic acid 2‐glucoside (AA‐2G) and L‐ascorbic acid as model compounds. Extraordinary distribution coefficient, superb molecular selectivity, large extraction capacity and good recyclability without using strong acids and salts were all achieved, with a small consumption of phosphonium bromide ionic liquid and aprotic molecular diluent. The essence of this method is the successful combination of both strong hydrogen‐bond basicity and good hydrophobicity along with significant preferential solvation phenomena of the constructed ionic solutions. Even if at a high feed concentration of 100 mg/mL, the purity of AA‐2G could be greatly elevated from 50% to 96.2% with an ultrahigh yield of almost 100% after five‐stage countercurrent extraction. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1373–1382, 2018     

Sorption and desorption parameters of water or ethanol in light‐cured dental dimethacrylate resins

Two cycles of sorption/desorption of water or ethanol by light‐cured dental resins of bisphenol A glycol dimethacrylate (Bis‐GMA), bisphenol A ethoxylated dimethacrylate (Bis‐EMA) urethane dimethacrylate (UDMA) triethylene glycol dimethacrylate and decanediol dimethacrylate (D₃MA) were studied. The experimental curves m_t = f(t) taken for the first water sorption by poly‐Bis‐GMA, poly‐Bis‐EMA and poly‐UDMA showed a maximum. A maximum was also observed in the curve obtained for first sorption of ethanol by poly‐Bis‐GMA. In all other cases, the curves for sorption or desorption of water or ethanol showed Fickian behavior. The experimental data obtained for first sorption of water or ethanol were perfectly fitted to a new proposed equation, which predicts water or ethanol sorption with simultaneous extraction of unreacted the monomer. This equation gave us the possibility for the determination of the diffusion coefficient of the extraction of the unreacted Bis‐GMA during the water and ethanol sorption, as well as the diffusion coefficient of the extraction of the unreacted Bis‐EMA and UDMA during the water sorption. The maximum water or ethanol absorbed at equilibrium and the diffusion coefficient are determined from the second sorption/desorption cycle during which the extraction of the monomer is negligible. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Cloud point and solvent extraction study of uranium(VI) by 8‐hydroxyquinoline

BACKGROUND: Cloud point extraction (CPE) is an attractive alternative to solvent extraction. However, comparisons between both techniques are lacking. In this paper, the extraction of uranium(VI) using 8‐hydroxyquinoline (HQ) as chelating agent was studied by CPE using Triton X‐114 as non‐ionic surfactant and by solvent extraction using CHCl₃ as diluent. RESULTS: Using CPE, a quantitative extraction was observed for pH higher than 4.5 with a HQ/U ratio of 10. Using solvent extraction an increase in the HQ/U ratio up to 50 is necessary to obtain a near quantitative extraction. Both extraction systems were then compared with respect to the nature of extracted species, and the extraction constants determined using log‐log analysis of the extraction data. In the solvent extraction system, the extracted species were identified as UO₂Q₂ and the corresponding extraction constant was found to be log k_ex = ? 3.6 ± 0.2 on the molar scale. Considering that UO₂Q₂ is also the extracted species in CPE, a slightly higher extraction constant, i.e. log k_ex = ? 2.5 ± 0.3, was found. CONCLUSION: Such a small difference in favour of the CPE system may arise from the combination of various phenomena, including effects of temperature and effects of ‘extractant environment’. However, a change in the nature of the extracted species, namely from UO₂Q₂ in the solvent extraction system to the formation of adducts, i.e. UO₂Q₂(HQ) and UO₂Q₂(HQ)₂ in the CPE system, due to higher HQ concentration in the surfactant‐rich phase compared with chloroform, cannot be precluded, but requires confirmation. Copyright © 2012 Society of Chemical Industry     

Ultrasonic extraction of ferulic acid from Angelica sinensis

In this paper, the extraction of ferulic acid, a pharmacologically active ingredient from the root of Angelica sinensis with ultrasonic extraction was investigated. Percolation and supercritical fluid extraction (SFE) were also employed to make comparisons with ultrasonic extraction. Three variables, which including the concentration of solvent, the ratio of solvent volume to sample (mL/g), and extraction time, were found to have great influence on ultrasonic extraction. The optimum extraction conditions were using pure ethanol with a ratio of solvent volume to sample 8:1 (mL/g) and extraction time of 30 min. Under the optimum extraction conditions, the extraction yield could reach 6.5% mass fraction, which was higher than that of SFE process with ethanol as co‐solvent and nearly a content of ferulic acid 1.0%; both the yield and the content of ferulic acid were higher than those obtained by percolation. Moreover, the time of ultrasonic extraction was significantly shortened. Overall, Ultrasonic extraction was shown to be highly efficient in the extraction of ferulic acid from Angelica sinensis.     

Solvent and Extraction Conditions Control the Assayable Phenolic Content and Antioxidant Activities of Seeds of Black Beans,Canola and Millet

The effects of extraction solvent and conditions on the total phenolic content (TPC) and antioxidant activity of black beans, canola and foxtail millet were investigated. The antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity (DRSA) and oxygen radical absorbance capacity (ORAC). Four solvent systems, namely 70 % acetone, 80 % ethanol, 80 % methanol and a mixture of acetone/methanol/water (7:7:6, v/v/v) were used. The extraction methods adopted in this study included refluxing, homogenization, cold extraction and sonication. The TPC as measured using the Folin Ciocalteu's method were 12.35–28.39, 2.43–16.73, and 1.78–5.06 µmol catechin equivalents/g dry matter (dm) for canola, black beans and foxtail millet, respectively. Aqueous acetone afforded the highest TPC for black beans and canola. Within the same solvent system used, the TPC, DRSA and ORAC obtained from different extraction techniques differed for black beans, canola and foxtail millet. The results demonstrated that the solvent system as well as method influenced the extraction of phenolic compounds and their antioxidant activities, depending on the type of matrix in which phenolics were embedded.     

Separation of NaOH by Solvent Extraction Using Weak Hydroxy Acids

Abstract

Separation of sodium hydroxide from aqueous salt solutions at elevated pH may be accomplished by use of solvent extraction with weak hydroxy acids. A series of lipophilic weak hydroxy acids, including alkyl phenols and fluorinated alcohols, has been characterized with regard to their ability to extract sodium into 1‐octanol as a function of temperature and extractant concentration. Isotherms are presented at 10, 25, and 60°C, employing extractant concentrations up to 1 M and aqueous NaOH concentrations up to 7 M. Near stoichiometric loading of all compounds tested may be achieved in a process postulated to be simple cation exchange. Extraction strength increases with the expected acidity of the hydroxy acids. Strongest extraction was observed with two alkyl phenols and 4‐n‐octyl‐α,α‐bis(trifluoromethyl)benzyl alcohol. Essentially complete removal of free hydroxide from a solution containing sodium hydroxide, nitrate, and aluminate was accomplished using 1 M 4‐tert‐octylphenol in 1‐octanol at 60°C. Consequently, as the pH of the solution was lowered, aluminum was observed to precipitate as the Bayerite form of Al(OH)₃. Contacting the loaded solvent with water released NaOH into the strip solution, and good selectivity for hydroxide vs. nitrate and aluminate was obtained. Since hydroxide equivalents rather than the hydroxide ion itself are believed to be extracted by the weak hydroxy acids, the process is referred to as pseudo‐hydroxide extraction. Application of this concept to sodium removal and caustic recycle in the treatment of alkaline nuclear waste appears feasible.     

Pressurized Liquid and Superheated Water Extraction of Active Constituents from Zingiber cassumunar Roxb. Rhizome

Active compounds, terpinene-4-ol and (E)-1-(3,4-dimethoxyphenyl) butadiene (DMPBD), displaying anti-inflammatory activity, were successfully extracted from the rhizome of Zingiber cassumunar Roxb. by pressurized liquid extraction (PLE) using methanol or ethanol and by superheated water extraction (SWE). Optimum conditions of both techniques were 1 mL/min flow rate and 5 min static time. The extraction temperature and dynamic time of the PLE and the SWE were 100°C 5 min and 140°C 20 min, respectively. Compared with water distillation, solvent sonication, and Soxhlet extraction, the PLE produced the highest amount of DMPBD and terpinene-4-ol, whereas the SWE and water distillation provided similar results.