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Extraction Process (extraction + process)
Kinds of Extraction Process Selected AbstractsLiquid,liquid,liquid microextraction followed by HPLC with UV detection for quantitation of ephedrine in urineJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2008Habib Bagheri Abstract Liquid,liquid,liquid microextraction (LLLME) in combination with HPLC and UV detection has been used as a sensitive method for the determination of ephedrine in urine samples. Extraction process was performed in a homemade total glass vial without using a Teflon ring, usually employed. Ephedrine was first extracted from 3.5 mL of urine sample (pH 12) into a microfilm of toluene/benzene (50:50). The analyte was subsequently back extracted into an acidic microdrop solution (pH 2) suspended in the organic phase. The extract was then injected into the HPLC system directly. An enrichment factor of 137 along with a good sample clean-up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 0.01,50 mg/L with regression coefficient corresponding to 0.998. The LODs and LOQs, based on a S/N of 3 and 10, were 5 and 10 ,g/L, respectively. The method was eventually applied for the determination of ephedrine in urine sample after oral administration of 5 mg single dose of drug. [source] Biological Natural Retting for Determining the Hierarchical Structuration of Banana FibersMACROMOLECULAR BIOSCIENCE, Issue 10 2004Piedad Gańán Abstract Summary: Extraction processes of natural fibers can be performed by different procedures that include mechanical, chemical and biological methods. Each method presents different advantages or drawbacks according to the amount of fiber produced or the quality and properties of fiber bundles obtained. In this study, biological natural retting was satisfactorily used for obtaining banana fibers from plant bunches. However, the most important contribution of this work refers to the description of the hierarchical microstructural ordering present in banana fiber bundles in both bundle surface and inner region. The chemical composition of banana fiber bundles has been evaluated by FTIR spectroscopy. Through exposure time, the fiber bundle configuration presents small variations in composition. The main changes are related to hemicellulose and pectins as they conform the outer walls of the bundle. Hierarchical helicoidal ordering in the bundle surface as well as orientation on the longitudinal axis of the bundle were observed by optical microscopy (OM) and scanning electron microscopy (SEM) for 3,4 ,m surface fibers and 10,15 ,m inner elementary fibers, respectively. With increasing exposure time, fiber bundle walls lose integrity, as reflected in their mechanical behavior. [source] New supported liquid membrane-capillary electrophoresis in-line arrangement for direct selective analysis of complex samplesELECTROPHORESIS, Issue 15 2006Leonor Nozal Abstract An in-line coupling of a micro-membrane extraction unit, based on supported liquid membrane, with commercially available capillary electrophoresis equipment is described. A main characteristic of this micro-membrane device, made from a simple Eppendorf tube, is that it permits the application of voltage in the acceptor solution to be applied during the extraction process. This has been shown as an alternative to enhance sensitivity, as the analytical signal achieved by applying 10,kV for 20,min was similar to that obtained without the application of voltage and with extraction time of 60,min. In addition, the design has been made permitting both in-line hydrodynamic and electrokinetic sample introduction into the electrophoretic capillary. The analytical potential of the proposed system has been demonstrated by the direct determination of nitroimidazoles from pig liver tissue. The high efficiency of the proposed system allowed the extraction and the determination of the analytes to be performed from a simple tissue homogenate obtained in water. The precision of the analysis of spiked samples, expressed in terms of relative standard deviation, was better than 4.8%. [source] Bioassays with caged Hyalella azteca to determine in situ toxicity downstream of two Saskatchewan, Canada, uranium operations,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2007Erin L. Robertson Abstract The main objectives of this in situ study were to evaluate the usefulness of an in situ bioassay to determine if downstream water bodies at the Key Lake and Rabbit Lake uranium operations (Saskatchewan, Canada) were toxic to Hyalella azteca and, if toxicity was observed, to differentiate between the contribution of surface water and sediment contamination to in situ toxicity. These objectives were achieved by performing 4-d in situ bioassays with laboratory-reared H. azteca confined in specially designed, paired, surface water and sediment exposure chambers. Results from the in situ bioassays revealed significant mortality, relative to the respective reference site, at the exposure sites at both Key Lake (p , 0.001) and Rabbit Lake (p = 0.001). No statistical differences were found between survival in surface water and sediment exposure chambers at either Key Lake (p = 0.232) or Rabbit Lake (p = 0.072). This suggests that surface water (the common feature of both types of exposure chambers) was the primary cause of in situ mortality of H. azteca at both operations, although this relationship was stronger at Key Lake. At Key Lake, the primary cause of aquatic toxicity to H. azteca did not appear to be correlated with the variables measured in this study, but most likely with a pulse of organic mill-process chemicals released during the time of the in situ study , a transient event that was caused by a problem with the mill's solvent extraction process. The suspected cause of in situ toxicity to H. azteca at Rabbit Lake was high levels of uranium in surface water, sediment, and pore water. [source] Antioxidant capacity of rapeseed meal and rapeseed oils enriched with meal extractEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 7 2010Aleksandra Szyd, owska-Czerniak Abstract Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables: solvent polarity and temperature of the extraction process on the antioxidant capacity (AC) and total phenolics content (TPC) in meal rapeseed extracts. The mean AC and TPC results for meal ranged between 1181,9974,µmol TE/100,g and 73.8,814,mg sinapic acid/100,g of meal. The experimental results of AC and TPC were close to the predicted values calculated from the polynomial response surface models equations (R2,=,0.9758 and 0.9603, respectively). The effect of solvent polarity on AC and TPC in the examined extracts was about 3.6 and 2.6 times greater, respectively, than the effect of processing temperature. The predicted optimum solvent polarity of ,,=,78.3 and 63.8, and temperature of 89.4 and 74.2°C resulted in an AC of 10,014,µmol TE/100,g and TPC of 863,mg SAE/100,g meal, respectively. The phenolic profile of rapeseed meal was determined by an HPLC method. The main phenolics in rapeseed meal were sinapine and sinapic acid. Refined rapeseed oils were fortified with an extract , rich in polyphenols , obtained from rapeseed meal. The supplemented rapeseed oil had higher AC and TPC than the refined oil without addition of meal extracts. However, AC and TPC in the enriched oils decreased during storage. The TPC in the studied meal extracts and rapeseed oils correlated significantly (p<0.0000001) positively with their AC (R2,=,0.9387). Practical applications: Many bioactive compounds extracted from rapeseed meal provide health benefits and have antioxidative properties. Therefore, it seems worth to consider the application of antioxidants extracted from the rapeseed meal for the production of rapeseed oils with potent AC. Moreover, antioxidants extracted from the rapeseed meal were added to refined rapeseed oil in order to enhance its AC. AC was then tested by FRAP assay. FRAP method is based on the reduction of the ferric tripyridyltriazine (Fe3+ -TPTZ) complex to the ferrous tripyridyltriazine (Fe2+ -TPTZ), and it is simple, fast, low cost, and robust method. FRAP method does not require specialized equipment and can be performed using automated, semi-automatic, or manual methods. Therefore the proposed FRAP method can be employed by the fat industry laboratories to asses the AC of rapeseed oils and meal. [source] Resolution of Racemic N -Benzyl ,-Amino Acids by Liquid-Liquid Extraction: A Practical Method Using a Lipophilic Chiral Cobalt(III) Salen Complex and Mechanistic StudiesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2008Pawel Dzygiel Abstract The efficient resolution of racemic N -benzyl ,-amino acids (N -Bn-AA) has been achieved by a liquid-liquid extraction process using the lipophilic chiral salen,cobalt(III) complex [CoIII(3)(OAc)]. As a result of the resolution by extraction, one enantiomer (S) of the N -benzyl ,-amino acid predominated in the aqueous phase, while the other enantiomer (R) was driven into the organic phase by complexation to cobalt. The complexed amino acid (R) was then quantitatively released by a reductive (CoIII,,,CoII) counter-extraction with aqueous sodium dithionite or L -ascorbic acid in methanol. Thereductive cleavage allowed to recover the [CoII(3)] complex in good yield, which could be easily re-oxidized to[CoIII(3)(OAc)] with air/AcOH and reused with essentially no loss of reactivity and selectivity. Investigation on the nitrogen substitution indicates that the presence of a single benzyl group on the amino acid nitrogen is important to obtain high enantioselectivity in the extraction process. The kinetic vs. thermodynamic nature of the resolution process was also investigated with an enantiomeric exchange experiment, which shows that the liquid-liquid extraction with [CoIII(3)(OAc)] is an equilibrium process operating under thermodynamic control. In the absence of a suitable crystal structure of the [CoIII(3)(N -Bn-AA)] complexes, computational and spectroscopic studies were used to investigate how the N -benzyl ,-amino acids are accommodated in the "binding pocket" of the chiral cobalt complex. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Extraction of Stimulus-Selective Intrinsic Optical Signals From the Cat Visual CortexIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 6 2009Midori Nagai Non-member Abstract Optical imaging based on intrinsic optical signals has been widely utilized in studies on the functional organization of various areas of the brain. Because of the small size of the optical signals and the large amount of background noise that is present, it is critical to be able to separate the stimulus-driven optical change from the background. In this study, we propose a novel method and apply it to the analysis of the orientation preference structure in cat area 17. The three criteria used to determine the activation included the amplitude of the optical change in the optical intensity, the statistical significance level of the change, and the temporal relationship between the optical change and the visual stimulation. In the activated region extracted by the new method, 82.4 ± 8.2% of the cells were electrophysiologically responsive to the stimuli that evoked the optical change. This was significantly higher than the 46.4 ± 7.1% value obtained when the activation region was extracted by the most widely used method, i.e. a differential map between two complementary stimuli, such as orthogonal orientations. Our newly proposed method provides a robust and an effective way to reduce manual operations used in the signal extraction process. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Silk Fibroin Waveguides: Biocompatible Silk Printed Optical Waveguides (Adv. Mater.ADVANCED MATERIALS, Issue 23 200923/2009) The cover shows an artistic rendition that merges silk and fiber optics. Supercontinuum white light is guided through a glass optical fiber that surrounds and illuminates silkworm cocoons. The silkworm cocoons shown here are used as the starting point of an extraction process to isolate pure silk fibroin protein in an aqueous solution. The silk is then reconstituted in the form of optical waveguides, as described by Fiorenzo Omenetto and co-workers on p. 2411, opening new opportunities to guide light in an entirely organic and biocompatible material. [source] A goal-driven approach for service request modelingINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 8 2010Chiung-Hon Leon Lee We propose a goal-driven approach to model the service request intention in service-oriented systems. The service request intention can be extracted from the user input and modeled by predefined goal models. We identify this problem as the service request intention extraction. If a service-oriented system has the abilities of user's intention extraction and can make some activities to satisfy the extracted intention, the system can provide a more convenient and efficient service for the user. We start the system construction from the view of goal-driven requirements engineering. The requirements specification is generated by the goal-based requirements analysis in which the functional and nonfunctional requirements will be extended with goal models. A set of computable goal models that represent the user requirements is selected and refined as the basis of system services. The designer can also design related system services based on the requirements specification. Based on the proposed intention extraction approach, the user's vague and imprecise intention will be extracted and mapped to computer understandable and computable goal models for representing the intention. A case-based method is developed to implement the intention extraction process. The intention interpretation knowledge is stored in a case base, and the intention interpretation is based on the process of case retrieval and adaptation. A general architecture for an intention-aware service-oriented system is proposed for demonstrating how to apply the proposed approach. © 2010 Wiley Periodicals, Inc. [source] One-Pot, Regioselective Synthesis of Substituted Arylglycines for Kinetic Resolution by Penicillin G AcylaseADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2008Peter Grundmann Abstract Amido-alkylation of electron-rich arenes with phenylacetamide and glyoxylic acid offers an inexpensive route to a large variety of N -phenylacetylated arylglycines that are suited for immediate enzymatic resolution by penicillin G acylase. When performed under mild conditions at 5,°C in acetic acid/HCl, this simple one-pot operation resulted in the formation of single regioisomers only (,98%). Subsequent kinetic resolution of the amino acid derivatives by penicillin G acylase at pH,8.0 occurred generally with E values>100 and thus furnished free (S)-configurated arylglycines with high enantiomeric purity. The corresponding enantiopure (R)-substrates, easily separable by a phase-selective extraction process, provided the corresponding (R)-enantiomers upon conventional hydrolysis. This one-pot, two-step procedure for arylglycine synthesis, resolution and work-up requires a minimum of equipment and grants rapid access to both enantiopure (S)- and (R)-antipodes of non-natural ,-amino acids in small- to large-scale quantities. [source] Water-Soluble Group 8 and 9 Transition Metal Complexes Containing a Trihydrazinophosphaadamantane Ligand: Catalytic Applications in Isomerization of Allylic Alcohols and Cycloisomerization of (Z)-Enynols in Aqueous MediumADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12-13 2006Abstract An optimized synthesis of the 2,4,10-trimethyl-1,2,4,5,7,10-hexaaza-3-phosphatricyclo[3.3.1.13,7]decane ligand (THPA) is described. It readily reacts with the dimers [{RuCl(,-Cl)(,6 -arene)}2] and [{MCl(,-Cl)(cod)}2] to yield the corresponding mononuclear complexes [RuCl2(THPA)(,6 -arene)] [arene=C6H6 (4a), p -cymene (4b), 1,3,5-C6H3Me3 (4c), C6Me6 (4d)] and [MCl(THPA)(cod)] [M=Rh (7a), Ir (7b)], respectively. Treatment of 4a and b with MeOTf affords the cationic derivatives [RuCl2(THPA-Me)(,6 -arene)][OTf] {arene=C6H6 (5a), p -cymene (5b); THPA-Me=1,2,4,10-tetramethyl-2,4,5,7,10-pentaaza-1-azonia-3-phosphatricyclo[3.3.1.13,7]decane}. The arene-ruthenium(II) complexes 4a,d and 5a and b are efficient catalysts for the redox isomerization of allylic alcohols into carbonyl compounds in both THF and aqueous media. The catalytic systems can be recycled by a simple extraction process and used in up to 4 consecutive runs. All the water-soluble complexes prepared in this work are able to promote the cycloisomerization of (Z)-enynols to afford furans in water, the best performance being obtained with the iridium catalyst 7b. Furthermore, 7b has shown an excellent recyclability (10 runs). This study represents the first example of iridium-catalyzed cycloisomerization of (Z)-enynols. [source] Thermal analysis of merino wool fibres without internal lipidsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007M. Martí Abstract Merino wool is made up of cuticle and cortical cells held together by the cell membrane complex (CMC), which contains a small amount of internal lipids (IWL) (1.5% by mass). IWL have been extracted from wool on account of their considerable dermatological interest owing to their proportion of ceramides. IWL have been extracted by different methods and solvents, methanol and acetone at laboratory and pilot plant levels. Thermal analysis of these extracted wool fibers is presented using thermogravimetry (TG) and differential scanning calorimetry (DSC). TG provides a measurement of the weight loss of the sample as a function of time and temperature. DSC gives information about possible structure modification of extracted wool fibers. Thermoporometry was applied to evaluate the pore size distribution of extracted wool fibers. The results showed that the extraction process increased the pore size distribution and the cumulated pore volume, which is consistent with some changes in the extracted wool CMC. Extracted fiber becomes more hydrophilic and absorbs a large amount of water. We can conclude that the lipid extraction of wool produced no relevant changes in the crystalline fraction when extracted with acetone. However, part of the amorphous keratin material was extracted with methanol, the rest of the crystalline material becoming more stable. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 545,551, 2007 [source] A reconstruction of the history of a Holocene sand dune on Great Barrier Island, northern New Zealand, using pollen and phytolith analysesJOURNAL OF BIOGEOGRAPHY, Issue 6 2000M. Horrocks Abstract Aim, To reconstruct the history of a Holocene sand dune using pollen and phytolith analyses, and to identify the strengths, weaknesses and compatibility of these two methods in the interpretation of Quaternary coastal environments. Location, Great Barrier Island, northern New Zealand. Methods, Pollen and phytolith analyses were carried out on a sequence through a Holocene sand dune containing a palaeosol. Results, Phytoliths were present throughout the sequence. Grass phytoliths increased at the expense of tree phytoliths following fire disturbance. Pollen (and spores) was preserved only in the palaeosol part of the profile. Pteridium fern spores increased at the expense of tall tree pollen following the fire disturbance. Main conclusions, Lack of phytolith production by many species and problems of taxonomic specificity in many others restricts the usefulness of phytolith analysis to defining only broad vegetation types. In New Zealand, gymnosperms are invisible in the phytolith record and ferns are extremely under-represented. In contrast, pollen analysis usually provides a great deal of information regarding the composition of a particular vegetation type. The loss of microscopic charcoal fragments during the phytolith extraction process is a disadvantage in the reconstruction of environments where fires have occurred. The greater durability of phytoliths compared with pollen means that phytoliths may be found in sediments where pollen has not been preserved. The phytolith record may also provide evidence of wetter environments that are not apparent in the pollen record. Unlike grass pollen, which is widely dispersed and therefore blurs the spatial record, the presence of grass phytoliths in sediments indicates a local source. The simultaneous application of both methods potentially provides a powerful tool in ecological interpretation and the reconstruction of Quaternary coastal environments. [source] Influence of acid treatment on the surface activity and mass transfer inhibition of a splittable surfactantJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2004Yuh-Lang Lee Abstract A splittable surfactant, Triton SP-190, was used to evaluate the effects of acid treatment on the mass transfer rate of an extraction process and on the interfacial tension-lowering activity of a system containing this surfactant. Equilibrium and dynamic interfacial tensions at the interface of CCl4 and the aqueous phase containing surfactant were measured by using pendent drop tensiometry enhanced by video digitization. A single-drop extraction apparatus was used to obtain the extraction percentage of acetic acid from the dispersed CCl4 droplets to the aqueous phase. The results indicate that the inorganic acid treatment can inhibit the dynamic and equilibrium interfacial tension-lowering activity of Triton SP-190. The mass transfer resistance induced by the addition of Triton SP-190 can also be reduced by the pre-treatment of acid. The effectiveness of acid treatment on both properties was greater at low pH values, lower surfactant concentrations, and longer treatment times. With HCl treatment, the equilibrium interfacial tension was not able to increase to the value of a surfactant-free system, but approached a maximum value which was independent of the pH value, but dependent on surfactant concentration. On the contrary, the extraction percentage, which has decreased due to the presence of surfactant, can be recovered completely to that of a surfactant-free system by acid treatment. The acid-treatment time required to achieve a significant recovery of mass transfer rate was much longer than that required to recover the interfacial tension. The present results also demonstrate that the constituents contained in an acid-treatment system had different effectiveness in affecting the interfacial tension and mass transfer rate due to the different mechanisms involved. Copyright © 2004 Society of Chemical Industry [source] Use of microemulsions for removal of color and dyes from textile wastewaterJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2004Tereza Neuma de Castro Dantas Abstract One of the major environmental problems in the textile dyeing industry is the removal of color from effluents. The present study deals with color removal from effluents using microemulsions. The wastewater used in this study was the reactive exhausted dye liquor from a dyeing house containing Procion Yellow H-E4R (CI Reactive Yellow 84), Procion Blue H-ERD (CI Reactive Blue 160) and Procion Red H-E3B (CI Reactive Red 120). Color removal was determined by CIEL*a*b* (CIELAB) color space, CIEL*a*b* color difference, ,E*ab, and absorbance. Color removal greater than 95% was achieved, attaining values lower than the consent requirements established by the Environmental Agency. It was observed that pH is an important parameter in color removal and effluent pH correction from 10.44 to 9 before extraction improved results. The results obtained were modeled using the Scheffé net method and evaluated through the construction of isoresponse diagrams by correlation graphics between experimental values and those obtained through use of model equations, providing an experimental error of less than 2%. The optimized method very efficiently removed all dyes contained in the effluent. The same microemulsion phase recovered after the extraction process can be used at least a further 14 times and all the extractions gave good color removal. Copyright © 2004 Society of Chemical Industry [source] ANALYSIS OF VARIABLES AND MODELING OF GEVUINA AVELLANA OIL EXTRACTION WITH ETHANOL NEAR AZEOTROPE CONDITIONSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2009DANIEL FRANCO ABSTRACT Oil extraction from Gevuina avellana Mol. (Chilean hazelnut) with ethanol, near the conditions of its azeotrope with water, was carried out in this work. The effects of solubility, liquid-to-solid ratio and moisture content of ethanol were studied using 92% ethanol, azeotropic (96%) and absolute ethanol (99.9%) as solvents. Water content had a high effect on oil solubility, which reached 140 g/L in 99.9% ethanol, whereas it was 40 g/L with azeotropic ethanol. Oil accounted for 93% of total extractable compounds with absolute ethanol. Kinetics studies of the extraction process were performed at 50C, giving as a result apparent diffusivity values near 10,11 m2/s, being the highest values obtained for ethanol 92% (7.5,16 × 10,11). It was also found that the higher the liquid-to-solid ratio, the higher the diffusivity. Simulation of four-stage countercurrent extraction with azeotropic ethanol yielded 23.5% oil extraction, whereas simulation of four-stage cross-flow extraction yielded 40.7%. Ethanol can be an alternative to batch cold pressing or hexane solvent extraction, for G. savellana seeds or meal processing. PRACTICAL APPLICATIONS The results presented in this paper are applicable for obtaining oil from oilseeds by extraction with ethanol. It includes relevant results for the optimization of extraction conditions and particularly those regarding liquid-to-solid ratio and percentage of water. Considering the more specific focus of this research, the results are applicable to obtaining Gevuina avellana oil by using an ethanol-based process, which will allow to avoid one of the cold-pressing process drawbacks: the high oil content of the meal, which is a factor limiting its lifetime. [source] APPLICATION OF EXPERIMENTAL DESIGN METHOD TO THE OIL EXTRACTION FROM OLIVE CAKEJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2009SMAIL MEZIANE ABSTRACT Olive cake is an important solid waste of the olive oil production. It still contains a certain quantity of oil that can be recovered by means of solvent extraction. In this study, two-level full factorial design was performed to evaluate the effects of four variables and their interactions on the oil extraction by the ethanol 96.0% in a batch reactor. The variables included size of particles, temperature, and time of contact and solvent-to-solids ratio. The statistical analysis of the experimental data showed that the extracted oil mass depends on all the examined variables. It also depends on the interactions between size of particles and solvent-to-solid ratio and size of particles and temperature. The experimental data were in good agreement with those predicted by the model. PRACTICAL APPLICATIONS Olive cake is solid waste of the olive oil industry that is available in large amounts in many Mediterranean countries and at very low cost. It can be treated or valorized, enabling at the same time the solution to environmental problems caused by the olive oil production process. The economic interest that it presents is especially because of the residual oil that it contains and that can be recovered by solvent extraction. However, this solid,liquid extraction depends on several parameters: the ones inherent to the products (structure and properties of the sample, nature of extraction solvent); and the others to the extraction process (time of contact, temperature of extraction, solvent-to-solid ratio, stirring velocity). The experimental design method enables to determine the most important variables and their interaction in the extraction process at the same time performing a low number of experiments. [source] Extraction and Removal of Caffeine from Green Tea by Ultrasonic-Enhanced Supercritical FluidJOURNAL OF FOOD SCIENCE, Issue 4 2010Wei-Qiang Tang ABSTRACT:, Low-caffeine or caffeine-removed tea and its products are widely welcomed on market in recent years. In the present study, we adopt ultrasonic-enhanced supercritical fluid extraction process to remove caffeine from green tea. An orthogonal experiment (L16 (45)) was applied to optimize the best removal conditions. Extraction pressure, extraction time, power of ultrasound, moisture content, and temperature were the main factors to influence the removal rate of caffeine from green tea. The 5 factors chosen for the present investigation were based on the results of a single-factor test. The optimum removal conditions were determined as follows: extraction pressure of 30 MPa, temperature at 55 °C, time of 4 h, 30% moisture content, and ultrasound power of 100 W. Chromatogram and ultraviolet analysis of raw material and decaffeinates suggests that under optimized conditions, the caffeine of green tea was effectively removed and minished without damaging the structure of active ingredients in green tea. [source] Greenhouse Gas Profile of a Plastic Material Derived from a Genetically Modified PlantJOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2000Devdatt Kurdikar Abstract: This article reports an assessment of the global warming potential associated with the life cycle of a biopolymer (poly(hydroxyalkanoate) or PHA) produced in genetically engineered corn developed by Monsanto. The grain corn is harvested in a conventional manner, and the polymer is extracted from the corn stover (i.e., residues such as stalks, leaves and cobs), which would be otherwise left on the field. While corn farming was assessed based on current practice, four different hypothetical PHA production scenarios were tested for the extraction process. Each scenario differed in the energy source used for polymer extraction and compounding, and the results were compared to polyethylene (PE). The first scenario involved burning of the residual biomass (primarily cellulose) remaining after the polymer was extracted from the stover. In the three other scenarios, the use of conventional energy sources of coal, oil, and natural gas were investigated. This study indicates that an integrated system, wherein biomass energy from corn stover provides energy for polymer processing, would result in a better greenhouse gas profile for PHA than for PE. However, plant-based PHA production using fossil fuel sources provides no greenhouse gas advantage over PE, in fact scoring worse than PE. These results are based on a "cradle-to-pellet" modeling as the PHA end-of-life was not quantitatively studied due to complex issues surrounding the actual fate of postconsumer PHA. [source] Kinetic and dynamic study of liquid,liquid extraction of copper in a HFMC: Experimentation, modeling, and simulationAICHE JOURNAL, Issue 6 2010M. Younas Abstract In this work, we present the dispersion-free liquid,liquid extraction of copper from aqueous streams in a hollow fiber membrane contactor (HFMC). Copper has been transferred from aqueous solutions to heptane using LIX 84-I (2-hydroxy-5-nonylacetephenone oxime) as extracting agent. In a first step, batch experiments have been performed to identify the extraction kinetics and to measure the partition coefficient of copper aqueous-organic phase system. Then, the continuous recycled-base extraction process has been performed in a HFMC Liqui-Cel® module. The module has been modeled from resistance in series concept to gain the exit concentrations, which are used to develop a dynamic model to calculate the exit concentration of copper from the output of storage tanks. The model has been validated with experimental data at various operating conditions. The integrated process model algorithm was scripted in MATLAB® 7.4 R (a). Simulations have been made for a range of different operating parameters to determine the optimum criterion conditions. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Solubility and degradation of polyhydroxyalkanoate biopolymers in propylene carbonateAICHE JOURNAL, Issue 6 2010Christopher W. J. McChalicher Abstract New biobased materials and chemicals require different processing strategies than petroleum-derived commodities. The extraction and recovery of polyhydroxyalkanoate (PHA) biopolymers from the residual cellular biomass is particularly difficult because the polymer is accumulated within the cell. PHAs have low solubility in many classical polymer solvents and are most often dissolved using undesirable chlorinated solvents. The solubility kinetics is greatly diminished when these polymers are highly crystalline. Here, 1,2-propylene carbonate is used to dissolve highly crystalline polyhydroxybutyrate at ambient pressures and moderate temperatures. We have used kinetic studies of the dissolution of the crystalline material to determine the energy barrier for dissolution of the system. Further, the degradation of polyhydroxybutyrate and similarly prepared PHA block copolymers were studied during this extraction process using molecular weight characterization by gel permeation chromatography. Finally, we have used these findings to extract PHA block copolymers from dried biomass at the bench scale. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] An ionic liquid proposed as solvent in aromatic hydrocarbon separation by liquid extractionAICHE JOURNAL, Issue 2 2010Ana B. Pereiro Abstract Liquid,liquid extraction is the most common method for extraction of aromatics from their mixtures with aliphatic hydrocarbons. An ionic liquid (IL) 1-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) imide [BMpyr][NTf2] was tested as solvent for this separation. The liquid,liquid equilibria (LLE) of the ternary mixtures heptane + benzene, or toluene, or ethylbenzene + [BMpyr][NTf2] were carried out at 298.15 K. The solvent ability of the IL was evaluated in terms of solute distribution ratio and selectivity. The results were compared with those previously reported for the extraction of aromatics from its mixtures with heptane by using ILs. The conventional process using sulfolane as solvent was discussed. The experimental LLE data were correlated by non-random two liquid equation. A proposal of extraction process with this IL as solvent is simulated by conventional software and the results are shown. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] An improved ultrasound-assisted extraction process of gossypol acetic acid from cottonseed soapstockAICHE JOURNAL, Issue 3 2009Guangfeng Jia Abstract To investigate the extracted process of gossypol acetic acid (G-AA) from cottonseed soapstock and explore the improvement of its yield and purity, a novel ultrasound-assisted extraction and crystallization method was introduced to this process. Under the optimized conditions, preliminary G-AA with the yield of 1300 mg and the purity of 95.9% could be obtained from 100 g of fresh soapstock by ultrasound-assisted extraction. In addition, UV, IR, and NMR spectrum further confirmed the detailed chemical structure of G-AA. Assay of inhibiting human prostate tumor cell line PC-3 and human breast cancer cell line MDA-MB-231 revealed its biological activity, the values of IC50 are 9.096 ,mol/L and 14.37 ,mol/L respectively. In comparison with the conventional solvent extraction, this novel process increases the content of G-AA over 90%, reduces the time of crystallization by 75%, and retains the anticancer activity of gossypol. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] A ceramic microfiltration tube membrane dispersion extractorAICHE JOURNAL, Issue 2 2004G. G. Chen Abstract Although the phase-free membrane extraction process has shown many advantages over the traditional extraction, the process is still at the experimental stage. On the other hand, in a new extractor a microfiltration membrane is used as a dispersion medium. The mass-transfer performance of the new extractor was tested with 30% TBP (in kerosene),nitric acid,H2O as an experimental system. The overall mass-transfer coefficient and the equipment efficiency were calculated with the concentrations of the inlet and outlet. The extractor was designed and constructed with two special inner elements for improving the performance further. The effects of the transmembrane pressure, the continuous-phase flow rate, and the geometric parameters of the inner elements on the mass-transfer performance, as well as on the flux of the dispersion phase, are discussed. The experimental results showed that very higher efficiency was reached. The inner elements could improve the mass-transfer performance greatly by changing the two-phase contact status. The results suggested that the mass-transfer process could be completed quickly while the drop size was in the range of micrometers. In addition, the flux of the dispersed phase was mainly influenced by the transmembrane pressure, not by the equipment structures, inner elements, and the continuous-phase flow rate. The new extractor can be operated with very higher efficiency and higher flux, and the efficiency can be predicted with a cubic polynomial. © 2004 American Institute of Chemical Engineers AIChE J, 50: 382,387, 2004 [source] Determination of gastrodin and vanillyl alcohol in Gastrodia elata Blume by pressurized liquid extraction at room temperatureJOURNAL OF SEPARATION SCIENCE, JSS, Issue 13 2007Eng Shi Ong Abstract Pressurized liquid extraction (PLE) at room temperature with a laboratory-assembled system was applied for the extraction of gastrodin (GA) and vanillyl alcohol (VA) in Gastrodia elata Blume. The proposed system setup for this current work was simpler as no heating and backpressure regulator was required. Extraction with PLE was carried out dynamically at a flow rate of 1.5 mL/min, at room temperature, under an applied pressure of 10,20 bars with an extraction time of 40,50 min. The extraction efficiencies of the proposed method using 20% aqueous ethanol were compared with heating under reflux using organic solvents such as methanol and ethanol/water (20:80) for different batches of medicinal plant materials. For the determination of GA and VA in G. elata Blume, the extraction efficiencies of PLE at room temperature were observed to be comparable with heating under reflux. The method precision was found to vary from 1.6 to 8.6% (RSD, n = 6) on different days. The marker compounds present in the various medicinal plant extracts were determined by gradient elution HPLC and HPLC/MS/MS. Our work demonstrated the possibility of implementation of PLE at room temperature and the advantages of minimizing the use of organic solvents in the extraction process. [source] Synthesis of Hydrated Aluminum Sulfate from Kaolin by Microwave ExtractionJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000Seong Soo Park The feasibility of extracting alumina from kaolin via a microwave extraction process was investigated by comparing reaction times, reaction temperatures, and acid concentrations under microwave treatment with the same factors under conventional thermal extraction. The maximum amount of alumina extracted from kaolin under conventional processing at 90°C for 240 min with 1M H2SO4 was 99.9%; the same amount of alumina was extracted under microwave processing at 90°C for 120 min with 1M H2SO4. [source] Extraction of pure lycopene from industrial tomato by-products in water using a new high-pressure processJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2008Daniele Naviglio Abstract BACKGROUND: Lycopene, a precursor of ,-carotene with a well-known antioxidant activity, contained in many natural products such as tomato (Lycopersicon esculentum Mill.), watermelon, red pepper and papaya, is usually recovered from natural vegetal sources using organic solvents and a purification step. In this paper an innovative process for the extraction of pure lycopene from tomato waste in water that uses the Naviglio® extractor and water as extracting phase is presented. RESULTS: Lycopene was obtained in the all- trans form at a very high grade of purity, not less than 98% (w/w), with an average recovery of 14% (w/w). The availability of high-purity trans -lycopene allowed measurement of the molar absorption coefficient. An alternative procedure for high-performance liquid chromatographic analysis using a phenyl-hexyl silicone phase as inverse phase and a linear gradient in water and acetonitrile is also described. CONCLUSIONS: The use of water as extracting phase considerably reduces the cost of the entire process when compared with the commonly used solvent-based procedure or with the newer supercritical extraction process of lycopene from tomato waste. Lycopene, not soluble in water, was recovered in a quasi-crystalline solid form and purified by solid-phase extraction using a small amount of organic solvent. Copyright © 2008 Society of Chemical Industry This article was published online on September 15, 2008. Errors in Figures 2 - 4 were subsequently identified. The publishers wish to apologise for these errors. This notice is included in the online and print versions to indicate that both have been corrected [September 19, 2008] [source] Optimization of extraction process for phenolic acids from black cohosh (Cimicifuga racemosa) by pressurized liquid extraction,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2006Sudarsan Mukhopadhyay Abstract An investigation to optimize the extraction of phenolic acids from black cohosh using a pressurized liquid extractor system was studied with the aim of developing a generalized approach for sample preparation of phenolic compounds from plant matrices. Operating parameters such as solvent composition, solid-to-solvent ratio, temperature, particle size distribution, and number of extraction cycles were identified as main variables that influence extraction efficiency. A mixture of methanol and water (60:40 v/v) was found to be the best solvent for total phenolics (TP) and individual phenolic acids. The four phenolic acids extracted from black cohosh were identified by HPLC and LC-MS as caffeic acid, ferulic acid, sinapic acid and isoferulic acid. Over 96% of the measured phenolics were extracted in first two cycles. The extraction efficiency for black cohosh with MeOH:H2O (60:40 v/v) was found to be maximum at a solid-to-solvent ratio of 80 mg ml,1. TP content of the extract was found to increase with temperature up to 90 °C. Particle size was found to have a large impact on extraction efficiency of TP. Samples with particle size between 0.25 mm and 0.425 mm provided optimum extraction of phenolics from black cohosh. Published in 2005 for SCI by John Wiley & Sons, Ltd. [source] Olive oil extractability index as a parameter for olive cultivar characterisationJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2003Gabriel Beltrán Abstract Extractability, when applied to the olive oil extraction process is defined as the percentage of oil extracted from the total oil content of the fruit. In this work, extractability index (EI), a new parameter determined in a laboratory oil mill, has been studied for 24 olive (Olea europaea L) cultivars from the Olive Germplasm Bank Collection of Mengibar (Spain). In order to evaluate the genetic variability of this new parameter, the influence of cultivar and tree on EI variability has been analysed in olive fruits collected at the same ripening index. The results indicate that cultivar is the most important variation source. Thus olive oil extractability depends on extraction process variables and cultivar. Extractability index could be used together with pulp oil content (on a dry matter basis) as a parameter for olive cultivar characterisation and selection for breeding projects. Copyright © 2003 Society of Chemical Industry [source] Carbonate extraction process for the metabolic, isozymic and proteomic profiling of rose-scented geranium (Pelargonium sp.), a hyper-acidic plantPHYTOCHEMICAL ANALYSIS, Issue 2 2008Rajender Singh Sangwan Abstract Rose-scented geranium (Pelargonium sp.) is a valuable monoterpene-yielding plant. It has been well characterised phytochemically through the isolation of >270 secondary metabolites, however, there is hardly any biochemical or metabolic information concerning this plant. Initial attempts to investigate its metabolism failed to produce any enzyme activity in the tissue extracts prepared in routine extraction buffers owing to the intrinsic properties of the tissue matrix. It was recognised that cellular hyper-acidity (cell sap pH ,3.0) gave rise to very low protein levels in the extracts, thus prohibiting detection of activities of even primary metabolic enzymes that are usually abundantly present in plants. Tissue extraction in Tris solution without pH adjustment (as used for studies involving citrus and banana) led to little or no improvement. Therefore, a novel approach using sodium carbonate solution as an efficient extraction system for enzymes and proteins from the plant was studied. Functionality of the carbonate extraction has been demonstrated through its effectiveness, a several-fold superior performance, in yielding protein, monitoring primary metabolism and secondary metabolic enzymes, and isozymic and polypeptide profiling. The process may also be helpful in the reliable analysis of other acidic plant tissues. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||