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Sample records for capillary supercritical fluid

  1. Materials processing using supercritical fluids

    Directory of Open Access Journals (Sweden)

    Orlović Aleksandar M.

    2005-01-01

    Full Text Available One of the most interesting areas of supercritical fluids applications is the processing of novel materials. These new materials are designed to meet specific requirements and to make possible new applications in Pharmaceuticals design, heterogeneous catalysis, micro- and nano-particles with unique structures, special insulating materials, super capacitors and other special technical materials. Two distinct possibilities to apply supercritical fluids in processing of materials: synthesis of materials in supercritical fluid environment and/or further processing of already obtained materials with the help of supercritical fluids. By adjusting synthesis parameters the properties of supercritical fluids can be significantly altered which further results in the materials with different structures. Unique materials can be also obtained by conducting synthesis in quite specific environments like reversed micelles. This paper is mainly devoted to processing of previously synthesized materials which are further processed using supercritical fluids. Several new methods have been developed to produce micro- and nano-particles with the use of supercritical fluids. The following methods: rapid expansion of supercritical solutions (RESS supercritical anti-solvent (SAS, materials synthesis under supercritical conditions and encapsulation and coating using supercritical fluids were recently developed.

  2. Supercritical fluids cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Butner, S.; Hjeresen, D.; Silva, L.; Spall, D.; Stephenson, R.

    1991-01-01

    This paper discusses a proposed multi-party research and development program which seeks to develop supercritical fluid cleaning technology as an alternative to existing solvent cleaning applications. While SCF extraction technology has been in commercial use for several years, the use of these fluids as cleaning agents poses several new technical challenges. Problems inherent in the commercialization of SCF technology include: the cleaning efficacy and compatibility of supercritical working fluids with the parts to be cleaned must be assessed for a variety of materials and components; process parameters and equipment design Have been optimized for extractive applications and must be reconsidered for application to cleaning; and co-solvents and entrainers must be identified to facilitate the removal of polar inorganic and organic contaminants, which are often not well solvated in supercritical systems. The proposed research and development program would address these issues and lead to the development and commercialization of viable SCF-based technology for precision cleaning applications. This paper provides the technical background, program scope, and delineates the responsibilities of each principal participant in the program.

  3. Supercritical fluids processing: emerging opportunities

    International Nuclear Information System (INIS)

    Kovaly, K.A.

    1985-01-01

    This publication on the emerging opportunities of supercritical fluids processing reveals the latest research findings and development trends in this field. These findings and development trends are highlighted, and the results of applications of technology to the business of supercritical fluids are reported. Applications of supercritical fluids to chemical intermediates, environmental applications, chemical reactions, food and biochemistry processing, and fuels processing are discussed in some detail

  4. Supercritical fluids in chemical processes

    International Nuclear Information System (INIS)

    Hertz, A.; Charton, F.

    2011-01-01

    When the pressure and temperature of a fluid are simultaneously higher than their critical point values, the fluid is said to be supercritical. Supercritical fluids have unique physico-chemical properties, in particular they have specific gravity close to that of liquids and viscosity close to that of gases. Carbon dioxide CO 2 (P c = 73.8 bars, T c = 31 C. degrees) is the most widely used compound in supercritical processes. In the nuclear field, chemistry inspired by liquid phase extraction has been developed for the supercritical CO 2 used as a diluent in association with extractant systems such as organo-phosphorus compounds or β-dike-tones. The Japanese Super-DIREX (Supercritical fluid Direct Extraction) process exploits the supercritical CO 2 - tri-n-butyl phosphate - nitric acid chemical system to extract actinides from spent fuel. In the United States, the same chemical system is utilized in an industrial facility to recover enriched uranium from incineration ash. Supercritical water H 2 O (P c = 221 bars, T c = 374 C. degrees) exhibits solvation properties close to those of organic solvents and can solubilise organic compounds that are insoluble in liquid water. In the nuclear field, CEA is studying oxidation in supercritical water, also called hydrothermal oxidation, for the mineralization of contaminated organic solvents. (A.C.)

  5. Supercritical fluid chromatography of fish, shark and seal oils

    DEFF Research Database (Denmark)

    Borch-Jensen, Christina; Mollerup, Jørgen

    1996-01-01

    Various natural and treated fish, shark liver and seal oils have been analyzed by supercritical fluid chromatography (SFC) using a non-polar capillary column. The lipids are separated according to molecular mass. The lipid groups found included free fatty acids, cholesterol, squalene, vitamins, wax...

  6. Supercritical fluid reverse micelle separation

    Science.gov (United States)

    Fulton, J.L.; Smith, R.D.

    1993-11-30

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

  7. Supercritical fluid reverse micelle separation

    Science.gov (United States)

    Fulton, John L.; Smith, Richard D.

    1993-01-01

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.

  8. Lipidomics by Supercritical Fluid Chromatography

    Science.gov (United States)

    Laboureur, Laurent; Ollero, Mario; Touboul, David

    2015-01-01

    This review enlightens the role of supercritical fluid chromatography (SFC) in the field of lipid analysis. SFC has been popular in the late 1980s and 1990s before almost disappearing due to the commercial success of liquid chromatography (LC). It is only 20 years later that a regain of interest appeared when new commercial instruments were introduced. As SFC is fully compatible with the injection of extracts in pure organic solvent, this technique is perfectly suitable for lipid analysis and can be coupled with either highly universal (UV or evaporative light scattering) or highly specific (mass spectrometry) detection methods. A short history of the use of supercritical fluids as mobile phase for the separation oflipids will be introduced first. Then, the advantages and drawbacks of SFC are discussed for each class of lipids (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, prenols, polyketides) defined by the LIPID MAPS consortium. PMID:26090714

  9. Chiral separations of cathinone and amphetamine-derivatives: Comparative study between capillary electrochromatography, supercritical fluid chromatography and three liquid chromatographic modes.

    Science.gov (United States)

    Albals, Dima; Heyden, Yvan Vander; Schmid, Martin G; Chankvetadze, Bezhan; Mangelings, Debby

    2016-03-20

    The screening part of an earlier defined chiral separation strategy in capillary electrochromatography (CEC) was used for the separation of ten cathinone- and amphetamine derivatives. They were analyzed using 4 polysaccharide-based chiral stationary phases (CSPs), containing cellulose tris(3,5-dimethylphenylcarbamate) (ODRH), amylose tris(3,5-dimethylphenylcarbamate) (ADH), amylose tris(5-chloro-2-methylphenylcarbamate) (LA2), and cellulose tris(4-chloro-3-methylphenylcarbamate) (LC4) as chiral selectors. After applying the screening to each compound, ADH and LC4 showed the highest success rate. In a second part of the study, a comparison between CEC and other analytical techniques used for chiral separations i.e., supercritical fluid chromatography (SFC), polar organic solvent chromatography (POSC), reversed-phase (RPLC) and normal-phase liquid chromatography (NPLC), was made. For this purpose, earlier defined screening approaches for each technique were applied to separate the 10 test substances. This allowed an overall comparison of the success rates of the screening steps of the 5 techniques for these compounds. The results showed that CEC had a similar enantioselectivity rate as NPLC and RPLC, producing the highest number of separations (9 out of 10 racemates). SFC resolved 7 compounds, while POSC gave only 2 separations. On the other hand, the baseline separation success rates for NPLC and RPLC was better than for CEC. For a second comparison, the same chiral stationary phases as in the CEC screening were also tested with all techniques at their specific screening conditions, which allowed a direct comparison of the performance of CEC versus the same CSPs in the other techniques. This comparison revealed that RPLC was able to separate all tested compounds, and also produced the highest number of baseline separations on the CSP that were used in the CEC screening step. CEC and NPLC showed the same success rate: nine out of ten substances were separated. When

  10. Technology with Supercritical Fluid. Part 2. Applications

    International Nuclear Information System (INIS)

    Marongiu, B.; De Giorgi, M. R.; Porcedda, S.; Cadoni, E.

    1998-01-01

    The present article is based on a bibliographical analysis of the main applications of the supercritical fluid in various fields, as: extraction from solid matrices, division of liquid charges, chromatography HPLC with supercritical eluent, chemical and biochemical reactions in supercritical solvents etc [it

  11. Supercritical Fluid Reactions for Coal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Charles A. Eckert

    1997-11-01

    Exciting opportunities exist for the application of supercritical fluid (SCF) reactions for the pre-treatment of coal. Utilizing reactants which resemble the organic nitrogen containing components of coal, we developed a method to tailor chemical reactions in supercritical fluid solvents for the specific application of coal denitrogenation. The tautomeric equilibrium of a Schiff base was chosen as one model system and was investigated in supercritical ethane and cosolvent modified supercritical ethane. The Diels-Alder reaction of anthracene and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) was selected as a second model system, and it was investigated in supercritical carbon dioxide.

  12. Application of supercritical fluid in nanolithographic processes.

    Science.gov (United States)

    Zhou, Jijie

    2010-06-01

    The supercritical state provides an energetic environment in which high-aspect-ratio or active surface structures can be reacted, swelled, cleaned, or coated. Due to both low viscosity and low interfacial tension, reagent, solvent, rinsing and drying media of supercritical fluids can be efficiently delivered into the nanointerstices of a substrate. This article summarizes recent patents in the field of using supercritical fluids in nanolithographic processing methods such as drying, removal of lithographic resist, and formation of hybrid structures. Some of our recent efforts on restoring the collapsed on-chip nanotube arrays, and synthesizing zeolite-polymer hybrid membrane materials are exemplified as applications of supercritical fluids. Introducing supercritical effects may guide sustainable technologies for the development of green processes.

  13. Geothermal energy production with supercritical fluids

    Science.gov (United States)

    Brown, Donald W.

    2003-12-30

    There has been invented a method for producing geothermal energy using supercritical fluids for creation of the underground reservoir, production of the geothermal energy, and for heat transport. Underground reservoirs are created by pumping a supercritical fluid such as carbon dioxide into a formation to fracture the rock. Once the reservoir is formed, the same supercritical fluid is allowed to heat up and expand, then is pumped out of the reservoir to transfer the heat to a surface power generating plant or other application.

  14. Nanotechnology and supercritical fluids | Hamidreza | Journal of ...

    African Journals Online (AJOL)

    Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO2 and H2O are extensively being used in the preparation of a great variety of nanomaterials. The interest in the preparation and application of nanometer size materials is increasing since they ...

  15. Nanostructured Materials: Symthesis in Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yuehe; Ye, Xiangrong; Wai, Chien M.

    2009-03-24

    This chapter summarizes the recent developent of synthesis and characterization of nanostructured materials synthesized in supercritical fluids. Nanocomposite catalysts such as Pt and Pd on carbon nanotube support have been synthesized and used for fuel cell applications.

  16. Supercritical fluid extraction as an on-line clean-up technique for determination of riboflavin vitamins in food samples by capillary electrophoresis with fluorimetric detection.

    Science.gov (United States)

    Zougagh, Mohammed; Ríos, Angel

    2008-08-01

    An automatic method for the separation and determination of riboflavin (RF) vitamins (RF, flavin mononucleotide and flavin adenine dinucleotide) in food samples (chicken liver, tablet and powder milk) is proposed. The method is based on the on-line coupling of a supercritical fluid extractor (SFE) with a continuous flow-CE system with guided optical fiber fluorimetric detection (CF-CE-FD). The whole SFE-CF-CE-FD arrangement allowed the automatic treatment of food samples (clean-up of the sample followed by the extraction of the analytes), and the direct introduction of a small volume of the extracted plug to the CE-FD system for the determination of RF vitamins. Fluorescence detection introduced an appropriated sensitivity and contributed to avoid interferences of nonfluorescent polar compounds coming from the matrix samples in the extracted plug. Electrophoretic responses were linear within the 0.05-1 microg/g range, whereas the detection limits of RF vitamins were in the 0.036-0.042 microg/g range. The proposed arrangement opens up interesting prospects for the direct determination of polar analytes in complex samples with a good throughput and high level of automation.

  17. Supercritical fluid extraction of hops

    Directory of Open Access Journals (Sweden)

    ZORAN ZEKOVIC

    2007-01-01

    Full Text Available Five cultivars of hop were extracted by the method of supercritical fluid extraction using carbon dioxide (SFE–CO2 as extractant. The extraction (50 g of hop sample using a CO2 flow rate of 97.725 L/h was done in the two steps: 1. extraction at 150 bar and 40°C for 2.5 h (sample of series A was obtained and, after that, the same sample of hop was extracted in the second step: 2. extraction at 300 bar and 40 °C for 2.5 h (sample of series B was obtained. The Magnum cultivar was chosen for the investigation of the extraction kinetics. For the qualitative and quantitative analysis of the obtained hop extracts, the GC-MS method was used. Two of four themost common compounds of hop aroma (a-humulene and b-caryophyllene were detected in samples of series A. In addition, isomerized a-acids and a high content of b-acids were detected. The a-acids content in the samples of series B was the highest in the extract of the Magnum cultivar (it is a bitter variety of hop. The low contents of a-acids in all the other hop samples resulted in extracts with low a-acids content, i.e., that contents were under the prescribed a-acids content.

  18. Using supercritical fluids to refine hydrocarbons

    Science.gov (United States)

    Yarbro, Stephen Lee

    2015-06-09

    A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.

  19. Supercritical Fluid Chromatographic Separation of Dimethylpolysiloxane Polymer

    Energy Technology Data Exchange (ETDEWEB)

    Pyo, Dong Jin; Lim, Chang Hyun [Kangwon National University, Chuncheon (Korea, Republic of)

    2005-02-15

    Water was used as a polar modifier and a μ-porasil column as a saturator column. The μ-porasil column was inserted between the pump outlet and the injection valve. During the passage of the supercritical fluid mobile phase through the silica column, a polar modifier (water) can be dissolved in the pressurized supercritical fluid. Dimethylpolysiloxane polymer has been known as more polar polymer than polystyrene polymer. Dimethylpolysiloxane polymer has never been separated using water modified mobile phase. In this paper, using a μ-porasil column as a saturator column, excellent supercritical fluid chromatograms of dimethylpolysiloxane oligomers were obtained. The use of compressed (dense) gases and supercritical fluids as chromatographic mobile phases in conjunction with liquid chromatographic (LC)-type packed columns was first reported by Klesper et al. in 1962. During its relatively short history, supercritical fluid chromatography (SFC) has become an attractive alternative to GC and LC in certain industrially important applications. SFC gives the advantage of high efficiency and allows the analysis of nonvolatile or thermally labile mixtures.

  20. Supercritical fluids technology. Pt. 1 General topics

    International Nuclear Information System (INIS)

    Marongiu, B.; De Giorgi, M. R.; Porcedda, S.; Cadoni, E.

    1998-01-01

    Supercritical fluids technology is among the emerging 'clean' technologies, that allows the minimization in the use of chemical and thermic treatments and products irradiation, diminishing the quantity of liquid wastes to be treated. In this first article phase equilibria thermodynamics and fluid mechanics of transport phenomena are reviewed [it

  1. Heat Transfer Phenomena of Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas [Forschungszentrum Karlsruhe, Institute for Nuclear and Energy Technologies, 76021 Karlsruhe (Germany)

    2008-07-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  2. Heat Transfer Phenomena of Supercritical Fluids

    International Nuclear Information System (INIS)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas

    2008-01-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  3. Liposomal preparation by supercritical fluids technology | Zhong ...

    African Journals Online (AJOL)

    From 1970s, supercritical fluids technology (SCF) has been utilized in liposomal preparation because of its friendliness, nontoxicity to the environment and its possibility to achieve solvent-free liposomes and industrial-scale of liposome production under the conditions of current good manufacturing practice (cGMP).

  4. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos

    2017-07-06

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration, and surfactant concentration; on the other hand, the contact angle responds to interfacial tensions, surface topography, invasion velocity, and chemical interactions. Interfaces are not isolated but interact through the fluid pressure and respond to external fields. Jumps, snap-offs and percolating wetting liquids along edges and crevices are ubiquitous in real, non-cylindrical porous networks. Pore- and macroscale instabilities together with pore structure variability-and-correlation favor fluid trapping and hinder recovery efficiency. The saturation-pressure characteristic curve is affected by the saturation-history, flow-rate, the mechanical response of the porous medium, and time-dependent reactive and diffusive processes; in addition, there are salient differences between unsaturation by internal gas nucleation and gas invasion. Capillary forces add to other skeletal forces in the porous medium and can generate open-mode discontinuities when the capillary entry pressure is high relative to the effective stress. Time emerges as an important variable in mixed-fluid conditions and common quasi-static analyses may fail to capture the system response.

  5. Solid catalyzed isoparaffin alkylation at supercritical fluid and near-supercritical fluid conditions

    Science.gov (United States)

    Ginosar, Daniel M.; Fox, Robert V.; Kong, Peter C.

    2000-01-01

    This invention relates to an improved method for the alkylation reaction of isoparaffins with olefins over solid catalysts including contacting a mixture of an isoparaffin, an olefin and a phase-modifying material with a solid acid catalyst member under alkylation conversion conditions at either supercritical fluid, or near-supercritical fluid conditions, at a temperature and a pressure relative to the critical temperature(T.sub.c) and the critical pressure(P.sub.c) of the reaction mixture. The phase-modifying phase-modifying material is employed to promote the reaction's achievement of either a supercritical fluid state or a near-supercritical state while simultaneously allowing for decreased reaction temperature and longer catalyst life.

  6. Operation and Performance of the Supercritical Fluids Reactor (SFR)

    National Research Council Canada - National Science Library

    Hanush, R

    1996-01-01

    The Supercritical Fluids Reactor (SFR) at Sandia National Laboratories, CA has been developed to examine and solve engineering, process, and fundamental chemistry issues regarding the development of supercritical water oxidation (SCWO...

  7. Structural behavior of supercritical fluids under confinement

    Science.gov (United States)

    Ghosh, Kanka; Krishnamurthy, C. V.

    2018-01-01

    The existence of the Frenkel line in the supercritical regime of a Lennard-Jones (LJ) fluid shown through molecular dynamics (MD) simulations initially and later corroborated by experiments on argon opens up possibilities of understanding the structure and dynamics of supercritical fluids in general and of the Frenkel line in particular. The location of the Frenkel line, which demarcates two distinct physical states, liquidlike and gaslike within the supercritical regime, has been established through MD simulations of the velocity autocorrelation (VACF) and radial distribution function (RDF). We, in this article, explore the changes in the structural features of supercritical LJ fluid under partial confinement using atomistic walls. The study is carried out across the Frenkel line through a series of MD simulations considering a set of thermodynamics states in the supercritical regime (P =5000 bar, 240 K ≤T ≤1500 K ) of argon well above the critical point. Confinement is partial, with atomistic walls located normal to z and extending to "infinity" along the x and y directions. In the "liquidlike" regime of the supercritical phase, particles are found to be distributed in distinct layers along the z axis with layer spacing less than one atomic diameter and the lateral RDF showing amorphous-like structure for specific spacings (packing frustration) and non-amorphous-like structure for other spacings. Increasing the rigidity of the atomistic walls is found to lead to stronger layering and increased structural order. For confinement with reflective walls, layers are found to form with one atomic diameter spacing and the lateral RDF showing close-packed structure for the smaller confinements. Translational order parameter and excess entropy assessment confirms the ordering taking place for atomistic wall and reflective wall confinements. In the "gaslike" regime of the supercritical phase, particle distribution along the spacing and the lateral RDF exhibit features

  8. Supercritical fluids in separation science--the dreams, the reality and the future.

    Science.gov (United States)

    Smith, R M

    1999-09-24

    The last 20 years have seen an intense interest in the use of supercritical fluids in separation science. This started with the introduction of commercial instruments first for packed and then for capillary chromatography and it looked as if this would be a technique to rival gas-liquid chromatography and HPLC. The activity developed quite rapidly into packed column supercritical fluid separations then into supercritical fluid extraction. However, in recent years there has been a decline in publications. These later techniques continue to be used but are now principally applied to a limited group of applications where they offer significant advantages over alternative techniques. This review looks back over this period and analyses how these methods were developed and the fluids, detectors and applications that were examined. It suggests why many of the initial applications have vanished and why the initial apparent promise was not fulfilled. The rise and fall of supercritical fluids represents a lesson in the way analysts approach new techniques and how we might view other new separation developments at the end of this millennium. The review looks forward to the future of supercritical fluids and their role at the end of the first century of separation science. Probably the most important idea that supercritical fluids have brought to separation science is a recognition that there is unity in the separation methods and that a continuum exists from gases to liquids.

  9. Effects of fluid dynamics on cleaning efficacy of supercritical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.R.; Willcox, W.A.; Silva, L.J.; Butner, R.S.

    1993-03-01

    Pacific Northwest Laboratory (PNL) and Boeing Aerospace Company are developing a process to clean metal parts using a supercritical solvent. This work is part of an effort to address issues inhibiting the rapid commercialization of Supercritical Fluid Parts Cleaning (SFPC). PNL assembled a SFPC test stand to observe the relationship between the fluid dynamics of the system and the mass transfer of a contaminant from the surface of a contaminated metal coupon into the bulk fluid. The bench-scale test stand consists of a Berty'' autoclave modified for these tests and supporting hardware to achieve supercritical fluids parts cleaning. Three separate sets of tests were conducted using supercritical carbon dioxide. For the first two tests, a single stainless steel coupon was cleaned with organic solvents to remove surface residue, doped with a single contaminant, and then cleaned in the SFPC test stand. Contaminants studied were Dow Corning 200 fluid (dimethylpolysiloxane) and Castle/Sybron X-448 High-temperature Oil (a polybutane/mineral oil mixture). A set of 5-minute cleaning runs was conducted for each dopant at various autoclave impeller speeds. Test results from the first two sets of experiments indicate that precision cleaning for difficult-to-remove contaminants can be dramatically improved by introducing and increasing turbulence within the system. Metal coupons that had been previously doped with aircraft oil were used in a third set of tests. The coupons were placed in the SFPC test stand and subjected to different temperatures, pressures, and run times at a constant impeller speed. The cleanliness of each part was measured by Optically Stimulated Electron Emission. The third set of tests show that levels of cleanliness attained with supercritical carbon dioxide compare favorably with solvent and aqueous cleaning levels.

  10. Effects of fluid dynamics on cleaning efficacy of supercritical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.R.; Willcox, W.A.; Silva, L.J.; Butner, R.S.

    1993-03-01

    Pacific Northwest Laboratory (PNL) and Boeing Aerospace Company are developing a process to clean metal parts using a supercritical solvent. This work is part of an effort to address issues inhibiting the rapid commercialization of Supercritical Fluid Parts Cleaning (SFPC). PNL assembled a SFPC test stand to observe the relationship between the fluid dynamics of the system and the mass transfer of a contaminant from the surface of a contaminated metal coupon into the bulk fluid. The bench-scale test stand consists of a ``Berty`` autoclave modified for these tests and supporting hardware to achieve supercritical fluids parts cleaning. Three separate sets of tests were conducted using supercritical carbon dioxide. For the first two tests, a single stainless steel coupon was cleaned with organic solvents to remove surface residue, doped with a single contaminant, and then cleaned in the SFPC test stand. Contaminants studied were Dow Corning 200 fluid (dimethylpolysiloxane) and Castle/Sybron X-448 High-temperature Oil (a polybutane/mineral oil mixture). A set of 5-minute cleaning runs was conducted for each dopant at various autoclave impeller speeds. Test results from the first two sets of experiments indicate that precision cleaning for difficult-to-remove contaminants can be dramatically improved by introducing and increasing turbulence within the system. Metal coupons that had been previously doped with aircraft oil were used in a third set of tests. The coupons were placed in the SFPC test stand and subjected to different temperatures, pressures, and run times at a constant impeller speed. The cleanliness of each part was measured by Optically Stimulated Electron Emission. The third set of tests show that levels of cleanliness attained with supercritical carbon dioxide compare favorably with solvent and aqueous cleaning levels.

  11. Using supercritical fluids to refine hydrocarbons

    Science.gov (United States)

    Yarbro, Stephen Lee

    2014-11-25

    This is a method to reactively refine hydrocarbons, such as heavy oils with API gravities of less than 20.degree. and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure using a selected fluid at supercritical conditions. The reaction portion of the method delivers lighter weight, more volatile hydrocarbons to an attached contacting device that operates in mixed subcritical or supercritical modes. This separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques. This method produces valuable products with fewer processing steps, lower costs, increased worker safety due to less processing and handling, allow greater opportunity for new oil field development and subsequent positive economic impact, reduce related carbon dioxide, and wastes typical with conventional refineries.

  12. Fast infrared spectroscopy in supercritical fluids

    International Nuclear Information System (INIS)

    Sun, X.

    2000-05-01

    Chapter 1: Introduction. A brief introduction to supercritical fluids is given, illustrating why supercritical fluids are unique solvents and why there is a wide application of supercritical fluids in industry and laboratories. Potential ways for solvation in supercritical fluids to affect reactivity are briefly reviewed. A general introduction to the photochemistry of organometallic complexes is also given. Chapter 2: Time resolved vibrational spectroscopy. Time resolved resonance Raman is introduced and compared with Time-resolved infrared spectroscopy (TRIR). The different approaches of TRIR, including microsecond, nanosecond, and ultrafast (picosecond and femtosecond) systems are discussed. The advantages and disadvantages of these systems are also compared. The TRIR apparatus using an IR diode laser used for work in this thesis are described in detail. Experimental procedures for supercritical fluid TRIR experiments are described with emphasis on handling the IR cell for supercritical fluids and preparation of supercritical fluid solutions. Chapter 3: Photochemistry of group VIB hexacarbonyl compounds in supercritical noble gases and CO 2 solutions. A systematic TRIR study of the photolysis of M(CO) 6 in supercritical Ar, Kr, Xe, and CO 2 and the observation of M(CO) 5 L (M = Cr, Mo, and W; L = Ar (W only), Kr, Xe, and CO 2 ) is described. The second-order rate constants for the reaction of M(CO) 5 L with CO have been evaluated and the reactivity for each metal is Kr > Xe ∼ CO 2 . For M(CO) 5 Kr, M(CO) 5 Xe, or M(CO) 5 (CO 2 ), the reactivity is Cr ∼ Mo > W. In supercritical Kr doped with either Xe or CO 2 , the M(CO) 5 moiety interacts with Xe or CO 2 in preference to Kr. The effect of solvent density on the rate of the reaction of W(CO) 5 (CO 2 ) with CO has been investigated. The reaction of W(CO) 5 (CO 2 ) with CO in scCO 2 is predominantly a dissociative process. The activation energies for the reaction of W(CO) 5 Xe and W(CO) 5 (CO 2 ) with CO and

  13. Supercritical Fluids Processing of Biomass to Chemicals and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Olson, Norman K. [Iowa State Univ., Ames, IA (United States)

    2011-09-28

    The main objective of this project is to develop and/or enhance cost-effective methodologies for converting biomass into a wide variety of chemicals, fuels, and products using supercritical fluids. Supercritical fluids will be used both to perform reactions of biomass to chemicals and products as well as to perform extractions/separations of bio-based chemicals from non-homogeneous mixtures. This work supports the Biomass Program’s Thermochemical Platform Goals. Supercritical fluids are a thermochemical approach to processing biomass that, while aligned with the Biomass Program’s interests in gasification and pyrolysis, offer the potential for more precise and controllable reactions. Indeed, the literature with respect to the use of water as a supercritical fluid frequently refers to “supercritical water gasification” or “supercritical water pyrolysis.”

  14. Development of a test facility for analyzing supercritical fluid blowdown

    Energy Technology Data Exchange (ETDEWEB)

    Roberto, Thiago D.; Alvim, Antonio C.M., E-mail: thiagodbtr@gmail.com [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Silva, Mario A.B. da, E-mail: mabs500@gmail.com [Universidade Federal de Pernambuco (CTG/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Lapa, Celso M.F., E-mail: lapa@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The generation IV nuclear reactors under development mostly use supercritical fluids as the working fluid because higher temperatures improve the thermal efficiency. Supercritical fluids are used by modern nuclear power plants to achieve thermal efficiencies of around 45%. With water as the supercritical working fluid, these plants operate at a high temperature and pressure. However, experiments on supercritical water are limited by technical and financial difficulties. These difficulties can be overcome by using model fluids, which have more feasible supercritical conditions and exhibit a lower critical pressure and temperature. Experimental research is normally used to determine the conditions under which model fluids represent supercritical fluids under steady-state conditions. A fluid-to-fluid scaling approach has been proposed to determine model fluids that can represent supercritical fluids in a transient state. This paper presents an application of fractional scale analysis to determine the simulation parameters for a depressurization test facility. Carbon dioxide (CO{sub 2}) and R134a gas were considered as the model fluids because their critical point conditions are more feasible than those of water. The similarities of water (prototype), CO{sub 2} (model) and R134a (model) for depressurization in a pressure vessel were analyzed. (author)

  15. Development of a test facility for analyzing supercritical fluid blowdown

    International Nuclear Information System (INIS)

    Roberto, Thiago D.; Alvim, Antonio C.M.

    2015-01-01

    The generation IV nuclear reactors under development mostly use supercritical fluids as the working fluid because higher temperatures improve the thermal efficiency. Supercritical fluids are used by modern nuclear power plants to achieve thermal efficiencies of around 45%. With water as the supercritical working fluid, these plants operate at a high temperature and pressure. However, experiments on supercritical water are limited by technical and financial difficulties. These difficulties can be overcome by using model fluids, which have more feasible supercritical conditions and exhibit a lower critical pressure and temperature. Experimental research is normally used to determine the conditions under which model fluids represent supercritical fluids under steady-state conditions. A fluid-to-fluid scaling approach has been proposed to determine model fluids that can represent supercritical fluids in a transient state. This paper presents an application of fractional scale analysis to determine the simulation parameters for a depressurization test facility. Carbon dioxide (CO 2 ) and R134a gas were considered as the model fluids because their critical point conditions are more feasible than those of water. The similarities of water (prototype), CO 2 (model) and R134a (model) for depressurization in a pressure vessel were analyzed. (author)

  16. Modern supercritical fluid technology for food applications.

    Science.gov (United States)

    King, Jerry W

    2014-01-01

    This review provides an update on the use of supercritical fluid (SCF) technology as applied to food-based materials. It advocates the use of the solubility parameter theory (SPT) for rationalizing the results obtained when employing sub- and supercritical media to food and nutrient-bearing materials and for optimizing processing conditions. Total extraction and fractionation of foodstuffs employing SCFs are compared and are illustrated by using multiple fluids and unit processes to obtain the desired food product. Some of the additional prophylactic benefits of using carbon dioxide as the processing fluid are explained and illustrated with multiple examples of commercial products produced using SCF media. I emphasize the role of SCF technology in the context of environmentally benign and sustainable processing, as well as its integration into an overall biorefinery concept. Conclusions are drawn in terms of current trends in the field and future research that is needed to secure new applications of the SCF platform as applied in food science and technology.

  17. Supercritical fluid technologies for ceramic-processing applications

    International Nuclear Information System (INIS)

    Matson, D.W.; Smith, R.D.

    1989-01-01

    This paper reports on the applications of supercritical fluid technologies for ceramic processing. The physical and chemical properties of these densified gases are summarized and related to their use as solvents and processing media. Several areas are identified in which specific ceramic processes benefit from the unique properties of supercritical fluids. The rapid expansion of supercritical fluid solutions provides a technique for producing fine uniform powders and thin films of widely varying materials. Supercritical drying technologies allow the formation of highly porous aerogel products with potentially wide application. Hydrothermal processes leading to the formation of large single crystals and microcrystalline powders can also be extended into the supercritical regime of water. Additional applications and potential applications are identified in the areas of extraction of binders and other additives from ceramic compacts, densification of porous ceramics, the formation of powders in supercritical micro-emulsions, and in preceramic polymer processing

  18. Introduction to supercritical fluids a spreadsheet-based approach

    CERN Document Server

    Smith, Richard; Peters, Cor

    2013-01-01

    This text provides an introduction to supercritical fluids with easy-to-use Excel spreadsheets suitable for both specialized-discipline (chemistry or chemical engineering student) and mixed-discipline (engineering/economic student) classes. Each chapter contains worked examples, tip boxes and end-of-the-chapter problems and projects. Part I covers web-based chemical information resources, applications and simplified theory presented in a way that allows students of all disciplines to delve into the properties of supercritical fluids and to design energy, extraction and materials formation systems for real-world processes that use supercritical water or supercritical carbon dioxide. Part II takes a practical approach and addresses the thermodynamic framework, equations of state, fluid phase equilibria, heat and mass transfer, chemical equilibria and reaction kinetics of supercritical fluids. Spreadsheets are arranged as Visual Basic for Applications (VBA) functions and macros that are completely (source code) ...

  19. Molecular dynamics simulation of supercritical fluids

    Science.gov (United States)

    Branam, Richard D.

    Axisymmetric injectors appear in a multitude of applications ranging from rocket engines to biotechnology. While experimentation is limited to larger injectors, much interest has been shown in the micro- and nano-scales as well. Experimentation at these scales can be cost prohibitive if even possible. Often, the operating regime involves supercritical fluids or complex geometries. Molecular dynamics modeling provides a unique way to explore these flow regimes, calculate hard to measure flow parameters accurately, and determine the value of potential improvements before investing in costly experiments or manufacturing. This research effort modeled sub- and supercritical fluid flow in a cylindrical tube being injected into a quiescent chamber. The ability of four wall models to provide an accurate simulation was compared. The simplest model, the diffuse wall, proved useful in getting results quickly but the results for the higher density cases are questionable, especially with respect to velocity profiles and density distributions. The one zone model, three layers of an fcc solid tethered to the lattice sites with a spring, proved very useful for this research primarily because it did not need as many CPU hours to equilibrate. The two zone wall uses springs as a two body potential and has a second stationary zone to hold the wall in place. The most complicated, the three zone wall, employed a reactionary zone, a stochastic zone and a stationary zone using a Lennard-Jones two body potential. Jet simulations were conducted on argon and nitrogen for liquid tube diameters from 20 to 65 A at both sub and supercritical temperatures (Ar: 130 K and 160 K, N2: 120 K and 130 K). The simulations focused on pressures above the critical pressure (Ar: 6 MPa, N2: 4 MPa). The diffusive wall showed some variation from the analytical velocity profile in the tube while the atomistically modeled walls performed very well. The walls were all able to maintain system temperature to reach

  20. Supercritical Fluid Extraction of Aflatoxin B 1 from Soil

    Science.gov (United States)

    This research describes the development of a Supercritical Fluid Extraction (SFE) method to recover aflatoxin B1 from fortified soil. The effects of temperature, pressure, modifier (identity and percentage), and extraction type were assessed. Using the optimized SFE conditions, ...

  1. Supercritical fluid technology for energy and environmental applications

    CERN Document Server

    Anikeev, Vladimir

    2014-01-01

    Supercritical Fluid Technology for Energy and Environmental Applications covers the fundamental principles involved in the preparation and characterization of supercritical fluids (SCFs) used in the energy production and other environmental applications. Energy production from diversified resources - including renewable materials - using clean processes can be accomplished using technologies like SCFs. This book is focused on critical issues scientists and engineers face in applying SCFs to energy production and environmental protection, the innovative solutions they have found, and the challenges they need to overcome. The book also covers the basics of sub- and supercritical fluids, like the thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations. A supercritical fluid is any substance at a temperature and pressure above its critical point where distinct liquid and gas phases do not exist. At this state the compound demonstrates unique properties, which can be "fine...

  2. Plastic reactor suitable for high pressure and supercritical fluid electrochemistry

    OpenAIRE

    Branch, Jack; Alibouri, Mehrdad; Cook, David A.; Richardson, Peter; Bartlett, Philip N.; Matefi-Tempfli, Maria; Matefi-Tempfli, Stefan; Bampton, Mark; Cookson, Tamsin; Connell, Phil; Smith, David

    2017-01-01

    The paper describes a reactor suitable for high pressure, particularly supercritical fluid, electrochemistry and electrodeposition at pressures up to 30 MPa at 115°C. The reactor incorporates two key, new design concepts; a plastic reactor vessel and the use of o-ring sealed brittle electrodes. These two innovations widen what can be achieved with supercritical fluid electrodeposition. The suitability of the reactor for electroanalytical experiments is demonstrated by studies of the voltammet...

  3. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  4. Plastic reactor suitable for high pressure and supercritical fluid electrochemistry

    DEFF Research Database (Denmark)

    Branch, Jack; Alibouri, Mehrdad; Cook, David A.

    2017-01-01

    The paper describes a reactor suitable for high pressure, particularly supercritical fluid, electrochemistry and electrodeposition at pressures up to 30 MPa at 115◦C. The reactor incorporates two key, new design concepts; a plastic reactor vessel and the use of o-ring sealed brittle electrodes....... These two innovations widen what can be achieved with supercritical fluid electrodeposition. The suitability of the reactor for electroanalytical experiments is demonstrated by studies of the voltammetry of decamethylferrocene in supercritical difluromethane and for electrodeposition is demonstrated...

  5. Injection of Fluids into Supercritical Environments

    National Research Council Canada - National Science Library

    Oschwald, M

    2004-01-01

    This paper summarizes and compares the results of systematic research programs at two independent laboratories regarding the injection of cryogenic liquids at subcritical and supercritical pressures...

  6. Particle Formation by Supercritical Fluid Extraction and Expansion Process

    Directory of Open Access Journals (Sweden)

    Sujuan Pan

    2013-01-01

    Full Text Available Supercritical fluid extraction and expansion (SFEE patented technology combines the advantages of both supercritical fluid extraction (SFE and rapid expansion of supercritical solution (RESS with on-line coupling, which makes the nanoparticle formation feasible directly from matrix such as Chinese herbal medicine. Supercritical fluid extraction is a green separation technology, which has been developed for decades and widely applied in traditional Chinese medicines or natural active components. In this paper, a SFEE patented instrument was firstly built up and controlled by LABVIEW work stations. Stearic acid was used to verify the SFEE process at optimized condition; via adjusting the preexpansion pressure and temperature one can get different sizes of particles. Furthermore, stearic acid was purified during the SFEE process with HPLC-ELSD detecting device; purity of stearic acid increased by 19%, and the device can purify stearic acid.

  7. Supercritical fluid chromatography in pharmaceutical analysis.

    Science.gov (United States)

    Desfontaine, Vincent; Guillarme, Davy; Francotte, Eric; Nováková, Lucie

    2015-09-10

    In the last few years, there has been a resurgence of supercritical fluid chromatography (SFC), which has been stimulated by the introduction of a new generation of instruments and columns from the main providers of chromatographic instrumentation, that are strongly committed to advancing the technology. The known limitations of SFC, such as weak UV sensitivity, limited reliability and poor quantitative performance have been mostly tackled with these advanced instruments. In addition, due to the obvious benefits of SFC in terms of kinetic performance and its complementarity to LC, advanced packed-column SFC represents today an additional strategy in the toolbox of the analytical scientist, which may be particularly interesting in pharmaceutical analysis. In the present review, the instrumentation and experimental conditions (i.e. stationary phase chemistry and dimensions, mobile phase nature, pressure and temperature) to perform "advanced SFC" are discussed. The applicability of SFC in pharmaceutical analysis, including the determination of drugs in formulations and biofluids is critically discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Design of preparative-supercritical fluid chromatography.

    Science.gov (United States)

    Rajendran, Arvind

    2012-08-10

    Preparative supercritical fluid chromatography (prep-SFC) is an important separation process in the chromatographers toolbox. Owing to the unique properties of the mobile phase, which is predominantly CO(2), the behavior of SFC is markedly different from high performance liquid chromatography (HPLC). This review article focuses on the scale-up of preparative chromatography. The basics of SFC, with particular focus on highlighting the key differences between SFC and HPLC, are introduced. Then, a framework for rational design of prep-SFC is proposed. This framework is based on obtaining basic system parameters from analytical scale equipment, i.e., with very small amount of material, and performing design and optimization in silico to evaluate process performance and to identify operating conditions for scale-up. The tools required to obtain the input parameters such as adsorption isotherms are discussed and the development of the design and optimization framework is elaborated. Examples from the literature which use this approach for successful scale-up are provided. Finally the design of multi-column SFC systems is discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Thermophysical properties of supercritical fluids and fluid mixtures

    International Nuclear Information System (INIS)

    Sengers, J.V.

    1991-07-01

    This research is concerned with the development of a quantitative scientific description of the thermodynamic and transport properties of supercritical and subcritical fluids and fluid mixtures. It is known that the thermophysical properties of fluids and fluid mixtures asymptotically close to the critical point satisfy scaling laws with universal critical exponents and universal scaling functions. However, the range of validity of these asymptotic scaling laws is quite small. As a consequence, the impact of the modern theory of critical phenomena on chemical engineering has been limited. On the other hand, an a priori estimate of the range of temperatures and densities, where critical fluctuations become significant, can be made on the basis of the so-called Ginzburg criterion. A recent analysis of this criterion suggests that this range is actually quite large and for a fluid like carbon dioxide can easily extend to 100 degrees or so above the critical temperature. Hence, the use of traditional engineering equations like cubic equations is not scientifically justified in a very wide range of temperatures and densities around the critical point. We have therefore embarked on a scientific approach to deal with the global effects of critical fluctuations on the thermophysical properties of fluids and fluid mixtures. For this purpose it is not sufficient to consider the asymptotic critical fluctuations but we need to deal also with the nonasymptotic critical fluctuations. The goal is to develop scientifically based questions that account for the crossover of the thermophysical properties from their asymptotic singular behavior in the near vicinity of the critical point to their regular behavior very far away from the critical point

  10. The Effects of Supercritical Fluids on High Performance Polymers

    Science.gov (United States)

    1989-02-01

    polyamides and other polymer types that might be useful for direct spinning of high performa-ce fibers. 5 II. SUPERCITCAL FUID FLOW EXPERMENTS. A...for tednical assiLtance and for loan of the supercritical fluid flow apparatus. Also the assistance of M. Mahar and W. Koza for static tensile tests...Supercritical Flow Apparatus 7 2 Ballistic Stress-Strain Oirves 11 3 Untreated Spectra 1000 17 4 Extracted Spectra 1000 18 5 Untreated Spectra 900 19 6

  11. Industrial applications and current trends in supercritical fluid technologies

    Directory of Open Access Journals (Sweden)

    Gamse Thomas

    2005-01-01

    Full Text Available Supercritical fluids have a great potential for wide fields of processes Although CO2 is still one of the most used supercritical gases, for special purposes propane or even fluorinated-chlorinated fluids have also been tested. The specific characteristics of supercritical fluids behaviour were analyzed such as for example the solubilities of different components and the phase equilibria between the solute and solvent. The application at industrial scale (decaffeinating of tea and coffee, hop extraction or removal of pesticides from rice, activity in supercritical extraction producing total extract from the raw material or different fractions by using the fractionated separation of beverages (rum, cognac, whisky, wine, beer cider, of citrus oils and of lipids (fish oils, tall oil were also discussed. The main interest is still for the extraction of natural raw materials producing food ingredients, nutraceuticals and phytopharmaceuticals but also cleaning purposes were tested such as the decontamination of soils the removal of residual solvents from pharmaceutical products, the extraction of flame retardants from electronic waste or precision degreasing and cleaning of mechanical and electronic parts. An increasing interest obviously exists for impregnation purposes based on supercritical fluids behaviour, as well as for the dying of fibres and textiles. The production of fine particles in the micron and submicron range, mainly for pharmaceutical products is another important application of supercritical fluids. Completely new products can be produced which is not possible under normal conditions. Supercritical fluid technology has always had to compete with the widespread opinion that these processes are very expensive due to very high investment costs in comparison with classical low-pressure equipment. Thus the opinion is that these processes should be restricted to high-added value products. A cost estimation for different plant sizes and

  12. Particle Formation and Product Formulation Using Supercritical Fluids.

    Science.gov (United States)

    Knez, Željko; Knez Hrnčič, Maša; Škerget, Mojca

    2015-01-01

    Traditional methods for solids processing involve either high temperatures, necessary for melting or viscosity reduction, or hazardous organic solvents. Owing to the negative impact of the solvents on the environment, especially on living organisms, intensive research has focused on new, sustainable methods for the processing of these substances. Applying supercritical fluids for particle formation may produce powders and composites with special characteristics. Several processes for formation and design of solid particles using dense gases have been studied intensively. The unique thermodynamic and fluid-dynamic properties of supercritical fluids can be used also for impregnation of solid particles or for the formation of solid powderous emulsions and particle coating, e.g., for formation of solids with unique properties for use in different applications. We give an overview of the application of sub- and supercritical fluids as green processing media for particle formation processes and present recent advances and trends in development.

  13. Supercritical fluid processing: opportunities for new resist materials and processes

    Science.gov (United States)

    Gallagher-Wetmore, Paula M.; Ober, Christopher K.; Gabor, Allen H.; Allen, Robert D.

    1996-05-01

    Over the past two decades supercritical fluids have been utilized as solvents for carrying out separations of materials as diverse as foods, polymers, pharmaceuticals, petrochemicals, natural products, and explosives. More recently they have been used for non-extractive applications such as recrystallization, deposition, impregnation, surface modification, and as a solvent alternative for precision parts cleaning. Today, supercritical fluid extraction is being practiced in the foods and beverage industries; there are commercial plants for decaffeinating coffee and tea, extracting beer flavoring agents from hops, and separating oils and oleoresins from spices. Interest in supercritical fluid processing of polymers has grown over the last ten years, and many new purification, fractionation, and even polymerization techniques have emerged. One of the most significant motivations for applying this technology to polymers has been increased performance demands. More recently, with increasing scrutiny of traditional solvents, supercritical fluids, and in particular carbon dioxide, are receiving widespread attention as 'environmentally conscious' solvents. This paper describes several examples of polymers applications, including a few involving photoresists, which demonstrate that as next- generation advanced polymer systems emerge, supercritical fluids are certain to offer advantages as cutting edge processing tools.

  14. Near- and supercritical water as a diameter manipulation and surface roughening agent in fused silica capillaries

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Planeta, Josef; Roth, Michal

    2013-01-01

    Roč. 85, č. 1 (2013), s. 327-333 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA ČR(CZ) GAP206/11/0138 Institutional support: RVO:68081715 Keywords : supercritical water * fused silica capillary * surface treatment Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.825, year: 2013

  15. Isoelectric focusing in continuously tapered fused silica capillary prepared by etching with supercritical water

    Czech Academy of Sciences Publication Activity Database

    Šlais, Karel; Horká, Marie; Karásek, Pavel; Planeta, Josef; Roth, Michal

    2013-01-01

    Roč. 85, č. 9 (2013), s. 4296-4300 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GAP106/12/0522; GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : capillary isoelectric focusing * resolution of ampholytes * supercritical water Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.825, year: 2013

  16. Determination of major aromatic constituents in vanilla using an on-line supercritical fluid extraction coupled with supercritical fluid chromatography.

    Science.gov (United States)

    Liang, Yanshan; Liu, Jiaqi; Zhong, Qisheng; Shen, Lingling; Yao, Jinting; Huang, Taohong; Zhou, Ting

    2018-04-01

    An on-line supercritical fluid extraction coupled with supercritical fluid chromatography method was developed for the determination of four major aromatic constituents in vanilla. The parameters of supercritical fluid extraction were systematically investigated using single factor optimization experiments and response surface methodology by a Box-Behnken design. The modifier ratio, split ratio, and the extraction temperature and pressure were the major parameters which have significant effects on the extraction. While the static extraction time, dynamic extraction time, and recycle time had little influence on the compounds with low polarity. Under the optimized conditions, the relative extraction efficiencies of all the constituents reached 89.0-95.1%. The limits of quantification were in the range of 1.123-4.747 μg. The limits of detection were in the range of 0.3368-1.424 μg. The recoveries of the four analytes were in the range of 76.1-88.9%. The relative standard deviations of intra- and interday precision ranged from 4.2 to 7.6%. Compared with other off-line methods, the present method obtained higher extraction yields for all four aromatic constituents. Finally, this method has been applied to the analysis of vanilla from different sources. On the basis of the results, the on-line supercritical fluid extraction-supercritical fluid chromatography method shows great promise in the analysis of aromatic constituents in natural products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Widom Lines in Binary Mixtures of Supercritical Fluids.

    Science.gov (United States)

    Raju, Muralikrishna; Banuti, Daniel T; Ma, Peter C; Ihme, Matthias

    2017-06-08

    Recent experiments on pure fluids have identified distinct liquid-like and gas-like regimes even under supercritical conditions. The supercritical liquid-gas transition is marked by maxima in response functions that define a line emanating from the critical point, referred to as Widom line. However, the structure of analogous state transitions in mixtures of supercritical fluids has not been determined, and it is not clear whether a Widom line can be identified for binary mixtures. Here, we present first evidence for the existence of multiple Widom lines in binary mixtures from molecular dynamics simulations. By considering mixtures of noble gases, we show that, depending on the phase behavior, mixtures transition from a liquid-like to a gas-like regime via distinctly different pathways, leading to phase relationships of surprising complexity and variety. Specifically, we show that miscible binary mixtures have behavior analogous to a pure fluid and the supercritical state space is characterized by a single liquid-gas transition. In contrast, immiscible binary mixture undergo a phase separation in which the clusters transition separately at different temperatures, resulting in multiple distinct Widom lines. The presence of this unique transition behavior emphasizes the complexity of the supercritical state to be expected in high-order mixtures of practical relevance.

  18. Extraction of metals using supercritical fluid and chelate forming ligand

    International Nuclear Information System (INIS)

    Wai, C.M.; Laintz, K.E.

    1998-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated β-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated β-diketone and a trialkyl phosphate, or a fluorinated β-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated β-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process. 7 figs

  19. Producing Polymer Fibers by Electrospinning in Supercritical Fluids

    Directory of Open Access Journals (Sweden)

    Lu Li

    2013-01-01

    Full Text Available Nanofibers have a wide range of applications, including filtration and biomedical engineering. Porous or hollow fibers with large surface-to-volume ratios are more popular in some fields than the common nanofibers. Porous nanofibers can be obtained through electrospinning with highly volatile solvents or through special treatment following electrospinning. A new process where electrospinning is conducted in supercritical or near-critical CO2 to produce porous or hollow nanofibers has been summarized. In addition, a process entailing compressed N2-assisted electrospinning was attempted to produce PVP nanofibers in this work, but it was proved to be unsuccessful. Since the fiber morphologies are dependent on the phase behavior of organic solvents in supercritical fluids, ASPEN PLUS 2006 was used to simulate the phase equilibrium of the solvent-supercritical fluid system to explain why porous or hollow fibers can be obtained in compressed CO2, but not in compressed N2.

  20. Capillary pressure and saturation relations for supercritical CO2 and brine in sand: High-pressure Pc(Sw) controller/meter measurements and capillary scaling predictions

    Science.gov (United States)

    Tokunaga, Tetsu K.; Wan, Jiamin; Jung, Jong-Won; Kim, Tae Wook; Kim, Yongman; Dong, Wenming

    2013-08-01

    In geologic carbon sequestration, reliable predictions of CO2 storage require understanding the capillary behavior of supercritical (sc) CO2. Given the limited availability of measurements of the capillary pressure (Pc) dependence on water saturation (Sw) with scCO2 as the displacing fluid, simulations of CO2 sequestration commonly rely on modifying more familiar air/H2O and oil/H2O Pc(Sw) relations, adjusted to account for differences in interfacial tensions. In order to test such capillary scaling-based predictions, we developed a high-pressure Pc(Sw) controller/meter, allowing accurate Pc and Sw measurements. Drainage and imbibition processes were measured on quartz sand with scCO2-brine at pressures of 8.5 and 12.0 MPa (45°C), and air-brine at 21°C and 0.1 MPa. Drainage and rewetting at intermediate Sw levels shifted to Pc values that were from 30% to 90% lower than predicted based on interfacial tension changes. Augmenting interfacial tension-based predictions with differences in independently measured contact angles from different sources led to more similar scaled Pc(Sw) relations but still did not converge onto universal drainage and imbibition curves. Equilibrium capillary trapping of the nonwetting phases was determined for Pc = 0 during rewetting. The capillary-trapped volumes for scCO2 were significantly greater than for air. Given that the experiments were all conducted on a system with well-defined pore geometry (homogeneous sand), and that scCO2-brine interfacial tensions are fairly well constrained, we conclude that the observed deviations from scaling predictions resulted from scCO2-induced decreased wettability. Wettability alteration by scCO2 makes predicting hydraulic behavior more challenging than for less reactive fluids.

  1. Supercritical fluid chromatography-A Hybrid of GC and LC

    Directory of Open Access Journals (Sweden)

    Neha Sethi

    2010-01-01

    Full Text Available High performance specifications and unique functionality of chromatographic techniques is a demand of pharmaceutical industry and research. This leads to the origin of Supercritical Fluid Chromatography (SFC. It is a rapidly expanding analytical technique. The main feature that differentiates SFC from other chromatographic techniques is the replacement of either the liquid or gas mobile phase with a supercritical fluid mobile phase. It is considered a hybrid of GC and LC technique. High diffusion coefficient and low viscosity of supercritical fluids is responsible for high speed analysis, high efficiency and high sensitivity. Low mobile-phase flow rate, density programming and compatability with GC and LC detectors make SFC a versatile chromatographic technique in analytical re-search and development. It has a unique characteristic of analyzing thermo labile or non-volatile substances. This review highlights the role of supercritical fluid chromatography in the separation of polymers, thermally labile pesticides, fatty acids, metal chelates and organometallic compounds, chiral and achiral molecules, identification and analysis of polar samples, explosives, drugs of abuse and application of SFC in forensic science (fingerprint-ing.

  2. Supercritical Fluid Chromatography- A Hybrid of GC and LC

    Directory of Open Access Journals (Sweden)

    Kaushal K Chandrul

    2010-03-01

    Full Text Available

    High performance specifications and unique functionality of chromatographic techniques is a demand of pharmaceutical industry and research. This leads to the origin of Supercritical Fluid Chromatography (SFC. It is a rapidly expanding analytical technique. The main feature that differentiates SFC from other chromatographic techniques is the replacement of either the liquid or gas mobile phase with a supercritical fluid mobile phase. It is considered a hybrid of GC and LC technique. High diffusion coefficient and low viscosity of supercritical fluids is responsible for high speed analysis, high efficiency and high sensitivity. Low mobile-phase flow rate, density programming and compatability with GC and LC detectors make SFC a versatile chromatographic technique in analytical research and development. It has a unique characteristic of analyzing thermo labile or non-volatile substances. This review highlights the role of supercritical fluid chromatography in the separation of polymers, thermally labile pesticides, fatty acids, metal chelates and organometallic compounds, chiral and achiral molecules, identification and analysis of polar samples, explosives, drugs of abuse and application of SFC in forensic science (fingerprinting. 

  3. Supercritical water-treated fused silica capillaries in analytical separations: Status review

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Horká, Marie; Šlais, Karel; Planeta, Josef; Roth, Michal

    2018-01-01

    Roč. 1539, MAR (2018), s. 1-11 ISSN 0021-9673 R&D Projects: GA MV VI20172020069; GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Institutional support: RVO:68081715 Keywords : supercritical water * fused silica capillary * surface treatment Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  4. Research activities on supercritical fluid science in food biotechnology.

    Science.gov (United States)

    Khosravi-Darani, Kianoush

    2010-06-01

    This article serves as an overview, introducing the currently popular area of supercritical fluids and their uses in food biotechnology. Within each application, and wherever possible, the basic principles of the technique, as well as a description of the history, instrumentation, methodology, uses, problems encountered, and advantages over the traditional, non-supercritical methods are given. Most current commercial application of the supercritical extraction involve biologically-produced materials; the technique may be particularly relevant to the extraction of biological compounds in cases where there is a requirement for low-temperature processing, high mass-transfer rates, and negligible carrying over of the solvent into the final product. Special applications to food processing include the decaffeination of green coffee beans, the production of hops extracts, the recovery of aromas and flavors from herbs and spices, the extraction and fractionation of edible oils, and the removal of contaminants, among others. New advances, in which the extraction is combined with reaction or crystallization steps, may further increase the attractiveness of supercritical fluids in the bioprocess industries. To develop and establish a novel and effective alternative to heating treatment, the lethal action of high hydrostatic pressure CO(2) on microorganisms, with none or only a minimal heating process, has recently received a great deal of attention.

  5. Intermolecular interactions and the thermodynamic properties of supercritical fluids.

    Science.gov (United States)

    Yigzawe, Tesfaye M; Sadus, Richard J

    2013-05-21

    The role of different contributions to intermolecular interactions on the thermodynamic properties of supercritical fluids is investigated. Molecular dynamics simulation results are reported for the energy, pressure, thermal pressure coefficient, thermal expansion coefficient, isothermal and adiabatic compressibilities, isobaric and isochoric heat capacities, Joule-Thomson coefficient, and speed of sound of fluids interacting via both the Lennard-Jones and Weeks-Chandler-Andersen potentials. These properties were obtained for a wide range of temperatures, pressures, and densities. For each thermodynamic property, an excess value is determined to distinguish between attraction and repulsion. It is found that the contributions of intermolecular interactions have varying effects depending on the thermodynamic property. The maxima exhibited by the isochoric and isobaric heat capacities, isothermal compressibilities, and thermal expansion coefficient are attributed to interactions in the Lennard-Jones well. Repulsion is required to obtain physically realistic speeds of sound and both repulsion and attraction are necessary to observe a Joule-Thomson inversion curve. Significantly, both maxima and minima are observed for the isobaric and isochoric heat capacities of the supercritical Lennard-Jones fluid. It is postulated that the loci of these maxima and minima converge to a common point via the same power law relationship as the phase coexistence curve with an exponent of β = 0.32. This provides an explanation for the terminal isobaric heat capacity maximum in supercritical fluids.

  6. Discovering geothermal supercritical fluids: a new frontier for seismic exploration.

    Science.gov (United States)

    Piana Agostinetti, Nicola; Licciardi, Andrea; Piccinini, Davide; Mazzarini, Francesco; Musumeci, Giovanni; Saccorotti, Gilberto; Chiarabba, Claudio

    2017-11-06

    Exploiting supercritical geothermal resources represents a frontier for the next generation of geothermal electrical power plant, as the heat capacity of supercritical fluids (SCF),which directly impacts on energy production, is much higher than that of fluids at subcritical conditions. Reconnaissance and location of intensively permeable and productive horizons at depth is the present limit for the development of SCF geothermal plants. We use, for the first time, teleseismic converted waves (i.e. receiver function) for discovering those horizons in the crust. Thanks to the capability of receiver function to map buried anisotropic materials, the SCF-bearing horizon is seen as the 4km-depth abrupt termination of a shallow, thick, ultra-high (>30%) anisotropic rock volume, in the center of the Larderello geothermal field. The SCF-bearing horizon develops within the granites of the geothermal field, bounding at depth the vapor-filled heavily-fractured rock matrix that hosts the shallow steam-dominated geothermal reservoirs. The sharp termination at depth of the anisotropic behavior of granites, coinciding with a 2 km-thick stripe of seismicity and diffuse fracturing, points out the sudden change in compressibility of the fluid filling the fractures and is a key-evidence of deep fluids that locally traversed the supercritical conditions. The presence of SCF and fracture permeability in nominally ductile granitic rocks open new scenarios for the understanding of magmatic systems and for geothermal exploitation.

  7. Surfactant/Supercritical Fluid Cleaning of Contaminated Substrates

    Science.gov (United States)

    White, Gary L.

    1997-01-01

    CFC's and halogenated hydrocarbon solvents have been the solvents of choice to degrease and otherwise clean precision metal parts to allow proper function. Recent regulations have, however, rendered most of these solvents unacceptable for these purposes. New processes which are being used or which have been proposed to replace these solvents usually either fail to remove water soluble contaminants or produce significant aqueous wastes which must then be disposed of. In this work, a new method for cleaning surfaces will be investigated. Solubility of typical contaminants such as lubricating greases and phosphatizing bath residues will be studied in several surfactant/supercritical fluid solutions. The effect of temperature, pressure, and the composition of the cleaning mixture on the solubility of oily, polar, and ionic contaminants will be investigated. A reverse micellar solution in a supercritical light hydrocarbon solvent will be used to clean samples of industrial wastes. A reverse micellar solution is one where water is dissolved into a non-polar solvent with the aid of a surfactant. The solution will be capable of dissolving both water-soluble contaminants and oil soluble contaminants. Once the contaminants have been dissolved into the solution they will be separated from the light hydrocarbon and precipitated by a relatively small pressure drop and the supercritical solvent will be available for recycle for reuse. The process will be compared to the efficacy of supercritical CO2 cleaning by attempting to clean the same types of substrates and machining wastes with the same contaminants using supercritical CO2. It is anticipated that the supercritical CO2 process will not be capable of removing ionic residues.

  8. Shale oil extraction with supercritical fluid and microwave energy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Maoqi [Southwest Research Institute (United States)

    2011-07-01

    Shale oil extraction, an industrial process for unconventional oil production, is usually performed above ground (ex situ processing) by mining the oil shale and then treating it in processing facilities. Other modern technologies perform the processing underground (on-site or in situ processing) by applying heat and extracting the oil via oil wells. This paper gives an overview of the past field applications of electromagnetic heating on shale oil extraction, including technical challenges and limitations. Unconventional extraction technologies, such as ultrasound, microwave (radio frequency, electromagnetic wave), and fusion are presented. Then, the benefits of a hybrid technology based on a combination of supercritical fluids and microwave energy (SCF-EM) for shale oil extraction are discussed. A combination of several supercritical fluids is analyzed, such as water and CO2, the latter has been used in enhanced oil recovery for decades. In the end, a detailed techno-economic analysis presents the technical challenges, possible solutions and the market barriers.

  9. Heat transfers and related effects in supercritical fluids

    CERN Document Server

    Zappoli, Bernard; Garrabos, Yves

    2015-01-01

    This book investigates the unique hydrodynamics and heat transfer problems that are encountered in the vicinity of the critical point of fluids. Emphasis is given on weightlessness conditions, gravity effects and thermovibrational phenomena. Near their critical point, fluids indeed obey universal behavior and become very compressible and expandable. Their comportment, when gravity effects are suppressed, becomes quite unusual. The problems that are treated in this book are of interest to students and researchers interested in the original behavior of near-critical fluids as well as to engineers that have to manage supercritical fluids. A special chapter is dedicated to the present knowledge of critical point phenomena. Specific data for many fluids are provided, ranging from cryogenics (hydrogen) to high temperature (water). Basic information in statistical mechanics, mathematics and measurement techniques is also included. The basic concepts of fluid mechanics are given for the non-specialists to be able to ...

  10. Purification of radioactive waste oil by a supercritical fluid

    International Nuclear Information System (INIS)

    Yoo, Jaeryong; Sung, Jinhyun; Park, Kwangheon; Kim, Hongdoo; Kim, Hakwon; Lim, Taeyoon; Yim, Sanghak; Yoon, Weonseob

    2006-01-01

    The radioactive waste oil from the nuclear industry is potentially hazardous due to its possibility to contaminate soil and underwater. Pollutants in waste oil are generally radioactive heavy metals or organo-metals. Radioactive waste oils are highly viscous fluids that are similar to used-motor oils. Several processes have been developed to regenerated used motor oil, such as acid clay treatment, chemical addition, vacuum distillation, thermal cracking and hydrofinishing. However, these technologies are difficult to apply to separating radioactive nuclides from radioactive waste oils. In recent years, our laboratory developed a membrane method for the regeneration of used motor oils. We applied supercritical Co2 (scCO2) as a viscosity reducing additive to waste oils at a lower process temperature in order to improve membrane permeability and thus the energy saving. However, the membrane cannot filter the contaminants in radioactive waste oil that are not particles, such as radioactive ions in impurity water in the oil. In this paper, we suggest a method extracting clean oil from the radioactive waste oil rather than filtering by a supercritical fluid. We selected R22, a refrigerant, as a solvent for extraction. R22 has a mild critical point - 96.1 .deg. and 49.9bar. Regeneration of waste oils by extracting clean oil using a supercritical fluid such as R22 is easy to handle and reduce secondary wastes. In this paper, we examine the feasibility of R22 in extracting clean oil from radioactive waste oils

  11. Supercritical Fluid Extraction of Metal Chelate: A Review.

    Science.gov (United States)

    Ding, Xin; Liu, Qinli; Hou, Xiongpo; Fang, Tao

    2017-03-04

    Supercritical fluid extraction (SFE), as a new green extraction technology, has been used in extracting various metal species. The solubilities of chelating agents and corresponding metal chelates are the key factors which influence the efficiency of SFE. Other main properties of them such as stability and selectivity are also reviewed. The extraction mechanisms of mainly used chelating agents are explained by typical examples in this paper. This is the important aspect of SFE of metal ions. Moreover, the extraction efficiencies of metal species also depend on other factors such as temperature, pressure, extraction time and matrix effect. The two main complexation methods namely in-situ and on-line chelating SFE are described in detail. As an efficient chelating agent, tributyl phosphate-nitric acid (TBP-HNO 3 ) complex attracts much attention. The SFE of metal ions, lanthanides and actinides as well as organometallic compounds are also summarized. With the proper selection of ligands, high efficient extraction of metal species can be obtained. As an efficient sample analysis method, supercritical fluid chromatography (SFC) is introduced in this paper. Recently, the extraction method combining ionic liquids (ILs) with supercritical fluid has been becoming a novel technology for treating metal ions. The kinetics related to SFE of metal species is discussed with some specific examples.

  12. Transport properties of supercritical fluids and their binary mixtures

    CERN Document Server

    Luedemann, H D

    2002-01-01

    The molecular dynamics of the two supercritical fluids most applied in industry and some of their mixtures are characterized by their self-diffusion coefficients D sub i , measured by high pressure high resolution nuclear magnetic resonance with the strengthened glass cell technique. The technical details of the apparatus will be given. The fluids studied are carbon dioxide and ammonia. For CO sub 2 , mixtures with C sub 6 H sub 6 , H sub 2 , CH sub 3 COOH and CH sub 3 OH were investigated. The NH sub 3 mixtures include C sub 6 H sub 6 , (CH sub 3) sub 3 N, CH sub 3 CN and CH sub 3 OH.

  13. Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

    Science.gov (United States)

    Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

    A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

  14. Phase equilibrium modeling of triglycerides in supercritical fluids

    International Nuclear Information System (INIS)

    Srinophakun, T.; Phithakchokchai, B.

    2011-01-01

    To design a reactor and separator for a supercritical biodiesel process, phase equilibria of multi-component mixtures in supercritical fluids should be determined using group contribution with association equation of state (GCA-EOS) as a thermodynamics method. The model is considered for two systems of reactants and products. System 1 is comprised of methanol and triglycerides from two sources (palm and Jatropha oils); and System 2 is unconverted methanol, FAME (product) and glycerol (by-product). Pressure and temperature diagrams were developed at different mole fraction of methanol (x MeOH ). As x MeOH increased, the critical temperature (T c ) and pressure (p c ) increased. The increasing temperature causes the immiscibility region and the amount of methanol at the plait point to decrease. The maximum plait point pressure was observed at 19.20 MPa for palm and 19.33 MPa for Jatropha oil systems.

  15. Carbon dioxide-based supercritical fluids as IC manufacturing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Sivils, L.D.; Pierce, T.; Tiefert, K.

    1999-05-11

    The production of integrated circuits (IC's) involves a number of discrete steps which utilize hazardous or regulated solvents and generate large waste streams. ES&H considerations associated with these chemicals have prompted a search for alternative, more environmentally benign solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Research work, conducted at Los Alamos in conjunction with the Hewlett-Packard Company, has lead to the development of a CO{sub 2}-based supercritical fluid treatment system for the stripping of hard-baked photoresists. This treatment system, known as Supercritical CO{sub 2} Resist Remover, or CORR, uses a two-component solvent composed of a nonhazardous, non-regulated compound, dissolved in supercritical CO{sub 2}. The solvent/treatment system has been successfully tested on metallized Si wafers coated with negative and positive photoresist, the latter both before and after ion-implantation. A description of the experimental data will be presented. Based on the initial laboratory results, the project has progressed to the design and construction of prototype, single-wafer photoresist-stripping equipment. The integrated system involves a closed-loop, recirculating cycle which continuously cleans and regenerates the CO{sub 2}, recycles the dissolved solvent, and separates and concentrates the spent resist. The status of the current design and implementation strategy of a treatment system to existing IC fabrication facilities will be discussed. Additional remarks will be made on the use of a SCORR-type system for the cleaning of wafers prior to processing.

  16. Fluid Delivery System For Capillary Electrophoretic Applications.

    Science.gov (United States)

    Li, Qingbo; Liu, Changsheng; Kane, Thomas E.; Kernan, John R.; Sonnenschein, Bernard; Sharer, Michael V.

    2002-04-23

    An automated electrophoretic system is disclosed. The system employs a capillary cartridge having a plurality of capillary tubes. The cartridge has a first array of capillary ends projecting from one side of a plate. The first array of capillary ends are spaced apart in substantially the same manner as the wells of a microtitre tray of standard size. This allows one to simultaneously perform capillary electrophoresis on samples present in each of the wells of the tray. The system includes a stacked, dual carrousel arrangement to eliminate cross-contamination resulting from reuse of the same buffer tray on consecutive executions from electrophoresis. The system also has a gel delivery module containing a gel syringe/a stepper motor or a high pressure chamber with a pump to quickly and uniformly deliver gel through the capillary tubes. The system further includes a multi-wavelength beam generator to generate a laser beam which produces a beam with a wide range of wavelengths. An off-line capillary reconditioner thoroughly cleans a capillary cartridge to enable simultaneous execution of electrophoresis with another capillary cartridge. The streamlined nature of the off-line capillary reconditioner offers the advantage of increased system throughput with a minimal increase in system cost.

  17. Element selective detection for supercritical-fluid chromatography.

    Science.gov (United States)

    Vela, N P; Caruso, J A

    2000-07-05

    This manuscript describes the use of Supercritical-Fluid Chromatography (SFC) with plasma spectrometric detection for the analysis of organometallics. An introduction on the principles and characteristics of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) is included, along with a discussion about requirements for coupling SFC to plasma detection and the different approaches for interfacing SFC to ICP. The last part of this review paper provides a comprehensive description of SFC-ICP applications for the analysis of organometallics containing iron, silicon, tin, chromium, arsenic, lead, mercury and antimony.

  18. Capillary pressure heterogeneity and hysteresis for the supercritical CO2/water system in a sandstone

    Science.gov (United States)

    Pini, Ronny; Benson, Sally M.

    2017-10-01

    We report results from an experimental investigation on the hysteretic behaviour of the capillary pressure curve for the supercritical CO2-water system in a Berea Sandstone core. Previous observations have highlighted the importance of subcore-scale capillary heterogeneity in developing local saturations during drainage; we show in this study that the same is true for the imbibition process. Spatially distributed drainage and imbibition scanning curves were obtained for mm-scale subsets of the rock sample non-invasively using X-ray CT imagery. Core- and subcore-scale measurements are well described using the Brooks-Corey formalism, which uses a linear trapping model to compute mobile saturations during imbibition. Capillary scaling yields two separate universal drainage and imbibition curves that are representative of the full subcore-scale data set. This enables accurate parameterisation of rock properties at the subcore-scale in terms of capillary scaling factors and permeability, which in turn serve as effective indicators of heterogeneity at the same scale even when hysteresis is a factor. As such, the proposed core-analysis workflow is quite general and provides the required information to populate numerical models that can be used to extend core-flooding experiments to conditions prevalent in the subsurface, which would be otherwise not attainable in the laboratory.

  19. On-line coupling of supercritical fluid extraction and chromatographic techniques.

    Science.gov (United States)

    Sánchez-Camargo, Andrea Del Pilar; Parada-Alfonso, Fabián; Ibáñez, Elena; Cifuentes, Alejandro

    2017-01-01

    This review summarizes and discusses recent advances and applications of on-line supercritical fluid extraction coupled to liquid chromatography, gas chromatography, and supercritical fluid chromatographic techniques. Supercritical fluids, due to their exceptional physical properties, provide unique opportunities not only during the extraction step but also in the separation process. Although supercritical fluid extraction is especially suitable for recovery of non-polar organic compounds, this technique can also be successfully applied to the extraction of polar analytes by the aid of modifiers. Supercritical fluid extraction process can be performed following "off-line" or "on-line" approaches and their main features are contrasted herein. Besides, the parameters affecting the supercritical fluid extraction process are explained and a "decision tree" is for the first time presented in this review work as a guide tool for method development. The general principles (instrumental and methodological) of the different on-line couplings of supercritical fluid extraction with chromatographic techniques are described. Advantages and shortcomings of supercritical fluid extraction as hyphenated technique are discussed. Besides, an update of the most recent applications (from 2005 up to now) of the mentioned couplings is also presented in this review. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism

    Science.gov (United States)

    Kawamoto, Tatsuhiko; Kanzaki, Masami; Mibe, Kenji; Ono, Shigeaki

    2012-01-01

    Subduction-zone magmatism is triggered by the addition of H2O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endpoint. We ascertain critical endpoints between aqueous fluids and sediment or high-Mg andesite (HMA) melts located, respectively, at 83-km and 92-km depths by using an in situ observation technique. These depths are within the mantle wedge underlying volcanic fronts, which are formed 90 to 200 km above subducting slabs. These data suggest that sediment-derived supercritical fluids, which are fed to the mantle wedge from the subducting slab, react with mantle peridotite to form HMA supercritical fluids. Such HMA supercritical fluids separate into aqueous fluids and HMA melts at 92 km depth during ascent. The aqueous fluids are fluxed into the asthenospheric mantle to form arc basalts, which are locally associated with HMAs in hot subduction zones. The separated HMA melts retain their composition in limited equilibrium with the surrounding mantle. Alternatively, they equilibrate with the surrounding mantle and change the major element chemistry to basaltic composition. However, trace element signatures of sediment-derived supercritical fluids remain more in the melt-derived magma than in the fluid-induced magma, which inherits only fluid-mobile elements from the sediment-derived supercritical fluids. Separation of slab-derived supercritical fluids into melts and aqueous fluids can elucidate the two slab-derived components observed in subduction zone magma chemistry. PMID:23112158

  1. Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism.

    Science.gov (United States)

    Kawamoto, Tatsuhiko; Kanzaki, Masami; Mibe, Kenji; Matsukage, Kyoko N; Ono, Shigeaki

    2012-11-13

    Subduction-zone magmatism is triggered by the addition of H(2)O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endpoint. We ascertain critical endpoints between aqueous fluids and sediment or high-Mg andesite (HMA) melts located, respectively, at 83-km and 92-km depths by using an in situ observation technique. These depths are within the mantle wedge underlying volcanic fronts, which are formed 90 to 200 km above subducting slabs. These data suggest that sediment-derived supercritical fluids, which are fed to the mantle wedge from the subducting slab, react with mantle peridotite to form HMA supercritical fluids. Such HMA supercritical fluids separate into aqueous fluids and HMA melts at 92 km depth during ascent. The aqueous fluids are fluxed into the asthenospheric mantle to form arc basalts, which are locally associated with HMAs in hot subduction zones. The separated HMA melts retain their composition in limited equilibrium with the surrounding mantle. Alternatively, they equilibrate with the surrounding mantle and change the major element chemistry to basaltic composition. However, trace element signatures of sediment-derived supercritical fluids remain more in the melt-derived magma than in the fluid-induced magma, which inherits only fluid-mobile elements from the sediment-derived supercritical fluids. Separation of slab-derived supercritical fluids into melts and aqueous fluids can elucidate the two slab-derived components observed in subduction zone magma chemistry.

  2. Thermophysical properties of supercritical fluids and fluid mixtures

    International Nuclear Information System (INIS)

    Sengers, J.V.

    1989-08-01

    The purpose of the research is to extend the theory of critical phenomena in fluids and fluid mixtures to obtain scientifically based equations that include the crossover from the asymptotic singular behavior of the thermophysical properties close to the critical point to the regular behavior of these properties far away from the critical point

  3. Modelling of heat transfer to fluids at a supercritical pressure

    International Nuclear Information System (INIS)

    Shuisheng, He

    2014-01-01

    A key feature of Supercritical Water-cooled Reactor (SCWR) is that, by raising the pressure of the reactor coolant fluid above the critical value, a phase change crisis is avoided. However, the changes in water density as it flows through the core of an SCWR are actually much higher than in the current water-cooled reactors. In a typical design, the ratio of the density of water at the core inlet to that at exit is as high as 7:1. Other fluid properties also vary significantly, especially around the pseudo-critical temperature (at which the specific heat capacity peaks). As a result, turbulent flow and heat transfer behaviour in the core is extremely complex and under certain conditions, significant heat transfer deterioration can potentially occur. Consequently, understanding and being able to predict flow and heat transfer phenomena under normal steady operation conditions and in start-up and hypothetical fault conditions are fundamental to the design of SCWR. There have been intensive studies on flow and heat transfer to fluids at supercritical pressure recently and several excellent review papers have been published. In the talk, we will focus on some turbulence modelling issues encountered in CFD simulations. The talk will first discuss some flow and heat transfer issues related to fluids at supercritical pressures and their potential implications in SCWR, and some recent developments in the understanding and modelling techniques of such problems, which will be followed by an outlook for some future developments.Factors which have a major influence on the flow and will be discussed are buoyancy and flow acceleration due to thermal expansion (both are due to density variations but involve different mechanisms) and the nonuniformity of other fluid properties. In addition, laminar-turbulent flow transition coupled with buoyancy and flow acceleration plays an important role in heat transfer effectiveness and wall temperature in the entrance region but such

  4. On-line supercritical fluid extraction-supercritical fluid chromatography-mass spectrometry of polycyclic aromatic hydrocarbons in soil.

    Science.gov (United States)

    Wicker, A Paige; Carlton, Doug D; Tanaka, Kenichiro; Nishimura, Masayuki; Chen, Vivian; Ogura, Tairo; Hedgepeth, William; Schug, Kevin A

    2018-04-11

    On-line supercritical fluid extraction - supercritical fluid chromatography - mass spectrometry (SFE-SFC-MS) has been applied for the determination of polycyclic aromatic hydrocarbons (PAHs) in soil. The purpose of this study was to develop and validate the first on-line SFE-SFC-MS method for the quantification of PAHs in various types of soil. By coupling the sample extraction on-line with chromatography and detection, sample preparation is minimized, diminishing sample loss and contamination, and significantly decreasing the required extraction time. Parameters for on-line extraction coupled to chromatographic analysis were optimized. The method was validated for concentrations of 10-1500 ng of PAHs per gram of soil in Certified Reference Material (CRM) sediment, clay, and sand with R 2  ≥ 0.99. Limits of detection (LOD) were found in the range of 0.001-5 ng/g, and limits of quantification (LOQ) in the range of 5-15 ng/g. The method developed in this study can be effectively applied to the study of PAHs in the environment, and may lay the foundation for further applications of on-line SFE-SFC-MS. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Selective chelation and extraction of lanthanides and actinides with supercritical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, R.D.; Carleson, T.E.; Harrington, J.D.; Jean, F.; Jiang, H.; Lin, Y.; Wai, C.M.

    1994-01-01

    This report is made up of three independent papers: (1) Supercritical Fluid Extraction of Thorium and Uranium with Fluorinated Beta-Diketones and Tributyl Phosphate, (2) Supercritical Fluid Extraction of Lanthanides with Beta-Diketones and Mixed Ligands, and (3) A Group Contribution Method for Predicting the Solubility of Solid Organic Compounds in Supercritical Carbon Dioxide. Experimental data are presented demonstrating the successful extraction of thorium and uranium using fluorinated beta-diketones to form stable complexes that are extracted with supercritical carbon dioxide. The conditions for extracting the lanthanide ions from liquid and solid materials using supercritical carbon dioxide are presented. In addition, the Peng-Robison equation of state and thermodynamic equilibrium are used to predict the solubilities of organic solids in supercritical carbon dioxide from the sublimation pressure, critical properties, and a centric factor of the solid of interest.

  6. Obtaining of the antioxidants by supercritical fluid extraction

    Directory of Open Access Journals (Sweden)

    Babović Nada V.

    2011-01-01

    Full Text Available One of the important trends in the food industry today is demand for natural antioxidants from plant material. Synthetic antioxidants such as butylated hydroxytoluene (BHT, and butylated hydroxyanisole (BHA are now being replaced by the natural antioxidants because of theirs possible toxicity and as they may act as promoters of carcinogens. The natural antioxidants may show equivalent or higher antioxidant activity than the endogenous or the synthetic antioxidants. Thus, great effort is being devoted to the search for alternative and cheap sources of natural antioxidants, as well as to the development of efficient and selective extraction techniques. The supercritical fluid extraction (SFE with carbon dioxide is considered to be the most suitable method for producing natural antioxidants for the use in food industry. The supercritical extract does not contain residual organic solvents as in conventional extraction processes, which makes these products suitable for use in food, cosmetic and pharmaceutical industry. The recovery of antioxidants from plant sources involves many problematic aspects: choice of an adequate source (in terms of availability, cost, difference in phenolic content with variety and season; selection of the optimal recovery procedure (in terms of yield, simplicity, industrial application, cost; chemical analysis of extracts (for optimization purposes a fast colorimetric method is more preferable than a chromatographic one; evaluation of the antioxidant power (preferably by the different assay methods. The paper presents information about different operational methods for SFE of bioactive compounds from natural sources. It also includes the various reports on the antioxidant activity of the supercritical extracts from Lamiaceae herbs, in comparison with the activity of the synthetic antioxidants and the extracts from Lamiaceae herbs obtained by the conventional methods.

  7. Analysis of antioxidants extracted from polypropylene by supercritical fluid extraction.

    Science.gov (United States)

    Garde, J A; Catalá, R; Gavara, R

    1998-01-01

    Maximal potential migration of six antioxidants (AO) from five polypropylene (PP) formulations was determined by two supercritical fluid extraction (SFE) procedures, both of which contained static and dynamic steps. All analytical conditions affecting the extraction were studied and optimized using Irgafos 168 as standard. SFE was more efficient as temperature and fluid density increased. During the static step in which the samples were exposed to the fluid without flux, the introduction of hexane and methanol as fluid modifiers significantly improved the extraction. Hexane appears to facilitate polymer swelling while methanol solvates the antioxidants. In the dynamic step (in which the extraction actually occurs) time is the key parameter. Extraction for 90 min results in an efficiency of around 75%. The introduction of modifiers during this step (by an HPLC-SFE procedure) did not produce any significant improvement. When SFE was carried out on all samples, extraction efficiency was around 75% except for Irganox 1010 and Hostanox O3. The large molecular volume of these antioxidants may be responsible for the considerable reduction of extraction efficiency. Particle size and shape of polymer sample were also important. The greater the surface to volume ratio the greater the extraction efficiency.

  8. Using hybrid neural models to describe supercritical fluid extraction processes

    Directory of Open Access Journals (Sweden)

    FONSECA A. P.

    1999-01-01

    Full Text Available This work presents the results of a hybrid neural model (HNM technique as applied to modeling supercritical fluid extraction (SCFE curves obtained from two Brazilian vegetable matrices. The serial HNM employed uses a neural network to estimate parameters of a phenomenological model. A small set of SCFE data for each vegetable was used to generate a semi-empirical extended data set, large enough for efficient network training, using three different approaches. Afterwards, other sets of experimental data, not used during the training procedure, were used to validate each approach. The HNM correlates well withthe experimental data, and it is shown that the predictions accomplished with this technique may be promising for SCFE purposes.

  9. Functionalization of whey proteins by reactive supercritical fluid extrusion

    Directory of Open Access Journals (Sweden)

    Khanitta Ruttarattanamongkol

    2012-09-01

    Full Text Available Whey protein, a by-product from cheese-making, is often used in a variety of food formulations due to its unsurpassednutritional quality and inherent functional properties. However, the possibilities for the improvement and upgrading of wheyprotein utilization still need to be explored. Reactive supercritical fluid extrusion (SCFX is a novel technique that has beenrecently reported to successfully functionalize commercially available whey proteins into a product with enhanced functionalproperties. The specific goal of this review is to provide fundamental understanding of the reinforcement mechanism andprocessing of protein functionalization by reactive SCFX process. The superimposed extrusion variables and their interactionmechanism affect the physico-chemical properties of whey proteins. By understanding the structure, functional properties andprocessing relationships of such materials, the rational design criteria for novel functionalized proteins could be developedand effectively utilized in food systems.

  10. Particle formation with supercritical fluids challenges and limitations

    CERN Document Server

    Türk, Michael

    2014-01-01

    Particle formation with supercritical fluids is a promising alternative to conventional precipitation processes as it allows the reduction of particle size and control of morphology and particle size distribution without degradation or contamination of the product. The book comprehensively examines the current status of research and development and provides perspectives and insights on promising future directions. The introduction to high pressure and high temperature phase equilibria and nucleation phenomena provides the basic principles of the underlying physical and chemical phenomena, allowing the reader an understanding of the relationship between process conditions and particle characteristics. Bridging the gap between theory and application, the book imparts the scientific and engineering fundamentals for innovative particle formation processes. The interdisciplinary "modus operandi" will encourage cooperation between scientists and researchers from different but complementary disciplines. Focuses on ...

  11. Multi-walled carbon nanotubes (MWCNTs) functionalized with amino groups by reacting with supercritical ammonia fluids

    International Nuclear Information System (INIS)

    Shao Lu; Bai Yongping; Huang Xu; Gao Zhangfei; Meng Linghui; Huang Yudong; Ma Jun

    2009-01-01

    For the first time, supercritical ammonia fluid was utilized to simply functionalize multi-walled carbon nanotube (MWCNT) with amino groups. The successful amino functionalization of MWCNTs was proven and the physicochemical properties of MWCNTs before and after supercritical ammonia fluids modifications were characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectroscopy. The results also indicated that the supercritical ammonia fluids had the visible effects on the nanostructure of carbon nanotubes. Our novel modification approach provides an easy way to modify MWCNTs with amino groups, which is very useful for realizing 'carbon nanotube economy' in the near future.

  12. Electro-capillary effects in capillary filling dynamics of electrorheological fluids.

    Science.gov (United States)

    Dhar, Jayabrata; Ghosh, Uddipta; Chakraborty, Suman

    2015-09-21

    The flow of electrorheological fluids is characterized by an apparent increase in viscosity manifested by the yield stress property of the fluid, which is a function of the applied electric field and the concentration of the suspended solute phase within the dielectric medium. This property of electrorheological fluids generally hinders flow through a capillary if the imposed shear stress is lower than the induced yield stress. This results in a plug-like zone in the flow profile, thus giving the fluid Bingham plastic properties. In the present work, we study such influences of the yield stress on the capillary filling dynamics of an electrorheological fluid by employing a rheologically consistent reduced order formalism. One important feature of the theoretical formalism is its ability to address the intricate interplay between the surface tension and viscous forces, both of which depend sensitively on the electric field. Our analysis reveals that the progress of the capillary front is hindered at an intermediate temporal regime, which is attributable to the increase of the span of the plug-zone across the channel width with time. With a preliminary understanding on the cessation of the capillary front advancement due to the yield stress property of the electrorheological fluids, we further strive to achieve a basic comparison with an experimental study made earlier. Reasonable agreements with the reported data support our theoretical framework. Comprehensive scaling analysis brings further insight to our reported observations over various temporal regimes.

  13. Broken-and-Intact Cell Model for Supercritical Fluid Extraction: Its Origin and Limits.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena

    2017-01-01

    Roč. 129, SI (2017), s. 3-8 ISSN 0896-8446. [Iberoamerican Conference on Supercritical Fluids ProSCiba 2016 /4./. Vina del Mar, 28.03.2016-01.04.2016] Institutional support: RVO:67985858 Keywords : modelling * extraction kinetics * supercritical CO2 Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.991, year: 2016

  14. Sustainable extraction of molecules for potable alcohol, cosmetics and pharmaceuticals: extraction in supercritical fluids

    International Nuclear Information System (INIS)

    Leone, Gian Paolo; Ferri, Donatella

    2015-01-01

    Since many years the Laboratory of Agro-Industrial Innovation (UTAGRI-INN) ENEA proposed research and development of extraction processes with supercritical fluids (SFE, Supercritical Fluid Extraction), aiming on the sustainability of the process characteristics. The technique, in fact, makes no use of organic solvents, It has reduced energy consumption and requires a number of process step lower than the extractions traditional. The process also responds to the requirements required by the regulations for food use, cosmetics and pharmaceutical extracts. [it

  15. Selective chelation-supercritical fluid extraction of metal ions from waste materials

    International Nuclear Information System (INIS)

    Wai, C.N.; Laintz, K.E.; Yonker, C.R.

    1993-01-01

    The removal of toxic organics, metals, and radioisotopes from solids or liquids is a major concern in the treatment of industrial and nuclear wastes. For this reason, developing methods for selective separation of toxic metals and radioactive materials from solutions of complex matrix is an important problem in environmental research. Recent developments indicate supercritical fluids are good solvents for organic compounds. Many gases become supercritical fluids under moderate temperatures and pressures. For example, the critical temperature and pressure of carbon dioxide are 31 degrees C and 73 atm, respectively. The high diffusivity, low viscosity, and T-P dependence of solvent strength are some attractive properties of supercritical fluid extraction (SFE). Since CO 2 offers the additional benefits of stability and non-toxicity, the SFE technique avoids generation of organic liquid waste and exposure of personnel to toxic solvents. While direct extraction of metal ions by supercritical fluids is highly inefficient, these ions when complexed with organic ligands become quite soluble in supercritical fluids. Specific ligands can be used to achieve selective extraction of metal ions in this process. After SFE, the fluid phase can be depressurized for precipitation of the metal chelates and recycled. The ligand can also be regenerated for repeated use. The success of this selective chelation-supercritical fluid extraction (SC-SFE) process depends on a number of factors including the efficiencies of the selective chelating agents, solubilities of metal chelates in supercritical fluids, rate of extraction, ease of regeneration of the ligands, etc. In this report, the authors present recent results on the studies of the solubilities of metal chelates in supercritical CO 2 , experimental ions from aqueous solution, and the development of selective chelating agents (ionizable crown ethers) for the extraction of lanthanides and actinides

  16. Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

    Science.gov (United States)

    Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

    2017-09-01

    A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preliminary Hazard Analysis of Supercritical Fluid Separation of Energetic Materials

    National Research Council Canada - National Science Library

    1997-01-01

    .... Army Research Laboratory (ARL) and elsewhere, particularly at the Phasex Corporation, Lawrence, MA, has demonstrated the feasibility of separating the energetic moieties by use of supercritical CO2...

  18. Dynamics, thermodynamics and structure of liquids and supercritical fluids: crossover at the Frenkel line

    Science.gov (United States)

    Fomin, Yu D.; Ryzhov, V. N.; Tsiok, E. N.; Proctor, J. E.; Prescher, C.; Prakapenka, V. B.; Trachenko, K.; Brazhkin, V. V.

    2018-04-01

    We review recent work aimed at understanding dynamical and thermodynamic properties of liquids and supercritical fluids. The focus of our discussion is on solid-like transverse collective modes, whose evolution in the supercritical fluids enables one to discuss the main properties of the Frenkel line separating rigid liquid-like and non-rigid gas-like supercritical states. We subsequently present recent experimental evidence of the Frenkel line showing that structural and dynamical crossovers are seen at a pressure and temperature corresponding to the line as predicted by theory and modelling. Finally, we link dynamical and thermodynamic properties of liquids and supercritical fluids by the new calculation of liquid energy governed by the evolution of solid-like transverse modes. The disappearance of those modes at high temperature results in the observed decrease of heat capacity.

  19. [Study on ingredients of essential oils of Curcuma wenyujin extracted by supercritical-CO2 fluid extraction and steam distillation].

    Science.gov (United States)

    Li, Hong-Xia; Yang, Tie-Yao; Yang, Tian-Liang; Ge, Fa-Huan; Pan, Wei-San; Yang, Xing-Gang; Chen, Ji-Min

    2006-09-01

    To compare the ingredients of essential oils of Curcuma wenyujin extracted by supercritical-CO2 fluid extraction and by steam distillation. GC-MS was applied in this experiment. The ingredients and physical and chemical properties of essential oils of C. wenyujin extracted by supercritical-CO2 fluid extraction and by steam distillation are similar. Supercritical-CO2 fluid extraction is better than steam distillation in extraction time, power consumption, recovery and purity.

  20. Supercritical fluid molecular spray thin films and fine powders

    Science.gov (United States)

    Smith, Richard D.

    1988-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. The solvent is vaporized and pumped away. Solution pressure is varied to determine, together with flow rate, the rate of deposition and to control in part whether a film or powder is produced and the granularity of each. Solution temperature is varied in relation to formation of a two-phase system during expansion to control porosity of the film or powder. A wide variety of film textures and powder shapes are produced of both organic and inorganic compounds. Films are produced with regular textural feature dimensions of 1.0-2.0 .mu.m down to a range of 0.01 to 0.1 .mu.m. Powders are formed in very narrow size distributions, with average sizes in the range of 0.02 to 5 .mu.m.

  1. Supercritical fluid molecular spray film deposition and powder formation

    Science.gov (United States)

    Smith, Richard D.

    1986-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. Upon expansion and supersonic interaction with background gases in the low pressure region, any clusters of solvent are broken up and the solvent is vaporized and pumped away. Solute concentration in the solution is varied primarily by varying solution pressure to determine, together with flow rate, the rate of deposition and to control in part whether a film or powder is produced and the granularity of each. Solvent clustering and solute nucleation are controlled by manipulating the rate of expansion of the solution and the pressure of the lower pressure region. Solution and low pressure region temperatures are also controlled.

  2. Supercritical fluid extraction of free amino acids from broccoli leaves.

    Science.gov (United States)

    Arnáiz, E; Bernal, J; Martín, M T; Nozal, M J; Bernal, J L; Toribio, L

    2012-08-10

    The extraction of free amino acids (AAs) from broccoli leaves using supercritical fluid extraction (SFE) with CO(2) modified with methanol, is presented in this work. The effect of the different variables was studied, showing the percentage of methanol a strong influence on the extraction. The best results in terms of extraction yield were obtained at 250 bar, 70°C, 35% methanol as organic modifier, a flow rate of 2 mL/min, and 5 min and 30 min as static and dynamic extraction times, respectively. The extraction yield obtained with the SFE method was comparable to that obtained employing conventional solvent extraction with methanol-water (70:30) and minor than using water, but the relative proportion of the AAs in the extracts was very different. For example, the use of SFE allowed the enrichment in proline and glutamine of the extracts. The selected conditions were applied to obtain SFE extracts of broccoli leaves from different varieties (Naxos, Nubia, Marathon, Parthenon and Viola). The highest levels of AAs were found in the SFE extracts from the Nubia variety. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Supercritical Fluid Extraction of Plant Flavors and Fragrances

    Directory of Open Access Journals (Sweden)

    Massimo E. Maffei

    2013-06-01

    Full Text Available Supercritical fluid extraction (SFE of plant material with solvents like CO2, propane, butane, or ethylene is a topic of growing interest. SFE allows the processing of plant material at low temperatures, hence limiting thermal degradation, and avoids the use of toxic solvents. Although today SFE is mainly used for decaffeination of coffee and tea as well as production of hop extracts on a large scale, there is also a growing interest in this extraction method for other industrial applications operating at different scales. In this review we update the literature data on SFE technology, with particular reference to flavors and fragrance, by comparing traditional extraction techniques of some industrial medicinal and aromatic crops with SFE. Moreover, we describe the biological activity of SFE extracts by describing their insecticidal, acaricidal, antimycotic, antimicrobial, cytotoxic and antioxidant properties. Finally, we discuss the process modelling, mass-transfer mechanisms, kinetics parameters and thermodynamic by giving an overview of SFE potential in the flavors and fragrances arena.

  4. Supercritical fluid extraction and separation of uranium from other actinides.

    Science.gov (United States)

    Quach, Donna L; Mincher, Bruce J; Wai, Chien M

    2014-06-15

    The feasibility of separating U from nitric acid solutions of mixed actinides using tri-n-butylphosphate (TBP)-modified supercritical fluid carbon dioxide (sc-CO2) was investigated. The actinides U, Np, Pu, and Am were extracted into sc-CO2 modified with TBP from a range of nitric acid concentrations, in the absence of, or in the presence of, a number of traditional reducing and/or complexing agents to demonstrate the separation of these metals from U under sc-CO2 conditions. The separation of U from Pu using sc-CO2 was successful at nitric acid concentrations of less than 3M in the presence of acetohydroxamic acid (AHA) or oxalic acid (OA) to mitigate Pu extraction, and the separation of U from Np was successful at nitric acid concentrations of less than 1M in the presence of AHA, OA, or sodium nitrite to mitigate Np extraction. Americium was not well extracted under any condition studied. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Use of supercritical fluid solution expansion processes for drug delivery, particle synthesis, and thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hybertson, B.M.

    1992-01-01

    Properties of the gases and aerosols resulting from the expansion of supercritical fluid solutions were studied. Film deposition, particle formation, and drug delivery processes using supercritical fluids were developed. Thin films of palladium, copper, aluminum, silver, and silicon dioxide were deposited by a method called supercritical fluid transport-chemical deposition (SFT-CD). In each case, a precursor compound was dissolved in a supercritical fluid and the solution was allowed to expand through a restrictor nozzle into a reaction chamber at subcritical pressure, resulting in the formation of aerosol particles of the precursor. A chemical reaction was induced to occur at the surface of a substrate, resulting in deposition of a thin film. Micron-sized particles of aluminum fluoride and copper oxide were synthesized by a method called supercritical fluid transport-chemical formation of particles (SFT-CFP). The process was similar to that in SFT-CD, but the chemical reactions were induced to occur in the gas phase instead of at a substrate surface, resulting in the formation of fine particles. A new method of pulmonary drug delivery called supercritical fluid drug delivery (SFDD) was conceived and demonstrated. In SFDD a drug compound is dissolved in a supercritical fluid, and the solution is allowed to expand through a restrictor nozzle. The resultant aerosol is directly inhaled by a human or animal subject and the fine drug particles are deposited in the lungs. Menthol, vanillin, camphor, cholesterol, Sudan III, and Oil Blue N were used as model drug compounds for SFDD. Delivery of [alpha]-tocopherol to rat lung tissue was demonstrated, with observed increases of 80-290% above background levels.

  6. Thermochemical conversion of Phellinus pomaceus via supercritical fluid extraction and pyrolysis processes

    International Nuclear Information System (INIS)

    Durak, Halil

    2015-01-01

    Highlights: • Phellinus pomaceus were converted to liquid and gas products. • Supercritical fluid extraction and pyrolysis processes were used in this research. • 60, 72 and 90 different types of compounds were identified by GC–MS. - Abstract: Thermochemical conversion processes such as supercritical fluid extraction and pyrolysis are used for producing biofuel from biomass. Supercritical fluid extraction process under supercritical conditions is the thermally disruption process of the lignocellulose or other organic materials at 250–400 °C temperature range under high pressure (4–5 MPa). Pyrolysis method is the process of decomposition of the organic materials with heat in the inert atmosphere or vacuum nature between high temperatures (350–800 °C). Two thermochemical processes, supercritical fluid extraction and slow pyrolysis, were used to produce bio-oils and biochars from Phellinus pomaceus. Supercritical fluid extraction trials were performed in a cylindrical reactor (75 mL) in organic solvents (acetone, ethanol) under supercritical conditions with (calcium hydroxide, sodium carbonate) and without catalyst at the temperatures of 250, 270 and 290 °C. Pyrolysis experiments were performed in a fixed-bed tubular reactor without and with same catalysts used in liquefaction at the temperatures of 400, 500 and 600 °C with constant heating rate (40 °C/min). The effects of process variables including temperature and catalyst on product yields were investigated. Product yields and composition of bio-oils were evaluated and compared for supercritical fluid extraction and pyrolysis. The produced liquids at 290 °C in supercritical liquefaction and at 500 °C in pyrolysis were analyzed and characterized by elemental, GC–MS and FT-IR. 60 and 72 different types of compounds that were identified by GC–MS obtained in acetone and ethanol respectively whereas pyrolysis liquids had 90 different types of compounds. Bio-oils from supercritical liquefaction

  7. US-UK Phase 3 Task 1 Oxidation in Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R. [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2017-03-20

    A presentation of the US-UK Phase 3 Task 1 Oxidation in Supercritical Fluids. Includes slides on Supercritical Steam, sCO2 Power Cycles – Indirect, sCO2 Power Cycles – Direct, Experimental Exposures, Alloys, Why Si, Results—Ni-xCr Alloys (5-24Cr), Fatigue Crack Growth$-$Experiment, and Alloys and Samples, Fatigue Crack Growth—Results (H282).

  8. Broken-and-Intact Cell Model for Supercritical Fluid Extraction: Its Origin and Limits.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena

    2017-01-01

    Roč. 129, SI (2017), s. 3-8 ISSN 0896-8446. [Iberoamerican Conference on Supercritical Fluid s ProSCiba 2016 /4./. Vina del Mar, 28.03.2016-01.04.2016] Institutional support: RVO:67985858 Keywords : modelling * extraction kinetics * supercritical CO2 Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.991, year: 2016

  9. Fluid-to-fluid scaling of heat transfer phenomena with supercritical pressure fluids: Results from RANS analyses

    International Nuclear Information System (INIS)

    Pucciarelli, A.; Ambrosini, W.

    2016-01-01

    Highlights: • A methodology for fluid-to-fluid scaling of heat transfer to supercritical fluids is proposed. • The methodology is based on a dimensionless formulation. • A first assessment of the methodology is obtained on the basis of RANS calculations. - Abstract: A methodology for fluid-to-fluid scaling of predicted heat transfer phenomena with supercritical pressure fluids is being developed with the aid of RANS calculations. The proposed approach rephrases and further develops a previous attempt, whose preliminary validation was limited by the considerable inaccuracy of the adopted turbulence models when applied to deteriorated heat transfer. A recent improvement in the accuracy of heat transfer predictions allowed this further step, also based on the broader experience gained in the mean time in the prediction of experimental data. Four representative experimental data cases related to water and CO 2 , for which reasonably accurate results have been obtained by RANS turbulence equations, are addressed by changing the working fluid and imposing an approximate invariance of the dimensionless trends of fluid enthalpy at the wall and in bulk. Intrinsic differences in the thermal behaviour of the considered fluids (e.g., in the Prandtl number) are reflected in corresponding changes in the value of a single dimensionless parameter, following an indication coming from simple theoretical considerations. Results of RANS models for different fluids are used as a preliminary support to the validity of the approach, showing an interesting persistence of heat transfer behaviour in dimensionless form in the four addressed cases. The present uncertainties in the proposed methodology are mainly a consequence of the limited accuracy of the adopted simulation models. The obtained indications can be used in planning experimental or better resolved computational analyses (LES, DNS) which may better clarify the promising features of this approach.

  10. Thermal induced flow oscillations in heat exchangers for supercritical fluids

    Science.gov (United States)

    Friedly, J. C.; Manganaro, J. L.; Krueger, P. G.

    1972-01-01

    Analytical model has been developed to predict possible unstable behavior in supercritical heat exchangers. From complete model, greatly simplified stability criterion is derived. As result of this criterion, stability of heat exchanger system can be predicted in advance.

  11. Impact of injection solvents on supercritical fluid chromatography.

    Science.gov (United States)

    Abrahamsson, Victor; Sandahl, Margareta

    2013-09-06

    Even though there has been a rapid development in instrumentation and applications of supercritical fluid chromatography (SFC), relatively little is known about retention mechanisms compared to high-performance liquid chromatography (HPLC). Much effort has been made to characterize the influence of injection solvents on chromatographic efficiency in HPLC, however has been left rather uninvestigated in the domain of SFC. In this study properties of different injection solvents have been studied and correlated with properties of seven various analytes on three different columns, a C18, a 2-ethylpyridine and a bare-silica column. Aided by calculations of correlation coefficients and principal component analysis (PCA), the physical properties of injection solvents and the interactions between injection solvent, solute and stationary phase were investigated. The findings of this work shows that interactions capable of masking accessible silanol groups on a C18 column are of importance in order to maximize the plate number. While solvents with dipolar and hydrogen bond interaction properties are associated negatively with chromatographic efficiency using polar columns. Properties such as molar density, vapor pressure and boiling point were related to sharper peaks, mostly likely because of solubility issues of the injection solvent into the methanol-modified carbon dioxide. However, no additional solubility due to hydrogen interactions between the injection solvent and the carbon dioxide in SFC was observed. Surface tension and viscosity was not particularly associated with a decrease in plate numbers. By increasing the injection volume a stronger correlation between solubility related properties and plate numbers were obtained. Additional experiments showed that the resistance in solubility became an issue when performing partial-loop injection where additional washing solvent entered the system, thus providing broadened peaks. Copyright © 2013 Elsevier B.V. All rights

  12. CO{sub 2}-based supercritical fluids as environmentally-friendly processing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Pierce, T. [Los Alamos National Lab., NM (United States). Physical Organic Chemistry Group; Tiefert, K. [Hewlett-Packard Co., Inc., Santa Clara, CA (United States)

    1999-03-01

    The production of integrated circuits involves a number of discrete steps that utilize hazardous or regulated solvents. Environmental, safety and health considerations associated with these chemicals have prompted a search for alternative, more environmentally benign, solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Supercritical CO{sub 2} (SCCO{sub 2}) is an excellent choice for IC manufacturing processes since it is non-toxic, non-flammable, inexpensive, and is compatible with all substrate and metallizations systems. Also, conditions of temperature and pressure needed to achieve the supercritical state are easily achievable with existing process equipment. The authors first describe the general properties of supercritical fluids, with particular emphasis on their application as alternative solvents. Next, they review some of the work which has been published involving the use of supercritical fluids, and particularly CO{sub 2}, as they may be applied to the various steps of IC manufacture, including wafer cleaning, thin film deposition, etching, photoresist stripping, and waste treatment. Next, they describe the research work conducted at Los Alamos, on behalf of Hewlett-Packard, on the use of SCCO{sub 2} in a specific step of the IC manufacturing process: the stripping of hard-baked photoresist.

  13. Biocatalytic Synthesis of Acrylates in Supercritical Fluids: Tuning Enzyme Activity by Changing Pressure

    Science.gov (United States)

    Kamat, Sanjay V.; Iwaskewycz, Brian; Beckman, Eric J.; Russell, Alan J.

    1993-04-01

    Supercritical fluids are a unique class of non-aqueous media in which biocatalytic reactions can occur. The physical properties of supercritical fluids, which include gas-like diffusivities and liquid-like densities, can be predictably controlled with changing pressure. This paper describes how adjustment of pressure, with the subsequent predictable changes of the dielectric constant and Hildebrand solubility parameter for fluoroform, ethane, sulfur hexafluoride, and propane, can be used to manipulate the activity of lipase in the transesterification of methylmethacrylate with 2-ethyl-1-hexanol. Of particular interest is that the dielectric constant of supercritical fluoroform can be tuned from approximately 1 to 8, merely by increasing pressure from 850 to 4000 psi (from 5.9 to 28 MPa). The possibility now exists to predictably alter both the selectivity and the activity of a biocatalyst merely by changing pressure.

  14. Computational fluid dynamics study of viscous fingering in supercritical fluid chromatography.

    Science.gov (United States)

    Subraveti, Sai Gokul; Nikrityuk, Petr; Rajendran, Arvind

    2018-01-26

    Axi-symmetric numerical simulations are carried out to study the dynamics of a plug introduced through a mixed-stream injection in supercritical fluid chromatographic columns. The computational fluid dynamics model developed in this work takes into account both the hydrodynamics and adsorption equilibria to describe the phenomena of viscous fingering and plug effect that contribute to peak distortions in mixed-stream injections. The model was implemented into commercial computational fluid dynamics software using user-defined functions. The simulations describe the propagation of both the solute and modifier highlighting the interplay between the hydrodynamics and plug effect. The simulated peaks showed good agreement with experimental data published in the literature involving different injection volumes (5 μL, 50 μL, 1 mL and 2 mL) of flurbiprofen on Chiralpak AD-H column using a mobile phase of CO 2 and methanol. The study demonstrates that while viscous fingering is the main source of peak distortions for large-volume injections (1 mL and 2 mL) it has negligible impact on small-volume injections (5 μL and 50 μL). Band broadening in small-volume injections arise mainly due to the plug effect. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  15. Separation of methicillin-resistant from methicillin-susceptible staphylococcus aureus by electrophoretic methods in fused silica capillaries etched with supercritical water

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Karásek, Pavel; Růžička, F.; Dvořáčková, M.; Sittová, M.; Roth, Michal

    2014-01-01

    Roč. 86, č. 19 (2014), s. 9701-9708 ISSN 0003-2700 R&D Projects: GA MV VG20112015021; GA ČR(CZ) GAP106/12/0522 Institutional support: RVO:68081715 Keywords : Staphylococcus aureus strains * capillary zone electrophoresis * supercritical water-treated capillary Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014 http://hdl.handle.net/11104/0236865

  16. Synthesis of biodiesel fuel additives from glycerol using green chemistry and supercritical fluids

    Science.gov (United States)

    For every 3 moles of fatty acid esters produced, 1 mole of glycerol remains, ~11% of the biodiesel volume. One new method of glycerol use could be as a biodiesel fuel additive/extender using eco-friendly heterogeneous catalysts and supercritical fluids (SFs). SFs have advantages such as greater diff...

  17. Processing of poly(hydroxybutyrate-co-hydroxyvalerate)-based bionanocomposite foams using supercritical fluids

    Science.gov (United States)

    Alireza Javadi; Yottha Srithep; Craig C. Clemons; L-S. Turng; Shaoqin. Gong

    2012-01-01

    Supercritical fluid (SCF) N2 was used as a physical foaming agent to fabricate microcellular injection-molded poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)–poly(butylene adipate-co-terephthalate) (PBAT)–hyperbranched-polymer (HBP)–nanoclay (NC) bionanocomposites. The effects of incorporating HBP and NC on the morphological, mechanical, and...

  18. Low-temperature, selective catalytic deoxygenation of vegetable oil in supercritical fluid media.

    Science.gov (United States)

    Kim, Seok Ki; Lee, Hong-Shik; Hong, Moon Hyun; Lim, Jong Sung; Kim, Jaehoon

    2014-02-01

    The effects of supercritical fluids on the production of renewable diesel-range hydrocarbons from natural triglycerides were investigated. Various supercritical fluids, which included CO2 (scCO2 ), propane (scC3 H8 ) and n-hexane (scC6 H14 ), were introduced with H2 and soybean oil into a fixed-bed reactor that contained pre-activated CoMo/γ-Al2 O3 . Among these supercritical fluids, scC3 H8 and scC6 H14 efficiently allowed the reduction of the reaction temperature by as much as 50 °C as a result of facilitated heat and mass transfer and afforded similar yields to reactions in the absence of supercritical fluids. The compositional analyses of the gas and liquid products indicated that the addition of scC3 H8 during the hydrotreatment of soybean oil promoted specific deoxygenation pathways, decarbonylation and decarboxylation, which consumed less H2 than the hydrodeoxygenation pathway. As a result, the quantity of H2 required to obtain a high yield of diesel-range hydrocarbons could be reduced to 57 % if scC3 H8 was used. As decarboxylation and decarbonylation are mildly endothermic reactions, the reduced heat transfer resistance in scC3 H8 may drive the deoxygenation reaction to thermodynamically favourable pathways. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Modeling the Supercritical Fluid Extraction of Essential Oils from Plant Materials

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena

    2012-01-01

    Roč. 1250, SI (2012), s. 27-33 ISSN 0021-9673 R&D Projects: GA TA ČR TA01010578 Institutional support: RVO:67985858 Keywords : supercritical fluid extraction * essential oils * model for kinetics Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 4.612, year: 2012

  20. Supercritical CO2 fluid radiochromatography system used to purify [11C]toluene for PET

    International Nuclear Information System (INIS)

    Muller, Ryan D.; Ferrieri, Richard A.; Gerasimov, Madina; Garza, Victor

    2002-01-01

    Abuse of inhalants in today's society has become such a widespread problem among today's adolescents that in many parts of the world their use exceeds that of many other illicit drugs or alcohol. Even so, little is known how such inhalants affect brain function to an extent that can lead to an abuse liability. While methodologies exist for radiolabeling certain inhalants of interest with short-lived positron emitting radioisotopes that would allow their investigation in human subjects using positron emission tomography (PET), the purification methodologies necessary to separate these volatile substances from the organic starting materials have not been developed. We've adapted supercritical fluid technology to this specific PET application by building a preparative-scale supercritical CO 2 fluid radiochromatograph, and applied it to the purification of [ 11 C]toluene. We've demonstrated that [ 11 C]toluene can be separated from the starting materials using a conventional C 18 HPLC column and pure supercritical CO 2 fluid as the mobile phase operating at 2000 psi and 40 deg. C. We've also shown that the purified radiotracer can be quantitatively captured on Tenax GR, a solid support material, as it exits the supercritical fluid stream, thus allowing for later desorption into a 1.5% cyclodextrin solution that is suitable for human injection, or into a breathing tube for direct inhalation

  1. A Novel Model for Multicomponent Supercritical Fluid Extraction and its Application to Ruta graveolens.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena; Sajfrtová, Marie; Stateva, R.P.

    2017-01-01

    Roč. 120, Part 1 (2017), s. 102-112 ISSN 0896-8446 R&D Projects: GA MŠk 2B06049 Institutional support: RVO:67985858 Keywords : supercritical fluid extraction * multicomponent equilibrium * kinetics Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.991, year: 2016

  2. Supercritical Fluid Extraction of Minor Components of Vegetable Oils: beta-Sitosterol

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena; Galushko, A.A.; Stateva, R.P.; Rochová, Kristina; Sajfrtová, Marie; Bártlová, Milena

    2010-01-01

    Roč. 101, č. 2 (2010), s. 201-209 ISSN 0260-8774 R&D Projects: GA MŠk 2B06024 Institutional research plan: CEZ:AV0Z40720504 Keywords : supercritical fluid extraction * sea buckthorn oil * beta-sitosterol Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.168, year: 2010

  3. Steps of Supercritical Fluid Extraction of Natural Products and Their Characteristic Times

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena

    2012-01-01

    Roč. 66, SI (2012), s. 73-79 ISSN 0896-8446 R&D Projects: GA MŠk 2B06049 Institutional support: RVO:67985858 Keywords : supercritical fluid extraction * vegetable oils * essential oils Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.732, year: 2012

  4. Development of artificial neural network models for supercritical fluid solvency in presence of co-solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shokir, Eissa Mohamed El-Moghawry; El-Midany, Ayman Abdel-Hamid [Cairo University, Giza (Egypt); Al-Homadhi, Emad Souliman; Al-Mahdy, Osama [King Saud University, Riyadh (Saudi Arabia)

    2014-08-15

    This paper presents the application of artificial neural networks (ANN) to develop new models of liquid solvent dissolution of supercritical fluids with solutes in the presence of cosolvents. The neural network model of the liquid solvent dissolution of CO{sub 2} was built as a function of pressure, temperature, and concentrations of the solutes and cosolvents. Different experimental measurements of liquid solvent dissolution of supercritical fluids (CO{sub 2}) with solutes in the presence of cosolvents were collected. The collected data are divided into two parts. The first part was used in building the models, and the second part was used to test and validate the developed models against the Peng- Robinson equation of state. The developed ANN models showed high accuracy, within the studied variables range, in predicting the solubility of the 2-naphthol, anthracene, and aspirin in the supercritical fluid in the presence and absence of co-solvents compared to (EoS). Therefore, the developed ANN models could be considered as a good tool in predicting the solubility of tested solutes in supercritical fluid.

  5. Ultrasound assisted supercritical fluid extraction of oil and coixenolide from adlay seed.

    Science.gov (United States)

    Hu, Ai-jun; Zhao, Shuna; Liang, Hanhua; Qiu, Tai-qiu; Chen, Guohua

    2007-02-01

    Oil and coixenolide are important components of adlay seed (Coix lachrymal-jobi L. var. Adlay) with many beneficial functions to human health. In this work, a novel extraction technique--ultrasound assisted supercritical fluid extraction (USFE)--was studied. Effects of operating conditions on the extraction, including extraction temperature (T), pressure (P), time (t), CO(2) flow rate (F) and ultrasonic power (I) were investigated. There are optimum temperatures which gives the maximum extraction yields (EYs) for the supercritical fluid extractions with and without ultrasound. The effect of pressure on EYs for is similar to that of pressure on CO(2) density. Based on the yield of extraction, the favorable conditions for supercritical fluid extraction (SFE) were: T at 45 degrees C, P at 25 MPa, t at 4.0 h and F at 3.5L/h. While ultrasound was applied as in USFE, the following parameters were preferred: T at 40 degrees C, P at 20 MPa, t at 3.5h and F at 3.0 L/h, respectively. The results show that supercritical fluid extraction with the assistance of ultrasound could reduce the temperature, pressure, CO(2) flow rate, as well as time used in the process. Compared with SFE, USFE could give a 14% increase in the yield for extracting oil and coixenolide from adlay seed with less severe operating conditions.

  6. Preheating of fluid in a supercritical Brayton cycle power generation system at cold startup

    Science.gov (United States)

    Wright, Steven A.; Fuller, Robert L.

    2016-07-12

    Various technologies pertaining to causing fluid in a supercritical Brayton cycle power generation system to flow in a desired direction at cold startup of the system are described herein. A sensor is positioned at an inlet of a turbine, wherein the sensor is configured to output sensed temperatures of fluid at the inlet of the turbine. If the sensed temperature surpasses a predefined threshold, at least one operating parameter of the power generation system is altered.

  7. Study of high-pressure adsorption from supercritical fluids by the potential theory

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Shapiro, Alexander

    2009-01-01

    The multicomponent potential theory of adsorption (MPTA), which has been previously used to study low-pressure adsorption of subcritical fluids, is extended to adsorption equilibria from supercritical fluids up to high pressures. The MPTA describes an adsorbed phase as an inhomogeneous fluid...... with thermodynamic properties that depend on the distance from the solid surface (or position in the porous space). The description involves the two kinds of interactions present in the adsorbed fluid, i.e. the fluid-fluid and fluid-solid interactions. accounted for by means of an equation of state (Eo......S) and interaction potential functions, respectively. This makes it possible to generate the different MPTA models by combination of the relevant EoS/potentials. In the present work, the simplified perturbed-chain statistical associating fluid theory (sPC-SAFT) EoS is used for the thermodynamic description of both...

  8. Numerical Study on Heat Transfer Performance of PCHE With Supercritical CO2 as Working Fluid

    International Nuclear Information System (INIS)

    Jeon, Sang Woo; Ngo, Ich-long; Byon, Chan

    2016-01-01

    The printed circuit heat exchanger (PCHE) is regarded as a promising candidate for advanced heat exchangers for the next-generation supercritical CO 2 power generation owing to its high compactness and rigid structure. In this study, an innovative type of PCHE, in which the channel sizes for the heat source fluid and heat sink fluid are different, is considered for analysis. The thermal performance of the PCHE, with supercritical CO 2 as the working fluid, is numerically analyzed. The results have shown that the thermal performance of the PCHE decreases monotonically when the channel size of either the heat source channel or the heat sink channel, because of the decreased flow velocity. On the other hand, the thermal performance of the PCHE is found to be almost independent of the spacing between the channels. In addition, it was found that the channel cross sectional shape has little effect on the thermal performance when the hydraulic diameter of the channel remains constant.

  9. Fundamental study of CO2-H2O-mineral interactions for carbon sequestration, with emphasis on the nature of the supercritical fluid-mineral interface.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R.; Dewers, Thomas A.; Heath, Jason E.; Wang, Yifeng; Matteo, Edward N.; Meserole, Stephen P.; Tallant, David Robert

    2013-09-01

    In the supercritical CO2-water-mineral systems relevant to subsurface CO2 sequestration, interfacial processes at the supercritical fluid-mineral interface will strongly affect core- and reservoir-scale hydrologic properties. Experimental and theoretical studies have shown that water films will form on mineral surfaces in supercritical CO2, but will be thinner than those that form in vadose zone environments at any given matric potential. The theoretical model presented here allows assessment of water saturation as a function of matric potential, a critical step for evaluating relative permeabilities the CO2 sequestration environment. The experimental water adsorption studies, using Quartz Crystal Microbalance and Fourier Transform Infrared Spectroscopy methods, confirm the major conclusions of the adsorption/condensation model. Additional data provided by the FTIR study is that CO2 intercalation into clays, if it occurs, does not involve carbonate or bicarbonate formation, or significant restriction of CO2 mobility. We have shown that the water film that forms in supercritical CO2 is reactive with common rock-forming minerals, including albite, orthoclase, labradorite, and muscovite. The experimental data indicate that reactivity is a function of water film thickness; at an activity of water of 0.9, the greatest extent of reaction in scCO2 occurred in areas (step edges, surface pits) where capillary condensation thickened the water films. This suggests that dissolution/precipitation reactions may occur preferentially in small pores and pore throats, where it may have a disproportionately large effect on rock hydrologic properties. Finally, a theoretical model is presented here that describes the formation and movement of CO2 ganglia in porous media, allowing assessment of the effect of pore size and structural heterogeneity on capillary trapping efficiency. The model results also suggest possible engineering approaches for optimizing trapping capacity and for

  10. Growth and Morphology of Supercritical Fluids, a Fluid Physics Experiment Conducted on Mir, Complete

    Science.gov (United States)

    Wilkinson, R. Allen

    2001-01-01

    The Growth and Morphology of Supercritical Fluids (GMSF) is an international experiment facilitated by the NASA Glenn Research Center and under the guidance of U.S. principal investor Professor Hegseth of the University of New Orleans and three French coinvestigators: Daniel Beysens, Yves Garrabos, and Carole Chabot. The GMSF experiments were concluded in early 1999 on the Russian space station Mir. The experiments spanned the three science themes of near-critical phase separation rates, interface dynamics in near-critical boiling, and measurement of the spectrum of density fluctuation length scales very close to the critical point. The fluids used were pure CO2 or SF6. Three of the five thermostats used could adjust the sample volume with the scheduled crew time. Such a volume adjustment enabled variable sample densities around the critical density as well as pressure steps (as distinct from the usual temperature steps) applied to the sample. The French-built ALICE II facility was used for these experiments. It allows tightly thermostated (left photograph) samples (right photograph) to be controlled and viewed/measured. Its diagnostics include interferometry, shadowgraph, high-speed pressure measurements, and microscopy. Data were logged on DAT tapes, and PCMCIA cards and were returned to Earth only after the mission was over. The ground-breaking near critical boiling experiment has yielded the most results with a paper published in Physical Review Letters (ref. 1). The boiling work also received press in Science Magazine (ref. 2). This work showed that, in very compressible near-critical two-phase pure fluids, a vapor bubble was induced to temporarily overheat during a rapid heating of the sample wall. The temperature rise in the vapor was 23-percent higher than the rise in the driving container wall. The effect is due to adiabatic compression of the vapor bubble by the rapid expansion of fluid near the boundary during heatup. Thermal diffusivity is low near the

  11. High-pressure cell for neutron reflectometry of supercritical and subcritical fluids at solid interfaces.

    Science.gov (United States)

    Carmichael, Justin R; Rother, Gernot; Browning, James F; Ankner, John F; Banuelos, Jose L; Anovitz, Lawrence M; Wesolowski, David J; Cole, David R

    2012-04-01

    A new high-pressure cell design for use in neutron reflectometry (NR) for pressures up to 50 MPa and a temperature range of 300-473 K is described. The cell design guides the neutron beam through the working crystal without passing through additional windows or the bulk fluid, which provides for a high neutron transmission, low scattering background, and low beam distortion. The o-ring seal is suitable for a wide range of subcritical and supercritical fluids and ensures high chemical and pressure stability. Wafers with a diameter of 5.08 cm (2 in.) and 5 mm or 10 mm thickness can be used with the cells, depending on the required pressure and momentum transfer range. The fluid volume in the sample cell is very small at about 0.1 ml, which minimizes scattering background and stored energy. The cell design and pressure setup for measurements with supercritical fluids are described. NR data are shown for silicon/silicon oxide and quartz wafers measured against air and subsequently within the high-pressure cell to demonstrate the neutron characteristics of the high-pressure cell. Neutron reflectivity data for supercritical CO(2) in contact with quartz and Si/SiO(2) wafers are also shown. © 2012 American Institute of Physics

  12. Solvent density inhomogeneities and solvation free energies in supercritical diatomic fluids: a density functional approach.

    Science.gov (United States)

    Husowitz, B; Talanquer, V

    2007-02-07

    Density functional theory is used to explore the solvation properties of a spherical solute immersed in a supercritical diatomic fluid. The solute is modeled as a hard core Yukawa particle surrounded by a diatomic Lennard-Jones fluid represented by two fused tangent spheres using an interaction site approximation. The authors' approach is particularly suitable for thoroughly exploring the effect of different interaction parameters, such as solute-solvent interaction strength and range, solvent-solvent long-range interactions, and particle size, on the local solvent structure and the solvation free energy under supercritical conditions. Their results indicate that the behavior of the local coordination number in homonuclear diatomic fluids follows trends similar to those reported in previous studies for monatomic fluids. The local density augmentation is particularly sensitive to changes in solute size and is affected to a lesser degree by variations in the solute-solvent interaction strength and range. The associated solvation free energies exhibit a nonmonotonous behavior as a function of density for systems with weak solute-solvent interactions. The authors' results suggest that solute-solvent interaction anisotropies have a major influence on the nature and extent of local solvent density inhomogeneities and on the value of the solvation free energies in supercritical solutions of heteronuclear molecules.

  13. Recrystallization of andrographolide using the supercritical fluid antisolvent process

    Science.gov (United States)

    Chen, Kexun; Zhang, Xingyuan; Pan, Jian; Yin, Wenhong

    2005-01-01

    The supercritical antisolvent (SAS) process was used to modify the solid-state properties of andrographolide. Ethanol was employed as solvents for the pharmaceutical compound and carbon dioxide was used as an antisolvent. The effect of process parameters on the precipitate crystals such as pressure, organic solution flow rate, and concentration of the andrographolide solution were investigated. The crystal habit is column-like and its size changed from longer and thicker to shorter and thinner when pressure increased and when the solution flow rate increased, the size of the crystal decreased. The X-ray diffraction (XRD) patterns revealed variations of crystallinity and crystal orientation depending on pressure, where the degree of crystallinity increased when pressure increased. The differential scanning calorimetry patterns also showed the same results as XRD.

  14. Fluid flow and solute migration within the capillary fringe.

    Science.gov (United States)

    Silliman, Stephen E; Berkowitz, Brian; Simunek, Jirka; van Genuchten, M Th

    2002-01-01

    Laboratory experiments involving both homogeneous and heterogeneous porous media are used to demonstrate that fluid flow and solute transport will occur regularly in the capillary fringe (CF), including both vertical (upward as well as downward) and horizontal flow velocities. Horizontal flow above the water table appears to be limited primarily to the region of high water saturation (i.e., the CF), an observation supported by numerical modeling and consistent with the literature. Beyond observations presented in prior literature, it was observed that exchange of water within the CF with water below the water table is active, with flux both from the CF downward across the water table and from the region below the water table, upward into the CF. This flux is enhanced by the presence of physical heterogeneity. These findings strongly contrast the common conceptualization of predominantly downward vertical fluid flow through the unsaturated zone, with transition to fully three-dimensional flow only below the water table. Based on these observations, it is suggested that the CF may affect, far more significantly than is usually assumed, the natural geochemical and microbial conditions present in the region of transition from unsaturated to saturated ground water flow.

  15. PROSPECTS FOR USE OF CONDENSED GASES AND SUPERCRITICAL FLUIDS IN PHYTOCHEMICAL PRODUCTION

    OpenAIRE

    Demyanenko DV; Breusova SV; Karpenko LA

    2017-01-01

    In the given review article analysis of the literature and patent sources concerning main methods for intensification of extraction processes of medicinal vegetative raw materials – use of condensed gases and supercritical fluids (SCF) on more acceptable extractants has been carried out for last 20 years. Urgency of the specified technologies consists in need for replacement of traditional extraction methods on power- and time-saving ones, and also in use of nontoxic, fire-proof and low-boili...

  16. Solute-matrix and Solute-Solute Interactions during Supercritical Fluid Extraction of Sea Buckthorn Leaves

    Czech Academy of Sciences Publication Activity Database

    Sajfrtová, Marie; Sovová, Helena

    2012-01-01

    Roč. 42, SI (2012), s. 1682-1691 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] R&D Projects: GA TA ČR TA01010578 Institutional support: RVO:67985858 Keywords : supercritical fluid extraction * sea buckthom leaves * solute-solute interaction Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  17. Rapid Determination of Two Triterpenoid Acids in Chaenomelis Fructus Using Supercritical Fluid Extraction On-line Coupled with Supercritical Fluid Chromatography.

    Science.gov (United States)

    Zhang, Xiaotian; Ji, Feng; Li, Yueqi; He, Tian; Han, Ya; Wang, Daidong; Lin, Zongtao; Chen, Shizhong

    2018-01-01

    In this study, an on-line supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) method was developed for the rapid determination of oleanoic acid and ursolic acid in Chaenomelis Fructus. After optimization of the conditions, the two triterpenoid acids was obtained by SFE using 20% methanol as a modifier at 35°C in 8 min. They were resolved on a Shim-pack UC-X Diol column (4.6 × 150 mm, 3 μm) in 14 min (0 - 10 min, 5 - 10%; 10 - 14 min, 10% methanol in CO 2 ) with a backpressure of 15 MPa at 40°C. The on-line SFE-SFC method could be completed within 40 min (10.79 mg/g dry plant, R s = 2.36), while the ultrasound-assisted extraction and HPLC method required at least 90 min (3.55 mg/g dry plant, R s = 1.92). This on-line SFE-SFC method is powerful to simplify the pre-processing and quantitative analysis of natural products.

  18. Evaluation of supercritical fluid engineered budesonide powder for respiratory delivery using nebulisers.

    Science.gov (United States)

    Amani, Amir; Chrystyn, Henry; Clark, Brian J; Abdelrahim, Mohamed E; York, Peter

    2009-12-01

    Currently, suspensions prepared from micronised drug substances are the only delivery system marketed for nebulisation of steroids, and reported inconsistent or low bioavailability arising from their use provides a rationale for researching alternative formulations. Supercritical fluid processing of drug substances to obtain respirable-sized particles has been used over the last decade to formulate dry powder inhalers. We aimed thus to process budesonide powder to improve its deposition characteristics. In an attempt to overcome the limitations of nebuliser suspensions when prepared from micronised drug particles, budesonide powder was processed using a supercritical fluid based process and suspended using Tween 80 as a surfactant to provide an aqueous nebuliser formulation. The in-vitro characteristics of the emitted dose on nebulisation for the prepared suspension were then compared to a commercially available suspension formulation of budesonide using a jet and a vibrating mesh nebuliser. The results showed a significant improvement of the in-vitro deposition properties of the suspension containing supercritical fluid engineered budesonide particles. The results indicated the benefit of such materials compared with traditionally micronised drug powders.

  19. Review on plasmas in extraordinary media: plasmas in cryogenic conditions and plasmas in supercritical fluids

    Science.gov (United States)

    Stauss, Sven; Muneoka, Hitoshi; Terashima, Kazuo

    2018-02-01

    Plasma science and technology has enabled advances in very diverse fields: micro- and nanotechnology, chemical synthesis, materials fabrication and, more recently, biotechnology and medicine. While many of the currently employed plasma tools and technologies are very advanced, the types of plasmas used in micro- and nanofabrication pose certain limits, for example, in treating heat-sensitive materials in plasma biotechnology and plasma medicine. Moreover, many physical properties of plasmas encountered in nature, and especially outer space, i.e. very-low-temperature plasmas or plasmas that occur in high-density media, are not very well understood. The present review gives a short account of laboratory plasmas generated under ’extreme’ conditions: at cryogenic temperatures and in supercritical fluids. The fundamental characteristics of these cryogenic plasmas and cryoplasmas, and plasmas in supercritical fluids, especially supercritical fluid plasmas, are presented with their main applications. The research on such exotic plasmas is expected to lead to further understanding of plasma physics and, at the same time, enable new applications in various technological fields.

  20. Isolation of carnosic acid from rosemary extracts using semi-preparative supercritical fluid chromatography.

    Science.gov (United States)

    Vicente, Gonzalo; García-Risco, Mónica R; Fornari, Tiziana; Reglero, Guillermo

    2013-04-19

    Supercritical fluid chromatography (SFC) in analytical and semi-preparative scale was studied to separate rosemary (Rosmarinus officinalis) supercritical extracts to produce fractions with high antioxidant activity. Carnosic acid, the major antioxidant present in rosemary supercritical extracts, was the target compound to be isolated in the fractions produced. First, rosemary extracts were produced in a supercritical CO2 pilot-plant employing different extraction conditions, in order to obtain samples with diverse composition. The content of carnosic acid was determined and the DPPH test was accomplished in order to assess the antioxidant activity of the different samples produced. Then, using some of these samples, experiments were carried out in a semi-preparative SFC system testing the performance of four different chromatographic columns to isolate and recover a fraction with high concentration of carnosic acid. The four chromatographic columns employed were silica and 2-ethylpyridine (especially packed for SFC) and silica and diol columns (packed for HPLC). The SFC fractionation conditions explored were in the ranges 10-20 MPa, 313-333 K and 5-20% of cosolvent (ethanol). Using the first three columns, it was possible to isolate fractions with concentrations of carnosic acid greater than 80% mass. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

    Directory of Open Access Journals (Sweden)

    Markus Armbruster

    2017-03-01

    Full Text Available Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employing supercritical fluid technology, our aim was to develop a birch bark dry extract suitable for stabilisation of lipophilic gels with improved properties while avoiding the use of toxic solvents. With supercritical carbon dioxide, three different particle formation methods from supercritical solutions have been tested. First, particle deposition was performed from a supercritical solution in an expansion chamber. Second, the Rapid Expansion of Supercritical Solutions (RESS method was used for particle generation. Third, a modified RESS-procedure, forming the particles directly into the thereby gelated liquid, was developed. All three methods gave yields from 1% to 5.8%, depending on the techniques employed. The triterpene composition of the three extracts was comparable: all three gave more stable oleogels compared to the use of an extract obtained by organic solvent extraction. Characterizing the rheological behaviour of these gels, a faster gelling effect was seen together with a lower concentration of the extract required for the gel formation with the supercritical fluid (SCF-extracts. This confirms the superiority of the supercritical fluid produced extracts with regard to the oleogel forming properties.

  2. Capillary Corner Flows With Partial and Nonwetting Fluids

    Science.gov (United States)

    Bolleddula, D. A.; Weislogel, M. M.

    2009-01-01

    Capillary flow in containers or conduits with interior corners are common place in nature and industry. The majority of investigations addressing such flows solve the problem numerically in terms of a friction factor for flows along corners with contact angles below the Concus-Finn critical wetting condition for the particular conduit geometry of interest. This research effort provides missing numerical data for the flow resistance function F(sub i) for partially and nonwetting systems above the Concus-Finn condition. In such cases the fluid spontaneously de-wets the interior corner and often retracts into corner-bound drops. A banded numerical coefficient is desirable for further analysis and is achieved by careful selection of length scales x(sub s) and y(sub s) to nondimensionalize the problem. The optimal scaling is found to be identical to the wetting scaling, namely x(sub s) = H and y(sub s) = Htan (alpha), where H is the height from the corner to the free surface and a is the corner half-angle. Employing this scaling produces a relatively weakly varying flow resistance F(sub i) and for subsequent analyses is treated as a constant. Example solutions to steady and transient flow problems are provided that illustrate applications of this result.

  3. Screening of hydrocarbons as supercritical ORCs working fluids by thermal stability

    International Nuclear Information System (INIS)

    Dai, Xiaoye; Shi, Lin; An, Qingsong; Qian, Weizhong

    2016-01-01

    Highlights: • A rapid evaluation method for thermal stability of hydrocarbons for ORCs. • Methane and hydrogen are confirmed to be decomposition indicators. • The decomposition temperatures for some hydrocarbons using the rapid method. • Long carbon chain hydrocarbons are not suitable for supercritical ORCs. - Abstract: Organic Rankine Cycle (ORC) systems are widely used for industrial waste heat recovery and renewable energy utilization. The supercritical ORC is currently one of the main development directions due to its low exergy loss, high thermal efficiency and high work output. The thermal stability is the major limitation of organic working fluid selection with high temperature heat sources. This paper presents a rapid experimental method for assessing the thermal stability of hydrocarbons for ORCs. The fluids were tested in a high temperature reactor with methane and hydrogen theoretically and experimentally confirmed to be the indicators of thermal decomposition. The thermal decomposition temperatures were obtained for n-hexane, n-pentane, isopentane, cyclopentane, n-butane and isobutane using the rapid experimental method. The results show that cycloalkanes are not the good choices by thermal stability and long carbon chain hydrocarbons (longer than C6) are not suitable for supercritical ORCs due to the thermal stability limitation.

  4. RED WINE EXTRACT OBTAINED BY MEMBRANE-BASED SUPERCRITICAL FLUID EXTRACTION: PRELIMINARY CHARACTERIZATION OF CHEMICAL PROPERTIES.

    Directory of Open Access Journals (Sweden)

    W. Silva

    Full Text Available ABSTRACT This study aims to obtain an extract from red wine by using membrane-based supercritical fluid extraction. This technique involves the use of porous membranes as contactors during the dense gas extraction process from liquid matrices. In this work, a Cabernet Sauvignon wine extract was obtained from supercritical fluid extraction using pressurized carbon dioxide as solvent and a hollow fiber contactor as extraction setup. The process was continuously conducted at pressures between 12 and 18 MPa and temperatures ranged from 30 to 50ºC. Meanwhile, flow rates of feed wine and supercritical CO2 varied from 0.1 to 0.5 mL min-1 and from 60 to 80 mL min-1 (NCPT, respectively. From extraction assays, the highest extraction percentage value obtained from the total amount of phenolic compounds was 14% in only one extraction step at 18MPa and 35ºC. A summarized chemical characterization of the obtained extract is reported in this work; one of the main compounds in this extract could be a low molecular weight organic acid with aromatic structure and methyl and carboxyl groups. Finally, this preliminary characterization of this extract shows a remarkable ORAC value equal to 101737 ± 5324 µmol Trolox equivalents (TE per 100 g of extract.

  5. Mechanisms underlying the volume regulation of interstitial fluid by capillaries: a simulation study

    Directory of Open Access Journals (Sweden)

    Yukiko Himeno

    2016-03-01

    Conclusion: Mathematical analyses revealed that the system of the capillary is stable near the equilibrium point at steady state and normal physiological capillary pressure. The time course of the tissue-volume change was determined by two kinetic mechanisms: rapid fluid exchange and slow protein fluxes.

  6. Numerical Analysis of Thermohydrodynamics Interfacing Supercritical Fluid and Liquid Metal

    International Nuclear Information System (INIS)

    Jung, Jong H.; Suh, Kune Y.; Jung, Wi S.

    2008-01-01

    A shell-and-tube heat exchanger is the most common type of heat exchanger in nuclear power plants as well as oil refineries and other large chemical processes, and is suited for higher-pressure applications. This type of heat exchanger comprises a vessel with a bundle of tubes inside. One fluid runs through the tubes, and another fluid flows over the tubes through the shell to transport heat in-between. The tube bundle contains such varying tubes as plain, longitudinally finned, and so forth. Heat exchangers may be divided into a shell-and-tube, double pipe, flat plate, helical coil or printed-circuit type according to geometry. The shell-and-tube heat exchanger is commonly adopted in a variety of power conversion systems. Tubular Exchanger Manufacturers Association (TEMA) categorized the shell-and-tube heat exchanger into a floating head, fixed tube sheet, Utube and kettle type. Maximization of the heat exchanger effectiveness tends to reduce the waste of energy, whereby increasing the efficiency of the nuclear power conversion system. A great deal of attempts has been made to improve efficiency of the heat exchanger by increasing the heat transfer surface area exposed to the working fluids and reducing the difference in temperature between the primary and secondary fluids. Limitations, though, exist to achievable tube densities based on manufacturing constraints and cooling requirements

  7. Fused silica capillaries with two segments of different internal diameters and inner surface roughnesses prepared by etching with supercritical water and used for volume coupling electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Karásek, Pavel; Roth, Michal; Šlais, Karel

    2017-01-01

    Roč. 38, 9-10 (2017), s. 1260-1267 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Institutional support: RVO:68081715 Keywords : fused silica capillary * supercritical water * volume coupling electrophoresis Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  8. Discussion of heat transfer phenomena in fluids at supercritical pressure with the aid of CFD models

    International Nuclear Information System (INIS)

    Sharabi, Medhat; Ambrosini, Walter

    2009-01-01

    The paper discusses heat transfer enhancement and deterioration phenomena observed in experimental data for fluids at supercritical pressure. The results obtained by the application of various CFD turbulence models in the prediction of experimental data for water and carbon dioxide flowing in circular tubes are firstly described. On this basis, the capabilities of the addressed models in predicting the observed phenomena are shortly discussed. Then, the analysis focuses on further results obtained by a low-Reynolds number k - ε model addressing one of the considered experimental apparatuses by changing the operating conditions. In particular, the usual imposed heat flux boundary condition is changed to assigned wall temperature, in order to highlight effects otherwise impossible to point out. The obtained results, supported by considerations drawn from experimental information, allow comparing the trends observed for heat transfer deterioration at supercritical pressure with those typical of the thermal crisis in boiling systems, clarifying old concepts of similarity among them

  9. Squalene Extraction by Supercritical Fluids from Traditionally Puffed Amaranthus hypochondriacus Seeds

    Directory of Open Access Journals (Sweden)

    Teresa Rosales-García

    2017-01-01

    Full Text Available Extraction of squalene, a potent natural antioxidant, from puffed A. hypochondriacus seeds was performed by supercritical fluid extraction (SCFE; besides, to have a blank for comparison, extraction was performed also by Soxhlet method using organic solvents (hexane. Chemical proximal composition and seed morphology were determined in raw, puffed, and SCFE-extracted seeds. Extracts were obtained with a 500 mL capacity commercial supercritical extractor and performed between 10 and 30 MPa at 313, 323, and 333 K under constant CO2 flow of 0.18 kg CO2/h during 8 h. The squalene content was determined and the fatty acids present in the extracts were identified by GC-MS. The extract obtained by SCFE from puffed amaranth seeds reached 460 ± 28.1 g/kg squalene in oily extract at 313 K/20 MPa.

  10. Supercritical fluid extraction of triterpenes and aliphatic hydrocarbons from olive tree derivatives

    Directory of Open Access Journals (Sweden)

    Aimen Issaoui

    2017-05-01

    Full Text Available Olive leaves and tree bark were extracted through supercritical fluid extraction (SFE and the chemical composition of the extracted mixture was determined by Gas Chromatography–Mass Spectrometry (GC–MS. Both samples contain a great number of triterpenes as squalene, which were used since 1997 as a main constituent of the flu vaccine (FLUAD, and the alpha-tocopherol the most biologically active form of vitamin E. We also underline the presence of many aliphatic compounds such nonacosane and heptacosane in low concentrations. The extractions were carried out at 313 and 333 K, at a pressure varying from 90 to 250 bars and using pure carbon dioxide in its supercritical phase. Therefore, their solubilities at equilibrium were numerically optimized via two assumptions and compared with the experimental values. Indeed, a good agreement between several results was shown.

  11. Supercritical fluid extraction of uranium from nitric acid medium and tissue paper matrix

    International Nuclear Information System (INIS)

    Kumar, Pradeep; Pal, Ankita; Saxena, M.K.; Ramakumar, K.L.

    2007-01-01

    Supercritical fluid extraction (SFE) is a novel technique for metal ion extraction, which offers a promising alternate to the conventional extraction process. The technique has advantage of minimization of radioactive liquid waste. In the present study, supercritical CO 2 containing small amount of TBP/TOPO as co-solvent were employed for uranium extraction. Uranium extraction efficiency of ∼ 98% was achievable from nitric acid medium employing TBP as co-solvent. However, uranium could be extracted to nearly same extent with lesser amount (1 ml) of TOPO. In SFE of uranium from tissue paper matrix extraction efficiency of 70% was obtained with TBP as co-solvent. Whereas nearly complete uranium extraction (∼99%) was achievable from tissue paper with TOPO as co-solvent. (author)

  12. Supercritical Fluid Extraction (SFE of Monoterpenes from the Leaves of Melaleuca alternifolia (Tea Tree

    Directory of Open Access Journals (Sweden)

    Deidre Tronson

    2001-01-01

    Full Text Available The technique of supercritical fluid extraction (SFE was applied to various sample matrices under a range of supercritical carbon dioxide (scCO2 densities and chamber temperatures. The purpose was to develop an effective extraction condition for the removal of eight target monoterpenes from Australian tea tree (Melaleuca alternifolia Cheel leaves. The optimum conditions for extraction were found to be 0.25 g/mL scCO2 density at a chamber temperature of 110oC. These condition were most effective when applied to whole fresh and rehydrated whole dried leaves, where it yielded maximum recovery of target analytes with minimum change in oil composition for the extractor system employed. This study demonstrates the importance of the type of sample matrix used in SFE work, and that a different extraction protocol would need to be developed for each matrix.

  13. [Comparison of supercritical fluid extraction and steam distillation methods for the extraction of essential oils from Schizonepeta tenuifolia Briq].

    Science.gov (United States)

    Qiu, Qin; Ling, Jianya; Ding, Yuping; Chang, Hongwen; Wang, Jiang; Liu, Tingli

    2005-11-01

    Essential oil was extracted from Schizonepeta tenuifolia Briq. by supercritical fluid extraction (SFE) and steam distillation (SD). The components extracted were determined by gas chromatography with area normalization method and identified by gas chromatography-mass spectrometry (GC-MS). The optimal chromatographic conditions were: capillary column, SE-54 (30 m x 0.25 mm i.d., 0.25 microm); column temperature, 50 degrees C (3 min) --> (5 degrees c/min) 180 degrees C (2 min --> (10 degrees C/ min) 260 degrees C 50 min); split injection, split ratio 1: 50; injector temperature, 280 degrees C. Fifty-four components were identified for the essential oils extracted by SFE, and its main components were found to be pulegone, menthone, linoleic acid chloride etc. Thirty-nine components were identified for the essential oil obtained by SD, and its main components were found to be pulegone, menthone, limonene etc. The SFE method is better than the SD method in reliability stability and reproducibility, and is thus well suitable for similar applications involving for extraction of other traditional Chinese herbal medicines.

  14. Supercritical fluid extraction of heather (Calluna vulgaris) and evaluation of anti-hepatitis C virus activity of the extracts

    OpenAIRE

    Rodríguez García-Risco, Mónica; Vázquez, Erika; Sheldon, Julie; Steinmann, Eike; Riebesehl, Nina; Fornari, Tiziana; Reglero, Guillermo

    2015-01-01

    Previous studies using lipid extracts of heather (Calluna vulgaris) leaves showed the presence of high concentrations of ursolic and oleanolic acid. These two compounds have been reported to present antiviral activity against hepatitis C virus (HCV). In this work, the supercritical fluid extraction of heather was studied with the aim of assessing a potential anti-HCV activity of the extracts owing to their triterpenic acid content. Supercritical extraction assays were carried out exploring th...

  15. Extraction of Plutonium From Spiked INEEL Soil Samples Using the Ligand-Assisted Supercritical Fluid Extraction (LA-SFE) Technique

    International Nuclear Information System (INIS)

    Fox, R.V.; Mincher, B.J.; Holmes, R.G.G.

    1999-01-01

    In order to investigate the effectiveness of ligand-assisted supercritical fluid extraction for the removal of transuranic contaminations from soils an Idaho National Engineering and Environmental Laboratory (INEEL) silty-clay soil sample was obtained from near the Radioactive Waste Management Complex area and subjected to three different chemical preparations before being spiked with plutonium. The spiked INEEL soil samples were subjected to a sequential aqueous extraction procedure to determine radionuclide portioning in each sample. Results from those extractions demonstrate that plutonium consistently partitioned into the residual fraction across all three INEEL soil preparations whereas americium partitioned 73% into the iron/manganese fraction for soil preparation A, with the balance partitioning into the residual fraction. Plutonium and americium were extracted from the INEEL soil samples using a ligand-assisted supercritical fluid extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction technique. Initial supercritical fluid extraction runs produced plutonium extraction efficiencies ranging from 14% to 19%. After a second round wherein the initial extraction parameters were changed, the plutonium extraction efficiencies increased to 60% and as high as 80% with the americium level in the post-extracted soil samples dropping near to the detection limits. The third round of experiments are currently underway. These results demonstrate that the ligand-assisted supercritical fluid extraction technique can effectively extract plutonium from the spiked INEEL soil preparations

  16. Comparison of supercritical fluid and Soxhlet extractions for the quantification of hydrocarbons from Euphorbia macroclada.

    Science.gov (United States)

    Ozcan, Adnan; Ozcan, Asiye Safa

    2004-10-08

    This study compares conventional Soxhlet extraction and analytical scale supercritical fluid extraction (SFE) for their yields in extracting of hydrocarbons from arid-land plant Euphorbia macroclada. The plant material was firstly sequentially extracted with supercritical carbon dioxide, modified with 10% methanol (v/v) in the optimum conditions that is a pressure of 400atm and a temperature of 50 degrees C and then it was sonicated in methylene chloride for an additional 4h. E. macroclada was secondly extracted by using a Soxhlet apparatus at 30 degrees C for 8h in methylene chloride. The validated SFE was then compared to the extraction yield of E. macroclada with a Soxhlet extraction by using the Student's t-test at the 95% confidence level. All of extracts were fractionated with silica-gel in a glass column to get better hydrocarbon yields. Thus, the highest hydrocarbons yield from E. macroclada was achieved with SFE (5.8%) when it compared with Soxhlet extractions (1.1%). Gas chromatography (GC) analysis was performed to determine the quantitative hydrocarbons from plant material. The greatest quantitative hydrocarbon recovery from GC was obtained by supercritical carbon dioxide extract (0.6mgg(-1)).

  17. Extraction of Stevia rebaudiana bertoni sweetener glycosides by supercritical fluid methods.

    Directory of Open Access Journals (Sweden)

    Juan José Hinojosa-González

    2017-05-01

    Full Text Available Aim. The aim was to evaluate the supercritical carbon dioxide extraction method with and without the addition of co-solvent to the system (mixture water: ethanol to obtain the glycosides from leaves of Stevia rebaudiana Bertoni. Methods. A SFT-150 SFE / SFR model with CO2 as a fluid was used for the supercritical extraction. The variables studied were temperature, pressure, extraction time and the presence or absence of the co-solvent (water-ethanol mixture in a concentration of 70:30 v/v, incorporated in different proportions to determine the effect on yield. The amount of glycoside sweeteners was analyzed by High Performance Liquid Chromatography (HPLC. Results. The pressure was the factor that favored the extraction, which was selective in obtaining Rebaudioside A with yields no greater than 2%. The inclusion of the co-solvent achieved an increase in yield to values of 2.9% Conclusion. Supercritical CO2 individually and mixed with ethanol-water as a co-solvent was not efficient to extract Stevia rebaudiana stevioside sweeteners

  18. Supercritical fluid extraction: spectroscopic study of interactions comparison to solvent extraction

    International Nuclear Information System (INIS)

    Rustenholtz Farawila, A.

    2005-06-01

    Supercritical fluid carbon dioxide (SF-CO 2 ) was chosen to study Supercritical Fluid Extraction (SFE) of cesium and uranium. At first, crown ethers were considered as chelating agents for the SFE of cesium. The role of water and its interaction with crown ethers were especially studied using Fourier-Transform Infra-Red (FT-IR) spectroscopy in SF-CO 2 . A sandwich configuration between two crown ethers and a water molecule was observed in the SF-CO 2 phase for the first time. The equilibrium between the single and the bridge configurations was defined. The enthalpy of the hydrogen bond formation was also calculated. These results were then compared to the one in different mixtures of chloroform and carbon tetra-chloride using Nuclear Magnetic Resonance (NMR). To conclude this first part and in order to understand the whole picture of the recovery of cesium, I studied the role of water in the equilibrium between the cesium and the di-cyclo-hexano18-crown-6.In a second part, the supercritical fluid extraction of uranium was studied in SF-CO 2 . For this purpose, different complexes of Tributyl Phosphate (TBP), nitric acid and water were used as chelating and oxidizing agents. I first used FT-IR to study the TBP-water interaction in SF-CO 2 . These results were then compared to the one obtained with NMR in chloroform. NMR spectroscopy was also used to understand the TBP-nitric acid-water interaction first alone and then in chloroform. To conclude my research work, I succeeded to improve the efficiency of uranium extraction and stripping into water for a pilot-plant where enriched uranium is extracted from incinerated waste coming from nuclear fuel fabrication. TBP-nitric acid complexes were used in SF-CO 2 for the extraction of uranium from ash. (author)

  19. Supercritical fluid extraction: spectroscopic study of interactions comparison to solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Rustenholtz Farawila, A

    2005-06-15

    Supercritical fluid carbon dioxide (SF-CO{sub 2}) was chosen to study Supercritical Fluid Extraction (SFE) of cesium and uranium. At first, crown ethers were considered as chelating agents for the SFE of cesium. The role of water and its interaction with crown ethers were especially studied using Fourier-Transform Infra-Red (FT-IR) spectroscopy in SF-CO{sub 2}. A sandwich configuration between two crown ethers and a water molecule was observed in the SF-CO{sub 2} phase for the first time. The equilibrium between the single and the bridge configurations was defined. The enthalpy of the hydrogen bond formation was also calculated. These results were then compared to the one in different mixtures of chloroform and carbon tetra-chloride using Nuclear Magnetic Resonance (NMR). To conclude this first part and in order to understand the whole picture of the recovery of cesium, I studied the role of water in the equilibrium between the cesium and the di-cyclo-hexano18-crown-6.In a second part, the supercritical fluid extraction of uranium was studied in SF-CO{sub 2}. For this purpose, different complexes of Tributyl Phosphate (TBP), nitric acid and water were used as chelating and oxidizing agents. I first used FT-IR to study the TBP-water interaction in SF-CO{sub 2}. These results were then compared to the one obtained with NMR in chloroform. NMR spectroscopy was also used to understand the TBP-nitric acid-water interaction first alone and then in chloroform. To conclude my research work, I succeeded to improve the efficiency of uranium extraction and stripping into water for a pilot-plant where enriched uranium is extracted from incinerated waste coming from nuclear fuel fabrication. TBP-nitric acid complexes were used in SF-CO{sub 2} for the extraction of uranium from ash. (author)

  20. [Study on condition for extraction of arctiin from fruits of Arctium lappa using supercritical fluid extraction].

    Science.gov (United States)

    Dong, Wen-hong; Liu, Ben

    2006-08-01

    To study the feasibility of supercritical fluid extraction (SFE) for arctiin from the fruits of Arctium lappa. The extracts were analyzed by HPLC, optimum extraction conditions were studied by orthogonal tests. The optimal extraction conditions were: pressure 40 MPa, temperature 70 degrees C, using methanol as modifier carrier at the rate of 0.55 mL x min(-1), static extraction time 5 min, dynamic extraction 30 min, flow rate of CO2 2 L x min(-1). SFE has the superiority of adjustable polarity, and has the ability of extracting arctiin.

  1. Online recovery of radiocesium from soil, tissue paper and plant samples by supercritical fluid extraction

    International Nuclear Information System (INIS)

    Kanekar, A.S.; Pathak, P.N.; Mohapatra, P.K.

    2014-01-01

    The feasibility of recovery of radio-cesium from soil, tissue papers, and plant samples has been evaluated by supercritical fluid extraction (SFE) route employing calix(4)arene-mono(crown-6) (CC) dissolved in acetonitrile. These studies showed that quantitative recovery of 137 Cs from soil samples was difficult under the conditions of these studies. However, experiments performed on tissue papers (cellulose matrix) showed quantitative recovery of 137 Cs. On the other hand, 137 Cs recovery from plant samples varied between ∼50 % (for stems) and ∼67.2 % (for leaves) employing 1x10 -3 M CC + 4 M HNO 3 dissolved in acetonitrile. (author)

  2. Processing of polyphenolic composites with supercritical fluid anti-solvent technology

    Science.gov (United States)

    Kurniawansyah, Firman; Mammucari, Raffaella; Foster, Neil R.

    2017-05-01

    Polyphenols have been developed, primarily exploiting their robust antioxidant properties, for medical and food applications. In spite of their advantages, polyphenolic compounds have drawbacks from their natural characteristics of being poorly soluble in aqueous solutions, thermo-labile and low oral bioavailaibility. In this article, strategy of processing with supercritical fluid (SCF) anti-solvent to improve the shortcomings is overviewed. Information obtained from the existing studies commonly confirms SCF technology applicability to produce composites of polyphenols with various morphology, size distributions and crystallinity. The application of SCF technology also enables to develop polyphenolic composites for alternative drug delivery such as in the pulmonary administrations.

  3. Evaluation of various Crown ethers for the supercritical fluid extraction of uranium from nitric acid medium

    International Nuclear Information System (INIS)

    Kumar, Pradeep; Rao, Ankita; Ramakumar, K.L.

    2009-01-01

    Various crowns have been evaluated for supercritical fluid extraction of uranium from nitric acid medium employing HPFOA as counter ion. Uranium extraction efficiency was found to be influenced by cavity size of crown ether and nature of substituents. Complexation tendency of UO 2 2+ increases with increasing cavity size of crown ether. Electron withdrawing substituents decreased the extraction efficiency which could be attributed to decrease in the basicity of four oxygen atoms and hence their bonding ability. Whereas electron donating substituents increased the efficiency due to increases in basicity of oxygen atoms and hence in increase in bonding ability. (author)

  4. Flow Rates in Liquid Chromatography, Gas Chromatography and Supercritical Fluid Chromatography: A Tool for Optimization

    Directory of Open Access Journals (Sweden)

    Joris Meurs

    2016-08-01

    Full Text Available This paper aimed to develop a standalone application for optimizing flow rates in liquid chromatography (LC, gas chromatography (GC and supercritical fluid chromatography (SFC. To do so, Van Deemter’s equation, Knox’ equation and Golay’s equation were implemented in a MATLAB script and subsequently a graphical user interface (GUI was created. The application will show the optimal flow rate or linear velocity and the corresponding plate height for the set input parameters. Furthermore, a plot will be shown in which the plate height is plotted against the linear flow velocity. Hence, this application will give optimized flow rates for any set conditions with minimal effort.

  5. Comparison of Supercritical Fluid and Soxhlet Extraction Methods for the Determination of Chlorothalonil from Cranberry Bog Soils.

    Science.gov (United States)

    Erstfeld; Chen

    1998-02-16

    The development and validation of an analytical method to determine the concentration of chlorothalonil from cranberry bog soil using supercritical fluid extraction (SFE) are reported. A self-built supercritical fluid extractor using CO(2) as the supercritical fluid (SCF) was used. The recovery of chlorothalonil was optimized by varying extraction temperature, pressure, time (static and dynamic), organic modifiers, and SCF flow rate. This method was then compared to a Soxhlet extraction procedure. SFE had more consistent performance than the Soxhlet extraction method for the recovery of chlorothalonil from both fortified bog soils and field samples. SFE provided cleaner extracts, had shorter extraction times, and used less organic solvent than the Soxhlet extraction method. This result is consistent with other SFE methods for determining pesticides from various environmental matrices. Thus, SFE is a preferred method for the extraction of chlorothalonil from cranberry bog soil.

  6. Understanding and diminishing the extra-column band broadening effects in supercritical fluid chromatography.

    Science.gov (United States)

    De Pauw, Ruben; Shoykhet Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

    2015-07-17

    Supercritical fluid chromatography, where a low-viscosity mobile phase such as carbon dioxide is used, proves to be an excellent technique for fast and efficient separations, especially when sub-2μm particles are used. However, to achieve high velocities when using these small particles, and in order to stay within the flow rate range of current SFC-instruments, narrow columns (e.g. 2.1mm ID) must be used. Unfortunately, state-of-the-art instrumentation is limiting the full separation power of these narrower columns due to significant extra-column band broadening effects. The present work identifies and quantifies the different contributions to extra-column band broadening in SFC such as the influence of the sample solvent, injection volume, extra-column volumes and detector cell volume/design. When matching the sample solvent to the mobile phase in terms of elution strength and polarity (e.g. using hexane/ethanol/isopropanol 85/10/5vol%) and lowering the injection volume to 0.4μL, the plate count can be increased from 7600 to 21,300 for a low-retaining compound (k'=2.3) on a 2.1mm×150mm column (packed with 1.8μm particles). The application of a water/acetonitrile mixture as sample solvent was also investigated. It was found that when the volumetric ratio of water/acetonitrile was optimized, only a slightly lower plate count was measured compared to the hexane-based solvent when minimizing injection and extra-column volume. This confirms earlier results that water/acetonitrile can be used if water-soluble samples are considered or when a less volatile solvent is preferred. Minimizing the ID of the connection capillaries from 250 to 65μm, however, gives no further improvement in obtained efficiency for early-eluting compounds when a standard system configuration with optimized sample solvent was used. When switching to a state-of-the-art detector design with reduced (dispersion) volume (1.7-0.6μL), an increase in plate count is observed (from 11,000 to 14

  7. Supercritical fluid chromatography approach for a sustainable manufacture of new stereoisomeric anticancer agent.

    Science.gov (United States)

    Ghinet, Alina; Zehani, Yasmine; Lipka, Emmanuelle

    2017-10-25

    Two routes aimed at the manufacture of unprecedented stereoisomeric combretastatin A-4 analogue were described: flash chromatography vs supercritical fluid chromatography. The latter has many advantages over liquid chromatography and was therefore chosen for the small scale separation of methyl 1-[(3-hydroxy-4-methoxyphenyl) (3,4,5-trimethoxyphenyl)methyl]-5-oxo-l-prolinate 5, with potential antitumoral activity. After a screening of six different polysaccharide based chiral stationary phases and four co-solvents, the percentage of co-solvent, the flow-rate and the outlet pressure were optimized through a design of experiments (DoE). The preparation of 50mg of each stereoisomer was achieved successfully on a Chiralpak AD-H with isopropanol as a co-solvent. Productivity (kkd), solvent usage and environmental factor (E Factor) were calculated. Flash chromatography and supercritical fluid chromatography approaches were compared in terms of yield and purity of each stereoisomer manufactured. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Supercritical fluid extraction assisted isolation of sesquiterpene lactones with antiproliferative effects from Centipeda minima.

    Science.gov (United States)

    Wu, Peng; Su, Miao-Xian; Wang, Ying; Wang, Guo-Cai; Ye, Wen-Cai; Chung, Hau-Yin; Li, Juan; Jiang, Ren-Wang; Li, Yao-Lan

    2012-04-01

    Pseudoguaianolide sesquiterpene lactones minimolides A (1), B (2), C (3) and D (4) and two guaianolide sesquiterpene lactones minimolides E (5) and F (6), along with seven known ones (7-13), were isolated from the supercritical fluid extract of Centipeda minima. The structures of these compounds were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D-NMR and 2D-NMR), and the complete structure and stereochemistry of 1 was further confirmed by X-ray diffraction analysis. Compounds 1, 5-8,11 and 13 displayed inhibitory activity against human nasopharyngeal cancer cells (CNE) with IC(50) values ranging from 1.1 to 20.3 μM. Compound 13 containing both α-methylene-γ-lactone and α, β-unsaturated cyclopentenone moieties exhibited even stronger inhibitory activity than that of cisplatin (positive control) through cell cycle arrest at G2/M phase. Isolation of six sesquiterpene lactones from Centipeda minima highlighted the potential of supercritical fluid extraction for enrichment of minor constituents for phytochemical study. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Liquids, gels, foams and supercritical fluids: four states of matter for radioactive decontamination of solids - 59158

    International Nuclear Information System (INIS)

    Faure, Sylvain; Causse, Jeremy; Fournel, Bruno

    2012-01-01

    Document available in abstract form only. Full text of publication follows: To face the future challenges in the nuclear industry as dismantling and decommissioning, the Advanced Decontamination Processes Laboratory (Laboratoire des Procedes Avances de Decontamination - LPAD) from the French Atomic Energy Commission (CEA) is developing new radioactive decontamination of solids processes to protect workers and to reduce strongly the quantity of secondary wastes produced. We have focused in the last past years on the use of four states of matter to develop new patented nuclear decontamination processes: micellar aqueous solutions, gels, foams and supercritical fluids. The conference gives an overview of these four ways to decontaminate a solid surface. The major applications and results obtained on real decontamination operations will be presented for each process. First, micellar solutions based on copolymers blocks surfactants are presented for radioactive degreasing. The advantage to formulate self-drying and cracking gels films sprayed on metallic surfaces is then detailed. For decontamination foams, an approach using new additives polymers or particles- is defended to obtain high life time foams that are able to treat huge and complex shape materials such as fission products tanks or steam generator. At the end, original works to treat textiles or gloves boxes using surfactants in CO 2 supercritical fluid are given. Finally, the major challenges to develop more secure processes and to reach a better decontamination efficiency are given. (authors)

  10. A study of power cycles using supercritical carbon dioxide as the working fluid

    Science.gov (United States)

    Schroder, Andrew Urban

    A real fluid heat engine power cycle analysis code has been developed for analyzing the zero dimensional performance of a general recuperated, recompression, precompression supercritical carbon dioxide power cycle with reheat and a unique shaft configuration. With the proposed shaft configuration, several smaller compressor-turbine pairs could be placed inside of a pressure vessel in order to avoid high speed, high pressure rotating seals. The small compressor-turbine pairs would share some resemblance with a turbocharger assembly. Variation in fluid properties within the heat exchangers is taken into account by discretizing zero dimensional heat exchangers. The cycle analysis code allows for multiple reheat stages, as well as an option for the main compressor to be powered by a dedicated turbine or an electrical motor. Variation in performance with respect to design heat exchanger pressure drops and minimum temperature differences, precompressor pressure ratio, main compressor pressure ratio, recompression mass fraction, main compressor inlet pressure, and low temperature recuperator mass fraction have been explored throughout a range of each design parameter. Turbomachinery isentropic efficiencies are implemented and the sensitivity of the cycle performance and the optimal design parameters is explored. Sensitivity of the cycle performance and optimal design parameters is studied with respect to the minimum heat rejection temperature and the maximum heat addition temperature. A hybrid stochastic and gradient based optimization technique has been used to optimize critical design parameters for maximum engine thermal efficiency. A parallel design exploration mode was also developed in order to rapidly conduct the parameter sweeps in this design space exploration. A cycle thermal efficiency of 49.6% is predicted with a 320K [47°C] minimum temperature and 923K [650°C] maximum temperature. The real fluid heat engine power cycle analysis code was expanded to study a

  11. Effect of supercritical fluid extraction on the reduction of toxic elements in fish oil compared with other extraction methods.

    Science.gov (United States)

    Hajeb, Parvaneh; Selamat, Jinap; Afsah-Hejri, Leili; Mahyudin, Nor Ainy; Shakibazadeh, Shahram; Sarker, Mohd Zaidul Islam

    2015-01-01

    High-quality fish oil for human consumption requires low levels of toxic elements. The aim of this study was to compare different oil extraction methods to identify the most efficient method for extracting fish oil of high quality with the least contamination. The methods used in this study were Soxhlet extraction, enzymatic extraction, wet reduction, and supercritical fluid extraction. The results showed that toxic elements in fish oil could be reduced using supercritical CO2 at a modest temperature (60°C) and pressure (35 MPa) with little reduction in the oil yield. There were significant reductions in mercury (85 to 100%), cadmium (97 to 100%), and lead (100%) content of the fish oil extracted using the supercritical fluid extraction method. The fish oil extracted using conventional methods contained toxic elements at levels much higher than the accepted limits of 0.1 μg/g.

  12. Diffusion of Supercritical Fluids through Single-Layer Nanoporous Solids: Theory and Molecular Simulations.

    Science.gov (United States)

    Oulebsir, Fouad; Vermorel, Romain; Galliero, Guillaume

    2018-01-16

    With the advent of graphene material, membranes based on single-layer nanoporous solids appear as promising devices for fluid separation, be it liquid or gaseous mixtures. The design of such architectured porous materials would greatly benefit from accurate models that can predict their transport and separation properties. More specifically, there is no universal understanding of how parameters such as temperature, fluid loading conditions, or the ratio of the pore size to the fluid molecular diameter influence the permeation process. In this study, we address the problem of pure supercritical fluids diffusing through simplified models of single-layer porous materials. Basically, we investigate a toy model that consists of a single-layer lattice of Lennard-Jones interaction sites with a slit gap of controllable width. We performed extensive equilibrium and biased molecular dynamics simulations to document the physical mechanisms involved at the molecular scale. We propose a general constitutive equation for the diffusional transport coefficient derived from classical statistical mechanics and kinetic theory, which can be further simplified in the ideal gas limit. This transport coefficient relates the molecular flux to the fluid density jump across the single-layer membrane. It is found to be proportional to the accessible surface porosity of the single-layer porous solid and to a thermodynamic factor accounting for the inhomogeneity of the fluid close to the pore entrance. Both quantities directly depend on the potential of mean force that results from molecular interactions between solid and fluid atoms. Comparisons with the simulations data show that the kinetic model captures how narrowing the pore size below the fluid molecular diameter lowers dramatically the value of the transport coefficient. Furthermore, we demonstrate that our general constitutive equation allows for a consistent interpretation of the intricate effects of temperature and fluid loading

  13. Relationships between fluid pressure and capillary pressure in ...

    African Journals Online (AJOL)

    In this work, the Bower's and Gardner's technique of velocity-to fluid pressure gradient methods were applied on seismic reflection data in order to predict fluid pressure of an X- oil field in Niger Delta Basin. Results show significant deflection common with fluid pressure zones . With average connate water saturation Swc ...

  14. Effect of variety and maturation of cheese on supercritical fluid extraction efficiency.

    Science.gov (United States)

    Yee, Jessica L; Walker, John; Khalil, Hany; Jiménez-Flores, Rafael

    2008-07-09

    Supercritical fluid extraction (SFE) has been utilized by the food industry in many applications to extract, fractionate, and recover compounds from various food matrices. However, little research has been conducted using SFE as an alternative process for producing reduced-fat cheese. Lipids in cheeses may be selectively extracted due to the nonpolar properties of supercritical carbon dioxide (SC-CO2), without leaving residual chemicals as is the case in solvent extraction. The objective of this study was to evaluate the influence on the extraction process due to cheese variety and protein breakdown by age. A Latin square design was utilized to test the extractability of lipids from Parmesan and Cheddar cheeses, aged young (9-10 months) or old (24 months). Extraction took place in a 500 mL SFE vessel using 100 g of grated cheese samples. The SFE parameters of the extraction were 350 bar, 35 degrees C, and supercritical carbon dioxide at a flow rate of 20 g/min for 55 min. Compositional analysis measured all treated samples and controls of total lipids, lipid profiling, total protein, protein/peptide analysis, moisture, ash, and pH. Cheese type was a major variable in fat extraction. The extraction in Cheddar showed an average fat reduction of 53.56% for young cheese, whereas that in old Cheddar was 47.90%. However, young Parmesan was reduced an average of 55.07%, but old Parmesan was reduced at 68.11%, measured on a dry basis. SFE extracted triglycerides and cholesterol, but did not remove phospholipids. This investigation introduces the observations of the effect of Cheddar and Parmesan varieties on SFE, offering data on the important parameters to consider in the design of SFE processes to reduce fat in cheese.

  15. Supercritical fluid extraction of uranium and thorium from nitric acid medium using organophosphorous compounds

    International Nuclear Information System (INIS)

    Pitchaiah, K.C.; Sujatha, K.; Rao, C.V.S. Brahmmananda; Subramaniam, S.; Sivaraman, N.; Rao, P.R. Vasudeva

    2015-01-01

    In recent years, Supercritical Fluid Extraction (SFE) technique has been widely used for the extraction of metal ions. In the present study, extraction of uranium from nitric acid medium was investigated using supercritical carbon dioxide (Sc-CO 2 ) containing various organophosphorous compounds such as trialkyl phosphates e.g. tri-iso-amyl phosphate (TiAP), tri-sec-butyl phosphate (TsBP) and tri-n-butyl phosphate (TBP), dialkylalkyl phosphonates, e.g. diamylamyl phosphonate (DAAP) and dibutyl butyl phosphonate (DBBP), dialkyl hydrogen phosphonates, e.g. dioctyl hydrogen phosphonate (DOHP), dioctylphosphineoxide (DOPO), trioctyl phosphine oxide (TOPO), n-octylphenyl N,N-diisobutyl carbamoylmethylphosphine oxide (CMPO) and di-2-ethyl-hexyl phosphoric acid (HDEHP). Some of these ligands have been investigated for the first time in the supercritical phase for the extraction of uranium. The extraction efficiency of uranium was studied with TiAP, DAAP and DBBP as a function of nitric acid concentration; the kinetics of the equilibration period (static extraction) and transportation of the metal complex (dynamic extraction) was investigated. The influence of pressure and temperature on the extraction behaviour of uranium with DAAP was studied from 4 N HNO 3 . The extraction efficiency of uranium from 4 N nitric acid medium was found to increase in the order of phosphates < phosphonates < HDEHP < TOPO < CMPO. In the case of phosphates and phosphonates, the maximum extraction of uranium was found to be from 4 N HNO 3 medium. The acidic extractants, HDEHP and DOHP showed relatively higher extraction at lower acidities. The relative extraction of uranium and thorium from their mixture was also examined using Sc-CO 2 containing phosphates, phosphonates and TOPO. The ligand, TsBP provided better fractionation between uranium and thorium compared to trialkyl phosphates, dialkyl alkyl phosphonates and TOPO.

  16. Modeling of mass transfer of Phospholipids in separation process with supercritical CO2 fluid by RBF artificial neural networks

    Science.gov (United States)

    An artificial Radial Basis Function (RBF) neural network model was developed for the prediction of mass transfer of the phospholipids from canola meal in supercritical CO2 fluid. The RBF kind of artificial neural networks (ANN) with orthogonal least squares (OLS) learning algorithm were used for mod...

  17. The Insecticidal Activity of Satureja hortensis L. Extracts Obtained by Supercritical Fluid Extraction and Traditional Extraction Techniques

    Czech Academy of Sciences Publication Activity Database

    Pavela, R.; Sajfrtová, Marie; Sovová, Helena; Bárnet, M.

    2008-01-01

    Roč. 43, č. 3 (2008), s. 377-382 ISSN 0021-4914 R&D Projects: GA MŠk 2B06049 Institutional research plan: CEZ:AV0Z40720504 Keywords : botanical insecticides * supercritical fluid extraction * satureja hortensis Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.600, year: 2008

  18. Computational fluid dynamic model for glycerol gasification in supercritical water in a tee junction shaped cylindrical reactor

    NARCIS (Netherlands)

    Yukananto, Riza; Pozarlik, Artur K.; Brem, Gerrit

    2018-01-01

    Gasification in supercritical water is a very promising technology to process wet biomass into a valuable gas. Providing insight of the process behavior is therefore very important. In this research a computational fluid dynamic model is developed to investigate glycerol gasification in

  19. Understanding physical rock properties and their relation to fluid-rock interactions under supercritical conditions

    Science.gov (United States)

    Kummerow, Juliane; Raab, Siegfried; Meyer, Romain

    2017-04-01

    The electrical conductivity of rocks is, in addition to lithological factors (mineralogy, porosity) and physical parameters (temperature, pressure) sensitive to the nature of pore fluids (phase, salinity), and thus may be an indicative measure for fluid-rock interactions. Especially near the critical point, which is at 374.21° C and 22.12 MPa for pure water, the physico-chemical properties of aqueous fluids change dramatically and mass transfer and diffusion-controlled chemical reactivity are enhanced, which in turn leads to the formation of element depletion/ enrichment patterns or cause mineral dissolution. At the same time, the reduction of the dielectric constant of water promotes ion association and consequently mineral precipitation. All this cause changes in the electrical conductivity of geothermal fluids and may have considerable effects on the porosity and hydraulic properties of the rocks with which they are in contact. In order to study the impact of fluid-rock interactions on the physical properties of fluids and rocks in near- and supercritical geological settings in more detail, in the framework of the EU-funded project "IMAGE" (Integrated Methods for Advanced Geothermal Exploration) hydraulic and electrical properties of rock cores from different active and exhumed geothermal areas on Iceland were measured up to supercritical conditions (Tmax = 380° C, pfluid = 23 MPa) during long-term (2-3 weeks) flow-through experiments in an internally heated gas pressure vessel at a maximum confining pressure of 42 MPa. In a second flow-through facility both the intrinsic T-dependent electrical fluid properties as well as the effect of mineral dissolution/ precipitation on the fluid conductivity were measured for increasing temperatures in a range of 24 - 422° C at a constant fluid pressure of 31 MPa. Petro- and fluid physical measurements were supplemented by a number of additional tests, comprising microstructural investigations as well as the chemical

  20. Processing of novel bioactive polymeric matrixes for tissue engineering using supercritical fluid technology

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Ana Rita C., E-mail: aduarte@dep.uminho.pt [3B' s Research Group, Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimaraes (Portugal); IBB, Institute for Biotechnology and Bioengineering, PT Government Associated Laboratory, Guimaraes (Portugal); Caridade, Sofia G.; Mano, Joao F.; Reis, Rui L. [3B' s Research Group, Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimaraes (Portugal); IBB, Institute for Biotechnology and Bioengineering, PT Government Associated Laboratory, Guimaraes (Portugal)

    2009-08-31

    The aim of this study was to develop a new process for the production of bioactive 3D scaffolds using a clean and environmentally friendly technology. The possibility of preparing composite scaffolds of Bioglass and a polymeric blend of starch and poly(L-lactic acid) (SPLA50) was evaluated. Supercritical phase-inversion technique was used to prepare inorganic particles loaded starch-based porous composite matrixes in a one-step process for bone tissue engineering purposes. Due to their osteoconductive properties some glasses and ceramics are interesting materials to be used for bone tissue engineering purposes; however their poor mechanical properties create the need of a polymeric support where the inorganic fraction can be dispersed. Samples impregnated with different concentrations of Bioglass (10 and 15% wt/wt polymer) were prepared at 200 bar and 55 deg. C. The presence of Bioglass did not affect the porosity or interconnectivity of the polymeric matrixes. Dynamic mechanical analysis has proven that the modulus of the SPLA50 scaffolds increases when glass particles are impregnated within the matrix. In vitro bioactivity studies were carried out using simulated body fluid and the results show that a calcium-phosphate layer started to be formed after only 1 day of immersion. Chemical analysis of the apatite layer formed on the surface of the scaffold was performed by different techniques, namely EDS and FTIR spectroscopy and X-ray diffraction (XRD). The ion concentration in the simulated body fluid was also carried out by ICP analysis. Results suggest that a bone-like apatite layer was formed. This study reports the feasibility of using supercritical fluid technology to process, in one step, a porous matrix loaded with a bioactive material for tissue engineering purposes.

  1. Phase Envelope Calculations for Reservoir Fluids in the Presence of Capillary Pressure

    DEFF Research Database (Denmark)

    Lemus, Diego; Yan, Wei; Michelsen, Michael L.

    2015-01-01

    Reservoir fluids are multicomponent mixtures in confined spaces, where the role of capillary force becomes important when the average pore size is on the order of tens of nanometers, such as in tight rocks and shale. We present an algorithm for calculating the phase envelope of multicomponent...... the bubble and dew point curves but also other quality lines with vapor fractions between 0 and 1. The algorithm has been used to calculate the phase envelopes of binary, multicomponent and reservoir fluid systems for pore radius from 10 to 50 nm. The presence of capillary pressure changes the saturation...

  2. Determination of Crude Fat in Food Products by Supercritical Fluid Extraction and Gravimetric Analysis

    Science.gov (United States)

    Snow, Nicholas H.; Dunn, Maureen; Patel, Sohita

    1997-09-01

    The use of supercritical fluid extraction (SFE), a recently developed analytical extraction method, in the undergraduate instrumental analysis laboratory is demonstrated. Specifically, the extraction and gravimetric analysis of the fats from a common commercial confection was performed by several groups of undergraduates, and the extraction recoveries were evaluated. The percentage of fat by weight in the candy bar sample was determined to be 21 +/- 2 %, a value found to be in agreement with the product labeling. Under the extraction conditions used, complete extraction required 400-700 mL of supercritical carbon dioxide, applied to a 1.0 g sample of candy in several extraction steps. Data relating extraction recovery to the volume of carbon dioxide used for extraction is shown. SFE is shown to be a versatile addition to the undergraduate instrumental analysis laboratory, requiring a minimum of training and supervision. Finally, SFE can be extended to myriad physical and analytical measurements in the undergraduate laboratories. Examples derived from the current analytical literature are proposed.

  3. Sedative and hypnotic effects of supercritical carbon dioxide fluid extraction from Schisandra chinensis in mice

    Directory of Open Access Journals (Sweden)

    Hongyan Zhu

    2016-10-01

    Full Text Available Schisandra chinensis is a traditional Chinese medicine that has been used for treating insomnia and neurasthenia for centuries. Lignans, which are considered to be the bioactive components, are apt to be extracted by supercritical carbon dioxide. This study was conducted to investigate the sedative and hypnotic activities of the supercritical carbon dioxide fluid extraction of S. chinensis (SFES in mice and the possible mechanisms. SFES exhibited an obvious sedative effect on shortening the locomotor activity in mice in a dose-dependent (10–200 mg/kg manner. SFES (50 mg/kg, 100 mg/kg, and 200 mg/kg, intragstrically showed a strong hypnotic effect in synergy with pentobarbital in mouse sleep, and reversal of insomnia induced by caffeine, p-chlorophenylalanine and flumazenil by decreasing sleep latency, sleep recovery, and increasing sleeping time. In addition, it produced a synergistic effect with 5-hydroxytryptophan (2.5 mg/kg, intraperitoneally. The behavioral pharmacological results suggest that SFES has significant sedative and hypnotic activities, and the mechanisms might be relevant to the serotonergic and γ-aminobutyric acid (GABAergic system.

  4. Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

    Directory of Open Access Journals (Sweden)

    M. S. T. Barroso

    2011-06-01

    Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

  5. Comparison of extraction techniques, including supercritical fluid, high-pressure solvent, and soxhlet, for organophosphorus hydraulic fluids from soil.

    Science.gov (United States)

    David, M D; Seiber, J N

    1996-09-01

    The efficiencies of three extraction techniques for removal of nonpesticidal organophosphates from soil were determined. Traditional Soxhlet extraction was compared to supercritical fluid extraction (SFE) and a low solvent volume flow through technique referred to here as high-pressure solvent extraction (HPSE). SFE, optimized by varying parameters of temperature, pressure, and methanol polarity modifier, showed at least 90% efficiency in the extraction of OPs from both spiked and native soils. HPSE experiments showed efficient and consistent recoveries over a range of temperatures up to 200 °C and pressures up to 170 atm. Recovery of TCP from spiked soils with HPSE depends on the system variables of temperature and pressure, which dictate density and flow rate. HPSE provided extraction efficiencies comparable to those obtained with Soxhlet extraction and SFE but with substantial savings of time and cost.

  6. Chemical Processing for Sol-Gel Derived Metal Oxide Thin Films using Supercritical Carbon Dioxide Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Asai, Y; Narishige, S; Fujioka, K; Uchida, H; Koda, S, E-mail: uchidah@sophia.ac.jp [Sophia University, Department of Materials and Life Sciences, Tokyo 102-8554 (Japan)

    2011-10-29

    Chemical processing using supercritical carbon dioxide fluid (scCO{sub 2}) was demonstrated for lowering processing temperature of sol-gel-derived metal oxide thin films. The film processing was performed in a hot-wall closed vessel filled with scCO{sub 2} fluid. Precursor films of titanium dioxide (TiO{sub 2}) on soda-glass substrates prepared by sol-gel coating using Ti-alkoxide solution were converted to crystalline TiO{sub 2} (anatase) films successfully by the scCO{sub 2} treatment at a fluid pressure of 15 MPa and a substrate temperature of 300deg. C whereas no crystallization was occurred by conventional heat treatment at 400 deg. C. XPS analysis indicated that the interface reaction related to Si element was suppressed successfully by scCO{sub 2} treatment at 300 deg. C. These results suggest that the sol-gel synthesis using scCO{sub 2} fluid would be a cadidate for low-temperature processing of crystalline oxide films, which is more preferable than conventional techniques based on the heat treatment.

  7. The Fast and Non-capillary Fluid Filling Mechanism in the Hummingbird's Tongue

    Science.gov (United States)

    Rico-Guevara, Alejandro; Fan, Tai-Hsi; Rubega, Margaret

    2014-03-01

    Hummingbirds gather nectar by inserting their beaks inside flowers and cycling their tongues at a frequency of up to 20 Hz. It is unclear how they achieve efficiency at this high licking rate. Ever since proposed in 1833, it has been believed that hummingbird tongues are a pair of tiny straws filled with nectar by capillary rise. Our discoveries are very different from this general consensus. The tongue does not draw up floral nectar via capillary action under experimental conditions that resemble natural ones. Theoretical models based on capillary rise were mistaken and unsuitable for estimating the fluid intake rate and to support foraging theories. We filmed (up to 1265 frames/s) the fluid uptake in 20 species of hummingbirds that belong to 7 out of the 9 main hummingbird clades. We found that the fluid filling within the portions of the tongue that remain outside the nectar is about five times faster than capillary filling. We present strong evidence to rule out the capillarity model. We introduce a new fluid-structure interaction and hydrodynamic model and compare the results with field experimental data to explain how hummingbirds actually extract fluid from flowers at the lick level.

  8. [Study on chemical constituents of the essential oil from Myristica fragrans Houtt. by supercritical fluid extraction and steam distillation].

    Science.gov (United States)

    Qiu, Qin; Zhang, Guoying; Sun, Xiaomin; Liu, Xinxin

    2004-11-01

    Essential oils were extracted from Myristica fragrans Houtt. by supercritical fluid extraction (SFE) and steam distillation (SD). Their components were analyzed by gas chromatography-mass spectrometry and compared. 48 compounds were identified for the essential oil extracted by supercritical carbon dioxide, and its main components have been found to be myristic acid, myristicin, terpinen-4-ol, alpha-pinene and safrole. 38 compounds were identified for the essential oil obtained by SD, and its main components have been found to be beta-pinene, terpinen-4-ol, alpha-pinene, gamma-terpinene and beta-phellandrene.

  9. Effect temperature of supercritical CO2 fluid extraction on phytochemical analysis and antioxidant activity of Zingiber officinale Roscoe

    Science.gov (United States)

    Sondari, Dewi; Irawadi, Tun Tedja; Setyaningsih, Dwi; Tursiloadi, Silvester

    2017-11-01

    Supercritical fluid extraction of Zingiber officinale Roscoe has been carried out at a pressure of 16 MPa, with temperatures between 20-40 °C, during extraction time of 6 hours and the flow rate of CO2 fluid 5.5 ml/min. The result of supercritical method was compared with the extraction maceration using a mixture of water and ethanol (70% v/v) for 24 hours. The main content in ginger that has a main role as an antioxidant is a gingerol compound that can help neutralize the damaging effects caused by free radicals in the body, as anti-coagulant, and inhibit the occurrence of blood clots. This study aims to determine the effect of temperature on chemical components contained in rough extract of Zingiber officinale Roscoe and its antioxidant activity, total phenol and total flavonoid content. To determine the chemical components contained in the crude extract of Zingiber officinale Roscoe extracted by supercritical fluid and maceration extraction, GC-MS analysis was performed. Meanwhile, the antioxidant activity of the extract was evaluated based on a 2.2-diphenyl-1-picrylhydrazyl (DPPH) free radical damping method. The results of the analysis show that the result of ginger extract by using the supercritical CO2 extraction method has high antioxidant activity than by using maceration method. The highest total phenol content and total flavonoids were obtained on ginger extraction using supercritical CO2 fluid extraction, indicating that phenol and flavonoid compounds contribute to antioxidant activity. Chromatographic analysis showed that the chemical profile of ginger extract containing oxygenated monoterpenes, monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated monoterpene gingerol and esters. In supercritical fluid extraction, the compounds that can be identified at a temperature of 20-40 °C contain 27 compounds, and 11 compounds from the result of maceration extract. The main component of Zingiber officinale Roscoe extracted using supercritical fluid

  10. Comparison of supercritical fluid and Soxhlet extractions for the isolation of nitro compounds from soils.

    Science.gov (United States)

    Bajerová, Petra; Eisner, Ales; Jezová, Vera; Adam, Martin; Ventura, Karel

    2008-05-01

    Supercritical fluid extraction (SFE) with CO(2), a clean and rapid alternative to conventional Soxhlet extraction, was investigated for the extraction of nitro compounds from soil samples. Quantitative extraction by SFE was accomplished at a pressure of 25 MPa and an extraction temperature of 60 degrees C, for 30 min in dynamic mode and using acetonitrile as modifier, and the results were comparable with those obtained by acetonitrile Soxhlet extraction (3 h) for all soil samples. Extracts from these two procedures were analyzed by gas chromatography coupled with mass spectrometry. Quantitative reproducibility for SFE extracts was acceptable (RSD 2-10%), and the quantity of solvent was reduced from 160 mL for Soxhlet extraction to 5 mL in the case of SFE.

  11. Cefuroxime axetil solid dispersions prepared using solution enhanced dispersion by supercritical fluids.

    Science.gov (United States)

    Jun, Seoung Wook; Kim, Min-Soo; Jo, Guk Hyun; Lee, Sibeum; Woo, Jong Soo; Park, Jeong-Sook; Hwang, Sung-Joo

    2005-12-01

    Cefuroxime axetil (CA) solid dispersions with HPMC 2910/PVP K-30 were prepared using solution enhanced dispersion by supercritical fluids (SEDS) in an effort to increase the dissolution rate of poorly water-soluble drugs. Their physicochemical properties in solid state were characterized by differential scanning calorimeter (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy. No endothermic and characteristic diffraction peaks corresponding to CA were observed for the solid dispersions in DSC and PXRD. FTIR analysis demonstrated the presence of intermolecular hydrogen bonds between CA and HPMC 2910/PVP K-30 in solid dispersions, resulting in the formation of amorphous or non-crystalline CA. Dissolution studies indicated that the dissolution rates were remarkably increased in solid dispersions compared with those in the physical mixture and drug alone. In conclusion, an amorphous or non-crystalline CA solid dispersion prepared using SEDS could be very useful for the formulation of solid dosage forms.

  12. Supercritical fluid extraction of lipids from linseed with on-line evaporative light scattering detection.

    Science.gov (United States)

    Abrahamsson, Victor; Rodriguez-Meizoso, Irene; Turner, Charlotta

    2015-01-01

    Supercritical fluid extraction (SFE) is a green alternative method of extraction for neutral lipids in seeds compared to conventional methods utilizing organic solvents. In this work, a novel method where SFE is hyphenated with an evaporative light scattering detector is presented. The method was subsequently applied to determine lipid content in crushed linseed. The new method enables rapid quantification of extracted lipids as well as be ability to continuously monitor the extraction rate in real-time, thus being able to determine the time point of completed extraction. Both the detector and the method was validated. The results show that any of several tested oils can be used to calibrate the detection method for the determination of lipids extraction from linseed. The overall method repeatability and intermediate precision was 2.6% relative standard deviations. The extracted amount was significantly less than that obtained using the standard method of Soxhlet with petroleum ether, 26.0±0.4% (95% CI, n=9) compared to 32.3±1.3% (95% CI, n=3) of extracted amounts. It was found that channeling effects were present, and by either performing sequential repeated extractions with decompression in-between or by using a relatively large vessel a more complete extraction could be obtained. Interestingly, a substantially higher extracted amount (approximately 50%) was obtained compared to both a single extraction by SFE and the Soxhlet method. Therefore, it is recommended that an additional extraction including a rapid decompression in-between should be included in the validation of a method using supercritical fluid extraction, in order to either rule out channeling effects or to acquire a full recovery. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Supercritical fluid chemical deposition of Pd nanoparticles on magnesium–scandium alloy for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Couillaud, Samuel; Kirikova, Marina [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Zaïdi, Warda; Bonnet, Jean-Pierre [LRCS, UMR CNRS 6007, 33 rue Saint-Leu, 80039-Amiens (France); Marre, Samuel; Aymonier, Cyril [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Zhang, Junxian; Cuevas, Fermin; Latroche, Michel [ICMPE, CNRS-UPEC, UMR 7182, 2-8 rue Henri Dunant, 94320-Thiais (France); Aymard, Luc [LRCS, UMR CNRS 6007, 33 rue Saint-Leu, 80039-Amiens (France); Bobet, Jean-Louis, E-mail: bobet@icmcb-bordeaux.cnrs.fr [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France)

    2013-10-15

    Highlights: •Nanoparticles of Pd were deposed on the binary compound Mg{sub 0.65}Sc{sub 0.35} using the Supercritical Fluid Chemical Deposition (SFCD) method. •Numerous parameters were tested and optimized in order to obtain a homogeneous deposition. •At the first step, Pd@Mg0.65Sc0.35 decomposes into ScH{sub 2} and MgH{sub 2} under hydrogen pressure (1 MPa) at 330 °C. •The mixture, after decomposition absorbs hydrogen reversibly on Mg/MgH{sub 2} couple with good kinetics. -- Abstract: The deposition of Pd nanoparticles on the binary compound Mg{sub 0.65}Sc{sub 0.35} using the Supercritical Fluid Chemical Deposition (SFCD) method was performed. There, the SFCD operating parameters (co-solvent, temperature, CO{sub 2} and hydrogen pressure, reaction time) have been optimized to obtain homogeneous deposition of Pd nanoparticles (around 10 nm). The hydrogenation properties of the optimized Pd@Mg{sub 0.65}Sc{sub 0.35} material were determined and compared to those of Mg{sub 0.65}Sc{sub 0.35}Pd{sub 0.024}. The latter compound forms at 300 °C and 1 MPa of H{sub 2} a hydride that crystallizes in the fluorite structure, absorbs reversibly 1.5 wt.% hydrogen and exhibits fast kinetics. In contrast, Pd@Mg{sub 0.65}Sc{sub 0.35} compound decomposes into ScH{sub 2} and MgH{sub 2} during hydrogen absorption under the same conditions. However, reversible sorption reaches 3.3 wt.% of hydrogen while keeping good kinetics. The possible roles of Pd on the hydrogen-induced alloy decomposition are discussed.

  14. Application of supercritical and subcritical fluids for the extraction of hazardous materials from soil

    Directory of Open Access Journals (Sweden)

    Skorupan Dara

    2002-01-01

    Full Text Available Subcritical and supercritical extractions are novel, non destructive techniques which can be applied for the removal of hazardous compounds from contaminated soil without any changes of the soil composition and structure. The aim of the presented review paper is to give information on up-to day results of this method commonly applied by several institutions worldwide. Interest in the application of SC CO2 has been more expressed in the last two decades, which may be related to its favorable characteristics (non-toxic, non-flammable, increase diffusion into small pores, low viscosity under SC conditions, low price and others. However, interest in wet oxidation (WO and especially in SCWO (the application of water under supercritical conditions with air has also increased in the last few years. Interest in H2O as a SC fluid, as well as in extraction with water under subcritical conditions may also be related to specific characteristics and the enhanced rate of extraction. Moreover, the solubility of some specific compounds present in soil can be easily changed by adjusting the pressure and temperature of extraction. The high price of the units designed to operate safely at a pressure and temperature much higher than the a critical one of the applied fluids is the main reason why, at present, there is no more broader application of such techniques for the removal hazardous materials from contaminated soil. In the present paper, among many literature citations and their overall review, some specific details related to the development of specific analytical methods under SC conditions are also considered.

  15. Modeling of the Kinetics of Supercritical Fluid Extraction of Lipids from Microalgae with Emphasis on Extract Desorption

    Science.gov (United States)

    Sovová, Helena; Nobre, Beatriz P.; Palavra, António

    2016-01-01

    Microalgae contain valuable biologically active lipophilic substances such as omega-3 fatty acids and carotenoids. In contrast to the recovery of vegetable oils from seeds, where the extraction with supercritical CO2 is used as a mild and selective method, economically viable application of this method on similarly soluble oils from microalgae requires, in most cases, much higher pressure. This paper presents and verifies hypothesis that this difference is caused by high adsorption capacity of microalgae. Under the pressures usually applied in supercritical fluid extraction from plants, microalgae bind a large fraction of the extracted oil, while under extremely high CO2 pressures their adsorption capacity diminishes and the extraction rate depends on oil solubility in supercritical CO2. A mathematical model for the extraction from microalgae was derived and applied to literature data on the extraction kinetics in order to determine model parameters. PMID:28773546

  16. Modeling of the Kinetics of Supercritical Fluid Extraction of Lipids from Microalgae with Emphasis on Extract Desorption

    Directory of Open Access Journals (Sweden)

    Helena Sovová

    2016-05-01

    Full Text Available Microalgae contain valuable biologically active lipophilic substances such as omega-3 fatty acids and carotenoids. In contrast to the recovery of vegetable oils from seeds, where the extraction with supercritical CO2 is used as a mild and selective method, economically viable application of this method on similarly soluble oils from microalgae requires, in most cases, much higher pressure. This paper presents and verifies hypothesis that this difference is caused by high adsorption capacity of microalgae. Under the pressures usually applied in supercritical fluid extraction from plants, microalgae bind a large fraction of the extracted oil, while under extremely high CO2 pressures their adsorption capacity diminishes and the extraction rate depends on oil solubility in supercritical CO2. A mathematical model for the extraction from microalgae was derived and applied to literature data on the extraction kinetics in order to determine model parameters.

  17. Supercritical carbon dioxide interpolymer complexes improve survival of B. longum Bb-46 in simulated gastrointestinal fluids.

    Science.gov (United States)

    Thantsha, Mapitsi S; Cloete, Thomas E; Moolman, Francis S; Labuschagne, Philip W

    2009-01-31

    Gastric acidity is the main factor affecting viability of probiotics in the gastrointestinal tract (GIT). This study investigated the survival in simulated gastrointestinal fluids of Bifidobacterium longum Bb-46 encapsulated in interpolymer complexes formed in supercritical carbon dioxide (scCO(2)). Bacteria were exposed sequentially to simulated gastric fluid (SGF, pH 2) for 2 h and simulated intestinal fluid (SIF, pH 6.8) for 6 or 24 h. Total encapsulated bacteria were determined by suspending 1 g of product in SIF for 6 h at 37 degrees C prior to plating out. Plates were incubated anaerobically at 37 degrees C for 72 h. The interpolymer complex displayed pH-responsive release properties, with little to no release in SGF and substantial release in SIF. There was a limited reduction in viable counts at the end of exposure period due to encapsulation. Protection efficiency of the interpolymer complex was improved by addition of glyceryl monostearate (GMS). Gelatine capsules delayed release of bacteria from the interpolymer complex thus minimizing time of exposure to the detrimental conditions. Use of poly(caprolactone) (PCL), ethylene oxide-propylene oxide triblock copolymer (PEO-PPO-PEO) decreased the protection efficiency of the matrix. Interpolymer complex encapsulation showed potential for protection of probiotics and therefore for application in food and pharmaceuticals.

  18. An oscillation free shock-capturing method for compressible van der Waals supercritical fluid flows

    International Nuclear Information System (INIS)

    Pantano, C.; Saurel, R.; Schmitt, T.

    2017-01-01

    Numerical solutions of the Euler equations using real gas equations of state (EOS) often exhibit serious inaccuracies. The focus here is the van der Waals EOS and its variants (often used in supercritical fluid computations). The problems are not related to a lack of convexity of the EOS since the EOS are considered in their domain of convexity at any mesh point and at any time. The difficulties appear as soon as a density discontinuity is present with the rest of the fluid in mechanical equilibrium and typically result in spurious pressure and velocity oscillations. This is reminiscent of well-known pressure oscillations occurring with ideal gas mixtures when a mass fraction discontinuity is present, which can be interpreted as a discontinuity in the EOS parameters. We are concerned with pressure oscillations that appear just for a single fluid each time a density discontinuity is present. As a result, the combination of density in a nonlinear fashion in the EOS with diffusion by the numerical method results in violation of mechanical equilibrium conditions which are not easy to eliminate, even under grid refinement.

  19. Supercritical-fluid carbon dioxide (SCCO{sub 2}) cleaning of nuclear weapon components

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.M.V.; Sivils, L.D.; Rubin, J.B.

    1998-05-01

    Supercritical fluid carbon dioxide (SCCO{sub 2}) has been evaluated as a cleaning solvent for the cleaning of plutonium (Pu) metal parts. The results of the evaluation show that SCCO{sub 2} is an effective alternative to halogenated solvents that are conventionally used for removing organic and inorganic contaminants from the surface of these parts. The cleaning process was demonstrated at the laboratory scale for steel and uranium substrates and has been found to be compatible with Pu. The efficacy of this cleaning method is found to be dependent on process conditions of pressure, temperature, fluid-flow rate, as well as cleaning time. Process parameters of P > 2,500 psi, T > 40 C, and moderate fluid flow rates, produced good cleaning results in less than 10 minutes using a simple flow-through process configuration. Within the parameter range studied, cleaning efficiency generally improved with increasing process pressure and flow rate. SCCO{sub 2} cleaning is suitable for a variety of component cleaning tasks and is adaptable to precision cleaning requirements. The SCCO{sub 2} cleaning process is currently being developed for deployment for weapons production at LANL.

  20. Shale Micromodel Experiments: Fluid Flow and Mobilization using Supercritical CO2

    Science.gov (United States)

    Porter, M. L.; Carey, J. W.; Viswanathan, H.

    2014-12-01

    In recent years, use of engineered micromodels to investigate pore-scale fluid flow and transport phenomena to better understand and model field-scale observables has steadily increased. Micromodels are thin porous structures in which flow is restricted to two-dimensions and have become common since they are effective, relatively inexpensive tools for visualizing and quantifying complex flow phenomena. We describe a unique micromodel experimental system recently developed at Los Alamos National Laboratory (LANL). The system consists of a pressure chamber, which allows us to conduct experiments at geologic conditions. The maximum working pressure and temperature is 1500 psig and 80° C, respectively, allowing for supercritical carbon dioxide (scCO2) to be used as a working fluid. Additionally, we have developed micromodels fabricated in geomaterials (e.g., shale and Portland cement), whereas typical micromodels are fabricated in engineered materials such as glass or silicon. The use of geomaterial micromodels allows us to better represent the fluid-rock interactions including wetting angles and chemical reactivity at conditions representative of natural subsurface environments. In this work, we present experimental results in simple fracture systems (e.g., straight channels, pore doublets) with applications to hydrocarbon mobility in hydraulically fractured shale. We use both shale and glass micromodels, allowing for a detailed comparison between flow phenomena in different materials. In the straight channel micromodels, we investigate interfacial velocities and compare the results with theoretical models. In the pore doublet micromodels, we investigate mobilization of oil blobs and contrast the effectiveness of water and scCO2 in the extraction of hydrocarbon from fracture networks. Next, we present experimental results in complex fracture network patterns derived from 3D x-ray tomography images of actual fractures created in shale rock cores. We discuss

  1. Micronutrient and protein-fortified whole grain puffed rice made by supercritical fluid extrusion.

    Science.gov (United States)

    Paraman, Ilankovan; Wagner, Michael E; Rizvi, Syed S H

    2012-11-07

    Supercritical fluid extrusion (SCFX) was used to produce shelf-stable puffed rice fortified with protein, dietary fiber, and micronutrients. Product ingredients and process parameters were evaluated for end-product nutritional and textural qualities. Supercritical carbon dioxide (SC-CO(2)) served as a viscosity-lowering plasticizer and blowing agent during the process, which has been shown to produce expanded products with good textural qualities at lower temperatures (~100 °C) than conventional steam-based extrusion (130-180 °C). The fortified puffed rice contained 8% dietary fiber, 21.5% protein, and iron, zinc, and vitamins A and C at their recommended daily values in 100 g of product. The SCFX process allowed for the complete retention of all added minerals, 55-58% retention of vitamin A, and 64-76% retention of vitamin C. All essential amino acids including lysine were retained at exceptionally high levels (98.6%), and no losses were observed due to Maillard reaction or oxidation. All of the essential amino acid contents were equal to the reference protein recommended by FAO/WHO. Soy protein fortification improved the total amount of protein in the final rice products and provided a complementary amino acid profile to that of rice; the lysine content improved from 35 to 60 mg/protein, making the end product an excellent source of complete protein. Thus, SC-CO(2)-assisted extrusion is an effective process-based approach to produce cereal grain-based, low-moisture (5-8%) expanded products fortified with protein and any cocktail of micronutrients, without compromising the end-product sensory or nutritional qualities. These products are ideally suited for consumption as breakfast cereals, snack foods, and as part of nutrition bars for school lunch programs. The balanced nutritional profile and use of staple crop byproducts such as broken rice makes these expanded crisps unique to the marketplace.

  2. Empirical Modeling of the Viscosity of Supercritical Carbon Dioxide Foam Fracturing Fluid under Different Downhole Conditions

    Directory of Open Access Journals (Sweden)

    Shehzad Ahmed

    2018-03-01

    Full Text Available High-quality supercritical CO2 (sCO2 foam as a fracturing fluid is considered ideal for fracturing shale gas reservoirs. The apparent viscosity of the fracturing fluid holds an important role and governs the efficiency of the fracturing process. In this study, the viscosity of sCO2 foam and its empirical correlations are presented as a function of temperature, pressure, and shear rate. A series of experiments were performed to investigate the effect of temperature, pressure, and shear rate on the apparent viscosity of sCO2 foam generated by a widely used mixed surfactant system. An advanced high pressure, high temperature (HPHT foam rheometer was used to measure the apparent viscosity of the foam over a wide range of reservoir temperatures (40–120 °C, pressures (1000–2500 psi, and shear rates (10–500 s−1. A well-known power law model was modified to accommodate the individual and combined effect of temperature, pressure, and shear rate on the apparent viscosity of the foam. Flow indices of the power law were found to be a function of temperature, pressure, and shear rate. Nonlinear regression was also performed on the foam apparent viscosity data to develop these correlations. The newly developed correlations provide an accurate prediction of the foam’s apparent viscosity under different fracturing conditions. These correlations can be helpful for evaluating foam-fracturing efficiency by incorporating them into a fracturing simulator.

  3. Supercritical Nonlinear Vibration of a Fluid-Conveying Pipe Subjected to a Strong External Excitation

    Directory of Open Access Journals (Sweden)

    Yan-Lei Zhang

    2016-01-01

    Full Text Available Nonlinear vibration of a fluid-conveying pipe subjected to a transverse external harmonic excitation is investigated in the case with two-to-one internal resonance. The excitation amplitude is in the same magnitude of the transverse displacement. The fluid in the pipes flows in the speed larger than the critical speed so that the straight configuration becomes an unstable equilibrium and two curved configurations bifurcate as stable equilibriums. The motion measured from each of curved equilibrium configurations is governed by a nonlinear integro-partial-differential equation with variable coefficients. The Galerkin method is employed to discretize the governing equation into a gyroscopic system consisting of a set of coupled nonlinear ordinary differential equations. The method of multiple scales is applied to analyze approximately the gyroscopic system. A set of first-order ordinary differential equations governing the modulations of the amplitude and the phase are derived via the method. In the supercritical regime, the subharmonic, superharmonic, and combination resonances are examined in the presence of the 2 : 1 internal resonance. The steady-state responses and their stabilities are determined. The various jump phenomena in the amplitude-frequency response curves are demonstrated. The effects of the viscosity, the excitation amplitude, the nonlinearity, and the flow speed are observed. The analytical results are supported by the numerical integration.

  4. Coal liquefaction process streams characterization and evaluation. Characterization of coal-derived materials by field desorption mass spectrometry, two-dimensional nuclear magnetic resonance, supercritical fluid extraction, and supercritical fluid chromatography/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.A.; Linehan, J.C.; Robins, W.H. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1992-07-01

    Under contract from the DOE , and in association with CONSOL Inc., Battelle, Pacific Northwest Laboratory (PNL) evaluated four principal and several complementary techniques for the analysis of non-distillable direct coal liquefaction materials in support of process development. Field desorption mass spectrometry (FDMS) and nuclear magnetic resonance (NMR) spectroscopic methods were examined for potential usefulness as techniques to elucidate the chemical structure of residual (nondistillable) direct coal liquefaction derived materials. Supercritical fluid extraction (SFE) and supercritical fluid chromatography/mass spectrometry (SFC/MS) were evaluated for effectiveness in compound-class separation and identification of residual materials. Liquid chromatography (including microcolumn) separation techniques, gas chromatography/mass spectrometry (GC/MS), mass spectrometry/mass spectrometry (MS/MS), and GC/Fourier transform infrared (FTIR) spectroscopy methods were applied to supercritical fluid extracts. The full report authored by the PNL researchers is presented here. The following assessment briefly highlights the major findings of the project, and evaluates the potential of the methods for application to coal liquefaction materials. These results will be incorporated by CONSOL into a general overview of the application of novel analytical techniques to coal-derived materials at the conclusion of CONSOL`s contract.

  5. Thermodynamic and Structural Properties of C-bearing Supercritical Aqueous Fluids

    Science.gov (United States)

    Seclaman, A. C.; Cohen, R. E.

    2016-12-01

    Aqueous fluids are important agents of mass transport in the Earth's crust and upper mantle. Their role in the deep mantle is poorly understood due to a lack of thermodynamic data at relevant pressures (P) and temperatures (T). Speciation of volatiles also plays a key role in understanding the reactivity of fluids, and the formation of complex anionic C species in supercritical fluids has been linked to the precipitation of diamond during fluid-rock interaction.1 Models have predicted equilibria between all oxidation states of C in aqueous fluids above 3 GPa.2 First principles approaches can help expand the PT range of models, and give an atomic-level understanding of fluid behavior. We are using first principles molecular dynamics to study the H-C-O system up to pressures of 40 GPa and 2500K, spanning a wide range of C concentrations. Since van der Waals (vdW) interactions play important roles in water and organic complexes we take into account vdW by using the non-local vdW-DF2 functional.3 From this data, we obtained the PVTX equation of state and investigated the dependence of pressure, temperature, and concentration on the C speciation. Water dissociation and the PT stability field of aqueous cations and anions were also investigated. The results of this work contribute to a better understanding of the C mantle cycle. Our work can help significantly expand the data sets employed by models4,5 used in the study of complex rock-fluid interactions. This work is supported by the ERC Advanced grant ToMCaT. 1. Sverjensky, D. A. & Huang, F. Nat. Commun. 53, 1689-1699 (2015). 2. Sverjensky, D. a., Stagno, V. & Huang, F. Nat. Geosci. 7, 909-913 (2014). 3. Lee, K., Murray, É. D., Kong, L., Lundqvist, B. I. & Langreth, D. C. Phys. Rev. B - Condens. Matter Mater. Phys. 82, 3-6 (2010). 4. Sverjensky, D. A., Harrison, B. & Azzolini, D. Geochim. Cosmochim. Acta 129, 125-145 (2014). 5. Ghiorso, M. S. & Gualda, G. A. R. Contrib. to Mineral. Petrol. 169, 1-30 (2015).

  6. HPLC/MS identification of the polyphenols present in an extract of Myrtus communis L. obtained by supercritical fluid extraction

    Directory of Open Access Journals (Sweden)

    Paula Pereira

    2017-12-01

    Full Text Available In this work, we studied an extract obtained by supercritical fluid extraction (SFE using a simpler method of cosolvent (ethanol addition. Instead of using a liquid pump, which is the most common process, the ethanol was directly introduced in the extraction cell, immediately after loading the cell with the plant sample. it was our intent to investigate if this change would have any effect in the composition of the extract obtained. The experimental conditions used were: temperature 48° C, pressure 10 MPa, supercritical fluid (SCF flow rate 130.71dm3h-1 (0.238 kgh-1 and an ethanol volume of 104 cm3. The composition of the extract obtained was different from previous tests, and the compounds identified by HPLC-MS were quinic acid, quinic acid 3,5-di-O-gallate, quinic acid 3,4,5-galloyl, myricetin-galactoside gallate, quercetin-galactoside gallate, quercetin, and myricetin-galactosiderhamnoside.

  7. Evaluation of the Use of Supercritical Fluids for the Extraction of Explosives and Their Degradation Products from Soil

    Science.gov (United States)

    1994-04-01

    nitro-1,3,5,7-tetrazocine) and TNB (1,3,5-tri- ganics such as polycyclic biphenyls and poly- nitrobenzene), the photodegradation product of chlorinated... pesticides were greatest at 5-109/6 moisture, eral sensitivity of SFE, not only to predictable whiledroppingconsiderably at09/6and 25%. Turn...efficiencies of chlorine and organophosphate pesticides from soil polycyclic aromatic hydrocarbons and polychlori- using supercritical fluid

  8. Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of polychlorinated biphenyls in environmental matrix standard reference materials.

    Science.gov (United States)

    Schantz, M M; Bøwadt, S; Benner, B A; Wise, S A; Hawthorne, S B

    1998-08-14

    Supercritical fluid extraction (SFE) was compared to traditional Soxhlet extraction for the determination of polychlorinated biphenyl congeners in three standard reference materials: SRM 1941a (Organics in Marine Sediment), SRM 1944 (New York/New Jersey Waterway Sediment) and SRM 2974 [Organics in Mussel Tissue (Mytilus edulis) (Freeze-Dried)]. The concentrations determined using SFE compared well with the certified concentrations for the majority of the polychlorinated biphenyl congeners.

  9. Lattice-Boltzmann modeling of experimental fluid displacement patterns, interfacial area and capillary trapped CO2

    Science.gov (United States)

    Porter, M. L.; Kang, Q.; Tarimala, S.; Abdel-Fattah, A.; Backhaus, S.; Carey, J. W.

    2010-12-01

    Successful sequestration of CO2 into deep saline aquifers presents an enormous challenge that requires fundamental understanding of reactive-multiphase flow and transport across many temporal and spatial scales. Of critical importance is accurately predicting the efficiency of CO2 trapping mechanisms. At the pore scale (e.g., microns to millimeters) the interfacial area between CO2 and brine, as well as CO2 and the solid phase, directly influences the amount of CO2 trapped due to capillary forces, dissolution and mineral precipitation. In this work, we model immiscible displacement micromodel experiments using the lattice-Boltzmann (LB) method. We focus on quantifying interfacial area as a function of capillary numbers and viscosity ratios typically encountered in CO2 sequestration operations. We show that the LB model adequately predicts the steady-state experimental flow patterns and interfacial area measurements. Based on the steady-state agreement, we use the LB model to investigate interfacial dynamics (e.g., fluid-fluid interfacial velocity and the rate of production of fluid-fluid interfacial area). In addition, we quantify the amount of interfacial area and the interfacial dynamics associated with the capillary trapped nonwetting phase. This is expected to be important for predicting the amount of nonwetting phase subsequently trapped due to dissolution and mineral precipitation.

  10. Phase Behaviors of Reservoir Fluids with Capillary Eff ect Using Particle Swarm Optimization

    KAUST Repository

    Ma, Zhiwei

    2013-05-06

    The study of phase behavior is important for the oil and gas industry. Many approaches have been proposed and developed for phase behavior calculation. In this thesis, an alternative method is introduced to study the phase behavior by means of minimization of Helmholtz free energy. For a system at fixed volume, constant temperature and constant number of moles, the Helmholtz free energy reaches minimum at the equilibrium state. Based on this theory, a stochastic method called Particle Swarm Optimization (PSO) algorithm, is implemented to compute the phase diagrams for several pure component and mixture systems. After comparing with experimental and the classical PT-ash calculation, we found the phase diagrams obtained by minimization of the Helmholtz Free Energy approach match the experimental and theoretical diagrams very well. Capillary effect is also considered in this thesis because it has a significant influence on the phase behavior of reservoir fluids. In this part, we focus on computing the phase envelopes, which consists of bubble and dew point lines. Both fixed and calculated capillary pressure from the Young-Laplace equation cases are introduced to study their effects on phase envelopes. We found that the existence of capillary pressure will change the phase envelopes. Positive capillary pressure reduces the dew point and bubble point temperatures under the same pressure condition, while the negative capillary pressure increases the dew point and bubble point temperatures. In addition, the change of contact angle and pore radius will affect the phase envelope. The effect of the pore radius on the phase envelope is insignificant when the radius is very large. These results may become reference for future research and study. Keywords: Phase Behavior; Particle Swarm Optimization; Capillary Pressure; Reservoir Fluids; Phase Equilibrium; Phase Envelope.

  11. Effects of supercritical fluid extraction pressure on chemical composition, microbial population, polar lipid profile, and microstructure of goat cheese.

    Science.gov (United States)

    Sánchez-Macías, D; Laubscher, A; Castro, N; Argüello, A; Jiménez-Flores, R

    2013-03-01

    The consumer trend for healthier food choices and preferences for low-fat products has increased the interest in low-fat cheese and nutraceutical dairy products. However, consumer preference is still for delicious food. Low- and reduced-fat cheeses are not completely accepted because of their unappealing properties compared with full-fat cheeses. The method reported here provides another option to the conventional cheese-making process to obtain lower fat cheese. Using CO(2) as a supercritical fluid offers an alternative to reduce fat in cheese after ripening, while maintaining the initial characteristics and flavor. The aim of this experiment was to evaluate the effect of pressure (10, 20, 30, and 40 × 10(6) Pa) of supercritical CO(2) on the amount of fat extracted, microbial population, polar lipid profile, and microstructure of 2 varieties of goat cheese: Majorero, a protected denomination of origin cheese from Spain, and goat Gouda-type cheese. The amount of fat was reduced 50 to 57% and 48 to 55% for Majorero and goat Gouda-type cheeses, respectively. Higher contents (on a fat basis) of sphingomyelin and phosphatidylcholine were found in Majorero cheese compared with control and goat Gouda-type cheeses. The microbial population was reduced after supercritical fluid extraction in both cheeses, and the lethality was higher as pressure increased in Majorero cheese, most noticeably on lactococcus and lactobacillus bacteria. The Gouda-type cheese did not contain any lactobacilli. Micrographs obtained from confocal laser scanning microscopy showed a more open matrix and whey pockets in the Majorero control cheese. This could explain the ease of extracting fat and reducing the microbial counts in this cheese after treatment with supercritical CO(2). Supercritical fluid extraction with CO(2) has great potential in the dairy industry and in commercial applications. The Majorero cheese obtained after the supercritical fluid extraction treatment was an excellent

  12. Prediction of wall friction for fluids at supercritical pressure with CFD models

    International Nuclear Information System (INIS)

    Angelucci, M.; Ambrosini, W.; Forgione, N.

    2011-01-01

    In this paper, the STAR-CCM+ CFD code is used in the attempt to reproduce the values of friction factor observed in experimental data at supercritical pressures at various operating conditions. A short survey of available data and correlations for smooth pipe friction in circular pipes puts the basis for the discussion, reporting observed trends of friction factor in the liquid-like and the gas-like regions and within the transitional region around the pseudo-critical temperature. For smooth pipes, a general decrease of the friction factor in the transitional region is reported, constituting one of the relevant effects to be predicted by the computational fluid-dynamic models. A limited number of low-Reynolds number models is adopted, making use of refined near-wall discretisations as required by the constraint y + < 1 at the wall. In particular, the Lien k-ε and the SST k-ω models are considered. The values of the wall shear stress calculated by the code are then post-processed on the basis of bulk fluid properties to obtain the Fanning and then the Darcy-Weisbach friction factors, basing on their classical definitions. The obtained values are compared with those provided by experimental tests and correlations, finding a reasonable qualitative agreement. Expectedly, the agreement is better in the gas-like and liquid-like regions, where fluid property changes are moderate, than in the transitional region, where the trends provided by available correlations are reproduced only in a qualitative way. (author)

  13. Immunomodulatory effects of supercritical fluid CO2 extracts from freeze-dried powder of Tenebrio molitor larvae (yellow mealworm

    Directory of Open Access Journals (Sweden)

    QingFeng TANG

    2016-01-01

    Full Text Available Abstract In order to take full advantage of Tenebrio molitor larvae (yellow mealworm resources, the supercritical CO2 fluid freeze-dried powder of T. molitor larvae (fdTML extraction on the immune systems of mice was carried out. The results about the effects of supercritical CO2 fluid fdTML extraction on carbon expurgation and phagocytosis of peritoneal macrophages experiments of mice indicated that the fdTML extraction enhanced observably carbon expurgatory index, phagocytic rate and phagocytic index. The fdTML extraction could stimulate response of delayed hypersensitivity. The proliferation of ConA-induced mitogenic reponse for spleen lymphocyte was also increased. The amount of hemolytic antibody in mice serum increased compared with those of the control group mice. The half of hemolysis values in serum of treated mice increased compared to the control group. Furthermore, serum NO content in all treatment groups was higher than that of the control group whereas acid phosphatase and alkaline phosphatase activity was only significantly higher relative to the control group. Our findings suggest that supercritical CO2 fluid the fdTML extraction has potential as a health food supplement.

  14. PROSPECTS FOR USE OF CONDENSED GASES AND SUPERCRITICAL FLUIDS IN PHYTOCHEMICAL PRODUCTION

    Directory of Open Access Journals (Sweden)

    Demyanenko DV

    2017-03-01

    Full Text Available In the given review article analysis of the literature and patent sources concerning main methods for intensification of extraction processes of medicinal vegetative raw materials – use of condensed gases and supercritical fluids (SCF on more acceptable extractants has been carried out for last 20 years. Urgency of the specified technologies consists in need for replacement of traditional extraction methods on power- and time-saving ones, and also in use of nontoxic, fire-proof and low-boiling solvents because the most of routine organic solvents (ethanol, methanol, acetone, chloroform, ethylacetate, etc. are toxic and/or flammable or expansive and rather hard to evaporate out from extracts obtained. The abovementioned trends are the most universal for intensification of extraction processes and sometimes purification of final or intermediate products acceptable for commercial scale of manufacture. The main advantages and disadvantages of the given methods are compared for different plant species and groups of biologically active substances (BAS. It has been shown that in most cases supercritical СО2 (SC-СО2 are inferior in its dissolving ability to number of condensed gases and, besides, such technology is much more expensive. The range of BAS taken with SC-СО2 is limited to mainly lipophilic compounds because of zero electrical dipole moment of SC-СО2 and its low polarity. As extractants alternative to SC-СО2 with higher dissolving ability SC - ethane, nitrogen monoxide, freons - R134а, R23, R32, R408 and number of others can be used. Also to enlarge range of extractable BAS it is possible to add different cosolvents, mainly ethanol or methanol in quantity up to 20%. At the same time in phytochemical production prospective alternatives to liquid or supercritical СО2 are certain condensed gases with wider range of physico-chemical properties: fluorinated derivatives of hydrocarbons (freons, liquid ammonia, dimethyl ether (DME

  15. Fabrication of fluorographene nanosheets with high yield and good quality based on supercritical fluid-phase exfoliation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qi; Ji, Yan; Zhang, Danying; Shi, Jia [Nanjing University of Science and Technology, Key Laboratory of Soft Chemistry and Functional Materials, College of Chemical Engineering (China); Xiao, Yinghong, E-mail: yhxiao@njnu.edu.cn [Nanjing Normal University, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, College of Chemistry and Materials Science (China); Che, Jianfei, E-mail: xiaoche@mail.njust.edu.cn [Nanjing University of Science and Technology, Key Laboratory of Soft Chemistry and Functional Materials, College of Chemical Engineering (China)

    2016-07-15

    This article presents a novel and simple method of supercritical fluid-phase exfoliation to fabricate fluorographene (FG) nanosheets with high yield and good quality. After soaking with supercritical CO{sub 2} and glycol at 10 MPa and 50 °C for 24 h, fluoride graphite powder was exfoliated by the intercalated CO{sub 2} and glycol molecules during an abrupt depressurization step. Here, supercritical CO{sub 2} acted as a penetrant and glycol acted as a “molecular wedge” to exfoliate fluoride graphite very well. The properties of FG nanosheets were detected by TEM, AFM, UV spectra, FTIR, XPS, Raman spectra, and XRD, which show the possibility of producing thickness-controlled FG nanosheets by varying numbers of supercritical CO{sub 2} process and the high yield of pure FG nanosheets of 32 wt%, four times higher than that of the sample treated only by the traditional method of sonication. Its simplicity, high productivity, low cost, and short processing time make this technique suitable for large-scale manufacturing of FG nanosheets.

  16. Molecular simulation of CO chemisorption on Co(0001) in presence of supercritical fluid solvent: A potential of mean force study

    Energy Technology Data Exchange (ETDEWEB)

    Asiaee, Alireza; Benjamin, Kenneth M., E-mail: kenneth.benjamin@sdsmt.edu [Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, 501 E. Saint Joseph St., Rapid City, South Dakota 57701 (United States)

    2016-08-28

    For several decades, heterogeneous catalytic processes have been improved through utilizing supercritical fluids (SCFs) as solvents. While numerous experimental studies have been established across a range of chemistries, such as oxidation, pyrolysis, amination, and Fischer-Tropsch synthesis, still there is little fundamental, molecular-level information regarding the role of the SCF on elementary heterogeneous catalytic steps. In this study, the influence of hexane solvent on the adsorption of carbon monoxide on Co(0001), as the first step in the reaction mechanism of many processes involving syngas conversion, is probed. Simulations are performed at various bulk hexane densities, ranging from ideal gas conditions (no SCF hexane) to various near- and super-critical hexane densities. For this purpose, both density functional theory and molecular dynamics simulations are employed to determine the adsorption energy and free energy change during CO chemisorption. Potential of mean force calculations, utilizing umbrella sampling and the weighted histogram analysis method, provide the first commentary on SCF solvent effects on the energetic aspects of the chemisorption process. Simulation results indicate an enhanced stability of CO adsorption on the catalyst surface in the presence of supercritical hexane within the reduced pressure range of 1.0–1.5 at a constant temperature of 523 K. Furthermore, it is shown that the maximum stability of CO in the adsorbed state as a function of supercritical hexane density at 523 K nearly coincides with the maximum isothermal compressibility of bulk hexane at this temperature.

  17. Supercritical fluid extraction of phenolic compounds and antioxidants from grape (Vitis labrusca B.) seeds.

    Science.gov (United States)

    Ghafoor, Kashif; Al-Juhaimi, Fahad Y; Choi, Yong Hee

    2012-12-01

    Supercritical fluid extraction (SFE) technique was applied and optimized for temperature, CO₂ pressure and ethanol (modifier) concentration using orthogonal array design and response surface methodology for the extract yield, total phenols and antioxidants from grape (Vitis labrusca B.) seeds. Effects of extraction temperature and pressure were found to be significant for all these response variables in SFE process. Optimum SFE conditions (44 ~ 46 °C temperature and 153 ~ 161 bar CO₂ pressure) along with ethanol (extract yield (12.09 %), total phenols (2.41 mg GAE/ml) and antioxidants (7.08 mg AAE/ml), were used to obtain extracts from grape seeds. The predicted values matched well with the experimental values (12.32 % extract yield, 2.45 mg GAE/ml total phenols and 7.08 mg AAE/ml antioxidants) obtained at optimum SFE conditions. The antiradical assay showed that SFE extracts of grape seeds can scavenge more than 85 % of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The grape seeds extracts were also analyzed for hydroxybenzoic acids which included gallic acid (1.21 ~ 3.84 μg/ml), protocatechuic acid (3.57 ~ 11.78 μg/ml) and p-hydroxybenzoic acid (206.72 ~ 688.18 μg/ml).

  18. Optimization of supercritical fluid consecutive extractions of fatty acids and polyphenols from Vitis vinifera grape wastes.

    Science.gov (United States)

    Aizpurua-Olaizola, Oier; Ormazabal, Markel; Vallejo, Asier; Olivares, Maitane; Navarro, Patricia; Etxebarria, Nestor; Usobiaga, Aresatz

    2015-01-01

    In this study, supercritical fluid extraction has been successfully applied to a sequential fractionation of fatty acids and polyphenols from wine wastes (2 different vitis vinifera grapes). To this aim, in a 1st step just fatty acids were extracted and in a 2nd one the polyphenols. The variables that affected to the extraction efficiency were separately optimized in both steps following an experimental design approach. The effect of extraction temperature flow, pressure, and time were thoroughly evaluated for the extraction of fatty acids, whereas the addition of methanol was also considered in the case of the polyphenols extraction. A quantitative extraction with high efficiency was achieved at a very short time and low temperatures. Concerning quantification, fatty acids were determined by means of gas chromatography coupled to mass spectrometry after a derivatization step, whereas the polyphenols were analyzed by means of high performance liquid chromatography coupled to tandem mass spectrometry and the Folin-Ciocalteu method. © 2014 Institute of Food Technologists®

  19. Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids.

    Science.gov (United States)

    Burguete, M Isabel; García-Verdugo, Eduardo; Luis, Santiago V

    2011-01-01

    This paper reviews the current trends in the combined use of supported catalytic systems, either on solid supports or in liquid phases and supercritical fluids (scFs), to develop selective and enantioselective chemical transformations under continuous and semi-continuous flow conditions. The results presented have been selected to highlight how the combined use of those two elements can contribute to: (i) Significant improvements in productivity as a result of the enhanced diffusion of substrates and reagents through the interfaces favored by the scF phase; (ii) the long term stability of the catalytic systems, which also contributes to the improvement of the final productivity, as the use of an appropriate immobilization strategy facilitates catalyst isolation and reuse; (iii) the development of highly efficient selective or, when applicable, enantioselective chemical transformations. Although the examples reported in the literature and considered in this review are currently confined to a limited number of fields, a significant development in this area can be envisaged for the near future due to the clear advantages of these systems over the conventional ones.

  20. Method of making supercritical fluid molecular spray films, powder and fibers

    Science.gov (United States)

    Smith, Richard D.

    1988-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a heated nozzle having a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. In another embodiment, the temperature of the solution and nozzle is elevated above the melting point of the solute, which is preferably a polymer, and the solution is maintained at a pressure such that, during expansion, the solute precipitates out of solution within the nozzle in a liquid state. Alternatively, a secondary solvent mutually soluble with the solute and primary solvent and having a higher critical temperature than that of primary solvent is used in a low concentration (<20%) to maintain the solute in a transient liquid state. The solute is discharged in the form of long, thin fibers. The fibers are collected at sufficient distance from the orifice to allow them to solidify in the low pressure/temperature region.

  1. Degradation of brominated flame retardant in computer housing plastic by supercritical fluids.

    Science.gov (United States)

    Wang, Yanmin; Zhang, Fu-Shen

    2012-02-29

    The degradation process of brominated flame retardant (BFR) and BFR-containing waste computer housing plastic in various supercritical fluids (water, methanol, isopropanol and acetone) was investigated. The results showed that the debromination and degradation efficiencies, final products were greatly affected by the solvent type. Among the four tested solvents, isopropanol was the most suitable solvent for the recovery of oil from BFR-containing plastic for its (1) excellent debromination effectiveness (debromination efficiency 95.7%), (2) high oil production (60.0%) and (3) mild temperature and pressure requirements. However, in this case, the removed bromine mostly existed in the oil. Introduction of KOH into the sc-isopropanol could capture almost all the inorganic bromine from the oil thus bromine-free oil could be obtained. Furthermore, KOH could enhance the depolymerization of the plastic. The obtained oil mainly consisted of single- and duplicate-ringed aromatic compounds in a carbon range of C9-C17, which had alkyl substituents or aliphatic bridges, such as butyl-benzene, (3-methylbutyl)-benzene, 1,1'-(1,3-propanediyl)bis benzene. Phenol, alkyl phenols and esters were the major oxygen-containing compounds in the oil. This study provides an efficient approach for debromination and simultaneous recovering valuable chemicals from BFR-containing plastic in e-waste. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Supercritical fluid extraction of Eucalyptus globulus bark-A promising approach for triterpenoid production.

    Science.gov (United States)

    Domingues, Rui M A; Oliveira, Eduardo L G; Freire, Carmen S R; Couto, Ricardo M; Simões, Pedro C; Neto, Carlos P; Silvestre, Armando J D; Silva, Carlos M

    2012-01-01

    Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids). In this work, the supercritical fluid extraction (SFE) of Eucalyptus globulus deciduous bark was carried out with pure and modified carbon dioxide to recover this fraction, and the results were compared with those obtained by Soxhlet extraction with dichloromethane. The effects of pressure (100-200 bar), co-solvent (ethanol) content (0, 5 and 8% wt), and multistep operation were studied in order to evaluate the applicability of SFE for their selective and efficient production. The individual extraction curves of the main families of compounds were measured, and the extracts analyzed by GC-MS. Results pointed out the influence of pressure and the important role played by the co-solvent. Ethanol can be used with advantage, since its effect is more important than increasing pressure by several tens of bar. At 160 bar and 40 °C, the introduction of 8% (wt) of ethanol greatly improves the yield of triterpenoids more than threefold.

  3. Supercritical Fluid Extraction of Eucalyptus globulus Bark—A Promising Approach for Triterpenoid Production

    Science.gov (United States)

    Domingues, Rui M. A.; Oliveira, Eduardo L. G.; Freire, Carmen S. R.; Couto, Ricardo M.; Simões, Pedro C.; Neto, Carlos P.; Silvestre, Armando J. D.; Silva, Carlos M.

    2012-01-01

    Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids). In this work, the supercritical fluid extraction (SFE) of Eucalyptus globulus deciduous bark was carried out with pure and modified carbon dioxide to recover this fraction, and the results were compared with those obtained by Soxhlet extraction with dichloromethane. The effects of pressure (100–200 bar), co-solvent (ethanol) content (0, 5 and 8% wt), and multistep operation were studied in order to evaluate the applicability of SFE for their selective and efficient production. The individual extraction curves of the main families of compounds were measured, and the extracts analyzed by GC-MS. Results pointed out the influence of pressure and the important role played by the co-solvent. Ethanol can be used with advantage, since its effect is more important than increasing pressure by several tens of bar. At 160 bar and 40 °C, the introduction of 8% (wt) of ethanol greatly improves the yield of triterpenoids more than threefold. PMID:22837719

  4. Supercritical fluid chromatography as a method of analysis for the determination of 4-hydroxybenzylglucosinolate degradation products.

    Science.gov (United States)

    Buskov, S; Hasselstrøm, J; Olsen, C E; Sørensen, H; Sørensen, J C; Sørensen, S

    2000-07-05

    In the present study analytical and preparative supercritical fluid chromatography (SFC) were used for investigation of myrosinase catalysed degradation of 4-hydroxybenzylglucosinolate (sinalbin). Sinalbin occurs as a major glucosinolate in seeds of Sinapis alba L., in various mustards and other food products. The degradation products were identified and quantified by analysis based on a developed SFC method using a bare silica column. Determinations comprised transformation products of sinalbin, produced both during degradation of isolated sinalbin, and during autolysis of meal from S. alba seeds. The conditions in the developed SFC method were used as basis for the preparative SFC procedure applied for isolation of the components prior to their identification by nuclear magnetic resonance (NMR) spectroscopy. Myrosinase catalysed sinalbin hydrolysis resulted in the reactive 4-hydroxybenzyl isothiocyanate as an initial product at pH values from 3.5 to 7.5 whereas 4-hydroxybenzyl cyanide was one of the major products at low pH values. 4-Hydroxybenzyl isothiocyanate was found to disappear from the aqueous reaction mixtures in a few hours, as it reacted easily with available nucleophilic reagents. 4-Hydroxybenzyl alcohol was found as the product from reaction with water, and with ascorbic acid, 4-hydroxybenzylascorbigen was produced.

  5. Supercritical fluid in the mantle transition zone deduced from H-D interdiffusion of wadsleyite

    Science.gov (United States)

    Sun, Wei; Yoshino, Takashi; Sakamoto, Naoya; Yurimoto, Hisayoshi

    2018-02-01

    Knowledge of the distribution of water in the Earth's mantle is key to understanding the mantle convection and geochemical evolution of the Earth. As wadsleyite and ringwoodite can incorporate large amounts of water in their crystal structures, proton conduction has been invoked to account for the widespread conductive anomalies observed in the mantle wedge, where descending slab stagnates at the transition zone. However, there is a lot of controversy on whether proton conduction by itself is able to explain such anomalies, because of large discrepancy in the extent of the water effect deduced from previous electrical conductivity measurements on hydrous polycrystalline wadsleyite and ringwoodite. Here we report the hydrogen self-diffusion coefficient obtained from H-D interdiffusion experiments in wadsleyite single-crystal couples. Our results demonstrate that the effect of water on the electrical conductivity of wadsleyite is limited and hydrous wadsleyite by itself is unable to explain conductive anomalies in the transition zone. In contrast, the expected hydrogen effective diffusion does not allow the wide propagation of water between the stagnant slab and surrounding mantle, probably leading to persistence of local water saturation and continuous release of supercritical fluids at the stagnant slab roof on geological time scales. This phenomenon provides an alternative explanation for both the high-conductivity and seismic-velocity anomalies observed in the mantle wedge at the transition-zone depth.

  6. Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of PCBs in seaweed samples.

    Science.gov (United States)

    Punín Crespo, M O; Lage Yusty, M A

    2005-06-01

    The efficiency of supercritical fluid extraction for the determination of 12 polychlorinated biphenyls from algae samples is compared to Soxhlet extraction. Analytical detection limits for the individual congeners ranged from 0.62 microgl(-1) to 19 microgl(-1). Recovery was tested for both methods using standard addition procedure. At maximum spike level of concentration, the mean recoveries were not significantly different (P>0.05) of all PCBs studied, with the exception of PCBs 28, 52, 77 and 169. Method precision for Soxhlet extraction (< or =3.9%) was slightly better than for SFE (< or =9.2%). Although both methods yield comparable results, SFE offers the advantage of detecting all PCBs studied at lower concentrations, reducing extraction time, and reducing the amount of solvents needed. The optimized methods were applied to the analysis of three real seaweed samples, except for PCB101 the concentrations of all PCBs were low or below the detection limits. The levels of PCB101 found in sample 1 were 6.6+/-0.54 ng g(-1) d.w., in sample 2 the levels were 8.2+/-0.86 ng g(-1) d.w. and in sample 3 they were 7.7+/-0.08 ng g(-1) d.w.

  7. Optimization of co-solvent addition in supercritical fluid extraction of fat with carbon dioxide

    Directory of Open Access Journals (Sweden)

    Ivanov Dušica S.

    2011-01-01

    Full Text Available This investigation is concerned with supercritical fluid extraction (SFE using CO2, as an analytical technique for total fat extraction from food and feed samples. Its most significant advantages are safety, cleanness, and shorter extraction time. The main limitation of this technique includes the difficulty of extracting polar lipids due to the non-polar character of the solvent (CO2 used for the extraction. The influence of ethanol as a co-solvent on the SFE of mash pig feed was investigated in this paper. Total fat content was determined by SFE and Soxhlet method for ten commercially available mesh pig feeds. Yields of the fat extracted by both methods were plotted one against the other and compared. Statistically significant difference (p ≤ 0.05 has been found only between the total fat obtained by the Soxhlet extraction and SFE by pure CO2. Based on the mathematical model, maximum yield of the extracted fat is achieved at an ethanol addition of 0.67 ml/g of sample, when the other parameters are the same as recommended by the producer’s procedure.

  8. Composition and antioxidant activity of Thymus vulgaris volatiles: comparison between supercritical fluid extraction and hydrodistillation.

    Science.gov (United States)

    Grosso, Clara; Figueiredo, Ana Cristina; Burillo, Jesus; Mainar, Ana M; Urieta, José S; Barroso, José G; Coelho, José A; Palavra, António M F

    2010-07-01

    Supercritical fluid extraction (SFE) of the volatile oil from Thymus vulgaris L. aerial flowering parts was performed under different conditions of pressure, temperature, mean particle size and CO(2) flow rate and the correspondent yield and composition were compared with those of the essential oil isolated by hydrodistillation (HD). Both the oils were analyzed by GC and GC-MS and 52 components were identified. The main volatile components obtained were p-cymene (10.0-42.6% for SFE and 28.9-34.8% for HD), gamma-terpinene (0.8-6.9% for SFE and 5.1-7.0% for HD), linalool (2.3-5.3% for SFE and 2.8-3.1% for HD), thymol (19.5-40.8% for SFE and 35.4-41.6% for HD), and carvacrol (1.4-3.1% for SFE and 2.6-3.1% for HD). The main difference was found to be the relative percentage of thymoquinone (not found in the essential oil) and carvacryl methyl ether (1.0-1.2% for HD versus t-0.4 for SFE) which can explain the higher antioxidant activity, assessed by Rancimat test, of the SFE volatiles when compared with HD. Thymoquinone is considered a strong antioxidant compound.

  9. Phytochemical Characterization and Biological Evaluation of the Aqueous and Supercritical Fluid Extracts from Salvia sclareoides Brot

    Directory of Open Access Journals (Sweden)

    Batista Daniela

    2017-04-01

    Full Text Available Plants belonging to the genus Salvia (Lamiaceae are known to have a wide range of biological properties. In this work, extracts obtained from the aerial parts of Salvia sclareoides Brot. were evaluated to investigate their chemical composition, toxicity, bioactivity, and stability under in vitro gastrointestinal conditions. The composition of the supercritical fluid extract was determined by GC and GC-MS, while the identification of the infusion constituents was performed by HPLC-DAD and LC-MS. The in vitro cytotoxicity of both extracts (0-2 mg/mL was evaluated in Caco-2 cell lines by the MTT assay. The anti-inflammatory and anticholinesterase activities were determined through the inhibition of cyclooxygenase-1 and acetylcholinesterase enzymes, while β-carotene/linoleic acid bleaching test and the DPPH assays were used to evaluate the antioxidant activity. The infusion inhibited cyclooxygenase-1 (IC50 = 271.0 μg/mL, and acetylcholinesterase (IC50 = 487.7 μg/ mL enzymes, also demonstrated significant antioxidant properties, as evaluated by the DPPH (IC50 = 10.4 μg/mL and β-carotene/linoleic acid (IC50 = 30.0 μg/mL assays. No remarkable alterations in the composition or in the bioactivities of the infusion were observed after in vitro digestion, which supports the potential of S. sclareoides as a source of bioactive ingredients with neuroprotective, anti-inflammatory and antioxidant properties.

  10. Stereoselective Determination of Tebuconazole in Water and Zebrafish by Supercritical Fluid Chromatography Tandem Mass Spectrometry.

    Science.gov (United States)

    Liu, Na; Dong, Fengshou; Xu, Jun; Liu, Xingang; Chen, Zenglong; Tao, Yan; Pan, Xinglu; Chen, XiXi; Zheng, Yongquan

    2015-07-22

    A simple and sensitive method for the enantioselective determination of tebuconazole enantiomers in water and zebrafish has been established using supercritical fluid chromatography (SFC)-MS/MS. The effects of the chiral stationary phases, mobile phase, auto back pressure regulator (ABPR) pressure, column temperature, flow rate of the mobile phase, and compensation pump solvent were evaluated. Finally, the optimal SFC-MS/MS working conditions were determined to include a CO2/MeOH mobile phase (87:13, v/v), 2.0 mL/min flow rate, 2200 psi ABPR, and 30 °C column temperature using a Chiralpak IA-3 chiral column under electrospray ionization positive mode. The modified QuEChERS method was applied to water and zebrafish samples. The mean recoveries for the tebuconazole enantiomers were 79.8-108.4% with RSDs ≤ 7.0% in both matrices. The LOQs ranged from 0.24 to 1.20 μg/kg. The developed analytical method was further validated by application to the analysis of authentic samples.

  11. Field—Based Supercritical Fluid Extraction of Hydrocarbons at Industrially Contaminated Sites

    Directory of Open Access Journals (Sweden)

    Peggy Rigou

    2002-01-01

    Full Text Available Examination of organic pollutants in groundwaters should also consider the source of the pollution, which is often a solid matrix such as soil, landfill waste, or sediment. This premise should be viewed alongside the growing trend towards field-based characterisation of contaminated sites for reasons of speed and cost. Field-based methods for the extraction of organic compounds from solid samples are generally cumbersome, time consuming, or inefficient. This paper describes the development of a field-based supercritical fluid extraction (SFE system for the recovery of organic contaminants (benzene, toluene, ethylbenzene, and xylene and polynuclear aromatic hydrocarbons from soils. A simple, compact, and robust SFE system has been constructed and was found to offer the same extraction efficiency as a well-established laboratory SFE system. Extraction optimisation was statistically evaluated using a factorial analysis procedure. Under optimised conditions, the device yielded recovery efficiencies of >70% with RSD values of 4% against the standard EPA Soxhlet method, compared with a mean recovery efficiency of 48% for a commercially available field-extraction kit. The device will next be evaluated with real samples prior to field deployment.

  12. Supercritical Fluid Extraction of Quinones from Compost for Microbial Community Analysis

    Directory of Open Access Journals (Sweden)

    Ni Luh Gede Ratna Juliasih

    2015-01-01

    Full Text Available Supercritical fluid extraction (SFE was used to extract quinones from compost to monitor the microbial community dynamics during composting. The 0.3 g of dried compost was extracted using 3 mL min−1 of carbon dioxide (90% and methanol (10% at 45°C and 25 MPa for a 30 min extraction time. The extracted quinones were analysed using ultra performance liquid chromatography (UPLC with 0.3 mL min−1 of methanol mobile phase for a 50 min chromatographic run time. A comparable detected amount of quinones was obtained using the developed method and an organic solvent extraction method, being 36.06 μmol kg−1 and 34.54 μmol kg−1, respectively. Significantly low value of dissimilarity index (D between the two methods (0.05 indicated that the quinone profile obtained by both methods was considered identical. The developed method was then applied to determine the maturity of the compost by monitoring the change of quinone during composting. The UQ-9 and MK-7 were predominant quinones in the initial stage of composting. The diversity of quinone became more complex during the cooling and maturation stages. This study showed that SFE had successfully extracted quinones from a complex matrix with simplification and rapidity of the analysis that is beneficial for routine analysis.

  13. Supercritical fluid particle design for poorly water-soluble drugs (review).

    Science.gov (United States)

    Sun, Yongda

    2014-01-01

    Supercritical fluid particle design (SCF PD) offers a number of routes to improve solubility and dissolution rate for enhancing the bioavailability of poorly water-soluble drugs, which can be adopted through an in-depth knowledge of SCF PD processes and the molecular properties of active pharmaceutical ingredients (API) and drug delivery system (DDS). Combining with research experiences in our laboratory, this review focuses on the most recent development of different routes (nano-micron particles, polymorphic particles, composite particles and bio-drug particles) to improve solubility and dissolution rate of poorly water-soluble drugs, covering the fundamental concept of SCF and the principle of SCF PD processes which are typically used to control particle size, shape, morphology and particle form and hence enable notable improvement in the dissolution rate of the poorly water-soluble drugs. The progress of the industrialization of SCF PD processes in pharmaceutical manufacturing environment with scaled-up plant under current good manufacturing process (GMP) specification is also considered in this review.

  14. Ultrahigh performance supercritical fluid chromatography of lipophilic compounds with application to synthetic and commercial biodiesel.

    Science.gov (United States)

    Ashraf-Khorassani, M; Yang, J; Rainville, P; Jones, M D; Fountain, K J; Isaac, G; Taylor, L T

    2015-03-01

    Ultrahigh performance supercritical fluid chromatography (UHPSFC) in combination with sub-2μm particles and either diode array ultraviolet (UV), evaporative light scattering, (ELSD), or mass spectrometric (MS) detection has been shown to be a valuable technique for the determination of acylglycerols in soybean, corn, sesame, and tobacco seed oils. Excellent resolution on an un-endcapped single C18 column (3.0mm×150mm) with a mobile phase gradient of acetonitrile and carbon dioxide in as little as 10min served greatly as an improvement on first generation packed column SFC instrumentation. Unlike high resolution gas chromatography and high performance liquid chromatography with mass spectrometric detection, UHPSFC/MS was determined to be a superior analytical tool for both separation and detection of mono-, di-, and tri-acylglycerols as well as free glycerol itself in biodiesel without derivatization. Baseline separation of residual tri-, di-, and mono-acylglycerols alongside glycerol at 0.05% (w/w) was easily obtained employing packed column SFC. The new analytical methodology was applied to both commercial B100 biodiesel (i.e. fatty acid methyl esters) derived from vegetable oil and to an "in-house" synthetic biodiesel (i.e. fatty acid ethyl esters) derived from tobacco seed oil and ethanol both before and after purification via column chromatography on bare silica. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Cytologic examination of hemorrhagic fluid by capillary centrifugation: a new technique.

    Science.gov (United States)

    Agarwal, Padam Kumari

    2009-01-01

    To develop a simplified technique for processing hemorrhagic body fluids, allowing elimination of red blood cells (RBCs) to obtain tumor cell-rich cytosmears for accurate diagnosis of malignancy. Hemorrhagic fluid is collected with ethylenediamine tetraacetic acid anticoagulant. The cells are separated by centrifugation in glass capillaries into 3 layers, with the uppermost containing supernatant, middle buffy coat and lowermost dark layer of RBCs. The smears of the buffy coat are prepared by breaking the capillaries at the junction of buffy coat and RBC layer. The procedure is named capillary centrifugation technique. This procedure was developed in the cytology laboratory at King George's Medical College, Lucknow, India in 1974. Cell yield is good and cellular details are well preserved. No cell debris is present on the slides. The background of the smears is absolutely clear. Any number of slides may be prepared for special study for exact typing of tumor cells This is a simple, economical procedure and a good substitute for a cytocentrifuge machine for preparing smears from small amount of fluids. Technicians learn it quickly and are quite comfortable with the procedure.

  16. Numerical analysis of capillary compensated micropolar fluid lubricated hole-entry journal bearings

    Directory of Open Access Journals (Sweden)

    Nathi Ram

    2016-06-01

    Full Text Available The micropolar lubricated symmetric/asymmetric hole-entry bearings using capillary restrictor have been analyzed in the present work. Reynolds equation for micropolar lubricant has been derived and solved by FEM. The results have been computed using selected parameters of micropolar lubricant for hole-entry hydrostatic/hybrid journal bearings. A significant increase in damping and stiffness coefficients is observed for bearings having micropolar parameter N2=0.9, lm=10 than similar bearings under Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant. The threshold speed gets increased when symmetric bearing lubricated under micropolar fluid than Newtonian lubricant.

  17. Ultra high efficiency/low pressure supercritical fluid chromatography with superficially porous particles for triglyceride separation.

    Science.gov (United States)

    Lesellier, E; Latos, A; de Oliveira, A Lopes

    2014-01-31

    This paper reports the development of the separation of vegetable oil triglycerides (TG) in supercritical chromatography (SFC), using superficially porous particles (SPPs). The SPP, having a small diameter (2-3μm), provide a higher theoretical plate number (N), which allows to improve separation of critical pairs of compounds. However, compared to fully porous particles of larger diameter (5μm), the pressure drop is also increased. Fortunately, supercritical fluids have a low viscosity, which allows coupling several columns to achieve high N values, while maintaining flow rate above 1ml/min, ensuring a ultra high efficiency (UHE) at low pressure (LP) (below 40MPa), with regards to the one reached with liquid and sub-two micron particles (around 100MPa). The use of two detector systems (UV and ELSD) connected in series to the UHE-LP-SFC system provides complementary responses, due to their specific detection principles. Working in a first part with three coupled Kinetex C18 columns (45cm total length), the effect of modifier nature and percentage were studied with two reference oils, argan and rapeseed, chosen for their different and well-known TG composition. The analytical method was developed from previous studies performed with fully porous particles (FPP). Optimized conditions with three Kinetex were as follows: 17°C, 12% of ACN/MeOH (90/10; v/v). With these conditions, and by using an increased length of Kinetex C18 column (60cm), another additional column was selected from ten different commercial SPP C18 bonded phases, by applying a Derringer function on varied parameters: theoretical plate number (TPN), separation index (SI) for critical pairs of peaks (the peaks of compounds difficult to separate due to subtle structural differences), the analysis duration, and the total peak number. This function normalizes the values of any parameters, between 0 and 1, from the worst value to the better, allowing to take account of various parameters in the final

  18. SAGE 2D and 3D Simulations of the Explosive Venting of Supercritical Fluids Through Porous Media

    Science.gov (United States)

    Weaver, R.; Gisler, G.; Svensen, H.; Mazzini, A.

    2008-12-01

    Magmatic intrusive events in large igneous provinces heat sedimentary country rock leading to the eventual release of volatiles. This has been proposed as a contributor to climate change and other environmental impacts. By means of numerical simulations, we examine ways in which these volatiles can be released explosively from depth. Gases and fluids cooked out of country rock by metamorphic heating may be confined for a time by impermeable clays or other barriers, developing high pressures and supercritical fluids. If confinement is suddenly breached (by an earthquake for example) in such a way that the fluid has access to porous sediments, a violent eruption of a non-magmatic mixture of fluid and sediment may result. Surface manifestations of these events could be hydrothermal vent complexes, kimberlite pipes, pockmarks, or mud volcanoes. These are widespread on Earth, especially in large igneous provinces, as in the Karoo Basin of South Africa, the North Sea off the Norwegian margin, and the Siberian Traps. We have performed 2D and 3D simulations with the Sage hydrocode (from Los Alamos and Science Applications International) of supercritical venting in a variety of geometries and configurations. The simulations show several different patterns of propagation and fracturing in porous or otherwise weakened overburden, dependent on depth, source conditions (fluid availability, temperature, and pressure), and manner of confinement breach. Results will be given for a variety of 2D and 3D simulations of these events exploring the release of volatiles into the atmosphere.

  19. Decoration of ultrafine platinum-ruthenium particles on functionalized graphene sheets in supercritical fluid and their electrocatalytic property

    Science.gov (United States)

    Zhao, Jian; Xue, Hao; Zhang, Lin; Yu, Jinhai; Hu, Haiqing

    2012-09-01

    We report a simple and effective supercritical fluid route to uniformly load ultrafine metal nanoparticles on the hydrophobic surfaces of graphene sheets. In the presence of supercritical carbon dioxide, PtRu alloy nanoparticles are decorated evenly on functionalized graphene sheets (FGSs) upon the reduction of organic platinum (II) and ruthenium (III) precursors, and its application as an electrocatalyst for methanol oxidation is studied. Transmission electron microscopy observation shows that highly dispersed PtRu metallic nanoparticles with an average size of about 3.11 nm are uniformly and densely distributed on the hydrophobic surface of FGSs. X-ray diffraction patterns demonstrate that the particles had a face-centered cubic crystal structure, and X-ray photoelectron spectroscopy analysis indicates the existence of zero-valence metals. Compared with the widely used Vulcan XC-72 carbon black, the PtRu/FGS composites exhibit superior catalytic activity and stability for methanol oxidation. The huge surface area of graphene and uniform distribution of nanosized metal particles are two critical factors for the significantly enhanced electrocatalytic efficiency. The findings suggest that the supercritical fluid method is highly efficient in preparing graphene-supported metallic catalysts, and FGSs serve as a favorable electrocatalytic carrier for direct methanol fuel cells.

  20. Clean synthesis of molecular recognition polymeric materials with chiral sensing capability using supercritical fluid technology. Application as HPLC stationary phases.

    Science.gov (United States)

    da Silva, Mara Soares; Vão, Eva R; Temtem, Márcio; Mafra, Luís; Caldeira, Jorge; Aguiar-Ricardo, Ana; Casimiro, Teresa

    2010-03-15

    Molecularly imprinted polymers (MIPs) of poly(ethylene glycol dimethacrylate) and poly(N-isopropylacrylamide-co-ethylene glycol dimethacrylate) were synthesized for the first time in supercritical carbon dioxide (scCO(2)), using Boc-L-tryptophan as template. Supercritical fluid technology provides a clean and one-step synthetic route for the preparation of affinity polymeric materials with sensing capability for specific molecules. The polymeric materials were tested as stationary HPLC phases for the enantiomeric separation of L- and D-tryptophan. HPLC results prove that the synthesized MIPs are able to recognize the template molecule towards its enantiomer which opens up potential applications in chromatographic chiral separation. (c) 2009 Elsevier B.V. All rights reserved.

  1. Motion of liquid plugs between vapor bubbles in capillary tubes: a comparison between fluids

    Science.gov (United States)

    Bertossi, Rémi; Ayel, Vincent; Mehta, Balkrishna; Romestant, Cyril; Bertin, Yves; Khandekar, Sameer

    2017-11-01

    Pulsating heat pipes (PHP) are now well-known devices in which liquid/vapor slug flow oscillates in a capillary tube wound between hot and cold sources. In this context, this paper focuses on the motion of the liquid plug, trapped between vapor bubbles, moving in capillary tubes, to try to better understand the thermo-physical phenomena involved in such devices. This study is divided into three parts. In the first part, an experimental study presents the evolution of the vapor pressure during the evaporation process of a liquid thin film deposited from a liquid plug flowing in a heated capillary tube: it is found that the behavior of the generated and removed vapor can be very different, according to the thermophysical properties of the fluids. In the second part, a transient model allows to compare, in terms of pressure and duration, the motion of a constant-length liquid plug trapped between two bubbles subjected to a constant difference of vapor pressure: the results highlight that the performances of the four fluids are also very different. Finally, a third model that can be considered as an improvement of the second one, is also presented: here, the liquid slug is surrounded by two vapor bubbles, one subjected to evaporation, the pressure in both bubbles is now a result of the calculation. This model still allows comparing the behaviors of the fluid. Even if our models are quite far from a complete model of a real PHP, results do indicate towards the applicability of different fluids as suitable working fluids for PHPs, particularly in terms of the flow instabilities which they generate.

  2. Solvation in supercritical water

    International Nuclear Information System (INIS)

    Cochran, H.D.; Cummings, P.T.; Karaborni, S.

    1991-01-01

    The aim of this work is to determine the solvation structure in supercritical water composed with that in ambient water and in simple supercritical solvents. Molecular dynamics studies have been undertaken of systems that model ionic sodium and chloride, atomic argon, and molecular methanol in supercritical aqueous solutions using the simple point charge model of Berendsen for water. Because of the strong interactions between water and ions, ionic solutes are strongly attractive in supercritical water, forming large clusters of water molecules around each ion. Methanol is found to be a weakly-attractive solute in supercritical water. The cluster of excess water molecules surrounding a dissolved ion or polar molecule in supercritical aqueous solutions is comparable to the solvent clusters surrounding attractive solutes in simple supercritical fluids. Likewise, the deficit of water molecules surrounding a dissolved argon atom in supercritical aqueous solutions is comparable to that surrounding repulsive solutes in simple supercritical fluids. The number of hydrogen bonds per water molecule in supercritical water was found to be about one third the number in ambient water. The number of hydrogen bonds per water molecule surrounding a central particle in supercritical water was only mildly affected by the identify of the central particle--atom, molecule, or ion. These results should be helpful in developing a qualitative understanding of important processes that occur in supercritical water. 29 refs., 6 figs

  3. Distribution coefficients of UO2(NO3)2 . 2TBP in supercritical fluid CO2 as determined by on-line time resolved laser induced fluorescence

    International Nuclear Information System (INIS)

    Addleman, R.S.; Wai, C.M.

    2001-01-01

    Time resolved laser induced fluorescence has been used for on-line analysis of uranium extraction from acidic solutions with tributyl phosphate modified supercritical carbo dioxide. The in-situ measurement allows direct characterization of the supercritical fluid extraction. The extractions were found to be first order with respect to uranium and the distribution coefficient was observed to increase with temperature and tributyl phosphate concentration. (orig.)

  4. Performance Analysis and Working Fluid Selection of a Supercritical Organic Rankine Cycle for Low Grade Waste Heat Recovery

    Directory of Open Access Journals (Sweden)

    Yourong Li

    2012-08-01

    Full Text Available The performance analysis of a supercritical organic Rankine cycle system driven by exhaust heat using 18 organic working fluids is presented. Several parameters, such as the net power output, exergy efficiency, expander size parameter (SP, and heat exchanger requirement of evaporator and the condenser, were used to evaluate the performance of this recovery cycle and screen the working fluids. The results reveal that in most cases, raising the expander inlet temperature is helpful to improve the net power output and the exergy efficiency. However, the effect of the expander inlet pressure on those parameters is related to the expander inlet temperature and working fluid used. Either lower expander inlet temperature and pressure, or higher expander inlet temperature and pressure, generally makes the net power output more. Lower expander inlet temperature results in larger total heat transfer requirement and expander size. According to the screening criteria of both the higher output and the lower investment, the following working fluids for the supercritical ORC system are recommended: R152a and R143a.

  5. Impact of wall potential on the fluid-wall interaction in a cylindrical capillary and a generalized Kelvin equation

    International Nuclear Information System (INIS)

    Jakubov, T.S.; Mainwaring, D.E.

    2006-01-01

    In the present work a generalized Kelvin equation for a fluid confined in thick-walled cylindrical capillary is developed. This has been accomplished by including the potential energy function for interaction between a solid wall of a capillary and a confined fluid into the Kelvin equation. Using the Lennard-Jones 12-6 potential, an explicit form of the potential energy functions as expressed by hypergeometrical functions have been derived-firstly, for the interaction between a solid wall and a test atom placed at an arbitrary point in a long open-end capillary, and thereafter for the body-body interaction between the solid wall and a confined Lennard-Jones fluid. Further, this generalized Kelvin equation has been applied to detailed description hysteresis phenomena in such capillaries. All numerical calculations have been carried out for the model argon-graphite system at 90 K

  6. Valuable natural products from marine and freshwater macroalgae obtained from supercritical fluid extracts.

    Science.gov (United States)

    Messyasz, Beata; Michalak, Izabela; Łęska, Bogusława; Schroeder, Grzegorz; Górka, Bogusława; Korzeniowska, Karolina; Lipok, Jacek; Wieczorek, Piotr; Rój, Edward; Wilk, Radosław; Dobrzyńska-Inger, Agnieszka; Górecki, Henryk; Chojnacka, Katarzyna

    2018-01-01

    The biologically active compounds (fatty acids, pigments, phenolics, and flavonoid content) were studied in supercritical fluid extracts from the biomass of marine ( Ulva clathrata , Cladophora glomerata , Polysiphonia fucoides , and their multi-species mixture) and freshwater ( C. glomerata ) macroalgae. Different extraction techniques were used in order to compare differences in the biologically active compound composition of the macroalgal extracts. The results indicated that the saturated and unsaturated fatty acids ranged from C9:0 to C22:0. The analysis of differences in the composition of unsaturated to saturated fatty acids in extracts showed that palmitic acid (C16:0) and oleic acid (C18:1, n-9) reached the highest value not only in marine monospecies and multi-species biomass but also in the freshwater macroalga C. glomerata . When comparing the similarity between the concentration of fatty acids and the ratio of the concentration of unsaturated fatty acids to saturated in macroalgal extracts, we found small but not statistically significant variations in values between years (up to 10%). This is acceptable for applications as a stable raw material for industrial purposes. Significantly higher values of fatty acids, carotenoids, and chlorophylls were obtained in the case of SC-CO 2 extraction. The active ingredients of polyphenols, possessing antioxidant activity ranged from approximately 2-4%. Moreover, flavonoids represented less than 10% of the total content of polyphenolic compounds. The extraction efficiency of polyphenols was higher from a mixture of marine algae for the ultrasound-assisted extraction compared to freshwater. All these findings show that marine and freshwater macroalgae, as a raw material, have the optimal biologically active compounds composition for cosmetics.

  7. Bioassay-guided supercritical fluid extraction of cyclooxygenase-2 inhibiting substances in Plantago major L.

    Science.gov (United States)

    Stenholm, A; Göransson, U; Bohlin, L

    2013-02-01

    Selective extraction of plant materials is advantageous for obtaining extracts enriched with desired constituents, thereby reducing the need for subsequent chromatography purification. Such compounds include three cyclooxygenase-2 (COX-2) inhibitory substances in Plantago major L. targeted in this investigation: α-linolenic acid (α-LNA) (18:3 ω-3) and the triterpenic acids ursolic acid and oleanolic acid. To investigate the scope for tuning the selectivity of supercritical fluid extraction (SFE) using bioassay guidance, and Soxhlet extraction with dichloromethane as solvent as a reference technique, to optimise yields of these substances. Extraction parameters were varied to optimise extracts' COX-2/COX-1 inhibitory effect ratios. The crude extracts were purified initially using a solid phase extraction (SPE) clean-up procedure and the target compounds were identified with GC-MS, LC-ESI-MS and LC-ESI-MS² using GC-FID for quantification. α-LNA was preferentially extracted in dynamic mode using unmodified carbon dioxide at 40°C and 172 bar, at a 0.04% (w/w) yield with a COX-2/COX-1 inhibitory effect ratio of 1.5. Ursolic and oleanolic acids were dynamically extracted at 0.25% and 0.06% yields, respectively, with no traces of (α-LNA) and a COX-2/COX-1-inhibitory effect ratio of 1.1 using 10% (v/v) ethanol as polar modifier at 75°C and 483 bar. The Soxhlet extracts had ursolic acid, oleanolic acid and αLNA yields up to 1.36%, 0.34% and 0.15%, respectively, with a COX-2/COX-1 inhibitory effect ratio of 1.2. The target substances can be extracted selectively by bioassay guided optimisation of SFE conditions. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Supercritical fluid extraction of peach (Prunus persica) almond oil: process yield and extract composition.

    Science.gov (United States)

    Mezzomo, Natália; Mileo, Bruna R; Friedrich, Maria T; Martínez, Julian; Ferreira, Sandra R S

    2010-07-01

    Peach kernels are industrial residues from the peach processing, contain oil with important therapeutic properties and attractive nutritional aspects because of the high concentration of oleic and linoleic acids. The extraction method used to obtain natural compounds from raw matter is critical for product quality definition. Thus, the aim of this work was to compare peach almond extraction yields obtained by different procedures: soxhlet extractions (Sox) with different solvents; hydrodistillation (HD); ethanolic maceration (Mac) followed by fractionation with various solvents, and supercritical fluid extraction (SFE) at 30, 40 and 50 degrees C and at 100, 200 and 300bar, performed with pure CO(2) and with a co-solvent. The extracts were evaluated with respect to fatty acid composition (FAC), fractionated chemical profile (FCP) and total phenolic content (TPC). The Sox total yields were generally higher than those obtained by SFE. The crossover pressure for SFE was between 260 and 280bar. The FAC results show oleic and linoleic acids as main components, especially for Sox and SFE extracts. The FCP for samples obtained by Sox and Mac indicated the presence of benzaldehyde and benzyl alcohol, components responsible for almond flavor and with important industrial uses, whereas the SFE extracts present a high content of a possible flavonoid. The higher TPC values were obtained by Sox and Mac with ethanol. In general, the maximum pressure in SFE produced the highest yield, TPC and oleic acid content. The use of ethanol at 5% as co-solvent in SFE did not result in a significant effect on any evaluated parameter. The production of peach almond oil through all techniques is substantially adequate and SFE presented advantages, with respect to the quality of the extracts due to the high oleic acid content, as presented by some Sox samples. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  9. Identification of Bioactivity, Volatile and Fatty Acid Profile in Supercritical Fluid Extracts of Mexican arnica

    Directory of Open Access Journals (Sweden)

    J. Saúl García-Pérez

    2016-09-01

    Full Text Available Supercritical fluid extraction (SFE is a sustainable technique used for the extraction of lipophilic metabolites such as pigments and fatty acids. Arnica plant is considered a potential candidate material with high antioxidant and antimicrobial activities. Therefore, in this study, a locally available Heterotheca inuloides, also known as Mexican arnica, was analyzed for the extraction of high-value compounds. Based on different pressure (P, temperature (T, and co-solvent (CoS, four treatments (T were prepared. A maximum 7.13% yield was recovered from T2 (T = 60 °C, P = 10 MPa, CoS = 8 g/min, followed by 6.69% from T4 (T = 60 °C, P = 30 MPa, CoS = 4 g/min. Some bioactive sesquiterpenoids such as 7-hydroxycadalene, caryophyllene and δ-cadinene were identified in the extracts by GC/MS. The fatty acid profile revealed that the main components were palmitic acid (C16:0, followed by linoleic acid (C18:2ω6c, α-linolenic acid (C18:3ω3 and stearic acid (C18:0 differing in percent yield per treatment. Antibacterial activities were determined by the agar diffusion method, indicating that all the treatments exerted strong antibacterial activity against S. aureus, C. albicans, and E. coli strains. The antioxidant capacity of the extracts was also measured by three in vitro assays, DPPH, TEAC and FRAP, using Trolox as a standard. Results showed high antioxidant capacity enabling pharmaceutical applications of Mexican arnica.

  10. Simultaneous measurement of fluoroquinolones in eggs by a combination of supercritical fluid extraction and high pressure liquid chromatography.

    Science.gov (United States)

    Shim, Jae Han; Lee, Mi Hyun; Kim, Mi Ra; Lee, Chang Joo; Kim, In Seon

    2003-06-01

    Simultaneous detection of the fluoroquinolone antibiotics ciprofloxacin, enrofloxacin, ofloxacin, and norfloxacin in eggs by a combination of supercritical fluid extraction (SFE) and high pressure liquid chromatography (HPLC) was studied. Lipid matrices that have been considered to result in poor extraction and isolation of fluoroquinolones in eggs were removed first by SFE with supercritical CO(2) alone, and then the fluoroquinolones were extracted by SFE with supercritical CO(2) containing 20% (v/v) methanol for HPLC analysis. A time-course study of the extraction of lipid matrices of eggs suggested that the SFE method successfully removed the matrices within 20 min. When the fluoroquinolones added to control eggs were extracted by SFE, the extraction efficiency was similar to that by the solvent extraction method, giving the recovery percentages from 83 to 96% in a 40 min-extraction time. The fluoroquinolones extracted from eggs by SFE were analyzed simultaneously by HPLC equipped with a fluorescence detector with detection sensitivity at about 10 ppb for the detection limit. The standard calibration profiles of fluoroquinolones showed linear responses to HPLC, showing more than 0.995 for the mean r(2) value. This is the first report of the simultaneous measurement of fluoroquinolones in eggs by a combination of SFE and HPLC. Using the SFE method allowed us to avoid extensive sample preparation such as solvent extraction and chromatographic cleanup that are basically required in extraction of fluoroquinolones.

  11. Direct measurements of the enthalpy of solution of solid solute in supercritical fluids: study on the CO2-naphthalene system.

    Science.gov (United States)

    Zhang, X; Han, B; Zhang, J; Li, H; He, J; Yan, H

    2001-10-01

    A setup for a calorimeter for simultaneously measuring the solubility and the solution enthalpy of solid solutes in supercritical fluids (SCFs) has been established. The enthalpy of solution of naphthalene in supercritical CO2 was measured at 308.15 K in the pressure range from 8.0-11.0 MPa. It was found that the enthalpy of solution (deltaH) was negative in the pressure range from 8.0 to 9.5 MPa, and the absolute value decreased with increasing pressure. In this pressure range, the dissolution of the solute was enthalpy driven. However, the deltaH became positive at pressures higher than 9.5 MPa, and the dissolution was entropy driven. Monte Carlo simulation was performed to analyze the local structural environment of the solvated naphthalene molecules in supercritical CO2 under the experimental conditions for the calorimetric measurements. By combining the enthalpy data and the simulation results, it can be deduced that the energy level of CO2 in the high compressible region is higher than that at higher pressures, which results in the large negative enthalpy of solution and the larger degree of solvent-solute clustering in the high compressible region.

  12. Literature survey of heat transfer and hydraulic resistance of water, carbon dioxide, helium and other fluids at supercritical and near-critical pressures

    Energy Technology Data Exchange (ETDEWEB)

    Pioro, I.L.; Duffey, R.B

    2003-04-01

    This survey consists of 430 references, including 269 Russian publications and 161 Western publications devoted to the problems of heat transfer and hydraulic resistance of a fluid at near-critical and supercritical pressures. The objective of the literature survey is to compile and summarize findings in the area of heat transfer and hydraulic resistance at supercritical pressures for various fluids for the last fifty years published in the open Russian and Western literature. The analysis of the publications showed that the majority of the papers were devoted to the heat transfer of fluids at near-critical and supercritical pressures flowing inside a circular tube. Three major working fluids are involved: water, carbon dioxide, and helium. The main objective of these studies was the development and design of supercritical steam generators for power stations (utilizing water as a working fluid) in the 1950s, 1960s, and 1970s. Carbon dioxide was usually used as the modeling fluid due to lower values of the critical parameters. Helium, and sometimes carbon dioxide, were considered as possible working fluids in some special designs of nuclear reactors. (author)

  13. Numerical Study on Heat Transfer Performance of PCHE With Supercritical CO{sub 2} as Working Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Sang Woo; Ngo, Ich-long; Byon, Chan [Yeungnam Univ., Gyeongsan (Korea, Republic of)

    2016-11-15

    The printed circuit heat exchanger (PCHE) is regarded as a promising candidate for advanced heat exchangers for the next-generation supercritical CO{sub 2} power generation owing to its high compactness and rigid structure. In this study, an innovative type of PCHE, in which the channel sizes for the heat source fluid and heat sink fluid are different, is considered for analysis. The thermal performance of the PCHE, with supercritical CO{sub 2} as the working fluid, is numerically analyzed. The results have shown that the thermal performance of the PCHE decreases monotonically when the channel size of either the heat source channel or the heat sink channel, because of the decreased flow velocity. On the other hand, the thermal performance of the PCHE is found to be almost independent of the spacing between the channels. In addition, it was found that the channel cross sectional shape has little effect on the thermal performance when the hydraulic diameter of the channel remains constant.

  14. Analysis of volatile flavour compounds and acrylamide in roasted Malaysian tropical almond (Terminalia catappa) nuts using supercritical fluid extraction.

    Science.gov (United States)

    Lasekan, Ola; Abbas, Kassim

    2010-01-01

    Considering the importance of tropical almond nuts as a snack item, a study was conducted to identify the flavour volatiles and acrylamide generated during the roasting of the nuts. The supercritical fluid extracted flavour components revealed 74 aroma active compounds made up of 27 hydrocarbons, 12 aldehydes, 11 ketones, 7 acids, 4 esters, 3 alcohols, 5 furan derivatives a pyrazine, and 2 unknown compounds. While low levels of acrylamide (8-86 microg/kg) were obtained in the roasted nuts, significant (P0.05) concentration of acrylamide was generated with mild roasting and shorter roasting period. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  15. Separation of racemic 1-(9-Anthryl)-2,2,2-trifluoroethanol by sub-/supercritical fluid chromatography.

    Science.gov (United States)

    Yang, Xiqin; Hsu, Leo; Terfloth, Gerald

    2013-01-01

    Supercritical fluid chromatography is an environmentally benign separation technology due to the use of carbon dioxide modified with organic solvents as the mobile phase. It has found widespread use in the separation of chiral compounds based on the relative ease of method development and high likelihood of success for obtaining acceptable chromatographic performance while providing short analysis time. In this chapter, we describe the separation of racemic 1-(9-Anthryl)-2,2,2-trifluoroethanol on a Phenomenex Lux Cellulose-1 column using methanol as the modifier and detection by UV at 230 nm.

  16. Metering the capillary-driven flow of fluids in paper-based microfluidic devices.

    Science.gov (United States)

    Noh, Hyeran; Phillips, Scott T

    2010-05-15

    This article describes an exceedingly simple and low-cost method for metering the capillary-driven flow rate of fluids within three-dimensional (3D) microfluidic, paper-based analytical devices (microPADs). Initial prototypes of 3D microPADs control the spatial distribution of fluids within a device, but they provide little control over how quickly (or slowly) fluids move within the device. The methods described in this article provide control over when and how quickly a fluid is distributed into detection zones. These methods are inexpensive (the metering regions are composed of paraffin wax), the devices are easy to fabricate, and they are capable of controlling the flow of fluids to detection zones with precise time delays (e.g., +/-6% of the total wicking time). We anticipate that this type of precise control over fluid distribution rates will be useful particularly for point-of-care assays that require multiple steps (where each step requires that the reagents interact for a defined period of time) or for simultaneously displaying the results of multiple different assays on a single device.

  17. Pre-concentration and separation of bacteria by volume coupling electrophoresis on supercritical water-etched fused silica capillary with two segments of different internal diameters and inner surface roughnesses

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Karásek, Pavel; Roth, Michal; Růžička, F.

    2018-01-01

    Roč. 410, č. 1 (2018), s. 167-175 ISSN 1618-2642 R&D Projects: GA MV(CZ) VI20172020069; GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Keywords : fused silica capillary * volume coupling electrophoresis * supercritical water * blood Subject RIV: CB - Analytical Chemistry , Separation OBOR OECD: Analytical chemistry Impact factor: 3.431, year: 2016

  18. Pre-concentration and separation of bacteria by volume coupling electrophoresis on supercritical water-etched fused silica capillary with two segments of different internal diameters and inner surface roughnesses

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Karásek, Pavel; Roth, Michal; Růžička, F.

    2018-01-01

    Roč. 410, č. 1 (2018), s. 167-175 ISSN 1618-2642 R&D Projects: GA MV(CZ) VI20172020069; GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Keywords : fused silica capillary * volume coupling electrophoresis * supercritical water * blood Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.431, year: 2016

  19. Effect of capillary forces on the nonstationary fall of a drop in an infinite fluid

    Science.gov (United States)

    Antanovskii, L. K.

    1991-12-01

    An explicit solution is presented for the linear problem concerning the motion of a drop in an infinite fluid in the presence of any number of surfactants (chemical reactions are not considered in the first approximation). It is shown that the behavior of the system considered is consistent with the Le Chatelier principle. The reactivity of the capillary forces is directly related to the fundamental principles of thermodynamics, which makes it possible to write equations of surfactant thermodiffusion in symmetric form and obtain a relatively simple solution to the linearized problem.

  20. Bio-Oil Separation and Stabilization by Supercritical Fluid Fractionation. 2014 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Agblevor, Foster [Utah State Univ., Logan, UT (United States); Petkovic, Lucia [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bennion, Edward [Utah State Univ., Logan, UT (United States); Quinn, Jason [Utah State Univ., Logan, UT (United States); Moses, John [CF Technologies, Hyde Park, MA (United States); Newby, Deborah [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ginosar, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-03-01

    The objective of this project is to use supercritical fluids to separate and fractionate algal-based bio-oils into stable products that can be subsequently upgraded to produce drop-in renewable fuels. To accomplish this objective, algae was grown and thermochemically converted to bio-oils using hydrothermal liquefaction (HTL), pyrolysis, and catalytic pyrolysis. The bio-oils were separated into an extract and a raffinate using near-critical propane or carbon dioxide. The fractions were then subjected to thermal aging studies to determine if the extraction process had stabilized the products. It was found that the propane extract fraction was twice as stable as the parent catalytic pyrolysis bio-oils as measured by the change in viscosity after two weeks of accelerated aging at 80°C. Further, in-situ NMR aging studies found that the propane extract was chemically more stable than the parent bio-oil. Thus the milestone of stabilizing the product was met. A preliminary design of the extraction plant was prepared. The design was based on a depot scale plant processing 20,000,000 gallons per year of bio-oil. It was estimated that the capital costs for such a plant would be $8,700,000 with an operating cost of $3,500,000 per year. On a per gallon of product cost and a 10% annual rate of return, capital costs would represent $0.06 per gallon and operating costs would amount to $0.20 per gallon. Further, it was found that the energy required to run the process represented 6.2% of the energy available in the bio-oil, meeting the milestone of less than 20%. Life cycle analysis and greenhouse gas (GHG) emission analysis found that the energy for running the critical fluid separation process and the GHG emissions were minor compared to all the inputs to the overall well to pump system. For the well to pump system boundary, energetics in biofuel conversion are typically dominated by energy demands in the growth, dewater, and thermochemical process. Bio-oil stabilization by

  1. Highly Sensitive and Miniaturized Fluorescence Detection System with an Autonomous Capillary Fluid Manipulation Chip

    Directory of Open Access Journals (Sweden)

    Ji Fang

    2012-05-01

    Full Text Available This paper presents a novel, highly sensitive and ultra-small fluorescent detection system, including an autonomous capillary fluid manipulation chip. The optical detector integrates a LED light source, all necessary optical components, and a photodiode with preamplifier into one package of about 2 cm × 2 cm × 2 cm. Also, the low-cost and simple pumpless microfluidic device works well in sample preparation and manipulation. This chip consists of capillary stop valves and trigger valves which are fabricated by lithography and then bonded with a polydimethylsiloxane-ethylene oxide polymer polydimethylsiloxane (PEO-PDMS cover. The contact angle of the PEO-PDMS can be adjusted by changing the concentration of the PEO. Hence, the fluidic chip can achieve functionalities such as timing features and basic logical functions. The prototype has been tested by fluorescence dye 5-Carboxyfluorescein (5-FAM dissolved into the solvent DMSO (Dimethyl Sulfoxide. The results prove a remarkable sensitivity at a pico-scale molar, around 1.08 pM. The low-cost and miniaturized optical detection system, with a self-control capillary-driven microfluidic chip developed in this work, can be used as the crucial parts in portable biochemical detection applications and point of care testing.

  2. High Yield Synthesis of Aspect Ratio Controlled Graphenic Materials from Anthracite Coal in Supercritical Fluids.

    Science.gov (United States)

    Sasikala, Suchithra Padmajan; Henry, Lucile; Yesilbag Tonga, Gulen; Huang, Kai; Das, Riddha; Giroire, Baptiste; Marre, Samuel; Rotello, Vincent M; Penicaud, Alain; Poulin, Philippe; Aymonier, Cyril

    2016-05-24

    This paper rationalizes the green and scalable synthesis of graphenic materials of different aspect ratios using anthracite coal as a single source material under different supercritical environments. Single layer, monodisperse graphene oxide quantum dots (GQDs) are obtained at high yield (55 wt %) from anthracite coal in supercritical water. The obtained GQDs are ∼3 nm in lateral size and display a high fluorescence quantum yield of 28%. They show high cell viability and are readily used for imaging cancer cells. In an analogous experiment, high aspect ratio graphenic materials with ribbon-like morphology (GRs) are synthesized from the same source material in supercritical ethanol at a yield of 6.4 wt %. A thin film of GRs with 68% transparency shows a surface resistance of 9.3 kΩ/sq. This is apparently the demonstration of anthracite coal as a source for electrically conductive graphenic materials.

  3. Optimization of microwave-assisted extraction and supercritical fluid extraction of carbamate pesticides in soil by experimental design methodology.

    Science.gov (United States)

    Sun, Lei; Lee, Hian Kee

    2003-10-03

    Orthogonal array design (OAD) was applied for the first time to optimize microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE) conditions for the analysis of four carbamates (propoxur, propham, methiocarb, chlorpropham) from soil. The theory and methodology of a new OA16 (4(4)) matrix derived from a OA16 (2(15)) matrix were developed during the MAE optimization. An analysis of variance technique was employed as the data analysis strategy in this study. Determinations of analytes were completed using high-performance liquid chromatography (HPLC) with UV detection. Four carbamates were successfully extracted from soil with recoveries ranging from 85 to 105% with good reproducibility (approximately 4.9% RSD) under the optimum MAE conditions: 30 ml methanol, 80 degrees C extraction temperature, and 6-min microwave heating. An OA8 (2(7)) matrix was employed for the SFE optimization. The average recoveries and RSD of the analytes from spiked soil by SFE were 92 and 5.5%, respectively except for propham (66.3+/-7.9%), under the following conditions: heating for 30 min at 60 degrees C under supercritical CO2 at 300 kg/cm2 modified with 10% (v/v) methanol. The composition of the supercritical fluid was demonstrated to be a crucial factor in the extraction. The addition of a small volume (10%) of methanol to CO2 greatly enhanced the recoveries of carbamates. A comparison of MAE with SFE was also conducted. The results indicated that >85% average recoveries were obtained by both optimized extraction techniques, and slightly higher recoveries of three carbamates (propoxur, propham and methiocarb) were achieved using MAE. SFE showed slightly higher recovery for chlorpropham (93 vs. 87% for MAE). The effects of time-aged soil on the extraction of analytes were examined and the results obtained by both methods were also compared.

  4. Method developments approaches in supercritical fluid chromatography applied to the analysis of cosmetics.

    Science.gov (United States)

    Lesellier, E; Mith, D; Dubrulle, I

    2015-12-04

    Analyses of complex samples of cosmetics, such as creams or lotions, are generally achieved by HPLC. These analyses are often multistep gradients, due to the presence of compounds with a large range of polarity. For instance, the bioactive compounds may be polar, while the matrix contains lipid components that are rather non-polar, thus cosmetic formulations are usually oil-water emulsions. Supercritical fluid chromatography (SFC) uses mobile phases composed of carbon dioxide and organic co-solvents, allowing for good solubility of both the active compounds and the matrix excipients. Moreover, the classical and well-known properties of these mobile phases yield fast analyses and ensure rapid method development. However, due to the large number of stationary phases available for SFC and to the varied additional parameters acting both on retention and separation factors (co-solvent nature and percentage, temperature, backpressure, flow rate, column dimensions and particle size), a simplified approach can be followed to ensure a fast method development. First, suited stationary phases should be carefully selected for an initial screening, and then the other operating parameters can be limited to the co-solvent nature and percentage, maintaining the oven temperature and back-pressure constant. To describe simple method development guidelines in SFC, three sample applications are discussed in this paper: UV-filters (sunscreens) in sunscreen cream, glyceryl caprylate in eye liner and caffeine in eye serum. Firstly, five stationary phases (ACQUITY UPC(2)) are screened with isocratic elution conditions (10% methanol in carbon dioxide). Complementary of the stationary phases is assessed based on our spider diagram classification which compares a large number of stationary phases based on five molecular interactions. Secondly, the one or two best stationary phases are retained for further optimization of mobile phase composition, with isocratic elution conditions or, when

  5. Maximizing kinetic performance in supercritical fluid chromatography using state-of-the-art instruments.

    Science.gov (United States)

    Grand-Guillaume Perrenoud, Alexandre; Hamman, Chris; Goel, Meenakshi; Veuthey, Jean-Luc; Guillarme, Davy; Fekete, Szabolcs

    2013-11-01

    Recently, there has been a renewed interest in supercritical fluid chromatography (SFC), due to the introduction of state-of-the-art instruments and dedicated columns packed with small particles. However, the achievable kinetic performance and practical possibilities of such modern SFC instruments and columns has not been described in details until now. The goal of the present contribution was to provide some information about the optimal column dimensions (i.e. length, diameter and particle size) suitable for such state-of the-art systems, with respect to extra-column band broadening and system upper pressure limit. In addition, the reliability of the kinetic plot methodology, successfully applied in RPLC, was also evaluated under SFC conditions. Taking into account the system variance, measured at ∼85μL(2), on modern SFC instruments, a column of 3mm I.D. was ideally suited for the current technology, as the loss in efficiency remained reasonable (i.e. less than 10% decrease for k>6). Conversely, these systems struggle with 2.1mm I.D. columns (55% loss in N for k=5). Regarding particle size, columns packed with 5μm particles provided unexpectedly high minimum reduced plate height values (hmin=3.0-3.4), while the 3.5 and 1.7μm packing provided lower reduced plate heights hmin=2.2-2.4 and hmin=2.7-3.2, respectively. Considering the system upper pressure limit, it appears that columns packed with 1.7μm particles give the lowest analysis time for efficiencies up to 40,000-60,000 plates, if the mobile phase composition is in the range of 2-19% MeOH. The 3.5μm particles were attractive for higher efficiencies, particularly when the modifier percentage was above 20%, while 5μm was never kinetically relevant with modern SFC instruments, due to an obvious limitation in terms of upper flow rate value. The present work also confirms that the kinetic plot methodology could be successfully applied to SFC, without the need for isopycnic measurements, as the difference

  6. Structural Characterisation of Acetogenins from Annona muricata by Supercritical Fluid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Laboureur, Laurent; Bonneau, Natacha; Champy, Pierre; Brunelle, Alain; Touboul, David

    2017-11-01

    Acetogenins are plant polyketides known to be cytotoxic and proposed as antitumor candidates. They are also suspected to be alimentary neurotoxins. Their occurrence as complex mixtures renders their dereplication and structural identification difficult using liquid chromatography coupled to tandem mass spectrometry and efforts are required to improve the methodology. To develop a supercritical fluid chromatography (SFC) high-resolution tandem mass spectrometry method, involving lithium post-column cationisation, for the structural characterisation of Annonaceous acetogenins in crude extracts. The seeds of Annona muricata L. were extracted with methanol. Supercritical fluid chromatography of the extract, using a 2-ethylpyridine stationary phase column, was monitored using a high-resolution quadrupole time-of-flight mass spectrometer. Lithium iodide was added post-column in the make-up solvent. For comparison, the same extract was analysed using high-pressure liquid chromatography coupled to the same mass spectrometer, with a column based on solid core particles. Sensitivity was similar for both HPLC and SFC approaches. Retention behaviour and fragmentation pathways of three different isomer groups are described. A previously unknown group of acetogenins was also evidenced for the first time. The use of SFC-MS/MS allows the reduction of the time of analysis, of environmental impact and an increase in the chromatographic resolution, compared to liquid chromatography. This new methodology enlightened a new group of acetogenins, isomers of montanacin-D. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Enhancement of antioxidant activity of C-phycocyanin of Spirulina powder treated with supercritical fluid carbon dioxide

    Directory of Open Access Journals (Sweden)

    Monchai Dejsungkranont

    2017-10-01

    Full Text Available The functionality and activity of proteins can be modified by supercritical fluid CO2 (SCFCO2. The objectives of this study were to investigate the possibility of enhanced antioxidant activity of C-phycocyanin (C-PC proteins from light-harvested Spirulina maxima powder using the SCFCO2 pretreatment and to optimize the SCFCO2 pretreatment conditions enhancing the antioxidant activity of C-PC. The Taguchi method was used to determine the optimum conditions for the SCFCO2 pretreatment. The experimental factors were the pretreatment temperature, pressure, pretreatment mode (static, dynamic and conjugated and duration. The optimal conditions of SCFCO2 pretreatment were: 60 °C, 24.13 MPa and 60 min in static batch mode. Using these pretreatment conditions, the maximum antioxidant activity of C-PC from the treated residual biomass was 410.1 μmole trolox/mg, which was 1.7-fold higher than the untreated biomass (control. The factor that most affected the antioxidant activity of C-PC was temperature (59%. A high pretreatment temperature could damage C-PC, but promoted antioxidant activity. Of note is that this work was the first to explore SCFCO2 treatment enhancing the antioxidant activity of C-PC in Spirulina sp. powder. Keywords: Antioxidant activity, C-phycocyanin, Spirulina sp., Supercritical fluid carbon dioxide pretreatment, Taguchi method

  8. Development and validation of spectroscopic methods for monitoring density changes in pressurized gaseous and supercritical fluid systems.

    Science.gov (United States)

    Blatchford, Marc A; Wallen, Scott L

    2002-04-15

    The further development of new processes utilizing liquid or supercritical CO2 as a solvent will benefit from the rational design of new CO2-philes. Understanding solvation structures and mechanisms of these molecules is an important part of this process. In such studies, determining the change in density as a function of the measured thermodynamic conditions (pressure and temperature) provides an excellent means of directly monitoring the solution conditions in the detection volume for a given technique. By integrating spectroscopic peaks, changes in area can be used to determine changes in analyte concentration in the detection volume, and thus, it should be possible to monitor the system density in situ. In the present study, we examine the utility of Raman and NMR spectroscopy as a means of following changes in solution density conditions and validate this approach in pure fluids and gases (N2 and CO2) and supercritical fluid mixtures (acetaldehyde vapor in N2). In addition, we present the design of a simple, inexpensive cell for conducting Raman and NMR measurements under moderate pressure conditions.

  9. Mathematical Model for Supercritical Fluid Extraction of Natural Products and Extraction Curve Evaluation

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena

    2005-01-01

    Roč. 33, č. 1 (2005), s. 35-52 ISSN 0896-8446 R&D Projects: GA AV ČR IAA4072102 Institutional research plan: CEZ:AV0Z4072921 Keywords : supercritical extraction * natural products * model Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.144, year: 2005

  10. Supercritical fluid technology in materials science and engineering: syntheses, properties, and applications

    National Research Council Canada - National Science Library

    Sun, Ya-Ping

    2002-01-01

    ... and polymer preparations and as alternative solvent systems for materials processing. In fact, materials-related applications have emerged as a new frontier in the development of supercritical fluid technology. I hope that this book will be a timely contribution to this emerging research field by serving at least two purposes. One is to provide intere...

  11. Supercritical fluid extraction for the detection of 2-dodecylcyclobutanone in low dose irradiated plant foods

    NARCIS (Netherlands)

    Horvatovich, Peter; Miesch, Michel; Hasselmann, Claude; Marchioni, Eric

    2002-01-01

    Supercritical carbon dioxide extraction [152 bar (15,200 kPa), 80 degrees C, 4 ml min(-1), 60 min], performed on lipids (2 g) previously extracted from irradiated plant foods, allowed a selective extraction of 2-dodecylcyclobutanone and its further detection by gas chromatography-mass spectrometry

  12. Supercritical fluid extraction of hydrocarbons and 2-alkylcyclobutanones for the detection of irradiated foodstuffs

    NARCIS (Netherlands)

    Horvatovich, P; Miesch, M; Hasselmann, C; Marchioni, E

    2000-01-01

    Supercritical carbon dioxide can be used to carry out a selective and fast extraction (30 min) of volatile hydrocarbons and 2-alkylcyclobutanones contained in irradiated foods. After elimination of the traces of triglycerides still contained in the extracts on a silica column, the compounds were

  13. Supercritical Fluid Behavior at Nanoscale Interfaces: Implications for CO2 Sequestration in Geologic Formations

    Czech Academy of Sciences Publication Activity Database

    Cole, D.R.; Chialvo, A. A.; Rother, G.; Vlček, Lukáš; Cummings, P. T.

    2010-01-01

    Roč. 90, 17-18 (2010), s. 2329-2363 ISSN 1478-6435 Institutional research plan: CEZ:AV0Z40720504 Keywords : sequestration * nanostructures * supercritical CO2 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.302, year: 2010

  14. SEPARATION OF OCTYLPHENOL POLYETHER ALCOHOLS SURFACTANTS BY CAPILLARY COLUMN SFC AND HPLC

    Science.gov (United States)

    Separation of nonionic octylphenol polyether alcohols (OPA) by supercritical fluid chromatography (SFC) and HPLC is described. Using a density programming and a 50-μm i.d. capillary column, a total of 18 group oligomers was separated. The effects of the operating parameters, such...

  15. Development and optimization of ultra-high performance supercritical fluid chromatography mass spectrometry method for high-throughput determination of tocopherols and tocotrienols in human serum

    Czech Academy of Sciences Publication Activity Database

    Pilařová, V.; Gottvald, T.; Svoboda, P.; Novák, Ondřej; Benešová, K.; Běláková, S.; Nováková, L.

    2016-01-01

    Roč. 934, AUG 31 (2016), s. 252-265 ISSN 0003-2670 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Ultra-high performance supercritical fluid chromatography * Mass spectrometry * Liquid liquid extraction Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.950, year: 2016

  16. COMPARISONS OF SOXHLET EXTRACTION, PRESSURIZED LIQUID EXTRACTION, SUPERCRITICAL FLUID EXTRACTION, AND SUBCRITICAL WATER EXTRACTION FOR ENVIRONMENTAL SOLIDS: RECOVERY, SELECTIVITY, AND EFFECTS ON SAMPLE MATRIX. (R825394)

    Science.gov (United States)

    Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100°C), supercritical fluid extraction (SFE) (1 h at 150°...

  17. Mass transfer of Disperse Red 153 and its crude dye in supercritical CO2 fluid

    Directory of Open Access Journals (Sweden)

    Zheng Huan-Da

    2017-01-01

    Full Text Available In this paper, polyester fibers were dyed with Disperse Red 153 and its crude dye in supercritical CO2. The effect of dyeing temperature, dyeing time, dyeing pressure, as well as auxiliaries in the commercialized Disperse Red 153 on the dyeing performance of polyester fibers was investigated. The obtained results showed that the dyeing effect of crude dye for polyester was better than that of Disperse Red 153 in the same dyeing condition. The color strength values of the dyed polyester samples were increased gradually with the increase of temperature and pressure since mass transfer of dye was improved. In addition, the mass transfer model of Disperse Red 153 in supercritical CO2 was also proposed.

  18. Use of the supercritical fluid technology to prepare efficient nanocomposite foams for environmental protection purpose

    OpenAIRE

    Urbanczyk, Laetitia; Thomassin, Jean-Michel; Huynen, Isabelle; Alexandre, Michaël; Jérôme, Christine

    2009-01-01

    This work reports on the preparation of novel nanocomposite foams that are efficient broadband microwave absorbers. Carbon nanotubes are first successfully dispersed into PCL and PMMA by melt blending. Then, foaming is promoted by supercritical CO2 by depressurization. Regular cellular structures are obtained in both cases with cells size around 10-50µm. The electromagnetic interference (EMI) shielding efficiency of these materials are then evaluated and compared to the non-foamed nanocomposi...

  19. Supercritical Fluid Extraction of Lignans and Cinnamic Acid from Schizandra chinensis.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena; Opletal, L.; Bártlová, Milena; Sajfrtová, Marie; Křenková, M.

    2007-01-01

    Roč. 42, 1 (2007) , s. 88-95 ISSN 0896-8446 R&D Projects: GA ČR(CZ) GA203/01/0550; GA AV ČR IAA4072102; GA AV ČR KSK4040110 Institutional research plan: CEZ:AV0Z40720504 Keywords : supercritical extraction * solubility * lignans Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.189, year: 2007

  20. Partitioning behaviour of organic compounds between ionic liquids and supercritical fluids

    Czech Academy of Sciences Publication Activity Database

    Roth, Michal

    2009-01-01

    Roč. 1216, č. 10 (2009), s. 1861-1880 ISSN 0021-9673 R&D Projects: GA ČR GA203/08/1465; GA ČR GA203/08/1536 Institutional research plan: CEZ:AV0Z40310501 Keywords : ionic liquid * supercritical carbon dioxide * review Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.101, year: 2009

  1. Volatile and Nonvolatile Constituents and Antioxidant Capacity of Oleoresins in Three Taiwan Citrus Varieties as Determined by Supercritical Fluid Extraction

    Directory of Open Access Journals (Sweden)

    Min-Hung Chen

    2016-12-01

    Full Text Available As local varieties of citrus fruit in Taiwan, Ponkan (Citrus reticulata Blanco, Tankan (C. tankan Hayata, and Murcott (C. reticulate × C. sinensis face substantial competition on the market. In this study, we used carbon dioxide supercritical technology to extract oleoresin from the peels of the three citrus varieties, adding alcohol as a solvent assistant to enhance the extraction rate. The supercritical fluid extraction was fractionated with lower terpene compounds in order to improve the oxygenated amounts of the volatile resins. The contents of oleoresin from the three varieties of citrus peels were then analyzed with GC/MS in order to identify 33 volatile compounds. In addition, the analysis results indicated that the non-volatile oleoresin extracted from the samples contains polymethoxyflavones (86.2~259.5 mg/g, limonoids (111.7~406.2 mg/g, and phytosterols (686.1~1316.4 μg/g. The DPPH (1,1-Diphenyl-2-picrylhydrazyl, ABTS [2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid] scavenging and inhibition of lipid oxidation, which test the oleoresin from the three kinds of citrus, exhibited significant antioxidant capacity. The component polymethoxyflavones contributed the greatest share of the overall antioxidant capacity, while the limonoid and phytosterol components effectively coordinated with its effects.

  2. Supercritical fluid extraction from spent coffee grounds and coffee husks: antioxidant activity and effect of operational variables on extract composition.

    Science.gov (United States)

    Andrade, Kátia S; Gonçalvez, Ricardo T; Maraschin, Marcelo; Ribeiro-do-Valle, Rosa Maria; Martínez, Julian; Ferreira, Sandra R S

    2012-01-15

    The present study describes the chemical composition and the antioxidant activity of spent coffee grounds and coffee husks extracts, obtained by supercritical fluid extraction (SFE) with CO(2) and with CO(2) and co-solvent. In order to evaluate the high pressure method in terms of process yield, extract composition and antioxidant activity, low pressure methods, such as ultrasound (UE) and soxhlet (SOX) with different organic solvents, were also applied to obtain the extracts. The conditions for the SFE were: temperatures of 313.15K, 323.15K and 333.15K and pressures from 100 bar to 300 bar. The SFE kinetics and the mathematical modeling of the overall extraction curves (OEC) were also investigated. The extracts obtained by LPE (low pressure extraction) with ethanol showed the best results for the global extraction yield (X(0)) when compared to SFE results. The best extraction yield was 15±2% for spent coffee grounds with ethanol and 3.1±04% for coffee husks. The antioxidant potential was evaluated by DPPH method, ABTS method and Folin-Ciocalteau method. The best antioxidant activity was showed by coffee husk extracts obtained by LPE. The quantification and the identification of the extracts were accomplished using HPLC analysis. The main compounds identified were caffeine and chlorogenic acid for the supercritical extracts from coffee husks. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Supercritical fluid chromatography coupled with in-source atmospheric pressure ionization hydrogen/deuterium exchange mass spectrometry for compound speciation.

    Science.gov (United States)

    Cho, Yunju; Choi, Man-Ho; Kim, Byungjoo; Kim, Sunghwan

    2016-04-29

    An experimental setup for the speciation of compounds by hydrogen/deuterium exchange (HDX) with atmospheric pressure ionization while performing chromatographic separation is presented. The proposed experimental setup combines the high performance supercritical fluid chromatography (SFC) system that can be readily used as an inlet for mass spectrometry (MS) and atmospheric pressure photo ionization (APPI) or atmospheric pressure chemical ionization (APCI) HDX. This combination overcomes the limitation of an approach using conventional liquid chromatography (LC) by minimizing the amount of deuterium solvents used for separation. In the SFC separation, supercritical CO2 was used as a major component of the mobile phase, and methanol was used as a minor co-solvent. By using deuterated methanol (CH3OD), AP HDX was achieved during SFC separation. To prove the concept, thirty one nitrogen- and/or oxygen-containing standard compounds were analyzed by SFC-AP HDX MS. The compounds were successfully speciated from the obtained SFC-MS spectra. The exchange ions were observed with as low as 1% of CH3OD in the mobile phase, and separation could be performed within approximately 20min using approximately 0.24 mL of CH3OD. The results showed that SFC separation and APPI/APCI HDX could be successfully performed using the suggested method. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents.

    Science.gov (United States)

    Müller, David; Cattaneo, Stefano; Meier, Florian; Welz, Roland; de Vries, Tjerk; Portugal-Cohen, Meital; Antonio, Diana C; Cascio, Claudia; Calzolai, Luigi; Gilliland, Douglas; de Mello, Andrew

    2016-04-01

    We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel method of sample preparation for the analysis of complex nanoparticle-containing samples, in our case a model sunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplified process using a lab scale supercritical fluid extraction system. The residual material was easily dispersed in an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenated with UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguous determination of the presence of nanoparticles within the sample, with almost no background from the matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained. These results are especially relevant in view of recently introduced regulatory requirements concerning the labeling of nanoparticle-containing products. The novel sample preparation method is potentially applicable to commercial sunscreens or other emulsion-based cosmetic products and has important ecological advantages over currently used sample preparation techniques involving organic solvents. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Supercritical Fluid Extraction and Ultra Performance Liquid Chromatography of Respiratory Quinones for Microbial Community Analysis in Environmental and Biological Samples

    Directory of Open Access Journals (Sweden)

    Koichi Fujie

    2012-03-01

    Full Text Available Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE and ultra performance liquid chromatography (UPLC method for the analysis of bacterial respiratory quinones (RQ in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA detector was successfully applied to the simultaneous determination of ubiquinones (UQ and menaquinones (MK without tedious pretreatment. Supercritical carbon dioxide (scCO2 extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost and biological samples (swine and Japanese quail feces.

  6. Supercritical fluid extraction and ultra performance liquid chromatography of respiratory quinones for microbial community analysis in environmental and biological samples.

    Science.gov (United States)

    Hanif, Muhammad; Atsuta, Yoichi; Fujie, Koichi; Daimon, Hiroyuki

    2012-03-05

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA) detector was successfully applied to the simultaneous determination of ubiquinones (UQ) and menaquinones (MK) without tedious pretreatment. Supercritical carbon dioxide (scCO(2)) extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost) and biological samples (swine and Japanese quail feces).

  7. New dimension of slow food movement using supercritical fluid technology and methods to influence society by effective marketing strategies.

    Science.gov (United States)

    Uzel, Ruhan Aşkın

    2016-07-01

    Although slow food movement is a well-known movement nowadays, in order to make it more widespread to the society, necessity to develop and to adapt new techniques has become inevitable for healthier consumption age. For this purpose, possibility of increased usage of healthy foods with addition of natural extracts using new techniques came out from relevant questionaries applied to people of different age groups. In this study, specific properties of supercritical carbon dioxide at distinct temperatures and water in subcritical conditions were used to obtain extracts rich in water-soluble organic compounds. Experiments were carried out at pressures of 10, 20, 30, and 40 MPa and temperatures ranging from 40 to 200 ℃ with and without modifier for 2 h of extraction time. The flow rate was kept at 4 and 1 ml/min for CO2 and water, respectively. The highest water-soluble organic compound recovery yield was 78.10%. Results were supported by marketing strategies to announce this new application and products to the society. Group of sample questions was prepared to investigate (a) frequency of staple food usage, (b) the brand names and relevant reasons that bring up consumers to buy specifically same branded products, (c) knowledge about the ingredients and how advertising effects purchasing decision, etc. Finally, efficiency increase in slow food consumption was proved with supercritical fluid technology to draw attention to the health of consumers with newer and functional healthy foods. © The Author(s) 2015.

  8. Supercritical fluid extraction of heather (Calluna vulgaris) and evaluation of anti-hepatitis C virus activity of the extracts.

    Science.gov (United States)

    García-Risco, Mónica Rodriguez; Vázquez, Erika; Sheldon, Julie; Steinmann, Eike; Riebesehl, Nina; Fornari, Tiziana; Reglero, Guillermo

    2015-02-16

    Previous studies using lipid extracts of heather (Calluna vulgaris) leaves showed the presence of high concentrations of ursolic and oleanolic acid. These two compounds have been reported to present antiviral activity against hepatitis C virus (HCV). In this work, the supercritical fluid extraction of heather was studied with the aim of assessing a potential anti-HCV activity of the extracts owing to their triterpenic acid content. Supercritical extraction assays were carried out exploring the pressure range of 20-50 MPa, temperatures of 40-70°C and 0-15% of ethanol cosolvent. The content of oleanolic and ursolic acid in the extracts were determined, and different samples were screened for cellular cytotoxicity and virus inhibition using a HCV cell culture infection system. Antiviral activity was observed in most extracts. In general, superior anti-HCV activity was observed for higher contents of oleanolic and ursolic acids in the extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Decontamination of uranium-contaminated waste oil using supercritical fluid and nitric acid

    International Nuclear Information System (INIS)

    Sung, J.; Kim, J.; Lee, Y.; Seol, J.; Ryu, J.; Park, K.

    2011-01-01

    The waste oil used in nuclear fuel processing is contaminated with uranium because of its contact with materials or environments containing uranium. Under current law, waste oil that has been contaminated with uranium is very difficult to dispose of at a radioactive waste disposal site. To dispose of the uranium-contaminated waste oil, the uranium was separated from the contaminated waste oil. Supercritical R-22 is an excellent solvent for extracting clean oil from uranium-contaminated waste oil. The critical temperature of R-22 is 96.15 deg. C and the critical pressure is 49.9 bar. In this study, a process to remove uranium from the uranium-contaminated waste oil using supercritical R-22 was developed. The waste oil has a small amount of additives containing N, S or P, such as amines, dithiocarbamates and dialkyldithiophosphates. It seems that these organic additives form uranium-combined compounds. For this reason, dissolution of uranium from the uranium-combined compounds using nitric acid was needed. The efficiency of the removal of uranium from the uranium-contaminated waste oil using supercritical R-22 extraction and nitric acid treatment was determined. (authors)

  10. Axisymmetric capillary-gravity waves at the interface of two viscous, immiscible fluids - Initial value problem

    Science.gov (United States)

    Farsoiya, Palas Kumar; Dasgupta, Ratul

    2017-11-01

    When the interface between two radially unbounded, viscous fluids lying vertically in a stable configuration (denser fluid below) at rest, is perturbed, radially propagating capillary-gravity waves are formed which damp out with time. We study this process analytically using a recently developed linearised theory. For small amplitude initial perturbations, the analytical solution to the initial value problem, represented as a linear superposition of Bessel modes at time t = 0 , is found to agree very well with results obtained from direct numerical simulations of the Navier-Stokes equations, for a range of initial conditions. Our study extends the earlier work by John W. Miles who studied this initial value problem analytically, taking into account, a single viscous fluid only. Implications of this study for the mechanistic understanding of droplet impact into a deep pool, will be discussed. Some preliminary, qualitative comparison with experiments will also be presented. We thank SERB Dept. Science & Technology, Govt. of India, Grant No. EMR/2016/000830 for financial support.

  11. Comparison of supercritical fluid extraction (SFE), Soxhlet and shaking methods for pendimethalin extraction from soils: effect of soil properties and water content

    Science.gov (United States)

    Spack, Lionel; Alvarez, Cristina; Martins, Jean M. F.; Tarradellas, Joseph

    1998-09-01

    Supercritical fluid extraction with CO 2 was applied to the analysis of traces of pendimethalin, a herbicide of the dinitroanilines group, in four different natural soils. The Supercritical Fluid Extraction (SFE) method was compared with the classical Soxhlet and shaking methods in terms of ease to run, extraction efficiency, selectivity and reproducibility. The influence of the physico-chemical properties of the soil matrix on herbicide extraction was then evaluated with the SFE method. The supercritical fluid extraction system used in the present study was found to be much easier to run than the other two methods, less time consuming and requires fewer operations as it was optimized for on-line sample clean up. SFE is the most selective of the three tested methods as fewer co-extracts are obtained in the final samples. SFE with CO 2 is particularly powerful because pendimethalin is highly hydrophobic. However, this makes pendimethalin a poor choice for a selectivity study of SFE as it is very rapidly extracted at any CO 2 density. Pendimethalin extraction with supercritical CO 2 was found to be almost complete with average recoveries of 96-99%, similarly to Soxhlet but with a much lower standard deviation (8-10%). The performance of SFE was shown to be unaffected by soil parameters except soil water content. It is demonstrated indeed that extraction efficiency is not linearly related to soil water content, and optimal recovery was found for water contents ranging from 2 to 15% depending on the type of soil. Soil water increases extraction efficiency because water acts as a modifier of the supercritical fluid and increases the penetration of the fluid inside the soil particles (clay swelling). In contrast to SFE and Soxhlet, the efficiency of the shaking method appeared to be partial and strongly dependent on soil properties. Although initial developments should be needed, the various benefits of SFE-CO 2 make this method attractive compared to traditional methods.

  12. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: james.friend@monash.edu.au [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)

    2011-02-15

    Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  13. Effects of supercritical fluid chromatography conditions on enantioselectivity and performance of polyproline-derived chiral stationary phases.

    Science.gov (United States)

    Novell, Arnau; Méndez, Alberto; Minguillón, Cristina

    2015-07-17

    The chromatographic behaviour and performance of four polyproline-derived chiral stationary phases (CSPs) were tested using supercritical fluid chromatography (SFC). A series of structurally related racemic compounds, whose enantioseparation was proved to be sensitive to the type of mobile phase used in NP-HPLC, were chosen to be tested in the SFC conditions. Good enantioselection ability was shown by the CSPs for the analytes tested in the new conditions. Resolution, efficiency and analysis time, were considerably improved with respect to NP-HPLC when CO2/alcohol mobile phases were used. Monolithic columns clearly show enhanced chromatographic parameters and improved performance respect to their bead-based counterparts. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Comparison of supercritical fluid extraction and Soxhlet extraction for the determination of aliphatic hydrocarbons in seaweed samples.

    Science.gov (United States)

    Punín Crespo, M O; Lage Yusty, M A

    2006-07-01

    Supercritical fluid extraction (SFE) and Soxhlet extraction methods were compared in a study of the aliphatic hydrocarbon profiles of seaweed samples. Method precision for Soxhlet extraction (Soxhlet extraction is a more suitable method. To evaluate the SFE and Soxhlet methods developed, three diverse Undaria pinnatifida samples collected at different dates and areas of the Galician coast were analyzed. n-Alkanes C18, C20, C22, C24, and C28 were found in all samples, with values lower than 7.9 microg g(-1) d.w. The total hydrocarbon content was within the range of 13.6-21.7 microg g(-1) d.w. C18 was found to be the most abundant.

  15. Computational fluid dynamic assisted control system design methodology using system identification technique for CANDU supercritical water cooled reactor (SCWR)

    International Nuclear Information System (INIS)

    Maitri, Rohit V.; Zhang, Chao; Jiang, Jin

    2017-01-01

    The supercritical water cooled reactor (SCWR) is one of the six Generation IV nuclear reactors. A novel control system design method for the Canadian SCWR, known as CANDU SCWR, is developed in this study. The main dynamic of this reactor can be represented as a multiple input and multiple output (MIMO) system governed by highly non-linear partial differential equations. Even though the non-linear governing equations of such a reactor can be solved using computational fluid dynamics (CFD) techniques, it is difficult to convert the existing non-linear partial differential equations to linear dynamic models to facilitate its control system design. To deal with this problem, a new approach is developed herein, which uses the results from CFD simulations to derive the linear dynamic models around several chosen operating points based on system identification techniques. The derived linear dynamic models have been validated by comparing it with the data from the non-linear dynamic model.

  16. [Comparison of the chemical components of essential oil extracted by supercritical CO2 fluid and steam distillation from Pteris multifida].

    Science.gov (United States)

    Chen, Feng; Chen, Huan; Li, Shu-Jie; Lin, Jing-Ming; Wang, Zhao-Yu

    2013-08-01

    To compare the chemical components of essential oil extracted by supercritical CO2 fluid extraction (SFE-CO2) and steam distillation extraction (SD) from Pteris multifida. The essential oil of Pteris multifida was extracted by SFE-CO2 and SD. The chemical components of essential oil were separated and analyzed by GC-MS. Their relative contents were determined by normalization of peak area. Twenty -seven compounds in the essential oil extracted by SFE-CO2 and 45 compounds in the essential oil extracted by SD were identified respectively. There were 11 common components. The chemical components of essential oil extracted by SFE-CO2 are different from that extracted by SD.

  17. Advanced Computational Thermal Fluid Physics (CTFP) and Its Assessment for Light Water Reactors and Supercritical Reactors

    International Nuclear Information System (INIS)

    D.M. McEligot; K. G. Condie; G. E. McCreery; H. M. McIlroy; R. J. Pink; L.E. Hochreiter; J.D. Jackson; R.H. Pletcher; B.L. Smith; P. Vukoslavcevic; J.M. Wallace; J.Y. Yoo; J.S. Lee; S.T. Ro; S.O. Park

    2005-01-01

    Background: The ultimate goal of the study is the improvement of predictive methods for safety analyses and design of Generation IV reactor systems such as supercritical water reactors (SCWR) for higher efficiency, improved performance and operation, design simplification, enhanced safety and reduced waste and cost. The objective of this Korean/US/laboratory/university collaboration of coupled fundamental computational and experimental studies is to develop the supporting knowledge needed for improved predictive techniques for use in the technology development of Generation IV reactor concepts and their passive safety systems. The present study emphasizes SCWR concepts in the Generation IV program

  18. Advanced Computational Thermal Fluid Physics (CTFP) and Its Assessment for Light Water Reactors and Supercritical Reactors

    Energy Technology Data Exchange (ETDEWEB)

    D.M. McEligot; K. G. Condie; G. E. McCreery; H. M. McIlroy; R. J. Pink; L.E. Hochreiter; J.D. Jackson; R.H. Pletcher; B.L. Smith; P. Vukoslavcevic; J.M. Wallace; J.Y. Yoo; J.S. Lee; S.T. Ro; S.O. Park

    2005-10-01

    Background: The ultimate goal of the study is the improvement of predictive methods for safety analyses and design of Generation IV reactor systems such as supercritical water reactors (SCWR) for higher efficiency, improved performance and operation, design simplification, enhanced safety and reduced waste and cost. The objective of this Korean / US / laboratory / university collaboration of coupled fundamental computational and experimental studies is to develop the supporting knowledge needed for improved predictive techniques for use in the technology development of Generation IV reactor concepts and their passive safety systems. The present study emphasizes SCWR concepts in the Generation IV program.

  19. Heavy metal ion extraction of crownether compounds with supercritical CO2 fluid

    International Nuclear Information System (INIS)

    Yun, Y. H.; Ko, M. S.; Kim, H. W.; Park, K. H.; Kim, H. D.

    2001-01-01

    Benzocrownether-diarylethene derivatives (5BCD, 6BCD) were synthesized and utilized to extract metal ions into supercritical CO 2 . In order to enhance the CO 2 -phillicity and the extraction capability, synthesized compounds have both perfluoro unit and benzocrown moiety and were compared with dicyclohexano 18-crown-6(DC18C6). With minimal amount of water and counter ions such as perfluorooctanesulphonic acid or perfluorooctanic acid, their metal ion(Sr 2+ , Co +2 , Na + ) extraction efficiency was investigated. 5BCD, 6BCD showed more than 50% extraction for Sr +2 , Na + ions and their extraction efficiency was better than that of DC18C6 compound

  20. A capillary electrophoresis method for identifying forensically relevant body fluids using miRNAs.

    Science.gov (United States)

    Mayes, Carrie; Seashols-Williams, Sarah; Hughes-Stamm, Sheree

    2018-01-01

    Body fluid identification (BFID) can provide crucial information during the course of an investigation. In recent years, microRNAs (miRNAs) have shown considerable body fluid specificity, are able to be co-extracted with DNA, and their small size (18-25 nucleotides) make them ideal for analyzing highly degraded forensic samples. In this study, we designed a preliminary 8-marker system for BFID including an endogenous reference gene (let-7g) to differentiate between venous blood (miR-451a and miR-142-3p), menstrual blood (miR-141-3p and miR-412-3p), semen (miR-891a and miR-10b), and saliva (miR-205) using a capillary electrophoresis approach. This panel uses a linear primer system in order to incorporate additional miRNA markers by forming a multiplex system. The miRNA system was able to distinguish between venous blood, menstrual blood, semen, and saliva using a rudimentary data interpretation strategy. All STR amplifications from co-extracted DNA yielded complete profiles from human identification purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Modeling meniscus rise in capillary tubes using fluid in rigid-body motion approach

    Science.gov (United States)

    Hamdan, Mohammad O.; Abu-Nabah, Bassam A.

    2018-04-01

    In this study, a new term representing net flux rate of linear momentum is introduced to Lucas-Washburn equation. Following a fluid in rigid-body motion in modeling the meniscus rise in vertical capillary tubes transforms the nonlinear Lucas-Washburn equation to a linear mass-spring-damper system. The linear nature of mass-spring-damper system with constant coefficients offers a nondimensional analytical solution where meniscus dynamics are dictated by two parameters, namely the system damping ratio and its natural frequency. This connects the numerous fluid-surface interaction physical and geometrical properties to rather two nondimensional parameters, which capture the underlying physics of meniscus dynamics in three distinct cases, namely overdamped, critically damped, and underdamped systems. Based on experimental data available in the literature and the understanding meniscus dynamics, the proposed model brings a new approach of understanding the system initial conditions. Accordingly, a closed form relation is produced for the imbibition velocity, which equals half of the Bosanquet velocity divided by the damping ratio. The proposed general analytical model is ideal for overdamped and critically damped systems. While for underdamped systems, the solution shows fair agreement with experimental measurements once the effective viscosity is determined. Moreover, the presented model shows meniscus oscillations around equilibrium height occur if the damping ratio is less than one.

  2. A new method for synthesizing fluid inclusions in fused silica capillaries containing organic and inorganic material

    Science.gov (United States)

    Chou, I.-Ming; Song, Yucai; Burruss, R. C.

    2008-11-01

    Considerable advances in our understanding of physicochemical properties of geological fluids and their roles in many geological processes have been achieved by the use of synthetic fluid inclusions. We have developed a new method to synthesize fluid inclusions containing organic and inorganic material in fused silica capillary tubing. We have used both round (0.3 mm OD and 0.05 or 0.1 mm ID) and square cross-section tubing (0.3 × 0.3 mm with 0.05 × 0.05 mm or 0.1 × 0.1 mm cavities). For microthermometric measurements in a USGS-type heating-cooling stage, sample capsules must be less than 25 mm in length. The square-sectioned capsules have the advantage of providing images without optical distortion. However, the maximum internal pressure ( P; about 100 MPa at 22 °C) and temperature ( T; about 500 °C) maintained by the square-sectioned capsules are less than those held by the round-sectioned capsules (about 300 MPa at room T, and T up to 650 °C). The fused silica capsules can be applied to a wide range of problems of interest in fluid inclusion and hydrothermal research, such as creating standards for the calibration of thermocouples in heating-cooling stages and frequency shifts in Raman spectrometers. The fused silica capsules can also be used as containers for hydrothermal reactions, especially for organic samples, including individual hydrocarbons, crude oils, and gases, such as cracking of C 18H 38 between 350 and 400 °C, isotopic exchanges between C 18H 38 and D 2O and between C 19D 40 and H 2O at similar temperatures. Results of these types of studies provide information on the kinetics of oil cracking and the changes of oil composition under thermal stress. When compared with synthesis of fluid inclusions formed by healing fractures in quartz or other minerals or by overgrowth of quartz at elevated P- T conditions, the new fused-silica method has the following advantages: (1) it is simple; (2) fluid inclusions without the presence of water can be

  3. [Supercritical CO2 fluid extraction and component analysis of leaves oil from Taxus chinensis var. mairei].

    Science.gov (United States)

    Tang, Bin; Zhang, Feng-su; Li, Xiang; Chen, Jian-wei; Yao, Xiao

    2013-12-01

    To research the optimal extraction process of supercritical CO2 extraction and analyze the component of the oil extracted from leaves of Taxus chinensis var. mairei. Using the yield of leaves oil from Taxus chinensis var. mairei as the index, investigated the effect of the extraction pressure, extraction temperature and extraction time on the extracting-rate of leaves oil. The chemical composition of the extracted leaves oil was analyzed by derivatized GC-MS. The optimal parameters of the supercritical CO2 extraction of the oil extracted from leaves of Taxus chinensis var. mairei were determined: CO2 compressor pump frequency was 10 Hz, the extraction pressure was 25 MPa and the temperature of extraction was 45 degrees C, the extraction time was 120 min, the isolator I pressure was 8.0 MPa and the temperature of extraction was 40 degrees C, the isolator II pressure was 5.0 MPa and the temperature of extraction was 35 degrees C. The extracted leaves oil was derivatized with boron trifluoride-methanol complex. Thirty-three kinds of fatty acids were identified by GC-MS. The yield of leaves oils are different from Taxus chinensis var. mairei from 3 habitats. The yield of leaves oil from Donggang, Wuxi city is the highest, about 2.61%. The kinds of fatty acids with high amounts in leaves oil from Taxus chinensis var. mairei is identical in general, the kinds of fatty acids with low amounts in leaves oil from Taxus chinensis var. mairei have differences.

  4. Supercritical fluid reactive extraction of Jatropha curcas L. seeds with methanol: A novel biodiesel production method.

    Science.gov (United States)

    Lim, Steven; Hoong, Shuit Siew; Teong, Lee Keat; Bhatia, Subhash

    2010-09-01

    The novel biodiesel production technology using supercritical reactive extraction from Jatropha curcas L. oil seeds in this study has a promising role to fill as a more cost-effective processing technology. Compared to traditional biodiesel production method, supercritical reactive extraction can successfully carry out the extraction of oil and subsequent esterification/transesterification process to fatty acid methyl esters (FAME) simultaneously in a relatively short total operating time (45-80 min). Particle size of the seeds (0.5-2.0 mm) and reaction temperature/pressure (200-300 degrees C) are two primary factors being investigated. With 300 degrees C reaction temperature, 240 MPa operating pressure, 10.0 ml/g methanol to solid ratio and 2.5 ml/g of n-hexane to seed ratio, optimum oil extraction efficiency and FAME yield can reach up to 105.3% v/v and 103.5% w/w, respectively which exceeded theoretical yield calculated based on n-hexane Soxhlet extraction of Jatropha oil seeds. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Construction of nanoscale liposomes loaded with melatonin via supercritical fluid technology.

    Science.gov (United States)

    Zhang, Quan; Ou, Chunfeng; Ye, Shengying; Song, Xianliang; Luo, Shucan

    2017-11-01

    Melatonin-loaded liposomes (MLL) were successfully prepared using rapid expansion of supercritical solution technology. The effects of supercritical pressure on encapsulation efficiency (EE) and average particle size were then analysed. Meanwhile, temperature, formation time and ethanol concentration in the products were studied and optimised based on the response surface methodology (RSM). An in vitro simulated digestion model was also established to evaluate the release performance of MLL. The results showed that 140 bar was the best pressure for maximising the EE value using RSM optimisation, reaching up to 82.2%. MLL characterisations were performed using analytic techniques including infrared spectroscopy, transmission electron microscopy, a laser scattering particle size analyser and gas chromatograph-mass spectrometer. The size distribution was uniform, with an average diameter of 66 nm. Stability tests proved that MLL maintained good preservation duration, and residual solvent experiments indicated that only 1.03% (mass ratio) of ethanol remained in the products. Simulated release experiments indicated the slow release feature in early digestive stages and more thorough characteristics in later stages of simulated digestion.

  6. SUPERCRITICAL FLUID TREATMENT OF THREE-DIMENSIONAL HYDROGEL MATRICES, COMPOSED OF CHITOSAN DERIVATIVES

    Directory of Open Access Journals (Sweden)

    P. S. Timashev

    2016-01-01

    Full Text Available Aim. Controlled treatment of the physico-chemical and mechanical properties of a three-dimensional crosslinked matrix based on reactive chitosan. Materials and methods. The three-dimensional matrices were obtained using photosensitive composition based on allyl chitosan (5 wt%, poly(ethylene glycol diacrylate (8 wt% and the photoinitiator Irgacure 2959 (1 wt% by laser stereolithography setting. The kinetic swelling curves were constructed for structures in the base and salt forms of chitosan using gravimetric method and the contact angles were measured using droplet spreading. The supercritical fl uid setting (40 °C, 12 MPa was used to process matrices during 1.5 hours. Using nanohardness Piuma Nanoindenter we calculated values of Young’s modulus. The study of cytotoxicity was performed by direct contact with the culture of the NIH 3T3 mouse fi broblast cell line. Results. Architectonics of matrices fully repeats the program model. Matrices are uniform throughout and retain their shape after being transferred to the base form. Matrices compressed by 5% after treatment in supercritical carbon dioxide (scCO2 . The elastic modulus of matrices after scCO2 treatment is 4 times higher than the original matrix. The kinetic swelling curves have similar form. In this case the maximum degree of swelling for matrices in base form is 2–2.5 times greater than that of matrices in salt form. There was a surface hydrophobization after the material was transferred to the base form: the contact angle is 94°, and for the salt form it is 66°. The basic form absorbs liquid approximately 1.6 times faster. The fi lm thickness was increased in the area of contact with the liquid droplets after absorption by 133 and 87% for the base and the salt forms, respectively. Treatment of samples in scCO2 reduces their cytotoxicity from 2 degree of reaction (initial samples down to 1 degree of reaction. Conclusion. The use of supercritical carbon dioxide for scaffolds

  7. Dissolution enhancement of glibenclamide by solid dispersion: solvent evaporation versus a supercritical fluid-based solvent -antisolvent technique.

    Science.gov (United States)

    Tabbakhian, M; Hasanzadeh, F; Tavakoli, N; Jamshidian, Z

    2014-01-01

    Glibenclamide (GLIB) is a poorly soluble drug with formulation-dependent bioavailability. Therefore, we attempted in this study to improve GLIB dissolution rate by preparing drug solid dispersions by solvent evaporation (SE) and supercritical fluid solvent-antisolvent techniques (SCF-SAS). A D-optimal mixture design was used to investigate the effects of different ratios of HPMCE5 (50-100%), PEG6000 (0-40%), and Poloxamer407 (0-20%) on drug dissolution from different solid dispersion (SD) formulations prepared by SE. The ratios of carriers used in SCF-SAS method were HPMCE5 (fixed at 60%), PEG6000 (20-40%), and Poloxamer407 (0-20%). A constant drug: carrier weight ratio of 1:10 was used in all experiments. The SDs obtained were physically characterized and subjected to the dissolution study. The major GLIB bands in FTIR spectra were indicative of drug integrity. The reduced intensity and the fewer number of peaks observed in X-ray diffractograms (XRD) of GLIB formulations was the indicative of at least partial transformation of crystalline to amorphous GLIB. This change and/or dilution of drug in much higher amounts of carriers present caused disappearance of distinctive endothermic peaks in differential scanning calorimetry thermograms of GLIB formulations. The model generated according to the results of the D-optimal mixture design indicated that GLIB formulations comprising HPMC (50%-60%), PEG (34-40%), and poloxamer (6-10%) had enhanced dissolution performances. As compared to SE method, the SCF-SAS technique produced formulations of higher dissolution performances, likely due to the effects of solution and the supercritical CO2 (SC-CO2) on enhanced plasticization of polymers and thus increased diffusion of the drug into the polymer matrix.

  8. Sustained release hGH microsphere formulation produced by a novel supercritical fluid technology: in vivo studies.

    Science.gov (United States)

    Jordan, F; Naylor, A; Kelly, C A; Howdle, S M; Lewis, A; Illum, L

    2010-01-25

    Novel sustained release formulations of hGH prepared by supercritical fluid processing of PLGA/PLA (the CriticalMix process) were produced in the form of microparticles for subcutaneous injection. The basis of the process is that PLGA/PLA polymers liquefy when exposed to supercritical CO(2), thereby allowing the hGH to be mixed efficiently into the polymers at an ambient temperature and in the absence of solvents. The CO(2) was removed from the mixture by depressurisation through a nozzle, resulting in the production of microparticles containing the hGH, which were collected in a cyclone. The best microparticle formulations showed an initial in vitro burst of around 35% and a sustained release over 14 days. When tested in the rat model, which displays a faster clearance rate of hGH than other animal models, two formulations showed prolonged release over 2-3 days with sustained plasma levels at 1-5 ng/ml whereas the soluble hGH formulation was cleared within 24h. Two selected sustained release formulations were tested in cynomolgus monkeys and compared to a single injection of soluble hGH. The burst release from the sustained release formulations was similar in magnitude to a daily dose of hGH and serum hGH levels were maintained for a seven day period. It is probable from the data that the sustained release would have continued for up to 14 days if sampling had been continued. The IGF-1 results showed there was no significant difference between the levels obtained for once daily injection of soluble hGH and the two sustained release formulations. Copyright 2009 Elsevier B.V. All rights reserved.

  9. Chemical kinetics and transport processes in supercritical fluid extraction of coal. Final report, August 10, 1990--December 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, B.J.; Smith, J.M.; Wang, M.; Zhang, C.J.

    1993-02-01

    The overall objective of this project was to study the supercritical fluid extraction of hydrocarbons from coal. Beyond the practical concern of deriving products from coal, the research has provided insights into the structure, properties, and reactivities of coal. Information on engineering fundamentals of coal thermolysis and extraction, including physical and chemical processes, is presented in this final report. To accomplish the goals of the project we developed continuous-flow experiments for fixed-bed samples of coal that allow two types of analysis of the extract: continuous spectrophotometric absorbance measurements of the lumped concentration of extract, and chromatographic determinations of molecular-weight distributions as a function of time. Thermolysis of coal yields a complex mixture of many extract products whose molecular-weight distribution (MWD) varies with time for continuous-flow, semibatch experiments. The flow reactor with a differential, fixed bed of coal particles contacted by supercritical t-butanol was employed to provide dynamic MWD data by means of HPLC gel permeation chromatography of the extract. The experimental results, time-dependent MWDs of extract molecules, were interpreted by a novel mathematical model based on continuous-mixture kinetics for thermal cleavage of chemical bonds in the coal network. The parameters for the MWDs of extractable groups in the coal and the rate constants for one- and two-fragment reaction are determined from the experimental data. The significant effect of temperature on the kinetics of the extraction was explained in terms of one- and two-fragment reactions in the coal.

  10. Highly Selective Deethylation of Rhodamine B on Prepared in Supercritical Fluids

    Directory of Open Access Journals (Sweden)

    Yuzun Fan

    2012-01-01

    Full Text Available Pure phase anatase TiO2 nanoparticles with sizes of 5–8 nm and varying crystallinity were synthesized in supercritical isopropanol/water using a continuous flow reactor. Their photodegradation of rhodamine B (RhB was evaluated under visible light irradiation. The as-prepared TiO2 nanoparticles show much higher photodegradation efficiencies than commercial Degussa P25 TiO2. Moreover, the photodegradation of RhB on the as-prepared TiO2 follows a different process from that on P25 TiO2, quicker N-deethylation and slower cleavage of conjugated chromophore structure. Based on PXRD, TEM, and BET measurements, these two photodegradation properties have been explained by the physicochemical properties of TiO2.

  11. Deposition of platinum nanoparticles on carbon nanotubes by supercritical fluid method.

    Science.gov (United States)

    Yen, Clive H; Cui, Xiaoli; Pan, Horng-Bin; Wang, Shaofen; Lin, Yuehe; Wai, Chien M

    2005-11-01

    Carbon nanotube-supported platinum nanoparticles with a 5-15 nm diameter size range can be synthesized by hydrogen reduction of platinum(ll) acetylacetonate in methanol modified supercritical carbon dioxide. X-ray photoelectron spectroscopy and X-ray diffraction spectra indicate that the carbon nanotubes contain zero-valent platinum metal and high-resolution transmission electron microscopy images show that the visible lattice fringes of platinum nanoparticles are crystallites. Carbon nanotubes synthesized with 25% by weight of platinum nanoparticles exhibit a higher activity for hydrogenation of benzene compared with a commercial carbon black platinum catalyst. The carbon nanotube-supported platinum nanocatalyst can be reused at least six times for the hydrogenation reaction without losing activity. The carbon nanotube-supported platinum nanoparticles are also highly active for electrochemical oxidation of methanol and for reduction of oxygen suggesting their potential use as a new electrocatalyst for proton exchange membrane fuel cell applications.

  12. Modelling small angle neutron scattering data from polymers in supercritical fluids

    International Nuclear Information System (INIS)

    Triolo, F.; Triolo, A.; Lo Celso, F.; Donato, D. I.; Triolo, R.; Johnson, J. S. Jr.

    2000-01-01

    In this paper we report a SANS investigation of micelle formation by fluorocarbon-hydrocarbon block copolymers in supercritical CO 2 (scCO 2 ) at 313K. A sharp unimer-micelle transition is obtained due to the tuning of the solvating ability of scCO 2 by profiling pressure. At high pressure the copolymer is in a monomeric state with a random coil structure. By lowering the pressure aggregates are formed with the hydrocarbon segments forming the core and the fluorocarbon segments forming the corona of spherical aggregates. This aggregate-unimer transition is driven by the gradual penetration of CO 2 molecules toward the core of the aggregate and is critically related to the density of the solvent, thus suggesting the definition of a critical micellization density (CMD)

  13. Supercritical fluid extraction on semibatch mode for the removal of terpene in citrus oil

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masaki; Goto, Motonobu; Hirose, Tsutomu [Kumamoto Univ. (Japan)

    1996-06-01

    Supercritical carbon dioxide extraction of a mixture of limonene and linalool was carried out with a rectification column in the semibatch operation mode. For the simple semibatch extraction where the column was controlled at the uniform temperature without an internal reflux, the Rayleigh equation, developed for the simple batch distillation, was applied to express the dynamic extraction behavior. In this paper the Peng-Robinson equation of state was used to estimate the ternary phase equilibria. The semibatch extraction with internal flux induced by a temperature gradient of the rectification column increased the separation selectivity. The internal reflux ratio was calculated by the measurement of the extraction rates at the top and bottom of the column, and it was 7.6 for the column having a temperature gradient from 313 K at the bottom to 333 K at the top at 8.8 MPa. Behavior in the rectification column was discussed by means of estimated physical properties.

  14. MODELING OF SUPERCRITICAL FLUID EXTRACTION KINETIC OF FLAXSEED OIL BY DIFFUSION CONTROL METHOD

    Directory of Open Access Journals (Sweden)

    Emir Zafer HOŞGÜN

    2013-06-01

    Full Text Available In this study, Flaxseed oil was extracted by Supercritical Carbondioxide Extraction, and extractionkinetics was modelled using diffusion controlled method.The effect of process parameters, such as pressure (20, 35, 55 MPa, temperature (323 and 343 K, and CO2 flow rate (1 and 3 L CO2 /min on the extraction yield and effective diffusivity (De was investigated. The effective diffusion coefficient varied between 2.4 x10-12 and 10.8 x10-12 m2s-1 for the entire range of experiments and increased with the pressure and flow rate. The model fitted well theexperimental data (ADD varied between 2.35 and 7.48%.

  15. A new analysing approach for the structure of density fluctuation of supercritical fluid

    International Nuclear Information System (INIS)

    Sato, T; Sugiyama, M; Itoh, K; Mori, K; Fukunaga, T; Misawa, M; Otomo, T; Takata, S

    2008-01-01

    Large scale structural evolution of supercritical carbon dioxide along the isotherm at 32 deg. C was investigated with small-angle neutron scattering. The maximum of the density fluctuation, the so-called 'ridge', was confirmed with Ornstein-Zernike analysis. To investigate the structural change in more detail, the molecular distribution over a large domain was determined with a newly developed reverse Monte Carlo method. From the molecular distribution obtained, the pair distribution function and cluster-size distribution can be calculated. With increasing density of carbon dioxide, the cluster size increases monotonically, whereas the pair distribution function for the range of sizes shorter than 10 A shows a monotonic decrease. From this result, it is suggested that the structural change along the isotherm is caused by the change of balance between growth of clusters and increase of the average density

  16. The influence of chemical composition of LNG on the supercritical heat transfer in an intermediate fluid vaporizer

    Science.gov (United States)

    Xu, Shuangqing; Chen, Xuedong; Fan, Zhichao; Chen, Yongdong; Nie, Defu; Wu, Qiaoguo

    2018-04-01

    A three-dimensional transient computational fluid dynamics (CFD) model has been established for the simulations of supercritical heat transfer of real liquefied natural gas (LNG) mixture in a single tube and a tube bundle of an intermediate fluid vaporizer (IFV). The influence of chemical composition of LNG on the thermal performance has been analyzed. The results have also been compared with those obtained from the one-dimensional steady-state calculations using the distributed parameter model (DPM). It is found that the current DPM approach can give reasonable prediction accuracy for the thermal performance in the tube bundle but unsatisfactory prediction accuracy for that in a single tube as compared with the corresponding CFD data. As benchmarked against pure methane, the vaporization of an LNG containing about 90% (mole fraction) of methane would lead to an absolute deviation of 5.5 K in the outlet NG temperature and a maximum relative deviation of 11.4% in the tube side HTC in a bundle of about 816 U tubes at the inlet pressure of 12 MPa and mass flux of 200 kg·m-2·s-1. It is concluded that the influence of LNG composition on the thermal performance should be taken into consideration in order to obtain an economic and reliable design of an IFV.

  17. Method for reactivating catalysts and a method for recycling supercritical fluids used to reactivate the catalysts

    Science.gov (United States)

    Ginosar, Daniel M.; Thompson, David N.; Anderson, Raymond P.

    2008-08-05

    A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

  18. The molecular clusters in a supercritical fluid-solid system should be considered as a phase-thermodynamic principle and evidence.

    Science.gov (United States)

    Hou, Minqiang; Zhang, Jianling; Han, Buxing; Mei, Qingqing; Ning, Hui; Yang, Dezhong

    2013-07-14

    In this work we propose a new thermodynamic principle in which a supercritical fluid (SCF)-solid system is divided into a solid phase, a cluster phase, and a bulk fluid phase, i.e., the molecular clusters in the system are considered as an individual phase. The phase equilibria of various SCF-solid systems are calculated using this principle in combination with Monte Carlo simulation and the Peng-Robinson equation of state (PR-EOS). It is shown that in the critical region of the supercritical (SC) solvents where the clustering is significant, the results calculated using this thermodynamic principle are much more consistent with the experimental data than those calculated using the conventional thermodynamic principle, confirming the validity of the principle proposed in this work.

  19. Comparison study of moisture content, colour properties and essential oil compounds extracted by hydrodistillation and supercritical fluid extraction between stem and leaves of lemongrass (Cymbopogun citratus)

    Science.gov (United States)

    Kamaruddin, Shazlin; Mustapha, Wan Aida Wan; Haiyee, Zaibunnisa Abdul

    2018-04-01

    The objectives of this study were to compare the properties of moisture content, colour and essential oil compounds between stem and leaves of lemongrass (Cymbopogun citratus). The essential oil was extracted using two different methods which are hydrodistillation and supercritical fluid extraction (SFE). There was no significant difference of moisture content between stem and leaves of lemongrass. The lightness (L) and yellowness (+b) values of the stems were significantly higher (pleaves. The highest yield of essential oil was obtained by extraction using supercritical fluid extraction (SFE) in leaves (˜ 0.7%) by treatment at 1700psi and 50°C. The main compound of extracted essential oil was citral (geranial and neral).

  20. Direct continuous supercritical fluid extraction as a novel method of wine analysis. Comparison with conventional indirect extraction and implications for wine variety identification

    Czech Academy of Sciences Publication Activity Database

    Karásek, Pavel; Planeta, Josef; Varaďová-Ostrá, Elena; Mikešová, Milena; Goliáš, J.; Roth, Michal; Vejrosta, Jiří

    2003-01-01

    Roč. 1002, 1-2 (2003), s. 13-23 ISSN 0021-9673 R&D Projects: GA ČR GA525/99/1570; GA AV ČR IBS4031110 Institutional research plan: CEZ:AV0Z4031919 Keywords : supercritical fluid extraction * wine analysis * multivariate statistics Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.922, year: 2003

  1. Supercritical fluid extraction (SFE) of ketamine metabolites from dried urine and on-line quantification by supercritical fluid chromatography and single mass detection (on-line SFE-SFC-MS).

    Science.gov (United States)

    Hofstetter, Robert; Fassauer, Georg M; Link, Andreas

    2018-02-15

    On-line solid-phase supercritical fluid extraction (SFE) and chromatography (SFC) coupled to mass spectrometry (MS) has been evaluated for its usefulness with respect to metabolic profiling and pharmacological investigations of ketamine in humans. The aim of this study was to develop and validate a rapid, highly selective and sensitive SFE-SFC-MS method for the quantification of ketamine and its metabolites in miniature amounts in human urine excluding liquid-liquid extraction (LLE). Several conditions were optimized systematically following the requirements of the European Medicines Agency: selectivity, carry-over, calibration curve parameters (LLOQ, range and linearity), within- and between-run accuracy and precision, dilution integrity, matrix effect, and stability. The method, which required a relatively small volume of human urine (20 μL per sample), was validated for pharmacologically and toxicologically relevant concentrations ranging from 25.0 to 1000 ng/mL (r 2  > 0.995). The lower limit of quantification (LLOQ) for all compounds was found to be as low as 0.5 ng. In addition, stability of analytes during removal of water from the urine samples using different conditions (filter paper or ISOLUTE® HM-N) was studied. In conclusion, the method developed in this study can be successfully applied to studies of ketamine metabolites in humans, and may pave the way for routine application of on-line SFE-SFC-MS in clinical investigations. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Casimir amplitudes and capillary condensation of near-critical fluids between parallel plates: renormalized local functional theory.

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2012-03-21

    We investigate the critical behavior of a near-critical fluid confined between two parallel plates in contact with a reservoir by calculating the order parameter profile and the Casimir amplitudes (for the force density and for the grand potential). Our results are applicable to one-component fluids and binary mixtures. We assume that the walls absorb one of the fluid components selectively for binary mixtures. We propose a renormalized local functional theory accounting for the fluctuation effects. Analysis is performed in the plane of the temperature T and the order parameter in the reservoir ψ(∞). Our theory is universal if the physical quantities are scaled appropriately. If the component favored by the walls is slightly poor in the reservoir, there appears a line of first-order phase transition of capillary condensation outside the bulk coexistence curve. The excess adsorption changes discontinuously between condensed and noncondensed states at the transition. With increasing T, the transition line ends at a capillary critical point T=T(c) (ca) slightly lower than the bulk critical temperature T(c) for the upper critical solution temperature. The Casimir amplitudes are larger than their critical point values by 10-100 times at off-critical compositions near the capillary condensation line. © 2012 American Institute of Physics

  3. Method optimization for drug impurity profiling in supercritical fluid chromatography: Application to a pharmaceutical mixture.

    Science.gov (United States)

    Muscat Galea, Charlene; Didion, David; Clicq, David; Mangelings, Debby; Vander Heyden, Yvan

    2017-12-01

    A supercritical chromatographic method for the separation of a drug and its impurities has been developed and optimized applying an experimental design approach and chromatogram simulations. Stationary phase screening was followed by optimization of the modifier and injection solvent composition. A design-of-experiment (DoE) approach was then used to optimize column temperature, back-pressure and the gradient slope simultaneously. Regression models for the retention times and peak widths of all mixture components were built. The factor levels for different grid points were then used to predict the retention times and peak widths of the mixture components using the regression models and the best separation for the worst separated peak pair in the experimental domain was identified. A plot of the minimal resolutions was used to help identifying the factor levels leading to the highest resolution between consecutive peaks. The effects of the DoE factors were visualized in a way that is familiar to the analytical chemist, i.e. by simulating the resulting chromatogram. The mixture of an active ingredient and seven impurities was separated in less than eight minutes. The approach discussed in this paper demonstrates how SFC methods can be developed and optimized efficiently using simple concepts and tools. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Production of polyhydroxyalkanoates from spent coffee grounds oil obtained by supercritical fluid extraction technology.

    Science.gov (United States)

    Cruz, Madalena V; Paiva, Alexandre; Lisboa, Pedro; Freitas, Filomena; Alves, Vítor D; Simões, Pedro; Barreiros, Susana; Reis, Maria A M

    2014-04-01

    Spent coffee grounds (SCG) oil was obtained by supercritical carbon dioxide (scCO2) extraction in a pilot plant apparatus, with an oil extraction yield of 90% at a 35kgkg(-1) CO2/SCG ratio. Cupriavidus necator DSM 428 was cultivated in 2L bioreactor using extracted SCG oil as sole carbon source for production of polyhydroxyalkanoates. The culture reached a cell dry weight of 16.7gL(-1) with a polymer content of 78.4% (w/w). The volumetric polymer productivity and oil yield were 4.7gL(-1)day(-1) and 0.77gg(-1), respectively. The polymer produced was a homopolymer of 3-hydroxybutyrate with an average molecular weight of 2.34×10(5) and a polydispersity index of 1.2. The polymer exhibited brittle behaviour, with very low elongation at break (1.3%), tensile strength at break of 16MPa and Young's Modulus of 1.0GPa. Results show that SCG can be a bioresource for polyhydroxyalkanoates production with interesting properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Green biodiesel production: a review on feedstock, catalyst, monolithic reactor, and supercritical fluid technology

    Directory of Open Access Journals (Sweden)

    Rizo Edwin Gumba

    2016-09-01

    Full Text Available The advancement of alternative energy is primarily catalyzed by the negative environmental impacts and energy depletion caused by the excessive usage of fossil fuels. Biodiesel has emerged as a promising substitute to petrodiesel because it is biodegradable, less toxic, and reduces greenhouse gas emission. Apart from that, biodiesel can be used as blending component or direct replacements for diesel fuel in automotive engines. A diverse range of methods have been reported for the conversion of renewable feedstocks (vegetable oil or animal fat into biodiesel with transesterification being the most preferred method. Nevertheless, the cost of producing biodiesel is higher compared to fossil fuel, thus impeding its commercialization potentials. The limited source of reliable feedstock and the underdeveloped biodiesel production route have prevented the full-scale commercialization of biodiesel in many parts of the world. In a recent development, a new technology that incorporates monoliths as support matrices for enzyme immobilization in supercritical carbon dioxide (SC-CO2 for continuous biodiesel production has been proposed to solve the problem. The potential of SC-CO2 system to be applied in enzymatic reactors is not well documented and hence the purpose of this review is to highlight the previous studies conducted as well as the future direction of this technology.

  6. Simultaneous Modeling of Waveforms Associated With Backscattered He-Ne Laser Light from a Fluid Filled Capillary Tube by Use of Geometrical Optics and Wave Theories

    International Nuclear Information System (INIS)

    Tarigan, Hendra J.

    2008-01-01

    Backscattered He-Ne laser light from a side illuminated fluid-filled fused silica capillary tube generates a series of fringes when viewed in an imaging plane. The light intensity variation as a function of scattering angle constitutes a waveform, which contains hills and valleys. Geometrical Optics and Wave Theories, simultaneously, are employed to model the waveforms and quantify the index of refraction of fluid in the capillary tube.

  7. Cytotoxic Activity of Kenaf Seed Oils from Supercritical Carbon Dioxide Fluid Extraction towards Human Colorectal Cancer (HT29 Cell Lines

    Directory of Open Access Journals (Sweden)

    Siti Aisyah Abd Ghafar

    2013-01-01

    Full Text Available Kenaf (Hibiscus cannabinus from the family Malvaceae, is a valuable fiber plant native to India and Africa and is currently planted as the fourth commercial crop in Malaysia. Kenaf seed oil contains alpha-linolenic acid, phytosterol such as β-sitosterol, vitamin E, and other antioxidants with chemopreventive properties. Kenaf seeds oil (KSO was from supercritical carbon dioxide extraction fluid (SFE at 9 different permutations of parameters based on range of pressures from 200 to 600 bars and temperature from 40 to 80°C. They were 200/40, 200/60, 200/80, 400/40, 400/60, 400/80, 600/40, 600/60, and 600/80. Extraction from 9 parameters of KSO-SFE was screened for cytotoxicity towards human colorectal cancer cell lines (HT29 and mouse embryonic fibroblast (NIH/3T3 cell lines using MTS assay. KSO-SFE at 600/40 showed the strongest cytotoxicity towards HT29 with IC50 of 200 µg/mL. The IC50 for NIH/3T3 was not detected even at highest concentration employed. Cell cycle analysis showed a significant increase in the accumulation of KSO-SFE-treated cells at sub-G1 phase, indicating the induction of apoptosis by KSO-SFE. Further apoptosis induction was confirmed by Annexin V/PI and AO/PI staining.

  8. Fatty acid composition and antioxidant activity of oils from two cultivars of Cantaloupe extracted by supercritical fluid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, M.; Mariod, A.; Bagalkotkar, G.; Ling, H. S

    2010-07-01

    The effect of supercritical fluid extraction (SFE) fractionation of three oil fractions (1st, 2nd, 3rd fraction) on the fatty acid composition and antioxidant activity of oils from two cultivars of cantaloupe were investigated. Rock melon oil (RMO) and Golden Langkawi oil (GLO) were extracted using SFE and the major fatty acids for both cultivars were linoleic, oleic, palmitic, and stearic acid. The SFA decreased from 15.78 to 14.14% in RMO 1st fraction, and MUFA decreased from 18.30 to 16.56% in RMO 2nd fraction, while PUFA increased from 65.9 to 69.30% in RMO 3rd fraction. On the other hand SFA decreased from 16.35 to 13.91% in GLO 1{sup s}t fraction, and MUFA decreased from 17.50 to 15.57% in GLO 2nd fraction, while PUFA increased from 66.15 to 70.52% in GLO 3rd fraction. The different fractions of the two oils showed high antioxidant activity in reducing the oxidation of {beta}-carotene in beta-carotene bleaching assay (BCB) and the quenching of 1,1-diphenyl-2-picrylhydrazyl (DPPH). (Author) 41 refs.

  9. Supercritical Fluid Chromatography of Drugs: Parallel Factor Analysis for Column Testing in a Wide Range of Operational Conditions

    Directory of Open Access Journals (Sweden)

    Ramia Z. Al Bakain

    2017-01-01

    Full Text Available Retention mechanisms involved in supercritical fluid chromatography (SFC are influenced by interdependent parameters (temperature, pressure, chemistry of the mobile phase, and nature of the stationary phase, a complexity which makes the selection of a proper stationary phase for a given separation a challenging step. For the first time in SFC studies, Parallel Factor Analysis (PARAFAC was employed to evaluate the chromatographic behavior of eight different stationary phases in a wide range of chromatographic conditions (temperature, pressure, and gradient elution composition. Design of Experiment was used to optimize experiments involving 14 pharmaceutical compounds present in biological and/or environmental samples and with dissimilar physicochemical properties. The results showed the superiority of PARAFAC for the analysis of the three-way (column × drug × condition data array over unfolding the multiway array to matrices and performing several classical principal component analyses. Thanks to the PARAFAC components, similarity in columns’ function, chromatographic trend of drugs, and correlation between separation conditions could be simply depicted: columns were grouped according to their H-bonding forces, while gradient composition was dominating for condition classification. Also, the number of drugs could be efficiently reduced for columns classification as some of them exhibited a similar behavior, as shown by hierarchical clustering based on PARAFAC components.

  10. Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation.

    Science.gov (United States)

    Franciò, Giancarlo; Hintermair, Ulrich; Leitner, Walter

    2015-12-28

    Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions. © 2015 The Authors.

  11. Supercritical Fluid Chromatography of Drugs: Parallel Factor Analysis for Column Testing in a Wide Range of Operational Conditions

    Science.gov (United States)

    Al-Degs, Yahya; Andri, Bertyl; Thiébaut, Didier; Vial, Jérôme

    2017-01-01

    Retention mechanisms involved in supercritical fluid chromatography (SFC) are influenced by interdependent parameters (temperature, pressure, chemistry of the mobile phase, and nature of the stationary phase), a complexity which makes the selection of a proper stationary phase for a given separation a challenging step. For the first time in SFC studies, Parallel Factor Analysis (PARAFAC) was employed to evaluate the chromatographic behavior of eight different stationary phases in a wide range of chromatographic conditions (temperature, pressure, and gradient elution composition). Design of Experiment was used to optimize experiments involving 14 pharmaceutical compounds present in biological and/or environmental samples and with dissimilar physicochemical properties. The results showed the superiority of PARAFAC for the analysis of the three-way (column × drug × condition) data array over unfolding the multiway array to matrices and performing several classical principal component analyses. Thanks to the PARAFAC components, similarity in columns' function, chromatographic trend of drugs, and correlation between separation conditions could be simply depicted: columns were grouped according to their H-bonding forces, while gradient composition was dominating for condition classification. Also, the number of drugs could be efficiently reduced for columns classification as some of them exhibited a similar behavior, as shown by hierarchical clustering based on PARAFAC components. PMID:28695040

  12. Efficient preparative separation of β-cypermethrin stereoisomers by supercritical fluid chromatography with a two-step combined strategy.

    Science.gov (United States)

    Yan, Yilun; Fan, Jun; Lai, Yecai; He, Jianfeng; Guo, Dong; Zhang, Hui; Zhang, Weiguang

    2017-12-20

    An efficient two-step method has been developed for the separation of β-cypermethrin stereoisomers by supercritical fluid chromatography with polysaccharide chiral stationary phases. With respect to retention, selectivity, and resolution of β-cypermethrin, the effects of chiral stationary phases, cosolvents, mobile phases, and column temperature have been studied in detail. Through a two-step separation, β-cypermethrin was firstly separated by using a cellulose-derived chiral stationary phase to obtain two stereoisomeric pairs, and further resolved on an amylose-based chiral stationary phase to produce four enantiopure stereoisomers. The electronic circular dichroism patterns of the first- and the third-eluted isomers in methanol solution showed the mirror image of each other in the wavelength range 200∼300 nm, indicating that they were a pair of enantiomers. Moreover, the second- and the fourth-eluted isomers were also enantiomers. This proposed two-step strategy showed low solvent consumption, fast separation speed, and high-purity, which may provide an effective approach for preparative separation of compounds with multiple chiral centers and difficult-to-separate multicomponent samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from Syzygium campanulatum Korth#

    Science.gov (United States)

    Memon, Abdul Hakeem; Hamil, Mohammad Shahrul Ridzuan; Laghari, Madeeha; Rithwan, Fahim; Zhari, Salman; Saeed, Mohammed Ali Ahmed; Ismail, Zhari; Majid, Amin Malik Shah Abdul

    2016-01-01

    Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%‒84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%‒66.00%). PMID:27604860

  14. Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation

    Science.gov (United States)

    Franciò, Giancarlo; Hintermair, Ulrich; Leitner, Walter

    2015-01-01

    Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions. PMID:26574523

  15. Characterization of Linum usitatissimum L. oil obtained from different extraction technique and in vitro antioxidant potential of supercritical fluid extract

    Science.gov (United States)

    Chauhan, Rishika; Chester, Karishma; Khan, Yasmeen; Tamboli, Ennus Tajuddin; Ahmad, Sayeed

    2015-01-01

    Aim: Present investigation was aimed to characterize the fixed oil of Linum usitatissimum L. using five different extraction methods: Supercritical fluid extraction (SFE), ultrasound-assistance, soxhlet extraction, solvent extraction, and three phase partitioning method. Materials and Methods: The SFE conditions (temperature, pressure, and volume of CO2) were optimized prior for better yield. The extracted oils were analyzed and compared for their physiochemical parameters, high performance thin layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), and Fourier-transformed infrared spectroscopy (FT-IR) fingerprinting. Antioxidant activity was also determined using 1,1-diphenyl-2-picrylhydrazyl and superoxide scavenging method. Result: The main fatty acids were α-linolenic acid, linoleic acid, palmitic acid, and stearic acid as obtained by GC-MS. HPTLC analysis revealed the presence of similar major components in chromatograms. Similarly, the pattern of peaks, as obtained in FT-IR and GC-MS spectra of same oils by different extraction methods, were superimposable. Conclusion: Analysis reported that the fixed oil of L. usitatissimum L. is a good source of n-3 fatty acid with the significant antioxidant activity of oil obtained from SFE extraction method. PMID:26681884

  16. Characterization of Linum usitatissimum L. oil obtained from different extraction technique and in vitro antioxidant potential of supercritical fluid extract.

    Science.gov (United States)

    Chauhan, Rishika; Chester, Karishma; Khan, Yasmeen; Tamboli, Ennus Tajuddin; Ahmad, Sayeed

    2015-01-01

    Present investigation was aimed to characterize the fixed oil of Linum usitatissimum L. using five different extraction methods: Supercritical fluid extraction (SFE), ultrasound-assistance, soxhlet extraction, solvent extraction, and three phase partitioning method. The SFE conditions (temperature, pressure, and volume of CO2) were optimized prior for better yield. The extracted oils were analyzed and compared for their physiochemical parameters, high performance thin layer chromatography (HPTLC), gas chromatography-mass spectrometry (GC-MS), and Fourier-transformed infrared spectroscopy (FT-IR) fingerprinting. Antioxidant activity was also determined using 1,1-diphenyl-2-picrylhydrazyl and superoxide scavenging method. The main fatty acids were α-linolenic acid, linoleic acid, palmitic acid, and stearic acid as obtained by GC-MS. HPTLC analysis revealed the presence of similar major components in chromatograms. Similarly, the pattern of peaks, as obtained in FT-IR and GC-MS spectra of same oils by different extraction methods, were superimposable. Analysis reported that the fixed oil of L. usitatissimum L. is a good source of n-3 fatty acid with the significant antioxidant activity of oil obtained from SFE extraction method.

  17. Characterization of Linum usitatissimum L. oil obtained from different extraction technique and in vitro antioxidant potential of supercritical fluid extract

    Directory of Open Access Journals (Sweden)

    Rishika Chauhan

    2015-01-01

    Full Text Available Aim: Present investigation was aimed to characterize the fixed oil of Linum usitatissimum L. using five different extraction methods: Supercritical fluid extraction (SFE, ultrasound-assistance, soxhlet extraction, solvent extraction, and three phase partitioning method. Materials and Methods: The SFE conditions (temperature, pressure, and volume of CO2 were optimized prior for better yield. The extracted oils were analyzed and compared for their physiochemical parameters, high performance thin layer chromatography (HPTLC, gas chromatography-mass spectrometry (GC-MS, and Fourier-transformed infrared spectroscopy (FT-IR fingerprinting. Antioxidant activity was also determined using 1,1-diphenyl-2-picrylhydrazyl and superoxide scavenging method. Result: The main fatty acids were α-linolenic acid, linoleic acid, palmitic acid, and stearic acid as obtained by GC-MS. HPTLC analysis revealed the presence of similar major components in chromatograms. Similarly, the pattern of peaks, as obtained in FT-IR and GC-MS spectra of same oils by different extraction methods, were superimposable. Conclusion: Analysis reported that the fixed oil of L. usitatissimum L. is a good source of n-3 fatty acid with the significant antioxidant activity of oil obtained from SFE extraction method.

  18. Preparation of zein nanoparticles by using solution-enhanced dispersion with supercritical CO2 and elucidation with computational fluid dynamics.

    Science.gov (United States)

    Li, Sining; Zhao, Yaping

    2017-01-01

    Nanoparticles have attracted more and more attention in the medicinal field. Zein is a biomacromolecule and can be used as a carrier for delivering active ingredients to prepare controlled release drugs. In this article, we presented the preparation of zein nanoparticles by solution-enhanced dispersion by supercritical CO 2 (SEDS) approach. Scanning electron microscopy and transmission electron microscopy were applied to characterize the size and morphology of the obtained particles. The nozzle structure and the CO 2 flow rate greatly affected the morphology and the size of the particles. The size of zein was able to be reduced to 50-350 nm according to the different conditions. The morphologies of the resultant zein were either sphere or the filament network consisted of nanoparticles. The influence of the nozzle structure and the CO 2 flow rate on the velocity field was elucidated by using computational fluid dynamics. The nozzle structure and the CO 2 flow rate greatly affected the distribution of the velocity field. However, a similar velocity field could also be obtained when the nozzle structure or the CO 2 flow rate, or both were different. Therefore, the influence of the nozzle structure and the CO 2 flow rate on the size and morphology of the particles, can boil down to the velocity field. The results demonstrated that the velocity field can be a potential criterion for producing nanoparticles with controllable morphology and size, which is useful to scale-up the SEDS process.

  19. Optimization and simulation of tandem column supercritical fluid chromatography separations using column back pressure as a unique parameter.

    Science.gov (United States)

    Wang, Chunlei; Tymiak, Adrienne A; Zhang, Yingru

    2014-04-15

    Tandem column supercritical fluid chromatography (SFC) has demonstrated to be a useful technique to resolve complex mixtures by serially coupling two columns of different selectivity. The overall selectivity of a tandem column separation is the retention time weighted average of selectivity from each coupled column. Currently, the method development merely relies on extensive screenings and is often a hit-or-miss process. No attention is paid to independently adjust retention and selectivity contributions from individual columns. In this study, we show how tandem column SFC selectivity can be optimized by changing relative dimensions (length or inner diameter) of the coupled columns. Moreover, we apply column back pressure as a unique parameter for SFC optimization. Continuous tuning of tandem column SFC selectivity is illustrated through column back pressure adjustments of the upstream column, for the first time. In addition, we show how and why changing coupling order of the columns can produce dramatically different separations. Using the empirical mathematical equation derived in our previous study, we also demonstrate a simulation of tandem column separations based on a single retention time measurement on each column. The simulation compares well with experimental results and correctly predicts column order and back pressure effects on the separations. Finally, considerations on instrument and column hardware requirements are discussed.

  20. A superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes with improved solubility and dissolution: Supercritical fluid process

    Directory of Open Access Journals (Sweden)

    Pan Hao

    2017-03-01

    Full Text Available Advantages of the supercritical fluid (SCF process compared to the conventional solution stirring method (CSSM in the preparation of daidzein-hydroxypropyl-β-cyclodextrin (HPβCD complexes were investigated. Formation of daidzein/ HPβCD inclusion complexes was confirmed by Fourier transformed-infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, X-ray diffraction (XRD and scanning electron microscopy (SEM. Particle size, inclusion yield, drug solubility and dissolution of daidzein/HPβCD complexes were evaluated. Compared to CSSM, the SCF process resulted in higher inclusion yield and higher solubility. Also, extended dissolution of daidzein from the SCF processed HPβCD inclusion complexes was observed, with only 22.94 % released in 45 min, compared to its rapid release from those prepared by CSSM, with 98.25 % drug release in 15 min. This extended release of daidzein from SCF prepared inclusion complexes was necessary to avoid drug precipitation and improve drug solubilisation in the gastrointestinal tract. The results showed that the SCF process is a superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes.

  1. Controlling the shape of LiCoPO₄ nanocrystals by supercritical fluid process for enhanced energy storage properties.

    Science.gov (United States)

    Truong, Quang Duc; Devaraju, Murukanahally Kempaiah; Ganbe, Yoshiyuki; Tomai, Takaaki; Honma, Itaru

    2014-02-05

    Lithium-ion batteries offer promising opportunities for novel energy storage systems and future application in hybrid electric vehicles or electric vehicles. Cathode materials with high energy density are required for practical application. Herein, high-voltage LiCoPO4 cathode materials with different shapes and well-developed facets such as nanorods and nanoplates with exposed {010} facets have been synthesized by a one-pot supercritical fluid (SCF) processing. The effect of different amines and their roles on the morphology-control has been investigated in detail. It was found that amine having long alkyl chain such as hexamethylenediamine played important roles to manipulate the shape of the nanocrystals by selective adsorption on the specific {010} facets. More importantly, the nanorods and nanoplates showed better electrochemical performance than that of nanoparticles which was attributed to their unique crystallographic orientation with short Li ion diffusion path. The present study emphasizes the importance of crystallographic orientation in improving the electrochemical performance of the high voltage LiCoPO4 cathode materials for Li-ion batteries.

  2. Quality Parameters of Curcuma Longa L. Extracts by Supercritical Fluid Extraction (SFE) and Ultrasonic Assisted Extraction (UAE)

    International Nuclear Information System (INIS)

    Zaibunnisa Abdul Haiyee; Siti Hafsah Mohd Shah; Khudzir Ismail; Nooraain Hashim; Wan Iryani Wan Ismail

    2016-01-01

    Turmeric is one of the prominently use herbal plants due to its diverse beneficial effects especially in Indian medicine. The rhizome part of the turmeric contains valuable compounds which have been said to owe its antimicrobial effects, anti-cancer, anti-inflammatory and enhance wound healing. Due to its short-life span and perishable properties, the conversion of the rhizome into turmeric extract is desirable. Several methods have been used for extraction such as Soxhlet extraction and pressurized liquid extraction (PLE). However, these techniques are tedious, laborious, time consuming and involves the usage of toxic organic solvent, of which safeness of the end product is doubtful. In this study, a rapid, reliable and green extraction method of supercritical fluid extraction (SFE) and ultrasonic assisted extraction (UAE) were used. SFE without modifier has resulted in 0.0006 mg/ 100 g of curcuminoids concentration and 5.62 % of yield (dry weight basis). UAE using ethanol was able to produce significantly the highest yield (6.40 %, dry weight basis) and the highest curcuminoids concentration (0.1020 mg/ 100 g). However, SFE was able to produce extract that contain significantly higher major volatile compounds; tumerone, ar-turmerone and curlone. Therefore, this study proves that both extraction methods were able to produce high quality turmeric extract. (author)

  3. Enhanced Thermal Conductivity of Graphene Nanoplatelet-Polymer Nanocomposites Fabricated via Supercritical Fluid-Assisted in Situ Exfoliation.

    Science.gov (United States)

    Hamidinejad, S Mahdi; Chu, Raymond K M; Zhao, Biao; Park, Chul B; Filleter, Tobin

    2018-01-10

    As electronic devices become increasingly miniaturized, their thermal management becomes critical. Efficient heat dissipation guarantees their optimal performance and service life. Graphene nanoplatelets (GnPs) have excellent thermal properties that show promise for use in fabricating commercial polymer nanocomposites with high thermal conductivity. Herein, an industrially viable technique for manufacturing a new class of lightweight GnP-polymer nanocomposites with high thermal conductivity is presented. Using this method, GnP-high-density polyethylene (HDPE) nanocomposites with a microcellular structure are fabricated by melt mixing, which is followed by supercritical fluid (SCF) treatment and injection molding foaming, which adds an extra layer of design flexibility. Thus, the microstructure is tailored within the nanocomposites and this improves their thermal conductivity. Therefore, the SCF-treated HDPE 17.6 vol % GnP microcellular nanocomposites have a solid-phase thermal conductivity of 4.13 ± 0.12 W m -1 K -1 . This value far exceeds that of their regular injection-molded counterparts (2.09 ± 0.03 W m -1 K -1 ) and those reported in the literature. This dramatic improvement results from in situ GnPs' exfoliation and dispersion, and from an elevated level of random orientation and interconnectivity. Thus, this technique provides a novel approach to the development of microscopically tailored structures for the production of lighter and more thermally conductive heat sinks for next generations of miniaturized electronic devices.

  4. Application of ultra-high performance supercritical fluid chromatography for the determination of carotenoids in dietary supplements.

    Science.gov (United States)

    Li, Bing; Zhao, Haiyan; Liu, Jing; Liu, Wei; Fan, Sai; Wu, Guohua; Zhao, Rong

    2015-12-18

    A quick and simple ultra-high performance supercritical fluid chromatography-photodiode array detector method was developed and validated for the simultaneous determination of 9 carotenoids in dietary supplements. The influences of stationary phase, co-solvent, pressure, temperature and flow rate on the separation of carotenoids were evaluated. The separation of the carotenoids was carried out using an Acquity UPC(2) HSS C18 SB column (150mm×3.0mm, 1.8μm) by gradient elution with carbon dioxide and a 1:2 (v:v) methanol/ethanol mixture. The column temperature was set to 35°C and the backpressure was 15.2MPa. Under these conditions, 9 carotenoids and the internal standard, β-apo-8'-carotenal, were successfully separated within 10min. The correlation coefficients (R(2)) of the calibration curves were all above 0.997, the limits of detection for the 9 carotenoids were in the range of 0.33-1.08μg/mL, and the limits of quantification were in the range of 1.09-3.58μg/mL. The mean recoveries were from 93.4% to 109.5% at different spiking levels, and the relative standard deviations were between 0.8% and 6.0%. This method was successfully applied to the determination of 9 carotenoids in commercial dietary supplements. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Characterization of immiscible fluid displacement processes with various capillary numbers and viscosity ratios in 3D natural sandstone

    Science.gov (United States)

    Tsuji, Takeshi; Jiang, Fei; Christensen, Kenneth T.

    2016-09-01

    To characterize the influence of reservoir conditions upon multiphase flow, we calculated fluid displacements (drainage processes) in 3D pore spaces of Berea sandstone using two-phase lattice Boltzmann (LB) simulations. The results of simulations under various conditions were used to classify the resulting two-phase flow behavior into three typical fluid displacement patterns on the diagram of capillary number (Ca) and viscosity ratio of the two fluids (M). In addition, the saturation of the nonwetting phase was calculated and mapped on the Ca-M diagram. We then characterized dynamic pore-filling events (i.e., Haines jumps) from the pressure variation of the nonwetting phase, and linked this behavior to the occurrence of capillary fingering. The results revealed the onset of capillary fingering in 3D natural rock at a higher Ca than in 2D homogeneous granular models, with the crossover region between typical displacement patterns broader than in the homogeneous granular model. Furthermore, saturation of the nonwetting phase mapped on the Ca-M diagram significantly depends on the rock models. These important differences between two-phase flow in 3D natural rock and in 2D homogeneous models could be due to the heterogeneity of pore geometry in the natural rock and differences in pore connectivity. By quantifying two-phase fluid behavior in the target reservoir rock under various conditions (e.g., saturation mapping on the Ca-M diagram), our approach could provide useful information for investigating suitable reservoir conditions for geo-fluid management (e.g., high CO2 saturation in CO2 storage).

  6. Supercritical fuel injection system

    Science.gov (United States)

    Marek, C. J.; Cooper, L. P. (Inventor)

    1980-01-01

    a fuel injection system for gas turbines is described including a pair of high pressure pumps. The pumps provide fuel and a carrier fluid such as air at pressures above the critical pressure of the fuel. A supercritical mixing chamber mixes the fuel and carrier fluid and the mixture is sprayed into a combustion chamber. The use of fuel and a carrier fluid at supercritical pressures promotes rapid mixing of the fuel in the combustion chamber so as to reduce the formation of pollutants and promote cleaner burning.

  7. Optimization of supercritical fluid extraction of essential oils and fatty acids from flixweed (Descurainia Sophia L.) seed using response surface methodology and central composite design.

    Science.gov (United States)

    Ara, Katayoun Mahdavi; Jowkarderis, Mina; Raofie, Farhad

    2015-07-01

    Essential oils and fatty acids of Descurainia sophia L. seed were obtained by supercritical CO2 extraction and steam distillation methods. The effect of different parameters such as pressure, temperature, modifier volume, dynamic and static extraction timeon the extraction yield were optimized using a central composite design after a 2 (n-1) fractional factorial design. The results showed that under the pressure of 355 bar, temperature of 65 °C, methanol volume of 150 μL, dynamic and static extraction times of 35 and 10 min, respectively, the major components were methyl linoleate (18.2 %), camphor (12.32 %), cis-thujone (11.3 %) and trans-caryophyllene (9.17 %). The results indicated that by using the proper conditions, the supercritical fluid extraction is more selective than the steam distillation method. Extraction yields based on supercritical fluid extraction varied in the range of 0.68 to 17.1 % (w/w), and the extraction yield based on the steam distillation was 0.25 % (v/w).

  8. Simultaneous analysis for water- and fat-soluble vitamins by a novel single chromatography technique unifying supercritical fluid chromatography and liquid chromatography.

    Science.gov (United States)

    Taguchi, Kaori; Fukusaki, Eiichiro; Bamba, Takeshi

    2014-10-03

    Chromatography techniques usually use a single state in the mobile phase, such as liquid, gas, or supercritical fluid. Chromatographers manage one of these techniques for their purpose but are sometimes required to use multiple methods, or even worse, multiple techniques when the target compounds have a wide range of chemical properties. To overcome this challenge, we developed a single method covering a diverse compound range by means of a "unified" chromatography which completely bridges supercritical fluid chromatography and liquid chromatography. In our method, the phase state was continuously changed in the following order; supercritical, subcritical and liquid. Moreover, the gradient of the mobile phase starting at almost 100% CO2 was replaced with 100% methanol at the end completely. As a result, this approach achieved further extension of the polarity range of the mobile phase in a single run, and successfully enabled the simultaneous analysis of fat- and water-soluble vitamins with a wide logP range of -2.11 to 10.12. Furthermore, the 17 vitamins were exceptionally separated in 4min. Our results indicated that the use of dense CO2 and the replacement of CO2 by methanol are practical approaches in unified chromatography covering diverse compounds. Additionally, this is a first report to apply the novel approach to unified chromatography, and can open another door for diverse compound analysis in a single chromatographic technique with single injection, single column and single system. Copyright © 2014. Published by Elsevier B.V.

  9. Organic Fluids and Passive Cooling in a Supercritical Rankine Cycle for Power Generation from Low Grade Heat Sources

    Science.gov (United States)

    Vidhi, Rachana

    Low grade heat sources have a large amount of thermal energy content. Due to low temperature, the conventional power generation technologies result in lower efficiency and hence cannot be used. In order to efficiently generate power, alternate methods need to be used. In this study, a supercritical organic Rankine cycle was used for heat source temperatures varying from 125°C to 200°C. Organic refrigerants with zero ozone depletion potential and their mixtures were selected as working fluid for this study while the cooling water temperature was changed from 10-25°C. Operating pressure of the cycle has been optimized for each fluid at every heat source temperature to obtain the highest thermal efficiency. Energy and exergy efficiencies of the thermodynamic cycle have been obtained as a function of heat source temperature. Efficiency of a thermodynamic cycle depends significantly on the sink temperature. At areas where water cooling is not available and ambient air temperature is high, efficient power generation from low grade heat sources may be a challenge. Use of passive cooling systems coupled with the condenser was studied, so that lower sink temperatures could be obtained. Underground tunnels, buried at a depth of few meters, were used as earth-air-heat-exchanger (EAHE) through which hot ambient air was passed. It was observed that the air temperature could be lowered by 5-10°C in the EAHE. Vertical pipes were used to lower the temperature of water by 5°C by passing it underground. Nocturnal cooling of stored water has been studied that can be used to cool the working fluid in the thermodynamic cycle. It was observed that the water temperature can be lowered by 10-20°C during the night when it is allowed to cool. The amount of water lost was calculated and was found to be approximately 0.1% over 10 days. The different passive cooling systems were studied separately and their effects on the efficiency of the thermodynamic cycle were investigated. They were

  10. Development of Nordic Standard for analysis of oil and fat in water based on supercritical fluid extraction. Preliminary study, part 2

    International Nuclear Information System (INIS)

    Jenssen, L.

    1994-06-01

    This report describes a preliminary study of a method of determining oil in water. The method is based on solid phase extraction and supercritical fluid extraction (SPE-SFE). The oil is extracted from the water by absorption to extraction disks from which it is then desorbed by supercritical carbon dioxide and detected by means of infrared spectrophotometry or gas chromatography. The results of the study will indicate if the method is suitable as a future substitute for the present Norwegian Standard, NS 9803 (Swedish Standard, SS 02 8145). The method has been validated using water samples with addition of real oil to 1-100 ppm. The accuracy is almost 70%, and the method has good repeatability and is linear in the 1-100 ppm range. 5 refs., 6 figs., 10 tabs

  11. Combined analysis by GC (RI), GC-MS and 13C NMR of the supercritical fluid extract of Abies alba twigs.

    Science.gov (United States)

    Duquesnoy, Emilie; Marongiu, Bruno; Castola, Vincent; Piras, Alessandra; Porcedda, Silvia; Casanova, Joseph

    2010-12-01

    Two samples (leaves and twigs) of Abies alba Miller from Corsica were extracted using supercritical CO2 and their chemical compositions were compared with those of the essential oils obtained from the same batch of plant material. In total 45 components were identified using combined analysis by GC (RI), GC-MS and 13C NMR. It was observed that the contents of monoterpenes (mainly represented by limonene, alpha-pinene and camphene) were significantly lower in the supercritical fluid extract (SFE) than in the essential oil (EO). Conversely, the proportions of sesquiterpenes were much higher in CO2 extracts than in essential oils (around 30% vs 4%). Cis-abienol, a diterpene alcohol, was identified only in SFE, and the proportions of this constituent (7.5% and 17.3%) were determined using quantitative 13C NMR since it was under estimated using the standard conditions of GC.

  12. The influence of different diffusion pattern to the sub- and super-critical fluid flow in brown coal

    Science.gov (United States)

    Peng, Peihuo

    2018-03-01

    Sub- and super-critical CO2 flowing in nanoscale pores are recently becoming of great interest due to that it is closely related to many engineering applications, such as geological burial and sequestration of carbon dioxide, Enhanced Coal Bed Methane recovery ( ECBM), super-critical CO2 fracturing and so on. Gas flow in nanopores cannot be described simply by the Darcy equation. Different diffusion pattern such as Fick diffusion, Knudsen diffusion, transitional diffusion and slip flow at the solid matrix separate the seepage behaviour from Darcy-type flow. According to the principle of different diffusion pattern, the flow of sub- and super-critical CO2 in brown coal was simulated by numerical method, and the results were compared with the experimental results to explore the contribution of different diffusion pattern and swelling effect in sub- and super-critical CO2 flow in nanoscale pores.

  13. Selective extraction of hydrocarbons, phosphonates and phosphonic acids from soils by successive supercritical fluid and pressurized liquid extractions.

    Science.gov (United States)

    Chaudot, X; Tambuté, A; Caude, M

    2000-01-14

    Hydrocarbons, dialkyl alkylphosphonates and alkyl alkylphosphonic acids are selectively extracted from spiked soils by successive implementation of supercritical carbon dioxide, supercritical methanol-modified carbon dioxide and pressurized water. More than 95% of hydrocarbons are extracted during the first step (pure supercritical carbon dioxide extraction) whereas no organophosphorus compound is evidenced in this first extract. A quantitative extraction of phosphonates is achieved during the second step (methanol-modified supercritical carbon dioxide extraction). Polar phosphonic acids are extracted during a third step (pressurized water extraction) and analyzed by gas chromatography under methylated derivatives (diazomethane derivatization). Global recoveries for these compounds are close to 80%, a loss of about 20% occurring during the derivatization process (co-evaporation with solvent). The developed selective extraction method was successfully applied to a soil sample during an international collaborative exercise.

  14. Capillary electrophoresis of free amino acids in physiological fluids without derivatization employing direct or indirect absorbance detection.

    Science.gov (United States)

    Zunić, Gordana D; Spasić, Slavica; Jelić-Ivanović, Zorana

    2012-01-01

    Whole blood and/or plasma amino acids are useful for monitoring whole body protein and amino acid metabolism in an organism under various physiological and pathophysiological conditions. Various methodological procedures are in use for their measurement in biological fluids. From the time when capillary electrophoresis was introduced as a technology offering rapid separation of various ionic and/or ionizable compounds with low sample and solvent consumption, there were many attempts to use it for the measurement of amino acids present in physiological fluids. As a rule, these methods require derivatization procedures for detection purposes.Here, we present two protocols for the analysis of free amino acids employing free zone capillary electrophoresis. Main advantage of both methods is an absence of any derivatization procedures that permits the analysis of free amino acid in physiological fluids. The method using direct detection and carrier electrolyte consisting of disodium monophosphate (10 mM at pH 2.90) permits determination of compounds that absorb in UV region (aromatic and sulfur containing amino acids, as well as some peptides, such as carnosine, reduced and oxidized glutathione). The other method uses indirect absorbance detection, employing 8 mM p-amino salicylic acid buffered with sodium carbonate at pH 10.2 as running electrolyte. It permits quantification of 30 underivatized physiological amino acids and peptides. In our experience, factorial design represents a useful tool for final optimization of the electrophoretic conditions if it is necessary.

  15. The differences in matrix effect between supercritical fluid chromatography and reversed phase liquid chromatography coupled to ESI/MS.

    Science.gov (United States)

    Svan, Alfred; Hedeland, Mikael; Arvidsson, Torbjörn; Pettersson, Curt E

    2018-02-13

    For many sample matrices, matrix effects are a troublesome phenomenon using the electrospray ionization source. The increasing use of supercritical fluid chromatography with CO 2 in combination with the electrospray ionization source for MS detection is therefore raising questions: is the matrix effect behaving differently using SFC in comparison with reversed phase LC? This was investigated using urine, plasma, influent- and effluent-wastewater as sample matrices. The matrix effect was evaluated using the post-extraction addition method and through post-column infusions. Matrix effect profiles generated from the post-column infusions in combination with time of flight-MS detection provided the most valuable information for the study. The combination of both qualitative and semi-quantitative information with the ability to use HRMS-data for identifying interfering compounds from the same experiment was very useful, and has to the authors' knowledge not been used this way before. The results showed that both LC and SFC are affected by matrix effects, however differently depending on sample matrix. Generally, both suppressions and enhancements were seen, with a higher amount of enhancements for LC, where 65% of all compounds and all sample matrices were enhanced, compared to only 7% for SFC. Several interferences were tentatively identified, with phospholipids, creatinine, and metal ion clusters as examples of important interferences, with different impact depending on chromatographic technique. SFC needs a different strategy for limiting matrix interferences, owing to its almost reverse retention order compared to RPLC. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods.

    Science.gov (United States)

    Lísa, Miroslav; Cífková, Eva; Khalikova, Maria; Ovčačíková, Magdaléna; Holčapek, Michal

    2017-11-24

    Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements

  17. Ammonia as a preferred additive in chiral and achiral applications of supercritical fluid chromatography for small, drug-like molecules.

    Science.gov (United States)

    Ventura, Manuel; Murphy, Brent; Goetzinger, Wolfgang

    2012-01-13

    Supercritical fluid chromatography is routinely utilized by analytical separations groups in the pharmaceutical industry to efficiently handle separations for discovery medicinal chemistry purposes. Purifications are performed on samples ranging from a few milligrams up to hundreds of grams. Basic additives dissolved into the liquid component of the SFC mobile phase are commonly used to improve peak shape and efficiency in achiral and chiral separations. While for purposes of analysis there is minimal consequence to additive introduction in the mobile phase, for preparative separations one needs to consider the potential effect of an additive's presence when concentrated with the desired compound. Following an SFC purification using an additive-containing modifier, the resulting fractions will contain an easily evaporated modifier, and after its evaporation perhaps still significant levels of the less volatile additive. Depending on the aqueous solubility and basicity of the final product, the process of removing basic amine additives can be time-consuming and can result in reduced yields. NMR analysis following preparative isolation and evaporation often reveals the fact of insufficient removal of the chromatographic additive even after aqueous work up steps. In this study, ammonia is evaluated as an alternative additive to strong bases such as diethylamine (DEA) in SFC purification and analysis and to the authors' knowledge no previous publication has been written describing the application of methanolic ammonia as an additive for SFC separations. Dimethylethylamine (DMEA), a more volatile additive than DEA, is also evaluated relative to ammonia for its potential to simplify the isolation process after purification and in terms of chromatographic performance. The loss in concentration of ammonia in methanol modifier over time due to evaporation and effects of that loss are also described. Furthermore, for ammonia the analytical benefit is shown to extend to on

  18. Turbo-alternator-compressor design for supercritical high density working fluids

    Science.gov (United States)

    Wright, Steven A.; Fuller, Robert L.

    2013-03-19

    Techniques for generating power are provided. Such techniques involve a thermodynamic system including a housing, a turbine positioned in a turbine cavity of the housing, a compressor positioned in a compressor cavity of the housing, and an alternator positioned in a rotor cavity between the turbine and compressor cavities. The compressor has a high-pressure face facing an inlet of the compressor cavity and a low-pressure face on an opposite side thereof. The alternator has a rotor shaft operatively connected to the turbine and compressor, and is supported in the housing by bearings. Ridges extending from the low-pressure face of the compressor may be provided for balancing thrust across the compressor. Seals may be positioned about the alternator for selectively leaking fluid into the rotor cavity to reduce the temperature therein.

  19. Seal assembly with anti-rotation pin for high pressure supercritical fluids

    Science.gov (United States)

    Wright, Steven A.; Fuller, Robert L.

    2014-08-05

    A seal assembly for sealing a machine with a first chamber and a second chamber is provided. A rotating shaft extends through the first and second chambers, and rotates therein. The seal assembly has a seal housing, a seal ring and a seal pin. The seal housing is positionable in the machine housing. The seal housing has a seal pocket extending into a fluid side thereof, and a housing receptacle extending into an inner diameter thereof at the seal pocket. The seal ring is positionable in the seal pocket of the seal housing for forming a seal therewith. The seal ring has a ring receptacle extending into an outer diameter thereof. The ring receptacle is positionable adjacent to the housing receptacle for defining a pin hole therebetween. The seal pin is loosely positionable in the pin hole whereby movement about the seal ring is accommodated while preventing rotation thereof.

  20. Solute partitioning between the ionic liquid 1-n-butyl-3-methylimidazolium tetrafluoroborate and supercritical CO.sub.2./sub. from capillary-column chromatography

    Czech Academy of Sciences Publication Activity Database

    Planeta, Josef; Roth, Michal

    2005-01-01

    Roč. 109, č. 31 (2005), s. 15165-15171 ISSN 1520-6106 R&D Projects: GA AV ČR(CZ) KJB400310504 Institutional research plan: CEZ:AV0Z40310501 Keywords : ionic liquid - supercritical CO2 system * solute partition coefficient * linear solvation energy relationship Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.033, year: 2005

  1. Thermal regulation in terrestrial environment using a two-phase fluid loop with capillary pumping; Regulation thermique en environnement terrestre par boucle fluide diphasique a pompage capillaire

    Energy Technology Data Exchange (ETDEWEB)

    Butto, C. [Universite Paul Sabatier, LESETH, 31 - Toulouse (France)

    1996-12-31

    Two-phase fluid loops with capillary pumping are particularly interesting silent devices which allow energy savings and do not create any noise pollution (no mechanical vibrations). In terrestrial environment, the gravity field, when judiciously used, allows to improve their performances and thus, their use in thermal regulation of big computers, power electronic components, transformers, etc, is particularly interesting. In this study, the main results concerning the functioning of such a loop in the gravity field are presented and used to highlight the conditions that allow to take advantage of this field and the improvements obtained. (J.S.) 5 refs.

  2. A fast and sensitive method for the separation of carotenoids using ultra-high performance supercritical fluid chromatography-mass spectrometry.

    Science.gov (United States)

    Jumaah, Firas; Plaza, Merichel; Abrahamsson, Victor; Turner, Charlotta; Sandahl, Margareta

    2016-08-01

    In this study, a rapid and sensitive ultra-high performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS) method has been developed and partially validated for the separation of carotenoids within less than 6 min. Six columns of orthogonal selectivity were examined, and the best separation was obtained by using a 1-aminoanthracene (1-AA) column. The length of polyene chain as well as the number of hydroxyl groups in the structure of the studied carotenoids determines their differences in the physiochemical properties and thus the separation that is achieved on this column. All of the investigated carotenoids were baseline separated with resolution values greater than 1.5. The effects of gradient program, back pressure, and column temperature were studied with respect to chromatographic properties such as retention and selectivity. Electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were compared in both positive and negative mode, using both direct infusion and hyphenated with UHPSFC. The ESI in positive mode provided the highest response. The coefficient of determination (R (2)) for all calibration curves were greater than 0.998. Limit of detection (LOD) was in the range of 2.6 and 25.2 ng/mL for α-carotene and astaxanthin, respectively, whereas limit of quantification (LOQ) was in the range of 7.8 and 58.0 ng/mL for α-carotene and astaxanthin, respectively. Repeatability and intermediate precision of the developed UHPSFC-MS method were determined and found to be RSD carotenoids in supercritical fluid extracts of microalgae and rosehip. Graphical Abstract Ultra-high performance supercritical fluid chromatography-a rapid separation method for the analysis of carotenoids in rosehip and microalgae samples.

  3. Effects of spatial gradients in thermophysical properties on the topology of turbulence in heated channel flow of supercritical fluids

    Science.gov (United States)

    Azih, Chukwudi; Yaras, Metin I.

    2018-01-01

    The current literature suggests that large spatial gradients of thermophysical properties, which occur in the vicinity of the pseudo-critical thermodynamic state, may result in significant variations in forced-convection heat transfer rates. Specifically, these property gradients induce inertia- and buoyancy-driven phenomena that may enhance or deteriorate the turbulence-dominated heat convection process. Through direct numerical simulations, the present study investigates the role of coherent flow structures in channel geometries for non-buoyant and buoyant flows of supercritical water, with buoyant configurations involving wall-normal oriented gravitational acceleration and downstream-oriented gravitational acceleration. This sequence of simulations enables the evaluation of the relative contributions of inertial and buoyancy phenomena to heat transfer variations. In these simulations, the state of the working fluid is in the vicinity of the pseudo-critical point. The uniform wall heat flux and the channel mass flux are specified such that the heat to mass flux ratio is 3 kJ/kg, with an inflow Reynolds number of 12 000 based on the channel hydraulic diameter, the area-averaged inflow velocity, and fluid properties evaluated at the bulk temperature and pressure of the inflow plane. In the absence of buoyancy forces, notable reductions in the density and viscosity in close proximity of the heated wall are observed to promote generation of small-scale vortices, with resultant breakdown into smaller scales as they interact with preexisting larger near-wall vortices. This interaction results in a reduction in the overall thermal mixing at particular wall-normal regions of the channel. Under the influence of wall-normal gravitational acceleration, the wall-normal density gradients are noted to enhance ejection motions due to baroclinic vorticity generation on the lower wall, thus providing additional wall-normal thermal mixing. Along the upper wall, the same mechanism

  4. Numerical analysis of refrigerant flow along non-adiabatic capillary tubes using a two-fluid model

    Energy Technology Data Exchange (ETDEWEB)

    Seixlack, A.L. [Department of Mechanical Engineering, Sao Paulo State University, 15385-000 Ilha Solteira, SP (Brazil)], E-mail: andre@dem.feis.unesp.br; Barbazelli, M.R. [Department of Mechanical Engineering, Sao Paulo State University, 15385-000 Ilha Solteira, SP (Brazil)

    2009-02-15

    This work presents a numerical model to simulate steady state refrigerant flow along capillary tube-suction line heat exchangers, commonly used in small refrigeration systems. The flow along the straight and horizontal capillary tube is divided into two regions: a single-phase and a two-phase flow region. The flow is taken as one-dimensional and the metastable flow phenomenon is neglected. The two-fluid model is employed for the two-phase flow region, considering the hydrodynamic and the thermodynamic non-equilibrium between the liquid and vapor phases. Comparisons are made with experimental measurements of the mass flow rate and temperature distribution along capillary tube-suction line heat exchangers working with refrigerant R134a in different operating conditions. The results indicate that the present model provides a good estimation of the refrigerant mass flow rate. Moreover, comparisons with a homogeneous model are also made. Some computational results referring to the quality, void fraction and velocities of each phase are also presented and discussed.

  5. Supercritical Synthesis of Biodiesel

    Directory of Open Access Journals (Sweden)

    Michel Vaultier

    2012-07-01

    Full Text Available The synthesis of biodiesel fuel from lipids (vegetable oils and animal fats has gained in importance as a possible source of renewable non-fossil energy in an attempt to reduce our dependence on petroleum-based fuels. The catalytic processes commonly used for the production of biodiesel fuel present a series of limitations and drawbacks, among them the high energy consumption required for complex purification operations and undesirable side reactions. Supercritical fluid (SCF technologies offer an interesting alternative to conventional processes for preparing biodiesel. This review highlights the advances, advantages, drawbacks and new tendencies involved in the use of supercritical fluids (SCFs for biodiesel synthesis.

  6. Research Update: Nickel filling in nanofeatures using supercritical fluid and its application to fabricating a novel catalyst structure for continuous growth of nanocarbon fibers

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Watanabe

    2014-10-01

    Full Text Available A novel catalyst structure for continuous growth of nanocarbon fibers is proposed. In this structure, catalyst nanofibers are embedded in a membrane that separates the growth ambient into carbon-supplying and carbon-precipitating environments. The catalyst nanofibers pierce through the membrane so that carbon source gas is supplied only to one end of the catalyst fibers and nanocarbon fibers grow continuously at the other end. To realize this structure, self-supporting anodized alumina was used as a membrane, and its nano-through-holes were filled with catalyst Ni in supercritical CO2 fluid. Direct carbon growth from the Ni nanofibers was confirmed using this catalyst structure.

  7. Dynamic generation of supercritical water fluid in a strong electrical discharge in a liquid

    Science.gov (United States)

    Antonov, V.; Kalinin, N.; Kovalenko, A.

    2016-11-01

    A new impetus for the development of electro physics is associated with using different types of electrical discharges in biology and medicine. These applications are based on their energetic and non-toxic factors affecting the medium on a cellular level. For the study of such processes, a mathematical model of a high-current low-temperature Z-discharge in a liquid, forming by the electrical explosion of a thin-walled metal shell, connected to a pulsed high-voltage generator, has been developed. High efficiency energy conversion, introduced into the plasma discharge to the energy of fluid motion, provides various bio chemical applications of such physical processes. The investigation is conducted through numerical solution of one-dimensional single-temperature non-stationary equations of radiation magneto hydrodynamics, one way describing the evolution of hydrodynamic, thermal and electrical characteristics of the medium throughout the area under consideration. The electrical approximation based on the assumption that the electric field in the discharge has a uniform distribution. The results are presented as a function of the electric current and the plasma channel length of time, as well as the temperature and pressure distributions at different time points along the radius of the cylindrical region in which the explosion occurs.

  8. Instability of a shear layer between multicomponent fluids at supercritical pressure

    Science.gov (United States)

    Fu, Qing-fei; Zhang, Yun-xiao; Mo, Chao-jie; Yang, Li-jun

    2018-04-01

    The temporal instability of a thin shear layer lying between streams of two components of fluids has been studied. The effects of density profile of the layer on the instability behavior were mainly considered. The detailed density profile was obtained through Linear Gradient Theory. The eigenvalue problem was calculated, and the temporal instability curves were obtained for the thermodynamic parameters, e.g. pressure and temperature. The results show that, increase of pressure leads to the increase of the maximum growth rate. However, increasing pressure has opposite effects on the disturbances with small and large wave length. The increase of temperature causes the decrease of disturbance growth rate. The instability behavior of the shear layers was determined mainly by the interval between the inflections of the velocity and density profiles, and the maximum density gradient. The total effects, determined by coupling density stratification, and interval between the inflections of the velocity and density profiles, were quite distinct for different ranges of temperature and pressure.

  9. Adiabatic packed column supercritical fluid chromatography using a dual-zone still-air column heater.

    Science.gov (United States)

    Helmueller, Shawn C; Poe, Donald P; Kaczmarski, Krzysztof

    2018-02-02

    An approach to conducting SFC separations under pseudo-adiabatic condition utilizing a dual-zone column heater is described. The heater allows for efficient separations at low pressures above the critical temperature by imposing a temperature profile along the column wall that closely matches that for isenthalpic expansion of the fluid inside the column. As a result, the efficiency loss associated with the formation of radial temperature gradients in this difficult region can be largely avoided in packed analytical scale columns. For elution of n-octadecylbenzene at 60 °C with 5% methanol modifier and a flow rate of 3 mL/min, a 250 × 4.6-mm column packed with 5-micron Kinetex C18 particles began to lose efficiency (8% decrease in the number of theoretical plates) at outlet pressures below 142 bar in a traditional forced air oven. The corresponding outlet pressure for onset of excess efficiency loss was decreased to 121 bar when the column was operated in a commercial HPLC column heater, and to 104 bar in the new dual-zone heater operated in adiabatic mode, with corresponding increases in the retention factor for n-octadecylbenzene from 2.9 to 6.8 and 14, respectively. This approach allows for increased retention and efficient separations of otherwise weakly retained analytes. Applications are described for rapid SFC separation of an alkylbenzene mixture using a pressure ramp, and isobaric separation of a cannabinoid mixture. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Ultra-high performance supercritical fluid chromatography-mass spectrometry procedure for analysis of monosaccharides from plant gum binders.

    Science.gov (United States)

    Pauk, Volodymyr; Pluháček, Tomáš; Havlíček, Vladimír; Lemr, Karel

    2017-10-09

    The ultra-high performance supercritical fluid chromatography-mass spectrometry (UHPSFC/MS) procedure for analysis of native monosaccharides was developed. Chromatographic conditions were investigated to separate a mixture of four hexoses, three pentoses, two deoxyhexoses and two uronic acids. Increasing water content in methanol modifier to 5% and formic acid to 4% improved peak shapes of neutral monosaccharides and allowed complete elution of highly polar uronic acids in a single run. An Acquity HSS C18SB column outperformed other three tested stationary phases (BEH (silica), BEH 2-ethylpyridine, CSH Fluoro-Phenyl) in terms of separation of isomers and analysis time (4.5 min). Limits of detection were in the range 0.01-0.12 ng μL -1 . Owing to separation of anomers, identification of critical pairs (arabinose-xylose and glucose-galactose) was possible. Feasibility of the new method was demonstrated on plant-derived polysaccharide binders. Samples of watercolor paints, painted paper and three plant gums widely encountered in painting media (Arabic, cherry and tragacanth) were decomposed prior the analysis by microwave-assisted hydrolysis at 40 bar initial pressure using 2 mol L -1 trifluoroacetic acid. Among tested temperatures, 120 °C ensured appropriate hydrolysis efficiency for different types of gum and avoided excessive degradation of labile monosaccharides. Procedure recovery tested on gum Arabic was 101% with an RSD below 8%. Aqueous hydrolysates containing monosaccharides in different ratios specific to each type of plant gum were diluted or analyzed directly. Filtration of samples before hydrolysis reduced interferences from a paper support and identification of gum Arabic in watercolor-painted paper samples was demonstrated. Successful identification of pure gum Arabic was confirmed for sample quantities as little as 1 μg. Two classification approaches were compared and principal component analysis was superior to analysis based on peak area

  11. A new method based on supercritical fluid extraction for polyacetylenes and polyenes from Echinacea pallida (Nutt.) Nutt. roots.

    Science.gov (United States)

    Tacchini, Massimo; Spagnoletti, Antonella; Brighenti, Virginia; Prencipe, Francesco Pio; Benvenuti, Stefania; Sacchetti, Gianni; Pellati, Federica

    2017-11-30

    The genus Echinacea (Asteraceae) includes species traditionally used in phytotherapy. Among them, Echinacea pallida (Nutt.) Nutt. root extracts are characterized by a representative antiproliferative activity, due to the presence of acetylenic compounds. In this study, supercritical fluid extraction (SFE) was applied and compared with conventional Soxhlet extraction (SE) in order to obtain a bioactive extract highly rich in polyacetylenes and polyenes from E. pallida roots. The composition of the extracts was monitored by means of HPLC-UV/DAD and HPLC-ESI-MS n by using an Ascentis Express C 18 column (150mm×3.0mm I.D., 2.7μm, Supelco, Bellefonte, PA, USA) with a mobile phase composed of (A) water and (B) acetonitrile, under gradient elution. By keeping SFE time at the threshold of 1h (15min static and 45min dynamic for 1 cycle) with the oven temperature set at 40-45°C and 90bar of pressure, an overall extraction yield of 1.18-1.21% (w/w) was obtained, with a high selectivity for not oxidized lipophilic compounds. The biological activity of the extracts was evaluated against human non-small lung A549 and breast carcinoma MCF-7 cancer cell lines. The cytotoxic effect of the SFE extract was more pronounced towards the MCF-7 than the A549 cancer cells, with IC 50 values ranging from 21.01±2.89 to 31.11±2.l4μg/mL; cell viability was affected mainly between 24 and 48h of exposure. The results show the possibility of a new "green" approach to obtain extracts highly rich in genuine polyacetylenes and polyenes from E. pallida roots. The bioactivity evaluation confirmed the cytotoxicity of E. pallida extracts against the considered cancer cell lines, especially against MCF-7 cells, thus suggesting to represent a valuable tool for applicative purposes in cancer prevention. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Determination of uric acid in plasma and allantoic fluid of chicken embryos by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Matějčková, J.; Tůma, P.; Samcová, E.; Zemanová, Zdeňka

    2007-01-01

    Roč. 30, č. 12 (2007), s. 1947-1952 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA304/04/0972 Grant - others:GA ČR(CZ) GA203/07/0896 Program:GA Institutional research plan: CEZ:AV0Z50110509 Keywords : capillary electrophoresis * microsamples of plasma * uric acid Subject RIV: CE - Biochemistry Impact factor: 2.632, year: 2007

  13. The role of concavo-convex walls of a nanopore on the density profile, adsorption, solvation force, and capillary condensation of confined fluids: A DFT study

    International Nuclear Information System (INIS)

    Helmi, Abbas; Keshavarzi, Ezat

    2014-01-01

    Highlights: • The effect of concavo-convex walls of nanopores on the density profile was studied. • For HS fluids the contact density at concave wall is greater than for convex wall. • For Yukawa fluid the contact density at concave wall can be less than convex wall. • Capillary condensation was observed for Yukawa fluids in the homocentric pores. - Abstract: We investigate the effects of concavo-convex walls of a nanopore on the structure and certain thermodynamic properties of confined fluids. Adsorption, solvation force, and capillary condensation in a nanopore formed between two homocentric spheres will be determined using the MFMT. For hard sphere fluids, contact density is greater at the concave wall than it is at the convex wall. In Yukawa fluids, for the thermodynamic state in which the energy effect is the dominant factor, contact density at a concave wall is less than that at a convex wall; this will be reversed for the thermodynamic state in which the entropy effect is the dominant factor. It is possible to find thermodynamic states in which contact densities at concave and convex walls become identical. The adsorption and solvation force of hard sphere fluid show an oscillatory behavior versus H. Capillary condensation is in certain cases observed for Yukawa fluids

  14. Pulsed discharge plasmas in supercritical carbon dioxide

    OpenAIRE

    Kiyan, Tsuyoshi; Uemura, A.; Tanaka, K.; Zhang, C.H.; Namihira, Takao; Sakugawa, Takashi; Katsuki, Sunao; Akiyama, Hidenori; Roy, B.C.; Sasaki, M.; Goto, M.; キヤン, ツヨシ; ナミヒラ, タカオ; サクガワ, タカシ; カツキ, スナオ

    2005-01-01

    In recent years, several studies about electrical discharge plasma in supercritical carbon dioxide (CO2) have been carried out. One of the unique characteristics of supercritical fluid is a large density fluctuation near the critical point that can result in marked dramatic changes of thermal conductivity. Therefore, the electrical discharge plasma produced in supercritical fluid has unique features and reactions unlike those of normal plasma produced in gas phase. In our experiments, two typ...

  15. Features of Calculation of the Equation of State, Composition, and Conductivity for a Plasma of Dense, Supercritical Metal Vapors—a Plasma Fluid

    Science.gov (United States)

    Khomkin, A. L.; Shumikhin, A. S.

    2017-12-01

    The caloric and thermal equations of state, composition, and conductivity have been calculated for a supercritical aluminum plasma fluid. A previously proposed chemical plasma model called the "3+"-component one was used for the calculations. The model includes atoms, electrons, ions, and an electron jellium. The thermodynamic functions have been calculated for the first time within the "3+" model for a plasma fluid. The magnification and compensation of intercharge and interatomic interactions when calculating the equation of state and composition are analyzed. The introduction of the jellium leads to an increase in conductivity under compression, while the compensation of interactions when calculating the composition leads to a virtually ideal-gas behavior of the equation of state. Comparison with the data from physical and numerical experiments has confirmed our conclusions and demonstrated that the hypothesis about jellium, a new gas-plasma component, is constructive.

  16. Modeling of the Kinetics of Supercritical Fluid Extraction of Lipids from Microalgae with Emphasis on Extract Desorption.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena; Nobre, B.P.; Palavra, A.

    2016-01-01

    Roč. 9, č. 6 (2016), s. 423-441 ISSN 1996-1944 Grant - others:FCT(PT) UID/QUI/00100/2013; FCT(PT) SFRH/BPD/100283/2014 Institutional support: RVO:67985858 Keywords : microalgae * supercritical extraction * kinetics Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.654, year: 2016

  17. using Supercritical Fluid Extraction

    African Journals Online (AJOL)

    functional components of Polygonatum. It contains various kinds of active ingredients, applicable to not only in the ... The identification of individual compounds was based on matching their mass spectra with standard spectral .... The variance analysis of this quadratic regression equation and significance of the coefficient of ...

  18. Thermo capillary and buoyancy convection in a fluid locally heated on its free surface; Convection thermocapillaire et thermogravitaire dans un fluide chauffe localement sur sa surface libre

    Energy Technology Data Exchange (ETDEWEB)

    Favre, E.

    1997-09-26

    coupled buoyancy and thermo-capillary convection lead to a convective motion of the interface liquid/gas which drastically changes the heat and mass transfer across the liquid layer. Two experiments were considered, depending on the fluid: oil or mercury. The liquid is set in a cooled cylindrical vessel, and heated by a heat flux across the center of the free surface. The basic flow, in the case of oil, is a torus. When the heat parameter increases, a stationary flow appears as petals or rays when the aspect ratio. The lateral confinement selects the azimuthal wavelength. In the case of petals-like flow, a sub-critical Hopf bifurcation is underlined. The turbulence is found to be `weak`, even for the largest values of the Marangoni number (Ma = 1.3 10{sup 5}). In the case of mercury, the thermo-capillary effect is reduced to zero to impurities at the surface which have special trajectories we describe and compare to a simpler experiment. Only the buoyancy forces induce a unstationary, weakly turbulent flow as soon as the heating power exceeds 4W (Ra = 4.5 10{sup 3}, calculated with h = 1 mm). The past part concerns the analysis of the effect on the flow of the boundary conditions, the geometry, the Prandtl number and the buoyancy force with the help of the literature. Results concerning heat transfer, in particular the exponent of the law Nusselt number vs. heating power, were compared with available data. (author) 115 refs.

  19. Optimized process for recovery of glass- and carbon fibers with retained mechanical properties by means of near- and supercritical fluids

    DEFF Research Database (Denmark)

    Sokoli, Hülya U.; Beauson, Justine; Simonsen, Morten E.

    2017-01-01

    Degradation of hybrid fiber composites using near-critical water or supercritical acetone has been investigated in this study. Process parameters such as temperature (T= 260-300 ºC), pressure (p = 60-300 bar) and composite/solvent (c/s = 0.29-2.1 g/mL) ratio were varied to determine the effect...... on the resin degradation efficiency and the quality of the recovered glass and carbon fibers. Supercritical acetone at 260 ºC, 60 bar and a c/s ratio up to 2.1 g/mL could achieve nearly complete degradation of the resin. The glass fibers were recovered with up to 89% retained tensile strength compared...

  20. Fatty acid composition and antioxidant activity of oils from two cultivars of Cantaloupe extracted by supercritical fluid extraction

    Directory of Open Access Journals (Sweden)

    Sy Ling, Hoe

    2010-03-01

    Full Text Available The effect of supercritical fluid extraction (SFE fractionation of three oil fractions (1st, 2nd, 3rd fraction on the fatty acid composition and antioxidant activity of oils from two cultivars of cantaloupe were investigated. Rock melon oil (RMO and Golden Langkawi oil (GLO were extracted using SFE and the major fatty acids for both cultivars were linoleic, oleic, palmitic, and stearic acid. The SFA decreased from 15.78 to 14.14% in RMO 1st fraction, and MUFA decreased from 18.30 to 16.56% in RMO 2nd fraction, while PUFA increased from 65.9 to 69.30% in RMO 3rd fraction. On the other hand SFA decreased from 16.35 to 13.91% in GLO 1st fraction, and MUFA decreased from 17.50 to 15.57% in GLO 2nd fraction, while PUFA increased from 66.15 to 70.52% in GLO 3rd fraction. The different fractions of the two oils showed high antioxidant activity in reducing the oxidation of β-carotene in beta-carotene bleaching assay (BCB and the quenching of 1,1-diphenyl-2-picrylhydrazyl (DPPH.El efecto del fraccionamiento mediante extracción con fluido supercrítico de tres fracciones (fracción 1ª, 2ª y 3ª sobre la composición de ácidos grasos y actividad antioxidante de aceites de dos variedades de melón fué investigado. Aceites de melón de los cultivares Rock (RMO y Golden Langkawi GLO fueron extraídos usando SFE y los principales ácidos grasos en cada cultivar fueron ácido linoleico, oleico, palmítico y esteárico. Los ácidos grasos saturados (SFA disminuyeron desde 15.78 a 14.14% en la 1ª fracción de RMO y los ácidos grasos monoinsaturados (MUFA disminuyeron desde 18.30 a 16.56% en la 2ª fracción de RMO, mientras que los ácidos grasos poliinsaturados (PUFA aumentaron de 65.9 a 69.30% en la 3ª fracción de RMO. Por otra parte, SFA disminuyo de 16.35 a 13.91% en la primera fracción de GLO y MUFA disminuyo de 17.50 a 15.57% en la 2ª fracción de GLO, mientras que PUFA aumento de 66.15 a 70.52% en la 3ª fracción de GLO. Las diferentes

  1. A comparison of chilled DI water/ozone and CO{sub 2}-based supercritical fluids as replacements for photoresist-stripping solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Barton, J.; Taylor, C.M.V. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.; Tiefert, K. [Hewlett-Packard Co., Santa Clara, CA (United States)

    1998-12-31

    Part of the Hewlett Packard Components Group`s Product Stewardship program is the ongoing effort to investigate ways to eliminate or reduce as much as possible the use of chemical substances from manufacturing processes. Currently used techniques to remove hard-baked photoresists from semiconductor wafers require the use of inorganic chemicals or organic strippers and associated organic solvents. Environmental, health and safety, as well as cost considerations prompted the search for alternative, more environmentally-benign, and cost-effective solutions. Two promising, emerging technologies were selected for evaluation: the chilled DI water/ozone technique and supercritical fluids based on carbon dioxide (CO{sub 2}). Evaluating chilled DI water/ozone shows this process to be effective for positive photoresist removal, but may not be compatible with all metallization systems. Testing of a closed-loop CO{sub 2}-based supercritical CO{sub 2} Resist Remover, or SCORR, at Los Alamos, on behalf of Hewlett-packard, shows that this treatment process is effective in removing photoresists, and is fully compatible with commonly used metallization systems. In this paper, the authors present details on the testing programs conducted with both the chilled DI H{sub 2}O/ozone and SCORR treatment processes.

  2. Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography-Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase.

    Science.gov (United States)

    Jumaah, Firas; Jędrkiewicz, Renata; Gromadzka, Justyna; Namieśnik, Jacek; Essén, Sofia; Turner, Charlotta; Sandahl, Margareta

    2017-09-20

    This study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO 2 ) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO 2 without addition of cosolvent in ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono- and diesters are separated on a 2-picolylamine column in less than 12 min. The presence and position of a hydroxyl group in the structure, the number of unsaturated bonds, and the acyl chain length play a significant role in the separation of MCPD esters. The flow rate, backpressure, and column oven temperature, which affect the density of the mobile phase, were shown to have a substantial impact on retention, efficiency, and selectivity. The developed method was successfully applied for the determination of MCPD esters in refined oils and showed a close to excellent green analysis score using the Analytical Eco-Scale.

  3. A novel analytical method for the determination of residual moisture in plutonium dioxide: Supercritical fluid extraction/Fourier transform infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, A.M.; Hollis, W.K.; Rubin, J.B.; Taylor, C.M.V.; Jasperson, M.N.; Vance, D.E.; Rodriguez, J.B.

    1999-02-01

    A novel approach has been developed at the Los Alamos National Laboratory for the quantitative determination of moisture content in impure plutonium oxide. The method combines a commercial supercritical fluid extraction instrument using supercritical carbon dioxide (SCCO{sub 2}) with on-line detection using a high-pressure Fourier Transform Infrared Spectroscopy (FTIR) cell. The combined SCCO{sub 2}/FTIR system has been modified for use inside a fully enclosed glove box. A series of validation experiments were performed using a pure, surrogate oxide (ThO{sub 2}) and an inorganic hydrate (CaSO{sub 4}{center_dot}2H{sub 2}O). The level of agreement between LOI and SCCO{sub 2}/FTIR for the surrogate oxide is excellent. The results for the inorganic hydrate showed excellent correlation with the known amount of water present. Results obtained for a group of nominally pure PuO{sub 2} samples were verified by independent measurement. The results of SCCO{sub 2}/FTIR for impure PuO{sub 2} samples is consistently lower than the results of obtained from the current analytical method (Loss On Ignition), indicating that the current method is inadequate for analytical purposes. While further verification experiments of the SCCO{sub 2}/FTIR method are underway, these initial results suggest that SCCO{sub 2}/FTIR could be used as an alternative analytical method for the Materials Identification and Surveillance program.

  4. Feasibility study of online supercritical fluid extraction-liquid chromatography-UV absorbance-mass spectrometry for the determination of proanthocyanidins in grape seeds.

    Science.gov (United States)

    Wang, Zhenyu; Ashraf-Khorassani, Mehdi; Taylor, Larry T

    2005-03-01

    Online coupling of supercritical fluid extraction (SFE) with liquid chromatography (LC)-UV absorbance-electrospray ionization (ESI)-mass spectrometry (MS) is evaluated for the determination of proanthocyanidins in grape seeds. The solid-phase intermediate trap is optimized in order to enhance the collection efficiency for the extracted polar components. Pure supercritical CO2 is used first to remove the oil in the seeds. Then methanol-modified CO2 is used to remove the polar components (e.g., phenolic compounds). Catechin and epicatechin (90%) are extracted out of the de-oiled after 240 min with 40% methanol as a modifier. Both singly-linked (B-type) and doubly-linked (A-type) procyanidins are identified by LC-ESI-MS, as well as their galloylated derivatives. The hyphenated system combines the extraction, separation, and detection in series. The experimental design minimizes the chance of analyte oxidation, degradation, and contamination. The traditional off-line SFE-LC method is also studied for comparison with the online method. Both advantages and disadvantages are observed for the online mode.

  5. Supercritical fluid extraction of grape seed oil and subsequent separation of free fatty acids by high-speed counter-current chromatography.

    Science.gov (United States)

    Cao, Xueli; Ito, Yoichiro

    2003-12-22

    Supercritical fluid extraction (SFE) of grape seed oil was performed to study the effect of various parameters such as pressure, temperature and the particle size of the sample on the yield and composition of oil using an analytical-scale SFE system. Then the extraction was scaled up by 125 times using a preparative SFE system under the optimized conditions of high pressure (30-40 MPa) and low temperature (35-40 degrees C) with medium particle size (20-40 mesh). The maximum yield of the oil can reach 6.2% with pure supercritical CO2 and 4.0% more oil can be obtained by adding 10% of ethanol as modifier. The unsaturated fatty acids (UFSs) make up about 70% in the oil on the basis of free fatty acids. The grape seed oil was then subjected to separation and purification for free fatty acids after saponification by high-speed counter-current chromatography coupled with evaporative light scattering detection (ELSD). The separation of 1.0 g of oil can yield about 430 mg pure linoleic acid at 99% purity. The fatty acids were analyzed by HPLC-ELSD.

  6. Application of response surface methodology for the optimization of supercritical fluid extraction of essential oil from pomegranate (Punica granatum L.) peel.

    Science.gov (United States)

    Ara, Katayoun Mahdavi; Raofie, Farhad

    2016-07-01

    Essential oils and volatile components of pomegranate ( Punica granatum L.) peel of the Malas variety from Meybod, Iran, were extracted using supercritical fluid extraction (SFE) and hydro-distillation methods. The experimental parameters of SFE that is pressure, temperature, extraction time, and modifier (methanol) volume were optimized using a central composite design after a (2 4-1 ) fractional factorial design. Detailed chemical composition of the essential oils and volatile components obtained by hydro-distillation and optimum condition of the supercritical CO 2 extraction were analyzed by GC-MS, and seventy-three and forty-six compounds were identified according to their retention indices and mass spectra, respectively. The optimum SFE conditions were 350 atm pressure, 55 °C temperature, 30 min extraction time, and 150 µL methanol. Results showed that oleic acid, palmitic acid and (-)-Borneol were major compounds in both extracts. The optimum extraction yield was 1.18 % (w/w) for SFE and 0.21 % (v/w) for hydro-distillation.

  7. [Comparison of Chemical Components of Essential Oil from Ocimum basilicum var. pilosum Extracted by Supercritical CO2 Fluid and Steam Distillation].

    Science.gov (United States)

    Wang, Zhao-yu; Zheng, Jia-huan; Shi, Sheng-ying; Luo, Zhi-xiong; Ni, Shun-yu; Lin, Jing-ming

    2015-11-01

    To compare the chemical components of essential oil prepared by steam distillation extraction (SD) and supercritical CO2 fluid extraction (SFE-CO2) from Ocimum basilicum var. pilosum whole plant. The essential oil of Ocimum basilicum var. pilosum were extracted by SD and SFE-CO2. The chemical components of essential oil were separated and analyzed by gas chromatography-mass spectrometry( GC-MS). Their relative contents were determined by normalization of peak area. 40 and 42 compounds were detected in the essential oil prepared by SD and SFE-CO2 respectively. 25 compounds were common. Thereare significant differences of the chemical components between the Ocimum basilicum var. pilosum essential oil prepared by SD and thatby SFE-CO2. Different methods showed different extraction efficiency with a special compound. It might be a good idea to unite several methods in the modern traditional Chinese medicine industry.

  8. Comparative analysis of essential oil composition of Iranian and Indian Nigella sativa L. extracted using supercritical fluid extraction and solvent extraction.

    Science.gov (United States)

    Ghahramanloo, Kourosh Hasanzadeh; Kamalidehghan, Behnam; Akbari Javar, Hamid; Teguh Widodo, Riyanto; Majidzadeh, Keivan; Noordin, Mohamed Ibrahim

    2017-01-01

    The objective of this study was to compare the oil extraction yield and essential oil composition of Indian and Iranian Nigella sativa L. extracted by using Supercritical Fluid Extraction (SFE) and solvent extraction methods. In this study, a gas chromatography equipped with a mass spectrophotometer detector was employed for qualitative analysis of the essential oil composition of Indian and Iranian N. sativa L. The results indicated that the main fatty acid composition identified in the essential oils extracted by using SFE and solvent extraction were linoleic acid (22.4%-61.85%) and oleic acid (1.64%-18.97%). Thymoquinone (0.72%-21.03%) was found to be the major volatile compound in the extracted N. sativa oil. It was observed that the oil extraction efficiency obtained from SFE was significantly ( P essential oil, which is composed of higher linoleic acid and thymoquinone contents compared to the essential oil obtained by the solvent extraction technique.

  9. Final Report: Development of a Chemical Model to Predict the Interactions between Supercritical CO2, Fluid and Rock in EGS Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, Brian J. [University of Utah; Pan, Feng [University of Utah

    2014-09-24

    This report summarizes development of a coupled-process reservoir model for simulating enhanced geothermal systems (EGS) that utilize supercritical carbon dioxide as a working fluid. Specifically, the project team developed an advanced chemical kinetic model for evaluating important processes in EGS reservoirs, such as mineral precipitation and dissolution at elevated temperature and pressure, and for evaluating potential impacts on EGS surface facilities by related chemical processes. We assembled a new database for better-calibrated simulation of water/brine/ rock/CO2 interactions in EGS reservoirs. This database utilizes existing kinetic and other chemical data, and we updated those data to reflect corrections for elevated temperature and pressure conditions of EGS reservoirs.

  10. Investigating sub-2 μm particle stationary phase supercritical fluid chromatography coupled to mass spectrometry for chemical profiling of chamomile extracts.

    Science.gov (United States)

    Jones, Michael D; Avula, Bharathi; Wang, Yan-Hong; Lu, Lu; Zhao, Jianping; Avonto, Cristina; Isaac, Giorgis; Meeker, Larry; Yu, Kate; Legido-Quigley, Cristina; Smith, Norman; Khan, Ikhlas A

    2014-10-17

    Roman and German chamomile are widely used throughout the world. Chamomiles contain a wide variety of active constituents including sesquiterpene lactones. Various extraction techniques were performed on these two types of chamomile. A packed-column supercritical fluid chromatography-mass spectrometry method was designed for the identification of sesquiterpenes and other constituents from chamomile extracts with no derivatization step prior to analysis. Mass spectrometry detection was achieved by using electrospray ionization. All of the compounds of interest were separated within 15 min. The chamomile extracts were analyzed and compared for similarities and distinct differences. Multivariate statistical analysis including principal component analysis and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used to differentiate between the chamomile samples. German chamomile samples confirmed the presence of cis- and trans-tonghaosu, chrysosplenols, apigenin diglucoside whereas Roman chamomile samples confirmed the presence of apigenin, nobilin, 1,10-epioxynobilin, and hydroxyisonobilin. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Functional Ginger Extracts from Supercritical Fluid Carbon Dioxide Extraction via In Vitro and In Vivo Assays: Antioxidation, Antimicroorganism, and Mice Xenografts Models

    Directory of Open Access Journals (Sweden)

    Chih-Chen Lee

    2013-01-01

    Full Text Available Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger. We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

  12. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Daijie Wang

    2012-01-01

    Full Text Available Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 ºC. Further separation and purification was established by high-speed counter-current chromatography (HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio. The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, ¹H-NMR and 13C-NMR.

  13. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Daijie; Lin, Yunliang; Lin, Xiaojing; Geng, Yanling; Wang, Xiao, E-mail: wxjn1998@126.com [Process Control Research Center of TCM. Shandong Academy of Sciences. Shandong Analysis and Test Center (China); Zhang, Jinjie [College of Biosystems Engineering and Food Science, Zhejiang University (China); Qiu, Jiying [Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Science, Shandong (China)

    2012-07-01

    Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 degree C. Further separation and purification was established by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio). The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, 1H-NMR and {sup 13}C-NMR. (author)

  14. Functional ginger extracts from supercritical fluid carbon dioxide extraction via in vitro and in vivo assays: antioxidation, antimicroorganism, and mice xenografts models.

    Science.gov (United States)

    Lee, Chih-Chen; Chiou, Li-Yu; Wang, Jheng-Yang; Chou, Sin-You; Lan, John Chi-Wei; Huang, Tsi-Shu; Huang, Kuo-Chuan; Wang, Hui-Min

    2013-01-01

    Supercritical fluid carbon dioxide extraction technology was developed to gain the active components from a Taiwan native plant, Zingiber officinale (ginger). We studied the biological effects of ginger extracts via multiple assays and demonstrated the biofunctions in each platform. Investigations of ginger extracts indicated antioxidative properties in dose-dependant manners on radical scavenging activities, reducing powers and metal chelating powers. We found that ginger extracts processed moderate scavenging values, middle metal chelating levels, and slight ferric reducing powers. The antibacterial susceptibility of ginger extracts on Staphylococcus aureus, Streptococcus sobrinus, S. mutans, and Escherichia coli was determined with the broth microdilution method technique. The ginger extracts had operative antimicroorganism potentials against both Gram-positive and Gram-negative bacteria. We further discovered the strong inhibitions of ginger extracts on lethal carcinogenic melanoma through in vivo xenograft model. To sum up, the data confirmed the possible applications as medical cosmetology agents, pharmaceutical antibiotics, and food supplements.

  15. [Analyze on chemical compositions of Dalbergia odorifera essential oils extracted by CO2-supercritical-fluid-extraction and steam distillation extraction].

    Science.gov (United States)

    Song, Wei-Feng; Liao, Mei-Jin; Luo, Shu-Yuan

    2011-11-01

    To analyze the chemical compositions of Dalbergia odorifera essential oils extacted by CO2-supercritical-fluid-extraction (SFE-CO2) and steam distillation extraction (SD). The essential oils of Dalbergia odorifera were extracted by steam distillation extraction and SFE-CO2. The chemical components were separated and analyzed by gas chromatography-mass spectrometry. 12 compounds were identified in SFE sample. The major components from essential oils were 2-propenoic acid-3(4-methoxyphenyl)-ethyl ester (14.53%), nerolidol (14.95%), ageratochromene (1.33%). 9 compounds were identified in SD sample. The major components from essential oils were nerolidol (26.61%), cedrol (1.65%). The SFE method is better than the SD method in reliability stability and reproducibility, and suitable for essential oils extraction of Dalbergia odorifera.

  16. Comparison of solid-phase microextraction, supercritical fluid extraction, steam distillation, and solvent extraction techniques for analysis of volatile consituents in Fructus Amomi.

    Science.gov (United States)

    Shen, Shun; Sha, Yunfei; Deng, Chunhui; Fu, Daxi; Chen, Jiakuan; Zhang, Xiangmin

    2005-01-01

    Four sampling techniques, solid-phase microextraction (SPME), supercritical fluid extraction (SFE), steam distillation (SD), and solvent extraction (SE), were compared for the analysis of volatile constituents from a traditional Chinese medicine (TCM) of the dried ripe fruit of Fructus Amomi (Sha Ren). A total of 38 compounds were identified by gas chromatography/mass spectrometry. Different SFE and SPME parameters (modifier content, extraction pressure, and temperature for SFE and fibers, extraction temperature, and time for SPME) were studied. The results by SFE and SPME were compared with those obtained by conventional SD and SE methods. The results showed that SFE and SPME are better sample preparation techniques than SD and SE. Due to SFE's requirement for expensive specialized instrumentation, the simplicity, low cost, and speed of SPME make it a more appropriate technique for extraction of volatile constituents in TCMs.

  17. Unstable Simple Volatiles and Gas Chromatography-Tandem Mass Spectrometry Analysis of Essential Oil from the Roots Bark of Oplopanax Horridus Extracted by Supercritical Fluid Extraction

    Directory of Open Access Journals (Sweden)

    Li Shao

    2014-11-01

    Full Text Available Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E-nerolidol (52.5%, τ-cadinol (21.6% and S-falcarinol (3.6%. Accordingly, the volatile oil (100 g was subjected to chromatographic separation and purification. As a result, the three compounds, (E-nerolidol (2 g, τ-cadinol (62 mg and S-falcarinol (21 mg, were isolated and purified from the volatile oil, the structures of which were unambiguously elucidated by detailed spectroscopic analysis including 1D- and 2D-NMR techniques.

  18. Supercritical fluid extraction of grape seeds: extract chemical composition, antioxidant activity and inhibition of nitrite production in LPS-stimulated Raw 264.7 cells.

    Science.gov (United States)

    Pérez, Concepción; Ruiz del Castillo, María Luisa; Gil, Carmen; Blanch, Gracia Patricia; Flores, Gema

    2015-08-01

    Grape by-products are a rich source of bioactive compounds having broad medicinal properties, but are usually wasted from juice/wine processing industries. The present study investigates the use of supercritical fluid extraction (SFE) for obtaining an extract rich in bioactive compounds. First, some variables involved in the extraction were applied. SFE conditions were selected based on the oil mass yield, fatty acid profile and total phenolic composition. As a result, 40 °C and 300 bar were selected as operational conditions. The phenolic composition of the grape seed oil was determined using LC-DAD. The antioxidant activity was determined by ABTS and DPPH assays. For the anti-inflammatory activity the inhibition of nitrite production was assessed. The grape seed oil extracted was rich in phenolic compounds and fatty acids with significant antioxidant and anti-inflammatory activities. From these results, added economic value to this agroindustrial residue is proposed using environmentally friendly techniques.

  19. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways.

    Science.gov (United States)

    Huang, Huey-Chun; Wei, Chien-Mei; Siao, Jen-Hung; Tsai, Tsang-Chi; Ko, Wang-Ping; Chang, Kuei-Jen; Hii, Choon-Hoon; Chang, Tsong-Min

    2016-01-01

    The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE) in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS). The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1-10 mg/mL) and its major fatty acids such as linoleic acid and oleic acid (6.25-50 μM) effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA), phosphatidylinositol-3-kinase (PI3K/Akt), and mitogen-activated protein kinases (MAPK) signaling pathways, which may be due to linoleic acid and oleic acid.

  20. Supercritical Fluid Extract of Spent Coffee Grounds Attenuates Melanogenesis through Downregulation of the PKA, PI3K/Akt, and MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Huey-Chun Huang

    2016-01-01

    Full Text Available The mode of action of spent coffee grounds supercritical fluid CO2 extract (SFE in melanogenesis has never been reported. In the study, the spent coffee grounds were extracted by the supercritical fluid CO2 extraction method; the chemical constituents of the SFE were investigated by gas chromatography-mass spectrometry (GC-MS. The effects of the SFE and its major fatty acid components on melanogenesis were evaluated by mushroom tyrosinase activity assay and determination of intracellular tyrosinase activity and melanin content. The expression level of melanogenesis-related proteins was analyzed by western blotting assay. The results revealed that the SFE of spent coffee grounds (1–10 mg/mL and its major fatty acids such as linoleic acid and oleic acid (6.25–50 μM effectively suppressed melanogenesis in the B16F10 murine melanoma cells. Furthermore, the SFE decreased the expression of melanocortin 1 receptor (MC1R, microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase-related protein-1 (TRP-1, and tyrosinase-related protein-2 (TRP-2. The SFE also decreased the protein expression levels of p-JNK, p-p38, p-ERK, and p-CREB. Our results revealed that the SFE of spent coffee grounds attenuated melanogenesis in B16F10 cells by downregulation of protein kinase A (PKA, phosphatidylinositol-3-kinase (PI3K/Akt, and mitogen-activated protein kinases (MAPK signaling pathways, which may be due to linoleic acid and oleic acid.

  1. Comparative analysis of essential oil composition of Iranian and Indian Nigella sativa L. extracted using supercritical fluid extraction and solvent extraction

    Directory of Open Access Journals (Sweden)

    Ghahramanloo KH

    2017-07-01

    Full Text Available Kourosh Hasanzadeh Ghahramanloo,1 Behnam Kamalidehghan,2 Hamid Akbari Javar,3 Riyanto Teguh Widodo,1 Keivan Majidzadeh,4 Mohamed Ibrahim Noordin1 1Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; 2Medical Genetics Department, National Institute of Genetic Engineering and Biotechnology (NIGEB, 3Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS, 4Breast Cancer Research Center (BCRC Academic Center for Education, Culture and Research, Tehran, Iran Abstract: The objective of this study was to compare the oil extraction yield and essential oil composition of Indian and Iranian Nigella sativa L. extracted by using Supercritical Fluid Extraction (SFE and solvent extraction methods. In this study, a gas chromatography equipped with a mass spectrophotometer detector was employed for qualitative analysis of the essential oil composition of Indian and Iranian N. sativa L. The results indicated that the main fatty acid composition identified in the essential oils extracted by using SFE and solvent extraction were linoleic acid (22.4%–61.85% and oleic acid (1.64%–18.97%. Thymoquinone (0.72%–21.03% was found to be the major volatile compound in the extracted N. sativa oil. It was observed that the oil extraction efficiency obtained from SFE was significantly (P<0.05 higher than that achieved by the solvent extraction technique. The present study showed that SFE can be used as a more efficient technique for extraction of N. Sativa L. essential oil, which is composed of higher linoleic acid and thymoquinone contents compared to the essential oil obtained by the solvent extraction technique. Keywords: Nigella sativa L., essential oil extraction, supercritical fluid extraction, solvent extraction, fatty acid composition, thymoquinone, linoleic acid

  2. Development and validation of a supercritical fluid chromatography method for the direct determination of enantiomeric purity of provitamin B5 in cosmetic formulations with mass spectrometric detection.

    Science.gov (United States)

    Khater, Syame; West, Caroline

    2015-01-01

    A rapid and efficient chiral supercritical fluid chromatography (SFC) method has been developed for the quantitative determination of panthenol enantiomers in cosmetic formulations (cream, lotion, wipe, and exfoliant). Indeed, the pharmacological effect only depends on the D form (Dexpanthenol) thus accurate measurement of its enantiomeric purity in formulated cosmetic products is of interest. The samples were prepared with liquid-liquid extraction followed by solid-phase extraction on Adsorbex amino cartridges. After testing several enantioselective columns in an attempt at reversing the elution order to have the minor enantiomer eluted first, the best separation of enantiomers and internal standard (N-acetyl-L-alanine) was achieved on a 3 μm-amylose-type immobilized polysaccharide chiral stationary phase (Chiralpak IA) in less than 6 min with a simple mobile phase comprising carbon dioxide and 11% methanol pumped at 2.3 mL/min, 25°C and 150 bar backpressure. Supercritical fluid chromatography coupled to both an optical diode-array detector and a user-friendly single-quadrupole mass spectrometer (Waters QDa) equipped with electrospray ionization source has been used. The on-line coupling ensures the technique to be more informative and improves detection sensitivity, as underivatized panthenol has a poor UV absorption. The limit of quantification (LOQ) achieved with single-ion recording was 0.5 μg/mL. The method was validated in terms of linearity, precision and accuracy and satisfactory results were obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Extraction with supercritical fluid and comparison of chemical composition from adults and young leaves of Zanthoxylum tingoassuiba

    Directory of Open Access Journals (Sweden)

    Lourenço L.B. Santana

    2011-03-01

    Full Text Available Plants differ in metabolism during their life cycle. In species used as phytotherapics, these changes determine the quality and effectiveness of the product. The aim of this study to evaluate the differences of chemical extracts obtained with supercritical CO2 from young and adult leaves of Zanthoxylum tingoassuiba St.-Hil., Rutaceae, a species used in the folk medicine in Brazil. The chemical composition of the extracts was elucidated by spectroscopic analysis and comparison with literature data. The results showed difference in the composition of the leaves from Z. tingoassuiba and allowed the determination of parameters for the extraction of α-bisabolol and furanocoumarins in this vegetal matrix.

  4. Extraction with supercritical fluid and comparison of chemical composition from adults and young leaves of Zanthoxylum tingoassuiba

    Directory of Open Access Journals (Sweden)

    Lourenço L.B. Santana

    2011-06-01

    Full Text Available Plants differ in metabolism during their life cycle. In species used as phytotherapics, these changes determine the quality and effectiveness of the product. The aim of this study to evaluate the differences of chemical extracts obtained with supercritical CO2 from young and adult leaves of Zanthoxylum tingoassuiba St.-Hil., Rutaceae, a species used in the folk medicine in Brazil. The chemical composition of the extracts was elucidated by spectroscopic analysis and comparison with literature data. The results showed difference in the composition of the leaves from Z. tingoassuiba and allowed the determination of parameters for the extraction of α-bisabolol and furanocoumarins in this vegetal matrix.

  5. Bio-inspired Nano-capillary Self-powered Fluid Transport in Nanocomposite (NBIT III)

    Science.gov (United States)

    2017-02-22

    J. A., and Hile, L. A., “Works in progress #6. Total hip arthroplasty using a hydroxyapatite-coated acetabular and femoral component”, Orthop. Rev...and a gamma detector (Wallac 1480 Wizard 3 gamma counter, Turku, Finland), the total cell number was quantified and the radioactive counts per...under revision ) [24] Dullien, F. A. L., "Porous Media. Fluid Transport and Pore Structure", Academic Press, (1992). List of Publications

  6. Enhancing power cycle efficiency for a supercritical Brayton cycle power system using tunable supercritical gas mixtures

    Science.gov (United States)

    Wright, Steven A.; Pickard, Paul S.; Vernon, Milton E.; Radel, Ross F.

    2017-08-29

    Various technologies pertaining to tuning composition of a fluid mixture in a supercritical Brayton cycle power generation system are described herein. Compounds, such as Alkanes, are selectively added or removed from an operating fluid of the supercritical Brayton cycle power generation system to cause the critical temperature of the fluid to move up or down, depending upon environmental conditions. As efficiency of the supercritical Brayton cycle power generation system is substantially optimized when heat is rejected near the critical temperature of the fluid, dynamically modifying the critical temperature of the fluid based upon sensed environmental conditions improves efficiency of such a system.

  7. PtRu/carbon nanotube nanocomposite synthesized in supercritical fluid: a novel electrocatalyst for direct methanol fuel cells.

    Science.gov (United States)

    Lin, Yuehe; Cui, Xiaoli; Yen, Clive H; Wai, Chien M

    2005-11-22

    Platinum/ruthenium nanoparticles were decorated on carbon nanotubes (CNT) in supercritical carbon dioxide, and the nanocomposites were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM images show that the particles size is in the range of 5-10 nm, and XRD patterns show a face-centered cubic crystal structure. Methanol electrooxidation in 1 M sulfuric acid electrolyte containing 2 M methanol were studied onPtRu/CNT (Pt, 4.1 wt%; Ru, 2.3 wt%; molar ratio approximately Pt/Ru = 45:55) catalysts using cyclic voltammetry, linear sweep voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. All the electrochemical results show that PtRu/CNT catalysts exhibit high activity for methanol oxidation which resulted from the high surface area of carbon nanotubes and the nanostructure of platinum/ruthenium particles. Compared with Pt/CNT, the onset potential is much lower and the ratio of forward anodic peak current to reverse anodic peak current is much higher for methanol oxidation, which indicates the higher catalytic activity of PtRu/CNT. The presence of Ru with Pt accelerates the rate of methanol oxidation. The results demonstrated the feasibility of processing bimetallic catalysts in supercritical carbon dioxide for fuel cell applications.

  8. Platinum/Carbon nanotube nanocomposite synthesized in supercritical fluid as electrocatalysts for low-temperature fuel cells.

    Science.gov (United States)

    Lin, Yuehe; Cui, Xiaoli; Yen, Clive; Wai, Chien M

    2005-08-04

    Carbon nanotube (CNT)-supported Pt nanoparticle catalysts have been synthesized in supercritical carbon dioxide (scCO(2)) using platinum(II) acetylacetonate as metal precursor. The structure of the catalysts has been characterized with transmission electron micrograph (TEM) and X-ray photoelectron spectroscopy (XPS). TEM images show that the platinum particles' size is in the range of 5-10 nm. XPS analysis indicates the presence of zero-valence platinum. The Pt-CNT exhibited high catalytic activity both for methanol oxidation and oxygen reduction reaction. The higher catalytic activity has been attributed to the large surface area of carbon nanotubes and the decrease in the overpotential for methanol oxidation and oxygen reduction reaction. Cyclic voltammetric measurements at different scan rates showed that the oxygen reduction reaction at the Pt-CNT electrode is a diffusion-controlled process. Analysis of the electrode kinetics using Tafel plot suggests that Pt-CNT from scCO(2) provides a strong electrocatalytic activity for oxygen reduction reaction. For the methanol oxidation reaction, a high ratio of forward anodic peak current to reverse anodic peak current was observed at room temperature, which implies good oxidation of methanol to carbon dioxide on the Pt-CNT electrode. This work demonstrates that Pt-CNT nanocomposites synthesized in supercritical carbon dioxide are effective electrocatalysts for low-temperature fuel cells.

  9. Comparison of the Behavior of Polymers in Supercritical Fluids and Organic Solvents Via Small Angle Neutron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Melnichenko, Y.B.; Kiran, E.; Heath, K.D.; Salaniwal, S.; Cochran, H.D.; Stamm, M.; Van Hook, W.A.; Wignall, G.D.

    1999-05-17

    Small-angle neutron scattering has been used to study the effect of temperature and pressure on the phase behavior of semidilute solutions of polymers dissolved in organic and supercritical solvents. Above the theta temperature (To), these systems exhibit a ''good solvent'' domain, where the molecules expand beyond the unperturbed dimensions in both organic solvents and in COZ. However, this transition can be made to occur at a critical ''theta pressure'' (PO) in CO2 and this represents a new concept in the physics of polymer-solvent systems. For T < To, and P < Po, the system enters the ''poor solvent'' domain where diverging concentration fluctuations prevent the chains from collapsing and allow them to maintain their unperturbed dimensions.

  10. Supercritical carbondioxide extraction of cypermethrin in different ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-12

    Apr 12, 2010 ... Table 3. Performance of drying agents through supercritical fluid extraction. Sample matrix size/g. Moisture in vessel before SFE/mg. Moisture in vessel after SFE/mg ... phase into the supercritical CO2 phase. In the case of. HMX .... Using Anhydrous Magnesium Sulfate for Sample Preparation). J. Agric.

  11. Quantification of the neurotransmitters melatonin and N-acetyl-serotonin in human serum by supercritical fluid chromatography coupled with tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wolrab, Denise; Frühauf, Peter; Gerner, Christopher, E-mail: christopher.gerner@univie.ac.at

    2016-09-21

    The aim of this study was developing a supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) method and an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method, for the analysis of N-acetyl-serotonin (NAS) and melatonin (Mel) in human serum, and to compare the performance of these methods. Deuterated isotopologues of the neurotransmitters were synthesized and evaluated for suitability as internal standards in sample preparation. Liquid-liquid extraction was selected as sample preparation procedure. With chloroform, the best extraction solvent tested, an extraction yield of 48 ± 2% for N-acetyl-serotonin and 101 ± 10% for melatonin was achieved. SFC separation was accomplished within 3 min on a BEH stationary phase, employing isocratic elution with 90% carbon dioxide and 0.1% formic acid as well as 0.05% ammonium formate in methanol. For the 4 min UHPLC gradient separation with 0.1% formic acid in water and methanol, respectively, a Kinetex XB-C18 was used as stationary phase. Both chromatographic techniques were optimized regarding mobile phase composition, additives to the mobile phase and column temperature. Multiple reaction monitoring (MRM) analysis was used for quantification of the metabolites. Both methods were validated regarding retention time stability, LOD, LOQ, repeatability and reproducibility of quantification, process efficiency, extraction recovery and matrix effects. LOD and LOQ were 0.017 and 0.05 pg μL{sup −1} for NAS and 0.006 and 0.018 pg μL{sup −1} for Mel in SFC-MS/MS compared to 0.028 and 0.1 pg μL{sup −1} for NAS and 0.006 and 0.017 pg μL{sup −1} for Mel in UHPLC-MS/MS. - Highlights: • Use of supercritical fluid chromatography (SFC) hyphenated with MS/MS. • Separation of biological relevant polar metabolites with SFC. • Critical comparison of validation parameters obtained with UHPLC.

  12. A new gas/supercritical fluid (SCF diffusivity measurement method for CO2 saturated polymer systems using a dielectric property

    Directory of Open Access Journals (Sweden)

    S. X. Yao

    2017-08-01

    Full Text Available In this research, theoretical CO2 diffusivity coefficients in amorphous polymers were calculated from dielectric constant changes during CO2 desorption. These values showed agreement with experimental diffusivity coefficients from a gravimetric method. Three amorphous polymer films made from Polystyrene (PS, Polycarbonate (PC, and Cyclic Olefin Polymer (COP resins were saturated with supercritical CO2 at 5.5 MPa and 25 °C for 24 hours in a pressure chamber. The CO2 infused films were removed from the chamber for gas desorption experiments. The capacitance of the samples were recorded with an Inductance, Capacitance and Resistance (LCR meter. These values were used to calculate the change in dielectric constants. CO2 weight percentages measured by a scale was used to calculate experimental diffusivity and solubility coefficients. It was found that the trend of dielectric constant changes was similar to that of the CO2 weight percentage changes during gas desorption. A mathematical model was built to predict the CO2 weight percentages during desorption from the measured dielectric constants. Theoretical diffusivity coefficients from this work agree well with literature data.

  13. In vivo hair growth-promoting effect of rice bran extract prepared by supercritical carbon dioxide fluid.

    Science.gov (United States)

    Choi, Jae-Suk; Jeon, Min-Hee; Moon, Woi-Sook; Moon, Jin-Nam; Cheon, Eun Jin; Kim, Joo-Wan; Jung, Sung Kyu; Ji, Yi-Hwa; Son, Sang Wook; Kim, Mi-Ryung

    2014-01-01

    The potential hair growth-promoting activity of rice bran supercritical CO2 extract (RB-SCE) and major components of RB-SCE, linoleic acid, policosanol, γ-oryzanol, and γ-tocotrienol, were evaluated with the histological morphology and mRNA expression levels of cell growth factors using real-time reverse transcriptase-polymerase chain reaction (PCR) in C57BL/6 mice. RB-SCE showed hair growth-promoting potential to a similar extent as 3% minoxidil, showing that the hair follicles were induced to be in the anagen stage. The numbers of the hair follicles were significantly increased. In addition, mRNA expression levels of vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and keratinocyte growth factor (KGF) were also significantly increased and that of transforming growth factor-β (TGF-β) decreased in RB-SCE-treated groups. Among the major components of RB-SCE, linoleic acid and γ-oryzanol induced the formation of hair follicles according to examination of histological morphology and mRNA expression levels of cell growth factors. In conclusion, our results demonstrate that RB-SCE, particularly linoleic acid and γ-oryzanol, promotes hair growth and suggests RB-SCE can be applied as hair loss treatment.

  14. Variation in the volatile oil composition of Eucalyptus citriodora produced by hydrodistillation and supercritical fluid extraction techniques.

    Science.gov (United States)

    Mann, Tavleen S; Babu, G D Kiran; Guleria, Shailja; Singh, Bikram

    2013-04-01

    This work reports variations in the yields and quality of volatiles produced from Eucalyptus citriodora leaves by different hydrodistillation (HD) and supercritical carbon dioxide extraction (SCE) techniques. HD techniques (1.5%) produced higher yields compared to SCE (0.7%). Citronellal, the major component, was maximum in the extract produced by SCE (79%) followed by oil produced by water-steam distillation (WSD) (72.6%) and water distillation (WD) (62.4%) techniques. Chemical composition of glycoside-bound volatiles produced by acid hydrolysis during HD was found to be very different from free volatiles, although in a minor quantity. The extent of artefact formation and release of aglycones was more profound in the bound volatile oil produced by WD than WSD. Highest oxygenated monoterpenes were found in SCE and WSD (93% each) followed by WD (91.4%). Although the SCE produced lower yields than the HD techniques, its extract is superior in quality in terms of higher concentration of citronellal.

  15. Methane dry reforming over Ni catalysts supported on Ce–Zr oxides prepared by a route involving supercritical fluids

    Directory of Open Access Journals (Sweden)

    Smirnova Marina Yu.

    2017-12-01

    Full Text Available Ce0.5Zr0.5O2 mixed oxides were prepared in a flow reactor in supercritical isopropanol with acetylacetone as a complexing agent. Variation of the nature of the Zr salt and the temperature of synthesis affected the phase composition, morphology and specific surface area of oxides. X-ray diffraction and Raman spectroscopy studies revealed formation of metastable t” and t’ phases. Oxides are comprised of agglomerates with sizes depending on the synthesis parameters. Loading NiO decreases the specific surface area without affecting X-ray particle sizes of supports. Such sintering was the most pronounced for a support with the highest specific surface area, which resulted in the lowest surface content of Ni as estimated by X-ray photoelectron spectroscopy and in the formation of flattened NiO particles partially embedded into the support. The catalytic activity and stability of these samples in the dry reforming of methane were determined by the surface concentration of Ni and the morphology of its particle controlled by the metal-support interaction, which also depends on the type of catalyst pretreatment. Samples based on ceria-zirconia oxides prepared under these conditions provide a higher specific catalytic activity as compared with the traditional Pechini route, which makes them promising for the practical application.

  16. Original research paper. A superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes with improved solubility and dissolution: Supercritical fluid process.

    Science.gov (United States)

    Pan, Hao; Wang, Han-Bing; Yu, Yi-Bin; Cheng, Bing-Chao; Wang, Xiao-Yu; Li, Ying

    2017-03-01

    Advantages of the supercritical fluid (SCF) process compared to the conventional solution stirring method (CSSM) in the preparation of daidzein-hydroxypropyl-β-cyclodextrin (HPβCD) complexes were investigated. Formation of daidzein/ HPβCD inclusion complexes was confirmed by Fourier transformed-infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Particle size, inclusion yield, drug solubility and dissolution of daidzein/HPβCD complexes were evaluated. Compared to CSSM, the SCF process resulted in higher inclusion yield and higher solubility. Also, extended dissolution of daidzein from the SCF processed HPβCD inclusion complexes was observed, with only 22.94 % released in 45 min, compared to its rapid release from those prepared by CSSM, with 98.25 % drug release in 15 min. This extended release of daidzein from SCF prepared inclusion complexes was necessary to avoid drug precipitation and improve drug solubilisation in the gastrointestinal tract. The results showed that the SCF process is a superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes.

  17. Effect of solvent type and ratio on betacyanins and antioxidant activity of extracts from Hylocereus polyrhizus flesh and peel by supercritical fluid extraction and solvent extraction.

    Science.gov (United States)

    Fathordoobady, Farahnaz; Mirhosseini, Hamed; Selamat, Jinap; Manap, Mohd Yazid Abd

    2016-07-01

    The main objective of the present study was to investigate the effect of solvent type and ratio as well as the extraction techniques (i.e. supercritical fluid extraction (SFE) and conventional solvent extraction) on betacyanins and antioxidant activity of the peel and fresh extract from the red pitaya (Hylocereus polyrhizus). The peel and flesh extracts obtained by SFE at 25MPa pressure and 10% EtOH/water (v/v) mixture as a co-solvent contained 24.58 and 91.27mg/100ml total betacyanin, respectively; while the most desirable solvent extraction process resulted in a relatively higher total betacyanin in the peel and flesh extracts (28.44 and 120.28mg/100ml, respectively). The major betacyanins identified in the pitaya peel and flesh extracts were betanin, isobetanin, phyllocactin, butyrylbetanin, isophyllocactin and iso-butyrylbetanin. The flesh extract had the stronger antioxidant activity than the peel extract when the higher proportion of ethanol to water (E/W) was applied for the extraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Simultaneous determination of 17 disperse dyes in textile by ultra-high performance supercritical fluid chromatography combined with tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Ying; Du, Zhenxia; Zhang, Yun

    2014-09-01

    A simple, highly sensitive and fast procedure for the control of 17 allergenic and prohibited disperse dyes in textile products was optimized. The method was based on ultrasound assisted extraction of textile samples with 10 mL of methanol under controlled conditions (30 min, 70°C). The extracts were analyzed by the ultra-high performance supercritical fluid chromatography (UHPSFC) system coupled with triple quadrupole tandem mass spectrometry (MS/MS). Four stationary phases (BEH, BEH 2-ethyl-pyridine, HSS C18 SB and CSH fluorophenyl) were screened as well as analytical conditions (modifier percentage, backpressure and column temperature) were investigated to improve the separation. All 17 disperse dyes were simultaneously separated and determined by UHPSFC-MS/MS in 5 min. The dyes were monitored via the ESI(+) ionization method and quantified by 3-channel multiple reaction monitoring (MRM). The calibrations were performed and good linear relationship (R≥0.99) was observed within the concentration range of 2-50 μg mL(-1). Satisfactory recoveries (70.55-103.03%) of all the disperse dyes spiked with standards at different levels were demonstrated. This is the first report on the simultaneous analysis of disperse dyes using UHPSFC-MS/MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Evaluation of a new preparative supercritical fluid chromatography system for compound library purification: the TharSFC SFC-MS Prep-100 system.

    Science.gov (United States)

    Ebinger, Katalin; Weller, Harold N; Kiplinger, Jeffrey; Lefebvre, Paul

    2011-06-01

    Preparative HPLC-MS is often the method of choice for purification of small amounts (libraries for drug discovery. The method is robust, well proven, and widely applicable. In contrast, preparative supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) has seen only slow acceptance for the same application--despite some potential scientific and economic advantages. One of the reasons for slow adoption of SFC-MS is the lack of well-proven, robust, and commercially available instrumentation. In early 2009, TharSFC (a Waters Company, Pittsburgh, PA) introduced a new fully integrated system for preparative SFC-MS: The SFC-MS Prep-100. We report herein an objective evaluation of the SFC-MS Prep-100, including tests for pump and autosampler performance, sample recovery, sample carryover, fraction triggering, detector/fraction collector synchronization, and overall robustness. Our results suggest that the SFC-MS Prep-100 represents a significant advance over previous generation instrumentation. Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.

  20. Supercritical fluid chromatography-photodiode array detection-electrospray ionization mass spectrometry as a framework for impurity fate mapping in the development and manufacture of drug substances.

    Science.gov (United States)

    Pirrone, Gregory F; Mathew, Rose M; Makarov, Alexey A; Bernardoni, Frank; Klapars, Artis; Hartman, Robert; Limanto, John; Regalado, Erik L

    2018-03-30

    Impurity fate and purge studies are critical in order to establish an effective impurity control strategy for approval of the commercial filing application of new medicines. Reversed phase liquid chromatography-diode array-mass spectrometry (RPLC-DAD-MS) has traditionally been the preferred tool for impurity fate mapping. However, separation of some reaction mixtures by LC can be very problematic requiring combination LC-UV for area % analysis and a different LC-MS method for peak identification. In addition, some synthetic intermediates might be chemically susceptible to the aqueous conditions used in RPLC separations. In this study, the use of supercritical fluid chromatography-photodiode array-electrospray ionization mass spectrometry (SFC-PDA-ESIMS) for fate and purge of two specified impurities in the 1-uridine starting material from the synthesis of a bis-piv 2'keto-uridine, an intermediate in the synthesis of uprifosbuvir, a treatment under investigation for chronic hepatitis C infection. Readily available SFC instrumentation with a Chiralpak IC column (4.6 × 150 mm, 3 μm) and ethanol: carbon dioxide based mobile phase eluent enabled the separation of closely related components from complex reaction mixtures where RLPC failed to deliver optimal chromatographic performance. These results illustrate how SFC combined with PDA and ESI-MS detection can become a powerful tool for direct impurity fate mapping across multiple reaction steps. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Characterization of Arachis hypogaea L. oil obtained from different extraction techniques and in vitro antioxidant potential of supercritical fluid extraction extract

    Directory of Open Access Journals (Sweden)

    Rishika Chauhan

    2016-01-01

    Full Text Available Aim: The present investigation was aimed to characterize the fixed oil of Arachis hypogaea L. using five different extraction methods: Supercritical fluid extraction (SFE, ultrasound assistance extraction, soxhlet extraction, solvent extraction, and three phase partitioning method. Materials and Methods: The SFE conditions (temperature, pressure, and volume of CO 2 were optimized prior for better yield. The extracted oils were analyzed and compared for their physiochemical parameters, high-performance thin layer chromatography (HPTLC, gas chromatography-mass spectrometry (GC-MS, and Fourier transform infrared spectrometry (FT-IR fingerprinting. Anti-oxidant activity was also determined using DPPH and superoxide scavenging method. Results: The main fatty acids were oleic, linoleic, palmitic, and stearic acids as obtained by GC-MS. HPTLC analysis revealed the presence of similar major components in chromatograms. Similarly, the pattern of peaks as obtained in FT-IR and GC-MS spectra of same oils by different extraction methods was superimposable. Conclusion: Analysis reported that the fixed oil of A. hypogaea L. is a good source of unsaturated fatty acid, mainly n-6 and n-9 fatty acid with a significant antioxidant activity of oil obtained from SFE extraction method.

  2. Supercritical Fluid Extraction of Eucalyptus globulus Bark—A Promising Approach for Triterpenoid Production

    Directory of Open Access Journals (Sweden)

    Carlos M. Silva

    2012-06-01

    Full Text Available Eucalyptus bark contains significant amounts of triterpenoids with demonstrated bioactivity, namely triterpenic acids and their acetyl derivatives (ursolic, betulinic, oleanolic, betulonic, 3-acetylursolic, and 3-acetyloleanolic acids. In this work, the supercritical fluid extraction (SFE of Eucalyptus globulus deciduous bark was carried out with pure and modified carbon dioxide to recover this fraction, and the results were compared with those obtained by Soxhlet extraction with dichloromethane. The effects of pressure (100–200 bar, co-solvent (ethanol content (0, 5 and 8% wt, and multistep operation were studied in order to evaluate the applicability of SFE for their selective and efficient production. The individual extraction curves of the main families of compounds were measured, and the extracts analyzed by GC-MS. Results pointed out the influence of pressure and the important role played by the co-solvent. Ethanol can be used with advantage, since its effect is more important than increasing pressure by several tens of bar. At 160 bar and 40 °C, the introduction of 8% (wt of ethanol greatly improves the yield of triterpenoids more than threefold.

  3. Automated analytical standard production with supercritical fluid chromatography for the quantification of bioactive C17-polyacetylenes: a case study on food processing waste.

    Science.gov (United States)

    Bijttebier, Sebastiaan; D'Hondt, Els; Noten, Bart; Hermans, Nina; Apers, Sandra; Exarchou, Vassiliki; Voorspoels, Stefan

    2014-12-15

    Food processing enterprises produce enormous amounts of organic waste that contains valuable phytochemicals (e.g. C17-polyacetylenes). Knowledge on the phytochemicals content is a first step towards valorisation. Quantification of C17-polyacetylenes is however often hampered by the lack of commercially available standards or by tedious multistep in-house standard production procedures. In the current study, a new and straightforward supercritical fluid chromatography purification procedure is described for the simultaneous production of 2 analytical C17-polyacetylene standards. Respectively, 5 and 6 mg of falcarinol and falcarindiol were purified in 17 h on analytical scale. After confirming the identity and quality (97% purity) by Nuclear Magnetic Resonance, accurate mass-Mass Spectrometry (am-MS) and Photo Diode Array (PDA) detection the C17-polyacetylene standards were used for the analysis of industrial vegetable waste with Liquid Chromatography coupled to PDA and am-MS detection. Measurements showed varying concentrations of C17-polyacetylenes in the organic waste depending on its nature and origin. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Volatile components and key odorants of fennel (Foeniculum vulgare Mill.) and thyme (Thymus vulgaris L.) oil extracts obtained by simultaneous distillation-extraction and supercritical fluid extraction.

    Science.gov (United States)

    Díaz-Maroto, M Consuelo; Díaz-Maroto Hidalgo, Ignacio Javier; Sánchez-Palomo, Eva; Pérez-Coello, M Soledad

    2005-06-29

    Volatile oil extracts of fennel seeds (Foeniculum vulgare Mill.) and thyme leaves (Thymus vulgaris L.) were obtained by simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectrometry (GC-MS). In general, fennel oil extracted by SDE and SFE showed similar compositions, with trans-anethole, estragole, and fenchone as the main components. In contrast, thymol and p-cymene, the most abundant compounds in thyme leaves, showed big differences, with generally higher amounts of monoterpenes obtained by SDE. However, in this case, the differences between the extracts were higher. Key odorants of fennel seeds determined by gas chromatography-olfactometry (GC-O) showed similar patterns when applying SDE and SFE. trans-Anethole (anise, licorice), estragole (anise, licorice, sweet), fenchone (mint, camphor, warm), and 1-octen-3-ol (mushroom) were the most intense odor compounds detected in fennel extracts. Thymol and carvacrol, with oregano, thyme, and spicy notes, were identified as key compounds contributing to the aroma of thyme leaves.

  5. Synthesis of an excellent electrocatalyst for oxygen reduction reaction with supercritical fluid: Graphene cellular monolith with ultrafine and highly dispersive multimetallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yazhou; Cheng, Xiaonong; Yen, Clive H.; Wai, Chien M.; Wang, Chongmin; Yang, Juan; Lin, Yuehe

    2017-04-01

    Graphene cellular monolith (GCM) can be used as an excellent support for nanoparticles in widespread applications. However, it's still a great challenge to deposit the desirable nanoparticles in GCM that have small size, controllable structure, composition, and high dispersion using the current methods. Here we demonstrate a green, efficient and large-scale method to address this challenge using supercritical fluid (SCF). By this superior method, graphene hydrogel can be transferred into GCM while being deposited with ultrafine and highly dispersive nanoparticles. Specifically, the bimetallic PtFe/GCM and the trimetallic PtFeCo/GCM catalysts are successfully synthesized, and their electrocatalytic performances toward oxygen reduction reaction (ORR) are also studied. The resultant PtFe/GCM shows the significant enhancement in ORR activity, including a factor of 8.47 enhancement in mass activity (0.72 A mgPt-1), and a factor of 7.67 enhancement in specific activity (0.92 mA cm-2), comparing with those of the commercial Pt/C catalyst (0.085 A mgPt-1, 0.12 mA cm-2). Importantly, by introducing the Co, the trimetallic PtFeCo/GCM exhibits the further improved ORR activities (1.28 A mgPt-1, 1.80 mA cm-2). The high ORR activity is probably attributed to the alloying structure, ultrafine size, highly dispersive, well-defined, and a better interface with 3D porous graphene support.

  6. Construction of a supercritical fluid extraction (SFE equipment: validation using annatto and fennel and extract analysis by thin layer chromatography coupled to image

    Directory of Open Access Journals (Sweden)

    Júlio Cezar Flores JOHNER

    2016-01-01

    Full Text Available Abstract The present work describes setting up a laboratory unit for supercritical fluid extraction. In addition to its construction, a survey of cost was done to compare the cost of the homemade unit with that of commercial units. The equipment was validated using an extraction of annatto seeds’ oil, and the extraction and fractionation of fennel oil were used to validate the two separators; for both systems, the solvent was carbon dioxide. The chemical profiles of annatto and fennel extracts were assessed using thin layer chromatography; the images of the chromatographic plates were processed using the free ImageJ software. The cost survey showed that the homemade equipment has a very low cost (~US$ 16,000 compared to commercial equipment. The extraction curves of annatto were similar to those obtained in the literature (yield of 3.8% oil. The separators were validated, producing both a 2.5% fraction of fennel seed extract rich in essential oils and another extract fraction composed mainly of oleoresins. The ImageJ software proved to be a low-cost tool for obtaining an initial evaluation of the chemical profile of the extracts.

  7. Investigation of Thermal and Thermomechanical Properties of Biodegradable PLA/PBSA Composites Processed via Supercritical Fluid-Assisted Foam Injection Molding

    Directory of Open Access Journals (Sweden)

    Sai Aditya Pradeep

    2017-01-01

    Full Text Available Bio-based polymer foams have been gaining immense attention in recent years due to their positive contribution towards reducing the global carbon footprint, lightweighting, and enhancing sustainability. Currently, polylactic acid (PLA remains the most abundant commercially consumed biopolymer, but suffers from major drawbacks such as slow crystallization rate and poor melt processability. However, blending of PLA with a secondary polymer would enhance the crystallization rate and the thermal properties based on their compatibility. This study investigates the physical and compatibilized blends of PLA/poly (butylene succinate-co-adipate (PBSA processed via supercritical fluid-assisted (ScF injection molding technology using nitrogen (N2 as a facile physical blowing agent. Furthermore, this study aims at understanding the effect of blending and ScF foaming of PLA/PBSA on crystallinity, melting, and viscoelastic behavior. Results show that compatibilization, upon addition of triphenyl phosphite (TPP, led to an increase in molecular weight and a shift in melting temperature. Additionally, the glass transition temperature (Tg obtained from the tanδ curve was observed to be in agreement with the Tg value predicted by the Gordon–Taylor equation, further confirming the compatibility of PLA and PBSA. The compatibilization of ScF-foamed PLA–PBSA was found to have an increased crystallinity and storage modulus compared to their physically foamed counterparts.

  8. Comprehensive on-line two-dimensional liquid chromatography × supercritical fluid chromatography with trapping column-assisted modulation for depolymerised lignin analysis.

    Science.gov (United States)

    Sun, Mingzhe; Sandahl, Margareta; Turner, Charlotta

    2018-03-16

    Lignin depolymerisation produces a large variety of low molecular weight phenolic compounds that can be upgraded to value-added chemicals. Detailed analysis of these complex depolymerisation mixtures is, however, hampered by the lack of resolving power of traditional analysis techniques. In this study, a novel online comprehensive two-dimensional reversed-phase liquid chromatography (RPLC) × supercritical fluid chromatography (SFC) method with trapping column interface was developed for the separation of phenolic compounds in depolymerised lignin samples. The trapping capacities of different trapping columns were evaluated. The influence of large volume water-containing injection on SFC performance was studied. The relation between peak capacity and first dimension flow rate and gradient was investigated. The optimized method was applied for the analysis of a depolymerised lignin sample. The RPLC × SFC system exhibited high degree of orthogonality. Compared with traditional loop based interface, trapping column interface can significantly shorten the analysis time and offer higher detectability, with the disadvantage of more severe undersampling in the first dimension. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Determination of persistent organic pollutants in solid environmental samples using accelerated solvent extraction and supercritical fluid extraction. Exhaustive extraction and sorption/desorption studies of PCBs

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerklund, E.

    1998-10-01

    Human activity is constantly causing environmental problems due to production and release of numerous chemicals. A group of compounds of special concern is persistent organic pollutants (POP). These toxic, lipophilic chemicals have a high chemical and biological stability, and tend to accumulate in the lipid phase of living organisms. A major sink for POPs are sediments, and consequently these are important for the distribution of POPs in the aquatic environment. Traditionally, determination of POPs relay on exhaustive extraction using liquid extraction techniques (e.g. Soxhlet extraction developed in the late 19th century) followed by gas chromatographic analysis. Since liquid-solid extraction normally requires large volumes of organic solvents in combination with long extraction times and extract clean-up, there has been an increasing demand for improved technology. This should result in reduced organic solvent consumption and sample preparation time, at the same time improving the environment and cutting costs for POP monitoring. In this thesis two modern techniques with capability of fulfilling at least one of these goals have been investigated: (1) Supercritical Fluid Extraction (SFE), and (2) Accelerated Solvent Extraction (ASE). Polychlorinated biphenyls (PCBs) were chosen as model compounds in all experiments performed on environmental matrices, since they cover a relatively large range of physiochemical parameters. Important parameters influencing the overall extraction efficiency in ASE and SFE, are discussed and illustrated for a large number of sediments. It was demonstrated that, by careful consideration of the experimental parameters, both techniques are capable of replacing old methods such as Soxhlet extraction. ASE is somewhat faster than SFE, but the extracts generated in SFE are much cleaner and can be analyzed without sample clean-up. Consequently the overall sample preparation time may be substantially lower using SFE. However, ASE is important

  10. Comparisons of soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and subcritical water extraction for environmental solids: recovery, selectivity and effects on sample matrix.

    Science.gov (United States)

    Hawthorne, S B; Grabanski, C B; Martin, E; Miller, D J

    2000-09-15

    Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100 degrees C), supercritical fluid extraction (SFE) (1 h at 150 degrees C with pure CO2), and subcritical water (1 h at 250 degrees C, or 30 min at 300 degrees C). Although minor differences in recoveries for some PAHs resulted from the different methods, quantitative agreement between all of the methods was generally good. However, the extract quality differed greatly. The organic solvent extracts (Soxhlet and PLE) were much darker, while the extracts from subcritical water (collected in toluene) were orange, and the extracts from SFE (collected in CH2Cl2) were light yellow. The organic solvent extracts also yielded more artifact peaks in the gas chromatography (GC)-mass spectrometry and GC-flame ionization detection chromatograms, especially compared to supercritical CO2. Based on elemental analysis (carbon and nitrogen) of the soil residues after each extraction, subcritical water, PLE, and Soxhlet extraction had poor selectivity for PAHs versus bulk soil organic matter (approximately 1/4 to 1/3 of the bulk soil organic matter was extracted along with the PAHs), while SFE with pure CO2 removed only 8% of the bulk organic matrix. Selectivities for different compound classes also vary with extraction method. Extraction of urban air particulate matter with organic solvents yields very high concentrations of n- and branched alkanes (approximately C18 to C30) from diesel exhaust as well as lower levels of PAHs, and no selectivity between the bulk alkanes and PAHs is obtained during organic solvent extraction. Some moderate selectivity with supercritical CO2 can be achieved by first extracting the bulk alkanes at mild conditions, followed by stronger conditions to extract the remaining PAHs, i.e., the least polar organics are the easiest organics to extract

  11. Fiscal 1997 report on the results of the introductory R and D of the New Sunshine Project under a consignment from NEDO. Introductory R and D of the supercritical fluid use technology; 1997 nendo `New Sunshine keikaku` sendo kenkyu kaihatsu Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku. Chorinkai ryutai riyo gijutsu sendo kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The R and D of chemical reaction using supercritical fluids started in fiscal 1997. In the R and D of solvent reaction, as the research on polymer decomposition with supercritical water, studies were conducted of the mechanism of conversion reaction to chemical materials, cleavage mechanism of stable chemical bonds, and synthetic reaction in the supercritical state reaction field. In the research on oxidation reaction, as the study of complete oxidation in supercritical water for high efficiency energy recovery, studies of complete oxidation of liquid fuels, and complete oxidation of solid fuels. In the research on hydrogenation, studies of lightening of heavy oil in supercritical water, etc. In the R and D of the basic technology, studies of corrosion mechanism of metals in supercritical water, construction of the basic framework for technical database of supercritical fluids, etc. In the survey of technical trends and new research themes, the introductory R and D of element technology, etc. were conducted, and the results were described of the survey of technical trends and new research themes and the trend survey of overseas technology. 314 refs., 87 figs., 81 tabs.

  12. FY 1998 'The New Sunshine Project' leading R and D. Report on the results of the leading R and D of supercritical fluid utilization technology; 1998 nendo 'New Sunshine Keikaku' sendo kenkyu kaihatsu. Chorinkai ryutai riyo gijutsu sendo kenkyu kaihatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The paper reported the FY 1998 achievement of the supercritical fluid utilization leading R and D which started in FY 1997 on a 3-year plan. In the R and D, solvolysis reaction, oxidation reaction and hydrogenation reaction were taken up in the chemical process using supercritical fluid. In the study of solvolysis reaction, the basic data were obtained on decomposition conditions of thermoplastic and thermosetting plastics in supercritical water. Further, concerning the synthesis of environmental friendly type carbonate using CO2, a conversion rate of almost 100% was obtained. About the oxidation reaction, conditions were found out for burning low grade coal in supercritical water without emitting acid gas. This is considered to lead to a possibility of the supercritical water power generation. Relating to the hydrogenation reaction, a study was made on lightening technology of heavy distillate using supercritical water, and the conditions for effective emission of methane and hydrogen were found out. As to the base technology, a study was made of metal materials with high corrosion resistance against supercritical water. (NEDO)

  13. Advanced Supercritical Carbon Dioxide Brayton Cycle Development

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark [Univ. of Wisconsin, Madison, WI (United States); Sienicki, James [Argonne National Lab. (ANL), Argonne, IL (United States); Moisseytsev, Anton [Argonne National Lab. (ANL), Argonne, IL (United States); Nellis, Gregory [Univ. of Wisconsin, Madison, WI (United States); Klein, Sanford [Univ. of Wisconsin, Madison, WI (United States)

    2015-10-21

    Fluids operating in the supercritical state have promising characteristics for future high efficiency power cycles. In order to develop power cycles using supercritical fluids, it is necessary to understand the flow characteristics of fluids under both supercritical and two-phase conditions. In this study, a Computational Fluid Dynamic (CFD) methodology was developed for supercritical fluids flowing through complex geometries. A real fluid property module was implemented to provide properties for different supercritical fluids. However, in each simulation case, there is only one species of fluid. As a result, the fluid property module provides properties for either supercritical CO2 (S-CO2) or supercritical water (SCW). The Homogeneous Equilibrium Model (HEM) was employed to model the two-phase flow. HEM assumes two phases have same velocity, pressure, and temperature, making it only applicable for the dilute dispersed two-phase flow situation. Three example geometries, including orifices, labyrinth seals, and valves, were used to validate this methodology with experimental data. For the first geometry, S-CO2 and SCW flowing through orifices were simulated and compared with experimental data. The maximum difference between the mass flow rate predictions and experimental measurements is less than 5%. This is a significant improvement as previous works can only guarantee 10% error. In this research, several efforts were made to help this improvement. First, an accurate real fluid module was used to provide properties. Second, the upstream condition was determined by pressure and density, which determines supercritical states more precise than using pressure and temperature. For the second geometry, the flow through labyrinth seals was studied. After a successful validation, parametric studies were performed to study geometric effects on the leakage rate. Based on these parametric studies, an optimum design strategy for the see

  14. Analysis of particulate polycyclic aromatic hydrocarbons by on-line coupled supercritical fluid extraction-liquid chromatography-gas chromatography-mass spectrometry

    Science.gov (United States)

    Shimmo, Masahiko; Adler, Heidi; Hyötyläinen, Tuulia; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

    An on-line supercritical fluid extraction-liquid chromatography-gas chromatography-mass spectrometry (SFE-LC-GC-MS) method was developed for the analysis of the particulate polycyclic aromatic hydrocarbons (PAHs). The limits of detection of the system for the quantification standards were in the range of 0.25-0.57 ng, while the limits of determinations for filter samples varied from 0.02 to 0.04 ng m -3 (24 h sampling). The linearity was excellent from 5 to 300 ng ( R2>0.967). The analysis could be carried out in a closed system without tedious manual sample pretreatment and with no risk of errors by contamination or loss of the analytes. The results of the SFE-LC-GC-MS method were comparable with those for Soxhlet and shake-flask extractions with GC-MS. The new method was applied to the analysis of PAHs collected by high-volume filter in the Helsinki area to study the seasonal trend of the concentrations. The individual PAH concentrations varied from 0.015 to more than 1 ng m -3, while total PAH concentrations varied from 0.81 to 5.68 ng m -3. The concentrations were generally higher in winter than in summer. The mass percentage of the total PAHs in total suspended particulates ranged from 2.85×10 -3% in July to 15.0×10 -3% in December. Increased emissions in winter, meteorological conditions, and more serious artefacts during the sampling in summer season may explain the concentration profiles.

  15. Supercritical fluid-mediated liposomes containing cyclosporin A for the treatment of dry eye syndrome in a rabbit model: comparative study with the conventional cyclosporin A emulsion.

    Science.gov (United States)

    Karn, Pankaj Ranjan; Kim, Hyun Do; Kang, Han; Sun, Bo Kyung; Jin, Su-Eon; Hwang, Sung-Joo

    2014-01-01

    The objective of this study was to compare the efficacy of cyclosporin (CsA)-encapsulated liposomes with the commercially available CsA emulsion (Restasis) for the treatment of dry eye syndrome in rabbits. Liposomes containing CsA were prepared by the supercritical fluid (SCF) method consisted of phosphatidylcholine from soybean (SCF-S100) and egg lecithins (SCF-EPCS). An in vitro permeation study was carried out using artificial cellulose membrane in Franz diffusion cells. Dry eye syndrome was induced in male albino rabbits and further subdivided into untreated, Restasis-treated, EPCS, and S100-treated groups. Tear formation in the dry-eye-induced rabbits was evaluated using the Schirmer tear test. All formulations were also evaluated by ocular irritation tests using the Draize eye and winking methods with the determination of CsA concentration in rabbit tears. After the treatment, the Schirmer tear test value significantly improved in EPCS-treated (P=0.005) and S100-treated (P=0.018) groups compared to the Restasis-treated group. The AUC₀₋₂₄ h for rabbit's tear film after the administration of SCF-S100 was 32.75±9.21 μg·h/mg which was significantly higher than that of 24.59±8.69 μg·h/mg reported with Restasis. Liposomal CsA formulations used in this study showed lower irritation in rabbit eyes compared with Restasis. These results demonstrate that the novel SCF-mediated liposomal CsA promises a significant improvement in overcoming the challenges associated with the treatment of dry eyes.

  16. Application of supercritical fluid extraction coupled with counter-current chromatography for extraction and online isolation of unstable chemical components from Rosa damascena.

    Science.gov (United States)

    Li, Sainan; Guo, Liping; Liu, Chunming; Zhang, Yuchi

    2013-07-01

    Supercritical fluid extraction (SFE) coupled with high-speed counter-current chromatography (HSCCC) was successfully used for the extraction and online isolation of the unstable compounds from Rosa damascene in a single extraction and separation operation in two stages. The solvent systems of SFE/HSCCC were optimized with the help of multiexponential function model. At the first stage, the upper phase of the solvent system of n-butanol-tert-butyl methyl ether-acetonitrile-0.1% aqueous TFA (1.7:1.0:0.8:4.0, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, and the target compounds were eluted with the corresponding lower phase to separate the hydrophobic compounds. At the second stage, the upper phase of the solvent system of n-hexane-ethyl acetate-methanol-water (3.2:1.0:2.8:2.6, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, followed by elution with the corresponding lower phase to separate the moderate hydrophobic compounds. Six compounds including formononetin, delphinidin, cyaniding, 5,6,4'-trihydroxy-7,8-dimethoxy flavone, 5,3'-dihydroxy-7,8-dimethoxy flavone, and 5-hydroxy-6,7,8,3',4'-pentamethoxy flavone were successfully separated in one extraction-separation operation within 300 min. The targeted compounds were identified by MS and NMR spectroscopy. This research has opened up great prospects for industrial application of SFE/HSCCC to the extraction and separation of unstable compounds. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preparative isolation and purification of capsaicin and dihydrocapsaicin from Capsici Fructus using supercritical fluid extraction combined with high speed countercurrent chromatography.

    Science.gov (United States)

    Yan, Rongwei; Zhao, Leilei; Tao, Junfei; Zou, Yong; Xu, Xinjun

    2017-10-11

    Supercritical fluid extraction with CO 2 (SFE-CO 2 ) was utilized for extraction of capsaicin (CA) and dihydrocapsaicin (DHCA) from Capsici Fructus, and then a two-step enrichment method for separating capsaicinoids from SFE-CO 2 extracts was developed. The process involved extraction with aqueous methanol and crystallization by alkali extraction and acid precipitation. Finally, a consecutive high-speed countercurrent chromatography (HSCCC) separation method was successfully applied in the purification of CA and DHCA from capsaicinoid crystal. The extraction pressure, extraction temperature and volume of co-solvent were optimized at 33 MPa, 41 °C and 75 mL, respectively, using response surface methodology; the extraction rates of CA and DHCA were about 93.18% and 93.49%, respectively. 407.43 mg capsaicinoid crystal was isolated from the SFE-CO 2 extracts obtained from 100 g capsicum powder by the two-step enrichment method. About 506 mg and 184 mg CA and DHCA with purities up to 98.31% and 96.68%, respectively, were obtained from 1 g capsaicinoid crystal in one HSCCC of three consecutive sample loadings without exchanging any solvent system. This method comprising SFE-CO 2 , a two-step enrichment and HSCCC was efficient, powerful and practical for the large-scale preparation of CA and DHCA from Capsici Fructus with high purity and high yield. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  18. Combination of supercritical fluid extraction with counter-current chromatography to isolate anthocyanidins from the petals of Chaenomeles sinensis based on mathematical calculations.

    Science.gov (United States)

    Li, Sainan; Guo, Liping; Liu, Chunming; Fu, Zi Ao; Zhang, Yuchi

    2013-11-01

    Supercritical fluid extraction (SFE) coupled with high-speed counter-current chromatography (HSCCC) was successfully used for the extraction and on-line isolation of the anthocyanidins from the petals of Chaenomeles sinensis in two stages. The SFE parameters were optimized by an orthogonal test, and the solvent systems of SFE and HSCCC were calculated and optimized with the help of a multiexponential function model. In the first stage, the lower phase of the solvent system of n-butanol/tert-butyl methyl ether/acetonitrile/0.1% aqueous TFA (0.715:1.0:0.134:1.592, v/v/v/v) was used as both the SFE modifier and the HSCCC stationary phase, after extraction, the extractants were pumped into HSCCC column, and then eluted with the corresponding upper phase to isolate the moderately hydrophobic compounds. In the second stage, the upper phase of the solvent system of n-butanol/ethyl acetate/acetonitrile/0.1% aqueous TFA (1.348:1.0:0.605:2.156, v/v/v/v) was used as both the SFE modifier and the HSCCC stationary phase, followed by elution with the corresponding lower phase to separate the hydrophobic compounds. With the help of two-stage SFE/HSCCC, six compounds including delphinidin-3-O-glucoside (Dp3G), cyanidin-3-O-glucoside (Cy3G), peonidin-3-O-glucoside (Pn3G), delphinidin (Dp), peonidin (Pn), and malvidin (Mv) were successfully separated within 300 min. The targeted compounds were identified by UV spectrophotometry, MS, and NMR spectroscopy. This research has opened up great prospects for the industrial application of SFE-HSCCC for the automatic extraction and separation of unstable compounds. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Coupled optical/thermal/fluid analysis and design requirements for operation and testing of a supercritical CO2 solar receiver.

    Energy Technology Data Exchange (ETDEWEB)

    Khivsara, Sagar [Indian Institute of Science, Bangalor (India)

    2015-01-01

    Recent studies have evaluated closed-loop supercritical carbon dioxide (s-CO2) Brayton cycles to be a higher energy-density system in comparison to conventional superheated steam Rankine systems. At turbine inlet conditions of 923K and 25 MPa, high thermal efficiency (~50%) can be achieved. Achieving these high efficiencies will make concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. To incorporate a s-CO2 Brayton power cycle in a solar power tower system, the development of a solar receiver capable of providing an outlet temperature of 923 K (at 25 MPa) is necessary. To satisfy the temperature requirements of a s-CO2 Brayton cycle with recuperation and recompression, it is required to heat s-CO2 by a temperature of ~200 K as it passes through the solar receiver. Our objective was to develop an optical-thermal-fluid model to design and evaluate a tubular receiver that will receive a heat input ~1 MWth from a heliostat field. We also undertook the documentation of design requirements for the development, testing and safe operation of a direct s-CO2 solar receiver. The main purpose of this document is to serve as a reference and guideline for design and testing requirements, as well as to address the technical challenges and provide initial parameters for the computational models that will be employed for the development of s-CO2 receivers.

  20. Supercritical-Carbon Dioxide Fluid Extract from Chrysanthemum indicum Enhances Anti-Tumor Effect and Reduces Toxicity of Bleomycin in Tumor-Bearing Mice

    Directory of Open Access Journals (Sweden)

    Hong-Mei Yang

    2017-02-01

    Full Text Available Bleomycin (BLM, a family of anti-tumor drugs, was reported to exhibit severe side effects limiting its usage in clinical treatment. Therefore, finding adjuvants that enhance the anti-tumor effect and reduce the detrimental effect of BLM is a prerequisite. Chrysanthemum indicum, an edible flower, possesses abundant bioactivities; the supercritical-carbon dioxide fluid extract from flowers and buds of C. indicum (CISCFE have strong anti-inflammatory, anti-oxidant, and lung protective effects. However, the role of CISCFE combined with BLM treatment on tumor-bearing mice remains unclear. The present study aimed to investigate the potential synergistic effect and the underlying mechanism of CISCFE combined with BLM in the treatment of hepatoma 22 (H22 tumor-bearing mice. The results suggested that the oral administration of CISCFE combined with BLM could markedly prolong the life span, attenuate the BLM-induced pulmonary fibrosis, suppress the production of pro-inflammatory cytokines (interleukin-6, tumor necrosis factor-α, activities of myeloperoxidase, and malondiadehyde. Moreover, CISCFE combined with BLM promoted the ascites cell apoptosis, the activities of caspases 3 and 8, and up-regulated the protein expression of p53 and down-regulated the transforming growth factor-β1 by activating the gene expression of miR-29b. Taken together, these results indicated that CISCFE could enhance the anti-cancer activity of BLM and reduce the BLM-induced pulmonary injury in H22 tumor-bearing mice, rendering it as a potential adjuvant drug with chemotherapy after further investigation in the future.

  1. Supercritical Water Process for the Chemical Recycling of Waste Plastics

    Science.gov (United States)

    Goto, Motonobu

    2010-11-01

    The development of chemical recycling of waste plastics by decomposition reactions in sub- and supercritical water is reviewed. Decomposition reactions proceed rapidly and selectively using supercritical fluids compared to conventional processes. Condensation polymerization plastics such as PET, nylon, and polyurethane, are relatively easily depolymerized to their monomers in supercritical water. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Recycling process of fiber reinforced plastics has been studied. Pilot scale or commercial scale plants have been developed and are operating with sub- and supercritical fluids.

  2. Sensitive determination of malondialdehyde in exhaled breath condensate and biological fluids by capillary electrophoresis with laser induced fluorescence detection

    Czech Academy of Sciences Publication Activity Database

    Lačná, J.; Foret, František; Kubáň, Petr

    2017-01-01

    Roč. 169, JUL (2017), s. 85-90 ISSN 0039-9140 Grant - others:GA ČR(CZ) GA13-21919S Keywords : malondialdehyde * capillary electrophoresis * laser induced fluorescence * blood plasma * saliva Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  3. Electromembrane extraction of amino acids from body fluids followed by capillary electrophoresis with capacitively coupled contactless conductivity detection

    Czech Academy of Sciences Publication Activity Database

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-01-01

    Roč. 1218, č. 37 (2011), s. 6248-6255 ISSN 0021-9673 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : electromembrane extraction * biological samples * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.531, year: 2011

  4. Sensitive determination of malondialdehyde in exhaled breath condensate and biological fluids by capillary electrophoresis with laser induced fluorescence detection

    Czech Academy of Sciences Publication Activity Database

    Lačná, J.; Foret, František; Kubáň, Petr

    Roč. 169, JUL (2017), s. 85-90 ISSN 0039-9140 Grant - others:GA ČR(CZ) GA13-21919S Keywords : malondialdehyde * capillary electrophoresis * laser induced fluorescence * blood plasma * saliva Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  5. Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO{sub 2}), as a function of plant provenance and plant parts

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Gislaine F.; Pereira, Marcos D.P.; Lopes, Lucia M.X., E-mail: lopesxl@iq.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica; Silva, Tito da [Universidade Federal do Maranhao (UFMA), Imperatriz, MA (Brazil). Centro de Ciencias Sociais, Saude e Tecnologia; Rosa, Paulo de T. Vieira e; Barbosa, Fernanda P. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica; Messiano, Gisele B. [Instituto Federal de Sao Paulo, SP (Brazil); Krettli, Antoniana U. [Fundacao Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG (Brazil). Instituto Rene Rachou

    2014-04-15

    Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. {sup 1}H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO{sub 2} were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated. (author)

  6. Thermodynamic Aspects of Supercritical Fluids Processing: Applications of Polymers and Wastes Treatment Aspects thermodynamiques des procédés mettant en oeuvre des fluides supercritiques : applications aux traitements des polymères et des déchets

    Directory of Open Access Journals (Sweden)

    Beslin P.

    2006-11-01

    Full Text Available Supercritical fluid processes are of increasing interest for many fields : in supercritical fluid separation (petroleum-chemistry separation and purification, food industry and supercritical fluid chromatography (analytical and preparative separation, determination of physicochemical properties; as reaction media with continuously adjustable properties from gas to liquid (low-density polyethylene, waste destruction, polymer recycling; in geology and mineralogy (volcanoes, geothermal energy, hydrothermal synthesis; in particle, fibber and substrate formations (pharmaceuticals, explosives, coatings; in drying materials (gels. This paper presents the unusual physicochemical properties of supercritical fluids in relation to their engineering applications. After a short report of fundamental concepts of critical behavior in pure fluids, we develop in more details the tunable physicochemical properties of fluid in the supercritical domain. The second part of this paper describes the engineering applications of supercritical fluids relevant of chemical reactions and polymer processing. Each application presentation is divided in two parts : the first one recalls the basic concepts including general background, physicochemical properties and the second one develops the engineering applications relevant of the advocated domain. La mise en Suvre des fluides supercritiques est d'un intérêt croissant dans de nombreux domaines : pour la séparation (séparation et purification en pétrochimie, industrie alimentaire et la chromatographie par fluides supercritiques (séparation analytique et préparatoire, détermination des propriétés physicochimiques, comme milieux réactifs aux propriétés continûment ajustables allant du gaz au liquide (polyéthylène de faible densité, élimination des déchets, recyclage des polymères, en géologie et en minéralogie (volcanologie, énergie géothermique, synthèse hydrothermique, dans la formation des particules

  7. Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE): Lunar Advanced Volatile Analysis (LAVA) Capillary Fluid Dynamic Restriction Effects on Gas Chromatography

    Science.gov (United States)

    Gonzalez, Marianne; Quinn, Jacqueline; Captain, Janine; Santiago-Bond, Josephine; Starr, Stanley

    2015-01-01

    The Resource Prospector (RP) mission with the Regolith and Environment Science and Oxygen Lunar Volatile Extraction (RESOLVE) payload aims to show the presence of water in lunar regolith, and establish a proving ground for NASAs mission to Mars. One of the analysis is performed by the Lunar Advanced Volatiles Analysis (LAVA) subsystem, which consists of a fluid network that facilitates the transport of volatile samples to a gas chromatograph and mass spectrometer (GC-MS) instrument. The understanding of fluid dynamics directed from the GC to the MS is important due to the influence of flow rates and pressures that affect the accuracy of and prevent the damage to the overall GC-MS instrument. The micro-scale capillary fluid network within the GC alone has various lengths and inner-diameters; therefore, determination of pressure differentials and flow rates are difficult to model computationally, with additional complexity from the vacuum conditions in space and lack of a lunar atmosphere. A series of tests were performed on an experimental set-up of the system where the inner diameters of the GC transfer line connecting to the MS were varied. The effect on chromatography readings were also studied by applying these lines onto a GC instrument. It was found that a smaller inner diameter transfer line resulted in a lower flow rate, as well as a lower pressure differential across the thermal conductivity detector (TCD) unit of the GC and a negligible pressure drop across the mock-up capillary column. The chromatography was affected with longer retention times and broader peak integrations. It was concluded that a 0.050 mm inner diameter line still proved most suitable for the systems flow rate preferences. In addition, it was evident that this small transfer line portrayed some expense to GC signal characteristics and the wait time for steady-state operation.

  8. Development of an achiral supercritical fluid chromatography method with ultraviolet absorbance and mass spectrometric detection for impurity profiling of drug candidates. Part I: Optimization of mobile phase composition.

    Science.gov (United States)

    Lemasson, Elise; Bertin, Sophie; Hennig, Philippe; Boiteux, Hélène; Lesellier, Eric; West, Caroline

    2015-08-21

    Supercritical fluid chromatography (SFC) is a very useful tool in the purpose of impurity profiling of drug candidates, as an adequate selection of stationary phases can provide orthogonal separations so as to maximize the chances to see all impurities. The purpose of the present work is to develop a method for chemical purity assessment. The first part, presented here, focuses on mobile phase selection to ensure adequate elution and detection of drug-like molecules, while the second part focuses on stationary phase selection for optimal separation and orthogonality. The use of additives in the carbon dioxide - solvent mobile phase in SFC is now commonplace, and enables in particular to increase the number of eluted compounds and to improve peak shapes. The objective of this first part was to test different additives (acids, bases, salts and water) for their chromatographic performance assessed in gradient elution with a diode-array detector, but also for the mass responses obtained with a single-quadrupole mass detector, equipped with an electrospray ionization source (Waters ACQUITY QDa). In this project, we used a selection of one hundred and sixty compounds issued from Servier Research Laboratories to screen a set of columns and additives in SFC with a Waters ACQUITY UPC(2) system. The selected columns were all high-performance columns (1.7-1.8μm with totally porous particles or 2.6-2.7μm with superficially porous particles) with a variety of stationary phase chemistries. Initially, eight additives dissolved in the methanol co-solvent were tested on a UPC(2) ACQUITY UPC(2) HSS C18 SB column. A Derringer desirability function was used to classify the additives according to selected criteria: elution capability, peak shapes, UV baseline drift, and UV and mass responses (signal-to-noise ratios). Following these tests, the two best additives (ammonium acetate and ammonium hydroxide) were tested on a larger number of columns (10) where the two additives appeared

  9. Ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples.

    Science.gov (United States)

    Prothmann, Jens; Sun, Mingzhe; Spégel, Peter; Sandahl, Margareta; Turner, Charlotta

    2017-12-01

    The conversion of lignin to potentially high-value low molecular weight compounds often results in complex mixtures of monomeric and oligomeric compounds. In this study, a method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) has been developed. Seven different columns were explored for maximum selectivity. Makeup solvent composition and ion source settings were optimised using a D-optimal design of experiment (DoE). Differently processed lignin samples were analysed and used for the method validation. The new UHPSFC/QTOF-MS method showed good separation of the 40 compounds within only 6-min retention time, and out of these, 36 showed high ionisation efficiency in negative electrospray ionisation mode. Graphical abstract A rapid and selective method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS).

  10. Effect of the spraying conditions and nozzle design on the shape and size distribution of particles obtained with supercritical fluid drying

    NARCIS (Netherlands)

    Bouchard, Andreanne; Jovanovic, Natasa; de Boer, Anne H.; Martin, Angel; Jiskoot, Wim; Crommelin, Daan J. A.; Hofland, Gerard W.; Witkamp, Geert-Jan

    In the perspective of production of dry therapeutic protein formulations, spray drying of lysozyme (as a model protein) into Supercritical carbon dioxide was studied. The effects of the nozzle (i.e., co-current coaxial converging and converging-diverging, and T-mixer impinging) and process

  11. Radiolytic and electron-transfer reactions in supercritical CO2

    International Nuclear Information System (INIS)

    Bartels, D. M.; Dimitrijevic, N. M.; Jonah, C. D.; Takahashi, K.

    2000-01-01

    Using supercritical fluids as solvents is useful for both practical and theoretical reasons. It has been proposed to use supercritical CO 2 as a solvent for synthesis because it eliminates the air pollution arising from other solvents. The properties of supercritical fluids can be easily varied with only modest changes in temperature and density, so they provide a way of testing theories of chemical reactions. It has also been proposed to use supercritical fluids for the treatment of hazardous mixed waste. For these reasons the authors have studied the production of radiolytic species in supercritical CO 2 and have measured their reactivity as a function of density. They have shown that the C 2 O 4 + is formed. They also have shown that the electron transfer reactions of dimethylaniline to C 2 O 4 + and CO 2 (e - ) to benzoquinone are diffusion controlled over a considerable density range

  12. Raman spectroscopic measurements of CO2 density: Experimental calibration with high-pressure optical cell (HPOC) and fused silica capillary capsule (FSCC) with application to fluid inclusion observations

    Science.gov (United States)

    Wang, X.; Chou, I-Ming; Hu, W.; Burruss, Robert; Sun, Q.; Song, Y.

    2011-01-01

    Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (Δ, cm−1) and CO2 density (ρ, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent calibration procedures and lack of measurements for CO2fluids having densities between 0.21 and 0.75 g/cm3, where liquid and vapor phases coexist near room temperature.In this study, a high-pressure optical cell and fused silica capillary capsules were used to prepare pure CO2 samples with densities between 0.0472 and 1.0060 g/cm3. The measured CO2 Fermi diad splits were calibrated with two well established Raman bands of benzonitrile at 1192.6 and 1598.9 cm−1. The relationship between the CO2 Fermi diad split and density can be represented by: ρ = 47513.64243 − 1374.824414 × Δ + 13.25586152 × Δ2 − 0.04258891551 × Δ3(r2 = 0.99835, σ = 0.0253 g/cm3), and this relationship was tested by synthetic fluid inclusions and natural CO2-rich fluid inclusions. The effects of temperature and the presence of H2O and CH4 on this relationship were also examined.

  13. Analysis of anabolic steroids in body fluids by capillary gas chromatography with a two-channel detection system and a computer.

    Science.gov (United States)

    Uralets, V P; Semenova, V A; Yakushin, M A; Semenov, V A

    1983-11-25

    A method is described for analysis of multi-component mixtures of steroid metabolites in biological fluids by means of capillary gas chromatography with glass and fused-silica columns and simultaneous detection of methoxylamine-trimethylsilyl derivatives with universal flame-ionization and selective nitrogen alkali flameionization detectors. A data system was applied to the on-line treatment of the results. Computer programs were designed for precise calculation of Kováts retention indices from the known values for selected natural urinary steroids. The programs allow the selection of nitrogen-containing components, normalized chromatogram plotting for both detection channels and qualitative and quantitative analysis. Results are presented on the detection of metabolites of methandrostenolone, 17 alpha-methyltestosterone, 19-nortestosterone and fluoxymesterone.

  14. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Low temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above

  15. Metal Nanoparticles Preparation In Supercritical Carbon Dioxide Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Harry W. Rollins

    2004-04-01

    The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take advantage of the unique properties of a supercritical fluid.(14&15) Through simple variations of temperature and pressure, the properties of a supercritical fluid can be continuously tuned from gas-like to liquid-like without undergoing a phase change. Nanoparticle preparation methods that utilize supercritical fluids are briefly reviewed below using the following categories: Rapid Expansion of Supercritical Solutions (RESS), Reactive Supercritical Fluid Processing, and Supercritical Fluid Microemulsions. Because of its easily accessible critical temperature and pressure and environmentally benign nature, carbon dioxide is the most widely used supercritical solvent. Supercritical CO2 is unfortunately a poor solvent for many polar or ionic species, which has impeded its use in the preparation of metal and semiconductor nanoparticles. We have developed a reactive supercritical fluid processing method using supercritical carbon dioxide for the preparation of metal and metal sulfide particles and used it to prepare narrowly distributed nanoparticles of silver (Ag) and silver sulfide

  16. View of supercritical state; Chorinkai jotai wo miru

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, K. [Chiba Univ., Chiba (Japan)

    2000-04-01

    The supercritical fluid as the second solvents is attracting public attention. Most material extraction separations and chemical reactions are conducted in liquids. While calling the normal liquid as the first solvent, the supercritical fluid is a solvent that has completely new characteristics. In this paper, specific properties of the supercritical fluid in comparison with the usual solvents, utilization, and connection of the specific properties with color changes of the supercritical fluid, are outlined. The manufacturing of the decaffeinated coffee is famous as a utilization of the extracting solvent of the supercritical fluid. In addition, purification of the flora and fauna oil, separation and extraction of unsaturated fatty acid, extraction of medicines and perfumes etc. are raised as the examples. The merit of utilizing the supercritical fluid as a reaction field is to freely control medium properties of liquids and gases under slight changes of temperature and pressure. As for the relation with the environmental problem, the research of the oxidation digestion technique of PCB and dioxin that are highly toxic and are difficult to be decomposed by the supercritical water is widely carried out. (NEDO)

  17. Capillary electrophoresis of a multiplex reverse transcription-polymerase chain reaction to target messenger RNA markers for body fluid identification.

    Science.gov (United States)

    Haas, Cordula; Hanson, Erin; Ballantyne, Jack

    2012-01-01

    The analysis of cell-specific mRNA expression is a promising new method for the identification of body fluids. A number of mRNA markers have been identified for the forensically most relevant body fluids: blood, saliva, semen, vaginal secretions, and menstrual blood. Apart from a significant improvement in specificity compared to conventional protein-based methods, other important advantages of body fluid identification by mRNA profiling include the possibility of simultaneously isolating RNA and DNA from the same piece of stain and the ability to multiplex numerous RNA markers for the identification of one or several body fluids. RNA profiling can be incorporated into current DNA analysis pipelines.

  18. Raman Scattering Study of Supercritical Bi-Component Mixtures Injected into a Subcritical Environment

    National Research Council Canada - National Science Library

    An, Young M

    2007-01-01

    .... Unique thermodynamic and transport properties of supercritical fluids along with phase transition phenomena during fuel injection process can significantly change combustion characteristics inside a scramjet combustor...

  19. Krichevskii parameters of heavy n-alkanes in carbon dioxide: comparison of the results from solubility measurements and from supercritical fluid chromatography

    Czech Academy of Sciences Publication Activity Database

    Roth, Michal

    2003-01-01

    Roč. 212, 1-2 (2003), s. 1-9 ISSN 0378-3812 R&D Projects: GA ČR GA203/02/1093; GA ČR GA203/02/0023 Institutional research plan: CEZ:AV0Z4031919 Keywords : dilute solution in supercritical solvent * partial molar volume * cubic equation of state Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.165, year: 2003

  20. Auraptene, a Major Compound of Supercritical Fluid Extract of Phalsak (Citrus Hassaku Hort ex Tanaka, Induces Apoptosis through the Suppression of mTOR Pathways in Human Gastric Cancer SNU-1 Cells

    Directory of Open Access Journals (Sweden)

    Jeong Yong Moon

    2015-01-01

    Full Text Available The supercritical extraction method is a widely used process to obtain volatile and nonvolatile compounds by avoiding thermal degradation and solvent residue in the extracts. In search of phytochemicals with potential therapeutic application in gastric cancer, the supercritical fluid extract (SFE of phalsak (Citrus hassaku Hort ex Tanaka fruits was analyzed by gas chromatography-mass spectrometry (GC-MS. Compositional analysis in comparison with the antiproliferative activities of peel and flesh suggested auraptene as the most prominent anticancer compound against gastric cancer cells. SNU-1 cells were the most susceptible to auraptene-induced toxicity among the tested gastric cancer cell lines. Auraptene induced the death of SNU-1 cells through apoptosis, as evidenced by the increased cell population in the sub-G1 phase, the appearance of fragmented nuclei, the proteolytic cleavage of caspase-3 and poly(ADP-ribose polymerase (PARP protein, and depolarization of the mitochondrial membrane. Interestingly, auraptene induces an increase in the phosphorylation of Akt, which is reminiscent of the effect of rapamycin, the mTOR inhibitor that triggers a negative feedback loop on Akt/mTOR pathway. Taken together, these findings provide valuable insights into the anticancer effects of the SFE of the phalsak peel by revealing that auraptene, the major compound of it, induced apoptosis in accompanied with the inhibition of mTOR in SNU-1 cells.

  1. Wettability of supercritical carbon dioxide/water/quartz systems: simultaneous measurement of contact angle and interfacial tension at reservoir conditions.

    Science.gov (United States)

    Saraji, Soheil; Goual, Lamia; Piri, Mohammad; Plancher, Henry

    2013-06-11

    Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact angle between the fluids and the rock mineral surface. A thorough study of these parameters and their variations with temperature and pressure will provide a better understanding of the carbon sequestration process and thus improve predictions of the sequestration efficiency. In this study, the controversial concept of wettability alteration of quartz surfaces in the presence of supercritical carbon dioxide (sc-CO2) was investigated. A novel apparatus for measuring interfacial tension and contact angle at high temperatures and pressures based on Axisymmetric Drop Shape Analysis with no-Apex (ADSA-NA) method was developed and validated with a simple system. Densities, interfacial tensions, and dynamic contact angles of CO2/water/quartz systems were determined for a wide range of pressures and temperatures relevant to geological sequestration of CO2 in the subcritical and supercritical states. Image analysis was performed with ADSA-NA method that allows the determination of both interfacial tensions and contact angles with high accuracy. The results show that supercritical CO2 alters the wettability of quartz surface toward less water-wet conditions compared to subcritical CO2. Also we observed an increase in the water advancing contact angles with increasing temperature indicating less water-wet quartz surfaces at higher temperatures.

  2. Comprehensive comparison of classic Soxhlet extraction with Soxtec extraction, ultrasonication extraction, supercritical fluid extraction, microwave assisted extraction and accelerated solvent extraction for the determination of polychlorinated biphenyls in soil.

    Science.gov (United States)

    Sporring, Sune; Bøwadt, Søren; Svensmark, Bo; Björklund, Erland

    2005-10-07

    This paper compares the extraction effectiveness of six different commonly applied extraction techniques for the determination of PCBs in soil. The techniques included are Soxhlet, Soxtec, ultrasonication extraction, supercritical fluid extraction, microwave-assisted extraction and accelerated solvent extraction. For none of the techniques were the extraction conditions optimized, but instead the extraction parameters were based on the experience from previous successful investigation published by a number of research groups worldwide. In general, all extraction techniques were capable of producing accurate data for one native PCB contaminated soil diluted with another soil sample to obtain two concentration levels. It could therefore be concluded that any of the investigated techniques can be used with success if the extraction conditions applied are chosen wisely.

  3. Catalytic and Non-catalytic Supercritical Water Gasification of Microalgae and Glycerol

    NARCIS (Netherlands)

    Chakinala, Anand G.; Brilman, Derk Willem Frederik; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

    2009-01-01

    In this study, we present the gasification of microalgae (Chlorella vulgaris) and glycerol in supercritical water (SCW) using batch (quartz capillaries) and continuous flow reactors. Preliminary tests of algae gasification were done with quartz capillaries at varying operating conditions such as

  4. Capillary electrophoresis in a fused-silica capillary with surface roughness gradient

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Šlais, Karel; Karásek, Pavel; Růžička, F.; Šalplachta, Jiří; Šesták, Jozef; Kahle, Vladislav; Roth, Michal

    2016-01-01

    Roč. 39, č. 19 (2016), s. 3827-3834 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA16-03749S; GA MZd(CZ) NV16-29916A Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supercritical water * surface roughness gradient Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 2.557, year: 2016

  5. Capillary pinning of immiscible gravity currents in porous media

    Science.gov (United States)

    Zhao, B.; MacMinn, C. W.; Huppert, H. E.; Juanes, R.

    2013-12-01

    Gravity currents in porous media have attracted interest recently in the context of geological carbon dioxide (CO2) storage, where supercritical CO2 is captured from the flue gas of power plants and injected underground into deep saline aquifers. Capillarity can be important in the spreading and migration of the buoyant CO2 after injection because the typical pore size is very small (~10-100 microns), but the impact of capillarity on these flows is not well understood. Here, we study the impact of capillarity on the buoyant spreading of a finite gravity current of non-wetting fluid into a dense, wetting fluid in a vertically confined, horizontal aquifer. We show via simple, table-top experiments using glass bead packs that capillary pressure hysteresis pins a portion of the fluid-fluid interface. The horizontal extent of the pinned portion of the interface grows over time and this is responsible for ultimately stopping the spreading of the buoyant current after a finite distance. In addition, capillarity blunts the leading edge of the buoyant current. We demonstrate through micromodel experiments that the characteristic height of the nose of the current is controlled by the pore throat size distribution and the balance between capillarity and gravity. We develop a theoretical model that captures the evolution of immiscible gravity currents and predicts the maximum migration distance. Our work suggests that capillary pinning and capillary blunting exert an important control on finite-release gravity currents in the context of CO2 sequestration in deep saline aquifers. Gravity driven flow of a buoyant, nonwetting fluid (air) over a dense, wetting fluid (propylene glycol). Starting with a vertical interface between the fluids, the flow first undergoes a lock-exchange process. The process models a finite release problem after the dense fluid hits the left boundary. In contrast to finite release of a miscible current that spreads indefinitely, spreading of an immiscible

  6. Application des fluides supercritiques à la production d'hydrocarbures. Exploitation des gisements par récupération assistée et applications diverses : pétrole, sables, schistes, charbons Application of Supercritical Fluids to Hydrocarbon Production. Enhanced Oi Recovery and Miscellaneous Applications: Oil, Tar Sands, Shales, Coals

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available Le taux moyen de récupération par drainage naturel des gisements pétroliers atteint à peine 30 %. La récupération assistée désigne l'ensemble des procédés d'exploitation qui permettent d'accroître très sensiblement ce taux. Parmi ces procédés, l'injection de fluides supercritiques joue un rôle prometteur. Les principaux fluides actuellement utilisés sont : le méthane (ou plus généralement les gaz hydrocarbures dits pauvres , l'azote et enfin le gaz carbonique. Les domaines d'application et les mécanismes thermodynamiques mis en jeu sont brièvement exposés, les sources de fluides supercritiques disponibles au voisinage des gisements pétroliers sont rapidement répertoriées et certains problèmes d'exploitation évoqués. Outre leur application en récupération assistée, les fluides supercritiques sont également impliqués dans des procédés de raffinage et d'extraction divers. C'est le procédé de désasphaltage de fractions pétrolières lourdes qui, en 1956, a fait l'objet de la première application industrielle exploitant les fortes variations du pouvoir solvant d'un fluide au voisinage de son point critique. Ce procédé connaît, depuis une dizaine d'années, un regain d'intérêt du fait de l'économie d'énergie qu'il permet de réaliser. D'autre part, les schistes bitumineux, les sables asphaltiques et les charbons, sources d'hydrocarbures considérables pour l'avenir, constituent des domaines d'applications potentielles originales des fluides supercritiques. Les procédés spécifiques, pour la plupart en cours de développement au stade pilote, sont passés en revue. The average recovery by natural drainage from oil fields is barely 30%. Enhanced recovery includes all production processes which appreciably increase this rate. Among such processes, supercritical fluid flooding is quite promising. The main fluids now used are methane (or, more generally, so-called leangaseous hydrocarbons, nitrogen and carbon

  7. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    Science.gov (United States)

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Supercritical Water Mixture (SCWM) Experiment

    Science.gov (United States)

    Hicks, Michael C.; Hegde, Uday G.

    2012-01-01

    The subject presentation, entitled, Supercritical Water Mixture (SCWM) Experiment, was presented at the International Space Station (ISS) Increment 33/34 Science Symposium. This presentation provides an overview of an international collaboration between NASA and CNES to study the behavior of a dilute aqueous solution of Na2SO4 (5% w) at near-critical conditions. The Supercritical Water Mixture (SCWM) investigation, serves as important precursor work for subsequent Supercritical Water Oxidation (SCWO) experiments. The SCWM investigation will be performed in DECLICs High Temperature Insert (HTI) for the purpose of studying critical fluid phenomena at high temperatures and pressures. The HTI includes a completely sealed and integrated test cell (i.e., Sample Cell Unit SCU) that will contain approximately 0.3 ml of the aqueous test solution. During the sequence of tests, scheduled to be performed in FY13, temperatures and pressures will be elevated to critical conditions (i.e., Tc = 374C and Pc = 22 MPa) in order to observe salt precipitation, precipitate agglomeration and precipitate transport in the presence of a temperature gradient without the influences of gravitational forces. This presentation provides an overview of the motivation for this work, a description of the DECLIC HTI hardware, the proposed test sequences, and a brief discussion of the scientific research objectives.

  9. Biomimetic Unidirectional Capillary Action

    Science.gov (United States)

    Rupert, Eric; Moran, Patrick; Dahl, Jason

    2017-11-01

    In arid environments animals require specialized adaptations to collect adequate water. The Texas horned lizard (P. cornutum) has superhydrophylic skin which draws water out of moist soil or directly from water sources. The water then makes its way into the lizard's unidirectional capillary system, made of overlapping scales, which serves to channel water to its mouth. Testing different channel geometries, repeated ``D'' shaped chambers as in Commans et al. (2015) and truncated isosceles triangle chambers, as found in P. cornutum, we show the ability to have passive, unidirectional, fluid transport. Tests were carried out with the capillaries in a horizontal configuration. While both capillary geometries produced the desired traits, the triangular chambers showed superior unidirectionality, with no observed back flow, while ``D'' chambers showed back flow under testing conditions. The chambers provided similar flow rates. These types of channel systems will find use in microfluidics, notably in medical, printing, and lab-on-chip applications.

  10. Kinetic models for supercritical CO2 extraction of oilseeds - a review

    Directory of Open Access Journals (Sweden)

    B. Nagy

    2011-01-01

    Full Text Available The supercritical fluid extraction of oilseeds is gaining increasing interest in commercial application for the last few decades, most particularly thanks to technical and environmental advantages of supercritical fluid extraction technology compared to current extraction methods with organic solvents. Furthermore, CO2 as a solvent is generally recognized as safe (GRAS. At present moment, supercritical fluid extractions on a commercial scale are limited to decaffeination, production of soluble hops extracts, sesame seed oil production and extraction of certain petroleum products. When considering industrial application, it is essential to test the applicability of the appropriate model for supercritical fluid extraction of oilseeds used for scale up of laboratory data to industrial design purposes. The aim of this paper is to review the most significant kinetic models reported in the literature for supercritical fluid extraction.

  11. Electrochemistry in near-critical and supercritical fluids. 3. Studies of Br/sup -/, I/sup -/, and hydroquinone in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Flarsheim, W.J.; Tsou, Y.M.; Trachtenberg, I.; Johnston, K.P.; Bard, A.J.

    1986-07-31

    A new type of apparatus has been constructed for carrying out electrochemistry in near-critical and supercritical aqueous solutions. The following systems have been studied at a platinum electrode: H/sub 2/O/O/sub 2/, I/sup -//I/sub 2/, Br/sup -//Br/sub 2/, and hydroquinone/benzoquinone. The compact alumina flow cell can be heated or cooled quickly and can be recharged with fresh electrolyte solution while at high temperature and pressure. A large reduction in the potential required for the electrolysis of water was observed. Diffusivities have been measured for iodide ions and hydroquinone. General agreement with the Stokes-Einstein model was observed in the temperature range 25-375/sup 0/C.

  12. Stability analysis of a heated channel cooled by supercritical water

    International Nuclear Information System (INIS)

    Magni, M. C.; Delmastro, D. F; Marcel, C. P

    2009-01-01

    A simple model to study thermal-hydraulic stability of a heated cannel under supercritical conditions is presented. Single cannel stability analysis for the SCWR (Supercritical Water Cooled Reactor) design was performed. The drastic change of fluid density in the reactor core of a SCWR may induce DWO (Density Wave Oscillations) similar to those observed in BWRs. Due to the similarities between subcritical and supercritical systems we may treat the supercritical fluid as a pseudo two-phase system. Thus, we may extend the modeling approach often used for boiling flow stability analysis to supercritical pressure operation conditions. The model developed in this work take into account three regions: a heavy fluid region, similar to an incompressible liquid; a zone where a heavy fluid and a light fluid coexist, similar to two-phase mixture; and a light fluid region which behaves like superheated steam. It was used the homogeneous equilibrium model (HEM) for the pseudo boiling zone, and the ideal gas model for the pseudo superheated steam zone. System stability maps were obtained using linear stability analysis in the frequency domain. Two possible instability mechanisms are observed: DWO and excursive Ledinegg instabilities. Also, a sensitivity analysis showed that frictions in pseudo superheated steam zone, together with acceleration effect, are the most destabilizing effects. On the other hand, frictions in pseudo liquid zone are the most important stabilizing effect. [es

  13. Capillary refill time during fluid resuscitation in patients with sepsis-related hyperlactatemia at the emergency department is related to mortality.

    Directory of Open Access Journals (Sweden)

    Barbara Lara

    Full Text Available Acute circulatory dysfunction in patients with sepsis can evolve rapidly into a progressive stage associated with high mortality. Early recognition and adequate resuscitation could improve outcome. However, since the spectrum of clinical presentation is quite variable, signs of hypoperfusion are frequently unrecognized in patients just admitted to the emergency department (ED. Hyperlactatemia is considered a key parameter to disclose tissue hypoxia but it is not universally available and getting timely results can be challenging in low resource settings. In addition, non-hypoxic sources can be involved in hyperlactatemia, and a misinterpretation could lead to over-resuscitation in an unknown number of cases. Capillary refill time (CRT is a marker of peripheral perfusion that worsens during circulatory failure. An abnormal CRT in septic shock patients after ICU-based resuscitation has been associated with poor outcome. The aim of this study was to determine the prevalence of abnormal CRT in patients with sepsis-related hyperlactatemia in the early phase after ED admission, and its relationship with outcome.We performed a prospective observational study. Septic patients with hyperlactemia at ED admission subjected to an initial fluid resuscitation (FR were included. CRT and other parameters were assessed before and after FR. CRT-normal or CRT-abnormal subgroups were defined according to the status of CRT following initial FR, and major outcomes were registered.Ninety-five hyperlactatemic septic patients were included. Thirty-one percent had abnormal CRT at ED arrival. After FR, 87 patients exhibited normal CRT, and 8 an abnormal one. Patients with abnormal CRT had an increased risk of adverse outcomes (88% vs. 20% p<0.001; RR 4.4 [2.7-7.4], and hospital mortality (63% vs. 9% p<0.001; RR 6.7 [2.9-16] as compared to those with normal CRT after FR. Specifically, CRT-normal patients required less frequently mechanical ventilation, renal replacement

  14. Steady state performance of subcritical and supercritical pressure natural circulation in the same test facility

    International Nuclear Information System (INIS)

    Swapnalee, B.T.; Vijayan, P.K; Sharma, Manish; Pilkhwal, D.S.; Saha, D.; Sinha, R.K.

    2011-01-01

    For supercritical pressure natural circulation loops, explicit correlation for steady state flow are not available. While using the subcritical natural circulation flow correlation for supercritical pressure data, it has been observed that subcritical flow correlation is not able to predict the steady state flow accurately near supercritical pressure condition. A generalized correlation has been proposed to estimate the steady state flow in supercritical pressure natural circulation loop based on a relationship between dimensionless density and dimensionless enthalpy reported in literature. This generalized correlation has been tested with the steady state supercritical pressure CO 2 data and found to be in good agreement. Subsequently supercritical pressure data for different working fluids reported in literature has also been compared with the proposed correlation. It is observed that the same generalized correlation is applicable for other fluids also. The present paper deals with the details of the test facility, the derivation of the generalized correlation and comparison with experimental data. (author)

  15. Comparison of Soxhlet, accelerated solvent and supercritical fluid extraction techniques for volatile (GC-MS and GC/FID) and phenolic compounds (HPLC-ESI/MS/MS) from Lamiaceae species.

    Science.gov (United States)

    Rodríguez-Solana, Raquel; Salgado, José Manuel; Domínguez, José Manuel; Cortés-Diéguez, Sandra

    2015-01-01

    Plants from the Lamiaceae family have been known traditionally for their beneficial health-promoting properties, attributed to their anti-inflammatory, anaesthetic and anti-microbial effects. The purposes of this study was to characterise the essential oils from four Lamiaceae plants by applying different extraction techniques. Accelerated solvent (ASE), Soxhlet and supercritical fluid (SFE) extraction methods were compared for their efficiency in obtaining the essential oils from plants. The volatile compounds were identified by GC-MS and the main chemotype was quantified by GC with flame ionisation detection (FID). Phenolic compounds were identified and quantified by HPLC and electrospray ionisation (ESI) with MS/MS. The essential oils Mentha piperita (ct. menthol/menthone), Rosmarinus officinalis L. (ct. eucalyptol/camphor) and Origanum vulgare (ct. carvacrol/thymol), whereas Thymus vulgaris L. was found to be a pure chemotype (ct. thymol). All three extracts also contained six phenolic compounds. The highest extraction yields were achieved by the Soxhlet and ASE techniques, with M. piperita and R. officinalis L. producing the highest concentrations of rosmarinic and carnosic acids. Finally, it was observed that M. piperita and O. vulgare produced the highest total phenolic content, whereas R. officinalis L. and T. vulgaris L. produced the highest anti-oxidant activity. The ASE and Soxhlet extraction techniques presented the highest yields of volatile and phenolic compounds, showing their suitability to characterise the chemical profile of aromatic plants. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Specific characterization of non-steroidal selective androgen peceptor modulators using supercritical fluid chromatography coupled to ion-mobility mass spectrometry: application to the detection of enobosarm in bovine urine.

    Science.gov (United States)

    Beucher, Laure; Dervilly-Pinel, Gaud; Cesbron, Nora; Penot, Mylène; Gicquiau, Audrey; Monteau, Fabrice; Le Bizec, Bruno

    2017-02-01

    Currently under development for therapeutic purposes in human medicine, non-steroidal selective androgen receptor modulators (non-steroidal SARMs) are also known to impact growth associated pathways. As such, they present a potential for abuse in sports and food-producing animals as interesting alternative anabolic substances. Forbidden since 2008 by the World Anti-Doping Agency (WADA) these compounds are however easily available and could be (mis)used in livestock production as growth promoters. To prevent such practices, dedicated analytical strategies have to be developed for specific and sensitive detection of these compounds in biological matrices. Using an innovative analytical platform constituted of supercritical fluid chromatography coupled to ion mobility-mass spectrometry, the present study enabled efficient separation and identification in urine of 4 of these drugs (andarine, bicalutamide, hydroxyflutamide, and enobosarm) in accordance with European Union criteria (Commission Decision 2002/657/EC). Besides providing information about compounds structure and behaviour in gas phase, such a coupling enabled reaching low limits of detection (LOD < 0.05 ng.mL -1 for andarine and limits of detection < 0.005 ng.mL -1 for the three others) in urine with good repeatability (CV < 21 %). The workflow has been applied to quantitative determination of enobosarm elimination in urine of treated bovine (200 mg, oral). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Fast supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection for multiresidue screening of organochlorine and organophosphorus pesticides in Brazil's medicinal plants.

    Science.gov (United States)

    Zuin, V G; Yariwake, J H; Bicchi, C

    2003-01-24

    A description is given of a rapid and environmentally friendly method to determine organochlorine and organophosphorus pesticide multiresidues--malathion, methidathion, fenitrothion, fenthion, parathion-ethyl, parathion-methyl, lindane, hexachlorobenzene, chlorothalonil, tetradifon, alpha-endosulfan, beta-endosulfan and dieldrin-in Passiflora alata Dryander and pasiflora edulis Sims. f. flavicarpa Deg. leaves by supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection (HRGC-ECD/FPD). The mild extraction conditions [pure CO2; 100 bar (1 bar = 10(5) Pa) and 40 degrees C (p = 0.62 g/ml); 5 min static+10 min dynamic extraction time; ODS trap and elution with 1 ml n-hexane at 2 ml/min] allow for direct analysis by HRGC-ECD/FPD with no prior cleaning procedure. The method provides. in accordance with the validation criteria of the European Pharmacopoeia, analytical results that are similar or even better than the official procedures, and is simpler, faster and cheaper. Mean recoveries of 69.8-107.1% were obtained, with 1.4-14.7% reproducibility (RSD). The method was applied to analyse commercial samples of Passiflora L. from Brazil. Twenty-three percent of the samples showed the presence of the organochlorine or organophosphorus pesticide residue investigated.

  18. The Protective Effects of the Supercritical-Carbon Dioxide Fluid Extract of Chrysanthemum indicum against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Modulating Toll-Like Receptor 4 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiao-Li Wu

    2014-01-01

    Full Text Available The supercritical-carbon dioxide fluid extract of Chrysanthemum indicum Linné. (CFE has been demonstrated to be effective in suppressing inflammation. The aim of this study is to investigate the preventive action and underlying mechanisms of CFE on acute lung injury (ALI induced by lipopolysaccharide (LPS in mice. ALI was induced by intratracheal instillation of LPS into lung, and dexamethasone was used as a positive control. Results revealed that pretreatment with CFE abated LPS-induced lung histopathologic changes, reduced the wet/dry ratio and proinflammatory cytokines productions (TNF-α, IL-1β, and IL-6, inhibited inflammatory cells migrations and protein leakages, suppressed the levels of MPO and MDA, and upregulated the abilities of antioxidative enzymes (SOD, CAT, and GPx. Furthermore, the pretreatment with CFE downregulated the activations of NF-κB and the expressions of TLR4/MyD88. These results suggested that CFE exerted potential protective effects against LPS-induced ALI in mice and was a potential therapeutic drug for ALI. Its mechanisms were at least partially associated with the modulations of TLR4 signaling pathways.

  19. Development of a supercritical fluid extraction-gas chromatography-mass spectrometry method for the identification of highly polar compounds in secondary organic aerosols formed from biogenic hydrocarbons in smog chamber experiments.

    Science.gov (United States)

    Chiappini, L; Perraudin, E; Durand-Jolibois, R; Doussin, J F

    2006-11-01

    A new one-step method for the analysis of highly polar components of secondary organic aerosols (SOA) has been developed. This method should lead to a better understanding of SOA formation and evolution since it enables the compounds responsible for SOA formation to be identified. Since it is based on supercritical fluid extraction coupled to gas chromatography-mass spectrometry, it minimizes the analysis time and significantly enhances sensitivity, which makes it suitable for trace-level compounds, which are constituents of SOA. One of the key features of this method is the in situ derivatisation step: an online silylation allowing the measurement of highly polar, polyfunctional compounds, which is a prerequisite for the elucidation of chemical mechanisms. This paper presents the development of this analytical method and highlights its ability to address this major atmospheric issue through the analysis of SOA formed from the ozonolysis of a biogenic hydrocarbon (sabinene). Ozonolysis of sabinene was performed in a 6 m3 Teflon chamber. The aerosol components were derivatised in situ. More than thirty products, such as sabinaketone, sabinic acid and other multifunctional compounds including dicarboxylic acids and oxoacids, were measured. Nine of them were identified and quantified. The sensitivity and the linearity (0.91

  20. Supercritical Airfoil Coordinates

    Data.gov (United States)

    National Aeronautics and Space Administration — Rectangular Supercritical Wing (Ricketts) - design and measured locations are provided in an Excel file RSW_airfoil_coordinates_ricketts.xls . One sheet is with Non...

  1. Computational Modeling of Supercritical and Transcritical Flows

    Science.gov (United States)

    2017-01-09

    pr Reduced pressure (p/pc) Tc Critical temperature Tr Reduced temperature (T/Tc) Vm Molar volume Xi Mole fraction of species i Z Compressibility ω...empirically based atomization and breakup models are insufficient, a complete interface tracking method like the volume of fluid approach can be used. In such...combustion between transcritical oxygen and supercritical hydrogen . It was found that intense property gradients were present that approached contact

  2. Coiled tubing drilling with supercritical carbon dioxide

    Science.gov (United States)

    Kolle , Jack J.

    2002-01-01

    A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC--CO.sub.2 much more effective than water jet erosion. SC--CO.sub.2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO.sub.2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO.sub.2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

  3. Use of supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Masayuki (Niigata Univ., Faculty of Engineering, Niigata, (Japan))

    1989-09-25

    Supercritical fluid extraction is a novel diffusion and separation technique which exploits simultaneously the increase of vapor pressure and the difference of chemical affinities of fluids near the critical point. A solvent which is used as the supercritical fluid has the following features: the critical point exists in the position of relatively ease of handling, the solvent is applicable to the extraction of a physiological active substance of thermal instability. Carbon dioxide as the solvent is non-flammable, non-corrosive, non-toxic, cheap, and readily available of high purity. The results of studies on the use of supercritical carbon dioxide (SC-CO{sub 2}) as a solvent for natural products in the fermentation and food industries, were collected. SC-CO{sub 2} extraction are used in many fields, examples for the application are as follows: removal of organic solvents from antibiotics; extraction of vegetable oils contained in wheat germ oil, high quality mustard seeds, rice bran and so on; brewing of sake using rice and rice-koji; use as a non-aqueous medium for the synthesis of precursors of the Aspartame; and use in sterilization. 66 refs., 17 figs., 21 tabs.

  4. Supercritical Carbon Dioxide and Its Potential as a Life-Sustaining Solvent in a Planetary Environment

    Directory of Open Access Journals (Sweden)

    Nediljko Budisa

    2014-08-01

    Full Text Available Supercritical fluids have different properties compared to regular fluids and could play a role as life-sustaining solvents on other worlds. Even on Earth, some bacterial species have been shown to be tolerant to supercritical fluids. The special properties of supercritical fluids, which include various types of selectivities (e.g., stereo-, regio-, and chemo-selectivity have recently been recognized in biotechnology and used to catalyze reactions that do not occur in water. One suitable example is enzymes when they are exposed to supercritical fluids such as supercritical carbon dioxide: enzymes become even more stable, because they are conformationally rigid in the dehydrated state. Furthermore, enzymes in anhydrous organic solvents exhibit a “molecular memory”, i.e., the capacity to “remember” a conformational or pH state from being exposed to a previous solvent. Planetary environments with supercritical fluids, particularly supercritical carbon dioxide, exist, even on Earth (below the ocean floor, on Venus, and likely on Super-Earth type exoplanets. These planetary environments may present a possible habitat for exotic life.

  5. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium

    Czech Academy of Sciences Publication Activity Database

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-01-01

    Roč. 32, č. 10 (2011), s. 1182-1189 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : electromembrane extraction * biological samples * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  6. Capillary thinning of polymeric filaments

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Szabo, Peter

    1999-01-01

    The capillary thinning of filaments of a Newtonian polybutene fluid and a viscoelastic polyisobutylene solution are analyzed experimentally and by means of numerical simulation. The experimental procedure is as follows. Initially, a liquid sample is placed between two cylindrical plates. Then...

  7. Sub- and supercritical jet disintegration

    Science.gov (United States)

    DeSouza, Shaun; Segal, Corin

    2017-04-01

    Shadowgraph visualization and Planar Laser Induced Fluorescence (PLIF) are applied to single orifice injection in the same facility and same fluid conditions to analyze sub- to supercritical jet disintegration and mixing. The comparison includes jet disintegration and lateral spreading angle. The results indicate that the shadowgraph data are in agreement with previous visualization studies but differ from the PLIF results that provided quantitative measurement of central jet plane density and density gradients. The study further evaluated the effect of thermodynamic conditions on droplet production and quantified droplet size and distribution. The results indicate an increase in the normalized drop diameter and a decrease in the droplet population with increasing chamber temperatures. Droplet size and distribution were found to be independent of chamber pressure.

  8. Extraction and isotopic analysis of medium molecular weight hydrocarbons from Murchison using supercritical carbon dioxide

    Science.gov (United States)

    Gilmour, Iain; Pillinger, Colin

    1993-03-01

    The large variety of organic compounds present in carbonaceous chondrites poses particular problems in their analysis not the least of which is terrestrial contamination. Conventional analytical approaches employ simple chromatographic techniques to fractionate the extractable compounds into broad classes of similar chemical structure. However, the use of organic solvents and their subsequent removal by evaporation results in the depletion or loss of semi-volatile compounds as well as requiring considerable preparative work to assure solvent purity. Supercritical fluids have been shown to provide a powerful alternative to conventional liquid organic solvents used for analytical extractions. A sample of Murchison from the Field Museum was analyzed. Two interior fragments were used; the first (2.85 g) was crushed in an agate pestel and mortar to a grain size of ca. 50-100 micron, the second (1.80 g) was broken into chips 3-8 mm in size. Each sample was loaded into a stainless steel bomb and placed in the extraction chamber of an Isco supercritical fluid extractor maintained at 35 C. High purity (99.9995 percent) carbon dioxide was used and was pressurized using an Isco syringe pump. The samples were extracted dynamically by flowing CO2 under pressure through the bomb and venting via a 50 micron fused filica capillary into 5 mls of hexane used as a collection solvent. The hexane was maintained at a temperature of 0.5 C. A series of extractions were done on each sample using CO2 of increasing density. The principal components extracted in each fraction are summarized.

  9. Fast determination of alkylphenol ethoxylates in leafy vegetables using a modified quick, easy, cheap, effective, rugged, and safe method and ultra-high performance supercritical fluid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jiang, Ze-Jun; Cao, Xiao-Lin; Li, Hui; Zhang, Chan; Abd El-Aty, A M; Jin, Fen; Shao, Hua; Jin, Mao-Jun; Wang, Shan-Shan; She, Yong-Xin; Wang, Jing

    2017-11-24

    In the present study, a quick and sensitive method was developed for simultaneous determination of nonylphenol ethoxylates (NPxEOs) and octylphenol ethoxylates (OPxEOs) (x=2-20) in three leafy vegetables, including cabbage, lettuce, and spinach using a modified "QuEChERS" method and ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MS/MS) with scheduled multiple reaction monitoring (MRM). Under optimized conditions, the 38 target analytes were analyzed within a short period of time (5 min). The linearities of the matrix-matched standard calibrations were satisfactory with coefficients of determination (R 2 )>0.99 and the limits of detection (LOD) and quantification (LOQ) were in between 0.02-0.27 and 0.18-1.75μgkg -1 , respectively. The recovery of all target analytes spiked at three (low, medium, and high) fortification levels in various leafy vegetables were ranged from 72.8-122.6% with relative standard deviation (RSD) ≤18.3%. The method was successfully applied to market samples and the target analytes were found in all monitored samples, with total concentrations of 0-8.67μgkg -1 and 15.75-95.75μgkg -1 for OPxEOs and NPxEOs (x=2-20), respectively. In conclusion, the newly developed UHPSFC-ESI-MS/MS method is rapid and versatile and could be extrapolated for qualitative and quantitative analysis of APxEOs in other leafy vegetables. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Extraction of Thyme Oil: Comparison between Hydrodistillation and Supercritical CO2 Extraction

    Czech Academy of Sciences Publication Activity Database

    Aleksovski, S. A.; Sovová, Helena; Poposka, F. A.

    2001-01-01

    Roč. 51, č. 4 (2001), s. 305-310 ISSN 1330-0075 Institutional research plan: CEZ:AV0Z4072921 Keywords : thymus serpyllum * supercritical fluid extraction * assential oil Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  11. Supercritical CO2 Extraction of Volatile Thymoquinone from Monarda didyma and M. fistulosa Herbs.

    Czech Academy of Sciences Publication Activity Database

    Sovová, Helena; Sajfrtová, Marie; Topiař, Martin

    2015-01-01

    Roč. 105, OCT (2015), s. 29-34 ISSN 0896-8446. [European Meeting on Supercritical Fluid s /14./. Marseille, 18.05.2014-21.05.2014] R&D Projects: GA TA ČR TA01010578 Institutional support: RVO:67985858 Keywords : supercritical fluid extraction * kinetics * volatile oil Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.579, year: 2015

  12. Hydrogenation of diesel aromatic compounds in supercritical solvent environment

    Directory of Open Access Journals (Sweden)

    E.P. Martins

    2000-09-01

    Full Text Available Reactions under supercritical conditions have been employed in many processes. Furthermore, an increasing number of commercial reactions have been conducted under supercritical or near critical conditions. These reaction conditions offer several advantages when compared to conditions in conventional catalytic processes in liquid-phase, gas-liquid interface, or even some gas-phase reactions. Basically, a supercritical solvent can diminish the reactant’s transport resistance from the bulk region to the catalyst surface due to enhancement of liquid diffusivity values and better solubility than those in different phases. Another advantage is that supercritical solvents permit prompt and easy changes in intermolecular properties in order to modify reaction parameters, such as conversion or selectivity, or even proceed with the separation of reaction products. Diesel fractions from petroleum frequently have larger than desirable quantities of aromatic compounds. Diesel hydrogenation is intended to decrease these quantities, i.e., to increase the quantity of paraffin present in this petroleum fraction. In this work, the hydrogenation of tetralin was studied as a model reaction for the aromatic hydrogenation process. A conventional gas-liquid-solid catalytic process was compared with that of supercritical carbon dioxide substrate under similar conditions. Additionally, an equilibrium conversion diagram was calculated for this reaction in a wide range of temperature and reactant ratios, so as to optimize the operational conditions and improve the results of subsequent experiments. An increase in the rate of reaction at 493 K in supercritical fluid, as compared to that in the conventional process, was observed.

  13. Design of experimental system for supercritical CO2 fracturing under confining pressure conditions

    Science.gov (United States)

    Wang, H.; Lu, Q.; Li, X.; Yang, B.; Zheng, Y.; Shi, L.; Shi, X.

    2018-03-01

    Supercritical CO2 has the characteristics of low viscosity, high diffusion and zero surface tension, and it is considered as a new fluid for non-polluting and non-aqueous fracturing which can be used for shale gas development. Fracturing refers to a method of utilizing the high-pressure fluid to generate fractures in the rock formation so as to improve the oil and gas flow conditions and increase the oil and gas production. In this article, a new type of experimental system for supercritical CO2 fracturing under confining pressure conditions is designed, which is based on characteristics of supercritical CO2, shale reservoir and down-hole environment. The experimental system consists of three sub-systems, including supercritical CO2 generation system, supercritical CO2 fracturing system and data analysis system. It can be used to simulate supercritical CO2 fracturing under geo-stress conditions, thus to study the rock initiation pressure, the formation of the rock fractures, fractured surface morphology and so on. The experimental system has successfully carried out a series of supercritical CO2 fracturing experiments. The experimental results confirm the feasibility of the experimental system and the high efficiency of supercritical CO2 in fracturing tight rocks.

  14. Eco-friendly ionic liquid assisted capillary electrophoresis and α-acid glycoprotein-assisted liquid chromatography for simultaneous determination of anticancer drugs in human fluids.

    Science.gov (United States)

    Abd El-Hady, Deia; Albishri, Hassan M; Rengarajan, Rajesh

    2015-06-01

    In the current work, two eco-friendly analytical methods based on capillary electrophoresis (CE) and reversed phase liquid chromatography (RPLC) were developed for simultaneous determination of the most commonly used anticancer drugs for Hodgkin's disease: methotrexate (MTX), vinblastine, chlorambucil and dacarbazine. A background electrolyte (BGE) of 12.5 mmol/L phosphate buffer at pH 7.4 and 0.1 µmol/L 1-butyl-3-methyl imidazolium bromide (BMImBr) ionic liquid (IL) was used for CE measurements at 250 nm detection wavelength, 20 kV applied voltage and 25 °C. The rinsing protocol was significantly improved to reduce the adsorption of IL on the interior surface of capillary. Moreover, RPLC method was developed on α-1-acid glycoprotein (AGP) column. Mobile phase was 10 mmol/L phosphate buffer at pH 6.0 (100% v/v) and flow rate at 0.1 mL/min. As AGP is a chiral column, it was successfully separated l-MTX from its enantiomer impurity d-MTX. Good linearity of quantitative analysis was achieved with coefficients of determinations (r(2) ) >0.995. The stability of drugs measurements was investigated with adequate recoveries up to 24 h storage time under ambient temperature. The limits of detection were <50 and 90 ng/mL by CE and RPLC, respectively. The using of short-chain IL as an additive in BGE achieved 600-fold sensitivity enhancement compared with conventional Capillary Zone Electrophoresis (CZE). Therefore, for the first time, the proposed methods were successfully applied to determine simultaneously the analytes in human plasma and urine samples at clinically relevant concentrations with fast and simple pretreatments. Developed IL-assisted CE and RPLC methods were also applied to measure MTX levels in patients' samples over time. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Geological model of supercritical geothermal reservoir related to subduction system

    Science.gov (United States)

    Tsuchiya, Noriyoshi

    2017-04-01

    Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550

  16. Comparison of hot Soxhlet and accelerated solvent extractions with microwave and supercritical fluid extractions for the determination of polycyclic aromatic hydrocarbons and nitrated derivatives strongly adsorbed on soot collected inside a diesel particulate filter.

    Science.gov (United States)

    Oukebdane, K; Portet-Koltalo, F; Machour, N; Dionnet, F; Desbène, P L

    2010-06-30

    Several methods of extraction were optimized to extract polycyclic aromatic hydrocarbons (PAHs), their nitrated derivatives and heavy n-alkanes from a highly adsorptive particulate matter resulting from the combustion of diesel fuel in a diesel engine. This particular carbonaceous particulate matter, collected at high temperatures in cordierite diesel particulate filters (DPF), which are optimized for removing diesel particles from diesel engine exhaust emissions, appeared extremely refractory to extractions using the classical extracting conditions for these pollutants. In particular, the method of accelerated solvent extraction (ASE) is described in detail here. Optimization was performed through experimental design to understand the impact of each factor studied and the factors' possible interactions on the recovery yields. The conventional extraction technique, i.e., Soxhlet extraction, was also carried out, but the lack of quantitative extractions led us to use a more effective approach: hot Soxhlet. It appeared that the extraction of the heaviest PAHs and nitroPAHs by either the optimized ASE or hot Soxhlet processes was far from complete. To enhance recovery yields, we tested original solvent mixtures of aromatic and heteroaromatic solvents. Thereafter, these two extraction techniques were compared to microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). In every case, the only solvent mixture that permitted quantitative extraction of the heaviest PAHs from the diesel soot was composed of pyridine and diethylamine, which has a strong electron-donor character. Conversely, the extraction of the nitrated PAHs was significantly improved by the use of an electron-acceptor solvent or by introducing a small amount of acetic acid into the pyridine. It was demonstrated that, for many desirable features, no single extraction technique stound out as the best: ASE, MAE or SFE could all challenge hot Soxhlet for favourable extractions

  17. Numerical study on flow rate limitation of open capillary channel flow through a wedge

    Directory of Open Access Journals (Sweden)

    Ting-Ting Zhang

    2016-04-01

    Full Text Available The flow characteristics of slender-column flow in wedge-shaped channel under microgravity condition are investigated in this work. The one-dimensional theoretical model is applied to predict the critical flow rate and surface contour of stable flow. However, the one-dimensional model overestimates the critical flow rate for not considering the extra pressure loss. Then, we develop a three-dimensional simulation method with OpenFOAM, a computational fluid dynamics tool, to simulate various phenomena in wedge channels with different lengths. The numerical results are verified with the capillary channel flow experimental data on the International Space Station. We find that the three-dimensional simulation perfectly predicts the critical flow rates and surface contours under various flow conditions. Meanwhile, the general behaviors in subcritical, critical, and supercritical flow are studied in three-dimensional simulation considering variations of flow rate and open channel length. The numerical techniques for three-dimensional simulation is validated for a wide range of configurations and is hopeful to provide valuable guidance for capillary channel flow experiment and efficient liquid management in space.

  18. Visualization study for forced convection heat transfer of supercritical carbon dioxide near pseudo-boiling point

    International Nuclear Information System (INIS)

    Sakurai, K.; Ko, H.S.; Okamoto, K.; Madarame, H.

    2001-01-01

    For development of new reactor, supercritical water is expected to be used as coolant to improve thermal efficiency. However, the thermal characteristics of supercritical fluid is not revealed completely because its difficulty for experiment. Specific phenomena tend to occur near the pseudo-boiling point which is characterised by temperature corresponding to the saturation point in ordinary fluid. Around this point, the physic properties such as density, specific heat and thermal conductivity are drastically varying. Although there is no difference between gas and liquid phases in supercritical fluids, phenomena similar to boiling (with heat transfer deterioration) can be observed round the pseudo-boiling point. Experiments of heat transfer have been done for supercritical fluid in forced convective condition. However, these experiments were mainly realised inside stainless steel cylinder pipes, for which flow visualisation is difficult. Consequently, this work has been devoted to the development of method allowing the visualisation of supercritical flows. The experiment setup is composed of main loop and test section for the visualisation. Carbon dioxide is used as test fluid. Supercritical carbon dioxide flows upward in rectangular channel and heated by one-side wall to generate forced convection heat transfer. Through window at mid-height of the test section, shadowgraphy was applied to visualize density gradient distribution. The behavior of the density wave in the channel is visualized and examined through the variation of the heat transfer coefficient. (author)

  19. Microfluidic study for investigating migration and residual phenomena of supercritical CO2 in porous media

    Science.gov (United States)

    Park, Gyuryeong; Wang, Sookyun; Lee, Minhee; Um, Jeong-Gi; Kim, Seon-Ok

    2017-04-01

    The storage of CO2 in underground geological formation such as deep saline aquifers or depleted oil and gas reservoirs is one of the most promising technologies for reducing the atmospheric CO2 release. The processes in geological CO2 storage involves injection of supercritical CO2 (scCO2) into porous formations saturated with brine and initiates CO2 flooding with immiscible displacement. The CO2 migration and porewater displacement within geological formations, and , consequentially, the storage efficiency are governed by the interaction of fluid and rock properties and are affected by the interfacial tension, capillarity, and wettability in supercritical CO2-brine-mineral systems. This study aims to observe the displacement pattern and estimate storage efficiency by using micromodels. This study aims to conduct scCO2 injection experiments for visualization of distribution of injected scCO2 and residual porewater in transparent pore networks on microfluidic chips under high pressure and high temperature conditions. In order to quantitatively analyze the porewater displacement by scCO2 injection under geological CO2 storage conditions, the images of invasion patterns and distribution of CO2 in the pore network are acquired through a imaging system with a microscope. The results from image analysis were applied in quantitatively investigating the effects of major environmental factors and scCO2 injection methods on porewater displacement process by scCO2 and storage efficiency. The experimental observation results could provide important fundamental information on capillary characteristics of reservoirs and improve our understanding of CO2 sequestration progress.

  20. Exp6-polar thermodynamics of dense supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Bastea, S; Fried, L E

    2007-12-13

    We introduce a simple polar fluid model for the thermodynamics of dense supercritical water based on a Buckingham (exp-6) core and point dipole representation of the water molecule. The proposed exp6-polar thermodynamics, based on ideas originally applied to dipolar hard spheres, performs very well when tested against molecular dynamics simulations. Comparisons of the model predictions with experimental data available for supercritical water yield excellent agreement for the shock Hugoniot, isotherms and sound speeds, and are also quite good for the self-diffusion constant and relative dielectric constant. We expect the present approach to be also useful for other small polar molecules and their mixtures.