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Sample records for paraneoplasiques endocriniens spe

  1. Interest of the PET with F DOPA in the exploration of endocrine para neoplastic syndromes (E.P.S.): about four cases; Interet de la TEP a la FDOPA dans l'exploration des syndromes paraneoplasiques endocriniens (SPE): a propos de 4 cas

    Energy Technology Data Exchange (ETDEWEB)

    Moreau Triby, C.; Pina, G.; Bournaud, C. [Centre de medecine nucleaire, groupement hospitalier Est, Lyon, (France); Billotey, C. [CERMEP, Lyon, (France); Raverot, G.; Borson Chazot, F. [service d' endocrinologie, groupement hospitalier Est, Lyon, (France)

    2009-05-15

    In front an ectopic secretion of adrenocorticotropic hormone (ACTH or corticotropin) or growth hormone (GH) the existence of an endocrine tumor must be evoked. The topographical diagnosis of these tumors is often difficult. The positron computed tomography with 6-fluoro-({sup 18}F)-L-dihydroxy-phenylalanine (PET-FDOPA) showed recently a good sensitivity in the detection of well differentiated endocrine tumors. We report our experience of the PET-FDOPA in the explorations of para-neoplasic endocrine syndromes. Our experience was relatively disappointing, this examination being a little contributive for our patients. The scintigraphy of receptors with somatostatin with octreoscan keeps all this place in this indication. (N.C.)

  2. Electronic publishing of SPE papers

    International Nuclear Information System (INIS)

    Perdue, J.M.

    1992-01-01

    This paper reports that the SPE is creating an electronic index to over 25,000 technical papers and will produce a CD-ROM as an initial product. This SPE CD-ROM Masterdisc will be available at the SPE Annual Meeting in Washington, D.C. on October 4-7, 1992. The SPE Board has appointed an Ad Hoc Committee on Electronic Publishing to coordinate and oversee this project and to recommend authoring standards for submitting SPE papers electronically in the future

  3. Consolidation and Disclosure of SPE

    OpenAIRE

    中野, 貴之

    2011-01-01

    The purpose of this study is to discuss what kinds of information are demanded by the users of financial statements and what kinds of problems plague the companies using SPE (special purpose equity), while considering the actual situations of the consolidation and disclosure of SPE in Japan. At present, there is the trend of consolidating a broad range of SPE in Japan, etc., but some users of financial statements point out that it became difficult to understand consolidated financial stat...

  4. Endocrinair : contamination de l'air ambiant : Contamination de l’air ambiant par les perturbateurs endocriniens en Ile de France et caractérisation d’effets toxiques associés

    OpenAIRE

    Chevreuil , Marc; Oziol , Lucie

    2012-01-01

    National audience; En Ile de France, la contamination permanente de l’air ambiant soulève de nouvelles interrogations quant à l’exposition de l’Homme à des perturbateurs endocriniens par cette voie et à la possibilité d’effets sur sa santé, même si ceux-ci sont à faible concentration (micropolluants). Ce qui constitue l’aspect innovant de ce programme, c’est la recherche de molécules semi-volatiles à l’état gazeux ou liées à des particules à l’extérieur et à l’intérieur de locaux (appartement...

  5. GCR and SPE Radiation Effects in Materials

    Science.gov (United States)

    Waller, Jess; Rojdev, Kristina; Nichols, Charles

    2016-01-01

    This Year 3 project provides risk reduction data to assess galactic cosmic ray (GCR) and solar particle event (SPE) space radiation damage in materials used in manned low-earth orbit, lunar, interplanetary, and Martian surface missions. Long duration (up to 50 years) space radiation damage is being quantified for materials used in inflatable structures (1st priority), and space suit and habitable composite materials (2nd priority). The data collected has relevance for nonmetallic materials (polymers and composites) used in NASA missions where long duration reliability is needed in continuous or intermittent space radiation fluxes.

  6. SPE dose prediction using locally weighted regression

    International Nuclear Information System (INIS)

    Hines, J. W.; Townsend, L. W.; Nichols, T. F.

    2005-01-01

    When astronauts are outside earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events (SPEs). The total dose received from a major SPE in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be mitigated with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train and provides predictions as accurate as neural network models previously used. (authors)

  7. New Insights into the Explosion Source from SPE

    Science.gov (United States)

    Patton, H. J.

    2015-12-01

    Phase I of the Source Physics Experiments (SPE) is a series of chemical explosions at varying depths and yields detonated in the same emplacement hole on Climax stock, a granitic pluton located on the Nevada National Security Site. To date, four of the seven planned tests have been conducted, the last in May 2015, called SPE-4P, with a scaled depth of burial of 1549 m/kt1/3 in order to localize the source in time and space. Surface ground motions validated that the source medium did not undergo spallation, and a key experimental objective was achieved where SPE-4P is the closest of all tests in the series to a pure monopole source and will serve as an empirical Green's function for analysis against other SPE tests. A scientific objective of SPE is to understand mechanisms of rock damage for generating seismic waves, particularly surface and S waves, including prompt damage under compressive stresses and "late-time" damage under tensile stresses. Studies have shown that prompt damage can explain ~75% of the seismic moment for some SPE tests. Spallation is a form of late-time damage and a facilitator of damage mechanisms under tensile stresses including inelastic brittle deformation and shear dilatancy on pre-existing faults or joints. As an empirical Green's function, SPE-4P allows the study of late-time damage mechanisms on other SPE tests that induce spallation and late-time damage, and I'll discuss these studies. The importance for nuclear monitoring cannot be overstated because new research shows that damage mechanisms can affect surface wave magnitude Ms more than tectonic release, and are a likely factor related to anomalous mb-Ms behavior for North Korean tests.

  8. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    Science.gov (United States)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  9. Cathare2 V1.3E post-test computations of SPE-1 and SPE-2 experiments at PMK-NVH facility

    International Nuclear Information System (INIS)

    Belliard, M.; Laugier, E.

    1994-01-01

    This paper presents the first CATHARE2 V1.3E simulations of the SPE-2 transients at PMK-NVH loop. Concerning the SPE-1 and the SPE-2 experimentations at PMK-NVH, it contains a description of the facilities and the transient, as well as different conditions of use. The paper includes also a presentation of the CATHARE2 model and different type of computation, such as the steady state computation or SPE-1 and SPE-2 transient (TEC). 4 refs., 12 figs., 4 tabs

  10. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

    Science.gov (United States)

    Savinell, Robert F.; Fritts, S. D.

    1987-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  11. Study of alkylphenols, indol and pyridinic nucleus of HPAN compounds by SPE/SI and SPE/C{sub 18}/NEC: application of SPE/Si phase to oils from the Alagoas sub-basin

    Energy Technology Data Exchange (ETDEWEB)

    Reboucas, L.M.C.; Nogueira, F.A.R.; Sabino, A.R.; Araujo, O.R.P.; Sant' Ana, A.E.G. [Universidade Federal de Alagoas (LABIS/UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia. Lab. de Analise de Biomarcadores e Semioquimicos], E-mail: lmcr@qui.ufal.br

    2008-10-15

    Alkylphenols (AP) and hydrocarbon polycyclic aromatic nitrogen (HPAN) compounds are important to study secondary migrations of petroleum. The behavior of AP and HPAN standards was investigated by solid phase extraction (SPE) on silica gel (SPE/Si) and C{sub 18}/NEC (SPE/C{sub 18}) stationary phases. The AP standards were eluted with dichloromethane (DCM) in the F2 fraction, on both SPE/Si and SPE/C{sub 18} phases. The basic and neutral HPAN compounds were eluted together with DCM, in F2 fraction, when a SPE/C18 column was used. However in the SPE/Si column the HPAN compounds were separated by their basic and neutral character in two different fractions. The neutral HPAN compounds were eluted with DCM, F2 fraction, and the HPAN basic compounds were eluted with the mixture DCM:isopropanol 5%, F3 fraction. In general, the quantity of recovered AP and HPAN compounds was higher with SPE/Si than SPE/C{sub 18}. The nine oil samples were analyzed by SPE/Si and the saturated and aromatic hydrocarbon were separated from the polar AP and HPAN. (author)

  12. Determination of 90Sr from aqueous solutions using SPE extraction

    International Nuclear Information System (INIS)

    Dulanska, S.; Rajec, P.; Matel, L.

    2008-01-01

    Solid Phase Extraction (SPE) is widely used technique for the isolation and concentration of analytes from liquid samples to achieve increased sensitivity in the analytical process. Three commercial sorbents produced by three different manufacturers were tested. 3M Empore TM Strontium Rad Disks, Sr resin and AnaLig Sr-01 were used to efficiently isolate strontium from aqueous samples. (authors)

  13. Volume overload cleanup: An approach for on-line SPE-GC, GPC-GC, and GPC-SPE-GC

    NARCIS (Netherlands)

    Kerkdijk, H.; Mol, H.G.J.; Nagel, B. van der

    2007-01-01

    A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the

  14. Autonomous Monitoring of Radiation Environment and Personal Systems for Crew Enhanced SPE Protection (AMORE and PSYCHE)

    Science.gov (United States)

    Narici, L.; Baiocco, G.; Berrilli, F.; Giraudo, M.; Ottolenghi, A.; Rizzo, A.; Salina, G.

    2018-02-01

    Understand the relationship between SPE precursors, the related SPE radiation inside the Deep Space Gateway, and the associated risk levels, validating existing models, proposing countermeasures actions via a real time, autonomous intelligent system.

  15. SPE5 Sub-Scale Test Series Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, Kevin S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reeves, Robert V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); DeHaven, Martin R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Strickland, Shawn L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-14

    A series of 2 SPE5 sub-scale tests were performed to experimentally confirm that a booster system designed and evaluated in prior tests would properly initiate the PBXN-110 case charge fill. To conduct the experiments, a canister was designed to contain the nominally 50 mm diameter booster tube with an outer fill of approximately 150 mm diameter by 150 mm in length. The canisters were filled with PBXN-110 at NAWS-China Lake and shipped back to LLNL for testing in the High Explosives Applications Facility (HEAF). Piezoelectric crystal pins were placed on the outside of the booster tube before filling, and a series of piezoelectric crystal pins along with Photonic Doppler Velocimetry (PDV) probes were placed on the outer surface of the canister to measure the relative timing and magnitude of the detonation. The 2 piezoelectric crystal pins integral to the booster design were also utilized along with a series of either piezoelectric crystal pins or piezoelectric polymer pads on the top of the canister or outside case that utilized direct contact, gaps, or different thicknesses of RTV cushions to obtain time of arrival data to evaluate the response in preparation for the large-scale SPE5 test. To further quantify the margin of the booster operation, the 1st test (SPE5SS1) was functioned with both detonators and the 2nd test (SPE5SS2) was functioned with only 1 detonator. A full detonation of the material was observed in both experiments as observed by the pin timing and PDV signals. The piezoelectric pads were found to provide a greater measured signal magnitude during the testing with an RTV layer present, and the improved response is due to the larger measurement surface area of the pad. This report will detail the experiment design, canister assembly for filling, final assembly, experiment firing, presentation of the diagnostic results, and a discussion of the results.

  16. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Margaret [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States); Obi, Curtis [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States)

    2015-04-30

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and farfield data that are available.This revised document includes reports on baseline shift corrections for the SPE-2 and SPE-3 shots that were missing from the original January 2015 version.

  17. NEAR FIELD MODELING OF SPE1 EXPERIMENT AND PREDICTION OF THE SECOND SOURCE PHYSICS EXPERIMENTS (SPE2)

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T; Xu, H; Vorobiev, O; Lomov, I

    2011-10-20

    Motion along joints and fractures in the rock has been proposed as one of the sources of near-source shear wave generation, and demonstrating the validity of this hypothesis is a focal scientific objective of the source physics experimental campaign in the Climax Stock granitic outcrop. A modeling effort has been undertaken by LLNL to complement the experimental campaign, and over the long term provide a validated computation capability for the nuclear explosion monitoring community. The approach involves performing the near-field nonlinear modeling with hydrodynamic codes (e.g., GEODYN, GEODYN-L), and the far-field seismic propagation with an elastic wave propagation code (e.g., WPP). the codes will be coupled together to provide a comprehensive source-to-sensor modeling capability. The technical approach involves pre-test predictions of each of the SPE experiments using their state of the art modeling capabilities, followed by code improvements to alleviate deficiencies identified in the pre-test predictions. This spiral development cycle wherein simulations are used to guide experimental design and the data from the experiment used to improve the models is the most effective approach to enable a transition from the descriptive phenomenological models in current use to the predictive, hybrid physics models needed for a science-based modeling capability for nuclear explosion monitoring. The objective of this report is to describe initial results of non-linear motion predictions of the first two SPE shots in the Climax Stock: a 220-lb shot at a depth of 180 ft (SPE No.1), and a 2570-lb shot at a depth of 150 ft (SPE No.2). The simulations were performed using the LLNL ensemble granite model, a model developed to match velocity and displacement attenuation from HARDHAT, PILE DRIVER, and SHOAL, as well as Russian and French nuclear test data in granitic rocks. This model represents the state of the art modeling capabilities as they existed when the SPE campaign was

  18. Data Release Report for Source Physics Experiments 2 and 3 (SPE-2 and SPE-3) Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Margaret [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site; Obi, Curtis [National Security Technologies, LLC, Las Vegas, NV (United States). Nevada Test Site

    2015-01-26

    The second Source Physics Experiment shot (SPE-2) was conducted in Nevada on October 25, 2011, at 1900:00.011623 Greenwich Mean Time (GMT). The explosive source was 997 kilograms (kg) trinitrotoluene (TNT) equivalent of sensitized heavy ammonium fuel oil (SHANFO) detonated at a depth of 45.7 meters (m). The third Source Physics Experiment shot (SPE-3) was conducted in Nevada on July 24, 2012, at 1800:00.44835 GMT. The explosive source was 905 kg TNT equivalent of SHANFO detonated at a depth of 45.8 m. Both shots were recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 m) and far-field (100 m or greater) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes at 15, 46, and 55 m depths around the shot and a set of single-component vertical accelerometers on the surface. The far-field network was composed of a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 m to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the second and third Source Physics Experiment shots and the various types of near-field and far-field data that are available.

  19. Effets perturbateurs endocriniens des pesticides organochlores.

    Science.gov (United States)

    Charlier, C; Plomteux, G

    2002-01-01

    Xenoestrogens such organochlorine pesticides are known to induce changes in reproductive development, function or behaviour in wildlife. Because these compounds are able to modify the estrogens metabolism, or to compete with estradiol for binding to the estrogen receptor, it may be possible that these products affect the risk of developing impaired fertility, precocious puberty or some kinds of cancer in man. Le plus ancien récit de lutte contre la pollution remonte à une légende indienne racontant que la divinité Sing-bonga était incommodée par les émanations des fours dans lesquels les Asuras fondaient leurs métaux (1). Evidemment depuis, la problématique n-a cessé de s-accroître et la contamination de la Terre par de nombreux polluants est devenue aujourd-hui un problème majeur de notre Société. La protection de notre environnement est une question capitale qui doit être respectée malgré la pression économique actuelle et qui ne cessera de croître au cours des prochaines années même si l-identification objective et indiscutable de ce qui est essentiel - donc devant être prioritairement garanti sur la planète - est difficile à cerner (2). « Un oiseau en mauvais état ne pond pas de bons oeufs » disait un proverbe grec. Mais ce n-est qu-à partir de la seconde moitié du XXème siècle que les toxicologues ont commencé à identifier les effets qu-avaient entraînés à l-échelle mondiale les pollutions émises aux XIXème siècle sur la faune sauvage et sur le cheptel (3). L-histoire contemporaine des pesticides industriels commence vers 1874 (synthèse des organochlorés) et se poursuit tout au long de ces 2 siècles en passant par la synthèse des organophosphorés (1950), des carbamates (1970) et des pyréthroïdes (1975) (4). Le dichlorodiphényltrichloroéthane (DDT) a été synthétisé pour la première fois par un étudiant en cours de préparation de sa thèse de doctorat : Othmer Zeidler. La production, reprise par les entreprises F.Mayo puis par la Geigy Co. a d-abord intéressé l-armée, puis l-agriculture. Dès la fin de la 2(ème) guerre mondiale, des mises en garde furent lancées à propos des effets nocifs du produit (4). Un déclin des populations de grives, d-aigles chauves, d-orfaies et de mammifères consommateurs de poissons fut constaté à partir des années 50 et dénoncé par Rachel Carson dans son célèbre appel du « Silent Spring » de 1962. Bien qu-il soit interdit en Occident depuis les années 70, ce produit a été tellement utilisé et présente une rémanence si longue qu-une contamination ubiquitaire existe aujourd-hui encore. De plus, ce produit continue à être produit aux USA pour être utilisé à des fins de démoustification dans les pays en voie de développement. Il en va de même de l-Hexachlorobenzène (HCB), un autre organochloré dont l-usage est interdit sous nos latitudes, mais reste fréquent dans d-autres pays. Ces deux exemples indiquent que le problème de la contamination continue à nous concerner, même pour des produits dont l-usage est aujourd-hui strictement réglementé ou interdit. Des effets sur la faune semblent encore actuellement devoir être attribués à ces produits. La diminution de la population des phoques dans la mer de Wadden pourrait être due à la forte contamination en composants organochlorés des poissons dont ces phoques se nourrissent (5). Exposé au DDT et à son métabolite dichlorodiphenyldichloroéthylène (DDE), le Seratherodon mossambicus présente une réduction de la sécrétion de cortisol par une action toxique cytospécifique sur l-axe hypothalamo-hypophysaire (6). Des travaux récents ont montré que le DDT et le DDE se lient chez les oiseaux et les mammifères au moyen de liaisons covalentes aux cellules de la zona fasciculata - homologue du tissu interrénal du poisson - induisant des microhémorragies. Cette « défaillance » cortisolique peut s-accompagner d-une perturbation du métabolisme glucidique et notamment d-un taux élevé de glycogène hépatique (7). Les pesticides organochlorés (DDT, DDE) entraînent également des perturbations d-ordre métabolique chez certaines espèces d-oiseaux, notamment le faucon pèlerin en Grande Bretagne et les oiseaux piscivores des grands lacs nord américains où l-on a constaté au cours des années 1960 que leur reproduction était menacée et qu-une des manifestations les plus évidentes des perturbations observées était le taux élevé de malformations (8). Des mortalités élevées de poissons ou de coquillages ont été rapportées dans des élevages situés à proximité des zones d-épandage de pesticides organophosphorés et de carbamates. En 1991, la dispersion aérienne de fenitrothion dans le but de provoquer la démoustication en Languedoc a été à l-origine de la perte de plusieurs tonnes de crevettes japonaises. L-utilisation de trichlorfon et de dichlorvos comme antiparasitaires dans des fermes d-élevages de saumons a provoqué des épisodes de mortalité importante (9).

  20. Pre-shot simulations of far-field ground motion for the Source Physics Experiment (SPE) Explosions at the Climax Stock, Nevada National Security Site: SPE2

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R J; Rodgers, A; Walter, W; Ford, S; Xu, H; Matzel, E; Myers, S; Petersson, N A; Sjogreen, B; Hauk, T; Wagoner, J

    2011-10-18

    The Source Physics Experiment (SPE) is planning a 1000 kg (TNT equivalent) shot (SPE2) at the Nevada National Security Site (NNSS) in a granite borehole at a depth (canister centroid) of 45 meters. This shot follows an earlier shot of 100 kg in the same borehole at a depth 60 m. Surrounding the shotpoint is an extensive array of seismic sensors arrayed in 5 radial lines extending out 2 km to the north and east and approximately 10-15 to the south and west. Prior to SPE1, simulations using a finite difference code and a 3D numerical model based on the geologic setting were conducted, which predicted higher amplitudes to the south and east in the alluvium of Yucca Flat along with significant energy on the transverse components caused by scattering within the 3D volume along with some contribution by topographic scattering. Observations from the SPE1 shot largely confirmed these predictions although the ratio of transverse energy relative to the vertical and radial components was in general larger than predicted. A new set of simulations has been conducted for the upcoming SPE2 shot. These include improvements to the velocity model based on SPE1 observations as well as new capabilities added to the simulation code. The most significant is the addition of a new source model within the finite difference code by using the predicted ground velocities from a hydrodynamic code (GEODYN) as driving condition on the boundaries of a cube embedded within WPP which provides a more sophisticated source modeling capability linked directly to source site materials (e.g. granite) and type and size of source. Two sets of SPE2 simulations are conducted, one with a GEODYN source and 3D complex media (no topography node spacing of 5 m) and one with a standard isotropic pre-defined time function (3D complex media with topography, node spacing of 5 m). Results were provided as time series at specific points corresponding to sensor locations for both translational (x,y,z) and rotational

  1. A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

    Energy Technology Data Exchange (ETDEWEB)

    Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

    2003-02-01

    Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

  2. Reflection processing of the large-N seismic data from the Source Physics Experiment (SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Paschall, Olivia C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-18

    The purpose of the SPE is to develop a more physics-based model for nuclear explosion identification to understand the development of S-waves from explosion sources in order to enhance nuclear test ban treaty monitoring.

  3. Characterization of plasma protein binding dissociation with online SPE-HPLC

    OpenAIRE

    Li, Ping; Fan, Yiran; Wang, Yunlong; Lu, Yaxin; Yin, Zheng

    2015-01-01

    A novel parameter of relative recovery (Rre) was defined and determined by online SPE-HPLC to characterize plasma protein binding (PPB) kinetics of highly plasma binding drugs. The proportional relationship of Rre with koff of PPB has been established with a new SPE model. A rapid, easy to use method could potentially be used to categorize PK properties of the drug candidates in the decision process of drug discovery and development.

  4. Analysis of xanthines in beverages using a fully automated SPE-SPC-DAD hyphenated system

    Energy Technology Data Exchange (ETDEWEB)

    Medvedovici, A. [Bucarest Univ., Bucarest (Romania). Faculty of Chemistry, Dept. of Analytical Chemistry; David, F.; David, V.; Sandra, P. [Research Institute of Chromatography, Kortrijk (Belgium)

    2000-08-01

    Analysis of some xanthines (caffeine, theophylline and theobromine) in beverages has been achieved by a fully automated on-line Solid Phase Extraction - Supercritical Fluid Chromatography - Diode Array Detection (Spe - Sofc - Dad). Three adsorbents have been tested for the Spe procedure: octadecyl modified silicagel (ODS) and two types of styrene-divinylbenzen copolymer based materials, from which Porapack proved to be the most suitable adsorbent. Optimisation and correlation of both Spe and Sofc operational parameters are also discussed. By this technique, caffeine was determined in ice tea and Coca-Cola in a concentration of 0.15 ppm, theobromine - 1.5 ppb, and theophylline - 0.15 ppb. [Italian] Si e' realizzata l'analis di alcune xantine (caffeina, teofillina e teobromina) mediante un sistema, in linea, completamente automatizzato basato su Estrazione in Fase Solida - Cromatografia in Fase Supercritica - Rivelazione con Diode Array (Spe - Sfc - Dad). Per la procedura Spe sono stati valutati tre substrati: silice ottadecilica (ODS) e due tipi di materiali polimerici a base stirene-divinilbenzene, di cui, quello denominato PRP-1, e' risultato essere il piu' efficiente. Sono discusse sia l'ottimizzazione che la correlazione dei parametri operazionali per la Spe e la Sfc. Con questa tecnica sono state determinate, in te' ghiacciato e Coca-Cola, la caffeina, la teobromina e la teofillina alle concentrazini di 0.15, 1.5 e 0.15 ppm.

  5. Vps33b pathogenic mutations preferentially affect VIPAS39/SPE-39-positive endosomes.

    Science.gov (United States)

    Tornieri, Karine; Zlatic, Stephanie A; Mullin, Ariana P; Werner, Erica; Harrison, Robert; L'hernault, Steven W; Faundez, Victor

    2013-12-20

    Mutations in Vps33 isoforms cause pigment dilution in mice (Vps33a, buff) and Drosophila (car) and the neurogenic arthrogryposis, renal dysfunction and cholestasis syndrome in humans (ARC1, VPS33B). The later disease is also caused by mutations in VIPAS39, (Vps33b interacting protein, apical-basolateral polarity regulator, SPE-39 homolog; ARC2), a protein that interacts with the HOmotypic fusion and Protein Sorting (HOPS) complex, a tether necessary for endosome-lysosome traffic. These syndromes offer insight into fundamental endosome traffic processes unique to metazoans. However, the molecular and cellular mechanisms underlying these mutant phenotypes remain poorly understood. Here we investigate interactions of wild-type and disease-causing mutations in VIPAS39/SPE-39 and Vps33b by yeast two hybrid, immunoprecipitation and quantitative fluorescent microscopy. We find that although few mutations prevent interaction between VIPAS39/SPE-39 and Vps33b, some mutants fragment VIPAS39/SPE-39-positive endosomes, but all mutants alter the subcellular localization of Vps33b to VIPAS39/SPE-39-positive endosomes. Our data suggest that the ARC syndrome may result through impaired VIPAS39/SPE-39 and Vps33b-dependent endosomal maturation or fusion.

  6. Inhibitory effect of SPE-39 due to tyrosine phosphorylation and ubiquitination on the function of Vps33B in the EGF-stimulated cells.

    Science.gov (United States)

    Ishii, Ayumi; Kamimori, Kanae; Hiyoshi, Mineyoshi; Kido, Hiroshi; Ohta, Takeshi; Konishi, Hiroaki

    2012-07-30

    Although SPE-39 is a binding protein to Vps33B that is one of the subunit in the mammalian HOPS complex, the elements of SPE-39 function remain unknown. Here, we show that tyrosine phosphorylation of SPE-39 following EGF stimulation plays a role in the stability of SPE-39 itself. Ubiquitination of the C-terminal region of SPE-39 was also elevated in response to EGF stimulation, and this process was regulated by the phosphorylation of Tyr-11 in SPE-39. However, association of Vps33B with SPE-39 inhibited the elevation of ubiquitination of SPE-39 following EGF stimulation, which might be responsible for the stabilization of SPE-39. Furthermore, an opposing functional relationship between SPE-39 and Vps33B on the downregulation of the EGF receptor was observed in EGF-stimulated COS-7 cells. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  7. Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG

    OpenAIRE

    Filippova, Ekaterina V.; Weigand, Steven; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Anderson, Wayne F.

    2015-01-01

    The spermidine N-acetyltransferase SpeG is a dodecameric enzyme that catalyzes the transfer of an acetyl group from acetyl-coenzyme A to polyamines such as spermidine and spermine. SpeG has an allosteric polyamine-binding site and acetylating polyamines regulates their intracellular concentrations. The structures of SpeG from Vibrio cholerae in complexes with polyamines and cofactor have been characterized earlier. Here, we present the dodecameric structure of SpeG from V. cholerae in a ligan...

  8. Glufosinate ammonium clean-up procedure from water samples using SPE

    Science.gov (United States)

    Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

    2015-09-01

    For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

  9. Solid-phase extraction (SPE) of Iron using Lanthanum Silicate ion exchange

    International Nuclear Information System (INIS)

    Kiarostami, V.; Husain, W.

    2002-01-01

    Solid-phase extraction (SPE) is gaining wide use as an effective and speedy technique which reduces solvent usage, disposal costs and extraction time. The analyte is adsorbed from solution onto a solid adsorbent, which is followed by elution of the analyte with a solvent appropriate for instrumental analysis. However, there is an increasing need for new selective adsorbents to expand the area of this technique. Lanthanum silicate ion exchanger, which shows unusual selectivity elements and in this study, it was employed to develop a SPE method for iron ion. Special experiments such as determination of distribution coefficient for iron ion in different solvent systems have been determined

  10. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    Science.gov (United States)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  11. Streptococcal pyogenic exotoxin B (SpeB) boosts the contact system via binding of a-1 antitrypsin

    DEFF Research Database (Denmark)

    Meinert Niclasen, Louise; Olsen, Johan G; Dagil, Robert

    2011-01-01

    The Streptococcus pyogenes cysteine protease SpeB (streptococcal pyrogenic exotoxin B) is important for the invasive potential of the bacteria, but its production is down-regulated following systemic infection. This prompted us to investigate if SpeB potentiated the host immune response after sys...

  12. Identification of Radical Scavenging Compounds in Rhaponticum carthamoides by Means of LC-DAD-SPE-NMR

    NARCIS (Netherlands)

    Miliauskas, G.; Beek, van T.A.; Waard, de P.; Venskutonis, R.P.; Sudhölter, E.J.R.

    2005-01-01

    A hyphenated LC-DAD-SPE-NMR setup in combination with on-line radical scavenging detection has been applied for the identification of radical scavenging compounds in extracts of Rhaponticum carthamoides. After NMR measurements, the pure compounds were infused into a mass spectrometer. The technique

  13. Preliminary X-ray crystallographic studies of Bacillus subtilis SpeA protein

    International Nuclear Information System (INIS)

    Liu, Xiao-Yan; Lei, Jian; Liu, Xiang; Su, Xiao-Dong; Li, Lanfen

    2009-01-01

    In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme the speA gene was amplified from B. subtilis genomic DNA and cloned. The enzyme was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 298 K. The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme in polyamine metabolism in B. subtilis. In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme, the speA gene was amplified from B. subtilis genomic DNA and cloned into the expression vector pET-28a(+). SpeA was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 289 K. The best crystal diffracted to 2.0 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 86.4, b = 63.3 c = 103.3 Å, β = 113.9°

  14. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Fellenz, Emily S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  15. Proceedings of the 1992 SPE oil and gas economics, finance and management conference

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This volume contains the proceedings of the SPE 1992 Oil and Gas Economics, Finance and Management Conference. Topics covered include: Iran's petroleum industry, planning and control of reserves, natural gas supply and demand. petroleum investment and exploration contracts, and project financing

  16. Design and construction of an on-line SPE-SFE-CGC system

    Directory of Open Access Journals (Sweden)

    Pinto Jair S. S.

    2001-01-01

    Full Text Available The construction of an on-line SPE-SFE-CGC system is described. The home-made system is of low cost and of easy construction and maintenance, making possible the analysis of organic micropollutants in liquid samples such as water in a fraction of the time spent using traditional methods.

  17. Time-Dependent Moment Tensors of the First Four Source Physics Experiments (SPE) Explosions

    Science.gov (United States)

    Yang, X.

    2015-12-01

    We use mainly vertical-component geophone data within 2 km from the epicenter to invert for time-dependent moment tensors of the first four SPE explosions: SPE-1, SPE-2, SPE-3 and SPE-4Prime. We employ a one-dimensional (1D) velocity model developed from P- and Rg-wave travel times for Green's function calculations. The attenuation structure of the model is developed from P- and Rg-wave amplitudes. We select data for the inversion based on the criterion that they show consistent travel times and amplitude behavior as those predicted by the 1D model. Due to limited azimuthal coverage of the sources and the mostly vertical-component-only nature of the dataset, only long-period, diagonal components of the moment tensors are well constrained. Nevertheless, the moment tensors, particularly their isotropic components, provide reasonable estimates of the long-period source amplitudes as well as estimates of corner frequencies, albeit with larger uncertainties. The estimated corner frequencies, however, are consistent with estimates from ratios of seismogram spectra from different explosions. These long-period source amplitudes and corner frequencies cannot be fit by classical P-wave explosion source models. The results motivate the development of new P-wave source models suitable for these chemical explosions. To that end, we fit inverted moment-tensor spectra by modifying the classical explosion model using regressions of estimated source parameters. Although the number of data points used in the regression is small, the approach suggests a way for the new-model development when more data are collected.

  18. Analysis of the Source Physics Experiment SPE4 Prime Using State-Of Parallel Numerical Tools.

    Science.gov (United States)

    Vorobiev, O.; Ezzedine, S. M.; Antoun, T.; Glenn, L.

    2015-12-01

    This work describes a methodology used for large scale modeling of wave propagation from underground chemical explosions conducted at the Nevada National Security Site (NNSS) fractured granitic rock. We show that the discrete natures of rock masses as well as the spatial variability of the fabric of rock properties are very important to understand ground motions induced by underground explosions. In order to build a credible conceptual model of the subsurface we integrated the geological, geomechanical and geophysical characterizations conducted during recent test at the NNSS as well as historical data from the characterization during the underground nuclear test conducted at the NNSS. Because detailed site characterization is limited, expensive and, in some instances, impossible we have numerically investigated the effects of the characterization gaps on the overall response of the system. We performed several computational studies to identify the key important geologic features specific to fractured media mainly the joints characterized at the NNSS. We have also explored common key features to both geological environments such as saturation and topography and assess which characteristics affect the most the ground motion in the near-field and in the far-field. Stochastic representation of these features based on the field characterizations has been implemented into LLNL's Geodyn-L hydrocode. Simulations were used to guide site characterization efforts in order to provide the essential data to the modeling community. We validate our computational results by comparing the measured and computed ground motion at various ranges for the recently executed SPE4 prime experiment. We have also conducted a comparative study between SPE4 prime and previous experiments SPE1 and SPE3 to assess similarities and differences and draw conclusions on designing SPE5.

  19. Targeted natural product isolation guided by HPLC-SPE-NMR: Constituents of Hubertia species

    DEFF Research Database (Denmark)

    Sprogoe, K.; Staek, D.; Jager, A.K.

    2007-01-01

    -hydroxyphenyl)acetyl]quinic acid (3), was performed. Finally, targeted isolation of 1 was achieved by SPE fractionation and preparative HPLC, followed by evaluation of its antioxidant and antimicrobial activity. In contrast to chlorogenic acid and 3,5-di-O-caffeoylquinic acid, which act as antioxidants...... full or partial identification of all major extract constituents and demonstrated the presence of unusual quinic acid derivatives containing the (1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl residue that exhibit strongly coupled ABXY patterns, the parameters of which were obtained by spin simulations....... Using homo- and heteronuclear 2D NMR data acquired in the HPLC-SPE-NMR mode, complete structure determination of three new natural products, i.e., 3,5-di-O-caffeoyl-4-O-[(1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl]quini c acid (1), its 2-hydroxy derivative (2), and 3,5-di-O-caffeoyl-4-O-[(4...

  20. Hindlimb suspension and SPE-like radiation impairs clearance of bacterial infections.

    Directory of Open Access Journals (Sweden)

    Minghong Li

    Full Text Available A major risk of extended space travel is the combined effects of weightlessness and radiation exposure on the immune system. In this study, we used the hindlimb suspension model of microgravity that includes the other space stressors, situational and confinement stress and alterations in food intake, and solar particle event (SPE-like radiation to measure the combined effects on the ability to control bacterial infections. A massive increase in morbidity and decrease in the ability to control bacterial growth was observed using 2 different types of bacteria delivered by systemic and pulmonary routes in 3 different strains of mice. These data suggest that an astronaut exposed to a strong SPE during extended space travel is at increased risk for the development of infections that could potentially be severe and interfere with mission success and astronaut health.

  1. Determination of DDT and metabolites in surface water and sediment using LLE, SPE, ACE and SE.

    Science.gov (United States)

    Sibali, Linda L; Okonkwo, Jonathan O; Zvinowanda, Caliphs

    2009-12-01

    Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD. The high recoveries exhibited by ACE compared very well with LLE and SE. This was not the case with SPE which exhibited the lowest value of recoveries for both 2,4 and 4,4'DDD, DDE and DDT standard samples. The mean concentrations of DDT and metabolites ranged from nd-1.10 μg/L, nd-0.80 μg/L, nd-1.21 μg/L and 1.92 μg/L for LLE, SPE, ACE and SE, respectively. The total DDT (2,4' and 4,4'-DDT) in water and sediment samples ranged from 1.20-3.25 μg/L and 1.82-5.24 μg/L, respectively. The low concentrations of the DDT metabolites obtained in the present study may suggest a recent contamination of the river by DDT.

  2. Coupling Hydrodynamic and Wave Propagation Codes for Modeling of Seismic Waves recorded at the SPE Test.

    Science.gov (United States)

    Larmat, C. S.; Rougier, E.; Delorey, A.; Steedman, D. W.; Bradley, C. R.

    2016-12-01

    The goal of the Source Physics Experiment (SPE) is to bring empirical and theoretical advances to the problem of detection and identification of underground nuclear explosions. For this, the SPE program includes a strong modeling effort based on first principles calculations with the challenge to capture both the source and near-source processes and those taking place later in time as seismic waves propagate within complex 3D geologic environments. In this paper, we report on results of modeling that uses hydrodynamic simulation codes (Abaqus and CASH) coupled with a 3D full waveform propagation code, SPECFEM3D. For modeling the near source region, we employ a fully-coupled Euler-Lagrange (CEL) modeling capability with a new continuum-based visco-plastic fracture model for simulation of damage processes, called AZ_Frac. These capabilities produce high-fidelity models of various factors believed to be key in the generation of seismic waves: the explosion dynamics, a weak grout-filled borehole, the surrounding jointed rock, and damage creation and deformations happening around the source and the free surface. SPECFEM3D, based on the Spectral Element Method (SEM) is a direct numerical method for full wave modeling with mathematical accuracy. The coupling interface consists of a series of grid points of the SEM mesh situated inside of the hydrodynamic code's domain. Displacement time series at these points are computed using output data from CASH or Abaqus (by interpolation if needed) and fed into the time marching scheme of SPECFEM3D. We will present validation tests with the Sharpe's model and comparisons of waveforms modeled with Rg waves (2-8Hz) that were recorded up to 2 km for SPE. We especially show effects of the local topography, velocity structure and spallation. Our models predict smaller amplitudes of Rg waves for the first five SPE shots compared to pure elastic models such as Denny &Johnson (1991).

  3. Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

    Science.gov (United States)

    Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.; hide

    2009-01-01

    Protection of astronauts and instrumentation from galactic cosmic rays (GCR) and solar particle events (SPE) in the harsh environment of space is of prime importance in the design of personal shielding, spacec raft, and mission planning. Early entry of radiation constraints into the design process enables optimal shielding strategies, but demands efficient and accurate tools that can be used by design engineers in every phase of an evolving space project. The radiation transport code , HZETRN, is an efficient tool for analyzing the shielding effectiveness of materials exposed to space radiation. In this paper, HZETRN is compared to the Monte Carlo codes HETC-HEDS and FLUKA, for a shield/target configuration comprised of a 20 g/sq cm Aluminum slab in front of a 30 g/cm^2 slab of water exposed to the February 1956 SPE, as mode led by the Webber spectrum. Neutron and proton fluence spectra, as well as dose and dose equivalent values, are compared at various depths in the water target. This study shows that there are many regions where HZETRN agrees with both HETC-HEDS and FLUKA for this shield/target configuration and the SPE environment. However, there are also regions where there are appreciable differences between the three computer c odes.

  4. SPE-GC/FTD determination of N-methyl-2-pyrrolidone and its metabolites in urine.

    Science.gov (United States)

    Kubota, Ryuichi; Endo, Yoko; Takeuchi, Akito; Inoue, Yoshinori; Ogata, Hiroko; Ogawa, Masanori; Nakagawa, Tomoo; Onda, Nobuhiko; Endo, Ginji

    2007-07-01

    An analytical method using a combination of solid-phase extraction (SPE) and gas chromatography with a flame thermionic detector (GC/FTD) was developed for determination of N-methyl-2-pyrrolidone (NMP), N-methylsuccinimide (MSI), and 2-hydroxy-N-methylsuccinimide (2-HMSI) in human urine. The SPE cartridge of poly(divinylbenzene/hydroxymethacrylate) used was directly loaded with urine sample, followed by elution with methyl isobutyl ketone (MIBK) and subsequent centrifugation, and the supernatant was injected into the capillary GC using a DB1701. This method allowed efficient separation of NMP, MSI, and 2-HMSI, which were nearly free of interference by other GC peaks arising from urine. Recoveries of NMP, MSI, and 2-HMSI from the SPE cartridge were about 98, 101, and 67%, respectively, with limits of detection of 0.04, 0.02, and 0.06 mg/L, respectively, which met the regulatory requirements. The present method was used for assay in biological monitoring of workers exposed to NMP in their occupational environment.

  5. SPE analysis of high efficiency PMTs for the DEAP-3600 dark matter detector

    International Nuclear Information System (INIS)

    Olsen, Kevin; Hallin, Aksel

    2011-01-01

    The Dark matter Experiment using Argon Pulse-shape discrimination is a collaborative effort to develop a next-generation, tonne-scale dark matter detector at SNOLAB. The detector will feature a single-phase liquid argon (LAr) target surrounded by an array of 266 photomultiplier tubes (PMTs). A new high-efficiency Hamamatsu R877-100 PMT has been delivered to the University of Alberta for evaluation by the DEAP collaboration. The increase in efficiency could lead to a much greater light yield, but other experiments have reported a slower rise time. We have placed the PMT in a small dark box and had a base and preamplifier designed to be used with either an oscilloscope or a multi-channel analyzer. With this setup we have demonstrated the PMT's ability to distinguish single photo-electrons (SPE) and characterized the PMT by measuring the SPE pulse height spectrum, the peak-to-valley ratio, the dark pulse rate, the baseline, time resolution and SPE efficiency for varying the high voltage supplied to the PMT.

  6. Ultra preconcentration of polycyclic aromatic hydrocarbons in smoked bacon by a combination of SPE and DLLME.

    Science.gov (United States)

    Liu, Xiaofang; Zhou, Shu; Zhu, Quanfei; Ye, Yong; Chen, Huaixia

    2014-09-01

    A sample pretreatment method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was established for the sensitive determination of polycyclic aromatic hydrocarbons (PAHs) in smoked bacon samples. In the SPE-DLLME process, three PAHs including naphthalene (Naph), phenanthrene (Phen) and pyrene (Pyr) were extracted from samples and transferred into C18 SPE cartridge. The target analytes were subsequently eluted with 1.2 ml of acetonitrile-dichloromethane (5:1, v/v) mixture solution. The eluent was injected directly into the 5.0 ml ultrapure water in the subsequent DLLME procedure. The sedimented phase was concentrated under a gentle nitrogen flow to 120.0 µl. Finally, the analytes in the extraction solvent were determined by high-performance liquid chromatography with a ultra-violet detector. Some important extraction parameters affecting the performance, such as the sample solution flow rate, breakthrough volume, salt addition as well as the type and volume of the elution solvent were optimized. The developed method provided an ultra enrichment factors for PAHs ranged from 3478 to 3824. The method was applied for the selective extraction and sensitive determination of PAHs in smoked bacon samples. The limits of detection (S/N = 3) were 0.05, 0.01, 0.02 μg kg(-1) for Naph, Phen, Pyr, respectively. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Targeted natural product isolation guided by HPLC-SPE-NMR: constituents of Hubertia species.

    Science.gov (United States)

    Sprogøe, Kennett; Staerk, Dan; Jäger, Anna K; Adsersen, Anne; Hansen, Steen Honoré; Witt, Matthias; Landbo, Anne-Katrine R; Meyer, Anne S; Jaroszewski, Jerzy W

    2007-09-01

    The hyphenated technique, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-SPE-NMR), has been applied for rapid identification of novel natural products in crude extracts of Hubertia ambavilla and Hubertia tomentosa. The technique allowed full or partial identification of all major extract constituents and demonstrated the presence of unusual quinic acid derivatives containing the (1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl residue that exhibit strongly coupled ABXY patterns, the parameters of which were obtained by spin simulations. Using homo- and heteronuclear 2D NMR data acquired in the HPLC-SPE-NMR mode, complete structure determination of three new natural products, i.e., 3,5-di-O-caffeoyl-4-O-[(1-hydroxy-4-oxocyclohexa-2,5-dienyl)acetyl]quinic acid (1), its 2-hydroxy derivative (2), and 3,5-di-O-caffeoyl-4-O-[(4-hydroxyphenyl)acetyl]quinic acid (3), was performed. Finally, targeted isolation of 1 was achieved by SPE fractionation and preparative HPLC, followed by evaluation of its antioxidant and antimicrobial activity. In contrast to chlorogenic acid and 3,5-di-O-caffeoylquinic acid, which act as antioxidants, compound 1 proved at the same conditions to possess prooxidant activity in an assay evaluating the oxidation of human low-density lipoprotein induced by Cu(2+).

  8. Analysis Study of Stevioside and Rebaudioside A from Stevia rebaudiana Bertoni by Normal Phase SPE and RP-HPLC

    Science.gov (United States)

    Martono, Y.; Rohman, A.; Riyanto, S.; Martono, S.

    2018-04-01

    Solid Phase Extraction (SPE) method using silica as sorbent for stevioside and rebaudiosida A analysis in Stevia rebaudiana Bertoni leaf have not been performed. The aim of this study is to develop SPE method using silica as sorbent for Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) analysis of stevioside and rebaudiosida A in S. rebaudiana leaf. The results of this study indicate that the optimal conditions for normal phase SPE (silica) are conditioned with 3.0 mL of hexane. The sample loading volume is 0.1 mL. Cartridge is eluted with 1.0 mL acetonitrile: water (80: 20, v/v) to separate both analytes. The cartridge is washed with chloroform and water of 0.3 mL respectively. The developed SPE sample preparation method meets the accuracy and precision test and can be used for the analysis of stevioside and rebaudioside A by RP-HPLC.

  9. Substrate-Induced Allosteric Change in the Quaternary Structure of the Spermidine N-Acetyltransferase SpeG.

    Science.gov (United States)

    Filippova, Ekaterina V; Weigand, Steven; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Anderson, Wayne F

    2015-11-06

    The spermidine N-acetyltransferase SpeG is a dodecameric enzyme that catalyzes the transfer of an acetyl group from acetyl coenzyme A to polyamines such as spermidine and spermine. SpeG has an allosteric polyamine-binding site and acetylating polyamines regulate their intracellular concentrations. The structures of SpeG from Vibrio cholerae in complexes with polyamines and cofactor have been characterized earlier. Here, we present the dodecameric structure of SpeG from V. cholerae in a ligand-free form in three different conformational states: open, intermediate and closed. All structures were crystallized in C2 space group symmetry and contain six monomers in the asymmetric unit cell. Two hexamers related by crystallographic 2-fold symmetry form the SpeG dodecamer. The open and intermediate states have a unique open dodecameric ring. This SpeG dodecamer is asymmetric except for the one 2-fold axis and is unlike any known dodecameric structure. Using a fluorescence thermal shift assay, size-exclusion chromatography with multi-angle light scattering, small-angle X-ray scattering analysis, negative-stain electron microscopy and structural analysis, we demonstrate that this unique open dodecameric state exists in solution. Our combined results indicate that polyamines trigger conformational changes and induce the symmetric closed dodecameric state of the protein when they bind to their allosteric sites. Copyright © 2015. Published by Elsevier Ltd.

  10. A novel polyamine allosteric site of SpeG from Vibrio cholerae is revealed by its dodecameric structure.

    Science.gov (United States)

    Filippova, Ekaterina V; Kuhn, Misty L; Osipiuk, Jerzy; Kiryukhina, Olga; Joachimiak, Andrzej; Ballicora, Miguel A; Anderson, Wayne F

    2015-03-27

    Spermidine N-acetyltransferase, encoded by the gene speG, catalyzes the initial step in the degradation of polyamines and is a critical enzyme for determining the polyamine concentrations in bacteria. In Escherichia coli, studies have shown that SpeG is the enzyme responsible for acetylating spermidine under stress conditions and for preventing spermidine toxicity. Not all bacteria contain speG, and many bacterial pathogens have developed strategies to either acquire or silence it for pathogenesis. Here, we present thorough kinetic analyses combined with structural characterization of the VCA0947 SpeG enzyme from the important human pathogen Vibrio cholerae. Our studies revealed the unexpected presence of a previously unknown allosteric site and an unusual dodecameric structure for a member of the Gcn5-related N-acetyltransferase superfamily. We show that SpeG forms dodecamers in solution and in crystals and describe its three-dimensional structure in several ligand-free and liganded structures. Importantly, these structural data define the first view of a polyamine bound in an allosteric site of an N-acetyltransferase. Kinetic characterization of SpeG from V. cholerae showed that it acetylates spermidine and spermine. The behavior of this enzyme is complex and exhibits sigmoidal curves and substrate inhibition. We performed a detailed non-linear regression kinetic analysis to simultaneously fit families of substrate saturation curves to uncover a simple kinetic mechanism that explains the apparent complexity of this enzyme. Our results provide a fundamental understanding of the bacterial SpeG enzyme, which will be key toward understanding the regulation of polyamine levels in bacteria during pathogenesis. Copyright © 2015. Published by Elsevier Ltd.

  11. Srv mediated dispersal of streptococcal biofilms through SpeB is observed in CovRS+ strains.

    Directory of Open Access Journals (Sweden)

    Kristie L Connolly

    Full Text Available Group A Streptococcus (GAS is a human specific pathogen capable of causing both mild infections and severe invasive disease. We and others have shown that GAS is able to form biofilms during infection. That is to say, they form a three-dimensional, surface attached structure consisting of bacteria and a multi-component extracellular matrix. The mechanisms involved in regulation and dispersal of these GAS structures are still unclear. Recently we have reported that in the absence of the transcriptional regulator Srv in the MGAS5005 background, the cysteine protease SpeB is constitutively produced, leading to increased tissue damage and decreased biofilm formation during a subcutaneous infection in a mouse model. This was interesting because MGAS5005 has a naturally occurring mutation that inactivates the sensor kinase domain of the two component regulatory system CovRS. Others have previously shown that strains lacking covS are associated with decreased SpeB production due to CovR repression of speB expression. Thus, our results suggest the inactivation of srv can bypass CovR repression and lead to constitutive SpeB production. We hypothesized that Srv control of SpeB production may be a mechanism to regulate biofilm dispersal and provide a mechanism by which mild infection can transition to severe disease through biofilm dispersal. The question remained however, is this mechanism conserved among GAS strains or restricted to the unique genetic makeup of MGAS5005. Here we show that Srv mediated control of SpeB and biofilm dispersal is conserved in the invasive clinical isolates RGAS053 (serotype M1 and MGAS315 (serotype M3, both of which have covS intact. This work provides additional evidence that Srv regulated control of SpeB may mediate biofilm formation and dispersal in diverse strain backgrounds.

  12. Determination of glyphosate and aminomethylphosphonic acid for assessing the quality tap water using SPE and HPLC

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Delmonico

    2014-02-01

    Full Text Available The use of pesticides in agriculture is one of the current problems that may result in contamination of both ground and surface water and groundwater. Considering the environmental importance and the increasing use of herbicides in Maringá region, in the present work methods for extraction and determination of glyphosate (GLYP and aminomethylphosphonic acid (AMPA using solid phase extraction (SPE and high performance liquid chromatography (HPLC were developed. For SPE, anion exchange resin was used and elution was done with hydrochloric acid 50.0 mmol L-1, achieving recovery rates of 82.5-116.2% and 67.1-104.0% for AMPA and GLYP, respectively. For HPLC determination the analytes were derivatized and injected in the HPLC with a C18 column and using mobile phase consisting of phosphate buffer 0.20 mol L-1 at pH 3.0 and acetonitrile (85:15; the monitoring was done at 240 nm. The analysis was performed in 8 min with the same limit of detection and limit of quantification for AMPA and GLYP of 0.09 and 0.20 mg L-1, respectively. The methods were applied to analysis of public water supply samples and concentrations from 2.1 up to 2.9 µg L-1 for AMPA and from 2.3 up to 3.3 µg L-1 for glyphosate were found.

  13. CATHARE2 calculation of SPE-3 test small break loca on PMK facility

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, E.; Radet, J. [Institut de Protection et de Surete Nucleaire, Cadarache (France)

    1995-09-01

    Bind and post test calculations with CATHARE2 have been performed concerning the SPE-4 exercise organized under the auspices of IAEA on the hungarian PMK-2 facility, a one loop scaled model of VVER 440/213 Nuclear Power Plant. The SPE-4 test is a cold leg SBLOCA associated to a {open_quotes}bleed and feed{close_quotes} procedure applied in the secondary circuit. The present paper is devoted to the analysis of the post test calculation. For the first part of the transient (until the end of the SIT activations), the primary and secondary pressures are rather well predicted, leading to a good agreement with the experimental trips, as scram, flow coast down, SIT beginning and end of activation. Nevertheless, some discrepancy with the experiment may be due to an over prediction of the thermal exchanges from the primary to the secondary circuits. For the second part of the transient, the predicted primary circuit repressurization is shifted after the SITs are off, while in the experiment this event immediately follows the end of SIT activation. The delay in the calculation leads to underpredict primary and secondary pressures, thus anticipating the timing of events, such as LPIS and emergency feedwater activation.

  14. Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

    DEFF Research Database (Denmark)

    Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard; Larsen, Martin Røssel

    2014-01-01

    min speLC-MS/MS experiment. Analysis by selected reaction monitoring by speLC-SRM-MS/MS of distinct peptides derived from the blood proteins IGF1, IGF2, IBP2, and IBP3 demonstrated protein quantification with CV values below 10% across 96 replicates. The speLC-MS/MS system is ideally suited for fast......The high peptide sequencing speed provided by modern hybrid tandem mass spectrometers enables the utilization of fast liquid chromatographic (LC) separation techniques. We present a robust solid-phase extraction/capillary LC system (speLC) for 5-10 min separation of semicomplex peptide mixtures...

  15. Gulf Coast Section SPE Production Operations Study Group-technical highlights from a series of frac pack treatment symposiums

    Energy Technology Data Exchange (ETDEWEB)

    McLarty, J.M.; DeBonis, V.

    1995-12-31

    One of the main functions of the SPE is to provide a means for collection, dissemination, and exchange of technical information and to provide technical forums that afford opportunities for members to maintain and upgrade their technical competence. The large chapters (such as Houston SPE) located near many oil company headquarters have the advantage of being able to bring together a cross section of service company and operator personnel representing operations and research from major and independent operators. This paper describes a series of 1-day symposiums on frac pack technology that were organized by the Houston-based Gulf Coast Section SPE Production Operations Study Group. These study sessions provided a means for the local members of the industry to further develop a new technology as a team. Publishing the major focus and contributions of the seminars will allow sharing of the technology with chapters outside of Houston.

  16. Explorative Solid-Phase Extraction (E-SPE) for Accelerated Microbial Natural Product Discovery, Dereplication, and Purification

    DEFF Research Database (Denmark)

    Månsson, Maria; Phipps, Richard Kerry; Gram, Lone

    2010-01-01

    Microbial natural products (NP) cover a high chemical diversity, and in consequence extracts from microorganisms are often complex to analyze and purify. A distribution analysis of calculated pK(a) values from the 34390 records in Antibase2008 revealed that within pH 2-11, 44% of all included......-phase extraction" (E-SPE) protocol using SAX, Oasis MAX, SCX, and LH-20 columns for targeted exploitation of chemical functionalities. E-SPE provides a minimum of fractions (15) for chemical and biological analyses and implicates development into a preparative scale methodology. Overall, this allows fast extract...

  17. SPE-HPLC purification of endocrine disrupting compounds from human serum for assessment of xenoestrogenic activity

    DEFF Research Database (Denmark)

    Hjelmborg, P.S.; Ghisari, Mandana; Bonefeld-Jørgensen, Eva

    2006-01-01

    Assessment of xenoestrogenic activity in human serum samples requires the removal of endogenous sex hormones to assure that the activity measured originates from xenobiotic compounds only. Serum samples representing high, medium and lower accumulation of persistent organic pollutants (POPs) were...... measured by ERE-CALUX was validated and considered to be a valuable tool to assess the combined ER effect of lipophilic serum POPs where additive/synergistic and agonistic/antagonistic effects are integrated giving an overall estimate of exposure and bioactivity....... for the study. MVLN cells, stably transfected with an estrogen receptor (ER) luciferase reporter vector (ERE-CALUX), were exposed to the reconstituted SPE-HPLC extracts for determination of the integrated estrogenic activity. The effects of PCBs were analyzed by direct in vitro exposure of PCBs (138, 153...

  18. HPLC-NMR revisited: Using time-slice HPLC-SPE-NMR with database assisted dereplication

    DEFF Research Database (Denmark)

    Johansen, Kenneth; Wubshet, Sileshi Gizachew; Nyberg, Nils

    2013-01-01

    Time based trapping of chromatographically separated compounds on to solid-phase extraction cartridges (SPE) and subsequent elution to NMR-tubes was done to emulate the function of HPLC–NMR for dereplication purposes. Sufficient mass sensitivity was obtained by the use of a state-of-the-art HPLC......–SPE–NMR-system with a cryogenically cooled probe head, designed for 1.7 mm NMR-tubes. The resulting 1H NMR spectra (600 MHz) were evaluated against a database of previously acquired and prepared spectra. The in-house developed matching algorithm, based on partitioning of the spectra and allowing for changes in the chemical shifts......, is described and the code included as Supplementary Information. Two mixtures of natural products was used to test the approach; one extract of Carthamus oxyacantha (wild safflower) containing an array of spiro compounds and one extract of the endophytic fungus Penicillum namyslowski containing griseofulvin...

  19. Characteristics of Four SPE Classes According to Onset Timing and Proton Acceleration Patterns

    Science.gov (United States)

    Kim, Roksoon

    2015-04-01

    In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low ( ~1 Rs) and close to the western limb, while the latter has a relatively higher (mean=6.05 Rs) and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux (mean=327 pfu) in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.

  20. Characteristics of four SPE groups with different origins and acceleration processes

    Science.gov (United States)

    Kim, R.-S.; Cho, K.-S.; Lee, J.; Bong, S.-C.; Joshi, A. D.; Park, Y.-D.

    2015-09-01

    Solar proton events (SPEs) can be categorized into four groups based on their associations with flare or CME inferred from onset timings as well as acceleration patterns using multienergy observations. In this study, we have investigated whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find the following: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (> 5000 particle flux per unit (pfu)) even if its associated flare and/or CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. (ii) For the former (Group A), the sites are very low (˜ 1 Rs) and close to the western limb, while the latter (Group C) have relatively higher (mean = 6.05 Rs) and wider acceleration sites. (iii) When the proton acceleration starts from the higher energy (Group B), a SPE tends to be a relatively weak event (pfu), although its associated CME is relatively stronger than previous groups. (iv) The SPEs categorized by the simultaneous acceleration in whole energy range within 10 min (Group D) tend to show the weakest proton flux (mean = 327 pfu) in spite of strong associated eruptions. Based on those results, we suggest that the different characteristics of SPEs are mainly due to the different conditions of magnetic connectivity and particle density, which are changed with longitude and height as well as their origin.

  1. Application of Nanofiber-packed SPE for Determination of Urinary 1-Hydroxypyrene Level Using HPLC.

    Science.gov (United States)

    Ifegwu, Okechukwu Clinton; Anyakora, Chimezie; Chigome, Samuel; Torto, Nelson

    2014-01-01

    It is always desirable to achieve maximum sample clean-up, extraction, and pre-concentration with the minimum possible organic solvent. The miniaturization of sample preparation devices was successfully demonstrated by packing 10 mg of 11 electrospun polymer nanofibers into pipette tip micro column and mini disc cartridges for efficient pre-concentration of 1-hydroxypyrene in urine samples. 1-hydroxypyrene is an extensively studied biomarker of the largest class of chemical carcinogens. Excretory 1-hydroxypyrene was monitored with HPLC/fluorescence detector. Important parameters influencing the percentage recovery such as fiber diameter, fiber packing amount, eluent, fiber packing format, eluent volume, surface area, porosity, and breakthrough parameters were thoroughly studied and optimized. Under optimized condition, there was a near perfect linearity of response in the range of 1-1000 μg/L with a coefficient of determination (r (2)) between 0.9992 and 0.9999 and precision (% RSD) ≤7.64% (n = 6) for all the analysis (10, 25, and 50 μg/L). The Limit of detection (LOD) was between 0.022 and 0.15 μg/L. When compared to the batch studies, both disc packed nanofiber sorbents and pipette tip packed sorbents exhibited evident dominance based on their efficiencies. The experimental results showed comparable absolute recoveries for the mini disc packed fibers (84% for Nylon 6) and micro columns (80% for Nylon 6), although the disc displayed slightly higher recoveries possibly due to the exposure of the analyte to a larger reacting surface. The results also showed highly comparative extraction efficiencies between the nanofibers and conventional C-18 SPE sorbent. Nevertheless, miniaturized SPE devices simplified sample preparation, reducing back pressure, time of the analysis with acceptable reliability, selectivity, detection levels, and environmental friendliness, hence promoting green chemistry.

  2. Signal processing to evaluate parameters affecting SPE for multi-residue analysis of personal care products.

    Science.gov (United States)

    Pietrogrande, Maria Chiara; Basaglia, Giulia; Dondi, Francesco

    2009-05-01

    This paper discusses the development of a comprehensive method for the simultaneous analysis of personal care products (PCPs) based on SPE and GC-MS. The method was developed on 29 target compounds to represent PCPs belonging to different chemical classes: surfactants in detergents (alkyl benzenes), fragrances in cosmetics (nitro and polycyclic musks), antioxidants and preservatives (phenols), plasticizers (phthalates) displaying a wide range of volatility, polarity, water solubility. In addition to the conventional C(18) stationary phase, a surface modified styrene divinylbenzene polymeric phase (Strata X SPE cartridge) has been investigated as suitable for the simultaneous extraction of several PCPs with polar and non-polar characteristics. For both sorbents different solvent compositions and eluting conditions were tested and compared in order to achieve high extraction efficiency for as many sample components as possible. Comparison of the behavior of the two cartridges reveals that, overall, Strata-X provides better efficiency with extraction recovery higher than 70% for most of the PCPs investigated. The best results were obtained under the following operative conditions: an evaporation temperature of 40 degrees C, elution on Strata-X cartridge using a volume of 15 mL of ethyl acetate (EA) as solvent and operating with slow flow rate (-10 KPa). In addition to the conventional method based on peak integration, a chemometric approach based on the computation of the experimental autocovariance function (EACVF(tot)) was applied to the complex GC-MS signal: the percentage recovery and information on peak abundance distribution can be evaluated for each procedure step. The PC-based signal processing proved very helpful in assisting the development of the analytical procedure, since it saves labor and time and increases result reliability in handling GC complex signals.

  3. Optimization of SPE for Analysis of Mandelic Acid as a Biomarker of Exposure to Ethyl Benzene

    Directory of Open Access Journals (Sweden)

    SJ Shahtaheri, M Abdollahi, F Golbabaei, A Rahimi-Froushani, F Ghamari

    2004-10-01

    Full Text Available Ethyl benzene is an important constituent of widely used solvents in industries and laboratories, causing widespread environmental and industrial pollutions. For evaluation of occupational exposure to such pollutants, biological monitoring is an essential process, in which, preparation of environmental and biological samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. The use of solid-phase extraction (SPE has been grown and is a fertile technique of sample preparation as it provides better results than those of liquid-liquid extraction (LLE. In this study, SPE using bonded silica has been optimized with regard to sample pH, sample concentration, elution solvent, elution volume, sorbent type, and sorbent mass. Through experimental evaluation, a strong anion exchange silica cartridge (SAX has been found successful in simplifying sample preparation. The present approach proved that, mandelic acid could be retained on SAX sorbent based on specific interaction. Further study was employed using 10% acetic acid to extract the analyte from spiked urine and gave a clean sample for HPLC-UV system. In this study, a high performance liquid chromatography, using reverse-phase column was used. The isocratic run was done at a constant flow rate of 0.85 ml/min, the mobile phase was water/methanol/acetic acid and a UV detector was used, setting at 225 nm. At the developed conditions the extraction recovery was exceeded 98%. The factors were evaluated statically and also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments.

  4. Isocratic Solid Phase Extraction-Liquid Chromatography (SPE-LC) Interfaced to High-Performance Tandem Mass Spectrometry for Rapid Protein Identification

    DEFF Research Database (Denmark)

    Hørning, Ole B; Kjeldsen, Frank; Theodorsen, Søren

    2008-01-01

    the isocratic solid phase extraction-liquid chromatography (SPE-LC) technology for rapid separation ( approximately 8 min) of simple peptide samples. We now extend these studies to demonstrate the potential of SPE-LC separation in combination with a hybrid linear ion trap-Orbitrap tandem mass spectrometer...

  5. A naturally occurring mutation in ropB suppresses SpeB expression and reduces M1T1 group A streptococcal systemic virulence.

    Directory of Open Access Journals (Sweden)

    Andrew Hollands

    Full Text Available Epidemiological studies of group A streptococcus (GAS have noted an inverse relationship between SpeB expression and invasive disease. However, the role of SpeB in the course of infection is still unclear. In this study we utilize a SpeB-negative M1T1 clinical isolate, 5628, with a naturally occurring mutation in the gene encoding the regulator RopB, to elucidate the role of RopB and SpeB in systemic virulence. Allelic exchange mutagenesis was used to replace the mutated ropB allele in 5628 with the intact allele from the well characterized isolate 5448. The inverse allelic exchange was also performed to replace the intact ropB in 5448 with the mutated allele from 5628. An intact ropB was found to be essential for SpeB expression. While the ropB mutation was shown to have no effect on hemolysis of RBC's, extracellular DNase activity or survival in the presence of neutrophils, strains with the mutated ropB allele were less virulent in murine systemic models of infection. An isogenic SpeB knockout strain containing an intact RopB showed similarly reduced virulence. Microarray analysis found genes of the SpeB operon to be the primary target of RopB regulation. These data show that an intact RopB and efficient SpeB production are necessary for systemic infection with GAS.

  6. Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Infantis Strain SPE101, Isolated from a Chronic Human Infection.

    Science.gov (United States)

    Iriarte, Andrés; Giner-Lamia, Joaquín; Silva, Claudia; Betancor, Laura; Astocondor, Lizeth; Cestero, Juan J; Ochoa, Theresa; García, Coralith; Puente, José L; Chabalgoity, José A; García-Del Portillo, Francisco

    2017-07-20

    We report a 4.99-Mb draft genome sequence of Salmonella enterica subsp. enterica serovar Infantis strain SPE101, isolated from feces of a 5-month-old breast-fed female showing diarrhea associated with severe dehydration and malnutrition. The infection prolonged for 6 months despite antibiotic treatment. Copyright © 2017 Iriarte et al.

  7. Micro-SPE in pipette tips as a tool for analysis of small-molecule drugs in serum

    Czech Academy of Sciences Publication Activity Database

    Vlčková, H.; Pilařová, V.; Novák, Ondřej; Solich, P.; Nováková, L.

    2017-01-01

    Roč. 9, č. 11 (2017), s. 887-901 ISSN 1757-6180 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : pipette tips * sample preparation * statin * uhplc-ms/ms * μ-SPE-PT Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Analytical chemistry Impact factor: 2.673, year: 2016

  8. Data Release Report for Source Physics Experiment 1 (SPE-1), Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Margaret [NSTec; Mercadente, Jennifer [NSTec

    2014-04-28

    The first Source Physics Experiment shot (SPE-1) was conducted in May 2011. The explosive source was a ~100-kilogram TNT-equivalent chemical set at a depth of 60 meters. It was recorded by an extensive set of instrumentation that includes sensors both at near-field (less than 100 meters) and far-field (more than 100 meters) distances. The near-field instruments consisted of three-component accelerometers deployed in boreholes around the shot and a set of singlecomponent vertical accelerometers on the surface. The far-field network comprised a variety of seismic and acoustic sensors, including short-period geophones, broadband seismometers, three-component accelerometers, and rotational seismometers at distances of 100 meters to 25 kilometers. This report coincides with the release of these data for analysts and organizations that are not participants in this program. This report describes the first Source Physics Experiment and the various types of near-field and far-field data that are available.

  9. Simulation of the SPE-4 small-break loss-of-coolant accident

    International Nuclear Information System (INIS)

    Cebull, P.; Hassan, Y.A.

    1993-01-01

    A small-break loss of coolant accident (SBLOCA) conducted at the PMK-2 integral test facility was analyzed using RELAP5/MOD3. 1. The experiment simulated a 7.4% break in the cold leg of a VVER-440/213-type nuclear power plant as part of the International Atomic Energy Agency's Fourth Standard Problem Exercise (SPE-4). The VVER design differs from pressurized water reactors (PWRS) of western origin, primarily in its use of horizontal steam generators, hot- and cold-leg loop seals, and safety injection tanks. Because of these differences, it will exhibit somewhat different transient behavior than most PWRS. The PMK-2 test facility, located at the KFKI Atomic Energy Research Institute (AEKI), is a scale model of the Paks nuclear power plant in Hungary with scaling factors of 1:2070 in power and volume and 1:1 in elevation. Primarily used to study SBLOCAs and natural circulation behavior of VVER reactors, it has been used in three previous SPEs

  10. 3D Orthorhombic Elastic Wave Propagation Pre-Test Simulation of SPE DAG-1 Test

    Science.gov (United States)

    Jensen, R. P.; Preston, L. A.

    2017-12-01

    A more realistic representation of many geologic media can be characterized as a dense system of vertically-aligned microfractures superimposed on a finely-layered horizontal geology found in shallow crustal rocks. This seismic anisotropy representation lends itself to being modeled as an orthorhombic elastic medium comprising three mutually orthogonal symmetry planes containing nine independent moduli. These moduli can be determined by observing (or prescribing) nine independent P-wave and S-wave phase speeds along different propagation directions. We have developed an explicit time-domain finite-difference (FD) algorithm for simulating 3D elastic wave propagation in a heterogeneous orthorhombic medium. The components of the particle velocity vector and the stress tensor are governed by a set of nine, coupled, first-order, linear, partial differential equations (PDEs) called the velocity-stress system. All time and space derivatives are discretized with centered and staggered FD operators possessing second- and fourth-order numerical accuracy, respectively. Additionally, we have implemented novel perfectly matched layer (PML) absorbing boundary conditions, specifically designed for orthorhombic media, to effectively suppress grid boundary reflections. In support of the Source Physics Experiment (SPE) Phase II, a series of underground chemical explosions at the Nevada National Security Site, the code has been used to perform pre-test estimates of the Dry Alluvium Geology - Experiment 1 (DAG-1). Based on literature searches, realistic geologic structure and values for orthorhombic P-wave and S-wave speeds have been estimated. Results and predictions from the simulations are presented.

  11. Lessons learned from accuracy assessment of IAEA-SPE-4 experiment predictions

    International Nuclear Information System (INIS)

    Prosek, A.

    2002-01-01

    The use of methods for code accuracy assessment has strongly increased in the last years. The methods suitable to provide quantitative comparison between the thermalhydraulic code predictions and experimental measurements were proposed e.g. fast Fourier transform based method (FFTBM), stochastic approximation ratio based method (SARBM) and a few methods used in the frame of the recently developed automated code assessment program (ACAP). Further, in the frame of FFTBM also a procedure to quantify the whole calculation was proposed with averaging of the results. The problem is that averaging may hide discrepancies highlighted in the qualitative analysis when only quantitative results are published. The purpose of the study was therefore to propose additional accuracy measures. New proposed measures were tested with IAEA-SPE-4 pre- and post-test predictions. The obtained results showed that the proposed measures improve the whole picture of the code accuracy. This is important when the reader is not provided with the accompanied qualitative analysis. The study shows that proposed accuracy measures efficiently increase the confidence in the quantitative results.(author)

  12. Determination of antibiotic compounds in water by on-line SPE-LC/MSD.

    Science.gov (United States)

    Choi, Keun-Joo; Kim, Sang-Goo; Kim, Chang-won; Kim, Seung-Hyun

    2007-01-01

    This study attempts to provide an improved approach for the analysis of antibiotics, which normally exist at low concentration in complex matrices such as receiving streams of wastewater treatment plant discharge. The analytical method developed in this study combines an existing pretreatment technique of solid-phase extraction (SPE) with liquid chromatography mass spectrometry (LC/MSD) through on-line connection. The on-line connection suppressed the target loss by keeping the cartridge from drying, which resulted in improvement of the recovery and saving of the analytical time. For the on-line solid-phase extraction of 10 ml water samples, recoveries were between 74.3% and 116.5% and average LOQ was 0.11 microg l(-1) for the sulfonamide antibiotics (SA) and 0.09 microg l(-1) for the tetracycline antibiotics (TA). Application of the developed method for the analysis of fourteen antibiotics revealed that several antibiotics were detected at concentrations above the LOQ in ARW. Treated and untreated sewage and agricultural wastewater were mostly responsible for the antibiotics contamination of the river. Antibiotics were detected at much higher concentrations in the agricultural wastewater sample than in the sewage sample, implying substantial use of antibiotics in the agricultural industry. Wastewater treatment was generally effective in separation of the antibiotics tested in this study. The extent of the treatment depended on the type of antibiotics. Hydrophobic antibiotics were more effectively separated from the solution than hydrophilic antibiotics.

  13. Rapid assessment of mycotoxins in wine by on-line SPE-UHPLC-FLD

    Directory of Open Access Journals (Sweden)

    Nistor Alina-Mihaela

    2017-01-01

    Full Text Available According to the latest statistics, grapes are one of the largest fruit crops worldwide. In this regard, it is important to consider all factors influencing quality of grapes and wine. In the last years, scientist focused on the study of mycotoxins that can influence the quality of wine. It is considered that toxins produced by moulds, causing significant economic losses, affect approximately one quarter of the world grape production. If the selective sorting of infected grapes is not done adequately, wine will present a major risk to consumers, mycotoxins being considered by the “International Agency for Cancer Research” a carcinogenic compound. The main mycotoxins monitored in this study come from Aspergillus sp., and are represented by aflatoxins B1, B2, G1, G2 and ochratoxin A. This study purpose is to develop a faster method for the analysis of mycotoxins, in order to increase rapidity and efficiency for the evaluation of the degree of infestation in wine. The purposed method is using an on-line large volume injection coupled to pre-concentration of sample (SPE which is directly transfer to the ultra-high-pressure liquid chromatography (UHPLC column for separation and the detection by means of the fluorescence detector (FLD. As the maximum tolerated level for mycotoxins in wines is 2 ppm, this method is able to detect under this limits of quantification with RSD below 2%.

  14. Identification of irradiation treatment in processed food. Pt. 2. Evaluation of a SPE-method for analyzing irradiation induced hydrocarbons

    International Nuclear Information System (INIS)

    Hartmann, M.; Ammon, J.; Berg, H.

    1996-01-01

    This paper deals with a solid phase extraction (SPE) method for the isolation of irradiation induced hydrocarbons which can replace the column chromatography described in the paragraph 35 LMBG (German Food Law) procedure L06.00-37. Using this new method, only a tenth of solvents and column material is necessary. The SPE method was a good as LC-LC-GC/FID or LC-LC-GC/MS in analyzing new or complex matrices like paprika or salmon. Additionally, it is fast, cheap and easy to perform. As far as we know, the detection of irradiation traetment in paprika powder by analyzing irradiation induced hydrocarbons has not been described before. The new method is a good alternative for the commonly used thermoluminescence procedure. (orig.) [de

  15. Development and validation of an SPE HG-AAS method for determination of inorganic arsenic in samples of marine origin

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Rie R.; Larsen, Erik H.; Sloth, Jens J. [Technical University of Denmark, National Food Institute, Division of Food Chemistry, Soeborg (Denmark); Hedegaard, Rikke V. [Technical University of Denmark, National Food Institute, Division of Food Chemistry, Soeborg (Denmark); University of Copenhagen, Faculty of Life Sciences, Department of Food Science, Frederiksberg (Denmark)

    2012-07-15

    The present paper describes a novel method for the quantitative determination of inorganic arsenic (iAs) in food and feed of marine origin. The samples were subjected to microwave-assisted extraction using diluted hydrochloric acid and hydrogen peroxide, which solubilised the analytes and oxidised arsenite (As{sup III}) to arsenate (As{sup V}). Subsequently, a pH buffering of the sample extract at pH 6 enabled selective elution of As{sup V} from a strong anion exchange solid-phase extraction (SPE) cartridge. Hydride generation atomic absorption spectrometry (HG-AAS) was applied to quantify the concentration of iAs (sum of As{sup III} and As{sup V}) as the total arsenic (As) in the SPE eluate. The results of the in-house validation showed that mean recoveries of 101-104% were achieved for samples spiked with iAs at 0.5, 1.0 and 1.5 mg.kg{sup -1}, respectively. The limit of detection was 0.08 mg kg{sup -1}, and the repeatability (RSD{sub r}) and intra-laboratory reproducibility (RSD{sub IR}) were less than 8% and 13%, respectively, for samples containing 0.2 to 1.5 mg kg{sup -1} iAs. The trueness of the SPE HG-AAS method was verified by confirming results obtained by parallel analysis using high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry. It was demonstrated that the two sets of results were not significantly different (P < 0.05). The SPE HG-AAS method was applied to 20 marine food and feed samples, and concentrations of up to 0.14 mg kg{sup -1} of iAs were detected. (orig.)

  16. A new piece of the Shigella Pathogenicity puzzle: spermidine accumulation by silencing of the speG gene [corrected].

    Directory of Open Access Journals (Sweden)

    Marialuisa Barbagallo

    Full Text Available The genome of Shigella, a gram negative bacterium which is the causative agent of bacillary dysentery, shares strong homologies with that of its commensal ancestor, Escherichia coli. The acquisition, by lateral gene transfer, of a large plasmid carrying virulence determinants has been a crucial event in the evolution towards the pathogenic lifestyle and has been paralleled by the occurrence of mutations affecting genes, which negatively interfere with the expression of virulence factors. In this context, we have analysed to what extent the presence of the plasmid-encoded virF gene, the major activator of the Shigella regulon for invasive phenotype, has modified the transcriptional profile of E. coli. Combining results from transcriptome assays and comparative genome analyses we show that in E. coli VirF, besides being able to up-regulate several chromosomal genes, which potentially influence bacterial fitness within the host, also activates genes which have been lost by Shigella. We have focused our attention on the speG gene, which encodes spermidine acetyltransferase, an enzyme catalysing the conversion of spermidine into the physiologically inert acetylspermidine, since recent evidence stresses the involvement of polyamines in microbial pathogenesis. Through identification of diverse mutations, which prevent expression of a functional SpeG protein, we show that the speG gene has been silenced by convergent evolution and that its inactivation causes the marked increase of intracellular spermidine in all Shigella spp. This enhances the survival of Shigella under oxidative stress and allows it to better face the adverse conditions it encounters inside macrophage. This is supported by the outcome of infection assays performed in mouse peritoneal macrophages and of a competitive-infection assay on J774 macrophage cell culture. Our observations fully support the pathoadaptive nature of speG inactivation in Shigella and reveal that the accumulation

  17. Inorganic arsenic –spe hg–aas method for rice tested in-house and collaboratively

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Qian, Yiting; Sloth, Jens Jørgen

    2013-01-01

    and is one of the major contributors to the iAs exposure in many countries. The work presented here describes the development, validation and application of a simple and inexpensive method for inorganic arsenic (iAs) determination in rice samples. The separation of iAs from organoarsenic compounds (MA...... sample extracts (pH 6±1) followed by selective elution of arsenate from a strong anion exchange SPE cartridge enabled the selective iAs quantification by HG-AAS, measuring total arsenic (As) in the SPE eluate. The in-house validation gave mean recoveries of 101–106 % for spiked rice samples and in two...... and DMA) was done by off-line solidphase extraction (SPE) followed by hydride generation atomic absorption spectrometry (HG-AAS) detection. Water bath heating (90 °C, 60 min) of samples with dilute nitric acid and hydrogen peroxide solubilised and oxidized all iAs to arsenate (AsV). Loading of buffered...

  18. Determination of Phthalate Plasticisers in Palm Oil Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC

    Directory of Open Access Journals (Sweden)

    Nazarudin Ibrahim

    2014-01-01

    Full Text Available Contamination of phthalates plasticisers to food has raised concern as some of the phthalates are suspected to be endocrine disruptors. The phthalates have high affinity with oily environment and analysing these chemicals in such matrices is difficult because of the trace amount of the analyte and interference from matrix. An online solid phase extraction (SPE technique using a large volume (3.5 mL injection was developed for the analysis of 6 common plasticisers in palm oil. A simple sample preparation involving alumina as a fat retainer and methanol : acetonitrile (1 : 1 as the extraction solvent was performed prior to the usage of online SPE-LC system. This system consists of two columns, C16 for the solid phase extraction (SPE and C18 as the analytical column, and a photo diode array detector. The calibration curves were linear from 5 to 1000 μg L−1, with correlation coefficients above 0.99. The instrumental limit of detection was 3 μg L−1 and satisfactory recovery was obtained. A screening on a few samples in the retail market revealed the presence of dibutyl phthalate (DBP and butylbenzylphthalate (BBP in the palm oil, with concentration less than 1 mg L−1.

  19. Development and optimization of the determination of pharmaceuticals in water samples by SPE and HPLC with diode-array detection.

    Science.gov (United States)

    Pavlović, Dragana Mutavdžić; Ašperger, Danijela; Tolić, Dijana; Babić, Sandra

    2013-09-01

    This paper describes the development, optimization, and validation of a method for the determination of five pharmaceuticals from different therapeutic classes (antibiotics, anthelmintics, glucocorticoides) in water samples. Water samples were prepared using SPE and extracts were analyzed by HPLC with diode-array detection. The efficiency of 11 different SPE cartridges to extract the investigated compounds from water was tested in preliminary experiments. Then, the pH of the water sample, elution solvent, and sorbent mass were optimized. Except for optimization of the SPE procedure, selection of the optimal HPLC column with different stationary phases from different manufacturers has been performed. The developed method was validated using spring water samples spiked with appropriate concentrations of pharmaceuticals. Good linearity was obtained in the range of 2.4-200 μg/L, depending on the pharmaceutical with the correlation coefficients >0.9930 in all cases, except for ciprofloxacin (0.9866). Also, the method has revealed that low LODs (0.7-3.9 μg/L), good precision (intra- and interday) with RSD below 17% and recoveries above 98% for all pharmaceuticals. The method has been successfully applied to the analysis of production wastewater samples from the pharmaceutical industry. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The SpeX Prism Library Analysis Toolkit: Design Considerations and First Results

    Science.gov (United States)

    Burgasser, Adam J.; Aganze, Christian; Escala, Ivana; Lopez, Mike; Choban, Caleb; Jin, Yuhui; Iyer, Aishwarya; Tallis, Melisa; Suarez, Adrian; Sahi, Maitrayee

    2016-01-01

    Various observational and theoretical spectral libraries now exist for galaxies, stars, planets and other objects, which have proven useful for classification, interpretation, simulation and model development. Effective use of these libraries relies on analysis tools, which are often left to users to develop. In this poster, we describe a program to develop a combined spectral data repository and Python-based analysis toolkit for low-resolution spectra of very low mass dwarfs (late M, L and T dwarfs), which enables visualization, spectral index analysis, classification, atmosphere model comparison, and binary modeling for nearly 2000 library spectra and user-submitted data. The SpeX Prism Library Analysis Toolkit (SPLAT) is being constructed as a collaborative, student-centered, learning-through-research model with high school, undergraduate and graduate students and regional science teachers, who populate the database and build the analysis tools through quarterly challenge exercises and summer research projects. In this poster, I describe the design considerations of the toolkit, its current status and development plan, and report the first published results led by undergraduate students. The combined data and analysis tools are ideal for characterizing cool stellar and exoplanetary atmospheres (including direct exoplanetary spectra observations by Gemini/GPI, VLT/SPHERE, and JWST), and the toolkit design can be readily adapted for other spectral datasets as well.This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. NNX15AI75G. SPLAT code can be found at https://github.com/aburgasser/splat.

  1. Optimization of a Pre-MEKC Separation SPE Procedure for Steroid Molecules in Human Urine Samples

    Directory of Open Access Journals (Sweden)

    Ilona Olędzka

    2013-11-01

    Full Text Available Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and labor-consuming and quite costly. Therefore, the aim of analytical laboratories is to develop a new, relatively low-cost and rapid implementation methodology for their determination in biological samples. Due to the fact that there is little literature data on concentrations of steroid hormones in urine samples, we have made attempts at the electrophoretic determination of these compounds. For this purpose, an extraction procedure for the optimized separation and simultaneous determination of seven steroid hormones in urine samples has been investigated. The isolation of analytes from biological samples was performed by liquid-liquid extraction (LLE with dichloromethane and compared to solid phase extraction (SPE with C18 and hydrophilic-lipophilic balance (HLB columns. To separate all the analytes a micellar electrokinetic capillary chromatography (MECK technique was employed. For full separation of all the analytes a running buffer (pH 9.2, composed of 10 mM sodium tetraborate decahydrate (borax, 50 mM sodium dodecyl sulfate (SDS, and 10% methanol was selected. The methodology developed in this work for the determination of steroid hormones meets all the requirements of analytical methods. The applicability of the method has been confirmed for the analysis of urine samples collected from volunteers—both men and women (students, amateur bodybuilders, using and not applying steroid doping. The data obtained during this work can be successfully used for further research on the determination of steroid hormones in urine samples.

  2. The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

    Energy Technology Data Exchange (ETDEWEB)

    Hill, April Ann [Iowa State Univ., Ames, IA (United States)

    2007-12-01

    The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature review on existing applications of C-SPE and similar techniques. Finally, a brief discussion of diffuse reflectance spectroscopy theory, which provides a means for analyte identification and quantification in C-SPE analyses, is presented. Following the Introduction, four research chapters are presented as separate manuscripts. Chapter 1 reports the results from microgravity testing of existing C-SPE methods and procedures aboard NASA's C-9 microgravity simulator. Chapter 2 discusses the development of a C-SPE method for determining the total concentration of biocidal silver (i.e., in both dissolved and colloidal forms) in water samples. Chapter 3 presents the first application of the C-SPE technique to the determination of an organic analyte (i.e., formaldehyde). Chapter 4, which is a departure from the main focus of the thesis, details the results of an investigation into the effect of substrate rotation on the kinetics involved in the antigen and labeling steps in sandwich immunoassays. These research chapters are followed by general conclusions and a prospectus section.

  3. Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies

    Energy Technology Data Exchange (ETDEWEB)

    Gazda, Daniel Bryan [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Although having recently been extremely successful gathering data on the surface of Mars, robotic missions are not an effective substitute for the insight and knowledge about our solar system that can be gained though first-hand exploration. Earlier this year, President Bush presented a ''new course'' for the U.S. space program that shifts NASA's focus to the development of new manned space vehicles to the return of humans to the moon. Re-establishing the human presence on the moon will eventually lead to humans permanently living and working in space and also serve as a possible launch point for missions into deeper space. There are several obstacles to the realization of these goals, most notably the lack of life support and environmental regeneration and monitoring hardware capable of functioning on long duration spaceflight. In the case of the latter, past experience on the International Space Station (ISS), Mir, and the Space Shuttle has strongly underscored the need to develop broad spectrum in-flight chemical sensors that: (1) meet current environmental monitoring requirements on ISS as well as projected requirements for future missions, and (2) enable the in-situ acquisition and analysis of analytical data in order to further define on-orbit monitoring requirements. Additionally, systems must be designed to account for factors unique to on-orbit deployment such as crew time availability, payload restrictions, material consumption, and effective operation in microgravity. This dissertation focuses on the development, ground testing, and microgravity flight demonstration of Colorimetric Solid Phase Extraction (C-SPE) as a candidate technology to meet the near- and long-term water quality monitoring needs of NASA. The introduction will elaborate further on the operational and design requirements for on-orbit water quality monitoring systems by discussing some of the characteristics of an ''ideal'' system. A

  4. Analysis of halogenated and priority pesticides at different concentration levels. Automated SPE extraction followed by isotope dilution-GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Planas, C.; Saulo, J.; Rivera, J.; Caixach, J. [Institut Investigacions Quimiques i Ambientals (IIQAB-CSIC), Barcelona (Spain)

    2004-09-15

    In this work, automatic SPE extraction of 16 pesticides and metabolites with the automated Power-Prep trademark system is evaluated at different concentration levels using polymeric (ENV+) and C{sub 18} sorbent phases. The method was optimised by comparing recoveries obtained using different eluting solvents. The optimised procedure was then applied to spiked water samples at concentration levels of 0.1{mu}g/L (quality standard for individual pesticides in drinking water) and 0.02{mu}g/L (close to the detection limit of most pesticides).

  5. Broad-spectrum antibiotic or G-CSF as potential countermeasures for impaired control of bacterial infection associated with an SPE exposure during spaceflight.

    Directory of Open Access Journals (Sweden)

    Minghong Li

    Full Text Available A major risk for astronauts during prolonged space flight is infection as a result of the combined effects of microgravity, situational and confinement stress, alterations in food intake, altered circadian rhythm, and radiation that can significantly impair the immune system and the body's defense systems. We previously reported a massive increase in morbidity with a decrease in the ability to control a bacterial challenge when mice were maintained under hindlimb suspension (HS conditions and exposed to solar particle event (SPE-like radiation. HS and SPE-like radiation treatment alone resulted in a borderline significant increase in morbidity. Therefore, development and testing of countermeasures that can be used during extended space missions in the setting of exposure to SPE radiation becomes a serious need. In the present study, we investigated the efficacy of enrofloxacin (an orally bioavailable antibiotic and Granulocyte colony stimulating factor (G-CSF (Neulasta on enhancing resistance to Pseudomonas aeruginosa infection in mice subjected to HS and SPE-like radiation. The results revealed that treatment with enrofloxacin or G-CSF enhanced bacterial clearance and significantly decreased morbidity and mortality in challenged mice exposed to suspension and radiation. These results establish that antibiotics, such as enrofloxacin, and G-CSF could be effective countermeasures to decrease the risk of bacterial infections after exposure to SPE radiation during extended space flight, thereby reducing both the risk to the crew and the danger of mission failure.

  6. Enrichment of steroid hormones in water with porous and hydrophobic polymer-based SPE followed by HPLC-UV determination.

    Science.gov (United States)

    Hu, Yinfen; Zhang, Man; Tong, Changlun; Wu, Jianmin; Liu, Weiping

    2013-10-01

    There have been great concerns about the persistence of steroid hormones in surface water. Since the concentrations of these compounds in water samples are usually at a trace level, the efficient enrichment of steroid hormones is vital for further analysis. In this work, a porous and hydrophobic polymer was synthesized and characterized. The composition of solvent used as porogen in the synthetic process was shown to have an effect on the morphology of the polymer, which was successfully used as an SPE sorbent for simultaneously enriching steroid hormones in surface water samples. The recoveries of the steroid hormones on the custom-made polymer ranged from 93.4 to 106.2%, whereas those on commercialized ENVI-18, LC-18, and Oasis HLB ranged from 54.8 to 104.9, 66 to 93.6, and 77.2 to 106%, respectively. Five types of steroid hormones were simultaneously measured using HPLC-UV after they were enriched by the custom-made sorbent. Based on these findings, the SPE-HPLC method was developed. The LODs of this method for estriol, estradiol, estrone, androstenedione, progesterone were 0.07, 0.43, 0.61, 0.27, and 0.42 μg/L, respectively, while precision and reproducibility RSDs were <6.40 and 7.49%, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

    Science.gov (United States)

    Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

    2015-05-01

    The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies.

  8. Sensitive determination of polycyclic aromatic hydrocarbons in water samples by HPLC coupled with SPE based on graphene functionalized with triethoxysilane.

    Science.gov (United States)

    Huang, Ke-Jing; Li, Jing; Liu, Yan-Ming; Wang, Lan

    2013-02-01

    The graphene functionalized with (3-aminopropyl) triethoxysilane was synthesized by a simple hydrothermal reaction and applied as SPE sorbents to extract trace polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. These sorbents possess high adsorption capacity and extraction efficiency due to strong adsorption ability of carbon materials and large specific surface area of nanoparticles, and only 10 mg of sorbents are required to extract PAHs from 100 mL water samples. Several condition parameters, such as eluent and its volume, adsorbent amount, sample volume, sample pH, and sample flow rate, were optimized to achieve good sensitivity and precision. Under the optimized extraction conditions, the method showed good linearity in the range of 1-100 μg/L, repeatability of the extraction (the RSDs were between 1.8 and 2.9%, n = 6), and satisfactory detection limits of 0.029-0.1 μg/L. The recoveries of PAHs spiked in environmental water samples ranged from 84.6 to 109.5%. All these results demonstrated that this new SPE technique was a viable alternative to conventional enrichment techniques for the extraction and analysis of PAHs in complex samples. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

    Science.gov (United States)

    Luo, Xiao-Fei; Yang, Yuan; Sun, Cheng-Jun

    2012-01-01

    To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

  10. Experimental design for TBT quantification by isotope dilution SPE-GC-ICP-MS under the European water framework directive.

    Science.gov (United States)

    Alasonati, Enrica; Fabbri, Barbara; Fettig, Ina; Yardin, Catherine; Del Castillo Busto, Maria Estela; Richter, Janine; Philipp, Rosemarie; Fisicaro, Paola

    2015-03-01

    In Europe the maximum allowable concentration for tributyltin (TBT) compounds in surface water has been regulated by the water framework directive (WFD) and daughter directive that impose a limit of 0.2 ng L(-1) in whole water (as tributyltin cation). Despite the large number of different methodologies for the quantification of organotin species developed in the last two decades, standardised analytical methods at required concentration level do not exist. TBT quantification at picogram level requires efficient and accurate sample preparation and preconcentration, and maximum care to avoid blank contamination. To meet the WFD requirement, a method for the quantification of TBT in mineral water at environmental quality standard (EQS) level, based on solid phase extraction (SPE), was developed and optimised. The quantification was done using species-specific isotope dilution (SSID) followed by gas chromatography (GC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The analytical process was optimised using a design of experiment (DOE) based on a factorial fractionary plan. The DOE allowed to evaluate 3 qualitative factors (type of stationary phase and eluent, phase mass and eluent volume, pH and analyte ethylation procedure) for a total of 13 levels studied, and a sample volume in the range of 250-1000 mL. Four different models fitting the results were defined and evaluated with statistic tools: one of them was selected and optimised to find the best procedural conditions. C18 phase was found to be the best stationary phase for SPE experiments. The 4 solvents tested with C18, the pH and ethylation conditions, the mass of the phases, the volume of the eluents and the sample volume can all be optimal, but depending on their respective combination. For that reason, the equation of the model conceived in this work is a useful decisional tool for the planning of experiments, because it can be applied to predict the TBT mass fraction recovery when the

  11. Análise de fármacos em águas por SPE-UPLC-ESI-MS/MS

    Directory of Open Access Journals (Sweden)

    Vanessa de Jesus Gaffney

    2014-01-01

    Full Text Available A method was developed for the analysis of 31 pharmaceutical compounds in Lisbon's drinking water system, using solid-phase extraction (SPE and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS. The method was validated through estimation of the linearity range, method detection and quantification limits, matrix effects, precision and accuracy. The method detection and quantification limit ranges were 0.009-10 and 0.03-33 ng/L, respectively. Analytes were quantified in water samples collected from the EPAL (Empresa Portuguesa das Águas Livres S.A. supply system. Carbamazepine, atenolol, sulfadiazine, sulfamethazine, sulfapyridine, sulfamethoxazole, acetaminophen, caffeine and erythromycin were quantified in the analysed samples.

  12. WDM compatible and electrically tunable SPE-OCDMA system based on the temporal self-imaging effect.

    Science.gov (United States)

    Tainta, S; Amaya, W; Erro, M J; Garde, M J; Sales, S; Muriel, M A

    2011-02-01

    A coding/decoding setup for a spectral phase encoding optical code-division multiple access (SPE-OCDMA) system has been developed. The proposal is based on the temporal self-imaging effect and the use of an easily tunable electro-optic phase modulator to achieve line-by-line coding of the transmitted signal, thus assuring compatibility with WDM techniques. Modulation of the code is performed at the same rate as the data, avoiding the use of high-bandwidth electro-optic modulators. As proof of concept of the technique, experimental results are presented for a back-to-back coder/decoder setup transmitting a 10 GHz unmodulated optical pulse train within an 80 GHz optical window and using 8-chip Hadamard codes.

  13. Determination of Benzo[α]pyrene in Edible Oil Using Tetraoxocalix[2]arene[2]triazine Bonded Silica SPE Sorbent.

    Science.gov (United States)

    Guo, Yun; Zhao, Wen-Jie; Deng, Zhi-Fen; Hongbo, Wang; Peng, Bin; Ma, Xue; Lan, Chen; Zhang, Shu-Sheng

    2018-06-01

    Benzo[α]pyrene (BaP) is a well-known carcinogen in edible oil. In this study, a method combined solid-phase extraction (SPE) with fluorescent detection was developed using tetraoxocalix[2]arene[2]triazine sorbent (SiO 2 -OCA) for the clean-up and enrichment of BaP. The interaction between SiO 2 -OCA and BaP involves a donor-acceptor complex mechanism. The experimental procedure was as follows: BaP was extracted from edible oil with DMF/H 2 O (9:1, v/v). Then, the ratio of DMF/H 2 O was adjusted to 1:2 prior to SPE. The final concentrate was analyzed using a fluorescence detector at excitation and emission wavelengths of 255 and 420 nm. The method was fully validated. The linearity was in the range of 0.1-100 μg kg -1 with a coefficient of 0.999. The limits of detection and quantification were 0.03 and 0.1 μg kg -1 , respectively. The average recoveries were in the range of 88.0-122.3%. The intraday and interday precisions were 6.8% and 9.2%, respectively. Compared with other methods, the method reported in this article shows a good detection limit, high reproducibility and recovery, and linearity over a broad concentration range. This established method was also applied to evaluate real samples. The concentration of six tested samples was below 5 μg kg -1 .

  14. Comparison of the Usefulness of SPE Cartridges for the Determination of β-Blockers and β-Agonists (Basic Drugs in Environmental Aqueous Samples

    Directory of Open Access Journals (Sweden)

    Magda Caban

    2015-01-01

    Full Text Available Even though the methodology used for the determination of β-blockers and β-agonists in environmental samples is based mainly on solid-phase extraction (SPE and gas chromatography or liquid chromatography with mass spectrometric detection, the available literature data on the applied SPE procedures is rather sparse. In this paper such comparison is presented. Moreover, the usefulness of the eight SPE cartridges for the determination of five β-blockers (acebutolol, atenolol, metoprolol, nadolol, and propranolol and two β-agonists (salbutamol and terbutaline in environmental aqueous samples using GC techniques is tested. Among them, three (the trifunction sorbent Strata Screen C, the copolymers LiChrolut EN, and the functionalized copolymer Isolute ENV+ were used for the first time for this purpose. It was confirmed that polystyrene-divinylbenzene-N-vinylpyrrolidone copolymers (PS-DVB-VP, Strata-X, and Oasis HLB cartridges have a better potential than a cation-exchange sorbent for the extraction of the target drugs from environmental water samples. However, it should be stressed out that the direct application of the tested SPE conditions for the analysis of real environmental water samples is not possible, and such parameters, like volume of loading sample, appropriate solvents for washing and elution steps, and so forth, must be optimized again in order to achieve satisfactory recovery values for the target compounds.

  15. Determination of radiation-induced hydrocarbons in processed food and complex lipid matrices. A new solid phase extraction (SPE) method for detection of irradiated components in food

    International Nuclear Information System (INIS)

    Hartmann, M.; Ammon, J.; Berg, H.

    1997-01-01

    Detection of irradiated components in processed food with complex lipid matrices can be affected by two problems. First, the processed food may contain only a small amount of the irradiated component, and the radiation-induced hydrocarbons may be diluted throughout the lipid matrix of the whole food. Second, in complex lipid matrices, the detection of prior irradiation is often disturbed by fat-associated compounds. In these cases, common solid phase extraction (SPE) Florisil clean-up alone is inadequate in the detection of prior irradiation. Subsequent SPE argentation chromatography of the Florisil eluate allows the measurement of small amounts of irradiated lipid-containing ingredients in processed food as well as the detection of prior irradiation in complex lipid matrices such as paprika and chilli. SPE argetation chromatography is the first method available for the selective enrichment of radiation-specific hydrocarbons from even complex lipid matrices, thus enabling the detection of irradiation does as low as 0.025 kGy. Furthermore, by using radiation-induced hydrocarbons in the detection of prior irradiation of paprika and chilli powder, a second independent method, the first being measurement of thermoluminescence, is available for the analysis of these matrices. Such analysis could be achieved by using this highly sensitive, cheap and easy to perform combined SPE Florisil/argentation chromatography method, without the need for sophisticated techniques like SFE-GC/MS or LC-GC/MS, so that highly sensitive detection of prior irradiation colud be performed in almost every laboratory

  16. Ultrahigh and High Resolution Structures and Mutational Analysis of Monomeric Streptococcus pyogenes SpeB Reveal a Functional Role for the Glycine-rich C-terminal Loop

    Energy Technology Data Exchange (ETDEWEB)

    González-Páez, Gonzalo E.; Wolan, Dennis W. (Scripps)

    2012-09-05

    Cysteine protease SpeB is secreted from Streptococcus pyogenes and has been studied as a potential virulence factor since its identification almost 70 years ago. Here, we report the crystal structures of apo mature SpeB to 1.06 {angstrom} resolution as well as complexes with the general cysteine protease inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and a novel substrate mimetic peptide inhibitor. These structures uncover conformational changes associated with maturation of SpeB from the inactive zymogen to its active form and identify the residues required for substrate binding. With the use of a newly developed fluorogenic tripeptide substrate to measure SpeB activity, we determined IC{sub 50} values for trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane and our new peptide inhibitor and the effects of mutations within the C-terminal active site loop. The structures and mutational analysis suggest that the conformational movements of the glycine-rich C-terminal loop are important for the recognition and recruitment of biological substrates and release of hydrolyzed products.

  17. Magnetic ligand fishing as a targeting tool for HPLC-HRMS-SPE-NMR: α-glucosidase inhibitory ligands and alkylresorcinol glycosides from Eugenia catharinae

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Brighente, Inês M. C.; Moaddel, Ruin

    2015-01-01

    A bioanalytical platform combining magnetic ligand fishing for α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of α-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled α-glucosidase we...

  18. Simultaneous analysis of multiple classes of antimicrobials in environmental water samples using SPE coupled with UHPLC-ESI-MS/MS and isotope dilution.

    Science.gov (United States)

    Tran, Ngoc Han; Chen, Hongjie; Do, Thanh Van; Reinhard, Martin; Ngo, Huu Hao; He, Yiliang; Gin, Karina Yew-Hoong

    2016-10-01

    A robust and sensitive analytical method was developed for the simultaneous analysis of 21 target antimicrobials in different environmental water samples. Both single SPE and tandem SPE cartridge systems were investigated to simultaneously extract multiple classes of antimicrobials. Experimental results showed that good extraction efficiencies (84.5-105.6%) were observed for the vast majority of the target analytes when extraction was performed using the tandem SPE cartridge (SB+HR-X) system under an extraction pH of 3.0. HPLC-MS/MS parameters were optimized for simultaneous analysis of all the target analytes in a single injection. Quantification of target antimicrobials in water samples was accomplished using 15 isotopically labeled internal standards (ILISs), which allowed the efficient compensation of the losses of target analytes during sample preparation and correction of matrix effects during UHPLC-MS/MS as well as instrument fluctuations in MS/MS signal intensity. Method quantification limit (MQL) for most target analytes based on SPE was below 5ng/L for surface waters, 10ng/L for treated wastewater effluents, and 15ng/L for raw wastewater. The method was successfully applied to detect and quantify the occurrence of the target analytes in raw influent, treated effluent and surface water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Locating S-wave sources for the SPE-5 explosion using time reversal methods and a close-in, 1000 sensor network

    Science.gov (United States)

    Myers, S. C.; Pitarka, A.; Mellors, R. J.

    2016-12-01

    The Source Physics Experiment (SPE) is producing new data to study the generation of seismic waves from explosive sources. Preliminary results show that far-field S-waves are generated both within the non-elastic volume surrounding explosive sources and by P- to S-wave scattering. The relative contribution of non-elastic phenomenology and elastic-wave scattering to far-field S-waves has been debated for decades, and numerical simulations based on the SPE experiments are addressing this question. The match between observed and simulated data degrades with event-station distance and with increasing time in each seismogram. This suggests that a more accurate model of subsurface elastic properties could result in better agreement between observed and simulated seismograms. A detailed model of subsurface structure has been developed using geologic maps and the extensive database of borehole logs, but uncertainty in structural details remains high. The large N instrument deployment during the SPE-5 experiment offers an opportunity to use time-reversal techniques to back project the wave field into the subsurface to locate significant sources of scattered energy. The large N deployment was nominally 1000, 5 Hz sensors (500 Z and 500 3C geophones) deployed in a roughly rectangular array to the south and east of the SPE-5 shot. Sensor spacing was nominally 50 meters in the interior portion of the array and 100 meters in the outer region, with two dense lines at 25 m spacing. The array covers the major geologic boundary between the Yucca Flat basin and the granitic Climax Stock in which the SPE experiments have been conducted. Improved mapping of subsurface scatterers is expected to result in better agreement between simulated and observed seismograms and aid in our understanding of S-wave generation from explosions. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  20. The SpeX Prism Library for Ultracool Dwarfs: A Resource for Stellar, Exoplanet and Galactic Science and Student-Led Research

    Science.gov (United States)

    Burgasser, Adam

    The NASA Infrared Telescope Facility's (IRTF) SpeX spectrograph has been an essential tool in the discovery and characterization of ultracool dwarf (UCD) stars, brown dwarfs and exoplanets. Over ten years of SpeX data have been collected on these sources, and a repository of low-resolution (R 100) SpeX prism spectra has been maintained by the PI at the SpeX Prism Spectral Libraries website since 2008. As the largest existing collection of NIR UCD spectra, this repository has facilitated a broad range of investigations in UCD, exoplanet, Galactic and extragalactic science, contributing to over 100 publications in the past 6 years. However, this repository remains highly incomplete, has not been uniformly calibrated, lacks sufficient contextual data for observations and sources, and most importantly provides no data visualization or analysis tools for the user. To fully realize the scientific potential of these data for community research, we propose a two-year program to (1) calibrate and expand existing repository and archival data, and make it virtual-observatory compliant; (2) serve the data through a searchable web archive with basic visualization tools; and (3) develop and distribute an open-source, Python-based analysis toolkit for users to analyze the data. These resources will be generated through an innovative, student-centered research model, with undergraduate and graduate students building and validating the analysis tools through carefully designed coding challenges and research validation activities. The resulting data archive, the SpeX Prism Library, will be a legacy resource for IRTF and SpeX, and will facilitate numerous investigations using current and future NASA capabilities. These include deep/wide surveys of UCDs to measure Galactic structure and chemical evolution, and probe UCD populations in satellite galaxies (e.g., JWST, WFIRST); characterization of directly imaged exoplanet spectra (e.g., FINESSE), and development of low

  1. Two-phase flow behaviour during a medium size cold leg LOCA test on PMK-2 (IAEA SPE-4)

    International Nuclear Information System (INIS)

    Szabados, L.; Prasser, H.M.; Schaefer, F.

    1995-08-01

    The experiment to the IAEA standard problem exercise No. 4 was carried out in April 1993 on the integral test facility PMK-2 in Budapest. It was a 3.2 mm break on the downcomer hed. The high pressure injection cooling was assumed to be not available. As an accident management measure bleed and feed on the secondary side of the steam generator was applied. Research Center Rossendorf contributed to the experiment of SPE-4 by supplying needle shaped conductivity probes for the measurement of local void fractions in the primary circuit of the PMK-II test facility. In the course of the standard problem exercise No. 4 RCR contributed with posttest calculations using the thermalhydraulic code ATHLET. The report comprises a description of the initial and boundary conditions of the test (chapter 3) and a phenomenological description of the thermalhydraulic events during the transient (chapter 4). The void fraction probe signals yields valuable information for deeper understanding of the thermalhydraulic occurrences and for code validation. This was the case particularly for correction of the level measurement. In chapter 5 a description of the thermalhydraulic occurrences from the viewpoint of code verification is given and the results of RELAP5 (KFKI-AEKI) and of ATHLET-calculations (RCR) are compared. Referring to this description, the sensitivity of the result to main influences is investigated using the ATHLET-code. (orig.) [de

  2. Phytochemical profile of aerial parts and roots of Wachendorfia thyrsiflora L. studied by LC-DAD-SPE-NMR.

    Science.gov (United States)

    Fang, Jingjing; Kai, Marco; Schneider, Bernd

    2012-09-01

    Hyphenated liquid chromatography - diode array detection - solid phase extraction - nuclear magnetic resonance spectroscopy (LC-DAD-SPE-NMR) was used to investigate the phytochemical composition of aerial parts and roots of Wachendorfia thyrsiflora (Haemodoraceae). Eleven phenylphenalenones and related compounds were identified in the aerial parts of the plant, ten compounds were found in the roots, and four additional compounds occurred in both plant parts. Twelve compounds are previously unreported natural products including five alkaloids (phenylbenzoisoquinolinones) are described here for the first time. In the work presented here, phenylphenalenones with an intact C(19) core structure were found only in the roots. Oxa analogs with a C(18)O scaffold occurred both in the roots and in the aerial plant parts, while most of the aza analogs with a C(18)N scaffold were detected in the aerial plant parts. This distribution pattern suggests that phenylphenalenones form in the roots, then the intact C(19) skeleton is converted into oxa analogs in the roots, translocated into the leaves and further reacted with amines or amino acids to form aza analogs (phenylbenzoisoquinolin-1,6-dione alkaloids). Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Analytical method for the determination of trace levels of steroid hormones and corticosteroids in soil, based on PLE/SPE/LC-MS/MS.

    Science.gov (United States)

    Gineys, N; Giroud, B; Vulliet, E

    2010-07-01

    The aim of this study was to develop an efficient, sensitive and reliable analytical method for the determination of traces of steroid hormones (including oestrogen, androgens and progestagens) and corticosteroids in soil. A method of sample preparation involving pressurized liquid extraction (PLE) and solid-phase extraction (SPE) was developed for the determination of six steroids and five corticosteroids in soils, followed by analysis by liquid chromatography-tandem mass spectrometry. The conditions employed for PLE involved acetone/methanol (50:50) as the extracting solvent, a temperature of 80 degrees C, two cycles and a static time of 5 min. The extraction was followed by a SPE clean-up based on a polymeric phase. With use of protocol, a residual matrix effect was, however, highlighted. The limit of detection in soil was 0.08-0.89 ng/g for steroids and 0.09-2.84 ng/g for corticosteroids.

  4. SpeX Spectroscopy of Unresolved Very Low-Mass Binaries. I. Identification of Seventeen Candidate Binaries Straddling the L Dwarf/T Dwarf Transition

    OpenAIRE

    Burgasser, Adam J.; Cruz, Kelle L.; Cushing, Michael C.; Gelino, Christopher R.; Looper, Dagny L.; Faherty, Jacqueline K.; Kirkpatrick, J. Davy; Reid, I. Neill

    2009-01-01

    We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13581 pairs of absolute flux-ca...

  5. Development of SPE for recovery of polysaccharides and its application to the determination of monosaccharides composition of the polysaccharide sample of a lactobacillus KLB 58.

    Science.gov (United States)

    Baik, Yoon Suk; Cheong, Won Jo

    2007-07-01

    A new SPE cartridge has been prepared in this study to purify polysaccharides of high molecular weights. A porous nonpolar styrene-divinylbenzene copolymer phase (Hamilton PRP-1) was used to make the new cartridge. The cartridge was conditioned with methanol, water, and ACN in sequence, and the sample dissolved in a small amount of water was loaded. Impurities of low molecular weights were removed first by elution of 80:20 or 90:10 v/v% ACN/water, and polysaccharides were quantitatively recovered by elution of 50:50 v/v% ACN/water or pure water. The recovery of pure dextran 10000 was 90-95%. The SPE method was applied to purification of the polysaccharide sample of KLB58, a new lactobacillus discovered in Korea. The purified KLB 58 sample (weight recovery after SPE purification; 60%) was hydrolyzed for analysis of composition of monosaccharides. The hydrolysate was found to be composed primarily of fructose, glucose, galactose, rhamnose, mannose with small amounts of fucose and ribose.

  6. Síntese e caracterização de MIP com fenilalanina visando sua aplicação na técnica de SPE

    Directory of Open Access Journals (Sweden)

    Layla Talita de Oliveira Alves

    2015-12-01

    Full Text Available Polímeros Molecularmente Impressos (MIPs são polímeros sintéticos que apresentam alta seletividade a uma molécula de interesse. O objetivo deste trabalho foi a síntese e caracterização de MIPs para aplicação na extração em fase sólida (SPE, visando a determinação de fenilalanina. Os MIPs foram sintetizados a partir do MAA, fenilalanina, EGDMA, AIBN, em clorofórmio. Também foi sintetizado o polímero não-impresso (NIP, para controle da seletividade dos MIPs. A dessorção da fenilalanina foi realizada em extrator Soxhlet. Os MIPs e NIP foram caracterizados pelas técnicas de análise: FTIR, UV-Vis, MEV, DSC e TG. O MIP apresentou maior capacidade adsortiva à fenilalanina do que o NIP, com uma taxa média de adsorção de 55% comparada a 11% para o NIP. Por MEV o MIP apresentou superfície mais porosa, importante característica para aplicação em SPE. Os estudos realizados mostraram que o MIP sintetizado apresentou grande potencial para aplicação em técnica de SPE.

  7. Magnetic Ligand Fishing as a Targeting Tool for HPLC-HRMS-SPE-NMR: α-Glucosidase Inhibitory Ligands and Alkylresorcinol Glycosides from Eugenia catharinae.

    Science.gov (United States)

    Wubshet, Sileshi G; Brighente, Inês M C; Moaddel, Ruin; Staerk, Dan

    2015-11-25

    A bioanalytical platform combining magnetic ligand fishing for α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of α-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled α-glucosidase were synthesized and characterized for their inherent catalytic activity. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of caffeine, ferulic acid, and luteolin before proof-of-concept with the crude extract of Eugenia catharinae. The combination of ligand fishing and HPLC-HRMS-SPE-NMR identified myricetin 3-O-α-L-rhamnopyranoside, myricetin, quercetin, and kaempferol as α-glucosidase inhibitory ligands in E. catharinae. Furthermore, HPLC-HRMS-SPE-NMR analysis led to identification of six new alkylresorcinol glycosides, i.e., 5-(2-oxopentyl)resorcinol 4-O-β-D-glucopyranoside, 5-propylresorcinol 4-O-β-D-glucopyranoside, 5-pentylresorcinol 4-O-[α-D-apiofuranosyl-(1→6)]-β-D-glucopyranoside, 5-pentylresorcinol 4-O-β-D-glucopyranoside, 4-hydroxy-3-O-methyl-5-pentylresorcinol 1-O-β-D-glucopyranoside, and 3-O-methyl-5-pentylresorcinol 1-O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside.

  8. SPE HG-AAS method for the determination of inorganic arsenic in rice—results from method validation studies and a survey on rice products

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Qian, Yiting; Sloth, Jens Jørgen

    2013-01-01

    spectrometry (HG-AAS) detection. This approach was earlier developed for seafood samples (Rasmussen et al., Anal Bioanal Chem 403:2825–2834, 2012) and has in the present work been tailored for rice products and further optimised for a higher sample throughput and a lower detection limit. Water bath heating (90...... °C, 60 min) of samples with dilute HNO3 and H2O2 solubilised and oxidised all iAs to arsenate (AsV). Loading of buffered sample extracts (pH 6 ± 1) followed by selective elution of arsenate from a strong anion exchange SPE cartridge enabled the selective iAs quantification by HG-AAS, measuring total...... arsenic (As) in the SPE eluate. The in-house validation gave mean recoveries of 101–106 % for spiked rice samples and in two reference samples. The limit of detection was 0.02 mg kg−1, and repeatability and intra-laboratory reproducibility were less than 6 and 9 %, respectively. The SPE HG-AAS method...

  9. Development of Chromatographic Fingerprints of Eurycoma longifolia (Tongkat Ali Roots Using Online Solid Phase Extraction-Liquid Chromatography (SPE-LC

    Directory of Open Access Journals (Sweden)

    Nor Nasriah Zaini

    2016-04-01

    Full Text Available E. longifolia is attracting interest due to its pharmacological properties and pro-vitality effects. In this study, an online SPE-LC approach using polystyrene divinyl benzene (PSDVB and C18 columns was developed in obtaining chromatographic fingerprints of E. longifolia. E. longifolia root samples were extracted using pressurized liquid extraction (PLE technique prior to online SPE-LC. The effects of mobile phase compositions and column switching time on the chromatographic fingerprint were optimized. Validation of the developed method was studied based on eurycomanone. Linearity was in the range of 5 to 50 µg∙mL−1 (r2 = 0.997 with 3.2% relative standard deviation of peak area. The developed method was used to analyze 14 E. longifolia root samples and 10 products (capsules. Selected chemometric techniques: cluster analysis (CA, discriminant analysis (DA, and principal component analysis (PCA were applied to the fingerprint datasets of 37 selected peaks to evaluate the ability of the chromatographic fingerprint in classifying quality of E. longifolia. Three groups were obtained using CA. DA yielded 100% correlation coefficient with 19 discriminant compounds. Using PCA, E. longifolia root samples were clearly discriminated from the products. This study showed that the developed online SPE-LC method was able to provide comprehensive evaluation of E. longifolia samples for quality control purposes.

  10. Rapid determination of 18 glucocorticoids in serum using reusable on-line SPE polymeric monolithic column coupled with LC-quadrupole/orbitrap high-resolution mass spectrometer.

    Science.gov (United States)

    Li, Hui; Ai, Lianfeng; Fan, Sufang; Wang, Yan; Sun, Dianxing

    2017-10-15

    A simple, rapid and sensitive method for the simultaneous determination of 18 glucocorticoids in serum was developed by coupling on-line solid-phase extraction (SPE) polymeric monolithic column to a liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometer. A simple poly(ethylene glycol dimethacrylate) monolith column (10mm×2.1mm i.d.) was fabricated, and the morphology, surface area and extraction performance of the monolithic column were characterized. Serum samples were extracted by acetonitrile (ACN). Then, online SPE was achieved on the synthesized monolithic column using a 10mmol/L ammonium acetate solution as the loading solvent. After the transfer from the monolith into analytical column (Capcell Pak ADME column) using ACN, the adsorbed analytes were separated on the analytical column and detected with a high-resolution hybrid quadrupole/orbitrap mass spectrometer with full scan/ddMS 2 scan mode Under optimized conditions, the method was linear with target linear correlation coefficient (R 2 ) higher than 0.995. Detection limits were in range of 0.1-0.6ng/mL, and the quantification limits were 0.3-1.5ng/mL. The recovery was between 71.9% and 89.2% in three spike levels with precision (n=5) of 5.40-12.1%. The serum sample was directly analyzed after a simple extraction procedure, and the on-line SPE and determination were achieved within only 16min. The method was used to analyze the dynamic contents variation of cortisone and hydrocortisone in serum before and after the surgery. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Hyphenation of solid-phase extraction with liquid chromatography and nuclear magnetic resonance: application of HPLC-DAD-SPE-NMR to identification of constituents of Kanahia laniflora.

    Science.gov (United States)

    Clarkson, Cailean; Staerk, Dan; Hansen, Steen Honoré; Jaroszewski, Jerzy W

    2005-06-01

    The introduction of on-line solid-phase extraction (SPE) in HPLC-NMR has dramatically enhanced the sensitivity of this technique by concentration of the analytes in a small-volume NMR flow cell and by increasing the amount of the analyte by multiple peak trapping. In this study, the potential of HPLC-DAD-SPE-NMR hyphenation was demonstrated by structure determination of complex constituents of flower, leaf, root, and stem extracts of an African medicinal plant Kanahia laniflora. The technique was shown to allow acquisition of high-quality homo- and heteronuclear 2D NMR data following analytical-scale HPLC separation of extract constituents. Four flavonol glycosides [kaempferol 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; kaempferol 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside; quercetin 3-O-(2,6-di-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside (rutin); and isorhamnetin, 3-O-(6-O-alpha-l-rhamnopyranosyl)-beta-d-glucopyranoside] and three 5alpha-cardenolides [coroglaucigenin 3-O-6-deoxy-beta-d-allopyranoside; coroglaucigenin 3-O-(4-O-beta-d-glucopyranosyl)-6-deoxy-beta-d-glucopyranoside; 3'-O-acetyl-3'-epiafroside] were identified, with complete assignments of 1H and 13C resonances based on HSQC and HMBC spectra whenever required. Confirmation of the structures was provided by HPLC-MS data. The HPLC-DAD-SPE-NMR technique therefore speeds up the dereplication of complex mixtures of natural origin significantly, by characterization of individual extract components prior to preparative isolation work.

  12. A Compact Laboratory Spectro-Goniometer (CLabSpeG) to Assess the BRDF of Materials. Presentation, Calibration and Implementation on Fagus sylvatica L. Leaves.

    Science.gov (United States)

    Biliouris, Dimitrios; Verstraeten, Willem W; Dutré, Phillip; Van Aardt, Jan A N; Muys, Bart; Coppin, Pol

    2007-09-07

    The design and calibration of a new hyperspectral Compact Laboratory Spectro-Goniometer (CLabSpeG) is presented. CLabSpeG effectively measures the bidirectionalreflectance Factor (BRF) of a sample, using a halogen light source and an AnalyticalSpectral Devices (ASD) spectroradiometer. The apparatus collects 4356 reflectance datareadings covering the spectrum from 350 nm to 2500 nm by independent positioning of thesensor, sample holder, and light source. It has an azimuth and zenith resolution of 30 and15 degrees, respectively. CLabSpeG is used to collect BRF data and extract BidirectionalReflectance Distribution Function (BRDF) data of non-isotropic vegetation elements suchas bark, soil, and leaves. Accurate calibration has ensured robust geometric accuracy of theapparatus, correction for the conicality of the light source, while sufficient radiometricstability and repeatability between measurements are obtained. The bidirectionalreflectance data collection is automated and remotely controlled and takes approximatelytwo and half hours for a BRF measurement cycle over a full hemisphere with 125 cmradius and 2.4 minutes for a single BRF acquisition. A specific protocol for vegetative leafcollection and measurement was established in order to investigate the possibility to extractBRDF values from Fagus sylvatica L. leaves under laboratory conditions. Drying leafeffects induce a reflectance change during the BRF measurements due to the laboratorySensors 2007, 7 1847 illumination source. Therefore, the full hemisphere could not be covered with one leaf. Instead 12 BRF measurements per leaf were acquired covering all azimuth positions for a single light source zenith position. Data are collected in radiance format and reflectance is calculated by dividing the leaf cycle measurement with a radiance cycle of a Spectralon reference panel, multiplied by a Spectralon reflectance correction factor and a factor to correct for the conical effect of the light source. BRF results

  13. A Compact Laboratory Spectro-Goniometer (CLabSpeG to Assess the BRDF of Materials. Presentation, Calibration and Implementation on Fagus sylvatica L. Leaves

    Directory of Open Access Journals (Sweden)

    Pol Coppin

    2007-09-01

    Full Text Available The design and calibration of a new hyperspectral Compact Laboratory Spectro-Goniometer (CLabSpeG is presented. CLabSpeG effectively measures the bidirectionalreflectance Factor (BRF of a sample, using a halogen light source and an AnalyticalSpectral Devices (ASD spectroradiometer. The apparatus collects 4356 reflectance datareadings covering the spectrum from 350 nm to 2500 nm by independent positioning of thesensor, sample holder, and light source. It has an azimuth and zenith resolution of 30 and15 degrees, respectively. CLabSpeG is used to collect BRF data and extract BidirectionalReflectance Distribution Function (BRDF data of non-isotropic vegetation elements suchas bark, soil, and leaves. Accurate calibration has ensured robust geometric accuracy of theapparatus, correction for the conicality of the light source, while sufficient radiometricstability and repeatability between measurements are obtained. The bidirectionalreflectance data collection is automated and remotely controlled and takes approximatelytwo and half hours for a BRF measurement cycle over a full hemisphere with 125 cmradius and 2.4 minutes for a single BRF acquisition. A specific protocol for vegetative leafcollection and measurement was established in order to investigate the possibility to extractBRDF values from Fagus sylvatica L. leaves under laboratory conditions. Drying leafeffects induce a reflectance change during the BRF measurements due to the laboratorySensors 2007, 7 1847 illumination source. Therefore, the full hemisphere could not be covered with one leaf. Instead 12 BRF measurements per leaf were acquired covering all azimuth positions for a single light source zenith position. Data are collected in radiance format and reflectance is calculated by dividing the leaf cycle measurement with a radiance cycle of a Spectralon reference panel, multiplied by a Spectralon reflectance correction factor and a factor to correct for the conical effect of the light

  14. High-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of anti-diabetic compounds in Eremanthus crotonoides (Asteraceae)

    DEFF Research Database (Denmark)

    Lana e Silva, Eder; Felipe Revoredo Lobo, Jonathas; Vinther, Joachim Møllesøe

    2016-01-01

    with an inhibitory concentration (IC50) of 34.5 μg/mL towards α-glucosidase was investigated by high-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR. This led to identification of six α-glucosidase inhibitors, namely quercetin (16), trans-tiliroside (17), luteolin (19), quercetin-3.......93 and 5.20 μM, respectively. This is the first report of the α-glucosidase inhibitory activity of compounds 20, 26, and 29, and the findings support the important role of Eremanthus species as novel sources of new drugs and/or herbal remedies for treatment of type 2 diabetes....

  15. Assessment of constituents in Allium by multivariate data analysis, high-resolution α-glucosidase inhibition assay and HPLC-SPE-NMR

    DEFF Research Database (Denmark)

    Schmidt, Jeppe Secher; Nyberg, Nils; Stærk, Dan

    2014-01-01

    Bulbs and leaves of 35 Allium species and cultivars bought or collected in 2010–2012 were investigated with multivariate data analysis, high-resolution α-glucosidase inhibition assays and HPLC-HRMS-SPE-NMR with the aim of exploring the potential of Allium as a future functional food for management...... of type 2 diabetes. It was found that 30 out of 106 crude extracts showed more than 80% inhibition of the α-glucosidase enzyme at a concentration of 40 mg/mL (dry sample) or 0.4 g/mL (fresh sample). High-resolution α-glucosidase biochromatograms of these extracts allowed fast identification of three...

  16. Novel radiosynthesis of PET HSV-tk gene reporter probes [18F]FHPG and [18F]FHBG employing dual Sep-Pak SPE techniques.

    Science.gov (United States)

    Wang, Ji-Quan; Zheng, Qi-Huang; Fei, Xiangshu; Mock, Bruce H; Hutchins, Gary D

    2003-11-17

    Positron emission tomography (PET) herpes simplex virus thymidine kinase (HSV-tk) gene reporter probes 9-[(3-[(18)F]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([(18)F]FHPG) and 9-(4-[(18)F]fluoro-3-hydroxymethylbutyl)guanine ([(18)F]FHBG) were prepared by nucleophilic substitution of the appropriate tosylated precursors with [(18)F]KF/Kryptofix 2.2.2 followed by a quick deprotection reaction and purification with a simplified dual Silica Sep-Pak solid-phase extraction (SPE) method in 15-30% radiochemical yield.

  17. Extração em fase sólida (SPE e micro extração em fase sólida (SPME de piretróides em água Solid-phase extraction (SPE and solid-phase microextraction of pyrethroids in water

    Directory of Open Access Journals (Sweden)

    Wilma Regina Barrionuevo

    2001-04-01

    Full Text Available The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE and solid phase microextraction (SPME. The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD. Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

  18. Use of diffusion-ordered NMR spectroscopy and HPLC-UV-SPE-NMR to identify undeclared synthetic drugs in medicines illegally sold as phytotherapies.

    Science.gov (United States)

    Silva, Lorena M A; Filho, Elenilson G A; Thomasi, Sérgio S; Silva, Bianca F; Ferreira, Antonio G; Venâncio, Tiago

    2013-09-01

    The informal (and/or illegal) e-commerce of pharmaceutical formulations causes problems that governmental health agencies find hard to control, one of which concerns formulas sold as natural products. The purpose of this work was to explore the advantages and limitations of DOSY and HPLC-UV-SPE-NMR. These techniques were used to identify the components of a formula illegally marketed in Brazil as an herbal medicine possessing anti-inflammatory and analgesic properties. DOSY was able to detect the major components present at higher concentrations. Complete characterization was achieved using HPLC-UV-SPE-NMR, and 1D and 2D NMR analyses enabled the identification of known synthetic drugs. These were ranitidine and a mixture of orphenadrine citrate, piroxicam, and dexamethasone, which are co-formulated in a remedy called Rheumazim that is used to relieve severe pain, but it is prohibited in Brazil because of a lack of sufficient pharmacokinetic and pharmacodynamic information. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Chemical Explosion Experiments to Improve Nuclear Test Monitoring - Developing a New Paradigm for Nuclear Test Monitoring with the Source Physics Experiments (SPE)

    International Nuclear Information System (INIS)

    Snelson, Catherine M.; Abbott, Robert E.; Broome, Scott T.; Mellors, Robert J.; Patton, Howard J.; Sussman, Aviva J.; Townsend, Margaret J.; Walter, William R.

    2013-01-01

    A series of chemical explosions, called the Source Physics Experiments (SPE), is being conducted under the auspices of the U.S. Department of Energy's National Nuclear Security Administration (NNSA) to develop a new more physics-based paradigm for nuclear test monitoring. Currently, monitoring relies on semi-empirical models to discriminate explosions from earthquakes and to estimate key parameters such as yield. While these models have been highly successful monitoring established test sites, there is concern that future tests could occur in media and at scale depths of burial outside of our empirical experience. This is highlighted by North Korean tests, which exhibit poor performance of a reliable discriminant, mb:Ms (Selby et al., 2012), possibly due to source emplacement and differences in seismic responses for nascent and established test sites. The goal of SPE is to replace these semi-empirical relationships with numerical techniques grounded in a physical basis and thus applicable to any geologic setting or depth

  20. On-line SPE-UHPLC method using fused core columns for extraction and separation of nine illegal dyes in chilli-containing spices.

    Science.gov (United States)

    Khalikova, Maria A; Satínský, Dalibor; Smidrkalová, Tereza; Solich, Petr

    2014-12-01

    The presented work describes the development of a simple, fast and effective on-line SPE-UHPLC-UV/vis method using fused core particle columns for extraction, separation and quantitative analysis of the nine illegal dyes, most frequently found in chilli-containing spices. The red dyes Sudan I-IV, Sudan Red 7B, Sudan Red G, Sudan Orange G, Para Red, and Methyl Red were separated and analyzed in less than 9 min without labor-consuming pretreatment procedure. The chromatographic separation was performed on Ascentis Express RP-Amide column with gradient elution using mixture of acetonitrile and water, as a mobile phase at a flow rate of 1.0 mL min(-1) and 55°C of temperature. As SPE sorbent for cleanup and pre-concentration of illegal dyes short guard fused core column Ascentis Express F5 was used. The applicability of proposed method was proven for three different chilli-containing commercial samples. Recoveries for all compounds were between 90% and 108% and relative standard deviation ranged from 1% to 4% for within- and from 2% to 6% for between-day. Limits of detection showed lower values than required by European Union regulations and were in the range of 3.3-10.3 µg L(-1) for standard solutions, 5.6-235.6 µg kg(-1) for chilli-containing spices. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Conductivity enhancement in K{sup +}-ion conducting dry Solid Polymer Electrolyte (SPE): [PEO: KNO{sub 3}]: A consequence of KI dispersal and nano-ionic effect

    Energy Technology Data Exchange (ETDEWEB)

    Kesharwani, Priyanka; Sahu, Dinesh K.; Mahipal, Y.K.; Agrawal, R.C., E-mail: rakesh_c_agrawal@yahoo.co.in

    2017-06-01

    Flexible films of dry Solid Polymer Electrolytes (SPEs): [PEO: KNO{sub 3}] in varying salt concentrations have been hot-press cast. Salt concentration dependent conductivity study revealed two SPE films: [95PEO: 5KNO{sub 3}] and [70PEO: 30KNO{sub 3}] exhibiting relatively higher room temperature conductivity (σ{sub rt}) ∼ 2.76 × 10{sup -7} S/cm and ∼4.31 × 10{sup -7} S/cm respectively. In order to increase σ{sub rt} further, two strategies have been adopted. Firstly, fractional amount of KI has been dispersed as IInd-phase active filler into above two SPE film compositions which acted as Ist-phase host and Composite Polymer Electrolyte (CPE) films were hot-press cast. Filler particle concentration dependent conductivity study identified CPE films: [(95PEO: 5KNO{sub 3}) + 7KI] and [(70PEO: 30KNO{sub 3}) + 10 KI] as optimum conducting films with σ{sub rt} ∼ 6.15 × 10{sup -6} S/cm and ∼3.98 × 10{sup -6} S/cm respectively. σ{sub rt}-enhancement of approximately an order of magnitude was achieved by this approach. In second approach, dry powder mixture of (KNO{sub 3} + KI), in ratio that of above two CPE films, were subjected to high energy ball-milling separately for different durations prior to casting the films again. The conductivity measurements as a function of milling time identified CPE films: [(95PEO: 5KNO{sub 3}) + 7KI] and [(70PEO: 30KNO{sub 3}) + 10 KI] in which two respective (KNO{sub 3} + KI) ratios milled for 4- and 6-h, exhibited almost similar value of σ{sub rt} ∼ 2.09 × 10{sup -5} S/cm. This approach increased σ{sub rt} further by ∼3–6 fold. The reason attributed for this has been Nano–ionic effect introduced at the interphase boundaries between KNO{sub 3} and KI, as a consequence of milling. These films have been referred to as milled CPE films. Subsequently, all the optimum conducting SPE and CPE (unmilled/milled) films were subjected to various characterization studies in order to evaluate their utility in potential All

  2. Effective application of freezing lipid precipitation and SCX-SPE for determination of pyrrolizidine alkaloids in high lipid foodstuffs by LC-ESI-MS/MS.

    Science.gov (United States)

    Yoon, Soo Hwan; Kim, Min-Sun; Kim, Sang Hoon; Park, Hyun Mee; Pyo, Heesoo; Lee, Yong Moon; Lee, Kyung-Tae; Hong, Jongki

    2015-06-15

    Pyrrolizidine alkaloids (PAs) are naturally occurring plant toxins associated with serious hepatic disease in humans and animals. In this study, rapid and sensitive analytical method was developed for the determination of 9 toxic PAs in popularly high lipid foodstuffs by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). PAs in lipid foodstuff were effectively purified by freezing lipid precipitation (FLP) and strong cation exchange (SCX)-solid-phase extraction (SPE). Especially, FLP could easily remove the large amounts of triacylglycerols in the lipid sample extract and effectively combine with SPE cleanup. During the FLP procedure, over 77% of the lipids in the foodstuff extracts were rapidly eliminated without any significant loss of the PAs with over 81% recovery. The elimination efficiency of lipids by FLP was tested with LC-atmospheric chemical ionization (APCI)-MS. For further purification, SCX-SPE cartridge could successfully purify PAs from the remaining interfering substances by the variation pH with 5% NH4OH in methanol. For precise quantification and confirmation of PAs in complicate sample matrices, appropriate transition ions in LC-MS/MS-multiple-ion reaction monitoring (MRM) mode were selected on the basis of MS/MS fragmentation pathways of PAs. The established analytical method was validated in terms of the linearity, limits of detection (LOD), and quantification (LOQ), precision, and accuracy. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision (relative standard deviation<11.06%). Overall limits of detection and quantitation of PAs were approximately 0.06-0.60ng/mL at a signal-to-noise ratio (S/N) of 3 and were about 0.20-1.99ng/mL at a S/N of 10 for all foodstuffs. The established method was successfully applied for the monitoring of toxic PAs in several types of high lipid foodstuffs such as soybeans, seed oil, milk, and margarine. Copyright

  3. Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

    Science.gov (United States)

    Norwood, Daniel L; Mullis, James O; Davis, Mark; Pennino, Scott; Egert, Thomas; Gonnella, Nina C

    2013-01-01

    The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds

  4. Development and validation of methodology SPE-LC-MS/MS for pharmaceuticals and illicit drug determination in the waters of Guarapiranga dam - Sao Paulo/SP, Brazil

    OpenAIRE

    SHIHOMATSU, HELENA M.

    2015-01-01

    Este estudo apresenta o desenvolvimento da metodologia de extração em fase sólida e separação em cromatográfica líquida acoplada a espectrometria de massas em sequencia, SPE-LC-MS/MS, para a determinação de 21 (vinte e um) fármacos pertencentes a diferentes classes terapeuticas, 1 (uma) droga de abuso e seu principal metabólito, em amostras de água superficial. A separação cromatográfica foi otimizada estudando o desempenho de fases estacionárias e fases móvies. A quantificação dos compostos ...

  5. Elevated urinary levels of carcinogenic N-nitrosamines in patients with urinary tract infections measured by isotope dilution online SPE LC–MS/MS

    International Nuclear Information System (INIS)

    Hu, Chiung-Wen; Shih, Ying-Ming; Liu, Hung-Hsin; Chiang, Yi-Chen; Chen, Chih-Ming; Chao, Mu-Rong

    2016-01-01

    Highlights: • Nine N-nitrosamines in urine were quantified by LC–MS/MS. • N-nitrosodiphenylamine was firstly identified in human urine. • UTI patients had much higher N-nitrosamines concentrations than healthy subjects. • N-nitrosamines were dramatically decreased after antibiotic treatment. • NDMA was correlated with the pH, WBC esterase activity or nitrite in UTI patients. - Abstract: N-nitrosamines (NAms) are well-documented for their carcinogenic potential. Human exposure to NAms may arise from the daily environment and endogenous formation via the reaction of secondary amines with nitrites or from bacteria infection. We describe the use of isotope dilution online solid-phase extraction (SPE) LC–MS/MS to quantify nine NAms in human urine. This method was validated and further applied to healthy subjects and patients with urinary tract infection (UTI). N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) were analyzed with an APCI source, while N-nitrosodiethylamine (NDEA), N-nitrosopiperidine (NPIP), N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDPhA) were quantified with an ESI source, due to their effect on the sensitivity and chromatography. NDMA was the most abundant N-nitrosamine, while NDPhA was firstly identified in human. UTI patients had three to twelve-fold higher concentrations for NDMA, NPIP, NDEA, NMOR and NDBA in urine than healthy subjects, and the NAms were significantly decreased after antibiotics treatment. NDMA concentrations were also significantly correlated with the pH value, leukocyte esterase activity or nitrite in urines of UTI patients. Our findings by online SPE LC–MS/MS method evidenced that UTI patients experienced various NAms exposures, especially the potent carcinogen NDMA, which was likely induced by bacteria infection.

  6. Coupled Hydrodynamic and Wave Propagation Modeling for the Source Physics Experiment: Study of Rg Wave Sources for SPE and DAG series.

    Science.gov (United States)

    Larmat, C. S.; Delorey, A.; Rougier, E.; Knight, E. E.; Steedman, D. W.; Bradley, C. R.

    2017-12-01

    This presentation reports numerical modeling efforts to improve knowledge of the processes that affect seismic wave generation and propagation from underground explosions, with a focus on Rg waves. The numerical model is based on the coupling of hydrodynamic simulation codes (Abaqus, CASH and HOSS), with a 3D full waveform propagation code, SPECFEM3D. Validation datasets are provided by the Source Physics Experiment (SPE) which is a series of highly instrumented chemical explosions at the Nevada National Security Site with yields from 100kg to 5000kg. A first series of explosions in a granite emplacement has just been completed and a second series in alluvium emplacement is planned for 2018. The long-term goal of this research is to review and improve current existing seismic sources models (e.g. Mueller & Murphy, 1971; Denny & Johnson, 1991) by providing first principles calculations provided by the coupled codes capability. The hydrodynamic codes, Abaqus, CASH and HOSS, model the shocked, hydrodynamic region via equations of state for the explosive, borehole stemming and jointed/weathered granite. A new material model for unconsolidated alluvium materials has been developed and validated with past nuclear explosions, including the 10 kT 1965 Merlin event (Perret, 1971) ; Perret and Bass, 1975). We use the efficient Spectral Element Method code, SPECFEM3D (e.g. Komatitsch, 1998; 2002), and Geologic Framework Models to model the evolution of wavefield as it propagates across 3D complex structures. The coupling interface is a series of grid points of the SEM mesh situated at the edge of the hydrodynamic code domain. We will present validation tests and waveforms modeled for several SPE tests which provide evidence that the damage processes happening in the vicinity of the explosions create secondary seismic sources. These sources interfere with the original explosion moment and reduces the apparent seismic moment at the origin of Rg waves up to 20%.

  7. Elevated urinary levels of carcinogenic N-nitrosamines in patients with urinary tract infections measured by isotope dilution online SPE LC–MS/MS

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chiung-Wen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Shih, Ying-Ming [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Chest Medicine, Department of Internal Medicine, Changhua Christian Hospital, Changhua 500, Taiwan (China); Liu, Hung-Hsin [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Chiang, Yi-Chen [Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan (China); School of Public Health, Xiamen University, Xiamen 361102, Fujian (China); Chen, Chih-Ming [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Chao, Mu-Rong, E-mail: chaomurong@gmail.com [Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

    2016-06-05

    Highlights: • Nine N-nitrosamines in urine were quantified by LC–MS/MS. • N-nitrosodiphenylamine was firstly identified in human urine. • UTI patients had much higher N-nitrosamines concentrations than healthy subjects. • N-nitrosamines were dramatically decreased after antibiotic treatment. • NDMA was correlated with the pH, WBC esterase activity or nitrite in UTI patients. - Abstract: N-nitrosamines (NAms) are well-documented for their carcinogenic potential. Human exposure to NAms may arise from the daily environment and endogenous formation via the reaction of secondary amines with nitrites or from bacteria infection. We describe the use of isotope dilution online solid-phase extraction (SPE) LC–MS/MS to quantify nine NAms in human urine. This method was validated and further applied to healthy subjects and patients with urinary tract infection (UTI). N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR) and N-nitrosomorpholine (NMOR) were analyzed with an APCI source, while N-nitrosodiethylamine (NDEA), N-nitrosopiperidine (NPIP), N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDPhA) were quantified with an ESI source, due to their effect on the sensitivity and chromatography. NDMA was the most abundant N-nitrosamine, while NDPhA was firstly identified in human. UTI patients had three to twelve-fold higher concentrations for NDMA, NPIP, NDEA, NMOR and NDBA in urine than healthy subjects, and the NAms were significantly decreased after antibiotics treatment. NDMA concentrations were also significantly correlated with the pH value, leukocyte esterase activity or nitrite in urines of UTI patients. Our findings by online SPE LC–MS/MS method evidenced that UTI patients experienced various NAms exposures, especially the potent carcinogen NDMA, which was likely induced by bacteria infection.

  8. Improved methods for urinary atrazine mercapturate analysis-Assessment of an enzyme-linked immunosorbent assay (ELISA) and a novel liquid chromatography-mass spectrometry (LC-MS) method utilizing online solid phase extraction (SPE)

    International Nuclear Information System (INIS)

    Koivunen, Marja E.; Dettmer, Katja; Vermeulen, Roel; Bakke, Berit; Gee, Shirley J.; Hammock, Bruce D.

    2006-01-01

    Elimination of interfering substances in urine by solid phase extraction (SPE) prior to analysis resulted in 10-fold improvement in the sensitivity of atrazine mercapturate (AM) enzyme-linked immunosorbent assay (ELISA) compared to previous reports. Of the two tested SPE systems, Oasis[reg] HLB and MCX, the mixed-mode MCX gave good recoveries (82%) of AM in spiked samples measured by ELISA, whereas the reverse-phase HLB phase was not compatible with the immunochemical method. At relatively high concentrations of urinary AM (>20 ng mL -1 ), sample dilution was effective enough for the elimination of interfering substances. The new liquid chromatography-mass spectrometry (LC-MS) method developed for AM utilizes online-SPE with Oasis[reg] HLB, column switching and a stable-isotope internal standard. The limit of quantification (0.05 ng mL -1 ) indicates improved sensitivity compared with most previously published LC-MS methods for AM. Validation of all three methods, LC-MS, ELISA + SPE and ELISA + dilution with spiked urine samples showed good correlation between the known and measured concentrations with R 2 values of 0.996, 0.957 and 0.961, respectively. When a set (n = 70 plus 12 blind duplicates) of urine samples from farmers exposed to atrazine was analyzed, there was a good agreement (R 2 = 0.917) between the log normalized data obtained by ELISA + SPE and LC-MS. High correlation among the data obtained by the two tested methods and the LC-MS method by the Center of Disease Control and Prevention (CDC), together with low variability among the blind duplicates, suggests that both methods reported here would be suitable for the analysis of urinary AM as a biomarker for human exposure of atrazine

  9. Generating and Purifying Fab Fragments from Human and Mouse IgG Using the Bacterial Enzymes IdeS, SpeB and Kgp.

    Science.gov (United States)

    Sjögren, Jonathan; Andersson, Linda; Mejàre, Malin; Olsson, Fredrik

    2017-01-01

    Fab fragments are valuable research tools in various areas of science including applications in imaging, binding studies, removal of Fc-mediated effector functions, mass spectrometry, infection biology, and many others. The enzymatic tools for the generation of Fab fragments have been discovered through basic research within the field of molecular bacterial pathogenesis. Today, these enzymes are widely applied as research tools and in this chapter, we describe methodologies based on bacterial enzymes to generate Fab fragments from both human and mouse IgG. For all human IgG subclasses, the IdeS enzyme from Streptococcus pyogenes has been applied to generate F(ab')2 fragments that subsequently can be reduced under mild conditions to generate a homogenous pool of Fab' fragments. The enzyme Kgp from Porphyromonas gingivalis has been applied to generate intact Fab fragments from human IgG1 and the Fab fragments can be purified using a CH1-specific affinity resin. The SpeB protease, also from S. pyogenes, is able to digest mouse IgGs and has been applied to digest antibodies and Fab fragments can be purified on light chain affinity resins. In this chapter, we describe methodologies that can be used to obtain Fab fragments from human and mouse IgG using bacterial proteases.

  10. High-Resolution Inhibition Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of PTP1B Inhibitors from Vietnamese Plants.

    Science.gov (United States)

    Trinh, Binh Thi Dieu; Jäger, Anna K; Staerk, Dan

    2017-07-20

    Protein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator in insulin signal transduction by deactivating the insulin receptor. Thus, PTP1B inhibition has emerged as a potential therapeutic strategy for curing insulin resistance. In this study, 40 extracts from 18 different plant species were investigated for PTP1B inhibitory activity in vitro. The most promising one, the EtOAc extract of Ficus racemosa , was investigated by high-resolution PTP1B inhibition profiling combined with HPLC-HRMS-SPE-NMR analysis. This led to the identification of isoderrone ( 1 ), derrone ( 2 ), alpinumisoflavone ( 3 ) and mucusisoflavone B ( 4 ) as PTP1B inhibitors. IC 50 of these compounds were 22.7 ± 1.7, 12.6 ± 1.6, 21.2 ± 3.8 and 2.5 ± 0.2 µM, respectively. Kinetics analysis revealed that these compounds inhibited PTP1B non-competitively with K i values of 21.3 ± 2.8, 7.9 ± 1.9, 14.3 ± 2.0, and 3.0 ± 0.5 µM, respectively. These findings support the important role of F. racemosa as a novel source of new drugs and/or as a herbal remedy for treatment of type 2 diabetes.

  11. High-Resolution Inhibition Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of PTP1B Inhibitors from Vietnamese Plants

    Directory of Open Access Journals (Sweden)

    Binh Thi Dieu Trinh

    2017-07-01

    Full Text Available Protein tyrosine phosphatase 1B (PTP1B plays a key role as a negative regulator in insulin signal transduction by deactivating the insulin receptor. Thus, PTP1B inhibition has emerged as a potential therapeutic strategy for curing insulin resistance. In this study, 40 extracts from 18 different plant species were investigated for PTP1B inhibitory activity in vitro. The most promising one, the EtOAc extract of Ficus racemosa, was investigated by high-resolution PTP1B inhibition profiling combined with HPLC-HRMS-SPE-NMR analysis. This led to the identification of isoderrone (1, derrone (2, alpinumisoflavone (3 and mucusisoflavone B (4 as PTP1B inhibitors. IC50 of these compounds were 22.7 ± 1.7, 12.6 ± 1.6, 21.2 ± 3.8 and 2.5 ± 0.2 µM, respectively. Kinetics analysis revealed that these compounds inhibited PTP1B non-competitively with Ki values of 21.3 ± 2.8, 7.9 ± 1.9, 14.3 ± 2.0, and 3.0 ± 0.5 µM, respectively. These findings support the important role of F. racemosa as a novel source of new drugs and/or as a herbal remedy for treatment of type 2 diabetes.

  12. Simultaneous determination of 30 hormones illegally added to anti-ageing functional foods using UPLC-MS/MS coupled with SPE clean-up.

    Science.gov (United States)

    He, Xiaoqin; Xi, Cunxian; Tang, Bobin; Wang, Guomin; Chen, Dongdong; Peng, Tao; Mu, Zhaode

    2014-01-01

    A novel analytical method employing solid-phase extraction (SPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 30 hormones in anti-ageing functional foods (capsules, powders and tablets). The analytes were extracted with acetic acid-acetonitrile (1-99 v/v), methanol and acetone, respectively. The extract was purified using a combined column, followed by analyte detection with electrospray ionisation in positive- or negative-ion modes. The results indicated that the 30 compounds had good linear correlations in the range of 1-1000 μg kg⁻¹, and the correlation coefficients were above 0.99. The limits of detection (LOD) and limits of quantification (LOQ) were 0.03-2 and 0.1-5 μg kg⁻¹, respectively. The average recovery of 30 compounds at the three spiked levels varied from 74.7% to 124.1%, and the relative standard deviation (RSD) was 2.4-15.0%. This method was applied to the analysis of hormones in 14 real samples of which seven hormones (such as estrone, dienestrol) were detected in four samples, but the remainder of the hormones were not detected. The developed method is sensitive, efficient, reliable and applicable to real samples.

  13. Autism and urinary exogenous neuropeptides: development of an on-line SPE-HPLC-tandem mass spectrometry method to test the opioid excess theory.

    Science.gov (United States)

    Dettmer, K; Hanna, D; Whetstone, P; Hansen, R; Hammock, B D

    2007-08-01

    Autism is a complex neurodevelopmental disorder with unknown etiology. One hypothesis regarding etiology in autism is the "opioid peptide excess" theory that postulates that excessive amounts of exogenous opioid-like peptides derived from dietary proteins are detectable in urine and that these compounds may be pathophysiologically important in autism. A selective LC-MS/MS method was developed to analyze gliadinomorphin, beta-casomorphin, deltorphin 1, and deltorphin 2 in urine. The method is based on on-line SPE extraction of the neuropeptides from urine, column switching, and subsequent HPLC analysis. A limit of detection of 0.25 ng/mL was achieved for all analytes. Analyte recovery rates from urine ranged between 78% and 94%, with relative standard deviations of 0.2-6.8%. The method was used to screen 69 urine samples from children with and without autism spectrum disorders for the occurrence of neuropeptides. The target neuropeptides were not detected above the detection limit in either sample set.

  14. Silica Modified with Polyaniline as a Potential Sorbent for Matrix Solid Phase Dispersion (MSPD) and Dispersive Solid Phase Extraction (d-SPE) of Plant Samples

    Science.gov (United States)

    Sowa, Ireneusz; Wójciak-Kosior, Magdalena; Strzemski, Maciej; Sawicki, Jan; Staniak, Michał; Dresler, Sławomir; Szwerc, Wojciech; Mołdoch, Jarosław; Latalski, Michał

    2018-01-01

    Polyaniline (PANI) is one of the best known conductive polymers with multiple applications. Recently, it was also used in separation techniques, mostly as a component of composites for solid-phase microextraction (SPME). In the present paper, sorbent obtained by in situ polymerization of aniline directly on silica gel particles (Si-PANI) was used for dispersive solid phase extraction (d-SPE) and matrix solid–phase extraction (MSPD). The efficiency of both techniques was evaluated with the use of high performance liquid chromatography with diode array detection (HPLC-DAD) quantitative analysis. The quality of the sorbent was verified by Raman spectroscopy and microscopy combined with automated procedure using computer image analysis. For extraction experiments, triterpenes were chosen as model compounds. The optimal conditions were as follows: protonated Si-PANI impregnated with water, 160/1 sorbent/analyte ratio, 3 min of extraction time, 4 min of desorption time and methanolic solution of ammonia for elution of analytes. The proposed procedure was successfully used for pretreatment of plant samples. PMID:29565297

  15. A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

    Directory of Open Access Journals (Sweden)

    Yuningsih

    2006-03-01

    Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

  16. SpeX spectroscopy of unresolved very low mass binaries. II. Identification of 14 candidate binaries with late-M/early-L and T dwarf components

    International Nuclear Information System (INIS)

    Bardalez Gagliuffi, Daniella C.; Burgasser, Adam J.; Nicholls, Christine P.; Gelino, Christopher R.; Looper, Dagny L.; Schmidt, Sarah J.; Cruz, Kelle; West, Andrew A.; Gizis, John E.; Metchev, Stanimir

    2014-01-01

    Multiplicity is a key statistic for understanding the formation of very low mass (VLM) stars and brown dwarfs. Currently, the separation distribution of VLM binaries remains poorly constrained at small separations (≤1 AU), leading to uncertainty in the overall binary fraction. We approach this problem by searching for late-M/early-L plus T dwarf spectral binaries whose combined light spectra exhibit distinct peculiarities, allowing for separation-independent identification. We define a set of spectral indices designed to identify these systems, and we use a spectral template fitting method to confirm and characterize spectral binary candidates from a library of 815 spectra from the SpeX Prism Spectral Libraries. We present 11 new binary candidates, confirm 3 previously reported candidates, and rule out 2 previously identified candidates, all with primary and secondary spectral types in the range M7-L7 and T1-T8, respectively. We find that subdwarfs and blue L dwarfs are the primary contaminants in our sample and propose a method for segregating these sources. If confirmed by follow-up observations, these systems may add to the growing list of tight separation binaries, whose orbital properties may yield further insight into brown dwarf formation scenarios.

  17. Silica Modified with Polyaniline as a Potential Sorbent for Matrix Solid Phase Dispersion (MSPD and Dispersive Solid Phase Extraction (d-SPE of Plant Samples

    Directory of Open Access Journals (Sweden)

    Ireneusz Sowa

    2018-03-01

    Full Text Available Polyaniline (PANI is one of the best known conductive polymers with multiple applications. Recently, it was also used in separation techniques, mostly as a component of composites for solid-phase microextraction (SPME. In the present paper, sorbent obtained by in situ polymerization of aniline directly on silica gel particles (Si-PANI was used for dispersive solid phase extraction (d-SPE and matrix solid–phase extraction (MSPD. The efficiency of both techniques was evaluated with the use of high performance liquid chromatography with diode array detection (HPLC-DAD quantitative analysis. The quality of the sorbent was verified by Raman spectroscopy and microscopy combined with automated procedure using computer image analysis. For extraction experiments, triterpenes were chosen as model compounds. The optimal conditions were as follows: protonated Si-PANI impregnated with water, 160/1 sorbent/analyte ratio, 3 min of extraction time, 4 min of desorption time and methanolic solution of ammonia for elution of analytes. The proposed procedure was successfully used for pretreatment of plant samples.

  18. Determination of urinary aromatic amines in smokers and nonsmokers using a MIPs-SPE coupled with LC-MS/MS method.

    Science.gov (United States)

    Yu, Jingjing; Wang, Sheng; Zhao, Ge; Wang, Bing; Ding, Li; Zhang, Xiaobing; Xie, Jianping; Xie, Fuwei

    2014-05-01

    Urinary aromatic amines (AAs) could be used as biomarkers for human exposure to AAs in cigarette smoke. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of urinary AAs (i.e. 1-naphthylamine (1-NA), 2-naphthylamine (2-NA), 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP)) in smokers and nonsmokers. A molecularly imprinted polymers (MIPs) solid phase extraction (SPE) cartridge was applied to purify urine samples and no derivatization reaction was involved. Each analytes used respective stable isotope internal standards, which could well compensate matrix effect. Lower limit of detections (LODs) for four AAs were obtained and in the range of 1.5-5ngL(-1). Recovery ranged from 87.7±4.5% to 111.3±6.4% and precision were less than 9.9%. The method was applied to analyze urine samples of 40 smokers and 10 nonsmokers. The 24h urinary excretion amounts of total AAs were higher for smokers compared with nonsmokers. What's more, 1-NA, 3-ABP and 4-ABP excretion amounts showed significant differences (p<0.05) between smokers and nonsmokers. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. High-resolution bioactivity profiling combined with HPLC-HRMS-SPE-NMR: α-Glucosidase inhibitors and acetylated ellagic acid rhamnosides from Myrcia palustris DC. (Myrtaceae).

    Science.gov (United States)

    Wubshet, Sileshi G; Moresco, Henrique H; Tahtah, Yousof; Brighente, Inês M C; Staerk, Dan

    2015-08-01

    Type 2 diabetes (T2D) is an endocrine metabolic disease with a worldwide prevalence of more than 8%, and an expected increase close to 50% in the next 15-20years. T2D is associated with severe and life-threatening complications like retinopathy, neuropathy, nephropathy, and cardiovascular diseases, and therefore improved drug leads or functional foods containing α-glucosidase inhibitors are needed for management of blood glucose. In this study, leaves of Myrcia palustris were investigated by high-resolution α-glucosidase inhibition profiling combined with HPLC-HRMS-SPE-NMR. This led to identification of casuarinin, myricetin 3-O-β-d-(6″-galloyl)galactopyranoside, kaempferol 3-O-β-d-galactopyranoside, myricetin, and quercetin as α-glucosidase inhibitors. In addition, four acetylated ellagic acid rhamnosides, i.e., 4-O-(2″,4″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, 4-O-(2″,3″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, 4-O-(3″,4″-O-diacetyl-α-l-rhamnopyranosyl)ellagic acid, and 4-O-(2″,3″,4″-O-triacetyl-α-l-rhamnopyranosyl)ellagic acid were identified. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. The combined SPE:ToxY-PAM phytotoxicity assay; application and appraisal of a novel biomonitoring tool for the aquatic environment.

    Science.gov (United States)

    Bengtson Nash, S M; Schreiber, U; Ralph, P J; Müller, J F

    2005-01-15

    Mounting concerns regarding the environmental impact of herbicides has meant a growing requirement for accurate, timely information regarding herbicide residue contamination of, in particular, aquatic systems. Conventional methods of detection remain limited in terms of practicality due to high costs of operation and the specialised information that analysis provides. A new phytotoxicity bioassay was trialled for the detection of herbicide residues in filter-purified (Milli-Q) as well as natural waters. The performance of the system, which combines solid-phase extraction (SPE) with the ToxY-PAM dual-channel yield analyser (Heinz Walz GmbH), was tested alongside the traditional method of liquid chromatography-mass spectrometry (LC-MS). The assay methodology was found to be highly sensitive (LOD 0.1 ng L(-1) diuron) with good reproducibility. The study showed that the assay protocol is time effective and can be employed for the aquatic screening of herbicide residues in purified as well as natural waters.

  1. Proceedings of ITOHOS 2008 : The 2008 SPE/PS/CHOA International Thermal Operations and Heavy Oil Symposium : Heavy Oil : Integrating the Pieces

    International Nuclear Information System (INIS)

    2008-10-01

    This multi-disciplinary conference and exhibition combined the Society of Petroleum Engineers (SPE) and the Petroleum Society's (PS) international thermal operations and heavy oil symposium, and the Canadian Heavy Oil Association's (CHOA) annual business meeting. The conference provided a forum to examine emerging technologies and other critical issues affecting the global heavy oil and bitumen industry. The most current technologies from around the world that enhance the recovery of heavy oil and bitumen from oil sand deposits were also showcased. The technical program encompassed the economic, technical, and environmental challenges that the petroleum industry is currently facing. The sessions of the conference were entitled: artificial lift; mining, extraction and cold production; simulation; solvent processes; reservoir characterization; steam generation and water treatment; and, in-situ combustion in Canada. The conference also featured a series of short courses and tutorials on heavy oil wellbore completions and design; drilling horizontal heavy oil wells and steam assisted gravity drainage (SAGD) wells; geomechanical based reservoir monitoring; thermal well design; fiber optic thermal monitoring; heavy oil thermal recovery and economics; wellbore slotting; advanced geomechanics; and, an overview of cold heavy oil production with sand (CHOPS). All 91 presentations from the conference have been catalogued separately for inclusion in this database. refs., tabs., figs

  2. Analytical method for the determination of atrazine and its dealkylated chlorotriazine metabolites in water using SPE sample preparation and GC-MSD analysis.

    Science.gov (United States)

    Huang, Sung-Ben; Stanton, Jeffrey S; Lin, Yi; Yokley, Robert A

    2003-12-03

    A method is reported for the determination of atrazine and its dealkylated chlorotriazine metabolites in ground, surface, and deionized water. Water samples are adjusted to pH 3-4 prior to loading onto two SPE cartridges in series: C-18 and C-18/cation exchange mixed-mode polymeric phases. The analytes are eluted from each of the two cartridges separately, and the pooled and concentrated fraction is analyzed using gas chromatography-mass selective detection in the selected ion monitoring mode. The lower limit of method validation is 0.10 micrograms/L (ppb) for 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), 2-amino-4-chloro-6-(isopropylamino)-s-triazine (G-30033, deethylatrazine), 2-amino-4-chloro-6-(ethylamino)-s-triazine (G-28279, deisopropylatrazine), and 2,4-diamino-6-chloro-s-triazine (G-28273, didealkyatrazine). The overall mean procedural recoveries (and standard deviations) are 96 (6.9), 96 (5.5), 95 (6.8), and 100% (10%) for atrazine, G-30033, G-28279, and G-28273, respectively (n = 49). The method validation study was conducted under U.S. EPA FIFRA Good Laboratory Practice Guidelines 40 CFR 160. The reported procedure accounts for residues of G-28273 in water.

  3. Proceedings of ITOHOS 2008 : The 2008 SPE/PS/CHOA International Thermal Operations and Heavy Oil Symposium : Heavy Oil : Integrating the Pieces

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-10-15

    This multi-disciplinary conference and exhibition combined the Society of Petroleum Engineers (SPE) and the Petroleum Society's (PS) international thermal operations and heavy oil symposium, and the Canadian Heavy Oil Association's (CHOA) annual business meeting. The conference provided a forum to examine emerging technologies and other critical issues affecting the global heavy oil and bitumen industry. The most current technologies from around the world that enhance the recovery of heavy oil and bitumen from oil sand deposits were also showcased. The technical program encompassed the economic, technical, and environmental challenges that the petroleum industry is currently facing. The sessions of the conference were entitled: artificial lift; mining, extraction and cold production; simulation; solvent processes; reservoir characterization; steam generation and water treatment; and, in-situ combustion in Canada. The conference also featured a series of short courses and tutorials on heavy oil wellbore completions and design; drilling horizontal heavy oil wells and steam assisted gravity drainage (SAGD) wells; geomechanical based reservoir monitoring; thermal well design; fiber optic thermal monitoring; heavy oil thermal recovery and economics; wellbore slotting; advanced geomechanics; and, an overview of cold heavy oil production with sand (CHOPS). All 91 presentations from the conference have been catalogued separately for inclusion in this database. refs., tabs., figs.

  4. Identification of adulterants in a Chinese herbal medicine by LC-HRMS and LC-MS-SPE/NMR and comparative in vivo study with standards in a hypertensive rat model.

    Science.gov (United States)

    Kesting, Julie Regitze; Huang, Jingqi; Sørensen, Dan

    2010-02-05

    Based on anecdotal evidence of anti-hypertensive effect of Gold Nine Soft Capsules, an in vivo study of this complex Chinese "herbal-based" medicine was initiated. Dosage of the content of Gold Nine capsules in spontaneous hypertensive rats showed a remarkably good effect. This led to further investigation of the components of the preparation and eventual identification of three known anti-hypertensive drugs; amlodipine, indapamide and valsartan, which were not declared on the label. Compounds were rapidly identified using LC-HRMS and LC-MS-SPE/NMR, quantified by HPLC, and the in vivo activity of a combination of commercially purchased standards was shown to be equivalent to that of the capsule content. Adulteration of herbal remedies and dietary supplements with synthetic drugs is an increasing problem that may lead to serious adverse effects. LC-MS-SPE/NMR as a method for the rapid identification of such adulterants is highlighted in this case study.

  5. Dual High-Resolution α-Glucosidase and Radical Scavenging Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of Minor and Major Constituents Directly from the Crude Extract of Pueraria lobata

    DEFF Research Database (Denmark)

    Liu, Bingrui; Kongstad, Kenneth Thermann; Qinglei, Sun

    2015-01-01

    The crude methanol extract of Pueraria lobata was investigated by dual high-resolution α-glucosidase inhibition and radical scavenging profiling combined with hyphenated HPLC-HRMS-SPE-NMR. Direct analysis of the crude extract without preceding purification was facilitated by combining chromatograms...... from two analytical-scale HPLC separations of 120 and 600 μg on-column, respectively. High-resolution α-glucosidase and radical scavenging profiles were obtained after microfractionation of the eluate in 96-well microplates. This allowed full bioactivity profiling of individual peaks in the HPLC...... chromatogram of the crude methanol extract. Subsequent HPLC-HRMS-SPE-NMR analysis allowed identification of 21 known compounds in addition to two new compounds, i.e., 3′-methoxydaidzein 8-C-[α-d-apiofuranosyl-(1→6)]-β-d-glucopyranoside and 6″-O-malonyl-3′-methoxydaidzin, as well as an unstable compound...

  6. Estudo de compostos orgânicos em lixiviado de aterros sanitários por EFS e CG/EM Study of organic compounds in landfill leachate by SPE and GC/MSD

    Directory of Open Access Journals (Sweden)

    Irajá do Nascimento Filho

    2001-08-01

    Full Text Available The main purpose of this work was the qualitative study of organic compounds in landfill leachate. The samples were collected from a sanitary landfill located at Gravataí, a southern Brazilian city, that receive both, industrial and domestic refuse. The samples were submitted to solid phase extraction (SPE with XAD-4 resin as the stationary phase. The instrumental analysis was performed by Gas Chromatography with a Mass Spectrometry Detector (GC/MSD. The compounds achieved in the SPE extracts were tentatively identified by the GC/MS library. It was found several oxygen and nitrogen compounds like carboxylic acids, ketones, amines and amides. Sulfur compounds and phthalate esters are also identified.

  7. Analysis of nitrosamines in water by automated SPE and isotope dilution GC/HRMS Occurrence in the different steps of a drinking water treatment plant, and in chlorinated samples from a reservoir and a sewage treatment plant effluent.

    Science.gov (United States)

    Planas, Carles; Palacios, Oscar; Ventura, Francesc; Rivera, Josep; Caixach, Josep

    2008-08-15

    A method based on automated solid-phase extraction (SPE) and isotope dilution gas chromatography/high resolution mass spectrometry (GC/HRMS) has been developed for the analysis of nine nitrosamines in water samples. The combination of automated SPE and GC/HRMS for the analysis of nitrosamines has not been reported previously. The method shows as advantages the selectivity and sensitivity of GC/HRMS analysis and the high efficiency of automated SPE with coconut charcoal EPA 521 cartridges. Low method detection limits (MDLs) were achieved, along with a greater facility of the procedure and less dependence on the operator with regard to the methods based on manual SPE. Quality requirements for isotope dilution-based methods were accomplished for most analysed nitrosamines, regarding to trueness (80-120%), method precision (water samples (16 samples from a drinking water treatment plant {DWTP}, 2 chlorinated samples from a sewage treatment plant {STP} effluent, and 1 chlorinated sample from a reservoir) were analysed. Concentrations of nitrosamines in the STP effluent were 309.4 and 730.2 ng/L, being higher when higher doses of chlorine were applied. N-Nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were the main compounds identified in the STP effluent, and NDEA was detected above 200 ng/L, regulatory level for NDMA in effluents stated in Ontario (Canada). Lower concentrations of nitrosamines were found in the reservoir (20.3 ng/L) and in the DWTP samples (n.d. -28.6 ng/L). NDMA and NDEA were respectively found in the reservoir and in treated and highly chlorinated DWTP samples at concentrations above 10 ng/L (guide value established in different countries). The highest concentrations of nitrosamines were found after chlorination and ozonation processes (ozonated, treated and highly chlorinated water) in DWTP samples.

  8. Liquid-Liquid Extraction/Low-Temperature Purification (LLE/LTP Followed by Dispersive Solid-Phase Extraction (d-SPE Cleanup for Multiresidue Analysis in Palm Oil by LC-QTOF-MS

    Directory of Open Access Journals (Sweden)

    Elham Sobhanzadeh

    2013-01-01

    Full Text Available An evaluation of the extraction of multiresidue pesticides from palm oil by liquid-liquid extraction/low-temperature purification (LLE/LTP coupled with dispersive solid-phase extraction (d-SPE as the cleanup procedure with the determination by liquid chromatography mass spectrometry using electrospray as the ionization source (LC-ESI-MS was carried out. Optimization approaches were studied in terms of d-SPE to select efficiency of type and mass of adsorbents to obtain the highest recovery yield of pesticides and the lowest coextract fat residues in the final extract. The optimal conditions of d-SPE were obtained using 3 g of palm oil, 4 g anhydrous MgSO4, 150 mg of PSA, and 50 mg of GCB (PSA: GCB (3 : 1 w/w. Recovery study was performed at three concentration levels (25, 50, and 100 ng kg−1, yielding recovery rates between 71.8 and 112.4% except diuron with relative standard deviations of 3.2–15.1%. Detection and quantification limits were lower than 2.7 and 8.2 ng kg−1, respectively. The proposed method was successfully applied to the analysis of market-purchased palm oil samples from two different brands collected in Kuala Lumpur, showing its potential applicability and revealing the presence of some of the target species in the ng g−1 range.

  9. Coupling HPLC-SPE-NMR with a microplate-based high-resolution antioxidant assay for efficient analysis of antioxidants in food--validation and proof-of-concept study with caper buds.

    Science.gov (United States)

    Wiese, Stefanie; Wubshet, Sileshi G; Nielsen, John; Staerk, Dan

    2013-12-15

    This work describes the coupling of a microplate-based antioxidant assay with a hyphenated system consisting of high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC-SPE-NMR/high-resolution antioxidant assay, for the analysis of complex food extracts. The applicability of the microplate-based antioxidant assay for high-resolution screening of common food phenolics as well as parameters related to their trapping efficiency, elution behavior, and recovery on/from SPE cartridges are described. It was found that the microplate-based high-resolution antioxidant assay is an attractive and easy implementable alternative to direct on-line screening methods. Furthermore, it was shown that Resin SH and Resin GP SPE material are superior to RP C18HD for trapping of phenolic compounds. Proof-of-concept study was performed with caper bud extract, revealing the most important antioxidants to be quercetin, kaempferol, rutin, kaempferol-3-O-β-rutinoside and N(1),N(5),N(10)-triphenylpropenoyl spermidine amides. Targeted isolation of the latter, and comprehensive NMR experiments showed them to be N(1),N(10)-di-(E)-caffeoyl-N(5)-p-(E)-coumaroyl spermidine, N(1)-(E)-caffeoyl-N(5),N(10)-di-p-(E)-coumaroyl spermidine, N(10)-(E)-caffeoyl-N(1),N(5)-di-p-(E)-coumaroyl spermidine, and N(1),N(5),N(10)-tri-p-(E)-coumaroyl spermidine amides. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Solvent-assisted dispersive micro-SPE by using aminopropyl-functionalized magnetite nanoparticle followed by GC-PID for quantification of parabens in aqueous matrices.

    Science.gov (United States)

    Abbasghorbani, Maryam; Attaran, Abdolmohammad; Payehghadr, Mahmood

    2013-01-01

    In this research, solvent-assisted dispersive micro-SPE was introduced as a simple modified technique for the determination of parabens in water and cosmetic samples. Aminopropyl-functionalized magnetite nanoparticles (MNPs) were successfully synthesized and applied. GC with photoionization detector was used for the separation and detection of parabens. In this method, hexylacetate (15 μL) as a solvent and aminopropyl-functionalized MNPs (5 μg) as a sorbent were added to an aqueous sample (10 mL) and then the sample was sonicated. Dispersed magnetite was collected in the bottom of the conical tube by using a strong magnet and then ACN was added as a desorption solvent. Forty microliters of this solvent was transferred into a microvial and then acetic anhydride and pyridine were added, thus derivatization was performed by acetic anhydride. After evaporation, 1 μL of derivatized sample was injected into a gas chromatograph for analysis. Several important parameters, such as kind of organic solvent, desorption solvent and volume, amount of aminopropyl-functionalized MNPs and effect of salt addition were investigated. Under optimum conditions, the limits of detection achieved were between 50 and 300 ng/L, with RSDs (n = 5) lower than 8%. Under the optimum conditions, the enrichment factors ranged from 217 to 1253 and the extraction recoveries ranged from 10 to 62%. The recoveries were obtained for the analytes in river water and mouthwash solution and hand cream in the range of 87-103%. The advantages of proposed method are simplicity of operation, rapidity, high extraction yields, and environmental friendly character. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Determination of perfluorinated sulfonate and perfluorinated acids in tissues of free-living European beaver (castor fiber L.) by d-SPE/ micro-UHPLC-MS/MS.

    Science.gov (United States)

    Surma, Magdalena; Giżejewski, Zygmunt; Zieliński, Henryk

    2015-10-01

    Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Quantification of isoflavones in coffee by using solid phase extraction (SPE) and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

    Science.gov (United States)

    Caprioli, Giovanni; Navarini, Luciano; Cortese, Manuela; Ricciutelli, Massimo; Torregiani, Elisabetta; Vittori, Sauro; Sagratini, Gianni

    2016-09-01

    A new method for extracting isoflavones from espresso coffee (EC) was coupled with high-performance liquid chromatography-tandem mass spectrometry (MS/MS) for the first time to analyse five isoflavones, which included both a glycosilated form, genistin and the aglycons daidzein, genistein, formononetin and biochanin A. Isoflavones were extracted from coffee samples using methanol, stored in a freezer overnight to precipitate proteic or lipidic residues and purified on SPE C18 cartridges before high-performance liquid chromatography-MS/MS analysis. The recovery percentages obtained by spiking the matrix at concentrations of 10 and 100 µg l(-1) with a standard mixture of isoflavones were in the range of 70 to 104%. The limits of detection and limits of quantification were in the range of 0.015-0.3 µg l(-1) and 0.05-1 µg l(-1) , respectively. Once validated, the method was used to analyze the concentrations of isoflavones in six ECs and ten ground coffee samples. Only formononetin and biochanin A were found, and their respective concentrations ranged from 0.36 to 0.41 µg l(-1) and from 0.58 to 3.26 µg l(-1) in ECs and from 0.36 to 4.27 µg kg(-1) and from 0.71 to 3.95 µg kg(-1) in ground coffees. This method confirms the high specificity and selectivity of MS/MS systems for detecting bioactives in complex matrices such as coffee.Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Development and validation of methodology SPE-LC-MS/MS for pharmaceuticals and illicit drug determination in the waters of Guarapiranga Dam, Sao Paulo, SP, Brazil

    International Nuclear Information System (INIS)

    Shihomatsu, Helena Miho

    2015-01-01

    This study presents the development of the methodology of solid phase extraction and liquid chromatography - tandem mass spectrometry, SPE-LC-MS/MS, for the determination of 21 (twenty one) pharmaceuticals belonging to different therapeutic groups, 1 (one) illicit drug and its major metabolite, in surface water samples. The chromatographic separation was optimized by studying the performance of different stationary and mobile phases. Quantitation of selected compounds was performed by electrospray ionization (ESI) and the mass spectrometer operating in a multiple reaction monitoring (MRM) mode. The validation of the proposed methodology was performed using the parameters of selectivity, matrix effect, dynamic range, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, recovery and robustness. The validation of methodology allowed to apply the methodology in the evaluation of the distribution of the 23 (twenty one) selected compounds, in Guarapiranga Dam waters, an of the major producer system of drinking water of the Metropolitan Region of Sao Paulo (MRSP). The presence of these pollutants in aquatic environments is from the direct release of urban sewage from the homes of your surroundings, as a result of poor sanitation system. The waters of Guarapiranga dam were evaluated in 14 (fourteen) locations strategically chosen and sampled in 3 (three) campaigns of sample collection (August 2011, September 2012 and April 2013). In these samples were quantified acetaminophen (9.6 - 254 ng L -1 ), atenolol (8.5 - 177 ng L -1 ), benzoylecgonine (7.9 - 139 ng L -1 ), caffeine (27 - 27386 ng L -1 ) carbamazepine (12 - 358 ng L -1 ), chlorthalidone (9.4 - 35 ng L -1 ), cocaine (12.8 - 2560 ng L -1 ), diclofenac (8 - 36 ng L -1 ), enalapril (20 ng L -1 ), losartan (6.7 - 114 ng L -1 ) and valsartan (9.7 - 47 ng L -1 ). The sample siting GU103-12 (23°41'88.5”S 46°44'67.3”W) was the region with the highest values in the level of

  14. Development, validation and clinical application of an online-SPE-LC-HRMS/MS for simultaneous quantification of phenobarbital, phenytoin, carbamazepine, and its active metabolite carbamazepine 10,11-epoxide.

    Science.gov (United States)

    Qu, Lihua; Fan, Yuanjie; Wang, Wenjun; Ma, Kai; Yin, Zheng

    2016-09-01

    A simple and efficient bioanalytical method for simultaneous determination of phenobarbital (PB), phenytoin (PHT), carbamazepine (CBZ), and its active metabolite carbamazepine 10,11-epoxide (CBZE) in human plasma using online solid phase extraction (SPE)-liquid chromatography (LC) coupled with high resolution mass spectrum (HRMS) under targeted MS/MS (t-MS(2)) analysis mode has been developed. The procedure integrated an automated sample clean-up of human plasma by Oasis®HLB SPE cartridge, a separation by ZORBAX SB-C18 analysis column, and a quantification by Q-Exactive Hybrid Quadrupole-Orbitrap. The total running time was 13min. The lower limit of quantification (LLOQ) of PB, PHT, CBZ, and CBZE were 0.008, 0.008, 0.0016 and 0.0016μgmL(-1) respectively and the linearities were in the range of 0.008-2.500, 0.008-2.500, 0.0016-0.500 and 0.0016-0.500μgmL(-1) respectively. The mean recovery was between 91.82% and 108.27% and the matrix effect was between 93.29% and 102.09%. The relative standard deviations of interday and intraday were less than 6.41%. The method has been successfully applied in therapeutic drug monitoring (TDM) of four Chinese epilepsy patients. This fully automated, simple, sensitive and reliable online-SPE-LC-HRMS/MS method serves well for TDM of PB, PHT, CBZ and CBZE at clinics for either single or combination treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. A Fully Automated Radiosynthesis of [18F]Fluoroethyl-Diprenorphine on a Single Module by Use of SPE Cartridges for Preparation of High Quality 2-[18F]Fluoroethyl Tosylate

    Directory of Open Access Journals (Sweden)

    Gjermund Henriksen

    2013-06-01

    Full Text Available We have developed a new method for automated production of 2-[18F]fluoroethyl tosylate ([18F]FETos that enables 18F-alkylation to provide PET tracers with high chemical purity. The method is based on the removal of excess ethylene glycol bistosylate precursor by precipitation and subsequent filtration and purification of the filtrate by means of solid phase extraction cartridges (SPE. The method is integrated to a single synthesis module and thereby provides the advantage over previous methods of not requiring HPLC purification, as demonstrated by the full radiosynthesis of the potent opioid receptor PET tracer [18F]fluoroethyldiprenorphine.

  16. Identification of adulterants in a Chinese herbal medicine by LC-HRMS and LC-MS-SPE/NMR and comparative in vivo study with standards in a hypertensive rat model

    DEFF Research Database (Denmark)

    Kesting, Julie Regitze; Huang, JingQi; Sørensen, Dan

    2010-01-01

    Based on anecdotal evidence of anti-hypertensive effect of Gold Nine Soft Capsules, an in vivo study of this complex Chinese "herbal-based" medicine was initiated. Dosage of the content of Gold Nine capsules in spontaneous hypertensive rats showed a remarkably good effect. This led to further...... of a combination of commercially purchased standards was shown to be equivalent to that of the capsule content. Adulteration of herbal remedies and dietary supplements with synthetic drugs is an increasing problem that may lead to serious adverse effects. LC-MS-SPE/NMR as a method for the rapid identification...

  17. Sequential determination of {sup 239,240}Pu, {sup 238} Pu, {sup 241} Am and {sup 90}Sr in radioactive wastes using SPE sorbents Analig Pu02, AnaLig Sr01 and TRU Resin; Sekvencne stanovenie {sup 239,240}Pu, {sup 238} Pu, {sup 241} Am a {sup 90}Sr v radioaktivnych odpadoch pouzitim SPE sorbentov Analig Pu02, AnaLig Sr01 a TRU Resin

    Energy Technology Data Exchange (ETDEWEB)

    Durkot, E; Dulanska, S [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra jadrovej chemie, 84215 Bratislava (Slovakia)

    2012-04-25

    A simple and rapid method of the sequential determination of radionuclides {sup 239,240}Pu, {sup 238} Pu, {sup 241} Am and {sup 90}Sr in radioactive sludge from the NPP Bohunice A1 with high radiochemical yields and efficient removal of interfering components from a matrix was developed. Separation method combines SPE sorbents Analig Pu02, AnaLig Sr01 made by IBC Advanced Technologies and TRU Resin (Eichrom Technologies) placed in tandem. Advantage of a single-stage column located on the vacuum box with a rapid flow is an effective pre-concentration and separation of radionuclides and minimization of sample separation time. (authors)

  18. Preparative separation and structural identification of impurities of a new α{sub 2}-Adrenoceptor agonist using stacking injection, LC-MS{sup n} and LC-SPE-NMR

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Josiane O.; Thomasi, Sérgio S.; Venâncio, Tiago; Oliveira, Regina V., E-mail: oliveirarv@ufscar.br [Universidade Federal de São Carlos (UFSCar), SP (Brazil). Departamento de Química; Pitta, Ivan R.; Lima, Maria do Carmo A. de [Universidade Federal de Pernambuco (NUPIT/UFPE), Recife, PE (Brazil). Núcleo de Pesquisa em Inovação Tecnológica

    2017-07-01

    Identifying impurities in drug substances has become one of the most important issues in pharmaceutical analysis since it can have a significant impact on the efficacy of new pharmaceutical products. Due to the purity requirements, in this paper a new synthetic α{sub 2}-adrenoceptor agonist, called LPSF-PT-31, was purified and its impurities were characterized by liquid chromatography multistage mass spectrometry (LC-MS{sup n}) and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR). The purification step was conducted using a semi-preparative liquid chromatography and stacked injections as a new approach to drug purification. As a result, a total yield of 75% of the pure LPSF-PT-31 and 2.9 L day{sup -}'1 in solvent reduction was obtained. The combination of semi-preparative stacking injection, LC-MS{sup n}, and LC-SPE-NMR, demonstrated to be efficient to purify active drugs and unambiguously identify its impurities. In addition, isolation and identification of drug impurities in the early stages of development can improve the synthetic pathway, preventing the formation of impurities or minimizing this formation to minimum levels. (author)

  19. Edible seaweed as future functional food: Identification of α-glucosidase inhibitors by combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR.

    Science.gov (United States)

    Liu, Bingrui; Kongstad, Kenneth T; Wiese, Stefanie; Jäger, Anna K; Staerk, Dan

    2016-07-15

    Crude chloroform, ethanol and acetone extracts of nineteen seaweed species were screened for their antioxidant and α-glucosidase inhibitory activity. Samples showing more than 60% α-glucosidase inhibitory activity, at a concentration of 1 mg/ml, were furthermore investigated using high-resolution α-glucosidase inhibition profiling combined with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC-HRMS-SPE-NMR). The results showed Ascophyllum nodosum and Fucus vesicolosus to be rich in antioxidants, equaling a Trolox equivalent antioxidant capacity of 135 and 108 mM Troloxmg(-1) extract, respectively. HR-bioassay/HPLC-HRMS-SPE-NMR showed the α-glucosidase inhibitory activity of A. nodosum, F. vesoculosus, Laminaria digitata, Laminaria japonica and Undaria pinnatifida to be caused by phlorotannins as well as fatty acids - with oleic acid, linoleic acid and eicosapentaenoic acid being the most potent with IC50 values of 0.069, 0.075 and 0.10 mM, respectively, and showing a mixed-type inhibition mode. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. FATAL GROUP A STREPTOCOCCAL TOXIC SHOCK-LIKE SYNDROME IN A CHILD WITH VARICELLA: REPORT OF THE FIRST WELL DOCUMENTED CASE WITH DETECTION OF THE GENETIC SEQUENCES THAT CODE FOR EXOTOXINS SPE A AND B, IN SÃO PAULO, BRAZIL

    Directory of Open Access Journals (Sweden)

    SZTAJNBOK Jaques

    1999-01-01

    Full Text Available A previously healthy seven-year-old boy was admitted to the intensive care unit because of toxaemia associated with varicella. He rapidly developed shock and multisystem organ failure associated with the appearance of a deep-seated soft tissue infection and, despite aggressive treatment, died on hospital day 4. An M-non-typable, spe A and spe B positive Group A Streptococcus was cultured from a deep soft tissue aspirate. The criteria for defining Streptococcal toxic shock-like syndrome were fulfilled. The authors discuss the clinical and pathophysiological aspects of this disease as well as some unusual clinical findings related to this case.

  1. Highly specific purification of N-glycans using phosphate-based derivatization as an affinity tag in combination with Ti{sup 4+}-SPE enrichment for mass spectrometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ying [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032 (China); Peng, Ye; Bin, Zhichao [Department of Chemistry, Fudan University, Shanghai 200032 (China); Wang, Huijie [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Lu, Haojie, E-mail: luhaojie@fudan.edu.cn [Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Department of Chemistry, Fudan University, Shanghai 200032 (China); Key Laboratory of Glycoconjugates Research Ministry of Public Health, Fudan University, Shanghai 200032 (China)

    2016-08-31

    N-linked protein glycosylation is involved in regulation of a wide variety of cellular processes and associated with numerous diseases. Highly specific identification of N-glycome remains a challenge while its biological significance is acknowledged. The relatively low abundance of glycan in complex biological mixtures, lack of basic sites for protonation, and suppression by other highly abundant proteins/peptides lead to the particularly poor detection sensitivity of N-glycans in the MS analysis. Therefore, the highly specific purification procedure becomes a crucial step prior to MS analysis of the N-glycome. Herein, a novel N-glycans enrichment approach based on phosphate derivatization combined with Ti{sup 4+}-SPE (solid phase extraction) was developed. Briefly, in this strategy, N-glycans were chemically labeled with a phospho-group at their reducing ends, such that the Ti{sup 4+}-SPE microspheres were able to capture the phospho-containing glycans. The enrichment method was developed and optimized using model oligosaccharides (maltoheptaose DP7 and sialylated glycan A1) and also glycans from a standard glycoprotein (asialofetuin, ASF). This method experimentally showed high derivatization efficiency (almost 100%), excellent selectivity (analyzing DP7 in the digests of bovine serum albumin at a mass ratio of 1:100), high enriching recovery (90%), good reproducibility (CV<15%) as well as high sensitivity (LOD at fmol level). At last, the proposed method was successfully applied in the profiling of N-glycome in human serum, in which a total of 31 N-glycan masses were identified. - Graphical abstract: A selective enrichment method for the N-glycome is reported. N-glycans were chemically labeled with a phosphate derivatization reagent (AMS), then the phospho-containing glycans were enriched using Ti{sup 4+}-microspheres. - Highlights: • A highly specific N-glycans purification method based on phosphate derivatization combined with Ti{sup 4+}-SPE was developed

  2. Development and validation of methodology SPE-LC-MS/MS for pharmaceuticals and illicit drug determination in the waters of Guarapiranga Dam, Sao Paulo, SP, Brazil; Desenvolvimento e validacao de metodologia SPE-LC-MS/MS para a determinacao de farmacos e droga de abuso nas aguas da represa Guarapiranga, Sao Paulo, SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Shihomatsu, Helena Miho

    2015-07-01

    This study presents the development of the methodology of solid phase extraction and liquid chromatography - tandem mass spectrometry, SPE-LC-MS/MS, for the determination of 21 (twenty one) pharmaceuticals belonging to different therapeutic groups, 1 (one) illicit drug and its major metabolite, in surface water samples. The chromatographic separation was optimized by studying the performance of different stationary and mobile phases. Quantitation of selected compounds was performed by electrospray ionization (ESI) and the mass spectrometer operating in a multiple reaction monitoring (MRM) mode. The validation of the proposed methodology was performed using the parameters of selectivity, matrix effect, dynamic range, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, recovery and robustness. The validation of methodology allowed to apply the methodology in the evaluation of the distribution of the 23 (twenty one) selected compounds, in Guarapiranga Dam waters, an of the major producer system of drinking water of the Metropolitan Region of Sao Paulo (MRSP). The presence of these pollutants in aquatic environments is from the direct release of urban sewage from the homes of your surroundings, as a result of poor sanitation system. The waters of Guarapiranga dam were evaluated in 14 (fourteen) locations strategically chosen and sampled in 3 (three) campaigns of sample collection (August 2011, September 2012 and April 2013). In these samples were quantified acetaminophen (9.6 - 254 ng L{sup -1}), atenolol (8.5 - 177 ng L{sup -1}), benzoylecgonine (7.9 - 139 ng L{sup -1}), caffeine (27 - 27386 ng L{sup -1}) carbamazepine (12 - 358 ng L{sup -1}), chlorthalidone (9.4 - 35 ng L{sup -1}), cocaine (12.8 - 2560 ng L{sup -1}), diclofenac (8 - 36 ng L{sup -1}), enalapril (20 ng L{sup -1}), losartan (6.7 - 114 ng L{sup -1}) and valsartan (9.7 - 47 ng L{sup -1}). The sample siting GU103-12 (23°41'88.5”S 46°44'67.3”W) was the

  3. Separation and identification of phenolic compounds of extra virgin olive oil from Olea europaea L. by HPLC-DAD-SPE-NMR/MS. Identification of a new diastereoisomer of the aldehydic form of oleuropein aglycone.

    Science.gov (United States)

    Pérez-Trujillo, Míriam; Gómez-Caravaca, Ana María; Segura-Carretero, Antonio; Fernández-Gutiérrez, Alberto; Parella, Teodor

    2010-08-25

    The phenolic fraction of a monovarietal extra virgin olive oil (EVOO) from Olea europaea L. var. Cornezuelo was studied by the hyphenated HPLC-DAD-SPE-NMR/MS techniques. This survey led to the identification of 25 main compounds. One was identified as a new diastereoisomer of the aldehydic form of oleuropein aglycone (AOA) and characterized by 1D and 2D NMR techniques. The relative configuration of this new AOA was determined as 5R*,8S*,9S* on the basis of the results obtained from the combination of NOE experiments and Monte Carlo conformational search calculations. Assuming, as for the described diastereoisomers, that the new AOA comes from the natural oleuropein aglycone (OA), the absolute configuration was proposed as 5S,8R,9R.

  4. Characterization of the metabolic transformation of thiamethoxam to clothianidin in Helicoverpa armigera larvae by SPE combined UPLC-MS/MS and its relationship with the toxicity of thiamethoxam to Helicoverpa armigera larvae.

    Science.gov (United States)

    Fan, Yinjun; Shi, Xueyan

    2017-09-01

    In order to characterize the metabolic transformation of thiamethoxam (TMX) to clothianidin (CLO) in Helicoverpa armigera larvae and clarify its relationship with the insecticidal toxicity of TMX, method for determination of TMX and its metabolite clothianidin (CLO) residues in H. armigera larvae by solid phase extraction (SPE) combined UPLC-MS/MS was established. Following acetonitrile extraction and purification by SPE on florisil cartridge and C 18 cartridge sequently, and cleanup by PSA adsorption, TMX and CLO residues in H. armigera larvae were successfully determined by UPLC-MS/MS. By using the established method, the concentration-time curves of TMX and its metabolite CLO in H. armigera larvae in vivo and metabolism of TMX by microsome of H. armigera larvae midguts in vitro were studied. TMX was quickly eliminated from H. armigera larvae with the elimination half-life as 4.2h. Meanwhile, only a small amount of CLO was formed from TMX metabolism, with the maximum CLO level in H. armigera larvae only accounts for the metabolic transformation of 7.99% of TMX, at 10h after intravenous TMX administration. Our results suggested that the low insecticidal efficacy of TMX against H. armigera larvae was related with the rapidly elimination of TMX from H. armigera larvae, meanwhile, CLO as TMX metabolite at a very low level in vivo didn't contribute to TMX toxicity to H. armigera larvae. In H. armigera larvae, TMX didn't act as proinsecticide for CLO in insecticidal efficacy of TMX. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Targeted isolation and identification of bioactive compounds lowering cholesterol in the crude extracts of crabapples using UPLC-DAD-MS-SPE/NMR based on pharmacology-guided PLS-DA.

    Science.gov (United States)

    Wen, Chao; Wang, Dongshan; Li, Xing; Huang, Tao; Huang, Cheng; Hu, Kaifeng

    2018-02-20

    The anti-hyperlipidemic effects of crude crabapple extracts derived from Malus 'Red jade', Malus hupehensis (Pamp.) Rehd. and Malus prunifolia (Willd.) Borkh. were evaluated on high-fat diet induced obese (HF DIO) mice. The results revealed that some of these extracts could lower serum cholesterol levels in HF DIO mice. The same extracts were also parallelly analyzed by LC-MS in both positive and negative ionization modes. Based on the pharmacological results, 22 LC-MS variables were identified to be correlated with the anti-hyperlipidemic effects using partial least square discriminant analysis (PLS-DA) and independent samples t-test. Further, under the guidance of the bioactivity-correlated LC-MS signals, 10 compounds were targetedly isolated and enriched using UPLC-DAD-MS-SPE and identified/elucidated by NMR together with MS/MS as citric acid(1), p-coumaric acid(2), hyperoside(3), myricetin(4), naringenin(5), quercetin(6), kaempferol(7), gentiopicroside(8), ursolic acid(9) and 8-epiloganic acid(10). Among these 10 compounds, 6 compounds, hyperoside(3), myricetin(4), naringenin(5), quercetin(6), kaempferol(7) and ursolic acid(9), were individually studied and reported to indeed have effects on lowering the serum lipid levels. These results demonstrated the efficiency of this strategy for drug discovery. In contrast to traditional routes to discover bioactive compounds in the plant extracts, targeted isolation and identification of bioactive compounds in the crude plant extracts using UPLC-DAD-MS-SPE/NMR based on pharmacology-guided PLS-DA of LC-MS data brings forward a new efficient dereplicated approach to natural products research for drug discovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Synthesis of chelating agent free-solid phase extractor (CAF-SPE) based on new SiO2/Al2O3/SnO2 ternary oxide and application for online preconcentration of Pb2+ coupled with FAAS

    International Nuclear Information System (INIS)

    Tarley, César R.T.; Scheel, Guilherme L.; Zappielo, Caroline D.; Suquila, Fabio A.C.; Ribeiro, Emerson S.

    2018-01-01

    A new online solid phase preconcentration method using the new SiO 2 /Al2O 3 /SnO 2 ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb 2+ determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence spectroscopy (XRF) and textural data. The method involves the preconcentration using time-based sampling of Pb 2+ solution at pH 4.3 through 100.0 mg of packed adsorbed into a mini-column under flow rate of 4.0 mL min -1 during 5 min. The elution step was accomplished by using 1.0 mol L -1 HCl. A wide range of analytical curve (5.0-400.0 μg L -1 ), high enrichment factor (40.5), low consumption index (0.5 mL) and low limits of quantification and detection, 5.0 and 1.5 μg L -1 , respectively, were obtained with the developed method. Practical application of method was tested on water samples, chocolate powder, Ginkgo biloba and sediment (certified reference material). On the basis of the results, the SiAlSn can be considered an effective adsorbent belonging to the class of CAF-SPE for Pb 2+ determination from different matrices. (author)

  7. Application of oxide fine-mesh electrodes composed of Sb-SnO2 for the electrochemical oxidation of Cibacron Marine FG using an SPE filter-press reactor

    International Nuclear Information System (INIS)

    Da Silva, Leonardo M.; Gonçalves, Ismael C.; Teles, José J.S.; Franco, Débora V.

    2014-01-01

    Highlights: • Oxide fine-mesh electrodes composed of Sb-SnO 2 (OFM-Sb-SnO 2 ) were fabricated and applied to the decolourisation and mineralisation of dye solutions using an SPE filter-press reactor. • An electrode mechanism was proposed for the irreversible parallel reactions comprising the oxygen evolution reaction (OER) and the electrochemical advanced oxidation process (EAOP) during the electrolysis of electrolyte-free dye solutions. • The reduction in current efficiency for the OER during the oxidation of Cibacron Marine FG (CMFG) increased the electrode stability. - Abstract: Oxide fine-mesh electrodes composed of tin dioxide doped with antimony (OFM-Sb-SnO 2 ), which had different percentages of Sb, were prepared using the thermal decomposition method on a stainless steel fine-mesh support for application in a solid polymer electrolyte (SPE) filter-press reactor. The electrochemical oxidation of Cibacron ® Marine FG (CMFG) was carried out during recirculation through a plug-flow reactor, using electrolyte-free dye solutions. An influence of the Sb content on the electrochemical oxidation of CMFG was verified. The highest combustion rate of CMFG was obtained using an electrode containing 6.57 mol% Sb. Studies were carried out as a function of the initial dye concentration (IDC) and the applied current density (j) for this particular electrode composition. It was verified that the decolourisation and mineralisation reactions were affected considerably by IDC and j. In trying to interpret the experimental findings, an electrode mechanism was proposed for the irreversible parallel reactions comprising the oxygen evolution reaction (OER) and the advanced oxidation process (EAOP). The instantaneous current efficiency (ICE) for the mineralisation reaction was calculated for the different cases using the average mass-transport coefficient () and the initial limiting current (j L 0 ) values. The energy consumption (EC) was also calculated for the

  8. Proceedings of the 2002 Petroleum Society of CIM/SPE/CHOA International Thermal Operations and Heavy Oil Symposium, International Conference on Horizontal Well Technology, and Canadian Heavy Oil Association Business Conference : Resources 2 Reserves 2 Results. CD ROM ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This three day conference combined the Petroleum Society's International Horizontal Well and Technology Conference, the Society of Petroleum Engineer's (SPE) International Thermal Operations and Heavy Oil Symposium, and the Canadian Heavy Oil Association's (CHOA) Annual Business Meeting. The 87 presentations covered all aspects of heavy oil, thermal, and horizontal well technology from geosciences and drilling to economics and environment. The themes included financing, turning projects into results, eliminating the downstream barriers to oil sand development in North America and the world, and emerging technologies for horizontal or heavy oil applications. The conference included the following 20 sessions: (1) thermal operations/engineering, (2) well testing/productivity of horizontal wells, (3) heavy oil operations, (4) environmental aspects of heavy oil projects, (5) upgrading/pipelines, (6) economics and project appraisal, (7) simulation studies of thermal projects, (8) multilaterals, (9) horizontal wells in conventional reservoirs, (10) cold production of heavy oil, (11) horizontal drilling in thermal projects, (12) simulation studies of horizontal wells, (13) horizontal drilling technology, (14) thermal field studies and horizontal wells in heavy oil, (15) completion/production technology of horizontal and thermal wells, (16) physics and PVT of heavy oil recovery processes, (17) reservoir characterization/geosciences, (18) horizontal injectors/produced water technology, (19) emerging technologies, and (20) reservoir geomechanics/fracturing. Tutorials were also organized to provide opportunity to review areas that have undergone major changes. A total of 73 papers were indexed separately for inclusion in the database. refs., tabs., figs.

  9. Identification of PTP1B and α-Glucosidase Inhibitory Serrulatanes from Eremophila spp. by Combined use of Dual High-Resolution PTP1B and α-Glucosidase Inhibition Profiling and HPLC-HRMS-SPE-NMR.

    Science.gov (United States)

    Wubshet, Sileshi G; Tahtah, Yousof; Heskes, Allison M; Kongstad, Kenneth T; Pateraki, Irini; Hamberger, Björn; Møller, Birger L; Staerk, Dan

    2016-04-22

    According to the International Diabetes Federation, type 2 diabetes (T2D) has reached epidemic proportions, affecting more than 382 million people worldwide. Inhibition of protein tyrosine phosphatase-1B (PTP1B) and α-glucosidase is a recognized therapeutic approach for management of T2D and its associated complications. The lack of clinical drugs targeting PTP1B and side effects of the existing α-glucosidase drugs, emphasize the need for new drug leads for these T2D targets. In the present work, dual high-resolution PTP1B and α-glucosidase inhibition profiles of Eremophila gibbosa, E. glabra, and E. aff. drummondii "Kalgoorlie" were used for pinpointing α-glucosidase and/or PTP1B inhibitory constituents directly from the crude extracts. A subsequent targeted high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-HRMS-SPE-NMR) analysis and preparative-scale HPLC isolation led to identification of 21 metabolites from the three species, of which 16 were serrulatane-type diterpenoids (12 new) associated with either α-glucosidase and/or PTP1B inhibition. This is the first report of serrulatane-type diterpenoids as potential α-glucosidase and/or PTP1B inhibitors.

  10. SPE coupled to AAS trace determination of Cd(II) and Zn(II) in food samples using amine functionalized GMA-MMA-EGDMA terpolymer: Isotherm and kinetic studies.

    Science.gov (United States)

    Islam, Aminul; Kumar, Suneel; Zaidi, Noushi; Ahmad, Hilal

    2016-12-15

    An ethylenediamine functionalized glycidyl methacrylate (GMA) based terpolymeric chelating resin was synthesized for the separation and preconcentration of Cd(II) and Zn(II) by SPE from bread, rice and fruit juice prior to FAAS determination. The resin was characterized by FT-IR, TGA/DTA, SEM, BET analysis and EDS. Synthesized resin shows a good capacity of 53.96mgg(-1) for Cd(II) and 24.19mgg(-1) for Zn(II) at pH 8.0. Five isotherm equilibrium models were studied to explain the sorption phenomenon out of which Langmuir, Dubinin-Radushkevich, Scatchard and Temkin models were found to be the best fitted. The limit of detection (LOD) and limit of quantification (LOQ) were observed to be 1.5 and 5.1μgL(-1) for Cd and 1.2 and 4.1μgL(-1) for Zn. The reliability of the method was investigated by the analysis of SRM and the recovery of analytes from various spiked food samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Preparation of a hollow porous molecularly imprinted polymer using tetrabromobisphenol A as a dummy template and its application as SPE sorbent for determination of bisphenol A in tap water.

    Science.gov (United States)

    Li, Jin; Zhang, Xuebin; Liu, Yuxin; Tong, Hongwu; Xu, Yeping; Liu, Shaomin

    2013-12-15

    In this paper, a highly selective sample cleanup procedure combing dummy molecular imprinting and solid-phase extraction (DMIP-SPE) was developed for the isolation and determination of bisphenol A (BPA) in tap water. The novel hollow porous dummy molecularly imprinted polymer (HPDMIP) was prepared adopting a sacrificial support approach, using tetrabromobisphenol A (TBBPA), whose structure was similar to that of BPA, as the dummy template and mesoporous MCM-48 nanospheres as the support. Owing to a very short distance between the binding sites and the surface, a large surface area and a good steric structure to match its imprint molecules, the maximum adsorption capacities (Qmax) of the dummy-imprinted and non-imprinted sorbents for BPA were as high as 445 and 340 μmol g(-1), respectively, and the adsorption reached about 73% of Qmax in 10 min. Meanwhile, a method was developed for the determination of BPA using HPDMIP as a solid-phase extraction enrichment sorbent coupled with HPLC. Under the optimum experimental conditions, HPDMIP exhibited satisfactory results in the enrichment and determination of BPA in tap water with a recovery rate of 95-105%, and relative standard deviations of below 6%, and it can achieve a limit of detection as low as 3 ng mL(-1). The developed extraction protocol eliminated the effect of template leakage on quantitative analysis and could be applied for the determination of BPA in complicated functional samples. © 2013 Elsevier B.V. All rights reserved.

  12. A high-throughput urinalysis of abused drugs based on a SPE-LC-MS/MS method coupled with an in-house developed post-analysis data treatment system.

    Science.gov (United States)

    Cheng, Wing-Chi; Yau, Tsan-Sang; Wong, Ming-Kei; Chan, Lai-Ping; Mok, Vincent King-Kuen

    2006-10-16

    A rapid urinalysis system based on SPE-LC-MS/MS with an in-house post-analysis data management system has been developed for the simultaneous identification and semi-quantitation of opiates (morphine, codeine), methadone, amphetamines (amphetamine, methylamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA)), 11-benzodiazepines or their metabolites and ketamine. The urine samples are subjected to automated solid phase extraction prior to analysis by LC-MS (Finnigan Surveyor LC connected to a Finnigan LCQ Advantage) fitted with an Alltech Rocket Platinum EPS C-18 column. With a single point calibration at the cut-off concentration for each analyte, simultaneous identification and semi-quantitation for the above mentioned drugs can be achieved in a 10 min run per urine sample. A computer macro-program package was developed to automatically retrieve appropriate data from the analytical data files, compare results with preset values (such as cut-off concentrations, MS matching scores) of each drug being analyzed and generate user-defined Excel reports to indicate all positive and negative results in batch-wise manner for ease of checking. The final analytical results are automatically copied into an Access database for report generation purposes. Through the use of automation in sample preparation, simultaneous identification and semi-quantitation by LC-MS/MS and a tailored made post-analysis data management system, this new urinalysis system significantly improves the quality of results, reduces the post-data treatment time, error due to data transfer and is suitable for high-throughput laboratory in batch-wise operation.

  13. Screening for illicit and medicinal drugs in whole blood using fully automated SPE and ultra-high-performance liquid chromatography with TOF-MS with data-independent acquisition.

    Science.gov (United States)

    Pedersen, Anders Just; Dalsgaard, Petur Weihe; Rode, Andrej Jaroslav; Rasmussen, Brian Schou; Müller, Irene Breum; Johansen, Sys Stybe; Linnet, Kristian

    2013-07-01

    A broad forensic screening method for 256 analytes in whole blood based on a fully automated SPE robotic extraction and ultra-high-performance liquid chromatography (UHPLC) with TOF-MS with data-independent acquisition has been developed. The limit of identification was evaluated for all 256 compounds and 95 of these compounds were validated with regard to matrix effects, extraction recovery, and process efficiency. The limit of identification ranged from 0.001 to 0.1 mg/kg, and the process efficiency exceeded 50% for 73 of the 95 analytes. As an example of application, 1335 forensic traffic cases were analyzed with the presented screening method. Of these, 992 cases (74%) were positive for one or more traffic-relevant drugs above the Danish legal limits. Commonly abused drugs such as amphetamine, cocaine, and frequent types of benzodiazepines were the major findings. Nineteen less frequently encountered drugs were detected e.g. buprenorphine, butylone, cathine, fentanyl, lysergic acid diethylamide, m-chlorophenylpiperazine, 3,4-methylenedioxypyrovalerone, mephedrone, 4-methylamphetamine, p-fluoroamphetamine, and p-methoxy-N-methylamphetamine. In conclusion, using UHPLC-TOF-MS screening with data-independent acquisition resulted in the detection of common drugs of abuse as well as new designer drugs and more rarely occurring drugs. Thus, TOF-MS screening of blood samples constitutes a practical way for screening traffic cases, with the exception of δ-9-tetrahydrocannabinol, which should be handled in a separate method. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. SPE dose prediction using locally weighted regression

    International Nuclear Information System (INIS)

    Hines, J. W.; Townsend, L. W.; Nichols, T. F.

    2005-01-01

    When astronauts are outside Earth's protective magnetosphere, they are subject to large radiation doses resulting from solar particle events. The total dose received from a major solar particle event in deep space could cause severe radiation poisoning. The dose is usually received over a 20-40 h time interval but the event's effects may be reduced with an early warning system. This paper presents a method to predict the total dose early in the event. It uses a locally weighted regression model, which is easier to train, and provides predictions as accurate as the neural network models that were used previously. (authors)

  15. Endocrine control of active sodium transport across frog skin; Le controle endocrinien du transport actif de sodium a travers la peau de grenouille

    Energy Technology Data Exchange (ETDEWEB)

    Maetz, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [French] I. Action des peptides neurohypophysaires chez Rana esculenta. 1) Le transport actif de Na est sensible a l'action de l'ocytocine mais non a l'hormone antidiuretique. 2) La posthypophyse de ces grenouilles contient un facteur plus specifique encore, puisque 12 fois plus actif que l'ocytocine. 3) Ce facteur est cependant tres voisin de l'ocytocine au point de vue chimique. lI. Action des corticoides surrenaliens chez Rana Esculenta. 1) L'adaptation des grenouilles a un milieu riche en sel a pour effet une diminution considerable du transport actif de sodium, visible in vivo et in vitro. 2) L'injection d'aldosterone a des grenouilles adaptees dans ces conditions restaure le transport actif a un niveau comparable a celui que l'on observe chez les animaux conserves dans de l'eau courante. 3) Ces faits suggerent que la surcharge en NaCI produirait chez les amphibiens, comme chez les mammiferes, une mise au repos de la fonction mineralotrope de la surrenale. (auteur)

  16. Évaluation in vitro et in vivo des perturbateurs endocriniens chez le poisson zèbre : cas de substances seules et en mélanges

    OpenAIRE

    Serra , Hélène

    2017-01-01

    This PhD thesis aims at assessing the potential of innovative in vitro and in vivo zebrafish based bioassays for biomonitoring of surface water contamination by xeno-estrogens. For this purpose, the bioassays were applied to assess the effect of environmentally relevant surface water pollutants, alone and in simple (artificial) and complex (environmental samples) mixtures. The screening of surface water samples in zebrafish- (ZELH-zfERβ2 cells) and human-based (MELNcells) bioassays revealed q...

  17. Endocrine control of active sodium transport across frog skin; Le controle endocrinien du transport actif de sodium a travers la peau de grenouille

    Energy Technology Data Exchange (ETDEWEB)

    Maetz, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [French] I. Action des peptides neurohypophysaires chez Rana esculenta. 1) Le transport actif de Na est sensible a l'action de l'ocytocine mais non a l'hormone antidiuretique. 2) La posthypophyse de ces grenouilles contient un facteur plus specifique encore, puisque 12 fois plus actif que l'ocytocine. 3) Ce facteur est cependant tres voisin de l'ocytocine au point de vue chimique. lI. Action des corticoides surrenaliens chez Rana Esculenta. 1) L'adaptation des grenouilles a un milieu riche en sel a pour effet une diminution considerable du transport actif de sodium, visible in vivo et in vitro. 2) L'injection d'aldosterone a des grenouilles adaptees dans ces conditions restaure le transport actif a un niveau comparable a celui que l'on observe chez les animaux conserves dans de l'eau courante. 3) Ces faits suggerent que la surcharge en NaCI produirait chez les amphibiens, comme chez les mammiferes, une mise au repos de la fonction mineralotrope de la surrenale. (auteur)

  18. Synthesis of chelating agent free-solid phase extractor (CAF-SPE) based on new SiO{sub 2}/Al{sub 2}O{sub 3}/SnO{sub 2} ternary oxide and application for online preconcentration of Pb{sup 2+} coupled with FAAS

    Energy Technology Data Exchange (ETDEWEB)

    Tarley, César R.T.; Scheel, Guilherme L.; Zappielo, Caroline D.; Suquila, Fabio A.C., E-mail: ctarleyquim@yahoo.com.br [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Química; Ribeiro, Emerson S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Grupo LaDANM

    2018-05-01

    A new online solid phase preconcentration method using the new SiO{sub 2}/Al2O{sub 3}/SnO{sub 2} ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb{sup 2+} determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence spectroscopy (XRF) and textural data. The method involves the preconcentration using time-based sampling of Pb{sup 2+} solution at pH 4.3 through 100.0 mg of packed adsorbed into a mini-column under flow rate of 4.0 mL min{sup -1} during 5 min. The elution step was accomplished by using 1.0 mol L{sup -1} HCl. A wide range of analytical curve (5.0-400.0 μg L{sup -1}), high enrichment factor (40.5), low consumption index (0.5 mL) and low limits of quantification and detection, 5.0 and 1.5 μg L{sup -1}, respectively, were obtained with the developed method. Practical application of method was tested on water samples, chocolate powder, Ginkgo biloba and sediment (certified reference material). On the basis of the results, the SiAlSn can be considered an effective adsorbent belonging to the class of CAF-SPE for Pb{sup 2+} determination from different matrices. (author)

  19. Para neoplastic cataplexy: evolution of PET with [{sup 18}F] -F.D.G. imaging; Cataplexie paraneoplasique: evolution de l'imagerie TEP au [18F]-FDG

    Energy Technology Data Exchange (ETDEWEB)

    Farida, K.; Fernandez, P.; Guyot, M.; Jeandot, R.; Allard, M. [Service de medecine nucleaire, CHU de Bordeaux, (France); Sibon, I. [service de neurologie, CHU de Bordeaux, (France)

    2009-05-15

    Cataplexy is sudden and transient episode of loss of muscle tone, often triggered by emotions. We find it in the Gelineau disease but it can be constitutes an exceptional clinical expression of para-neoplasic syndromes. We report the evolution of the PET imaging for a patient during a para-neoplasic syndrome secondary to a testes teratoma associated to the presence of antibodies anti-Ma2. Different aspects of the {sup 18}F-F.D.G. fixation can be observed during the para-neoplasic syndromes affecting the central nervous system. Their values in term of prognosis and help to the therapy decision are still to define. (N.C.)

  20. Combining results of two GC separations partly achieves determination of all cis and trans 16:1, 18:1, 18:2 and 18:3 except CLA isomers of milk fat as demonstrated using Ag-ion SPE fractionation.

    Science.gov (United States)

    Kramer, John K G; Hernandez, Marta; Cruz-Hernandez, Cristina; Kraft, Jana; Dugan, Michael E R

    2008-03-01

    Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short-, long- and branch-chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver-ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100-m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 degrees C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t-18:2 and the c/c/t-18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag(+)-SPE columns, and comparing the fractions to the total milk fat. The Ag(+)-SPE technique was modified to obtain pure saturated, trans- and cis-monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver-ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag(+)-HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200

  1. A novel optimised and validated method for analysis of multi-residues of pesticides in fruits and vegetables by microwave-assisted extraction (MAE)-dispersive solid-phase extraction (d-SPE)-retention time locked (RTL)-gas chromatography-mass spectrometry with Deconvolution reporting software (DRS).

    Science.gov (United States)

    Satpathy, Gouri; Tyagi, Yogesh Kumar; Gupta, Rajinder Kumar

    2011-08-01

    A rapid, effective and ecofriendly method for sensitive screening and quantification of 72 pesticides residue in fruits and vegetables, by microwave-assisted extraction (MAE) followed by dispersive solid-phase extraction (d-SPE), retention time locked (RTL) capillary gas-chromatographic separation in trace ion mode mass spectrometric determination has been validated as per ISO/IEC: 17025:2005. Identification and reporting with total and extracted ion chromatograms were facilitated to a great extent by Deconvolution reporting software (DRS). For all compounds LOD were 0.002-0.02mg/kg and LOQ were 0.025-0.100mg/kg. Correlation coefficients of the calibration curves in the range of 0.025-0.50mg/kg were >0.993. To validate matrix effects repeatability, reproducibility, recovery and overall uncertainty were calculated for the 35 matrices at 0.025, 0.050 and 0.100mg/kg. Recovery ranged between 72% and 114% with RSD of <20% for repeatability and intermediate precision. The reproducibility of the method was evaluated by an inter laboratory participation and Z score obtained within ±2. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. SPE-NMR metabolite sub-profiling of urine

    NARCIS (Netherlands)

    Jacobs, D.M.; Spiesser, L.; Garnier, M.; Roo, de N.; Dorsten, van F.; Hollebrands, B.; Velzen, van E.; Draijer, R.; Duynhoven, van J.P.M.

    2012-01-01

    NMR-based metabolite profiling of urine is a fast and reproducible method for detection of numerous metabolites with diverse chemical properties. However, signal overlap in the (1)H NMR profiles of human urine may hamper quantification and identification of metabolites. Therefore, a new method has

  3. Solid Phase Extraction (SPE) for Biodiesel Processing and Analysis

    Science.gov (United States)

    2017-12-13

    similar applications.[7] Nanoporous scaffolds within a macrotextured structure offered an alternative to currently available commercial dry wash...D) is an image of the hydrophilic (left) and hydrophobic (right) materials in water. METHODS Batch type experiments were used to characterize the...

  4. Predicting SPE Fluxes: Coupled Simulations and Analysis Tools

    Science.gov (United States)

    Gorby, M.; Schwadron, N.; Linker, J.; Caplan, R. M.; Wijaya, J.; Downs, C.; Lionello, R.

    2017-12-01

    Presented here is a nuts-and-bolts look at the coupled framework of Predictive Science Inc's Magnetohydrodynamics Around a Sphere (MAS) code and the Energetic Particle Radiation Environment Module (EPREM). MAS simulated coronal mass ejection output from a variety of events can be selected as the MHD input to EPREM and a variety of parameters can be set to run against: bakground seed particle spectra, mean free path, perpendicular diffusion efficiency, etc.. A standard set of visualizations are produced as well as a library of analysis tools for deeper inquiries. All steps will be covered end-to-end as well as the framework's user interface and availability.

  5. Researches on the adaptation of green frogs to environment with various salinity level, and its endocrine determinism; Recherches sur l'adaptation de grenouilles vertes a des milieux de salinite diverse et, sur son determinisme endocrinien

    Energy Technology Data Exchange (ETDEWEB)

    Jard, Serge

    1958-06-09

    This research thesis reports a study in which the author examined whether modifications of sodium flows noticed during the adaptation to environments displaying a different salinity would result from a hormonal determinism. The author first reports in vitro studies which aimed at determining whether the neuro-hypophysis hormone was itself able to explain noticed observations. Knowing that for mammals, a sodium-rich regime results in a resting mineralotropic function of the adrenal cortex, the author studied, by in vivo administering of aldosterone, whether the sodium flow variations through the animal skin due to a prolonged stay in a high salinity bath would result from a similar mechanism. [French] Chez Rana esculenta, la conservation prolongee dans une solution de NaCl isotonique au plasma d'une part, dans de l'eau desionisee d'autre part modifie les flux de sodium a travers la peau mesures dans une solution diluee de NaCl (25 μg Na/ml). La conservation dans une solution de NaCl 7 0/00 entraine: une diminution du transport actif de sodium a travers la peau, in vivo et in vitro et d'autre part une augmentation de la diffusion passive de cet ion a travers la peau (flux de sortie augmente). La conservation dans un milieu appauvri en Na entraine les modifications inverses (augmentation du flux d'entree de sodium a travers la peau, flux net nul). Par ailleurs une forte salinite du milieu exterieur entraine une surcharge sodique plasmatique et tissulaire, la conservation dans un milieu pauvre en sodium une depletion sodique plasmatique et tissulaire. In vitro, l'ocytocine ne peut pas, a elle seule, rendre compte des modifications du transport actif de sodium a travers la peau des animaux conserves au prealable dans des milieux de salinite differente. Par contre, in vivo, des injections repetees d'aldosterone provoquent une augmentation du flux d'entree de sodium a travers la peau des animaux conserves dans la solution de NaCl a 7 0/00 comparable a celle observee chez des grenouilles du meme groupe plongees dans de l'eau courante. Ceci suggere, d'une part, l'existence chez Rana esculenta d'un controle de la fonction surrenalienne par la salinite du milieu exterieur, d'autre part, l'existence d'une regulation possible du transport actif de sodium par les mineralocorticoides. (auteur)

  6. Modification of a solid polymer electrolyte (SPE) electrolyser to ensure tritium compatibility

    International Nuclear Information System (INIS)

    Eichelhardt, F.; Cristescu, I.; Michling, R.; Welte, S.

    2010-01-01

    A Water Detritiation System (WDS) is required for the ITER Tritium Plant in order to process tritiated water which is accumulated in various subsystems (e.g. the hall ventilation systems). For the ITER-WDS, the Combined Electrolysis Catalytic Exchange (CECE) process with an electrolyser unit as one of the major components is envisaged. An experimental WDS was built and commissioned at the Tritium Laboratory Karlsruhe (TLK) for the investigation of various subsystems of the CECE process in tritium environment. The TLK-WDS consists of an 8 m Liquid Phase Catalytic Exchange column and two Solid Polymer Electrolyte electrolysers, each with a maximum hydrogen output of 1 m 3 /h. The commercially available Hogen40 electrolyser units from Proton Energy Systems are not tritium compatible concerning materials, joints and quality documentation (e.g. necessary certificates). In order to process tritiated water with tritium concentrations up to 370 GBq/kg, tritium compatibility had to be ensured by appropriate modifications. Up to now, the modified system has been operated with tritiated water for 3500 h, the maximum tritium concentration in the electrolysers being 190 GBq/kg. This contribution reports on the necessary modifications of the electrolyser units and the experiences gained thereby. The results are equally important for the ITER-WDS, where the maximum tritium concentration in the feed water of the electrolyser units will be even higher with 11 TBq/kg.

  7. Determination of fusaric acid in maize using molecularly imprinted SPE clean-up

    Science.gov (United States)

    A new liquid chromatography method to detect fusaric acid in maize is reported based on molecularly imprinted polymer solid phase extraction clean-up (MISPE) using mimic-templated molecularly-imprinted polymers. Picolinic acid was used as a toxin analog for imprinting polymers during a thermolytic s...

  8. Analysis of patulin in dutch food, an evaluation of a SPE based method

    NARCIS (Netherlands)

    Boonzaaijer, G.; Bobeldijk, I.; Osenbruggen, W.A. van

    2005-01-01

    A reliable method for the determination of patulin in apple juice, apple puree and apples was developed using two clean-up steps and high performance liquid chromatography and diode array (HPLC-DAD) analysis. Baseline separation from hydroxymethyl furfural (HMF) was obtained. The performance

  9. Anthropopedia in spe. Vzniká první internetová Encyklopedie antropologie

    Czech Academy of Sciences Publication Activity Database

    Filipský, Jan; Malina, J.

    2010-01-01

    Roč. 1, č. 1 (2010), s. 95-98 ISSN 1804-6657 Institutional research plan: CEZ:AV0Z90210515 Keywords : holistic anthropology * database * on-going project Subject RIV: AC - Archeology, Anthropology, Ethnology

  10. SPE/TLC/Densitometric Quantification of Selected Synthetic Food Dyes in Liquid Foodstuffs and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Anna W. Sobańska

    2017-01-01

    Full Text Available Selected synthetic food dyes (tartrazine, Ponceau 4R, Brilliant Blue, orange yellow, and azorubine were isolated from liquid preparations (mouthwashes and beverages by Solid Phase Extraction on aminopropyl-bonded silica with diluted aqueous sodium hydroxide as an eluent. The extraction step was followed by thin layer chromatography on silica gel 60 with chloroform-isopropanol-25% aq. ammonia 1 : 3 : 1 (v/v/v as mobile phase and the densitometric quantification of dyes was achieved using quadratic calibration plots (R2>0.997; LOQ = 0.04–0.09 μgspot−1. The overall recoveries for all studied dyes were at the average level of over 90% and the repeatability of the proposed procedure (CV ≤ 4.1% was sufficient to recommend it for the routine quantification of the aforementioned dyes in liquid matrices.

  11. Determination of psilocin, bufotenine, LSD and its metabolites in serum, plasma and urine by SPE-LC-MS/MS.

    Science.gov (United States)

    Martin, Rafaela; Schürenkamp, Jennifer; Gasse, Angela; Pfeiffer, Heidi; Köhler, Helga

    2013-05-01

    A validated method for the simultaneous determination of psilocin, bufotenine, lysergic acid diethylamide and its metabolites in serum, plasma and urine using liquid chromatography-electrospray ionization/tandem mass spectrometry was developed. During the solid-phase extraction procedure with polymeric mixed-mode cation exchange columns, the unstable analytes were protected by ascorbic acid, drying with nitrogen and exclusion of light. The limits of detection and quantitation for all analytes were low. Recovery was ≥86 % for all analytes and no significant matrix effects were observed. Interday and intraday imprecisions at different concentrations ranged from 1.1 to 8.2 % relative standard deviation, bias was within ±5.3 %. Processed samples were stable in the autosampler for at least 2 days. Furthermore, freeze/thaw and long-term stability were investigated. The method was successfully applied to authentic serum and urine samples.

  12. Development and validation of an SPE HG-AAS method for determination of inorganic arsenic in samples of marine origin

    DEFF Research Database (Denmark)

    Rasmussen, Rie Romme; Hedegaard, Rikke Susanne Vingborg; Larsen, Erik Huusfeldt

    2012-01-01

    The present paper describes a novel method for the quantitative determination of inorganic arsenic (iAs) in food and feed of marine origin. The samples were subjected to microwave-assisted extraction using diluted hydrochloric acid and hydrogen peroxide, which solubilised the analytes and oxidised...

  13. Transport and environmental sustainability: An adapted SPE approach for modelling interactions between transport, infrastructure, economy and environment

    Energy Technology Data Exchange (ETDEWEB)

    Verhoef, Erik; Van den Bergh, Jeroen [Department of Spatial Economics, Faculty of Economics and Econometrics, Free University Amsterdam, Amsterdam (Netherlands)

    1994-05-01

    The present paper aims at shedding some light on the concept of `sustainable transport`. Within the context of a sustainable development, the consequences of interdependencies between transport, infrastructure, economy and environment for the formulation of optimal regulatory policies are investigated. The Spatial Price Equilibrium approach is adapted for the analysis of sustainable spatio-economic development, and for the evaluation of first-best and second-best regulatory policies on the issues at hand. The analysis demonstrates the need for integration of elements concerning economic structure, infrastructure, transportation, environment and space in one single analytical framework when considering questions on sustainability in relation to transport. 2 figs., 1 appendix, 10 refs.

  14. Simultaneous determination of 15 phenolic constituents of Chinese black rice wine by HPLC-MS/MS with SPE.

    Science.gov (United States)

    Wang, Yutang; Liu, Yuanyuan; Xiao, Chunxia; Liu, Laping; Hao, Miao; Wang, Jianguo; Liu, Xuebo

    2014-06-01

    This study established a new method for quantitative and qualitative determination of certain components in black rice wine, a traditional Chinese brewed wine. Specifically, we combined solid-phase extraction and high-performance liquid chromatography (HPLC) with triple quadrupole mass spectrometry (MS/MS) to determine 8 phenolic acids, 3 flavonols, and 4 anthocyanins in black rice wine. First, we clean samples with OASIS HLB cartridges and optimized extraction parameters. Next, we performed separation on a SHIM-PACK XR-ODS column (I.D. 3.0 mm × 75 mm, 2.2 μm particle size) with a gradient elution of 50% aqueous acetonitrile (V/V) and water, both containing 0.2% formic acid. We used multiple-reaction monitoring scanning for quantification, with switching electrospray ion source polarity between positive and negative modes in a single chromatographic run. We detected 15 phenolic compounds properly within 38 min under optimized conditions. Limits of detection ranged from 0.008 to 0.030 mg/L, and average recoveries ranged from 60.8 to 103.1% with relative standard deviation ≤8.6%. We validated the method and found it to be sensitive and reliable for quantifying phenolic compounds in rice wine matrices. This study developed a new, reliable HPLC-MS/MS method for simultaneous determination of 15 bioactive components in black rice wine. This method was validated and found to be sensitive and reliable for quantifying phenolic compounds in rice wine. © 2014 Institute of Food Technologists®

  15. METHODOLOGY OF ORGANIZATION OF INTEGRATED LESSONS OF NATURAL-SCIENCE CYCLE (ON THE EXAMPLE OF TEACHING SPE STUDENTS

    Directory of Open Access Journals (Sweden)

    Alsou Raufovna Kamaleeva

    2015-09-01

    Full Text Available In the process of transition of Russian organizations of secondary professional education to educational standards of the third generation educational process is reduced to formation of students’ competences. This article presents methodology of creating integrated lessons of natural-science cycle (for example, in physics and informatics. These lessons are constructed on the basis of interdisciplinary integration and focused on task solution. The main purpose is to teach students how to solve particular tasks in physics with the use of informatics, in particular on the basis of algorithmization and programming (Pascal language. Didactic conditions, which are the basis of the algorithm of designing corresponding tasks, are described in this article. Structural components of the integrated lessons created on the traditional principle are marked out. During the research we observed that realization of all stages of the corresponding lessons in practice allows the teacher to create educational process over the borders of disciplinary basis. This approach helps to form generalization of knowledge. Being one of the most optimal forms of education, an integrated lesson allows students to solve various educational and professional problems in non-standard situations and stimulates their cognitive activity and their involvement in the process of education and their responsibility for the result which promotes an intensification of educational process.

  16. Simultaneous determination of metal traces by ICP-MS in environmental waters using SPE preconcentration on different polymeric sorbents

    Czech Academy of Sciences Publication Activity Database

    Holubova, Z.; Moos, Martin; Sommer, L.

    2012-01-01

    Roč. 65, č. 10 (2012), s. 899-906 ISSN 0366-6352 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : solid phase extraction * Amberlite XAD-16 * Amberlite SDB-L * ICP-MS * industrial waters * metal contaminants Subject RIV: EH - Ecology, Behaviour Impact factor: 0.879, year: 2012

  17. Fully automated SPE-based synthesis and purification of 2-[{sup 18}F]fluoroethyl-choline for human use

    Energy Technology Data Exchange (ETDEWEB)

    Schmaljohann, Joern [Department of Nuclear Medicine, University of Bonn, Bonn (Germany); Department of Nuclear Medicine, University of Aachen, Aachen (Germany); Schirrmacher, Esther [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Waengler, Bjoern; Waengler, Carmen [Department of Nuclear Medicine, Ludwig-Maximilians University, Munich (Germany); Schirrmacher, Ralf, E-mail: ralf.schirrmacher@mcgill.c [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Guhlke, Stefan, E-mail: stefan.guhlke@ukb.uni-bonn.d [Department of Nuclear Medicine, University of Bonn, Bonn (Germany)

    2011-02-15

    Introduction: 2-[{sup 18}F]Fluoroethyl-choline ([{sup 18}F]FECH) is a promising tracer for the detection of prostate cancer as well as brain tumors with positron emission tomography (PET). [{sup 18}F]FECH is actively transported into mammalian cells, becomes phosphorylated by choline kinase and gets incorporated into the cell membrane after being metabolized to phosphatidylcholine. So far, its synthesis is a two-step procedure involving at least one HPLC purification step. To allow a wider dissemination of this tracer, finding a purification method avoiding HPLC is highly desirable and would result in easier accessibility and more reliable production of [{sup 18}F]FECH. Methods: [{sup 18}F]FECH was synthesized by reaction of 2-bromo-1-[{sup 18}F]fluoroethane ([{sup 18}F]BFE) with dimethylaminoethanol (DMAE) in DMSO. We applied a novel and very reliable work-up procedure for the synthesis of [{sup 18}F]BFE. Based on a combination of three different solid-phase cartridges, the purification of [{sup 18}F]BFE from its precursor 2-bromoethyl-4-nitrobenzenesulfonate (BENos) could be achieved without using HPLC. Following the subsequent reaction of the purified [{sup 18}F]BFE with DMAE, the final product [{sup 18}F]FECH was obtained as a sterile solution by passing the crude reaction mixture through a combination of two CM plus cartridges and a sterile filter. The fully automated synthesis was performed using as well a Raytest SynChrom module (Raytest, Germany) or a Scintomics HotboxIII module (Scintomics, Germany). Results: The radiotracer [{sup 18}F]FECH can be synthesized in reliable radiochemical yields (RCY) of 37{+-}5% (Synchrom module) and 33{+-}5% (Hotbox III unit) in less than 1 h using these two fully automated commercially available synthesis units without HPLC involvement for purification. Detailed quality control of the final injectable [{sup 18}F]FECH solution proved the high radiochemical purity and the absence of Kryptofix2.2.2, DMAE and DMSO used in the course of synthesis. Sterility and bacterial endotoxin testing following standard procedures verified that the described production method for [{sup 18}F]FECH is suitable for human applications. Conclusions: The routine production of [{sup 18}F]FECH with sufficient RCYs was established by reliable and fast solid-phase extraction purifications of both the secondary labeling precursor [{sup 18}F]BFE and the final product [{sup 18}F]FECH, avoiding complex and sensitive HPLC equipment. The purity of the product was >95%, rendering the tracer suitable for human application. The newly developed purification procedure for [{sup 18}F]BFE significantly reduces the complexity of the automated synthesis unit, hence reducing the cost for routine production in a clinical setup and allowing easy transfer to different synthesis modules.

  18. Structure of the Mature Streptococcal Cysteine Protease Exotoxin mSpeB in Its Active Dimeric Form

    DEFF Research Database (Denmark)

    Olsen, Johan G; Dagil, Robert; Niclasen, Louise Meinert

    2009-01-01

    Invasive infections of Streptococcus pyogenes are dependent on the cysteine protease streptococcal pyrogenic exotoxin B. Previous structures of the enzyme have not disclosed the proper active-site configuration. Here, the crystal structure of the mature enzyme is presented to 1.55 A, disclosing...

  19. Rapid method for quantification of nine sulfonamides in bovine milk using HPLC/MS/MS and without using SPE.

    Science.gov (United States)

    Nebot, Carolina; Regal, Patricia; Miranda, Jose Manuel; Fente, Cristina; Cepeda, Alberto

    2013-12-01

    Sulfonamides are antimicrobial agents widely employed in animal production and their residues in food could be an important risk to human health. In the dairy industry, large quantities of milk are monitored daily for the presence of sulfonamides. A simple and low-cost extraction protocol followed by a liquid chromatographic-tandem mass spectrometry method was developed for the simultaneous detection of nine sulfonamides in whole milk. The method was validated at the maximum residue limits established by European legislation. The limits of quantification obtained for most sulfonamides were between 12.5 and 25 μg kg(-1), detection capabilities ranged from 116 to 145 μg kg(-1), and recoveries, at 100 μg kg(-1), were greater than 89±12.5%. The method was employed to analyse 100 raw whole bovine milk samples collected from dairy farms in the northwest region of Spain. All of the samples were found to be compliant, but two were positive; one for sulfadiazine and the other for sulfamethoxipyridazine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Rapid method for quantification of seven synthetic pigments in colored Chinese steamed buns using UFLC-MS/MS without SPE.

    Science.gov (United States)

    Gao, He-Gang; Gong, Wen-Jie; Zhao, Yong-Gang

    2015-01-01

    Synthetic pigments are still used instead of natural pigments in many foods and their residues in food could be an important risk to human health. A simple and rapid analytical method combining the low-cost extraction protocol with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed for the simultaneous determination of seven synthetic pigments used in colored Chinese steamed buns. For the first time, ethanol/ammonia solution/water (7:2:1, v/v/v) was used as extraction solution for the synthetic pigments in colored Chinese steamed buns. The results showed that the property of the extraction solution used in this method was more effective than critic acid solution, which is used in the polyamide adsorption method. The limits of quantification for the seven synthetic pigments ranged from 0.15 to 0.50 μg/kg. The present method was successfully applied to samples of colored Chinese steamed buns for food-safety risk monitoring in Zhejiang Province, China. The results found sunset yellow pigment in six out of 300 colored Chinese steamed buns (from 0.50 to 32.6 μg/kg).

  1. stockées Ephestia kuehniella (Lepidoptera)

    African Journals Online (AJOL)

    PR BOKO

    de Rebat (2008). [5] - B. DOUMANDJI-MITICHI. Etude d'un ravageur des denrées stockées E. Kuehiella, Am.El Harrach. (1997). [6] - F. TAIBI. Etude comparée du développement et de la reproduction chez deux ravageurs des denrées stockées Ephestia Kuehniella et Tenebrio molitor. Aspect endocrinien en rapport avec.

  2. Facteurs predictifs d'atteinte ganglionnaire centrale dans les ...

    African Journals Online (AJOL)

    Les cancers papillaires et vésiculaires de la thyroïde sont les cancers endocriniens les plus fréquents. L'envahissement ganglionnaire semble peu influencer la survie globale, mais majore les risques de récidive locorégionale et de métastases à distance. Cet envahissement est une complication fréquente des cancers ...

  3. Optimization and validation of bioanalytical SPE – HPLC method for the simultaneous determination of carbamazepine and its main metabolite, carbamazepine-10, 11-epoxide, in plasma

    Directory of Open Access Journals (Sweden)

    Jasmina Tonic – Ribarska

    2012-03-01

    Full Text Available Carbamazepine is widely used as an antiepileptic drug in the treatment of partial and generalized tonic-clonic seizures. Carbamazepine 10,11-epoxide is the most important metabolite of carbamazepine, because it is a pharmacologically active compound with anticonvulsant properties. According to that, the routine analysis of carbamazepine 10,11-epoxide along with carbamazepine may provide optimal therapeutic monitoring of carbamazepine treatment. The aim of this study was to optimize and validate a simple and reliable solid - phase extraction method followed by RP-HPLC for the simultaneous determination of plasma levels of carbamazepine and carbamazepine-10,11-epoxide, in order to assure the implementation of the method for therapeutic monitoring. The extraction of the analytes from the plasma samples was performed by means of a solid-phase extraction procedure. The separation was carried out on a reversed-phase column using isocratic elution with acetonitrile and water (35:65, v/v as a mobile phase. The temperature was 30°C and UV detection was set at 220 nm. The extraction yield values were more than 98% for all analytes, measured at four concentration levels of the linear concentration range. The method displayed excellent selectivity, sensitivity, linearity, precision and accuracy. Stability studies indicate that stock solutions and plasma samples were stabile under different storage conditions at least during the observed period. The method was successfully applied to determine the carbamazepine and carbamazepine-10,11-epoxide in plasma of epileptic patients treated with carbamazepine as monotherapy and in polytherapy. In conclusion, the proposed method is suitable for application in therapeutic drug monitoring of epileptic patients undergoing treatment with carbamazepine.

  4. Discovery of C5-C17 poly- and perfluoroalkyl substances in water by in-line SPE-HPLC-Orbitrap with in-source fragmentation flagging.

    Science.gov (United States)

    Liu, Yanna; Pereira, Alberto Dos Santos; Martin, Jonathan W

    2015-04-21

    The presence of unknown organofluorine compounds in environmental samples has prompted the development of nontargeted analytical methods capable of detecting new perfluoroalkyl and polyfluoroalkyl substances (PFASs). By combining high volume injection with high performance liquid chromatography (HPLC) and ultrahigh resolution Orbitrap mass spectrometry, a sensitive (0.003-0.2 ng F/mL for model mass-labeled PFASs) untargeted workflow was developed for discovery and characterization of novel PFASs in water. In the first step, up to 5 mL of water is injected to in-line solid phase extraction, chromatographed by HPLC, and detected by electrospray ionization with mass spectral acquisition in parallel modes cycling back and forth: (i) full scan with ultrahigh resolving power (RP = 120,000, mass accuracy ≤3 ppm), and (ii) in-source fragmentation flagging scans designed to yield marker fragment ions including [C2F5](-) (m/z 118.992), [C3F7](-) (m/z 168.988), [SO4H](-) (m/z 96.959), and [Cl](-) (m/z 34.9). For flagged PFASs, plausible empirical formulas were generated from accurate masses, isotopic patterns, and fragment ions. In the second step, another injection is made to collect high resolution MS/MS spectra of suspect PFAS ions, allowing further confirmation of empirical formulas while also enabling preliminary structural characterization. The method was validated by applying it to an industrial wastewater, and 36 new PFASs were discovered. Of these, 26 were confidently assigned to 3 new PFAS classes that have not previously been reported in the environment: polyfluorinated sulfates (CnFn+3Hn-2SO4(-); n = 5, 7, 9, 11, 13, and 15), chlorine substituted perfluorocarboxylates (ClCnF2nCO2(-); n = 4-11), and hydro substituted perfluorocarboxylates (HCnF2nCO2(-); n = 5-16). Application of the technique to environmental water samples is now warranted.

  5. A simple, fast and cheap non-SPE screening method for antibacterial residue analysis in milk and liver using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Martins, Magda Targa; Melo, Jéssica; Barreto, Fabiano; Hoff, Rodrigo Barcellos; Jank, Louise; Bittencourt, Michele Soares; Arsand, Juliana Bazzan; Schapoval, Elfrides Eva Scherman

    2014-11-01

    In routine laboratory work, screening methods for multiclass analysis can process a large number of samples in a short time. The main challenge is to develop a methodology to detect as many different classes of residues as possible, combined with speed and low cost. An efficient technique for the analysis of multiclass antibacterial residues (fluoroquinolones, tetracyclines, sulfonamides and trimethoprim) was developed based on simple, environment-friendly extraction for bovine milk, cattle and poultry liver. Acidified ethanol was used as an extracting solvent for milk samples. Liver samples were treated using EDTA-washed sand for cell disruption, methanol:water and acidified acetonitrile as extracting solvent. A total of 24 antibacterial residues were detected and confirmed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), at levels between 10, 25 and 50% of the maximum residue limit (MRL). For liver samples a metabolite (sulfaquinoxaline-OH) was also monitored. A validation procedure was conducted for screening purposes in accordance with European Union requirements (2002/657/EC). The detection capability (CCβ) false compliant rate was less than 5% at the lowest level for each residue. Specificity and ruggedness were also discussed. Incurred and routine samples were analyzed and the method was successfully applied. The results proved that this method can be an important tool in routine analysis, since it is very fast and reliable. Copyright © 2014. Published by Elsevier B.V.

  6. Development and application of SPE/CZE method for detection and determination of selected non-steroidal anti-inflammatory drugs in wastewater

    Czech Academy of Sciences Publication Activity Database

    Čapka, Lukáš; Lacina, P.; Vávrová, M.

    2012-01-01

    Roč. 21, 11A (2012), s. 3312-3317 ISSN 1018-4619 Institutional research plan: CEZ:AV0Z40310501 Keywords : Non-steroidal anti-inflammatory drugs * capillary zone electrophoresis * solid phase extraction * wastewater Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.641, year: 2012

  7. Simultaneous determination of metolazone and valsartan in plasma by on-line SPE coupled with liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Zhou, Jiezhao; Chen, Meiling; Li, Ying; Yu, Fanglin; Cheng, Xiaohui; Yang, Yang; Liu, Yan; Xie, Xiangyang; Li, Zhiping; Zhang, Hui; Mei, Xingguo

    2017-10-01

    Combination of metolazone (0.5 mg) and valsartan (80 mg) has been verified as a promising therapy treatment for hypertension. In order to facilitate to pharmacokinetic research, it needs a method for the simultaneously determination of metolazone and valsartan in biological samples. However, there are no relative reports so far. In order to facilitate to pharmacokinetic research, an on-line solid phase extraction coupled with liquid chromatography-tandem mass spectrometry method for the simultaneous determination of metolazone and valsartan in beagle dog plasma was developed and validated in this study. An on-line solid phase extraction column Retain PEP Javelin (10 mm × 2.1 mm) was used to remove impurities in plasma samples. The metolazone, valsartan and internal standard (losartan) were separated on a Poroshell 120 SB-C18 column (4.6 mm × 50 mm × 2.7 µm) with a gradient elution procedure. Acidified acetonitrile/water mixture was used as a mobile phase. The selected multiple-reaction monitoring mode in positive ion was performed and the parent to the product transitions m/z 366/259, m/z 436.2/291 and m/z 423.4/207 were used to measure the metolazone, valsartan and losartan. The method was linear over the range of 0.1-100 ng/mL and 1-1000 ng/mL for metolazone and valsartan, respectively. This method was validated in terms of specificity, linearity, sensitivity, precision, accuracy, matrix effect, and stability and then successfully applied to pharmacokinetic studies of the metolazone and valsartan combination tablets in beagle dogs.

  8. High-resolution hyaluronidase inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of anti-necrosis constituents in Chinese plants used to treat snakebite

    DEFF Research Database (Denmark)

    Liu, Yueqiu; Stærk, Dan; Nielsen, Mia N.

    2015-01-01

    for the 22 plants showing highest hyaluronidase inhibition, and the results were used to guide subsequent structural analysis towards specific hyaluronidase inhibitors. Structural analysis was performed by high-performance liquid chromatography, high-resolution mass spectrometry, solid-phase extraction...... and nuclear magnetic resonance spectroscopy, i.e., HPLC–HRMS–SPE–NMR. This allowed identification of four non-tannin inhibitors, i.e., lansiumamide B (6) from Clausena excavata Burm.f., myricetin 3-O-β-d-glucopyranoside (7) from Androsace umbellata (Lour.) Merr., and vitexin (8) and 4′,7-dihydroxy-5...

  9. High-resolution bacterial growth inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of antibacterial constituents in Chinese plants used to treat snakebites

    DEFF Research Database (Denmark)

    Liu, Yueqiu; Nielsen, Mia; Stærk, Dan

    2014-01-01

    Bacillus subtilis, Staphylococcus aureus, Escherichia coli or Pseudomonas aeruginosa. The biochromatograms demonstrated that tannins play a main role for the bacterial growth inhibition observed for all above-mentioned plants except for Polygonum cuspidatum. Furthermore, the high-resolution bacterial...... growth inhibition profiling combined with HPLC–HRMS–SPE–NMR allowed fast identification of three non-tannin active compounds, i.e., piceid, resveratrol and emodin from ethanol extract of Polygonum cuspidatum. Conclusion The high-resolution bacterial growth inhibition profiling allowed fast pinpointing...... of constituents responsible for the bioactivity, e.g., either showing tannins being the main bacterial growth inhibitors as observed for the majority of the active plants, or combined with HPLC–HRMS–SPE–NMR for fast structural identification of non-tannin constituents correlated with antibacterial activity....

  10. UHPLC-MS/MS determination of ochratoxin A and fumonisins in coffee using QuEChERS extraction combined with mixed-mode SPE purification.

    Science.gov (United States)

    Nielsen, Kristian Fog; Ngemela, Archard Ferdinand; Jensen, Lene Bai; de Medeiros, Lívia Soman; Rasmussen, Peter Have

    2015-01-28

    A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed by mixed-mode reversed phase-anion exchange solid phase extraction. OTA and FB2 were detected at levels down to 0.5 and 2 μg/kg by UHPLC-MS/MS and quantitated via isotope dilution using U-(13)C-labeled FB2 and OTA as internal standards. Mixing 20% isopropanol in the acetonitrile of the acidic UHPLC gradient system increased the signal intensity by 50% and decreased the ion-suppression with 50-75% in roasted coffee samples. About half of the roasted coffee samples (n = 57, from 9 countries) contained detectable levels of OTA, however, with only 5 samples above the EU regulatory limit of 5 μg/kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting experiments. Here fumonisins could not be detected after roasting of the green, 164 μg/kg coffee, sample. Under the same conditions, OTA was reduced from 2.4 to 0.5 μg/kg.

  11. UHPLC-MS/MS Determination of Ochratoxin A and Fumonisins in Coffee Using QuEChERS Extraction Combined with Mixed-Mode SPE Purification

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Ngemela, Archard Ferdinand; Jensen, Lene Bai

    2015-01-01

    A method was developed for simultaneous determination of the mycotoxins: ochratoxin A (OTA) and fumonisins B2 (FB2), B4 (FB4), and B6 (FB6) in green, roasted, and instant coffee. Extraction was performed by QuEChERS (quick, easy, cheap, effective, rugged, and safe) under acidic conditions followed....../kg and the highest with 21 μg/kg. None of the 25 instant coffee samples contained OTA above the EU regulatory level of 10 μg/kg. Nonetheless, the toxin could be detected in 56% of the analyzed instant coffee samples. Fumonisins were not detected in any of the roasted or instant coffee samples (n = 82). However......, in the green coffee samples (n = 18) almost half of the samples were positive with a maximum value of 164 μg/kg (sum of FB2, FB4, and FB6). This discrepancy between green coffee and processed coffees indicated that the fumonisins decompose during the roasting process, which was confirmed in roasting...

  12. Amphetamines analysis in wastewaters - method performance of solid phase extraction - higher performance liquid chromatography mass spectrometry techniques (SPE-HPLC MS/MS)

    Science.gov (United States)

    Mustapha, Aliru Olajide; Ajao, Usman L

    2011-01-01

    Recently, many articles have reported different levels and distribution of amphetamine hitherto detected in biological fluids now appreciably found in aquatic environment at ng/L levels. Identification and measurement of amphetamine and its metabolites in surface and sewage waters using higher performance liquid chromatographic methodologies in the literatures now on current trend have provided information that are of scientific interest and effectively replaced immunological methods which only suggest the presence of these substances. Active research on both distribution and impacts of this important drug of abuse and related metabolites in the wastewaters are on-going. PMID:27857670

  13. Development of a triple hyphenated HPLC-radical scavenging detection-DAD-SPE-NMR system for the rapid identification of antioxidants in complex plant extracts

    NARCIS (Netherlands)

    Pukalskas, A.; Beek, van T.A.; Waard, de P.

    2005-01-01

    A rapid method for the simultaneous detection and identification of radical scavenging compounds in plant extracts was developed by combining an HPLC with on-line radical scavenging using DPPH as a model radical and an HPLC¿DAD¿SPE¿NMR system. Using this method a commercial rosemary extract was

  14. Cleanup strategies and advantages in the determination of several therapeutic classes of pharmaceuticals in wastewater samples by SPE-LC-MS/MS.

    Science.gov (United States)

    Sousa, M A; Gonçalves, C; Cunha, E; Hajšlová, J; Alpendurada, M F

    2011-01-01

    This work describes the development and validation of an offline solid-phase extraction with simultaneous cleanup capability, followed by liquid chromatography-(electrospray ionisation)-ion trap mass spectrometry, enabling the concurrent determination of 23 pharmaceuticals of diverse chemical nature, among the most consumed in Portugal, in wastewater samples. Several cleanup strategies, exploiting the physical and chemical properties of the analytes vs. interferences, alongside with the use of internal standards, were assayed in order to minimise the influence of matrix components in the ionisation efficiency of target analytes. After testing all combinations of adsorbents (normal-phase, ion exchange and mixed composition) and elution solvents, the best results were achieved with the mixed-anion exchange Oasis MAX cartridges. They provided recovery rates generally higher than 60%. The precision of the method ranged from 2% to 18% and 4% to 19% (except for diclofenac (22%) and simvastatin (26%)) for intra- and inter-day analysis, respectively. Method detection limits varied between 1 and 20 ng L(-1), while method quantification limits were diclofenac and bezafibrate were detected in concentrations ranging from 1 to 20 μg L(-1), while gemfibrozil, simvastatin, ketoprofen, azithromycin, bisoprolol, lorazepam and paroxetine were quantified in levels below 1 μg L(-1). These WWTPs were given particular attention since they discharge their effluents into the Douro river, where water is extracted for the production of drinking water. Some sampling spots in this river were also analysed.

  15. Simultaneous determination of metal traces using SPE preconcentration on Amberlite XAD-7 by ICP-MS in environmental water and sample ecotoxicology assessment

    Czech Academy of Sciences Publication Activity Database

    Holubova, Z.; Sommer, L.; Moos, Martin; Kuta, J.

    2012-01-01

    Roč. 21, 10A (2012), s. 3127-3135 ISSN 1018-4619 Institutional support: RVO:67179843 Keywords : Solid Phase Extraction * Amberlite XAD-7 * ICP-MS and Waters * Ecotoxicology Subject RIV: EH - Ecology, Behaviour Impact factor: 0.641, year: 2012

  16. Chiral Analysis of Methadone and its Main Metabolite, EDDP, in Postmorten Brain and Blood by Automated SPE and Liquid Chromatography-Mass Spectrometry

    DEFF Research Database (Denmark)

    Holm, Karen Marie Dollerup; Linnet, Kristian

    2012-01-01

    Vi udviklede en metode baseret på væskekromatografi med tandem-massespektrometri til kvantificering af de individuelle enantiomer af metadon og dets primære metabolit, R/S-2-ethyl-1,5-dimethyl- 3,3-diphenylpyrrolinium (EDDP), i postmortem blod og hjernevæv. Prøvebehandlingen blev udført på et Tec...

  17. Identification of Alternaria alternata Mycotoxins by LC-SPE-NMR and Their Cytotoxic Effects to Soybean (Glycine max Cell Suspension Culture

    Directory of Open Access Journals (Sweden)

    Edson Rodrigues-Filho

    2013-02-01

    Full Text Available This present work describes the application of liquid chromatograpy-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1, alternariol (2, 3'-hydroxyalternariol monomethyl ether (3, and alternariol monomethyl ether (4, were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max cell cultures as a model. EC50 values which range from 0.11 (±0.02 to 4.69 (±0.47 μM showed the high cytotoxicity of these compounds.

  18. High-resolution bioactivity profiling combined with HPLC-HRMS-SPE-NMR: α-glucosidase inhibitors and acetylated ellagic acid rhamnosides from Myrcia palustris DC. (Myrtaceae)

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Moresco, Henrique H.; Tahtah, Yousof

    2015-01-01

    , and therefore improved drug leads or functional foods containing α-glucosidase inhibitors are needed for management of blood glucose. In this study, leaves of Myrcia palustris were investigated by high-resolution α-glucosidase inhibition profiling combined with HPLC–HRMS–SPE–NMR. This led to identification...

  19. Combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for investigation of antidiabetic principles in crude plant extracts

    DEFF Research Database (Denmark)

    Kongstad, Kenneth Thermann; Özdemir, Ceylan; Barzak, Asmah

    2015-01-01

    Type 2 diabetes is a metabolic disorder affecting millions of people worldwide, and new drug leads or functional foods containing selective α-glucosidase inhibitors are needed. Crude extract of 24 plants were assessed for α-glucosidase inhibitory activity. Methanol extracts of Cinnamomum zeylanicum...... bark, Rheum rhabarbarum peel, and Rheum palmatum root and ethyl acetate extracts of C. zeylanicum bark, Allium ascalonicum peel, and R. palmatum root showed IC50 values below 20 μg/mL. Subsequently, high-resolution α-glucosidase profiling was used in combination with high-performance liquid...... chromatography–high-resolution mass spectrometry–solid-phase extraction–nuclear magnetic resonance spectroscopy for identification of metabolites responsible for the α-glucosidase inhibitory activity. Quercetin (1) and its dimer (2), trimer (3), and tetramer (4) were identified as main α-glucosidase inhibitors...

  20. Screening for illicit and medicinal drugs in whole blood using fully automated SPE and UHPLC-TOF-MS with data-independent acquisition

    DEFF Research Database (Denmark)

    Pedersen, Anders Just; Dalsgaard, Petur Weihe; Rode, Andrej Jaroslav

    2013-01-01

    , butylone, cathine, fentanyl, LSD, mCPP, MDPV, mephedrone, 4-methylamphetamine, p-fluoroamphetamine, and PMMA. In conclusion, using UHPLC-TOF-MS screening with data-independent acquisition resulted in detection of common drugs of abuse as well as new designer-drugs and more rarely occurring drugs. Thus, TOF...

  1. Optimizing an online SPE-HPLC method for analysis of (R)-[11C]1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)- 3-isoquinolinecarboxamide [(R)-[11C]PK11195] and its metabolites in humans

    International Nuclear Information System (INIS)

    Greuter, Henri N.J.M.; van Ophemert, Patricia L.B.; Luurtsema, Gert; van Berckel, Bart N.M.; Franssen, Eric J.F.; Windhorst, Bert D.; Lammertsma, Adriaan A.

    2005-01-01

    (R)-[ 11 C]PK11195 is used as a positron emission tomography tracer for activated microglia in several neurological disorders. Quantification of specific binding requires a metabolite-corrected plasma input function. In this study, a high-performance liquid chromatography (HPLC) procedure with online solid phase extraction was modified for analyzing (R)-[ 11 C]PK11195 plasma samples, yielding total sample recoveries of more than 98%. When applied to human studies, the use of two HPLC systems enabled analysis of up to seven plasma samples under regular conditions. Online radioactivity detection was compared with offline sample measurements of HPLC profiles. Offline measurements provided the most reliable results especially for late plasma samples. In 10 patients, an average decrease of parent compound from 94.6% at 2.5 min to 45.2% at 1 h after administration was observed

  2. Oszacowanie efektów zewnętrznych stosowania wybranych OZE w elektrociepłowni, w kontekście spełniania celów środowiskowych

    OpenAIRE

    Ciechelska, Agnieszka; Pol, Małgorzata Maria

    2015-01-01

    Estimating the effects of external application of selected renewable energy source using in the power plant, in the context of meeting the environmental objectives Increasing problems associated with greenhouse gas emissions, resource management, and increasing the amount of municipal waste generated, causing tightening of environmental regulations, and these in turn need to search for new solutions. One of the biggest CO2 emitters and consumers of non-renewable resource is the CHP sector, wh...

  3. Edible seaweed as future functional food: Identification of α-glucosidase inhibitors by combined use of high-resolution α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR

    DEFF Research Database (Denmark)

    Liu, Bingrui; Kongstad, Kenneth Thermann; Wiese, Stefanie

    2016-01-01

    -glucosidase inhibition profiling combined with high-performance liquid chromatography–high-resolution mass spectrometry–solid-phase extraction–nuclear magnetic resonance spectroscopy (HR-bioassay/HPLC–HRMS–SPE–NMR). The results showed Ascophyllum nodosum and Fucus vesicolosus to be rich in antioxidants, equaling...... as fatty acids – with oleic acid, linoleic acid and eicosapentaenoic acid being the most potent with IC50 values of 0.069, 0.075 and 0.10 mM, respectively, and showing a mixed-type inhibition mode....

  4. Determination of antibiotics in influents and effluents of wastewater-treatment-plants in the Czech Republic – development and application of the SPE and a UHPLC-ToFMS method

    Czech Academy of Sciences Publication Activity Database

    Tylová, Tereza; Flieger, Miroslav; Olšovská, Jana

    2013-01-01

    Roč. 5, č. 8 (2013), s. 2110-2118 ISSN 1759-9660 R&D Projects: GA MŠk 1M06011 Institutional support: RVO:61388971 Keywords : TANDEM MASS-SPECTROMETRY * PERFORMANCE LIQUID-CHROMATOGRAPHY * ANTIMICROBIAL CONSUMPTION ESAC Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.938, year: 2013

  5. Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill

    DEFF Research Database (Denmark)

    Silva, Eder Lana e; Almeida-Lafetá, Rita C.; Borges, Ricardo Moreira

    2017-01-01

    Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosida......Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α...

  6. RESÍDUOS DE AGROTÓXICOS EM ÁGUA POTÁVEL USANDO SPE E DETERMINAÇÃO RÁPIDA POR LC-MS/MS E GC-MS/MS

    OpenAIRE

    Filipe Fagan Donato

    2012-01-01

    O uso de agrotóxicos sempre esteve associado à efetividade no controle de pragas ou plantas invasoras para aumentar a produção de alimentos. No entanto, o uso indiscriminado dessas substâncias vem causando a degradação dos recursos hídricos. No Brasil, o Ministério da Saúde através da Portaria 2914 define diversos parâmetros de potabilidade, entre eles, os limites máximos permitidos para alguns agrotóxicos. No presente trabalho foi desenvolvido e validado um método para a deter...

  7. Population structure of Bactrocera dorsalis s.s., B. papayae and B. philippinensis (Diptera: Tephri- tidae) in southeast Asia: evidence for a single spe- cies hypothesis using mitochondrial DNA and wing-shape data

    Energy Technology Data Exchange (ETDEWEB)

    Schutze, Mark K; Krosch, Matthew N; Clarke, Anthony R [CRC for National Plant Biosecurity (Australia); School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, QLD (Australia); Armstrong, Karen F; Chapman, Toni A; Englezou, Anna; Hailstones, Deborah [CRC for National Plant Biosecurity (Australia); Cameron, Stephen L [School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, QLD (Australia); Chomic, Anastasija

    2013-01-15

    Background: Bactrocera dorsalis s.s. is a pestiferous tephritid fruit fly distributed from Pakistan to the Pacific, with the Thai/Malay peninsula its southern limit. Sister pest taxa, B. papayae and B. philippinensis, occur in the southeast Asian archipelago and the Philippines, respectively. The relationship among these species is unclear due to their high molecular and morphological similarity. This study analysed population structure of these three species within a southeast Asian biogeographical context to assess potential dispersal patterns and the validity of their current taxonomic status. Results: Geometric morphometric results generated from 15 landmarks for wings of 169 flies revealed significant differences in wing shape between almost all sites following canonical variate analysis. For the combined data set there was a greater isolation-by-distance (IBD) effect under a 'non-Euclidean' scenario which used geographical distances within a biogeographical 'Sundaland context' (r{sup 2} = 0.772, P < 0.0001) as compared to a 'Euclidean' scenario for which direct geographic distances between sample sites was used (r{sup 2} = 0.217, P < 0.01). COI sequence data were obtained for 156 individuals and yielded 83 unique haplotypes with no correlation to current taxonomic designations via a minimum spanning network. BEAST analysis provided a root age and location of 540kya in northern Thailand, with migration of B. dorsalis s.l. into Malaysia 470kya and Sumatra 270kya. Two migration events into the Philippines are inferred. Sequence data revealed a weak but significant IBD effect under the 'non-Euclidean' scenario (r{sup 2} = 0.110, P < 0.05), with no historical migration evident between Taiwan and the Philippines. Results are consistent with those expected at the intra-specific level. Conclusions: Bactrocera dorsalis s.s., B. papayae and B. philippinensis likely represent one species structured around the South China Sea, having migrated from northern Thailand into the southeast Asian archipelago and across into the Philippines. No migration is apparent between the Philippines and Taiwan. This information has implications for quarantine, trade and pest management. (author)

  8. Detection of monohydroxylated polycyclic aromatic hydrocarbons in urine and particulate matter using LC separations coupled with integrated SPE and fluorescence detection or coupled with high-resolution time-of-flight mass spectrometry.

    Science.gov (United States)

    Lintelmann, Jutta; Wu, Xiao; Kuhn, Evelyn; Ritter, Sebastian; Schmidt, Claudia; Zimmermann, Ralf

    2018-05-01

    A high-performance liquid chromatographic (HPLC) method with integrated solid-phase extraction for the determination of 1-hydroxypyrene and 1-, 2-, 3-, 4- and 9-hydroxyphenanthrene in urine was developed and validated. After enzymatic treatment and centrifugation of 500 μL urine, 100 μL of the sample was directly injected into the HPLC system. Integrated solid-phase extraction was performed on a selective, copper phthalocyanine modified packing material. Subsequent chromatographic separation was achieved on a pentafluorophenyl core-shell column using a methanol gradient. For quantification, time-programmed fluorescence detection was used. Matrix-dependent recoveries were between 94.8 and 102.4%, repeatability and reproducibility ranged from 2.2 to 17.9% and detection limits lay between 2.6 and 13.6 ng/L urine. A set of 16 samples from normally exposed adults was analyzed using this HPLC-fluorescence detection method. Results were comparable with those reported in other studies. The chromatographic separation of the method was transferred to an ultra-high-performance liquid chromatography pentafluorophenyl core-shell column and coupled to a high-resolution time-of-flight mass spectrometer (HR-TOF-MS). The resulting method was used to demonstrate the applicability of LC-HR-TOF-MS for simultaneous target and suspect screening of monohydroxylated polycyclic aromatic hydrocarbons in extracts of urine and particulate matter. Copyright © 2018 John Wiley & Sons, Ltd.

  9. Caracterización molecular de Streptococcus pyogenes causantes de enfermedad invasora y síndrome de shock tóxico estreptocócico Molecular characterization of Streptococcus pyogenes from invasive disease and streptococcal toxic shock syndrome episodes

    Directory of Open Access Journals (Sweden)

    F. Traverso

    2010-02-01

    Full Text Available Streptococcus pyogenes es el agente causal de varias enfermedades comunes entre las que se incluyen la faringoamigdalitis, la escarlatina y el impétigo. Sin embargo, en las últimas décadas se ha registrado mundialmente un resurgimiento de casos de enfermedad invasora y síndrome de shock tóxico estreptocócico (SSTE. El propósito del presente trabajo fue estudiar la diversidad genética, los factores de virulencia (genes spe, sme, ssa y la sensibilidad a los antibióticos de 10 cepas de S. pyogenes causantes de enfermedad invasora y SSTE. Los aislamientos fueron recuperados de hemocultivos de pacientes internados en el Hospital Santamarina y en la Nueva Clínica Chacabuco (Tandil, Argentina entre diciembre de 2000 y abril de 2005. Predominaron 2 patrones de electroforesis en campo pulsante. El más frecuente comprendió 5 aislamientos del tipo emm1-T1, con perfil de toxinas speA, speB, speF, speG y smeZ. El segundo patrón más frecuente incluyó 2 aislamientos tipo emm3-TNT (speB, speF, speG. Estos dos tipos (emm1 y emm3 fueron los prevalentes en las infecciones invasoras. Las otras tres cepas correspondieron a los tipos emm49-TNT (speB, speC, speF, speG, emm75-T25 (speB, speF, speG y emm83-TNT (speB, speF, speG, ssa, smeZ. Se encontró diversidad genética entre las cepas aisladas, pero todos los aislamientos fueron sensibles a penicilina, cefotaxima, eritromicina, clindamicina, cloranfenicol, tetraciclina y rifampicina. Por tal motivo, aún es válido el tratamiento empírico con penicilina asociada a clindamicina.Streptococcus pyogenes causes a variety of common human diseases, including pharyngitis, scarlet fever and impetigo. Nevertheless, the past decades have witnessed a worldwide resurgence in invasive disease and streptococcal toxic shock syndrome (STSS. The objective of the present study is to evaluate the genetic diversity, virulence gene distribution (spe, sme and ssa genes and susceptibility pattern of 10 S. pyogenes isolates

  10. Une histoire d'hypophyse, évolution des représentations et des concepts au cours du temps.

    OpenAIRE

    JEDIDI, Haroun; JEDIDI, Zayd; BECKERS, Albert

    2014-01-01

    De par le rôle essentiel qu’il occupe, l’axe hypothalamo-hypophysaire, véritable chef d’orchestre du système endocrinien, constitue au niveau médical un important pourvoyeur de désordres. Il est assez paradoxal de constater que malgré l’importance de ce système, celui-ci ait été presque complètement méconnu par les physiologistes des siècles passés. En nous basant sur les conceptions physiologiques des médecins philosophes de l’antiquité puis du moyen-âge et de la renaissance nous tenterons d...

  11. Micropollutants in urban receiving waters

    OpenAIRE

    Musolff, Andreas; Hunkeler, Daniel; Schirmer, Mario

    2010-01-01

    À ce jour, la moitié de la population mondiale vit à l’intérieur des villes. Cette utilisation du territoire a un énorme impact sur le bilan hydrique urbain. Non seulement la quantité de l’eau est désormais limitée mais sa qualité s’est également détériorée. Les micropolluants provenant des eaux usées domestiques et industrielles représentent une préoccupation grandissante. Malgré leur présence en faible concentration, ces micropolluants peuvent agir comme perturbateurs endocriniens et comme ...

  12. Monitoring multiple myeloma patients treated with daratumumab

    DEFF Research Database (Denmark)

    McCudden, Christopher; Axel, Amy E; Slaets, Dominique

    2016-01-01

    BACKGROUND: Monoclonal antibodies are promising anti-myeloma treatments. As immunoglobulins, monoclonal antibodies have the potential to be identified by serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). Therapeutic antibody interference with standard clinical SPE and ...

  13. Electrochemical Quantification of the Antioxidant Capacity of Medicinal Plants Using Biosensors

    OpenAIRE

    Erika Rodríguez-Sevilla; María-Teresa Ramírez-Silva; Mario Romero-Romo; Pedro Ibarra-Escutia; Manuel Palomar-Pardavé

    2014-01-01

    The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric eval...

  14. Pneumothorax Secondary to Septic Pulmonary Emboli in a Long-term Hemodialysis Patient with Psoas Abscess.

    Science.gov (United States)

    Okabe, Masahiro; Kasai, Kenji; Yokoo, Takashi

    2017-12-01

    Pneumothorax secondary to septic pulmonary embolism (SPE) is rare but life-threatening. We herein report a long-term hemodialysis patient with psoas abscess caused by methicillin-resistant Staphylococcus aureus, associated with other muscle and splenic abscesses and SPE. Intravenous vancomycin treatment and percutaneous drainage of the psoas abscess rapidly improved her condition. However, the SPE lesions continued to increase, and right-sided pneumothorax occurred 10 days after treatment. The pneumothorax resolved after two months and SPE and all abscesses after four months of treatment. Since late-onset pneumothorax caused by SPE can occur despite successful treatment of the primary infection, care should be taken with such patients.

  15. Detection of a Giardia lamblia coproantigen by using a commercially available immunoenzymatic assay, in Belo Horizonte, Brazil Avaliação do ProSpeT Giardia ensaio em microplaca na detecção de coproantígenos de Giardia lamblia, em fezes de pacientes de Belo Horizonte, Brasil

    Directory of Open Access Journals (Sweden)

    Míriam Oliveira e ROCHA

    1999-05-01

    Full Text Available It is known that fecal examination to detect Giardia lamblia cysts or trophozoites produces a high percentage of false-negative results. A commercially available immunoenzymatic assay (ProSpecT Giardia Microplate Assay, Alexon, Inc., BIOBRÁS to detect G. lamblia specific coproantigen was evaluated for the first time in Brazil. A total of 90 specimens were tested. Each specimen was first tested as unpreserved stool, and then it was preserved in 10% Formalin to be tested 2 months later. The assay was able to identify all the 30 positive patients (sensitivity = 100.0% by visual or spectrophotometric examination in the unpreserved specimens and was negative in 57 of the 60 patients without G. lamblia (specificity = 95.0%. The assay identified 27 of the 30 positive patients (sensitivity = 90.0% and was negative in 59 of the 60 negatives (specificity = 98.3% in the preserved stools according to both readings. A marked difference was observed in the optical densities in both groups, preserved and unpreserved stools, when the G. lamblia-positive specimens were compared to the negative or positive for other intestinal parasites than G. lamblia. The assay seems a good alternative for giardiasis diagnosis, especially when the fecal examination was repeatedly negative and the patient presents giardiasislike symptoms.O diagnóstico da giardíase através da pesquisa de trofozoítos ou cistos do parasita nas fezes apresenta uma elevada percentagem de resultados falso-negativos. No presente trabalho foi feita, pela primeira vez no Brasil, uma avaliação do ProSpecT Giardia Ensaio em Microplaca (Alexon, Inc., BIOBRÁS, utilizando amostras fecais de pacientes de Belo Horizonte, Brasil. Um total de 90 amostras fecais foram testadas, primeiramente como fezes frescas e, então, preservadas em formalina 10%, para um novo teste 2 meses após. Com as amostras frescas, o ensaio imunoenzimático, através de leitura visual ou no espectrofotômetro, foi capaz de identificar todos os 30 pacientes positivos no exame parasitológico de fezes (EPF e foi negativo em 57 dos 60 pacientes sem G. lamblia (sensibilidade = 100,0%, especificidade = 95,0%. Com as amostras preservadas em formalina 10% durante 2 meses, o teste identificou 27 das 30 amostras fecais positivas (sensibilidade = 90,0% e foi negativo em 59 das 60 amostras negativas no EPF (especificidade = 98,3%. Comparando-se as leituras das densidades óticas nas amostras fecais positivas para G. lamblia com as amostras com EPF negativo ou contendo outros parasitas intestinais que não a G. lamblia, foi observada uma nítida diferença, tanto nas fezes frescas como nas fezes conservadas em formalina 10% durante 2 meses. O ProSpecT Giardia Ensaio em Microplaca mostrou-se uma boa alternativa para o diagnóstico da G. lamblia, especialmente para aqueles casos em que o EPF foi repetidamente negativo e o paciente apresenta sintomas compatíveis com a giardíase.

  16. Silver-coated ion exchange membrane electrode applied to electrochemical reduction of carbon dioxide

    International Nuclear Information System (INIS)

    Hori, Y.; Ito, H.; Okano, K.; Nagasu, K.; Sato, S.

    2003-01-01

    Silver-coated ion exchange membrane electrodes (solid polymer electrolyte, SPE) were prepared by electroless deposition of silver onto ion exchange membranes. The SPE electrodes were used for carbon dioxide (CO 2 ) reduction with 0.2 M K 2 SO 4 as the electrolyte with a platinum plate (Pt) for the counterelectrode. In an SPE electrode system prepared from a cation exchange membrane (CEM), the surface of the SPE was partly ruptured during CO 2 reduction, and the reaction was rapidly suppressed. SPE electrodes made of an anion exchange membrane (SPE/AEM) sustained reduction of CO 2 to CO for more than 2 h, whereas, the electrode potential shifted negatively during the electrolysis. The reaction is controlled by the diffusion of CO 2 through the metal layer of the SPE electrode at high current density. Ultrasonic radiation, applied to the preparation of SPE/AEM, was effective to improve the electrode properties, enhancing the electrolysis current of CO 2 reduction. Observation by a scanning electron microscope (SEM) showed that the electrode metal layer became more porous by the ultrasonic radiation treatment. The partial current density of CO 2 reduction by SPE/AEM amounted to 60 mA cm -2 , i.e. three times the upper limit of the conventional electrolysis by a plate electrode. Application of SPE device may contribute to an advancement of CO 2 fixation at ambient temperature and pressure

  17. Fifty years of solid-phase extraction in water analysis--historical development and overview.

    Science.gov (United States)

    Liska, I

    2000-07-14

    The use of an appropriate sample handling technique is a must in an analysis of organic micropollutants in water. The efforts to use a solid phase for the recovery of analytes from a water matrix prior to their detection have a long history. Since the first experimental trials using activated carbon filters that were performed 50 years ago, solid-phase extraction (SPE) has become an established sample preparation technique. The initial experimental applications of SPE resulted in widespread use of this technique in current water analysis and also to adoption of SPE into standardized analytical methods. During the decades of its evolution, chromatographers became aware of the advantages of SPE and, despite many innovations that appeared in the last decade, new SPE developments are still expected in the future. A brief overview of 50 years of the history of the use of SPE in organic trace analysis of water is given in presented paper.

  18. [Application of saw palmetto fruit extract in the treatment of prostate diseases].

    Science.gov (United States)

    Zhan, Xu-xin; Shang, Xue-jun; Huang, Yu-feng

    2015-09-01

    Saw palmetto fruit extract (SPE), as a herbal product, is widely used for the treatment of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Recent studies show that SPE also has some therapeutic effects on chronic prostatitis, prostate cancer, sexual dysfunction, and so on. This article presents an overview on the application of SPE in the treatment of BPH, prostate cancer, and chronic prostatitis/chronic pelvic pain syndrome, with a discussion on its action mechanisms.

  19. Effects of dietary saw palmetto on the prostate of transgenic adenocarcinoma of the mouse prostate model (TRAMP).

    Science.gov (United States)

    Wadsworth, Teri L; Worstell, Teresa R; Greenberg, Norman M; Roselli, Charles E

    2007-05-01

    Several of the proposed mechanisms for the actions of the liposterolic extract of saw palmetto (SPE) are exerted on known risk factors for prostate cancer (CaP). This study investigated whether SPE could prevent the progression of CaP in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Two different doses of SPE designed to deliver 50 mg/kg/day SPE and 300 mg/kg/day SPE were administered in a custom diet to TRAMP mice for 12 or 24 weeks. Body and organ weights were used to evaluate toxicity, and radioimmunoassay was used to measure plasma and tissue androgen levels to monitor effects of SPE on 5alpha reductase activity. Prostate tissues were evaluated histologically to determine the effect of treatment on tumor grade, cell proliferation, and apoptosis. Treatment with 300 mg/kg/day SPE from 4 to 24 weeks of age significantly reduced the concentration of 5alpha-dihydrotestosterone (DHT) in the prostate and resulted in a significant increase in apoptosis and significant decrease in pathological tumor grade and frank tumor incidence. Dietary supplementation with SPE may be effective in controlling CaP tumorigenesis. SPE suppression of prostatic DHT levels lends support to the hypothesis that inhibition of the enzyme 5alpha-reductase is a mechanism of action of this substance. (c) 2007 Wiley-Liss, Inc.

  20. Evaluation of Offline Tandem and Online Solid-Phase Extraction with Liquid Chromatography/Electrospray Ionization-Mass Spectrometry for Analysis of Antibiotics in Ambient Water and Comparison to an Independent Method

    Science.gov (United States)

    Meyer, M.T.; Lee, E.A.; Ferrell, G.M.; Bumgarner, J.E.; Varns, Jerry

    2007-01-01

    This report describes the performance of an offline tandem solid-phase extraction (SPE) method and an online SPE method that use liquid chromatography/mass spectrometry for the analysis of 23 and 35 antibiotics, respectively, as used in several water-quality surveys conducted since 1999. In the offline tandem SPE method, normalized concentrations for the quinolone, macrolide, and sulfonamide antibiotics in spiked environmental samples averaged from 81 to 139 percent of the expected spiked concentrations. A modified standard-addition technique was developed to improve the quantitation of the tetracycline antibiotics, which had 'apparent' concentrations that ranged from 185 to 1,200 percent of their expected spiked concentrations in matrix-spiked samples. In the online SPE method, normalized concentrations for the quinolone, macrolide, sulfonamide, and tetracycline antibiotics in matrix-spiked samples averaged from 51 to 142 percent of their expected spiked concentrations, and the beta-lactam antibiotics in matrix-spiked samples averaged from 22 to 76 percent of their expected spiked concentration. Comparison of 44 samples analyzed by both the offline tandem SPE and online SPE methods showed 50 to 100 percent agreement in sample detection for overlapping analytes and 68 to 100 percent agreement in a presence-absence comparison for all analytes. The offline tandem and online SPE methods were compared to an independent method that contains two overlapping antibiotic compounds, sulfamethoxazole and trimethoprim, for 96 and 44 environmental samples, respectively. The offline tandem SPE showed 86 and 92 percent agreement in sample detection and 96 and 98 percent agreement in a presence-absence comparison for sulfamethoxazole and trimethoprim, respectively. The online SPE method showed 57 and 56 percent agreement in sample detection and 72 and 91 percent agreement in presence-absence comparison for sulfamethoxazole and trimethoprim, respectively. A linear regression with

  1. Survey on workforce retention and attrition

    Science.gov (United States)

    Showstack, Randy

    2013-03-01

    The Society of Petroleum Engineers (SPE) is conducting a survey to gather information on why technical professionals change jobs or quit working. The survey, prompted by concern about the retention of skilled workers, aims to provide information to employers that can assist them in addressing practices that can lead to significant workforce attrition. To participate in the survey, which is open to everyone (including those who are not SPE members), go to http://research.spe.org/se.ashx?s=705E3F1335720258 through 15 May 2013. For more information, contact speresearch@spe.org.

  2. Comparison of solvent extraction and solid-phase extraction for the determination of polychlorinated biphenyls in transformer oil.

    Science.gov (United States)

    Mahindrakar, A N; Chandra, S; Shinde, L P

    2014-01-01

    Solid-phase extraction (SPE) of nine polychlorinated biphenyls (PCBs) from transformer oil samples was evaluated using octadecyl (CI8)-bonded porous silica. The efficiency of SPE of these PCBs was compared with those obtained by solvent extraction with DMSO and hexane. Average recoveries exceeding 95% for these PCBs were obtained via the SPE method using small cartridges containing 100mg of 40 pm CI8-bonded porous silica. The average recovery by solvent extraction with DMSO and hexane exceeded 83%. It was concluded that the recoveries and precision for the solvent extraction of PCBs were poorer than those for the SPE. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. 1993 US petroleum engineering manpower supply and demand

    International Nuclear Information System (INIS)

    Wattenbarger, R.A.; Morriss, S.

    1994-01-01

    Each year, the SPE Manpower Committee reports on the results of petroleum engineering manpower supply and demand surveys to inform SPE members about hiring patterns of engineers in the petroleum industry and the supply of graduates from US petroleum engineering schools. The SPE Manpower Committee's US surveys show that large companies will decrease their hiring while small companies and service companies will increase their hiring of engineers. During 1992--93, only about 65% of graduating petroleum engineering students were known to have jobs. Another finding is that, overall, new US SPE membership is decreasing while non-US membership is increasing

  4. Direct 13C NMR Detection in HPLC Hyphenation Mode

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Johansen, Kenneth; Nyberg, Nils

    2012-01-01

    Solid phase extraction (SPE) was introduced as a crucial step in the HPLC-SPE-NMR technique to enable online analyte enrichment from which proton-detected NMR experiments on submicrogram amounts from complex mixtures were possible. However, the significance of direct-detected (13)C NMR experiments...... application of HPLC-SPE-NMR analysis using direct-detected (13)C NMR spectra. HPLC column loading, accumulative SPE trappings, and the effect of different elution solvents were evaluated and optimized. A column loading of approximately 600 mug of a prefractionated triterpenoid mixture, six trappings...

  5. Biological applications of novel nonlinear optical microscopy

    International Nuclear Information System (INIS)

    Kajiyama, Shin'ichiro; Ozeki, Yasuyuki; Itoh, Kazuyoshi; Fukui, Kiichi

    2010-01-01

    Two types of newly developed nonlinear optical microscopes namely stimulated parametric emission (SPE) microscope and stimulated Raman scattering (SRS) microscope were presented together with their biological applications.

  6. Methylglyoxal synthase regulates cell elongation via alterations of cellular methylglyoxal and spermidine content in Bacillus subtilis.

    Science.gov (United States)

    Shin, Sang-Min; Song, Sung-Hyun; Lee, Jin-Woo; Kwak, Min-Kyu; Kang, Sa-Ouk

    2017-10-01

    Methylglyoxal regulates cell division and differentiation through its interaction with polyamines. Loss of their biosynthesizing enzyme causes physiological impairment and cell elongation in eukaryotes. However, the reciprocal effects of methylglyoxal and polyamine production and its regulatory metabolic switches on morphological changes in prokaryotes have not been addressed. Here, Bacillus subtilis methylglyoxal synthase (mgsA) and polyamine biosynthesizing genes encoding arginine decarboxylase (SpeA), agmatinase (SpeB), and spermidine synthase (SpeE), were disrupted or overexpressed. Treatment of 0.2mM methylglyoxal and 1mM spermidine led to the elongation and shortening of B. subtilis wild-type cells to 12.38±3.21μm (P<0.05) and 3.24±0.73μm (P<0.01), respectively, compared to untreated cells (5.72±0.68μm). mgsA-deficient (mgsA - ) and -overexpressing (mgsA OE ) mutants also demonstrated cell shortening and elongation, similar to speB- and speE-deficient (speB - and speE - ) and -overexpressing (speB OE and speE OE ) mutants. Importantly, both mgsA-depleted speB OE and speE OE mutants (speB OE /mgsA - and speE OE /mgsA - ) were drastically shortened to 24.5% and 23.8% of parental speB OE and speE OE mutants, respectively. These phenotypes were associated with reciprocal alterations of mgsA and polyamine transcripts governed by the contents of methylglyoxal and spermidine, which are involved in enzymatic or genetic metabolite-control mechanisms. Additionally, biophysically detected methylglyoxal-spermidine Schiff bases did not affect morphogenesis. Taken together, the findings indicate that methylglyoxal triggers cell elongation. Furthermore, cells with methylglyoxal accumulation commonly exhibit an elongated rod-shaped morphology through upregulation of mgsA, polyamine genes, and the global regulator spx, as well as repression of the cell division and shape regulator, FtsZ. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Current status of environmental, health, and safety issues of lithium polymer electric vehicle batteries

    Energy Technology Data Exchange (ETDEWEB)

    Corbus, D; Hammel, C J

    1995-02-01

    Lithium solid polymer electrolyte (SPE) batteries are being investigated by researchers worldwide as a possible energy source for future electric vehicles (EVs). One of the main reasons for interest in lithium SPE battery systems is the potential safety features they offer as compared to lithium battery systems using inorganic and organic liquid electrolytes. However, the development of lithium SPE batteries is still in its infancy, and the technology is not envisioned to be ready for commercialization for several years. Because the research and development (R&D) of lithium SPE battery technology is of a highly competitive nature, with many companies both in the United States and abroad pursuing R&D efforts, much of the information concerning specific developments of lithium SPE battery technology is proprietary. This report is based on information available only through the open literature (i.e., information available through library searches). Furthermore, whereas R&D activities for lithium SPE cells have focused on a number of different chemistries, for both electrodes and electrolytes, this report examines the general environmental, health, and safety (EH&S) issues common to many lithium SPE chemistries. However, EH&S issues for specific lithium SPE cell chemistries are discussed when sufficient information exists. Although lithium batteries that do not have a SPE are also being considered for EV applications, this report focuses only on those lithium battery technologies that utilize the SPE technology. The lithium SPE battery technologies considered in this report may contain metallic lithium or nonmetallic lithium compounds (e.g., lithium intercalated carbons) in the negative electrode.

  8. Pharmacological effects of saw palmetto extract in the lower urinary tract.

    Science.gov (United States)

    Suzuki, Mayumi; Ito, Yoshihiko; Fujino, Tomomi; Abe, Masayuki; Umegaki, Keizo; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

    2009-03-01

    Saw palmetto extract (SPE), an extract from the ripe berries of the American dwarf palm, has been widely used as a therapeutic remedy for urinary dysfunction due to benign prostatic hyperplasia (BPH) in Europe. Numerous mechanisms of action have been proposed for SPE, including the inhibition of 5alpha-reductase. Today, alpha(1)-adrenoceptor antagonists and muscarinic cholinoceptor antagonists are commonly used in the treatment of men with voiding symptoms secondary to BPH. The improvement of voiding symptoms in patients taking SPE may arise from its binding to pharmacologically relevant receptors in the lower urinary tract, such as alpha(1)-adrenoceptors, muscarinic cholinoceptors, 1,4-dihyropyridine receptors and vanilloid receptors. Furthermore, oral administration of SPE has been shown to attenuate the up-regulation of alpha(1)-adrenoceptors in the rat prostate induced by testosterone. Thus, SPE at clinically relevant doses may exert a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and an overactive bladder. SPE does not have interactions with co-administered drugs or serious adverse events in blood biochemical parameters, suggestive of its relative safety, even with long-term intake. Clinical trials (placebo-controlled and active-controlled trials) of SPE conducted in men with BPH were also reviewed. This review should contribute to the understanding of the pharmacological effects of SPE in the treatment of patients with BPH and associated lower urinary tract symptoms (LUTS).

  9. Noise-modulated self-polarization effect of impurity doped quantum dots under simultaneous presence of hydrostatic pressure and temperature

    Science.gov (United States)

    Bera, Aindrila; Ghosh, Manas

    2017-10-01

    We explore the profiles of self-polarization effect (SPE) of doped GaAs QD under simultaneous presence of hydrostatic pressure (HP), temperature and in presence of noise. Noise term carries Gaussian white character and it has been administered to the system via two different pathways; additive and multiplicative. Profiles of SPE have been monitored as a function of HP, temperature and noise strength. Under a given condition of HP and temperature, noise marks its prominent signature on the SPE profile. However, the extent to which noise affects the SPE profile visibly depends on the noise strength and the pathway through which noise is introduced. As interesting observations we have found that SPE exhibits minimization at a pressure of ∼ 170 kbar in absence of noise and at ∼ 150 kbar when noise is present. Furthermore, in presence of multiplicative noise SPE exhibits a very faint decrease with increase in T up to T ∼ 420 K. However, beyond T ∼ 420 K, further increase in temperature causes abrupt fall of SPE in a highly sharp way. The findings highlight viable ways of tuning SPE of doped QD system through subtle interplay between HP, temperature and noise.

  10. Female nutrition and assisted reproduction in European eel: influences on oogenesis and egg quality

    DEFF Research Database (Denmark)

    da Silva, Filipa

    of egg production involves a long-term hormonal treatment of salmon or carp pituitary extracts (SPE or CPE) followed by the induction of oocyte maturation and ovulation which includes a SPE primer and a maturation-inducing hormone (MIH), generally 17α, 20β-dihydroxy-4-pregnen-3-one (DHP). Recent progress...

  11. Invasive group A streptococcal disease in The Netherlands : Evidence for a protective role of anti-exotoxin A antibodies

    NARCIS (Netherlands)

    Mascini, EM; Jansze, M; Schellekens, JFP; Musser, JM; Faber, JAJ; Verhoef-Verhage, LAE; Schouls, L; van Leeuwen, WJ; Verhoef, J; van Dijk, H

    As part of a nationwide surveillance in The Netherlands during 1994-1997, 53 patients with invasive group A streptococcal (GAS) infections were evaluated for medical history, symptoms, and outcome. Patients' isolates were tested for the production of pyrogenic exotoxins A (SPE-A) and B (SPE-B).

  12. Seismic Imaging of the Source Physics Experiment Site with the Large-N Seismic Array

    Science.gov (United States)

    Chen, T.; Snelson, C. M.; Mellors, R. J.

    2017-12-01

    The Source Physics Experiment (SPE) consists of a series of chemical explosions at the Nevada National Security Site. The goal of SPE is to understand seismic wave generation and propagation from these explosions. To achieve this goal, we need an accurate geophysical model of the SPE site. A Large-N seismic array that was deployed at the SPE site during one of the chemical explosions (SPE-5) helps us construct high-resolution local geophysical model. The Large-N seismic array consists of 996 geophones, and covers an area of approximately 2 × 2.5 km. The array is located in the northern end of the Yucca Flat basin, at a transition from Climax Stock (granite) to Yucca Flat (alluvium). In addition to the SPE-5 explosion, the Large-N array also recorded 53 weight drops. Using the Large-N seismic array recordings, we perform body wave and surface wave velocity analysis, and obtain 3D seismic imaging of the SPE site for the top crust of approximately 1 km. The imaging results show clear variation of geophysical parameter with local geological structures, including heterogeneous weathering layer and various rock types. The results of this work are being incorporated in the larger 3D modeling effort of the SPE program to validate the predictive models developed for the site.

  13. New practical algorithm for modelling analyte recovery in bioanalytical reversed phase and mixed-mode solid phase extraction

    NARCIS (Netherlands)

    Hendriks, G.; Uges, D. R. A.; Franke, J. P.

    2008-01-01

    Solid phase extraction (SPE) is a widely used method for sample cleanup and sample concentration in bioanalytical sample preparation. A few methods to model the retention behaviour on SPE cartridges have been described previously but they are either not applicable to ionised species or are not

  14. 48 CFR 819.705 - Appeal of Contracting Officer decisions.

    Science.gov (United States)

    2010-10-01

    ... the Senior Procurement Executive (SPE) within 5 working days. The SPE shall have 15 working days to... decision. The contracting officer has 5 working days to reply to the challenge by either revising the... filed within 5 working days of receipt of the contracting officer's decision. The HCA has 5 working days...

  15. Influence of Salvadora persica (miswak) extract on physical and antimicrobial properties of glass ionomer cement

    NARCIS (Netherlands)

    El-Tatari, A.; de Soet, J.J.; de Gee, A.J.; Abou Shelib, M.; van Amerongen, W.E.

    2011-01-01

    AIM: To investigate physical and antimicrobial properties of Glass Ionomer Cement (GIC) combined with Salvadora Persica Extract (SPE). METHODS: SPE was added to GIC (Fuji IX) in concentrations of 1%, 2% and 4% w/w. The compressive strength and diametral tensile strength were measured at 1 h, 24 h

  16. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

    NARCIS (Netherlands)

    Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

    2003-01-01

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS

  17. Developments in coupled solid-phase extraction-capillary electrophoresis 2013-2015.

    Science.gov (United States)

    Ramautar, Rawi; Somsen, Govert W; de Jong, Gerhardus J

    2016-01-01

    An overview of the design and application of coupled solid-phase extraction-capillary electrophoresis (SPE-CE) systems reported in the literature between July 2013 and June 2015 is provided in this paper. The present article is a continuation of our previous review papers on this topic which covered the time period 2000-2013 (Electrophoresis 2008, 29, 108-128; Electrophoresis 2010, 31, 44-54; Electrophoresis 2012, 33, 243-250; Electrophoresis 2014, 35, 128-137). The use of in-line and on-line SPE-CE approaches is treated and outlined in this review. Recent advancements, such as, for example, the use of aptamers as affinity material for in-line SPE-CE, the use of a bead string design for in-line fritless SPE-CE, and new interfacing techniques for the on-line coupling of SPE to CE, are outlined. Selected examples demonstrate the applicability of the coupled SPE-CE systems for biomedical, pharmaceutical, environmental, and food studies. A complete overview of the recent SPE-CE studies is given in table format, providing information on sample type, SPE sorbent, coupling mode, detection mode, and LOD. Finally, some general conclusions and perspectives are provided. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. METHOD 544. DETERMINATION OF MICROCYSTINS AND NODULARIN IN DRINKING WATER BY SOLID PHASE EXTRACTION AND LIQUID CHROMATOGRAPHY/TANDEM MASS SPECTROMETRY (LC/MS/MS)

    Science.gov (United States)

    Method 544 is an accurate and precise analytical method to determine six microcystins (including MC-LR) and nodularin in drinking water using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE-LC/MS/MS). The advantage of this SPE-LC/MS/MS is its sensi...

  19. Liquid chromatography-tandem mass spectrometry determination of synthetic cathinones and phenethylamines in influent wastewater of eight European cities

    DEFF Research Database (Denmark)

    Bade, Richard; Bijlsma, Lubertus; Sancho, Juan V.

    2017-01-01

    (SPE) with Oasis MCX cartridges. Isotopically labelled internal standards were used to correct for matrix effects and potential SPE losses. Following chromatographic separation on a C18 column within 6 min, the compounds were measured by tandem mass spectrometry in positive ionization mode. The method...

  20. Development of an interface for directly coupled solid-phase extraction and GC-MS analysis

    NARCIS (Netherlands)

    Öllers, M.J.H.; van Lieshout, H.P.M.; Janssen, J.G.M.; Cramers, C.A.M.G.

    Solid-phase extraction (SPE) is widely used as a sample preparation technique in numerous application areas of chromatography. Large-volume injection is an attractive technique for coupling SPE to gas chromatography (GC) because it provides improved detection limits and circumvents the need for

  1. The Application of Integrated Design System for HTR-PM Design

    International Nuclear Information System (INIS)

    Qi Shi; Xiaojing Kang

    2014-01-01

    SmartPlant Enterprise(SPE) developed by Intergraph from America is a new generation integrated solution for engineering design. Combined with the application in a nuclear engineering, this paper introduced the composition and the data flow of Integrated Design System established by SPE, analyzed the advantages and the insufficiency, and provided the direction of continuous improvement. (author)

  2. Hydrogen-oxygen proton-exchange membrane fuel cells and electrolyzers

    Science.gov (United States)

    Baldwin, R.; Pham, M.; Leonida, A.; Mcelroy, J.; Nalette, T.

    1990-01-01

    A flight experiment is planned for the validation, in a microgravity environment, of several ground-proven simplification features relating to SPE fuel cells and SPE electrolyzers. With a successful experiment, these features can be incorporated into equipment designs for specific extraterrestrial energy storage applications.

  3. Periodontitis-associated septic pulmonary embolism caused by Actinomyces species identified by anaerobic culture of bronchoalveolar lavage fluid: a case report.

    Science.gov (United States)

    Endo, Shun; Mishima, Eikan; Takeuchi, Yoichi; Ohi, Takashi; Ishida, Masatsugu; Yanai, Masaru; Kiyomoto, Hideyasu; Nagasawa, Tasuku; Ito, Sadayoshi

    2015-12-01

    Periodontal disease is a less common but important cause of septic pulmonary embolism (SPE). However, the pathogens causing periodontal disease-associated SPE (PD-SPE) have been poorly understood. Actinomyces species are resident microbiota in the oral cavity. Here we report a case of PD-SPE caused by Actinomyces species, which was identified by anaerobic culture of bronchoalveolar lavage fluid (BAL). A 64-year-old Asian man, complicated with severe chronic periodontitis, was admitted with chest pain and fever. Chest CT revealed multiple bilateral pulmonary nodules located subpleurally. We diagnosed the case as SPE associated with periodontitis. Although blood cultures were negative for the usual 5-day incubation, anaerobic culture of the BAL fluid sample yielded Actinomyces species. Antibacterial therapy alone did not ameliorate the symptoms; however, additional dental treatment, including tooth extraction, promptly did. The patient was discharged 23 days after admission. The 3-month follow-up revealed no recurrence of the symptoms and complete resolution of the lung lesions. This case demonstrated that Actinomyces species can cause PD-SPE. Additionally, clinicians should consider performing appropriate anaerobic culture of BAL fluid to identify the pathogen of SPE, and to ordering dental treatment, if necessary, in addition to antibiotics for the initial management of PD-SPE.

  4. Characteristics, Effectiveness, and Prospects of Supplementary Professional Education

    Science.gov (United States)

    Kliucharev, Grigorii Arturovich

    2010-01-01

    Today the system of supplementary professional education (SPE) is the main institutionalized subunit that is oriented toward "adult learners". Surveys have shown that in many cases investment in SPE is more profitable, predictable, reliable, and short term than that in any other form of education. Data on supplemental professional…

  5. Heterogeneity in semantic priming effect with a lexical decision task in patients after left hemisphere stroke

    Directory of Open Access Journals (Sweden)

    Candice Steffen Holderbaum

    Full Text Available ABSTRACT Investigations on the semantic priming effect (SPE in patients after left hemisphere (LH lesions have shown disparities that may be explained by the variability in performance found among patients. The aim of the present study was to verify the existence of subgroups of patients after LH stroke by searching for dissociations between performance on the lexical decision task based on the semantic priming paradigm and performance on direct memory, semantic association and language tasks. All 17 patients with LH lesions after stroke (ten non-fluent aphasics and seven non aphasics were analyzed individually. Results indicated the presence of three groups of patients according to SPE: one exhibiting SPE at both stimulus onset asynchronies (SOAs, one with SPE only at long SOA, and another, larger group with no SPE.

  6. Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Tsai, M F

    2000-01-01

    Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

  7. Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Sun, M C

    2001-01-01

    This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

  8. Magnetic-field-induced decrease of the spin Peltier effect in Pt/Y3Fe5O12 system at room temperature

    Science.gov (United States)

    Itoh, Ryuichi; Iguchi, Ryo; Daimon, Shunsuke; Oyanagi, Koichi; Uchida, Ken-ichi; Saitoh, Eiji

    2017-11-01

    We report the observation of magnetic-field-induced decrease of the spin Peltier effect (SPE) in a junction of a paramagnetic metal Pt and a ferrimagnetic insulator Y3Fe5O12 (YIG) at room temperature. For driving the SPE, spin currents are generated via the spin Hall effect from applied charge currents in the Pt layer, and injected into the adjacent thick YIG film. The resultant temperature modulation is detected by a commonly used thermocouple attached to the Pt/YIG junction. The output of the thermocouple shows sign reversal when the magnetization is reversed and linearly increases with the applied current, demonstrating the detection of the SPE signal. We found that the SPE signal decreases with the magnetic field. The observed decreasing rate was found to be comparable to that of the spin Seebeck effect (SSE), suggesting the dominant and similar contribution of the low-energy magnons in the SPE as in the SSE.

  9. Fluorine incorporation during Si solid phase epitaxy

    International Nuclear Information System (INIS)

    Impellizzeri, G.; Mirabella, S.; Romano, L.; Napolitani, E.; Carnera, A.; Grimaldi, M.G.; Priolo, F.

    2006-01-01

    We have investigated the F incorporation and segregation in preamorphized Si during solid phase epitaxy (SPE) at different temperatures and for several implanted-F energies and fluences. The Si samples were amorphized to a depth of 550 nm by implanting Si at liquid nitrogen temperature and then enriched with F at different energies (65-150 keV) and fluences (0.07-5 x 10 14 F/cm 2 ). Subsequently, the samples were regrown by SPE at different temperatures: 580, 700 and 800 deg. C. We have found that the amount of F incorporated after SPE strongly depends on the SPE temperature and on the energy and fluence of the implanted-F, opening the possibility to tailor the F profile during SPE

  10. Effects of saw palmetto extract on micturition reflex of rats and its autonomic receptor binding activity.

    Science.gov (United States)

    Oki, Tomomi; Suzuki, Mayumi; Nishioka, Yasuhiko; Yasuda, Akio; Umegaki, Keizo; Yamada, Shizuo

    2005-04-01

    We examined the effects of saw palmetto extract (SPE) on the rat micturition reflex and on autonomic receptors in the lower urinary tract. The effect of SPE was examined on cystometrograms of anesthetized rats induced by intravesical infusion of saline or 0.1% acetic acid. SHR/NDmc-cp (cp/cp) rats received repeat oral administration of SPE and nighttime urodynamic function was determined. The autonomic receptor binding activity of SPE in the rat bladder and prostate was examined by radioligand binding assay. Intraduodenal administration of SPE (60 mg/kg) in anesthetized rat cystometry caused a significant increase in the micturition interval, micturition volume and bladder capacity during intravesical saline infusion. Also, similar administration of SPE at doses of 12 and 20 mg/kg significantly reversed the shortened micturition interval as well as the decreased micturition volume and bladder capacity due to 0.1% acetic acid infusion in a dose dependent manner. In conscious SHR/NDmc-cp (cp/cp) rats repeat oral administration of SPE (6 mg/kg daily) constantly increased the micturition interval and concomitantly decreased voiding frequency. SPE inhibited specific binding of [H]NMS ([N-methyl-H]scopolamine methyl chloride) (bladder) and [H]prazosin (prostate) with IC50 values of 46.1 and 183 microg/ml, respectively. SPE significantly alleviates urodynamic symptoms in hyperactive rat bladders by increasing bladder capacity and subsequently prolonging the micturition interval. Our data may support the clinical efficacy of SPE for the treatment of lower urinary tract symptoms.

  11. Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

    International Nuclear Information System (INIS)

    Furlong, E.T.; Koleis, J.C.; Gates, P.M.

    1995-01-01

    Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations

  12. Extraction optimization and pixel-based chemometric analysis of semi-volatile organic compounds in groundwater

    DEFF Research Database (Denmark)

    Christensen, Peter; Tomasi, Giorgio; Kristensen, Mette

    2017-01-01

    . In this study, we tested the combination of solid phase extraction (SPE) with dispersive liquid-liquid micro extraction (DLLME), or with stir bar sorptive extraction (SBSE), as an extraction method for semi-VOCs in groundwater. Combining SPE with DLLME or SBSE resulted in better separation of peaks...... in an unresolved complex mixture. SPE-DLLME was chosen as the preferred extraction method. SPE-DLLME covered a larger polarity range (logKo/w 2.0-11.2), had higher extraction efficiency at logKo/w 2.0-3.8 and 5.8-11.2, and was faster compared to SPE-SBSE. SPE-DLLME extraction combined with chemical analysis by gas...... chromatography-mass spectrometry (GC-MS) and pixel-based data analysis of summed extraction ion chromatograms (sEICs) was tested as a new method for chemical fingerprinting of semi-VOCs in 15 groundwater samples. The results demonstrate that SPE-DLLME-GC-MS provides an excellent compromise between compound...

  13. [Optimization of solid-phase extraction for enrichment of toxic organic compounds in water samples].

    Science.gov (United States)

    Zhang, Ming-quan; Li, Feng-min; Wu, Qian-yuan; Hu, Hong-ying

    2013-05-01

    A concentration method for enrichment of toxic organic compounds in water samples has been developed based on combined solid-phase extraction (SPE) to reduce impurities and improve recoveries of target compounds. This SPE method was evaluated in every stage to identify the source of impurities. Based on the analysis of Waters Oasis HLB without water samples, the eluent of SPE sorbent after dichloromethane and acetone contributed 85% of impurities during SPE process. In order to reduce the impurities from SPE sorbent, soxhlet extraction of dichloromethane followed by acetone and lastly methanol was applied to the sorbents for 24 hours and the results had proven that impurities were reduced significantly. In addition to soxhlet extraction, six types of prevalent SPE sorbents were used to absorb 40 target compounds, the lgK(ow) values of which were within the range of 1.46 and 8.1, and recovery rates were compared. It was noticed and confirmed that Waters Oasis HLB had shown the best recovery results for most of the common testing samples among all three styrenedivinylbenzene (SDB) polymer sorbents, which were 77% on average. Furthermore, Waters SepPak AC-2 provided good recovery results for pesticides among three types of activated carbon sorbents and the average recovery rates reached 74%. Therefore, Waters Oasis HLB and Waters SepPak AC-2 were combined to obtain a better recovery and the average recovery rate for the tested 40 compounds of this new SPE method was 87%.

  14. Development of novel strategies for enhancing the cycle life of lithium solid polymer electrolyte batteries. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, Digby D.; Urquidi-Macdonald, Mirna; Allcock, Harry; Engelhard, George; Bomberger, N.; Gao, L.; Olmeijer, D.

    2001-04-30

    Lithium/solid polymer electrolyte (Li/SPE) secondary batteries are under intense development as power sources for portable electronic devices as well as electric vehicles. These batteries offer high specific energy, high energy density, very low self-discharge rates, and flexibility in packaging; however, problems have inhibited their introduction into the marketplace. This report summarizes findings to examine processes that occur with Li/SPE secondary batteries upon cyclic charging/discharging. The report includes a detailed analysis of the impedance measured on the Li/SPE/IC and IC/SPE/IC systems. The SPE was a derivative of methoxyethoxyethoxyphosphazene (MEEP) with lithium triflate salt as the electrolyte, while the intercalated cathodes (IC) comprised mixtures of manganese dioxide, carbon powder, and MEEP as a binder. Studies on symmetrical Li/SPE/Li laminates show that cycling results in a significant expansion of the structure over the first few tens of cycles; however, no corresponding increase in the impedance was noted. The cycle life of the intercalation cathode was found to be very sensitive to the method of fabrication. Results indicate that the cycle life is due to the failure of the IC, not to the failure of the lithium/SPE interface. A pattern recognition neural network was developed to predict the cycle life of a battery from the charge/discharge characteristics.

  15. An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes.

    Science.gov (United States)

    Fattah, N F A; Ng, H M; Mahipal, Y K; Numan, Arshid; Ramesh, S; Ramesh, K

    2016-06-06

    Solid polymer electrolyte (SPE) composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene) [P(VdF-HFP)] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl) imide [EMI-BTI] and graphene oxide (GO) was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC). The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP)-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD) and thermogravimetric analysis (TGA) studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge-discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g -1 , which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.

  16. An Approach to Solid-State Electrical Double Layer Capacitors Fabricated with Graphene Oxide-Doped, Ionic Liquid-Based Solid Copolymer Electrolytes

    Directory of Open Access Journals (Sweden)

    N. F. A. Fattah

    2016-06-01

    Full Text Available Solid polymer electrolyte (SPE composed of semi-crystalline poly (vinylidene fluoride-hexafluoropropylene [P(VdF-HFP] copolymer, 1-ethyl-3-methylimidazolium bis (trifluoromethyl sulphonyl imide [EMI-BTI] and graphene oxide (GO was prepared and its performance evaluated. The effects of GO nano-filler were investigated in terms of enhancement in ionic conductivity along with the electrochemical properties of its electrical double layer capacitors (EDLC. The GO-doped SPE shows improvement in ionic conductivity compared to the P(VdF-HFP-[EMI-BTI] SPE system due to the existence of the abundant oxygen-containing functional group in GO that assists in the improvement of the ion mobility in the polymer matrix. The complexation of the materials in the SPE is confirmed in X-ray diffraction (XRD and thermogravimetric analysis (TGA studies. The electrochemical performance of EDLC fabricated with GO-doped SPE is examined using cyclic voltammetry and charge–discharge techniques. The maximum specific capacitance obtained is 29.6 F∙g−1, which is observed at a scan rate of 3 mV/s in 6 wt % GO-doped, SPE-based EDLC. It also has excellent cyclic retention as it is able keep the performance of the EDLC at 94% even after 3000 cycles. These results suggest GO doped SPE plays a significant role in energy storage application.

  17. Dermatopathology effects of simulated solar particle event radiation exposure in the porcine model.

    Science.gov (United States)

    Sanzari, Jenine K; Diffenderfer, Eric S; Hagan, Sarah; Billings, Paul C; Gridley, Daila S; Seykora, John T; Kennedy, Ann R; Cengel, Keith A

    2015-07-01

    The space environment exposes astronauts to risks of acute and chronic exposure to ionizing radiation. Of particular concern is possible exposure to ionizing radiation from a solar particle event (SPE). During an SPE, magnetic disturbances in specific regions of the Sun result in the release of intense bursts of ionizing radiation, primarily consisting of protons that have a highly variable energy spectrum. Thus, SPE events can lead to significant total body radiation exposures to astronauts in space vehicles and especially while performing extravehicular activities. Simulated energy profiles suggest that SPE radiation exposures are likely to be highest in the skin. In the current report, we have used our established miniature pig model system to evaluate the skin toxicity of simulated SPE radiation exposures that closely resemble the energy and fluence profile of the September, 1989 SPE using either conventional radiation (electrons) or proton simulated SPE radiation. Exposure of animals to electron or proton radiation led to dose-dependent increases in epidermal pigmentation, the presence of necrotic keratinocytes at the dermal-epidermal boundary and pigment incontinence, manifested by the presence of melanophages in the derm is upon histological examination. We also observed epidermal hyperplasia and a reduction in vascular density at 30 days following exposure to electron or proton simulated SPE radiation. These results suggest that the doses of electron or proton simulated SPE radiation results in significant skin toxicity that is quantitatively and qualitatively similar. Radiation-induced skin damage is often one of the first clinical signs of both acute and non-acute radiation injury where infection may occur, if not treated. In this report, histopathology analyses of acute radiation-induced skin injury are discussed. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  18. Solid-phase extraction of the alcohol abuse biomarker phosphatidylethanol using newly synthesized polymeric sorbent materials containing quaternary heterocyclic groups.

    Science.gov (United States)

    Duarte, Mariana; Jagadeesan, Kishore Kumar; Billing, Johan; Yilmaz, Ecevit; Laurell, Thomas; Ekström, Simon

    2017-10-13

    Phosphatidylethanol (PEth) is an interesting biomarker finding increased use for detecting long term alcohol abuse with high specificity and sensitivity. Prior to detection, sample preparation is an unavoidable step in the work-flow of PEth analysis and new protocols may facilitate it. Solid-phase extraction (SPE) is a versatile sample preparation method widely spread in biomedical laboratories due to its simplicity of use and the possibility of automation. In this work, SPE was used for the first time to directly extract PEth from spiked human plasma and spiked human blood. A library of polymeric SPE materials with different surface functionalities was screened for PEth extraction in order to identify the surface characteristics that control PEth retention and recovery. The plasma samples were diluted 1:10 (v/v) in water and spiked at different concentrations ranging from 0.3 to 5μM. The library of SPE materials was then evaluated using the proposed SPE method and detection was done by LC-MS/MS. One SPE material efficiently retained and recovered PEth from spiked human plasma. With this insight, four new SPE materials were formulated and synthesized based on the surface characteristics of the best SPE material found in the first screening. These new materials were tested with spiked human blood, to better mimic a real clinical sample. All the newly synthetized materials outperformed the pre-existing commercially available materials. Recovery values for the new SPE materials were found between 29.5% and 48.6% for the extraction of PEth in spiked blood. A material based on quaternized 1-vinylimidazole with a poly(trimethylolpropane trimethacrylate) backbone was found suitable for PEth extraction in spiked blood showing the highest analyte recovery in this experiment, 48.6%±6.4%. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    International Nuclear Information System (INIS)

    Wang Ziming; Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi; Ma Qiang; Lu Chunmei; Dong Deming

    2013-01-01

    Highlights: ► An absorbing microwave μ-SPE device packed with activated carbon was used. ► Absorbing microwave μ-SPE device was made and used to enrich the analytes. ► Absorbing microwave μ-SPE device was made and used to heat samples directly. ► MAE-μ-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 °C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC–MS without any clean-up process. The recoveries were in the range of 93.5–104.6%, and the relative standard deviations were lower than 8.7%.

  20. The protective role of saffron petal extracts on gentamicininduced nephrotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Arash Omidi

    2016-07-01

    Full Text Available Different potentially therapeutic approaches to prevent or attenuate gentamicin sulfate (GM induced nephrotoxicity have been proposed. The present study was conducted to investigate the effect of the saffron petals extracts (Crocus sativus (SPE on male Wistar rats with kidney failure. Rats (40 were randomly assigned into five groups of 8 animals each: i the control group, that received normal saline (0.5 mL/kg; ii the GM group, that received GM (80 mg/kg by intraperitoneal (i.p. injection on a daily basis; iii the GM+SPE group that received the same dose of GM and SPE (40 mg/kg by i.p. injection on a daily basis; iv the GM+2SPE group, that received the same dose of GM and twofold of SPE (80 mg/kg by i.p. injection on a daily basis; whereas v 2SPE+GM group, that received 80 mg/kg of SPE a week before initiating the treatment with GM (prevention group. Significant differences were seen in the concentration of glucose, blood urea nitrogen (BUN, and creatinine between treatment groups and control in the male Wistar rats. GM was observed to cause nephrotoxicity, which was evidenced by an elevation of serum BUN and creatinine levels. The biochemical findings of the current study are concordant with those of histopathologic findings. The results of this study indicate that SPE especially in dose of 40 mg/kg can ameliorate harmful effects of GM on the kidney. The present results may suggest that the SPE have ameliorative effects on kidney failures induced by GM.

  1. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ziming, E-mail: wangziming@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Zhao Xin; Xu Xu; Wu Lijie; Su Rui; Zhao Yajing; Jiang Chengfei; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ma Qiang [Chinese Academy of Inspection and Quarantine, Beijing 100123 (China); Lu Chunmei [College of Technology Center, Jilin Entry-Exit Inspection and Quarantine Bureau, Changchun 130062 (China); Dong Deming [College of Environment and Resources, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer An absorbing microwave {mu}-SPE device packed with activated carbon was used. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to enrich the analytes. Black-Right-Pointing-Pointer Absorbing microwave {mu}-SPE device was made and used to heat samples directly. Black-Right-Pointing-Pointer MAE-{mu}-SPE was applied to the extraction of OPPs with non-polar solvent only. - Abstract: A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction ({mu}-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave {mu}-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in {mu}-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave {mu}-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60 Degree-Sign C for 10 min. The extracts obtained by MAE-{mu}-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%.

  2. Liver and water metabolism; Foie et metabolisme de l'eau

    Energy Technology Data Exchange (ETDEWEB)

    Fallot, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de Grenoble, 38 (France)

    1959-07-01

    The causes for the disturbance of hydro-electrolytic equilibrium observed in cirrhosis patients are far from clear. Studies on the static distribution of liquid in the organism and also on anomalies in the distribution of deuterium oxide and tritiated water provide no direct explanation of the nature of the water retaining mechanism. At the period when the illness is established, endocrine factors and electrolytic perturbations contribute to maintaining or increasing oliguresis, but they cannot be held solely responsible in the initial stages of evolution. An explanation of the ascites should therefore be looked for in a non-functioning of the polygonal or Kupffer cells. The hypothesis of an insufficient rejection of water outside the lymph spaces of the liver during cirrhosis is put forward, but the experimental demonstration of such a phenomenon proves very difficult. (author) [French] Les causes du desequilibre hydroelectrolytique observe chez les malades cirrhotiques sont loin d'etre elucidees. Les etudes de la repartition du liquide de l'organisme ainsi que celles des anomalies de la distribution de l'oxyde de deuterium et de l'eau tritiee n'apportent aucune explication directe sur la nature du mecanisme de la retention de l'eau. A la periode d'etat de la maladie, les facteurs endocriniens et les perturbations electrolytiques contribuent a entretenir ou a accroitre l'oligurie mais ils ne peuvent etre seuls invoques lors des stades initiaux de l'evolution. Il faudrait donc rechercher dans un dysfonctionnement des cellules polygonales ou kupfferiennes l'explication de l'ascite. L'hypothese d'une insuffisance du rejet de l'eau hors des espaces lymphatiques du foie au cours de la cirrhose est evoquee mais la demonstration d'un tel phenomene s'avere tres difficile sur le plan experimental. (auteur)

  3. Liver and water metabolism; Foie et metabolisme de l'eau

    Energy Technology Data Exchange (ETDEWEB)

    Fallot, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de Grenoble, 38 (France)

    1959-07-01

    The causes for the disturbance of hydro-electrolytic equilibrium observed in cirrhosis patients are far from clear. Studies on the static distribution of liquid in the organism and also on anomalies in the distribution of deuterium oxide and tritiated water provide no direct explanation of the nature of the water retaining mechanism. At the period when the illness is established, endocrine factors and electrolytic perturbations contribute to maintaining or increasing oliguresis, but they cannot be held solely responsible in the initial stages of evolution. An explanation of the ascites should therefore be looked for in a non-functioning of the polygonal or Kupffer cells. The hypothesis of an insufficient rejection of water outside the lymph spaces of the liver during cirrhosis is put forward, but the experimental demonstration of such a phenomenon proves very difficult. (author) [French] Les causes du desequilibre hydroelectrolytique observe chez les malades cirrhotiques sont loin d'etre elucidees. Les etudes de la repartition du liquide de l'organisme ainsi que celles des anomalies de la distribution de l'oxyde de deuterium et de l'eau tritiee n'apportent aucune explication directe sur la nature du mecanisme de la retention de l'eau. A la periode d'etat de la maladie, les facteurs endocriniens et les perturbations electrolytiques contribuent a entretenir ou a accroitre l'oligurie mais ils ne peuvent etre seuls invoques lors des stades initiaux de l'evolution. Il faudrait donc rechercher dans un dysfonctionnement des cellules polygonales ou kupfferiennes l'explication de l'ascite. L'hypothese d'une insuffisance du rejet de l'eau hors des espaces lymphatiques du foie au cours de la cirrhose est evoquee mais la demonstration d'un tel phenomene s'avere tres difficile sur le plan experimental. (auteur)

  4. State-of-the-art in solid-phase extraction of biofluids (M10)

    International Nuclear Information System (INIS)

    Boos, K.-S.; Fleischer, C.T.

    2002-01-01

    Full text: A major drawback of many SPE protocols in bioanalytical LC is a rather unselective and/or time consuming clean-up procedure. In order to optimize SPE based sample processing with regard to selectivity and speed we investigated tailor-made SPE adorbents, distinct SPE column hardware as well as a novel software (ChromSword ADS, Merck KGaA) for LC(MS)-integrated SPE using column-switching. Restricted Access Materials (RAM) are one family of such special SPE column packing. RAMs are characterized in that they have a defined size-selective exclusion barrier and a non-adsorptive outer particle surface towards macromolecular matrix components (e.g. proteins, nucleic acids, polysaccharides). Low-molecular compounds (e.g. drugs) have free access to the binding centers and thus can be extracted and enriched prior to their analytical separation and MS detection. A RAM-SPE column (e.g. LiChrospher ADS, Merck KGaA, Germany) allows the direct, multiple injection and fractionation of crude, complex samples such as hemolyzed blood, plasma, serum, milk, saliva, urine, fermentation broth and cell-culture or tissue homogenate supernatant. In order to improve the selectivity, we extended this on-line sample clean-up protocol by coupling a reversed-phase modified RAM-SPE column with a second short column packed with a Molecularly Imprinted Polymeric (MIP) adsorbent. MIP-SPE adsorbents can be compared with immunoaffinity adsorbents. Besides selective/specific molecular recognition properties, these artificial antibodies exhibit a high stability with respect to pressure, pH, temperature as well as organic solvents. These innovative adsorbents are also attractive because of the ease, low-cost and high reproducibility of preparation. Using MIPS in combination with RAMs we developed a generic SPE platform and protocol, respectively, for highly selective clean-up of complex (bio)fluids. Finally, we succeeded in speeding up the RAM fractionation step (e.g. extraction of 50 pl of

  5. Polyamines are essential for virulence in Salmonella enterica serovar Gallinarum despite evolutionary decay of polyamine biosynthesis genes

    DEFF Research Database (Denmark)

    Schroll, Casper; Christensen, Jens P.; Christensen, Henrik

    2014-01-01

    . Typhi and S. Gallinarum and happened through independent events. The remaining polyamine biosynthesis pathway was found to be essential for oral infection with S. Gallinarum since single and double mutants in speB and speE, encoding the pathways from agmatine to putrescine and from putrescine...... to putrescine. The first pathway is not active in S. Gallinarum and S. Typhi, and this prompted us to investigate the importance of polyamines for virulence in S. Gallinarum. Bioinformatic analysis of all sequenced genomes of Salmonella revealed that pseudogene formation of the speC gene was exclusive for S...

  6. C18, C8, and perfluoro reversed phases on diamond for solid-phase extraction.

    Science.gov (United States)

    Saini, Gaurav; Wiest, Landon A; Herbert, David; Biggs, Katherine N; Dadson, Andrew; Vail, Michael A; Linford, Matthew R

    2009-04-17

    In spite of advances in solid-phase extraction (SPE) technology there are certain disadvantages to current SPE silica-based, column packings. The pH range over which extraction can occur is limited and each column is generally only used once. New diamond-based reversed SPE phases (C(18), C(8), and perfluorinated) were developed in our laboratories. Studies were done which show that these phases do not have the same limitations as traditional silica-based stationary phases. The synthesis and properties of these diamond-based phases are presented, and the stability, percent recovery, and column capacity are given for the C(18) phase.

  7. Fuel cell power plants for automotive applications

    Science.gov (United States)

    McElroy, J. F.

    1983-02-01

    While the Solid Polymer Electrolyte (SPE) fuel cell has until recently not been considered competitive with such commercial and industrial energy systems as gas turbine generators and internal combustion engines, electrical current density improvements have markedly improved the capital cost/kW output rating performance of SPE systems. Recent studies of SPE fuel cell applicability to vehicular propulsion have indicated that with adequate development, a powerplant may be produced which will satisfy the performance, size and weight objectives required for viable electric vehicles, and that the cost for such a system would be competitive with alternative advanced power systems.

  8. Spectral phase encoding of ultra-short optical pulse in time domain for OCDMA application.

    Science.gov (United States)

    Wang, Xu; Wada, Naoya

    2007-06-11

    We propose a novel reconfigurable time domain spectral phase encoding (SPE) scheme for coherent optical code-division-multiple-access application. In the proposed scheme, the ultra-short optical pulse is stretched by dispersive device and the SPE is done in time domain using high speed phase modulator. The time domain SPE scheme is robust to wavelength drift of the light source and is very flexible and compatible with the fiber optical system. Proof-of-principle experiments of encoding with 16-chip, 20 GHz/chip binary-phase-shift-keying codes and 1.25 Gbps data transmission have been successfully demonstrated together with an arrayed-wave-guide decoder.

  9. A clinical and bacteriologic investigation of invasive streptococcal infections in Japan on the basis of serotypes, toxin production, and genomic DNA fingerprints.

    Science.gov (United States)

    Nakashima, K; Ichiyama, S; Iinuma, Y; Hasegawa, Y; Ohta, M; Ooe, K; Shimizu, Y; Igarashi, H; Murai, T; Shimokata, K

    1997-08-01

    In a survey of invasive streptococcal infections in Japan, we analyzed isolates of Streptococcus pyogenes collected between 1992 and 1994. Genomic DNA fingerprints produced by pulsed-field gel electrophoresis (PFGE) were compared by computer-assisted analysis. Conventional serologic M types were subdivided into PFGE types showing close genetic similarity. Among the 42 isolates from patients with invasive diseases, 16 PFGE types were identified and genetic diversity was clearly demonstrated. Identical fingerprints were observed in both invasive and noninvasive isolates. Only 43% of invasive isolates produced streptococcal pyrogenic exotoxin A (SPE A), and 31% did not contain the speA gene. These findings suggest that the dissemination of a specific clone is not sufficient to explain all cases of these diseases in Japan and pose a question as to the role of SPE A as a major virulent factor. Bacterial factors other than SPE A and host factors should be considered in evaluation of the pathogenesis of the diseases.

  10. A survey for the presence of microcystins in aquaculture ponds in ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... form of blue green algae in an aquaculture pond, they. *Corresponding author. ... passing through the food chain. Fish and other ... Some of these aqua- culture ponds supply their products (harvested fish) directly to spe-.

  11. IRTF NEAR-IR SPECTROSCOPY OF ASTEROIDS V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains low-resolution, near-infrared (0.8 - 2.5 micron) spectra of asteroids obtained with SpeX at the NASA Infrared Telescope Facility (IRTF) on...

  12. Solid Phase Extraction and Spectrophotometric Determination of ...

    African Journals Online (AJOL)

    NJD

    2005-04-15

    Apr 15, 2005 ... to the economy and has significant industrial applications. The development of a ... Waters Solid Phase Extraction (SPE) device (the device can carry out twenty ... HPLC grade dimethyl formamide (DMF) (Fisher. Corporation ...

  13. Recent Developments in Solid-Phase Extraction for Near and Attenuated Total Reflection Infrared Spectroscopic Analysis

    Directory of Open Access Journals (Sweden)

    Christian W. Huck

    2016-05-01

    Full Text Available A review with more than 100 references on the principles and recent developments in the solid-phase extraction (SPE prior and for in situ near and attenuated total reflection (ATR infrared spectroscopic analysis is presented. New materials, chromatographic modalities, experimental setups and configurations are described. Their advantages for fast sample preparation for distinct classes of compounds containing different functional groups in order to enhance selectivity and sensitivity are discussed and compared. This is the first review highlighting both the fundamentals of SPE, near and ATR spectroscopy with a view to real sample applicability and routine analysis. Most of real sample analyses examples are found in environmental research, followed by food- and bioanalysis. In this contribution a comprehensive overview of the most potent SPE-NIR and SPE-ATR approaches is summarized and provided.

  14. An Efficient Upscaling Procedure Based on Stokes-Brinkman Model and Discrete Fracture Network Method for Naturally Fractured Carbonate Karst Reservoirs

    KAUST Repository

    Qin, Guan; Bi, Linfeng; Popov, Peter; Efendiev, Yalchin; Espedal, Magne

    2010-01-01

    , fractures and their interconnectivities in coarse-scale simulation models. In this paper, we present a procedure based on our previously proposed Stokes-Brinkman model (SPE 125593) and the discrete fracture network method for accurate and efficient upscaling

  15. Infrasound Predictions Using the Weather Research and Forecasting Model: Atmospheric Green's Functions for the Source Physics Experiments 1-6.

    Energy Technology Data Exchange (ETDEWEB)

    Poppeliers, Christian; Aur, Katherine Anderson; Preston, Leiph

    2018-03-01

    This report shows the results of constructing predictive atmospheric models for the Source Physics Experiments 1-6. Historic atmospheric data are combined with topography to construct an atmo- spheric model that corresponds to the predicted (or actual) time of a given SPE event. The models are ultimately used to construct atmospheric Green's functions to be used for subsequent analysis. We present three atmospheric models for each SPE event: an average model based on ten one- hour snap shots of the atmosphere and two extrema models corresponding to the warmest, coolest, windiest, etc. atmospheric snap shots. The atmospheric snap shots consist of wind, temperature, and pressure profiles of the atmosphere for a one-hour time window centered at the time of the predicted SPE event, as well as nine additional snap shots for each of the nine preceding years, centered at the time and day of the SPE event.

  16. Recyclable amplification for single-photon entanglement from photon loss and decoherence

    Science.gov (United States)

    Zhou, Lan; Chen, Ling-Quan; Zhong, Wei; Sheng, Yu-Bo

    2018-01-01

    We put forward a highly efficient recyclable single-photon assisted amplification protocol, which can protect single-photon entanglement (SPE) from photon loss and decoherence. Making use of quantum nondemolition detection gates constructed with the help of cross-Kerr nonlinearity, our protocol has some attractive advantages. First, the parties can recover less-entangled SPE to be maximally entangled SPE, and reduce photon loss simultaneously. Second, if the protocol fails, the parties can repeat the protocol to reuse some discarded items, which can increase the success probability. Third, when the protocol is successful, they can similarly repeat the protocol to further increase the fidelity of the SPE. Thereby, our protocol provides a possible way to obtain high entanglement, high fidelity and high success probability simultaneously. In particular, our protocol shows higher success probability in the practical high photon loss channel. Based on the above features, our amplification protocol has potential for future application in long-distance quantum communication.

  17. EVALUATION OF ANALYTICAL METHODS FOR DETERMINING PESTICIDES IN BABY FOOD

    Science.gov (United States)

    Three extraction methods and two detection techniques for determining pesticides in baby food were evaluated. The extraction techniques examined were supercritical fluid extraction (SFE), enhanced solvent extraction (ESE), and solid phase extraction (SPE). The detection techni...

  18. Comparison of extraction and clean-up techniques for the ...

    African Journals Online (AJOL)

    user

    ultrasonication and mechanical shaking used in the extraction of a low-level PAH soil certified ... hydrocarbons (PAHs), soil, solid phase extraction (SPE), soxhlet extraction, ultrasonication. ... soxhlet) (Lopez-Avila et al., 1993) supercritical fluid.

  19. Direct modification of hydrogen/deuterium-terminated diamond particles with polymers to form reversed and strong cation exchange solid phase extraction sorbents.

    Science.gov (United States)

    Yang, Li; Jensen, David S; Vail, Michael A; Dadson, Andrew; Linford, Matthew R

    2010-12-03

    We describe direct polymer attachment to hydrogen and deuterium-terminated diamond (HTD and DTD) surfaces using a radical initiator (di-tert-amyl peroxide, DTAP), a reactive monomer (styrene) and a crosslinking agent (divinylbenzene, DVB) to create polystyrene encapsulated diamond. Chemisorbed polystyrene is sulfonated with sulfuric acid in acetic acid. Surface changes were followed by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFT). Finally, both polystyrene-modified DTD and sulfonated styrene-modified DTD were used in solid phase extraction (SPE). Percent recovery and column capacity were investigated for both phenyl (polystyrene) and sulfonic acid treated polystyrene SPE columns. These diamond-based SPE supports are stable under basic conditions, which is not the case for silica-based SPE supports. Copyright © 2010. Published by Elsevier B.V.

  20. Advanced Reservoir Characterization and Evaluation of CO{sub 2} Gravity Drainage in the Naturally Fractured Spraberry Trend Area, Class III

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Bill; Schechter, David S.

    2001-11-19

    The goal of this project was to assess the economic feasibility of CO{sub 2} flooding the naturally fractured Spraberry Trend Area in west Texas. This objective was accomplished through research in four areas: (1) extensive characterization of the reservoirs, (2) experimental studies of crude oil/brine/rock (COBR) interactions in the reservoirs, (3) reservoir performance analysis, and (4) experimental investigations on CO{sub 2} gravity drainage in Spraberry whole cores. The four areas have been completed and reported in the previous annual reports. This report provides the results of the final year of the project including two SPE papers (SPE 71605 and SPE 71635) presented in the 2001 SPE Annual Meeting in New Orleans, two simulation works, analysis of logging observation wells (LOW) and progress of CO{sub 2} injection.

  1. Utilizing ion-pairing hydrophilic interaction chromatography solid phase extraction for efficient glycopeptide enrichment in glycoproteomics

    DEFF Research Database (Denmark)

    Mysling, Simon; Palmisano, Giuseppe; Højrup, Peter

    2010-01-01

    Glycopeptide enrichment is a prerequisite to enable structural characterization of protein glycosylation in glycoproteomics. Here we present an improved method for glycopeptide enrichment based on zwitter-ionic hydrophilic interaction chromatography solid phase extraction (ZIC-HILIC SPE...

  2. Rapid determination of trace nitrophenolic organics in water by combining solid-phase extraction with surface-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Shiea, J; Sunner, J

    2000-01-01

    A rapid technique for the screening of trace compounds in water by combining solid-phase extraction (SPE) with activated carbon surface-assisted laser desorption/ionization (SALDI) time-of-flight mass spectrometry is demonstrated. Activated carbon is used both as the sorbent in SPE and as the solid in the SALDI matrix system. This eliminates the need for an SPE elution process. After the analytes have been adsorbed on the surfaces of the activated carbon during SPE extraction, the activated carbon is directly mixed with the SALDI liquid and mass spectrometric analysis is performed. Trace phenolic compounds in water were used to demonstrate the effectiveness of the method. The detection limit for these compounds is in the ppb to ppt range. Copyright 2000 John Wiley & Sons, Ltd.

  3. dimethylglyoxime ion-imprinted polymer into electrospun

    African Journals Online (AJOL)

    2011-02-03

    Feb 3, 2011 ... Contamination of water by heavy metals is a major concern around the ... exchange (Shaoet al., 1991), activated carbon adsorption (Wilson et al.,2006) ... and solid phase extraction (Hennion, 1999) (SPE), have been used to ...

  4. Enhancement of the spin Peltier effect in multilayers

    Science.gov (United States)

    Uchida, K.; Iguchi, R.; Daimon, S.; Ramos, R.; Anadón, A.; Lucas, I.; Algarabel, P. A.; Morellón, L.; Aguirre, M. H.; Ibarra, M. R.; Saitoh, E.

    2017-05-01

    The spin Peltier effect (SPE), heat-current generation as a result of spin-current injection, has been investigated in alternately stacked Pt/Fe3O4 multilayer films. The temperature modulation induced by the SPE in the [Pt/Fe3O4]×n films was found to be significantly enhanced with increasing the number of Pt/Fe3O4 bilayers n . This SPE enhancement is much greater than that expected for a simple stack of independent Pt/Fe3O4 bilayers. The observed n dependence of the SPE can be explained by introducing spin-current redistribution in the multilayer films in the thickness direction, in a manner similar to the enhancement of the spin Seebeck effect in multilayers.

  5. Lock-in thermography measurements of the spin Peltier effect in a compensated ferrimagnet and its comparison to the spin Seebeck effect

    Science.gov (United States)

    Yagmur, A.; Iguchi, R.; Geprägs, S.; Erb, A.; Daimon, S.; Saitoh, E.; Gross, R.; Uchida, K.

    2018-05-01

    The spin Peltier effect (SPE) in a junction comprising a gadolinium-iron-garnet (GdIG) slab and a Pt film has been investigated around the magnetization compensation temperature of GdIG by means of the lock-in thermography method. When a charge current is applied to the Pt layer, a spin current is generated across the Pt/GdIG interface via the spin Hall effect in Pt. This spin current induces a heat current and a measurable temperature change near the Pt/GdIG interface due to the SPE. The SPE signal in the Pt/GdIG junction shows a sign change around the magnetization compensation temperature, demonstrating the similar temperature dependence of the SPE and the spin Seebeck effect for the Pt/GdIG hybrid system.

  6. Measurement of trace levels of antibiotics in river water using on-line enrichment and triple-quadrupole LC-MS/MS.

    Science.gov (United States)

    Dinh, Quoc Tuc; Alliot, Fabrice; Moreau-Guigon, Elodie; Eurin, Joëlle; Chevreuil, Marc; Labadie, Pierre

    2011-09-15

    This study presents the development of an automated on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of 23 antibiotics in environmental water samples. After optimisation of LC-MS/MS conditions, SPE parameters such as sorbent type, sample pH or sample volume were optimised. Antibiotic recoveries ranged from 64% to 98% and compared favourably with those achieved using off-line SPE. Limits of detection were in the range 0.5-13.7 ng L(-1). This on-line SPE-LC-MS/MS procedure was applied to the analysis of water samples taken in three rivers within the Seine River basin, near Paris (France). The obtained results revealed the occurrence of 12 antibiotics, including tylosin, erythromycin, tetracycline, amoxicillin, trimethoprim, sulfamethoxazole, oxolinic acid, flumequine, norfloxacin, ciprofloxacin, ofloxacin, and vancomycin (2-1435 ng L(-1)). Copyright © 2011 Elsevier B.V. All rights reserved.

  7. IRTF NEAR-IR SPECTROSCOPY OF ASTEROIDS V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains low-resolution, near-infrared (0.8 - 2.5 micron) spectra of asteroids obtained with SpeX at the NASA Infrared Telescope Facility (IRTF) on...

  8. Evaluation of solid polymer electrolytes for use in conducting polymer/nanotube actuators

    Science.gov (United States)

    Lewis, Trevor W.; Kim, B. C.; Spinks, Geoffrey M.; Wallace, Gordon G.

    2000-06-01

    The stringent requirements for a solid polymer electrolyte (SPE) in solid state devices such as batteries or supercapacitors are even more demanding when used in electromechanical actuators. Not only is the SPE expected to exhibit good conductivity, mechanical properties, adhesion and mechanical/electrical stability, but it must also be flexible, maintained good adhesion while flexing, be easily processible and be able to function in air. In this work polyacrylonitrile and Kynar based non-aqueous SPEs and water based polyacrylamide hydrogel ion source/sinks containing various perchlorate salts were tested for their applicability to polypyrrole and carbon nanotube actuators and supercapacitors. The results indicate that the optimum SPE for both polypyrrole and carbon nanotube actuators would be a polyacrylonitrile plasticized with propylene carbonate and ethylene carbonate containing 1.0M NaClO4. It is also apparent that the same SPE would be the most suitable for supercapacitor applications with these materials.

  9. The kinetics of solid phase epitaxy in As-doped buried amorphous silicon layers

    International Nuclear Information System (INIS)

    McCallum, J.C.

    1998-01-01

    The kinetics of dopant-enhanced solid phase epitaxy (SPE) have been measured in buried a-Si layers doped with arsenic. SPE rates were measured over the temperature range 480 - 660 deg C for buried a-Si layers containing ten different As concentrations. In the absence of H-retardation effects, the dopant-enhanced SPE rate is observed to depend linearly on the As concentration over the entire range of concentrations, 1-16 x 10 19 cm -3 covered in the study. The Fermi level energy was calculated as a function of doping and find an equation that can provide good fits to the data. The implications of these results for models of the SPE process is discussed

  10. FIEBER-BEYER IRTF MAINBELT ASTEROID SPECTRA V2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set contains observations obtained with the NASA IRTF SpeX instrument covering the 0.7 to 2.5 micron near-infrared portion of the spectrum. The data set...

  11. 48 CFR 1201.301-70 - Amendment of (TAR) 48 CFR chapter 12.

    Science.gov (United States)

    2010-10-01

    ...) 48 CFR chapter 12 is maintained by the SPE through the TAR/TAM change process. This process consists... (C) To issue guidance which may be effective for a period of 1 year or less. (ii) Each TN will expire...

  12. Fulltext PDF

    Indian Academy of Sciences (India)

    R Gadagkar (Bangalore). The course will have lectures on Mendelian genetics, Population genetics, Quantitative genetics, Genes and development, Molecular genetics, Genomics, Evolutionary theory, Spe- ciation, Molecular evolution, Phylogenetic reconstruction and related areas. Besides lectures, intensive practicals will ...

  13. Gut morpbology of tbe Otomyine rodents: an arid-mesic comparison

    African Journals Online (AJOL)

    1998-06-15

    Jun 15, 1998 ... Despite the broad similarity in the gross gastro-intestinal anatomy between the speCies ... Present address: Department of Physiology, University of the Western ..... on growth and renal performance of juvenile Namib rodents.

  14. REDDY MAIN BELT ASTEROID SPECTRA V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains low-resolution (R~150) near-infrared (0.7-2.5 microns) spectra of 90 main belt asteroids observed with the SpeX instrument on the NASA...

  15. Phase 2 - GASB Statement 34 compliance : development of a fixed asset (infrastructure) for the Alabama Department of Transportation

    Science.gov (United States)

    2003-05-01

    The Alabama Department of Transportation (ALDOT) Bureau of Materials and Tests has been working with the University of Alabama's Management Information Systems Department to provide a tool for road maintenance and optimization associated funding. Spe...

  16. Diversity in the neuronal machine: order and variability in interneuronal microcircuits

    National Research Council Canada - National Science Library

    Soltesz, Ivan

    2006-01-01

    ... Disorders 42 3: Order in Diversity: From Phenomenology to Function 45 Diversity at Multiple Levels of Neuronal Organization 45 Linnean Order in Diversity: A Modern Compendium of Interneuronal Spe...

  17. Cyclic olefin polymers: emerging materials for lab-on-a-chip applications

    DEFF Research Database (Denmark)

    Nunes, Pedro; Ohlsson, Pelle; Sala, Olga Ordeig

    2010-01-01

    of chemical analysis techniques have already been implemented. These include microchip electrophoresis (MCE), chromatography, solid phase extraction (SPE), isoelectric focusing (IEF) and mass spectrometry (MS). Still much additional work is needed to characterise and utilise the full potential of COP...

  18. Solid phase extraction method for determination of mitragynine in ...

    African Journals Online (AJOL)

    All rights reserved. ... 1Department of Pharmacology, 2Department of Applied Science, 3Police Forensic Science Center 10, Yala 95000, 4Natural ... Purpose: To develop a solid phase extraction (SPE) method that utilizes reverse-phase high.

  19. Phylogeny of Fish-Infecting Calyptospora species (Apicomplexa: Eimeriorina)

    Science.gov (United States)

    There are numerous species of apicomplexans that infect poikilothermic vertebrates such as fishes, and possess unique morphological features that provide insight into the evolution of this important phylum of parasites. Here the relationship of the fish-infecting Calyptospora spe...

  20. Molecular determinants of odorant receptor function in insects

    Indian Academy of Sciences (India)

    2014-07-20

    Jul 20, 2014 ... other host-odor responsive receptors from vector insect spe- cies would .... those that mediate host-seeking behaviour in insect disease vectors and ... receptors are transmitted and processed via olfactory circuits. (Vosshall ...

  1. Water-Dispersible Silica-Polyelectrolyte Nanocomposites Prepared via Acid-Triggered Polycondensation of Silicic Acid and Directed by Polycations

    Directory of Open Access Journals (Sweden)

    Philip Overton

    2016-03-01

    Full Text Available The present work describes the acid-triggered condensation of silicic acid, Si(OH4, as directed by selected polycations in aqueous solution in the pH range of 6.5–8.0 at room temperature, without the use of additional solvents or surfactants. This process results in the formation of silica-polyelectrolyte (S-PE nanocomposites in the form of precipitate or water-dispersible particles. The mean hydrodynamic diameter (dh of size distributions of the prepared water-dispersible S-PE composites is presented as a function of the solution pH at which the composite formation was achieved. Poly(2-(dimethylaminoethyl methacrylate (PDMAEMA and block copolymers of DMAEMA and oligo(ethylene glycol methyl ether methacrylate (OEGMA were used as weak polyelectrolytes in S-PE composite formation. The activity of the strong polyelectrolytes poly(methacryloxyethyl trimethylammonium iodide (PMOTAI and PMOTAI-b-POEGMA in S-PE formation is also examined. The effect of polyelectrolyte strength and the OEGMA block on the formation of the S-PE composites is assessed with respect to the S-PE composites prepared using the PDMAEMA homopolymer. In the presence of the PDMAEMA60 homopolymer (Mw = 9400 g/mol, the size of the dispersible S-PE composites increases with solution pH in the range pH 6.6–8.1, from dh = 30 nm to dh = 800 nm. S-PDMAEMA60 prepared at pH 7.8 contained 66% silica by mass (TGA. The increase in dispersible S-PE particle size is diminished when directed by PDMAEMA300 (Mw = 47,000 g/mol, reaching a maximum of dh = 75 nm. S-PE composites formed using PDMAEMA-b-POEGMA remain in the range dh = 20–30 nm across this same pH regime. Precipitated S-PE composites were obtained as spheres of up to 200 nm in diameter (SEM and up to 65% mass content of silica (TGA. The conditions of pH for the preparation of dispersible and precipitate S-PE nanocomposites, as directed by the five selected polyelectrolytes PDMAEMA60, PDMAEMA300, PMOTAI60, PDMAEMA60-b-POEGMA38 and

  2. Pipette-tip selective extraction of glycoproteins with lectin modified gold nano-particles on a polymer monolithic phase

    OpenAIRE

    Alwael, Hassan Omar Salem; Connolly, Damian; Clarke, Paul A.; Thompson, Roisin; Twamley, Brendan; O'Connor, Brendan; Paull, Brett

    2011-01-01

    The selective extraction of specific proteins (non glycosylated, glycosylated or different glycoforms) from complex sample matrices utilising selective solid phase extration (SPE) is of significant interest within the fields of proteomics and glycoproteomics. Polymer monoliths have proven to be an excellent solid support for SPE applications in bio-analysis due to their excellent mass transfer characteristics for large biomolecules. Although biorecognition molecules such as lectins can be cov...

  3. A rapid solid-phase extraction method for measurement of non-metabolised peripheral benzodiazepine receptor ligands, [18F]PBR102 and [18F]PBR111, in rat and primate plasma

    International Nuclear Information System (INIS)

    Katsifis, Andrew; Loc'h, Christian; Henderson, David; Bourdier, Thomas; Pham, Tien; Greguric, Ivan; Lam, Peter; Callaghan, Paul; Mattner, Filomena; Eberl, Stefan; Fulham, Michael

    2011-01-01

    Objectives: To develop a rapid and reliable method for estimating non-metabolised PBR ligands fluoroethoxy ([ 18 F]PBR102)- and fluoropropoxy ([ 18 F]PBR111)-substituted 2-(6-chloro-2-phenyl)imidazo[1,2-a]pyridine-3-yl)-N,N-diethylacetamides in plasma. Methods: Rats and baboons were imaged with PET up to 2 h postinjection of [ 18 F]PBR102 and [ 18 F]PBR111 under baseline conditions, after pre-blocking or displacement with PK11195. Arterial plasma samples were directly analysed by reverse-phase solid-phase extraction (RP-SPE) and RP-HPLC and by normal-phase TLC. SPE cartridges were successively washed with acetonitrile/water mixtures. SPE eluant radioactivity was measured in a γ-counter to determine the parent compound fraction and then analysed by HPLC and TLC for validation. Results: In SPE, hydrophilic and lipophilic radiolabelled metabolites were eluted in water and 20% acetonitrile/water. All non-metabolised [ 18 F]PBR102 and [ 18 F]PBR111 were in SPE acetonitrile fraction as confirmed by HPLC and TLC analysis. Unchanged (%) [ 18 F]PBR102 and [ 18 F]PBR111 from SPE analysis in rat and baboon plasma agreed with those from HPLC and TLC analysis. In rats and baboons, the fraction of unchanged tracer followed a bi-exponential decrease, with half-lives of 7 to 10 min for the fast component and >80 min for the slow component for both tracers. Conclusions: Direct plasma SPE analysis of [ 18 F]PBR102 and [ 18 F]PBR111 can reliably estimate parent compound fraction. SPE was superior to HPLC for samples with low activity; it allows rapid and accurate metabolite analysis of a large number of plasma samples for improved estimation of metabolite-corrected input function during quantitative PET imaging studies.

  4. Saw palmetto extract enhances erectile responses by inhibition of phosphodiesterase 5 activity and increase in inducible nitric oxide synthase messenger ribonucleic acid expression in rat and rabbit corpus cavernosum.

    Science.gov (United States)

    Yang, Surong; Chen, Changrui; Li, Yiying; Ren, Zhenghua; Zhang, Yungang; Wu, Gantong; Wang, Hao; Hu, Zhenzhen; Yao, Minghui

    2013-06-01

    To evaluate whether saw palmetto extract (SPE) relaxes corpus cavernosum and explore the underlying mechanisms. Forty Sprague-Dawley rats and 30 New Zealand rabbits were randomly allocated into 3 SPE-treated groups (low-, middle-, and high-dose) and 1 saline-treated control group. SPE was administered intragastrically for 7 consecutive days. Another 23 rats treated with sildenafil were used to appraise the erectile response to electrical stimulation of nerves in the corpus cavernosum. The erectile functions of rats and rabbits were evaluated 24 hours after the last SPE administration or 15 minutes after intragastric sildenafil. Outcome measures included corpus cavernosum electrical activity recording, phosphodiesterase 5 (PDE5) activity detected by the colorimetric quantitative method, and messenger ribonucleic acid (mRNA) expression level for PDE5 and inducible nitric oxide synthase (iNOS) determined using real-time polymerase chain reaction. In the SPE-treated animals, the relaxant response to electrical stimulation of nerves in the corpus cavernosum, reflected by the amplitude of the electrical activity within the cavernosum, was significantly and dose-dependently augmented. Similar effects were observed in the sildenafil-treated rats. PDE5 activity in rat and rabbit corpus cavernosum tissues was significantly and dose-dependently inhibited in SPE-treated animals, whereas the iNOS mRNA level increased compared with the saline group. PDE5 mRNA, however, was only significantly enhanced in the rats treated with the middle dose of SPE. The results suggest that SPE may have potential application value for the prevention or treatment of erectile dysfunction through an increase in iNOS mRNA expression and inhibition of PDE5 activity in corpus cavernosum smooth muscles. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Analyses of ionic conductivity and dielectric behavior of solid polymer electrolyte based 2-hydroxyethyl cellulose doped ammonium nitrate plasticized with ethylene carbonate

    Science.gov (United States)

    Hafiza, M. N.; Isa, M. I. N.

    2017-09-01

    A solid polymer electrolyte (SPE) based 2-hydroxyethyl cellulose (2-HEC) doped ammonium nitrate (NH4NO3) plasticized with ethylene carbonate (EC) has been investigated using electrical impedance spectroscopy (EIS). The highest ionic conductivity of (1.17±0.01) × 10-3 Scm-1 was obtained for 2-HEC-NH4NO3 plasticized with 16 wt.% EC. Dielectric and modulus study showed non-Debye type of 2-HEC-NH4NO3-EC SPE.

  6. Carbon Nanotubes as a New Solid Phase Extraction Sorbent for Analysis of Environmental Pollutants

    OpenAIRE

    Constantin, Bele

    2010-01-01

    SPE is an increasingly useful technique for sample concentration and clean-up in environmental applications and can be easily incorporated into automated analytical procedures. The future of SPE is closely related to improvement of sorbents that can be more effective in obtaining high enrichment efficiency of analytes. The unusual properties of CNTs, their large sorption capacity, wide surface area and the presence of a wide spectrum of surface functional groups have generated a great interes...

  7. Integration of Solid-phase Extraction with Electrothermal Atomic Absorption Spectrometry for Determination of Trace Elements

    OpenAIRE

    NUKATSUKA, Isoshi; OHZEKI, Kunio

    2006-01-01

    An enrichment step in a sample treatment is essential for trace analysis to improve the sensitivity and to eliminate the matrix of the sample. Solid-phase extraction (SPE) is one of the widely used enrichment technique. Electrothermal atomic absorption spectrometry (ETAAS) is a well-established determination technique for trace elements. The integration of SPE with ETAAS leads to further improvement of sensitivity, an automation of the measurement and the economy in the sample size, amounts o...

  8. Emergence of Streptococcus pyogenes emm102 causing toxic shock syndrome in Southern Taiwan during 2005-2012.

    Directory of Open Access Journals (Sweden)

    Jiun-Nong Lin

    Full Text Available BACKGROUND: Streptococcal toxic shock syndrome (STSS is an uncommon but life-threatening disease caused by Streptococcus pyogenes. METHODS: To understand the clinical and molecular characteristics of STSS, we analyzed clinical data and explored the emm types, superantigen genes, and pulsed-field gel electrophoresis of causative S. pyogenes isolates obtained between 2005 and 2012. RESULTS: In total, 53 patients with STSS were included in this study. The median age of the patients was 57 years (range: 9-83 years, and 81.1% were male. The most prevalent underlying disease was diabetes mellitus (45.3%. Skin and soft-tissue infection accounted for 86.8% of STSS. The overall mortality rate was 32.1%. Underlying diseases had no statistical impact on mortality. A total of 19 different emm types were identified. The most prevalent emm type was emm102 (18.9%, followed by emm11 (17%, emm1 (11.3%, emm87 (9.4%, and emm89 (7.5%. There was no statistically significant association between emm type and a fatal outcome. Among the superantigen genes, speB was the most frequently detected one (92.5%, followed by smeZ (90.6%, speG (81.1%, speC (39.6%, and speF (39.6%. The majority of emm102 strains were found to have speB, speC, speG, and smeZ. The presence of speG was negatively associated with a fatal outcome (P = 0.045. CONCLUSIONS: Our surveillance revealed the emergence of uncommon emm types, particularly emm102, causing STSS in southern Taiwan. Characterization of clinical, epidemiological, and molecular characteristics of STSS will improve our understanding of this life-threatening disease.

  9. An overview analysis of IAEA standard problem exercises

    International Nuclear Information System (INIS)

    Parzer, I.; Mavko, B.; Petelin, S.

    1992-01-01

    The modelling of some loss-of-coolant accident tests (IAEA-SPE), performed on the PMK-NVH integral test facility, have been studied in the present paper. A universal RELAP5 model of the facility has been developed at IJS, first for RELAP5/MOD2 and later upgraded for RELAP5/MOD3 use. To verify the modelling and determine the important details in the model, a nodalization study has been performed on the case of IAEA-SPE-2 experiment. In parallel MOD2 and MOD3 capabilities of modelling highly non-equilibrium processes, as took place in IAEA-SPE-2 experiment, have been compared. Using the most detailed of the developed models, the capabilities of both code versions have been compared on the case of IAEA-SPE-1 and 2 (Small Break Loss-of-Coolant Accidents - SB LOCAs) and IAEA-SPE-3 (Steam Generator Tube Rupture - SGTR), adapted only accordingly to the three SPE experiment arrangements. The calculations nave been performed with RELAP5/MOD2/36.05 and MOD3 5m5 code versions on a VAX 4000-200 computer. (author)

  10. Muscarinic and alpha 1-adrenergic receptor binding characteristics of saw palmetto extract in rat lower urinary tract.

    Science.gov (United States)

    Suzuki, Mayumi; Oki, Tomomi; Sugiyama, Tomomi; Umegaki, Keizo; Uchida, Shinya; Yamada, Shizuo

    2007-06-01

    To elucidate the in vitro and ex vivo effects of saw palmetto extract (SPE) on autonomic receptors in the rat lower urinary tract. The in vitro binding affinities for alpha 1-adrenergic, muscarinic, and purinergic receptors in the rat prostate and bladder were measured by radioligand binding assays. Rats received vehicle or SPE (0.6 to 60 mg/kg/day) orally for 4 weeks, and alpha 1-adrenergic and muscarinic receptor binding in tissues of these rats were measured. Saw palmetto extract inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-(3)H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. Such alteration by SPE was selective to the receptors in the lower urinary tract. Saw palmetto extract exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.

  11. Structure and properties of solid polymer electrolyte based on chitosan and ZrO{sub 2} nanoparticle for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Sudaryanto,, E-mail: dryanto@batan.go.id; Yulianti, Evi, E-mail: yulianti@batan.go.id [Center for Sains and Technology Advanced Materials – BATAN Kawasan Puspiptek Serpong, Tangerang Selatan, BantenV 15314 (Indonesia); Patimatuzzohrah, E-mail: pzohrah@yahoo.com [Department Of Physics, Mataram University, Jl. Majapahit 62, Mataram, NTB 83125 (Indonesia)

    2016-02-08

    In order to develop all solid lithium ion battery, study on the structure and properties of solid polymer electrolytes (SPE) based on chitosan has been done. The SPE were prepared by adding Zirconia (ZrO{sub 2}) nanoparticle and LiClO{sub 4} as lithium salt into the chitosan solution followed by casting method. Effect of the ZrO{sub 2} and salt concentration to the structure and properties of SPE were elaborated using several methods. The structure of the SPE cast film, were characterized mainly by using X-ray diffractometer (XRD). While the electrical properties of SPE were studied by electrochemical impedance spectrometer (EIS) and ion transference number measurement. XRD profiles show that the addition of ZrO{sub 2} and LiClO{sub 4} disrupts the crystality of chitosan. The decrease in sample crytalinity with the nanoparticle and salt addition may increase the molecular mobility result in the increasing sample conductivity and cathionic transference number as determined by EIS and ion transference number measurement, respectively. The highest ionic conductivity (3.58×10{sup −4} S cm{sup −1}) was obtained when 4 wt% of ZrO{sub 2} nanoparticle and 40 wt% of LiClO{sub 4} salt were added to the chitosan. The ion transference number with that composition was 0.55. It is high enough to be used as SPE for lithium ion battery.

  12. Electrochemical Quantification of the Antioxidant Capacity of Medicinal Plants Using Biosensors

    Directory of Open Access Journals (Sweden)

    Erika Rodríguez-Sevilla

    2014-08-01

    Full Text Available The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA, cross-linking using glutaraldehyde (GA, and cross-linking using GA and human serum albumin (HSA; the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km′, of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km′ (57 ± 7 µM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC was determined from infusions prepared with “mirto” (Salvia microphylla, “hHierba dulce” (Lippia dulcis and “salve real” (Lippia alba, medicinal plants commonly used in Mexico.

  13. Electrochemical Quantification of the Antioxidant Capacity of Medicinal Plants Using Biosensors

    Science.gov (United States)

    Rodríguez-Sevilla, Erika; Ramírez-Silva, María-Teresa; Romero-Romo, Mario; Ibarra-Escutia, Pedro; Palomar-Pardavé, Manuel

    2014-01-01

    The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km′, of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km′ (57 ± 7) μM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with “mirto” (Salvia microphylla), “hHierba dulce” (Lippia dulcis) and “salve real” (Lippia alba), medicinal plants commonly used in Mexico. PMID:25111237

  14. Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

    2011-01-01

    Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

  15. Attenuation Model Using the Large-N Array from the Source Physics Experiment

    Science.gov (United States)

    Atterholt, J.; Chen, T.; Snelson, C. M.; Mellors, R. J.

    2017-12-01

    The Source Physics Experiment (SPE) consists of a series of chemical explosions at the Nevada National Security Site. SPE seeks to better characterize the influence of subsurface heterogeneities on seismic wave propagation and energy dissipation from explosions. As a part of this experiment, SPE-5, a 5000 kg TNT equivalent chemical explosion, was detonated in 2016. During the SPE-5 experiment, a Large-N array of 996 geophones (half 3-component and half z-component) was deployed. This array covered an area that includes loosely consolidated alluvium (weak rock) and weathered granite (hard rock), and recorded the SPE-5 explosion as well as 53 weight drops. We use these Large-N recordings to develop an attenuation model of the area to better characterize how geologic structures influence source energy partitioning. We found a clear variation in seismic attenuation for different rock types: high attenuation (low Q) for alluvium and low attenuation (high Q) for granite. The attenuation structure correlates well with local geology, and will be incorporated into the large simulation effort of the SPE program to validate predictive models. (LA-UR-17-26382)

  16. Electrochemical quantification of the antioxidant capacity of medicinal plants using biosensors.

    Science.gov (United States)

    Rodríguez-Sevilla, Erika; Ramírez-Silva, María-Teresa; Romero-Romo, Mario; Ibarra-Escutia, Pedro; Palomar-Pardavé, Manuel

    2014-08-08

    The working area of a screen-printed electrode, SPE, was modified with the enzyme tyrosinase (Tyr) using different immobilization methods, namely entrapment with water-soluble polyvinyl alcohol (PVA), cross-linking using glutaraldehyde (GA), and cross-linking using GA and human serum albumin (HSA); the resulting electrodes were termed SPE/Tyr/PVA, SPE/Tyr/GA and SPE/Tyr/HSA/GA, respectively. These biosensors were characterized by means of amperometry and EIS techniques. From amperometric evaluations, the apparent Michaelis-Menten constant, Km', of each biosensor was evaluated while the respective charge transfer resistance, Rct, was assessed from impedance measurements. It was found that the SPE/Tyr/GA had the smallest Km' (57 ± 7) µM and Rct values. This electrode also displayed both the lowest detection and quantification limits for catechol quantification. Using the SPE/Tyr/GA, the Trolox Equivalent Antioxidant Capacity (TEAC) was determined from infusions prepared with "mirto" (Salvia microphylla), "hHierba dulce" (Lippia dulcis) and "salve real" (Lippia alba), medicinal plants commonly used in Mexico.

  17. Ion transport property studies on PEO-PVP blended solid polymer electrolyte membranes

    International Nuclear Information System (INIS)

    Chandra, Angesh; Agrawal, R C; Mahipal, Y K

    2009-01-01

    The ion transport property studies on Ag + ion conducting PEO-PVP blended solid polymer electrolyte (SPE) membranes, (1 - x)[90PEO : 10AgNO 3 ] : xPVP, where x = 0, 1, 2, 3, 5, 7, 10 (wt%), are reported. SPE films were caste using a novel hot-press technique instead of the traditional solution cast method. The conventional solid polymeric electrolyte (SPE) film, (90PEO : 10AgNO 3 ), also prepared by the hot-press method and identified as the highest conducting composition at room temperature on the basis of PEO-AgNO 3 -salt concentration dependent conductivity studies, was used as the first-phase polymer electrolyte host into which PVP were dispersed as second-phase dispersoid. A two-fold conductivity enhancement from that of the PEO host could be achieved at room temperature for PVP blended SPE film composition: 98(90PEO : 10AgNO 3 ) : 2PVP. This has been referred to as optimum conducting composition (OCC). The formation of SPE membranes and material characterizations were done with the help of the XRD and DSC techniques. The ion transport mechanism in this SPE OCC has been characterized with the help of basic ionic parameters, namely ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n) and ionic transference number (t ion ). Solid-state polymeric batteries were fabricated using OCC as electrolyte and the cell-potential discharge characteristics were studied under different load conditions.

  18. Evaluation of the Potency, Neutralizing Antibody Response, and Stability of a Recombinant Fusion Protein Vaccine for Streptococcus pyogenes.

    Science.gov (United States)

    Burlet, E; HogenEsch, H; Dunham, A; Morefield, G

    2017-05-01

    Streptococcus pyogenes or group A streptococcus (GAS) is a Gram-positive bacterium that can cause a wide range of diseases, including pharyngitis, impetigo, scarlet fever, necrotizing fasciitis, rheumatic fever, and streptococcal toxic shock syndrome. Despite the increasing burden on global health caused by GAS, there is currently no licensed vaccine available. In this study, we evaluated immunogenicity, induction of neutralizing antibodies, and stability of a new recombinant fusion protein vaccine that targets infections from GAS. The recombinant fusion protein (SpeAB) combines inactive mutant forms of streptococcal pyrogenic exotoxin A (SpeA) and streptococcal pyrogenic exotoxin B (SpeB). The SpeAB vaccine evaluated in this study was adsorbed to an aluminum adjuvant and demonstrated robust immunogenicity, eliciting production of specific neutralizing antibodies against SpeA and SpeB, two major virulence factors of S. pyogenes. Stability studies suggest that the vaccine will retain immunogenicity for at least 2 years when stored at refrigerated temperatures. This novel vaccine shows great potential to provide protection against GAS infections and to reduce the burden of GAS disease globally.

  19. Putrescine importer PlaP contributes to swarming motility and urothelial cell invasion in Proteus mirabilis.

    Science.gov (United States)

    Kurihara, Shin; Sakai, Yumi; Suzuki, Hideyuki; Muth, Aaron; Phanstiel, Otto; Rather, Philip N

    2013-05-31

    Previously, we reported that the speA gene, encoding arginine decarboxylase, is required for swarming in the urinary tract pathogen Proteus mirabilis. In addition, this previous study suggested that putrescine may act as a cell-to-cell signaling molecule (Sturgill, G., and Rather, P. N. (2004) Mol. Microbiol. 51, 437-446). In this new study, PlaP, a putative putrescine importer, was characterized in P. mirabilis. In a wild-type background, a plaP null mutation resulted in a modest swarming defect and slightly decreased levels of intracellular putrescine. In a P. mirabilis speA mutant with greatly reduced levels of intracellular putrescine, plaP was required for the putrescine-dependent rescue of swarming motility. When a speA/plaP double mutant was grown in the presence of extracellular putrescine, the intracellular levels of putrescine were greatly reduced compared with the speA mutant alone, indicating that PlaP functioned as the primary putrescine importer. In urothelial cell invasion assays, a speA mutant exhibited a 50% reduction in invasion when compared with wild type, and this defect could be restored by putrescine in a PlaP-dependent manner. The putrescine analog Triamide-44 partially inhibited the uptake of putrescine by PlaP and decreased both putrescine stimulated swarming and urothelial cell invasion in a speA mutant.

  20. Using a formative simulated patient exercise for curriculum evaluation

    Directory of Open Access Journals (Sweden)

    Thompson Margaret E

    2004-05-01

    Full Text Available Abstract Background It is not clear that teaching specific history taking, physical examination and patient teaching techniques to medical students results in durable behavioural changes. We used a quasi-experimental design that approximated a randomized double blinded trial to examine whether a Participatory Decision-Making (PDM educational module taught in a clerkship improves performance on a Simulated Patient Exercise (SPE in another clerkship, and how this is influenced by the time between training and assessment. Methods Third year medical students in an internal medicine clerkship were assessed on their use of PDM skills in an SPE conducted in the second week of the clerkship. The rotational structure of the third year clerkships formed a pseudo-randomized design where students had 1 completed the family practice clerkship containing a training module on PDM skills approximately four weeks prior to the SPE, 2 completed the family medicine clerkship and the training module approximately 12 weeks prior to the SPE or 3 had not completed the family medicine clerkship and the PDM training module at the time they were assessed via the SPE. Results Based on limited pilot data there were statistically significant differences between students who received PDM training approximately four weeks prior to the SPE and students who received training approximately 12 weeks prior to the SPE. Students who received training 12 weeks prior to the SPE performed better than those who received training four weeks prior to the SPE. In a second comparison students who received training four weeks prior to the SPE performed better than those who did not receive training but the differences narrowly missed statistical significance (P Conclusion This pilot study demonstrated the feasibility of a methodology for conducting rigorous curricular evaluations using natural experiments based on the structure of clinical rotations. In addition, it provided preliminary data

  1. Simple and accurate measurement of carbamazepine in surface water by use of porous membrane-protected micro-solid-phase extraction coupled with isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Teo, Hui Ling [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Wong, Lingkai [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Liu, Qinde, E-mail: liu_qinde@hsa.gov.sg [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Teo, Tang Lin; Lee, Tong Kooi [Chemical Metrology Division, Applied Sciences Group, Health Sciences Authority, 1 Science Park Road, #01-05/06, The Capricorn, Singapore Science Park II, Singapore 117528 (Singapore); Lee, Hian Kee, E-mail: chmleehk@nus.edu.sg [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore)

    2016-03-17

    To achieve fast and accurate analysis of carbamazepine in surface water, we developed a novel porous membrane-protected micro-solid-phase extraction (μ-SPE) method, followed by liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) analysis. The μ-SPE device (∼0.8 × 1 cm) was fabricated by heat-sealing edges of a polypropylene membrane sheet to devise a bag enclosing the sorbent. The analytes (both carbamazepine and isotope-labelled carbamazepine) were first extracted by μ-SPE device in the sample (10 mL) via agitation, then desorbed in an organic solvent (1 mL) via ultrasonication. Several parameters such as organic solvent for pre-conditioning of μ-SPE device, amount of sorbent, adsorption time, and desorption solvent and time were investigated to optimize the μ-SPE efficiency. The optimized method has limits of detection and quantitation estimated to be 0.5 ng L{sup −1} and 1.6 ng L{sup −1}, respectively. Surface water samples spiked with different amounts of carbamazepine (close to 20, 500, and 1600 ng L{sup −1}, respectively) were analysed for the validation of method precision and accuracy. Good precision was obtained as demonstrated by relative standard deviations of 0.7% for the samples with concentrations of 500 and 1600 ng kg{sup −1}, and 5.8% for the sample with concentration of 20 ng kg{sup −1}. Good accuracy was also demonstrated by the relative recoveries in the range of 96.7%–103.5% for all samples with uncertainties of 1.1%–5.4%. Owing to the same chemical properties of carbamazepine and isotope-labelled carbamazepine, the isotope ratio in the μ-SPE procedure was accurately controlled. The use of μ-SPE coupled with IDMS analysis significantly facilitated the fast and accurate measurement of carbamazepine in surface water. - Highlights: • μ-SPE coupled with IDMS for the measurement of carbamazepine. • The method is the first report of coupling μ-SPE with IDMS. • μ-SPE is fast, time

  2. Evolutionary paths of streptococcal and staphylococcal superantigens

    Directory of Open Access Journals (Sweden)

    Okumura Kayo

    2012-08-01

    Full Text Available Abstract Background Streptococcus pyogenes (GAS harbors several superantigens (SAgs in the prophage region of its genome, although speG and smez are not located in this region. The diversity of SAgs is thought to arise during horizontal transfer, but their evolutionary pathways have not yet been determined. We recently completed sequencing the entire genome of S. dysgalactiae subsp. equisimilis (SDSE, the closest relative of GAS. Although speG is the only SAg gene of SDSE, speG was present in only 50% of clinical SDSE strains and smez in none. In this study, we analyzed the evolutionary paths of streptococcal and staphylococcal SAgs. Results We compared the sequences of the 12–60 kb speG regions of nine SDSE strains, five speG+ and four speG–. We found that the synteny of this region was highly conserved, whether or not the speG gene was present. Synteny analyses based on genome-wide comparisons of GAS and SDSE indicated that speG is the direct descendant of a common ancestor of streptococcal SAgs, whereas smez was deleted from SDSE after SDSE and GAS split from a common ancestor. Cumulative nucleotide skew analysis of SDSE genomes suggested that speG was located outside segments of steeper slopes than the stable region in the genome, whereas the region flanking smez was unstable, as expected from the results of GAS. We also detected a previously undescribed staphylococcal SAg gene, selW, and a staphylococcal SAg -like gene, ssl, in the core genomes of all Staphylococcus aureus strains sequenced. Amino acid substitution analyses, based on dN/dS window analysis of the products encoded by speG, selW and ssl suggested that all three genes have been subjected to strong positive selection. Evolutionary analysis based on the Bayesian Markov chain Monte Carlo method showed that each clade included at least one direct descendant. Conclusions Our findings reveal a plausible model for the comprehensive evolutionary pathway of streptococcal and

  3. Saw palmetto extract suppresses insulin-like growth factor-I signaling and induces stress-activated protein kinase/c-Jun N-terminal kinase phosphorylation in human prostate epithelial cells.

    Science.gov (United States)

    Wadsworth, Teri L; Carroll, Julie M; Mallinson, Rebecca A; Roberts, Charles T; Roselli, Charles E

    2004-07-01

    A common alternative therapy for benign prostatic hyperplasia (BPH) is the extract from the fruit of saw palmetto (SPE). BPH is caused by nonmalignant growth of epithelial and stromal elements of the prostate. IGF action is important for prostate growth and development, and changes in the IGF system have been documented in BPH tissues. The main signaling pathways activated by the binding of IGF-I to the IGF-I receptor (IGF-IR) are the ERK arm of the MAPK cascade and the phosphoinositol-3-kinase (PI3K)/protein kinase B (PKB/Akt) cascade. We tested the hypothesis that SPE suppresses growth and induces apoptosis in the P69 prostate epithelial cell line by inhibiting IGF-I signaling. Treatment with 150 microg/ml SPE for 24 h decreased IGF-I-induced proliferation of P69 cells and induced cleavage of the enzyme poly(ADP-ribose)polymerase (PARP), an index of apoptosis. Treatment of serum-starved P69 cells with 150 microg/ml SPE for 6 h reduced IGF-I-induced phosphorylation of Akt (assessed by Western blot) and Akt activity (assessed by an Akt kinase assay). Western blot analysis showed that SPE reduced IGF-I-induced phosphorylation of the adapter protein insulin receptor substrate-1 and decreased downstream effects of Akt activation, including increased cyclin D1 levels and phosphorylation of glycogen synthase kinase-3 and p70(s6k). There was no effect on IGF-I-induced phosphorylation of MAPK, IGF-IR, or Shc. Treatment of starved cells with SPE alone induced phosphorylation the proapoptotic protein JNK. SPE treatment may relieve symptoms of BPH, in part, by inhibiting specific components of the IGF-I signaling pathway and inducing JNK activation, thus mediating antiproliferative and proapoptotic effects on prostate epithelia.

  4. High-Efficiency On-Line Solid-Phase Extraction Coupling to 15-150 um I.D. Column Liquid Chromatography for Proteomic Analysis

    International Nuclear Information System (INIS)

    Shen, Yufeng; Moore, Ronald J.; Zhao, Rui; Blonder, Josip; Auberry, Deanna L.; Masselon, Christophe D.; Pasa Tolic, Ljiljana; Hixson, Kim K.; Auberry, Kenneth J.; Smith, Richard D.

    2003-01-01

    Flexible manipulation of various properties of proteomic samples is important for proteomic analyses, but it has been little explored for newly developed approaches based on liquid chromatography (LC) in combination with mass spectrometry (MS). With miniaturization of the LC column inner diameter dimensions (required for improving the analysis sensitivity), this issue becomes more challenging due to the small flow rates and the increasing effects of extra column volume on the separation quality and its use for resolving complex proteomic mixtures. In this study, we used commercial switching valves (150-mm channels) to implement the on-line coupling of capillary LC columns with relatively large solid phase extraction (SPE) columns operated at 10,000 psi. With optimized column connections, switching modes, and SPE column dimensions, high-efficiency on-line SPE-capillary and nanoscale LC separations were obtained with peak capacities of ∼1000 for capillaries having inner diameters between 15 to 150 mm. The on-line coupled SPE columns increased the sample processing capabilities by ∼400-fold for sample solution volume and ∼10-fold for sample mass. The proteomic applications of this on-line SPE-capillary LC system were evaluated for analysis of both soluble and membrane protein tryptic digests. Used with an ion trap tandem MS we could typically identify 1100-1500 peptides for analyses in a single 5-hour run. Peptides extracted on the SPE column and eluted from the LC column covered a hydrophilicity/hydrophobicity range that include an estimated ∼98% of all the tryptic peptides. The present implementation also facilitates automation and enables use of both disposable SPE columns and electrospray emitters, providing a robust basis for routine proteomic analyses.

  5. A sensitive and efficient method for routine pesticide multiresidue analysis in bee pollen samples using gas and liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Vázquez, P Parrilla; Lozano, A; Uclés, S; Ramos, M M Gómez; Fernández-Alba, A R

    2015-12-24

    Several clean-up methods were evaluated for 253 pesticides in pollen samples concentrating on efficient clean-up and the highest number of pesticides satisfying the recovery and precision criteria. These were: (a) modified QuEChERS using dSPE with PSA+C18; (b) freeze-out prior to QuEChERS using dSPE with PSA+C18; (c) freeze-out prior to QuEChERS using dSPE with PSA+C18+Z-Sep; and (d) freeze-out followed by QuEChERS using dSPE with PSA+C18 and SPE with Z-Sep. Determinations were made using LC-MS/MS and GC-MS/MS. The modified QuEChERS protocol applying a freeze-out followed by dSPE with PSA+C18 and SPE clean-up with Z-Sep was selected because it provided the highest number of pesticides with mean recoveries in the 70-120% range, as well as relative standard deviations (RSDs) typically below 20% (12.2% on average) and ensured much better removal of co-extracted matrix compounds of paramount importance in routine analysis. Limits of quantification at levels as low as 5μgkg(-1) were obtained for the majority of the pesticides. The proposed methodology was applied to the analysis of 41 pollen bee samples from different areas in Spain. Pesticides considered potentially toxic to bees (DL50bee) were detected in some samples with concentrations up to 72.7μgkg(-1), which could negatively affect honeybee health. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Principles and applications of colorimetric solid-phase extraction with negligible depletion

    International Nuclear Information System (INIS)

    Dias, Neil C.; Porter, Marc D.; Fritz, James S.

    2006-01-01

    Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed

  7. Dosimetric predictors of radiation-induced pericardial effusion in esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ogino, Ichiro; Watanabe, Shigenobu [Yokohama City University Medical Center, Department of Radiation Oncology, Minami-ku, Yokohama, Kanagawa-prefecture (Japan); Sakamaki, Kentaro [Yokohama City University, Department of Biostatistics, Yokohama City University, Yokohama (Japan); Ogino, Yuka [Tokyo Institute of Technology, Department of Systems and Control Engineering, Tokyo (Japan); Kunisaki, Chikara [Yokohama City University Medical Center, Department of Surgery, Gastroenterological Center, Yokohama (Japan); Kimura, Kazuo [Yokohama City University Medical Center, Division of Cardiology, Yokohama (Japan)

    2017-07-15

    To evaluate the dose-volume parameters of the pericardium and heart in order to reduce the risk of radiation-induced pericardial effusion (PE) and symptomatic PE (SPE) in esophageal cancer patients treated with concurrent chemoradiotherapy. In 86 of 303 esophageal cancer patients, follow-up CT was obtained at least 24 months after concurrent chemoradiotherapy. Correlations between clinical factors, including risk factors for cardiac disease, dosimetric factors, and the incidence of PE and SPE after radiotherapy were analyzed using Cox proportional hazard regression analysis. Significant dosimetric factors with the highest hazard ratios were investigated using zones separated according to their distance from esophagus. PE developed in 49 patients. Univariate analysis showed the mean heart dose, heart V{sub 5}-V{sub 55}, mean pericardium dose, and pericardium V{sub 5}-V{sub 50} to all significantly affect the incidence of PE. Additionally, body surface area was correlated with the incidence of PE in multivariate analysis. Grade 3 and 4 SPE developed in 5 patients. The pericardium V{sub 50} and pericardium D{sub 10} significantly affected the incidence of SPE. The pericardium V{sub 50} in patients with SPE ranged from 17.1 to 21.7%. Factors affecting the incidence of SPE were the V{sub 50} of the pericardium zones within 3 cm and 4 cm of the esophagus. A wide range of radiation doses to the heart and pericardium were related to the incidence of PE. A pericardium V{sub 50} ≤ 17% is important to avoid symptomatic PE in esophageal cancer patients treated with concurrent chemoradiotherapy. (orig.) [German] Beurteilung der Dosis-Volumen-Parameter fuer Perikard und Herz zur Risikoreduzierung eines strahleninduzierten Perikardergusses (PE) und eines symptomatischen PE (SPE) bei mit kombinierter Strahlenchemotherapie behandelten Speiseroehrenkrebspatienten. Bei 86 von 303 Speiseroehrenkrebspatienten wurde mindestens 24 Monate nach der Strahlenchemotherapie ein Kontroll

  8. DNA purification using dynamic solid-phase extraction on a rotationally-driven polyethylene-terephthalate microdevice

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.R. [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Borba, J.C. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Meija, M. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Mills, D.L. [TeGrex Technologies, Sperryville, VA 22740 (United States); Haverstick, D.M. [Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States); Olson, K.E.; Aranda, R. [Office of the Chief Scientist, Defense Forensic Science Center, N 31st Street, Atlanta, GA 30297 (United States); Garner, G.T. [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Carrilho, E. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos-SP (Brazil); Landers, J.P., E-mail: landers@virginia.edu [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Department of Pathology, University of Virginia, Charlottesville, VA 22904 (United States)

    2016-09-21

    We report the development of a disposable polyester toner centrifugal device for semi-automated, dynamic solid phase DNA extraction (dSPE) from whole blood samples. The integration of a novel adhesive and hydrophobic valving with a simple and low cost microfabrication method allowed for sequential addition of reagents without the need for external equipment for fluid flow control. The spin-dSPE method yielded an average extraction efficiency of ∼45% from 0.6 μL of whole blood. The device performed single sample extractions or accommodate up to four samples for simultaneous DNA extraction, with PCR-readiness DNA confirmed by effective amplification of a β-globin gene. The purity of the DNA was challenged by a multiplex amplification with 16 targeted amplification sites. Successful multiplexed amplification could routinely be obtained using the purified DNA collected post an on-chip extraction, with the results comparable to those obtained with commercial DNA extraction methods. This proof-of-principle work represents a significant step towards a fully-automated low cost DNA extraction device. - Highlights: • dSPE design on centrifugal PeT device with a unique mixing strategy was proposed. • Increased fluidic control with novel adhesive tape valves on a PeT device. • Multiplexed spin-dSPE device to run up to 4 samples simultaneously. • Demonstrated strong singleplexed and multiplexed amplification following chip dSPE.

  9. Isolation and pharmacological characterization of fatty acids from saw palmetto extract.

    Science.gov (United States)

    Abe, Masayuki; Ito, Yoshihiko; Suzuki, Asahi; Onoue, Satomi; Noguchi, Hiroshi; Yamada, Shizuo

    2009-04-01

    Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary-tract symptoms secondary to benign prostatic hyperplasia. The mechanisms of pharmacological effects of SPE include the inhibition of 5alpha-reductase, anti-androgenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine calcium channel (1,4-DHP) receptors in the prostate and bladder of rats, whereas its active constituents have not been fully clarified. The present investigation is aimed to identify the main active components contained in hexane and diethyl ether extracts of SPE with the use of column chromatography and preparative HPLC. Based on the binding activity with alpha(1)-adrenergic, muscarinic, and 1,4-DHP receptors, both isolated oleic and lauric acids were deduced to be active components. Authentic samples of oleic and lauric acids also exhibited similar binding activities to these receptors as the fatty acids isolated from SPE, consistent with our findings. In addition, oleic and lauric acids inhibited 5alpha-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.

  10. Optimization of the Determination Method for Dissolved Cyanobacterial Toxin BMAA in Natural Water.

    Science.gov (United States)

    Yan, Boyin; Liu, Zhiquan; Huang, Rui; Xu, Yongpeng; Liu, Dongmei; Lin, Tsair-Fuh; Cui, Fuyi

    2017-10-17

    There is a serious dispute on the existence of β-N-methylamino-l-alanine (BMAA) in water, which is a neurotoxin that may cause amyotrophic lateral sclerosis/Parkinson's disease (ALS/PDC) and Alzheimer' disease. It is believed that a reliable and sensitive analytical method for the determination of BMAA is urgently required to resolve this dispute. In the present study, the solid phase extraction (SPE) procedure and the analytical method for dissolved BMAA in water were investigated and optimized. The results showed both derivatized and underivatized methods were qualified for the measurement of BMAA and its isomer in natural water, and the limit of detection and the precision of the two methods were comparable. Cartridge characteristics and SPE conditions could greatly affect the SPE performance, and the competition of natural organic matter is the primary factor causing the low recovery of BMAA, which was reduced from approximately 90% in pure water to 38.11% in natural water. The optimized SPE method for BMAA was a combination of rinsed SPE cartridges, controlled loading/elution rates and elution solution, evaporation at 55 °C, reconstitution of a solution mixture, and filtration by polyvinylidene fluoride membrane. This optimized method achieved > 88% recovery of BMAA in both algal solution and river water. The developed method can provide an efficient way to evaluate the actual concentration levels of BMAA in actual water environments and drinking water systems.

  11. Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain); Ferreira, Vicente, E-mail: vferre@unizar.es [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain)

    2010-02-15

    This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R{sup 2} > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

  12. Development of andrographolide molecularly imprinted polymer for solid-phase extraction

    Science.gov (United States)

    Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

    2011-06-01

    A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

  13. Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

    International Nuclear Information System (INIS)

    Andrade, Natasha A.; Centofanti, Tiziana; McConnell, Laura L.; Hapeman, Cathleen J.; Torrents, Alba; Nguyen, Anh; Beyer, W. Nelson; Chaney, Rufus L.; Novak, Jeffrey M.; Anderson, Marya O.; Cantrell, Keri B.

    2014-01-01

    Improved approaches are needed to assess bioavailability of hydrophobic organic compounds in contaminated soils. Performance of thin-film solid-phase extraction (TF-SPE) using vials coated with ethylene vinyl acetate was compared to earthworm bioassay (Lumbricus terrestris). A DDT and dieldrin contaminated soil was amended with four organic carbon materials to assess the change in bioavailability. Addition of organic carbon significantly lowered bioavailability for all compounds except for 4,4′-DDT. Equilibrium concentrations of compounds in the polymer were correlated with uptake by earthworms after 48d exposure (R 2 = 0.97; p 40yr of aging. Results show that TF-SPE can be useful in examining potential risks associated with contaminated soils and to test effectiveness of remediation efforts. -- Highlights: • Bioavailability of pesticides in soil were assessed using TF-SPE and earthworms. • Soil from a historical orchard was used to examine aged residues of dieldrin and DDT. • TF-SPE results were strongly correlated with earthworm bioaccumulation factors. • Ethylene vinyl acetate polymer has sorptive capacity similar to earthworm lipid. • TF-SPE useful to estimate bioavailability of hydrophobic organic pesticides in soil. -- Capsule A thin-film polymer sampler proved to be efficient in estimating the differences in bioavailability to earthworms in a soil treated with organic amendments

  14. Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

    International Nuclear Information System (INIS)

    Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan; Ferreira, Vicente

    2010-01-01

    This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R 2 > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

  15. Forecasting solar proton event with artificial neural network

    Science.gov (United States)

    Gong, J.; Wang, J.; Xue, B.; Liu, S.; Zou, Z.

    Solar proton event (SPE), relatively rare but popular in solar maximum, can bring hazard situation to spacecraft. As a special event, SPE always accompanies flare, which is also called proton flare. To produce such an eruptive event, large amount energy must be accumulated within the active region. So we can investigate the character of the active region and its evolving trend, together with other such as cm radio emission and soft X-ray background to evaluate the potential of SEP in chosen area. In order to summarize the omen of SPEs in the active regions behind the observed parameters, we employed AI technology. Full connecting neural network was chosen to fulfil this job. After constructing the network, we train it with 13 parameters that was able to exhibit the character of active regions and their evolution trend. More than 80 sets of event parameter were defined to teach the neural network to identify whether an active region was potential of SPE. Then we test this model with a data base consisting SPE and non-SPE cases that was not used to train the neural network. The result showed that 75% of the choice by the model was right.

  16. [Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

    Science.gov (United States)

    Sauer, Richard; Rutz, Jeffrey; Schultz, John

    2005-01-01

    A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.

  17. An absorbing microwave micro-solid-phase extraction device used in non-polar solvent microwave-assisted extraction for the determination of organophosphorus pesticides.

    Science.gov (United States)

    Wang, Ziming; Zhao, Xin; Xu, Xu; Wu, Lijie; Su, Rui; Zhao, Yajing; Jiang, Chengfei; Zhang, Hanqi; Ma, Qiang; Lu, Chunmei; Dong, Deming

    2013-01-14

    A single-step extraction-cleanup method, including microwave-assisted extraction (MAE) and micro-solid-phase extraction (μ-SPE), was developed for the extraction of ten organophosphorus pesticides in vegetable and fruit samples. Without adding any polar solvent, only one kind of non-polar solvent (hexane) was used as extraction solvent in the whole extraction step. Absorbing microwave μ-SPE device, was prepared by packing activated carbon with microporous polypropylene membrane envelope, and used as not only the sorbent in μ-SPE, but also the microwave absorption medium. Some experimental parameters effecting on extraction efficiency was investigated and optimized. 1.0 g of sample, 8 mL of hexane and three absorbing microwave μ-SPE devices were added in the microwave extraction vessel, the extraction was carried out under 400 W irradiation power at 60°C for 10 min. The extracts obtained by MAE-μ-SPE were directly analyzed by GC-MS without any clean-up process. The recoveries were in the range of 93.5-104.6%, and the relative standard deviations were lower than 8.7%. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Thermographic measurements of the spin Peltier effect in metal/yttrium-iron-garnet junction systems

    Science.gov (United States)

    Daimon, Shunsuke; Uchida, Ken-ichi; Iguchi, Ryo; Hioki, Tomosato; Saitoh, Eiji

    2017-07-01

    The spin Peltier effect (SPE), heat-current generation due to spin-current injection, in various metal (Pt, W, and Au single layers and Pt/Cu bilayer)/ferrimagnetic insulator [yttrium-iron-garnet (YIG)] junction systems has been investigated by means of a lock-in thermography (LIT) method. The SPE is excited by a spin current across the metal/YIG interface, which is generated by applying a charge current to the metallic layer via the spin Hall effect. The LIT method enables the thermal imaging of the SPE free from the Joule-heating contribution. Importantly, we observed spin-current-induced temperature modulation not only in the Pt/YIG and W/YIG systems, but also in the Au/YIG and Pt/Cu/YIG systems, excluding the possible contamination by anomalous Ettingshausen effects due to proximity-induced ferromagnetism near the metal/YIG interface. As demonstrated in our previous study, the SPE signals are confined only in the vicinity of the metal/YIG interface; we buttress this conclusion by reducing a spatial blur due to thermal diffusion in an infrared-emission layer on the sample surface used for the LIT measurements. We also found that the YIG-thickness dependence of the SPE is similar to that of the spin Seebeck effect measured in the same Pt/YIG sample, implying the reciprocal relation between them.

  19. Development of an in-house mixed-mode solid-phase extraction for the determination of 16 basic drugs in urine by High Performance Liquid Chromatography-Ion Trap Mass Spectrometry.

    Science.gov (United States)

    Musile, Giacomo; Cenci, Lucia; Piletska, Elena; Gottardo, Rossella; Bossi, Alessandra M; Bortolotti, Federica

    2018-07-27

    The aim of the present work was to develop a novel in-house mixed-mode SPE sorbent to be used for the HPLC-Ion TrapMS determination of 16 basic drugs in urine. By using a computational modelling, a virtual monomer library was screened identifying three suitable functional monomers, methacrylic acid (MAA), itaconic acid (IA) and 2-acrylamide-2-methylpropane sulfonic acid (AMPSA), respectively. Three different sorbents were then synthetized based on these monomers, and using as cross-linker trimethylolpropane trimethacrylate (TMPTMA). The sorbent characterization analyses brought to the selection of the AMPSA based phase. Using this novel in-house sorbent, a SPE-HPLC-Ion TrapMS method for drug analysis in urine was validated proving to be selective and accurate and showing a sensitivity adequate for toxicological urine analysis. The comparison of the in-house mixed-mode SPE sorbent with two analogous commercial mixed-mode SPE phases showed that the first one was better not only in terms of process efficiency, but also in terms of quality-price rate. To the best of our knowledge, this is the first time in which an in-house SPE procedure has been applied to the toxicological analysis of a complex matrix, such as urine. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Integrated electrokinetically driven microfluidic devices with pH-mediated solid-phase extraction coupled to microchip electrophoresis for preterm birth biomarkers.

    Science.gov (United States)

    Sonker, Mukul; Knob, Radim; Sahore, Vishal; Woolley, Adam T

    2017-07-01

    Integration in microfluidics is important for achieving automation. Sample preconcentration integrated with separation in a microfluidic setup can have a substantial impact on rapid analysis of low-abundance disease biomarkers. Here, we have developed a microfluidic device that uses pH-mediated solid-phase extraction (SPE) for the enrichment and elution of preterm birth (PTB) biomarkers. Furthermore, this SPE module was integrated with microchip electrophoresis for combined enrichment and separation of multiple analytes, including a PTB peptide biomarker (P1). A reversed-phase octyl methacrylate monolith was polymerized as the SPE medium in polyethylene glycol diacrylate modified cyclic olefin copolymer microfluidic channels. Eluent for pH-mediated SPE of PTB biomarkers on the monolith was optimized using different pH values and ionic concentrations. Nearly 50-fold enrichment was observed in single channel SPE devices for a low nanomolar solution of P1, with great elution time reproducibility (electrophoresis in our integrated device with ∼15-fold enrichment. This device shows important progress towards an integrated electrokinetically operated platform for preconcentration and separation of biomarkers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A solid-phase extraction method for analyzing trace amounts of polychlorinated dibenzo-p-dioxins and dibenzofurans in waste water

    Directory of Open Access Journals (Sweden)

    Hye-Sung Cho

    2011-03-01

    Full Text Available The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fsin waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to bereinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in wastewater. Liquid-liquid extraction (LLE is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes itinadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE method for the analysisof dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompressionpump, which enables continuous semi-automated extraction. Small (0.5 L and large (7 L samples were extracted using LLE andSPE methods, respectively. The method detection limits (MDLs were 0.001−0.25 and 0.015−4.1 pg I-TEQ/L for the SPE andLLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrationsof several congeners that were not detected with the LLE method were quantified using the SPE method

  2. Automated sample preparation using membrane microtiter extraction for bioanalytical mass spectrometry.

    Science.gov (United States)

    Janiszewski, J; Schneider, P; Hoffmaster, K; Swyden, M; Wells, D; Fouda, H

    1997-01-01

    The development and application of membrane solid phase extraction (SPE) in 96-well microtiter plate format is described for the automated analysis of drugs in biological fluids. The small bed volume of the membrane allows elution of the analyte in a very small solvent volume, permitting direct HPLC injection and negating the need for the time consuming solvent evaporation step. A programmable liquid handling station (Quadra 96) was modified to automate all SPE steps. To avoid drying of the SPE bed and to enhance the analytical precision a novel protocol for performing the condition, load and wash steps in rapid succession was utilized. A block of 96 samples can now be extracted in 10 min., about 30 times faster than manual solvent extraction or single cartridge SPE methods. This processing speed complements the high-throughput speed of contemporary high performance liquid chromatography mass spectrometry (HPLC/MS) analysis. The quantitative analysis of a test analyte (Ziprasidone) in plasma demonstrates the utility and throughput of membrane SPE in combination with HPLC/MS. The results obtained with the current automated procedure compare favorably with those obtained using solvent and traditional solid phase extraction methods. The method has been used for the analysis of numerous drug prototypes in biological fluids to support drug discovery efforts.

  3. Protecting single-photon entanglement with practical entanglement source

    Science.gov (United States)

    Zhou, Lan; Ou-Yang, Yang; Wang, Lei; Sheng, Yu-Bo

    2017-06-01

    Single-photon entanglement (SPE) is important for quantum communication and quantum information processing. However, SPE is sensitive to photon loss. In this paper, we discuss a linear optical amplification protocol for protecting SPE. Different from the previous protocols, we exploit the practical spontaneous parametric down-conversion (SPDC) source to realize the amplification, for the ideal entanglement source is unavailable in current quantum technology. Moreover, we prove that the amplification using the entanglement generated from SPDC source as auxiliary is better than the amplification assisted with single photons. The reason is that the vacuum state from SPDC source will not affect the amplification, so that it can be eliminated automatically. This protocol may be useful in future long-distance quantum communications.

  4. A Simple Engineering Analysis of Solar Particle Event High Energy Tails and Their Impact on Vehicle Design

    Science.gov (United States)

    Singleterry, Robert C., Jr.; Walker, Steven A.; Clowdsley, Martha S.

    2016-01-01

    The mathematical models for Solar Particle Event (SPE) high energy tails are constructed with several di erent algorithms. Since limited measured data exist above energies around 400 MeV, this paper arbitrarily de nes the high energy tail as any proton with an energy above 400 MeV. In order to better understand the importance of accurately modeling the high energy tail for SPE spectra, the contribution to astronaut whole body e ective dose equivalent of the high energy portions of three di erent SPE models has been evaluated. To ensure completeness of this analysis, simple and complex geometries were used. This analysis showed that the high energy tail of certain SPEs can be relevant to astronaut exposure and hence safety. Therefore, models of high energy tails for SPEs should be well analyzed and based on data if possible.

  5. [Treatment-refractory-dental-extraction-associated pyothorax involving infection by 2 species of oral originated bacteria requires surgical debridement by video assisted thoracoscopic surgery (VATS)].

    Science.gov (United States)

    Rai, Kammei; Matsuo, Kiyoshi; Yonei, Toshiro; Sato, Toshio

    2008-09-01

    Cases of septic pulmonary embolism (SPE) diagnosed clinically by CT after dental extraction rarely include verification of bacteria from the local infection site. We report the case of a 70-year-old man without background disease suffering severe pyothrax after dental extraction. We detected two species of oral bacteria from his pleural effusion. Treatment was so difficult that it required surgical debridement by video assisted thoracoscopic surgery (VATS), even after the appropriate administration of antibiotics. According to the American Heart Association (AHA) prophylaxis guidelines for preventing infective endocarditis indicate that it is uncommon to prescribe antibiotics to patients without background disease after dental extraction. No appropriate Japanese guidelines exist considering the prevention of SPE causing severe pyothorax as in our case. The hematogenous spread of bacteria such as SPE caused by sepsis after tooth extraction thus requires more attended careful consideration in clinical practice if patients are to be properly protected against potentially serious complications.

  6. Molecularly imprinted solid-phase extraction in the analysis of agrochemicals.

    Science.gov (United States)

    Yi, Ling-Xiao; Fang, Rou; Chen, Guan-Hua

    2013-08-01

    The molecular imprinting technique is a highly predeterminative recognition technology. Molecularly imprinted polymers (MIPs) can be applied to the cleanup and preconcentration of analytes as the selective adsorbent of solid-phase extraction (SPE). In recent years, a new type of SPE has formed, molecularly imprinted polymer solid-phase extraction (MISPE), and has been widely applied to the extraction of agrochemicals. In this review, the mechanism of the molecular imprinting technique and the methodology of MIP preparations are explained. The extraction modes of MISPE, including offline and online, are discussed, and the applications of MISPE in the analysis of agrochemicals such as herbicides, fungicides and insecticides are summarized. It is concluded that MISPE is a powerful tool to selectively isolate agrochemicals from real samples with higher extraction and cleanup efficiency than commercial SPE and that it has great potential for broad applications.

  7. Rapid Conformational Analysis of Protein Drugs in Formulation by Hydrogen/Deuterium Exchange Mass Spectrometry (HDX-MS)

    DEFF Research Database (Denmark)

    Esmail Nazari, Zeinab; van de Weert, Marco; Bou-Assaf, George

    2016-01-01

    Hydrogen Deuterium Exchange coupled to Mass Spectrometry (HDX-MS) has become an established method for analysis of protein higher-order structure. Here, we use HDX-MS methodology based on manual Solid-Phase Extraction (SPE) to allow fast and simplified conformational analysis of proteins under...... pharmaceutically relevant formulation conditions. Of significant practical utility, the methodology allows global HDX-MS analyses to be performed without refrigeration or external cooling of the setup. In Mode 1, we used DMSO-containing solvents for SPE, allowing the HDX-MS analysis to be performed at acceptable...... in formulation, using an internal HDX reference peptide (P7I) to control for any sample-to-sample variations in back exchange. Advantages of the methodology include low sample use, optimized excipient removal using multiple solvents, and fast data acquisition. Our results indicate that the SPE-HDX-MS system can...

  8. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids.

    Science.gov (United States)

    Schellen, Anniek; Ooms, Bert; van de Lagemaat, Dick; Vreeken, Rob; van Dongen, William D

    2003-05-25

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS system were optimized in an integrated approach to maximize the application range and minimize the method development time. The optimized generic SPE-LC-MS/MS protocol was evaluated for 11 drugs with different physicochemical properties. Good quantification for 10 out of 11 of the pharmaceuticals in serum or plasma could be readily achieved. The quantitative assays gave recoveries better than 95%, lower quantification limits of 0.2-2.0 ng/ml, acceptable precision and accuracy and good linearity over 2-4 orders of magnitude. Carry-over was determined to be in the range of 0.02-0.10%, without optimization.

  9. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  10. Anti-Inflammatory Effects of Spirulina platensis Extract via the Modulation of Histone Deacetylases

    Directory of Open Access Journals (Sweden)

    Tho X. Pham

    2016-06-01

    Full Text Available We previously demonstrated that the organic extract of Spirulina platensis (SPE, an edible blue-green alga, possesses potent anti-inflammatory effects. In this study, we investigated if the regulation of histone deacetylases (HDACs play a role in the anti-inflammatory effect of SPE in macrophages. Treatment of macrophages with SPE rapidly and dose-dependently reduced HDAC2, 3, and 4 proteins which preceded decreases in their mRNA levels. Degradation of HDAC4 protein was attenuated in the presence of inhibitors of calpain proteases, lysosomal acidification, and Ca2+/calmodulin-dependent protein kinase II, respectively, but not a proteasome inhibitor. Acetylated histone H3 was increased in SPE-treated macrophages to a similar level as macrophages treated with a pan-HDAC inhibitor, with concomitant inhibition of inflammatory gene expression upon LPS stimulation. Knockdown of HDAC3 increased basal and LPS-induced pro-inflammatory gene expression, while HDAC4 knockdown increased basal expression of interleukin-1β (IL-1β, but attenuated LPS-induced inflammatory gene expression. Chromatin immunoprecipitation showed that SPE decreased p65 binding and H3K9/K14 acetylation at the Il-1β and tumor necrosis factor α (Tnfα promoters. Our results suggest that SPE increased global histone H3 acetylation by facilitating HDAC protein degradation, but decreases histone H3K9/K14 acetylation and p65 binding at the promoters of Il-1β and Tnfα to exert its anti-inflammatory effect.

  11. Constraining the sources and cycling of dissolved organic carbon in a large oligotrophic lake using radiocarbon analyses

    Science.gov (United States)

    Zigah, Prosper K.; Minor, Elizabeth C.; McNichol, Ann P.; Xu, Li; Werne, Josef P.

    2017-07-01

    We measured the concentrations and isotopic compositions of solid phase extracted (SPE) dissolved organic carbon (DOC) and high molecular weight (HMW) DOC and their constituent organic components in order to better constrain the sources and cycling of DOC in a large oligotrophic lacustrine system (Lake Superior, North America). SPE DOC constituted a significant proportion (41-71%) of the lake DOC relative to HMW DOC (10-13%). Substantial contribution of 14C-depleted components to both SPE DOC (Δ14C = 25-43‰) and HMW DOC (Δ14C = 22-32‰) was evident during spring mixing, and depressed their radiocarbon values relative to the lake dissolved inorganic carbon (DIC; Δ14C ∼ 59‰). There was preferential removal of 14C-depleted (older) and thermally recalcitrant components from HMW DOC and SPE DOC in the summer. Contemporary photoautotrophic addition to HMW DOC was observed during summer stratification in contrast to SPE DOC, which decreased in concentration during stratification. Serial thermal oxidation radiocarbon analysis revealed a diversity of sources (both contemporary and older) within the SPE DOC, and also showed distinct components within the HMW DOC. The thermally labile components of HMW DOC were 14C-enriched and are attributed to heteropolysaccharides (HPS), peptides/amide and amino sugars (AMS) relative to the thermally recalcitrant components reflecting the presence of older material, perhaps carboxylic-rich alicyclic molecules (CRAM). The solvent extractable lipid-like fraction of HMW DOC was very 14C-depleted (as old as 1270-2320 14C years) relative to the carbohydrate-like and protein-like substances isolated by acid hydrolysis of HMW DOC. Our data constrain relative influences of contemporary DOC and old DOC, and DOC cycling in a modern freshwater ecosystem.

  12. A dipole-assisted solid-phase extraction microchip combined with inductively coupled plasma-mass spectrometry for online determination of trace heavy metals in natural water.

    Science.gov (United States)

    Shih, Tsung-Ting; Hsu, I-Hsiang; Chen, Shun-Niang; Chen, Ping-Hung; Deng, Ming-Jay; Chen, Yu; Lin, Yang-Wei; Sun, Yuh-Chang

    2015-01-21

    We employed a polymeric material, poly(methyl methacrylate) (PMMA), for fabricating a microdevice and then implanted the chlorine (Cl)-containing solid-phase extraction (SPE) functionality into the PMMA chip to develop an innovative on-chip dipole-assisted SPE technique. Instead of the ion-ion interactions utilized in on-chip SPE techniques, the dipole-ion interactions between the highly electronegative C-Cl moieties in the channel interior and the positively charged metal ions were employed to facilitate the on-chip SPE procedures. Furthermore, to avoid labor-intensive manual manipulation, a programmable valve manifold was designed as an interface combining the dipole-assisted SPE microchip and inductively coupled plasma-mass spectrometry (ICP-MS) to achieve the fully automated operation. Under the optimized operation conditions for the established system, the detection limits for each analyte ion were obtained based on three times the standard deviation of seven measurements of the blank eluent solution. The limits ranged from 3.48 to 20.68 ng L(-1), suggesting that this technique appears uniquely suited for determining the levels of heavy metal ions in natural water. Indeed, a series of validation procedures demonstrated that the developed method could be satisfactorily applied to the determination of trace heavy metals in natural water. Remarkably, the developed device was durable enough to be reused more than 160 times without any loss in its analytical performance. To the best of our knowledge, this is the first study reporting on the combination of a dipole-assisted SPE microchip and elemental analysis instrument for the online determination of trace heavy metal ions.

  13. Multi-scale fracture damage associated with underground chemical explosions

    Science.gov (United States)

    Swanson, E. M.; Sussman, A. J.; Wilson, J. E.; Townsend, M. J.; Prothro, L. B.; Gang, H. E.

    2018-05-01

    Understanding rock damage induced by explosions is critical for a number of applications including the monitoring and verification of underground nuclear explosions, mine safety issues, and modeling fluid flow through fractured rock. We use core observations, televiewer logs, and thin section observations to investigate fracture damage associated with two successive underground chemical explosions (SPE2 and SPE3) in granitic rock at both the mesoscale and microscale. We compare the frequency and orientations of core-scale fractures, and the frequency of microfractures, between a pre-experiment core and three post-experiment cores. Natural fault zones and explosion-induced fractures in the vicinity of the explosive source are readily apparent in recovered core and in thin sections. Damage from faults and explosions is not always apparent in fracture frequency plots from televiewer logs, although orientation data from these logs suggests explosion-induced fracturing may not align with the pre-existing fracture sets. Core-scale observations indicate the extent of explosion-induced damage is 10.0 m after SPE2 and 6.8 m after SPE3, despite both a similar size and location for both explosions. At the microscale, damage is observed to a range distance of 10.2 ± 0.9 m after SPE2, and 16.6 ± 0.9 and 11.2 ± 0.6 in two different cores collected after SPE3. Additional explosion-induced damage, interpreted to be the result of spalling, is readily apparent near the surface, but only in the microfracture data. This depth extent and intensity of damage in the near-surface region also increased after an additional explosion. This study highlights the importance of evaluating structural damage at multiple scales for a more complete characterization of the damage, and particularly shows the importance of microscale observations for identifying spallation-induced damage.

  14. Oxidation reaction of polyether-based material and its suppression in lithium rechargeable battery using 4 V class cathode, LiNi1/3Mn1/3Co1/3O2.

    Science.gov (United States)

    Kobayashi, Takeshi; Kobayashi, Yo; Tabuchi, Masato; Shono, Kumi; Ohno, Yasutaka; Mita, Yuichi; Miyashiro, Hajime

    2013-12-11

    The all solid-state lithium battery with polyether-based solid polymer electrolyte (SPE) is regarded as one of next-generation lithium batteries, and has potential for sufficient safety because of the flammable-electrolyte-free system. It has been believed that polyether-based SPE is oxidized at the polymer/electrode interface with 4 V class cathodes. Therefore, it has been used for electric devices such as organic transistor, and lithium battery under 3 V. We estimated decomposition reaction of polyether used as SPE of all solid-state lithium battery. We first identified the decomposed parts of polyether-based SPE and the conservation of most main chain framework, considering the results of SPE analysis after long cycle operations. The oxidation reaction was found to occur slightly at the ether bond in the main chain with the branched side chain. Moreover, we resolved the issue by introducing a self-sacrificing buffer layer at the interface. The introduction of sodium carboxymethyl cellulose (CMC) to the 4 V class cathode surface led to the suppression of SPE decomposition at the interface as a result of the preformation of a buffer layer from CMC, which was confirmed by the irreversible exothermic reaction during the first charge, using electrochemical calorimetry. The attained 1500 cycle operation is 1 order of magnitude longer than those of previously reported polymer systems, and compatible with those of reported commercial liquid systems. The above results indicate to proceed to an intensive research toward the realization of 4 V class "safe" lithium polymer batteries without flammable liquid electrolyte.

  15. Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

    Science.gov (United States)

    Steinheimer, T.R.; Brooks, M.G.

    1984-01-01

    A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 ??g/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.A multi-residue method is described for the determination of triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0. 1 mu g/L in a 1-litre sample. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

  16. Source characterization of underground explosions from hydrodynamic-to-elastic coupling simulations

    Science.gov (United States)

    Chiang, A.; Pitarka, A.; Ford, S. R.; Ezzedine, S. M.; Vorobiev, O.

    2017-12-01

    A major improvement in ground motion simulation capabilities for underground explosion monitoring during the first phase of the Source Physics Experiment (SPE) is the development of a wave propagation solver that can propagate explosion generated non-linear near field ground motions to the far-field. The calculation is done using a hybrid modeling approach with a one-way hydrodynamic-to-elastic coupling in three dimensions where near-field motions are computed using GEODYN-L, a Lagrangian hydrodynamics code, and then passed to WPP, an elastic finite-difference code for seismic waveform modeling. The advancement in ground motion simulation capabilities gives us the opportunity to assess moment tensor inversion of a realistic volumetric source with near-field effects in a controlled setting, where we can evaluate the recovered source properties as a function of modeling parameters (i.e. velocity model) and can provide insights into previous source studies on SPE Phase I chemical shots and other historical nuclear explosions. For example the moment tensor inversion of far-field SPE seismic data demonstrated while vertical motions are well-modeled using existing velocity models large misfits still persist in predicting tangential shear wave motions from explosions. One possible explanation we can explore is errors and uncertainties from the underlying Earth model. Here we investigate the recovered moment tensor solution, particularly on the non-volumetric component, by inverting far-field ground motions simulated from physics-based explosion source models in fractured material, where the physics-based source models are based on the modeling of SPE-4P, SPE-5 and SPE-6 near-field data. The hybrid modeling approach provides new prospects in modeling explosion source and understanding the uncertainties associated with it.

  17. Multi-layer solid-phase extraction and evaporation-enrichment methods for polar organic chemicals from aqueous matrices.

    Science.gov (United States)

    Köke, Niklas; Zahn, Daniel; Knepper, Thomas P; Frömel, Tobias

    2018-03-01

    Analysis of polar organic chemicals in the aquatic environment is exacerbated by the lack of suitable and widely applicable enrichment methods. In this work, we assessed the suitability of a novel combination of well-known solid-phase extraction (SPE) materials in one cartridge as well as an evaporation method and for the enrichment of 26 polar model substances (predominantly log D evaporation method were investigated for the recovery and matrix effects of the model substances and analyzed with hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). In total, 65% of the model substances were amenable (> 10% recovery) to the mlSPE method with a mean recovery of 76% while 73% of the model substances were enriched with the evaporation method achieving a mean recovery of 78%. Target and non-target screening comparison of both methods with a frequently used reversed-phase SPE method utilizing "hydrophilic and lipophilic balanced" (HLB) material was performed. Target analysis showed that the mlSPE and evaporation method have pronounced advantages over the HLB method since the HLB material retained only 30% of the model substances. Non-target screening of a ground water sample with the investigated enrichment methods showed that the median retention time of all detected features on a HILIC system decreased in the order mlSPE (3641 features, median t R 9.7 min), evaporation (1391, 9.3 min), HLB (4414, 7.2 min), indicating a higher potential of the described methods to enrich polar analytes from water compared with HLB-SPE. Graphical abstract Schematic of the method evaluation (recovery and matrix effects) and method comparison (target and non-target analysis) of the two investigated enrichment methods for very polar chemicals in aqueousmatrices.

  18. An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

    OpenAIRE

    Sodré, Fernando F.; Locatelli, Marco Antonio F.; Jardim, Wilson F.

    2010-01-01

    A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...

  19. Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais An in-line clean system for the solid-phase extraction of emerging contaminants in natural waters

    Directory of Open Access Journals (Sweden)

    Fernando F. Sodré

    2010-01-01

    Full Text Available A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L using commercial solid-phase extraction (SPE cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus is robust and less expensive than the typical available system. Its also provides less experimental handling, avoiding cross contamination and sample losses.

  20. Screening and dereplication of microbial natural products extracts

    DEFF Research Database (Denmark)

    Månsson, Maria; Vynne, Nikolaj Grønnegaard; Wietz, Matthias

    expedition,1 we use a combination of chemical profiling2 and explorative solid-phase extraction (E-SPE)3 to assess the bacteria’s potential to produce new and interesting molecules. We found the use of chemical profiling by LC-UV/MS very useful for marine bacteria such as Vibrio4 and Pseudoalteromonas.5....... The chemical profile could be linked to a bioactivity profile using E-SPE,3 which through the use of three different ion-exchangers and a size-exclusion column gives information about the charge, size, and polarity of active components in an extract. This can be used to discriminate between possible candidates...

  1. Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

    Science.gov (United States)

    Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

    2016-04-01

    Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

  2. Targeting high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance analysis with high-resolution radical scavenging profiles - bioactive secondary metabolites from the endophytic fungus Penicillium namyslowskii

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Nyberg, Nils; Tejesvi, Mysore V.

    2013-01-01

    The high-resolution radical scavenging profile of an extract of the endophytic fungus Penicillium namyslowskii was used to target analysis by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC...... NMR probe designed for 1.7-mm NMR tubes. To further explore the potential of the above HPLC-HRMS-SPE-NMR platform for analysis of endophytic extracts, six peaks displaying no radical scavenging activity were also analyzed. This allowed unambiguous identification of six metabolites, i...... and griseofulvin, directly from crude extract via HPLC-HRMS-SPE-NMR. Dechlorodehydrogriseofulvin was reported for the first time from nature....

  3. Characteristic of New Solid-Phase Extraction Sorbent: Activated Carbon Prepared from Rice Husks under Base Treated Condition

    OpenAIRE

    Afrida Kurnia Putri; Wang-Hsien Ding; Han-Wen Kuo

    2012-01-01

    A characterization of activated carbon (ACs) prepared from rice husks (RHs) under base treated condition as a new sorbent for solid-phase extraction (SPE) to extract 4-nonylphenol isomers (4-NPs) in water samples has been done. The ACs prepared from RHs usually exhibits low specific surface area due to its high ash content, but in case of its application for SPE, there are other factors need to be considered, such as the existence of functional groups inside the sorbent, that can enhance inte...

  4. Dosimetric control on board the MIR space station during the solar proton events of September-October 1989

    International Nuclear Information System (INIS)

    Benghin, V.V.; Petrov, V.M.; Chernykh, I.V.; Teltsov, M.V.; Shumshurov, V.I.

    1992-01-01

    A set of dosimetric units for the control of radiation doses to cosmonauts on board the MIR space station contains an active dosimeter R-16 and a personal display dosimeter IPD-2. During the powerful solar proton events (SPE) in September-October 1989, the readings of these devices were used for the control of the crew's radiation damage. Results of the dose measurements and analysis of the dynamics caused by some heliogeophysical factors are given. It is shown that the total doses from SPE registered by the dosimeters R-16 and IPD-2 were 3.6 x 10 -2 and 0.9 x 10 -2 Gy, respectively. (author)

  5. Status of solid polymer electrolyte fuel cell technology and potential for transportation applications

    Science.gov (United States)

    McElroy, J. F.; Nuttall, L. J.

    The solid polymer electrolyte (SPE) fuel cell represents the first fuel cell technology known to be used operationally. Current activities are mainly related to the development of a space regenerative fuel cell system for energy storage on board space stations, or other large orbiting vehicles and platforms. During 1981, a study was performed to determine the feasibility of using SPE fuel cells for automotive or other vehicular applications, using methanol as the fuel. The results of this study were very encouraging. Details concerning a conceptual automotive fuel cell power plant study are discussed, taking into account also a layout of major components for compact passenger car installation.

  6. Validation of an semi-automated multi component method using protein precipitation LC-MS-MS for the analysis of whole blood samples

    DEFF Research Database (Denmark)

    Slots, Tina

    BACKGROUND: Solid phase extraction (SPE) are one of many multi-component methods, but can be very time-consuming and labour-intensive. Protein precipitation is, on the other hand, a much simpler and faster sample pre-treatment than SPE, and protein precipitation also has the ability to cover a wi......-mortem whole blood sample preparation for toxicological analysis; from the primary sample tube to a 96-deepwell plate ready for injection on the liquid chromatography mass spectrometry (LC-MS/MS)....

  7. Solid polymer electrolyte water electrolyser based on Nafion-TiO{sub 2} composite membrane for high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Baglio, V.; Antonucci, V.; Arico, A.S. [CNR-ITAE, Messina (Italy); Matteucci, F.; Martina, F.; Zama, I. [Tozzi Renewable Energy SpA, Mezzano (Italy); Ciccarella, G. [National Nanotechnology Laboratory (NNL) of INFM-CNR, Distretto Tecnologico ISUFI, Innovazione, Universita del Salento, Lecce (Italy); Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Queretaro Sanfandila (Mexico); Ornelas, R.

    2009-06-15

    A composite Nafion-TiO{sub 2} membrane was manufactured by a recast procedure, using an in-house prepared TiO{sub 2}. This membrane has shown promising properties for high temperature operation in an SPE electrolyser allowing to achieve higher performance with respect to a commercial Nafion 115 membrane. This effect is mainly due to the water retention properties of the TiO{sub 2} filler. A promising increase in electrical efficiency was recorded at low current densities for the composite membrane-based SPE electrolyser at high temperature compared to conventional membrane-based devices. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  8. [Hemostatic system parameters of placental extracts in normal pregnancy and severe preeclampsia].

    Science.gov (United States)

    López-Ramírez, Ysabel; Carvajal, Zoila; Arocha-Piñango, Carmen Luisa

    2006-09-01

    To better understand the role of the hemostatic mechanism in preeclampsia, placental extracts obtained from 26 normal pregnant women (NP) and 12 patients with severe pre-eclampsia (SPE) were analyzed to determine thrombomodulin (TM), tissue factor (TF), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor (PAI) 1 and 2, and TF pathway inhibitor (TFPI). The results showed similar concentrations of TF, TM and PAI-2 in both groups, while tPA increased no significantly and TFPI and PAI-1 increased significantly in SPE placentas.

  9. Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

    Science.gov (United States)

    Meyer, M.T.; Mills, M.S.; Thurman, E.M.

    1993-01-01

    An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

  10. Sistema limpo em linha para extração em fase sólida de contaminantes emergentes em águas naturais

    OpenAIRE

    Sodré,Fernando F.; Locatelli,Marco Antonio F.; Jardim,Wilson F.

    2010-01-01

    A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus i...

  11. From retrospective assessment to prospective decisions in natural product isolation

    DEFF Research Database (Denmark)

    Johansen, Kenneth T; Wubshet, Sileshi G; Nyberg, Nils T

    2011-01-01

    An extract of Carthamus oxyacantha (wild safflower) was investigated using two approaches: a traditional, nontarget fractionation by VLC and HPLC, and the hyphenated technique HPLC-PDA-HRMS-SPE-NMR followed by targeted isolation of selected constituents for inclusion in a screening library of pure......, HPLC-HRMS-guided, targeted isolation scheme aiming exclusively at a series of identified spiro compounds. Thus, HPLC-PDA-HRMS-SPE-NMR is a dereplication technique of choice, allowing economical acquisition of comprehensive data about compounds in crude extracts, which can be used for rational...

  12. Fases fluoradas como sorventes para extração em fase sólida de pesticidas e compostos perfluorados

    OpenAIRE

    Cristiane Vidal

    2015-01-01

    Resumo: Fases sólidas fluoradas apresentam características oriundas das propriedades da ligação C-F, como o alto momento de dipolo e a baixa polarizabilidade e isto confere seletividades peculiares a elas. Existem diversas fases estacionárias alquilperfluoradas e fenilperfluoradas comerciais para cromatografia líquida, entretanto, a oferta de fases sólidas fluoradas para extração em fase sólida (SPE) é menor. Assim, este trabalho descreve um novo método de SPE utilizando uma fase fluorada pre...

  13. Preconcentrate of thorium in solid phase and its direct determination by X-ray fluorescence in natural waters

    International Nuclear Information System (INIS)

    Carvalho, Marcelo S. de; Domingues, Maria de Lourdes F.; Mantovano, Jose Luiz; Cunha, Jose Waldemar S.D. da

    2000-01-01

    This paper describe a methodology to pre concentrate thorium from natural water samples by using solid phase extraction (SPE) before its direct determination by X-ray fluorescence. Polyurethane foam supporting 2- ethyl hexyl phosfonic acid was used as SPE. The extraction was maximum at 0.25 mol/L in hydrochloric acid, for 30 minutes of shaking time. At least 8 mg/L thorium could be determined what allowed us to apply this methodology successfully for determination of thorium in natural water reference samples. (author)

  14. Toxicity of organic chemical pollution in groundwater downgradient of a landfill (Grindsted, Denmark)

    DEFF Research Database (Denmark)

    Baun, Anders; Jensen, S. D.; Bjerg, Poul Løgstrup

    2000-01-01

    The aim of the present study was to describe the occurrence and distribution of toxicity related to organic chemical contaminants in the leachate plume downgradient of the Grindsted Landfill (Denmark). A total of 27 groundwater samples were preconcentrated by solidphase extraction (SPE) using XAD-2...... bioassays, it was concluded that SPE extracts of groundwater collected close to the landfill were toxic. The toxicity decreased with the distance from the landfill. At distances greater than 80 m from the border of the landfill, the groundwater toxicity was not significantly different from the background...... characterization and hazard ranking of groundwater polluted with complex chemical mixtures, such as landfill leachates....

  15. Danske mejere - en fauna i vækst

    DEFF Research Database (Denmark)

    Enghoff, Henrik; Pedersen, Jan; Toft, Søren

    2014-01-01

    Since 1985 the num ber of harvestmen spe cies re corded from Den mark has grown from 17 to 25. The new spe cies and the year of their first Dan ish re cord are: Opilio canestrinii (Thorell, 1876) – 1985; Lacinius horridus (Pan zer, 1794) – 1994; Odiellus spinosus (Bosc, 1792) – 2006; Dicranopalpus...... tisciae Avram, 1968 (= L. rupestre auct.) in Den mark; and Nemastoma dentigerum Canestrini, 1873, N. bimaculatum (Fabricius, 1775), Lacinius dentiger (C.L. Koch, 1848), Leiobunum limbatum L. Koch, 1861, and Nelima doriae (Canestrini, 1871) are men tioned as can di dates for fu ture dis cov er ies...

  16. Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    da Silva, Filipa; Støttrup, Josianne Gatt; Kjørsvik, Elin

    2016-01-01

    Farmed female eels were fed two experimental diets with similar proximate composition but different n-3 polyunsaturated fatty acid (PUFA) levels. Both diets had similar levels of arachidonic acid (ARA), while levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in one diet were...... approximately 4.5 and 2.6 times higher compared to the other diet, respectively. After the feeding period, each diet group was divided into two and each half received one of two hormonal treatments using salmon pituitary extract (SPE) for 13 weeks: i) a constant hormone dose of 18.75mg SPE/kg initial body...

  17. Hydrogen-bromine fuel cell advance component development

    Science.gov (United States)

    Charleston, Joann; Reed, James

    1988-01-01

    Advanced cell component development is performed by NASA Lewis to achieve improved performance and longer life for the hydrogen-bromine fuel cells system. The state-of-the-art hydrogen-bromine system utilizes the solid polymer electrolyte (SPE) technology, similar to the SPE technology developed for the hydrogen-oxygen fuel cell system. These studies are directed at exploring the potential for this system by assessing and evaluating various types of materials for cell parts and electrode materials for Bromine-hydrogen bromine environment and fabricating experimental membrane/electrode-catalysts by chemical deposition.

  18. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol [Gyeongsang National University Hospital, Jinju (Korea, Republic of)] (and others)

    2006-05-15

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration ({rho} < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn ({rho} < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules

  19. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    International Nuclear Information System (INIS)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol

    2006-01-01

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration (ρ < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn (ρ < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules or

  20. Development of magnetic micro-solid phase extraction for analysis of phthalate esters in packaged food.

    Science.gov (United States)

    Makkliang, Fonthip; Kanatharana, Proespichaya; Thavarungkul, Panote; Thammakhet, Chongdee

    2015-01-01

    A novel, simple and low cost magnetic multi-walled carbon nanotubes-poly (vinyl alcohol) cryogel-micro-solid phase extraction (magnetic-MWCNTs-PVA cryogel-μ-SPE) sorbent was synthesized by incorporating magnetic particles and MWCNTs into a PVA cryogel. The magnetic-MWCNTs-PVA cryogel-μ-SPE sorbent developed, with a large surface area and macro-porous structure, provided good sorbent-to-sorbent reproducibility (%RSDclear chicken soup samples in the range 0.02-0.07 μg mL(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The development and application of solid polymer electrolysis enrichment device of tritium in water

    International Nuclear Information System (INIS)

    Wen Xuelian; Yang Hailan Wu Bin; Yang Huaiyuan

    2003-01-01

    This paper briefly describes the working principle of solid polymer electrolysis enrichment device of tritium in water, presents experiments and works in development of SPE tritium automatic electrolysis enrichment device by CIRP, with which the water samples had been processed for TRIC2000, and the measurement results are satisfied

  2. A rapid and validated HPLC method to quantify sphingosine 1-phosphate in human plasma using solid-phase extraction followed by derivatization with fluorescence detection

    NARCIS (Netherlands)

    Butter, Jan J.; Koopmans, Richard P.; Michel, Martin C.

    2005-01-01

    We describe the development and validation of analytical methodology for the determination of sphingosine 1-phosphate (S1P) in plasma. It uses solid-phase extraction (SPE) followed by an automated reversed-phase gradient HPLC column-switching system with a pre-column derivatization with

  3. Process-based species pools reveal the hidden signature of biotic interactions amid the influence of temperature filtering

    DEFF Research Database (Denmark)

    Lessard, Jean-Philippe; Weinstein, Ben G.; Borregaard, Michael Krabbe

    2016-01-01

    A persistent challenge in ecology is to tease apart the in-fluence of multiple processes acting simultaneously and interacting in complex ways to shape the structure of species assemblages. We implement a heuristic approach that relies on explicitly defining spe-cies pools and permits assessment ...

  4. Analysis of microcontaminants in aqueous samples by fully automated on-line solid-phase extraction-gas chromatography-mass selective detection.

    NARCIS (Netherlands)

    Louter, A.J.H.; van Beekvelt, C.A.; Cid Montanes, P.; Slobodník, J.; Vreuls, J.J.; Brinkman, U.A.T.

    1996-01-01

    The trace-level analysis of unknown organic pollutants in water requires the use of fast and sensitive methods which also provide structural information. In the present study, an on-line technique was used which combines sample preparation by means of solid-phase extraction (SPE) on a small

  5. Bio-Activity and Dereplication-Based Discovery of Ophiobolins and Other Fungal Secondary Metabolites Targeting Leukemia Cells

    DEFF Research Database (Denmark)

    Bladt, Tanja Thorskov; Dürr, Claudia; Knudsen, Peter Boldsen

    2013-01-01

    The purpose of this study was to identify and characterize fungal natural products (NPs) with in vitro bioactivity towards leukemia cells. We based our screening on a combined analytical and bio-guided approach of LC-DAD-HRMS dereplication, explorative solid-phase extraction (E-SPE), and a co...

  6. Development of an analytical methodology for the determination of the antiparasitic drug toltrazuril and its two metabolites in surface water, soil and animal manure

    DEFF Research Database (Denmark)

    Olsen, Jesper; Björklund, Erland; Krogh, Kristine A

    2012-01-01

    ... with an EC 50 of 3.16 mg L ‚àí1 for toltrazuril [9]. Due to toltrazurils frequent usage ... a LC-MS/MS methodology to determine toltrazuril , toltrazuril sulfoxide and toltrazuril sulfone in ... SPE), and in agricultural soil, animal manure and sediment using pressurized liquid extraction ( PLE ). ...

  7. Susceptibility of Bunch Grape and Muscadine Cultivars to Berry Splitting and Spotted-Wing Drosophila Oviposition

    Science.gov (United States)

    One of the main disorders that widely reduces fruit quality and commercial value is fruit splitting. Fruit splitting is a physiological disorder that produces surface cracks that promotes disease and insect damage. Moreover, the spotted wing Drosophila (SWD), Drosophila suzukii (Matsumura), is a spe...

  8. Current referral practices and adolescent transition to Adult clinic ...

    African Journals Online (AJOL)

    2016-02-02

    Feb 2, 2016 ... is either one of transfer to adult services, long term retention ... care in the type and level of support, decision-making, ... of Pediatrics (AAP), the American Academy of Family ... cians (ACP) issued a joint statement that defined spe- ... other countries attending Paediatric Association of ..... Diabetes Manage-.

  9. Distribution and protection of endemic or threatened rodents ...

    African Journals Online (AJOL)

    highest in the south-western parts of the country, and hotspots of endemism cOincide with those of species rich- ness. However, Red ... species richness hotspot in the Succulent Karoo contains no existing reserves, whereas all Red Data Book spe- ... conserve all aspects of biodiversity, but of historical ad hoc decisions ...

  10. Identification of the western tarnished plant bug (lygus hesperus) olfactory co-receptor orco: expression profile and confirmation of atypical membrane topology

    Science.gov (United States)

    Lygus hesperus (western tarnished plant bug) is an agronomically important pest species of numerous cropping systems. Similar to other insects, a critical component underlying behaviors is the perception and discrimination of olfactory cues. Consequently, the molecular basis of olfaction in this spe...

  11. AFRREV LALIGENS

    African Journals Online (AJOL)

    First Lady

    syllables” (104). The syllable is important to this study because it is the domain for the ... Words. Segments/sounds. Syllable Structure. Eye/ I. /aɪ/. V. Pay. /peɪ/. CV. Spay. /speɪ/ ..... click clap; tick tock; lash/lush;flash/flush, etc. In many cases ...

  12. Recent developments in the rapid analysis of plants and tracking their bioactive constituents

    NARCIS (Netherlands)

    Beek, van T.A.; Tetala, K.K.R.; Koleva, I.; Dapkevicius, A.; Exarchou, V.; Jeurissen, S.M.F.; Claassen, F.W.; Klift, van der E.J.C.

    2009-01-01

    Natural products chemistry has witnessed many new developments in the last 5 years like extractions with subcritical water and ionic liquids, LC/HRMS and LC/SPE/cryo-NMR, UHPLC, TLC/MS, MS-based preparative HPLC, comprehensive chromatography (GC × GC, LC × LC), high-throughput screening,

  13. Thermophysical Modeling of Contact Binary Near-Earth Asteroid 1996 HW1

    NARCIS (Netherlands)

    Magri, C.; Howell, E. S.; Nolan, M. C.; Taylor, P. A.; Fernández, Y. R.; Mueller, M.; Rivkin, A. S.; Vervack, R. J., Jr.

    2011-01-01

    Near-Earth asteroid (8567) 1996 HW1 was observed spectroscopically at 1.9-4.0 microns during August- October 2008 using the SpeX instrument at NASA's Infrared Telescope Facility (IRTF). These spectra are being modeled using a new thermophysical program that accounts for the object's spin orientation

  14. Partial chord diagrams and matrix models

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Fuji, Hiroyuki; Manabe, Masahide

    In this article, the enumeration of partial chord diagrams is discussed via matrix model techniques. In addition to the basic data such as the number of backbones and chords, we also consider the Euler characteristic, the backbone spectrum, the boundary point spectrum, and the boundary length spe...

  15. 49 CFR 391.49 - Alternative physical qualification standards for the loss or impairment of limbs.

    Science.gov (United States)

    2010-10-01

    ..., and date signed. Depending upon the motor carrier's organizational structure (corporation, partnership... for which SPE certificate is requested. (2) Description of the type of operation the driver will be... will be driving and/or on duty, per day; (iii) Type of commodities or cargo to be transported; (iv...

  16. Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide ...

    Indian Academy of Sciences (India)

    lenovo

    Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide: Phosphorus containing polyethers for. Li‒ion conductivities. Heeralal Vignesh Babu, Billakanti Srinivas and Krishnamurthi Muralidharan*. School of Chemistry, University of Hyderabad, Hyderabad - 500046, India. Table of Contents. TGA plots of SPE2.

  17. Some laws governing the electrosynthesis of organic compounds with a solid polymetric electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rodionova, N.A.; Avrutskaya, I.A.; Fioshin, M. Ya.; Khrizolitova, M.A.

    1986-01-01

    The electrosynthesis of organic compounds with a solid polymetric electrolyte (SPE) makes it possible to carry out the process in the absence of a supporting electrolyte. This facilitates the recovery of the desired product, eliminates the inorganic waste products, and allows a small interelectrode distance, and the absence of the accumulation of gases lowers the voltage in the cell. Some laws governing syntheses of SPE were studied in the example cases of the electrochemical reduction of 2,2,6,6-tetramethyl-4-oxopiperidine to 2,2,6,6-tetramethyl-4-hydroxy-piperidine, the reduction of triacetonamine oxime and triacetonamine azine to 2,2,6,6-tetramethyl-4- aminopiperidine and the oxidation of isobutanol to isobutyric acid. The electrolysis with an SPE was carried out under galvanostatic conditions in an electrolyzer of the filter-press type with forced circulation of the catholyte and anolyte. Low reaction rates are found to be characteristic of all the compounds investigated when the electrolysis is carried out with an SPE.

  18. A manpower policy for primary health care: report of a study

    National Research Council Canada - National Science Library

    1978-01-01

    ... and Resources Development REPORT OF A STUDY May 1978 NATIONAL ACADEMY of SCIENCES Washington, D.C. i Copyrightthe true use are Please breaks Page inserted. accidentally typesetting been have may original the from errors not the retained, typographic book, paper some original from created cannot however, be files XML from recomposed formatting, been typesetting-spe...

  19. Determination of nanomolar chromate in drinking water with solid phase extraction and a portable spectrophotometer.

    Science.gov (United States)

    Ma, Jian; Yang, Bo; Byrne, Robert H

    2012-06-15

    Determination of chromate at low concentration levels in drinking water is an important analytical objective for both human health and environmental science. Here we report the use of solid phase extraction (SPE) in combination with a custom-made portable light-emitting diode (LED) spectrophotometer to achieve detection of chromate in the field at nanomolar levels. The measurement chemistry is based on a highly selective reaction between 1,5-diphenylcarbazide (DPC) and chromate under acidic conditions. The Cr-DPC complex formed in the reaction can be extracted on a commercial C18 SPE cartridge. Concentrated Cr-DPC is subsequently eluted with methanol and detected by spectrophotometry. Optimization of analytical conditions involved investigation of reagent compositions and concentrations, eluent type, flow rate (sample loading), sample volume, and stability of the SPE cartridge. Under optimized conditions, detection limits are on the order of 3 nM. Only 50 mL of sample is required for an analysis, and total analysis time is around 10 min. The targeted analytical range of 0-500 nM can be easily extended by changing the sample volume. Compared to previous SPE-based spectrophotometric methods, this analytical procedure offers the benefits of improved sensitivity, reduced sample consumption, shorter analysis time, greater operational convenience, and lower cost. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Direct anthelmintic effects of a purified chicory extract against free-living stages of Cooperia oncophora: preliminary results

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Williams, A.; Enemark, Heidi L.

    2013-01-01

    with methanol as the extraction medium. The resulting extract was dried and fractionated using solid-phase extraction (SPE) cartridges to enhance isolation of secondary metabolites such as sesquiterpene lactones. The obtained elutate was dried, dissolved in 100 % DMSO and serially diluted to obtain...

  1. Cleanup and analysis of sugar phosphates in biological extracts by using solid phase extraction and anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Smith, Hans Peter; Cohen, A.; Buttler, T.

    1998-01-01

    of Saccharomyces cerevisiae obtained by using cold methanol as quenching agent and chloroform as extraction solvent. It was shown that pretreatment of the cell extract with SPE markedly improved the quality of the liquid chromatography analysis with recoveries of the sugar phosphates close to 100%. Furthermore...

  2. Kinetics of pressure induced structural phase transitions—A review

    Indian Academy of Sciences (India)

    Unknown

    The experimental technique using the diamond anvil cell (DAC) and image processing gets spe- cial mention as it promises to impart a new .... cal picture of the microscopic changes accompanying a transition. In fact, the major strides made ... 1983, 1986; Vohra et al 1986; Mao et al 1990; Yousuf. 1998). Also, in shock wave ...

  3. Synthesis of iron nanoparticles with poly(1-vinylpyrrolidone-co-vinyl acetate) and its application to nitrate reduction

    DEFF Research Database (Denmark)

    Lee, Nara; Choi, Kyunghoon; Uthuppu, Basil

    2014-01-01

    This study aimed to synthesize dispersed and reactive nanoscale zero-valent iron (nZVI) with poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP/VA), nontoxic and biodegradable stabilizer. The nZVI used for the experiments was prepared by reduction of ferric solution in the presence of PVP/VA with spe...

  4. Phytosterol conjugation in cold-storage apple fruit is linked to oxidative stress and ripening

    Science.gov (United States)

    Low temperature stress is implicated in a wide-range of apple fruit postharvest necrotic disorders. Previously, untargeted metabolic profiling identified alterations in multiple metabolic processes that precede superficial scald symptom development. Metabolites with free sterol (FS) –like mass spe...

  5. Phytosterol conjugation in cold-stored apple fruit is linked to oxidative stress and ripening

    Science.gov (United States)

    Low temperature stress is implicated in a wide-range of apple fruit postharvest necrotic disorders. Previously, untargeted metabolic profiling identified alterations in multiple metabolic processes that precede superficial scald symptom development. Metabolites with free sterol (FS) –like mass spe...

  6. Trace-level mercury ion (Hg2+) analysis in aqueous sample based on solid-phase extraction followed by microfluidic immunoassay.

    Science.gov (United States)

    Date, Yasumoto; Aota, Arata; Terakado, Shingo; Sasaki, Kazuhiro; Matsumoto, Norio; Watanabe, Yoshitomo; Matsue, Tomokazu; Ohmura, Naoya

    2013-01-02

    Mercury is considered the most important heavy-metal pollutant, because of the likelihood of bioaccumulation and toxicity. Monitoring widespread ionic mercury (Hg(2+)) contamination requires high-throughput and cost-effective methods to screen large numbers of environmental samples. In this study, we developed a simple and sensitive analysis for Hg(2+) in environmental aqueous samples by combining a microfluidic immunoassay and solid-phase extraction (SPE). Using a microfluidic platform, an ultrasensitive Hg(2+) immunoassay, which yields results within only 10 min and with a lower detection limit (LOD) of 0.13 μg/L, was developed. To allow application of the developed immunoassay to actual environmental aqueous samples, we developed an ion-exchange resin (IER)-based SPE for selective Hg(2+) extraction from an ion mixture. When using optimized SPE conditions, followed by the microfluidic immunoassay, the LOD of the assay was 0.83 μg/L, which satisfied the guideline values for drinking water suggested by the United States Environmental Protection Agency (USEPA) (2 μg/L; total mercury), and the World Health Organisation (WHO) (6 μg/L; inorganic mercury). Actual water samples, including tap water, mineral water, and river water, which had been spiked with trace levels of Hg(2+), were well-analyzed by SPE, followed by microfluidic Hg(2+) immunoassay, and the results agreed with those obtained from reduction vaporizing-atomic adsorption spectroscopy.

  7. Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic flourescence spectrometry

    Science.gov (United States)

    Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydrid...

  8. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    ... to their several spe- cial properties such as large thermal expansion coefficients, ... increase the conductivity of these glasses is to increase the modifier or dopant ... phosphate glasses were measured by the a.c. impedance spectroscopic .... and Fe2O3-doped Ag2O–P2O5 glasses were determined from. DSC curves and ...

  9. 77 FR 841 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to U.S. Navy Operations of...

    Science.gov (United States)

    2012-01-06

    ... and the Single Ping Equivalent (SPE) To model potential impacts to marine animals from exposure to... Atmospheric Administration 50 CFR Part 218 Taking and Importing Marine Mammals: Taking Marine Mammals... [Docket No. 110808485-1534-01] RIN 0648-BB14 Taking and Importing Marine Mammals: Taking Marine Mammals...

  10. 1ST International Conference on Small Satellites: New Technologies, Achievements, Problems and Prospects for International Co-Operation in the New Millenium

    Science.gov (United States)

    1998-01-01

    degradation , and to detect, track and map airborne contaminants. Spe- cific, environmentally-directed science objectives of the RAMOS program include the ...Northeast Northeast Cerrado , Northeast Amazon, Northeast Amazon, Northeast Amazon In order to fulfill these applications, the SSR will carry an...efficiency and lack of coordination of the conservancy activity, a significant environmental degradation has been occurring. Industry-developed regions

  11. “Mapping the regional variation in potential vulnerability in Indian ...

    African Journals Online (AJOL)

    GREG

    namely, Bio-Physical vulnerability index and Socio-Economic vulnerability index to develop the final overall vulnerability index. ... Agriculture is the backbone of Indian economy more spe- cifically of the rural livelihood security system. ... of the total workforce) in spite of the diversification of eco- nomic activity. It is also an ...

  12. Toward Molecular Magnets of Organic Origin via Anion-π Interaction Involving m-Aminyl Diradical: A Theoretical Study

    DEFF Research Database (Denmark)

    Bhattacharya, Debojit; Shil, Suranjan; Misra, Anirban

    2016-01-01

    Here we study a set of novel magnetic organic molecular species with different halide ions (fluoride, chloride, bromide) absorbed ∼2 Å above or below the center of an aromatic π-ring in an m-aminyl diradical. Focus is on the nature of anion-π interaction and its impact on magnetic properties, spe...

  13. TIMP2 gene polymorphisms are associated with hypertension in ...

    Indian Academy of Sciences (India)

    2014-08-06

    Aug 6, 2014 ... 5Epidemiologic and Health Service Research Unit, Again Area, Centro Médico Nacional Siglo XXI,. Instituto ... TIMPs are proteins of 21 to 30 kDa and belong to a family of spe- ... characterized-clinical cohort of Mexican Mestizo patients. We also ... 200 mg/dL and/or low-density lipoprotein cholesterol ≥.

  14. Simultaneous determination of naproxen, ibuprofen and diclofenac ...

    African Journals Online (AJOL)

    2017-04-02

    Apr 2, 2017 ... of non-steroidal anti-inflammatory drugs (NSAIDs). ... human metabolism, followed by excretion in urine and faeces ... Overdose or chronic abuse of NSAIDs can lead to toxic ... During SPE, the pH of wastewater samples was adjusted to 2.5; then 100 mL .... and stored in the refrigerator (4°C) until analysis.

  15. A direct mining approach to efficient constrained graph pattern discovery

    DEFF Research Database (Denmark)

    Zhu, Feida; Zhang, Zequn; Qu, Qiang

    2013-01-01

    Despite the wealth of research on frequent graph pattern mining, how to efficiently mine the complete set of those with constraints still poses a huge challenge to the existing algorithms mainly due to the inherent bottleneck in the mining paradigm. In essence, mining requests with explicitly-spe...

  16. Blood plasma sample preparation method to determine thyroid hormone-disrupting compounds in Effect-Directed Analysis

    NARCIS (Netherlands)

    Simon, E.; Bytingsvik, J.; Jonker, W.; Leonards, P.E.G.; de Boer, J.; Jenssen, B.M.; Lie, E.; Aars, J.; Hamers, T.H.M.; Lamoree, M.H.

    2011-01-01

    A sample preparation method combining solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was developed to be used in Effect-Directed Analysis (EDA) of blood plasma. Until now such a method was not available. It can be used for extraction of a broad range of thyroid hormone

  17. A SIMPLE AND FAST EXTRACTION METHOD FOR ORGANOCHLORINE PESTICIDES AND POLYCHLORINATED BIPHENYLS IN SMALL VOLUMES OF AVIAN SERUM

    Science.gov (United States)

    A solid-phase extraction (SPE) method was developed using 8 M urea to desorb and extract organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) from avian serum for analysis by capillary gas chromatography with electron capture detection (GC-ECD). The analytes were ...

  18. A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants.

    Science.gov (United States)

    Heub, Sarah; Tscharner, Noe; Kehl, Florian; Dittrich, Petra S; Follonier, Stéphane; Barbe, Laurent

    2016-01-01

    A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17β-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 µl of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

  19. Spectrum of spontaneous photon emission as a promising biophysical indicator for breast cancer research.

    Science.gov (United States)

    Zhao, Xiaolei; Yang, Meina; Wang, Yong; Pang, Jingxiang; Wijk, Eduard Van; Liu, Yanli; Fan, Hua; Zhang, Liewei; Han, Jinxiang

    2017-10-12

    In this study, we investigated the spectral characteristics of Spontaneous Photon Emission (SPE) from the body surface of a human breast cancer-bearing nude mice model during the overall growth process of breast cancers. By comparing and analyzing the data, we found that there was a striking difference between tumor mice and healthy controls in the spectral distribution of SPE from the body surface of lesion site, even when the morphological changes at the lesion site were not obvious. The spectral distribution of SPE from the healthy site of the tumor mice also differed from that of the healthy controls as the breast cancer developed to a certain stage. In addition, the difference in spectrum was related with different growth states of tumors. Interestingly, there was a positive correlation between the spectral ratio (610-630/395-455 nm) and the logarithm of the tumor volume for both the lesion site (R 2  = 0.947; p spectrum of SPE was sensitive to changes in the tumor status.

  20. Linear sweep anodic stripping voltammetry: Determination of ...

    Indian Academy of Sciences (India)

    The aim of this work is to determine Cr(VI) in water resources by anodic stripping voltammetry using SPE-. AuNPs modified electrode .... surface area about 4 fold). 3.2 Optimization of Parameters ..... in water samples. The above system offers a.

  1. Selective posterior lumbosacral rhizotomy for the management ...

    African Journals Online (AJOL)

    tion in 95% of cases. The majority showed ... selective posterior rhizotomy technique whereby the cauda equina ... assessed pre- and postoperatively by means of clinical examination ... were attending cerebral palsy schools and receiving spe- cialised ... root sections on cats demonstrated clearly that posterior root section ...

  2. Section Preequating under the Equivalent Groups Design without IRT

    Science.gov (United States)

    Guo, Hongwen; Puhan, Gautam

    2014-01-01

    In this article, we introduce a section preequating (SPE) method (linear and nonlinear) under the randomly equivalent groups design. In this equating design, sections of Test X (a future new form) and another existing Test Y (an old form already on scale) are administered. The sections of Test X are equated to Test Y, after adjusting for the…

  3. Gas chromatographic determination of acid herbicides in surface water samples with electron-capture detection and mass spectrometric confirmation

    NARCIS (Netherlands)

    Vink, M.; Poll, J.M. van der

    1996-01-01

    The development of a multi-residue method for the determination of eight polar acidic herbicides (MCPA, MCPB, mecoprop, 2,4-D, dichlorprop, bentazone, dicamba and dikegulac) in surface water is described. The method involves an off-line solid-phase extraction (SPE) procedure prior to instrumental

  4. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, M.; Mulder, P.P.J.; Bire, R.; Hess, P.; Boer, de J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC¿MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  5. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, A. M.; Mulder, P.P.J.; Bire, L.; Hess, P.; de Boer, J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  6. Comparing the IRT Pre-equating and Section Pre-equating: A Simulation Study.

    Science.gov (United States)

    Hwang, Chi-en; Cleary, T. Anne

    The results obtained from two basic types of pre-equatings of tests were compared: the item response theory (IRT) pre-equating and section pre-equating (SPE). The simulated data were generated from a modified three-parameter logistic model with a constant guessing parameter. Responses of two replication samples of 3000 examinees on two 72-item…

  7. Residue analysis of sixty pesticides in red swamp crayfish using QuEChERS with high-performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    In this study, a multi-residue analytical method using QuEChERS extraction and dispersive solid-phase extraction (d-SPE) cleanup followed by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) was developed for rapid determination of 60 pesticide residues in whole crayfish a...

  8. Molecularly imprinted solid-phase extraction for selective extraction of bisphenol analogues in beverages and canned food.

    Science.gov (United States)

    Yang, Yunjia; Yu, Jianlong; Yin, Jie; Shao, Bing; Zhang, Jing

    2014-11-19

    This study aimed to develop a selective analytical method for the simultaneous determination of seven bisphenol analogues in beverage and canned food samples by using a new molecularly imprinted polymer (MIP) as a sorbent for solid-phase extraction (SPE). Liquid chromatography coupled to triple-quadruple tandem mass spectrometry (LC-MS/MS) was used to identify and quantify the target analytes. The MIP-SPE method exhibited a higher level of selectivity and purification than the traditional SPE method. The developed procedures were further validated in terms of accuracy, precision, and sensitivity. The obtained recoveries varied from 50% to 103% at three fortification levels and yielded a relative standard deviation (RSD, %) of less than 15% for all of the analytes. The limits of quantification (LOQ) for the seven analytes varied from 0.002 to 0.15 ng/mL for beverage samples and from 0.03 to 1.5 ng/g for canned food samples. This method was used to analyze real samples that were collected from a supermarket in Beijing. Overall, the results revealed that bisphenol A and bisphenol F were the most frequently detected bisphenols in the beverage and canned food samples and that their concentrations were closely associated with the type of packaging material. This study provides an alternative method of traditional SPE extraction for screening bisphenol analogues in food matrices.

  9. Associating Changes in Endogenous Metabolite Profiles of Field-Deployed Fish with Chemical Contaminants and Other Stressors

    Science.gov (United States)

    Assessing risk from contaminant exposure in the aquatic environment typically begins (and often ends) with identification of “listed” chemicals in water samples. While providing useful information about potential exposures, this approach to monitoring – in the absence of site-spe...

  10. Impact of storm events on the structure of a stream microbiome

    Science.gov (United States)

    The microbial structural and/or functional state in a stream community is assumed to be in relative stasis until a perturbation (e.g., runoff event with entrained pollutants) affects the community structure and its functional state. Quantifying these changes and resolving the spe...

  11. Pyogenic Liver Abscess Associated with Septic Pulmonary Embolism

    Directory of Open Access Journals (Sweden)

    Por-Wen Yang

    2008-09-01

    Conclusion: There is diagnostic value in performing a chest CT scan in diabetic patients who have liver abscess plus abnormal CXR findings with multiple ill-defined peripheral round densities, in order to detect SPE, which has a relatively poor outcome in patients with liver abscess.

  12. Surface wave propagation in a double liquid layer over a liquid ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. The frequency equation is derived for surface waves in a liquid- saturated porous half-space supporting a double layer, that of inhomogeneous and homogeneous liquids. Asymptotic approximations of Bessel functions are used for long and short wavelength cases. Certain other problems are discussed as spe-.

  13. Combinatorial enzyme technology: Conversion of pectin to oligo species and its effect on microbial growth

    Science.gov (United States)

    Plant cell wall polysaccharides, which consist of polymeric backbones with various types of substitution, were studied using the concept of combinatorial enzyme technology for conversion of agricultural fibers to functional products. Using citrus pectin as the starting substrate, an active oligo spe...

  14. Enhancing the performance of green solid-state electric double-layer capacitor incorporated with fumed silica nanoparticles

    Science.gov (United States)

    Chong, Mee Yoke; Numan, Arshid; Liew, Chiam-Wen; Ng, H. M.; Ramesh, K.; Ramesh, S.

    2018-06-01

    Solid polymer electrolyte (SPE) based on fumed silica nanoparticles as nanofillers, hydroxylethyl cellulose (HEC) as host polymer, magnesium trifluoromethanesulfonate salt and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid is prepared by solution casting technique. The ionic conductivity, interactions of adsorbed ions on the host polymer, structural crystallinity and thermal stability are evaluated by electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Ionic conductivity studies at room temperature reveals that the SPE with 2 wt. % of fumed silica nanoparticles gives the highest conductivity compared to its counterpart. The XRD and FTIR studies confirm the dissolution of salt, ionic liquid and successful incorporation of fumed silica nanoparticles with host polymer. In order to examine the performance of SPEs, electric double-layer capacitor (EDLC) are fabricated by using activated carbon electrodes. EDLC studies demonstrate that SPE incorporated with 2 wt. % fumed silica nanoparticles gives high specific capacitance (25.0 F/g) at a scan rate of 5 mV/s compared to SPE without fumed silica. Additionally, it is able to withstand 71.3% of capacitance from its initial capacitance value over 1600 cycles at a current density of 0.4 A/g.

  15. Trace-level determination of polar flavour compounds in butter by solid-phase extraction and gas chromatography-mass spectrometry.

    NARCIS (Netherlands)

    Adahchour, M.; Vreuls, J.J.; van der Heijden, A.; Brinkman, U.A.T.

    1999-01-01

    Volatile compounds are responsible for the aromas of butter. A simple technique for the determination of these components is described which is based on solid-phase extraction (SPE) after melting of the butter and separation of the aqueous phase from the fat. Volatile flavours present in the water

  16. Solid-phase extraction of carotenoids.

    Science.gov (United States)

    Shen, Yao; Hu, Yumin; Huang, Ke; Yin, Shi'an; Chen, Bo; Yao, Shouzhuo

    2009-07-24

    In this work, solid-phase extraction (SPE) trapping performance of lutein and beta-carotene, which were used as the model molecules of carotenoids, was investigated. The absorption, elution, and enrichment of carotenoids on SPE cartridges with four different sorbents, i.e. C(30), C(18), diol, and silica, were compared respectively with the help of frontal analysis technique. The high retentions of both lutein and beta-carotene were achieved on the C(18) and C(30) cartridges. The diol and silica cartridges only had good retention for lutein. The optimized SPE method for sample pretreatment for the carotenoids analysis was obtained after the investigation of trapping performance. The method was applied successfully to the analysis of biological sample, i.e. serum and human breast milk. The recovery, accuracy, and precision of SPE method comparing with those of traditional liquid-liquid extraction (LLE) method for the sample pretreatment for the analysis of carotenoids owned a number of advantages such as rapid, no chloroform used, and accurate versus LLE.

  17. Empowered interaction through creativity

    DEFF Research Database (Denmark)

    Hasselblad, Stefan; Petersson, Eva; Brooks, Tony

    2007-01-01

    This paper reflects upon a case study where exploration, play and empowerment in interactive therapy sessions with audio and visual stimuli resulted in achievement, self-esteem and a shared pride between a young adult with profound and multiple learning disabilities (PMLD), his mother and the spe...

  18. Lithium ion conducting PVA:PVdF polymer electrolytes doped with nano SiO2 and TiO2 filler

    Science.gov (United States)

    Hema, M.; Tamilselvi, P.

    2016-09-01

    The effect of nano SiO2 and TiO2 fillers on the thermal, mechanical and electrochemical properties of PVA:PVdF:LiCF3SO3 have been investigated by three optimized systems of SPE (80PVA:20PVdF:15LiCF3SO3), CPE-I (SPE:8SiO2) and CPE-II (SPE:4TiO2). From the TGA curve least weight loss has been observed for CPE-II indicating high thermal stability compared to other systems. Stress-strain curve of the prepared samples confirm the enhancement of tensile strength in CPE-II compared to CPE-I and SPE. Conductivity studies show that addition of TiO2 filler slightly enhances ionic conductivity 3.7×10-3 S cm-1 compared to filler free system at 303 K. Dielectric plots have been analyzed and CPE-II possesses higher dielectric constant compared to CPE-I and filler free system. Temperature dependence of modulus plots has been studied for highest conductivity possessing sample. Wider electrochemical stability has been obtained for nano-composite polymer electrolytes. The results conclude that the prepared CPE-II shows the best performance and it will be well suited for lithium ion batteries.

  19. Project Execution Plan Project 98L-EWW-460 Plutonium Stabilization and Handling DOE No. 98-D-453

    International Nuclear Information System (INIS)

    HOLSTEIN, W.A.

    1999-01-01

    This Project Execution Plan (PEP) describes the management methods and responsibilities of the project participants. Project W-460 is sufficiently large to warrant a stand alone PEP. This project specific PEP describes the relationships and responsibilities of the project team and identifies the technical, schedule, and cost baselines that have been established for the project. The Department of Energy (DOE), Hanford Works (Hanford), at Richland, WA., currently does not have a system capable of stabilizing or packaging large quantities of plutonium-bearing solids to meet DOE technical standard DOE-STD-3013-96. This project will allow Hanford to meet this standard by installing stabilization and packaging equipment (SPE). The SPE is capable of stabilizing and packaging the current inventory of greater than 50 percent plutonium-bearing materials currently stored in the Plutonium Finishing Plant's (PFP) vaults into 3013 storage containers. The scope of this project is to procure and install the SPE via a Hanford contract and coordination with the Savannah River Site. In addition, the project will modify PFP vaults and upgrade the PFP Laboratory measurement systems. The Facility infrastructure will be modified to support the new SPE system and the new standardized storage container configuration. Use of this document is described in the Project Hanford Policy and Procedure System under HNF-PRO-1999, Construction Program Conceptual Phase

  20. Project Execution Plan Project 98L-EWW-460 Plutonium Stabilization and Handling DOE 98-D-453

    International Nuclear Information System (INIS)

    MCGRATH, G.M.

    2000-01-01

    This Project Execution Plan (PEP) describes the management methods and responsibilities of the project participants. Project W-460 is sufficiently large to warrant a stand alone PEP. This project specific PEP describes the relationships and responsibilities of the project team and identifies the technical, schedule, and cost baselines that have been established for the project. The Department of Energy (DOE), Hanford Works (Hanford), at Richland, Wa. currently does not have a system capable of stabilizing or packaging large quantities of plutonium-bearing solids to meet DOE technical standard DOE-STD-3013-99. This project will allow Hanford to meet this standard by installing stabilization and packaging equipment (SPE). The SPE is capable of stabilizing and packaging the current inventory of greater than 30 percent plutonium-bearing materials currently stored in the Plutonium Finishing Plant's (PFP) vaults into 3013 storage containers. The scope of this project is to procure and install the SPE via a Hanford contract and coordination with the Savannah River Site. In addition, the project will modify PFP vaults and upgrade the PFP Laboratory measurement systems. The Facility infrastructure will be modified to support the new SPE system and the new standardized storage container configuration

  1. Making Conditional Cash Transfer Programs More Efficient : Designing for Maximum Effect of the Conditionality

    OpenAIRE

    de Janvry, Alain; Sadoulet, Elisabeth

    2006-01-01

    Conditional cash transfer programs are now used extensively to encourage poor parents to increase investments in their children's human capital. These programs can be large and expensive, motivating a quest for greater efficiency through increased impact of the programs' imposed conditions on human capital formation. This requires designing the programs' targeting and calibration rules spe...

  2. Effects of alternative cryoprotectants, diluents, straw size and cholesterol addition on cryopreserved rooster sperm

    Science.gov (United States)

    Rooster sperm do not cryopreserve well. This is due in part to osmotic changes that sperm undergo during addition and removal of cryoprotectant (CPA), as well as membrane damage during the membrane phase transition from fluid at 37 degrees C to gel at low temperatures. When a CPA is removed from spe...

  3. Validated method for the detection and quantitation of synthetic ...

    African Journals Online (AJOL)

    These methods were applied to postmortem cases from the Johannesburg Forensic Pathology Services Medicolegal Laboratory (FPS-MLL) to assess the prevalence of these synthetic cannabinoids amongst the local postmortem population. Urine samples were extracted utilizing a solid phase extraction (SPE) method, ...

  4. Determination of phenolic derivatives of antipyrine in plasma with solid-phase extraction and high-performance liquid chromatography-atmospheric-pressure chemical ionization mass spectrometry

    NARCIS (Netherlands)

    Coolen, S.A.J.; Ligor, T.; Lieshout, van H.P.M.; Huf, F.A.

    1999-01-01

    This manuscript describes a method to determine antipyrine and its phenolic derivatives in plasma by reversed-phase high-performance liquid chromatography–mass spectrometry (RP-HPLC–MS). The sample pretreatment consisted of a C18 solid-phase extraction (SPE), to remove the salts and proteins. The

  5. Demonstration of visualization techniques for the control room engineer in 2030

    DEFF Research Database (Denmark)

    Marinelli, Mattia; Heussen, Kai; Strasser, Thomas

    2017-01-01

    Deliverable 8.1 reports results on analytics and visualizations of real time flexibility in support of voltage and frequency control in 2030+ power system. The investigation is carried out by means of relevant control room scenarios in order to derive the appropriate analytics needed for each spe...

  6. Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples.

    Science.gov (United States)

    Chan, Sue Hay; Lee, Warren; Asmawi, Mohd Zaini; Tan, Soo Choon

    2016-07-01

    A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Medical Students' Acquisition of Adolescent Interview Skills after Coached Role Play.

    Science.gov (United States)

    Kaul, Paritosh; Fisher, Jennifer H; Hanson, Janice L

    2018-04-01

    To develop and evaluate an educational activity designed to teach the adolescent Home, Education and employment, Eating, Activities, Drugs, Sexuality, Suicide/depression, and Safety (HEADS) examination. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Participants were third-year medical students in their pediatric clerkships. Students received an article on the HEADS interview and attended an adolescent medicine educational session. The session included individualized goal-setting and coached role play. Students' skills in doing a HEADS interview were evaluated through a standardized patient encounter (SPE) with a checklist and a retrospective pre- and post-test survey. The SPE checklist was used to assess whether the students included questions in 6 key areas of a HEADS interview. One hundred fifty-two students participated. During the SPE, 90% of students queried the adolescent's home life, 91% education, 82% activities, 84% drug/substance abuse, 95% sexual history, and 61% symptoms of depression. Pre- and postintervention data were compared using the Kruskal-Wallis Test and showed a statistically significant difference in the students' ability to list key topic areas of the HEADS exam (P interview using the HEADS exam (P interview during a SPE. Only three-fifths of the students, however, included questions about symptoms of depression. Coached role play with goal-setting facilitated effective learning of this approach to adolescent interviewing. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  8. High sensitive multiresidue analysis of pharmaceuticals and antifungals in surface water using U-HPLC-Q-Exactive Orbitrap HRMS. Application to the Danube river basin on the Romanian territory

    NARCIS (Netherlands)

    Chitescu, C.L.; Kaklamanos, George; Nicolau, A.I.; Stolker, Linda

    2015-01-01

    The occurrence of 67 pharmaceutical and antifungal residues in the Danube river on the Romanian territory was studied by using solid-phase extraction (SPE) and LC-Q Exactive Orbitrap high resolution MS in both full scan (FS) MS and targeted MS/MS modes. A single-laboratory validation procedure

  9. Polycyclic aromatic hydrocarbons (PAH) in Danish barbecued meat

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Aaslyng, Margit Dall; Meinert, Lene

    2015-01-01

    Barbecuing is known to result in the formation of polycyclic aromatic hydrocarbons (PAHs). A validated method that employed pressurized liquid extraction (PLE), gel permeation chromatography (GPC) followed by solid phase extraction (SPE) on Silica and analytical determination by GC-MS was applied...

  10. Comparison of Pseudomonas aeruginosa isolates from mink by serotyping and pulsed-field gel electrophoresis

    DEFF Research Database (Denmark)

    Hammer, Anne Sofie; Pedersen, Karl; Andersen, Thomas Holmen

    2003-01-01

    Isolates of Pseudomonas aeruginosa from clinical infections in mink were subjected to serotyping and pulsed-field gel electrophoresis (PFGE) using SpeI. A total of 212 isolates of P aeruginosa from the year 1998 to 2001 were included in this study: 168 isolates from mink obtained from 74 farm out...

  11. The T cell response to major grass allergens is regulated and includes IL-10 production in atopic but not in non-atopic subjects

    DEFF Research Database (Denmark)

    Domdey, A; Liu, A; Millner, A

    2010-01-01

    The incidence of allergic diseases is increasing in industrialized countries and the immunological mechanisms leading to tolerance or allergy are poorly understood. Cytokines with suppressive abilities and CD4(+)CD25(+) regulatory T cells have been suggested to play a central role in allergen-spe...

  12. Acoustic propagations in the presence of a subsurface cold core eddy in the Bay of Bengal - A case study

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Navelkar, G.S.; Murty, T.V.R.; Murty, C.S.

    Acoustic characteristics of a cold core eddy, observed in the Bay of Bengal during southwest monsoon period is studied using CTD data along the western boundary. The presence of eddy brings about a reduction in the ambient sound speEd. by 10 m.s sup...

  13. Electrophoresis test prevalence, requesting patterns, yield and ...

    African Journals Online (AJOL)

    Most of the appropriate SPE test requests were from clinical haematology, renal ... implementation of principles of demand management and the ... electrophoresis (IFE)) in a South African (SA) pathology laboratory setting are limited. Objectives. ... (NHLS) hospital information system database from 1 July 2010 to. 30 June ...

  14. Evaluation of a new carbon/zirconia-based sorbent for the cleanup of food extracts in multiclass analysis of pesticides and environmental contaminants

    Science.gov (United States)

    A novel carbon/zirconia based material, SupelTM QuE Verde (Verde), was evaluated in a filter-vial dispersive solid phase extraction (d-SPE) cleanup of QuEChERS extracts of pork, salmon, kale, and avocado for residual analysis of pesticides and environmental contaminants. Low pressure (LP) GC-MS/MS w...

  15. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC

  16. Liquid chromatography tandem mass spectrometry method using solid-phase extraction and bead-beating-assisted matrix solid-phase dispersion to quantify the fungicide tebuconazole in controlled frog exposure study: analysis of water and animal tissue

    DEFF Research Database (Denmark)

    Hansen, Martin; Poulsen, Rikke; Luong, Xuan

    2014-01-01

    and on tissue from exposed and non-exposed adult X. laevis. Using solid-phase extraction (SPE), the analytical method allows for quantification of tebuconazole at concentrations as low as 3.89 pg mL(-1) in 10 mL water samples. Using bead-beating-assisted matrix solid-phase dispersion (MSPD), it was possible...

  17. Sorption behavior of charged and neutral polar organic compounds on solid phase extraction materials: which functional group governs sorption?

    NARCIS (Netherlands)

    Bäuerlein, P.S.; Mansell, J.E.; ter Laak, T.L.; de Voogt, P.

    2012-01-01

    Numerous polar anthropogenic organic chemicals have been found in the aqueous environment. Solid phase extraction (SPE) has been applied for the isolation of these from aqueous matrices, employing various materials. Nevertheless, little is known about the influence of functional groups on the

  18. Multiplexed Colorimetric Solid-Phase Extraction

    Science.gov (United States)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  19. Utilizing thin-film solid-phase extraction to assess the effect of organic carbon amendments on the bioavailability of DDT and dieldrin to earthworms

    Science.gov (United States)

    Improved approaches are needed to rapidly and accurately assess the bioavailability of persistent, hydrophobic organic compounds in soils at contaminated sites. The performance of a thin-film solid-phase extraction (TF-SPE) assay using vials coated with ethylene vinyl acetate polymer was compared to...

  20. Technical note: New applications for on-line automated solid phase extraction

    OpenAIRE

    MacFarlane, John D.

    1997-01-01

    This technical note explains the disadvantages of manual solid phase extraction (SPE) techniques and the benefits to be gained with automatic systems. The note reports on a number of general and highly specific applications using the Sample Preparation Unit OSP-2A.

  1. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  2. Core-shell indium (III) sulfide@metal-organic framework nanocomposite as an adsorbent for the dispersive solid-phase extraction of nitro-polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Jia, Yuqian; Zhao, Yanfang; Zhao, Mei; Wang, Zhenhua; Chen, Xiangfeng; Wang, Minglin

    2018-05-25

    A core-shell discoid shaped indium (III) sulfide@metal-organic framework (MIL-125(Ti)) nanocomposite was synthesized by a solvothermal method and explored as an adsorbent material for dispersive solid-phase extraction (d-SPE). The as-synthesized sorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, powder X-ray diffraction, N 2 adsorption-desorption analysis, and Fourier transform infrared spectroscopy. The extraction performance was evaluated by the d-SPE of 16 nitro-polycyclic aromatic hydrocarbons (NPAHs) from water samples. The analysis was carried out by gas chromatography (GC) coupled with triple quadruple mass spectrometer in negative chemical ionization (NCI) mode. The selected ion monitoring (SIM) was used in the quantification of the target NPAHs. Extraction factors affecting the d-SPE, including the ionic strength, extraction temperature, and extraction time were optimized by the response surface methodology. The developed d-SPE method showed good linear correlations from 10 to 1000 ng L -1 (r > 0.99), low detection limits (2.9-83.0 ng L -1 ), satisfactory repeatability (relative standard deviation of <10%, n = 6), and acceptable recoveries (71.3%-112.2%) for water samples. The developed method was used for the food and environmental sample analysis. The results demonstrated that the method could be used for sample preparation of trace NPAHs in real samples. Copyright © 2018. Published by Elsevier B.V.

  3. Streamlined sample cleanup using combined dispersive solid-phase extraction and in-vial filtration for analysis of pesticides and environmental pollutants in shrimp

    Science.gov (United States)

    A new method of sample preparation was developed and is reported for the first time. The approach combines in-vial filtration with dispersive solid-phase extraction (d-SPE) in a fast and convenient cleanup of QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts. The method was appli...

  4. An LC-MS Assay with Isocratic Separation and On-Line Solid Phase Extraction to Improve the Routine Therapeutic Drug Monitoring of Busulfan in Plasma

    Directory of Open Access Journals (Sweden)

    Ialongo Cristiano

    2017-04-01

    Full Text Available Background: Busulfan (Bu requires therapeutic drug monitoring (TDM in subjects undergoing a conditioning regimen for hematopoietic stem cell transplantation (HSCT. To speed up the procedure and increase reproducibility, we improved our routine LC-MS/MS assay using the on-line solid-phase extraction (SPE of samples.

  5. Serum protein profiling by miniaturized solid-phase extraction and matrix-assisted laser desorption/ionization mass spectrometry

    DEFF Research Database (Denmark)

    Callesen, Anne K; Mohammed, Shabaz; Bunkenborg, Jakob

    2005-01-01

    for translation of MALDI-MS based diagnostic methods to clinical applications. We have investigated a number of MALDI matrices and several miniaturized solid-phase extraction (SPE) methods for serum protein concentration and desalting with the aim of generating reproducible, high-quality protein profiles by MALDI...

  6. Multifunctional silver nanoparticle-doped silica for solid-phase extraction and surface-enhanced Raman scattering detection

    Science.gov (United States)

    Markina, Natalia E.; Markin, Alexey V.; Zakharevich, Andrey M.; Gorin, Dmitry A.; Rusanova, Tatiana Yu.; Goryacheva, Irina Yu.

    2016-12-01

    Multifunctional silica gel with embedded silver nanoparticles (SiO2-AgNP) is proposed for application as sorbent for solid-phase extraction (SPE) and simultaneously as substrate for surface-enhanced Raman spectroscopy (SERS) due to their high sorption properties and ability to enhance Raman signal (SERS-active sorbents). SiO2-AgNP was synthesized via alkaline hydrolysis of tetraethyl orthosilicate with simultaneous reduction of silver ions to silver nanoparticles (AgNP) within the SiO2 bulk. Synthesis of AgNP directly to the SiO2 matrix enables to exclude any additional stabilizers for the nanoparticles that educes signal-to-noise ratio during SERS measurement. Apart from Raman spectroscopy, obtained sorbents were also characterized by scanning electron microscopy and UV-visible diffuse reflectance spectroscopy. The influence of AgNO3 concentration used during the SiO2-AgNP synthesis on its gelling time, color, diffuse reflectance spectra, and enhancement of Raman signal was investigated. A Raman enhancement factor of SiO2-AgNP with optimal composition was around 105. Finally, the sorbents were applied for SPE and subsequent SERS detection of model compounds (rhodamine 6G and folic acid). It was found that SPE enables to decrease detectable concentrations by two orders. Therefore, SPE combined with SERS has high potential for further analytical investigations.

  7. Solid-phase extraction of polar pesticides from environmental water samples on graphitized carbon and Empore-activated carbon disks and on-line coupling to octadecyl-bonded silica analytical columns.

    NARCIS (Netherlands)

    Slobodník, J.; Oztekizan, O.; Lingeman, H.; Brinkman, U.A.T.

    1996-01-01

    The suitability of Empore-activated carbon disks (EACD), Envi-Carb graphitized carbon black (GCB) and CPP-50 graphitized carbon for the trace enrichment of polar pesticides from water samples was studied by means of off-line and on-line solid-phase extraction (SPE). In the off-line procedure, 0.5-2

  8. after solid phase extraction on modified sawdust s

    African Journals Online (AJOL)

    Preferred Customer

    extraction (SPE) techniques are widely used for the determination of trace metal ions in aqueous samples, because ... adsorption resin [16] and modified activated carbon [17]. ... washed with distilled water, and dried in oven at 40 ºC for 24 h.

  9. Production of unusual dispiro metabolites in Pestalotiopsis virgatula endophyte cultures

    DEFF Research Database (Denmark)

    Kesting, Julie Regitze; Olsen, Lars; Stærk, Dan

    2011-01-01

    supported by time-dependent density-functional theory calculations (B3LYP/TZVP level). This work demonstrates that a largely complete structure elucidation of numerous metabolites present in a raw fermentation medium extract can be performed by the HPLC-SPE-NMR technique using only a small amount...

  10. Observation of the Spin Peltier Effect for Magnetic Insulators

    NARCIS (Netherlands)

    Flipse, J.; Dejene, F.K.; Wagenaar, D.; Bauer, G.E.W.; Ben Youssef, J.; Van Wees, B.J.

    2014-01-01

    We report the observation of the spin Peltier effect (SPE) in the ferrimagnetic insulator yttrium iron garnet (YIG), i.e., a heat current generated by a spin current flowing through a platinum (Pt)|YIG interface. The effect can be explained by the spin transfer torque that transforms the spin

  11. Screen-Printed Carbon Electrodes Modified with Cobalt Phthalocyanine for Selective Sulfur Detection in Cosmetic Products

    Directory of Open Access Journals (Sweden)

    Ying Shih

    2011-06-01

    Full Text Available Cobalt phthalocyanine (CoPc films were deposited on the surface of a screen-printed carbon electrode using a simple drop coating method. The cyclic voltammogram of the resulting CoPc modified screen-printed electrode (CoPc/SPE prepared under optimum conditions shows a well-behaved redox couple due to the (CoI/CoII system. The CoPc/SPE surface demonstrates excellent electrochemical activity towards the oxidation of sulfur in a 0.01 mol·L−1 NaOH. A linear calibration curve with the detection limit (DL, S/N = 3 of 0.325 mg·L−1 was achieved by CoPc/SPE coupled with flow injection analysis of the sulfur concentration ranging from 4 to 1120 mg·L−1. The precision of the system response was evaluated (3.60% and 3.52% RSD for 12 repeated injections, in the range of 64 and 480 mg·L−1 sulfur. The applicability of the method was successfully demonstrated in a real sample analysis of sulfur in anti-acne creams, and good recovery was obtained. The CoPc/SPE displayed several advantages in sulfur determination including easy fabrication, high stability, and low cost.

  12. Tandem Solid Phase Extraction for the Determination of Pharmaceuticals in Wastewater

    International Nuclear Information System (INIS)

    Licaberth Ismail; Rozita Osman; Norashikin Saim

    2013-01-01

    In this study, a simple and rapid tandem solid phase extraction (SPE) was developed for the analysis of seven pharmaceuticals (acetaminophen, caffeine, carbamazepine, diclofenac, naproxen, ibuprofen and metaprolol) in wastewater sample. The novel aspect of coupling SPE cartridge in tandem is the ability to simplify the SPE procedure (sample introduction step) as no single sorbent was able to retain and concentrate all selected compounds since these compounds are of different physicochemical properties. A tandem SPE cartridges using Oasis HLB and octadecyl bonded silica (C 18 ) was found to be efficient with the advantages of minimizing sample volume and reducing analysis time. Using this approach, carbamazepine, diclofenac, naproxen and metaprolol were trapped in the Oasis HLB while acetaminophen, caffeine and ibuprofen were trapped in the second cartridge (C 18 ). The instrumental limits of detection (LOD) ranged from 0.01 to 0.04 μg/ L and satisfactory recoveries were obtained between 76 % to 104 %. The calibration curves were linear from 0.1 to 5.0 μg/ mL, with correlation coefficients (R 2 ) in the range of 0.995 to 0.999. The developed method was applied to the analysis of pharmaceuticals in wastewater samples. The amount of pharmaceuticals detected in wastewater samples varied from 0.4 to 24.5 mg/ L. (author)

  13. Electrochemical Behavior and Determination of Chlorogenic Acid Based on Multi-Walled Carbon Nanotubes Modified Screen-Printed Electrode

    Directory of Open Access Journals (Sweden)

    Xiaoyan Ma

    2016-10-01

    Full Text Available In this paper, the multi-walled carbon nanotubes modified screen-printed electrode (MWCNTs/SPE was prepared and the MWCNTs/SPE was employed for the electrochemical determination of the antioxidant substance chlorogenic acids (CGAs. A pair of well-defined redox peaks of CGA was observed at the MWCNTs/SPE in 0.10 mol/L acetic acid-sodium acetate buffer (pH 6.2 and the electrode process was adsorption-controlled. Cyclic voltammetry (CV and differential pulse voltammetry (DPV methods for the determination of CGA were proposed based on the MWCNTs/SPE. Under the optimal conditions, the proposed method exhibited linear ranges from 0.17 to 15.8 µg/mL, and the linear regression equation was Ipa (µA = 4.1993 C (×10−5 mol/L + 1.1039 (r = 0.9976 and the detection limit for CGA could reach 0.12 µg/mL. The recovery of matrine was 94.74%–106.65% (RSD = 2.92% in coffee beans. The proposed method is quick, sensitive, reliable, and can be used for the determination of CGA.

  14. Miniaturized solid-phase extraction of macrolide antibiotics in honey and bovine milk using mesoporous MCM-41 silica as sorbent.

    Science.gov (United States)

    Du, Li-Jing; Yi, Ling; Ye, Li-Hong; Chen, Yu-Bo; Cao, Jun; Peng, Li-Qing; Shi, Yu-Ting; Wang, Qiu-Yan; Hu, Yu-Han

    2018-02-16

    A simple and effective method of miniaturized solid-phase extraction (mini-SPE) was developed for the simultaneous purification and enrichment of macrolide antibiotics (MACs) (i.e. azithromycin, clarithromycin, erythromycin, lincomycin and roxithromycin) from honey and skim milk. Mesoporous MCM-41 silica was synthesized and used as sorbent in mini-SPE. Several key parameters affecting the performance of mini-SPE procedure were thoroughly investigated, including sorbent materials, amount of sorbent and elution solvents. Under the optimized condition, satisfactory linearity (r 2  > 0.99), acceptable precision (RSDs, 0.3-7.1%), high sensitivity (limit of detection in the range of 0.01-0.76 μg/kg), and good recoveries (83.21-105.34%) were obtained. With distinct advantages of simplicity, reliability and minimal sample requirement, the proposed mini-SPE procedure coupled with ultrahigh performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry could become an alternative tool to analyze the residues of MACs in complex food matrixes. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Long-term degradation of chemical structures and mechanical properties in polyethylene induced by ion-beam irradiation

    International Nuclear Information System (INIS)

    Oka, T.; Hama, Y.

    2004-01-01

    The long-term degradation in polyethylene irradiated with ion beams was studied. We found the changes of the chemical structures and the mechanical properties with time storage. S-PE has a good resistance to ion-beam irradiation because the crystallinity and density were very low. (author)

  16. Multifunctional silver nanoparticle-doped silica for solid-phase extraction and surface-enhanced Raman scattering detection

    Energy Technology Data Exchange (ETDEWEB)

    Markina, Natalia E.; Markin, Alexey V., E-mail: av-markin@mail.ru; Zakharevich, Andrey M.; Gorin, Dmitry A.; Rusanova, Tatiana Yu.; Goryacheva, Irina Yu. [Saratov State University (Russian Federation)

    2016-12-15

    Multifunctional silica gel with embedded silver nanoparticles (SiO{sub 2}–AgNP) is proposed for application as sorbent for solid-phase extraction (SPE) and simultaneously as substrate for surface-enhanced Raman spectroscopy (SERS) due to their high sorption properties and ability to enhance Raman signal (SERS-active sorbents). SiO{sub 2}–AgNP was synthesized via alkaline hydrolysis of tetraethyl orthosilicate with simultaneous reduction of silver ions to silver nanoparticles (AgNP) within the SiO{sub 2} bulk. Synthesis of AgNP directly to the SiO{sub 2} matrix enables to exclude any additional stabilizers for the nanoparticles that educes signal-to-noise ratio during SERS measurement. Apart from Raman spectroscopy, obtained sorbents were also characterized by scanning electron microscopy and UV-visible diffuse reflectance spectroscopy. The influence of AgNO{sub 3} concentration used during the SiO{sub 2}–AgNP synthesis on its gelling time, color, diffuse reflectance spectra, and enhancement of Raman signal was investigated. A Raman enhancement factor of SiO{sub 2}–AgNP with optimal composition was around 10{sup 5}. Finally, the sorbents were applied for SPE and subsequent SERS detection of model compounds (rhodamine 6G and folic acid). It was found that SPE enables to decrease detectable concentrations by two orders. Therefore, SPE combined with SERS has high potential for further analytical investigations.

  17. LC-UV-solid-phase extraction-NMR-MS combined with a cryogenic flow probe and its application to the identification of compounds present in Greek oregano

    NARCIS (Netherlands)

    Exarchou, V.; Godejohann, M.; Beek, van T.A.; Gerothanassis, I.P.; Vervoort, J.J.M.

    2003-01-01

    Structure elucidation of natural products usually relies on a combination of NMR spectroscopy with mass spectrometry whereby NMR trails MS in terms of the minimum sample amount required. In the present study, the usefulness of on-line solid-phase extraction (SPE) in LC-NMR for peak storage after the

  18. Determination of phenprocoumon in plasma and urine using at-line solid-phase extraction-capillary electrophoresis.

    NARCIS (Netherlands)

    Veraart, J.R.; Gooijer, C.; Lingeman, H.; Velthorst, N.H.; Brinkman, U.A.T.

    1998-01-01

    The use of capillary electrophoresis (CE) for the analysis of biological samples is rather problematic because of the large number of interferences present in the matrix. One of the possibilities to solve such problems is to couple solid-phase extraction (SPE) at-line with CE, a technique developed

  19. ORF Alignment: NC_003280 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_003280 gi|25149956 >1tx4A 1 170 679 853 1e-24 ... gb|AAN38752.1| axon identity spe...form b ... [Caenorhabditis elegans] ref|NP_495592.2| SYnapse ... Defective SYD-1, axon identity

  20. Extraction and characterization of radish seed oils using different ...

    African Journals Online (AJOL)

    Purpose: To evaluate the impact of three different extraction methods on oil yield, physicochemical properties and bioactive ingredients of radish seeds. Methods: Radish seed oil was prepared by traditional solvent extraction (SE), supercritical carbon dioxide extraction (SCE) and sub-critical propane extraction (SPE).