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Sample records for lynn mass direct

  1. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  2. Travels with Lynn: June 2010

    Science.gov (United States)

    hotel in Ottawa, June 14, 2010. DoD photo by Cherie Cullen Related Links Biography: William J. Lynn III growing, and affects national and economic security, Deputy Defense Secretary William J. Lynn III said Lynn Meets With Canadian Leaders Deputy Defense Secretary William J. Lynn III takes questions from

  3. Direct neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Weinheimer, Christian, E-mail: weinheimer@uni-muenster.de [Westfaelische Wilhelms-Universitaet, Institut fuer Kernphysik (Germany)

    2013-03-15

    Direct neutrino mass experiments are complementary to searches for neutrinoless double {beta}-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c{sup 2} . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c{sup 2} by increasing strongly the statistics and-at the same time-reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium {beta}-decay experiments cryo-bolometers investigating the endpoint region of {sup 187}Re {beta}-decay or the electron capture of {sup 163}Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.

  4. Current Direct Neutrino Mass Experiments

    Directory of Open Access Journals (Sweden)

    G. Drexlin

    2013-01-01

    Full Text Available In this contribution, we review the status and perspectives of direct neutrino mass experiments, which investigate the kinematics of β-decays of specific isotopes (3H, 187Re, 163Ho to derive model-independent information on the averaged electron (antineutrino mass. After discussing the kinematics of β-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re. We then describe the Karlsruhe Tritium Neutrino (KATRIN experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.. To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium β-decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

  5. Direct measurements of neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Holzschuh, E [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    The direct measurements have so far given no indication for a nonzero (positive) mass of any of the three known neutrinos. The experiments measuring the tau and the muon neutrino are good shape. The tritium experiments are in an unfortunate situation. It is unclear to me whether the problems are experimental or theoretical or a combination of both. The electronic final states distribution have been calculated, but the results have never been tested experimentally. The most important question to be answered is about the validity of the sudden approximation. (author) 9 figs., 2 tabs., 16 refs.

  6. Direct measurements of neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1991-01-01

    Some recent developments in the experimental search for neutrino mass are discussed. New data from Los Alamos on the electron neutrino mass as measured in tritium beta decay give an upper limit of 9.3 eV at the 95% confidence level. This result is not consistent with the long-standing ITEP result of 26(5) eV within a ''model-independent'' range of 17 to 40 eV. It now appears that the electron neutrino is not sufficiently massive to close the universe by itself. Hime and Jelley report finding new evidence for a 17-keV neutrino in the Β decay of 35 S and 63 Ni. Many other experiments are being reported and the situation is still unresolved. 56 refs., 1 fig., 3 tabs

  7. Simultaneous mass detection for direct inlet mass spectrometry

    International Nuclear Information System (INIS)

    Gordon, R.L.

    1979-05-01

    The evolution of analytical techniques for application in trace analysis has led to interest in practical methods for real-time monitoring. Direct inlet mass spectrometry (DIMS) has been the subject of considerable activity in recent years. A DIMS instrument is described which consists of an inlet system designed to permit particles entrained in the inlet air stream to strike a hot, oxidized rhenium filament which serves as a surface ionization source. A mass analyzer and detection system then permits identification of the elemental composition of particulates which strike the filament

  8. AFSC/ABL: Lynn Canal Overwinter Acoustic Survey, 2004-2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

  9. AFSC/ABL: Lynn Canal Echo-Integrated Trawl Surveys, 2001-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The acoustic trawl database for Lynn Canals echo-trawl survey was conducted from 2001 to 2004 throughout southern Lynn Canal in southeast Alaska. Acoustic surveys...

  10. A critical review of Richard Lynn's reports on reaction time and race.

    Science.gov (United States)

    Thomas, Drew M

    2011-01-01

    In the early 1990s, psychologist Richard Lynn published papers documenting average reaction times and decision times in samples of nine-year-olds taken from across the world. After summarizing these data, Lynn interpreted his results as evidence of national and racial differences in decision time and general intelligence. Others have also interpreted Lynn's data as evidence of racial differences in decision time and intelligence. However, comparing Lynn's summaries with his original reports shows that Lynn misreported and omitted some of his own data. Once these errors are fixed the rankings of nations in Lynn's datasets are unstable across different decision time measures. This instability, as well as within-race heterogeneity and between-race overlap in decision times, implies that Lynn's reaction time data do not permit generalizations about the decision times and intelligence of people of different races.

  11. Lynn Sorbara, PhD | Division of Cancer Prevention

    Science.gov (United States)

    Dr. Lynn Sorbara earned her PhD from Albert Einstein College of Medicine in 1986. Her thesis research was in the areas of the mechanism of action of the drug, Taxol, and of multidrug resistance. After postdoctoral fellowships at the Rockefeller University and the Mount Sinai College of Medicine in Manhattan, she came to the NIH as a Senior Staff Fellow in the Diabetes Branch

  12. Halo-independent direct detection analyses without mass assumptions

    International Nuclear Information System (INIS)

    Anderson, Adam J.; Fox, Patrick J.; Kahn, Yonatan; McCullough, Matthew

    2015-01-01

    Results from direct detection experiments are typically interpreted by employing an assumption about the dark matter velocity distribution, with results presented in the m χ −σ n plane. Recently methods which are independent of the DM halo velocity distribution have been developed which present results in the v min −g-tilde plane, but these in turn require an assumption on the dark matter mass. Here we present an extension of these halo-independent methods for dark matter direct detection which does not require a fiducial choice of the dark matter mass. With a change of variables from v min to nuclear recoil momentum (p R ), the full halo-independent content of an experimental result for any dark matter mass can be condensed into a single plot as a function of a new halo integral variable, which we call h-til-tilde(p R ). The entire family of conventional halo-independent g-tilde(v min ) plots for all DM masses are directly found from the single h-tilde(p R ) plot through a simple rescaling of axes. By considering results in h-tilde(p R ) space, one can determine if two experiments are inconsistent for all masses and all physically possible halos, or for what range of dark matter masses the results are inconsistent for all halos, without the necessity of multiple g-tilde(v min ) plots for different DM masses. We conduct a sample analysis comparing the CDMS II Si events to the null results from LUX, XENON10, and SuperCDMS using our method and discuss how the results can be strengthened by imposing the physically reasonable requirement of a finite halo escape velocity

  13. Halo-Independent Direct Detection Analyses Without Mass Assumptions

    CERN Document Server

    Anderson, Adam J.; Kahn, Yonatan; McCullough, Matthew

    2015-10-06

    Results from direct detection experiments are typically interpreted by employing an assumption about the dark matter velocity distribution, with results presented in the $m_\\chi-\\sigma_n$ plane. Recently methods which are independent of the DM halo velocity distribution have been developed which present results in the $v_{min}-\\tilde{g}$ plane, but these in turn require an assumption on the dark matter mass. Here we present an extension of these halo-independent methods for dark matter direct detection which does not require a fiducial choice of the dark matter mass. With a change of variables from $v_{min}$ to nuclear recoil momentum ($p_R$), the full halo-independent content of an experimental result for any dark matter mass can be condensed into a single plot as a function of a new halo integral variable, which we call $\\tilde{h}(p_R)$. The entire family of conventional halo-independent $\\tilde{g}(v_{min})$ plots for all DM masses are directly found from the single $\\tilde{h}(p_R)$ plot through a simple re...

  14. Lynn White Jr. and the greening-of-religion hypothesis.

    Science.gov (United States)

    Taylor, Bron; Van Wieren, Gretel; Zaleha, Bernard Daley

    2016-10-01

    Lynn White Jr.'s "The Historical Roots of Our Ecologic Crisis," which was published in Science in 1967, has played a critical role in precipitating interdisciplinary environmental studies. Although White advances a multifaceted argument, most respondents focus on his claim that the Judeo-Christian tradition, especially Christianity, has promoted anthropocentric attitudes and environmentally destructive behaviors. Decades later, some scholars argue contrarily that Christianity in particular and the world's predominant religions in general are becoming more environmentally friendly, known as the greening-of-religion hypothesis. To test these claims, we conducted a comprehensive review of over 700 articles-historical, qualitative, and quantitative-that are pertinent to them. Although definitive conclusions are difficult, we identified many themes and dynamics that hinder environmental understanding and mobilization, including conservative theological orientations and beliefs about the role of divine agency in preventing or promoting natural events, whether the religion is an Abrahamic tradition or originated in Asia. On balance, we found the thrust of White's thesis is supported, whereas the greening-of-religion hypothesis is not. We also found that indigenous traditions often foster proenvironmental perceptions. This finding suggests that indigenous traditions may be more likely to be proenvironmental than other religious systems and that some nature-based cosmologies and value systems function similarly. Although we conclude White's thesis and subsequent claims are largely born out, additional research is needed to better understand under what circumstances and communication strategies religious or other individuals and groups may be more effectively mobilized to respond to contemporary environmental challenges. © 2016 Society for Conservation Biology.

  15. [Individual Identification of Cartilage by Direct Amplification in Mass Disasters].

    Science.gov (United States)

    Wang, C H; Xu, C; Li, X Q; Wu, Y; Du, Z

    2017-06-01

    To explore the effectiveness of direct amplification for the STR analysis of cartilage, and to accelerate the effectiveness of disaster victim identification. Eighty-eight cartilage samples were directly amplified by PowerPle® 21 kit, and the results of genotyping were compared with that obtained by the magnetic beads method. In 88 cartilage samples, the STR genotypes were successfully detected from 84 samples by direct amplification and magnetic beads method, and both the results of genotyping by two method were consistent. Direct amplification with PowerPlex® 21 kit can be used for STR genotyping of cartilages. This method is operated easily and promptly, which has a potential application in the individual identification of mass disasters. Copyright© by the Editorial Department of Journal of Forensic Medicine

  16. Direct bounds on the tau neutrino mass from LEP

    International Nuclear Information System (INIS)

    Passalacqua, L.

    1996-11-01

    A review of direct bounds on the mass of the tau neutrino obtained at the LEP collider is presented. In addition to published results it includes preliminary results presented at recent conferences and new results presented at the 1996 Tau Workshop. The different techniques and decay modes employed by the ALEPH, DELPHI and OPAL collaborations are compared. The impact of the theoretical modelling of tau decays is also discussed. The most stringent 95 % CL limit on the tau neutrino mass is now obtained by a preliminary ALEPH analysis which combines the results from τ → 5 π ± (π 0 ) v τ and τ → 3 π ± v τ decays. This bound constraints the mass of the tau neutrino below 18.2 M e V / c 2

  17. Direct mass measurements of neutron-deficient xenon isotopes using the ISOLTRAP mass spectrometer

    CERN Document Server

    Dilling, J; Beck, D; Bollen, G; Herfurth, F; Kellerbauer, A G; Kluge, H J; Moore, R B; Scheidenberger, C; Schwarz, S; Sikler, G

    2004-01-01

    The masses of the noble-gas Xe isotopes with 114 $\\leq$ A $\\leq$ 123 have been directly measured for the first time. The experiments were carried out with the ISOLTRAP triple trap spectrometer at the online mass separator ISOLDE/CERN. A mass resolving power of the Penning trap spectrometer of $m/\\Delta m$ of close to a million was chosen resulting in an accuracy of $\\delta m \\leq 13$ keV for all investigated isotopes. Conflicts with existing, indirectly obtained, mass data by several standard deviations were found and are discussed. An atomic mass evaluation has been performed and the results are compared to information from laser spectroscopy experiments and to recent calculations employing an interacting boson model.

  18. Direct Detection of Biotinylated Proteins by Mass Spectrometry

    Science.gov (United States)

    2015-01-01

    Mass spectrometric strategies to identify protein subpopulations involved in specific biological functions rely on covalently tagging biotin to proteins using various chemical modification methods. The biotin tag is primarily used for enrichment of the targeted subpopulation for subsequent mass spectrometry (MS) analysis. A limitation of these strategies is that MS analysis does not easily discriminate unlabeled contaminants from the labeled protein subpopulation under study. To solve this problem, we developed a flexible method that only relies on direct MS detection of biotin-tagged proteins called “Direct Detection of Biotin-containing Tags” (DiDBiT). Compared with conventional targeted proteomic strategies, DiDBiT improves direct detection of biotinylated proteins ∼200 fold. We show that DiDBiT is applicable to several protein labeling protocols in cell culture and in vivo using cell permeable NHS-biotin and incorporation of the noncanonical amino acid, azidohomoalanine (AHA), into newly synthesized proteins, followed by click chemistry tagging with biotin. We demonstrate that DiDBiT improves the direct detection of biotin-tagged newly synthesized peptides more than 20-fold compared to conventional methods. With the increased sensitivity afforded by DiDBiT, we demonstrate the MS detection of newly synthesized proteins labeled in vivo in the rodent nervous system with unprecedented temporal resolution as short as 3 h. PMID:25117199

  19. Direct gravimetric determination of aerosol mass concentration in central antarctica.

    Science.gov (United States)

    Annibaldi, Anna; Truzzi, Cristina; Illuminati, Silvia; Scarponi, Giuseppe

    2011-01-01

    In Antarctica, experimental difficulties due to extreme conditions have meant that aerosol mass has rarely been measured directly by gravimetry, and only in coastal areas where concentrations were in the range of 1-7 μg m(-3). The present work reports on a careful differential weighing methodology carried out for the first time on the plateau of central Antarctica (Dome C, East Antarctica). To solve problems of accurate aerosol mass measurements, a climatic room was used for conditioning and weighing filters. Measurements were carried out in long stages of several hours of readings with automatic recording of temperature/humidity and mass. This experimental scheme allowed us to sample from all the measurements (up to 2000) carried out before and after exposure, those which were recorded under the most stable humidity conditions and, even more importantly, as close to each other as possible. The automatic reading of the mass allowed us in any case to obtain hundreds of measurements from which to calculate average values with uncertainties sufficiently low to meet the requirements of the differential weighing procedure (±0.2 mg in filter weighing, between ±7% and ±16% both in aerosol mass and concentration measurements). The results show that the average summer aerosol mass concentration (aerodynamic size ≤10 μm) in central Antarctica is about 0.1 μg m(-3), i.e., about 1/10 of that of coastal Antarctic areas. The concentration increases by about 4-5 times at a site very close to the station.

  20. LEAD SLOWING DOWN SPECTROSCOPY FOR DIRECT Pu MASS MEASUREMENTS

    International Nuclear Information System (INIS)

    Ressler, Jennifer J.; Smith, Leon E.; Anderson, Kevin K.

    2008-01-01

    The direct measurement of Pu in previously irradiated fuel assemblies is a recognized need in the international safeguards community. A suitable technology could support more timely and independent material control and accounting (MC and A) measurements at nuclear fuel storage areas, the head-end of reprocessing facilities, and at the product-end of recycled fuel fabrication. Lead slowing down spectroscopy (LSDS) may be a viable solution for directly measuring not only the mass of 239Pu in fuel assemblies, but also the masses of other fissile isotopes such as 235U and 241Pu. To assess the potential viability of LSDS, an LSDS spectrometer was modeled in MCNP5 and 'virtual assays' of nominal PWR assemblies ranging from 0 to 60 GWd/MTU burnup were completed. Signal extraction methods, including the incorporation of nonlinear fitting to account for self-shielding effects in strong resonance regions, are described. Quantitative estimates of Pu uncertainty are given for simplistic and more realistic fuel isotopic inventories calculated using ORIGEN. A discussion of additional signal-perturbing effects that will be addressed in future work, and potential signal extraction approaches that could improve Pu mass uncertainties, are also discussed

  1. First direct mass measurements on nobelium and lawrencium with the Penning trap mass spectrometer SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Dworschak, Michael Gerhard

    2009-12-08

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt was set up for high-precision mass measurements of heavy radionuclides produced in fusion evaporation reactions and separated from the primary beam by the velocity filter SHIP. It consists of a gas stopping cell for the deceleration of the high energetic reaction products, an RFQ cooler and buncher for cooling and accumulation of the ions, and a double Penning trap system to perform mass measurements. The mass is determined by measuring the cyclotron frequency of the ion of interest in a strong homogeneous magnetic field and comparing it to the frequency of a well-known reference ion. With this method relative uncertainties in the order of 10{sup -8} can be achieved. Recently, mass measurements of the three nobelium isotopes {sup 252-254}No (Z=102) and the lawrencium isotope {sup 255}Lr (Z=103) were performed successfully. These were the first direct mass measurements of transuranium elements ever per- formed. The production rate of the atoms of interest was about one per second or less. The results of the measurements on nobelium confirm the previous mass values which were deduced from Q{sub {alpha}} values. In the case of {sup 255}Lr the mass excess value, which was previously only estimated from systematic trends, was for the first time directly measured. These results mark the first step in the exploration of the region of transuranium elements which is planned at SHIPTRAP. The main objective is to fix the endpoints of {alpha} decay chains which are originating from superheavy elements close to the predicted island of stability. (orig.)

  2. Wartime Women Rape: A Means of Moral Attack and Emasculation in Lynn Nottage’s Ruined

    Directory of Open Access Journals (Sweden)

    Elaff Ganim Salih

    2016-05-01

    Full Text Available Women rape at warfare was considered a consequence of war in the social, literary and political world for a long period of time. Some criminals of rape escaped justice and others were persecuted on the basis that they were involved in mass rape because it was a natural consequence of war. But, women are targeted with rape in time of war because they are the symbolic representation of a culture, ethnicity, and the unifying fabric of their people and nation. The objective of this paper is to show that war rape is not a result of war; instead it is a means of human destruction through moral attack and emasculation. It aims to show that women rape in warfare is neither a misogynist act nor a sexual violence but it is a pre-planned weapon used strategically and systematically to fulfill certain political and military agenda. The study focuses on the sexual abuse of women in the Democratic Republic of Congo in time of war in Lynn Nottage’s Pulitzer Prize play, Ruined (2007. The study applies Jonathan Gottschall’s Strategic Rape theory, which highlights war rape as a pre-planned military strategy. The enemy emasculates men and attacks them morally by raping their women. Consequently, men’s failure to protect their women causes them to give up resistance, leave their lands and families because of shame and humiliation. The study concludes that women rape in time of war is a tactic followed by conquerors intentionally to facilitate and guarantee the achievement of certain pre-planned goals as was the case of mass rape in the DRC.

  3. Direct analysis of traditional Chinese medicines by mass spectrometry.

    Science.gov (United States)

    Wong, Melody Yee-Man; So, Pui-Kin; Yao, Zhong-Ping

    2016-07-15

    Analysis of traditional Chinese medicines (TCMs) plays important roles in quality control of TCMs and understanding their pharmacological effects. Mass spectrometry (MS) is a technique of choice for analysis of TCMs due to its superiority in speed, sensitivity and specificity. However, conventional MS analysis of TCMs typically requires extensive sample pretreatment and chromatographic separation, which could be time-consuming and laborious, prior to the analysis. The expanding usage of TCMs worldwide demands development of rapid, cost-effective and reliable methods for analysis of TCMs. In recent years, new sample preparation and ionization techniques have been developed to enable direct analysis of TCMs by MS, significantly reducing the analysis time and cost. In this review, various MS-based techniques, mainly including ambient ionization-MS and MALDI-MS based techniques, applied for direct analysis of TCMs are summarized and their applicability and future prospects are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Petroleomics by Direct Analysis in Real Time-Mass Spectrometry.

    Science.gov (United States)

    Romão, Wanderson; Tose, Lilian V; Vaz, Boniek G; Sama, Sara G; Lobinski, Ryszard; Giusti, Pierre; Carrier, Hervé; Bouyssiere, Brice

    2016-01-01

    The analysis of crude oil and its fractions by applying ambient ionization techniques remains underexplored in mass spectrometry (MS). Direct analysis in real time (DART) in the positive-ion mode was coupled to a linear quadrupole ion trap Orbitrap mass spectrometer (LTQ Orbitrap) to analyze crude oil, paraffin samples, and porphyrin standard compounds. The ionization parameters of DART-MS were optimized for crude oil analysis. DART-MS rendered the optimum conditions of the operation using paper as the substrate, T = 400°C, helium as the carrier gas, and a sample concentration ≥6 mg mL(-1). In the crude oils analysis, the DART(+)-Orbitrap mass spectra detected the typical N, NO, and O-containing compounds. In the paraffin samples, oxidized hydrocarbon species (Ox classes, where x = 1-4) with double-bond equivalent of 1-4 were detected, and their structures and connectivity were confirmed by collision-induced dissociation (CID) experiments. DART(+)-MS has identified the porphyrin standard compounds as [M + H](+) ions of m/z 615.2502 and 680.1763, where M = C44H30N4 and C44H28N4OV, respectively, based on the formula assignment and by phenyl losses observed on CID experiments.

  5. Direct geoelectrical evidence of mass transfer at the laboratory scale

    Science.gov (United States)

    Swanson, Ryan D.; Singha, Kamini; Day-Lewis, Frederick D.; Binley, Andrew; Keating, Kristina; Haggerty, Roy

    2012-10-01

    Previous field-scale experimental data and numerical modeling suggest that the dual-domain mass transfer (DDMT) of electrolytic tracers has an observable geoelectrical signature. Here we present controlled laboratory experiments confirming the electrical signature of DDMT and demonstrate the use of time-lapse electrical measurements in conjunction with concentration measurements to estimate the parameters controlling DDMT, i.e., the mobile and immobile porosity and rate at which solute exchanges between mobile and immobile domains. We conducted column tracer tests on unconsolidated quartz sand and a material with a high secondary porosity: the zeolite clinoptilolite. During NaCl tracer tests we collected nearly colocated bulk direct-current electrical conductivity (σb) and fluid conductivity (σf) measurements. Our results for the zeolite show (1) extensive tailing and (2) a hysteretic relation between σf and σb, thus providing evidence of mass transfer not observed within the quartz sand. To identify best-fit parameters and evaluate parameter sensitivity, we performed over 2700 simulations of σf, varying the immobile and mobile domain and mass transfer rate. We emphasized the fit to late-time tailing by minimizing the Box-Cox power transformed root-mean square error between the observed and simulated σf. Low-field proton nuclear magnetic resonance (NMR) measurements provide an independent quantification of the volumes of the mobile and immobile domains. The best-fit parameters based on σf match the NMR measurements of the immobile and mobile domain porosities and provide the first direct electrical evidence for DDMT. Our results underscore the potential of using electrical measurements for DDMT parameter inference.

  6. 78 FR 18849 - Drawbridge Operation Regulations; Saugus River, Saugus and Lynn, MA

    Science.gov (United States)

    2013-03-28

    ... regulation governing the operation of the Route 107 temporary bridge across the Saugus River, mile 2.5, between Saugus and Lynn, Massachusetts. The bridge will not open for vessel traffic during the installation of the moveable span. This deviation allows the bridge to remain closed for six days. DATES: This...

  7. John Falk and Lynn Dierking: Building the Field of Informal/Free-Choice Science Education

    Science.gov (United States)

    Rennie, Léonie J.

    2016-01-01

    This article establishes the importance of "context", a concept that underpins the academic contributions that John Falk and Lynn Dierking have made in building the field of informal/free-choice learning in science education. I consider, in turn, the individual contributions made by each of them prior to their seminal co-authored work,…

  8. The Mean Southern Italian Children IQ Is Not Particularly Low: A Reply to R. Lynn (2010)

    Science.gov (United States)

    Cornoldi, Cesare; Belacchi, Carmen; Giofre, David; Martini, Angela; Tressoldi, Patrizio

    2010-01-01

    Working with data from the PISA study (OECD, 2007), Lynn (2010) has argued that individuals from South Italy average an IQ approximately 10 points lower than individuals from North Italy, and has gone on to put forward a series of conclusions on the relationship between average IQ, latitude, average stature, income, etc. The present paper…

  9. New Directions in Mass Communications Research: Physiological Measurement.

    Science.gov (United States)

    Fletcher, James E.

    Psychophysiological research into the effects of mass media, specifically the music of the masses, promises increased insight into the control the media exert on all their consumers. Attention and retention of mass media messages can be tested by measuring the receiver's electrodernal activity, pupil dilation, peripheral vasodilation, and heart…

  10. Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors

    Science.gov (United States)

    Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura

    2018-03-01

    We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.

  11. Comparative efficacy of Rubini, Jeryl-Lynn and Urabe mumps vaccine in an Asian population.

    Science.gov (United States)

    Ong, Gary; Goh, Kee Tai; Ma, Stefan; Chew, Suok Kai

    2005-11-01

    The comparative efficacy of the three mumps vaccine strains (Jeryl-Lynn, Urabe and Rubini) was conducted in an Asian population from data arising from an epidemiological investigation of seven institutional outbreaks of mumps in Singapore. Demographic information (gender, age, ethnic group), clinical presentation and vaccination history (date and place of mumps vaccination, type of mumps vaccine received) of all children who attended the six childcare centres and one primary school where outbreaks of 20 or more cases of mumps occurred in 1999 were collected. The attack rate of the unvaccinated group and the attack rates of the vaccine groups (for each vaccine strain) were determined and the vaccine efficacy of the three vaccines calculated. The vaccine efficacy of the Jeryl-Lynn strain, Urabe strain and Rubini strain mumps vaccine were 80.7, 54.4 and -55.3%, respectively. Rubini strain mumps vaccine conferred no protection and has since been deregistered in Singapore.

  12. First Direct Mass Measurements of Nuclides around Z =100 with a Multireflection Time-of-Flight Mass Spectrograph

    Science.gov (United States)

    Ito, Y.; Schury, P.; Wada, M.; Arai, F.; Haba, H.; Hirayama, Y.; Ishizawa, S.; Kaji, D.; Kimura, S.; Koura, H.; MacCormick, M.; Miyatake, H.; Moon, J. Y.; Morimoto, K.; Morita, K.; Mukai, M.; Murray, I.; Niwase, T.; Okada, K.; Ozawa, A.; Rosenbusch, M.; Takamine, A.; Tanaka, T.; Watanabe, Y. X.; Wollnik, H.; Yamaki, S.

    2018-04-01

    The masses of 246Es, 251Fm, and the transfermium nuclei Md-252249 and 254No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N =152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of 246Es and 249,250,252Md were measured for the first time. Using the masses of Md,250249 as anchor points for α decay chains, the masses of heavier nuclei, up to 261Bh and 266Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ2 n derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N =152 neutron shell closure for Md and Lr.

  13. Interaction of hemoglobin Grey Lynn (Vientiane) with a non-deletional α(+)-thalassemia in an adult Thai proband.

    Science.gov (United States)

    Singha, Kritsada; Fucharoen, Goonnapa; Fucharoen, Supan

    2014-01-01

    Hemoglobin (Hb) Grey Lynn is a Hb variant caused by a substitution of Phe for Leu at position 91 of α1-globin chain, originally described in individual of unknown ethnic background. This article addresses the interaction of Hb Grey Lynn with a non-deletional α(+)-thalassemia found in Thailand, a hitherto un-described condition. The proband was adult Thai woman referred for investigation of mild anemia with Hb 90 g/L. Hb analyses using low pressure liquid chromatography raised a suspicion of abnormal Hb presence, which was failed to demonstrate by cellulose acetate electrophoresis and capillary electrophoresis. DNA sequencing identified a CTT (Leu) to TTT (Phe) mutation at codon 91 corresponding to the Hb Grey Lynn (Vientiane) [α91(FG3)Leu>Phe (α1) on α1-globin gene and a C deletion between codons 36 and 37 on α2-globin gene causing α(+)-thalassemia. As compared to those observed in a compound heterozygote for Hb Grey Lynn / α(0)-thalassemia reported previously, higher MCV (81.7 fL) and MCH (26.3 pg) values with a lower level of Hb Grey Lynn (19.7%) were observed in the proband. The normochromic normocytic anemia observed could be due to the interaction of Hb Grey Lynn with α(+)-thalassemia. The two mutations could be identified using PCR-RFLP and allele-specific PCR assays developed.

  14. Direct mass measurements of neutron-deficient xenon isotopes with the ISOLTRAP mass spectrometer

    International Nuclear Information System (INIS)

    Dilling, J.; Audi, G.; Beck, D.; Bollen, G.; Henry, S.; Herfurth, F.; Kellerbauer, A.; Kluge, H.-J.; Lunney, D.; Moore, R.B.; Scheidenberger, C.; Schwarz, S.; Sikler, G.; Szerypo, J.

    2002-01-01

    The masses of Xe isotopes with 124≥A≥114 have been measured using the ISOLTRAP spectrometer at the on-line mass separator ISOLDE/CERN. A mass resolving power of 500 000 was chosen resulting in an accuracy of δm∼12 keV for all isotopes investigated. Conflicts with existing mass data of several standard deviations were found

  15. High-Precision Direct Mass Determination of Unstable Isotopes

    CERN Multimedia

    2002-01-01

    The extension of systematic high-precision measurements of the nuclear mass to nuclei far from the valley of $\\beta$ stability is of great interest in nuclear physics and astrophysics. The mass, or binding energy, is a fundamental gross property and a key input parameter for nuclear matter calculations. It is also a sensitive probe for collective and single-particle effects in nuclear structure. \\\\ \\\\ For such purposes, nuclear masses need to be known to an accuracy of about 10$^{-7}$ (i.e. $\\Delta$M~$\\leq$~10~keV for A~=~100). To resolve a particular mass from its nuclear isomers and isobars, resolving power of 10$^6$ are often required. To achieve this, the ions delivered by the on-line mass separator ISOLDE are confined in a Penning quadrupole trap. This trap is placed in the very homogeneous and stable magnetic field of a superconducting magnet. Here, the cyclotron frequency and hence the mass are determined. \\\\ \\\\ The first measurements using this new technique have been completed for a long chain of Cs ...

  16. Mass spectrometry allows direct identification of proteins in large genomes

    DEFF Research Database (Denmark)

    Küster, B; Mortensen, Peter V.; Andersen, Jens S.

    2001-01-01

    Proteome projects seek to provide systematic functional analysis of the genes uncovered by genome sequencing initiatives. Mass spectrometric protein identification is a key requirement in these studies but to date, database searching tools rely on the availability of protein sequences derived fro...

  17. Emerging mass spectrometry techniques for the direct analysis of microbial colonies

    OpenAIRE

    Fang, Jinshu; Dorrestein, Pieter C.

    2014-01-01

    One of the emerging areas in microbiology is detecting specialized metabolites produced by microbial colonies and communities with mass spectrometry. In this review/perspective, we illustrate the emerging mass spectrometry methodologies that enable the interrogation of specialized metabolites directly from microbial colonies. Mass spectrometry techniques such as imaging mass spectrometry and real-time mass spectrometry allow two and three dimensional visualization of the distri...

  18. Frontiers in Cancer Nanomedicine: Directing Mass Transport through Biological Barriers

    Science.gov (United States)

    Ferrari, Mauro

    2010-01-01

    The physics of mass transport within body compartments and across biological barriers differentiates cancers from healthy tissues. Variants of nanoparticles can be manufactured in combinatorially large sets, varying only one transport-affecting design parameter at a time. Nanoparticles can also be used as building blocks for systems that perform sequences of coordinated actions, in accordance to a prescribed logic. These are referred to as Logic-Embedded Vectors “(LEV)” in the following. Nanoparticles and LEVs are ideal probes for the determination of mass transport laws in tumors, acting as imaging contrast enhancers, and can be employed for the lesion-selective delivery of therapy. Their size, shape, density and surface chemistry dominate convective transport in the blood stream, margination, cell adhesion, selective cellular uptake, as well as sub-cellular trafficking and localization. As argued here, the understanding of transport differentials in cancer, termed ‘transport oncophysics’ unveils a new promising frontier in oncology: the development of lesion-specific delivery particulates that exploit mass transport differentials to deploy treatment of greater efficacy and reduced side effects. PMID:20079548

  19. Ion Mobility Mass Spectrometry Direct Isotope Abundance Analysis

    International Nuclear Information System (INIS)

    Manard, Manuel J.; Weeks, Stephan; Kyle, Kevin

    2010-01-01

    The nuclear forensics community is currently engaged in the analysis of illicit nuclear or radioactive material for the purposes of non-proliferations and attribution. One technique commonly employed for gathering nuclear forensics information is isotope analysis. At present, the state-of-the-art methodology for obtaining isotopic distributions is thermal ionization mass spectrometry (TIMS). Although TIMS is highly accurate at determining isotope distributions, the technique requires an elementally pure sample to perform the measurement. The required radiochemical separations give rise to sample preparation times that can be in excess of one to two weeks. Clearly, the nuclear forensics community is in need of instrumentation and methods that can expedite their decision making process in the event of a radiological release or nuclear detonation. Accordingly, we are developing instrumentation that couples a high resolution IM drift cell to the front end of a MS. The IM cell provides a means of separating ions based upon their collision cross-section and mass-to-charge ratio (m/z). Two analytes with the same m/z, but with different collision cross-sections (shapes) would exit the cell at different times, essentially enabling the cell to function in a similar manner to a gas chromatography (GC) column. Thus, molecular and atomic isobaric interferences can be effectively removed from the ion beam. The mobility selected chemical species could then be introduced to a MS for high-resolution mass analysis to generate isotopic distributions of the target analytes. The outcome would be an IM/MS system capable of accurately measuring isotopic distributions while concurrently eliminating isobaric interferences and laboratory radiochemical sample preparation. The overall objective of this project is developing instrumentation and methods to produce near real-time isotope distributions with a modular mass spectrometric system that performs the required gas-phase chemistry and

  20. THE MASS-METALLICITY RELATION WITH THE DIRECT METHOD ON STACKED SPECTRA OF SDSS GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Brett H.; Martini, Paul, E-mail: andrews@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2013-03-10

    The relation between galaxy stellar mass and gas-phase metallicity is a sensitive diagnostic of the main processes that drive galaxy evolution, namely cosmological gas inflow, metal production in stars, and gas outflow via galactic winds. We employed the direct method to measure the metallicities of {approx}200,000 star-forming galaxies from the Sloan Digital Sky Survey that were stacked in bins of (1) stellar mass and (2) both stellar mass and star formation rate (SFR) to significantly enhance the signal-to-noise ratio of the weak [O III] {lambda}4363 and [O II] {lambda}{lambda}7320, 7330 auroral lines required to apply the direct method. These metallicity measurements span three decades in stellar mass from log(M{sub *}/M{sub Sun }) = 7.4-10.5, which allows the direct method mass-metallicity relation to simultaneously capture the high-mass turnover and extend a full decade lower in mass than previous studies that employed more uncertain strong line methods. The direct method mass-metallicity relation rises steeply at low mass (O/H {proportional_to} M{sub *} {sup 1/2}) until it turns over at log(M{sub *}/M{sub Sun }) = 8.9 and asymptotes to 12 + log(O/H) = 8.8 at high mass. The direct method mass-metallicity relation has a steeper slope, a lower turnover mass, and a factor of two to three greater dependence on SFR than strong line mass-metallicity relations. Furthermore, the SFR-dependence appears monotonic with stellar mass, unlike strong line mass-metallicity relations. We also measure the N/O abundance ratio, an important tracer of star formation history, and find the clear signature of primary and secondary nitrogen enrichment. N/O correlates tightly with oxygen abundance, and even more so with stellar mass.

  1. A direct measurement of the baryonic mass function of galaxies & implications for the galactic baryon fraction

    NARCIS (Netherlands)

    Papastergis, Emmanouil; Cattaneo, Andrea; Huang, Shan; Giovanelli, Riccardo; Haynes, Martha P.

    2012-01-01

    We use both an HI-selected and an optically-selected galaxy sample to directly measure the abundance of galaxies as a function of their "baryonic" mass (stars + atomic gas). Stellar masses are calculated based on optical data from the Sloan Digital Sky Survey (SDSS) and atomic gas masses are

  2. Dissociations and dissociation theory in hypnosis: comment on Kirsch and Lynn (1998)

    Science.gov (United States)

    Kihlstrom, J F

    1998-03-01

    I. Kirsch and S. J. Lynn's (1998) critique of the neodissociation theory of divided consciousness fails to consider evidence of dissociations between explicit and implicit memory and perception in hypnosis. Contrary to their conclusions, evidence that the rate of hidden observer response (like other hypnotic responses) varies with the wording of instructions does not contradict neodissociation theory; rather, it underscores the fact that hypnosis entails social interaction as well as alterations in conscious awareness. Neodissociation and sociocognitive theories of hypnosis complement each other. Each draws attention to aspects of the experience of hypnosis that the other neglects.

  3. Direct Energy Conversion for Nuclear Propulsion at Low Specific Mass

    Science.gov (United States)

    Scott, John H.

    2014-01-01

    The project will continue the FY13 JSC IR&D (October-2012 to September-2013) effort in Travelling Wave Direct Energy Conversion (TWDEC) in order to demonstrate its potential as the core of a high potential, game-changing, in-space propulsion technology. The TWDEC concept converts particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a plasma thruster. In a more advanced concept (explored in the Phase 1 NIAC project), the TWDEC could also be utilized to condition the particle beam such that it may transfer directed kinetic energy to a target propellant plasma for the purpose of increasing thrust and optimizing the specific impulse. The overall scope of the FY13 first-year effort was to build on both the 2012 Phase 1 NIAC research and the analysis and test results produced by Japanese researchers over the past twenty years to assess the potential for spacecraft propulsion applications. The primary objective of the FY13 effort was to create particle-in-cell computer simulations of a TWDEC. Other objectives included construction of a breadboard TWDEC test article, preliminary test calibration of the simulations, and construction of first order power system models to feed into mission architecture analyses with COPERNICUS tools. Due to funding cuts resulting from the FY13 sequestration, only the computer simulations and assembly of the breadboard test article were completed. The simulations, however, are of unprecedented flexibility and precision and were presented at the 2013 AIAA Joint Propulsion Conference. Also, the assembled test article will provide an ion current density two orders of magnitude above that available in previous Japanese experiments, thus enabling the first direct measurements of power generation from a TWDEC for FY14. The proposed FY14 effort will use the test article for experimental validation of the computer simulations and thus complete to a greater fidelity the

  4. Directional mass transport in an atmospheric pressure surface barrier discharge.

    Science.gov (United States)

    Dickenson, A; Morabit, Y; Hasan, M I; Walsh, J L

    2017-10-25

    In an atmospheric pressure surface barrier discharge the inherent physical separation between the plasma generation region and downstream point of application reduces the flux of reactive chemical species reaching the sample, potentially limiting application efficacy. This contribution explores the impact of manipulating the phase angle of the applied voltage to exert a level of control over the electrohydrodynamic forces generated by the plasma. As these forces produce a convective flow which is the primary mechanism of species transport, the technique facilitates the targeted delivery of reactive species to a downstream point without compromising the underpinning species generation mechanisms. Particle Imaging Velocimetry measurements are used to demonstrate that a phase shift between sinusoidal voltages applied to adjacent electrodes in a surface barrier discharge results in a significant deviation in the direction of the plasma induced gas flow. Using a two-dimensional numerical air plasma model, it is shown that the phase shift impacts the spatial distribution of the deposited charge on the dielectric surface between the adjacent electrodes. The modified surface charge distribution reduces the propagation length of the discharge ignited on the lagging electrode, causing an imbalance in the generated forces and consequently a variation in the direction of the resulting gas flow.

  5. Kádár Lynn, Katalin, ed.: " Through an American Lens, Hungary, 1938: Photographs by Margaret Bourke-White"

    Directory of Open Access Journals (Sweden)

    Joyce Berczik Corbett

    2011-01-01

    Full Text Available Kádár Lynn, Katalin, ed. Through an American Lens, Hungary, 1938: Photographs by Margaret Bourke-White.Trans. Mario Fenyő. Essays by: Károly Szerencsés, Katalin Kádár Lynn, Péter Strausz. East European Monographs. Boulder: Columbia UP, Distributor, 2010.111 pp. ISBN: 978-0-88033-678-9.(Hungarian edition: Szerk.: Kádár Lynn Katalin, Szerencsés Károly esszéivel. Strausz Péter jegyzeteivel. Magyarország 1938: egy amerikai szemével, Margaret Bourke-White fotói. Budapest: L’Harmattan, Budapest, 2008. ISBN: 978-963-236-005-8 Reviewed by Joyce Berczik Corbett, Curatorial Consultant.

  6. Proposal and Research Direction of Soil Mass Organic Reorganization

    Science.gov (United States)

    Zhang, Lu; Han, Jichang

    2018-01-01

    Land engineering as a new discipline has been temporarily outrageous. The proposition of soil body organic reorganization undoubtedly enriches the research content for the construction of land engineering disciplines. Soil body organic reconstruction is designed to study how to realize the ecological ecology of the land by studying the external force of nature, to study the influence of sunlight, wind and water on soil body, how to improve the soil physical structure, to further strengthen the research of biological enzymes and microbes, and promote the release and utilization of beneficial inert elements in soil body. The emerging of frontier scientific research issues with soil body organic reorganization to indicate directions for the future development of soil engineering.

  7. The Process in Completing a Nontraditional Group Dissertation in Practice for the Carnegie Project on the Education Doctorate, the Ed.D. Educational Leadership Program at Lynn University

    Science.gov (United States)

    Vickers, Jerome

    2016-01-01

    This study focused on how a cohort of scholarly practitioners extended the traditional Doctorate in Education (Ed.D.) model at Lynn University by undertaking a nontraditional group Dissertation in Practice (DiP). The participants were a cohort of 11 scholarly practitioners known as Cohort 5 who became the first Lynn University doctoral students to…

  8. Terverticillate Penicillia studied by direct electrospray mass spectrometric profiling of crude extracts: I. Chemosystematics

    DEFF Research Database (Denmark)

    Smedsgaard, Jørn; Frisvad, Jens Christian

    1997-01-01

    ) and Yeast Extract Sucrose agar (YES) directly into the electrospray source of the mass spectrometer. A data matrix was made from each substrate by transferring the complete centroid mass spectrum from 200 to 700 amu as 501 variables to individual columns. No attempt was made to identify ions in the mass......A chemosystematic study of 339 isolates from all known terverticillate Penicillium taxa was performed using electrospray mass spectrometric analysis of extractable metabolites. The mass profiles were made by injecting crude plug extracts made from cultures grown on Czapek Yeast Autolysate agar (CYA...

  9. New directions in information organization

    CERN Document Server

    Park, Jung-ran; Spink, Amanda

    2013-01-01

    New Directions in Information Organization, co-edited by Dr. Jung-ran Park and Dr. Lynne Howarth seeks to provide an overview and understanding of the future directions, leading edge theories and models for research and practice in information organization.

  10. Direct Analysis of Large Living Organism by Megavolt Electrostatic Ionization Mass Spectrometry

    Science.gov (United States)

    Ng, Kwan-Ming; Tang, Ho-Wai; Man, Sin-Heng; Mak, Pui-Yuk; Choi, Yi-Ching; Wong, Melody Yee-Man

    2014-09-01

    A new ambient ionization method allowing the direct chemical analysis of living human body by mass spectrometry (MS) was developed. This MS method, namely Megavolt Electrostatic Ionization Mass Spectrometry, is based on electrostatic charging of a living individual to megavolt (MV) potential, illicit drugs, and explosives on skin/glove, flammable solvent on cloth/tissue paper, and volatile food substances in breath were readily ionized and detected by a mass spectrometer.

  11. 77 FR 32625 - William J. Stevenson, Estate of Lynn E. Stevenson, Black Canyon Bliss, LLC; Notice of Application...

    Science.gov (United States)

    2012-06-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 8866-010] William J. Stevenson, Estate of Lynn E. Stevenson, Black Canyon Bliss, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On April 23, 2012, William J. Stevenson, Estate...

  12. 76 FR 43997 - N. Stanley Standal and Loretta M. Standal; Lynn E. Stevenson; Notice of Change in Docket Numbers

    Science.gov (United States)

    2011-07-22

    ...; Project Nos. 8866-006 and 8866- 007] N. Stanley Standal and Loretta M. Standal; Lynn E. Stevenson; Notice.... Stevenson to N. Stanley and Loretta M. Standal. Shortly thereafter, on July 20, 2004, the Commission issued... transfer and amendment orders. N. Stanley and Loretta M. Standal are correctly identified as the licensees...

  13. Differences in Achievement Not in Intelligence in the North and South of Italy: Comments on Lynn (2010a, 2010b)

    Science.gov (United States)

    D'Amico, Antonella; Cardaci, Maurizio; Di Nuovo, Santo; Naglieri, Jack A.

    2012-01-01

    Lynn (2010a, 2010b) argued that individuals from south Italy have a lower IQ than individuals from north Italy, and that these differences in IQ are at the basis of north-south gap in income, education, infant mortality, stature, and literacy. In the present paper, we discuss several theoretical and methodological aspects which we regard as flaws…

  14. In vitro and in vivo growth alter the population dynamic and properties of a Jeryl Lynn mumps vaccine.

    Science.gov (United States)

    Connaughton, Sarah M; Wheeler, Jun X; Vitková, Eva; Minor, Philip; Schepelmann, Silke

    2015-08-26

    Mumps vaccines are live attenuated viruses. They are known to vary in effectiveness, degree of attenuation and adverse event profile. However, the underlying reasons are poorly understood. We studied two closely related mumps vaccines which originate from the same attenuated Jeryl Lynn-5 strain but have different efficacies. Jeryl Lynn-Canine Kidney (JL-CK), produced on primary canine kidney cells, is less effective than RIT4385, which is produced on chicken embryo fibroblasts. JL-CK and RIT4385 could be distinguished by a number of in vitro and in vivo properties. JL-CK produced heterogeneous, generally smaller plaques than RIT4385, but gave 100-fold higher titres when grown in cells and showed a higher degree of hydrocephalus formation in neonatal rat brains. Sanger sequencing of JL-CK identified 14 regions of heterogeneity throughout the genome. Plaque purification of JL-CK demonstrated the presence of five different Jeryl Lynn-5 variants encompassing the 14 mutations. One JL-CK mutation was associated with a small plaque phenotype, the effects of the others in vitro or in vivo were less clear. Only 4% of the JL-CK population corresponded to the parental Jeryl Lynn-5 strain. Next generation sequencing of JL-CK and virus before and after growth in cell lines or neonatal rat brains showed that propagation in vitro or in vivo altered the population dramatically. Our findings indicate that growth of JL-CK in primary canine kidney cells resulted in the selection of a mixture of mumps virus variants that have different biological properties compared to the parent Jeryl Lynn-5 virus. We also report three previously unknown heterogenic regions within the N gene of the RIT4385 vaccine. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Comparison of direct and geodetic mass balances on a multi-annual time scale

    Directory of Open Access Journals (Sweden)

    A. Fischer

    2011-02-01

    Full Text Available The geodetic mass balances of six Austrian glaciers over 19 periods between 1953 and 2006 are compared to the direct mass balances over the same periods. For two glaciers, Hintereisferner and Kesselwandferner, case studies showing possible reasons for discrepancies between the geodetic and the direct mass balance are presented. The mean annual geodetic mass balance for all periods is −0.5 m w.e. a−1, the mean annual direct mass balance −0.4 m w.e. a−1. The mean cumulative difference is −0.6 m w.e., the minimum −7.3 m w.e., and the maximum 5.6 m w.e. The accuracy of geodetic mass balance may depend on the accuracy of the DEMs, which ranges from 2 m w.e. for photogrammetric data to 0.02 m w.e. for airborne laser scanning (LiDAR data. Basal melt, seasonal snow cover, and density changes of the surface layer also contribute up to 0.7 m w.e. to the difference between the two methods over the investigated period of 10 yr. On Hintereisferner, the fraction of area covered by snow or firn has been changing within 1953–2006. The accumulation area is not identical with the firn area, and both are not coincident with areas of volume gain. Longer periods between the acquisition of the DEMs do not necessarily result in a higher accuracy of the geodetic mass balance. Trends in the difference between the direct and the geodetic data vary from glacier to glacier and can differ systematically for specific glaciers under specific types of climate forcing. Ultimately, geodetic and direct mass balance data are complementary, and great care must be taken when attempting to combine them.

  16. Direct measurement of the top quark mass in $p\\bar p$ collisions at D0

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Oleg [Kirchhoff Inst. Phys.

    2017-10-11

    The mass of the top quark is a fundamental parameter of the Standard Model and has to be determined experimentally. In these proceedings, I review recent direct measurements of the top quark mass in $p\\bar p$ collisions at $\\sqrt s=1.96$ TeV recorded by the D0 experiment at the Tevatron. The measurements are performed in final states containing one and two charged leptons. I will present the legacy combination of all top quark mass measurements from the D0 experiment and their combination with results from the CDF experiment. A relative precision of down to 0.3\\% is attained.

  17. No evidence for directional evolution of body mass in herbivorous theropod dinosaurs

    Science.gov (United States)

    Zanno, Lindsay E.; Makovicky, Peter J.

    2013-01-01

    The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at least facultative herbivory in the fossil record—all of which also achieve relative gigantism (more than 3000 kg). Ordinary least-squares regressions on natural log-transformed mean mass recover significant correlations between increasing mass and geological time. However, tests for directional evolution in body mass find no support for a phylogenetic trend, instead favouring passive models of trait evolution. Cross-correlation of sympatric taxa from five localities in Asia reveals that environmental influences such as differential habitat sampling and/or taphonomic filtering affect the preserved record of dinosaurian body mass in the Cretaceous. Our results are congruent with studies documenting that behavioural and/or ecological factors may mitigate the benefit of increasing mass in extant taxa, and suggest that the hypothesis can be extrapolated to herbivorous lineages across geological time scales. PMID:23193135

  18. Direct Analysis of Samples of Various Origin and Composition Using Specific Types of Mass Spectrometry.

    Science.gov (United States)

    Byliński, Hubert; Gębicki, Jacek; Dymerski, Tomasz; Namieśnik, Jacek

    2017-07-04

    One of the major sources of error that occur during chemical analysis utilizing the more conventional and established analytical techniques is the possibility of losing part of the analytes during the sample preparation stage. Unfortunately, this sample preparation stage is required to improve analytical sensitivity and precision. Direct techniques have helped to shorten or even bypass the sample preparation stage; and in this review, we comment of some of the new direct techniques that are mass-spectrometry based. The study presents information about the measurement techniques using mass spectrometry, which allow direct sample analysis, without sample preparation or limiting some pre-concentration steps. MALDI - MS, PTR - MS, SIFT - MS, DESI - MS techniques are discussed. These solutions have numerous applications in different fields of human activity due to their interesting properties. The advantages and disadvantages of these techniques are presented. The trends in development of direct analysis using the aforementioned techniques are also presented.

  19. Direct olive oil analysis by mass spectrometry: A comparison of different ambient ionization methods.

    Science.gov (United States)

    Lara-Ortega, Felipe J; Beneito-Cambra, Miriam; Robles-Molina, José; García-Reyes, Juan F; Gilbert-López, Bienvenida; Molina-Díaz, Antonio

    2018-04-01

    Analytical methods based on ambient ionization mass spectrometry (AIMS) combine the classic outstanding performance of mass spectrometry in terms of sensitivity and selectivity along with convenient features related to the lack of sample workup required. In this work, the performance of different mass spectrometry-based methods has been assessed for the direct analyses of virgin olive oil for quality purposes. Two sets of experiments have been setup: (1) direct analysis of untreated olive oil using AIMS methods such as Low-Temperature Plasma Mass Spectrometry (LTP-MS) or paper spray mass spectrometry (PS-MS); or alternatively (2) the use of atmospheric pressure ionization (API) mass spectrometry by direct infusion of a diluted sample through either atmospheric pressure chemical ionization (APCI) or electrospray (ESI) ionization sources. The second strategy involved a minimum sample work-up consisting of a simple olive oil dilution (from 1:10 to 1:1000) with appropriate solvents, which originated critical carry over effects in ESI, making unreliable its use in routine; thus, ESI required the use of a liquid-liquid extraction to shift the measurement towards a specific part of the composition of the edible oil (i.e. polyphenol rich fraction or lipid/fatty acid profile). On the other hand, LTP-MS enabled direct undiluted mass analysis of olive oil. The use of PS-MS provided additional advantages such as an extended ionization coverage/molecular weight range (compared to LTP-MS) and the possibility to increase the ionization efficiency towards nonpolar compounds such as squalene through the formation of Ag + adducts with carbon-carbon double bounds, an attractive feature to discriminate between oils with different degree of unsaturation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

    International Nuclear Information System (INIS)

    Tao, S.; Liu, Y.N.; Lang, C.; Wang, W.T.; Yuan, H.S.; Zhang, D.Y.; Qiu, W.X.; Liu, J.M.; Liu, Z.G.; Liu, S.Z.; Yi, R.; Ji, M.; Liu, X.X.

    2008-01-01

    A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test. - A novel directional passive air sampler was developed and tested for monitoring PAHs in air masses from different directions

  1. Direct mass measurements of 100Sn and magic nuclei near the N=Z line

    International Nuclear Information System (INIS)

    Chartier, M.

    1996-01-01

    The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A ≅ 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a 78 Kr beam on a nat Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of 70 Se and 71 Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus 100 Sn was successfully performed, using this original technique. Secondary ions of 100 Ag, 100 Cd, 100 In and 100 Sn produced via fusion-evaporation reaction 50 Cr + 58 Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of 100 Cd and, for the first time, the masses of 100 Sn were determined directly with respect to the reference mass of 100 Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author)

  2. Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry by direct injection nebulization for selenium speciation

    DEFF Research Database (Denmark)

    Bendahl, Lars; Gammelgaard, Bente; Jons, O.

    2001-01-01

    A demountable direct injection high efficiency nebulizer operating at low sample uptake rates was developed and used for coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS). When the nebulizer was used for continuous sample introduction, detection...

  3. [EXPRESS IDENTIFICATION OF POSITIVE BLOOD CULTURES USING DIRECT MALDI-TOF MASS SPECTROMETRY].

    Science.gov (United States)

    Popov, D A; Ovseenko, S T; Vostrikova, T Yu

    2015-01-01

    To evaluate the effectiveness of direct identification of pathogens of bacteremia by direct matrix assisted laser desorption ionization time-flight mass spectrometry (mALDI-TOF) compared to routine method. A prospective study included 211 positive blood cultures obtained from 116 patients (106 adults and 10 children, aged from 2 weeks to 77 years old in the ICU after open heart surgery. Incubation was carried out under aerobic vials with a sorbent for antibiotics Analyzer BacT/ALERT 3D 120 (bioMerieux, France) in parallel with the primary sieving blood cultures on solid nutrient media with subsequent identification of pure cultures using MALDI-TOF mass spectrometry analyzer Vitek MS, bioMerieux, France routine method), after appropriate sample preparation we carried out a direct (without screening) MALDI-TOF mass spectrometric study of monocomponental blood cultures (n = 201). using a routine method in 211 positive blood cultures we identified 23 types of microorganisms (Staphylococcus (n = 87), Enterobacteria- ceae (n = 71), Enterococci (n = 20), non-fermentative Gram-negative bacteria (n = 18), others (n = 5). The average time of incubation of samples to obtain a signal of a blood culture growth was 16.2 ± 7.4 h (from 3.75 to 51 hours.) During the first 12 hours of incubation, growth was obtained in 32.4% of the samples, and on the first day in 92.2%. In the direct mass spectrometric analysis mnonocomponental blood cultures (n = 201) is well defined up to 153 species of the sample (76.1%), while the share of successful identification of Gram-negative bacteria was higher than that of Gram-positive (85.4 and 69, 1%, respectively p = 0.01). The high degree of consistency in the results of standard and direct method of identifying blood cultures using MALDI-TOF mass spectrometry (κ = 0.96, p direct mass spectrometric analysis, including sample preparation, was no longer than 1 hour: The method of direct MALDI-TOF mass spectrometry allows to significantly speed up

  4. Three-dimensional two-phase mass transport model for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Yang, W.W.; Zhao, T.S.; Xu, C.

    2007-01-01

    A three-dimensional (3D) steady-state model for liquid feed direct methanol fuel cells (DMFC) is presented in this paper. This 3D mass transport model is formed by integrating five sub-models, including a modified drift-flux model for the anode flow field, a two-phase mass transport model for the porous anode, a single-phase model for the polymer electrolyte membrane, a two-phase mass transport model for the porous cathode, and a homogeneous mist-flow model for the cathode flow field. The two-phase mass transport models take account the effect of non-equilibrium evaporation/ condensation at the gas-liquid interface. A 3D computer code is then developed based on the integrated model. After being validated against the experimental data reported in the literature, the code was used to investigate numerically transport behaviors at the DMFC anode and their effects on cell performance

  5. Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan

    2012-01-01

    Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. Considering a wide range of coupling schemes, we derive antiproton and direct detection constraints using the latest data and paying close attention to astrophysical and nuclear uncertainties. Both signals are strongly enhanced in the presence of degenerate dark matter and scalar masses, but we show that the effect is especially dramatic in direct detection. Accordingly, the latest direct detection limits take the lead over antiprotons. We find that antiproton and direct detection data set stringent lower limits on the mass splitting, reaching 19% at a 300 GeV dark matter mass for a unity coupling. Interestingly, these limits are orthogonal to ongoing collider searches at the Large Hadron Collider, making it feasible to close in on degenerate dark matter scenarios within the next years

  6. Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

    2012-07-15

    Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. Considering a wide range of coupling schemes, we derive antiproton and direct detection constraints using the latest data and paying close attention to astrophysical and nuclear uncertainties. Both signals are strongly enhanced in the presence of degenerate dark matter and scalar masses, but we show that the effect is especially dramatic in direct detection. Accordingly, the latest direct detection limits take the lead over antiprotons. We find that antiproton and direct detection data set stringent lower limits on the mass splitting, reaching 19% at a 300 GeV dark matter mass for a unity coupling. Interestingly, these limits are orthogonal to ongoing collider searches at the Large Hadron Collider, making it feasible to close in on degenerate dark matter scenarios within the next years.

  7. Modelling Geomechanical Heterogeneity of Rock Masses Using Direct and Indirect Geostatistical Conditional Simulation Methods

    Science.gov (United States)

    Eivazy, Hesameddin; Esmaieli, Kamran; Jean, Raynald

    2017-12-01

    An accurate characterization and modelling of rock mass geomechanical heterogeneity can lead to more efficient mine planning and design. Using deterministic approaches and random field methods for modelling rock mass heterogeneity is known to be limited in simulating the spatial variation and spatial pattern of the geomechanical properties. Although the applications of geostatistical techniques have demonstrated improvements in modelling the heterogeneity of geomechanical properties, geostatistical estimation methods such as Kriging result in estimates of geomechanical variables that are not fully representative of field observations. This paper reports on the development of 3D models for spatial variability of rock mass geomechanical properties using geostatistical conditional simulation method based on sequential Gaussian simulation. A methodology to simulate the heterogeneity of rock mass quality based on the rock mass rating is proposed and applied to a large open-pit mine in Canada. Using geomechanical core logging data collected from the mine site, a direct and an indirect approach were used to model the spatial variability of rock mass quality. The results of the two modelling approaches were validated against collected field data. The study aims to quantify the risks of pit slope failure and provides a measure of uncertainties in spatial variability of rock mass properties in different areas of the pit.

  8. Direct molecular mass determination of trehalose monomycolate from 11 species of mycobacteria by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Fujita, Yukiko; Naka, Takashi; Doi, Takeshi; Yano, Ikuya

    2005-05-01

    Direct estimation of the molecular mass of single molecular species of trehalose 6-monomycolate (TMM), a ubiquitous cell-wall component of mycobacteria, was performed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. When less than 1 microg TMM was analysed by MALDI-TOF mass spectrometry, quasimolecular ions [M+Na]+ of each molecular species were demonstrated and the numbers of carbons and double bonds (or cyclopropane rings) were determined. Since the introduction of oxygen atoms such as carbonyl, methoxy and ester groups yielded the appropriate shift of mass ions, the major subclasses of mycolic acid (alpha, methoxy, keto and wax ester) were identified without resorting to hydrolytic procedures. The results showed a marked difference in the molecular species composition of TMM among mycobacterial species. Unexpectedly, differing from other mycoloyl glycolipids, TMM from Mycobacterium tuberculosis showed a distinctive mass pattern, with abundant odd-carbon-numbered monocyclopropanoic (or monoenoic) alpha-mycolates besides dicyclopropanoic mycolate, ranging from C75 to C85, odd- and even-carbon-numbered methoxymycolates ranging from C83 to C94 and even- and odd-carbon-numbered ketomycolates ranging from C83 to C90. In contrast, TMM from Mycobacterium bovis (wild strain and BCG substrains) possessed even-carbon-numbered dicyclopropanoic alpha-mycolates. BCG Connaught strain lacked methoxymycolates almost completely. These results were confirmed by MALDI-TOF mass analysis of mycolic acid methyl esters liberated by alkaline hydrolysis and methylation of the original TMM. Wax ester-mycoloyl TMM molecular species were demonstrated for the first time as an intact form in the Mycobacterium avium-intracellulare group, M. phlei and M. flavescens. The M. avium-intracellulare group possessed predominantly C85 and C87 wax ester-mycoloyl TMM, while M. phlei and the rapid growers tested contained C80, C81, C82 and C83 wax ester

  9. Direct and preequilibrium effects in the fission-product mass range

    International Nuclear Information System (INIS)

    Gruppelaar, H.; Hogenbirk, A.

    1992-07-01

    Until recently inelastic scattering did not gain the proper attention in fission-product cross section evaluations. In many existing evaluations global spherical optical models have been used, neglecting direct and pre-equilibrium effects. There are also few experimental data relevant to inelastic scattering in fission products. This paper is focussed on the anomalously high inelastic scattering cross sections observed in even-mass nuclei near mass A=100 at low energies. Both more data and more refined theoretical analyses are required. A number of suggestions for relevant coupled-channel calculations is made. (author). 29 refs., 5 figs., 1 tab

  10. Methyl Radicals in Oxidative Coupling of Methane Directly Confirmed by Synchrotron VUV Photoionization Mass Spectroscopy

    Science.gov (United States)

    Luo, Liangfeng; Tang, Xiaofeng; Wang, Wendong; Wang, Yu; Sun, Shaobo; Qi, Fei; Huang, Weixin

    2013-01-01

    Gas-phase methyl radicals have been long proposed as the key intermediate in catalytic oxidative coupling of methane, but the direct experimental evidence still lacks. Here, employing synchrotron VUV photoionization mass spectroscopy, we have directly observed the formation of gas-phase methyl radicals during oxidative coupling of methane catalyzed by Li/MgO catalysts. The concentration of gas-phase methyl radicals correlates well with the yield of ethylene and ethane products. These results lead to an enhanced fundamental understanding of oxidative coupling of methane that will facilitate the exploration of new catalysts with improved performance. PMID:23567985

  11. Histology-directed and imaging mass spectrometry: an emerging technology in ectopic calcification

    OpenAIRE

    Taverna, Domenico; Boraldi, Federica; De Santis, Giorgio; Caprioli, Richard M; Quaglino, Daniela

    2015-01-01

    The present study was designed to demonstrate the potential of an optimized histology directed protein identification combined with imaging mass spectrometry technology to reveal and identify molecules associated to ectopic calcification in human tissue. As a proof of concept, mineralized and non-mineralized areas were compared within the same dermal tissue obtained from a patient affected by Pseudoxanthoma elasticum, a genetic disorder characterized by calcification only at specific sites of...

  12. Direct solution introduction using conventional nebulizers with a short torch for plasma mass spectrometry

    International Nuclear Information System (INIS)

    Westphal, Craig S.; Montaser, Akbar

    2006-01-01

    A new torch, a shortened version of a standard demountable torch, is proposed for facilitating direct injection of liquid samples into an inductively coupled plasma mass spectrometer using conventional and micro-pneumatic nebulizers. The proposed arrangement reduces the cost of the direct injector nebulizer by a factor of 5, typically from $2000 to $400, although a different torch is required. The analytical performance of the high efficiency nebulizer-short torch arrangement is compared to that obtained with the direct injection high efficiency nebulizer interfaced to the conventional torch. Optimum operating conditions for the high efficiency nebulizer-short torch arrangement are generally similar to those of the direct injection high efficiency nebulizer: high RF power (1500 W), low nebulizer gas flow rates (0.09 L/min) and low solution uptake rates (5-85 μL/min). Sensitivity with the high efficiency nebulizer-short torch system at 85 μL/min is improved by a factor of 2.4 on average compared to the direct injection high efficiency nebulizer, while precision values (%RSD) and detection limits are generally comparable or slightly degraded (on average by a factor of 1.7), respectively. Sensitivity is also better at lower solution uptake rates (5 μL/min) by factors ranging from 2 ( 82 Se) to 7 ( 59 Co) compared to the direct injection high efficiency nebulizer. Additionally, the %RSD values are better at 5 μL/min, ranging from 3.5% to 6.0% for the high efficiency nebulizer-short torch combination compared to 4.7 to 9.1% for the direct injection high efficiency nebulizer. The utility of the high efficiency nebulizer-short torch arrangement is demonstrated through the microscale flow injection analysis of Cr-DNA adducts and the analysis of four certified reference materials (Lyphochek urine metals control, SRM 1515: Apple Leaves, SRM 1570a: Spinach Leaves, SRM 1577b: Bovine Liver). Peak to peak precision values (N = 3) for the microscale flow injection analysis

  13. Diagnosing impaired glucose tolerance using direct infusion mass spectrometry of blood plasma.

    Directory of Open Access Journals (Sweden)

    Petr G Lokhov

    Full Text Available The goal of this study was to evaluate the capacity for mass spectrometry of blood plasma to diagnose impaired glucose tolerance (IGT. For this study, blood plasma samples from control subjects (n = 30 and patients with IGT (n = 20 were treated with methanol and low molecular weight fraction were then analyzed by direct infusion mass spectrometry. A total of 51 metabolite ions strongly associated with IGT were detected. The area under a receiver operating characteristic (ROC curve (AUC for diagnosing IGT that was based on an analysis of all these metabolites was 0.93 (accuracy 90%, specificity 90%, and sensitivity 90%. The associated reproducibility was 85%. The metabolites identified were also consistent with risk factors previously associated with the development of diabetes. Thus, direct infusion mass spectrometry of blood plasma metabolites represents a rapid, single-step, and reproducible method for the analysis of metabolites. Moreover, this method has the potential to serve as a prototype for clinical analyses that could replace the currently used glucose tolerance test with a more patient-friendly assay.

  14. A new processing scheme for ultra-high resolution direct infusion mass spectrometry data

    Science.gov (United States)

    Zielinski, Arthur T.; Kourtchev, Ivan; Bortolini, Claudio; Fuller, Stephen J.; Giorio, Chiara; Popoola, Olalekan A. M.; Bogialli, Sara; Tapparo, Andrea; Jones, Roderic L.; Kalberer, Markus

    2018-04-01

    High resolution, high accuracy mass spectrometry is widely used to characterise environmental or biological samples with highly complex composition enabling the identification of chemical composition of often unknown compounds. Despite instrumental advancements, the accurate molecular assignment of compounds acquired in high resolution mass spectra remains time consuming and requires automated algorithms, especially for samples covering a wide mass range and large numbers of compounds. A new processing scheme is introduced implementing filtering methods based on element assignment, instrumental error, and blank subtraction. Optional post-processing incorporates common ion selection across replicate measurements and shoulder ion removal. The scheme allows both positive and negative direct infusion electrospray ionisation (ESI) and atmospheric pressure photoionisation (APPI) acquisition with the same programs. An example application to atmospheric organic aerosol samples using an Orbitrap mass spectrometer is reported for both ionisation techniques resulting in final spectra with 0.8% and 8.4% of the peaks retained from the raw spectra for APPI positive and ESI negative acquisition, respectively.

  15. The direct limit on the Higgs Mass and the SM Fit

    International Nuclear Information System (INIS)

    Chanowitz, Michael S.

    2003-01-01

    Because of two 3σ anomalies, the Standard Model (SM) fit of the precision electroweak data has a poor confidence level, CL = 0.02. Since both anomalies involve challenging systematic issues, it might appear that the SM could still be valid if the anomalies resulted from underestimated systematic error. Indeed the CL of the global fit could then increase to 0.71, but that fit predicts a small Higgs boson mass, m H = 45 GeV, that is inconsistent at 95% CL with the lower limit, m H > 114 GeV, established by direct searches. The data then favor new physics whether the anomalous measurements are excluded from the fit or not, and the Higgs boson mass cannot be predicted until the new physics is understood. Some measure of statistical fluctuation would be needed to maintain the validity of the SM. New physics is favored, but the SM is not definitively excluded

  16. Direct mass measurements of light neutron-rich nuclei using fast recoil spectrometers

    International Nuclear Information System (INIS)

    Vieira, D.J.; Wouters, J.M.

    1987-01-01

    Extensive new mass measurement capabilities have evolved with the development of recoil spectrometers. In the Z = 3 to 9 neutron-rich region alone, 12 neutron-rich nuclei have been determined for the first time by the fast-recoil direct mass measurement method. A recent experiment using the TOFI spectrometer illustrates this technique. A systematic investigation of nuclei that lie along or near the neutron-drip line has provided a valuable first glimpse into the nuclear structure of such nuclei. No evidence for a large single-particle energy gap at N = 14 is observed; however, a change in the two-neutron separation model calculations, and is interpreted in terms of the smaller 1s/sub 1/2/ - 1s/sub 1/2/ interaction compared to that of the 0d/sub 5/2/ - 0d/sub 5/2/ neutron-neutron interaction. 18 refs., 7 figs., 1 tab

  17. Structural Mass Saving Potential of a 5-MW Direct-Drive Generator Designed for Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Sethuraman, Latha [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hayes, Austin [Rochester Institute of Technology

    2017-11-09

    As wind turbine blade diameters and tower height increase to capture more energy in the wind, higher structural loads results in more structural support material increasing the cost of scaling. Weight reductions in the generator transfer to overall cost savings of the system. Additive manufacturing facilitates a design-for-functionality approach, thereby removing traditional manufacturing constraints and labor costs. The most feasible additive manufacturing technology identified for large, direct-drive generators in this study is powder-binder jetting of a sand cast mold. A parametric finite element analysis optimization study is performed, optimizing for mass and deformation. Also, topology optimization is employed for each parameter-optimized design.The optimized U-beam spoked web design results in a 24 percent reduction in structural mass of the rotor and 60 percent reduction in radial deflection.

  18. Methods of direct (non-chromatographic) quantification of body metabolites utilizing chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Mee, J.M.L.

    1978-01-01

    For quantitative determination of known metabolites from the biological sample by direct chemical ionization mass spectrometry (CI-MS), the method of internal standard using stable isotopically labelled analogs appears to be the method of choice. In the case where stable isotope ratio determinations could not be applied, and alternative quantification can be achieved using non-labelled external or internal standards and a calibration curve (sum of peak height per a given number of scans versus concentration). The technique of computer monitoring permits display and plotting of ion current profiles (TIC and SIC) or spectra per a given number of scans or a given range of mass per charge. Examples are given in areas of clinical application and the quantitative data show very good agreement with the conventional chromatographic measurements. (Auth.)

  19. Model-independent determination of the WIMP mass from direct dark matter detection data

    International Nuclear Information System (INIS)

    Drees, Manuel; Shan, Chung-Lin

    2008-01-01

    Weakly interacting massive particles (WIMPs) are one of the leading candidates for dark matter. We develop a model-independent method for determining the mass m χ of the WIMP by using data (i.e. measured recoil energies) of direct detection experiments. Our method is independent of the as yet unknown WIMP density near the Earth, of the form of the WIMP velocity distribution, as well as of the WIMP–nucleus cross section. However, it requires positive signals from at least two detectors with different target nuclei. In a background-free environment, m χ ∼50 GeV could in principle be determined with an error of ∼35% with only 2 × 50 events; in practice, upper and lower limits on the recoil energy of signal events, imposed to reduce backgrounds, can increase the error. The method also loses precision if m χ significantly exceeds the mass of the heaviest target nucleus used

  20. Cell-patterned glass spray for direct drug assay using mass spectrometry

    International Nuclear Information System (INIS)

    Wu, Jing; Wang, Shiqi; Chen, Qiushui; Jiang, Hao; Liang, Shuping; Lin, Jin-Ming

    2015-01-01

    In this work, the establishment of a glass spray mass spectrometry (GS-MS) platform for direct cell-based drug assay was described. Cell co-culture, drug-induced cell apoptosis, proliferation analysis and intracellular drug absorption measurement were performed simultaneously on this specifically designed platform. Two groups of co-cultured cells (NIH-3T3/HepG2 and HepG2/MCF-7) were cultivated and they showed high viability within 3 days. The biocompatibility of the platform facilitated the subsequent bioassays, in which, cyclophosphamide (CPA) and genistein were used as the model drugs. The distinctions of cell apoptosis and proliferation between the mono-cultured and co-cultured cells were clearly observed and well explained by in situ GS-MS measurements. A satisfactory linearity of the calibration curve between the relative MS intensity and CPA concentrations was obtained using stable isotope labeling method (y = 0.16545 + 0.0985x, R"2 = 0.9937). The variations in the quantity of absorbed drug were detected and the results were consistent with the concentration-dependence of cell apoptosis. All the results demonstrated that direct cell-based drug assay could be performed on the stable isotope labeling assisted GS-MS platform in a facile and quantitative manner. - Highlights: • A versatile glass spray mass spectrometry (GS-MS) platform for direct cell-based drug assay was developed in this paper. • It has characteristics of the atmospheric pressure ionization method. • It is multifunctional for cell co-culture, bioassays, qualitative and quantitative intracellular drug absorption measurement. • GS-MS has the potential to increase the use of mass spectrometry in biological analysis.

  1. Stephanie Lynn Budin: The Myth of Sacred Prostitution in Antiquity. Cambridge u.a.: Cambridge University Press 2008. Stephanie Lynn Budin: The Myth of Sacred Prostitution in Antiquity. Cambridge u.a.: Cambridge University Press 2008.

    Directory of Open Access Journals (Sweden)

    Julian Herbert Köck

    2010-03-01

    Full Text Available Stephanie Lynn Budin liefert mit vorliegender Studie einen wichtigen Beitrag zur Debatte um die Existenz von Tempelprostitution im Altertum. Systematisch untersucht sie die Quellen zur Tempelprostitution und kann weitgehend überzeugend darlegen, dass die betreffenden Stellen nicht für die Existenz von Tempelprostitution im Altertum sprechen, sondern nur aufgrund von tendenziösen Interpretationen so verstanden wurden. Dabei greift die Studie die Ergebnisse anderer Wissenschaftler/-innen auf, bietet aber – besonders zu Herodot und Strabon – auch neue Erkenntnisse.Stephanie Lynn Budin’s study offers up an important contribution to the debate on the existence of temple prostitution during antiquity. She systematically examines the sources on temple prostitution and can demonstrate, fairly convincingly, that the passages in question do not prove the existence of temple prostitution during antiquity, but instead have been merely understood to do so based on tendentious interpretations. In so doing, the study takes up conclusions offered by other scholars, but it also provides – especially when it comes to Herodotus and Strabo – new insights.

  2. Use of Maldi-Tof Mass spectrometry in direct microorganism identification in clinical laboratories

    Directory of Open Access Journals (Sweden)

    Tamara Brunelli

    2010-09-01

    Full Text Available Mass Spectrometry is an old technique that has recently been introduced in the clinical microbiology laboratory as Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS. MALDI is a soft ionization technique used in mass spectrometry that allows the analysis of biomolecules and large organic molecules which tend to be fragile and fragment when ionized.To obtain ions biological specimens are mixed with a matrix which specifically absorbs the ionization source (a laser beam. The high energy impact is followed by the formation of ions which are extract through an elastic field, focussed and detected as mass/charge (m/z spectrum.The differences between ions are seen with TOF, a revelation system that relates the time of flight of a ion to the charge/mass value: ion with a higher m/z have are slower (a bigger time of flight than ions with lower m/z. MALDI-TOF MS, in clinical microbiology laboratory, is used to identify bacteria and fungi directly from samples. The identification of microorganisms can be performed directly from body fluids (e.g. urine, blood culture, after centrifugation and recovery of microorganisms or from colonies (after cultivation. The rapidity of identification is of great importance in blood cultures. Positive cultures with one microorganism are processed in a different way than those with more than one microorganism. In positive monomicrobial cultures, after separation of microbs from blood cells,we can perform an immediate identification with MALDI-TOF MS that we can communicate to the clinician, and that gives indication to perform the correct antibiogram. Major problems are present when more than one microorganism are in the culture: in this case we have to use the method of subcultivation and then the identification with mass-spectrometry can be performed. MALDI-TOF MS is a rapid, reliable and low cost technique, that can identify a growing number of microorganisms. This technique can

  3. Automated work-flow for processing high-resolution direct infusion electrospray ionization mass spectral fingerprints

    DEFF Research Database (Denmark)

    Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn

    2007-01-01

    an automated data processing pipeline to compare large numbers of fingerprint spectra from direct infusion experiments analyzed by high resolution MS. We describe some of the intriguing problems that have to be addressed. starting with the conversion and pre-processing of the raw data to the final data......The use of mass spectrometry (MS) is pivotal in analyses of the metabolome and presents a major challenge for subsequent data processing. While the last few years have given new high performance instruments, there has not been a comparable development in data processing. In this paper we discuss...

  4. Physics Implications of Flat Directions in Free Fermionic Superstring Models; 1, Mass Spectrum and Couplings

    CERN Document Server

    Cleaver, G; Espinosa, J R; Everett, L; Langacker, P G; Wang, J

    1999-01-01

    From the "top-down" approach we investigate physics implications of the class of D- and F- flat directions formed from non-Abelian singlets which are proven flat to all orders in the nonrenormalizable superpotential, for a prototype quasi-realistic free fermionic string model with the standard model gauge group and three families (CHL5). These flat directions have at least an additional U(1)' unbroken at the string scale. For each flat direction, the complete set of effective mass terms and effective trilinear superpotential terms in the observable sector are computed to all orders in the VEV's of the fields in the flat direction. The "string selection-rules" disallow a large number of couplings allowed by gauge invariance, resulting in a massless spectrum with a large number of exotics, in most cases excluded by experiment, thus signifying a generic flaw of these models. Nevertheless, the resulting trilinear couplings of the massless spectrum possess a number of interesting features which we analyse for two ...

  5. Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Nelson, E J; Klunder, G L [Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

    2007-04-15

    A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse experiments have demonstrated simultaneous detection of up to 14 elements present in glasses in the ppm range. However, detection of the components has produced non-stoichiometric results due to difference in ionization potentials and fractionation effects. Time-of-flight secondary ionization mass spectrometry (TOF-SIMS) was used to spatially map elemental species on the surface and provide further evidence of fractionation effects. Resolution (m/{delta}m) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

  6. Using direct infusion mass spectrometry for serum metabolomics in Alzheimer's disease.

    Science.gov (United States)

    González-Domínguez, R; García-Barrera, T; Gómez-Ariza, J L

    2014-11-01

    Currently, there is no cure for Alzheimer's disease and early diagnosis is very difficult, since no biomarkers have been established with the necessary reliability and specificity. For the discovery of new biomarkers, the application of omics is emerging, especially metabolomics based on the use of mass spectrometry. In this work, an analytical approach based on direct infusion electrospray mass spectrometry was applied for the first time to blood serum samples in order to elucidate discriminant metabolites. Complementary methodologies of extraction and mass spectrometry analysis were employed for comprehensive metabolic fingerprinting. Finally, the application of multivariate statistical tools allowed us to discriminate Alzheimer patients and healthy controls, and identify some compounds as potential markers of disease. This approach provided a global vision of disease, given that some important metabolic pathways could be studied, such as membrane destabilization processes, oxidative stress, hypometabolism, or neurotransmission alterations. Most remarkable results are the high levels of phospholipids containing saturated fatty acids, respectively, polyunsaturated ones and the high concentration of whole free fatty acids in Alzheimer's serum samples. Thus, these results represent an interesting approximation to understand the pathogenesis of disease and the identification of potential biomarkers.

  7. External meeting: KATRIN - direct measurement of neutrino masses with sub-eV sensitivity

    CERN Multimedia

    2007-01-01

    GENEVA UNIVERSITY - ECOLE DE PHYSIQUE Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet 1211 GENEVE 4 - Tél : 022 379 62 73 - Fax: 022 379 69 92 Wednesday 18 April 2007 PARTICLE PHYSICS SEMINAR at 17:00 - Stückelberg Auditorium KATRIN - direct measurement of neutrino masses with sub-eV sensitivity by Prof. Guido Drexlin, Karlsruhe Institute of Technology KIT The major scientific objective of the international Karlsruhe Tritum Neutrino (KATRIN) Experiment is the model independent measurement of the electron neutrino mass in tritium beta decay with a sensitivity of 200 meV. In the cosmological context, this allows an investigation of whether massive relic neutrinos left over from the Big Bang play a specific role as hot dark matter in the evolution of large scale structures of the universe. In particle physics KATRIN will allow for discrimination between different neutrino mass models (either of quasi-degenerate or hierarchical pattern).The key components of KATRIN comprise...

  8. Direct Analysis in Real Time Mass Spectrometry for Characterization of Large Saccharides.

    Science.gov (United States)

    Ma, Huiying; Jiang, Qing; Dai, Diya; Li, Hongli; Bi, Wentao; Da Yong Chen, David

    2018-03-06

    Polysaccharide characterization posts the most difficult challenge to available analytical technologies compared to other types of biomolecules. Plant polysaccharides are reported to have numerous medicinal values, but their effect can be different based on the types of plants, and even regions of productions and conditions of cultivation. However, the molecular basis of the differences of these polysaccharides is largely unknown. In this study, direct analysis in real time mass spectrometry (DART-MS) was used to generate polysaccharide fingerprints. Large saccharides can break down into characteristic small fragments in the DART source via pyrolysis, and the products are then detected by high resolution MS. Temperature was shown to be a crucial parameter for the decomposition of large polysaccharide. The general behavior of carbohydrates in DART-MS was also studied through the investigation of a number of mono- and oligosaccharide standards. The chemical formula and putative ionic forms of the fragments were proposed based on accurate mass with less than 10 ppm mass errors. Multivariate data analysis shows the clear differentiation of different plant species. Intensities of marker ions compared among samples also showed obvious differences. The combination of DART-MS analysis and mechanochemical extraction method used in this work demonstrates a simple, fast, and high throughput analytical protocol for the efficient evaluation of molecular features in plant polysaccharides.

  9. Direct Energy Conversion for Low Specific Mass In-Space Power and Propulsion

    Science.gov (United States)

    Scott, John H.; George, Jeffrey A.; Tarditi, Alfonso G.

    2013-01-01

    "Changing the game" in space exploration involves changing the paradigm for the human exploration of the Solar System, e.g, changing the human exploration of Mars from a three-year epic event to an annual expedition. For the purposes of this assessment an "annual expedition" capability is defined as an in-space power & propulsion system which, with launch mass limits as defined in NASA s Mars Architecture 5.0, enables sending a crew to Mars and returning them after a 30-day surface stay within one year, irrespective of planetary alignment. In this work the authors intend to show that obtaining this capability requires the development of an in-space power & propulsion system with an end-to-end specific mass considerably less than 3 kg/kWe. A first order energy balance analysis reveals that the technologies required to create a system with this specific mass include direct energy conversion and nuclear sources that release energy in the form of charged particle beams. This paper lays out this first order approximation and details these conclusions.

  10. Polyquant CT: direct electron and mass density reconstruction from a single polyenergetic source

    Science.gov (United States)

    Mason, Jonathan H.; Perelli, Alessandro; Nailon, William H.; Davies, Mike E.

    2017-11-01

    Quantifying material mass and electron density from computed tomography (CT) reconstructions can be highly valuable in certain medical practices, such as radiation therapy planning. However, uniquely parameterising the x-ray attenuation in terms of mass or electron density is an ill-posed problem when a single polyenergetic source is used with a spectrally indiscriminate detector. Existing approaches to single source polyenergetic modelling often impose consistency with a physical model, such as water-bone or photoelectric-Compton decompositions, which will either require detailed prior segmentation or restrictive energy dependencies, and may require further calibration to the quantity of interest. In this work, we introduce a data centric approach to fitting the attenuation with piecewise-linear functions directly to mass or electron density, and present a segmentation-free statistical reconstruction algorithm for exploiting it, with the same order of complexity as other iterative methods. We show how this allows both higher accuracy in attenuation modelling, and demonstrate its superior quantitative imaging, with numerical chest and metal implant data, and validate it with real cone-beam CT measurements.

  11. Detection of Low Molecular Weight Adulterants in Beverages by Direct Analysis in Real Time Mass Spectrometry.

    Science.gov (United States)

    Sisco, Edward; Dake, Jeffrey

    2016-04-14

    Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to detect the presence of non-narcotic adulterants in beverages. The non-narcotic adulterants that were examined in this work incorporated a number low molecular weight alcohols, acetone, ammonium hydroxide, and sodium hypochlorite. Analysis of the adulterants was completed by pipetting 1 µL deposits onto glass microcapillaries along with an appropriate dopant species followed by introduction into the DART gas stream. It was found that detection of these compounds in the complex matrices of common beverages (soda, energy drinks, etc.) was simplified through the use of a dopant species to allow for adduct formation with the desired compound(s) of interest. Other parameters that were investigated included DART gas stream temperature, in source collision induced dissociation, ion polarity, and DART needle voltage. Sensitivities of the technique were found to range from 0.001 % volume fraction to 0.1 % volume fraction, comparable to traditional analyses completed using headspace gas chromatography mass spectrometry (HS-GC/MS). Once a method was established using aqueous solutions, , fifteen beverages were spiked with each of the nine adulterants, to simulate real world detection, and in nearly all cases the adulterant could be detected either in pure form, or complexed with the added dopant species. This technique provides a rapid way to directly analyze beverages believed to be contaminated with non-narcotic adulterants at sensitivities similar to or exceeding those of traditional confirmatory analyses.

  12. Cost Analysis of Direct Methanol Fuel Cell Stacks for Mass Production

    Directory of Open Access Journals (Sweden)

    Mauro Francesco Sgroi

    2016-11-01

    Full Text Available Fuel cells are very promising technologies for efficient electrical energy generation. The development of enhanced system components and new engineering solutions is fundamental for the large-scale deployment of these devices. Besides automotive and stationary applications, fuel cells can be widely used as auxiliary power units (APUs. The concept of a direct methanol fuel cell (DMFC is based on the direct feed of a methanol solution to the fuel cell anode, thus simplifying safety, delivery, and fuel distribution issues typical of conventional hydrogen-fed polymer electrolyte fuel cells (PEMFCs. In order to evaluate the feasibility of concrete application of DMFC devices, a cost analysis study was carried out in the present work. A 200 W-prototype developed in the framework of a European Project (DURAMET was selected as the model system. The DMFC stack had a modular structure allowing for a detailed evaluation of cost characteristics related to the specific components. A scale-down approach, focusing on the model device and projected to a mass production, was used. The data used in this analysis were obtained both from research laboratories and industry suppliers specialising in the manufacturing/production of specific stack components. This study demonstrates that mass production can give a concrete perspective for the large-scale diffusion of DMFCs as APUs. The results show that the cost derived for the DMFC stack is relatively close to that of competing technologies and that the introduction of innovative approaches can result in further cost savings.

  13. Direct search for neutrino mass and anomaly in the tritium beta-spectrum: Status of 'Troitsk neutrino mass' experiment

    International Nuclear Information System (INIS)

    Lobashev, V.M.; Aseev, V.N.; Belesev, A.I.; Berlev, A.I.; Geraskin, E.V.; Golubev, A.A.; Kazachenko, O.V.; Kuznetsov, Yu.E.; Ostroumov, R.P.; Rivkis, L.A.; Stern, B.E.; Titov, N.A.; Zadoroghny, C.V.; Zakharov, Yu.I.

    2000-01-01

    Results of the 'Troitsk ν-mass' experiment on search for the neutrino rest mass in the tritium beta-decay are presented. New data on the time dependence of the anomalous, bump-like structure at the end of the beta spectrum reported earlier are discussed. Possible systematics is considered in view of contradiction of 'Troitsk nu-mass' observation with those of 'Mainz neutrino' set-up. An upper limit for electron antineutrino rest mass remains at m ν 2 at 95% C.L

  14. Chemometric brand differentiation of commercial spices using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Pavlovich, Matthew J; Dunn, Emily E; Hall, Adam B

    2016-05-15

    Commercial spices represent an emerging class of fuels for improvised explosives. Being able to classify such spices not only by type but also by brand would represent an important step in developing methods to analytically investigate these explosive compositions. Therefore, a combined ambient mass spectrometric/chemometric approach was developed to quickly and accurately classify commercial spices by brand. Direct analysis in real time mass spectrometry (DART-MS) was used to generate mass spectra for samples of black pepper, cayenne pepper, and turmeric, along with four different brands of cinnamon, all dissolved in methanol. Unsupervised learning techniques showed that the cinnamon samples clustered according to brand. Then, we used supervised machine learning algorithms to build chemometric models with a known training set and classified the brands of an unknown testing set of cinnamon samples. Ten independent runs of five-fold cross-validation showed that the training set error for the best-performing models (i.e., the linear discriminant and neural network models) was lower than 2%. The false-positive percentages for these models were 3% or lower, and the false-negative percentages were lower than 10%. In particular, the linear discriminant model perfectly classified the testing set with 0% error. Repeated iterations of training and testing gave similar results, demonstrating the reproducibility of these models. Chemometric models were able to classify the DART mass spectra of commercial cinnamon samples according to brand, with high specificity and low classification error. This method could easily be generalized to other classes of spices, and it could be applied to authenticating questioned commercial samples of spices or to examining evidence from improvised explosives. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Evaluation of three gas chromatography and two direct mass spectrometry techniques for aroma analysis of dried red bell peppers

    NARCIS (Netherlands)

    Ruth, van S.M.; Boscaini, E.; Mayr, D.; Pugh, J.; Posthumus, M.A.

    2003-01-01

    Three gas chromatography methods and two direct mass spectrometry techniques were compared for the analysis of the aroma of rehydrated diced red bell peppers. Gas chromatography methods included systems with olfactometry detection (GC-O), flame ionisation detection (GC-FID) and mass spectrometry

  16. Profiling of Piper betle Linn. cultivars by direct analysis in real time mass spectrometric technique.

    Science.gov (United States)

    Bajpai, Vikas; Sharma, Deepty; Kumar, Brijesh; Madhusudanan, K P

    2010-12-01

    Piper betle Linn. is a traditional plant associated with the Asian and southeast Asian cultures. Its use is also recorded in folk medicines in these regions. Several of its medicinal properties have recently been proven. Phytochemical analysis showed the presence of mainly terpenes and phenols in betel leaves. These constituents vary in the different cultivars of Piper betle. In this paper we have attempted to profile eight locally available betel cultivars using the recently developed mass spectral ionization technique of direct analysis in real time (DART). Principal component analysis has also been employed to analyze the DART MS data of these betel cultivars. The results show that the cultivars of Piper betle could be differentiated using DART MS data. Copyright © 2010 John Wiley & Sons, Ltd.

  17. Direct characterization of commercial lecithins by easy ambient sonic-spray ionization mass spectrometry.

    Science.gov (United States)

    Fernandes, Gabriel D; Alberici, Rosana M; Pereira, Gustavo G; Cabral, Elaine C; Eberlin, Marcos N; Barrera-Arellano, Daniel

    2012-12-01

    Commercial lecithins are composed mainly of phospholipids and triacylglycerols. The analysis of the commercial lecithins, including their fraction of phospholipids, normally involves laborious and expensive protocols. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to be an efficient technique for the analysis of lipids. Samples of commercial lecithins including standards, refined, deoiled and modified soy lecithin were tested. Characteristic profiles of phosphatidylcholines and triacylglycerols are detected by EASI(+)-MS, whereas EASI(-)-MS provided phosphatidylethanolamines, glycophospholipids and free fatty acids profiles. Acetylated lecithins also displayed characteristic acetylated derivatives. EASI-MS data was also compared to MALDI-MS, and found to display richer compositional information. The industrial process applied to lecithin fabrication was also characterised via typical EASI-MS profiles. EASI-MS both in its positive and negative ion modes offers a direct, fast and efficient technique able to characterise commercial lecithin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Direct Surface Analysis of Fungal Species by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Valentine, Nancy B.(BATTELLE (PACIFIC NW LAB)); Wahl, Jon H.(BATTELLE (PACIFIC NW LAB)); Kingsley, Mark T.(BATTELLE (PACIFIC NW LAB)); Wahl, Karen L.(BATTELLE (PACIFIC NW LAB))

    2001-12-01

    Intact spores and/or hyphae of Aspergillus niger, Rhizopus oryzae, Trichoderma reesei and Phanerochaete chrysosporium are analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). This study investigates various methods of sample preparation and matrices to determine optimum collection and analysis criteria for fungal analysis by MALDI-MS. Fungi are applied to the MALDI sample target as untreated, sonicated, acid/heat treated, or blotted directly from the fungal culture with double-stick tape. Ferulic acid or sinapinic acid matrix solution is layered over the dried samples and analyzed by MALDI-MS. Statistical analysis of the data show that simply using double stick tape to collect and transfer to a MALDI sample plate typically worked as well as the other preparation methods, but requires the least sample handling.

  19. A direct method for soil-structure interaction analysis based on frequency-dependent soil masses

    International Nuclear Information System (INIS)

    Danisch, R.; Delinic, K.; Marti, J.; Trbojevic, V.M.

    1993-01-01

    In a soil-structure interaction analysis, the soil, as a subsystem of the global vibrating system, exerts a strong influence on the response of the nuclear reactor building to the earthquake excitation. The volume of resources required for dealing with the soil have led to a number of different types of frequency-domain solutions, most of them based on the impedance function approach. These procedures require coupling the soil to the lumped-mass finite-element model of the reactor building. In most practical cases, the global vibrating system is analysed in the time domain (i.e. modal time history, linear or non-linear direct time-integration). Hence, it follows that the frequency domain solution for soil must be converted to an 'equivalent' soil model in the time domain. Over the past three decades, different approaches have been developed and used for earthquake analysis of nuclear power plants. In some cases, difficulties experienced in modelling the soil have affected the methods of global analysis, thus leading to approaches like the substructuring technique, e.g. 3-step method. In the practical applications, the limitations of each specific method must be taken into account in order to avoid unrealistic results. The aim of this paper is to present the recent development on an equivalent SDOF system for soil including frequency-dependent soil masses. The method will be compared with the classical 3-step method. (author)

  20. Analysis of writing inks on paper using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Jones, Roger W; McClelland, John F

    2013-09-10

    Ink analysis is central to questioned document examination. We applied direct analysis in real time mass spectrometry (DART MS) to ballpoint, gel, and fluid writing ink analysis. DART MS acquires the mass spectrum of an ink while it is still on a document without altering the appearance of the document. Spectra were acquired from ink on a variety of papers, and the spectrum of the blank paper could be subtracted out to produce a cleanly isolated ink spectrum in most cases. Only certain heavy or heavily processed papers interfered. The time since an ink is written on paper has a large effect on its spectrum. DART spectra change radically during the first few months after an ink is written as the more volatile components evaporate, but the spectra stabilize after that. A library-search study involving 166 well-aged inks assessed the ability to identify inks from their DART spectra. The aggregate success rate was 92%. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  2. On the Existence of Low-Mass Dark Matter and its Direct Detection

    Science.gov (United States)

    Bateman, James; McHardy, Ian; Merle, Alexander; Morris, Tim R.; Ulbricht, Hendrik

    2015-01-01

    Dark Matter (DM) is an elusive form of matter which has been postulated to explain astronomical observations through its gravitational effects on stars and galaxies, gravitational lensing of light around these, and through its imprint on the Cosmic Microwave Background (CMB). This indirect evidence implies that DM accounts for as much as 84.5% of all matter in our Universe, yet it has so far evaded all attempts at direct detection, leaving such confirmation and the consequent discovery of its nature as one of the biggest challenges in modern physics. Here we present a novel form of low-mass DM χ that would have been missed by all experiments so far. While its large interaction strength might at first seem unlikely, neither constraints from particle physics nor cosmological/astronomical observations are sufficient to rule out this type of DM, and it motivates our proposal for direct detection by optomechanics technology which should soon be within reach, namely, through the precise position measurement of a levitated mesoscopic particle which will be perturbed by elastic collisions with χ particles. We show that a recently proposed nanoparticle matter-wave interferometer, originally conceived for tests of the quantum superposition principle, is sensitive to these collisions, too. PMID:25622565

  3. Direct analysis of ethylenediaminetetraacetic acid (EDTA) on concrete by reactive-desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Lebeau, D; Reiller, P E; Lamouroux, C

    2015-01-01

    Analysis of organic ligands such as ethylenediaminetetraacetic acid (EDTA) is today an important challenge due to their ability to increase the mobility of radionuclides and metals. Reactive desorption electrospray ionization mass spectrometry (reactive-DESI-MS) was used for direct analysis of EDTA on concrete samples. EDTA forms complexes and those with Fe(III) ions are among the most thermodynamically favored. This complexing capacity was used to improve the specific detection of EDTA directly on a concrete matrix by doping the solvent spray of DESI with a solution of FeCl3 to selectively create the complex between EDTA and Fe(III). Thus, EDTA sensitivity was largely improved by two orders of magnitude with reactive-DESI-MS experiments thanks to the specific detection of EDTA as a [EDTA-4H+Fe(III)](-) complex. The proof of principle that reactive DESI can be applied to concrete samples to detect EDTA has been demonstrated. Its capacity for semi-quantitative determination and localization of EDTA under ambient conditions and with very little sample preparation, minimizing sample manipulations and solvent volumes, two important conditions for the development of new methodologies in the field of analytical chemistry, has been shown. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. On the Existence of Low-Mass Dark Matter and its Direct Detection

    Science.gov (United States)

    Bateman, James; McHardy, Ian; Merle, Alexander; Morris, Tim R.; Ulbricht, Hendrik

    2015-01-01

    Dark Matter (DM) is an elusive form of matter which has been postulated to explain astronomical observations through its gravitational effects on stars and galaxies, gravitational lensing of light around these, and through its imprint on the Cosmic Microwave Background (CMB). This indirect evidence implies that DM accounts for as much as 84.5% of all matter in our Universe, yet it has so far evaded all attempts at direct detection, leaving such confirmation and the consequent discovery of its nature as one of the biggest challenges in modern physics. Here we present a novel form of low-mass DM χ that would have been missed by all experiments so far. While its large interaction strength might at first seem unlikely, neither constraints from particle physics nor cosmological/astronomical observations are sufficient to rule out this type of DM, and it motivates our proposal for direct detection by optomechanics technology which should soon be within reach, namely, through the precise position measurement of a levitated mesoscopic particle which will be perturbed by elastic collisions with χ particles. We show that a recently proposed nanoparticle matter-wave interferometer, originally conceived for tests of the quantum superposition principle, is sensitive to these collisions, too.

  5. Metabolic Profiling Directly from the Petri Dish Using Nanospray Desorption Electrospray Ionization Imaging Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, Jeramie D.; Roach, Patrick J.; Heath, Brandi S.; Alexandrov, Theodore; Laskin, Julia; Dorrestein, Pieter C.

    2013-11-05

    Understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. However, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. Here, we report the use of nanospray desorption electrospray ionization (nanoDESI) imaging mass spectrometry for in vivo metabolic profiling of living bacterial colonies directly from the Petri dish with absolutely no sample preparation needed. Using this technique, we investigated single colonies of Shewanella oneidensis MR-1, Bacillus subtilis 3610, and Streptomyces coelicolor A3(2) as well as a mixed biofilm of S. oneidensis MR-1 and B. subtilis 3610. Data from B. subtilis 3610 and S. coelicolor A3(2) provided a means of validation for the method while data from S. oneidensis MR-1 and the mixed biofilm showed a wide range of compounds that this bacterium uses for the dissimilatory reduction of extracellular metal oxides, including riboflavin, iron-bound heme and heme biosynthetic intermediates, and the siderophore putrebactin.

  6. Private I: The Protagonists in Lynne Rae Perkins' Newbery-Winning Novel Are Shy, Talented, and Extremely Thoughtful--Kind of Like the Author

    Science.gov (United States)

    Barstow, Barb

    2006-01-01

    Lynne Rae Perkins is the author of "Criss Cross," which won the Newbery Medal, the nation's most prestigious prize for children's book. Perkins grew up in Cheswick, PA, near Pittsburgh, majored in printmaking at Penn State, and attended grad school at the University of Wisconsin-Milwaukee. She moved to Leelanau County, MI, in 1987 with her…

  7. The fate of the Data Retention Directive: about mass surveillance and fundamental rights in the EU legal order

    NARCIS (Netherlands)

    Marin, Luisa; Mitsilegas, Valsamis; Bergstrom, Maria; Konstadinides, Theodore

    2016-01-01

    The chapter explores the fate of the Data Retention Directive, the Digital Rights Ireland case and its implications for mass surveillance and data protection. After the Introduction, setting the issue within the context of Snowden’s revelations, the chapter presents the Data Retention Directive and

  8. Terverticillate penicillia studied by direct electrospray mass spectrometric profiling of crude extracts II. Database and identification

    DEFF Research Database (Denmark)

    Smedsgaard, Jørn

    1997-01-01

    A mass spectral database was built using standard instrument software from 678 electrospray mass spectra (mass profiles) from crude fungal extracts of terverticillate taxa within the genus Penicillium. The match factors calculated from searching all the mass profiles stored in the database were...

  9. Rapid quantification of free cholesterol in tears using direct insertion/electron ionization-mass spectrometry.

    Science.gov (United States)

    Wei, Xiaojia Eric; Korth, John; Brown, Simon H J; Mitchell, Todd W; Truscott, Roger J W; Blanksby, Stephen J; Willcox, Mark D P; Zhao, Zhenjun

    2013-12-09

    To establish a simple and rapid analytical method, based on direct insertion/electron ionization-mass spectrometry (DI/EI-MS), for measuring free cholesterol in tears from humans and rabbits. A stable-isotope dilution protocol employing DI/EI-MS in selected ion monitoring mode was developed and validated. It was used to quantify the free cholesterol content in human and rabbit tear extracts. Tears were collected from adult humans (n = 15) and rabbits (n = 10) and lipids extracted. Screening, full-scan (m/z 40-600) DI/EI-MS analysis of crude tear extracts showed that diagnostic ions located in the mass range m/z 350 to 400 were those derived from free cholesterol, with no contribution from cholesterol esters. DI/EI-MS data acquired using selected ion monitoring (SIM) were analyzed for the abundance ratios of diagnostic ions with their stable isotope-labeled analogues arising from the D6-cholesterol internal standard. Standard curves of good linearity were produced and an on-probe limit of detection of 3 ng (at 3:1 signal to noise) and limit of quantification of 8 ng (at 10:1 signal to noise). The concentration of free cholesterol in human tears was 15 ± 6 μg/g, which was higher than in rabbit tears (10 ± 5 μg/g). A stable-isotope dilution DI/EI-SIM method for free cholesterol quantification without prior chromatographic separation was established. Using this method demonstrated that humans have higher free cholesterol levels in their tears than rabbits. This is in agreement with previous reports. This paper provides a rapid and reliable method to measure free cholesterol in small-volume clinical samples.

  10. Interaction of Hb Grey Lynn (Vientiane) [α91(FG3)Leu>Phe (α1)] with Hb E [β26(B8) Glu>Lys] and α(+)-thalassemia: Molecular and Hematological Analysis.

    Science.gov (United States)

    Singha, Kritsada; Fucharoen, Goonnapa; Fucharoen, Supan

    2015-01-01

    Hemoglobin (Hb) Grey Lynn is a Hb variant caused by a mutation at codon 91 of α1-globin gene whereas Hb E is a common β-globin chain variant among Southeast Asian population. We report two hitherto undescribed conditions of Hb Grey Lynn found in Thai individuals. The study was done on two unrelated Thai subjects. Hematological parameters were recorded and Hb analysis was carried out using automated Hb analyzers. Mutations were identified by DNA analysis. Hematological features of the patients were compared with those of various forms of Hb Grey Lynn documented previously. Hb and DNA analyses identified a heterozygous Hb Grey Lynn in one patient and a double heterozygous Hb Grey Lynn and Hb E with α(+)-thalassemia in another. Interaction of α(Grey Lynn) with β(E) chains leads to the formation of a new Hb variant, namely the Hb Grey Lynn E (α(GL)2β(E)2), detectable by liquid chromatography (10.3%) but masked by Hb E on capillary electrophoresis. Interaction of these multiple globin gene defects could lead to complex hemoglobinopathies requiring combined analysis with multiple Hb analyzers followed by DNA testing to provide accurate diagnosis of the cases.

  11. Rapid quality assessment of Radix Aconiti Preparata using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Zhu, Hongbin; Wang, Chunyan; Qi, Yao; Song, Fengrui; Liu, Zhiqiang; Liu, Shuying

    2012-11-08

    This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in combination with multivariate data analysis provides a very flexible and reliable method for quality assessment of toxic herbal medicine. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Direct infusion mass spectrometry metabolomics dataset: a benchmark for data processing and quality control

    Science.gov (United States)

    Kirwan, Jennifer A; Weber, Ralf J M; Broadhurst, David I; Viant, Mark R

    2014-01-01

    Direct-infusion mass spectrometry (DIMS) metabolomics is an important approach for characterising molecular responses of organisms to disease, drugs and the environment. Increasingly large-scale metabolomics studies are being conducted, necessitating improvements in both bioanalytical and computational workflows to maintain data quality. This dataset represents a systematic evaluation of the reproducibility of a multi-batch DIMS metabolomics study of cardiac tissue extracts. It comprises of twenty biological samples (cow vs. sheep) that were analysed repeatedly, in 8 batches across 7 days, together with a concurrent set of quality control (QC) samples. Data are presented from each step of the workflow and are available in MetaboLights. The strength of the dataset is that intra- and inter-batch variation can be corrected using QC spectra and the quality of this correction assessed independently using the repeatedly-measured biological samples. Originally designed to test the efficacy of a batch-correction algorithm, it will enable others to evaluate novel data processing algorithms. Furthermore, this dataset serves as a benchmark for DIMS metabolomics, derived using best-practice workflows and rigorous quality assessment. PMID:25977770

  13. Direct analysis in real time-Mass spectrometry (DART-MS) in forensic and security applications.

    Science.gov (United States)

    Pavlovich, Matthew J; Musselman, Brian; Hall, Adam B

    2018-03-01

    Over the last decade, direct analysis in real time (DART) has emerged as a viable method for fast, easy, and reliable "ambient ionization" for forensic analysis. The ability of DART to generate ions from chemicals that might be present at the scene of a criminal activity, whether they are in the gas, liquid, or solid phase, with limited sample preparation has made the technology a useful analytical tool in numerous forensic applications. This review paper summarizes many of those applications, ranging from the analysis of trace evidence to security applications, with a focus on providing the forensic scientist with a resource for developing their own applications. The most common uses for DART in forensics are in studying seized drugs, drugs of abuse and their metabolites, bulk and detonated explosives, toxic chemicals, chemical warfare agents, inks and dyes, and commercial plant and animal products that have been adulterated for economic gain. This review is meant to complement recent reviews that have described the fundamentals of the ionization mechanism and the general use of DART. We describe a wide range of forensic applications beyond the field of analyzing drugs of abuse, which dominates the literature, including common experimental and data analysis methods. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:171-187, 2018. © 2016 Wiley Periodicals, Inc.

  14. Mass-produced multi-walled carbon nanotubes as catalyst supports for direct methanol fuel cells.

    Science.gov (United States)

    Jang, In Young; Park, Ki Chul; Jung, Yong Chae; Lee, Sun Hyung; Song, Sung Moo; Muramatsu, Hiroyuki; Kim, Yong Jung; Endo, Morinobu

    2011-01-01

    Commercially mass-produced multi-walled carbon nanotubes, i.e., VGNF (Showa Denko Co.), were applied to support materials for platinum-ruthenium (PtRu) nanoparticles as anode catalysts for direct methanol fuel cells. The original VGNFs are composed of high-crystalline graphitic shells, which hinder the favorable surface deposition of the PtRu nanoparticles that are formed via borohydride reduction. The chemical treatment of VGNFs with potassium hydroxide (KOH), however, enables highly dispersed and dense deposition of PtRu nanoparticles on the VGNF surface. This capability becomes more remarkable depending on the KOH amount. The electrochemical evaluation of the PtRu-deposited VGNF catalysts showed enhanced active surface areas and methanol oxidation, due to the high dispersion and dense deposition of the PtRu nanoparticles. The improvement of the surface deposition states of the PtRu nanoparticles was significantly due to the high surface area and mesorporous surface structure of the KOH-activated VGNFs.

  15. A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

    Science.gov (United States)

    Sarver, Scott A.; Chetwani, Nishant; Dovichi, Norman J.; Go, David B.; Gartner, Carlos A.

    2014-04-01

    A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS have been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were one to two orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50 %, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one-half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating that improvements in spectral quality may benefit certain compounds or classes of compounds, on an individual basis.

  16. Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry

    Science.gov (United States)

    Vega, Carolina; Spence, Corina; Zhang, Chengsen; Bills, Brandon J.; Manicke, Nicholas E.

    2016-04-01

    Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached -90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent.

  17. Direct analysis of samples by mass spectrometry: From elements to bio-molecules using laser ablation inductively couple plasma mass spectrometry and laser desorption/ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Perdian, David C. [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    Mass spectrometric methods that are able to analyze solid samples or biological materials with little or no sample preparation are invaluable to science as well as society. Fundamental research that has discovered experimental and instrumental parameters that inhibit fractionation effects that occur during the quantification of elemental species in solid samples by laser ablation inductively coupled plasma mass spectrometry is described. Research that determines the effectiveness of novel laser desorption/ionization mass spectrometric methods for the molecular analysis of biological tissues at atmospheric pressure and at high spatial resolution is also described. A spatial resolution is achieved that is able to analyze samples at the single cell level.

  18. Determination of drugs and drug-like compounds in different samples with direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Chernetsova, Elena S; Morlock, Gertrud E

    2011-01-01

    Direct analysis in real time (DART), a relatively new ionization source for mass spectrometry, ionizes small-molecule components from different kinds of samples without any sample preparation and chromatographic separation. The current paper reviews the published data available on the determination of drugs and drug-like compounds in different matrices with DART-MS, including identification and quantitation issues. Parameters that affect ionization efficiency and mass spectra composition are also discussed. Copyright © 2011 Wiley Periodicals, Inc.

  19. Study of mass and momentum transfer and their effect on the direct fluorination of uranium oxide

    International Nuclear Information System (INIS)

    Cross, P.E.

    1983-01-01

    The mechanism for the fluorination of solid U 3 O 8 to gaseous UF 6 was found to be a two-step process with solid UO 2 F 2 as an intermediate. The highest particle temperatures were found to be associated with the initial reaction step to UO 2 F 2 ; it was recommended that these temperatures be maintained below 1700 0 F. The chemical equilibrium constant for the fluorination of PuF 4 to PuF 6 was found to be unexpectedly low at typical flame tower temperatures. Although not confirmed, there is an indication in the literature that a similar equilibrium constant is associated with the fluorination of NpF 4 and other transuranic molecules. It was recommended that uranium oxides which are significantly contaminated with transuranics should not be processed through a direct fluorination reactor such as the UF 6 flame tower. Reaction rate equations were developed for the fluorination of U 3 O 8 , UF 4 , PuF 4 and NpF 4 . During the course of the development, a significant discrepancy was found in the literature for the activation energy of the fluorination of U 3 O 8 . Equations were developed for both a high and low limit rate constant for the fluorination of U 3 O 8 . A variey of momentum, heat and mass transfer equations were developed for both oxide particles and the gas phase within the flame tower. Equations were developed to estimate the physical and transport properties of each gaseous component and the gas mixture as a whole. These properties and the transport equations were used to estimate the reaction time and distance for oxide particles with both the low and high limit reaction rate constant. The procedures used to perform these calculations is limited to constant temperature and an oxide feed comprised of a single particle size. The results indicate that above 1000 0 F the mass transfer of reactants and products becomes increasingly important to the overall rate of the reaction

  20. Direct mass measurements in the light neutron-rich region using a combined energy and time-of-flight technique

    International Nuclear Information System (INIS)

    Pillai, C.; Swenson, L.W.; Vieira, D.J.; Butler, G.W.; Wouters, J.M.; Rokni, S.H.; Vaziri, K.; Remsberg, L.P.

    1985-01-01

    This experiment has demonstrated that direct mass measurements can be performed (albeit of low precision in this first attempt) using the M proportional to ET 2 method. This technique has the advantage that many particle-bound nuclei, produced in fragmentation reactions can be measured simultaneously, independent of their N or Z. The main disadvantage of this approach is that both energy and time-of-flight must be measured precisely on an absolute scale. Although some mass walk with N and Z was observed in this experiment, these uncertainties were largely removed by extrapolating the smooth dependence observed for known nuclei which lie closer to the valley of β-stability. Mass measurements for several neutron-rich light nuclei ranging from 17 C to 26 Ne have been performed. In all cases these measurements agree with the latest mass compilation of Wapstra and Audi. The masses of 20 N and 24 F have been determined for the first time

  1. Limits on the production of large transverse momentum direct photons deduced from the measurement of low-mass electron pairs

    International Nuclear Information System (INIS)

    Cobb, J.H.; Iwata, S.; Palmer, R.B.; Rahm, D.C.; Rehak, P.; Stumer, I.; Fabjan, C.W.; Fowler, E.; Mannelli, I.; Mouzourakis, P.; Nakamura, K.; Nappi, A.; Willis, W.J.; Goldberg, M.; Horwitz, N.; Moneti, G.C.; Lankford, A.J.; Kourkoumelis, C.

    1978-01-01

    The hadronic production of electron pairs with masses between 200 and 500 MeV and large transverse momentum has been measured at the CERN Intersecting Storage Rings (ISR). The expected relation between low-mass electron pairs and real photons is used to determine the direct hadronic production of photons. Contrary to indications from some previous experiments, the observed spectrum is consistent with expectations from the decay of known mesons, and leads to a value for the ratio of direct photons to π 0 of γ/π 0 =(0.55+-0.92)% for 2 = 55 GeV. (Auth.)

  2. Direct mass measurements of {sup 100}Sn and magic nuclei near the N=Z line; Mesures directes des masses de {sup 100}Sn et de noyaux exotiques proches de la ligne N = Z

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, M

    1996-10-31

    The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A {approx_equal} 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a {sup 78}Kr beam on a {sup nat}Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of {sup 70}Se and {sup 71}Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus {sup 100}Sn was successfully performed, using this original technique. Secondary ions of {sup 100}Ag, {sup 100}Cd, {sup 100}In and {sup 100}Sn produced via fusion-evaporation reaction {sup 50}Cr + {sup 58}Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of {sup 100}Cd and, for the first time, the masses of {sup 100}Sn were determined directly with respect to the reference mass of {sup 100}Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author). 96 refs.

  3. Rapid quality assessment of Radix Aconiti Preparata using direct analysis in real time mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Hongbin; Wang Chunyan; Qi Yao [Changchun Center of Mass Spectrometry and Chemical Biology Laboratory, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Song Fengrui, E-mail: songfr@ciac.jl.cn [Changchun Center of Mass Spectrometry and Chemical Biology Laboratory, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Liu Zhiqiang; Liu Shuying [Changchun Center of Mass Spectrometry and Chemical Biology Laboratory, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-11-08

    Highlights: Black-Right-Pointing-Pointer DART MS combined with PCA and HCA was used to rapidly identify markers of Radix Aconiti. Black-Right-Pointing-Pointer The DART MS behavior of six aconitine-type alkaloids was investigated. Black-Right-Pointing-Pointer Chemical markers were recognized between the qualified and unqualified samples. Black-Right-Pointing-Pointer DART MS was shown to be an effective tool for quality control of Radix Aconiti Preparata. - Abstract: This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in

  4. Rapid quality assessment of Radix Aconiti Preparata using direct analysis in real time mass spectrometry

    International Nuclear Information System (INIS)

    Zhu Hongbin; Wang Chunyan; Qi Yao; Song Fengrui; Liu Zhiqiang; Liu Shuying

    2012-01-01

    Highlights: ► DART MS combined with PCA and HCA was used to rapidly identify markers of Radix Aconiti. ► The DART MS behavior of six aconitine-type alkaloids was investigated. ► Chemical markers were recognized between the qualified and unqualified samples. ► DART MS was shown to be an effective tool for quality control of Radix Aconiti Preparata. - Abstract: This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in combination with multivariate data analysis provides a very flexible and reliable method for quality

  5. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    International Nuclear Information System (INIS)

    Silva, V.S.; Ruffmann, B.; Vetter, S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M.; Nunes, S.P.

    2006-01-01

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion[reg] 112 was used as reference material. DMFC tests were also performed at 50 deg. C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion[reg] 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD = 71% showed to have similar performance, or even better, as that of Nafion[reg] 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD = 52%

  6. Direct analysis in real time mass spectrometry for analysis of sexual assault evidence.

    Science.gov (United States)

    Musah, Rabi A; Cody, Robert B; Dane, A John; Vuong, Angela L; Shepard, Jason R E

    2012-05-15

    Sexual assault crimes are vastly underreported and suffer from alarmingly low prosecution and conviction rates. The key scientific method to aid in prosecution of such cases is forensic DNA analysis, where biological evidence such as semen collected using a rape test kit is used to determine a suspect's DNA profile. However, the growing awareness by criminals of the importance of DNA in the prosecution of sexual assaults has resulted in increased condom use by assailants as a means to avoid leaving behind their DNA. Thus, other types of trace evidence are important to help corroborate victims' accounts, exonerate the innocent, link suspects to the crime, or confirm penetration. Direct Analysis in Real Time Mass Spectrometry (DART-MS) was employed for the comprehensive characterization of non-DNA trace evidence associated with sexual assault. The ambient ionization method associated with DART-MS is extremely rapid and samples are processed instantaneously, without the need for extraction, sample preparation, or other means that might compromise forensic evidence for future analyses. In a single assay, we demonstrated the ability to identify lubricant formulations associated with sexual assault, such as the spermicide nonoxynol-9, compounds used in condom manufacture, and numerous other trace components as probative evidence. In addition, the method can also serve to identify compounds within trace biological residues, such as fatty acids commonly identified in latent fingerprints. Characterization of lubricant residues as probative evidence serves to establish a connection between the victim and the perpetrator, and the availability of these details may lead to higher rates of prosecution and conviction, as well as more severe penalties. The methodology described here opens the way for the adoption of a comprehensive, rapid, and sensitive analysis for use in crime labs, while providing knowledge that can inform and guide criminal justice policy and practice

  7. Direct trace analysis of metals and alloys in a quadrupole ion-trap mass spectrometer

    CERN Document Server

    Song, K S; Yang, M; Cha, H K; Lee, J M; Lee, G H

    1999-01-01

    An ion-trap mass spectrometer adopting a quadrupole ion-trap and laser ablation/ionization method was constructed. The developed system was tested for composition analysis of some metals (Cu, stainless), and alloys (hastalloy C, mumetal) by mass spectrometry. Samples were analyzed by using laser ablation from a sample probe tip followed by a mass analysis with the quadrupole ion-trap. The quadrupole ion-trap was modified to enable laser ablation by a XeCl excimer laser pulse that passed radially through the ring electrode. A mass scan of the produced ions was performed in the mass selective instability mode wherein trapped ions were successively detected by increasing the rf voltage through the ring electrode. Factors affecting the mass resolution, such as pressure of buffer gas and ablation laser power, are discussed.

  8. Quantitation of mycotoxins using direct analysis in real time (DART)-mass spectrometry (MS)

    Science.gov (United States)

    Ambient ionization represents a new generation of mass spectrometry ion sources which is used for rapid ionization of small molecules under ambient conditions. The combination of ambient ionization and mass spectrometry allows analyzing multiple food samples with simple or no sample treatment, or in...

  9. Direct Detection of Pharmaceuticals and Personal Care Products from Aqueous Samples with Thermally-Assisted Desorption Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Campbell, Ian S.; Ton, Alain T.; Mulligan, Christopher C.

    2011-07-01

    An ambient mass spectrometric method based on desorption electrospray ionization (DESI) has been developed to allow rapid, direct analysis of contaminated water samples, and the technique was evaluated through analysis of a wide array of pharmaceutical and personal care product (PPCP) contaminants. Incorporating direct infusion of aqueous sample and thermal assistance into the source design has allowed low ppt detection limits for the target analytes in drinking water matrices. With this methodology, mass spectral information can be collected in less than 1 min, consuming ~100 μL of total sample. Quantitative ability was also demonstrated without the use of an internal standard, yielding decent linearity and reproducibility. Initial results suggest that this source configuration is resistant to carryover effects and robust towards multi-component samples. The rapid, continuous analysis afforded by this method offers advantages in terms of sample analysis time and throughput over traditional hyphenated mass spectrometric techniques.

  10. Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry.

    Science.gov (United States)

    Perez-Hurtado, P; Palmer, E; Owen, T; Aldcroft, C; Allen, M H; Jones, J; Creaser, C S; Lindley, M R; Turner, M A; Reynolds, J C

    2017-11-30

    The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump-based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis. Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples. The interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively. The described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats. © 2017 The Authors. Rapid Communications in Mass

  11. The Use of Low Temperature Detectors for Direct Measurements of the Mass of the Electron Neutrino

    Directory of Open Access Journals (Sweden)

    A. Nucciotti

    2016-01-01

    Full Text Available Recent years have witnessed many exciting breakthroughs in neutrino physics. The detection of neutrino oscillations has proved that neutrinos are massive particles, but the assessment of their absolute mass scale is still an outstanding challenge in today particle physics and cosmology. Since low temperature detectors were first proposed for neutrino physics experiments in 1984, there has been tremendous technical progress: today this technique offers the high energy resolution and scalability required to perform competitive experiments challenging the lowest electron neutrino masses. This paper reviews the thirty-year effort aimed at realizing calorimetric measurements with sub-eV neutrino mass sensitivity using low temperature detectors.

  12. Direct search for neutrino mass and anomaly in the tritium beta-spectrum

    International Nuclear Information System (INIS)

    Lobashev, V.M.; Assev, V.N.; Belesev, A.I.; Berlev, A.I.; Geraskin, E.V.; Golubev, A.A.; Kazachenko, O.V.; Kuznetsov, Y.E.; Ostroumov, R.P.; Rivkis, L.A.; Stern, B.E.; Titov, N.A.; Zasoroghny, C.V.; Zakharov, Y.I.

    2001-01-01

    Results of the ''Troitsk ν-mass'' experiment on search for the neutrino rest mass in the tritium beta-decay are presented. Study of time dependence of anomalous, bump-like structure at the end of the beta spectrum reported earlier gives indication of a periodic shift of the position of the bump with respect to the end-point energy with period of 0.5 year. New upper limit for electron antineutrino rest mass m ν 2 is derived after accounting for the bump. (authors)

  13. Direct Energy Conversion for Nuclear Propulsion at Low Specific Mass Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Low specific mass (< 3  kg/kW) in-space electric power and propulsion can drastically alter the paradigm for exploration of the Solar System, changing human...

  14. Native Liquid Extraction Surface Analysis Mass Spectrometry: Analysis of Noncovalent Protein Complexes Directly from Dried Substrates

    Science.gov (United States)

    Martin, Nicholas J.; Griffiths, Rian L.; Edwards, Rebecca L.; Cooper, Helen J.

    2015-08-01

    Liquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)2 4H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The `contact' LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS.

  15. The direct determination of double bond positions in lipid mixtures by liquid chromatography/in-line ozonolysis/mass spectrometry

    International Nuclear Information System (INIS)

    Sun, Chenxing; Zhao, Yuan-Yuan; Curtis, Jonathan M.

    2013-01-01

    Highlights: ► An ozonolysis reactor was coupled in-line with mass spectrometry (O 3 -MS). ► Double bond positions in FAME were determined unambiguously without standards. ► LC directly connected to O 3 -MS allowed double bond localization in lipid mixtures. ► LC/O 3 -MS applied to bovine fat demonstrated practical use in lipid analysis. -- Abstract: The direct determination of double bond positions in unsaturated lipids using in-line ozonolysis-mass spectrometry (O 3 -MS) is described. In this experiment, ozone penetrates through the semi-permeable Teflon AF-2400 tubing containing a flow of a solution of fatty acid methyl esters (FAME). Unsaturated FAME are thus oxidized by the ozone and cleaved at the double bond positions. The ozonolysis products then flow directly into the atmospheric pressure photoionization (APPI) source of a mass spectrometer for analysis. Aldehyde products retaining the methyl ester group are indicative of the double bond positions in unsaturated FAME. For the first time, O 3 -MS is able to couple directly to high performance liquid chromatography (HPLC), making the double bond localization in lipid mixtures possible. The application of LC/O 3 -MS has been demonstrated for a fat sample from bovine adipose tissue. A total of 9 unsaturated FAME including 6 positional isomers were identified unambiguously, without comparison to standards. The in-line ozonolysis reaction apparatus is applicable to most mass spectrometers without instrumental modification; it is also directly compatible with various LC columns. The LC/O 3 -MS method described here is thus a practical, versatile and easy to use new approach to the direct determination of double bond positions in lipids, even in complex mixtures

  16. The direct determination of double bond positions in lipid mixtures by liquid chromatography/in-line ozonolysis/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chenxing; Zhao, Yuan-Yuan [Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5 (Canada); Curtis, Jonathan M., E-mail: jcurtis1@ualberta.ca [Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5 (Canada)

    2013-01-31

    Highlights: ► An ozonolysis reactor was coupled in-line with mass spectrometry (O{sub 3}-MS). ► Double bond positions in FAME were determined unambiguously without standards. ► LC directly connected to O{sub 3}-MS allowed double bond localization in lipid mixtures. ► LC/O{sub 3}-MS applied to bovine fat demonstrated practical use in lipid analysis. -- Abstract: The direct determination of double bond positions in unsaturated lipids using in-line ozonolysis-mass spectrometry (O{sub 3}-MS) is described. In this experiment, ozone penetrates through the semi-permeable Teflon AF-2400 tubing containing a flow of a solution of fatty acid methyl esters (FAME). Unsaturated FAME are thus oxidized by the ozone and cleaved at the double bond positions. The ozonolysis products then flow directly into the atmospheric pressure photoionization (APPI) source of a mass spectrometer for analysis. Aldehyde products retaining the methyl ester group are indicative of the double bond positions in unsaturated FAME. For the first time, O{sub 3}-MS is able to couple directly to high performance liquid chromatography (HPLC), making the double bond localization in lipid mixtures possible. The application of LC/O{sub 3}-MS has been demonstrated for a fat sample from bovine adipose tissue. A total of 9 unsaturated FAME including 6 positional isomers were identified unambiguously, without comparison to standards. The in-line ozonolysis reaction apparatus is applicable to most mass spectrometers without instrumental modification; it is also directly compatible with various LC columns. The LC/O{sub 3}-MS method described here is thus a practical, versatile and easy to use new approach to the direct determination of double bond positions in lipids, even in complex mixtures.

  17. Direct Analysis in Real-time Mass Spectrometry for Rapid Identification of Traditional Chinese Medicines with Coumarins as Primary Characteristics.

    Science.gov (United States)

    Chen, Zhiyong; Yang, Yuanyuan; Tao, Hongxun; Liao, Liping; Li, Ye; Zhang, Zijia

    2017-05-01

    The increasing popularity of traditional Chinese medicines (TCMs) necessitates rapid and reliable methods for controlling their quality. Direct analysis in real-time mass spectrometry (DART-MS) represents a novel approach to analysing TCMs. To develop a quick and reliable method of identifying TCMs with coumarins as primary characteristics. DART-MS coupled with ion trap mass spectrometry was employed to rapidly identify TCMs with coumarins as primary characteristics and to explore the ionisation mechanisms of simple coumarins, furocoumarins and pyranocoumarins in detail. With minimal sample pretreatment, mass spectra of Fraxini Cortex, Angelicae Pubescentis Radix, Peucedani Radix and Psoraleae Fructus samples were obtained within seconds. The operating parameters of the DART ion source (e.g. grid electrode voltage and ionisation gas temperature) were carefully investigated to obtain high-quality mass spectra. The mass spectra of samples and DART-MS/MS spectra of marker compounds were used to identify sample materials. Successful authentication was achieved by analysing the same materials of different origins. Some simple coumarins, furocoumarins and pyranocoumarins can be directly detected by DART-MS as marker compounds. Our results demonstrated that DART-MS can provide a rapid and reliable method for the identification of TCMs containing different configurations of coumarins; the method may also be applicable to other plants. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Characterization of anti-theft devices directly from the surface of banknotes via easy ambient sonic spray ionization mass spectrometry.

    Science.gov (United States)

    Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Cuelbas, Claudio José; Zacca, Jorge Jardim; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Sawaya, Alexandra Christine Helena Frankland; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2015-09-01

    Using Brazilian banknotes as a test case, forensic examination and identification of Rhodamine B dye anti-theft device (ATD) staining on banknotes were performed. Easy ambient sonic spray ionization mass spectrometry (EASI-MS) was used since it allows fast and simple analysis with no sample preparation providing molecular screening of the surface with direct desorption and ionization of the security dye. For a more accurate molecular characterization of the ATD dye, Q Exactive Orbitrap™ Fourier transform (tandem) mass spectrometry using eletrospray ionization (ESI-HRMS/MS) was also applied. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Chemotaxonomic markers of organic, natural, and genetically modified soybeans detected by direct infusion electrospray ionization mass spectrometry

    International Nuclear Information System (INIS)

    Santos, L.S.; Catharino, R.R.; Eberlin, M.N.; Tsai, S.M.

    2006-01-01

    The crude methanolic extracts of a single bean from samples of organic, natural or genetically modified (GM) soybeans [Glycine max. (Merrill) L.] were analyzed by direct infusion electrospray ionization mass spectrometry (ESI-MS). These extracts, containing the most polar natural products of soybeans (free aglycones, monoglucosides, diglucosides and esters including isoflavones and flavones) provide characteristic fingerprinting mass spectra owing to different proportions or sets of components. Spectra distinctiveness is confirmed by chemometric multivariate analysis of the ESIMS data, which place the three-types of beans into well-defined groups. When ESI-MS is applied, these polar components constitute therefore unique chemotaxonomic markers able to provide fast soybean typification. (author)

  20. Rapid identification and susceptibility testing of Candida spp. from positive blood cultures by combination of direct MALDI-TOF mass spectrometry and direct inoculation of Vitek 2.

    Science.gov (United States)

    Idelevich, Evgeny A; Grunewald, Camilla M; Wüllenweber, Jörg; Becker, Karsten

    2014-01-01

    Fungaemia is associated with high mortality rates and early appropriate antifungal therapy is essential for patient management. However, classical diagnostic workflow takes up to several days due to the slow growth of yeasts. Therefore, an approach for direct species identification and direct antifungal susceptibility testing (AFST) without prior time-consuming sub-culturing of yeasts from positive blood cultures (BCs) is urgently needed. Yeast cell pellets prepared using Sepsityper kit were used for direct identification by MALDI-TOF mass spectrometry (MS) and for direct inoculation of Vitek 2 AST-YS07 card for AFST. For comparison, MALDI-TOF MS and Vitek 2 testing were performed from yeast subculture. A total of twenty four positive BCs including twelve C. glabrata, nine C. albicans, two C. dubliniensis and one C. krusei isolate were processed. Applying modified thresholds for species identification (score ≥ 1.5 with two identical consecutive propositions), 62.5% of BCs were identified by direct MALDI-TOF MS. AFST results were generated for 72.7% of BCs directly tested by Vitek 2 and for 100% of standardized suspensions from 24 h cultures. Thus, AFST comparison was possible for 70 isolate-antifungal combinations. Essential agreement (minimum inhibitory concentration difference ≤ 1 double dilution step) was 88.6%. Very major errors (VMEs) (false-susceptibility), major errors (false-resistance) and minor errors (false categorization involving intermediate result) amounted to 33.3% (of resistant isolates), 1.9% (of susceptible isolates) and 1.4% providing 90.0% categorical agreement. All VMEs were due to fluconazole or voriconazole. This direct method saved on average 23.5 h for identification and 15.1 h for AFST, compared to routine procedures. However, performance for azole susceptibility testing was suboptimal and testing from subculture remains indispensable to validate the direct finding.

  1. Rapid identification and susceptibility testing of Candida spp. from positive blood cultures by combination of direct MALDI-TOF mass spectrometry and direct inoculation of Vitek 2.

    Directory of Open Access Journals (Sweden)

    Evgeny A Idelevich

    Full Text Available Fungaemia is associated with high mortality rates and early appropriate antifungal therapy is essential for patient management. However, classical diagnostic workflow takes up to several days due to the slow growth of yeasts. Therefore, an approach for direct species identification and direct antifungal susceptibility testing (AFST without prior time-consuming sub-culturing of yeasts from positive blood cultures (BCs is urgently needed. Yeast cell pellets prepared using Sepsityper kit were used for direct identification by MALDI-TOF mass spectrometry (MS and for direct inoculation of Vitek 2 AST-YS07 card for AFST. For comparison, MALDI-TOF MS and Vitek 2 testing were performed from yeast subculture. A total of twenty four positive BCs including twelve C. glabrata, nine C. albicans, two C. dubliniensis and one C. krusei isolate were processed. Applying modified thresholds for species identification (score ≥ 1.5 with two identical consecutive propositions, 62.5% of BCs were identified by direct MALDI-TOF MS. AFST results were generated for 72.7% of BCs directly tested by Vitek 2 and for 100% of standardized suspensions from 24 h cultures. Thus, AFST comparison was possible for 70 isolate-antifungal combinations. Essential agreement (minimum inhibitory concentration difference ≤ 1 double dilution step was 88.6%. Very major errors (VMEs (false-susceptibility, major errors (false-resistance and minor errors (false categorization involving intermediate result amounted to 33.3% (of resistant isolates, 1.9% (of susceptible isolates and 1.4% providing 90.0% categorical agreement. All VMEs were due to fluconazole or voriconazole. This direct method saved on average 23.5 h for identification and 15.1 h for AFST, compared to routine procedures. However, performance for azole susceptibility testing was suboptimal and testing from subculture remains indispensable to validate the direct finding.

  2. Increased mitochondrial mass in cells with functionally compromised mitochondria after exposure to both direct gamma radiation and bystander factors.

    LENUS (Irish Health Repository)

    Nugent, Sharon M E

    2007-07-01

    The bystander effect describes radiation-like damage in unirradiated cells either in the vicinity of irradiated cells or exposed to medium from irradiated cells. This study aimed to further characterize the poorly understood mitochondrial response to both direct irradiation and bystander factor(s) in human keratinocytes (HPV-G) and Chinese hamster ovarian cells (CHO-K1). Oxygen consumption rates were determined during periods of state 4, state 3 and uncoupled respiration. Mitochondrial mass was determined using MitoTracker FM. CHO-K1 cells showed significantly reduced oxygen consumption rates 4 h after exposure to 5 Gy direct radiation and irradiated cell conditioned medium (ICCM) and an apparent recovery 12-24 h later. The apparent recovery was likely due to the substantial increase in mitochondrial mass observed in these cells as soon as 4 h after exposure. HPV-G cells, on the other hand, showed a sustained increase in oxygen consumption rates after ICCM exposure and a transient increase 4 h after exposure to 5 Gy direct radiation. A significant increase in mitochondrial mass per HPV-G cell was observed after exposure to both direct radiation and ICCM. These findings are indicative of a stress response to mitochondrial dysfunction that increases the number of mitochondria per cell.

  3. Direct mass spectrometric screening of antibiotics from bacterial surfaces using liquid extraction surface analysis.

    Science.gov (United States)

    Kai, Marco; González, Ignacio; Genilloud, Olga; Singh, Sheo B; Svatoš, Aleš

    2012-10-30

    There is a need to find new antibiotic agents to fight resistant pathogenic bacteria. To search successfully for novel antibiotics from bacteria cultivated under diverse conditions, we need a fast and cost-effective screening method. A combination of Liquid Extraction Surface Analysis (LESA), automated chip-based nanoelectrospray ionization, and high-resolution mass or tandem mass spectrometry using an Orbitrap XL was tested as the screening platform. Actinobacteria, known to produce well-recognized thiazolyl peptide antibiotics, were cultivated on a plate of solid medium and the antibiotics were extracted by organic solvent mixtures from the surface of colonies grown on the plate and analyzed using mass spectrometry (MS). LESA combined with high-resolution MS is a powerful tool with which to extract and detect thiazolyl peptide antibiotics from different Actinobacteria. Known antibiotics were correctly detected with high mass accuracy (antibiotics in particular and natural products in general. The method described in this paper is suitable for (1) screening the natural products produced by bacterial colonies on cultivation plates within the first 2 min following extraction and (2) detecting antibiotics at high mass accuracy; the cost is around 2 Euro per sample. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Direct molecular analysis of whole-body animal tissue sections by MALDI imaging mass spectrometry.

    Science.gov (United States)

    Reyzer, Michelle L; Chaurand, Pierre; Angel, Peggi M; Caprioli, Richard M

    2010-01-01

    The determination of the localization of various compounds in a whole animal is valuable for many applications, including pharmaceutical absorption, distribution, metabolism, and excretion (ADME) studies and biomarker discovery. Imaging mass spectrometry is a powerful tool for localizing compounds of biological interest with molecular specificity and relatively high resolution. Utilizing imaging mass spectrometry for whole-body animal sections offers considerable analytical advantages compared to traditional methods, such as whole-body autoradiography, but the experiment is not straightforward. This chapter addresses the advantages and unique challenges that the application of imaging mass spectrometry to whole-body animal sections entails, including discussions of sample preparation, matrix application, signal normalization, and image generation. Lipid and protein images obtained from whole-body tissue sections of mouse pups are presented along with detailed protocols for the experiments.

  5. Direct measurement of the centre of mass location in walking persons

    African Journals Online (AJOL)

    h-1 on a motorised treadmill are presented. These data are the first direct measurements of COM oscillation in walking humans over an entire stride. Data found using other, less direct methods are not dissimilar to the data obtained for COM ...

  6. The yeast metabolome addressed by electrospray ionization mass spectrometry: Initiation of a mass spectral library and its applications for metabolic footprinting by direct infusion mass spectrometry

    DEFF Research Database (Denmark)

    Højer-Pedersen, Jesper Juul; Smedsgaard, Jørn; Nielsen, Jens

    2008-01-01

    Mass spectrometry (MS) has been a major driver for metabolomics, and gas chromatography (GC)-MS has been one of the primary techniques used for microbial metabolomics. The use of liquid chromatography (LC)-MS has however been limited, but electrospray ionization (ESI) is very well suited...... for ionization of microbial metabolites without any previous derivatization needed. To address the capabilities of ESI-MS in detecting the metabolome of Saccharomyces cerevisiae, the in silico metabolome of this organism was used as a template to present a theoretical metabolome. This showed that in combination......, which could be assigned using the in silico metabolome. By this approach metabolic footprinting can advance from a classification method that is used to derive biological information based on guilt-by-association, to a tool for extraction of metabolic differences, which can guide new targeted biological...

  7. Direct coupling of electromembrane extraction to mass spectrometry – Advancing the probe functionality toward measurements of zwitterionic drug metabolites

    DEFF Research Database (Denmark)

    Kige Rye, Torstein; Fuchs, David; Pedersen-Bjergaard, Stig

    2017-01-01

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow......-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min-1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes......, the system can potentially be used for direct analysis of various kinds of chemical reactions that have to be run at pH conditions unfavorable for direct analyte extractions....

  8. DILEMMAS OF COMMUNITY-DIRECTED MASS DRUG ADMINISTRATION FOR LYMPHATIC FILARIASIS CONTROL

    DEFF Research Database (Denmark)

    Kisoka, William; Mushi, Declare; Meyrowitsch, Dan W.

    2017-01-01

    There has in recent years been a growing interest in the social significance of global health policy and associated interventions. This paper is concerned with neglected tropical disease control, which prescribes annual mass drug administration to interrupt transmission of, among others, lymphati...

  9. Quantification of Endogenous Cholesterol in Human Serum on Paper Using Direct Analysis in Real Time Mass Spectrometry.

    Science.gov (United States)

    Hsieh, Hua-Yi; Li, Li-Hua; Hsu, Ren-Yu; Kao, Wei-Fong; Huang, Ying-Chen; Hsu, Cheng-Chih

    2017-06-06

    Blood testing for endogenous small metabolites to determine physiological and biochemical states is routine for laboratory analysis. Here we demonstrate that by combining the commercial direct analysis in real time (DART) ion source with an ion trap mass spectrometer, native cholesterol in its free alcohol form is readily detected from a few hundred nanoliters of human serum loaded onto chromatography paper. Deuterium-labeled cholesterol was used as the internal standard to obtain the absolute quantity of the endogenous cholesterol. The amount of the cholesterol measured by this paper-loaded DART mass spectrometry (pDART-MS) is statistically comparable with that obtained by using commercially available fluorometric-enzymatic assay and liquid chromatography/mass spectrometry. Furthermore, sera from 21 participants at three different time points in an ultramarathon were collected to obtain their cholesterol levels. The test requires only very minimal sample preparation, and the concentrations of cholesterol in each sample were acquired within a minute.

  10. DETECTION OF WHITE DWARF COMPANIONS TO BLUE STRAGGLERS IN THE OPEN CLUSTER NGC 188: DIRECT EVIDENCE FOR RECENT MASS TRANSFER

    Energy Technology Data Exchange (ETDEWEB)

    Gosnell, Natalie M.; Mathieu, Robert D. [Department of Astronomy, University of Wisconsin - Madison, 475 N. Charter St., Madison, WI 53706 (United States); Geller, Aaron M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208 (United States); Sills, Alison [Department of Physics and Astronomy, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4M1 (Canada); Leigh, Nathan [Department of Physics, University of Alberta, CCIS 4-183, Edmonton, AB T6G 2E1 (Canada); Knigge, Christian, E-mail: gosnell@astro.wisc.edu [School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 IBJ (United Kingdom)

    2014-03-01

    Several possible formation pathways for blue straggler stars have been developed recently, but no one pathway has yet been observationally confirmed for a specific blue straggler. Here we report the first findings from a Hubble Space Telescope Advanced Camera for Surveys/Solar Blind Channel far-UV photometric program to search for white dwarf companions to blue straggler stars. We find three hot and young white dwarf companions to blue straggler stars in the 7 Gyr open cluster NGC 188, indicating that mass transfer in these systems ended less than 300 Myr ago. These companions are direct and secure observational evidence that these blue straggler stars were formed through mass transfer in binary stars. Their existence in a well-studied cluster environment allows for observational constraints of both the current binary system and the progenitor binary system, mapping the entire mass transfer history.

  11. Detection of nicotine as an indicator of tobacco smoke by direct analysis in real time (DART) tandem mass spectrometry

    Science.gov (United States)

    Kuki, Ákos; Nagy, Lajos; Nagy, Tibor; Zsuga, Miklós; Kéki, Sándor

    2015-01-01

    The residual tobacco smoke contamination (thirdhand smoke, THS) on the clothes of a smoker was examined by direct analysis in real time (DART) mass spectrometry. DART-MS enabled sensitive and selective analysis of nicotine as the indicator of tobacco smoke pollution. Tandem mass spectrometric (MS/MS) experiments were also performed to confirm the identification of nicotine. Transferred thirdhand smoke originated from the fingers of a smoker onto other objects was also detected by DART mass spectrometry. DART-MS/MS was utilized for monitoring the secondhand tobacco smoke (SHS) in the air of the laboratory using nicotine as an indicator. To the best of our knowledge, this is the first report on the application of DART-MS and DART-MS/MS to the detection of thirdhand smoke and to the monitoring of secondhand smoke.

  12. Direct Analysis in Real Time Mass Spectrometry of Potential By-Products from Homemade Nitrate Ester Explosive Synthesis

    OpenAIRE

    Sisco, Edward; Forbes, Thomas P.

    2015-01-01

    This work demonstrates the coupling of direct analysis in real time (DART) ionization with time-of-flight mass spectrometry (MS) in an off-axis configuration for the trace detection and analysis of potential partially nitrated and dimerized by-products of homemade nitrate ester explosive synthesis. Five compounds relating to the synthesis of nitroglycerin (NG) and pentaerythritol tetranitrate (PETN) were examined. Deprotonated ions and adducts with molecular oxygen, nitrite, and nitrate were ...

  13. Laser desorption/ionization mass spectrometry for direct profiling and imaging of small molecules from raw biological materials

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Sangwon [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    Matrix-assisted laser desorption/ionization(MALDI) mass spectrometry(MS) has been widely used for analysis of biological molecules, especially macromolecules such as proteins. However, MALDI MS has a problem in small molecule (less than 1 kDa) analysis because of the signal saturation by organic matrixes in the low mass region. In imaging MS (IMS), inhomogeneous surface formation due to the co-crystallization process by organic MALDI matrixes limits the spatial resolution of the mass spectral image. Therefore, to make laser desorption/ionization (LDI) MS more suitable for mass spectral profiling and imaging of small molecules directly from raw biological tissues, LDI MS protocols with various alternative assisting materials were developed and applied to many biological systems of interest. Colloidal graphite was used as a matrix for IMS of small molecules for the first time and methodologies for analyses of small metabolites in rat brain tissues, fruits, and plant tissues were developed. With rat brain tissues, the signal enhancement for cerebroside species by colloidal graphite was observed and images of cerebrosides were successfully generated by IMS. In addition, separation of isobaric lipid ions was performed by imaging tandem MS. Directly from Arabidopsis flowers, flavonoids were successfully profiled and heterogeneous distribution of flavonoids in petals was observed for the first time by graphite-assisted LDI(GALDI) IMS.

  14. Temperature-dependent release of volatile organic compounds of eucalypts by direct analysis in real time (DART) mass spectrometry.

    Science.gov (United States)

    Maleknia, Simin D; Vail, Teresa M; Cody, Robert B; Sparkman, David O; Bell, Tina L; Adams, Mark A

    2009-08-01

    A method is described for the rapid identification of biogenic, volatile organic compounds (VOCs) emitted by plants, including the analysis of the temperature dependence of those emissions. Direct analysis in real time (DART) enabled ionization of VOCs from stem and leaf of several eucalyptus species including E. cinerea, E. citriodora, E. nicholii and E. sideroxylon. Plant tissues were placed directly in the gap between the DART ionization source skimmer and the capillary inlet of the time-of-flight (TOF) mass spectrometer. Temperature-dependent emission of VOCs was achieved by adjusting the temperature of the helium gas into the DART ionization source at 50, 100, 200 and 300 degrees C, which enabled direct evaporation of compounds, up to the onset of pyrolysis of plant fibres (i.e. cellulose and lignin). Accurate mass measurements facilitated by TOF mass spectrometry provided elemental compositions for the VOCs. A wide range of compounds was detected from simple organic compounds (i.e. methanol and acetone) to a series of monoterpenes (i.e. pinene, camphene, cymene, eucalyptol) common to many plant species, as well as several less abundant sesquiterpenes and flavonoids (i.e. naringenin, spathulenol, eucalyptin) with antioxidant and antimicrobial properties. The leaf and stem tissues for all four eucalypt species showed similar compounds. The relative abundances of methanol and ethanol were greater in stem wood than in leaf tissue suggesting that DART could be used to investigate the tissue-specific transport and emissions of VOCs. Copyright (c) 2009 John Wiley & Sons, Ltd.

  15. Real-time measurement of plutonium in air by direct-inlet surface ionization mass spectrometry. Status report

    International Nuclear Information System (INIS)

    Stoffels, J.J.

    1980-04-01

    A new technique is being developed for monitoring low-level airborne plutonium on a real-time basis. The technique is based on surface ionization mass spectrometry of airborne particles. It will be capable of measuring plutonium concentrations below the maximum permissible concentration (MPC) level. A complete mass spectrometer was designed and constructed for this purpose. Major components which were developed and made operational for the instrument include an efficient inlet for directly sampling particles in air, a wide dynamic range ion detector and a minicomputer-based ion-burst measurement system. Calibration of the direct-inlet mass spectrometer (DIMS) was initiated to establish the instrument's response to plutonium dioxide as a function of concentration and particle size. This work revealed an important problem - bouncing of particles upon impact with the ionizing filament. Particle bounce results in a significant loss of measurement sensitivity. The feasibility of using an oven ionizer to overcome the particle bounce problem has been demonstrated. A rhenium oven ionizer was designed and constructed for the purpose of trapping particles which enter via the direct inlet. High-speed particles were trapped in the oven yielding a measurement sensitivity comparable to that for particles which are preloaded. Development of the Pu DIMS can now be completed by optimizing the oven design and calibrating the instrument's performance with UO 2 and CeO 2 particles as analogs to PuO 2 particles

  16. Atmospheric pressure surface sampling/ionization techniques for direct coupling of planar separations with mass spectrometry.

    Science.gov (United States)

    Pasilis, Sofie P; Van Berkel, Gary J

    2010-06-18

    Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  17. A new direction for dark matter research: intermediate-mass compact halo objects

    Energy Technology Data Exchange (ETDEWEB)

    Chapline, George F. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA (United States); Frampton, Paul H., E-mail: george.chapline@gmail.com, E-mail: paul.h.frampton@gmail.com [15 Summerheights, 29 Water Eaton Road, Oxford OX2 7PG (United Kingdom)

    2016-11-01

    The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15 M {sub ⊙} may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for magnification of stars outside our galaxy due to gravitational microlensing of these stars by MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the micro-lensing brightening curves provides a promising approach to testing over the course of next several years the hypothesis that dark matter consists of massive compact objects.

  18. Direct Measurements of Gas/Particle Partitioning and Mass Accommodation Coefficients in Environmental Chambers.

    Science.gov (United States)

    Krechmer, Jordan E; Day, Douglas A; Ziemann, Paul J; Jimenez, Jose L

    2017-10-17

    Secondary organic aerosols (SOA) are a major contributor to fine particulate mass and wield substantial influences on the Earth's climate and human health. Despite extensive research in recent years, many of the fundamental processes of SOA formation and evolution remain poorly understood. Most atmospheric aerosol models use gas/particle equilibrium partitioning theory as a default treatment of gas-aerosol transfer, despite questions about potentially large kinetic effects. We have conducted fundamental SOA formation experiments in a Teflon environmental chamber using a novel method. A simple chemical system produces a very fast burst of low-volatility gas-phase products, which are competitively taken up by liquid organic seed particles and Teflon chamber walls. Clear changes in the species time evolution with differing amounts of seed allow us to quantify the particle uptake processes. We reproduce gas- and aerosol-phase observations using a kinetic box model, from which we quantify the aerosol mass accommodation coefficient (α) as 0.7 on average, with values near unity especially for low volatility species. α appears to decrease as volatility increases. α has historically been a very difficult parameter to measure with reported values varying over 3 orders of magnitude. We use the experimentally constrained model to evaluate the correction factor (Φ) needed for chamber SOA mass yields due to losses of vapors to walls as a function of species volatility and particle condensational sink. Φ ranges from 1-4.

  19. Influence of high range of mass transfer coefficient and convection heat transfer on direct contact membrane distillation performance

    KAUST Repository

    Lee, Jung Gil

    2017-11-03

    In order to improve water production of membrane distillation (MD), the development of high performance membrane having better mass transfer and enhancement of convection heat transfer in MD module have been continuously investigated. This paper presents the relationship between the heat and mass transfer resistance across the membrane and the performance improvement. Various ranges of mass transfer coefficient (MTC) from normal (0.3×10−6 to 2.1×10−6kg/m2sPa: currently available membranes) to high (>2.1×10−6kg/m2sPa: membranes under development) were simulated using an experimentally validated model at different ranges of convection heat transfer by varying the inlet flow rates and spacer enhancement factor. The effect of mass transfer and convection heat transfer on the MD performance parameters including temperature polarization coefficient (TPC), mean permeate flux, and specific energy consumption were investigated in a direct contact MD (DCMD) configuration. Results showed that improving the MTC at the low ranges is more important than that at the high ranges where the heat transfer resistance becomes dominant and hence the convection heat transfer coefficient must be increased. Therefore, an effort on designing MD modules using feed and permeate spacers and controlling the membrane surface roughness to increase the convection heat transfer and TPC in the channel aiming to enhance the flux is required because the currently developed mass transfer has almost reached the critical point.

  20. Direct measurement of burn up monitor by Pulsed Laser Deposition (PLD) followed by Isotopic Dilution Mass Spectrometry

    International Nuclear Information System (INIS)

    Sajimol, R.; Manoravi, P.; NaIini, S.; Balasubramanian, R.; Joseph, M.

    2012-01-01

    Burn-up measurement is an important aspect in the assessment of fuel performance especially for experimental nuclear fuels. Conventional mass spectrometric technique offer the best accuracy for determination of burn-up but they suffer from the labour intensive and time consuming chemical separation procedures followed by mass spectrometric analysis. Our laboratory has reported a potential laser mass spectrometric technique with advantages of (i) direct and fast measurement of ion intensities of selected rare earth element and residual heavy element atoms to deduce burn up and (ii) adaptability to remote handling of radioactive samples. Direct quantification of burn up monitor element in fuel in the form of pellet as well as liquid was probed by pulsed laser deposition followed by Isotopic Dilution Mass Spectrometric technique (IDMS). The procedure involving laser ablation of heavy element (namely U and Pu) and fission product (Nd, La etc) from a simulated spent fuel matrix followed by isotopic dilution mass spectrometry using thermal ionization mass spectrometry (TIMS) has been presently attempted to arrive at the rare earth element to heavy element ratio to deduce burn up using the methodology described in our earlier work. The details of IDMS technique has been reviewed by Heumann et al. Accurately weighed amounts of major rare earth fission products such as Nd, La, Ce and Sm in solution form were mixed with known quantity of uranium solution (all the weights are corresponding to their fission yields and the residual heavy element atoms after a given burn up) and mixed together to attain uniformity. The solution is then dried and resulting powder was pelletized and sintered. Subsequently, the pellet was ablated with pulsed laser (8 ns, 532 nm, Nd-YAG) and the plume was deposited on a glass plate. This deposit was dissolved in minimum amount of nitric acid. A known volume of the solution was mixed with spike (for e.g., 150 Nd/ 142 Nd, 233 U/ 238 U in this study

  1. Direct imaging of plant metabolites in leaves and petals by Desorption Electrospray Ionization mass spectrometry

    DEFF Research Database (Denmark)

    Li, Bin; Hansen, Steen Honore'; Janfelt, Christian

    2013-01-01

    and demonstrated on leaves and petals of Hypericum perforatum. The direct imaging approaches are in contrast to previous DESI imaging studies where indirect analysis via imprints were used in order to overcome the morphological barrier presented by the layer of cuticular waxes covering the surface of a leaf...... of very long chain fatty acids (VLCFAs), a significant class of metabolites located in the cuticle layer in leaves and petals, as well as other plant metabolites. In the case of the petals of H. perforatum, all common metabolites could be imaged directly using the ternary solvent, whereas in the case...... of leaves from the same plant, only some of the metabolites were accessible, even with the ternary solvent system. For these samples, the leaves could be imaged with direct DESI after chloroform had been used to remove most of the cuticle, thus exposing lower layers in the leaf structure. A number...

  2. Direct drive TFPM wind generator analytical design optimised for minimum active mass usage

    DEFF Research Database (Denmark)

    Nica, Florin Valentin Traian; Leban, Krisztina Monika; Ritchie, Ewen

    2013-01-01

    The paper focuses of the Transverse Flux Permanent (TFPM) Generator as a solution for offshore direct drive wind turbines. A complex design algorithm is presented. Two topologies (U core and C core) of TFPM were considered. The analytical design is optimised using a combination of genetic...

  3. Direct sampling of chemical weapons in water by photoionization mass spectrometry.

    Science.gov (United States)

    Syage, Jack A; Cai, Sheng-Suan; Li, Jianwei; Evans, Matthew D

    2006-05-01

    The vulnerability of water supplies to toxic contamination calls for fast and effective means for screening water samples for multiple threats. We describe the use of photoionization (PI) mass spectrometry (MS) for high-speed, high-throughput screening and molecular identification of chemical weapons (CW) threats and other hazardous compounds. The screening technology can detect a wide range of compounds at subacute concentrations with no sample preparation and a sampling cycle time of approximately 45 s. The technology was tested with CW agents VX, GA, GB, GD, GF, HD, HN1, and HN3, in addition to riot agents and precursors. All are sensitively detected and give simple PI mass spectra dominated by the parent ion. The target application of the PI MS method is as a routine, real-time early warning system for CW agents and other hazardous compounds in air and in water. In this work, we also present comprehensive measurements for water analysis and report on the system detection limits, linearity, quantitation accuracy, and false positive (FP) and false negative rates for concentrations at subacute levels. The latter data are presented in the form of receiver operating characteristic curves of the form of detection probability P(D) versus FP probability P(FP). These measurements were made using the CW surrogate compounds, DMMP, DEMP, DEEP, and DIMP. Method detection limits (3sigma) obtained using a capillary injection method yielded 1, 6, 3, and 2 ng/mL, respectively. These results were obtained using 1-microL injections of water samples without any preparation, corresponding to mass detection limits of 1, 6, 3, and 2 pg, respectively. The linear range was about 3-4 decades and the dynamic range about 4-5 decades. The relative standard deviations were generally <10% at CW subacute concentrations levels.

  4. Bi-directional vibration control of offshore wind turbines using a 3D pendulum tuned mass damper

    Science.gov (United States)

    Sun, C.; Jahangiri, V.

    2018-05-01

    Offshore wind turbines suffer from excessive bi-directional vibrations due to wind-wave misalignment and vortex induced vibrations. However, most of existing research focus on unidirectional vibration attenuation which is inadequate for real applications. The present paper proposes a three dimensional pendulum tuned mass damper (3d-PTMD) to mitigate the tower and nacelle dynamic response in the fore-aft and side-side directions. An analytical model of the wind turbine coupled with the 3d-PTMD is established wherein the interaction between the blades, the tower and the 3d-PTMD is modeled. Aerodynamic loading is computed using the Blade Element Momentum method where the Prandtls tip loss factor and the Glauert correction are considered. JONSWAP spectrum is adopted to generate wave data. Wave loading is computed using Morisons equation in collaboration with the strip theory. Via a numerical search approach, the design formula of the 3d-PTMD is obtained and examined on a National Renewable Energy Lab (NREL) monopile 5 MW baseline wind turbine model under misaligned wind, wave and seismic loading. Dual linear tuned mass dampers (TMDs) deployed in the fore-aft and side-side directions are utilized for comparison. It is found that the 3d-PTMD with a mass ratio of 2 % can improve the mitigation of the root mean square and peak response by around 10 % when compared with the dual linear TMDs in controlling the bi-directional vibration of the offshore wind turbines under misaligned wind, wave and seismic loading.

  5. First direct mass measurements of stored neutron-rich 129,130,131Cd isotopes with FRS-ESR

    Directory of Open Access Journals (Sweden)

    R. Knöbel

    2016-03-01

    Full Text Available A 410 MeV/u 238U projectile beam was used to create cadmium isotopes via abrasion-fission in a beryllium target placed at the entrance of the in-flight separator FRS at GSI. The fission fragments were separated by the FRS and injected into the isochronous storage ring ESR for mass measurements. Isochronous Mass Spectrometry (IMS was performed under two different experimental conditions, with and without Bρ-tagging at the high-resolution central focal plane of the FRS. In the experiment with Bρ-tagging the magnetic rigidity of the injected fragments was determined with an accuracy of 2⋅10−4. A new method of data analysis, which uses a correlation matrix for the combined data set from both experiments, has provided experimental mass values of 25 rare isotopes for the first time. The high sensitivity and selectivity of the method have given access to nuclides detected with a rate of a few atoms per week. In this letter we present for the 129,130,131Cd isotopes mass values directly measured for the first time. The experimental mass values of cadmium as well as for tellurium and tin isotopes show a pronounced shell effect towards and at N=82. Shell quenching cannot be deduced from a single new mass value, nor by a better agreement with a theoretical model which explicitly takes into account a quenching feature. This is in agreement with the conclusion from γ-ray spectroscopy and confirms modern shell-model calculations.

  6. A new method for the measurement of two-phase mass flow rate using average bi-directional flow tube

    International Nuclear Information System (INIS)

    Yoon, B. J.; Uh, D. J.; Kang, K. H.; Song, C. H.; Paek, W. P.

    2004-01-01

    Average bi-directional flow tube was suggested to apply in the air/steam-water flow condition. Its working principle is similar with Pitot tube, however, it makes it possible to eliminate the cooling system which is normally needed to prevent from flashing in the pressure impulse line of pitot tube when it is used in the depressurization condition. The suggested flow tube was tested in the air-water vertical test section which has 80mm inner diameter and 10m length. The flow tube was installed at 120 of L/D from inlet of test section. In the test, the pressure drop across the average bi-directional flow tube, system pressure and average void fraction were measured on the measuring plane. In the test, fluid temperature and injected mass flow rates of air and water phases were also measured by a RTD and two coriolis flow meters, respectively. To calculate the phasic mass flow rates : from the measured differential pressure and void fraction, Chexal drift-flux correlation was used. In the test a new correlation of momentum exchange factor was suggested. The test result shows that the suggested instrumentation using the measured void fraction and Chexal drift-flux correlation can predict the mass flow rates within 10% error of measured data

  7. Direct metabolic fingerprinting of commercial herbal tinctures by nuclear magnetic resonance spectroscopy and mass spectrometry.

    Science.gov (United States)

    Politi, Matteo; Zloh, Mire; Pintado, Manuela E; Castro, Paula M L; Heinrich, Michael; Prieto, Jose M

    2009-01-01

    Tinctures are widely used liquid pharmaceutical preparations traditionally obtained by maceration of one or more medicinal plants in ethanol-water solutions. Such a process results in the extraction of virtually hundreds of structurally diverse compounds with different polarities. Owing to the large chemical diversity of the constituents present in the herbal tinctures, the analytical tools used for the quality control of tinctures are usually optimised only for the detection of single chemical entities or specific class of compounds. In order to overcome the major limitations of the current methods used for analysis of tinctures, a new methodological approach based on NMR spectroscopy and MS spectrometry has been tested with different commercial tinctures. Diffusion-edited 1H-NMR (1D DOSY) and 1H-NMR with suppression of the ethanol and water signals have been applied here for the first time to the direct analysis of commercial herbal tinctures derived from Echinacea purpurea, Hypericum perforatum, Ginkgo biloba and Valeriana officinalis. The direct injection of the tinctures in the MS detector in order to obtain the corresponding metabolic profiles was also performed. Using both NMR and MS methods it was possible, without evaporation or separation steps, to obtain a metabolic fingerprint able to distinguish between tinctures prepared with different plants. Batch-to-batch homogeneity, as well as degradation after the expiry date of a batch, was also investigated. The techniques proposed here represent fast and convenient direct analyses of medicinal herbal tinctures.

  8. Direct mass and lifetime measurements of neutron-rich nuclei up to A∼100 using the TOFI spectrometer at LAMPF

    International Nuclear Information System (INIS)

    Lind, V.G.

    1993-01-01

    This project was directed toward the study of neutron-rich nuclei using the experimental facilities at LAMPF, which is a part of LANL. The principal results of the investigation include the discovery of many new isotopes along with a measurement of their masses and in particular those nuclides in the Z = 7--19 and 14 --26 regions of the chart of the nuclides.Thirty-four new nuclides were detected and studied with their masses being measured with relatively high accuracy, and an additional twenty-six that were previously known and measured were remeasured to an improved accuracy. Besides providing new information about the mass surface in new and extended redons of the chart of the nuclides, this investigation enabled properties and previously unknown structure of some of the nuclei to be determined such as nuclear deformation among some of the nuclides. Also a study of the neutron pairing gaps and the proton pairing gaps among these nuclides was made. Other developments also achieved included instrument (TOFI) improvements and upgrades and theoretical investigations into the masses of the hadrons

  9. Mass-ablation-rate measurements in direct-drive cryogenic implosions using x-ray self-emission images

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A. K., E-mail: adavi@lle.rochester.edu; Michel, D. T.; Hu, S. X.; Craxton, R. S.; Epstein, R.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14636 (United States)

    2014-11-15

    A technique to measure the mass ablation rate in direct-drive inertial confinement fusion implosions using a pinhole x-ray framing camera is presented. In target designs consisting of two layers of different materials, two x-ray self-emission peaks from the coronal plasma were measured once the laser burned through the higher-Z outer layer. The location of the inner peak is related to the position of the ablation front and the location of the outer peak corresponds to the position of the interface of the two layers in the plasma. The emergence of the second peak was used to measure the burnthrough time of the outer layer, giving the average mass ablation rate of the material and instantaneous mass remaining. By varying the thickness of the outer layer, the mass ablation rate can be obtained as a function of time. Simulations were used to validate the methods and verify that the measurement techniques are not sensitive to perturbation growth at the ablation surface.

  10. Direct analysis in real time mass spectrometry of potential by-products from homemade nitrate ester explosive synthesis.

    Science.gov (United States)

    Sisco, Edward; Forbes, Thomas P

    2016-04-01

    This work demonstrates the coupling of direct analysis in real time (DART) ionization with time-of-flight mass spectrometry (MS) in an off-axis configuration for the trace detection and analysis of potential partially nitrated and dimerized by-products of homemade nitrate ester explosive synthesis. Five compounds relating to the synthesis of nitroglycerin (NG) and pentaerythritol tetranitrate (PETN) were examined. Deprotonated ions and adducts with molecular oxygen, nitrite, and nitrate were observed in the mass spectral responses of these compounds. A global optimum temperature of 350 °C for the by-products investigated here enabled single nanogram to sub nanogram trace detection. Matrix effects were examined through a series of mixtures containing one or more compounds (sugar alcohol precursors, by-products, and/or explosives) across a range of mass loadings. The explosives MS responses experienced competitive ionization in the presence of all by-products. The magnitude of this influence corresponded to both the degree of by-product nitration and the relative mass loading of the by-product to the explosive. This work provides a characterization of potential by-products from homemade nitrate ester synthesis, including matrix effects and potential challenges that might arise from the trace detection of homemade explosives (HMEs) containing impurities. Detection and understanding of HME impurities and complex mixtures may provide valuable information for the screening and sourcing of homemade nitrate ester explosives. Published by Elsevier B.V.

  11. Direct isotope determination of isotopically labelled lipids by field desorption mass spectrometry

    International Nuclear Information System (INIS)

    Lehmann, W.D.; Kessler, M.

    1982-01-01

    Lipids labelled with deuterium or carbon-14 have been investigated by field desorption mass spectrometry for determination of their degree of labelling. This application is demonstrated for free fatty acids, cholesterol, cholesteryl esters, triglycerides, and L-α-phosphatidylcholines. Comparison of the molecular ion groups of the non-labelled and of the labelled compounds enables a fast and reliable determination of the degree of labelling. For multiply labelled compounds the label distribution is also obtained from the molecular ion group. In addition, for cholesteryl esters and for phosphatidylcholines structurally significant fragment ions provide information about the position of the label. Several hundred nanograms of the compound are typically required for a single analysis with a relative standard error of 0.5-2% in the value calculated for atom% hydrogen-2 or for the specific carbon-14 activity. (orig.) [de

  12. Perlappendiceal inflammatory masses: CT-directed management and clinical outcome in 70 patients

    International Nuclear Information System (INIS)

    Jeffrey, R.B. Jr.; Tolentino, C.S.; Federle, M.P.

    1987-01-01

    The clinical outcome was reviewed in 70 patients with CT evidence of periappendiceal inflammatory masses. Thirty-two patients had either phlegmons or small abscesses (less than 3 cm). These patients were initially treated with antibiotic therapy alone, with resolution of the inflammatory process in 28 of the patients (88%). Twenty-eight patients underwent percutaneous abscess drainage of periappendiceal abscesses that was successful in 26 patients (93%). Although 13 patients (46%) had low-output fistulas communicating with the cecum, 12 of 13 closed with 2 weeks of drainage. Ten patients had early surgical drainage for extensive, poorly defined abscesses. Based on CT, a rational approach can be chosen to reduce morbidity and optimize clinical outcome

  13. Heat and mass transfer effects in a direct methanol fuel cell: A 1D model

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, V.B.; Falcao, D.S.; Pinto, A.M.F.R. [Centro de Estudos de Fenomenos de Transporte, Departamento de Eng. Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Rangel, C.M. [INETI - Unidade de Electroquimica e Materiais, Paco do Lumiar, 22,1649-038 (Portugal)

    2008-07-15

    Models are a fundamental tool for the design process of fuel cells and fuel cell systems. In this work, a steady-state, one-dimensional model accounting for coupled heat and mass transfer, along with the electrochemical reactions occurring in the DMFC, is presented. The model output is the temperature profile through the cell and the water balance and methanol crossover between the anode and the cathode. The model predicts the correct trends for the influence of current density and methanol feed concentration on both methanol and water crossover. The model estimates the net water transfer coefficient through the membrane, {alpha}, a very important parameter to describe water management in the DMFC. Suitable operating ranges can be set up for different MEA structures maintaining the crossover of methanol and water within acceptable levels. The model is rapidly implemented and is therefore suitable for inclusion in real-time system level DMFC calculations. (author)

  14. Application of visual basic in high-throughput mass spectrometry-directed purification of combinatorial libraries.

    Science.gov (United States)

    Li, B; Chan, E C Y

    2003-01-01

    We present an approach to customize the sample submission process for high-throughput purification (HTP) of combinatorial parallel libraries using preparative liquid chromatography electrospray ionization mass spectrometry. In this study, Visual Basic and Visual Basic for Applications programs were developed using Microsoft Visual Basic 6 and Microsoft Excel 2000, respectively. These programs are subsequently applied for the seamless electronic submission and handling of data for HTP. Functions were incorporated into these programs where medicinal chemists can perform on-line verification of the purification status and on-line retrieval of postpurification data. The application of these user friendly and cost effective programs in our HTP technology has greatly increased our work efficiency by reducing paper work and manual manipulation of data.

  15. Mass spectrometry-based proteomics: basic principles and emerging technologies and directions.

    Science.gov (United States)

    Van Riper, Susan K; de Jong, Ebbing P; Carlis, John V; Griffin, Timothy J

    2013-01-01

    As the main catalytic and structural molecules within living systems, proteins are the most likely biomolecules to be affected by radiation exposure. Proteomics, the comprehensive characterization of proteins within complex biological samples, is therefore a research approach ideally suited to assess the effects of radiation exposure on cells and tissues. For comprehensive characterization of proteomes, an analytical platform capable of quantifying protein abundance, identifying post-translation modifications and revealing members of protein complexes on a system-wide level is necessary. Mass spectrometry (MS), coupled with technologies for sample fractionation and automated data analysis, provides such a versatile and powerful platform. In this chapter we offer a view on the current state of MS-proteomics, and focus on emerging technologies within three areas: (1) New instrumental methods; (2) New computational methods for peptide identification; and (3) Label-free quantification. These emerging technologies should be valuable for researchers seeking to better understand biological effects of radiation on living systems.

  16. Leaf spray: direct chemical analysis of plant material and living plants by mass spectrometry.

    Science.gov (United States)

    Liu, Jiangjiang; Wang, He; Cooks, R Graham; Ouyang, Zheng

    2011-10-15

    The chemical constituents of intact plant material, including living plants, are examined by a simple spray method that provides real-time information on sugars, amino acids, fatty acids, lipids, and alkaloids. The experiment is applicable to various plant parts and is demonstrated for a wide variety of species. An electrical potential is applied to the plant and its natural sap, or an applied solvent generates an electrospray that carries endogenous chemicals into an adjacent benchtop or miniature mass spectrometer. The sharp tip needed to create a high electric field can be either natural (e.g., bean sprout) or a small nick can be cut in a leaf, fruit, bark, etc. Stress-induced changes in glucosinolates can be followed on the minute time scale in several plants, including potted vegetables. Differences in spatial distributions and the possibility of studying plant metabolism are demonstrated. © 2011 American Chemical Society

  17. Direct Analysis of Proteins from Solutions with High Salt Concentration Using Laser Electrospray Mass Spectrometry

    Science.gov (United States)

    Karki, Santosh; Shi, Fengjian; Archer, Jieutonne J.; Sistani, Habiballah; Levis, Robert J.

    2018-05-01

    The detection of lysozyme, or a mixture of lysozyme, cytochrome c, and myoglobin, from solutions with varying salt concentrations (0.1 to 250 mM NaCl) is compared using laser electrospray mass spectrometry (LEMS) and electrospray ionization-mass spectrometry (ESI-MS). Protonated protein peaks were observed up to a concentration of 250 mM NaCl in the case of LEMS. In the case of ESI-MS, a protein solution with salt concentration > 0.5 mM resulted in predominantly salt-adducted features, with suppression of the protonated protein ions. The constituents in the mixture of proteins were assignable up to 250 mM NaCl for LEMS and were not assignable above a NaCl concentration of 0.5 mM for ESI. The average sodium adducts () bound to the 7+ charge state of lysozyme for LEMS measurements from salt concentrations of 2.5, 25, 50, and 100 mM NaCl are 1.71, 5.23, 5.26, and 5.11, respectively. The conventional electrospray measurements for lysozyme solution containing salt concentrations of 0.1, 1, 2, and 5 mM NaCl resulted in of 2.65, 6.44, 7.57, and 8.48, respectively. LEMS displays an approximately two orders of magnitude higher salt tolerance in comparison with conventional ESI-MS. The non-equilibrium partitioning of proteins on the surface of the charged droplets is proposed as the mechanism for the high salt tolerance phenomena observed in the LEMS measurements. [Figure not available: see fulltext.

  18. Reconciling ocean mass content change based on direct and inverse approaches by utilizing data from GRACE, altimetry and Swarm

    Science.gov (United States)

    Rietbroek, R.; Uebbing, B.; Lück, C.; Kusche, J.

    2017-12-01

    Ocean mass content (OMC) change due to the melting of the ice-sheets in Greenland and Antarctica, melting of glaciers and changes in terrestrial hydrology is a major contributor to present-day sea level rise. Since 2002, the GRACE satellite mission serves as a valuable tool for directly measuring the variations in OMC. As GRACE has almost reached the end of its lifetime, efforts are being made to utilize the Swarm mission for the recovery of low degree time-variable gravity fields to bridge a possible gap until the GRACE-FO mission and to fill up periods where GRACE data was not existent. To this end we compute Swarm monthly normal equations and spherical harmonics that are found competitive to other solutions. In addition to directly measuring the OMC, combination of GRACE gravity data with altimetry data in a global inversion approach allows to separate the total sea level change into individual mass-driven and steric contributions. However, published estimates of OMC from the direct and inverse methods differ not only depending on the time window, but also are influenced by numerous post-processing choices. Here, we will look into sources of such differences between direct and inverse approaches and evaluate the capabilities of Swarm to derive OMC. Deriving time series of OMC requires several processing steps; choosing a GRACE (and altimetry) product, data coverage, masks and filters to be applied in either spatial or spectral domain, corrections related to spatial leakage, GIA and geocenter motion. In this study, we compare and quantify the effects of the different processing choices of the direct and inverse methods. Our preliminary results point to the GIA correction as the major source of difference between the two approaches.

  19. Analysis of hairy root culture of Rauvolfia serpentina using direct analysis in real time mass spectrometric technique.

    Science.gov (United States)

    Madhusudanan, K P; Banerjee, Suchitra; Khanuja, Suman P S; Chattopadhyay, Sunil K

    2008-06-01

    The applicability of a new mass spectrometric technique, DART (direct analysis in real time) has been studied in the analysis of the hairy root culture of Rauvolfia serpentina. The intact hairy roots were analyzed by holding them in the gap between the DART source and the mass spectrometer for measurements. Two nitrogen-containing compounds, vomilenine and reserpine, were characterized from the analysis of the hairy roots almost instantaneously. The confirmation of the structures of the identified compounds was made through their accurate molecular formula determinations. This is the first report of the application of DART technique for the characterization of compounds that are expressed in the hairy root cultures of Rauvolfia serpentina. Moreover, this also constitutes the first report of expression of reserpine in the hairy root culture of Rauvolfia serpentina. Copyright (c) 2008 John Wiley & Sons, Ltd.

  20. Big lie, small world: what E. Lynn Harris wanted readers to understand about the struggle for African American, homosexual males seeking to attain the American dream.

    Science.gov (United States)

    Jackson, Lisa D

    2012-01-01

    This article will examine the social implications for African American homosexual males seeking to achieve the American Dream. Invisible Life and Just as I Am-the first two novels in a trilogy by the late E. Lynn Harris writing from a semi-autobiographical perspective in late-twentieth century America-will serve as the texts that drive this research topic. Careful analysis of these works will substantiate the assertion that the American Dream, even on the cusp of the new millennium, is just beyond the grasp of this specific subpopulation.

  1. Direct observation of mass oscillations due to ablative Richtmyer-Meshkov instability and feedout in planar plastic targets

    International Nuclear Information System (INIS)

    Aglitskiy, Y.; Velikovich, A.L.; Karasik, M.; Serlin, V.; Pawley, C.J.; Schmitt, A.J.; Obenschain, S.P.; Mostovych, A.N.; Gardner, J.H.; Metzler, N.

    2002-01-01

    Perturbations that seed Rayleigh-Taylor (RT) instability in laser-driven targets form during the early-time period. This time includes a shock wave transit from the front to the rear surface of the target, and a rarefaction wave transit in the opposite direction. During this time interval, areal mass perturbations caused by all sources of nonuniformity (laser imprint, surface ripple) are expected to oscillate. The first direct experimental observations of the areal mass oscillations due to ablative Richtmyer-Meshkov (RM) instability and feedout followed by the RT growth of areal mass modulation are discussed. The experiments were made with 40-99 μm thick planar plastic targets rippled either on the front or on the rear with a sine wave ripple with either 30 or 45 μm wavelength and with 0.5, 1, or 1.5 μm amplitude. Targets were irradiated with 4 ns long Nike KrF laser pulses at ∼50 TW/cm2. The oscillations were observed with our novel diagnostic technique, a monochromatic x-ray imager coupled to a streak camera. For the ablative RM instability (front side ripple), the mass modulation amplitude was typically observed to grow, reach a peak, and then decrease, after which the exponential RT growth started. In some cases, one phase reversal due to the ablative RM instability was observed. For the feedout geometry (rear side ripple), in all cases two phase reversals were observed: a distinct half-oscillation was followed by the onset of the RT growth, resulting in a second phase reversal

  2. Final Report: Mass Production Cost Estimation of Direct H2 PEM Fuel Cell Systems for Transportation Applications (2012-2016)

    Energy Technology Data Exchange (ETDEWEB)

    James, Brian David [Strategic Analysis Inc., Arlington, VA (United States); Huya-Kouadio, Jennie Moton [Strategic Analysis Inc., Arlington, VA (United States); Houchins, Cassidy [Strategic Analysis Inc., Arlington, VA (United States); DeSantis, Daniel Allen [Strategic Analysis Inc., Arlington, VA (United States)

    2016-09-01

    This report summarizes project activities for Strategic Analysis, Inc. (SA) Contract Number DE-EE0005236 to the U.S. Department of Energy titled “Transportation Fuel Cell System Cost Assessment”. The project defined and projected the mass production costs of direct hydrogen Proton Exchange Membrane fuel cell power systems for light-duty vehicles (automobiles) and 40-foot transit buses. In each year of the five-year contract, the fuel cell power system designs and cost projections were updated to reflect technology advances. System schematics, design assumptions, manufacturing assumptions, and cost results are presented.

  3. SHP1 Regulates Bone Mass by Directing Mesenchymal Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Menghui Jiang

    2016-07-01

    Full Text Available Osteoblasts and adipocytes are derived from a common precursor, mesenchymal stem cells (MSCs. Alterations in the normal fate of differentiating MSCs are involved in the development of obesity and osteoporosis. Here, we report that viable motheaten (mev mice, which are deficient in the SH2-domain-containing phosphatase-1 (SHP1, develop osteoporosis spontaneously. Consistently, MSCs from mev/mev mice exhibit significantly reduced osteogenic potential and greatly increased adipogenic potential. When MSCs were transplanted into nude mice, SHP1-deficient MSCs resulted in diminished bone formation compared with wild-type MSCs. SHP1 was found to bind to GSK3β and suppress its kinase activity by dephosphorylating pY216, thus resulting in β-catenin stabilization. Mice, in which SHP1 was deleted in MSCs using SHP1fl/flDermo1-cre, displayed significantly decreased bone mass and increased adipose tissue. Taken together, these results suggest a possible role for SHP1 in controlling tissue homeostasis through modulation of MSC differentiation via Wnt signaling regulation.

  4. Direct Analyses of Secondary Metabolites by Mass Spectrometry Imaging (MSI) from Sunflower (Helianthus annuus L.) Trichomes.

    Science.gov (United States)

    Brentan Silva, Denise; Aschenbrenner, Anna-Katharina; Lopes, Norberto Peporine; Spring, Otmar

    2017-05-10

    Helianthus annuus (sunflower) displays non-glandular trichomes (NGT), capitate glandular trichomes (CGT), and linear glandular trichomes (LGT), which reveal different chemical compositions and locations in different plant tissues. With matrix-assisted laser desorption/ionization (MALDI) and laser desorption/ionization (LDI) mass spectrometry imaging (MSI) techniques, efficient methods were developed to analyze the tissue distribution of secondary metabolites (flavonoids and sesquiterpenes) and proteins inside of trichomes. Herein, we analyzed sesquiterpene lactones, present in CGT, from leaf transversal sections using the matrix 2,5-dihydroxybenzoic acid (DHB) and α-cyano-4-hydroxycinnamic acid (CHCA) (mixture 1:1) with sodium ions added to increase the ionization in positive ion mode. The results observed for sesquiterpenes and polymethoxylated flavones from LGT were similar. However, upon desiccation, LGT changed their shape in the ionization source, complicating analyses by MSI mainly after matrix application. An alternative method could be applied to LGT regions by employing LDI (without matrix) in negative ion mode. The polymethoxylated flavones were easily ionized by LDI, producing images with higher resolution, but the sesquiterpenes were not observed in spectra. Thus, the application and viability of MALDI imaging for the analyses of protein and secondary metabolites inside trichomes were confirmed, highlighting the importance of optimization parameters.

  5. Electrochemical kinetic and mass transfer model for direct ethanol alkaline fuel cell (DEAFC)

    Science.gov (United States)

    Abdullah, S.; Kamarudin, S. K.; Hasran, U. A.; Masdar, M. S.; Daud, W. R. W.

    2016-07-01

    A mathematical model is developed for a liquid-feed DEAFC incorporating an alkaline anion-exchange membrane. The one-dimensional mass transport of chemical species is modelled using isothermal, single-phase and steady-state assumptions. The anode and cathode electrochemical reactions use the Tafel kinetics approach, with two limiting cases, for the reaction order. The model fully accounts for the mixed potential effects of ethanol oxidation at the cathode due to ethanol crossover via an alkaline anion-exchange membrane. In contrast to a polymer electrolyte membrane model, the current model considers the flux of ethanol at the membrane as the difference between diffusive and electroosmotic effects. The model is used to investigate the effects of the ethanol and alkali inlet feed concentrations at the anode. The model predicts that the cell performance is almost identical for different ethanol concentrations at a low current density. Moreover, the model results show that feeding the DEAFC with 5 M NaOH and 3 M ethanol at specific operating conditions yields a better performance at a higher current density. Furthermore, the model indicates that crossover effects on the DEAFC performance are significant. The cell performance decrease from its theoretical value when a parasitic current is enabled in the model.

  6. Lynn Westdal | NREL

    Science.gov (United States)

    scientists in the Photobiology Group, which is part of NREL's Bioenergy Science and Technology Directorate . She holds a Bachelor of Arts degree in Music Education. Professional Experience Administrative

  7. A predicted directional bias of the mass asymmetry in 230Th(n,f)

    International Nuclear Information System (INIS)

    Lang, D.W.

    1983-01-01

    Heavy and light fragments in fission usually share a common angular distribution, associated with a defined parity for an isolated saddle-point state. In 230 Th(n,f) at 708 keV, the triple-humped fission barrier model suggests an overlap of two saddle-point states of opposite parity based on the same asymmetric configuration. The model then predicts fore-and-aft asymmetry for, say, the distribution of heavy fragments at a given neutron energy. For neutrons polarized perpendicular to the beam there is asymmetry in the third perpendicular direction. Experimental verification may depend critically on energy resolution. At lower energies the effect may be more general in fissionable nuclei and there is a possibility of detecting and identifying p-wave resonances at much lower energies. (Auth.)

  8. Molecularly imprinted polymer (MIP) membrane assisted direct spray ionization mass spectrometry for agrochemicals screening in foodstuffs.

    Science.gov (United States)

    Pereira, Igor; Rodrigues, Marcella Ferreira; Chaves, Andréa Rodrigues; Vaz, Boniek Gontijo

    2018-02-01

    Paper spray ionization (PSI) has some limitations such as low sensitivity and ionization suppression when complex samples are analyzed. The use of sample preparation devices directly coupled to MS can avoid these restrictions. Molecularly imprinted polymers (MIPs) are materials widely used as adsorbent in sample preparation methods such as solid-phase extraction and solid-phase microextraction, and they can provide specifics cavities with affinity to a target molecule. Here, we introduce a new MIP membrane spray ionization method combining MIP and PSI. MIP was synthesized directly on a cellulose membrane. Monuron and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were used as template molecules in MIP synthesis for diuron and 2,4-D (2,4-dichlorophenoxyacetic acid) analyte sequesters, respectively. Apple, banana and grape methanolic extracts were used as matrices. The MIP membrane spray showed signal intensities of diuron and 2,4-D that were much higher compared to those obtained by non-imprinted polymers(NIP). Calibration curves exhibited R 2 > 0.99 for diuron and 2,4-D in all fruit extracts analyzed. LODs were found less than 0.60µgL -1 and LLOQs were found less than 2.00µgL -1 . The coefficients of variation and relative errors were less than 15% for almost all analyses. The apparent recovery test results ranged between 92,5% and 116.9%. Finally, the MIP membrane spray method was employed for the quantification of diuron and 2,4-D in real samples. Diuron contents were only found in three bananas (4.0, 6.5, and 9.9µgL -1 ). The proposed MIP membrane spray ionization method was straightforward, fast to carry out and provided satisfactory results for analyses of diuron and 2,4-D in apple, banana and grape samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Metabolomic study of lipids in serum for biomarker discovery in Alzheimer's disease using direct infusion mass spectrometry.

    Science.gov (United States)

    González-Domínguez, R; García-Barrera, T; Gómez-Ariza, J L

    2014-09-01

    In this study, we demonstrated the potential of direct infusion mass spectrometry for the lipidomic characterization of Alzheimer's disease. Serum samples were extracted for lipids recovery, and directly analyzed using an electrospray source. Metabolomic fingerprints were subjected to multivariate analysis in order to discriminate between groups of patients and healthy controls, and then some key-compounds were identified as possible markers of Alzheimer's disease. Major differences were found in lipids, although some low molecular weight metabolites also showed significant changes. Thus, important metabolic pathways involved in neurodegeneration could be studied on the basis of these perturbations, such as membrane breakdown (phospholipids and diacylglycerols), oxidative stress (prostaglandins, imidazole and histidine), alterations in neurotransmission systems (oleamide and putrescine) and hyperammonaemia (guanidine and arginine). Moreover, it is noteworthy that some of these potential biomarkers have not been previously described for Alzheimer's disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Ultrasonic nebulization extraction/low pressure photoionization mass spectrometry for direct analysis of chemicals in matrices.

    Science.gov (United States)

    Liu, Chengyuan; Zhu, Yanan; Zhou, Zhongyue; Yang, Jiuzhong; Qi, Fei; Pan, Yang

    2015-09-03

    A novel ultrasonic nebulization extraction/low-pressure photoionization (UNE-LPPI) system has been designed and employed for the rapid mass spectrometric analysis of chemicals in matrices. An ultrasonic nebulizer was used to extract the chemicals in solid sample and nebulize the solvent in the nebulization cell. Aerosols formed by ultrasonic were evaporated by passing through a transferring tube, and desolvated chemicals were ionized by the emitted light (10.6 eV) from a Krypton discharge lamp at low pressure (∼68 Pa). First, a series of semi/non-volatile compounds with different polarities, such as polycyclic aromatic hydrocarbons (PAHs), amino acids, dipeptides, drugs, nucleic acids, alkaloids, and steroids were used to test the system. Then, the quantification capability of UNE-LPPI was checked with: 1) pure chemicals, such as 9,10-phenanthrenequinone and 1,4-naphthoquinone dissolved in solvent; 2) soil powder spiked with different amounts of phenanthrene and pyrene. For pure chemicals, the correlation coefficient (R(2)) for the standard curve of 9,10-phenanthrenequinone in the range of 3 ng-20 μg mL(-1) was 0.9922, and the measured limits of detection (LOD) was 1 ng ml(-1). In the case of soil powder, linear relationships for phenanthrene and pyrene from 10 to 400 ng mg(-1) were obtained with correlation coefficients of 0.9889 and 0.9893, respectively. At last, the feasibility of UNE-LPPI for the detection of chemicals in real matrices such as tablets and biological tissues (tea, Citrus aurantium peel and sage (Salvia officinalis) leaf) were successfully demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Direct Observations of Magnetic Flux Rope Formation during a Solar Coronal Mass Ejection

    Science.gov (United States)

    Song, H.; Zhang, J.; Chen, Y.; Cheng, X.

    2014-12-01

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are results of eruptions of magnetic flux ropes (MFRs). However, a heated debate is on whether MFRs pre-exist before the eruptions or they are formed during the eruptions. Several coronal signatures, e.g., filaments, coronal cavities, sigmoid structures and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which support the pre existing MFR scenario. There is almost no reported observation about MFR formation during the eruption. In this presentation, we present an intriguing observation of a solar eruptive event with the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, which shows a detailed formation process of the MFR during the eruption. The process started with the expansion of a low lying coronal arcade, possibly caused by the flare magnetic reconnection underneath. The newly-formed ascending loops from below further pushed the arcade upward, stretching the surrounding magnetic field. The arcade and stretched magnetic field lines then curved-in just below the arcade vertex, forming an X-point. The field lines near the X-point continued to approach each other and a second magnetic reconnection was induced. It is this high-lying magnetic reconnection that led to the formation and eruption of a hot blob (~ 10 MK), presumably a MFR, producing a CME. We suggest that two spatially-separated magnetic reconnections occurred in this event, responsible for producing the flare and the hot blob (CME), respectively.

  12. DIRECT OBSERVATIONS OF MAGNETIC FLUX ROPE FORMATION DURING A SOLAR CORONAL MASS EJECTION

    International Nuclear Information System (INIS)

    Song, H. Q.; Chen, Y.; Zhang, J.; Cheng, X.

    2014-01-01

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are the results of eruptions of magnetic flux ropes (MFRs). However, there is heated debate on whether MFRs exist prior to the eruptions or if they are formed during the eruptions. Several coronal signatures, e.g., filaments, coronal cavities, sigmoid structures, and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which support the pre-existing MFR scenario. There is almost no reported observation of MFR formation during the eruption. In this Letter, we present an intriguing observation of a solar eruptive event that occurred on 2013 November 21 with the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, which shows the formation process of the MFR during the eruption in detail. The process began with the expansion of a low-lying coronal arcade, possibly caused by the flare magnetic reconnection underneath. The newly formed ascending loops from below further pushed the arcade upward, stretching the surrounding magnetic field. The arcade and stretched magnetic field lines then curved in just below the arcade vertex, forming an X-point. The field lines near the X-point continued to approach each other and a second magnetic reconnection was induced. It is this high-lying magnetic reconnection that led to the formation and eruption of a hot blob (∼10 MK), presumably an MFR, producing a CME. We suggest that two spatially separated magnetic reconnections occurred in this event, which were responsible for producing the flare and the hot blob (CME)

  13. DIRECT OBSERVATIONS OF MAGNETIC FLUX ROPE FORMATION DURING A SOLAR CORONAL MASS EJECTION

    Energy Technology Data Exchange (ETDEWEB)

    Song, H. Q.; Chen, Y. [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment and Institute of Space Sciences, Shandong University, Weihai, Shandong 264209 (China); Zhang, J. [School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, VA 22030 (United States); Cheng, X., E-mail: hqsong@sdu.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093 (China)

    2014-09-10

    Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are the results of eruptions of magnetic flux ropes (MFRs). However, there is heated debate on whether MFRs exist prior to the eruptions or if they are formed during the eruptions. Several coronal signatures, e.g., filaments, coronal cavities, sigmoid structures, and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which support the pre-existing MFR scenario. There is almost no reported observation of MFR formation during the eruption. In this Letter, we present an intriguing observation of a solar eruptive event that occurred on 2013 November 21 with the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, which shows the formation process of the MFR during the eruption in detail. The process began with the expansion of a low-lying coronal arcade, possibly caused by the flare magnetic reconnection underneath. The newly formed ascending loops from below further pushed the arcade upward, stretching the surrounding magnetic field. The arcade and stretched magnetic field lines then curved in just below the arcade vertex, forming an X-point. The field lines near the X-point continued to approach each other and a second magnetic reconnection was induced. It is this high-lying magnetic reconnection that led to the formation and eruption of a hot blob (∼10 MK), presumably an MFR, producing a CME. We suggest that two spatially separated magnetic reconnections occurred in this event, which were responsible for producing the flare and the hot blob (CME)

  14. Direct matrix-assisted laser desorption ionization time-of-flight mass spectrometry improves appropriateness of antibiotic treatment of bacteremia.

    Directory of Open Access Journals (Sweden)

    Anne L M Vlek

    Full Text Available Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS allows the identification of microorganisms directly from positive blood culture broths. Use of the MALDI-TOF MS for rapid identification of microorganisms from blood culture broths can reduce the turnaround time to identification and may lead to earlier appropriate treatment of bacteremia. During February and April 2010, direct MALDI-TOF MS was routinely performed on all positive blood cultures. During December 2009 and March 2010 no direct MALDI-TOF MS was used. Information on antibiotic therapy was collected from the hospital and intensive care units' information systems from all positive blood cultures during the study period. In total, 253 episodes of bacteremia were included of which 89 during the intervention period and 164 during the control period. Direct performance of MALDI-TOF MS on positive blood culture broths reduced the time till species identification by 28.8-h and was associated with an 11.3% increase in the proportion of patients receiving appropriate antibiotic treatment 24 hours after blood culture positivity (64.0% in the control period versus 75.3% in the intervention period (p0.01. Routine implementation of this technique increased the proportion of patients on adequate antimicrobial treatment within 24 hours.

  15. Direct matrix-assisted laser desorption ionization time-of-flight mass spectrometry improves appropriateness of antibiotic treatment of bacteremia.

    Science.gov (United States)

    Vlek, Anne L M; Bonten, Marc J M; Boel, C H Edwin

    2012-01-01

    Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows the identification of microorganisms directly from positive blood culture broths. Use of the MALDI-TOF MS for rapid identification of microorganisms from blood culture broths can reduce the turnaround time to identification and may lead to earlier appropriate treatment of bacteremia. During February and April 2010, direct MALDI-TOF MS was routinely performed on all positive blood cultures. During December 2009 and March 2010 no direct MALDI-TOF MS was used. Information on antibiotic therapy was collected from the hospital and intensive care units' information systems from all positive blood cultures during the study period. In total, 253 episodes of bacteremia were included of which 89 during the intervention period and 164 during the control period. Direct performance of MALDI-TOF MS on positive blood culture broths reduced the time till species identification by 28.8-h and was associated with an 11.3% increase in the proportion of patients receiving appropriate antibiotic treatment 24 hours after blood culture positivity (64.0% in the control period versus 75.3% in the intervention period (p0.01)). Routine implementation of this technique increased the proportion of patients on adequate antimicrobial treatment within 24 hours.

  16. Direct Visualization of Neurotransmitters in Rat Brain Slices by Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI - MS)

    Science.gov (United States)

    Fernandes, Anna Maria A. P.; Vendramini, Pedro H.; Galaverna, Renan; Schwab, Nicolas V.; Alberici, Luciane C.; Augusti, Rodinei; Castilho, Roger F.; Eberlin, Marcos N.

    2016-12-01

    Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials. The amino acids γ-aminobutyric (GABA), glutamate, aspartate, serine, as well as acetylcholine, dopamine, and choline were successfully imaged using a commercial DESI source coupled to a hybrid quadrupole-Orbitrap mass spectrometer. The spatial distribution of the analyzed compounds in different brain regions was determined. We conclude that the ambient matrix-free DESI-MSI is suitable for neurotransmitter imaging and could be applied in studies that involve evaluation of imbalances in neurotransmitters levels.

  17. Analysis of wastewater samples by direct combination of thin-film microextraction and desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Strittmatter, Nicole; Düring, Rolf-Alexander; Takáts, Zoltán

    2012-09-07

    An analysis method for aqueous samples by the direct combination of C18/SCX mixed mode thin-film microextraction (TFME) and desorption electrospray ionization mass spectrometry (DESI-MS) was developed. Both techniques make analytical workflow simpler and faster, hence the combination of the two techniques enables considerably shorter analysis time compared to the traditional liquid chromatography mass spectrometry (LC-MS) approach. The method was characterized using carbamazepine and triclosan as typical examples for pharmaceuticals and personal care product (PPCP) components which draw increasing attention as wastewater-derived environmental contaminants. Both model compounds were successfully detected in real wastewater samples and their concentrations determined using external calibration with isotope labeled standards. Effects of temperature, agitation, sample volume, and exposure time were investigated in the case of spiked aqueous samples. Results were compared to those of parallel HPLC-MS determinations and good agreement was found through a three orders of magnitude wide concentration range. Serious matrix effects were observed in treated wastewater, but lower limits of detection were still found to be in the low ng L(-1) range. Using an Orbitrap mass spectrometer, the technique was found to be ideal for screening purposes and led to the detection of various different PPCP components in wastewater treatment plant effluents, including beta-blockers, nonsteroidal anti-inflammatory drugs, and UV filters.

  18. Apparent directional mass-transfer capacity coefficients in three-dimensional anisotropic heterogeneous aquifers under radial convergent transport

    Science.gov (United States)

    Pedretti, D.; Fernàndez-Garcia, D.; Sanchez-Vila, X.; Bolster, D.; Benson, D. A.

    2014-02-01

    Aquifer hydraulic properties such as hydraulic conductivity (K) are ubiquitously heterogeneous and typically only a statistical characterization can be sought. Additionally, statistical anisotropy at typical characterization scales is the rule. Thus, regardless of the processes governing solute transport at the local (pore) scale, transport becomes non-Fickian. Mass-transfer models provide an efficient tool that reproduces observed anomalous transport; in some cases though, these models lack predictability as model parameters cannot readily be connected to the physical properties of aquifers. In this study, we focus on a multirate mass-transfer model (MRMT), and in particular the apparent capacity coefficient (β), which is a strong indicator of the potential of immobile zones to capture moving solute. We aim to find if the choice of an apparent β can be phenomenologically related to measures of statistical anisotropy. We analyzed an ensemble of random simulations of three-dimensional log-transformed multi-Gaussian permeability fields with stationary anisotropic correlation under convergent flow conditions. It was found that apparent β also displays an anisotropic behavior, physically controlled by the aquifer directional connectivity, which in turn is controlled by the anisotropic correlation model. A high hydraulic connectivity results in large β values. These results provide new insights into the practical use of mass-transfer models for predictive purposes.

  19. Mass-spectrometry-directed analysis and purification of pyrrolizidine alkaloid cis/trans isomers in Gynura japonica.

    Science.gov (United States)

    Fang, Lianxiang; Xiong, Aizhen; Yang, Xiao; Cheng, Wenzhi; Yang, Li; Wang, Zhengtao

    2014-08-01

    Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass-directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)-seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid-induced toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Rapid determination of ginkgolic acids in Ginkgo biloba kernels and leaves by direct analysis in real time-mass spectrometry.

    Science.gov (United States)

    Huang, Zhongping; Xu, Yueting; Huang, Yilei; Liu, Charles; Jiang, Kezhi; Wang, Lili

    2017-12-01

    A novel method based on direct analysis in real time integrated with mass spectrometry was established and applied into rapid determination of ginkgolic acids in Ginkgo biloba kernels and leaves. Instrument parameter settings were optimized to obtain the sensitive and accurate determination of ginkgolic acids. At the sample introduction speed of 0.2 mm/s, high intensity of [M-H] - ions for ginkgolic acids were observed in the negative ion mode by utilization of high-purity helium gas at 450°C. Two microliters of methanol extract of G. biloba kernels or leaves dropped on the surface of Quick-Strip module was analyzed after solvent evaporated to dryness. A series of standard solutions of ginkgolic acid 13:0 in the range of 2-50 mg/L were analyzed with a correlation coefficient r = 0.9981 and relative standard deviation (n = 5) from 12.5 to 13.7%. The limit of detection was 0.5 mg/L. The results of direct analysis in real time-mass spectrometry were in agreement with those observed by thermochemolysis gas chromatography. The proposed method demonstrated significant potential in the application of the high-throughput screening and rapid analysis for ginkgolic acids in dietary supplements. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Direct Analysis in Real Time Mass Spectrometry for the Nondestructive Investigation of Conservation Treatments of Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Marcello Manfredi

    2016-01-01

    Full Text Available Today the long-term conservation of cultural heritage is a big challenge: often the artworks were subjected to unknown interventions, which eventually were found to be harmful. The noninvasive investigation of the conservation treatments to which they were subjected to is a crucial step in order to undertake the best conservation strategies. We describe here the preliminary results on a quick and direct method for the nondestructive identification of the various interventions of parchment by means of direct analysis in real time (DART ionization and high-resolution time-of-flight mass spectrometry and chemometrics. The method has been developed for the noninvasive analysis of the Dead Sea Scrolls, one of the most important archaeological discoveries of the 20th century. In this study castor oil and glycerol parchment treatments, prepared on new parchment specimens, were investigated in order to evaluate two different types of operations. The method was able to identify both treatments. In order to investigate the effect of the ion source temperature on the mass spectra, the DART-MS analysis was also carried out at several temperatures. Due to the high sensitivity, simplicity, and no sample preparation requirement, the proposed analytical methodology could help conservators in the challenging analysis of unknown treatments in cultural heritage.

  2. Real time analysis of brain tissue by direct combination of ultrasonic surgical aspiration and sonic spray mass spectrometry.

    Science.gov (United States)

    Schäfer, Karl-Christian; Balog, Júlia; Szaniszló, Tamás; Szalay, Dániel; Mezey, Géza; Dénes, Júlia; Bognár, László; Oertel, Matthias; Takáts, Zoltán

    2011-10-15

    Direct combination of cavitron ultrasonic surgical aspirator (CUSA) and sonic spray ionization mass spectrometry is presented. A commercially available ultrasonic surgical device was coupled to a Venturi easy ambient sonic-spray ionization (V-EASI) source by directly introducing liquified tissue debris into the Venturi air jet pump. The Venturi air jet pump was found to efficiently nebulize the suspended tissue material for gas phase ion production. The ionization mechanism involving solely pneumatic spraying was associated with that of sonic spray ionization. Positive and negative ionization spectra were obtained from brain and liver samples reflecting the primary application areas of the surgical device. Mass spectra were found to feature predominantly complex lipid-type constituents of tissues in both ion polarity modes. Multiply charged peptide anions were also detected. The influence of instrumental settings was characterized in detail. Venturi pump geometry and flow parameters were found to be critically important in ionization efficiency. Standard solutions of phospholipids and peptides were analyzed in order to test the dynamic range, sensitivity, and suppression effects. The spectra of the intact tissue specimens were found to be highly specific to the histological tissue type. The principal component analysis (PCA) and linear discriminant analysis (LDA) based data analysis method was developed for real-time tissue identification in a surgical environment. The method has been successfully tested on post-mortem and ex vivo human samples including astrocytomas, meningeomas, metastatic brain tumors, and healthy brain tissue. © 2011 American Chemical Society

  3. Calibration strategy for semi-quantitative direct gas analysis using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Gerdes, Kirk; Carter, Kimberly E.

    2011-01-01

    A process is described by which an ICP-MS equipped with an Octopole Reaction System (ORS) is calibrated using liquid phase standards to facilitate direct analysis of gas phase samples. The instrument response to liquid phase standards is analyzed to produce empirical factors relating ion generation and transmission efficiencies to standard operating parameters. Empirical factors generated for liquid phase samples are then used to produce semi-quantitative analysis of both mixed liquid/gas samples and pure gas samples. The method developed is similar to the semi-quantitative analysis algorithms in the commercial software, which have here been expanded to include gas phase elements such as Xe and Kr. Equations for prediction of relative ionization efficiencies and isotopic transmission are developed for several combinations of plasma operating conditions, which allows adjustment of limited parameters between liquid and gas injection modes. In particular, the plasma temperature and electron density are calculated from comparison of experimental results to the predictions of the Saha equation. Comparisons between operating configurations are made to determine the robustness of the analysis to plasma conditions and instrument operating parameters. Using the methods described in this research, the elemental concentrations in a liquid standard containing 45 analytes and treated as an unknown sample were quantified accurately to ± 50% for most elements using 133 Cs as a single internal reference. The method is used to predict liquid phase mercury within 12% of the actual concentration and gas phase mercury within 28% of the actual concentration. The results verify that the calibration method facilitates accurate semi-quantitative, gas phase analysis of metal species with sufficient sensitivity to quantify metal concentrations lower than 1 ppb for many metallic analytes.

  4. Review of Calculation vs. Context: Quantitative Literacy and Its Implications for Teacher Education by Bernard L. Madison and Lynn Arthur Steen (Editors

    Directory of Open Access Journals (Sweden)

    Maura B. Mast

    2009-07-01

    Full Text Available Madison, Bernard L. and Steen, Lynn Arthur (Eds.. Calculation vs. Context: Quantitative Literacy and Its Implications for Teacher Education. (Washington, DC: Mathematical Association of America, 2009. 197 pp. Softcover. ISBN 978-0-88385-908-7. Available free on the MAA website at http://www.maa.org/ql/calcvscontext.htmlThe papers in Calculation vs. Context discuss the role of quantitative literacy in the K-12 curriculum and in teacher education. The papers present a varied set of perspectives and address three themes: the changing environment of education in American society; the challenges, and the necessity, of preparing teachers to teach quantitative literacy and of including quantitative literacy in the K-12 education; and cross-disciplinary approaches to quantitative literacy. While the conclusion reached by several of the authors is that the best place to teach quantitative literacy is at the college level, the book offers serious considerations of how quantitative literacy can and should inform the K-12 curriculum. The book also marks a turning point in the quantitative literacy movement as “QL explorers,” as Lynn Steen calls them, move beyond issues of definitions and content to a discussion of how to bring quantitative literacy into a broader setting.

  5. Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak.

    Science.gov (United States)

    Rubin, Steven A; Qi, Li; Audet, Susette A; Sullivan, Bradley; Carbone, Kathryn M; Bellini, William J; Rota, Paul A; Sirota, Lev; Beeler, Judy

    2008-08-15

    Recent mumps outbreaks in older vaccinated populations were caused primarily by genotype G viruses, which are phylogenetically distinct from the genotype A vaccine strains used in the countries affected by the outbreaks. This finding suggests that genotype A vaccine strains could have reduced efficacy against heterologous mumps viruses. The remote history of vaccination also suggests that waning immunity could have contributed to susceptibility. To examine these issues, we obtained consecutive serum samples from children at different intervals after vaccination and assayed the ability of these samples to neutralize the genotype A Jeryl Lynn mumps virus vaccine strain and a genotype G wild-type virus obtained during the mumps outbreak that occurred in the United States in 2006. Although the geometric mean neutralizing antibody titers against the genotype G virus were approximately one-half the titers measured against the vaccine strain, and although titers to both viruses decreased with time after vaccination, antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralized the outbreak-associated virus at all time points tested.

  6. Direct dose mapping versus energy/mass transfer mapping for 4D dose accumulation: fundamental differences and dosimetric consequences.

    Science.gov (United States)

    Li, Haisen S; Zhong, Hualiang; Kim, Jinkoo; Glide-Hurst, Carri; Gulam, Misbah; Nurushev, Teamour S; Chetty, Indrin J

    2014-01-06

    The direct dose mapping (DDM) and energy/mass transfer (EMT) mapping are two essential algorithms for accumulating the dose from different anatomic phases to the reference phase when there is organ motion or tumor/tissue deformation during the delivery of radiation therapy. DDM is based on interpolation of the dose values from one dose grid to another and thus lacks rigor in defining the dose when there are multiple dose values mapped to one dose voxel in the reference phase due to tissue/tumor deformation. On the other hand, EMT counts the total energy and mass transferred to each voxel in the reference phase and calculates the dose by dividing the energy by mass. Therefore it is based on fundamentally sound physics principles. In this study, we implemented the two algorithms and integrated them within the Eclipse treatment planning system. We then compared the clinical dosimetric difference between the two algorithms for ten lung cancer patients receiving stereotactic radiosurgery treatment, by accumulating the delivered dose to the end-of-exhale (EE) phase. Specifically, the respiratory period was divided into ten phases and the dose to each phase was calculated and mapped to the EE phase and then accumulated. The displacement vector field generated by Demons-based registration of the source and reference images was used to transfer the dose and energy. The DDM and EMT algorithms produced noticeably different cumulative dose in the regions with sharp mass density variations and/or high dose gradients. For the planning target volume (PTV) and internal target volume (ITV) minimum dose, the difference was up to 11% and 4% respectively. This suggests that DDM might not be adequate for obtaining an accurate dose distribution of the cumulative plan, instead, EMT should be considered.

  7. Direct coupling of a dense (supercritical) gas chromatograph to a mass spectrometer using a supersonic molecular beam interface

    International Nuclear Information System (INIS)

    Randall, L.G.; Wahrhaftig, A.L.

    1981-01-01

    A detecting mass spectrometer has been successfully coupled to a dense gas (supercritical fluid) chromatograph to produce an instrument (DGC/MS) that may be an alternative to high performance liquid chromatograph/mass spectrometer instruments (HPLC/MS) and gas chromatograph/mass spectrometer instruments (GC/MS) for analysis of involatile and/or thermally labile compounds. The mobile phase in DGC is a gas held at temperatures above the critical temperature and at pressures sufficient to obtain nearly liquid-like densities. DGC combines advantages of GC and HPLC: rapid separations, moderate operating temperatures, and analysis of involatile compounds. An advantage unique to DGC is the solvent power dependence upon pressure. While several groups have studied DGC, its development has been limited by the lack of a sensitive and selective detector. Hence, work has been directed towards the design and construction of a DGC/MS resulting in a trial instrument capable of chromatographic pressures of at least 300 atm and temperatures from 10 0 to 60 0 C. The DGC/MS coupling has been accomplished by the use of a supersonic molecular beam interface. This application of molecular beam formation appears to be unique in its requirements of a large pressure ratio (approx.10 8 ), low flow rates, and low final pressures. The authors outline characteristics of supersonic jets and molecular beams pertinent to the design of such an instrument. The interface which uses pumping speeds of 2400 and 1200 l/s in the beam forming chambers is described in detail, while the other components: the detecting mass spectrometer, the dense gas supply, and the DGC: are briefly described. Preliminary work with this instrument has established the feasibility of DGC/MS as an analytical technique and further development is recommended

  8. Rapid analysis of Δ-9-tetrahydrocannabinol in hair using direct analysis in real time ambient ionization orbitrap mass spectrometry.

    Science.gov (United States)

    Duvivier, Wilco F; van Beek, Teris A; Pennings, Ed J M; Nielen, Michel W F

    2014-04-15

    Forensic hair analysis methods are laborious, time-consuming and provide only a rough retrospective estimate of the time of drug intake. Recently, hair imaging methods using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were reported, but these methods require the application of MALDI matrix and are performed under vacuum. Direct analysis of entire locks of hair without any sample pretreatment and with improved spatial resolution would thus address a need. Hair samples were attached to stainless steel mesh screens and scanned in the X-direction using direct analysis in real time (DART) ambient ionization orbitrap MS. The DART gas temperature and the accuracy of the probed hair zone were optimized using Δ-9-tetrahydrocannabinol (THC) as a model compound. Since external contamination is a major issue in forensic hair analysis, sub-samples were measured before and after dichloromethane decontamination. The relative intensity of the THC signal in spiked blank hair versus that of quinine as the internal standard showed good reproducibility (26% RSD) and linearity of the method (R(2)  = 0.991). With the DART hair scan THC could be detected in hair samples from different chronic cannabis users. The presence of THC was confirmed by quantitative liquid chromatography/tandem mass spectrometry. Zones with different THC content could be clearly distinguished, indicating that the method might be used for retrospective timeline assessments. Detection of THC in decontaminated drug user hair showed that the DART hair scan not only probes THC on the surface of hair, but penetrates deeply enough to measure incorporated THC. A new approach in forensic hair analysis has been developed by probing complete locks of hair using DART-MS. Longitudinal scanning enables detection of incorporated compounds and can be used as pre-screening for THC without sample preparation. The method could also be adjusted for the analysis of other drugs of abuse. Copyright

  9. Characterisation of a smartphone image sensor response to direct solar 305nm irradiation at high air masses.

    Science.gov (United States)

    Igoe, D P; Amar, A; Parisi, A V; Turner, J

    2017-06-01

    This research reports the first time the sensitivity, properties and response of a smartphone image sensor that has been used to characterise the photobiologically important direct UVB solar irradiances at 305nm in clear sky conditions at high air masses. Solar images taken from Autumn to Spring were analysed using a custom Python script, written to develop and apply an adaptive threshold to mitigate the effects of both noise and hot-pixel aberrations in the images. The images were taken in an unobstructed area, observing from a solar zenith angle as high as 84° (air mass=9.6) to local solar maximum (up to a solar zenith angle of 23°) to fully develop the calibration model in temperatures that varied from 2°C to 24°C. The mean ozone thickness throughout all observations was 281±18 DU (to 2 standard deviations). A Langley Plot was used to confirm that there were constant atmospheric conditions throughout the observations. The quadratic calibration model developed has a strong correlation between the red colour channel from the smartphone with the Microtops measurements of the direct sun 305nm UV, with a coefficient of determination of 0.998 and very low standard errors. Validation of the model verified the robustness of the method and the model, with an average discrepancy of only 5% between smartphone derived and Microtops observed direct solar irradiances at 305nm. The results demonstrate the effectiveness of using the smartphone image sensor as a means to measure photobiologically important solar UVB radiation. The use of ubiquitous portable technologies, such as smartphones and laptop computers to perform data collection and analysis of solar UVB observations is an example of how scientific investigations can be performed by citizen science based individuals and groups, communities and schools. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2017-04-01

    Full Text Available This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope’s modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity.

  11. Direct surface analysis of pesticides on soil, leaves, grass, and stainless steel by static secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, J.C.; Groenewold, G.S.; Appelhans, A.D.; Delmore, J.E.; Olson, J.E.; Miller, D.L. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-02-01

    Direct surface analyses by static secondary ion mass spectrometry (SIMS) were performed for the following pesticides adsorbed on dandelion leaves, grass, soil, and stainless steel samples: alachlor, atrazine, captan, carbofuran, chlorpyrifos, chlorosulfuron, chlorthal-dimethyl, cypermethrin, 2,4-D, diuron, glyphosate, malathion, methomyl, methyl arsonic acid, mocap, norflurazon, oxyfluorfen, paraquat, temik, and trifluralin. The purpose of this study was to evaluate static SIMS as a tool for pesticide analysis, principally for use in screening samples for pesticides. The advantage of direct surface analysis compared with conventional pesticide analysis methods is the elimination of sample pretreatment including extraction, which streamlines the analysis substantially; total analysis time for SIMS analysis was ca. 10 min/sample. Detection of 16 of the 20 pesticides on all four substrates was achieved. Of the remaining four pesticides, only one (trifluralin) was not detected on any of the samples. The minimum detectable quantity was determined for paraquat on soil in order to evaluate the efficacy of using SIMS as a screening tool. Paraquat was detected at 3 pg/mm{sup 2} (c.a. 0.005 monolayers). The results of these studies suggest that SIMS is capable of direct surface detection of a range of pesticides, with low volatility, polar pesticides being the most easily detected. 25 refs., 2 figs., 2 tabs.

  12. Control of Strobilurin Fungicides in Wheat Using Direct Analysis in Real Time Accurate Time-of-Flight and Desorption Electrospray Ionization Linear Ion Trap Mass Spectrometry

    NARCIS (Netherlands)

    Schurek, J.; Vaclavik, L.; Hooijerink, H.; Lacina, O.; Poustka, J.; Sharman, M.; Caldow, M.; Nielen, M.W.F.; Hajslova, J.

    2008-01-01

    Ambient mass spectrometry has been used for the analysis of strobilurin residues in wheat. The use of this novel, challenging technique, employing a direct analysis in a real time (DART) ion-source coupled with a time-of-flight mass spectrometer (TOF MS) and a desorption electrospray ionization

  13. Modeling 3D conjugate heat and mass transfer for turbulent air drying of Chilean papaya in a direct contact dryer

    Science.gov (United States)

    Lemus-Mondaca, Roberto A.; Vega-Gálvez, Antonio; Zambra, Carlos E.; Moraga, Nelson O.

    2017-01-01

    A 3D model considering heat and mass transfer for food dehydration inside a direct contact dryer is studied. The k- ɛ model is used to describe turbulent air flow. The samples thermophysical properties as density, specific heat, and thermal conductivity are assumed to vary non-linearly with temperature. FVM, SIMPLE algorithm based on a FORTRAN code are used. Results unsteady velocity, temperature, moisture, kinetic energy and dissipation rate for the air flow are presented, whilst temperature and moisture values for the food also are presented. The validation procedure includes a comparison with experimental and numerical temperature and moisture content results obtained from experimental data, reaching a deviation 7-10 %. In addition, this turbulent k- ɛ model provided a better understanding of the transport phenomenon inside the dryer and sample.

  14. Multi-layer membrane model for mass transport in a direct ethanol fuel cell using an alkaline anion exchange membrane

    Science.gov (United States)

    Bahrami, Hafez; Faghri, Amir

    2012-11-01

    A one-dimensional, isothermal, single-phase model is presented to investigate the mass transport in a direct ethanol fuel cell incorporating an alkaline anion exchange membrane. The electrochemistry is analytically solved and the closed-form solution is provided for two limiting cases assuming Tafel expressions for both oxygen reduction and ethanol oxidation. A multi-layer membrane model is proposed to properly account for the diffusive and electroosmotic transport of ethanol through the membrane. The fundamental differences in fuel crossover for positive and negative electroosmotic drag coefficients are discussed. It is found that ethanol crossover is significantly reduced upon using an alkaline anion exchange membrane instead of a proton exchange membrane, especially at current densities higher than 500 A m

  15. Quantitative Profiling of Major Neutral Lipid Classes in Human Meibum by Direct Infusion Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Chen, Jianzhong; Green, Kari B.; Nichols, Kelly K.

    2013-01-01

    Purpose. The purpose of this investigation was to better understand lipid composition in human meibum. Methods. Intact lipids in meibum samples were detected by direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis in positive detection mode using sodium iodide (NaI) as an additive. The peak intensities of all major types of lipid species, that is, wax esters (WEs), cholesteryl esters (CEs), and diesters (DEs) were corrected for peak overlapping and isotopic distribution; an additional ionization efficiency correction was performed for WEs and CEs, which was simplified by the observation that the corresponding ionization efficiency was primarily dependent on the specific lipid class and saturation degree of the lipids while independent of the carbon chain length. A set of WE and CE standards was spiked in meibum samples for ionization efficiency determination and absolute quantitation. Results. The absolute amount (μmol/mg) for each of 51 WEs and 31 CEs in meibum samples was determined. The summed masses for 51 WEs and 31 CEs accounted for 48 ± 4% and 40 ± 2%, respectively, of the total meibum lipids. The mass percentages of saturated and unsaturated species were determined to be 75 ± 2% and 25 ± 1% for CEs and 14 ± 1% and 86 ± 1% for WEs. The profiles for two types of DEs were also obtained, which include 42 α,ω Type II DEs, and 21 ω Type I-St DEs. Conclusions. Major neutral lipid classes in meibum samples were quantitatively profiled by ESI-MS analysis with NaI additive. PMID:23847307

  16. In-silico oncology: an approximate model of brain tumor mass effect based on directly manipulated free form deformation

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Stefan; Mang, Andreas; Toma, Alina; Buzug, Thorsten M. [University of Luebeck (Germany). Institute of Medical Engineering

    2010-12-15

    The present work introduces a novel method for approximating mass effect of primary brain tumors. The spatio-temporal dynamics of cancerous cells are modeled by means of a deterministic reaction-diffusion equation. Diffusion tensor information obtained from a probabilistic diffusion tensor imaging atlas is incorporated into the model to simulate anisotropic diffusion of cancerous cells. To account for the expansive nature of the tumor, the computed net cell density of malignant cells is linked to a parametric deformation model. This mass effect model is based on the so-called directly manipulated free form deformation. Spatial correspondence between two successive simulation steps is established by tracking landmarks, which are attached to the boundary of the gross tumor volume. The movement of these landmarks is used to compute the new configuration of the control points and, hence, determines the resulting deformation. To prevent a deformation of rigid structures (i.e. the skull), fixed shielding landmarks are introduced. In a refinement step, an adaptive landmark scheme ensures a dense sampling of the tumor isosurface, which in turn allows for an appropriate representation of the tumor shape. The influence of different parameters on the model is demonstrated by a set of simulations. Additionally, simulation results are qualitatively compared to an exemplary set of clinical magnetic resonance images of patients diagnosed with high-grade glioma. Careful visual inspection of the results demonstrates the potential of the implemented model and provides first evidence that the computed approximation of tumor mass effect is sensible. The shape of diffusive brain tumors (glioblastoma multiforme) can be recovered and approximately matches the observations in real clinical data. (orig.)

  17. ERNE observations of energetic particles associated with Earth-directed coronal mass ejections in April and May, 1997

    Directory of Open Access Journals (Sweden)

    A. Anttila

    2000-11-01

    Full Text Available Two Earth-directed coronal mass ejections (CMEs, which were most effective in energetic (~1–50 MeV particle acceleration during the first 18 months since the Solar and Heliospheric Observatory (SOHO launch, occurred on April 7 and May 12, 1997. In the analysis of these events we have deconvoluted the injection spectrum of energetic protons by using the method described by Anttila et al. In order to apply the method developed earlier for data of a rotating satellite (Geostationary Operational Environmental Satellites, GOES, we first had to develop a method to calculate the omnidirectional energetic particle intensities from the observations of Energetic and Relativistic Nuclei and Electrons (ERNE, which is an energetic particle detector onboard the three-axis stabilized SOHO spacecraft. The omnidirectional intensities are calculated by fitting an exponential pitch angle distribution from directional information of energetic protons observed by ERNE. The results of the analysis show that, compared to a much faster and more intensive CMEs observed during the previous solar maximum, the acceleration efficiency decreases fast when the shock propagates outward from the Sun. The particles injected at distances <0.5 AU from the Sun dominate the particle flux during the whole period, when the shock propagates to the site of the spacecraft. The main portion of particles injected by the shock during its propagation further outward from the Sun are trapped around the shock, and are seen as an intensity increase at the time of the shock passage.Key words: Interplanetary physics (interplanetary shocks – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections

  18. ERNE observations of energetic particles associated with Earth-directed coronal mass ejections in April and May, 1997

    Directory of Open Access Journals (Sweden)

    A. Anttila

    Full Text Available Two Earth-directed coronal mass ejections (CMEs, which were most effective in energetic (~1–50 MeV particle acceleration during the first 18 months since the Solar and Heliospheric Observatory (SOHO launch, occurred on April 7 and May 12, 1997. In the analysis of these events we have deconvoluted the injection spectrum of energetic protons by using the method described by Anttila et al. In order to apply the method developed earlier for data of a rotating satellite (Geostationary Operational Environmental Satellites, GOES, we first had to develop a method to calculate the omnidirectional energetic particle intensities from the observations of Energetic and Relativistic Nuclei and Electrons (ERNE, which is an energetic particle detector onboard the three-axis stabilized SOHO spacecraft. The omnidirectional intensities are calculated by fitting an exponential pitch angle distribution from directional information of energetic protons observed by ERNE. The results of the analysis show that, compared to a much faster and more intensive CMEs observed during the previous solar maximum, the acceleration efficiency decreases fast when the shock propagates outward from the Sun. The particles injected at distances <0.5 AU from the Sun dominate the particle flux during the whole period, when the shock propagates to the site of the spacecraft. The main portion of particles injected by the shock during its propagation further outward from the Sun are trapped around the shock, and are seen as an intensity increase at the time of the shock passage.

    Key words: Interplanetary physics (interplanetary shocks – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections

  19. Authentication of animal fats using direct analysis in real time (DART) ionization-mass spectrometry and chemometric tools.

    Science.gov (United States)

    Vaclavik, Lukas; Hrbek, Vojtech; Cajka, Tomas; Rohlik, Bo-Anne; Pipek, Petr; Hajslova, Jana

    2011-06-08

    A combination of direct analysis in real time (DART) ionization coupled to time-of-flight mass spectrometry (TOFMS) and chemometrics was used for animal fat (lard and beef tallow) authentication. This novel instrumentation was employed for rapid profiling of triacylglycerols (TAGs) and polar compounds present in fat samples and their mixtures. Additionally, fat isolated from pork, beef, and pork/beef admixtures was analyzed. Mass spectral records were processed by principal component analysis (PCA) and stepwise linear discriminant analysis (LDA). DART-TOFMS profiles of TAGs were found to be more suitable for the purpose of discrimination among the examined fat types as compared to profiles of polar compounds. The LDA model developed using TAG data enabled not only reliable classification of samples representing neat fats but also detection of admixed lard and tallow at adulteration levels of 5 and 10% (w/w), respectively. The presented approach was also successfully applied to minced meat prepared from pork and beef with comparable fat content. Using the DART-TOFMS TAG profiles of fat isolated from meat mixtures, detection of 10% pork added to beef and vice versa was possible.

  20. Chemical discrimination of lubricant marketing types using direct analysis in real time time-of-flight mass spectrometry.

    Science.gov (United States)

    Maric, Mark; Harvey, Lauren; Tomcsak, Maren; Solano, Angelique; Bridge, Candice

    2017-06-30

    In comparison to other violent crimes, sexual assaults suffer from very low prosecution and conviction rates especially in the absence of DNA evidence. As a result, the forensic community needs to utilize other forms of trace contact evidence, like lubricant evidence, in order to provide a link between the victim and the assailant. In this study, 90 personal bottled and condom lubricants from the three main marketing types, silicone-based, water-based and condoms, were characterized by direct analysis in real time time of flight mass spectrometry (DART-TOFMS). The instrumental data was analyzed by multivariate statistics including hierarchal cluster analysis, principal component analysis, and linear discriminant analysis. By interpreting the mass spectral data with multivariate statistics, 12 discrete groupings were identified, indicating inherent chemical diversity not only between but within the three main marketing groups. A number of unique chemical markers, both major and minor, were identified, other than the three main chemical components (i.e. PEG, PDMS and nonoxynol-9) currently used for lubricant classification. The data was validated by a stratified 20% withheld cross-validation which demonstrated that there was minimal overlap between the groupings. Based on the groupings identified and unique features of each group, a highly discriminating statistical model was then developed that aims to provide the foundation for the development of a forensic lubricant database that may eventually be applied to casework. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Development of soft ionization using direct current pulse glow discharge plasma source in mass spectrometry for volatile organic compounds analysis

    Science.gov (United States)

    Nunome, Yoko; Kodama, Kenji; Ueki, Yasuaki; Yoshiie, Ryo; Naruse, Ichiro; Wagatsuma, Kazuaki

    2018-01-01

    This study describes an ionization source for mass analysis, consisting of glow discharge plasma driven by a pulsed direct-current voltage for soft plasma ionization, to detect toxic volatile organic compounds (VOCs) rapidly and easily. The novelty of this work is that a molecular adduct ion, in which the parent molecule attaches with an NO+ radical, [M + NO]+, can be dominantly detected as a base peak with little or no fragmentation of them in an ambient air plasma at a pressure of several kPa. Use of ambient air as the discharge plasma gas is suitable for practical applications. The higher pressure in an ambient air discharge provided a stable glow discharge plasma, contributing to the soft ionization of organic molecules. Typical mass spectra of VOCs toluene, benzene, o-xylene, chlorobenzene and n-hexane were observed as [M + NO]+ adduct ion whose peaks were detected at m/z 122, 108, 136, 142 and 116, respectively. The NO generation was also confirmed by emission bands of NO γ-system. The ionization reactions were suggested, such that NO+ radical formed in an ambient air discharge could attach with the analyte molecule.

  2. Ambient mass spectrometry employing direct analysis in real time (DART) ion source for olive oil quality and authenticity assessment

    International Nuclear Information System (INIS)

    Vaclavik, Lukas; Cajka, Tomas; Hrbek, Vojtech; Hajslova, Jana

    2009-01-01

    A novel approach for the authentication of olive oil samples representing different quality grades has been developed. A new type of ion source, direct analysis in real time (DART), coupled to a high-resolution time-of-flight mass spectrometer (TOFMS) was employed for the comprehensive profiling of triacylglycerols (TAGs) and/or polar compounds extracted with a methanol-water mixture. The main parameters influencing the ionization efficiency of TAGs were the type of sample solvent, degree of sample dilution, ion beam temperature, and presence of a dopant (ammonia vapors). The ionization yield of polar compounds depended mainly on a content of water in the extract and ion beam temperature. Using DART-TOFMS, not only differentiation among extra virgin olive oil (EVOO), olive pomace oil (OPO) and olive oil (OO) could be easily achieved, but also EVOO adulteration with commonly used adulterant, hazelnut oil (HO), was feasible. Based on the linear discriminant analysis (LDA), the introduced method allowed detection of HO addition of 6 and 15% (v/v) when assessing DART-TOFMS mass profiles of polar compounds and TAGs, respectively.

  3. Ambient mass spectrometry employing direct analysis in real time (DART) ion source for olive oil quality and authenticity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Vaclavik, Lukas; Cajka, Tomas; Hrbek, Vojtech [Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 5, 166 28 Prague 6 (Czech Republic); Hajslova, Jana, E-mail: jana.hajslova@vscht.cz [Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2009-07-10

    A novel approach for the authentication of olive oil samples representing different quality grades has been developed. A new type of ion source, direct analysis in real time (DART), coupled to a high-resolution time-of-flight mass spectrometer (TOFMS) was employed for the comprehensive profiling of triacylglycerols (TAGs) and/or polar compounds extracted with a methanol-water mixture. The main parameters influencing the ionization efficiency of TAGs were the type of sample solvent, degree of sample dilution, ion beam temperature, and presence of a dopant (ammonia vapors). The ionization yield of polar compounds depended mainly on a content of water in the extract and ion beam temperature. Using DART-TOFMS, not only differentiation among extra virgin olive oil (EVOO), olive pomace oil (OPO) and olive oil (OO) could be easily achieved, but also EVOO adulteration with commonly used adulterant, hazelnut oil (HO), was feasible. Based on the linear discriminant analysis (LDA), the introduced method allowed detection of HO addition of 6 and 15% (v/v) when assessing DART-TOFMS mass profiles of polar compounds and TAGs, respectively.

  4. Mass spectrometric method for the determination of the stable isotopic content of nitrous oxide by the technique of direct injection

    International Nuclear Information System (INIS)

    Rahn, T.; Wahlen, M.

    2002-01-01

    A method for the direct isotopic analysis of N 2 O has been developed for VG-Prism H dynamic dual inlet stable isotope mass spectrometer. Tests have shown extreme sensitivity to contamination by carbon dioxide with a dependence of 6.8 per mille per % CO 2 for δ 15 N and 12.4 per mille per % CO 2 for δ 18 O. Trace amounts of CO 2 have proven difficult to eliminate, particularly for small sample sizes. In order to ensure accurate analyses an indicator of CO 2 contamination must be monitored and corrections applied when necessary. We have found that ions with mass to charge ratios of 12 and 22 are excellent proxies for CO 2 contamination. Empirical relationships between these indicator species and CO 2 contamination are documented which allow for corrections to be applied to raw data. Additional corrections required due to the presence of isobaric molecules containing 17 O are described. Issues of standardization are discussed and sample handling procedures described. Finally, these methods and corrections are applied to a suite of stratospheric air samples. (author)

  5. Investigations on the direct introduction of cigarette smoke for trace elements analysis by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Chang, Michael J.; Naworal, John D.; Walker, Kathleen; Connell, Chris T.

    2003-01-01

    Direct introduction of mainstream cigarette smoke into an inductively coupled plasma mass spectrometry (ICP-MS) has been investigated with respect to its feasibility for on-line analysis of trace elements. An automated apparatus was designed and built interfacing a smoking machine with an ICP-MS for smoke generation, collection, injection and analysis. Major and minor elements present in the particulate phase and the gas phase of mainstream cigarette smoke of 2R4F reference cigarettes have been qualitatively identified by examination of their full mass spectra. This method provides a rapid-screening analysis of the transfer of trace elements into mainstream smoke during cigarette combustion. A full suite of elements present in the whole cigarette smoke has been identified, including As, B, Ba, Br, Cd, Cl, Cs, Cu, Hg, I, K, Li, Mn, Na, Pb, Rb, Sb, Sn, Tl and Zn. Of these elements, the major portions of B, Ba, Cs, Cu, K, Li, Mn, Na, Pb, Rb, Sn, Tl and Zn are present in the particulate phase, whereas the major portion of Hg is present in the gas phase. As, Br, Cd, Cl, I and Sb exist in a distribution between the gas phase and the particulate phase. Depending on the element, the precision of measurement ranges from 5 to 25% in terms of relative standard deviation of peak height and peak area, based on the fourth puff of 2R4F mainstream cigarette smoke analyzed in five smoking replicates

  6. Analysis of selected antibiotics in surface freshwater and seawater using direct injection in liquid chromatography electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Bayen, Stéphane; Yi, Xinzhu; Segovia, Elvagris; Zhou, Zhi; Kelly, Barry C

    2014-04-18

    Emerging contaminants such as antibiotics have received recent attention as they have been detected in natural waters and health concerns over potential antibiotic resistance. With the purpose to investigate fast and high-throughput analysis, and eventually the continuous on-line analysis of emerging contaminants, this study presents results on the analysis of seven selected antibiotics (sulfadiazine, sulfamethazine, sulfamerazine, sulfamethoxazole, chloramphenicol, lincomycin, tylosin) in surface freshwater and seawater using direct injection of a small sample volume (20μL) in liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Notably, direct injection of seawater in the LC-ESI-MS/MS was made possible on account of the post-column switch on the system, which allows diversion of salt-containing solutions flushed out of the column to the waste. Mean recoveries based on the isotope dilution method average 95±14% and 96±28% amongst the compounds for spiked freshwater and seawater, respectively. Linearity across six spiking levels was assessed and the response was linear (r(2)>0.99) for all compounds. Direct injection concentrations were compared for real samples to those obtained with the conventional SPE-based analysis and both techniques concurs on the presence/absence and levels of the compounds in real samples. These results suggest direct injection is a reliable method to detect antibiotics in both freshwater and seawater. Method detection limits for the direct injection technique (37pg/L to 226ng/L in freshwater, and from 16pg/to 26ng/L in seawater) are sufficient for a number of environmental applications, for example the fast screening of water samples for ecological risk assessments. In the present study of real samples, this new method allowed for example the positive detection of some compounds (e.g. lincomycin) down to the sub ng/L range. The direct injection method appears to be relatively cheaper and faster

  7. Direct measurements of 3d structure, chemistry and mass density during the induction period of C3s hydration

    International Nuclear Information System (INIS)

    Hu, Qinang; Aboustait, Mohammed; Kim, Taehwan; Ley, M. Tyler; Bullard, Jeffrey W.; Scherer, George; Hanan, Jay C.; Rose, Volker; Winarski, Robert; Gelb, Jeffrey

    2016-01-01

    The reasons for the start and end of the induction period of cement hydration remain a topic of controversy. One long-standing hypothesis is that a thin metastable hydrate forming on the surface of cement grains significantly reduces the particle dissolution rate; the eventual disappearance of this layer re-establishes higher dissolution rates at the beginning of the acceleration period. However, the importance, or even the existence, of this metastable layer has been questioned because it cannot be directly detected in most experiments. In this work, a combined analysis using nano-tomography and nano-X-ray fluorescence makes the direct imaging of early hydration products possible. These novel X-ray imaging techniques provide quantitative measurements of 3D structure, chemical composition, and mass density of the hydration products during the induction period. This work does not observe a low density product on the surface of the particle, but does provide insights into the formation of etch pits and the subsequent hydration products that fill them.

  8. Bioprofiling of unknown antibiotics in herbal extracts: Development of a streamlined direct bioautography using Bacillus subtilis linked to mass spectrometry.

    Science.gov (United States)

    Jamshidi-Aidji, Maryam; Morlock, Gertrud E

    2015-11-13

    Working in the field of profiling and identification of bioactive compounds in herbal extracts is faced with the challenge that common chromatographic methods do not directly link to bioactive compounds. Direct bioautography, the combination of TLC/HPTLC with bioassays, linked to structure elucidating techniques is demonstrated to overcome this challenge. The combination of TLC and Bacillus subtilis bioassay was already demonstrated to detect the antibiotics in samples. However, previous studies in this field were faced with some challenges, like being time-consuming, leading not to a homogenous plate background or being restricted to a non-acidic mobile phase. In this study, these aspects were investigated and a streamlined HPTLC-B. subtilis bioassay was developed that generated a homogenous plate background, which was crucial to yield a good baseline for biodensitometry. Two commonly used broths for B. subtilis and a self-designed medium were compared with regard to their capability of detection and baseline noise. The workflow developed allowed the use of acidic mobile phases for the first time. To prove this, 20 herbal extracts were screened for antimicrobial substances developed in parallel with an acidic mobile phase. The main antimicrobial substance in Salvia officinalis tincture detected was further characterized by microchemical reactions, Aliivibrio fischeri, β-glucosidase and acetylcholinesterase (bio)assays as well as mass spectrometry. Scientists looking for new herbal-based medicine may benefit from this time-saving and streamlined bioactivity profiling. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry of drug residues from latent fingerprints.

    Science.gov (United States)

    Clemons, Kristina; Wiley, Rachel; Waverka, Kristin; Fox, James; Dziekonski, Eric; Verbeck, Guido F

    2013-07-01

    Here, we present a method of extracting drug residues from fingerprints via Direct Analyte-Probed Nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS). This instrumental technique provides higher selectivity and lower detection limits over current methods, greatly reducing sample preparation, and does not compromise the integrity of latent fingerprints. This coupled to Raman microscopy is an advantageous supplement for location and identification of trace particles. DAPNe uses a nanomanipulator for extraction and differing microscopies for localization of chemicals of interest. A capillary tip with solvent of choice is placed in a nanopositioner. The surface to be analyzed is placed under a microscope, and a particle of interest is located. Using a pressure injector, the solvent is injected onto the surface where it dissolves the analyte, and then extracted back into the capillary tip. The solution is then directly analyzed via NSI-MS. Analyses of caffeine, cocaine, crystal methamphetamine, and ecstasy have been performed successfully. © 2013 American Academy of Forensic Sciences.

  10. Rapid Determination of Clenbuterol in Pork by Direct Immersion Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Ye, Diru; Wu, Susu; Xu, Jianqiao; Jiang, Ruifen; Zhu, Fang; Ouyang, Gangfeng

    2016-02-01

    Direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid analysis of clenbuterol in pork for the first time. In this work, a low-cost homemade 44 µm polydimethylsiloxane (PDMS) SPME fiber was employed to extract clenbuterol in pork. After extraction, derivatization was performed by suspending the fiber in the headspace of the 2 mL sample vial saturated with a vapor of 100 µL hexamethyldisilazane. Lastly, the fiber was directly introduced to GC-MS for analysis. All parameters that influenced absorption (extraction time), derivatization (derivatization reagent, time and temperature) and desorption (desorption time) were optimized. Under optimized conditions, the method offered a wide linear range (10-1000 ng g(-1)) and a low detection limit (3.6 ng g(-1)). Finally, the method was successfully applied in the analysis of pork from the market, and recoveries of the method for spiked pork were 97.4-105.7%. Compared with the traditional solvent extraction method, the proposed method was much cheaper and fast. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Microorganisms direct identification from blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Ferreira, L; Sánchez-Juanes, F; Porras-Guerra, I; García-García, M I; García-Sánchez, J E; González-Buitrago, J M; Muñoz-Bellido, J L

    2011-04-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows a fast and reliable bacterial identification from culture plates. Direct analysis of clinical samples may increase its usefulness in samples in which a fast identification of microorganisms can guide empirical treatment, such as blood cultures (BC). Three hundred and thirty BC, reported as positive by the automated BC incubation device, were processed by conventional methods for BC processing, and by a fast method based on direct MALDI-TOF MS. Three hundred and eighteen of them yield growth on culture plates, and 12 were false positive. The MALDI-TOF MS-based method reported that no peaks were found, or the absence of a reliable identification profile, in all these false positive BC. No mixed cultures were found. Among these 318 BC, we isolated 61 Gram-negatives (GN), 239 Gram-positives (GP) and 18 fungi. Microorganism identifications in GN were coincident with conventional identification, at the species level, in 83.3% of BC and, at the genus level, in 96.6%. In GP, identifications were coincident with conventional identification in 31.8% of BC at the species level, and in 64.8% at the genus level. Fungaemia was not reliably detected by MALDI-TOF. In 18 BC positive for Candida species (eight C. albicans, nine C. parapsilosis and one C. tropicalis), no microorganisms were identified at the species level, and only one (5.6%) was detected at the genus level. The results of the present study show that this fast, MALDI-TOF MS-based method allows bacterial identification directly from presumptively positive BC in a short time (<30 min), with a high accuracy, especially when GN bacteria are involved. © 2010 The Authors. Clinical Microbiology and Infection © 2010 European Society of Clinical Microbiology and Infectious Diseases.

  12. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    Energy Technology Data Exchange (ETDEWEB)

    Ketelaer, Jens

    2010-06-14

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N {proportional_to} 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of {sup 241}Am could be measured directly for the first time. (orig.)

  13. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    International Nuclear Information System (INIS)

    Ketelaer, Jens

    2010-01-01

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N ∝ 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of 241 Am could be measured directly for the first time. (orig.)

  14. Discovery of a Probable 4-5 Jupiter-mass Exoplanet to HD 95086 by Direct Imaging

    Science.gov (United States)

    Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Boccaletti, A.; Quanz, S. P.; Bonnefoy, M.; Girard, J. H.; Delorme, P.; Desidera, S.; Klahr, H.; Mordasini, C.; Dumas, C.; Bonavita, M.

    2013-08-01

    Direct imaging has only begun to inventory the population of gas giant planets on wide orbits around young stars in the solar neighborhood. Following this approach, we carried out a deep imaging survey in the near-infrared using VLT/NaCo to search for substellar companions. Here we report the discovery of a probable companion orbiting the young (10-17 Myr), dusty, early-type (A8) star HD 95086 at 56 AU in L' (3.8 μm) images. This discovery is based on observations with more than a year time lapse. Our first epoch clearly revealed the source at ~= 10σ, while our second epoch lacks good observing conditions, yielding a ~= 3σ detection. Various tests were thus made to rule out possible artifacts. This recovery is consistent with the signal at the first epoch but requires cleaner confirmation. Nevertheless, our astrometric precision suggests that the companion is comoving with the star with a 3σ confidence level. The planetary nature of the source is reinforced by a non-detection in the Ks-band (2.18 μm) images according to its possible extremely red Ks-L' color. Conversely, background contamination is rejected with good confidence level. The luminosity yields a predicted mass of about 4-5 M Jup (at 10-17 Myr) using "hot-start" evolutionary models, making HD 95086 b the exoplanet with the lowest mass ever imaged around a star. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under program Nos. 087.C-0292, 088.C.0085, 090.C-0538, 090.C-0698, and 090.C-0728.

  15. Analysis of Silicones Released from Household Items and Baby Articles by Direct Analysis in Real Time-Mass Spectrometry

    Science.gov (United States)

    Gross, Jürgen H.

    2015-03-01

    Direct analysis in real time-mass spectrometry (DART-MS) enables screening of articles of daily use made of polydimethylsiloxanes (PDMS), commonly known as silicone rubber, to assess their tendency to release low molecular weight silicone oligomers. DART-MS analyses were performed on a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Flexible silicone baking molds, a watch band, and a dough scraper, as baby articles different brands of pacifiers, nipples, and a teething ring have been examined. While somewhat arbitrarily chosen, the set can be regarded as representative of household items, baby articles, and other objects made of silicone rubber. For comparison, two brands of silicone septa and as blanks a glass slide and a latex pacifier were included. Differences between the objects were mainly observed in terms of molecular weight distribution and occasional release of other compounds in addition to PDMS. Other than that, all objects made of silicone rubber released significant amounts of PDMS during DART analysis. To provide a coarse quantification, a calibration based on silicone oil was established, which delivered PDMS losses from 20 μg to >100 μg during the 16-s period per measurement. Also, the extraction of baking molds in rapeseed oil demonstrated a PDMS release at the level of 1 μg mg-1. These findings indicate a potential health hazard from frequent or long-term use of such items. This work does not intend to blame certain brands of such articles. Nonetheless, a higher level of awareness of this source of daily silicone intake is suggested.

  16. Connecting speeds, directions and arrival times of 22 coronal mass ejections from the sun to 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Möstl, C.; Veronig, A. M.; Rollett, T.; Temmer, M.; Peinhart, V. [Kanzelhöhe Observatory-IGAM, Institute of Physics, University of Graz (Austria); Amla, K.; Hall, J. R.; Liewer, P. C.; De Jong, E. M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Colaninno, R. C. [Space Sciences Division, Naval Research Laboratory, Washington, DC (United States); Davies, J. A.; Harrison, R. A. [RAL Space, Harwell Oxford, Didcot (United Kingdom); Lugaz, N.; Farrugia, C. J.; Galvin, A. B. [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH (United States); Liu, Y. D. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Luhmann, J. G. [Space Science Laboratory, University of California, Berkeley, CA (United States); Vršnak, B., E-mail: christian.moestl@uni-graz.at [Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kačićeva 26, HR-10000, Zagreb (Croatia)

    2014-06-01

    Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to 2700 km s{sup –1}). We track the CMEs to 34.9 ± 7.1 deg elongation from the Sun with J maps constructed using the SATPLOT tool, resulting in prediction lead times of –26.4 ± 15.3 hr. The geometrical models we use assume different CME front shapes (fixed-Φ, harmonic mean, self-similar expansion) and constant CME speed and direction. We find no significant superiority in the predictive capability of any of the three methods. The absolute difference between predicted and observed ICME arrival times is 8.1 ± 6.3 hr (rms value of 10.9 hr). Speeds are consistent to within 284 ± 288 km s{sup –1}. Empirical corrections to the predictions enhance their performance for the arrival times to 6.1 ± 5.0 hr (rms value of 7.9 hr), and for the speeds to 53 ± 50 km s{sup –1}. These results are important for Solar Orbiter and a space weather mission positioned away from the Sun-Earth line.

  17. Direct coupling of electromembrane extraction to mass spectrometry - Advancing the probe functionality toward measurements of zwitterionic drug metabolites.

    Science.gov (United States)

    Rye, Torstein Kige; Fuchs, David; Pedersen-Bjergaard, Stig; Petersen, Nickolaj Jacob

    2017-08-29

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow channel, and mixed inside the probe with 7.5 μL min -1 of 1 M formic acid as make-up flow from a second flow channel. Following this acidification, the drug substances and their related metabolites were continuously extracted by EME at 400 V, across a supported liquid membrane (SLM) comprising 2-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min -1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes was followed continuously as function of time. The triple-flow EME probe was used for co-extraction of positively charged parent drugs and their zwitterionic drug metabolites (hydroxyzine and its carboxylic acid metabolite cetirizine; and vortioxetine and its carboxylic acid metabolite Lu AA34443). While the zwitterionic metabolites could not be extracted at pH 7.4, it was shown that by acidifying the sample solution the zwitterionic metabolites could be extracted effectively. Various extraction parameters like make-up flow, extraction voltage and SLM composition were optimized for simultaneous extraction of parent drugs and metabolites. It was found that TPP added to the SLM improved extraction efficiencies of certain drug metabolites. Finally the optimized and characterized triple-flow EME probe was used for online studying the in-vitro metabolism of hydroxyzine and vortioxetine by rat liver microsomes. Due to the automated pre-extraction acidification of the rat liver microsomal solutions, it was possible to continuously monitor formation of the zwitterionic drug

  18. Trace analysis of total naphthenic acids in aqueous environmental matrices by liquid chromatography/mass spectrometry-quadrupole time of flight mass spectrometry direct injection.

    Science.gov (United States)

    Brunswick, Pamela; Shang, Dayue; van Aggelen, Graham; Hindle, Ralph; Hewitt, L Mark; Frank, Richard A; Haberl, Maxine; Kim, Marcus

    2015-07-31

    A rapid and sensitive liquid chromatography quadrupole time of flight method has been established for the determination of total naphthenic acid concentrations in aqueous samples. This is the first methodology that has been adopted for routine, high resolution, high throughput analysis of total naphthenic acids at trace levels in unprocessed samples. A calibration range from 0.02 to 1.0μgmL(-1) total Merichem naphthenic acids was validated and demonstrated excellent accuracy (97-111% recovery) and precision (1.9% RSD at 0.02μgmL(-1)). Quantitative validation was also demonstrated in a non-commercial oil sands process water (OSPW) acid extractable organics (AEOs) fraction containing a higher percentage of polycarboxylic acid isomers than the Merichem technical mix. The chromatographic method showed good calibration linearity of ≥0.999 RSQ to 0.005μgmL(-1) total naphthenic acids with a precision <3.1% RSD and a calculated detection limit of 0.0004μgmL(-1) employing Merichem technical mix reference material. The method is well suited to monitoring naturally occurring and industrially derived naphthenic acids (and other AEOs) present in surface and ground waters in the vicinity of mining developments. The advantage of the current method is its direct application to unprocessed environmental samples and to examine natural naphthenic acid isomer profiles. It is noted that where the isomer profile of samples differs from that of the reference material, results should be considered semi-quantitative due to the lack of matching isomer content. The fingerprint profile of naphthenic acids is known to be transitory during aging and the present method has the ability to adapt to monitoring of these changes in naphthenic acid content. The method's total ion scan approach allows for data previously collected to be examined retrospectively for specific analyte mass ions of interest. A list of potential naphthenic acid isomers that decrease in response with aging is proposed

  19. Direct quantification of creatinine in human urine by using isotope dilution extractive electrospray ionization tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li Xue [Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, Applied Chemistry Department, East China Institute of Technology, Nanchang 330013 (China); Fang Xiaowei [Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, Applied Chemistry Department, East China Institute of Technology, Nanchang 330013 (China); Yu Zhiqiang; Sheng Guoying [Guangdong Key Laboratory of Environmental Protection and Resource Utilization, State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Wu Minghong [Shanghai Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Fu Jiamo [Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Guangdong Key Laboratory of Environmental Protection and Resource Utilization, State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Huanwen, E-mail: chw8868@gmail.com [Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation, Applied Chemistry Department, East China Institute of Technology, Nanchang 330013 (China)

    2012-10-20

    Highlights: Black-Right-Pointing-Pointer High throughput analysis of urinary creatinine is achieved by using ID-EESI-MS/MS. Black-Right-Pointing-Pointer Urine sample is directly analyzed and no sample pre-treatment is required. Black-Right-Pointing-Pointer Accurate quantification is accomplished with isotope dilution technique. - Abstract: Urinary creatinine (CRE) is an important biomarker of renal function. Fast and accurate quantification of CRE in human urine is required by clinical research. By using isotope dilution extractive electrospray ionization tandem mass spectrometry (EESI-MS/MS) a high throughput method for direct and accurate quantification of urinary CRE was developed in this study. Under optimized conditions, the method detection limit was lower than 50 {mu}g L{sup -1}. Over the concentration range investigated (0.05-10 mg L{sup -1}), the calibration curve was obtained with satisfactory linearity (R{sup 2} = 0.9861), and the relative standard deviation (RSD) values for CRE and isotope-labeled CRE (CRE-d3) were 7.1-11.8% (n = 6) and 4.1-11.3% (n = 6), respectively. The isotope dilution EESI-MS/MS method was validated by analyzing six human urine samples, and the results were comparable with the conventional spectrophotometric method (based on the Jaffe reaction). Recoveries for individual urine samples were 85-111% and less than 0.3 min was taken for each measurement, indicating that the present isotope dilution EESI-MS/MS method is a promising strategy for the fast and accurate quantification of urinary CRE in clinical laboratories.

  20. Direct quantification of creatinine in human urine by using isotope dilution extractive electrospray ionization tandem mass spectrometry

    International Nuclear Information System (INIS)

    Li Xue; Fang Xiaowei; Yu Zhiqiang; Sheng Guoying; Wu Minghong; Fu Jiamo; Chen Huanwen

    2012-01-01

    Highlights: ► High throughput analysis of urinary creatinine is achieved by using ID-EESI–MS/MS. ► Urine sample is directly analyzed and no sample pre-treatment is required. ► Accurate quantification is accomplished with isotope dilution technique. - Abstract: Urinary creatinine (CRE) is an important biomarker of renal function. Fast and accurate quantification of CRE in human urine is required by clinical research. By using isotope dilution extractive electrospray ionization tandem mass spectrometry (EESI–MS/MS) a high throughput method for direct and accurate quantification of urinary CRE was developed in this study. Under optimized conditions, the method detection limit was lower than 50 μg L −1 . Over the concentration range investigated (0.05–10 mg L −1 ), the calibration curve was obtained with satisfactory linearity (R 2 = 0.9861), and the relative standard deviation (RSD) values for CRE and isotope-labeled CRE (CRE-d3) were 7.1–11.8% (n = 6) and 4.1–11.3% (n = 6), respectively. The isotope dilution EESI–MS/MS method was validated by analyzing six human urine samples, and the results were comparable with the conventional spectrophotometric method (based on the Jaffe reaction). Recoveries for individual urine samples were 85–111% and less than 0.3 min was taken for each measurement, indicating that the present isotope dilution EESI–MS/MS method is a promising strategy for the fast and accurate quantification of urinary CRE in clinical laboratories.

  1. Direct solid phase microextraction combined with gas chromatography - Mass spectrometry for the determination of biogenic amines in wine.

    Science.gov (United States)

    Papageorgiou, Myrsini; Lambropoulou, Dimitra; Morrison, Calum; Namieśnik, Jacek; Płotka-Wasylka, Justyna

    2018-06-01

    A direct method based on immersion solid phase microextraction (DI-SPME) gas chromatography mass-spectrometry (GC-MS) was optimized and validated for the determination of 16 biogenic amines in Polish wines. In the analysis two internal standards were used: 1,7-diaminoheptane and bis-3-aminopropylamine. The method allows for simultaneous extraction and derivatization, providing a simple and fast mode of extraction and enrichment. Different parameters which affect the extraction procedure were studied and optimized including ionic strength (0-25%), fiber materials (PDMS/DVB, PDMS/DVD + OC, Polyacrylate, Carboxen/PDMS and DVB/CAR/PDMS) and timings of the extraction, derivatization and desorption processes. Validation studies confirmed the linearity, sensitivity, precision and accuracy of the method. The method was successfully applied to the analysis of 44 wine samples originating from several regions of Poland and 3 wine samples from other countries. Analysis showed that many of the samples contained all examined biogenic amines. The method, assessed using an Eco-Scale tool with satisfactory results, was found to be green in terms of hazardous chemicals and solvents usage, energy consumption and production of waste. Therefore the proposed method can be safely used in the wine industry for routine analysis of BAs in wine samples with a minimal detrimental impact on human health and the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Argon direct analysis in real time mass spectrometry in conjunction with makeup solvents: a method for analysis of labile compounds.

    Science.gov (United States)

    Yang, Hongmei; Wan, Debin; Song, Fengrui; Liu, Zhiqiang; Liu, Shuying

    2013-02-05

    Helium direct analysis in real time (He-DART) mass spectrometry (MS) analysis of labile compounds usually tends to be challenging because of the occurrence of prominent fragmentation, which obscures the assigning of an ion to an independent species or merely a fragment in a mixture. In the present work, argon DART (Ar-DART) MS in conjunction with makeup solvents has been demonstrated to analyze a variety of labile compounds including nucleosides, alkaloids, glucose, and other small molecules. The results presented here confirm that Ar-DART can generate significantly less energetic ions than conventional He-DART and is able to produce the intact molecular ions with little or no fragmentation in both positive and negative ion modes. Adding a makeup solvent (absolute ethyl alcohol, methanol, fluorobenzene, or acetone) to the argon gas stream at the exit of the DART ion source can result in 1-2 orders of magnitude increase in detection signals. The sensitivity attainable by Ar-DART was found to be comparable to that by He-DART. The investigation of influence of solvents improves our understanding of the fundamental desorption and ionization processes in DART. The practical application of this rapid and high throughput method is demonstrated by the successful analysis of a natural product (Crude Kusnezoff Monkshood) extract, demonstrating the great potential in mixture research.

  3. Some new features of Direct Analysis in Real Time mass spectrometry utilizing the desorption at an angle option.

    Science.gov (United States)

    Chernetsova, Elena S; Revelsky, Alexander I; Morlock, Gertrud E

    2011-08-30

    The present study is a first step towards the unexplored capabilities of Direct Analysis in Real Time (DART) mass spectrometry (MS) arising from the possibility of the desorption at an angle: scanning analysis of surfaces, including the coupling of thin-layer chromatography (TLC) with DART-MS, and a more sensitive analysis due to the preliminary concentration of analytes dissolved in large volumes of liquids on glass surfaces. In order to select the most favorable conditions for DART-MS analysis, proper positioning of samples is important. Therefore, a simple and cheap technique for the visualization of the impact region of the DART gas stream onto a substrate was developed. A filter paper or TLC plate, previously loaded with the analyte, was immersed in a derivatization solution. On this substrate, owing to the impact of the hot DART gas, reaction of the analyte to a colored product occurred. An improved capability of detection of DART-MS for the analysis of liquids was demonstrated by applying large volumes of model solutions of coumaphos into small glass vessels and drying these solutions prior to DART-MS analysis under ambient conditions. This allowed the introduction of, by up to more than two orders of magnitude, increased quantities of analyte compared with the conventional DART-MS analysis of liquids. Through this improved detectability, the capabilities of DART-MS in trace analysis could be strengthened. Copyright © 2011 John Wiley & Sons, Ltd.

  4. Rapid process development of chromatographic process using direct analysis in real time mass spectrometry as a process analytical technology tool.

    Science.gov (United States)

    Yan, Binjun; Chen, Teng; Xu, Zhilin; Qu, Haibin

    2014-06-01

    The concept of quality by design (QbD) is widely applied in the process development of pharmaceuticals. However, the additional cost and time have caused some resistance about QbD implementation. To show a possible solution, this work proposed a rapid process development method, which used direct analysis in real time mass spectrometry (DART-MS) as a process analytical technology (PAT) tool for studying the chromatographic process of Ginkgo biloba L., as an example. The breakthrough curves were fast determined by DART-MS at-line. A high correlation coefficient of 0.9520 was found between the concentrations of ginkgolide A determined by DART-MS and HPLC. Based on the PAT tool, the impacts of process parameters on the adsorption capacity were discovered rapidly, which showed a decreased adsorption capacity with the increase of the flow rate. This work has shown the feasibility and advantages of integrating PAT into QbD implementation for rapid process development. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Rapid detection of sugar alcohol precursors and corresponding nitrate ester explosives using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Sisco, Edward; Forbes, Thomas P

    2015-04-21

    This work highlights the rapid detection of nitrate ester explosives and their sugar alcohol precursors by direct analysis in real time mass spectrometry (DART-MS) using an off-axis geometry. Demonstration of the effect of various parameters, such as ion polarity and in-source collision induced dissociation (CID) on the detection of these compounds is presented. Sensitivity of sugar alcohols and nitrate ester explosives was found to be greatest in negative ion mode with sensitivities ranging from hundreds of picograms to hundreds of nanograms, depending on the characteristics of the particular molecule. Altering the in-source CID potential allowed for acquisition of characteristic molecular ion spectra as well as fragmentation spectra. Additional studies were completed to identify the role of different experimental parameters on the sensitivity for these compounds. Variables that were examined included the DART gas stream temperature, the presence of a related compound (i.e., the effect of a precursor on the detection of a nitrate ester explosive), incorporation of dopant species and the role of the analysis surface. It was determined that each variable affected the response and detection of both sugar alcohols and the corresponding nitrate ester explosives. From this work, a rapid and sensitive method for the detection of individual sugar alcohols and corresponding nitrate ester explosives, or mixtures of the two, has been developed, providing a useful tool in the real-world identification of homemade explosives.

  6. Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ying; Shi, Zeming; Zong, Qinxia; Wu, Peng; Su, Jing [Sichuan Provincial Key Laboratory of Nuclear Technology in Geology, College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059 (China); Liu, Rui, E-mail: liur.ray@gmail.com [Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2014-02-17

    Graphical abstract: -- Highlights: •Simple, sensitive, and accurate method is established for mercury determination in cosmetics. •The sample preparation procedure is highly simplified. •Isotope dilution efficiently eliminates matrix effect. •First report of using formic acid based method in combination with PVG-ID-ICP MS for mercury quantitation in cosmetics. -- Abstract: A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched {sup 201}Hg isotopic spike is added to cosmetics and the isotope ratios of {sup 201}Hg/{sup 202}Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL{sup −1}. Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

  7. Determination of pesticides and pesticide degradates in filtered water by direct aqueous-injection liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Sandstrom, Mark W.; Kanagy, Leslie K.; Anderson, Cyrissa A.; Kanagy, Christopher J.

    2016-01-11

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for determination of 229 pesticides compounds (113 pesticides and 116 pesticide degradates) in filtered water samples from stream and groundwater sites. The pesticides represent a broad range of chemical classes and were selected based on criteria such as current-use intensity, probability of occurrence in streams and groundwater, and toxicity to humans or aquatic organisms. More than half of the analytes are pesticide degradates. The method involves direct injection of a 100-microliter (μL) sample onto the LC-MS/MS without any sample preparation other than filtration. Samples are analyzed with two injections, one in electrospray ionization (ESI) positive mode and one in ESI negative mode, using dynamic multiple reaction monitoring (MRM) conditions, with two MRM transitions for each analyte. The LC-MS/MS instrument parameters were optimized for highest sensitivity for the most analytes. This report describes the analytical method and presents characteristics of the method validation including bias and variability, detection levels, and holding-time studies.

  8. Direct sample introduction-gas chromatography-mass spectrometry for the determination of haloanisole compounds in cork stoppers.

    Science.gov (United States)

    Cacho, J I; Nicolás, J; Viñas, P; Campillo, N; Hernández-Córdoba, M

    2016-12-02

    A solventless analytical method is proposed for analyzing the compounds responsible for cork taint in cork stoppers. Direct sample introduction (DSI) is evaluated as a sample introduction system for the gas chromatography-mass spectrometry (GC-MS) determination of four haloanisoles (HAs) in cork samples. Several parameters affecting the DSI step, including desorption temperature and time, gas flow rate and other focusing parameters, were optimized using univariate and multivariate approaches. The proposed method shows high sensitivity and minimises sample handling, with detection limits of 1.6-2.6ngg -1 , depending on the compound. The suitability of the optimized procedure as a screening method was evaluated by obtaining decision limits (CCα) and detection capabilities (CCβ) for each analyte, which were found to be in 6.9-11.8 and 8.7-14.8ngg -1 , respectively, depending on the compound. Twenty-four cork samples were analysed, and 2,4,6-trichloroanisole was found in four of them at levels between 12.6 and 53ngg -1 . Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin; Gary, D. E. [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Bastian, T. S., E-mail: bin.chen@cfa.harvard.edu [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

    2014-10-20

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  10. Direct Evidence of an Eruptive, Filament-hosting Magnetic Flux Rope Leading to a Fast Solar Coronal Mass Ejection

    Science.gov (United States)

    Chen, Bin; Bastian, T. S.; Gary, D. E.

    2014-10-01

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  11. Direct evidence of an eruptive, filament-hosting magnetic flux rope leading to a fast solar coronal mass ejection

    International Nuclear Information System (INIS)

    Chen, Bin; Gary, D. E.; Bastian, T. S.

    2014-01-01

    Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestation of an MFR with relatively cool filament material collecting near its bottom. However, observational evidence of eruptive, filament-hosting MFR systems has been elusive for those originating in active regions. By utilizing multi-passband extreme-ultraviolet (EUV) observations from Solar Dynamics Observatory/Atmospheric Imaging Assembly, we present direct evidence of an eruptive MFR in the low corona that exhibits a hot envelope and a cooler core; the latter is likely the upper part of a filament that undergoes a partial eruption, which is later observed in the upper corona as the coiled kernel of a fast, WL CME. This MFR-like structure exists more than 1 hr prior to its eruption, and displays successive stages of dynamical evolution, in which both ideal and non-ideal physical processes may be involved. The timing of the MFR kinematics is found to be well correlated with the energy release of the associated long-duration C1.9 flare. We suggest that the long-duration flare is the result of prolonged energy release associated with the vertical current sheet induced by the erupting MFR.

  12. Measurement of the W mass by direct reconstruction in e+e-collisions at 172 GeV

    Science.gov (United States)

    ALEPH Collaboration; Barate, R.; Buskulic, D.; Decamp, D.; Ghez, P.; Goy, C.; Jezequel, S.; Lees, J. P.; Lucotte, A.; Minard, M. N.; Nief, J. Y.; Pietrzyk, B.; Boix, G.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Graugès, E.; Juste, A.; Martinez, M.; Merino, G.; Miquel, R.; Mir, Ll. M.; Morawitz, P.; Park, I. C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Alemany, R.; Becker, U.; Bright-Thomas, P.; Casper, D.; Cattaneo, M.; Cerutti, F.; Ciulli, V.; Dissertori, G.; Drevermann, H.; Forty, R. W.; Frank, M.; Gianotti, F.; Hagelberg, R.; Hansen, J. B.; Harvey, J.; Janot, P.; Jost, B.; Lehraus, I.; Mato, P.; Minten, A.; Moneta, L.; Pacheco, A.; Pusztaszeri, J. F.; Ranjard, F.; Rolandi, L.; Rousseau, D.; Schlatter, D.; Schmitt, M.; Schneider, O.; Tejessy, W.; Teubert, F.; Tomalin, I. R.; Vreeswijk, M.; Wachsmuth, H.; Wagner, A.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rosnet, P.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Rensch, B.; Wäänänen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rougé, A.; Rumpf, M.; Valassi, A.; Videau, H.; Boccali, T.; Focardi, E.; Parrini, G.; Zachariadou, K.; Cavanaugh, R.; Corden, M.; Georgiopoulos, C.; Huehn, T.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Lynch, J. G.; Negus, P.; O'Shea, V.; Raine, C.; Scarr, J. M.; Smith, K.; Teixeira-Dias, P.; Thompson, A. S.; Thomson, E.; Thomson, F.; Ward, J. J.; Buchmüller, O.; Dhamotharan, S.; Geweniger, C.; Graefe, G.; Hanke, P.; G. Hansper, N.; Hepp, V.; Kluge, E. E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Girone, M.; Goodsir, S.; Martin, E. B.; Marinelli, N.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Spagnolo, P.; Williams, M. D.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Buck, P. G.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Whelan, E. P.; Williams, M. I.; Giehl, I.; Hoffmann, C.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Carr, J.; Coyle, P.; Ealet, A.; Fouchez, D.; Leroy, O.; Motsch, F.; Payre, P.; Talby, M.; Sadouki, A.; Thulasidas, M.; Tilquin, A.; Trabelsi, K.; Aleppo, M.; Antonelli, M.; Ragusa, F.; Berlich, R.; Blum, W.; Büscher, V.; Dietl, H.; Ganis, G.; Gotzhein, C.; Kroha, H.; Lütjens, G.; Lutz, G.; Mannert, C.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Chen, S.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Höcker, A.; Jacholkowska, A.; Kado, M. M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Serin, L.; Tournefier, E.; Veillet, J.-J.; Videau, I.; Zerwas, D.; Azzurri, P.; Bagliesi, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; dell'Orso, R.; Fantechi, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Sguazzoni, G.; Steinberger, J.; Tenchini, R.; Vannini, C.; Venturi, A.; Verdini, P. G.; Blair, G. A.; Bryant, L. M.; Chambers, J. T.; Coles, J.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Fabbro, B.; Faïf, G.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Przysiezniak, H.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Kim, H. Y.; Konstantinidis, N.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Kelly, M. S.; Lehto, M.; Reeve, J.; Thompson, L. F.; Affholderbach, K.; Böhrer, A.; Brandt, S.; Cowan, G.; Foss, J.; Grupen, C.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Williams, R. W.; Armstrong, S. R.; Charles, E.; Elmer, P.; Ferguson, D. P. S.; Gao, Y.; González, S.; Greening, T. C.; Hayes, O. J.; Hu, H.; Jin, S.; McNamara, P. A., III; Nachtman, J. M.; Nielsen, J.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Scott, I. J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zobernig, G.

    1998-03-01

    The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 10.65 pb-1 collected with the ALEPH detector at a mean centre-of-mass energy of 172.09 GeV. The invariant mass distribution of simulated events are fitted to the experimental distributions and the following W masses are obtained:The statistical errors are the expected errors for Monte Carlo samples of the same integrated luminosity as the data. The combination of these three measurements gives:

  13. Measurement of the W mass by direct reconstruction in $e^+ e^-$ collisions at 172 GeV

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Boix, G; Casado, M P; Chmeissani, M; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Morawitz, P; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bright-Thomas, P G; Casper, David William; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Gianotti, F; Hagelberg, R; Hansen, J B; Harvey, J; Janot, P; Jost, B; Lehraus, Ivan; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rolandi, Luigi; Rousseau, D; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Vreeswijk, M; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Fearnley, Tom; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Blondel, A; Brient, J C; Machefert, F P; Rougé, A; Rumpf, M; Valassi, Andrea; Videau, H L; Boccali, T; Focardi, E; Parrini, G; Zachariadou, K; Cavanaugh, R J; Corden, M; Georgiopoulos, C H; Hühn, T; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Ward, J J; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Moutoussi, A; Nash, J; Sedgbeer, J K; Spagnolo, P; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Buck, P G; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Whelan, E P; Williams, M I; Giehl, I; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Carr, J; Coyle, P; Ealet, A; Fouchez, D; Leroy, O; Motsch, F; Payre, P; Talby, M; Sadouki, A; Thulasidas, M; Tilquin, A; Trabelsi, K; Aleppo, M; Antonelli, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Mannert, C; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Kado, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Serin, L; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sciabà, A; Sguazzoni, G; Steinberger, Jack; Tenchini, Roberto; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Coles, J; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Fabbro, B; Faïf, G; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Przysiezniak, H; Rander, J; Renardy, J F; Rosowsky, A; Roussarie, A; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Reeve, J; Thompson, L F; Affholderbach, K; Böhrer, A; Brandt, S; Cowan, G D; Foss, J; Grupen, Claus; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Pütz, J; Rothberg, J E; Wasserbaech, S R; Williams, R W; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1998-01-01

    The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 10.65~pb$^{-1}$ collected with the ALEPH detector at a mean centre-of-mass energy of 172.09 \\GEV. The invariant mass distribution of simulated events are fitted to the experimental distributions and the following W masses are obtained: $WW \\to q\\overline{q}q\\overline{q } m_W = 81.30 +- 0.47(stat.) +- 0.11(syst.) GeV/c^2$, $WW \\to l\

  14. Soft ionization of saturated hydrocarbons, alcohols and nonpolar compounds by negative-ion direct analysis in real-time mass spectrometry.

    Science.gov (United States)

    Cody, Robert B; Dane, A John

    2013-03-01

    Large polarizable n-alkanes (approximately C18 and larger), alcohols, and other nonpolar compounds can be detected as negative ions when sample solutions are injected directly into the sampling orifice of the atmospheric pressure interface of the time-of-flight mass spectrometer with the direct analysis in real time (DART) ion source operating in negative-ion mode. The mass spectra are dominated by peaks corresponding to [M + O2]‾(•). No fragmentation is observed, making this a very soft ionization technique for samples that are otherwise difficult to analyze by DART. Detection limits for cholesterol were determined to be in the low nanogram range.

  15. Rapid determination of benzodiazepines, zolpidem and their metabolites in urine using direct injection liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Jeong, Yu-Dong; Kim, Min Kyung; Suh, Sung Ill; In, Moon Kyo; Kim, Jin Young; Paeng, Ki-Jung

    2015-12-01

    Benzodiazepines and zolpidem are generally prescribed as sedative, hypnotics, anxiolytics or anticonvulsants. These drugs, however, are frequently misused in drug-facilitated crime. Therefore, a rapid and simple liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for identification and quantification of benzodiazepines, zolpidem and their metabolites in urine using deuterium labeled internal standards (IS). Urine samples (120 μL) mixed with 80 μL of the IS solution were centrifuged. An aliquot (5 μL) of the sample solution was directly injected into the LC-MS/MS system for analysis. The mobile phases consisted of water and acetonitrile containing 2mM ammonium trifluoroacetate and 0.2% acetic acid. The analytical column was a Zorbax SB-C18 (100 mm × 2.1 mm i.d., 3.5 μm, Agilent). The separation and detection of 18 analytes were achieved within 10 min. Calibration curves were linear over the concentration ranges of 0.5-20 ng/mL (zolpidem), 1.0-40 ng/mL (flurazepam and temazepam), 2.5-100 ng/mL (7-aminoclonazepam, 1-hydroxymidazolam, midazolam, flunitrazepam and alprazolam), 5.0-200 ng/mL (zolpidem phenyl-4-carboxylic acid, α-hydroxyalprazolam, oxazepam, nordiazepam, triazolam, diazepam and α-hydroxytriazolam), 10-400 ng/mL (lorazepam and desalkylflurazepam) and 10-100 ng/mL (N-desmethylflunitrazepam) with the coefficients of determination (r(2)) above 0.9971. The dilution integrity of the analytes was examined for supplementation of short linear range. Dilution precision and accuracy were tested using two, four and ten-folds dilutions and they ranged from 3.7 to 14.4% and -12.8 to 12.5%, respectively. The process efficiency for this method was 63.0-104.6%. Intra- and inter-day precisions were less than 11.8% and 9.1%, while intra- and inter-day accuracies were less than -10.0 to 8.2%, respectively. The lower limits of quantification were lower than 10 ng/mL for each analyte. The applicability of the developed method was successfully

  16. Lipidomic analysis of biological samples: Comparison of liquid chromatography, supercritical fluid chromatography and direct infusion mass spectrometry methods.

    Science.gov (United States)

    Lísa, Miroslav; Cífková, Eva; Khalikova, Maria; Ovčačíková, Magdaléna; Holčapek, Michal

    2017-11-24

    Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements

  17. Direct surface analysis coupled to high-resolution mass spectrometry reveals heterogeneous composition of the cuticle of Hibiscus trionum petals.

    Science.gov (United States)

    Giorio, Chiara; Moyroud, Edwige; Glover, Beverley J; Skelton, Paul C; Kalberer, Markus

    2015-10-06

    Plant cuticle, which is the outermost layer covering the aerial parts of all plants including petals and leaves, can present a wide range of patterns that, combined with cell shape, can generate unique physical, mechanical, or optical properties. For example, arrays of regularly spaced nanoridges have been found on the dark (anthocyanin-rich) portion at the base of the petals of Hibiscus trionum. Those ridges act as a diffraction grating, producing an iridescent effect. Because the surface of the distal white region of the petals is smooth and noniridescent, a selective chemical characterization of the surface of the petals on different portions (i.e., ridged vs smooth) is needed to understand whether distinct cuticular patterns correlate with distinct chemical compositions of the cuticle. In the present study, a rapid screening method has been developed for the direct surface analysis of Hibiscus trionum petals using liquid extraction surface analysis (LESA) coupled with high-resolution mass spectrometry. The optimized method was used to characterize a wide range of plant metabolites and cuticle monomers on the upper (adaxial) surface of the petals on both the white/smooth and anthocyanic/ridged regions, and on the lower (abaxial) surface, which is entirely smooth. The main components detected on the surface of the petals are low-molecular-weight organic acids, sugars, and flavonoids. The ridged portion on the upper surface of the petal is enriched in long-chain fatty acids, which are constituents of the wax fraction of the cuticle. These compounds were not detected on the white/smooth region of the upper petal surface or on the smooth lower surface.

  18. Direct determination of acrylamide in food by gas chromatography-high-resolution time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dunovska, Lenka [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Cajka, Tomas [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Hajslova, Jana [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)]. E-mail: jana.hajslova@vscht.cz; Holadova, Katerina [Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)

    2006-09-25

    Simple and rapid gas chromatographic (GC) method employing a high-resolution time-of-flight mass analyzer that enables direct analysis (no derivatization) of acrylamide in various heat-processed foodstuffs has been developed and validated. Co-isolation of acrylamide precursors such as sugars and asparagine, constituting the risk of results overestimation due to additional formation of analyte in hot GC injector, is avoided by the extraction with n-propanol followed by solvent exchange to acetonitrile (MeCN). Introduction of a novel purification strategy, dispersive solid phase extraction, based on addition of primary-secondary amine (PSA) sorbent into deffated extract in MeCN, provides a significant reduction of some abundant matrix co-extracts (mainly free fatty acids). Isotope dilution technique (d{sub 3}-acrylamide as an internal standard) is employed for compensation of potential target analyte losses and/or matrix-inducted chromatographic response enhancement. Limits of quantifications (LOQs) ranged between 15 and 40 {mu}g kg{sup -1} and recoveries were between 97 and 108% depending on the examined food matrix. The repeatability of measurements (expressed as relative standard deviation, R.S.D.) was as low as 1.9% for potato crisps containing acrylamide at a level of 1 mg kg{sup -1}. Slightly higher values (R.S.D. < 4.0%) were achieved for breakfast cereals and crisp bread with approximately 10 times lower content of this processing contaminant. Trueness of results generated by this new method was demonstrated via FAPAS[reg] (Food Analysis Performance Assessment Scheme) interlaboratory proficiency tests.

  19. Hydrolysis of VX on concrete: rate of degradation by direct surface interrogation using an ion trap secondary ion mass spectrometer.

    Science.gov (United States)

    Groenewold, Gary S; Williams, John M; Appelhans, Anthony D; Gresham, Garold L; Olson, John E; Jeffery, Mark T; Rowland, Brad

    2002-11-15

    The nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate) is lethal at very low levels of exposure, which can occur by dermal contact with contaminated surfaces. Hence, behavior of VX in contact with common urban or industrial surfaces is a subject of acute interest. In the present study, VX was found to undergo complete degradation when in contact with concrete surfaces. The degradation was directly interrogated at submonolayer concentrations by periodically performing secondary ion mass spectrometry (SIMS) analyses after exposure of the concrete to VX. The abundance of the [VX + H]+ ion in the SIMS spectra was observed to decrease in an exponential fashion, consistent with first-order or pseudo-first-order behavior. This phenomenon enabled the rate constant to be determined at 0.005 min(-1) at 25 degrees C, which corresponds to a half-life of about 3 h on the concrete surface. The decrease in [VX + H]+ was accompanied by an increase in the abundance of the principal degradation product diisopropylaminoethanethiol (DESH), which arises by cleavage of the P-S bond. Degradation to form DESH is accompanied by the formation of ethyl methylphosphonic acid, which is observable only in the negative ion spectrum. A second degradation product was also implicated, which corresponded to a diisopropylvinylamine isomer (perhaps N,N-diisopropyl aziridinium) that arose via cleavage of the S-C bond. No evidence was observed for the formation of the toxic S-2-diisopropylaminoethyl methylphosphonothioic acid. The degradation rate constants were measured at four different temperatures (24-50 degrees C), which resulted in a linear Arrhenius relationship and an activation energy of 52 kJ mol(-1). This value agrees with previous values observed for VX hydrolysis in alkaline solutions, which suggests that the degradation of submonolayer VX is dominated by alkaline hydrolysis within the adventitious water film on the concrete surface.

  20. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-01-01

    The center-of-mass angular distribution of direct photon events, resulting from proton-antiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermi lab ( CDF) during the 1988-1089 experimental run, is presented. The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momentum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator.

  1. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-04-01

    The center-of-mass angular distribution of direct photon events, resulting from protonantiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermilab ( CDF) during the 1988-1089 experimental run, is presented . The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momemtum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator

  2. Effect of mass and charge transport speed and direction in porous anodes on microbial electrolysis cell performance

    NARCIS (Netherlands)

    Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.

    2011-01-01

    The use of porous electrodes like graphite felt as anode material has the potential of achieving high volumetric current densities. High volumetric current densities, however, may also lead to mass transport limitations within these porous materials. Therefore, in this study we investigated the mass

  3. Characterization of olive oil volatiles by multi-step direct thermal desorption-comprehensive gas chromatography-time-of-flight mass spectrometry using a programmed temperature vaporizing injector

    NARCIS (Netherlands)

    de Koning, S.; Kaal, E.; Janssen, H.-G.; van Platerink, C.; Brinkman, U.A.Th.

    2008-01-01

    The feasibility of a versatile system for multi-step direct thermal desorption (DTD) coupled to comprehensive gas chromatography (GC × GC) with time-of-flight mass spectrometric (TOF-MS) detection is studied. As an application the system is used for the characterization of fresh versus aged olive

  4. Prediction of acrylamide formation in biscuits based on fingerprint data generated by ambient ionization mass spectrometry employing direct analysis in real time (DART) ion source

    NARCIS (Netherlands)

    Vaclavik, Lukas; Capuano, Edoardo; Gökmen, Vural; Hajslova, Jana

    2015-01-01

    The objective of this study is the evaluation of the potential of high-throughput direct analysis in real time-high resolution mass spectrometry (DART-HRMS) fingerprinting and multivariate regression analysis in prediction of the extent of acrylamide formation in biscuit samples prepared by

  5. Community-directed mass drug administration is undermined by status seeking in friendship networks and inadequate trust in health advice networks

    NARCIS (Netherlands)

    Chami, Goylette F.; Kontoleon, Andreas A.; Bulte, Erwin; Fenwick, Alan; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2017-01-01

    Over 1.9 billion individuals require preventive chemotherapy through mass drug administration (MDA). Community-directed MDA relies on volunteer community medicine distributors (CMDs) and their achievement of high coverage and compliance. Yet, it is unknown if village social networks influence

  6. Community-directed mass drug administration is undermined by status seeking in friendship networks and inadequate trust in health advice networks

    NARCIS (Netherlands)

    Chami, Goylette F.; Kontoleon, Andreas A.; Bulte, Erwin; Fenwick, Alan; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2017-01-01

    Over 1.9 billion individuals require preventive chemotherapy through mass drug administration (MDA). Community-directed MDA relies on volunteer community medicine distributors (CMDs) and their achievement of high coverage and compliance. Yet, it is unknown if village social networks influence

  7. THE DEVELOPMENT OF IODINE BASED IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF HG USING DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

    Science.gov (United States)

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hgo) in EPA Method 5 type sampling. An iodine based impinger solutoin proved to be ver...

  8. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Prabhakar Sripadi

    Full Text Available BACKGROUND: Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. METHODS AND PRINCIPAL FINDINGS: Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3 transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI mass spectrometry (MS. Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1 and PC(O-34:1 plasmalogens were displaced by PC(30:0 and PC(32:0 species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. CONCLUSIONS AND SIGNIFICANCE: We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3

  9. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

    Science.gov (United States)

    Sripadi, Prabhakar; Shrestha, Bindesh; Easley, Rebecca L; Carpio, Lawrence; Kehn-Hall, Kylene; Chevalier, Sebastien; Mahieux, Renaud; Kashanchi, Fatah; Vertes, Akos

    2010-09-07

    Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3) transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC) lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1) and PC(O-34:1) plasmalogens were displaced by PC(30:0) and PC(32:0) species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3), expression-specific (Tax1 vs. Tax3) and cell-type-specific (T lymphocytes vs. kidney

  10. Direct chemical-analysis of uv laser-ablation products of organic polymers by using selective ion monitoring mode in gas-chromatography mass-spectrometry

    Science.gov (United States)

    Cho, Yirang; Lee, H.W.; Fountain, S.T.; Lubman, D.M.

    1994-01-01

    Trace quantities of laser ablated organic polymers were analyzed by using commercial capillary column gas chromatography/mass spectrometry; the instrument was modified so that the laser ablation products could be introduced into the capillary column directly and the constituents of each peak in the chromatogram were identified by using a mass spectrometer. The present study takes advantage of the selective ion monitoring mode for significantly improving the sensitivity of the mass spectrometer as a detector, which is critical in analyzing the trace quantities and confirming the presence or absence of the species of interest in laser ablated polymers. The initial composition of the laser ablated polymers was obtained by using an electron impact reflectron time-of-flight mass spectrometer and the possible structure of the fragments observed in the spectra was proposed based on the structure of the polymers.

  11. Emissions of Water and Carbon Dioxide from Fossil-Fuel Combustion Contribute Directly to Ocean Mass and Volume Increases

    Science.gov (United States)

    Skuce, A. G.

    2014-12-01

    The direct, non-climate, contribution of carbon dioxide and water emissions from fossil-fuel (FF) combustion to the volume and mass of the oceans has been omitted from estimates of sea-level rise (SLR) in IPCC reports. Following the method of Gornitz et al. (1997), H2O emissions are estimated using carbon emissions from the Carbon Dioxide Information Analysis Center, along with typical carbon and hydrogen contents of FF. Historic H2O emissions from 1750 to 2010 amount to 430 ±50 PgH2O, equivalent to 1.2 ±0.2 mmSLR. Sometime in this decade the volume of H2O from historic FF combustion will exceed the volume of Lake Erie (480 km3). CO2 dissolved in the ocean increases the seawater volume by 31-33 mL mol-1 CO2. From 1750 to 2010, 370 ±70 PgCO2 from FF combustion has dissolved in the oceans, causing 0.7 ±0.2 mmSLR. Combined H2O+CO2emissions from FF have therefore added 1.9 ±0.4 mm to sea levels in the Industrial Era. Combustion of FF in 2010 resulted in emissions of 32 PgCO2 and 12 ±1 PgH2O. SLR contributions for that year from FF emissions were 0.033 ±0.005 mm from H2O and 0.011±0.003 mm from dissolved CO2, a total rate of 0.044 ±0.008 mm yr-1. Emissions incorporated in socio-economic models underlying the RCP 8.5 and 2.6 scenarios are used along with concentration-driven CMIP5 Earth System Models results to estimate future sea-level rise from FF combustion. From 2010 to 2100, RCP8.5 and 2.6 models respectively produce 9 ±2 mmSLR and 5 ±1 mmSLR from FF H2O+CO2. For perspective, these amounts are larger than the modelled contributions from loss of glaciers in the Andes. The direct contribution of FF emissions to SLR is small (1-2%) relative to current rates and projected estimates under RCP scenarios up to 2100. The magnitude is similar to SLR estimates from other minor sources such as the melting of floating ice, land-use emissions and produced water from oil operations, none of which are currently included in SLR assessments. As uncertainties in

  12. Solid-Phase Microextraction Coupled to Capillary Atmospheric Pressure Photoionization-Mass Spectrometry for Direct Analysis of Polar and Nonpolar Compounds.

    Science.gov (United States)

    Mirabelli, Mario F; Zenobi, Renato

    2018-04-17

    A novel capillary ionization source based on atmospheric pressure photoionization (cAPPI) was developed and used for the direct interfacing between solid-phase microextraction (SPME) and mass spectrometry (MS). The efficiency of the source was evaluated for direct and dopant-assisted photoionization, analyzing both polar (e.g., triazines and organophosphorus pesticides) and nonpolar (polycyclic aromatic hydrocarbons, PAHs) compounds. The results show that the range of compound polarity, which can be addressed by direct SPME-MS can be substantially extended by using cAPPI, compared to other sensitive techniques like direct analysis in real time (DART) and dielectric barrier discharge ionization (DBDI). The new source delivers a very high sensitivity, down to sub parts-per-trillion (ppt), making it a viable alternative when compared to previously reported and less comprehensive direct approaches.

  13. Direct sampling of sub-µm atmospheric particulate organic matter in sub-ng m-3 mass concentrations by proton-transfer-reaction mass spectrometry

    Science.gov (United States)

    Armin, W.; Mueller, M.; Klinger, A.; Striednig, M.

    2017-12-01

    A quantitative characterization of the organic fraction of atmospheric particulate matter is still challenging. Herein we present the novel modular "Chemical Analysis of Aerosol Online" (CHARON) particle inlet system coupled to a new-generation proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF 6000 X2, Ionicon Analytik, Austria) that quantitatively detects organic analytes in real-time and sub-pptV levels by chemical ionization with hydronium reagent ions. CHARON consists of a gas-phase denuder for stripping off gas-phase analytes (efficiency > 99.999%), an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. With typical particle enrichment factors of around 30 for particle diameters (DP) between 120 nm and 1000 nm (somewhat reduced enrichment for 60 nm 6000) and excellent mass accuracies (< 10 ppm) chemical compositions can be assigned and included in further analyses. In addition to a detailed characterization of the CHARON PTR-TOF 6000 X2 we will present first results on the chemical composition of sub-µm particulate organic matter in the urban atmosphere in Innsbruck (Austria).

  14. Direct determination of the samarium:neodymium ratio in geological materials by inductively coupled plasma quadrupole mass spectrometry with cryogenic desolvation. Comparison with isotope dilution thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Pin, Christian; Telouk, Philippe; Imbert, J.-L.

    1995-01-01

    A cryogenic desolvation unit in the sample introduction system reduces differences in oxide formation between Sm and Nd to very low levels, enabling the direct, standardless determination of their ratio in bulk solutions by inductively coupled plasma mass spectrometry. The measured values are in reasonably good agreement with those determined by the isotope dilution thermal ionization mass spectrometry (ID-TIMS) reference technique. Although this method cannot, at present, compete with ID-TIMS in terms of precision and accuracy, it is much more straightforward and can be used in geochemistry for studies involving the screening of a large number of samples. (author)

  15. Mass production of chemicals from biomass-derived oil by directly atmospheric distillation coupled with co-pyrolysis

    Science.gov (United States)

    Zhang, Xue-Song; Yang, Guang-Xi; Jiang, Hong; Liu, Wu-Jun; Ding, Hong-Sheng

    2013-01-01

    Production of renewable commodity chemicals from bio-oil derived from fast pyrolysis of biomass has received considerable interests, but hindered by the presence of innumerable components in bio-oil. In present work, we proposed and experimentally demonstrated an innovative approach combining atmospheric distillation of bio-oil with co-pyrolysis for mass production of renewable chemicals from biomass, in which no waste was produced. It was estimated that 51.86 wt.% of distillate just containing dozens of separable organic components could be recovered using this approach. Ten protogenetic and three epigenetic compounds in distillate were qualitatively identified by gas chromatography/mass spectrometry and quantified by gas chromatography. Among them, the recovery efficiencies of acetic acid, propanoic acid, and furfural were all higher than 80 wt.%. Formation pathways of the distillate components in this process were explored. This work opens up a fascinating prospect for mass production of chemical feedstock from waste biomass. PMID:23350028

  16. Asteroseismology of old open clusters with Kepler: direct estimate of the integrated red giant branch mass-loss in NGC 6791 and 6819

    DEFF Research Database (Denmark)

    Miglio, A.; Brogaard, Karsten Frank; Stello, D.

    2012-01-01

    Mass-loss of red giant branch (RGB) stars is still poorly determined, despite its crucial role in the chemical enrichment of galaxies. Thanks to the recent detection of solar-like oscillations in G–K giants in open clusters with Kepler, we can now directly determine stellar masses...... for a statistically significant sample of stars in the old open clusters NGC 6791 and 6819. The aim of this work is to constrain the integrated RGB mass-loss by comparing the average mass of stars in the red clump (RC) with that of stars in the low-luminosity portion of the RGB [i.e. stars with L≲L(RC)]. Stellar...... masses were determined by combining the available seismic parameters νmax and Δν with additional photometric constraints and with independent distance estimates. We measured the masses of 40 stars on the RGB and 19 in the RC of the old metal-rich cluster NGC 6791. We find that the difference between...

  17. Influence of high range of mass transfer coefficient and convection heat transfer on direct contact membrane distillation performance

    KAUST Repository

    Lee, Jung Gil; Jeong, Sanghyun; Alsaadi, Ahmad Salem; Ghaffour, NorEddine

    2017-01-01

    (>2.1×10−6kg/m2sPa: membranes under development) were simulated using an experimentally validated model at different ranges of convection heat transfer by varying the inlet flow rates and spacer enhancement factor. The effect of mass transfer

  18. Mass spectrometry and site-directed mutagenesis identify several autophosphorylated residues required for the activity of PrkC, a Ser/Thr kinase from Bacillus subtilis

    DEFF Research Database (Denmark)

    Madec, Edwige; Stensballe, Allan; Kjellström, Sven

    2003-01-01

    We have shown recently that PrkC, which is involved in developmental processes in Bacillus subtilis, is a Ser/Thr kinase with features of the receptor kinase family of eukaryotic Hanks kinases. In this study, we expressed and purified from Escherichia coli the cytoplasmic domain of PrkC containing...... the kinase and a short juxtamembrane region. This fragment, which we designate PrkCc, undergoes autophosphorylation in E.coli. PrkCc is further autophosphorylated in vitro, apparently through a trans-kinase, intermolecular reaction. PrkC also displays kinase activity with myelin basic protein. Using high...... mass accuracy electrospray tandem mass spectrometry (LC-MS/MS) and nanoelectrospray tandem mass spectrometry, we identified seven phosphorylated threonine and one serine residue in PrkCc. All the corresponding residues were replaced by systematic site-directed mutagenesis and the purified mutant...

  19. Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Direct Bacterial Identification from Positive Blood Culture Pellets ▿

    OpenAIRE

    Prod'hom, Guy; Bizzini, Alain; Durussel, Christian; Bille, Jacques; Greub, Gilbert

    2010-01-01

    An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.

  20. Matrix-assisted laser desorption ionization-time of flight mass spectrometry for direct bacterial identification from positive blood culture pellets.

    Science.gov (United States)

    Prod'hom, Guy; Bizzini, Alain; Durussel, Christian; Bille, Jacques; Greub, Gilbert

    2010-04-01

    An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.

  1. Direct atomic spectrometric analysis by slurry atomisation: Pt. 7. Analysis of coal using inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ebdon, Les; Foulkes, M E; Parry, H G.M.; Tye, C T

    1988-09-01

    The application of slurry atomisation - inductively coupled plasma mass spectrometry (ICP-MS) to major, minor and trace element determination in coals has been investigated. Eight certified reference material (CRM) coals have been ground by the bottle and bead method and analysed using both rapid scan semi-quantitative analysis, employing a single rhodium internal standard, and full quantitative analysis using simple aqueous standards for calibration. The semi-quantitative mode, which determines the concentration using the mass-response curve for 68 elements against the single internal standard, produced values which were within a factor of two of the certified reference value, in most instances. The full quantitative determination gave excellent agreement with the certified reference material coals for a large number of elemental constituents. The results from the determination of 16 elements of interest are discussed including the effects of polyatomic interferents and isotope sensitivity.

  2. Direct Growth of Bacteria in Headspace Vials Allows for Screening of Volatiles by Gas Chromatography Mass Spectrometry

    OpenAIRE

    Collin M. Timm; Evan P. Lloyd; Amanda Egan; Ray Mariner; David Karig

    2018-01-01

    Bacterially produced volatile organic compounds (VOCs) can modify growth patterns of eukaryotic hosts and competing/cohabiting microbes. These compounds have been implicated in skin disorders and attraction of biting pests. Current methods to detect and characterize VOCs from microbial cultures can be laborious and low-throughput, making it difficult to understand the behavior of microbial populations. In this work we present an efficient method employing gas chromatography/mass spectrometry ...

  3. Preliminary description of a dedicated commercial ultra-sensitive mass spectrometer for direct atom counting of 14C

    International Nuclear Information System (INIS)

    Purser, K.H.; Schneider, R.J.; Post, R.; Dobbs, J.McG.

    1981-01-01

    A description is presented of a commercial, tandem-accelerator centered secondary ion double mass spectrometer dedicated to 14 C/ 13 C/ 12 C ratio measurements. Some design philosophy of the instrument is presented and the performance is described. A scanning cesium ion source with primary beam diameters between 100 to 200 micrometers is used to produce C - beam intensities of 10 to 20μA with the intensities remaining constant to better than 0.1% per minute after the source stabilizes. For recent carbon, these currents correspond to 14 C count rates from the ion source of 60 to 120 particles per second. Resolution of the first mass defining system, M/ΔM, is greater than 120 with the capability of rapid mass switching between isotopes. The measured isotopic ratios at the ion source for carbon are constant to better than 0.25%. The virtues of the 3MV parallel-fed Cockroft-Walton accelerator supply are presented. At the operating voltage of 2.5MV, the stability is better than 1:4000 with a terminal ripple 13 C 3+ and 12 C 3+ ions which originate from mass-14 molecular ions are measured to be 3.6mm away from the beam axis and so can be completely eliminated by the slits. Isotopic ratios have been measured beyond these slits, and it is shown that these ratios are constant to better than half a percent using recent samples. The final strong focusing magnet has a rejection ratio for unwanted carbon ions greater than 10 7

  4. Is Mass Society a Threat to Representative Democracy? Revisiting David Riesman’s “Other-Directed Character”

    Directory of Open Access Journals (Sweden)

    Pekka Sulkunen

    2012-07-01

    Full Text Available Representative democracy has been based on the idea that interest groups form parliaments through competitive elections, and legislate in favour of their supporters. Declining electoral participation, rise of populist rightwing parties, contingent coalitions, personalized electoral success and scandaldriven politics indicate a crisis in representative democracy. Mass society theories after the Second World War predicted a decline of democracy on the basis of homogenisation of mass consumption societies. The threat was seen to involve totalitarian rule, combined with bureaucracy serving the interests of elites. This paper examines the underlying presuppositions of mass society theory, and argues that the homogeneity argument is insufficient to fit the realities. Following David Riesman, it is argued that the otherdirected character growsfrom unstable interest group identities, but its determinant is not sameness but agency and therefore difference. To have agency is to orient oneself to others as a self, as unique, separate and autonomous subject. This is vindicated by trends in public administration since the 1980s, which stress citizens’ selfcontrol,autonomy and partnership rather than conformity. Political disputes arise around contradictions between difference and autonomy in societies where agency is a principle of justification. Universal autonomy requires homogeneity but agency stresses difference and uniqueness.

  5. A direct gravitational lensing test for 10 exp 6 solar masses black holes in halos of galaxies

    Science.gov (United States)

    Wambsganss, Joachim; Paczynski, Bohdan

    1992-01-01

    We propose a method that will be able to detect or exclude the existence of 10 exp 6 solar masses black holes in the halos of galaxies. VLBA radio maps of two milliarcsecond jets of a gravitationally lensed quasar will show the signature of these black holes - if they exist. If there are no compact objects in this mass range along the line of sight, the two jets should be linear mappings of each other. If they are not, there must be compact objects of about 10 exp 6 solar masses in the halo of the galaxy that deform the images by gravitational deflection. We present numerical simulations for the two jets A and B of the double quasar 0957 + 561, but the method is valid for any gravitationally lensed quasar with structure on milliarcsecond scales. As a by-product from high-quality VLBA maps of jets A and B, one will be able to tell which features in the maps are intrinsic in the original jet and which are only an optical illusion, i.e., gravitational distortions by black holes along the line of sight.

  6. A Comparison of Tissue Spray and Lipid Extract Direct Injection Electrospray Ionization Mass Spectrometry for the Differentiation of Eutopic and Ectopic Endometrial Tissues

    Science.gov (United States)

    Chagovets, Vitaliy; Wang, Zhihao; Kononikhin, Alexey; Starodubtseva, Natalia; Borisova, Anna; Salimova, Dinara; Popov, Igor; Kozachenko, Andrey; Chingin, Konstantin; Chen, Huanwen; Frankevich, Vladimir; Adamyan, Leila; Sukhikh, Gennady

    2018-02-01

    Recent research revealed that tissue spray mass spectrometry enables rapid molecular profiling of biological tissues, which is of great importance for the search of disease biomarkers as well as for online surgery control. However, the payback for the high speed of analysis in tissue spray analysis is the generally lower chemical sensitivity compared with the traditional approach based on the offline chemical extraction and electrospray ionization mass spectrometry detection. In this study, high resolution mass spectrometry analysis of endometrium tissues of different localizations obtained using direct tissue spray mass spectrometry in positive ion mode is compared with the results of electrospray ionization analysis of lipid extracts. Identified features in both cases belong to three lipid classes: phosphatidylcholines, phosphoethanolamines, and sphingomyelins. Lipids coverage is validated by hydrophilic interaction liquid chromatography with mass spectrometry of lipid extracts. Multivariate analysis of data from both methods reveals satisfactory differentiation of eutopic and ectopic endometrium tissues. Overall, our results indicate that the chemical information provided by tissue spray ionization is sufficient to allow differentiation of endometrial tissues by localization with similar reliability but higher speed than in the traditional approach relying on offline extraction.

  7. Revisiting the theoretical basis of the endosymbiotic origin of plastids in the original context of Lynn Margulis on the origin of mitosing, eukaryotic cells.

    Science.gov (United States)

    Sato, Naoki

    2017-12-07

    Fifty years ago, Lynn Margulis proposed a comprehensive hypothesis on the origin of eukaryotic cells with an emphasis on the origin of mitosis. This hypothesis postulated that the eukaryotic cell is a composite of different parts as a result of the symbiosis of various different bacteria. In this hypothesis, she integrated previously proposed ideas that mitochondria and chloroplasts were descendants of endosymbionts that originated from aerobic bacteria and blue-green algae (now cyanobacteria), respectively. However, the major part of her hypothesis, which she believed to be original, was the origin of mitosis. The core of her postulate involved a chromosome partition mechanism dependent on DNA-microtubule binding, which originated from a hypothetical centriole-DNA complex, with an ability to replicate. Surprisingly, her complete lack of real experimental works in the cytoskeleton, cell motility, or paleontology did not prevent this 29-year-old junior scientist from assembling archival knowledge and constructing a narrative on the evolution of all organisms. Whether the centriole-DNA complex originated from a spirochete or not was a minor anecdote in this initial postulate. Unfortunately, this hypothesis on the origin of mitosis, which she believed to be a holistic unity, testable by experiments, was entirely refuted. Despite falsification of her original narrative as a whole, her success as a founder of endosymbiotic theory on the origin of mitochondria and chloroplasts is undoubted. We will discuss the reasons for her success in terms of the historical situation in the latter half of the 20th century. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. A quantitative approach for pesticide analysis in grape juice by direct interfacing of a matrix compatible SPME phase to dielectric barrier discharge ionization-mass spectrometry.

    Science.gov (United States)

    Mirabelli, Mario F; Gionfriddo, Emanuela; Pawliszyn, Janusz; Zenobi, Renato

    2018-02-12

    We evaluated the performance of a dielectric barrier discharge ionization (DBDI) source for pesticide analysis in grape juice, a fairly complex matrix due to the high content of sugars (≈20% w/w) and pigments. A fast sample preparation method based on direct immersion solid-phase microextraction (SPME) was developed, and novel matrix compatible SPME fibers were used to reduce in-source matrix suppression effects. A high resolution LTQ Orbitrap mass spectrometer allowed for rapid quantification in full scan mode. This direct SPME-DBDI-MS approach was proven to be effective for the rapid and direct analysis of complex sample matrices, with limits of detection in the parts-per-trillion (ppt) range and inter- and intra-day precision below 30% relative standard deviation (RSD) for samples spiked at 1, 10 and 10 ng ml -1 , with overall performance comparable or even superior to existing chromatographic approaches.

  9. Mass Production Cost Estimation for Direct H2 PEM Fuel Cell Systems for Automotive Applications. 2009 Update

    Energy Technology Data Exchange (ETDEWEB)

    James, Brian D. [Directed Technologies, Arlington, VA (United States); Kalinoski, Jeffrey A. [Directed Technologies, Arlington, VA (United States); Baum, Kevin N. [Directed Technologies, Arlington, VA (United States)

    2010-01-01

    This report is the third annual update of a comprehensive automotive fuel cell cost analysis. It contains estimates for material and manufacturing cost of complete 80 kWnet direct hydrogen proton exchange membrane fuel cell systems suitable for powering light duty automobiles.

  10. Mass Production Cost Estimation For Direct H2 PEM Fuel Cell Systesm for Automotive Applications. 2010 Update

    Energy Technology Data Exchange (ETDEWEB)

    James, Brian D. [Directed Technologies, Arlington, VA (United States); Kalinoski, Jeffrey A. [Directed Technologies, Arlington, VA (United States); Baum, Kevin N. [Directed Technologies, Arlington, VA (United States)

    2010-09-30

    This report is the fourth annual update of a comprehensive automotive fuel cell cost analysis. It contains estimates for material and manufacturing costs of complete 80 kWnet direct-hydrogen proton exchange membrane fuel cell systems suitable for powering light-duty automobiles.

  11. C-reactive protein levels and body mass index: elucidating direction of causation through reciprocal Mendelian randomization

    DEFF Research Database (Denmark)

    Timpson, N J; Nordestgaard, B G; Harbord, R M

    2011-01-01

    randomization, we aim to assess the direction of causality in relationships between BMI and CRP and to demonstrate this as a promising analytical technique.Participants and methods:The study was based on a large, cross-sectional European study from Copenhagen, Denmark. Genetic associates of BMI (FTO(rs9939609...

  12. Enzyme Kinetics By Directly Imaging A Porous Silicon Microfluidic Reactor Using Desorption/Ionization on Silicon Mass Spectrometry

    NARCIS (Netherlands)

    Nichols, K.P.F.; Azoz, Seyla; Gardeniers, Johannes G.E.

    2008-01-01

    Enzyme kinetics were obtained in a porous silicon microfluidic channel by combining an enzyme and substrate droplet, allowing them to react and deposit a small amount of residue on the channel walls, and then analyzing this residue by directly ionizing the channel walls using a matrix assisted laser

  13. Direct analysis of anabolic steroids in urine using Leidenfrost phenomenon assisted thermal desorption-dielectric barrier discharge ionization mass spectrometry.

    Science.gov (United States)

    Saha, Subhrakanti; Mandal, Mridul Kanti; Nonami, Hiroshi; Hiraoka, Kenzo

    2014-08-11

    Rapid detection of trace level anabolic steroids in urine is highly desirable to monitor the consumption of performance enhancing anabolic steroids by athletes. The present article describes a novel strategy for identifying the trace anabolic steroids in urine using Leidenfrost phenomenon assisted thermal desorption (LPTD) coupled to dielectric barrier discharge (DBD) ionization mass spectrometry. Using this method the steroid molecules are enriched within a liquid droplet during the thermal desorption process and desorbed all-together at the last moment of droplet evaporation in a short time domain. The desorbed molecules were ionized using a dielectric barrier discharge ion-source in front of the mass spectrometer inlet at open atmosphere. This process facilitates the sensitivity enhancement with several orders of magnitude compared to the thermal desorption at a lower temperature. The limits of detection (LODs) of various steroid molecules were found to be in the range of 0.05-0.1 ng mL(-1) for standard solutions and around two orders of magnitude higher for synthetic urine samples. The detection limits of urinary anabolic steroids could be lowered by using a simple and rapid dichloromethane extraction technique. The analytical figures of merit of this technique were evaluated at open atmosphere using suitable internal standards. The technique is simple and rapid for high sensitivity and high throughput screening of anabolic steroids in urine. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Characterization of direct current He-N{sub 2} mixture plasma using optical emission spectroscopy and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Flores, O.; Castillo, F.; Martinez, H. [Laboratorio de Espectroscopia, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Villa, M.; Reyes, P. G. [Facultad de Ciencias, Universidad Autónoma del Estado de México, Estado de México (Mexico); Villalobos, S. [Laboratorio de Espectroscopia, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62251, Cuernavaca, Morelos (Mexico); Facultad de Ingeniería, Universidad Nacional Autónoma de México, México D.F. (Mexico)

    2014-05-15

    This study analyses the glow discharge of He and N{sub 2} mixture at the pressure of 2.0 Torr, power of 10 W, and flow rate of 16.5 l/min, by using optical emission spectroscopy and mass spectrometry. The emission bands were measured in the wavelength range of 200–1100 nm. The principal species observed were N{sub 2}{sup +} (B{sup 2}Σ{sup +}{sub u}→X{sup 2}Σ{sup +}{sub g}), N{sub 2} (C{sup 3}Π{sub u}→B{sup 3}Π{sub g}), and He, which are in good agreement with the results of mass spectrometry. Besides, the electron temperature and ion density were determined by using a double Langmuir probe. Results indicate that the electron temperature is in the range of 1.55–2.93 eV, and the electron concentration is of the order of 10{sup 10} cm{sup −3}. The experimental results of electron temperature and ion density for pure N{sub 2} and pure He are in good agreement with the values reported in the literature.

  15. Two-phase, mass-transport model for direct methanol fuel cells with effect of non-equilibrium evaporation and condensation

    Science.gov (United States)

    Yang, W. W.; Zhao, T. S.

    A two-phase, mass-transport model for liquid-feed direct methanol fuel cells (DMFCs) is developed by taking into account the effect of non-equilibrium evaporation and condensation of methanol and water. The comparison between the present model and other models indicates that the present model yields more reasonable predictions of cell performance. Particularly, it is shown that the models that invoke a thermodynamic-equilibrium assumption between phases will overestimate mass-transport rates of methanol and water, thereby resulting in an inaccurate prediction of cell performance. The parametric study using the present model reveals that the gas coverage at the flow channel-diffusion-layer interface is directly related to the gas-void fraction inside the anode porous region; increasing the gas-void fraction will increase the mass-transfer resistance of methanol and thus lower cell performance. The effects of the geometric dimensions of the cell structure, such as channel width and rib width, on cell performance are also investigated with the model developed in this work.

  16. Does Ultrasound-Guided Directional Vacuum-Assisted Removal Help Eliminate Abnormal Nipple Discharge in Patients with Benign Intraductal Single Mass?

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jung Min; Cho, Na Ri Ya; Moon, Woo Kyung [Seoul National University Hospital, Seoul (Korea, Republic of); Park, Jeong Seon [Hanyang University Hospital, Seoul (Korea, Republic of); Chung, Se Yeong [Seoul National University Boramae Hospital, Seoul (Korea, Republic of); Jang, Mi Jung [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2009-12-15

    To evaluate whether the removal of an intraductal mass using an ultrasound (US)-guided directional vacuum-assisted device can eliminate symptoms in patients presenting with abnormal nipple discharge. Between March 2004 and October 2006, 36 patients who presented with abnormal nipple discharge, underwent US-guided, 11-gauge vacuum-assisted biopsy for a benign intraductal single mass on US. The ability of the procedure to eliminate nipple discharge was evaluated by physical examination during follow-up US. Lesion characteristics, biopsy variables, and histologic features were analyzed to identify factors affecting symptom resolution. Of the 36 lesions, 25 (69%) were intraductal papillomas, 10 (28%) were fibrocystic changes, and one (3%) was a fibroadenoma. The nipple discharge disappeared in 69% (25 of 36) of the women at a mean follow-up time of 25 months (range 12-42 month). There was no difference in the lesion characteristics, biopsy variables, and the histologic features between groups that eliminated the symptom compared those with persistent nipple discharge. US-guided directional vacuum-assisted removal of an intraductal mass appears to eliminate nipple discharge in only 69% of patients and thus, it should not be considered as an alternative to surgical excision.

  17. A novel method for sampling the suspended sediment load in the tidal environment using bi-directional time-integrated mass-flux sediment (TIMS) samplers

    Science.gov (United States)

    Elliott, Emily A.; Monbureau, Elaine; Walters, Glenn W.; Elliott, Mark A.; McKee, Brent A.; Rodriguez, Antonio B.

    2017-12-01

    Identifying the source and abundance of sediment transported within tidal creeks is essential for studying the connectivity between coastal watersheds and estuaries. The fine-grained suspended sediment load (SSL) makes up a substantial portion of the total sediment load carried within an estuarine system and efficient sampling of the SSL is critical to our understanding of nutrient and contaminant transport, anthropogenic influence, and the effects of climate. Unfortunately, traditional methods of sampling the SSL, including instantaneous measurements and automatic samplers, can be labor intensive, expensive and often yield insufficient mass for comprehensive geochemical analysis. In estuaries this issue is even more pronounced due to bi-directional tidal flow. This study tests the efficacy of a time-integrated mass sediment sampler (TIMS) design, originally developed for uni-directional flow within the fluvial environment, modified in this work for implementation the tidal environment under bi-directional flow conditions. Our new TIMS design utilizes an 'L' shaped outflow tube to prevent backflow, and when deployed in mirrored pairs, each sampler collects sediment uniquely in one direction of tidal flow. Laboratory flume experiments using dye and particle image velocimetry (PIV) were used to characterize the flow within the sampler, specifically, to quantify the settling velocities and identify stagnation points. Further laboratory tests of sediment indicate that bidirectional TIMS capture up to 96% of incoming SSL across a range of flow velocities (0.3-0.6 m s-1). The modified TIMS design was tested in the field at two distinct sampling locations within the tidal zone. Single-time point suspended sediment samples were collected at high and low tide and compared to time-integrated suspended sediment samples collected by the bi-directional TIMS over the same four-day period. Particle-size composition from the bi-directional TIMS were representative of the array of

  18. Galaxy And Mass Assembly (GAMA): gas fuelling of spiral galaxies in the local Universe II. - direct measurement of the dependencies on redshift and host halo mass of stellar mass growth in central disc galaxies

    Science.gov (United States)

    Grootes, M. W.; Dvornik, A.; Laureijs, R. J.; Tuffs, R. J.; Popescu, C. C.; Robotham, A. S. G.; Liske, J.; Brown, M. J. I.; Holwerda, B. W.; Wang, L.

    2018-06-01

    We present a detailed analysis of the specific star formation rate-stellar mass (sSFR-M*) of z ≤ 0.13 disc central galaxies using a morphologically selected mass-complete sample (M* ≥ 109.5 M⊙). Considering samples of grouped and ungrouped galaxies, we find the sSFR-M* relations of disc-dominated central galaxies to have no detectable dependence on host dark-matter halo (DMH) mass, even where weak-lensing measurements indicate a difference in halo mass of a factor ≳ 5. We further detect a gradual evolution of the sSFR-M* relation of non-grouped (field) central disc galaxies with redshift, even over a Δz ≈ 0.04 (≈5 × 108 yr) interval, while the scatter remains constant. This evolution is consistent with extrapolation of the `main sequence of star-forming-galaxies' from previous literature that uses larger redshift baselines and coarser sampling. Taken together, our results present new constraints on the paradigm under which the SFR of galaxies is determined by a self-regulated balance between gas inflows and outflows, and consumption of gas by star formation in discs, with the inflow being determined by the product of the cosmological accretion rate and a fuelling efficiency - \\dot{M}_{b,halo}ζ. In particular, maintaining the paradigm requires \\dot{M}_{b,halo}ζ to be independent of the mass Mhalo of the host DMH. Furthermore, it requires the fuelling efficiency ζ to have a strong redshift dependence (∝(1 + z)2.7 for M* = 1010.3 M⊙ over z = 0-0.13), even though no morphological transformation to spheroids can be invoked to explain this in our disc-dominated sample. The physical mechanisms capable of giving rise to such dependencies of ζ on Mhalo and z for discs are unclear.

  19. Direct injection liquid chromatography/electrospray ionization mass spectrometric horse urine analysis for the quantification and confirmation of threshold substances for doping control. II. Determination of theobromine.

    Science.gov (United States)

    Vonaparti, A; Lyris, E; Panderi, I; Koupparis, M; Georgakopoulos, C

    2009-04-01

    In equine sport, theobromine is prohibited with a threshold level of 2 microg mL(-1) in urine, hence doping control laboratories have to establish quantitative and qualitative methods for its determination. Two simple liquid chromatography/mass spectrometry (LC/MS) methods for the identification and quantification of theobromine were developed and validated using the same sample preparation procedure but different mass spectrometric systems: ion trap mass spectrometry (ITMS) and time-of-flight mass spectrometry (TOFMS). Particle-free diluted urine samples were directly injected into the LC/MS systems, avoiding the time-consuming extraction step. 3-Propylxanthine was used as the internal standard. The tested linear range was 0.75-15 microg mL(-1). Matrix effects were evaluated analyzing calibration curves in water and different fortified horse urine samples. A great variation in the signal of theobromine and the internal standard was observed in different matrices. To overcome matrix effects, a standard additions calibration method was applied. The relative standard deviations of intra- and inter-day analysis were lower than 8.6 and 7.2%, respectively, for the LC/ITMS method and lower than 5.7 and 5.8%, respectively, for the LC/TOFMS method. The bias was less than 8.7% for both methods. The methods were applied to two case samples, demonstrating simplicity, accuracy and selectivity. Copyright (c) 2009 John Wiley & Sons, Ltd.

  20. Implementation of dipolar direct current (DDC) collision-induced dissociation in storage and transmission modes on a quadrupole/time-of-flight tandem mass spectrometer.

    Science.gov (United States)

    Webb, Ian K; Londry, Frank A; McLuckey, Scott A

    2011-09-15

    Means for effecting dipolar direct current collision-induced dissociation (DDC CID) on a quadrupole/time-of-flight in a mass spectrometer have been implemented for the broadband dissociation of a wide range of analyte ions. The DDC fragmentation method in electrodynamic storage and transmission devices provides a means for inducing fragmentation of ions over a large mass-to-charge range simultaneously. It can be effected within an ion storage step in a quadrupole collision cell that is operated as a linear ion trap or as ions are continuously transmitted through the collision cell. A DDC potential is applied across one pair of rods in the quadrupole collision cell of a QqTOF hybrid mass spectrometer to effect fragmentation. In this study, ions derived from a small drug molecule, a model peptide, a small protein, and an oligonucleotide were subjected to the DDC CID method in either an ion trapping or an ion transmission mode (or both). Several key experimental parameters that affect DDC CID results, such as time, voltage, low mass cutoff, and bath gas pressure, are illustrated with protonated leucine enkephalin. The DDC CID dissociation method gives a readily tunable, broadband tool for probing the primary structures of a wide range of analyte ions. The method provides an alternative to the narrow resonance conditions of conventional ion trap CID and it can access more extensive sequential fragmentation, depending upon conditions. The DDC CID approach constitutes a collision analog to infrared multiphoton dissociation (IRMPD). Copyright © 2011 John Wiley & Sons, Ltd.

  1. Investigations of the mass and charge distribution of fission products from the 238U(n14,f) reaction by direct Ge(Li) method

    International Nuclear Information System (INIS)

    Daroczy, S.

    1979-01-01

    The fission yields can be measured by the well-known activation method if it is taken into account that the fission process results in 5-6 nuclides in an isobaric chain. The method which is based only on the gamma-spectrometric measurement of the irradiated fissioning sample is referred to as the direct Ge(Li) method for fission yield measurement. The thesis contains detailed description of the direct Ge(Li) method. The method was tested by the measurement of cumulative yields of 47 fission products and independent yields of 7 products in the reaction of 238 U(n 14 ,f). These are the members of 37 mass chains in the A=83-149 mass number region. The half-lives of the studied products are in the range of Tsub(1/2)=10 2 -10 9 s; the gamma spectrometric method was improved by extending its applicability to the measurement of short-lived products. Applying short irradiation time (5 min) the yields of 16 fission products with half-lives shorter than 1 hour could be measured. The lowest measured partial fission cross sections (yields) are in the order of 1 mb (0.1%). The accuracy of the yield measured by the direct Ge(Li) method is as high as or higher than that obtained radiochemically, especially for the products measured by many intensive gamma lines. (author)

  2. Rapid fingerprinting of sterols and related compounds in vegetable and animal oils and phytosterol enriched- margarines by transmission mode direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Alberici, Rosana M; Fernandes, Gabriel D; Porcari, Andréia M; Eberlin, Marcos N; Barrera-Arellano, Daniel; Fernández, Facundo M

    2016-11-15

    Plant-derived sterols, often referred to as phytosterols, are important constituents of plant membranes where they assist in maintaining phospholipid bilayer stability. Consumption of phytosterols has been suggested to positively affect human health by reducing cholesterol levels in blood via inhibition of its absorption in the small intestine, thus protecting against heart attack and stroke. Sterols are challenging analytes for mass spectrometry, since their low polarity makes them difficult to ionize by both electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI), typically requiring derivatization steps to overcome their low ionization efficiencies. We present a fast and reliable method to characterize the composition of phytosterols in vegetable oils and enriched margarines. The method requires no derivatization steps or sample extraction procedures thanks to the use of transmission mode direct analysis in real time mass spectrometry (TM-DART-MS). Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. [Rapid screening the alkaloids of poppy shell in hot pot condiment, beef noodle soup and seasoning by direct analysis in real time-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Baile; Gao, Lihong; Xie, Yingshuang; Zhou, Wei; Chen, Xiaofeng; Lei, Chunni; Zhang, Huan

    2017-07-08

    A direct analysis in real time tandem mass spectrometry (DART-MS/MS) method was established for quickly screening five illegally added alkaloids of poppy shell from the hot pot condiment, beef noodle soup and seasoning. The samples were extracted and purified by acetonitrile, and then injected under the conditions of ionization temperature of 300℃, grid electrode voltage of 150 V and sampling rate of 0.8 mm/s using DART in the positive ion mode. The determination was conducted by tandem mass spectrometry in positive ESI mode under multiple reaction monitoring (MRM) mode. The method is simple and rapid, and can meet the requirement of rapid screening and analysis of large quantities of samples.

  4. An Integrated Hot-Stage Microscope-Direct Analysis in Real Time-Mass Spectrometry System for Studying the Thermal Behavior of Materials.

    Science.gov (United States)

    Ashton, Gage P; Harding, Lindsay P; Parkes, Gareth M B

    2017-12-19

    This paper describes a new analytical instrument that combines a precisely temperature-controlled hot-stage with digital microscopy and Direct Analysis in Real Time-mass spectrometry (DART-MS) detection. The novelty of the instrument lies in its ability to monitor processes as a function of temperature through the simultaneous recording of images, quantitative color changes, and mass spectra. The capability of the instrument was demonstrated through successful application to four very varied systems including profiling an organic reaction, decomposition of silicone polymers, and the desorption of rhodamine B from an alumina surface. The multidimensional, real-time analytical data provided by this instrument allow for a much greater insight into thermal processes than could be achieved previously.

  5. Detection of polydimethylsiloxanes transferred from silicone-coated parchment paper to baked goods using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Jakob, Andreas; Crawford, Elizabeth A; Gross, Jürgen H

    2016-04-01

    The non-stick properties of parchment papers are achieved by polydimethylsiloxane (PDMS) coatings. During baking, PDMS can thus be extracted from the silicone-coated parchment into the baked goods. Positive-ion direct analysis in real time (DART) mass spectrometry (MS) is highly efficient for the analysis of PDMS. A DART-SVP source was coupled to a quadrupole-time-of-flight mass spectrometer to detect PDMS on the contact surface of baked goods after use of silicone-coated parchment papers. DART spectra from the bottom surface of baked cookies and pizzas exhibited signals because of PDMS ions of the general formula [(C2H6SiO)n  + NH4 ](+) in the m/z 800-1900 range. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Direct Analysis of Organic Compounds in Liquid Using a Miniature Photoionization Ion Trap Mass Spectrometer with Pulsed Carrier-Gas Capillary Inlet.

    Science.gov (United States)

    Lu, Xinqiong; Yu, Quan; Zhang, Qian; Ni, Kai; Qian, Xiang; Tang, Fei; Wang, Xiaohao

    2017-08-01

    A miniature ion trap mass spectrometer with capillary direct sampling and vacuum ultraviolet photoionization source was developed to conduct trace analysis of organic compounds in liquids. Self-aspiration sampling is available where the samples are drawn into the vacuum chamber through a capillary with an extremely low flow rate (less than 1 μL/min), which minimizes sample consumption in each analysis to tens of micrograms. A pulsed gas-assisted inlet was designed and optimized to promote sample transmission in the tube and facilitate the cooling of ions, thereby improving instrument sensitivity. A limit of detection of 2 ppb could be achieved for 2,4-dimethylaniline in a methanol solution. The sampling system described in the present study is specifically suitable for a miniature photoionization ion trap mass spectrometer that can perform rapid and online analysis for liquid samples. Graphical Abstract ᅟ.

  7. Rapid screening and distribution of bioactive compounds in different parts of Berberis petiolaris using direct analysis in real time mass spectrometry

    Directory of Open Access Journals (Sweden)

    Awantika Singh

    2015-10-01

    Full Text Available Berberis petiolaris Wall. ex G. Don, an unexplored medicinal plant belonging to the family Berberidaceae, is a large deciduous shrub found in Western Himalaya between 1800–3000 m. Chemical profiling of fruit, leaf, root and stem was done by direct analysis in real time mass spectrometry followed by multivariate analysis for discrimination among the plant parts. The bioactive compounds, including magnoflorine, berberine, jatrorrhizine, thalifendine/berberrubine, demethyleneberberine, reticuline, 8-oxoberberine, N-methyltetrahydroberberine, tetrahydropalmatine, tetrahydroberberine and palmatine, were identified by their exact mass measurement and the corresponding molecular formula of each compound. A comparative study of distribution pattern for all these bioactive alkaloids showed qualitative and quantitative variations in different parts of B. petiolaris. Principal component analysis clearly discriminated each part of B. petiolaris plant. Keywords: Berberis petiolaris, Alkaloids, Profiling, DART–TOF–MS, Statistical analysis

  8. On the impact of using downscaled reanalysis data instead of direct measurements for modeling the mass balance of a tropical glacier (Cordillera Blanca, Peru)

    Science.gov (United States)

    Galos, Stephan; Hofer, Marlis; Marzeion, Ben; Mölg, Thomas; Großhauser, Martin

    2013-04-01

    Due to their setting, tropical glaciers are sensitive indicators of mid-tropospheric meteorological variability and climate change. Furthermore these glaciers are of particular interest because they respond faster to climatic changes than glaciers located in mid- or high-latitudes. As long-term direct meteorological measurements in such remote environments are scarce, reanalysis data (e.g. ERA-Interim) provide a highly valuable source of information. Reanalysis datasets (i) enable a temporal extension of data records gained by direct measurements and (ii) provide information from regions where direct measurements are not available. In order to properly derive the physical exchange processes between glaciers and atmosphere from reanalysis data, downscaling procedures are required. In the present study we investigate if downscaled atmospheric variables (air temperature and relative humidity) from a reanalysis dataset can be used as input for a physically based, high resolution energy and mass balance model. We apply a well validated empirical-statistical downscaling model, fed with ERA-Interim data, to an automated weather station (AWS) on the surface of Glaciar Artesonraju (8.96° S | 77.63° W). The downscaled data is then used to replace measured air temperature and relative humidity in the input for the energy and mass balance model, which was calibrated using ablation data from stakes and a sonic ranger. In order to test the sensitivity of the modeled mass balance to the downscaled data, the results are compared to a reference model run driven solely with AWS data as model input. We finally discuss the results and present future perspectives for further developing this method.

  9. Evaluation of MALDI-TOF mass spectrometry and Sepsityper Kit™ for the direct identification of organisms from sterile body fluids in a Canadian pediatric hospital

    OpenAIRE

    Tadros, Manal; Petrich, Astrid

    2013-01-01

    Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to identify bacteria directly from positive blood and sterile fluid cultures. The authors evaluated a commercially available kit – the Sepsityper Kit (Bruker Daltonik, Germany) – and MALDI-TOF MS for the rapid identification of organisms from 80 flagged positive blood culture broths, of which 73 (91.2%) were blood culture specimens and seven (8.7%) were cerebrospinal fluid specimens, in com...

  10. Direct Surface and Droplet Microsampling for Electrospray Ionization Mass Spectrometry Analysis with an Integrated Dual-Probe Microfluidic Chip

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Cong-Min [Institute of Microanalytical; Zhu, Ying [Institute of Microanalytical; Jin, Di-Qiong [Institute of Microanalytical; Kelly, Ryan T. [Environmental; Fang, Qun [Institute of Microanalytical

    2017-08-15

    Ambient mass spectrometry (MS) has revolutionized the way of MS analysis and broadened its application in various fields. This paper describes the use of microfluidic techniques to simplify the setup and improve the functions of ambient MS by integrating the sampling probe, electrospray emitter probe, and online mixer on a single glass microchip. Two types of sampling probes, including a parallel-channel probe and a U-shaped channel probe, were designed for dryspot and liquid-phase droplet samples, respectively. We demonstrated that the microfabrication techniques not only enhanced the capability of ambient MS methods in analysis of dry-spot samples on various surfaces, but also enabled new applications in the analysis of nanoliter-scale chemical reactions in an array of droplets. The versatility of the microchip-based ambient MS method was demonstrated in multiple different applications including evaluation of residual pesticide on fruit surfaces, sensitive analysis of low-ionizable analytes using postsampling derivatization, and high-throughput screening of Ugi-type multicomponent reactions.

  11. Direct detection of illicit drugs from biological fluids by desorption/ionization mass spectrometry with nanoporous silicon microparticles.

    Science.gov (United States)

    Guinan, T M; Kirkbride, P; Della Vedova, C B; Kershaw, S G; Kobus, H; Voelcker, N H

    2015-12-07

    Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is a high throughput analytical technique capable of detecting low molecular weight analytes, including illicit drugs, and with potential applications in forensic toxicology as well as athlete and workplace testing, particularly for biological fluids (oral fluids, urine and blood). However, successful detection of illicit drugs using SALDI-MS often requires extraction steps to reduce the inherent complexity of biological fluids. Here, we demonstrate an all-in-one extraction and analytical system consisting of hydrophobically functionalized porous silicon microparticles (pSi-MPs) for affinity SALDI-MS of prescription and illicit drugs. This novel approach allows for the analysis of drugs from multiple biological fluids without sample preparation protocols. The effect of pSi-MP size, pore diameter, pore depth and functionalization on analytical performance is investigated. pSi-MPs were optimized for the rapid and high sensitivity detection of methadone, cocaine and 3,4-methylenedioxymethamphetamine (MDMA). This optimized system allowed extraction and detection of methadone from spiked saliva and clinical urine samples. Furthermore, by detecting oxycodone in additional clinical saliva and plasma samples, we were able to demonstrate the versatility of the pSi-MP SALDI-MS technique.

  12. Direct Growth of Bacteria in Headspace Vials Allows for Screening of Volatiles by Gas Chromatography Mass Spectrometry.

    Science.gov (United States)

    Timm, Collin M; Lloyd, Evan P; Egan, Amanda; Mariner, Ray; Karig, David

    2018-01-01

    Bacterially produced volatile organic compounds (VOCs) can modify growth patterns of eukaryotic hosts and competing/cohabiting microbes. These compounds have been implicated in skin disorders and attraction of biting pests. Current methods to detect and characterize VOCs from microbial cultures can be laborious and low-throughput, making it difficult to understand the behavior of microbial populations. In this work we present an efficient method employing gas chromatography/mass spectrometry with autosampling to characterize VOC profiles from solid-phase bacterial cultures. We compare this method to complementary plate-based assays and measure the effects of growth media and incubation temperature on the VOC profiles from a well-studied Pseudomonas aeruginosa PAO1 system. We observe that P. aeruginosa produces longer chain VOCs, such as 2-undecanone and 2-undecanol in higher amounts at 37°C than 30°C. We demonstrate the throughput of this method by studying VOC profiles from a representative collection of skin bacterial isolates under three parallel growth conditions. We observe differential production of various aldehydes and ketones depending on bacterial strain. This generalizable method will support screening of bacterial populations in a variety of research areas.

  13. Direct Growth of Bacteria in Headspace Vials Allows for Screening of Volatiles by Gas Chromatography Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Collin M. Timm

    2018-03-01

    Full Text Available Bacterially produced volatile organic compounds (VOCs can modify growth patterns of eukaryotic hosts and competing/cohabiting microbes. These compounds have been implicated in skin disorders and attraction of biting pests. Current methods to detect and characterize VOCs from microbial cultures can be laborious and low-throughput, making it difficult to understand the behavior of microbial populations. In this work we present an efficient method employing gas chromatography/mass spectrometry with autosampling to characterize VOC profiles from solid-phase bacterial cultures. We compare this method to complementary plate-based assays and measure the effects of growth media and incubation temperature on the VOC profiles from a well-studied Pseudomonas aeruginosa PAO1 system. We observe that P. aeruginosa produces longer chain VOCs, such as 2-undecanone and 2-undecanol in higher amounts at 37°C than 30°C. We demonstrate the throughput of this method by studying VOC profiles from a representative collection of skin bacterial isolates under three parallel growth conditions. We observe differential production of various aldehydes and ketones depending on bacterial strain. This generalizable method will support screening of bacterial populations in a variety of research areas.

  14. Direct Analysis of Amphetamine Stimulants in a Whole Urine Sample by Atmospheric Solids Analysis Probe Tandem Mass Spectrometry

    Science.gov (United States)

    Crevelin, Eduardo J.; Salami, Fernanda H.; Alves, Marcela N. R.; De Martinis, Bruno S.; Crotti, Antônio E. M.; Moraes, Luiz A. B.

    2016-05-01

    Amphetamine-type stimulants (ATS) are among illicit stimulant drugs that are most often used worldwide. A major challenge is to develop a fast and efficient methodology involving minimal sample preparation to analyze ATS in biological fluids. In this study, a urine pool solution containing amphetamine, methamphetamine, ephedrine, sibutramine, and fenfluramine at concentrations ranging from 0.5 pg/mL to 100 ng/mL was prepared and analyzed by atmospheric solids analysis probe tandem mass spectrometry (ASAP-MS/MS) and multiple reaction monitoring (MRM). A urine sample and saliva collected from a volunteer contributor (V1) were also analyzed. The limit of detection of the tested compounds ranged between 0.002 and 0.4 ng/mL in urine samples; the signal-to-noise ratio was 5. These results demonstrated that the ASAP-MS/MS methodology is applicable for the fast detection of ATS in urine samples with great sensitivity and specificity, without the need for cleanup, preconcentration, or chromatographic separation. Thus ASAP-MS/MS could potentially be used in clinical and forensic toxicology applications.

  15. Goal-Directed Fluid Resuscitation Protocol Based on Arterial Waveform Analysis of Major Burn Patients in a Mass Burn Casualty.

    Science.gov (United States)

    Chiao, Hao-Yu; Chou, Chang-Yi; Tzeng, Yuan-Sheng; Wang, Chih-Hsin; Chen, Shyi-Gen; Dai, Niann-Tzyy

    2018-02-01

    Adequate fluid titration during the initial resuscitation period of major burn patients is crucial. This study aimed to evaluate the feasibility and efficacy of a goal-directed fluid resuscitation protocol that used hourly urine output plus the arterial waveform analysis FloTrac (Edwards LifeSciences, Irvine, Calif) system for major burns to avoid fluid overload. We conducted a retrospective cohort study of 43 major burn patients at the Tri-Service General Hospital after the Formosa Fun Coast Dust Explosion on June 27, 2015. Because of the limited capacity of intensive care units (ICUs), 23 intubated patients were transferred from the burn wards or emergency department to the ICU within 24 hours. Fluid administration was adjusted to achieve a urine output of 30 to 50 mL/h, cardiac index greater than 2.5 L/min/m, and stroke volume variation (SVV) less than 12%. The hourly crystalloid fluid infusion rate was titrated based on SVV and hourly urine output. Of the 23 critically burned patients admitted to the ICU, 13 patients who followed the goal-directed fluid resuscitation protocol within 12 hours postburn were included in the analysis. The mean age (years) was 21.8, and the mean total body surface area (TBSA) burned (%) was 68.0. The mean Revised Baux score was 106.8. All patients sustained inhalation injury. The fluid volumes administered to patients in the first 24 hours and the second 24 hours (mL/kg/% total body surface area) were 3.62 ± 1.23 and 2.89 ± 0.79, respectively. The urine outputs in the first 24 hours and the second 24 hours (mL/kg/h) were 1.13 ± 0.66 and 1.53 ± 0.87, respectively. All patients achieved the established goals within 32 hours postburn. In-hospital mortality rate was 0%. The SVV-based goal-directed fluid resuscitation protocol leads to less unnecessary fluid administration during the early resuscitation phase. Clinicians can efficaciously manage the dynamic body fluid changes in major burn patients under the guidance of the protocol.

  16. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Science.gov (United States)

    Mascuch, Samantha J; Moree, Wilna J; Hsu, Cheng-Chih; Turner, Gregory G; Cheng, Tina L; Blehert, David S; Kilpatrick, A Marm; Frick, Winifred F; Meehan, Michael J; Dorrestein, Pieter C; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  17. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry

    Science.gov (United States)

    Mascuch, Samantha J.; Moree, Wilna J.; Cheng-Chih Hsu, Cheng-Chih; Turner, Gregory G.; Cheng, Tina L.; Blehert, David S.; Kilpatrick, A. Marm; Frick, Winifred F.; Meehan, Michael J.; Dorrestein, Pieter C.; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  18. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Samantha J Mascuch

    Full Text Available White-nose syndrome (WNS caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  19. Analysis of Chloroquine and Metabolites Directly from Whole-body Animal Tissue Sections by Liquid Extraction Surface Analysis (LESA) and Tandem Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Parson, Whitney B [ORNL; Koeniger, Stormy L [Abbott Laboratories; Johnson, Robert W [Abbott Laboratories; Erickson, Jamie [Abbott Laboratories; Tian, Yu [Abbott Laboratories; Stedman, Christopher A. [Abbott Laboratories; Schwartz, Annette [Abbott Laboratories; Tarcsa, Edit [Abbott Laboratories; Cole, Roderic [ORNL; Van Berkel, Gary J [ORNL

    2012-01-01

    The rapid and direct analysis of the amount and spatial distribution of exogenous chloroquine and chloroquine metabolites from tissue sections by liquid extraction surface sampling analysis coupled with tandem mass spectrometry (LESA-MS) was demonstrated. LESA-MS results compared well with previously published chloroquine quantification data collected by organ excision, extraction and fluorescent detection. The ability to directly sample and analyze spatially-resolved exogenous molecules from tissue sections with minimal sample preparation and analytical method development has the potential to facilitate the assessment of target tissue penetration of pharmaceutical compounds, to establish pharmacokinetic/pharmacodynamic (PK/PD) relationships, and to complement established pharmacokinetic methods used in the drug discovery process during tissue distribution assessment.

  20. Direct Determination of Six Cytokinin Nucleotide Monophosphates in Coconut Flesh by Reversed-Phase Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Cao, Zhao-Yun; Ma, You-Ning; Sun, Li-Hua; Mou, Ren-Xiang; Zhu, Zhi-Wei; Chen, Ming-Xue

    2017-11-15

    Coconut contains many uncharacterized cytokinins that have important physiological effects in plants and humans. In this work, a method based on liquid chromatography-tandem mass spectrometry was developed for identification and quantification of six cytokinin nucleotide monophosphates in coconut flesh. Excellent separation was achieved using a low-coverage C18 bonded-phase column with an acidic mobile phase, which greatly improved the retention of target compounds. To enable high-throughput analysis, a single-step solid-phase extraction using mixed-mode anion-exchange cartridges was employed for sample preparation. This proved to be an effective method to minimize matrix effects and ensure high selectivity. The limits of detection varied from 0.06 to 0.3 ng/mL, and the limits of quantification ranged from 0.2 to 1.0 ng/mL. The linearity was statistically verified over 2 orders of magnitude, giving a coefficient of determination (R 2 ) greater than 0.9981. The mean recoveries were from 81 to 108%; the intraday precision (n = 6) was less than 11%; and the interday precision (n = 11) was within 14%. The developed method was applied to the determination of cytokinin nucleotide monophosphates in coconut flesh samples, and four of them were successfully identified and quantified. The results showed that trans-zeatin riboside-5'-monophosphate was the dominant cytokinin, with a concentration of 2.7-34.2 ng/g, followed by N 6 -isopentenyladenosine-5'-monophosphate (≤12.9 ng/g), while the concentrations of cis-zeatin riboside-5'-monophosphate and dihydrozeatin riboside-5'-monophosphate were less than 2.2 and 4.9 ng/g, respectively.

  1. Measuremental analysis of thermal performance of direct gain houses in Kanto district. Effects of thermal mass and caves; Kanto chiho ni tatsu direct gain jutaku no netsuseino jissoku. Netsuyoryo to hisashi no koka

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, K; Sunaga, N; Muro, K [Tokyo Metropolitan University, Tokyo (Japan)

    1996-10-27

    The thermal performance of direct gain passive solar houses was measured. Mr. M`s two-storied RC residence with double glazing windows and thermal storage floors, walls and ceilings of brick or concrete was provided for measurement. Its double eaves of the south window and both SE and SW overhanging exterior walls play a role in sunshade. Mr. I`s two-storied wooden residence with thermal storage RC floors and brick walls, and no eaves of the south window and no overhanging exterior walls was also provided. The summer and winter measurement results were in complete contrast between the residences. In summer, large thermal mass and eaves of Mr. M`s residence were effective, while in winter, small thermal mass and no eaves of Mr. I`s residence were effective. The following ideas are important in design from the viewpoint of indoor thermal environment: a movable sunshade for taking in solar radiation as much as possible in winter, well-balanced arrangement of thermal storage parts with suitable thermal mass corresponding to movement of the sun, a large screen door for cross ventilation in summer, and a night insulation shutter for reducing heat loss in winter. 2 refs., 10 figs., 1 tab.

  2. Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

    International Nuclear Information System (INIS)

    Owen, Andrew W.; McAulay, Edith A.J.; Nordon, Alison; Littlejohn, David; Lynch, Thomas P.; Lancaster, J. Steven; Wright, Robert G.

    2014-01-01

    Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min −1 , respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to generate

  3. Direct determination of 3-chloropropanol esters in edible vegetable oils using high resolution mass spectrometry (HRMS-Orbitrap).

    Science.gov (United States)

    Graziani, Giulia; Gaspari, Anna; Chianese, Donato; Conte, Lanfranco; Ritieni, Alberto

    2017-11-01

    A series of refined edible oils derived from mixed seeds, peanuts, corn, sunflower and palm obtained from the local supermarket were analyzed for their content of 3-MCPD esters. A direct analytical method for the determination of 3-monochloropropane-1,2-diol esters (3-MCPD esters) was applied to investigate the major MCPD esters found in common edible oils; in particular seven types of monoesters and eleven types of diesters were detected. The limits of detection (LODs) for monoesters and diesters of 3-MCPD were in the range of 0.079-12.678 µg kg -1 and 0.033-18.610 µg kg -1 in edible oils, and the ranges of limits of quantitation (LOQs) were 0.979-38.035 µg kg -1 and 0.100-55 µg kg -1 , respectively. The recoveries of 3-MCPD esters from oil samples were in the range of 80-100%, with RSD ranging between 1.9 and 11.8%. The concentration levels of total 3-MCPD diesters in vegetable oil samples were in the range from 0.106 up to 3.444 μg g -1 whereas total monoesters ranged from 0.005 up to 1.606 μg g -1 .

  4. Superior performance asymmetric supercapacitors based on a directly grown commercial mass 3D Co3O4@Ni(OH)2 core-shell electrode.

    Science.gov (United States)

    Tang, Chun-hua; Yin, Xuesong; Gong, Hao

    2013-11-13

    Pseudocapacitors based on fast surface Faradaic reactions can achieve high energy densities together with high power densities. Usually, researchers develop a thin layer of active materials to increase the energy density by enhancing the surface area; meanwhile, this sacrifices the mass loading. In this work, we developed a novel 3D core-shell Co3O4@Ni(OH)2 electrode that can provide high energy density with very high mass loading. Core-shell porous nanowires (Co3O4@Ni(OH)2) were directly grown on a Ni current collector as an integrated electrode/collector for the supercapacitor anode. This Co3O4@Ni(OH)2 core-shell nanoarchitectured electrode exhibits an ultrahigh areal capacitance of 15.83 F cm(-2). The asymmetric supercapacitor prototypes, assembled using Co3O4@Ni(OH)2 as the anode, reduced graphene oxide (RGO) or active carbon (AC) as the cathode, and 6 M aqueous KOH as the electrolyte, exhibit very high energy densities falling into the energy-density range of Li-ion batteries. Because of the large mass loading and high energy density, the prototypes can drive a minifan or light a bulb even though the size is very small. These results indicate that our asymmetric supercapacitors have outstanding potential in commercial applications. Systematic study and scientific understanding were carried out.

  5. Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

    International Nuclear Information System (INIS)

    Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo

    2013-01-01

    The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field

  6. Direct detection of benzene, toluene, and ethylbenzene at trace levels in ambient air by atmospheric pressure chemical ionization using a handheld mass spectrometer.

    Science.gov (United States)

    Huang, Guangming; Gao, Liang; Duncan, Jason; Harper, Jason D; Sanders, Nathaniel L; Ouyang, Zheng; Cooks, R Graham

    2010-01-01

    The capabilities of a portable mass spectrometer for real-time monitoring of trace levels of benzene, toluene, and ethylbenzene in air are illustrated. An atmospheric pressure interface was built to implement atmospheric pressure chemical ionization for direct analysis of gas-phase samples on a previously described miniature mass spectrometer (Gao et al. Anal. Chem.2006, 78, 5994-6002). Linear dynamic ranges, limits of detection and other analytical figures of merit were evaluated: for benzene, a limit of detection of 0.2 parts-per-billion was achieved for air samples without any sample preconcentration. The corresponding limits of detection for toluene and ethylbenzene were 0.5 parts-per-billion and 0.7 parts-per-billion, respectively. These detection limits are well below the compounds' permissible exposure levels, even in the presence of added complex mixtures of organics at levels exceeding the parts-per-million level. The linear dynamic ranges of benzene, toluene, and ethylbenzene are limited to approximately two orders of magnitude by saturation of the detection electronics. 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

  7. Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Youngsu; Lee, Jonghee; Kim, Seongsoo [Agency for Defense Development, Daejeon (Korea, Republic of)

    2013-09-15

    The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.

  8. Analysis of green kiwi fruit (Actinidia deliciosa cv. Hayward) proteinases by two-dimensional zymography and direct identification of zymographic spots by mass spectrometry.

    Science.gov (United States)

    Larocca, Marilena; Rossano, Rocco; Riccio, Paolo

    2010-11-01

    Proteinases present in kiwi fruits are potentially allergenic enzymes belonging to the papain family of cysteine proteinases. Actinidin is a prominent kiwi enzyme. The study of kiwi proteinases is important for the follow-up of fruit maturation, a deeper insight in the allergenic properties of individual proteins, and the application of kiwi proteinases for meat tenderisation and other industrial purposes. Kiwi crude extracts were analysed by two-dimensional zymography on gelatin-containing gels. The digestion by the reactivated proteolytic enzymes after electrophoresis resulted in insights into kiwi proteinases. A mixture of several enzyme isotypes with the same pI but different molecular mass was observed. Clear spots, corresponding to the proteolytic activities, were excised, digested with trypsin, and submitted to MALDI-ToF mass spectrometry for protein identification. The most representative enzyme was actinidin. The innovative achievements of the present study are the: (1) two-dimensional zymographic map of kiwi gelatinases without the need for extensive purification; and (2) direct identification of proteinase isotypes by means of direct MALDI-ToF MS analysis of the zymographic spots. 2010 Society of Chemical Industry

  9. Ranked solutions to a class of combinatorial optimizations—with applications in mass spectrometry based peptide sequencing and a variant of directed paths in random media

    Science.gov (United States)

    Doerr, Timothy P.; Alves, Gelio; Yu, Yi-Kuo

    2005-08-01

    Typical combinatorial optimizations are NP-hard; however, for a particular class of cost functions the corresponding combinatorial optimizations can be solved in polynomial time using the transfer matrix technique or, equivalently, the dynamic programming approach. This suggests a way to efficiently find approximate solutions-find a transformation that makes the cost function as similar as possible to that of the solvable class. After keeping many high-ranking solutions using the approximate cost function, one may then re-assess these solutions with the full cost function to find the best approximate solution. Under this approach, it is important to be able to assess the quality of the solutions obtained, e.g., by finding the true ranking of the kth best approximate solution when all possible solutions are considered exhaustively. To tackle this statistical issue, we provide a systematic method starting with a scaling function generated from the finite number of high-ranking solutions followed by a convergent iterative mapping. This method, useful in a variant of the directed paths in random media problem proposed here, can also provide a statistical significance assessment for one of the most important proteomic tasks-peptide sequencing using tandem mass spectrometry data. For directed paths in random media, the scaling function depends on the particular realization of randomness; in the mass spectrometry case, the scaling function is spectrum-specific.

  10. Atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry of friction modifier additives analyzed directly from base oil solutions.

    Science.gov (United States)

    Widder, Lukas; Brennerb, Josef; Huttera, Herbert

    2014-01-01

    To develop new products and to apply measures of quality control quick and simple accessibility of additive composition in automo- tive lubrication is important. The aim of this study was to investigate the possibility of analyzing organic friction modifier additives by means of atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry [AP-MALDI-MS] from lubricant solu- tions without the use of additional separation techniques. Analyses of selected friction modifier ethoxylated tallow amines and oleic acid amide were compared using two ionization methods, positive-ion electrospray ionization (ESI) and AP-MALDI, using a LTQ Orbitrap mass spectrometer. Pure additives were characterized from solvent solutions, as well as from synthetic and mineral base oil mixtures. Detected ions of pure additive samples consisted mainly of [M + H]+, but also alkaLi metal adducts [M + Na]+ and [M + K]+ could be seen. Characterizations of blends of both friction modifiers from the base oil mixtures were carried out as well and showed significant inten- sities for several additive peaks. Thus, this work shows a method to directly analyze friction modifier additives used in the automotive industry from an oil blend via the use of AP-MALDI without any further separation steps. The method presented will further simplify the acquisition of data on lubricant composition and additives. Furthermore, it allows the perspective of analyzing additive reaction products directly from formulated oil blends.

  11. Direct determination of trace rare earth elements in ancient porcelain samples with slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Xiang Guoqiang; Jiang Zucheng; He Man; Hu Bin

    2005-01-01

    A method for the direct determination of trace rare earth elements in ancient porcelain samples by slurry sampling fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry was developed with the use of polytetrafluoroethylene as fluorinating reagent. It was found that Si, as a main matrix element in ancient porcelain sample, could be mostly removed at the ashing temperature of 1200 deg. C without considerable losses of the analytes. However, the chemical composition of ancient porcelain sample is very complicated, which makes the influences resulting from other matrix elements not be ignored. Therefore, the matrix effect of ancient porcelain sample was also investigated, and it was found that the matrix effect is obvious when the matrix concentration was larger than 0.8 g l -1 . The study results of particle size effect indicated that when the sample particle size was less than 0.057 mm, the particle size effect is negligible. Under the optimized operation conditions, the detection limits for rare earth elements by fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry were 0.7 ng g -1 (Eu)-33.3 ng g -1 (Nd) with the precisions of 4.1% (Yb)-10% (La) (c = 1 μg l -1 , n = 9). The proposed method was used to directly determine the trace rare earth elements in ancient porcelain samples produced in different dynasty (Sui, Ming and Qing), and the analytical results are satisfactory

  12. Direct analysis of intact biological macromolecules by low-energy, fiber-based femtosecond laser vaporization at 1042 nm wavelength with nanospray postionization mass spectrometry.

    Science.gov (United States)

    Shi, Fengjian; Flanigan, Paul M; Archer, Jieutonne J; Levis, Robert J

    2015-03-17

    A fiber-based laser with a pulse duration of 435 fs and a wavelength of 1042 nm was used to vaporize biological macromolecules intact from the condensed phase into the gas phase for nanospray postionization and mass analysis. Laser vaporization of dried standard protein samples from a glass substrate by 10 Hz bursts of 20 pulses having 10 μs pulse separation and energy resulted in signal comparable to a metal substrate. The protein signal observed from an aqueous droplet on a glass substrate was negligible compared to either a droplet on metal or a thin film on glass. The mass spectra generated from dried and aqueous protein samples by the low-energy, fiber laser were similar to the results from high-energy (500 μJ), 45-fs, 800-nm Ti:sapphire-based femtosecond laser electrospray mass spectrometry (LEMS) experiments, suggesting that the fiber-based femtosecond laser desorption mechanism involves a nonresonant, multiphoton process, rather than thermal- or photoacoustic-induced desorption. Direct analysis of whole blood performed without any pretreatment resulted in features corresponding to hemoglobin subunit-heme complex ions. The observation of intact molecular ions with low charge states from protein, and the tentatively assigned hemoglobin α subunit-heme complex from blood suggests that fiber-based femtosecond laser vaporization is a "soft" desorption source at a laser intensity of 2.39 × 10(12) W/cm(2). The low-energy, turnkey fiber laser demonstrates the potential of a more robust and affordable laser for femtosecond laser vaporization to deliver biological macromolecules into the gas phase for mass analysis.

  13. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  14. Direct introduction of volatile carbon compounds into the spray chamber of an inductively coupled plasma mass spectrometer: Sensitivity enhancement for selenium

    International Nuclear Information System (INIS)

    Kovacevic, Miroslav; Goessler, Walter

    2005-01-01

    The effect of signal enhancement of elements with ionization potentials in the range from 9 to 11 eV by carbon-containing compounds is a well-known phenomenon in inductively coupled plasma mass spectrometry (ICPMS). It has traditionally been exploited through the addition of organic solvents to the sample matrix or to the mobile phase to improve sensitivity. In the present work, aqueous solutions of volatile carbon compounds (acetone, methanol and acetic acid) were directly introduced into the thermostatted spray chamber rather than being added to the sample matrix. It is presumed that no aerosol is produced from these solutions and only vapors of organic compounds are swept into the plasma together with the sample aerosol. When a 0.40 mol l -1 aqueous solution of acetone was introduced directly into the spray chamber, the signals for arsenic and selenium were enhanced by a factor of 4.2. The usefulness of this approach was demonstrated through the achievement of lower instrumental detection limits for selenium at m/z 82 (0.1 ng ml -1 ) compared to the system without direct introduction of volatile carbon compounds (0.5 ng ml -1 ). The method was successfully applied in the determination of traces of selenium in natural water, urine and bovine liver reference material

  15. Fast analysis of glycosides based on HKUST-1-coated monolith solid-phase microextraction and direct analysis in real-time mass spectrometry.

    Science.gov (United States)

    Li, Xianjiang; Wang, Xin; Ma, Wen; Ai, Wanpeng; Bai, Yu; Ding, Li; Liu, Huwei

    2017-04-01

    Glycosides are a kind of highly important natural aromatic precursors in tobacco leaves. In this study, a novel HKUST-1-coated monolith dip-it sampler was designed for the fast and sensitive analysis of trace glycosides using direct analysis in real-time mass spectrometry. This device was prepared in two steps: in situ polymerization of monolith in a glass capillary of dip-it and layer-by-layer growth of HKUST-1 on the surface of monolith. Sufficient extraction was realized by immersing the tip to solution and in situ desorption was carried out by plasma direct analysis in real time. Compared with traditional solid-phase microextraction protocols, sample desorption was not needed anymore, and only extraction conditions were needed to be optimized in this method, including the gas temperature of direct analysis in real time, extraction time, and CH 3 COONH 4 additive concentration. This method enabled the simultaneous detection of six kinds of glycosides with the limits of detection of 0.02-0.05 μg/mL and the linear ranges covering two orders of magnitude with the limits of quantitation of 0.05-0.1 μg/mL. Moreover, the developed method was applied for the glycosides analysis of three tobacco samples, which only took about 2 s for every sample. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Direct profiling of phytochemicals in tulip tissues and in vivo monitoring of the change of carbohydrate content in tulip bulbs by probe electrospray ionization mass spectrometry.

    Science.gov (United States)

    Yu, Zhan; Chen, Lee Chuin; Suzuki, Hiroaki; Ariyada, Osamu; Erra-Balsells, Rosa; Nonami, Hiroshi; Hiraoka, Kenzo

    2009-12-01

    Probe electrospray ionization (PESI) is a recently developed ESI-based ionization technique which generates electrospray from the tip of a solid needle. In this study, we have applied PESI interfaced with a time of flight mass spectrometer (TOF-MS) for direct profiling of phytochemicals in a section of a tulip bulb in different regions, including basal plate, outer and inner rims of scale, flower bud and foliage leaves. Different parts of tulip petals and leaves have also been investigated. Carbohydrates, amino acids and other phytochemicals were detected. A series of in vivo PESI-MS experiments were carried out on the second outermost scales of four living tulip bulbs to monitoring the change of carbohydrate content during the first week of initial growth. The breakdown of carbohydrates was observed which was in accordance with previous reports achieved by other techniques. This study has indicated that PESI-MS can be used for rapid and direct analysis of phytochemicals in living biological systems with advantages of low sample consumption and little sample preparation. Therefore, PESI-MS can be a new choice for direct analysis/profiling of bioactive compounds or monitoring metabolic changes in living biological systems.

  17. Direct gravimetric measurements of the mass of the antarctic aerosol collected by high volume sampler: PM10 summer seasonal variation at Terra Nova Bay.

    Science.gov (United States)

    Truzzi, Cristina; Lambertucci, Luca; Illuminati, Silvia; Annibaldi, Anna; Scarponi, Giuseppe

    2005-01-01

    An on-site procedure was set up for direct gravimetric measurement of the mass of aerosol collected using high volume impactors (aerodynamic size cut point of 10 microm, PM10); this knowledge has hitherto been unavailable. Using a computerized microbalance in a clean chemistry laboratory, under controlled temperature (+/-0.5 degrees C) and relative humidity (+/-1%), continuous, long time filter mass measurements (hours) were carried out before and after exposure, after a 48 h minimun equilibration at the laboratory conditions. The effect of the electrostatic charge was exhausted in 30-60 min, after which stable measurements were obtained. Measurements of filters exposed for 7-11 days (1.13 m3 min(-1)) in a coastal site near Terra Nova Bay (December 2000 - February 2001), gave results for aerosol mass in the order of 10-20 mg (SD approximately 2 mg), corresponding to atmospheric concentrations of 0.52-1.27 microg m(-3). Data show a seasonal behaviour in the PM10 content with an increase during December - early January, followed by a net decrease. The above results compare well with estimates obtained from proxy data for the Antarctic Peninsula (0.30 microg m(-3)), the Ronne Ice Shelf (1.49 microg m(-3)), and the South Pole (0.18 microg m(-3), summer 1974-1975, and 0.37 microg m(-3), average summer seasons 1975-1976 and 1977-1978), and from direct gravimetric measurements recently obtained from medium volume samplers at McMurdo station (downwind 3.39 microg m(-3), upwind 4.15 microg m(-3)) and at King George Island (2.5 microg m(-3), summer, particle diameter <20 microm). This finding opens the way to the direct measurement of the chemical composition of the Antarctic aerosol and, in turn, to a better knowledge of the snow/air relationships as required for the reconstruction of the chemical composition of past atmospheres from deep ice core data.

  18. Determination of 20 trace elements and arsenic species for a realgar-containing traditional Chinese medicine Niuhuang Jiedu tablets by direct inductively coupled plasma-mass spectrometry and high performance liquid chromatography-inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Jin, Pengfei; Liang, Xiaoli; Xia, Lufeng; Jahouh, Farid; Wang, Rong; Kuang, Yongmei; Hu, Xin

    2016-01-01

    Niuhuang Jiedu tablet (NHJDT) is a realgar-containing traditional Chinese medicine. A direct inductively coupled plasma-mass spectrometry (ICP-MS) method for the simultaneous determination of 20 trace elements (Mg, K, Ca, Na, Fe, As, Zn, Sr, Ba, Cu, Mn, Ni, Pb, V, Cr, Se, Co, Mo, Cd, Hg) in NHJDT, as well as in water, gastric fluid and intestinal fluid was established. Meanwhile, a high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) method was developed for the determination of arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and for the identification of arsenobetaine (AsB) and arsenocholine (AsC) in these extracts. Both methods were fully validated in the respect of linearity, sensitivity, precision, stability and accuracy. The reliability of the ICP-MS method was further evaluated using a certified standard reference material prepared from dried tomato leaves (NIST, SRM 1572a). The analysis showed that some manufacturers formulated lower amount of realgar than required in the Chinese Pharmacopoeia (ChP) in their preparations. In addition, almost same extraction profiles for total As and inorganic As were found in water and in gastrointestinal fluids, while higher extraction rates for other 19 elements were observed in gastrointestinal fluids. Our findings show that the toxicities of Hg, Cu, Cd and Pb in NHJDP are low, while the real As toxicity in NHJDT should be deeply investigated. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Direct thermal desorption in the analysis of cheese volatiles by gas chromatography and gas chromatography-mass spectrometry: comparison with simultaneous distillation-extraction and dynamic headspace.

    Science.gov (United States)

    Valero, E; Sanz, J; Martínez-Castro, I

    2001-06-01

    Direct thermal desorption (DTD) has been used as a technique for extracting volatile components of cheese as a preliminary step to their gas chromatographic (GC) analysis. In this study, it is applied to different cheese varieties: Camembert, blue, Chaumes, and La Serena. Volatiles are also extracted using other techniques such as simultaneous distillation-extraction and dynamic headspace. Separation and identification of the cheese components are carried out by GC-mass spectrometry. Approximately 100 compounds are detected in the examined cheeses. The described results show that DTD is fast, simple, and easy to automate; requires only a small amount of sample (approximately 50 mg); and affords quantitative information about the main groups of compounds present in cheeses.

  20. Extinctions and Distances to Dark Clouds from 2MASS, MegaCam and IPHAS Surveys: LDN 1525 in the Direction of the Aur OB1 Association

    Directory of Open Access Journals (Sweden)

    Straižys V.

    2010-12-01

    Full Text Available The possibility of applying photometry from the 2MASS J, H, Ks, MegaCam u, g and IPHAS r, i, Hα surveys for determining the distance to the dark cloud LDN1525 (TGU 1192 in the direction of the Aur OB1 association is investigated using the red clump giants. The main dust cloud, probably related to the emission nebulae Sh 2-232, Sh 2-233, Sh 2-235, the molecular cloud and the association Aur OB2, is found to be located at a distance of 1.3 kpc from the Sun. The nebula Sh 2-231 can be an object of the Perseus arm. The maximum extinction AV found in the cloud is close to 6 mag.

  1. Evaluation of MALDI-TOF Mass Spectrometry and Sepsityper Kit™ for the Direct Identification of Organisms from Sterile Body Fluids in a Canadian Pediatric Hospital

    Directory of Open Access Journals (Sweden)

    Manal Tadros

    2013-01-01

    Full Text Available Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS can be used to identify bacteria directly from positive blood and sterile fluid cultures. The authors evaluated a commercially available kit – the Sepsityper Kit (Bruker Daltonik, Germany – and MALDI-TOF MS for the rapid identification of organisms from 80 flagged positive blood culture broths, of which 73 (91.2% were blood culture specimens and seven (8.7% were cerebrospinal fluid specimens, in comparison with conventional identification methods. Correct identification to the genus and species levels was obtained in 75 of 80 (93.8% and 39 of 50 (78% blood culture broths, respectively. Applying the blood culture analysis module, a newly developed software tool, improved the species identification of Gram-negative organisms from 94.7% to 100% and of Gram-positive organisms from 66.7% to 70%.

  2. Galaxy-M: a Galaxy workflow for processing and analyzing direct infusion and liquid chromatography mass spectrometry-based metabolomics data.

    Science.gov (United States)

    Davidson, Robert L; Weber, Ralf J M; Liu, Haoyu; Sharma-Oates, Archana; Viant, Mark R

    2016-01-01

    Metabolomics is increasingly recognized as an invaluable tool in the biological, medical and environmental sciences yet lags behind the methodological maturity of other omics fields. To achieve its full potential, including the integration of multiple omics modalities, the accessibility, standardization and reproducibility of computational metabolomics tools must be improved significantly. Here we present our end-to-end mass spectrometry metabolomics workflow in the widely used platform, Galaxy. Named Galaxy-M, our workflow has been developed for both direct infusion mass spectrometry (DIMS) and liquid chromatography mass spectrometry (LC-MS) metabolomics. The range of tools presented spans from processing of raw data, e.g. peak picking and alignment, through data cleansing, e.g. missing value imputation, to preparation for statistical analysis, e.g. normalization and scaling, and principal components analysis (PCA) with associated statistical evaluation. We demonstrate the ease of using these Galaxy workflows via the analysis of DIMS and LC-MS datasets, and provide PCA scores and associated statistics to help other users to ensure that they can accurately repeat the processing and analysis of these two datasets. Galaxy and data are all provided pre-installed in a virtual machine (VM) that can be downloaded from the GigaDB repository. Additionally, source code, executables and installation instructions are available from GitHub. The Galaxy platform has enabled us to produce an easily accessible and reproducible computational metabolomics workflow. More tools could be added by the community to expand its functionality. We recommend that Galaxy-M workflow files are included within the supplementary information of publications, enabling metabolomics studies to achieve greater reproducibility.

  3. Simulation study of the effect of molar mass dispersity on domain interfacial roughness in lamellae forming block copolymers for directed self-assembly

    International Nuclear Information System (INIS)

    Peters, Andrew J; Lawson, Richard A; Nation, Benjamin D; Ludovice, Peter J; Henderson, Clifford L

    2015-01-01

    A coarse-grained molecular dynamics model was used to study the thin film self-assembly and resulting pattern properties of block copolymer (BCP) systems with various molar mass dispersities. Diblock copolymers (i.e. A–b–B type) were simulated in an aligned lamellar state, which is one of the most common patterns of potential use for integrated circuit fabrication via directed self-assembly of BCPs. Effects of the molar mass dispersity (Ð) on feature pitch and interfacial roughness, which are critical lithographic parameters that have a direct impact on integrated circuit performance, were simulated. It was found that for a realistic distribution of polymer molecular weights, modeled by a Wesslau distribution, both line edge roughness (LER) and line width roughness (LWR) increase approximately linearly with increasing Ð, up to ∼45% of the monodisperse value at Ð = 1.5. Mechanisms of compensation for increased A–A and B–B roughness were considered. It was found that long and short chain positions were not correlated, and that long chains were significantly deformed in shape. The increase in LWR was due to the increase in LER and a constant correlation between the line edges. Unaligned systems show a correlation between domain width and local molecular weight, while systems aligned on an alternating pattern of A and B lines did not show any correlation. When the volume fraction of individual chains was allowed to vary, similar results were found when considering the Ð of the block as opposed to the Ð of the entire system. (paper)

  4. Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples.

    Science.gov (United States)

    Goacher, Robyn E; Braham, Erick J; Michienzi, Courtney L; Flick, Robert M; Yakunin, Alexander F; Master, Emma R

    2017-12-29

    The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion. © 2017 Scandinavian Plant Physiology Society.

  5. Use of microextraction by packed sorbent directly coupled to an electron ionization single quadrupole mass spectrometer as an alternative for non-separative determinations.

    Science.gov (United States)

    Casas Ferreira, Ana María; Moreno Cordero, Bernardo; Pérez Pavón, José Luis

    2017-02-01

    Sometimes it is not necessary to separate the individual compounds of a sample to resolve an analytical problem, it is enough to obtain a signal profile of the sample formed by all the components integrating it. Within this strategy, electronic noses based on the direct coupling of a headspace sampler with a mass spectrometer (HS-MS) have been proposed. Nevertheless, this coupling is not suitable for the analysis of non-volatile compounds. In order to propose an alternative to HS-MS determinations for non-volatile compounds, here we present the first 'proof of concept' use of the direct coupling of microextraction by packed sorbents (MEPS) to a mass spectrometer device using an electron ionization (EI) and a single quadrupole as ionization source and analyzer, respectively. As target compounds, a set of analytes with different physic-chemical properties were evaluated (2-ethyl-1-hexanol, styrene, 2-heptanone, among others). The use of MEPS extraction present many advantages, such as it is fast, simple, easy to automate and requires small volumes of sample and organic solvents. Moreover, MEPS cartridges are re-usable as samples can be extracted more than 100 times using the same syringe. In order to introduce into the system all the elution volume from the MEPS extraction, a programmable temperature vaporizer (PTV) is proposed as the injector device. Results obtained with the proposed methodology (MEPS-PTV/MS) were compared with the ones obtained based on the separative scheme, i.e. using gas chromatography separation (MEPS-PTV-GC/MS), and both methods provided similar results. Limits of detection were found to be between 3.26 and 146.6μgL -1 in the non-separative scheme and between 0.02 and 1.72μgL -1 when the separative methodology was used. Repeatability and reproducibility were evaluated with values below 17% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. High throughput screening of phenoxy carboxylic acids with dispersive solid phase extraction followed by direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Wang, Jiaqin; Zhu, Jun; Si, Ling; Du, Qi; Li, Hongli; Bi, Wentao; Chen, David Da Yong

    2017-12-15

    A high throughput, low environmental impact methodology for rapid determination of phenoxy carboxylic acids (PCAs) in water samples was developed by combing dispersive solid phase extraction (DSPE) using velvet-like graphitic carbon nitride (V-g-C 3 N 4 ) and direct analysis in real time mass spectrometry (DART-MS). Due to the large surface area and good dispersity of V-g-C 3 N 4 , the DSPE of PCAs in water was completed within 20 s, and the elution of PCAs was accomplished in 20 s as well using methanol. The eluents were then analyzed and quantified using DART ionization source coupled to a high resolution mass spectrometer, where an internal standard was added in the samples. The limit of detection ranged from 0.5 ng L -1 to 2 ng L -1 on the basis of 50 mL water sample; the recovery 79.9-119.1%; and the relative standard deviation 0.23%-9.82% (≥5 replicates). With the ease of use and speed of DART-MS, the whole protocol can complete within mere minutes, including sample preparation, extraction, elution, detection and quantitation. The methodology developed here is simple, fast, sensitive, quantitative, requiring little sample preparation and consuming significantly less toxic organic solvent, which can be used for high throughput screening of PCAs and potentially other contaminants in water. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Direct analysis in real time mass spectrometry and multivariate data analysis: a novel approach to rapid identification of analytical markers for quality control of traditional Chinese medicine preparation.

    Science.gov (United States)

    Zeng, Shanshan; Wang, Lu; Chen, Teng; Wang, Yuefei; Mo, Huanbiao; Qu, Haibin

    2012-07-06

    The paper presents a novel strategy to identify analytical markers of traditional Chinese medicine preparation (TCMP) rapidly via direct analysis in real time mass spectrometry (DART-MS). A commonly used TCMP, Danshen injection, was employed as a model. The optimal analysis conditions were achieved by measuring the contribution of various experimental parameters to the mass spectra. Salvianolic acids and saccharides were simultaneously determined within a single 1-min DART-MS run. Furthermore, spectra of Danshen injections supplied by five manufacturers were processed with principal component analysis (PCA). Obvious clustering was observed in the PCA score plot, and candidate markers were recognized from the contribution plots of PCA. The suitability of potential markers was then confirmed by contrasting with the results of traditional analysis methods. Using this strategy, fructose, glucose, sucrose, protocatechuic aldehyde and salvianolic acid A were rapidly identified as the markers of Danshen injections. The combination of DART-MS with PCA provides a reliable approach to the identification of analytical markers for quality control of TCMP. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Direct determination of fatty acid esters of 3-chloro-1, 2-propanediol in edible vegetable oils by isotope dilution - ultra high performance liquid chromatography - triple quadrupole mass spectrometry.

    Science.gov (United States)

    Li, Heli; Chen, Dawei; Miao, Hong; Zhao, Yunfeng; Shen, Jianzhong; Wu, Yongning

    2015-09-04

    A selective and sensitive ultra-high performance liquid chromatography - triple quadrupole mass spectrometry (UHPLC-MS/MS) method coupled with matrix solid phase dispersion (MSPD) extraction was developed for the direct determination of fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD esters) in edible vegetable oils. The method integrated the isotope dilution technique, MSPD extraction and UHPLC - MS/MS analysis with multi-reaction monitoring mode (MRM). Matrix-matched calibration curves showed good linearity within the range of 0.01-10mgL(-1) with the correlation coefficient not less than 0.999. Limits of detection (LODs) and limit of quantification (LOQs) of the 3-MCPD esters fell into the range of 0.0001-0.02mgkg(-1) and 0.0004-0.05mgkg(-1), respectively. The recoveries for the spiked extra virgin olive oils ranged from 94.4% to 108.3%, with the relative standard deviations (RSD) ranging from 0.6% to 10.5%. The method was applied for the oil sample (T2642) of the official Food Analysis Performance Assessment Scheme (FAPAS) in 2014 and other real samples from supermarket, and the results showed that the present method was comparative to the gas chromatography-mass spectrometry (GC-MS) method based on the improved German Society for Fat Science (DGF) standard method C-III 18 (09) except for palm oil. Copyright © 2015. Published by Elsevier B.V.

  9. Capillary column switching restricted-access media-liquid chromatography-electrospray ionization-tandem mass spectrometry system for simultaneous and direct analysis of drugs in biofluids.

    Science.gov (United States)

    Santos-Neto, Alvaro J; Markides, Karin E; Sjöberg, Per J R; Bergquist, Jonas; Lancas, Fernando M

    2007-08-15

    Capillary online restricted-access media-liquid chromatography-electrospray ionization-tandem mass spectrometry (RAM-LC-ESI-MS/MS) for direct analysis of drugs and metabolites spiked in biological fluids was developed. Using a column switching setup it was possible to perform effective sample preparation and analysis of raw biological fluids (plasma and urine) without matrix effects in the electrospray mass spectrometric detection step. The peak focusing efficiency of the extraction column was more effective in backflush compared to foreflush mode. The system was able to concentrate diminished samples of polar drugs and their metabolites reaching quantifiable results as low as 1 ng/mL utilizing a sample volume of only 333 nL of biofluids. New column hardware was developed to circumvent clogging problems experienced with plasma injections. The glass fiber filter frit, which is commonly used, was replaced with a short piece of 20 microm i.d. fused silica capillary. The extraction columns were able to handle up to 60 injections and showed a high loading capacity, making the saturation of the MS detector the limiting factor on the linear dynamic range. The simultaneous separation and detection of 10 drugs and metabolites was obtained in 8 min of analysis, including the online sample preparation and enrichment step.

  10. Predictors Associated with Increase in Skeletal Muscle Mass after Sustained Virological Response in Chronic Hepatitis C Treated with Direct Acting Antivirals

    Directory of Open Access Journals (Sweden)

    Kazunori Yoh

    2017-10-01

    Full Text Available Aims: We aimed to examine changes in skeletal muscle mass in chronic hepatitis C (CHC patients undergoing interferon (IFN-free direct acting antivirals (DAAs therapy who achieved sustained virological response (SVR. Patients and methods: A total of 69 CHC patients treated with DAAs were analyzed. We compared the changes in skeletal muscle index (SMI using bio-impedance analysis at baseline and SMI at SVR. SMI was calculated as the sum of skeletal muscle mass in upper and lower extremities divided by height squared (cm2/m2. Further, we identified pretreatment parameters contributing to the increased SMI at SVR. Results: SMI in males at baseline ranged from 6.73 to 9.08 cm2/m2 (median, 7.65 cm2/m2, while that in females ranged from 4.45 to 7.27 cm2/m2 (median, 5.81 cm2/m2. At SVR, 36 patients (52.2% had increased SMI as compared with baseline. In the univariate analysis, age (p = 0.0392, hyaluronic acid (p = 0.0143, and branched-chain amino acid to tyrosine ratio (BTR (p = 0.0024 were significant pretreatment factors linked to increased SMI at SVR. In the multivariate analysis, only BTR was an independent predictor linked to the increased SMI at SVR (p = 0.0488. Conclusion: Pretreatment BTR level can be helpful for predicting increased SMI after SVR in CHC patients undergoing IFN-free DAAs therapy.

  11. Direct identification of bacteria in blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a new methodological approach.

    Science.gov (United States)

    Kroumova, Vesselina; Gobbato, Elisa; Basso, Elisa; Mucedola, Luca; Giani, Tommaso; Fortina, Giacomo

    2011-08-15

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently been demonstrated to be a powerful tool for the rapid identification of bacteria from growing colonies. In order to speed up the identification of bacteria, several authors have evaluated the usefulness of this MALDI-TOF MS technology for the direct and quick identification bacteria from positive blood cultures. The results obtained so far have been encouraging but have also shown some limitations, mainly related to the bacterial growth and to the presence of interference substances belonging to the blood cultures. In this paper, we present a new methodological approach that we have developed to overcome these limitations, based mainly on an enrichment of the sample into a growing medium before the extraction process, prior to mass spectrometric analysis. The proposed method shows important advantages for the identification of bacterial strains, yielding an increased identification score, which gives higher confidence in the results. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry of targeted carotenoids from red Habanero peppers (Capsicum chinense Jacq.).

    Science.gov (United States)

    Zoccali, Mariosimone; Giuffrida, Daniele; Dugo, Paola; Mondello, Luigi

    2017-10-01

    Recently, supercritical fluid chromatography coupled to mass spectrometry has gained attention as a fast and useful technology applied to the carotenoids analysis. However, no reports are available in the literature on the direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry. The aim of this research was the development of an online method coupling supercritical fluid extraction and supercritical fluid chromatography for a detailed targeted native carotenoids characterization in red habanero peppers. The online nature of the system, compared to offline approaches, improves run-to-run precision, enables the setting of batch-type applications, and reduces the risks of sample contamination. The extraction has been optimized using different temperatures, starting from 40°C up to 80°C. Multiple extractions, until depletion, were performed on the same sample to evaluate the extraction yield. The range of the first extraction yield, carried out at 80°C, which was the best extraction temperature, was 37.4-65.4%, with a %CV range of 2-12. Twenty-one targeted analytes were extracted and identified by the developed methodology in less than 17 min, including free, monoesters, and diesters carotenoids, in a very fast and efficient way. Quantification of the β-carotene was carried out by using the optimized conditions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Direct atmospheric pressure chemical ionization-tandem mass spectrometry for the continuous real-time trace analysis of benzene, toluene, ethylbenzene, and xylenes in ambient air.

    Science.gov (United States)

    Badjagbo, Koffi; Picard, Pierre; Moore, Serge; Sauvé, Sébastien

    2009-05-01

    Real-time monitoring of benzene, toluene, ethylbenzene, and xylenes (BTEX) in ambient air is essential for the early warning detection associated with the release of these hazardous chemicals and in estimating the potential exposure risks to humans and the environment. We have developed a tandem mass spectrometry (MS/MS) method for continuous real-time determination of ambient trace levels of BTEX. The technique is based on the sampling of air via an atmospheric pressure inlet directly into the atmospheric pressure chemical ionization (APCI) source. The method is linear over four orders of magnitude, with correlation coefficients greater than 0.996. Low limits of detection in the range 1-2 microg/m(3) are achieved for BTEX. The reliability of the method was confirmed through the evaluation of quality parameters such as repeatability and reproducibility (relative standard deviation below 8% and 10%, respectively) and accuracy (over 95%). The applicability of this method to real-world samples was evaluated through measurements of BTEX levels in real ambient air samples and results were compared with a reference GC-FID method. This direct APCI-MS/MS method is suitable for real-time analysis of BTEX in ambient air during regulation surveys as well as for the monitoring of industrial processes or emergency situations.

  14. Direct trace-elemental analysis of urine samples by laser ablation-inductively coupled plasma mass spectrometry after sample deposition on clinical filter papers.

    Science.gov (United States)

    Aramendía, Maite; Rello, Luis; Vanhaecke, Frank; Resano, Martín

    2012-10-16

    Collection of biological fluids on clinical filter papers shows important advantages from a logistic point of view, although analysis of these specimens is far from straightforward. Concerning urine analysis, and particularly when direct trace elemental analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) is aimed at, several problems arise, such as lack of sensitivity or different distribution of the analytes on the filter paper, rendering obtaining reliable quantitative results quite difficult. In this paper, a novel approach for urine collection is proposed, which circumvents many of these problems. This methodology consists on the use of precut filter paper discs where large amounts of sample can be retained upon a single deposition. This provides higher amounts of the target analytes and, thus, sufficient sensitivity, and allows addition of an adequate internal standard at the clinical lab prior to analysis, therefore making it suitable for a strategy based on unsupervised sample collection and ulterior analysis at referral centers. On the basis of this sampling methodology, an analytical method was developed for the direct determination of several elements in urine (Be, Bi, Cd, Co, Cu, Ni, Sb, Sn, Tl, Pb, and V) at the low μg L(-1) level by means of LA-ICPMS. The method developed provides good results in terms of accuracy and LODs (≤1 μg L(-1) for most of the analytes tested), with a precision in the range of 15%, fit-for-purpose for clinical control analysis.

  15. Ultra trace determination of 31 pesticides in water samples by direct injection-rapid resolution liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Díaz, Laura; Llorca-Pórcel, Julio; Valor, Ignacio

    2008-08-22

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the detection of pesticides in tap and treated wastewater was developed and validated according to the ISO/IEC 17025:1999. Key features of this method include direct injection of 100 microL of sample, an 11 min separation by means of a rapid resolution liquid chromatography system with a 4.6 mm x 50 mm, 1.8 microm particle size reverse phase column and detection by electrospray ionization (ESI) MS-MS. The limits of detection were below 15 ng L(-1) and correlation coefficients for the calibration curves in the range of 30-2000 ng L(-1) were higher than 0.99. Precision was always below 20% and accuracy was confirmed by external evaluation. The main advantages of this method are direct injection of sample without preparative procedures and low limits of detection that fulfill the requirements established by the current European regulations governing pesticide detection.

  16. Occupancy of a C2-C2 type 'zinc-finger' protein domain by copper. Direct observation by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Hutchens, T W; Allen, M H; Li, C M; Yip, T T

    1992-09-07

    The metal ion specificity of most 'zinc-finger' metal binding domains is unknown. The human estrogen receptor protein contains two different C2-C2 type 'zinc-finger' sequences within its DNA-binding domain (ERDBD). Copper inhibits the function of this protein by mechanisms which remain unclear. We have used electrospray ionization mass spectrometry to evaluate directly the 71-residue ERDBD (K180-M250) in the absence and presence of Cu(II) ions. The ERDBD showed a high affinity for Cu and was completely occupied with 4 Cu bound; each Cu ion was evidently bound to only two ligand residues (net loss of only 2 Da per bound Cu). The Cu binding stoichiometry was confirmed by atomic absorption. These results (i) provide the first direct physical evidence for the ability of the estrogen receptor DNA-binding domain to bind Cu and (ii) document a twofold difference in the Zn- and Cu-binding capacity. Differences in the ERDBD domain structure with bound Zn and Cu are predicted. Given the relative intracellular contents of Zn and Cu, our findings demonstrate the need to investigate further the Cu occupancy of this and other zinc-finger domains both in vitro and in vivo.

  17. Rapid identification of pathogens directly from blood culture bottles by Bruker matrix-assisted laser desorption laser ionization-time of flight mass spectrometry versus routine methods.

    Science.gov (United States)

    Jamal, Wafaa; Saleem, Rola; Rotimi, Vincent O

    2013-08-01

    The use of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identification of microorganisms directly from blood culture is an exciting dimension to the microbiologists. We evaluated the performance of Bruker SepsiTyper kit™ (STK) for direct identification of bacteria from positive blood culture. This was done in parallel with conventional methods. Nonrepetitive positive blood cultures from 160 consecutive patients were prospectively evaluated by both methods. Of 160 positive blood cultures, the STK identified 114 (75.6%) isolates and routine conventional method 150 (93%). Thirty-six isolates were misidentified or not identified by the kit. Of these, 5 had score of >2.000 and 31 had an unreliable low score of <1.7. Four of 8 yeasts were identified correctly. The average turnaround time using the STK was 35 min, including extraction steps and 30:12 to 36:12 h with routine method. The STK holds promise for timely management of bacteremic patients. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Evaluation of MALDI-TOF mass spectrometry and Sepsityper Kit™ for the direct identification of organisms from sterile body fluids in a Canadian pediatric hospital.

    Science.gov (United States)

    Tadros, Manal; Petrich, Astrid

    2013-01-01

    Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to identify bacteria directly from positive blood and sterile fluid cultures. The authors evaluated a commercially available kit - the Sepsityper Kit (Bruker Daltonik, Germany) - and MALDI-TOF MS for the rapid identification of organisms from 80 flagged positive blood culture broths, of which 73 (91.2%) were blood culture specimens and seven (8.7%) were cerebrospinal fluid specimens, in comparison with conventional identification methods. Correct identification to the genus and species levels was obtained in 75 of 80 (93.8%) and 39 of 50 (78%) blood culture broths, respectively. Applying the blood culture analysis module, a newly developed software tool, improved the species identification of Gram-negative organisms from 94.7% to 100% and of Gram-positive organisms from 66.7% to 70%. MALDI-TOF MS is a promising tool for the direct identification of organisms cultured from sterile sites.

  19. Direct infusion electrospray ionization–ion mobility–mass spectrometry for comparative profiling of fatty acids based on stable isotope labeling

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Jiapeng, E-mail: jpleng@126.com [Department of Chemical Engineering, North University of China, Taiyuan 030051 (China); Guan, Qing [Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center (FUSCC), Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Sun, Tuanqi, E-mail: tuanqisun@163.com [Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center (FUSCC), Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Wang, Haoyang [National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032 (China); Cui, Jianlan; Liu, Qinghao [Department of Chemical Engineering, North University of China, Taiyuan 030051 (China); Zhang, Zhixu; Zhang, Manyu [Agilent Technologies China Co., Ltd, Shanghai 200080 (China); Guo, Yinlong, E-mail: ylguo@sioc.ac.cn [National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032 (China)

    2015-08-05

    A rapid method for fatty acids (FAs) comparative profiling based on carboxyl-specific stable isotope labeling (SIL) and direct infusion electrospray ionization–ion mobility–mass spectrometry (ESI–IM–MS) is established. The design of the method takes advantage of the three-dimensional characteristics of IM–MS including drift time, m/z and ion intensity, for comparison of d0-/d6-2,4-dimethoxy-6-piperazin-1-yl pyrimidine (DMPP)-labeled FAs. In particular, without chromatographic separation, the method allowed direct FAs profiling in complex samples due to the advantageous priority of DMPP in signal enhancement as well as the extra resolution that IM–MS offered. Additionally, the d0-/d6-DMPP-labeled FAs showed expected features, including very similar drift times, 6 Da mass deviations, specific reporter ions, similar MS responses, and adherence to the drift time rule regarding the influence of carbon chain length and unsaturation on relative drift times. Therefore, the introduction of isotope analogs minimized the matrix effect and variations in quantification and ensured accurate identification of non-targeted FAs by those typical features. Peak intensity ratios between d0-/d6-DMPP-labeled ions were subsequently used in relative quantification for the detected FAs. The established strategy has been applied successfully in the rapid profiling of trace free FAs between normal and cancerous human thyroid tissues. Sixteen free FAs were found with the increased level with a statistically significant difference (p < 0.05) compared to the normal tissue samples. The integrated SIL technique and ESI–IM–MS are expected to serve as an alternative tool for high-throughput analysis of FAs in complex samples. - Highlights: • A novel method based on IM–MS and SIL was developed for FAs comparative profiling. • Without LC separation, the method allowed direct infusion profiling of FAs in complex samples. • Both of the efficiency and accuracy for FAs analyses

  20. Effect-directed fingerprints of 77 botanical extracts via a generic high-performance thin-layer chromatography method combined with assays and mass spectrometry.

    Science.gov (United States)

    Krüger, S; Hüsken, L; Fornasari, R; Scainelli, I; Morlock, G E

    2017-12-22

    Quantitative effect-directed profiles of 77 industrially and freshly extracted botanicals like herbs, spices, vegetables and fruits, widely used as food ingredients, dietary supplements or traditional medicine, gave relevant information on their quality. It allows the assessment of food, dietary supplements and phytomedicines with regard to potential health-promoting activities. In contrary to sum parameter assays and targeted analysis, chromatography combined with effect-directed analysis allows fast assignment of single active compounds and evaluation of their contribution to the overall activity, originating from a food or botanical sample. High-performance thin-layer chromatography was hyphenated with UV/Vis/FLD detection and effect-directed analysis, using the 2,2-diphenyl-1-picrylhydrazyl radical, Gram-negative Aliivibrio fischeri, Gram-positive Bacillus subtilis, acetylcholinesterase and tyrosinase assays. Bioactive compounds of interest were eluted using an elution head-based interface and further characterized by electrospray ionization (high-resolution) mass spectrometry. This highly streamlined workflow resulted in a hyphenated HPTLC-UV/Vis/FLD-EDA-ESI + /ESI - -(HR)MS method. The excellent quantification power of the method was shown on three compounds. For rosmarinic acid, contents ranged from 4.5mg/g (rooibos) to 32.6mg/g (rosemary), for kaempferol-3-glucoside from 0.6mg/g (caraway) to 4.4mg/g (wine leaves), and for quercetin-3-glucoside from 1.1mg/g (hawthorn leaves) to 17.7mg/g (thyme). Three mean repeatabilities (%RSD) over 18 quantifications for the three compounds were ≤2.2% and the mean intermediate precision over three different days (%RSD, n=3) was 5.2%. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Development of iodine based impinger solutions for the efficient capture of Hg{sup 0} using direct injection nebulization-inductively coupled plasma mass spectrometry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, E.; Lee, T.G.; Biswas, P.; Zhuang, Y. [US Environmental Protection Agency, Cincinnati, OH (USA). National Exposure Research Laboratory

    2001-09-15

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hg{sup 0}) in EPA Method 5 type sampling. An iodine based impinger solution proved to be very efficient for Hg{sup 0} capture and was amenable to direct analysis by DIN-ICP/MS. Hg{sup 0} capture efficiency using aqueous iodine (I{sub 3}{sup -}) was comparable to Hg{sup 0} capture using acidified potassium permanganate impinger solutions which were analyzed by cold vapor atomic absorption spectrometry (CVAAS) with greater than 98% capture of Hg{sup 0} in the oxidizing impinger. Using DIN-ICP/MS, it was demonstrated for the first time that iodine can be generated just prior to impinger sampling for efficiently oxidizing Hg{sup 0} and retailing it in solution as HgI{sub 4}{sup 2-}. Due to the increased interest in Hg speciation from combustion sources and the potential for using DIN-ICP/MS for multiple metals analyses, an impinger sampling train for gaseous Hg speciation and multiple metals analyses using DIN-ICP/MS analyses is presented. The unique feature of such a sampling train is that each impinger solution in the series is amenable to direct analysis by DIN-ICP/MS. A bituminous coal was combusted in a bench scale coal system, and gaseous Hg species (oxidized and elemental) were determined using the proposed impinger train. The DIN-ICP/Ms instrumental detection limit was 0.003 ppb, and MDLs ranged from 0.007 to 0.116 {mu}g/L (ppb) in a variety of impinger solutions used for Hg capture. 33 refs., 5 figs., 7 tabs.

  2. Metabolic profiling of potential lung cancer biomarkers using bronchoalveolar lavage fluid and the integrated direct infusion/ gas chromatography mass spectrometry platform.

    Science.gov (United States)

    Callejón-Leblic, Belén; García-Barrera, Tamara; Grávalos-Guzmán, Jesús; Pereira-Vega, Antonio; Gómez-Ariza, José Luis

    2016-08-11

    Lung cancer is one of the ten most common causes of death worldwide, so that the search for early diagnosis biomarkers is a very challenging task. Bronchoalveolar lavage fluid (BALF) provides information on cellular and biochemical epithelial surface of the lower respiratory tract constituents and no previous metabolomic studies have been performed with BALF samples from patients with lung cancer. Therefore, this fluid has been explored looking for new contributions in lung cancer metabolism. In this way, two complementary metabolomics techniques based on direct infusion high resolution mass spectrometry (DI-ESI-QTOF-MS) and gas chromatography mass spectrometry (GC-MS) have been applied to compare statistically differences between lung cancer (LC) and control (C) BALF samples, using partial least square discriminant analysis (PLS-DA) in order to find and identify potential biomarkers of the disease. A total of 42 altered metabolites were found in BALF from LC. The metabolic pathway analysis showed that glutamate and glutamine metabolism pathway was mainly altered by this disease. In addition, we assessed the biomarker specificity and sensitivity according to the area under the receiver operator characteristic (ROC) curves, indicating that glycerol and phosphoric acid were potential sensitive and specific biomarkers for lung cancer diagnosis and prognosis. The search for early diagnosis of lung cancer is a very challenging task because of the high mortality associated to this disease and its critical linkage to the initiation of treatment. Bronchoalveolar lavage fluid provides information on cellular and biochemical epithelial surface of the lower respiratory tract constituents and no previous metabolomic studies have been performed with BALF samples from patients with lung cancer. Since BALF is in close interaction with lung tissue it is a more representative sample of lung status than other peripheral biofluids as blood or urine studied in previous works

  3. Looking into individual coffee beans during the roasting process: direct micro-probe sampling on-line photo-ionisation mass spectrometric analysis of coffee roasting gases.

    Science.gov (United States)

    Hertz-Schünemann, Romy; Streibel, Thorsten; Ehlert, Sven; Zimmermann, Ralf

    2013-09-01

    A micro-probe (μ-probe) gas sampling device for on-line analysis of gases evolving in confined, small objects by single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) was developed. The technique is applied for the first time in a feasibility study to record the formation of volatile and flavour compounds during the roasting process within (inside) or in the direct vicinity (outside) of individual coffee beans. A real-time on-line analysis of evolving volatile and semi-volatile organic compounds (VOC and SVOC) as they are formed under the mild pyrolytic conditions of the roasting process was performed. The soft-ionisation mass spectra depict a molecular ion signature, which is well corresponding with the existing knowledge of coffee roasting and evolving compounds. Additionally, thereby it is possible to discriminate between Coffea arabica (Arabica) and Coffea canephora (Robusta). The recognized differences in the roasting gas profiles reflect the differences in the precursor composition of the coffee cultivars very well. Furthermore, a well-known set of marker compounds for Arabica and Robusta, namely the lipids kahweol and cafestol (detected in their dehydrated form at m/z 296 and m/z 298, respectively) were observed. If the variation in time of different compounds is observed, distinctly different evolution behaviours were detected. Here, phenol (m/z 94) and caffeine (m/z 194) are exemplary chosen, whereas phenol shows very sharp emission peaks, caffeine do not have this highly transient behaviour. Finally, the changes of the chemical signature as a function of the roasting time, the influence of sampling position (inside, outside) and cultivar (Arabica, Robusta) is investigated by multivariate statistics (PCA). In summary, this pilot study demonstrates the high potential of the measurement technique to enhance the fundamental knowledge of the formation processes of volatile and semi-volatile flavour compounds inside the individual coffee bean.

  4. Direct glycan structure determination of intact N-linked glycopeptides by low-energy collision-induced dissociation tandem mass spectrometry and predicted spectral library searching.

    Science.gov (United States)

    Pai, Pei-Jing; Hu, Yingwei; Lam, Henry

    2016-08-31

    Intact glycopeptide MS analysis to reveal site-specific protein glycosylation is an important frontier of proteomics. However, computational tools for analyzing MS/MS spectra of intact glycopeptides are still limited and not well-integrated into existing workflows. In this work, a new computational tool which combines the spectral library building/searching tool, SpectraST (Lam et al. Nat. Methods2008, 5, 873-875), and the glycopeptide fragmentation prediction tool, MassAnalyzer (Zhang et al. Anal. Chem.2010, 82, 10194-10202) for intact glycopeptide analysis has been developed. Specifically, this tool enables the determination of the glycan structure directly from low-energy collision-induced dissociation (CID) spectra of intact glycopeptides. Given a list of possible glycopeptide sequences as input, a sample-specific spectral library of MassAnalyzer-predicted spectra is built using SpectraST. Glycan identification from CID spectra is achieved by spectral library searching against this library, in which both m/z and intensity information of the possible fragmentation ions are taken into consideration for improved accuracy. We validated our method using a standard glycoprotein, human transferrin, and evaluated its potential to be used in site-specific glycosylation profiling of glycoprotein datasets from LC-MS/MS. In addition, we further applied our method to reveal, for the first time, the site-specific N-glycosylation profile of recombinant human acetylcholinesterase expressed in HEK293 cells. For maximum usability, SpectraST is developed as part of the Trans-Proteomic Pipeline (TPP), a freely available and open-source software suite for MS data analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Performance assessment of two lysis methods for direct identification of yeasts from clinical blood cultures using MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Jeddi, Fakhri; Yapo-Kouadio, Gisèle Cha; Normand, Anne-Cécile; Cassagne, Carole; Marty, Pierre; Piarroux, Renaud

    2017-02-01

    In cases of fungal infection of the bloodstream, rapid species identification is crucial to provide adapted therapy and thereby ameliorate patient outcome. Currently, the commercial Sepsityper kit and the sodium-dodecyl sulfate (SDS) method coupled with MALDI-TOF mass spectrometry are the most commonly reported lysis protocols for direct identification of fungi from positive blood culture vials. However, the performance of these two protocols has never been compared on clinical samples. Accordingly, we performed a two-step survey on two distinct panels of clinical positive blood culture vials to identify the most efficient protocol, establish an appropriate log score (LS) cut-off, and validate the best method. We first compared the performance of the Sepsityper and the SDS protocols on 71 clinical samples. For 69 monomicrobial samples, mass spectrometry LS values were significantly higher with the SDS protocol than with the Sepsityper method (P < .0001), especially when the best score of four deposited spots was considered. Next, we established the LS cut-off for accurate identification at 1.7, based on specimen DNA sequence data. Using this LS cut-off, 66 (95.6%) and 46 (66.6%) isolates were correctly identified at the species level with the SDS and the Sepsityper protocols, respectively. In the second arm of the survey, we validated the SDS protocol on an additional panel of 94 clinical samples. Ninety-two (98.9%) of 93 monomicrobial samples were correctly identified at the species level (median LS = 2.061). Overall, our data suggest that the SDS method yields more accurate species identification of yeasts, than the Sepsityper protocol. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Direct analysis of ultra-trace semiconductor gas by inductively coupled plasma mass spectrometry coupled with gas to particle conversion-gas exchange technique.

    Science.gov (United States)

    Ohata, Masaki; Sakurai, Hiromu; Nishiguchi, Kohei; Utani, Keisuke; Günther, Detlef

    2015-09-03

    An inductively coupled plasma mass spectrometry (ICPMS) coupled with gas to particle conversion-gas exchange technique was applied to the direct analysis of ultra-trace semiconductor gas in ambient air. The ultra-trace semiconductor gases such as arsine (AsH3) and phosphine (PH3) were converted to particles by reaction with ozone (O3) and ammonia (NH3) gases within a gas to particle conversion device (GPD). The converted particles were directly introduced and measured by ICPMS through a gas exchange device (GED), which could penetrate the particles as well as exchange to Ar from either non-reacted gases such as an air or remaining gases of O3 and NH3. The particle size distribution of converted particles was measured by scanning mobility particle sizer (SMPS) and the results supported the elucidation of particle agglomeration between the particle converted from semiconductor gas and the particle of ammonium nitrate (NH4NO3) which was produced as major particle in GPD. Stable time-resolved signals from AsH3 and PH3 in air were obtained by GPD-GED-ICPMS with continuous gas introduction; however, the slightly larger fluctuation, which could be due to the ionization fluctuation of particles in ICP, was observed compared to that of metal carbonyl gas in Ar introduced directly into ICPMS. The linear regression lines were obtained and the limits of detection (LODs) of 1.5 pL L(-1) and 2.4 nL L(-1) for AsH3 and PH3, respectively, were estimated. Since these LODs revealed sufficiently lower values than the measurement concentrations required from semiconductor industry such as 0.5 nL L(-1) and 30 nL L(-1) for AsH3 and PH3, respectively, the GPD-GED-ICPMS could be useful for direct and high sensitive analysis of ultra-trace semiconductor gas in air. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Development of a Microfluidic Open Interface with Flow Isolated Desorption Volume for the Direct Coupling of SPME Devices to Mass Spectrometry.

    Science.gov (United States)

    Tascon, Marcos; Alam, Md Nazmul; Gómez-Ríos, Germán Augusto; Pawliszyn, Janusz

    2018-02-20

    Technologies that efficiently integrate the sampling and sample preparation steps with direct introduction to mass spectrometry (MS), providing simple and sensitive analytical workflows as well as capabilities for automation, can generate a great impact in a vast variety of fields, such as in clinical, environmental, and food-science applications. In this study, a novel approach that facilitates direct coupling of Bio-SPME devices to MS using a microfluidic design is presented. This technology, named microfluidic open interface (MOI), which operates under the concept of flow-isolated desorption volume, consists of an open-to-ambient desorption chamber (V ≤ 7 μL) connected to an ionization source. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such as electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Using this setup, the desorption chamber is used to release target compounds from the coating, while the isolation of the flow enables the ionization source to be continuously fed with solvent, all without the necessity of employment of additional valves. As a proof of concept, the design was applied to an ESI-MS/MS system for experimental validation. Furthermore, numerical simulations were undertaken to provide a detailed understanding of the fluid flow pattern inside the interface, then used to optimize the system for better efficiency. The analytical workflow of the developed Bio-SPME-MOI-MS setup consists of the direct immersion of SPME fibers into the matrix to extract/enrich analytes of interest within a short period of time, followed by a rinsing step with water to remove potentially adhering proteins, salts, and/or other interfering compounds. Next, the fiber is inserted into the

  8. Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Bernard La Scola

    Full Text Available BACKGROUND: With long delays observed between sampling and availability of results, the usefulness of blood cultures in the context of emergency infectious diseases has recently been questioned. Among methods that allow quicker bacterial identification from growing colonies, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF mass spectrometry was demonstrated to accurately identify bacteria routinely isolated in a clinical biology laboratory. In order to speed up the identification process, in the present work we attempted bacterial identification directly from blood culture bottles detected positive by the automate. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively analysed routine MALDI-TOF identification of bacteria detected in blood culture by two different protocols involving successive centrifugations and then lysis by trifluoroacetic acid or formic acid. Of the 562 blood culture broths detected as positive by the automate and containing one bacterial species, 370 (66% were correctly identified. Changing the protocol from trifluoroacetic acid to formic acid improved identification of Staphylococci, and overall correct identification increased from 59% to 76%. Lack of identification was observed mostly with viridans streptococci, and only one false positive was observed. In the 22 positive blood culture broths that contained two or more different species, only one of the species was identified in 18 samples, no species were identified in two samples and false species identifications were obtained in two cases. The positive predictive value of bacterial identification using this procedure was 99.2%. CONCLUSIONS/SIGNIFICANCE: MALDI-TOF MS is an efficient method for direct routine identification of bacterial isolates in blood culture, with the exception of polymicrobial samples and viridans streptococci. It may replace routine identification performed on colonies, provided improvement for the specificity of blood culture

  9. Direct identification of pathogens from positive blood cultures using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Rodríguez-Sánchez, B; Sánchez-Carrillo, C; Ruiz, A; Marín, M; Cercenado, E; Rodríguez-Créixems, M; Bouza, E

    2014-07-01

    In recent years, matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) has proved a rapid and reliable method for the identification of bacteria and yeasts that have already been isolated. The objective of this study was to evaluate this technology as a routine method for the identification of microorganisms directly from blood culture bottles (BCBs), before isolation, in a large collection of samples. For this purpose, 1000 positive BCBs containing 1085 microorganisms have been analysed by conventional phenotypic methods and by MALDI-TOF MS. Discrepancies have been resolved using molecular methods: the amplification and sequencing of the 16S rRNA gene or the Superoxide Dismutase gene (sodA) for streptococcal isolates. MALDI-TOF predicted a species- or genus-level identification of 81.4% of the analysed microorganisms. The analysis by episode yielded a complete identification of 814 out of 1000 analysed episodes (81.4%). MALDI-TOF identification is available for clinicians within hours of a working shift, as oppose to 18 h later when conventional identification methods are performed. Moreover, although further improvement of sample preparation for polymicrobial BCBs is required, the identification of more than one pathogen in the same BCB provides a valuable indication of unexpected pathogens when their presence may remain undetected in Gram staining. Implementation of MALDI-TOF identification directly from the BCB provides a rapid and reliable identification of the causal pathogen within hours. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  10. Development of a rapid and simplified protocol for direct bacterial identification from positive blood cultures by using matrix assisted laser desorption ionization time-of- flight mass spectrometry.

    Science.gov (United States)

    Jakovljev, Aleksandra; Bergh, Kåre

    2015-11-06

    Bloodstream infections represent serious conditions carrying a high mortality and morbidity rate. Rapid identification of microorganisms and prompt institution of adequate antimicrobial therapy is of utmost importance for a successful outcome. Aiming at the development of a rapid, simplified and efficient protocol, we developed and compared two in-house preparatory methods for the direct identification of bacteria from positive blood culture flasks (BD BACTEC FX system) by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF MS). Both methods employed saponin and distilled water for erythrocyte lysis. In method A the cellular pellet was overlaid with formic acid on the MALDI TOF target plate for protein extraction, whereas in method B the pellet was exposed to formic acid followed by acetonitrile prior to placing on the target plate. Best results were obtained by method A. Direct identification was achieved for 81.9 % and 65.8 % (50.3 % and 26.2 % with scores >2.0) of organisms by method A and method B, respectively. Overall concordance with final identification was 100 % to genus and 97.9 % to species level. By applying a lower cut-off score value, the levels of identification obtained by method A and method B increased to 89.3 % and 77.8 % of organisms (81.9 % and 65.8 % identified with scores >1.7), respectively. Using the lowered score criteria, concordance with final results was obtained for 99.3 % of genus and 96.6 % of species identifications. The reliability of results, rapid performance (approximately 25 min) and applicability of in-house method A have contributed to implementation of this robust and cost-effective method in our laboratory.

  11. Direct identification of bacteria in positive blood culture bottles by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry.

    Science.gov (United States)

    La Scola, Bernard; Raoult, Didier

    2009-11-25

    With long delays observed between sampling and availability of results, the usefulness of blood cultures in the context of emergency infectious diseases has recently been questioned. Among methods that allow quicker bacterial identification from growing colonies, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry was demonstrated to accurately identify bacteria routinely isolated in a clinical biology laboratory. In order to speed up the identification process, in the present work we attempted bacterial identification directly from blood culture bottles detected positive by the automate. We prospectively analysed routine MALDI-TOF identification of bacteria detected in blood culture by two different protocols involving successive centrifugations and then lysis by trifluoroacetic acid or formic acid. Of the 562 blood culture broths detected as positive by the automate and containing one bacterial species, 370 (66%) were correctly identified. Changing the protocol from trifluoroacetic acid to formic acid improved identification of Staphylococci, and overall correct identification increased from 59% to 76%. Lack of identification was observed mostly with viridans streptococci, and only one false positive was observed. In the 22 positive blood culture broths that contained two or more different species, only one of the species was identified in 18 samples, no species were identified in two samples and false species identifications were obtained in two cases. The positive predictive value of bacterial identification using this procedure was 99.2%. MALDI-TOF MS is an efficient method for direct routine identification of bacterial isolates in blood culture, with the exception of polymicrobial samples and viridans streptococci. It may replace routine identification performed on colonies, provided improvement for the specificity of blood culture broths growing viridans streptococci is obtained in the near future.

  12. Gas chromatography/isotope ratio mass spectrometry: analysis of methanol, ethanol and acetic acid by direct injection of aqueous alcoholic and acetic acid samples.

    Science.gov (United States)

    Ai, Guomin; Sun, Tong; Dong, Xiuzhu

    2014-08-15

    Methanol, ethanol, and acetic acid are not easily extracted from aqueous samples and are susceptible to isotope fractionation in gas chromatography/isotope ratio mass spectrometry (GC/IRMS) analysis. Developing a direct dilution GC/IRMS method for aqueous samples, by adjusting the sample concentrations in common solvents to be similar to each other and using a fixed GC split ratio, is very convenient and important because any linearity effects caused by amount-dependent isotope fractionation can be avoided. The suitability of acetonitrile and acetone solvents for the GC/IRMS analysis of pure methanol, ethanol and acetic acid, and commercial liquor and vinegar samples was evaluated using n-hexane and water as control solvents. All the solvents including water were separated from the analyte on a HP-INNOWAX column and were diverted away from the combustion interface. The influence of liquor matrix on the ethanol GC/IRMS analyses was evaluated by adding pure ethanol to liquor samples. Acetonitrile and acetone gave similar δ(13) C values for pure ethanol and pure acetic acid to those obtained in water and n-hexane, and also gave similar δ(13) C values of ethanol in liquor and acetic acid in white vinegar to that obtained in water. For methanol analysis, acetonitrile and refined acetone gave similar δ(13) C values to that obtained in water, but n-hexane was not a suitable solvent. In addition, isotopic fractionation caused by solvent and solute interactions was observed. We recommend using acetonitrile for the GC/IRMS analysis of aqueous alcoholic samples, and acetone for the analysis of aqueous acetic acid samples. This direct dilution method can provide high accurate and precise GC/IRMS analysis of the relative changes in δ(13) C values of methanol, ethanol, and acetic acid. Copyright © 2014 John Wiley & Sons, Ltd.

  13. Gold nanoparticles bridging infra-red spectroscopy and laser desorption/ionization mass spectrometry for direct analysis of over-the-counter drug and botanical medicines.

    Science.gov (United States)

    Chau, Siu-Leung; Tang, Ho-Wai; Ng, Kwan-Ming

    2016-05-05

    With a coating of gold nanoparticles (AuNPs), over-the-counter (OTC) drugs and Chinese herbal medicine granules in KBr pellets could be analyzed by Fourier Transform Infra-red (FT-IR) spectroscopy and Surface-assisted Laser Desorption/Ionization mass spectrometry (SALDI-MS). FT-IR spectroscopy allows fast detection of major active ingredient (e.g., acetaminophen) in OTC drugs in KBr pellets. Upon coating a thin layer of AuNPs on the KBr pellet, minor active ingredients (e.g., noscapine and loratadine) in OTC drugs, which were not revealed by FT-IR, could be detected unambiguously using AuNPs-assisted LDI-MS. Moreover, phytochemical markers of Coptidis Rhizoma (i.e. berberine, palmatine and coptisine) could be quantified in the concentrated Chinese medicine (CCM) granules by the SALDI-MS using standard addition method. The quantitative results matched with those determined by high-performance liquid chromatography with ultraviolet detection. Being strongly absorbing in UV yet transparent to IR, AuNPs successfully bridged FT-IR and SALDI-MS for direct analysis of active ingredients in the same solid sample. FT-IR allowed the fast analysis of major active ingredient in drugs, while SALDI-MS allowed the detection of minor active ingredient in the presence of excipient, and also quantitation of phytochemicals in herbal granules. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Detection of Nonvolatile Inorganic Oxidizer-Based Explosives from Wipe Collections by Infrared Thermal Desorption-Direct Analysis in Real Time Mass Spectrometry.

    Science.gov (United States)

    Forbes, Thomas P; Sisco, Edward; Staymates, Matthew

    2018-05-07

    Infrared thermal desorption (IRTD) was coupled with direct analysis in real time mass spectrometry (DART-MS) for the detection of both inorganic and organic explosives from wipe collected samples. This platform generated discrete and rapid heating rates that allowed volatile and semivolatile organic explosives to thermally desorb at relatively lower temperatures, while still achieving elevated temperatures required to desorb nonvolatile inorganic oxidizer-based explosives. IRTD-DART-MS demonstrated the thermal desorption and detection of refractory potassium chlorate and potassium perchlorate oxidizers, compounds difficult to desorb with traditional moderate-temperature resistance-based thermal desorbers. Nanogram to sub-nanogram sensitivities were established for analysis of a range of organic and inorganic oxidizer-based explosive compounds, with further enhancement limited by the thermal properties of the most common commercial wipe materials. Detailed investigations and high-speed visualization revealed conduction from the heated glass-mica base plate as the dominant process for heating of the wipe and analyte materials, resulting in thermal desorption through boiling, aerosolization, and vaporization of samples. The thermal desorption and ionization characteristics of the IRTD-DART technique resulted in optimal sensitivity for the formation of nitrate adducts with both organic and inorganic species. The IRTD-DART-MS coupling and IRTD in general offer promising explosive detection capabilities to the defense, security, and law enforcement arenas.

  15. Ultra high performance liquid chromatography-electrospray ionization-tandem mass spectrometry screening method for direct analysis of designer drugs, "spice" and stimulants in oral fluid.

    Science.gov (United States)

    Strano-Rossi, Sabina; Anzillotti, Luca; Castrignanò, Erika; Romolo, Francesco Saverio; Chiarotti, Marcello

    2012-10-05

    An ultra high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) screening method for the direct analysis in oral fluid (OF) of 24 drugs, including new synthetic cannabinoids and so-called "smart" designer drugs, in a single chromatographic run was set up. Benzylpiperazine, methylone, 5,6-methylenedioxy-2-aminoindane (MDAI), fenproporex, 4-fluoroamphetamine (4-FA), 4-methyl-N-ethylcathinone (4-MEC), 4-methylamphetamine (4-MA), methylbenzodioxolylbutanamine (MBDB), mephedrone, methylthioamphetamine (MTA), methylenedioxypyrovalerone (MDPV), mefenorex, nabilone, furfenorex, clobenzorex, JWH-200, AM 694, JWH-250, JWH-073, JWH-018, JWH-019, JWH-122, HU 210 and CP 47497 were determined in a chromatographic run of 9 min only with no sample pre-treatment, after addition of ISs and dilution in mobile phase A. This method is designed to be applied to 250 μL of OF sample, anyway is suitable to be used on smaller volumes (till 100 μL). LODs vary from 1ng/mL to 20 ng/mL. No interfering peaks were observed due to similar analytes, common therapeutic drugs or endogenous compounds. Matrix effect, although present especially for mephedrone, is acceptable, allowing the detection of the compounds at the LODs described. The developed method was applied on 400 real OF samples from on-site tests performed by police officers. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Direct analysis in real time mass spectrometry, a process analytical technology tool for real-time process monitoring in botanical drug manufacturing.

    Science.gov (United States)

    Wang, Lu; Zeng, Shanshan; Chen, Teng; Qu, Haibin

    2014-03-01

    A promising process analytical technology (PAT) tool has been introduced for batch processes monitoring. Direct analysis in real time mass spectrometry (DART-MS), a means of rapid fingerprint analysis, was applied to a percolation process with multi-constituent substances for an anti-cancer botanical preparation. Fifteen batches were carried out, including ten normal operations and five abnormal batches with artificial variations. The obtained multivariate data were analyzed by a multi-way partial least squares (MPLS) model. Control trajectories were derived from eight normal batches, and the qualification was tested by R(2) and Q(2). Accuracy and diagnosis capability of the batch model were then validated by the remaining batches. Assisted with high performance liquid chromatography (HPLC) determination, process faults were explained by corresponding variable contributions. Furthermore, a batch level model was developed to compare and assess the model performance. The present study has demonstrated that DART-MS is very promising in process monitoring in botanical manufacturing. Compared with general PAT tools, DART-MS offers a particular account on effective compositions and can be potentially used to improve batch quality and process consistency of samples in complex matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Direct injection of tissue extracts in liquid chromatography/tandem mass spectrometry for the determination of pharmaceuticals and other contaminants of emerging concern in mollusks.

    Science.gov (United States)

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kelly, Barry C

    2015-07-01

    In the present study, a straightforward approach was validated for the analysis of pharmaceutically active compounds and endocrine-disrupting chemicals in the mollusk tissues, with a focus on two species commonly consumed in Southeast Asia (green mussels: Perna viridis; lokan clams: Polymesoda expansa). This approach relied on a simple solvent extraction (shaker table) followed by direct injection in liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). This "cleanup-free" approach was made possible by the use of isotopically labeled surrogates (to correct for matrix effects) and a post-column switch on the LC-MS/MS system (to remove potential interfering material). Altogether, relative recoveries were satisfactory for 36 out of 44 compounds (26-163% range) and excellent for 27 out of 44 compounds (79-107% range). Method detection limits (MDLs) were usually expressed in the nanogram per gram wet weight (ww) range and below. The method was successfully applied to 16 batches of green mussel samples collected in Singapore coastal waters. Trace levels of six compounds were detected in mussel tissues: caffeine (0.22-1.55 ng g(-1) ww), carbamazepine (

  18. Trace analysis of pesticides in paddy field water by direct injection using liquid chromatography-quadrupole-linear ion trap-mass spectrometry.

    Science.gov (United States)

    Pareja, Lucía; Martínez-Bueno, M J; Cesio, Verónica; Heinzen, Horacio; Fernández-Alba, A R

    2011-07-29

    A multiresidue method was developed for the quantification and confirmation of 70 pesticides in paddy field water. After its filtration, water was injected directly in a liquid chromatograph coupled to a hybrid triple quadrupole-linear ion trap-mass spectrometer (QqLIT). The list of target analytes included organophosphates, phenylureas, sulfonylureas, carbamates, conazoles, imidazolinones and others compounds widely used in different countries where rice is cropped. Detection and quantification limits achieved were in the range from 0.4 to 80 ng L(-1) and from 2 to 150 ng L(-1), respectively. Correlation coefficients for the calibration curves in the range 0.1-50 μg L(-1) were higher than 0.99 except for diazinon (0.1-25 μg L(-1)). Only 9 pesticides presented more than 20% of signal suppression/enhancement, no matrix effect was observed in the studied conditions for the rest of the target pesticides. The method developed was used to investigate the occurrence of pesticides in 59 water samples collected in paddy fields located in Spain and Uruguay. The study shows the presence of bensulfuron methyl, tricyclazole, carbendazim, imidacloprid, tebuconazole and quinclorac in a concentration range from 0.08 to 7.20 μg L(-1). Copyright © 2011 Elsevier B.V. All rights reserved.

  19. A comparison of continuous pneumatic nebulization and flow injection-direct injection nebulization for sample introduction in inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Crain, J.S.; Kiely, J.T.

    1995-08-01

    Dilute nitric acid blanks and solutions containing Ni, Cd, Pb, and U (including two laboratory waste samples) were analyzed eighteen times over a two-month period using inductively coupled plasma-mass spectrometry (ICP-MS). Two different sample introduction techniques were employed: flow injection-direct injection nebulization (FI-DIN) and continuous pneumatic nebulization (CPN). Using comparable instrumental measurement procedures, FI-DIN analyses were 33% faster and generated 52% less waste than CPN analyses. Instrumental limits of detection obtained with FI-DIN and CPN were comparable but not equivalent (except in the case of Pb) because of nebulizer-related differences in sensitivity (i.e., signal per unit analyte concentration) and background. Substantial and statistically significant differences were found between FI-DIN and CPN Ni determinations, and in the case of the laboratory waste samples, there were also small but statistically significant differences between Cd determinations. These small (2 to 3%) differences were not related to polyatomic ion interference (e.g., 95 Mo 16 O + ), but in light of the time savings and waste reduction to be realized, they should not preclude the use of FI-DIN in place of CPN for determination of Cd, Pb, U and chemically

  20. Analysis of select Dalbergia and trade timber using direct analysis in real time and time-of-flight mass spectrometry for CITES enforcement.

    Science.gov (United States)

    Lancaster, Cady; Espinoza, Edgard

    2012-05-15

    International trade of several Dalbergia wood species is regulated by The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In order to supplement morphological identification of these species, a rapid chemical method of analysis was developed. Using Direct Analysis in Real Time (DART) ionization coupled with Time-of-Flight (TOF) Mass Spectrometry (MS), selected Dalbergia and common trade species were analyzed. Each of the 13 wood species was classified using principal component analysis and linear discriminant analysis (LDA). These statistical data clusters served as reliable anchors for species identification of unknowns. Analysis of 20 or more samples from the 13 species studied in this research indicates that the DART-TOFMS results are reproducible. Statistical analysis of the most abundant ions gave good classifications that were useful for identifying unknown wood samples. DART-TOFMS and LDA analysis of 13 species of selected timber samples and the statistical classification allowed for the correct assignment of unknown wood samples. This method is rapid and can be useful when anatomical identification is difficult but needed in order to support CITES enforcement. Published 2012. This article is a US Government work and is in the public domain in the USA.

  1. Identification of pathogenic microorganisms directly from positive blood vials by matrix-assisted laser desorption/ionization time of flight mass spectrometry

    DEFF Research Database (Denmark)

    Nonnemann, Bettina; Tvede, Michael; Bjarnsholt, Thomas

    2013-01-01

    Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is a promising and fast method for identifying fungi and bacteria directly from positive blood cultures. Various pre-treatment methods for MALDI-TOF MS identification have been reported for this purpose. In......-house results for identification of bacterial colonies by MALDI-TOF MS using a cut-off score of 1.5 did not reduce the diagnostic accuracy compared with the recommended cut-off score of 1.8. A 3-month consecutive study of positive blood cultures was carried out in our laboratory to evaluate whether...... the Sepsityper™ Kit (Bruker Daltonics) with Biotyper 2.0 software could be used as a fast diagnostic tool for bacteria and fungi and whether a 1.5 cut-off score could improve species identification compared with the recommended score of 1.8. Two hundred and fifty-six positive blood vials from 210 patients and 19...

  2. Direct analysis of psychoactive tryptamine and harmala alkaloids in the Amazonian botanical medicine ayahuasca by liquid chromatography-electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    McIlhenny, Ethan H; Pipkin, Kelly E; Standish, Leanna J; Wechkin, Hope A; Strassman, Rick; Barker, Steven A

    2009-12-18

    A direct injection/liquid chromatography-electrospray ionization-tandem mass spectrometry procedure has been developed for the simultaneous quantitation of 11 compounds potentially found in the increasingly popular Amazonian botanical medicine and religious sacrament ayahuasca. The method utilizes a deuterated internal standard for quantitation and affords rapid detection of the alkaloids by a simple dilution assay, requiring no extraction procedures. Further, the method demonstrates a high degree of specificity for the compounds in question, as well as low limits of detection and quantitation despite using samples for analysis that had been diluted up to 200:1. This approach also appears to eliminate potential matrix effects. Method bias for each compound, examined over a range of concentrations, was also determined as was inter- and intra-assay variation. Its application to the analysis of three different ayahuasca preparations is also described. This method should prove useful in the study of ayahuasca in clinical and ethnobotanical research as well as in forensic examinations of ayahuasca preparations.

  3. Assessing direct analysis in real-time-mass spectrometry (DART-MS) for the rapid identification of additives in food packaging.

    Science.gov (United States)

    Ackerman, L K; Noonan, G O; Begley, T H

    2009-12-01

    The ambient ionization technique direct analysis in real time (DART) was characterized and evaluated for the screening of food packaging for the presence of packaging additives using a benchtop mass spectrometer (MS). Approximate optimum conditions were determined for 13 common food-packaging additives, including plasticizers, anti-oxidants, colorants, grease-proofers, and ultraviolet light stabilizers. Method sensitivity and linearity were evaluated using solutions and characterized polymer samples. Additionally, the response of a model additive (di-ethyl-hexyl-phthalate) was examined across a range of sample positions, DART, and MS conditions (temperature, voltage and helium flow). Under optimal conditions, molecular ion (M+H+) was the major ion for most additives. Additive responses were highly sensitive to sample and DART source orientation, as well as to DART flow rates, temperatures, and MS inlet voltages, respectively. DART-MS response was neither consistently linear nor quantitative in this setting, and sensitivity varied by additive. All additives studied were rapidly identified in multiple food-packaging materials by DART-MS/MS, suggesting this technique can be used to screen food packaging rapidly. However, method sensitivity and quantitation requires further study and improvement.

  4. HPLC/ESI-quadrupole ion trap mass spectrometry for characterization and direct quantification of amphoteric and nonionic surfactants in aqueous samples

    Science.gov (United States)

    Levine, Lanfang H.; Garland, Jay L.; Johnson, Jodie V.

    2002-01-01

    An amphoteric (cocamidopropylbetaine, CAPB) and a nonionic (alcohol polyethoxylate, AE) surfactant were characterized by electrospray ionization quadrupole ion trap mass spectrometry (ESI-MS) as to their homologue distribution and ionization/fragmentation chemistry. Quantitative methods involving reversed-phase gradient HPLC and (+)ESI-MSn were developed to directly determine these surfactants in hydroponic plant growth medium that received simulated graywater. The predominant homologues, 12 C alkyl CAPB and 9 EO AE, were monitored to represent the total amount of the respective surfactants. The methods demonstrated dynamic linear ranges of 0.5-250 ng (r2 > 0.996) for CAPB and 8-560 ng (r2 > 0.998) for AE homologue mixture, corresponding to minimum quantification limits of 25 ppb CAPB and 0.4 ppm AE with 20-microL injections. This translated into an even lower limit for individual components due to the polydispersive nature of the surfactants. The procedure was successfully employed for the assessment of CAPB and AE biodegradation in a hydroponic plant growth system used as a graywater bioreactor.

  5. The Occurrence of Propyl Lactate in Chinese Baijius (Chinese Liquors Detected by Direct Injection Coupled with Gas Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jihong Wu

    2015-10-01

    Full Text Available As one of the oldest distillates in the world, flavor compounds of Chinese Baijiu (Chinese liquor were extremely complex. Propyl lactate was firstly detected by direct injection and gas chromatography-mass spectrometry (GC-MS in 72 Chinese Baijius. The objectives were to detect the contents of propyl lactate and evaluate its contribution to the aroma of Chinese Baijiu based on odor activity values (OAVs. The levels of propyl lactate in these distillates were determined by internal standard method and selective ion monitoring (SIM, which ranged from 0.050 to 1.900 mg∙L−1 under investigation. Its detection threshold was determined by Three-Alternative Forced-Choice (3-AFC and curve fitting (CF, which was 0.740 mg∙L−1 in 38% ethanol solution. The contribution of propyl lactate on the aroma of these distillate drinks was evaluated by their odor activity values (OAVs, which varied from 0.066 to 4.440. The OAVs of propyl lactate were found to exceed 1 in 13 Chinese Baijius, including 50° Jingzhi Guniang 5 years (4.440, 52° Jingzhi Guniang 10 years (3.024, Jingyanggang (2.568, Xianghe Ronghe Shaofang (2.313, and 1956 Laolang (1.431, which indicated that propyl lactate was one of odor-active components in these Chinese Baijius.

  6. Bulk derivatization and direct injection of human cerebrospinal fluid for trace-level quantification of endogenous estrogens using trap-and-elute liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Fan, Hui; Papouskova, Barbora; Lemr, Karel; Wigginton, Jane G; Schug, Kevin A

    2014-08-01

    Although there are existing methods for determining estrogen in human bodily fluids including blood plasma and serum, very little information is available regarding estrogen levels in human cerebrospinal fluid (CSF), which is critical to assess in studies of neuroprotective functions and diffusion of neuroprotective estrogens across the blood-brain barrier. To address this problem, a liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of four endogenous estrogens (estrone, 17α-estradiol, 17β-estradiol, and estriol) in human CSF was developed. An aliquot (300 μL) of human CSF was bulk derivatized using dansyl chloride in the sample and 10 μL was directly injected onto a restricted-access media trap column for protein removal. No off-line sample extraction or cleanup was needed. The limits of detection of estrone, 17α-estradiol, 17β-estradiol, and estriol were 17, 28, 13, and 30 pg/mL, respectively, which is in the parts-per-trillion regime. The method was then applied to human CSF collected from ischemic trauma patients. Endogenous estrogens were detected and quantified, demonstrating the effectiveness of this method. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Classification of Obesity Varies between Body Mass Index and Direct Measures of Body Fat in Boys and Girls of Asian and European Ancestry

    Science.gov (United States)

    McConnell-Nzunga, J.; Naylor, P. J.; Macdonald, H.; Rhodes, R. E.; Hofer, S. M.; McKay, H.

    2018-01-01

    Body mass index is a common proxy for proportion of body fat. However, body mass index may not classify youth similarly across ages and ethnicities. We used sex- and ethnic-specific receiver operating characteristic curves to determine how obesity classifications compared between body mass index and dual energy x-ray absorptiometry-based body fat…

  8. Direct detection of carbapenemase-associated proteins of Acinetobacter baumannii using nanodiamonds coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Chang, Kai-Chih; Chung, Chin-Yi; Yeh, Chen-Hsing; Hsu, Kuo-Hsiu; Chin, Ya-Ching; Huang, Sin-Siang; Liu, Bo-Rong; Chen, Hsi-An; Hu, Anren; Soo, Po-Chi; Peng, Wen-Ping

    2018-04-01

    reached 100% as compared to polymerase chain reaction (PCR) result. Our approach could directly detect the carbapenemase-associated proteins of A. baumannii within 90 min and does not require addition of carbapenemase substrate which is required in the MHT or other mass spectrometric methods. For future applications, our method could be efficiently used in the detection of other carbapenemase-producing bacteria. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Quantitative real-time monitoring of multi-elements in airborne particulates by direct introduction into an inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Suzuki, Yoshinari; Sato, Hikaru; Hiyoshi, Katsuhiro; Furuta, Naoki

    2012-01-01

    A new calibration system for real-time determination of trace elements in airborne particulates was developed. Airborne particulates were directly introduced into an inductively coupled plasma mass spectrometer, and the concentrations of 15 trace elements were determined by means of an external calibration method. External standard solutions were nebulized by an ultrasonic nebulizer (USN) coupled with a desolvation system, and the resulting aerosol was introduced into the plasma. The efficiency of sample introduction via the USN was calculated by two methods: (1) the introduction of a Cr standard solution via the USN was compared with introduction of a Cr(CO) 6 standard gas via a standard gas generator and (2) the aerosol generated by the USN was trapped on filters and then analyzed. The Cr introduction efficiencies obtained by the two methods were the same, and the introduction efficiencies of the other elements were equal to the introduction efficiency of Cr. Our results indicated that our calibration method for introduction efficiency worked well for the 15 elements (Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Sn, Sb, Ba, Tl and Pb). The real-time data and the filter-collection data agreed well for elements with low-melting oxides (V, Co, As, Mo, Sb, Tl, and Pb). In contrast, the real-time data were smaller than the filter-collection data for elements with high-melting oxides (Ti, Cr, Mn, Ni, Cu, Zn, Sn, and Ba). This result implies that the oxides of these 8 elements were not completely fused, vaporized, atomized, and ionized in the initial radiation zone of the inductively coupled plasma. However, quantitative real-time monitoring can be realized after correction for the element recoveries which can be calculated from the ratio of real-time data/filter-collection data. - Highlights: ► APs were directly introduced into ICP-MS and real-time analysis was performed. ► The real-time data were calibrated by a multi-element standard solution from USN. ► During real

  10. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    Science.gov (United States)

    Cheng, Heyong; Liu, Jinhua; Xu, Zigang; Yin, Xuefeng

    2012-07-01

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1-0.8 μL), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L- 1 glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L- 1 glucose was downscaled to 0.8 μL. Further reducing the sampling volume to 0.4 μL, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 μL was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 μL min- 1 for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection (μFI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h- 1 with the detection limit of 19.8 and 10.4 ng L- 1 for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion. The recoveries of three Chinese

  11. Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Thomas, Andreas; Wachsmuth, Philipp; Orlovius, Anne-Katrin; Sigmund, Gerd; Thevis, Mario; Schänzer, Wilhelm

    2016-11-30

    So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β 2 -agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Direct detection of additives and degradation products from polymers by liquid extraction surface analysis employing chip-based nanospray mass spectrometry.

    Science.gov (United States)

    Paine, Martin R L; Barker, Philip J; Maclauglin, Shane A; Mitchell, Todd W; Blanksby, Stephen J

    2012-02-29

    Polymer-based surface coatings in outdoor applications experience accelerated degradation due to exposure to solar radiation, oxygen and atmospheric pollutants. These deleterious agents cause undesirable changes to the aesthetic and mechanical properties of the polymer, reducing its lifetime. The use of antioxidants such as hindered amine light stabilisers (HALS) retards these degradative processes; however, mechanisms for HALS action and polymer degradation are poorly understood. Detection of the HALS TINUVIN®123 (bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate) and the polymer degradation products directly from a polyester-based coil coating was achieved by liquid extraction surface analysis (LESA) coupled to a triple quadrupole QTRAP® 5500 mass spectrometer. The detection of TINUVIN®123 and melamine was confirmed by the characteristic fragmentation pattern observed in LESA-MS/MS spectra that was identical to that reported for authentic samples. Analysis of an unstabilised coil coating by LESA-MS after exposure to 4 years of outdoor field testing revealed the presence of melamine (1,3,5-triazine-2,4,6-triamine) as a polymer degradation product at elevated levels. Changes to the physical appearance of the coil coating, including powder-like deposits on the coating's surface, were observed to coincide with melamine deposits and are indicative of the phenomenon known as polymer 'blooming'. For the first time, in situ detection of analytes from a thermoset polymer coating was accomplished without any sample preparation, providing advantages over traditional extraction-analysis approaches and some contemporary ambient MS methods. Detection of HALS and polymer degradation products such as melamine provides insight into the mechanisms by which degradation occurs and suggests LESA-MS is a powerful new tool for polymer analysis. Copyright © 2012 John Wiley & Sons, Ltd.

  13. Rapid screening and quantification of residual pesticides and illegal adulterants in red wine by direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Guo, Tianyang; Fang, Pingping; Jiang, Juanjuan; Zhang, Feng; Yong, Wei; Liu, Jiahui; Dong, Yiyang

    2016-11-04

    A rapid method to screen and quantify multi-class analytic targets in red wine has been developed by direct analysis in real time (DART) coupled with triple quadruple tandem mass spectrometry (QqQ-MS). A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure was used for increasing analytical speed and reducing matrix effect, and the multiple reaction monitoring (MRM) in DART-MS/MS ensured accurate analysis. One bottle of wine containing 50 pesticides and 12 adulterants, i.e., preservatives, antioxidant, sweeteners, and azo dyes, could be totally determined less than 12min. This method exhibited proper linearity (R 2 ≥0.99) in the range of 1-1000ng/mL for pesticides and 10-5000ng/mL for adulterants. The limits of detection (LODs) were obtained in a 0.5-50ng/mL range for pesticides and 5-50ng/mL range for adulterants, and the limits of quantification (LOQs) were in a 1-100ng/mL range for pesticides and 10-250ng/mL range for adulterants. Three spiked levels for each analyte in wine were evaluated, and the recoveries were in a scope of 75-120%. The results demonstrated DART-MS/MS was a rapid and simple method, and could be applied to rapid analyze residual pesticides and illegal adulterants in a large quantities of red wine. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Principal component directed partial least squares analysis for combining nuclear magnetic resonance and mass spectrometry data in metabolomics: Application to the detection of breast cancer

    International Nuclear Information System (INIS)

    Gu Haiwei; Pan Zhengzheng; Xi Bowei; Asiago, Vincent; Musselman, Brian; Raftery, Daniel

    2011-01-01

    Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) are the two most commonly used analytical tools in metabolomics, and their complementary nature makes the combination particularly attractive. A combined analytical approach can improve the potential for providing reliable methods to detect metabolic profile alterations in biofluids or tissues caused by disease, toxicity, etc. In this paper, 1 H NMR spectroscopy and direct analysis in real time (DART)-MS were used for the metabolomics analysis of serum samples from breast cancer patients and healthy controls. Principal component analysis (PCA) of the NMR data showed that the first principal component (PC1) scores could be used to separate cancer from normal samples. However, no such obvious clustering could be observed in the PCA score plot of DART-MS data, even though DART-MS can provide a rich and informative metabolic profile. Using a modified multivariate statistical approach, the DART-MS data were then reevaluated by orthogonal signal correction (OSC) pretreated partial least squares (PLS), in which the Y matrix in the regression was set to the PC1 score values from the NMR data analysis. This approach, and a similar one using the first latent variable from PLS-DA of the NMR data resulted in a significant improvement of the separation between the disease samples and normals, and a metabolic profile related to breast cancer could be extracted from DART-MS. The new approach allows the disease classification to be expressed on a continuum as opposed to a binary scale and thus better represents the disease and healthy classifications. An improved metabolic profile obtained by combining MS and NMR by this approach may be useful to achieve more accurate disease detection and gain more insight regarding disease mechanisms and biology.

  15. Principal component directed partial least squares analysis for combining nuclear magnetic resonance and mass spectrometry data in metabolomics: application to the detection of breast cancer.

    Science.gov (United States)

    Gu, Haiwei; Pan, Zhengzheng; Xi, Bowei; Asiago, Vincent; Musselman, Brian; Raftery, Daniel

    2011-02-07

    Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) are the two most commonly used analytical tools in metabolomics, and their complementary nature makes the combination particularly attractive. A combined analytical approach can improve the potential for providing reliable methods to detect metabolic profile alterations in biofluids or tissues caused by disease, toxicity, etc. In this paper, (1)H NMR spectroscopy and direct analysis in real time (DART)-MS were used for the metabolomics analysis of serum samples from breast cancer patients and healthy controls. Principal component analysis (PCA) of the NMR data showed that the first principal component (PC1) scores could be used to separate cancer from normal samples. However, no such obvious clustering could be observed in the PCA score plot of DART-MS data, even though DART-MS can provide a rich and informative metabolic profile. Using a modified multivariate statistical approach, the DART-MS data were then reevaluated by orthogonal signal correction (OSC) pretreated partial least squares (PLS), in which the Y matrix in the regression was set to the PC1 score values from the NMR data analysis. This approach, and a similar one using the first latent variable from PLS-DA of the NMR data resulted in a significant improvement of the separation between the disease samples and normals, and a metabolic profile related to breast cancer could be extracted from DART-MS. The new approach allows the disease classification to be expressed on a continuum as opposed to a binary scale and thus better represents the disease and healthy classifications. An improved metabolic profile obtained by combining MS and NMR by this approach may be useful to achieve more accurate disease detection and gain more insight regarding disease mechanisms and biology. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Study of device mass production capability of the character projection based electron beam direct writing process technology toward 14 nm node and beyond

    Science.gov (United States)

    Kojima, Yoshinori; Takahashi, Yasushi; Takakuwa, Masaki; Ohshio, Shuzo; Sugatani, Shinji; Tujimura, Ryo; Takita, Hiroshi; Ogino, Kozo; Hoshino, Hiromi; Ito, Yoshio; Miyajima, Masaaki; Kon, Jun-ichi

    2012-03-01

    Techniques to appropriately control the key factors for a character projection (CP) based electron beam direct writing (EBDW) technology for mass production are shown and discussed. In order to achieve accurate CD control, the CP technique using the master CP is adopted. Another CP technique, the Packed CP, is used to obtain suitable shot count. For the alignment on the some critical layers which have the normally an even surface, the alignment methodology differ from photolithography is required. The process that etches the SiO2 material in the shallow trench isolation is added and then the alignment marks can be detected using electron beam even at the gate layer, which is normally on an even surface. The proximity effect correction using the simplified electron energy flux model and the hybrid exposure are used to obtain enough process margins. As a result, the sufficient CD accuracy, overlay accuracy, and yield are obtained on the 65 nm node device. The condition in our system is checked using self-diagnosis on a regular basis, and scheduled maintenances have been properly performed. Due to the proper system control, more than 10,000 production wafers have been successfully exposed so far without any major system downtime. It is shown that those techniques can be adapted to the 32 nm node production with slight modifications. For the 14 nm node and beyond, however, the drastic increment of the shot count becomes more of a concern. The Multi column cell (MCC) exposure method, the key concept of which is the parallelization of the electron beam columns with a CP, can overcome this concern. It is expected that by using the MCC exposure system, those techniques will be applicable to the rapid establishment for the 14 nm node technology.

  17. Directly Formed Alucone on Lithium Metal for High-Performance Li Batteries and Li-S Batteries with High Sulfur Mass Loading.

    Science.gov (United States)

    Chen, Lin; Huang, Zhennan; Shahbazian-Yassar, Reza; Libera, Joseph A; Klavetter, Kyle C; Zavadil, Kevin R; Elam, Jeffrey W

    2018-02-28

    Lithium metal is considered the "holy grail" of next-generation battery anodes. However, severe parasitic reactions at the lithium-electrolyte interface deplete the liquid electrolyte and the uncontrolled formation of high surface area and dendritic lithium during cycling causes rapid capacity fading and battery failure. Engineering a dendrite-free lithium metal anode is therefore critical for the development of long-life batteries using lithium anodes. In this study, we deposit a conformal, organic/inorganic hybrid coating, for the first time, directly on lithium metal using molecular layer deposition (MLD) to alleviate these problems. This hybrid organic/inorganic film with high cross-linking structure can stabilize lithium against dendrite growth and minimize side reactions, as indicated by scanning electron microscopy. We discovered that the alucone coating yielded several times longer cycle life at high current rates compared to the uncoated lithium and achieved a steady Coulombic efficiency of 99.5%, demonstrating that the highly cross-linking structured material with great mechanical properties and good flexibility can effectively suppress dendrite formation. The protected Li was further evaluated in lithium-sulfur (Li-S) batteries with a high sulfur mass loading of ∼5 mg/cm 2 . After 140 cycles at a high current rate of ∼1 mA/cm 2 , alucone-coated Li-S batteries delivered a capacity of 657.7 mAh/g, 39.5% better than that of a bare lithium-sulfur battery. These findings suggest that flexible coating with high cross-linking structure by MLD is effective to enable lithium protection and offers a very promising avenue for improved performance in the real applications of Li-S batteries.

  18. Direct and non-destructive proof of authenticity for the 2nd generation of Brazilian real banknotes via easy ambient sonic spray ionization mass spectrometry.

    Science.gov (United States)

    Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Regino, Karen Gomes; Lehmann, Eraldo Luiz; Arruda, Marco Aurélio Zezzi; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2014-12-01

    Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on chemical profiles obtained directly from the banknote surface. Characteristic profiles were observed for authentic, seized suspect counterfeit and counterfeited homemade banknotes from inkjet and laserjet printers. The chemicals in the authentic banknotes' surface were detected via a few minor sets of ions, namely from the plasticizers bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP), most likely related to the official offset printing process, and other common quaternary ammonium cations, presenting a similar chemical profile to 1st-generation R$. The seized suspect counterfeit banknotes, however, displayed abundant diagnostic ions in the m/z 400-800 range due to the presence of oligomers. High-accuracy FT-ICR MS analysis enabled molecular formula assignment for each ion. The ions were separated by 44 m/z, which enabled their characterization as Surfynol® 4XX (S4XX, XX=40, 65, and 85), wherein increasing XX values indicate increasing amounts of ethoxylation on a backbone of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol® 104). Sodiated triethylene glycol monobutyl ether (TBG) of m/z 229 (C10H22O4Na) was also identified in the seized counterfeit banknotes via EASI(+) FT-ICR MS. Surfynol® and TBG are constituents of inks used for inkjet printing. Copyright © 2014. Published by Elsevier Ireland Ltd.

  19. Species identification of Aspergillus, Fusarium and Mucorales with direct surface analysis by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    De Carolis, E; Posteraro, B; Lass-Flörl, C; Vella, A; Florio, A R; Torelli, R; Girmenia, C; Colozza, C; Tortorano, A M; Sanguinetti, M; Fadda, G

    2012-05-01

    Accurate species discrimination of filamentous fungi is essential, because some species have specific antifungal susceptibility patterns, and misidentification may result in inappropriate therapy. We evaluated matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for species identification through direct surface analysis of the fungal culture. By use of culture collection strains representing 55 species of Aspergillus, Fusarium and Mucorales, a reference database was established for MALDI-TOF MS-based species identification according to the manufacturer's recommendations for microflex measurements and MALDI BioTyper 2.0 software. The profiles of young and mature colonies were analysed for each of the reference strains, and species-specific spectral fingerprints were obtained. To evaluate the database, 103 blind-coded fungal isolates collected in the routine clinical microbiology laboratory were tested. As a reference method for species designation, multilocus sequencing was used. Eighty-five isolates were unequivocally identified to the species level (≥99% sequence similarity); 18 isolates producing ambiguous results at this threshold were initially rated as identified to the genus level only. Further molecular analysis definitively assigned these isolates to the species Aspergillus oryzae (17 isolates) and Aspergillus flavus (one isolate), concordant with the MALDI-TOF MS results. Excluding nine isolates that belong to the fungal species not included in our reference database, 91 (96.8%) of 94 isolates were identified by MALDI-TOF MS to the species level, in agreement with the results of the reference method; three isolates were identified to the genus level. In conclusion, MALDI-TOF MS is suitable for the routine identification of filamentous fungi in a medical microbiology laboratory. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  20. Direct identification of bacteria from charcoal-containing blood culture bottles using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry.

    Science.gov (United States)

    Wüppenhorst, N; Consoir, C; Lörch, D; Schneider, C

    2012-10-01

    Several protocols for direct matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) from positive blood cultures are currently used to speed up the diagnostic process of bacteraemia. Identification rates are high and results are accurate for the BACTEC™ system and for charcoal-free bottles. Only a few studies have evaluated protocols for charcoal-containing BacT/ALERT bottles reaching substantially lower identification rates. We established a new protocol for sample preparation from aerobic and anaerobic positive charcoal-containing BacT/ALERT blood culture bottles and measured the protein profiles (n = 167). Then, we integrated this protocol in the routine workflow of our laboratory (n = 212). During the establishment of our protocol, 74.3 % of bacteria were correctly identified to the species level, in 23.4 %, no result and in 2.4 %, a false identification were obtained. Reliable criteria for correct species identification were a score value ≥1.400 and a best match on rank 1-3 of the same species. Identification rates during routine workflow were 77.8 % for correct identification, 20.8 % for not identified samples and 1.4 % for discordant identification. In conclusion, our results indicate that MALDI-TOF MS is possible, even from charcoal-containing blood cultures. Reliable criteria for correct species identification are a score value ≥1.400 and a best match on rank 1-3 of a single species.

  1. Direct bacterial identification in positive blood cultures by use of two commercial matrix-assisted laser desorption ionization-time of flight mass spectrometry systems.

    Science.gov (United States)

    Chen, Jonathan H K; Ho, Pak-Leung; Kwan, Grace S W; She, Kevin K K; Siu, Gilman K H; Cheng, Vincent C C; Yuen, Kwok-Yung; Yam, Wing-Cheong

    2013-06-01

    Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of bacteria and fungi was recently introduced in microbiology laboratories. This technology could greatly improve the clinical management of patients and guidance for chemotherapy. In this study, we used a commercial MALDI Sepsityper extraction method to evaluate the performance of two commercial MALDI-TOF MS systems, the Vitek MS IVD (bioMérieux) and the Microflex LT Biotyper (Bruker Daltonics) for direct bacterial identification in positive blood cultures. In 181 monomicrobial cultures, both systems generated genus to species level identifications for >90% of the specimens (Biotyper, 177/181 [97.8%]; Vitek MS IVD, 167/181 [92.3%]). Overall, the Biotyper system generated significantly more accurate identifications than the Vitek MS IVD system (P = 0.016; 177 versus 167 out of 181 specimens). The Biotyper system identified the minority species among polymicrobial blood cultures. We also compared the performance of an in-house extraction method with that of the Sepsityper on both MALDI-TOF MS systems. The in-house method generated more correct identifications at the genus level than the Sepsityper (96.7% versus 93.5%) on the Biotyper system, whereas the two methods exhibited the same performance level (88.0% versus 88.0%) on the Vitek MS IVD system. Our study confirmed the practical advantages of MALDI-TOF MS, and our in-house extraction method reduced the reagent cost to $1 per specimen, with a shorter turnaround time of 3 h, which is highly cost-effective for a diagnostic microbiology service.

  2. Effects of aromatics, olefins and distillation temperatures (T50 & T90) on particle mass and number emissions from gasoline direct injection (GDI) vehicles

    International Nuclear Information System (INIS)

    Zhu, Rencheng; Hu, Jingnan; Bao, Xiaofeng; He, Liqiang; Zu, Lei

    2017-01-01

    Abstratct: Fuel quality is among the primary reasons for severe vehicle pollution. A limited understanding of the effects of gasoline properties on modern vehicle emissions is one obstacle for the establishment of stricter fuel standards in China. The goal of this study was to evaluate the effects of aromatic and olefin contents and T50 and T90 (defined as the 50%v and 90%v distillation temperatures) on tailpipe emissions from gasoline direct injection (GDI) vehicles compliant with China 4 standards. Both gaseous and particle emissions using different types of gasoline were measured. Changing aromatic and olefin contents had relatively small impacts on fuel consumption. Compared with olefins and T90, the regulated gaseous emissions were impacted more by aromatics and T50. Evident decreases of the particle mass (PM) and particle number (PN) emissions were noticed when the aromatic content and T90 decreased. Reducing the olefin content slightly decreased the PM emissions and increased the PN emissions. With decreasing T50, the PM emissions increased and the PN emissions slightly decreased. These results suggest that aromatic content and T90 should be decreased to reduce particle emissions from GDI vehicles. The information presented in this study provides some suggestions for how to improve gasoline quality in China. - Highlights: • Effect of aromatics, olefins, T50 and T90 on GDI vehicle emissions was investigated. • Aromatics and olefins had little impact on fuel consumption and CO 2 emissions. • Reducing the aromatic content and T90 significantly decreased PM and PN emissions. • Changing the olefin content and T50 had a minor impact on particle emissions. • Thresholds of aromatics and T90 should be tightened in future gasoline regulations.

  3. Transcranial direct current stimulation (tDCS) Paired with massed practice training to promote adaptive plasticity and motor recovery in chronic incomplete tetraplegia: a pilot study.

    Science.gov (United States)

    Potter-Baker, Kelsey A; Janini, Daniel P; Lin, Yin-Liang; Sankarasubramanian, Vishwanath; Cunningham, David A; Varnerin, Nicole M; Chabra, Patrick; Kilgore, Kevin L; Richmond, Mary Ann; Frost, Frederick S; Plow, Ela B

    2017-08-07

    Objective Our goal was to determine if pairing transcranial direct current stimulation (tDCS) with rehabilitation for two weeks could augment adaptive plasticity offered by these residual pathways to elicit longer-lasting improvements in motor function in incomplete spinal cord injury (iSCI). Design Longitudinal, randomized, controlled, double-blinded cohort study. Setting Cleveland Clinic Foundation, Cleveland, Ohio, USA. Participants Eight male subjects with chronic incomplete motor tetraplegia. Interventions Massed practice (MP) training with or without tDCS for 2 hrs, 5 times a week. Outcome Measures We assessed neurophysiologic and functional outcomes before, after and three months following intervention. Neurophysiologic measures were collected with transcranial magnetic stimulation (TMS). TMS measures included excitability, representational volume, area and distribution of a weaker and stronger muscle motor map. Functional assessments included a manual muscle test (MMT), upper extremity motor score (UEMS), action research arm test (ARAT) and nine hole peg test (NHPT). Results We observed that subjects receiving training paired with tDCS had more increased strength of weak proximal (15% vs 10%), wrist (22% vs 10%) and hand (39% vs. 16%) muscles immediately and three months after intervention compared to the sham group. Our observed changes in muscle strength were related to decreases in strong muscle map volume (r=0.851), reduced weak muscle excitability (r=0.808), a more focused weak muscle motor map (r=0.675) and movement of weak muscle motor map (r=0.935). Conclusion Overall, our results encourage the establishment of larger clinical trials to confirm the potential benefit of pairing tDCS with training to improve the effectiveness of rehabilitation interventions for individuals with SCI. Trial Registration NCT01539109.

  4. A rapid, simple method for the genetic discrimination of intact Arabidopsis thaliana mutant seeds using metabolic profiling by direct analysis in real-time mass spectrometry

    Directory of Open Access Journals (Sweden)

    Jang Young

    2011-06-01

    Full Text Available Abstract Background Efficient high throughput screening systems of useful mutants are prerequisite for study of plant functional genomics and lots of application fields. Advance in such screening tools, thanks to the development of analytic instruments. Direct analysis in real-time (DART-mass spectrometry (MS by ionization of complex materials at atmospheric pressure is a rapid, simple, high-resolution analytical technique. Here we describe a rapid, simple method for the genetic discrimination of intact Arabidopsis thaliana mutant seeds using metabolic profiling by DART-MS. Results To determine whether this DART-MS combined by multivariate analysis can perform genetic discrimination based on global metabolic profiling, intact Arabidopsis thaliana mutant seeds were subjected to DART-MS without any sample preparation. Partial least squares-discriminant analysis (PLS-DA of DART-MS spectral data from intact seeds classified 14 different lines of seeds into two distinct groups: Columbia (Col-0 and Landsberg erecta (Ler ecotype backgrounds. A hierarchical dendrogram based on partial least squares-discriminant analysis (PLS-DA subdivided the Col-0 ecotype into two groups: mutant lines harboring defects in the phenylpropanoid biosynthetic pathway and mutants without these defects. These results indicated that metabolic profiling with DART-MS could discriminate intact Arabidopsis seeds at least ecotype level and metabolic pathway level within same ecotype. Conclusion The described DART-MS combined by multivariate analysis allows for rapid screening and metabolic characterization of lots of Arabidopsis mutant seeds without complex metabolic preparation steps. Moreover, potential novel metabolic markers can be detected and used to clarify the genetic relationship between Arabidopsis cultivars. Furthermore this technique can be applied to predict the novel gene function of metabolic mutants regardless of morphological phenotypes.

  5. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Heyong [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Liu, Jinhua [College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China); Xu, Zigang [Institute of Analytical and Applied Chemistry, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); Yin, Xuefeng, E-mail: yinxf@zju.edu.cn [Institute of Microanalytical Systems, Department of Chemistry, Zhejiang University, Hangzhou, 310027 (China); College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036 (China)

    2012-07-15

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1-0.8 {mu}L), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L{sup -1} glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L{sup -1} glucose was downscaled to 0.8 {mu}L. Further reducing the sampling volume to 0.4 {mu}L, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 {mu}L was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 {mu}L min{sup -1} for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection ({mu}FI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h{sup -1} with the detection limit of 19.8 and 10.4 ng L{sup -1} for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion

  6. A micro-fluidic sub-microliter sample introduction system for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry using external aqueous calibration

    International Nuclear Information System (INIS)

    Cheng, Heyong; Liu, Jinhua; Xu, Zigang; Yin, Xuefeng

    2012-01-01

    A microfluidic sub-microliter sample introducing system was developed for direct analysis of Chinese rice wine by inductively coupled plasma mass spectrometry (ICP-MS). It consisted of a microfluidic chip integrating variable-volume sampling channels (0.1–0.8 μL), an eight-way multi-functional valve used in flow injection analysis (FIA), a syringe pump and a peristaltic pump of the Ar ICP-MS instrument. Three solutions, i.e., 15, 40 and 100 g L −1 glucose in 20% ethanol were used to simulate Chinese rice wine of the dry type, the semidry type and the semisweet type, each. The effects of their volume introduced into ICP-MS on the plasma stability and ICP-MS intensities were studied. The experimental results showed that neither alteration of plasma stability nor carbon deposition was observed when the sampling volume of 20% ethanol containing 100 g L −1 glucose was downscaled to 0.8 μL. Further reducing the sampling volume to 0.4 μL, no significant difference between the intensities of multi-element standard prepared in three simulated Chinese rice wine matrices and those in aqueous solution was observed. It indicated no negative effect of Chinese rice wine matrix on the ICP-MS intensities. A sampling volume of 0.4 μL was considered to be a good compromise between sensitivity and matrix effect. The flow rate of the carrier was chosen as 20 μL min −1 for obtaining peaks with the highest peak height within the shortest time. Based on these observations, a microflow injection (μFI) method for the direct determination of cadmium and lead in Chinese rice wine by ICP-MS using an external aqueous calibration was developed. The sample throughput was 45 h −1 with the detection limit of 19.8 and 10.4 ng L −1 for Cd and Pb, respectively. The contents of Cd and Pb in 10 Chinese rice wine samples were measured. The results agreed well with those determined by ICP-MS with the conventional sampling system after microwave assisted digestion. The recoveries of three

  7. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained...

  8. Direct gas injection method: A simple modification to an elemental analyzer/isotope ratio mass spectrometer for stable isotope analysis of N and C from N2O and CO2 gases in nanomolar concentrations

    Science.gov (United States)

    A simple modification to the Elemental Analyzer coupled to Isotope Ratio Mass-Spectrometer (EA-IRMS) setup is described. This modification allows the users to measure nitrous oxide (N2O) and carbon dioxide (CO2) by injecting the gases directly into an online injector placed befor...

  9. Analysis of carbohydrates in Fusarium verticillioides using size-exclusion HPLC – DRI and direct analysis in real time ionization – time-of-flight – mass spectrometry (DART-MS)

    Science.gov (United States)

    Direct analysis in real time ionization – time-of-flight – mass spectrometry (DART-MS) and size-exclusion HPLC – DRI are used, respectively, to qualitatively and quantitatively determine the carbohydrates extracted from the corn rot fungus Fusarium verticillioides. In situ permethylation in the DART...

  10. Study of matrix effects on the direct trace analysis of acidic pesticides in water using various liquid chromatographic modes coupled to tandem mass spectrometric detection.

    Science.gov (United States)

    Dijkman, E; Mooibroek, D; Hoogerbrugge, R; Hogendoorn, E; Sancho, J V; Pozo, O; Hernández, F

    2001-08-10

    This study investigated the effects of matrix interferences on the analytical performance of a triple quadrupole mass spectrometric (MS-MS) detector coupled to various reversed-phase liquid chromatographic (LC) modes for the on-line determination of various types of acidic herbicides in water using external calibration for quantification of the analytes tested at a level of 0.4 microg/l. The LC modes included (i) a single-column configuration (LC), (ii) precolumn switching (PC-LC) and (iii) coupled-column LC (LC-LC). As regards detection, electrospray (ESI) and atmospheric pressure chemical ionization (APCI) in both positive (PI) and negative (NI) ionization modes were examined. Salinity and dissolved organic carbon (DOC) were selected as interferences to study matrix effects in this type of analysis. Therefore, Milli-Q and tap water samples both fortified with 12 mg/l DOC and spiked with sulfometuron-methyl, bentazone, bromoxynil, 2-methyl-4-chlorophenoxyacetic acid, and 2-methyl-4-chlorophenoxypropionic acid at a level of about 0.4 microg/l were analyzed with the various LC-MS approaches. Direct sample injection was performed with volumes of 0.25 ml or 2.0 ml on a column of 2.1 mm I.D. or 4.6 mm I.D. for the ESI and APCI modes, respectively. The recovery data were used to compare and evaluate the analytical performance of the various LC approaches. As regards matrix effects, the salinity provided a dramatic decrease in response for early eluting analytes (k value of about 1) when using the LC mode. Both PC-LC and LC-LC efficiently eliminated this problem. The high DOC content hardly effected the responses of analytes in the ESI mode, while in most cases the responses increased when using APCI-MS-MS detection. Of all the tested configurations, LC-LC-ESI-MS-MS with the column combination Discovery C18/ABZ+ was the most favorable as regards elimination of matrix effects and provided reliable quantification of all compounds using external calibration at the tested

  11. Rapid characterization of chemical markers for discrimination of Moutan Cortex and its processed products by direct injection-based mass spectrometry profiling and metabolomic method.

    Science.gov (United States)

    Li, Chao-Ran; Li, Meng-Ning; Yang, Hua; Li, Ping; Gao, Wen

    2018-06-01

    Processing of herbal medicines is a characteristic pharmaceutical technique in Traditional Chinese Medicine, which can reduce toxicity and side effect, improve the flavor and efficacy, and even change the pharmacological action entirely. It is significant and crucial to perform a method to find chemical markers for differentiating herbal medicines in different processed degrees. The aim of this study was to perform a rapid and reasonable method to discriminate Moutan Cortex and its processed products, and to reveal the characteristics of chemical components depend on chemical markers. Thirty batches of Moutan Cortex and its processed products, including 11 batches of Raw Moutan Cortex (RMC), 9 batches of Moutan Cortex Tostus (MCT) and 10 batches of Moutan Cortex Carbonisatus (MCC), were directly injected in electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF MS) for rapid analysis in positive and negative mode. Without chromatographic separation, each run was completed within 3 min. The raw MS data were automatically extracted by background deduction and molecular feature (MF) extraction algorithm. In negative mode, a total of 452 MFs were obtained and then pretreated by data filtration and differential analysis. After that, the filtered 85 MFs were treated by principal component analysis (PCA) to reduce the dimensions. Subsequently, a partial least squares discrimination analysis (PLS-DA) model was constructed for differentiation and chemical markers detection of Moutan Cortex in different processed degrees. The positive mode data were treated as same as those in negative mode. RMC, MCT and MCC were successfully classified. Moreover, 14 and 3 chemical markers from negative and positive mode respectively, were screened by the combination of their relative peak areas and the parameter variable importance in the projection (VIP) values in PLS-DA model. The content changes of these chemical markers were employed in order to illustrate

  12. Determination of human-use pharmaceuticals in filtered water by direct aqueous injection: high-performance liquid chromatography/tandem mass spectrometry

    Science.gov (United States)

    Furlong, Edward T.; Noriega, Mary C.; Kanagy, Christopher J.; Kanagy, Leslie K.; Coffey, Laura J.; Burkhardt, Mark R.

    2014-01-01

    This report describes a method for the determination of 110 human-use pharmaceuticals using a 100-microliter aliquot of a filtered water sample directly injected into a high-performance liquid chromatograph coupled to a triple-quadrupole tandem mass spectrometer using an electrospray ionization source operated in the positive ion mode. The pharmaceuticals were separated by using a reversed-phase gradient of formic acid/ammonium formate-modified water and methanol. Multiple reaction monitoring of two fragmentations of the protonated molecular ion of each pharmaceutical to two unique product ions was used to identify each pharmaceutical qualitatively. The primary multiple reaction monitoring precursor-product ion transition was quantified for each pharmaceutical relative to the primary multiple reaction monitoring precursor-product transition of one of 19 isotope-dilution standard pharmaceuticals or the pesticide atrazine, using an exact stable isotope analogue where possible. Each isotope-dilution standard was selected, when possible, for its chemical similarity to the unlabeled pharmaceutical of interest, and added to the sample after filtration but prior to analysis. Method performance for each pharmaceutical was determined for reagent water, groundwater, treated drinking water, surface water, treated wastewater effluent, and wastewater influent sample matrixes that this method will likely be applied to. Each matrix was evaluated in order of increasing complexity to demonstrate (1) the sensitivity of the method in different water matrixes and (2) the effect of sample matrix, particularly matrix enhancement or suppression of the precursor ion signal, on the quantitative determination of pharmaceutical concentrations. Recovery of water samples spiked (fortified) with the suite of pharmaceuticals determined by this method typically was greater than 90 percent in reagent water, groundwater, drinking water, and surface water. Correction for ambient environmental

  13. Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)

    Energy Technology Data Exchange (ETDEWEB)

    Shum, Sam [Iowa State Univ., Ames, IA (United States)

    1993-05-01

    This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization.

  14. Profiling Nonrecipients of Mass Drug Administration for Schistosomiasis and Hookworm Infections : A Comprehensive Analysis of Praziquantel and Albendazole Coverage in Community-Directed Treatment in Uganda

    NARCIS (Netherlands)

    Chami, Goylette F.; Kontoleon, Andreas A.; Bulte, Erwin; Fenwick, Alan; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2016-01-01

    Background. Repeated mass drug administration (MDA) with preventive chemotherapies is the mainstay of morbidity control for schistosomiasis and soil-transmitted helminths, yet the World Health Organization recently reported that less than one-third of individuals who required preventive

  15. Non-targeted screening for contaminants in paper and board food-contact materials using effect-directed analysis and accurate mass spectrometry

    DEFF Research Database (Denmark)

    Bengtström, Linda; Rosenmai, Anna Kjerstine; Trier, Xenia

    2016-01-01

    Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including......R) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries...... in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven...

  16. Paper Spray and Extraction Spray Mass Spectrometry for the Direct and Simultaneous Quantification of Eight Drugs of Abuse in Whole Blood

    NARCIS (Netherlands)

    Espy, R.D.; Teunissen, S.F.; Manicke, N.E.; Ren, Y.; Ouyang, Z.; van Asten, A.; Cooks, R.G.

    2014-01-01

    Determination of eight drugs of abuse in blood has been performed using paper spray or extraction spray mass spectrometry in under 2 min with minimal sample preparation. A method has been optimized for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA),

  17. Reduced bone mass in obese young rats through PPAR omega suppression of wnt/beta-catenin signaling and direct action of free fatty acids (NEFA)

    Science.gov (United States)

    The relationship of obesity to skeletal development is unclear. We utilized total enteral nutrition to feed high and low fat diets (HFD and LFD) to rats for 4 wks to produce obesity. Weight gain was matched but fat mass, serum leptin and NEFA were increased by HFD (P < 0.05). HFD lowered total bone ...

  18. Rapid activity-directed screening of estrogens by parallel coupling of liquid chromatography with a functional gene reporter assay and mass spectrometry

    NARCIS (Netherlands)

    Jonker, W.; Lamoree, M.H.; Houtman, C.J.; Hamers, T.; Somsen, G.W.; Kool, J.

    2015-01-01

    In this study we developed a new LC nanofractionation platform that combines a human cell (BG1.Luc) gene reporter assay with a high resolution mass spectrometer for the detection and identification of estrogenic and anti-estrogenic compounds in environmental waters. The selection of this assay was

  19. Profiling Nonrecipients of Mass Drug Administration for Schistosomiasis and Hookworm Infections: A Comprehensive Analysis of Praziquantel and Albendazole Coverage in Community-Directed Treatment in Uganda

    NARCIS (Netherlands)

    Chami, G.; Kontoleon, Andreas A.; Bulte, E.H.; Fenwick, Alan

    2016-01-01

    Background. Repeated mass drug administration (MDA) with preventive chemotherapies is the mainstay of morbidity control for schistosomiasis and soil-transmitted helminths, yet the World Health Organization recently reported that less than one-third of individuals who required preventive

  20. Direct detection of dark matter with the EDELWEISS-III experiment: signals induced by charge trapping, data analysis and characterization of cryogenic detector sensitivity to low-mass WIMPs

    International Nuclear Information System (INIS)

    Arnaud, Quentin

    2015-01-01

    The EDELWEISS-III experiment is dedicated to direct dark matter searches aiming at detecting WIMPS. These massive particles should account for more than 80% of the mass of the Universe and be detectable through their elastic scattering on nuclei constituting the absorber of a detector. As the expected WIMP event rate is extremely low ( 20 GeV). Finally, a study dedicated to the optimization of solid cryogenic detectors to low mass WIMP searches is presented. This study is performed on simulated data using a statistical test based on a profiled likelihood ratio that allows for statistical background subtraction and spectral shape discrimination. This study combined with results from Run308, has lead the EDELWEISS experiment to favor low mass WIMP searches ( [fr

  1. Rapid Detection and Identification of Candidemia by Direct Blood Culturing on Solid Medium by Use of Lysis-Centrifugation Method Combined with Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS)

    Science.gov (United States)

    Idelevich, Evgeny A.; Grünastel, Barbara

    2016-01-01

    ABSTRACT Candida sepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successful Candida species identification by matrix-assisted laser desorption–ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems. PMID:27795344

  2. Rapid Detection and Identification of Candidemia by Direct Blood Culturing on Solid Medium by Use of Lysis-Centrifugation Method Combined with Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Idelevich, Evgeny A; Grünastel, Barbara; Becker, Karsten

    2017-01-01

    Candida sepsis is a life-threatening condition with increasing prevalence. In this study, direct blood culturing on solid medium using a lysis-centrifugation procedure enabled successful Candida species identification by matrix-assisted laser desorption-ionization time of flight mass spectrometry on average 3.8 h (Sabouraud agar) or 7.4 h (chocolate agar) before the positivity signal for control samples in Bactec mycosis-IC/F or Bactec Plus aerobic/F bottles, respectively. Direct culturing on solid medium accelerated candidemia diagnostics compared to that with automated broth-based systems. Copyright © 2016 American Society for Microbiology.

  3. Identification of Blood Culture Isolates Directly from Positive Blood Cultures by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and a Commercial Extraction System: Analysis of Performance, Cost, and Turnaround Time

    OpenAIRE

    Lagacé-Wiens, Philippe R. S.; Adam, Heather J.; Karlowsky, James A.; Nichol, Kimberly A.; Pang, Paulette F.; Guenther, Jodi; Webb, Amanda A.; Miller, Crystal; Alfa, Michelle J.

    2012-01-01

    Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry represents a revolution in the rapid identification of bacterial and fungal pathogens in the clinical microbiology laboratory. Recently, MALDI-TOF has been applied directly to positive blood culture bottles for the rapid identification of pathogens, leading to reductions in turnaround time and potentially beneficial patient impacts. The development of a commercially available extraction kit (Bruker Sepsit...

  4. An in-house assay is superior to Sepsityper for direct matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identification of yeast species in blood cultures.

    Science.gov (United States)

    Bidart, Marie; Bonnet, Isabelle; Hennebique, Aurélie; Kherraf, Zine Eddine; Pelloux, Hervé; Berger, François; Cornet, Muriel; Bailly, Sébastien; Maubon, Danièle

    2015-05-01

    We developed an in-house assay for the direct identification, by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, of yeasts in blood culture. Sixty-one representative strains from 12 species were analyzed in spiked blood cultures. Our assay accurately identified 95 of 107 (88.8%) positive blood cultures and outperformed the commercial Sepsityper kit (81.7% identification). Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. "Gone are the days of mass-media marketing plans and short term customer relationships": tobacco industry direct mail and database marketing strategies.

    Science.gov (United States)

    Lewis, M Jane; Ling, Pamela M

    2016-07-01

    As limitations on traditional marketing tactics and scrutiny by tobacco control have increased, the tobacco industry has benefited from direct mail marketing which transmits marketing messages directly to carefully targeted consumers utilising extensive custom consumer databases. However, research in these areas has been limited. This is the first study to examine the development, purposes and extent of direct mail and customer databases. We examined direct mail and database marketing by RJ Reynolds and Philip Morris utilising internal tobacco industry documents from the Legacy Tobacco Document Library employing standard document research techniques. Direct mail marketing utilising industry databases began in the 1970s and grew from the need for a promotional strategy to deal with declining smoking rates, growing numbers of products and a cluttered media landscape. Both RJ Reynolds and Philip Morris started with existing commercial consumer mailing lists, but subsequently decided to build their own databases of smokers' names, addresses, brand preferences, purchase patterns, interests and activities. By the mid-1990s both RJ Reynolds and Philip Morris databases contained at least 30 million smokers' names each. These companies valued direct mail/database marketing's flexibility, efficiency and unique ability to deliver specific messages to particular groups as well as direct mail's limited visibility to tobacco control, public health and regulators. Database marketing is an important and increasingly sophisticated tobacco marketing strategy. Additional research is needed on the prevalence of receipt and exposure to direct mail items and their influence on receivers' perceptions and smoking behaviours. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. “Gone are the days of mass-media marketing plans and short term customer relationships”: tobacco industry direct mail and database marketing strategies

    Science.gov (United States)

    Lewis, M Jane; Ling, Pamela M

    2015-01-01

    Background As limitations on traditional marketing tactics and scrutiny by tobacco control have increased, the tobacco industry has benefited from direct mail marketing which transmits marketing messages directly to carefully targeted consumers utilising extensive custom consumer databases. However, research in these areas has been limited. This is the first study to examine the development, purposes and extent of direct mail and customer databases. Methods We examined direct mail and database marketing by RJ Reynolds and Philip Morris utilising internal tobacco industry documents from the Legacy Tobacco Document Library employing standard document research techniques. Results Direct mail marketing utilising industry databases began in the 1970s and grew from the need for a promotional strategy to deal with declining smoking rates, growing numbers of products and a cluttered media landscape. Both RJ Reynolds and Philip Morris started with existing commercial consumer mailing lists, but subsequently decided to build their own databases of smokers’ names, addresses, brand preferences, purchase patterns, interests and activities. By the mid-1990s both RJ Reynolds and Philip Morris databases contained at least 30 million smokers’ names each. These companies valued direct mail/database marketing’s flexibility, efficiency and unique ability to deliver specific messages to particular groups as well as direct mail’s limited visibility to tobacco control, public health and regulators. Conclusions Database marketing is an important and increasingly sophisticated tobacco marketing strategy. Additional research is needed on the prevalence of receipt and exposure to direct mail items and their influence on receivers’ perceptions and smoking behaviours. PMID:26243810

  7. Charge symmetry breaking via Δ I = 1 group theory or by the u-d quark mass difference and direct photon exchange

    International Nuclear Information System (INIS)

    Coon, S.A.; Scadron, M.D.

    2000-01-01

    Charge symmetry breaking (CSB) in the strong N N interaction is believed to have its origins at the quark level. However, the meson-exchange potentials which successfully describe the empirical CSB utilize instead values of the Δ I = 1 π η and ρ ω mixing obtained with the aid of group theory from a hadronic tadpole Hamiltonian introduced by Coleman and Glashow to describe electromagnetic mass splitting in hadronic isospin multiplets. We review i) the CSB N N potentials so constructed and their nuclear charge asymmetry effects, i i) the universal scale of the Coleman-Glashow tadpole, and i i i) the quark loop evaluation of both meson mass differences and meson mixing. The latter quark loop calculations, which use chiral symmetry to evaluate the integrals, demonstrate clearly that the u-d constituent quark mass difference, long suspected as the origin of CSB, does quantitatively yield the universal Coleman-Glashow tadpole scale which underlies the successful meson-exchange description of CSB in nuclear physics. (Author) 38 refs., 3 figs

  8. Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction

    Science.gov (United States)

    Whiteside, Jessica H.; Olsen, Paul E.; Eglinton, Timothy; Brookfield, Michael E.; Sambrotto, Raymond N.

    2010-01-01

    A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO2. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (n-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO2 super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date. PMID:20308590

  9. Direct determination of cadmium in foods by solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry using a tungsten coil trap

    Science.gov (United States)

    Zhang, Ying; Mao, Xuefei; Liu, Jixin; Wang, Min; Qian, Yongzhong; Gao, Chengling; Qi, Yuehan

    2016-04-01

    In this work, a solid sampling device consisting of a tungsten coil trap, porous carbon vaporizer and on-line ashing furnace of a Ni-Cr coil was interfaced with inductively coupled plasma mass spectrometry (ICP-MS). A modified double gas circuit system was employed that was composed of carrier and supplemental gas lines controlled by separate gas mass flow controllers. For Cd determination in food samples using the assembled solid sampling ICP-MS, the optimal ashing and vaporization conditions, flow rate of the argon-hydrogen (Ar/H2) (v:v = 24:1) carrier gas and supplemental gas, and minimum sampling mass were investigated. Under the optimized conditions, the limit of quantification was 0.5 pg and the relative standard deviation was within a 10.0% error range (n = 10). Furthermore, the mean spiked recoveries for various food samples were 99.4%-105.9% (n = 6). The Cd concentrations measured by the proposed method were all within the certified values of the reference materials or were not significantly different (P > 0.05) from those of the microwave digestion ICP-MS method, demonstrating the good accuracy and precision of the solid sampling ICP-MS method for Cd determination in food samples.

  10. Non-targeted screening for contaminants in paper and board food-contact materials using effect-directed analysis and accurate mass spectrometry.

    Science.gov (United States)

    Bengtström, Linda; Rosenmai, Anna Kjerstine; Trier, Xenia; Jensen, Lisbeth Krüger; Granby, Kit; Vinggaard, Anne Marie; Driffield, Malcolm; Højslev Petersen, Jens

    2016-06-01

    Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including extraction, high-performance liquid chromatography (HPLC) fractionation, tentative identification of relevant substances and in vitro testing of selected tentatively identified substances. As a case study, we used two fractions from a recycled pizza box sample which exhibited aryl hydrocarbon receptor (AhR) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven were commercially available and subsequently tested in vitro and quantified. Of these seven, the identities of three pigments found in printing inks were confirmed by UHPLC tandem mass spectrometry (QqQ MS/MS). Two pigments had entries in the database, meaning that a material relevant accurate mass database can provide a fast tentative identification. Pure standards of the seven tentatively identified substances were tested in vitro but could not explain a significant proportion of the AhR-response in the extract. Targeted analyses of dioxins and PCBs, both well-known AhR agonists, was performed. However, the dioxins could explain approximately 3% of the activity observed in the pizza box extract indicating that some very AhR active substance(s) still remain to be

  11. Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography–mass spectrometry

    NARCIS (Netherlands)

    Akoto, L.; Vreuls, R.J.J.; Irth, H.; Pel, R.; Stellaard, F.

    2008-01-01

    Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

  12. Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry.

    NARCIS (Netherlands)

    Akoto, L.; Vreuls, J.J.; Irth, H.; Pel, R.; Stellaard, F.

    2008-01-01

    Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

  13. Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Akoto, Lawrence; Vreuls, Rene J. J.; Irth, Hubertus; Pel, Roel; Stellaard, Frans

    2008-01-01

    Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

  14. At-line gas chromatographic-mass spectrometric analysis of fatty acid profiles of green microalgae using a direct thermal desorption interface

    NARCIS (Netherlands)

    Blokker, P.; Pel, R.; Akoto, L.; Udo, A.; Brinkman, U.A.Th.; Vreuls, R.J.J.

    2002-01-01

    Thermally assisted hydrolysis and methylation¯gas chromatography (THM¯GC) is an important tool to analyse fatty acid in complex matrices. Since THM¯GC has major drawbacks such as isomerisation when applied to fatty acids in natural matrices, a direct thermal desorption (DTD) interface and an

  15. Direct Determination of Lean Body Mass by CT in F-18 FDG PET/CT Studies: Comparison with Estimates Using Predictive Equations.

    Science.gov (United States)

    Kim, Chang Guhn; Kim, Woo Hyoung; Kim, Myoung Hyoun; Kim, Dae-Weung

    2013-06-01

    The purpose of this study was to estimate lean body mass (LBM) using CT (LBM CTs) and compare the results with LBM estimates of four different predictive equations (LBM PEs) to assess whether LBM CTs and LBM PEs can be used interchangeably for SUV normalization. Whole-body F-18 FDG PET/CT studies were conducted on 392 patients. LBM CT1 is modified adipose tissue-free body mass, and LBM CT2 is adipose tissue-free body mass. Four different PEs were used for comparison (LBM PE1-4). Agreement between the two measurement methods was assessed by Bland-Altman analysis. We calculated the difference between two methods (bias), the percentage of difference, and the limits of agreement, expressed as a percentage. For LBM CTs vs. LBM PEs, except LBM PE3, the ranges of biases and limits of agreement were -3.77 to 3.81 kg and 26.60-35.05 %, respectively, indicating the wide limits of agreement and differing magnitudes of bias. For LBM CTs vs. LBM PE3, LBM PE3 had wider limits of agreement and greater positive bias (44.28-46.19 % and 10.49 to 14.04 kg, respectively), showing unacceptably large discrepancies between LBM CTs and LBM PE3. This study demonstrated that there are substantial discrepancies between individual LBM CTs and LBM PEs, and this should be taken into account when LBM CTs and LBM PEs are used interchangeably between patients.

  16. Direct nano ESI time-of-flight mass spectrometric investigations on lanthanide BTP complexes in the extraction-relevant diluent 1-octanol

    International Nuclear Information System (INIS)

    Steppert, M.; Walther, C.; Geist, A.; Fanghanel, Th.

    2009-01-01

    The present work focuses on investigations of a highly selective ligand for Am(III)/Ln(III) separation: bis-triazinyl-pyridine (BTP). By means of nano-electro-spray mass spectrometry, complex formation of BTP with selected elements of the lanthanide series is investigated. We show that the diluent drastically influences complex speciation. Measurements obtained in the extraction-relevant diluent 1-octanol show the occurrence of Ln(BTP) i (i 1-3) species in different relative abundances, depending on the lanthanide used. Here, the relative abundances of the Ln(BTP) 3 complexes correlate with the distribution ratios for extraction to the organic phase of the respective lanthanide. (authors)

  17. Evaluation of analytical performance and reliability of direct nanoLC-nanoESI-high resolution mass spectrometry for profiling the (xeno)metabolome.

    Science.gov (United States)

    Chetwynd, Andrew J; David, Arthur; Hill, Elizabeth M; Abdul-Sada, Alaa

    2014-10-01

    Mass spectrometry (MS) profiling techniques are used for analysing metabolites and xenobiotics in biofluids; however, detection of low abundance compounds using conventional MS techniques is poor. To counter this, nanoflow ultra-high-pressure liquid chromatography-nanoelectrospray ionization-time-of-flight MS (nUHPLC-nESI-TOFMS), which has been used primarily for proteomics, offers an innovative prospect for profiling small molecules. Compared to conventional UHPLC-ESI-TOFMS, nUHPLC-nESI-TOFMS enhanced detection limits of a variety of (xeno)metabolites by between 2 and 2000-fold. In addition, this study demonstrates for the first time excellent repeatability and reproducibility for analysis of urine and plasma samples using nUHPLC-nESI-TOFMS, supporting implementation of this platform as a novel approach for high-throughput (xeno)metabolomics. Copyright © 2014 John Wiley & Sons, Ltd.

  18. Direct-immersion solid-phase microextraction coupled to fast gas chromatography mass spectrometry as a purification step for polycyclic aromatic hydrocarbons determination in olive oil.

    Science.gov (United States)

    Purcaro, Giorgia; Picardo, Massimo; Barp, Laura; Moret, Sabrina; Conte, Lanfranco S

    2013-09-13

    The aim of the present work was to optimize a preparation step for polycyclic aromatic hydrocarbons in a fatty extract. Solid-phase microextraction is an easy preparation technique, which allows to minimize solvent consumption and reduce sample manipulation. A Carbopack Z/polydimethylsiloxane fiber, particularly suitable for extraction of planar compounds, was employed to extract polycyclic aromatic hydrocarbons from a hexane solution obtained after a previous extraction with acetonitrile from oil, followed by a liquid-liquid partition between acetonitrile and hexane. The proposed method was a rapid and sensitive solution to reduce the interference of triglycerides saving the column life and avoiding frequent cleaning of the mass spectrometer ion source. Despite the non-quantitative extraction of polycyclic aromatic hydrocarbons from oil using acetonitrile, the signal-to-noise ratio was significantly improved obtaining a limit of detection largely below the performance criteria required by the European Union legislation. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Electrophoretic extraction of low molecular weight cationic analytes from sodium dodecyl sulfate containing sample matrices for their direct electrospray ionization mass spectrometry.

    Science.gov (United States)

    Kinde, Tristan F; Lopez, Thomas D; Dutta, Debashis

    2015-03-03

    While the use of sodium dodecyl sulfate (SDS) in separation buffers allows efficient analysis of complex mixtures, its presence in the sample matrix is known to severely interfere with the mass-spectrometric characterization of analyte molecules. In this article, we report a microfluidic device that addresses this analytical challenge by enabling inline electrospray ionization mass spectrometry (ESI-MS) of low molecular weight cationic samples prepared in SDS containing matrices. The functionality of this device relies on the continuous extraction of analyte molecules into an SDS-free solvent stream based on the free-flow zone electrophoresis (FFZE) technique prior to their ESI-MS analysis. The reported extraction was accomplished in our current work in a glass channel with microelectrodes fabricated along its sidewalls to realize the desired electric field. Our experiments show that a key challenge to successfully operating such a device is to suppress the electroosmotically driven fluid circulations generated in its extraction channel that otherwise tend to vigorously mix the liquid streams flowing through this duct. A new coating medium, N-(2-triethoxysilylpropyl) formamide, recently demonstrated by our laboratory to nearly eliminate electroosmotic flow in glass microchannels was employed to address this issue. Applying this surface modifier, we were able to efficiently extract two different peptides, human angiotensin I and MRFA, individually from an SDS containing matrix using the FFZE method and detect them at concentrations down to 3.7 and 6.3 μg/mL, respectively, in samples containing as much as 10 mM SDS. Notice that in addition to greatly reducing the amount of SDS entering the MS instrument, the reported approach allows rapid solvent exchange for facilitating efficient analyte ionization desired in ESI-MS analysis.

  20. Nano-objects emitted during maintenance of common particle generators: direct chemical characterization with aerosol mass spectrometry and implications for risk assessments

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Patrik T., E-mail: patrik.nilsson@design.lth.se; Isaxon, Christina [Lund University, Ergonomics and Aerosol Technology (Sweden); Eriksson, Axel C. [Lund University, Nuclear Physics (Sweden); Messing, Maria E. [Lund University, Solid State Physics (Sweden); Ludvigsson, Linus; Rissler, Jenny [Lund University, Ergonomics and Aerosol Technology (Sweden); Hedmer, Maria; Tinnerberg, Håkan [Lund University, Division of Occupational and Environmental Medicine, Department of Laboratory Medicine (Sweden); Gudmundsson, Anders [Lund University, Ergonomics and Aerosol Technology (Sweden); Deppert, Knut [Lund University, Solid State Physics (Sweden); Bohgard, Mats; Pagels, Joakim H. [Lund University, Ergonomics and Aerosol Technology (Sweden)

    2013-11-15

    Nanotechnology gives us materials with enhanced or completely new properties. At the same time, inhalation of manufactured nano-objects has been related to an array of adverse biological effects. We characterized particle emissions, which occurred during maintenance of common metal nanoparticle generators and contrasted the properties of the emitted particles with those originally produced by the generators. A new approach using online aerosol mass spectrometry (AMS), for time- and size-resolved measurements of the particle chemical composition, was applied in combination with more conventional techniques for particle sampling and analysis, including electron microscopy. Emissions during maintenance work, in terms of mass and surface area concentration in the size range of 0.02–10 μm, were dominated by large agglomerates (1–5 μm). With AMS, we show that the particle composition depends on both generator type and maintenance task being performed and that the instrument can be used for highly time-resolved selective studies of metal nanoparticle emissions. The emitted agglomerates have a relatively high probability to be deposited in the lower respiratory tract, since the mean particle diameter coincided with a peak in the lung deposition curve. Each of these agglomerates consisted of a very high number (10{sup 3}–10{sup 5}/agglomerate) of nanometer-sized primary particles originating from the particle synthesis process. This made them possess large surface areas, one of the key properties in nanotoxicology. Similar agglomerates may be emitted in a wide range of processes when nanoparticles are manufactured or handled. The fate of such agglomerates, once deposited in the respiratory tract, is unknown and should therefore be considered in future particle toxicological studies. Our results highlight the importance of including micrometer-sized particles in exposure and emission assessments.

  1. Nano-objects emitted during maintenance of common particle generators: direct chemical characterization with aerosol mass spectrometry and implications for risk assessments

    International Nuclear Information System (INIS)

    Nilsson, Patrik T.; Isaxon, Christina; Eriksson, Axel C.; Messing, Maria E.; Ludvigsson, Linus; Rissler, Jenny; Hedmer, Maria; Tinnerberg, Håkan; Gudmundsson, Anders; Deppert, Knut; Bohgard, Mats; Pagels, Joakim H.

    2013-01-01

    Nanotechnology gives us materials with enhanced or completely new properties. At the same time, inhalation of manufactured nano-objects has been related to an array of adverse biological effects. We characterized particle emissions, which occurred during maintenance of common metal nanoparticle generators and contrasted the properties of the emitted particles with those originally produced by the generators. A new approach using online aerosol mass spectrometry (AMS), for time- and size-resolved measurements of the particle chemical composition, was applied in combination with more conventional techniques for particle sampling and analysis, including electron microscopy. Emissions during maintenance work, in terms of mass and surface area concentration in the size range of 0.02–10 μm, were dominated by large agglomerates (1–5 μm). With AMS, we show that the particle composition depends on both generator type and maintenance task being performed and that the instrument can be used for highly time-resolved selective studies of metal nanoparticle emissions. The emitted agglomerates have a relatively high probability to be deposited in the lower respiratory tract, since the mean particle diameter coincided with a peak in the lung deposition curve. Each of these agglomerates consisted of a very high number (10 3 –10 5 /agglomerate) of nanometer-sized primary particles originating from the particle synthesis process. This made them possess large surface areas, one of the key properties in nanotoxicology. Similar agglomerates may be emitted in a wide range of processes when nanoparticles are manufactured or handled. The fate of such agglomerates, once deposited in the respiratory tract, is unknown and should therefore be considered in future particle toxicological studies. Our results highlight the importance of including micrometer-sized particles in exposure and emission assessments

  2. FI/SI on-line solvent extraction/back extraction preconcentration coupled to direct injection nebulization inductively coupled plasma mass spectrometry for determination of copper and lead

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection on-line preconcentration procedure for determination of trace levels of copper and lead via solvent extraction/back extraction coupled to ICP-MS is described. In citrate buffer of pH 3, neutral complexes between the analytes and the chelating reagent, ammonium...... loop, the content of which is subsequently introduced into the ICP-MS, via a direct injection high efficiency nebulizer (DIHEN), for quantification. Enrichment factors of 29.6 (Cu) and 23.3 (Pb), detection limits of 17 ng/l (Cu) and 11 ng/l (Pb), along with a sampling frequency of 13 s/h were obtained...

  3. Direct maldi-tof mass spectrometry assay of blood culture broths for rapid identification of Candida species causing bloodstream infections: an observational study in two large microbiology laboratories.

    Science.gov (United States)

    Spanu, Teresa; Posteraro, Brunella; Fiori, Barbara; D'Inzeo, Tiziana; Campoli, Serena; Ruggeri, Alberto; Tumbarello, Mario; Canu, Giulia; Trecarichi, Enrico Maria; Parisi, Gabriella; Tronci, Mirella; Sanguinetti, Maurizio; Fadda, Giovanni

    2012-01-01

    We evaluated the reliability of the Bruker Daltonik's MALDI Biotyper system in species-level identification of yeasts directly from blood culture bottles. Identification results were concordant with those of the conventional culture-based method for 95.9% of Candida albicans (187/195) and 86.5% of non-albicans Candida species (128/148). Results were available in 30 min (median), suggesting that this approach is a reliable, time-saving tool for routine identification of Candida species causing bloodstream infection.

  4. Critical Mass

    CERN Multimedia

    AUTHOR|(CDS)2070299

    2017-01-01

    Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. At CERN it is held once a year in conjunction with the national Swiss campaing "Bike to work".

  5. Determination of organotin compounds in waters by headspace solid phase microextraction gas chromatography triple quadrupole tandem mass spectrometry under the European Water Framework Directive.

    Science.gov (United States)

    Moscoso-Pérez, C; Fernández-González, V; Moreda-Piñeiro, J; López-Mahía, P; Muniategui-Lorenzo, S; Prada-Rodríguez, D

    2015-03-13

    The European Union Water Framework Directive (2013/39/EU) sets very restrictive environmental quality standards for 45 priority substances and other pollutants, including organotin compounds (OTCs). Therefore, it is necessary to develop analytical methods in compliance with the environmental quality standard (EQSs) proposed to protect the aquatic environment and humans. The proposed method (HS-SPME-GC-QqQ-MS/MS) allows the determination of OTCs, i.e. monobutyltin (MBT), dibutyltin (DBT) and TBT in water in the range of few ng L(-1). The method is nearly full automated, sensitive and simple; it involves less reagents, reduces waste, and is less-time consuming than traditional methods for OTCs. As such, the procedure connects with the principles of green analytical chemistry. Additionally, good precision (RSD<20%), a very low method quantification limit (MQL) (0.76 ng L(-1) for TBT by using only 10 mL of sample) and excellent linearity (range MQL-20 ng L(-1)) are achieved. Under these conditions, the very restrictive limits for the environmental quality standards (EQS) fixed by the 2013/39/EU Directive are achieved. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Determination of phthalate esters in vegetable oils using direct immersion solid-phase microextraction and fast gas chromatography coupled with triple quadrupole mass spectrometry.

    Science.gov (United States)

    Barp, Laura; Purcaro, Giorgia; Franchina, Flavio A; Zoccali, Mariosimone; Sciarrone, Danilo; Tranchida, Peter Q; Mondello, Luigi

    2015-08-05

    Phthalates are a group of synthetic compounds mainly used as plasticizers, which have been classified as endocrine-disrupting chemicals and potential human-cancer causing agents. They can be found in high amounts in foods, deriving mainly from plastic packaging. The analytical determination of these compounds is very challenging since they are ubiquitous. Therefore, minimization of sample manipulation is highly desirable. The present work exploited the application of a solid-phase microextraction method for the analysis of phthalates in vegetable oil. A preliminary comparison between a polydimethylsiloxane (PDMS) and a Carbopack Z/PDMS fiber was carried out both in the headspace and direct immersion extraction modes. Before immersing the fiber, a rapid liquid-liquid extraction was performed using acetonitrile to remove the bulk of triglycerides. PDMS in the direct immersion mode showed the best performance. The method was fully validated obtaining a good linearity with a coefficient of correlation of over 0.9960 for all compounds, repeatability and accuracy values generally better than 10%, and very good limit of quantification values. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Spatial localisation of curcumin and rapid screening of the chemical compositions of turmeric rhizomes (Curcuma longa Linn.) using Direct Analysis in Real Time-Mass Spectrometry (DART-MS).

    Science.gov (United States)

    Rahman, A F M Motiur; Angawi, Rihab F; Kadi, Adnan A

    2015-04-15

    Curcumin is a potent antioxidant agent having versatile biological activities is present in turmeric rhizomes (Curcuma longa Linn.). Powder of turmeric rhizomes is consumes as curry spicy worldwide, especially in Asia. In this study, we demonstrate that, bioactive curcumin and its analog demethoxycurcumin are chiefly concentrated in the pith rather than the other parts of the turmeric rhizomes and it was discovered using modern atmospheric ionisation source 'Direct Analysis in Real Time' (DART) connected with an Ion Trap Mass Spectrometry. In addition, all the major components present in turmeric rhizomes were detected in positive and/or in negative ion mode using DART. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effect of the Ion Mass and Energy on the Response of 70-nm SOI Transistors to the Ion Deposited Charge by Direct Ionization

    International Nuclear Information System (INIS)

    Raine, M.; Gaillardin, M.; Sauvestre, J.E.; Flament, O.; Bournel, A.; Aubry-Fortuna, V.

    2010-01-01

    The response of SOI transistors under heavy ion irradiation is analyzed using Geant4 and Synopsys Sentaurus device simulations. The ion mass and energy have a significant impact on the radial ionization profile of the ion deposited charge. For example, for an identical LET, the higher the ion energy per nucleon, the wider the radial ionization track. For a 70-nm SOI technology, the track radius of high energy ions (≥ 10 MeV/a) is larger than the transistor sensitive volume; part of the ion charge recombines in the highly doped source or drain regions and does not participate to the transistor electric response. At lower energy (≤ 10 MeV/a), as often used for ground testing, the track radius is smaller than the transistor sensitive volume, and the entire charge is used for the transistor response. The collected charge is then higher, corresponding to a worst-case response of the transistor. Implications for the hardness assurance of highly-scaled generations are discussed. (authors)

  9. Comparison of dielectric barrier discharge, atmospheric pressure radiofrequency-driven glow discharge and direct analysis in real time sources for ambient mass spectrometry of acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Kratzer, Jan [Institute for National Measurement Standards, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada); Institute of Analytical Chemistry of the ASCR, v.v.i., Veveri 97, CZ-602 00 Brno (Czech Republic); Mester, Zoltan [Institute for National Measurement Standards, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada); Sturgeon, Ralph E., E-mail: Ralph.Sturgeon@nrc-cnrc.gc.ca [Institute for National Measurement Standards, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada)

    2011-08-15

    Three plasma-based ambient pressure ion sources were investigated; laboratory constructed dielectric barrier and rf glow discharges, as well as a commercial corona discharge (DART source). All were used to desorb and ionize a model analyte, providing sampling techniques for ambient mass spectrometry (MS). Experimental parameters were optimized to achive highest signal for acetaminophen as the analyte. Insight into the mechanisms of analyte desorption and ionization was obtained by means of emission spectrometry and ion current measurements. Desorption and ionization mechanisms for this analyte appear to be identical for all three plasma sources. Emission spectra differ only in the intensities of various lines and bands. Desorption of solid analyte requires transfer of thermal energy from the plasma source to sample surface, in the absence of which complete loss of MS response occurs. For acetaminophen, helium was the best plasma gas, providing 100- to 1000-fold higher analyte response than with argon or nitrogen. The same trend was also evident with background ions (protonated water clusters). MS analyte signal intensity correlates with the ion density (expressed as ion current) in the plasma plume and with emission intensity from excited state species in the plasma. These observations support an ionization process which occurs via proton transfer from protonated water clusters to analyte molecules.

  10. Analysis of processing contaminants in edible oils. Part 1. Liquid chromatography-tandem mass spectrometry method for the direct detection of 3-monochloropropanediol monoesters and glycidyl esters.

    Science.gov (United States)

    MacMahon, Shaun; Mazzola, Eugene; Begley, Timothy H; Diachenko, Gregory W

    2013-05-22

    A new analytical method has been developed and validated for the detection of glycidyl esters (GEs) and 3-monochloropropanediol (3-MCPD) monoesters in edible oils. The target compounds represent two classes of potentially carcinogenic chemical contaminants formed during the processing of edible oils. Target analytes are separated from edible oil matrices using a two-step solid-phase extraction (SPE) procedure. The extracts are then analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). Chromatographic conditions that separate sn-1 and sn-2 monoesters of 3-MCPD have been developed for the first time. The method has been validated for GEs, sn-1 3-MCPD monoesters of lauric, myristic, linolenic, linoleic, oleic, and stearic acids, and sn-2 3-MCPD monoesters of oleic and palmitic acids in coconut, olive, and palm oils using an external calibration curve. The range of average recoveries and relative standard deviations (RSDs) across the three oil matrices at three spiking concentrations are 84-115% (3-16% RSD) for the GEs, 95-113% (1-10% RSD) for the sn-1 3-MCPD monoesters, and 76.8-103% (5.1-11.2% RSD) for the sn-2 3-MCPD monoesters, with limits of quantitation at or below 30 ng/g for the GEs, 60 ng/g for sn-1 3-MCPD monoesters, and 180 ng/g for sn-2 3-MCPD monoesters.

  11. Analysis of processing contaminants in edible oils. Part 2. Liquid chromatography-tandem mass spectrometry method for the direct detection of 3-monochloropropanediol and 2-monochloropropanediol diesters.

    Science.gov (United States)

    MacMahon, Shaun; Begley, Timothy H; Diachenko, Gregory W

    2013-05-22

    A method was developed and validated for the detection of fatty acid diesters of 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) in edible oils. These analytes are potentially carcinogenic chemical contaminants formed during edible oil processing. After separation from oil matrices using a two-step solid-phase extraction (SPE) procedure, the target compounds are quantitated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). The first chromatographic conditions have been developed that separate intact diesters of 2-MCPD and 3-MCPD, allowing for their individual quantitation. The method has been validated for 28 3-MCPD diesters of lauric, myristic, palmitic, linolenic, linoleic, oleic, and stearic acids in coconut, olive, and palm oils, as well as 3 2-MCPD diesters, using an external calibration curve. The range of average recoveries and relative standard deviations (RSDs) across the three oil matrices at three spiking concentrations are 88-118% (2-16% RSD) with maximum limits of quantitation of 30 ng/g (ppb).

  12. Direct identification of bacteria from positive BacT/ALERT blood culture bottles using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry.

    Science.gov (United States)

    Mestas, Javier; Felsenstein, Susanna; Bard, Jennifer Dien

    2014-11-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is a fast and robust method for the identification of bacteria. In this study, we evaluate the performance of a laboratory-developed lysis method (LDT) for the rapid identification of bacteria from positive BacT/ALERT blood culture bottles. Of the 168 positive bottles tested, 159 were monomicrobial, the majority of which were Gram-positive organisms (61.0% versus 39.0%). Using a cut-off score of ≥1.7, 80.4% of the organisms were correctly identified to the species level, and the identification rate of Gram-negative organisms (90.3%) was found to be significantly greater than that of Gram-positive organisms (78.4%). The simplicity and cost-effectiveness of the LDT enable it to be fully integrated into the routine workflow of the clinical microbiology laboratory, allowing for rapid identification of Gram-positive and Gram-negative bacteria within an hour of blood culture positivity. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Detection of caffeine in tea, instant coffee, green tea beverage, and soft drink by direct analysis in real time (DART) source coupled to single-quadrupole mass spectrometry.

    Science.gov (United States)

    Wang, Lei; Zhao, Pengyue; Zhang, Fengzu; Bai, Aijuan; Pan, Canping

    2013-01-01

    Ambient ionization direct analysis in real time (DART) coupled to single-quadrupole MS (DART-MS) was evaluated for rapid detection of caffeine in commercial samples without chromatographic separation or sample preparation. Four commercial samples were examined: tea, instant coffee, green tea beverage, and soft drink. The response-related parameters were optimized for the DART temperature and MS fragmentor. Under optimal conditions, the molecular ion (M+H)+ was the major ion for identification of caffeine. The results showed that DART-MS is a promising tool for the quick analysis of important marker molecules in commercial samples. Furthermore, this system has demonstrated significant potential for high sample throughput and real-time analysis.

  14. Rapid method for direct identification of bacteria in urine and blood culture samples by matrix-assisted laser desorption ionization time-of-flight mass spectrometry: intact cell vs. extraction method.

    Science.gov (United States)

    Ferreira, L; Sánchez-Juanes, F; Muñoz-Bellido, J L; González-Buitrago, J M

    2011-07-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable technology for the identification of microorganisms with proteomics approaches. Here, we compare an intact cell method and a protein extraction method before application on the MALDI plate for the direct identification of microorganisms in both urine and blood culture samples from clinical microbiology laboratories. The results show that the intact cell method provides excellent results for urine and is a good initial method for blood cultures. The extraction method complements the intact cell method, improving microorganism identification from blood culture. Thus, we consider that MALDI-TOF MS performed directly on urine and blood culture samples, with the protocols that we propose, is a suitable technique for microorganism identification, as compared with the routine methods used in the clinical microbiology laboratory. © 2010 The Authors. Clinical Microbiology and Infection © 2010 European Society of Clinical Microbiology and Infectious Diseases.

  15. Direct detection of the plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae in infected rice seedlings using matrix assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Kajiwara, Hideyuki

    2016-01-01

    The plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae were directly detected in extracts from infected rice seedlings by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This method did not require culturing of the pathogens on artificial medium. In the MALDI-TOF MS analysis, peaks originating from bacteria were found in extracts from infected rice seedlings. The spectral peaks showed significantly high scores, in spite of minor differences in spectra. The spectral peaks originating from host plant tissues did not affect this direct MALDI-TOF MS analysis for the rapid identification of plant pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Direct identification from positive blood broth culture by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Barberino, Maria Goreth; Silva, Marcio de Oliveira; Arraes, Ana Carolina Palmeiras; Correia, Luís Cláudio; Mendes, Ana Verena

    Bloodstream infections (BSIs) are among the most concerning bacterial infections. They are one of the leading causes of morbidity and mortality, and occur in 30-70% of critical care patients. The prompt identification of the causative microorganism can help choosing the appropriate antimicrobial therapy that will lead to better clinical outcomes. Blood culture is one of the most relevant tests for microbiological diagnosis of bacterial infections. The introduction of the MALDI-TOF microbiological diagnosis significantly decreased the time of identifying microorganisms. However, it depends on the growth on solid culture medium. In this study, 538 bottles of positive blood cultures were evaluated to test the accuracy of an in house modified protocol. The study sample consisted of 198 Gram-negative and 350 Gram-positive bacteria. In all, 460 (83.94%) species were identified based on the direct plate findings. The protocol allowed the identification of 185/198 (93.43%) of the Gram-negative bacteria, including aerobes, anaerobes, and non-fermenters, and 275/350 (78.85%) of the Gram-positive bacteria. The proposed method has the potential to provide accurate results in comparison to the traditional method with the potential to reduce the turnaround time for the results and optimize antimicrobial therapy in BSI. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  17. Direct identification from positive blood broth culture by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS

    Directory of Open Access Journals (Sweden)

    Maria Goreth Barberino

    2017-05-01

    Full Text Available Bloodstream infections (BSIs are among the most concerning bacterial infections. They are one of the leading causes of morbidity and mortality, and occur in 30–70% of critical care patients. The prompt identification of the causative microorganism can help choosing the appropriate antimicrobial therapy that will lead to better clinical outcomes. Blood culture is one of the most relevant tests for microbiological diagnosis of bacterial infections. The introduction of the MALDI-TOF microbiological diagnosis significantly decreased the time of identifying microorganisms. However, it depends on the growth on solid culture medium. In this study, 538 bottles of positive blood cultures were evaluated to test the accuracy of an in house modified protocol. The study sample consisted of 198 Gram-negative and 350 Gram-positive bacteria. In all, 460 (83.94% species were identified based on the direct plate findings. The protocol allowed the identification of 185/198 (93.43% of the Gram-negative bacteria, including aerobes, anaerobes, and non-fermenters, and 275/350 (78.85% of the Gram-positive bacteria. The proposed method has the potential to provide accurate results in comparison to the traditional method with the potential to reduce the turnaround time for the results and optimize antimicrobial therapy in BSI.

  18. Direct analysis and identification of pathogenic Lichtheimia species by matrix-assisted laser desorption ionization-time of flight analyzer-mediated mass spectrometry.

    Science.gov (United States)

    Schrödl, Wieland; Heydel, Tilo; Schwartze, Volker U; Hoffmann, Kerstin; Grosse-Herrenthey, Anke; Walther, Grit; Alastruey-Izquierdo, Ana; Rodriguez-Tudela, Juan Luis; Olias, Philipp; Jacobsen, Ilse D; de Hoog, G Sybren; Voigt, Kerstin

    2012-02-01

    Zygomycetes of the order Mucorales can cause life-threatening infections in humans. These mucormycoses are emerging and associated with a rapid tissue destruction and high mortality. The resistance of Mucorales to antimycotic substances varies between and within clinically important genera such as Mucor, Rhizopus, and Lichtheimia. Thus, an accurate diagnosis before onset of antimycotic therapy is recommended. Matrix-assisted laser desorption ionization (MALDI)-time of flight (TOF) mass spectrometry (MS) is a potentially powerful tool to rapidly identify infectious agents on the species level. We investigated the potential of MALDI-TOF MS to differentiate Lichtheimia species, one of the most important agents of mucormycoses. Using the Bruker Daltonics FlexAnalysis (version 3.0) software package, a spectral database library with m/z ratios of 2,000 to 20,000 Da was created for 19 type and reference strains of clinically relevant Zygomycetes of the order Mucorales (12 species in 7 genera). The database was tested for accuracy by use of 34 clinical and environmental isolates of Lichtheimia comprising a total of five species. Our data demonstrate that MALDI-TOF MS can be used to clearly discriminate Lichtheimia species from other pathogenic species of the Mucorales. Furthermore, the method is suitable to discriminate species within the genus. The reliability and robustness of the MALDI-TOF-based identification are evidenced by high score values (above 2.3) for the designation to a certain species and by moderate score values (below 2.0) for the discrimination between clinically relevant (Lichtheimia corymbifera, L. ramosa, and L. ornata) and irrelevant (L. hyalospora and L. sphaerocystis) species. In total, all 34 strains were unequivocally identified by MALDI-TOF MS with score values of >1.8 down to the generic level, 32 out of 34 of the Lichtheimia isolates (except CNM-CM 5399 and FSU 10566) were identified accurately with score values of >2 (probable species

  19. Direct Analysis and Identification of Pathogenic Lichtheimia Species by Matrix-Assisted Laser Desorption Ionization–Time of Flight Analyzer-Mediated Mass Spectrometry

    Science.gov (United States)

    Schrödl, Wieland; Heydel, Tilo; Schwartze, Volker U.; Hoffmann, Kerstin; Große-Herrenthey, Anke; Walther, Grit; Alastruey-Izquierdo, Ana; Rodriguez-Tudela, Juan Luis; Olias, Philipp; Jacobsen, Ilse D.; de Hoog, G. Sybren

    2012-01-01

    Zygomycetes of the order Mucorales can cause life-threatening infections in humans. These mucormycoses are emerging and associated with a rapid tissue destruction and high mortality. The resistance of Mucorales to antimycotic substances varies between and within clinically important genera such as Mucor, Rhizopus, and Lichtheimia. Thus, an accurate diagnosis before onset of antimycotic therapy is recommended. Matrix-assisted laser desorption ionization (MALDI)–time of flight (TOF) mass spectrometry (MS) is a potentially powerful tool to rapidly identify infectious agents on the species level. We investigated the potential of MALDI-TOF MS to differentiate Lichtheimia species, one of the most important agents of mucormycoses. Using the Bruker Daltonics FlexAnalysis (version 3.0) software package, a spectral database library with m/z ratios of 2,000 to 20,000 Da was created for 19 type and reference strains of clinically relevant Zygomycetes of the order Mucorales (12 species in 7 genera). The database was tested for accuracy by use of 34 clinical and environmental isolates of Lichtheimia comprising a total of five species. Our data demonstrate that MALDI-TOF MS can be used to clearly discriminate Lichtheimia species from other pathogenic species of the Mucorales. Furthermore, the method is suitable to discriminate species within the genus. The reliability and robustness of the MALDI-TOF-based identification are evidenced by high score values (above 2.3) for the designation to a certain species and by moderate score values (below 2.0) for the discrimination between clinically relevant (Lichtheimia corymbifera, L. ramosa, and L. ornata) and irrelevant (L. hyalospora and L. sphaerocystis) species. In total, all 34 strains were unequivocally identified by MALDI-TOF MS with score values of >1.8 down to the generic level, 32 out of 34 of the Lichtheimia isolates (except CNM-CM 5399 and FSU 10566) were identified accurately with score values of >2 (probable species

  20. Still mesoendemic onchocerciasis in two Cameroonian community-directed treatment with ivermectin projects despite more than 15 years of mass treatment

    Directory of Open Access Journals (Sweden)

    Guy-Roger Kamga

    2016-11-01

    Full Text Available Abstract Background After more than a decade of community-directed treatment with ivermectin (CDTI in Centre and Littoral Regions of Cameroon, onchocerciasis endemicity was still high in some communities according to the 2011 epidemiological evaluations. Some corrective measures were undertaken to improve the CDTI process and therefore reduce the burden of the disease. The objective of the present study was to assess the progress made towards the elimination of onchocerciasis in the Centre 1 and Littoral 2 CDTI projects where the worst performances were found in 2011. To this end, a cross-sectional survey was conducted in April 2015 in eight communities in two health districts (HD, Bafia in Centre 1 and Yabassi in Littoral 2, chosen because assessed at baseline and in 2011. All volunteers living for at least five years in the community, aged five years or more, underwent clinical and parasitological examinations. Individual compliance to ivermectin treatment was also assessed. Analyses of data were weighted proportionally to age and gender distribution in the population. Results In the Bafia and Yabassi HD, 514 and 242 individuals were examined with a mean age of 35.1 (standard deviation, SD: 20.7 and 44.6 (SD: 16.3 years, respectively. In the Bafia HD, the weighted prevalences varied from 24.4 to 57.0 % for microfilaridermia and from 3.6 to 37.4 % for nodule presence across the surveyed communities. The community microfilarial load (CMFL, expressed in microfilariae/skin snip (mf/ss, significantly dropped from 20.84–114.50 mf/ss in 1991 to 0.31–1.62 mf/ss in 2015 in all the surveyed communities. In the Yabassi HD, the weighted prevalences varied from 12.3 to 59.3 % for microfilaridermia and from 1.5 to 3.7 % for nodule presence across the surveyed communities, while a significant drop was observed in CMFL, from 20.40–28.50 mf/ss in 1999 to 0.48–1.74 mf/ss in 2015. The 2014 weighted therapeutic coverage of participants varied from 65

  1. Direct bacterial identification from positive blood cultures using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry: A systematic review and meta-analysis.

    Science.gov (United States)

    Ruiz-Aragón, Jesús; Ballestero-Téllez, Mónica; Gutiérrez-Gutiérrez, Belén; de Cueto, Marina; Rodríguez-Baño, Jesús; Pascual, Álvaro

    2017-10-27

    The rapid identification of bacteraemia-causing pathogens could assist clinicians in the timely prescription of targeted therapy, thereby reducing the morbidity and mortality of this infection. In recent years, numerous techniques that rapidly and directly identify positive blood cultures have been marketed, with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) being one of the most commonly used. The aim of this systematic review and meta-analysis was to evaluate the accuracy of MALDI-TOF (Bruker ® ) for the direct identification of positive blood culture bottles. A meta-analysis was performed to summarize the results of the 32 studies evaluated. The overall quality of the studies was moderate. For Gram-positive bacteria, overall rates of correct identification of the species ranged from 0.17 to 0.98, with a cumulative rate (random-effects model) of 0.72 (95% CI: 0.64-0.80). For Gram-negative bacteria, correct identification rates ranged from 0.66 to 1.00, with a cumulative effect of 0.92 (95% CI: 0.88-0.95). For Enterobacteriaceae, the rate was 0.96 (95% CI: 0.94-0.97). MALDI-TOF mass spectrometry shows high accuracy for the correct identification of Gram-negative bacteria, particularly Enterobacteriaceae, directly from positive blood culture bottles, and moderate accuracy for the identification of Gram-positive bacteria (low for some species). Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  2. Identification of blood culture isolates directly from positive blood cultures by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry and a commercial extraction system: analysis of performance, cost, and turnaround time.

    Science.gov (United States)

    Lagacé-Wiens, Philippe R S; Adam, Heather J; Karlowsky, James A; Nichol, Kimberly A; Pang, Paulette F; Guenther, Jodi; Webb, Amanda A; Miller, Crystal; Alfa, Michelle J

    2012-10-01

    Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry represents a revolution in the rapid identification of bacterial and fungal pathogens in the clinical microbiology laboratory. Recently, MALDI-TOF has been applied directly to positive blood culture bottles for the rapid identification of pathogens, leading to reductions in turnaround time and potentially beneficial patient impacts. The development of a commercially available extraction kit (Bruker Sepsityper) for use with the Bruker MALDI BioTyper has facilitated the processing required for identification of pathogens directly from positive from blood cultures. We report the results of an evaluation of the accuracy, cost, and turnaround time of this method for 61 positive monomicrobial and 2 polymicrobial cultures representing 26 species. The Bruker MALDI BioTyper with the Sepsityper gave a valid (score, >1.7) identification for 85.2% of positive blood cultures with no misidentifications. The mean reduction in turnaround time to identification was 34.3 h (P MALDI-TOF was used for all blood cultures and 26.5 h in a more practical setting where conventional identification or identification from subcultures was required for isolates that could not be directly identified by MALDI-TOF. Implementation of a MALDI-TOF-based identification system for direct identification of pathogens from blood cultures is expected to be associated with a marginal increase in operating costs for most laboratories. However, the use of MALDI-TOF for direct identification is accurate and should result in reduced turnaround time to identification.

  3. Variation of polycyclic aromatic hydrocarbons in atmospheric PM2.5 during winter haze period around 2014 Chinese Spring Festival at Nanjing: Insights of source changes, air mass direction and firework particle injection.

    Science.gov (United States)

    Kong, Shaofei; Li, Xuxu; Li, Li; Yin, Yan; Chen, Kui; Yuan, Liang; Zhang, Yingjie; Shan, Yunpeng; Ji, Yaqin

    2015-07-01

    Daily PM2.5 samples were collected at a suburban site of Nanjing around 2014 Chinese Spring Festival (SF) and analyzed for 18 kinds of polycyclic aromatic hydrocarbons (PAHs) by GC-MS. Comparison of PAH concentrations during different periods, with different air mass origins and under different pollution situations was done. Sources were analyzed by diagnostics ratios and principal component analysis (PCA). The threat of PAHs was assessed by BaP equivalent concentrations (BaPeq) and incremental lifetime cancer risk (ILCR). The averaged PAHs for pre-SF, SF and after SF periods were 50.6, 17.2 and 29 ng m(-3), indicating the variations of PAH sources, with reduced traffic, industrial and construction activities during SF and gradually re-starting of them after-SF. According to PAH mass concentrations, their relative abundance to particles, ratio of PAHs (3-ring+4-ring)/PAHs(5-ring+6-ring), mass concentrations of combustion-derived and carcinogenic PAHs, fireworks burning is an important source for PAHs during SF. The ILCR values for Chinese New Year day were 0.68 and 3.3 per 100,000 exposed children and adults. It suggested the necessity of controlling fireworks burning during Chinese SF period which was always companied with serious regional haze pollution. PAH concentrations exhibited decreasing trend when air masses coming from the following directions as North China Plain (63.9 ng m(-3))>Central China (53.0 ng m(-3))>Shandong Peninsula (46.6 ng m(-3))>Northwest China (18.8 ng m(-3))>Sea (15.8 ng m(-3)). For different pollution situations, they decreased as haze (44.5 ng m(-3))>fog-haze (28.4 ng m(-3))>clear (12.2 ng m(-3))>fog day (9.2 ng m(-3)). Coal combustion, traffic emission, industrial processes and petroleum (only for non-SF holiday periodss) were the main sources of PM2.5 associated PAHs. Fireworks burning contributed 14.0% of PAHs during SF period. Directly measurement of PAHs from fireworks burning is urgently needed for source apportionment studies in

  4. Gas chromatography: mass selective detector

    International Nuclear Information System (INIS)

    Lapinskas, R.

    1988-01-01

    The mechanism of mass spectrometry technique directed for detecting molecular structures is described, with some considerations about its operational features. This mass spectrometer is used as a gas chromatography detector. (author)

  5. Measurements of neutrino mass

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1985-01-01

    Direct experimental information of neutrino mass as derived from the study of nuclear and elementary-particle weak decays is reviewed. Topics include tritium beta decay; the 3 He-T mass difference; electron capture decay of 163 Ho and 158 Tb; and limits on massive neutrinos from cosmology. 38 references

  6. The sensitivity of direct identification from positive BacT/ALERT™ (bioMérieux) blood culture bottles by matrix-assisted laser desorption ionization time-of-flight mass spectrometry is low.

    Science.gov (United States)

    Szabados, F; Michels, M; Kaase, M; Gatermann, S

    2011-02-01

    Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been presented as a novel method for the direct identification of bacteria from positive blood culture bottles. The rate of the MALDI TOF MS-based identification in the present study from positive BacT/ALERT (bioMérieux, Marcy l'Etoile, France) blood culture bottles was 30%, which is far below the previously reported sensitivities using the BACTEC (Becton Dickinson, Franklin Lakes, NJ, USA) system. We also found evidence that the Biotyper algorithm did not identify a second pathogen in cases of positive BacT/ALERT blood culture bottles containing two different species. © 2010 The Authors. Journal Compilation © 2010 European Society of Clinical Microbiology and Infectious Diseases.

  7. High-speed homogenization coupled with microwave-assisted extraction followed by liquid chromatography-tandem mass spectrometry for the direct determination of alkaloids and flavonoids in fresh Isatis tinctoria L. hairy root cultures.

    Science.gov (United States)

    Jiao, Jiao; Gai, Qing-Yan; Zhang, Lin; Wang, Wei; Luo, Meng; Zu, Yuan-Gang; Fu, Yu-Jie

    2015-06-01

    A new, simple and efficient analysis method for fresh plant in vitro cultures-namely, high-speed homogenization coupled with microwave-assisted extraction (HSH-MAE) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-was developed for simultaneous determination of six alkaloids and eight flavonoids in Isatis tinctoria hairy root cultures (ITHRCs). Compared with traditional methods, the proposed HSH-MAE offers the advantages of easy manipulation, higher efficiency, energy saving, and reduced waste. Cytohistological studies were conducted to clarify the mechanism of HSH-MAE at cellular/tissue levels. Moreover, the established LC-MS/MS method showed excellent linearity, precision, repeatability, and reproducibility. The HSH-MAE-LC-MS/MS method was also successfully applied for screening high-productivity ITHRCs. Overall, this study opened up a new avenue for the direct determination of secondary metabolic profiles from fresh plant in vitro cultures, which is valuable for improving quality control of plant cell/organ cultures and sheds light on the metabolomic analysis of biological samples. Graphical Abstract HSH-MAE-LC-MS/MS opened up a new avenue for the direct determination of alkaloids and flavonoids in fresh Isatis tinctoria hairy root cultures.

  8. Direct identification of microorganisms from positive blood cultures using the lysis-filtration technique and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS): a multicentre study.

    Science.gov (United States)

    Farina, Claudio; Arena, Fabio; Casprini, Patrizia; Cichero, Paola; Clementi, Massimo; Cosentino, Marina; Degl'Innocenti, Roberto; Giani, Tommaso; Luzzaro, Francesco; Mattei, Romano; Mauri, Carola; Nardone, Maria; Rossolini, Gian Maria; Serna Ortega, Paula Andrea; Vailati, Francesca

    2015-04-01

    Microbial identification from blood cultures is essential to institute optimal antibiotic therapy and improve survival possibilities. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been successfully applied to identify bacteria and yeasts from positive blood cultures broths. The aim of this multicentre study was to evaluate the reliability of the lysis-filtration technique associated with MALDI-TOF MS to directly identify microorganisms from 765 positive blood cultures collected in six Italian hospitals. Overall, 675/765 (78.1%) blood isolates were correctly identified at the species level, with significant differences between Gram-negative and Gram-positive bacteria (92.6%, and 69.8%, respectively). Some difficulties arise in identifying Streptococcus pneumoniae, Staphylococcus aureus, yeasts and anaerobes. The lysis-filtration protocol is a suitable procedure in terms of performance in identifying microorganisms, but it is quite expensive and technically time-consuming since the time of filtration is not regular for all the samples. The application of the MALDI-TOF MS technique to the direct microbial identification from positive blood cultures is a very promising approach, even if more experience must be gained to minimize errors and costs.

  9. Direct identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS from positive blood culture bottles: An opportunity to customize growth conditions for fastidious organisms causing bloodstream infections

    Directory of Open Access Journals (Sweden)

    Megha Sharma

    2017-01-01

    Full Text Available Culture-negative bacteraemia has been an enigmatic entity with respect to its aetiological agents. In an attempt to actively identify those positive blood cultures that escape isolation and detection on routine workflow, an additional step of MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry based detection was carried out directly from the flagged blood culture bottles. Blood samples from 200 blood culture bottles that beeped positive with automated (BACTEC system and showed no growth of organism on routine culture media, were subjected to analysis by MALDI-TOF MS. Forty seven of the 200 (23.5% bacterial aetiology could be established by bottle-based method. Based on these results, growth on culture medium could be achieved for the isolates by providing special growth conditions to the fastidious organisms. Direct identification by MALDI-TOF MS from BACTEC-positive bottles provided an opportunity to isolate those fastidious organisms that failed to grow on routine culture medium by providing them with necessary alterations in growth environment.

  10. Direct identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from positive blood culture bottles: An opportunity to customize growth conditions for fastidious organisms causing bloodstream infections.

    Science.gov (United States)

    Sharma, Megha; Gautam, Vikas; Mahajan, Monika; Rana, Sudesh; Majumdar, Manasi; Ray, Pallab

    2017-10-01

    Culture-negative bacteraemia has been an enigmatic entity with respect to its aetiological agents. In an attempt to actively identify those positive blood cultures that escape isolation and detection on routine workflow, an additional step of MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) based detection was carried out directly from the flagged blood culture bottles. Blood samples from 200 blood culture bottles that beeped positive with automated (BACTEC) system and showed no growth of organism on routine culture media, were subjected to analysis by MALDI-TOF MS. Forty seven of the 200 (23.5%) bacterial aetiology could be established by bottle-based method. Based on these results, growth on culture medium could be achieved for the isolates by providing special growth conditions to the fastidious organisms. Direct identification by MALDI-TOF MS from BACTEC-positive bottles provided an opportunity to isolate those fastidious organisms that failed to grow on routine culture medium by providing them with necessary alterations in growth environment.

  11. Characterization of TiAlN thin film annealed under O2 by in situ time of flight direct recoil spectroscopy/mass spectroscopy of recoiled ions and ex situ x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Tempez, A.; Bensaoula, A.; Schultz, A.

    2002-01-01

    The oxidation of an amorphous TiAlN coating has been studied by in situ direct recoil spectroscopy (DRS) and mass spectroscopy of recoiled ions (MSRI) and ex situ x-ray photoelectron spectroscopy (XPS). DRS and MSRI monitored the changes in surface composition as the sample was heated to 460 deg. C under an 18 O 2 pressure of 10 -6 Torr. Angular resolved XPS data were acquired for thickness-dependence information. The initial surface was partially oxidized from air exposure. Both DRS and XPS showed the Al-rich near surface and the presence of N in the subsurface. As shown by DRS and MSRI, oxidation at elevated temperatures yielded surface nitrogen loss and Ti enrichment. XPS confirmed the preferential formation of TiO 2 on the surface. This study also provides a comparison between the direct recoil (neutrals and ions) and the ionic recoil signals. In our conditions, the negative ionic fraction of all elements except H tracks their true surface content variations given by DRS. The results were compared with early work performed on identical samples. In this case the TiAlN film was oxidized with an O 2 pressure in the mTorr range and the surface changes are followed in situ by positive MSRI and XPS. This experiment also indicates that Al and N are buried under TiO 2 but from 600 deg. C

  12. Direct Identification and Antimicrobial Susceptibility Testing of Bacteria From Positive Blood Culture Bottles by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry and the Vitek 2 System.

    Science.gov (United States)

    Jo, Sung Jin; Park, Kang Gyun; Han, Kyungja; Park, Dong Jin; Park, Yeon-Joon

    2016-03-01

    We evaluated the reliability and accuracy of the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial identification and Vitek 2 antimicrobial susceptibility testing (AST) for bacteria from positive blood culture bottles. Direct identification and AST were performed in parallel to the standard methods in monomicrobial positive blood culture bottles. In total, 254 isolates grown on aerobic and/or anaerobic bottles were identified with MALDI-TOF Vitek MS (bioMérieux, France), and 1,978 microorganism/antimicrobial agent combinations were assessed. For isolates from anaerobic bottles, an aliquot of the culture broth was centrifuged, washed, and filtered through a nylon mesh. For isolates from aerobic/pediatric bottles, a lysis step using 9.26% ammonium chloride solution and 2% saponin solution was included. The overall correct identification rate was 81.8% (208/254) and that for gram-positive/gram-negative isolates was 73.9%/92.6%, respectively, and it was 81.8%, 87.6%, and 57.9% for isolates from aerobic, anaerobic, and pediatric bottles, respectively. Identification was not possible in 45 cases, and most of these isolates were streptococci (N=14) and coagulase-negative staphylococci (N=11). Misidentification occurred only in one case. Compared with standard methods, direct AST showed 97.9% (1,936/1,978) agreement with very major error of 0.25%, major error of 0.05%, and minor error of 1.8%. This simple and cost-effective sample preparation method gives reliable results for the direct identification and AST of bacteria. For the identification of streptococci and coagulase-negative staphylococci, the method should be further improved.

  13. ZZ-CENPL, Chinese Evaluated Nuclear Parameter Library. ZZ CENPL-DLS, Discrete Level Schemes and Gamma Branching Ratios Library; ZZ CENPL-FBP, Fission Barrier Parameter Library; ZZ CENPL-GDRP, Giant Dipole Resonance Parameter Library; ZZ CENPL-NLD, Nuclear Level Density Parameter Library; ZZ CENPL-MCC, Nuclear Ground State Atomic Masses Library; ZZ CENPL-OMP, Optical Model Parameter Library

    International Nuclear Information System (INIS)

    Su Zongdi

    1995-01-01

    Description of program or function: CENPL - GDRP (Giant Dipole Resonance Parameters for Gamma-Ray): - Format: special format described in documentation; - Nuclides: V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Lu, Ta, W, Re, Os, Ir, Pt, Au, Hg, Pb, Bi, Th, U, Np, Pu. - Origin: Experimental values offered by S.S. Dietrich and B.L. Berman. CENPL - FBP (Fission Barrier Parameter Sub-Library): - Format: special format described in documentation; - Nuclides: (1) 51 nuclei region from Th-230 to Cf-255, (2) 46 nuclei region from Th-229 to Cf-253, (3) 24 nuclei region from Pa-232 to Cf-253; - Origin: (1) Lynn, (2) Analysis of experimental data by Back et al., (3) Ohsawa. CENPL - DLS (Discrete level scheme and branch ratio of gamma decay: - Format: Special format described in documentation; - Origin: ENSDF - BNL. CENPL - NLD (Nuclear Level Density): - Format: Special format described in documentation; - Origin: Huang Zhongfu et al. CENPL - OMP (Optical model parameter sub-library): - Format: special format described in documentation ; - Origin: CENDL, ENDF/B-VI, JENDL-3. CENPL - MC (I) and (II) (Atomic masses and characteristic constants for nuclear ground states) : - Format: Brief table format; - Nuclides: 4760 nuclides ranging from Z=0 A=1 to Z=122 A=318. - Origin: Experimental data and systematic results evaluated by Wapstra, theoretical results calculated by Moller, ENSDF - BNL and Nuclear Wallet Cards. CENPL contains the following six sub-libraries: 1. Atomic Masses and Characteristic Constants for nuclear ground states (MCC). This data consists of calculated and in most cases also measured mass excesses, atomic masses, total binding energies, spins, parities, and half-lives of nuclear ground states, abundances, etc. for 4800 nuclides. 2. Discrete Level Schemes and branching ratios of gamma decay (DLS). The data on nuclear discrete levels are based on the Evaluated

  14. 直接实时分析质谱超速分析在药品监管中的应用%Ultra Speed Direct Analysis in Real Time Mass Spectrometry(DART-MS)for Drug Administration

    Institute of Scientific and Technical Information of China (English)

    王铁松; 张喆; 赵明; 车宝泉; 高青; 王威

    2011-01-01

    目的 建立直接实时分析质谱(DART-MS)超速分析方法应用于药品监管检验工作.方法 DART-MS将实时直接分析离子源(DART)与离子阱质谱联用,离子源放电电压为4kV,载气为氦气,流速为6L· min(-1),温度为400℃.在不进行样品色谱分离的前提下,直接分析被测物质或其溶液.结果 DART-MS与液质联用相比检定效率提高近50倍,对西地那非、米诺地尔等已知物质可在20s内检测出,对未知衍生物可在4 min内完成其多级质谱研究,对传统液相色谱法难以分析的辅料如混合脂肪酸甘油酯等也能准确分析.结论 DART-MS样品处理简单,方法准确速度快,能广泛应用于非法添加、药物污染、制剂辅料成分的快速检定,开创了药品监管的新方法,能有效提高对突发安全事件的反应能力.%OBJECTIVE To establish an ultra speed direct analysis in real time (DART)-ion trap mass spectrometry method for screening of shampoo and herbal remedies for the presence of illegal additives. METHODS The DART temperature was 400 ℃, the helium flow rate was 6 L · min-1 and the mass cone voltage was 4 kV. The solution was directly screened using a 12-DIP sampler. RESULTS The speed of DART-MS was 50 times faster than that of LC-MS for identifying the additives including minoxidil,sildenafil,and mixed glycerides. CONCLUSION Each additive studied was rapidly identified within 20 seconds by DART-MS/MS, sugggesting this technique can be used for drug administration. However,its sensitivity and quantitation still requires further study and improvement.

  15. Direct analysis of prostaglandin-E2 and -D2 produced in an inflammatory cell reaction and its application for activity screening and potency evaluation using turbulent flow chromatography liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Shin, Jeong-Sook; Peng, Lei; Kang, Kyungsu; Choi, Yongsoo

    2016-09-09

    Direct analysis of prostaglandin-E2 (PGE2) and -D2 (PGD2) produced from a RAW264.7 cell-based reaction was performed by liquid chromatography high-resolution mass spectrometry (LC-HRMS), which was online coupled with turbulent flow chromatography (TFC). The capability of this method to accurately measure PG levels in cell reaction medium containing cytokines or proteins as a reaction byproduct was cross-validated by two conventional methods. Two methods, including an LC-HRMS method after liquid-liquid extraction (LLE) of the sample and a commercial PGE2 enzyme-linked immunosorbent assay (ELISA), showed PGE2 and/or PGD2 levels almost similar to those obtained by TFC LC-HRMS over the reaction time after LPS stimulation. After the cross-validation, significant analytical throughputs, allowing simultaneous screening and potency evaluation of 80 natural products including 60 phytochemicals and 20 natural product extracts for the inhibition of the PGD2 produced in the cell-based inflammatory reaction, were achieved using the TFC LC-HRMS method developed. Among the 60 phytochemicals screened, licochalcone A and formononetin inhibited PGD2 production the most with IC50 values of 126 and 151nM, respectively. For a reference activity, indomethacin and diclofenac were used, measuring IC50 values of 0.64 and 0.21nM, respectively. This method also found a butanol extract of Akebia quinata Decne (AQ) stem as a promising natural product for PGD2 inhibition. Direct and accurate analysis of PGs in the inflammatory cell reaction using the TFC LC-HRMS method developed enables the high-throughput screening and potency evaluation of as many as 320 samples in less than 48h without changing a TFC column. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Direct Determination of Molecular Weight Distribution of Calf-Thymus DNAs and Study of Their Fragmentation under Ultrasonic and Low-Energy IR Irradiations. A Charge Detection Mass Spectrometry Investigation.

    Science.gov (United States)

    Halim, Mohammad A; Bertorelle, Franck; Doussineau, Tristan; Antoine, Rodolphe

    2018-06-09

    Calf-thymus (CT-DNA) is widely used as binding agent. The commercial samples are known to be "highly polymerized DNA" samples. CT-DNA is known to be fragile in particular upon ultrasonic wave irradiation. Degradation products might have dramatic consequence on its bio-sensing activity, and an accurate determination of the molecular weight distribution and stability of commercial samples is highly demanded. We investigated the sensitivity of charge detection mass spectrometry (CDMS), a single-molecule MS method, both with single-pass and ion trap CDMS ("Benner" trap) modes to the determination of the composition and stability (under multiphoton IR irradiation) of calf-thymus DNAs. We also investigated the changes of molecular weight distributions in the course of sonication by irradiating ultrasonic wave to CT-DNA. We report for the first time, the direct molecular weight (MW) distribution of DNA sodium salt from calf-thymus revealing two populations at high (~10 MDa) and low (~3 MDa) molecular weights. We evidence a transition between the high-MW to the low-MW distribution, confirming that the low-MW distribution results from degradation of CT-DNA. Finally, we report also IRMPD experiments carried out on trapped single-stranded linear DNAs from calf-thymus allowing to extract their activation energy for unimolecular dissociation. We show that single-pass CDMS is a direct, efficient and accurate MS-based approach to determine the composition of calf-thymus DNAs. Furthermore, ion trap CDMS allows us to evaluate the stability (both under multiphoton IR irradiation and in the course of sonication by irradiating ultrasonic wave) of calf-thymus DNAs. This article is protected by copyright. All rights reserved.

  17. Direct Detection of Complex Organic Products in Ultraviolet (Lyα) and Electron-irradiated Astrophysical and Cometary Ice Analogs Using Two-step Laser Ablation and Ionization Mass Spectrometry

    Science.gov (United States)

    Henderson, Bryana L.; Gudipati, Murthy S.

    2015-02-01

    As discovery of complex molecules and ions in our solar system and the interstellar medium has proliferated, several groups have turned to laboratory experiments in an effort to simulate and understand these chemical processes. So far only infrared (IR) and ultraviolet (UV) spectroscopy has been able to directly probe these reactions in ices in their native, low-temperature states. Here we report for the first time results using a complementary technique that harnesses two-step two-color laser ablation and ionization to measure mass spectra of energetically processed astrophysical and cometary ice analogs directly without warming the ices—a method for hands-off in situ ice analysis. Electron bombardment and UV irradiation of H2O, CH3OH, and NH3 ices at 5 K and 70 K led to complex irradiation products, including HCO, CH3CO, formamide, acetamide, methyl formate, and HCN. Many of these species, whose assignment was also strengthened by isotope labeling studies and correlate with IR-based spectroscopic studies of similar irradiated ices, are important ingredients for the building blocks of life. Some of them have been detected previously via astronomical observations in the interstellar medium and in cometary comae. Other species such as CH3CO (acetyl) are yet to be detected in astrophysical ices or interstellar medium. Our studies suggest that electron and UV photon processing of astrophysical ice analogs leads to extensive chemistry even in the coldest reaches of space, and lend support to the theory of comet-impact-induced delivery of complex organics to the inner solar system.

  18. Fast and robust direct immersion solid phase microextraction coupled with gas chromatography-time-of-flight mass spectrometry method employing a matrix compatible fiber for determination of triazole fungicides in fruits.

    Science.gov (United States)

    Silva, Érica A Souza; Lopez-Avila, Viorica; Pawliszyn, Janusz

    2013-10-25

    A fast and robust method was developed for the determination of ten triazole fungicides in fruit samples using direct immersion solid-phase microextraction coupled to gas chromatography with time-of-flight mass spectrometry detection (DI-SPME-GC-ToFMS). In this work, a newly developed concept of solid-phase microextraction (SPME) sorbent, which allows for direct immersion extraction in complex food matrices, has been applied in the analysis of 10 triazole fungicides in grapes and strawberries pulps. Potential factors affecting the extraction efficiency were investigated and optimized, including extraction temperature, sample pH, and ionic strength, agitation speed, extraction and desorption times. Under optimized conditions, the method was linear for over 4 orders of magnitude in concentration, with linear regression coefficients (R(2)) greater than 0.99 for all test compounds in both matrices. Method reproducibility, as determined by analysis of spiked grapes and strawberries, was better than ±20%. The limits of quantitation objective (LOQs) ranged from 0.25 to 5 ng g(-1) for both matrices, well below the maximum residues levels allowed for those compounds in both matrices. The method was successfully applied in the analysis of commercial samples of grapes and strawberries. Finally, the new SPME method was compared to a modified version of t QuEChERS AOAC method: the limits of quantitation reached by SPME were at least one order of magnitude lower than those achieved by the QuEChERS method, whereas precision and accuracy were comparable for both methods. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Mass discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Broeckman, A. [Rijksuniversiteit Utrecht (Netherlands)

    1978-12-15

    In thermal ionization mass spectrometry the phenomenon of mass discrimination has led to the use of a correction factor for isotope ratio-measurements. The correction factor is defined as the measured ratio divided by the true or accepted value of this ratio. In fact this factor corrects for systematic errors of the whole procedure; however mass discrimination is often associated just with the mass spectrometer.

  20. Negative mass

    International Nuclear Information System (INIS)

    Hammond, Richard T

    2015-01-01

    Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantu