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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...

  2. Obituary: Lynne Karen Deutsch, 1954-2004

    Science.gov (United States)

    Sprague, Ann L.

    2004-12-01

    -96) at Smith College where she had a significant impact on undergraduate research, especially for women, whom she enjoyed mentoring. Lynne joined the faculty in the Astronomy Department of Boston University in 1996 where she taught instrumentation principles and techniques to undergraduate and graduate students. Over the course of her faculty career, she received numerous research grants and fellowships that were used to support her research, her students, and her postdoctoral associates. She was the principal investigator of Boston University's advanced technologies and instrumentation program MIRABU: A Mid-Infrared Array. As her health declined and the rigors of a full teaching schedule became unacceptably taxing, Lynne took a leave of absence from Boston University and returned to Harvard University and the Center for Astrophysics in 2001. There she became a very active member of the Infrared Group in the OIR Division and a member of the IRAC/Spitzer Space Telescope team. Her research in infrared astronomy covered many areas including star formation, planetary and protoplanetary nebulae, solar system objects, the interstellar medium and infrared-luminous galaxies. Her most recent research with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope concentrated on high-mass star formation and the related evolution of the interstellar medium. In her short life, Lynne made many devoted friends and colleagues and was active in encouraging school-age girls to pursue their interests in the sciences. In her short career, she published more than seventy-five articles. She was an outstanding observer and instrumentalist, whose promising career was tragically cut short. Lynne was also a devoted mother and wife, and, while still well, she found the time to be an active participant in her son's elementary school. She is very greatly missed by her family. She is survived by her husband Douglas Sondak, PhD and her son Reed Deutsch-Sondak who live in Acton, MA, and her

  3. Zona Lynn Unveiled in CBD

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On September 29,many fashion industry elites gathered at the Beijing Fortune Plaza at the heart of the Beijing Central Business District(CBD) for a press conference on Zona Lynn,a high-end tailor-made clothing brand.Amid beautiful flowers and applauses,

  4. Direct neutrino mass measurements

    Science.gov (United States)

    Thümmler, T.

    2011-07-01

    The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments. Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino flavour mixing, the neutrino mass parameter appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows β-spectroscopy close to the T 2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/ c 2 (90% C.L.) on the neutrino rest mass.

  5. Reality versus fantasy: reply to Lynn et al. (2014).

    Science.gov (United States)

    Dalenberg, Constance J; Brand, Bethany L; Loewenstein, Richard J; Gleaves, David H; Dorahy, Martin J; Cardeña, Etzel; Frewen, Paul A; Carlson, Eve B; Spiegel, David

    2014-05-01

    We respond to Lynn et al.'s (2014) comments on our review (Dalenberg et al., 2012) demonstrating the superiority of the trauma model (TM) over the fantasy model (FM) in explaining the trauma-dissociation relationship. Lynn et al. conceded that our meta-analytic results support the TM hypothesis that trauma exposure is a causal risk factor for the development of dissociation. Although Lynn et al. suggested that our meta-analyses were selective, we respond that each omitted study failed to meet inclusion criteria; our meta-analyses thus reflect a balanced view of the predominant trauma-dissociation findings. In contrast, Lynn et al. were hypercritical of studies that supported the TM while ignoring methodological problems in studies presented as supportive of the FM. We clarify Lynn et al.'s misunderstandings of the TM and demonstrate consistent superiority in prediction of time course of dissociative symptoms, response to psychotherapy of dissociative patients, and pattern of relationships of trauma to dissociation. We defend our decision not to include studies using the Dissociative Experiences Scale-Comparison, a rarely used revision of the Dissociative Experiences Scale that shares less than 10% of the variance with the original scale. We highlight several areas of agreement: (a) Trauma plays a complex role in dissociation, involving indirect and direct paths; (b) dissociation-suggestibility relationships are small; and (c) controls and measurement issues should be addressed in future suggestibility and dissociation research. Considering the lack of evidence that dissociative individuals simply fantasize trauma, future researchers should examine more complex models of trauma and valid measures of dissociation.

  6. Lynne Cherry's World: A Celebration of Nature.

    Science.gov (United States)

    Winarski, Diana L.

    1995-01-01

    Profiles Lynne Cherry, author-illustrator whose books convey her interest in environmentalism and preserving natural resources. Describes her career, process of illustrating several recent books, and founding of the Center for Children's Environmental Literature in 1992. (TM)

  7. 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.

  8. 76 FR 58105 - Regulated Navigation Area; Saugus River, Lynn, MA

    Science.gov (United States)

    2011-09-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Saugus River, Lynn, MA AGENCY... River in Lynn, MA. Establishing this temporary rule will allow the necessary stabilization work to be... on the Energy Systems Pipeline Bridge on the Saugus River in Lynn, MA. The regulated area...

  9. Current Direct Neutrino Mass Experiments

    CERN Document Server

    Drexlin, G; Mertens, S; Weinheimer, C

    2013-01-01

    In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

  10. 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.

  11. Simultaneous mass detection for direct inlet mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. 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...

  13. 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...

  14. Repair of acute Achilles tendon ruptures using Lynn method

    Directory of Open Access Journals (Sweden)

    Tolga Tolunay

    2013-09-01

    Full Text Available Objectives: Efficiency assessment of Lynn method onopen primary repair of acute Achilles tendon ruptures.Methods: Data were evaluated from 19 patients whotreated with the Lynne method due to acute Achilles tendonrupture. Average follow-up length was 12.3 months(range 8-15 months. Dominant side was the right sideby all patients and all patients were males. Plantaris tendonaugmentation was applied after end-to-end repair bymodified Kessler suture technique.Results: The mean postoperative AOFAS score (TheAmerican Orthopaedic Foot and Ankle Society hindfootclinical outcome scores was 93.5 (range 82-100. Theaverage of Achilles tendon postoperative assessmentscore, as developed by Thermann and colleagues, was93.3. Both assessment scores were between 90-100 andwere evaluated as very good. None of the patients developedpost-operative wound infection. The Thompson testwas negative on all patients and bilateral motor strengthwas 5/5.Conclusion: Lynn method, especially in young and activepatients with acute Achilles tendon rupture is a methodthat should be considered in treatment protocols.Key words: Achilles tendon, Lynn method, AOFAS score

  15. Mentor-Mentee Relationship in an Educational Leadership Doctoral Program at Lynn University

    Science.gov (United States)

    Reedy, Katherine; Taylor-Dunlop, Korynne

    2015-01-01

    Lynn University embraces the Carnegie Project on the Education Doctorate (CPED) initiative, signature pedagogies and the development of scholarly practitioners. In response to the evolution of educational leadership, Lynn University values the need for doctoral candidates to understand the group process and to be able to work within a diverse…

  16. Another Failure to Replicate Lynn's Estimate of the Average IQ of Sub-Saharan Africans

    Science.gov (United States)

    Wicherts, Jelte M.; Dolan, Conor V.; Carlson, Jerry S.; van der Maas, Han L. J.

    2010-01-01

    In his comment on our literature review of data on the performance of sub-Saharan Africans on Raven's Progressive Matrices, Lynn (this issue) criticized our selection of samples of primary and secondary school students. On the basis of the samples he deemed representative, Lynn concluded that the average IQ of sub-Saharan Africans stands at 67…

  17. Saugus River and Tributaries Flood Damage Reduction Study: Lynn, Malden, Revere and Saugus, Massachusetts. Section 1. Feasibility Report.

    Science.gov (United States)

    1989-12-01

    Flood Damage Reduction Study: Lynn, Malden, Revere, and Saugus, MassachusetLs: Section I Feasibility Report 12. PERSONAL AUTHOR(S) Robert Hunt - Project...employ- Problem Identification 20 ment in the communities is characterized by personal services, rather than higher paying professional services. Many...Formulation 50 LYNN BEACH LYNN DIKES AND gLYNN HARBOR -GE FL~TIA 1w IVER FODAE U -~z~POINT OF EAST SAUGUSWALREEMN PROTECT STORAGE PONDING AREA SAUGUS91

  18. Direct Measurement of the Top Quark Mass

    Science.gov (United States)

    Abachi, S.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amidi, E.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Borders, J.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Drinkard, J.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M.; Fatyga, M. K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Geld, T. L.; Genik, R. J., II; Genser, K.; Gerber, C. E.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grim, G.; Grinstein, S.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Lan, H.; Lander, R.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Q.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Mani, S.; Mao, H. S.; Markeloff, R.; Markosky, L.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; de Miranda, J. M.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Nes̆iĆ, D.; Nicola, M.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Pang, M.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Pus̆eljić, D.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rapidis, P. A.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, A.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stoianova, D. A.; Stoker, D.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Q.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1997-08-01

    We measure the top quark mass mt using tt¯ pairs produced in the D0 detector by s = 1.8 TeVpp¯ collisions in a 125 pb-1 exposure at the Fermilab Tevatron. We make a two constraint fit to mt in tt¯-->bW+b¯W- final states with one W decaying to qq¯ and the other to eν or μν. Events are binned in fit mass versus a measure of probability for events to be signal rather than background. Likelihood fits to the data yield mt = 173.3+/-5.6\\(stat\\)+/-6.2\\(syst\\) GeV/c2.

  19. 76 FR 60489 - Lynn E. Stevenson; Notice of Termination of License by Implied Surrender and Soliciting Comments...

    Science.gov (United States)

    2011-09-29

    ... Energy Regulatory Commission Lynn E. Stevenson; Notice of Termination of License by Implied Surrender and... No.: 8866-009. c. Date Initiated: September 23, 2011 (notice date). d. Licensee: Lynn E. Stevenson. e... Lynn E. Stevenson.\\1\\ The project has not operated since a downstream landslide in 1993 and has...

  20. Towards direct mass measurements of nobelium at SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Block, M.; Ackermann, D.; Blaum, K.; Eliseev, S.; Herfurth, S.; Hebberger, F.P.; Hofmann, S.; Kluge, H.J.; Maero, G.; Martin, A.; Mazzocco, M.; Mukherjee, M.; Quint, W.; Rahaman, S.; Rauth, C.; Scheidenberger, C.; Vorobjev, G.; Weber, C. [Gesellschaft fur Schwerionenforschung, Darmstadt (Germany); Blaum, K.; Ferrer, R.; Weber, C. [Johannes-Gutenberg-Univ., Institut fur Physik, Mainz (Germany); Chaudhuri, A.; Marx, G.; Schweikhard, L. [Ernst-Moritz-Arndt-Univ., Institut fur Physik, Greifswald (Germany); Eliseev, S.; Vorobjev, G. [Saint Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Di, Z.; Plab, W.R.; Scheidenberger, C. [Justus-Liebig-Univ., Physikalisches Institut, Gieben (Germany); Habs, D.; Neumayr, J.B.; Thirolf, P.G. [Ludwig-Maximilians-Univ. Munchen, Dept. fur Physik, Garching (Germany); Kluge, H.J. [Ruprecht-Karls-Univ., Physikalisches Institut, Heidelberg (Germany); Rodruguez, D. [IN2P3, LPC-ENSICAEN, 14 - Caen (France)

    2007-10-15

    The Penning-trap mass spectrometer SHIPTRAP allows precision mass measurements of rare isotopes produced in fusion-evaporation reactions. In the first period of operation the masses of more than 50 neutron-deficient radionuclides have been measured. In this paper the perspectives for direct mass measurements of rare isotopes around nobelium are discussed and the achievable precision is addressed. The temporal stability of the magnetic field, an important issue for the long measurement times resulting from the low production rates, was investigated and the time-dependent uncertainty due to magnetic field fluctuations was determined. Based on the present performance direct mass measurements of nobelium isotopes are already feasible. With several technical improvements heavier elements between Z=102-105 will be in reach. (authors)

  1. Direct Protocol for Ambient Mass Spectrometry Imaging on Agar Culture.

    Science.gov (United States)

    Angolini, Célio Fernando F; Vendramini, Pedro Henrique; Araújo, Francisca D S; Araújo, Welington L; Augusti, Rodinei; Eberlin, Marcos N; de Oliveira, Luciana Gonzaga

    2015-07-07

    Herein we describe a new protocol that allows direct mass spectrometry imaging (IMS) of agar cultures. A simple sample dehydration leads to a thin solid agar, which enables the direct use of spray-based ambient mass spectrometry techniques. To demonstrate its applicability, metal scavengers siderophores were imaged directly from agar culture of S. wadayamensis, and well resolved and intense images were obtained using both desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) with well-defined selective spatial distributions for the free and the metal-bound molecules, providing clues for their roles in cellular metabolism.

  2. Saugus River and Tributaries, Lynn Malden, Revere and Saugus, Massachusetts. Flood Damage Reduction. Volume 6. Appendix I. Planning Correspondence: Lynn, Malden, Revere, Saugus, Interest Groups, and News Articles

    Science.gov (United States)

    1989-06-01

    TUMORS . LOBSTER HAD HIGH LEVELS OF CANCER CAUSING PCB"S AND CLAMS SHOWED HIGH LEVELS OF VIRUSES AND DISEASES. THIS IS FACT IN BOSTON HARBOR AND QUINCY BAY...te corp IsI ’paring plans far I. An Is million Roughans Peb VIATTL. - Par I 1-9 DAILY EVENING ITEM. Lynn, Mama .. Friday, May 16, 1986 Flood control

  3. 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.

  4. Studying Gaugino mass in Semi-Direct Gauge Mediation

    Energy Technology Data Exchange (ETDEWEB)

    Ibe, M.; /SLAC; Izawa, K.-I.; /Kyoto U., Yukawa Inst., Kyoto /Tokyo U., IPMU; Nakai, Y.; /Kyoto U., Yukawa Inst., Kyoto

    2010-06-11

    We study gaugino mass generation in the context of semi-direct gauge mediation models, where the messengers are charged under both the hidden sector and the standard model gauge groups while they do not play important roles in dynamical supersymmetry breaking. We clarify the cancellation of the leading contributions of the supersymmetry breaking effects to the gaugino mass in this class of models in terms of the macroscopic effective theory of the hidden sector dynamics. We also consider how to retrofit the model so that we obtain the non-vanishing leading contribution to the gaugino mass.

  5. The Future of Direct Supermassive Black Hole Mass Estimates

    CERN Document Server

    Batcheldor, D

    2009-01-01

    (Abridged) The repeated discovery of supermassive black holes (SMBHs) at the centers of galactic bulges, and the discovery of relations between the SMBH mass (M) and the properties of these bulges, has been fundamental in directing our understanding of both galaxy and SMBH formation and evolution. However, there are still many questions surrounding the SMBH - galaxy relations. For example, are the scaling relations linear and constant throughout cosmic history, and do all SMBHs lie on the scaling relations? These questions can only be answered by further high quality direct M estimates from a wide range in redshift. In this paper we determine the observational requirements necessary to directly determine SMBH masses, across cosmological distances, using current M modeling techniques. We also discuss the SMBH detection abilities of future facilities. We find that if different M modeling techniques, using different spectral features, can be shown to be consistent, then both 30 m ground- and 16 m space-based tel...

  6. Halo-Independent Direct Detection Analyses Without Mass Assumptions

    CERN Document Server

    Anderson, Adam 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 $m_\\chi-\\sigma_n$ 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...

  7. 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. Keywords: women rape, strategy, emasculation, moral attack, strategic rape theory

  8. Direct search for low mass dark matter particles with CCDs

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, J. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro (Brazil); Cease, H.; Diehl, H.T. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Estrada, J., E-mail: estrada@fnal.gov [Fermi National Accelerator Laboratory, Batavia, IL (United States); Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Molina, J. [Facultad de Ingenieria, Universidad Nacional de Asuncion (FIUNA), Asuncion (Paraguay); Smith, J. [Fermi National Accelerator Laboratory, Batavia, IL (United States); Schwarz, T. [University of California at Davis, CA (United States); Sonnenschein, A. [Fermi National Accelerator Laboratory, Batavia, IL (United States)

    2012-05-15

    A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (R.M.S. {approx}7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses ({approx}5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

  9. 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

    ... Energy Regulatory Commission William J. Stevenson, Estate of Lynn E. Stevenson, Black Canyon Bliss, LLC... 23, 2012, William J. Stevenson, Estate of Lynn E. Stevenson (transferor) and Black Canyon Bliss, LLC (transferee) filed an application for the transfer of license for the Stevenson No. 2 Project (FERC No....

  10. 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

    .... Stanley Standal and Loretta M. Standal; Lynn E. Stevenson; Notice of Change in Docket Numbers 1. On March 18, 1986, the Commission issued two licenses to the Lynn E. Stevenson, one for Project No. 1, FERC... (1986). \\2\\ 34 FERC ] 62,530 (1986). 2. Several years later, Mr. Stevenson died and, on March 18,...

  11. 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.

  12. 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

  13. 76 FR 21330 - Lynn Canal/Icy Straits Resource Advisory Committee

    Science.gov (United States)

    2011-04-15

    ...The Lynn Canal/Icy Straits Resource Advisory Committee will meet in Juneau, Alaska, April 25, 2011. The purpose of this meeting is to orient the new appointees as to the Secure Rural Schools and Community Self-Determination Act of 2008, provide operational guidelines, discuss and adopt specific bylaws for the RAC, and elect a RAC...

  14. 78 FR 18849 - Drawbridge Operation Regulations; Saugus River, Saugus and Lynn, MA

    Science.gov (United States)

    2013-03-28

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Saugus and Lynn, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  15. 77 FR 42433 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2012-07-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  16. 76 FR 73510 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2011-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  17. 78 FR 9588 - Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA

    Science.gov (United States)

    2013-02-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Saugus River, Lynn and Revere, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulation. SUMMARY: The U.S....

  18. An Adolescent's Best Friend: The Roles of Animals in Lynn Hall's Fiction.

    Science.gov (United States)

    Brown, Joanne

    1994-01-01

    Discusses the way Lynn Hall uses animals in her novels. Shows how her use of animals varies from background to the focus of the story, often as central object of the heroine's affection. Analyzes Hall's animal novels as archetypically romantic in pattern. (HB)

  19. An Interview Forum on Interlibrary Loan/Document Delivery with Lynn Wiley and Tom Delaney

    Science.gov (United States)

    Hasty, Douglas F.

    2003-01-01

    The Virginia Boucher-OCLC Distinguished ILL Librarian Award is the most prestigious commendation given to practitioners in the field. The following questions about ILL were posed to the two most recent recipients of the Boucher Award: Tom Delaney (2002), Coordinator of Interlibrary Loan Services at Colorado State University and Lynn Wiley (2001),…

  20. Direct and Convenient Mass Spectrometry Sampling with Ambient Flame Ionization

    Science.gov (United States)

    Liu, Xiao-Pan; Wang, Hao-Yang; Zhang, Jun-Ting; Wu, Meng-Xi; Qi, Wan-Shu; Zhu, Hui; Guo, Yin-Long

    2015-11-01

    Recent innovations in ambient ionization technology for the direct analysis of various samples in their native environment facilitate the development and applications of mass spectrometry in natural science. Presented here is a novel, convenient and flame-based ambient ionization method for mass spectrometric analysis of organic compounds, termed as the ambient flame ionization (AFI) ion source. The key features of AFI ion source were no requirement of (high) voltages, laser beams and spray gases, but just using small size of n-butane flame (height approximately 1 cm, about 500 oC) to accomplish the rapid desorption and ionization for direct analysis of gaseous-, liquid- and solid-phase organic compounds, as well as real-world samples. This method has high sensitivity with a limit of detection of 1 picogram for propyphenazone, which allows consuming trace amount of samples. Compared to previous ionization methods, this ion source device is extremely simple, maintain-free, low-cost, user-friendly so that even an ordinary lighter (with n-butane as fuel) can achieve efficient ionization. A new orientation to mass spectrometry ion source exploitation might emerge from such a convenient, easy and inexpensive AFI ion source.

  1. 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.

  2. 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.)

  3. Saugus River and Tributaries, Lynn Malden, Revere and Saugus, Massachusetts. Flood Damage Reduction. Volume 7. Appendix J. Feasibility Study and EIS/EIR Comments and Responses. Section B. Attachments

    Science.gov (United States)

    1989-12-01

    project also provides the o~portunity to further protect the valuable resources in the estuary, not otherwise afforded without the project. Miese ...Lynn side of the Saucus River about 700 feet easterly of the General Edwards Bridge, traverses in a generally southerly direction for approximately...of Carey Circle and would traverse in an easterly direction a distance of about 230 feet ending at Reach "B". A stone revetment at elevation 13.2 feet

  4. 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

    2012-01-01

    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.

  5. Histology-directed MALDI mass spectrometry for the diagnostic pathology

    Science.gov (United States)

    Kim, Hark Kyun; Kim, In-Hoo

    2012-10-01

    With the advent of targeted agents, it has become clinically important to distinguish histologic types of non-small cell lung cancers (NSCLCs) using biopsy samples. We investigated whether direct tissue matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) analysis on lipid may classify histology of NSCLCs. Twentyone pairs of frozen, resected NSCLCs were analyzed using histology-directed, MALDI MS. 2,5-dihydroxybenzoic acid/α-cyano-4-hydroxycinnamic acid were manually deposited on areas of each tissue section enriched in epithelial cells to identify lipid profiles, and mass spectra were acquired using a MALDI-time of flight instrument. Squamous cell carcinomas and adenocarcinomas, two major histologic types of NSCLC, were found to have different lipid profiles. Discriminatory lipids correctly classified the histology of 80.4% of independent NSCLC surgical tissue samples (41 out of 51) in validation set, suggesting that lipid profiles can classify NSCLCs according to the histologic type. We also found that protein and lipid MALDI MS profiles can classify 30 breast cancers according to the intrinsic subtypes. Immunohistochemistry-defined, luminal, HER2+, and triple-negative tumors demonstrated different protein and lipid profiles, as evidenced by cross validation P values < 0.01. Discriminatory proteins and lipids classified tumors according to the intrinsic subtype with median prediction accuracies of 80.0-81.3% in 100 random test sets. Potential advantages of this label-free approach may include small tissue requirement, relatively rapid procedure, and low reagent cost. Day-today variation of this technology is also acceptable, with the Pearson correlation of 0.95. Taken together, these results suggest the possible clinical utility of histology-directed, lipid and protein MALDI MS.

  6. High-throughput mass-directed parallel purification incorporating a multiplexed single quadrupole mass spectrometer.

    Science.gov (United States)

    Xu, Rongda; Wang, Tao; Isbell, John; Cai, Zhe; Sykes, Christopher; Brailsford, Andrew; Kassel, Daniel B

    2002-07-01

    We report on the development of a parallel HPLC/MS purification system incorporating an indexed (i.e., multiplexed) ion source. In the method described, each of the flow streams from a parallel array of HPLC columns is directed toward the multiplexed (MUX) ion source and sampled in a time-dependent, parallel manner. A visual basic application has been developed and monitors in real-time the extracted ion current from each sprayer channel. Mass-directed fraction collection is initiated into a parallel array of fraction collectors specific for each of the spray channels. In the first embodiment of this technique, we report on a four-column semipreparative parallel LC/MS system incorporating MUX detection. In this parallel LC/MS application (in which sample loads between 1 and 10 mg on-column are typically made), no cross talk was observed. Ion signals from each of the channels were found reproducible over 192 injections, with interchannel signal variations between 11 and 17%. The visual basic fraction collection application permits preset individual start collection and end collection thresholds for each channel, thereby compensating for the slight variation in signal between sprayers. By incorporating postfraction collector UV detection, we have been able to optimize the valve-triggering delay time with precut transfer tubing between the mass spectrometer and fraction collectors and achieve recoveries greater than 80%. Examples of the MUX-guided, mass-directed fraction purification of both standards and real library reaction mixtures are presented within.

  7. 77 FR 55452 - Lynn Canal-Icy Strait Resource Advisory Committee

    Science.gov (United States)

    2012-09-10

    ...The Lynn Canal-Icy Strait Resource Advisory Committee (LC-IS RAC) will meet in Juneau, AK. The committee is authorized under the Secure Rural Schools and Community Self-Determination Act (Pub. L. 112- 141) (the Act) and operates in compliance with the Federal Advisory Committee Act. The purpose of the committee is to improve collaborative relationships and to provide advice and recommendations......

  8. Ambient Mass Spectrometry Imaging Using Direct Liquid Extraction Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Lanekoff, Ingela

    2015-11-13

    Mass spectrometry imaging (MSI) is a powerful analytical technique that enables label-free spatial localization and identification of molecules in complex samples.1-4 MSI applications range from forensics5 to clinical research6 and from understanding microbial communication7-8 to imaging biomolecules in tissues.1, 9-10 Recently, MSI protocols have been reviewed.11 Ambient ionization techniques enable direct analysis of complex samples under atmospheric pressure without special sample pretreatment.3, 12-16 In fact, in ambient ionization mass spectrometry, sample processing (e.g., extraction, dilution, preconcentration, or desorption) occurs during the analysis.17 This substantially speeds up analysis and eliminates any possible effects of sample preparation on the localization of molecules in the sample.3, 8, 12-14, 18-20 Venter and co-workers have classified ambient ionization techniques into three major categories based on the sample processing steps involved: 1) liquid extraction techniques, in which analyte molecules are removed from the sample and extracted into a solvent prior to ionization; 2) desorption techniques capable of generating free ions directly from substrates; and 3) desorption techniques that produce larger particles subsequently captured by an electrospray plume and ionized.17 This review focuses on localized analysis and ambient imaging of complex samples using a subset of ambient ionization methods broadly defined as “liquid extraction techniques” based on the classification introduced by Venter and co-workers.17 Specifically, we include techniques where analyte molecules are desorbed from solid or liquid samples using charged droplet bombardment, liquid extraction, physisorption, chemisorption, mechanical force, laser ablation, or laser capture microdissection. Analyte extraction is followed by soft ionization that generates ions corresponding to intact species. Some of the key advantages of liquid extraction techniques include the ease

  9. Testing Gaugino Mass Unification Directly at the LHC

    CERN Document Server

    Nelson, Brent D

    2010-01-01

    We report on the first step of a systematic study of how gaugino mass unification can be probed at the LHC in a quasi-model independent manner. Here we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. Using a statistical method to optimize our signature selection we arrive at three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with approximately 10 inverse femptobarns of integrated luminosity.

  10. Testing Gaugino Mass Unification Directly at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Brent D. [Department of Physics, Northeastern University, Boston, Massachusetts (United States)

    2010-03-15

    We report on the first step of a systematic study of how gaugino mass unification can be probed at the CERN LHC in a quasi-model independent manner. Here we focus our attention on the theoretically well-motivated mirage pattern of gaugino masses, a one-parameter family of models of which universal (high scale) gaugino masses are a limiting case. Using a statistical method to optimize our signature selection we arrive at three ensembles of observables targeted at the physics of the gaugino sector, allowing for a determination of this non-universality parameter without reconstructing individual mass eigenvalues or the soft supersymmetry-breaking gaugino masses themselves. In this controlled environment we find that approximately 80% of the supersymmetric parameter space would give rise to a model for which our method will detect non-universality in the gaugino mass sector at the 10% level with O(10fb{sup -1}) of integrated luminosity.

  11. Introduction to direct neutrino mass measurements and KATRIN

    CERN Document Server

    Thümmler, Thomas

    2010-01-01

    The properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double beta decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. On the other hand experiments such as MARE, KATRIN and the recently proposed Project 8 will investigate the spectral shape of beta-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Here, because of neutrino flavour mixing, the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. It combines an ultra-luminous molecular windowless gaseous tritium source with an i...

  12. Mass spectrometric methods for the direct elemental and isotopic analysis of solid material

    Science.gov (United States)

    Ganeev, A. A.; Gubal, A. R.; Potapov, S. V.; Agafonova, N. N.; Nemets, V. M.

    2016-04-01

    Methods for the direct analysis of solids have a number of undeniable advantages over the methods that require preliminary dissolution of samples. High sensitivity and selectivity make the direct mass spectrometric techniques the most in-demand. The review concerns spark source mass spectrometry, laser ionization mass spectrometry, laser ablation inductively coupled plasma mass spectrometry, secondary ion mass spectrometry, secondary neutral mass spectrometry and glow discharge mass spectrometry. Basic principles, analytical characteristics and trends in the development of these techniques are discussed. Particular attention is given to applications of the techniques as well as to their competitive advantages and drawbacks. The bibliography includes 123 references.

  13. Common Sense, Ontology and Time: A Critique of Lynne Rudder Baker's View of Temporal Reality

    Directory of Open Access Journals (Sweden)

    L. Nathan Oaklander

    Full Text Available ABSTRACT The aim of this paper is twofold: First, to critically discuss Lynne Rudder's Baker BA-theory of time, and second to contrast it with the R-theory (after Russell. In the course of my discussion I will contrast three different methodological approaches regarding the relation between common sense and ontology; clarify Russell's authentic view in contrast to the B-theory which is McTaggart's misrepresentation of Russell, and consider how the R-theory can respond to objections Baker makes to eternalism (as she understands it.

  14. Direct mass measurements beyond the proton drip-line

    CERN Document Server

    Rauth, C; Blaum, K; Block, M; Chaudhuri, A; Eliseev, S; Ferrer, R; Habs, D; Herfurth, F; Hessberger, F P; Hofmann, S; Kluge, H J; Maero, G; Martin, A; Marx, G; Mukherjee, M; Neumayr, J B; Plass, W R; Quint, W; Rahaman, S; Rodríguez, D; Scheidenberger, C; Schweikhard, L; Thirolf, P G; Vorobjev, G; Weber, C; Di, Z

    2007-01-01

    First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about $7\\cdot 10^{-8}$, nine of them for the first time. Four nuclides ($^{144, 145}$Ho and $^{147, 148}$Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies.

  15. 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...... genome and allows identification, mapping, cloning and assistance in gene prediction of any protein for which minimal mass spectrometric information can be obtained. Several novel proteins from Arabidopsis thaliana and human have been discovered in this way....

  16. 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 ...

  17. Introduction to direct neutrino mass measurements and KATRIN

    Science.gov (United States)

    Thümmler, T.; Katrin Collaboration

    2012-08-01

    The properties of neutrinos and especially their rest mass play an important role at the intersections of cosmology, particle physics and astroparticle physics. At present there are two complementary approaches to address this topic in laboratory experiments. The search for neutrinoless double beta decay probes whether neutrinos are Majorana particles and determines an effective neutrino mass value. On the other hand experiments such as MARE, KATRIN and the recently proposed Project 8 will investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Here, because of neutrino flavour mixing, the neutrino mass appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. It combines an ultra-luminous molecular windowless gaseous tritium source with an integrating high-resolution spectrometer of MAC-E filter type. It will investigate the neutrino rest mass with 0.2 eV/c (90% C.L.) sensitivity and allow β spectroscopy close to the T endpoint at 18.6 keV with unprecedented precision.

  18. Recent directions of electrospray mass spectrometry for elemental speciation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schaumloeffel, Dirk [Universite de Pau et des Pays de l' Adour/CNRS UMR 5254, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement/IPREM, Pau (France); Tholey, Andreas [Christian-Albrechts-Universitaet, Institute for Experimental Medicine - Div. Systematic Proteome Research, Kiel (Germany)

    2011-06-15

    A brief survey is given of the last 2 years' literature on electrospray mass spectrometry (ESI-MS) for speciation analysis. As observed for many years, the main recent applications in this field concern arsenic and selenium species, especially in studies encompassing combined use of molecular and element mass spectrometry. A further application field is the stoichiometric characterization of metal complexes by ESI-MS, which in some studies was assisted by nuclear magnetic resonance spectroscopy. A few examples are presented to illustrate arsenic species involved in metabolic pathways, sulfur species in oils and bitumen, and aluminum complexes. On the basis of this review, we also give an outlook of expected future developments and trends in this research field. (orig.)

  19. 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

  20. 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 calcula

  1. Direct Measurement of the Top Quark Mass at D0

    CERN Document Server

    Abbott, B; Acharya, B S; Adam, I; Adams, D L; Adams, M; Ahn, S; Aihara, H; Alves, G A; Amos, N; Anderson, E W; Astur, R; Baarmand, M M; Baden, A; Balamurali, V; Balderston, J; Baldin, B Yu; Banerjee, S; Bantly, J; Barberis, E; Bartlett, J F; Bazizi, K; Belyaev, A; Beri, S B; Bertram, I; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Biswas, N; Blazey, G C; Blessing, S K; Bloom, P; Böhnlein, A; Bozhko, N; Borcherding, F O; Boswell, C; Brandt, A; Brock, R L; Bross, A D; Buchholz, D A; Burtovoi, V S; Butler, J M; Carvalho, W S; Casey, D; Casilum, Z; Castilla-Valdez, H; Chakraborty, D; Chang, S M; Chekulaev, S V; Chen, L P; Chen, W; Choi, S; Chopra, S; Choudhary, B C; Christenson, J H; Chung, M; Claes, D; Clark, A R; Cobau, W G; Cochran, J; Coney, L; Cooper, W E; Cretsinger, C E; Cullen-Vidal, D E; Cummings, M A C; Cutts, D; Dahl, O I; Davis, K; De, K; Del Signore, K; Demarteau, M; Denisov, D S; Denisov, S P; Diehl, H T; Diesburg, M; DiLoreto, G; Draper, P; Ducros, Y; Dudko, L V; Dugad, S R; Edmunds, D L; Ellison, J; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Evdokimov, V N; Fahland, T; Fatyga, M K; Fehér, S; Fein, D K; Ferbel, T; Finocchiaro, G; Fisk, H E; Fisyak, Yu; Flattum, E M; Forden, G E; Fortner, M R; Frame, K C; Fuess, S; Gallas, E J; Galjaev, A N; Gartung, P E; Geld, T L; Genik, R J; Genser, K; Gerber, C E; Gibbard, B; Glenn, S; Gobbi, B; Goldschmidt, A; Gómez, B; Gómez, G; Goncharov, P I; González-Solis, J L; Gordon, H; Goss, L T; Gounder, K; Goussiou, A; Graf, N; Grannis, P D; Green, D R; Greenlee, H; Grim, G P; Grinstein, S; Grossman, N L; Grudberg, P M; Grünendahl, S; Guglielmo, G; Guida, J A; Guida, J M; Sen-Gupta, A; Gurzhev, S N; Gutíerrez, P; Gutnikov, Yu E; Hadley, N J; Haggerty, H; Hagopian, S L; Hagopian, V; Hahn, K S; Hall, R E; Hanlet, P; Hansen, S; Hauptman, J M; Hedin, D; Heinson, A P; Heintz, U; Hernández-Montoya, R; Heuring, T C; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoftun, J S; Hsieh, F; Ting Hu Tong Hu; Hühn, T; Ito, A S; James, E; Jaques, J; Jerger, S A; Jesik, R; Jiang, J Z Y; Joffe-Minor, T M; Johns, K; Johnson, M; Jonckheere, A M; Jones, M; Jöstlein, H; Jun, S Y; Jung, C K; Kahn, S; Kalbfleisch, G R; Kang, J S; Karmanov, D E; Karmgard, D J; Kehoe, R; Kelly, M L; Kim, C L; Kim, S K; Klatchko, A; Klima, B; Klopfenstein, C; Klioukhine, V I; Kochetkov, V I; Kohli, J M; Koltick, D S; Kostritskii, A V; Kotcher, J; Kotwal, A V; Kourlas, J; Kozelov, A V; Kozlovskii, E A; Krane, J; Krishnaswamy, M R; Krzywdzinski, S; Kunori, S; Lami, S; Lander, R; Landry, F J; Landsberg, G L; Lauer, B M; Leflat, A; Li, H; Li, J; Li-Demarteau, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J T; Lipton, R; Liu, Y C; Lobkowicz, F; Loken, S C; Lökös, S; Lueking, L H; Lyon, A L; Maciel, A K A; Madaras, R J; Madden, R; Magana-Mendoza, L; Manankov, V; Mani, S; Mao, H S; Markeloff, R; Marshall, T; Martin, M I; Mauritz, K M; May, B; Mayorov, A A; McCarthy, R; McDonald, J; McKibben, T; McKinley, J; McMahon, T; Melanson, H L; Merkin, M; Merritt, K W B; Miettinen, H; Mincer, A; Mishra, C S; Mokhov, N V; Mondal, N K; Montgomery, H E; Mooney, P; Da Motta, H; Murphy, C; Nang, F; Narain, M; Narasimham, V S; Narayanan, A; Neal, H A; Negret, J P; Némethy, P; Norman, D; Oesch, L H; Oguri, V; Oliveira, E; Oltman, E; Oshima, N; Owen, D; Padley, P; Para, A; Park, Y M; Partridge, R; Parua, N; Paterno, M; Pawlik, B; Perkins, J; Peters, M; Piegaia, R; Piekarz, H; Pishchalnikov, Yu M; Podstavkov, V M; Pope, B G; Prosper, H B; Protopopescu, S D; Qian, J; Quintas, P Z; Raja, R; Rajagopalan, S; Ramírez, O; Rasmussen, L; Reucroft, S; Rijssenbeek, M; Rockwell, T; Roco, M T; Roe, N A; Rubinov, P M; Ruchti, R C; Rutherfoord, John P; Sánchez-Hernández, A; Santoro, A F S; Sawyer, L; Schamberger, R D; Schellman, H; Scully, J R; Shabalina, E; Shaffer, C; Shankar, H C; Shivpuri, R K; Shupe, M A; Singh, H; Singh, J B; Sirotenko, V I; Smart, W; Smith, E; Smith, R P; Snihur, R; Snow, G A; Snow, J; Snyder, S; Solomon, J; Sood, P M; Sosebee, M; Sotnikova, N; Souza, M; Spadafora, A L; Steinbruck, G; Stephens, R W; Stevenson, M L; Stewart, D; Stichelbaut, F; Stoyanova, D A; Stoker, D; Strauss, M; Streets, K; Strovink, M; Sznajder, A; Tamburello, P D; Tarazi, J; Tartaglia, M; Thomas, T L T; Thompson, J; Trippe, T G; Tuts, P M; Varelas, N; Varnes, E W; Vititoe, D L; Volkov, A A; Vorobev, A P; Wahl, H D; Wang, G; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; White, J T; Wightman, J A; Willis, S; Wimpenny, S J; Wirjawan, J V D; Womersley, J; Won, E; Wood, D R; Xu, H; Yamada, R; Yamin, P; Yang, J; Yasuda, T; Yepes, P; Yoshikawa, C; Youssef, S; Yu, J; Yu, Y; Zhu, Z H; Zieminska, D; Zieminski, A; Zverev, E G; Zylberstejn, A

    1998-01-01

    We determine the top quark mass m_t using t-tbar pairs produced in the D0 detector by \\sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar W^- final states with one W boson decaying to q-qbar and the other to e-nu or mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +- 5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +- 4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst) GeV/C^2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented.

  2. Direct Biofluid Analysis Using Hydrophobic Paper Spray Mass Spectrometry.

    Science.gov (United States)

    Damon, Deidre E; Davis, Kathryn M; Moreira, Camila R; Capone, Patricia; Cruttenden, Riley; Badu-Tawiah, Abraham K

    2016-02-01

    Ambient electrostatic paper spray ionization from a hydrophobic paper occurs when a DC potential is applied to the dry paper triangle. Online liquid/liquid extraction of small organic compounds from a drop of biological fluid present on the dry hydrophobic paper is achieved with an organic spray solvent in under 1 min and utilizes in situ electrostatic-spray ionization for more efficient detection of extracted molecules. Direct analysis of small volumes of biofluids with no sample pretreatment is possible, which is applicable in point-of-care analyses. High sensitivity and quantitative accuracy was achieved for the direct analysis of illicit drugs in 4 μL of raw blood, serum, and whole urine. The study was extended to monitor the activity of alanine transaminase enzyme, a key biomarker for the detection of liver injury in patients (with HIV and tuberculosis) who typically take several medications at once.

  3. 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.

  4. 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

  5. Direct Maximization of Protein Identifications from Tandem Mass Spectra*

    Science.gov (United States)

    Spivak, Marina; Weston, Jason; Tomazela, Daniela; MacCoss, Michael J.; Noble, William Stafford

    2012-01-01

    The goal of many shotgun proteomics experiments is to determine the protein complement of a complex biological mixture. For many mixtures, most methodological approaches fall significantly short of this goal. Existing solutions to this problem typically subdivide the task into two stages: first identifying a collection of peptides with a low false discovery rate and then inferring from the peptides a corresponding set of proteins. In contrast, we formulate the protein identification problem as a single optimization problem, which we solve using machine learning methods. This approach is motivated by the observation that the peptide and protein level tasks are cooperative, and the solution to each can be improved by using information about the solution to the other. The resulting algorithm directly controls the relevant error rate, can incorporate a wide variety of evidence and, for complex samples, provides 18–34% more protein identifications than the current state of the art approaches. PMID:22052992

  6. Strategies for Inclusion of Structural Mass Estimates in the Direct-Drive Generator Optimization Process

    DEFF Research Database (Denmark)

    Henriksen, Matthew Lee; Jensen, Bogi Bech

    2013-01-01

    Usage of a lookup table containing the structural mass and air gap deformation for direct-drive wind turbines of various dimensions is demonstrated. The development of the table is described in detail. Optimal generator designs while both neglecting and considering the structural mass are also...

  7. Letter: High-mass capabilities of positive-ion and negative-ion direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Gross, Jürgen H

    2016-01-01

    Of the ionic liquid 1-butyl-3-methylimidazolium (C(+)) tricyanomethide (A(-)) high-mass cluster ions of both positive ([C(n)A(n-1)](+)) and negative ([C(n-1)A(n)](-)) charge were generated and detected by direct analysis in real time (DART) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). After optimization of the settings of the DART ionization source and of the mass analyzer ions of m/z values unprecedented in DART-MS were detected. Thus, the upper m/z limits of positive-ion and negative-ion DART- MS were substantially expanded. Negative-ion DART-MS delivered cluster ions up to [C(15)A(16)](-), m/z 3527 (nominal mass of monoisotopic ion), while positive-ion DART-MS even yielded ions up to [C(30)A(29)](+), m/z 6784. The identification of the cluster ions is supported by their accurate mass and exact mass differences corresponding to CA between adjacent cluster ion peaks.

  8. Direct measurement of the mass difference between top and antitop quarks.

    Science.gov (United States)

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Andeen, T; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Atramentov, O; Avila, C; Backusmayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; Devaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gómez, B; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jamin, D; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, W M; Leflat, A; Lellouch, J; Li, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Mättig, P; Magaña-Villalba, R; Magerkurth, A; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Mendoza, L; Menezes, D; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, A; Meyer, J; Mitrevski, J; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nikolaev, I; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero Y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Popov, A V; Prado da Silva, W L; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Tiller, B; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vilanova, D; Vint, P; Vokac, P; Voutilainen, M; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Welty-Rieger, L; Wenger, A; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zutshi, V; Zverev, E G

    2009-09-25

    We present a measurement of the mass difference between t and t[over] quarks in lepton + jets final states of tt[over] events in 1 fb;{-1} of data collected with the D0 detector from Fermilab Tevatron Collider pp[over] collisions at sqrt[s] = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and t[over ] masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.

  9. Identification and Mapping of Soils, Vegetation, and Water Resources of Lynn County, Texas, by Computer Analysis of ERTS MSS Data

    Science.gov (United States)

    Baumgardner, M. F.; Kristof, S. J.; Henderson, J. A., Jr.

    1973-01-01

    Results of the analysis and interpretation of ERTS multispectral data obtained over Lynn County, Texas, are presented. The test site was chosen because it embodies a variety of problems associated with the development and management of agricultural resources in the Southern Great Plains. Lynn County is one of ten counties in a larger test site centering around Lubbock, Texas. The purpose of this study is to examine the utility of ERTS data in identifying, characterizing, and mapping soils, vegetation, and water resources in this semiarid region. Successful application of multispectral remote sensing and machine-processing techniques to arid and seminarid land-management problems will provide valuable new tools for the more than one-third of the world's lands lying in arid-semiarid regions.

  10. North American Regional Security: A Trilateral Framework. By Richard J. Kilroy, Jr., Abelardo Rodriquez Sumano, and Todd S. Hataley, Boulder, CO: Lynne Rienner Press, 2013.

    Directory of Open Access Journals (Sweden)

    Robert Stewart-Ingersoll

    2014-04-01

    Full Text Available North American Regional Security: A Trilateral Framework. By Richard J. Kilroy, Jr., Abelardo Rodriquez Sumano, and Todd S. Hataley, Boulder, CO: Lynne Rienner Press, 2013. ISBN 978-1-58826-854-9.

  11. Placing direct limits on the mass of earth-bound dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Stephen L [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)], E-mail: adler@ias.edu

    2008-10-17

    We point out that by comparing the total mass (in gravitational units) of the earth-moon system, as determined by lunar laser ranging, with the sum of the lunar mass as independently determined by its gravitational action on satellites or asteroids, and the earth mass, as determined by the LAGEOS geodetic survey satellite, one can get a direct measure of the mass of earth-bound dark matter lying between the radius of the moon's orbit and the geodetic satellite orbit. Current data show that the mass of such earth-bound dark matter must be less than 4 x 10{sup -9} of the earth's mass. (fast track communication)

  12. The Gaia-ESO survey: Hydrogen lines in red giants directly trace stellar mass

    CERN Document Server

    Bergemann, Maria; Schoenrich, Ralph; Ruchti, Greg; Korn, Andreas; Hekker, Saskia; Kovalev, Mikhail; Mashonkina, Lyudmila; Gilmore, Gerry; Randich, Sofia; Asplund, Martin; Rix, Hans-Walter; Casey, Andrew R; Jofre, Paula; Pancino, Elena; Recio-Blanco, Alejandra; de Laverny, Patrick; Smiljanic, Rodolfo; Tautvaisiene, Grazina; Bayo, Amelia; Lewis, Jim; Koposov, Sergey; Hourihane, Anna; Worley, Clare; Morbidelli, Lorenzo; Franciosini, Elena; Sacco, Germano; Magrini, Laura; Damiani, Francesco; Bestenlehner, Joachim M

    2016-01-01

    Red giant stars are perhaps the most important type of stars for Galactic and extra-galactic archaeology: they are luminous, occur in all stellar populations, and their surface temperatures allow precise abundance determinations for many different chemical elements. Yet, the full star formation and enrichment history of a galaxy can be traced directly only if two key observables can be determined for large stellar samples - age and chemical composition. While spectroscopy is a powerful method to analyse the detailed abundances of stars, stellar ages are the "missing link in the chain", since they are not a direct observable. However, spectroscopy should be able to estimate stellar masses, which for red giants directly infer ages provided their chemical composition is known. Here we establish a new empirical relation between the shape of the hydrogen line in the observed spectra of red giants and stellar mass determined from asteroseismology. The relation allows to determine stellar masses and ages with the ac...

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

    Science.gov (United States)

    Zanno, Lindsay E; Makovicky, Peter J

    2013-01-22

    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.

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

    CERN Document Server

    Papastergis, Emmanouil; 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 calculated using atomic hydrogen (HI) emission line data from the Arecibo Legacy Fast ALFA (ALFALFA) survey. By using the technique of abundance matching, we combine the measured baryonic function (BMF) of galaxies with the dark matter halo mass function in a LCDM universe, in order to determine the galactic baryon fraction as a function of host halo mass. We find that the baryon fraction of low-mass halos is much smaller than the cosmic value, even when atomic gas is taken into account. We find that the galactic baryon deficit increases monotonically with decreasing halo mass, in contrast with previous studies which suggested an approximately constant baryon fraction at the low-mass end. We argue that the observed baryon...

  15. The characteristic black hole mass resulting from direct collapse in the early Universe

    Science.gov (United States)

    Latif, M. A.; Schleicher, D. R. G.; Schmidt, W.; Niemeyer, J. C.

    2013-12-01

    Black holes of a billion solar masses are observed in the infant Universe a few hundred million years after the big bang. The direct collapse of protogalactic gas clouds in primordial haloes with Tvir ≥ 104 K provides the most promising way to assemble massive black holes. In this study, we aim to determine the characteristic mass scale of seed black holes and the time evolution of the accretion rates resulting from the direct collapse model. We explore the formation of supermassive black holes via cosmological large eddy simulations (LES) by employing sink particles and following their evolution for 20 000 yr after the formation of the first sink. As the resulting protostars were shown to have cool atmospheres in the presence of strong accretion, we assume here that UV feedback is negligible during this calculation. We confirm this result in a comparison run without sinks. Our findings show that black hole seeds with characteristic mass of 105 M⊙ are formed in the presence of strong Lyman-Werner flux which leads to an isothermal collapse. The characteristic mass is about two times higher in LES compared to the implicit large eddy simulations. The accretion rates increase with time and reach a maximum value of 10 M⊙ yr-1 after 104 yr. Our results show that the direct collapse model is clearly feasible as it provides the expected mass of the seed black holes.

  16. 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...... algorithms and three dimensional finite element (FEM) analyses to obtain a minimum active mass for the generator....

  17. Direct observation of the autophosphorylation of insulin receptor kinase by mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Zhi Li Li

    2009-01-01

    The catalytic and signaling activities of insulin receptor kinase(IRK)are regulated by the autophosphorylation of three tyrosine residues in a cytoplasmic protein-tyrosine kinase domain at Tyro 1158,Tyro 1162 and Tyro 1163.In this study,time-course of the auphosphorylation of the core kinase(residues 978-1283)from IRK was directly investigated by online electrospray ionization mass spectrometry.It is found that two tyrosine residues were phosphorylated in reaction time range of 30 min.This study implies that mass spectrometric technique must be a powerful tool to directly monitor the biological macromolecular modification and will also provide the information of the order and the mechanism of autophosphorylation at the tyrosine sites coupled with tandem mass spectrometric technique.

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

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Mathias [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22603 Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan, E-mail: mathias.garny@desy.de, E-mail: ibarra@tum.de, E-mail: miguel.pato@tum.de, E-mail: stefan.vogl@tum.de [Physik-Department T30d, Technische Universität München, James-Franck-Straße, 85748 Garching (Germany)

    2012-11-01

    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.

  19. 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.

  20. 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

    Publication date: Available online 24 April 2013 Source:International Journal of Mass Spectrometry Author(s): Bin Li , Steen Honoré Hansen , Christian Janfelt Two different approaches to direct imaging of plant material with desorption electrospray ionization (DESI) mass spectrometry are presented...... 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...... or a petal. In order to enable direct imaging of such plant materials, a new ternary solvent system is introduced, providing a higher and more stable signal from soft plant materials than the binary solvent systems typically used in DESI. With this ternary solvent system, it was possible to image a number...

  1. 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

  2. Rezension zu: 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

    2010-01-01

    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.

  3. 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.

  4. The Methods for Direct Detection of WIMP with Mass <0.5 GeV

    CERN Document Server

    Ovchinnikov, B M; Parusov, V V

    2015-01-01

    The chamber for direct detection of WIMP with mass <0.5 Gev/c2 was developed. The chamber is filled with gas mixture Ne+10%H2 (0-1bar)+0,15ppm Ge(CH3)4. For events detection used GEM+pin-anodes , which provides the energy threshold about eV. The electron background is suppressed owing to photosensitive addition Ge(CH3)4 . It is proposed also for direct detection of WIMP the liquid argon chamber with H2 dissolved in liquid argon at a concentration 100ppm+0,015ppm Ge(CH3)4 .

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    of transmission. The qualitative research presented here followed the implementation of mass drug administration in Lindi and Morogoro Regions, Tanzania, in 2011 to understand the different forms of involvement in the campaign and the experiences of stakeholders of their part in community-directed distribution......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, lymphatic...... filariasis. In Tanzania, this intervention is conducted through community-directed distribution, which aims to improve drug uptake by promoting community participation and local ownership in the intervention. However, the average uptake of drugs often remains too low to achieve the intended interruption...

  6. 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

    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...... 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...... analysis. Illustrated on the direct infusion analysis (ESI-TOF-MS) of complex mixtures the method exploits the full quality of the high-resolution present in the mass spectra. Although the method is illustrated as a new library search method for high resolution MS, we demonstrate that the output...

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

    CERN Document Server

    Axelrod, T; Dawson, W; Frampton, P H

    2016-01-01

    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 solar masses 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 gravitational microlensing of stars outside our galaxy to directly detect the presence of MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the microlensing brightening curves provides a promising approach to confirming over the course of next several years that dark matter consists of MACHOs.

  8. Quiescence correlates strongly with directly-measured black hole mass in central galaxies

    CERN Document Server

    Terrazas, Bryan A; Henriques, Bruno M B; White, Simon D M; Cattaneo, Andrea; Woo, Joanna

    2016-01-01

    Roughly half of all stars reside in galaxies without significant ongoing star formation. However, galaxy formation models indicate that it is energetically challenging to suppress the cooling of gas and the formation of stars in galaxies that lie at the centers of their dark matter halos. In this Letter, we show that the dependence of quiescence on black hole and stellar mass is a powerful discriminant between differing models for the mechanisms that suppress star formation. Using observations of 91 star-forming and quiescent central galaxies with directly-measured black hole masses, we find that quiescent galaxies host more massive black holes than star-forming galaxies with similar stellar masses. This observational result is in qualitative agreement with models that assume that effective, more-or-less continuous AGN feedback suppresses star formation, strongly suggesting the importance of the black hole in producing quiescence in central galaxies.

  9. Quiescence Correlates Strongly with Directly Measured Black Hole Mass in Central Galaxies

    Science.gov (United States)

    Terrazas, Bryan A.; Bell, Eric F.; Henriques, Bruno M. B.; White, Simon D. M.; Cattaneo, Andrea; Woo, Joanna

    2016-10-01

    Roughly half of all stars reside in galaxies without significant ongoing star formation. However, galaxy formation models indicate that it is energetically challenging to suppress the cooling of gas and the formation of stars in galaxies that lie at the centers of their dark matter halos. In this Letter, we show that the dependence of quiescence on black hole and stellar mass is a powerful discriminant between differing models for the mechanisms that suppress star formation. Using observations of 91 star-forming and quiescent central galaxies with directly measured black hole masses, we find that quiescent galaxies host more massive black holes than star-forming galaxies with similar stellar masses. This observational result is in qualitative agreement with models that assume that effective, more-or-less continuous active galactic nucleus feedback suppresses star formation, strongly suggesting the importance of the black hole in producing quiescence in central galaxies.

  10. Mass, Speed, Direction: John Buridan's 14th century concept of momentum

    CERN Document Server

    Graney, Christopher M

    2013-01-01

    In the 14th century the French thinker John Buridan developed a theory of motion that bears a strong resemblance to Newtonian momentum. Buridan's ideas include a quantity of motion which is determined by an object's mass, speed, and direction; in the absence of resistive effects, this quantity remains with the object. Buridan's work is an interesting story in the history of physics. Buridan's insights have value for introducing concepts of inertia and momentum to physics students.

  11. Direct metabolomics for plant cells by live single-cell mass spectrometry.

    Science.gov (United States)

    Fujii, Takashi; Matsuda, Shuichi; Tejedor, Mónica Lorenzo; Esaki, Tsuyoshi; Sakane, Iwao; Mizuno, Hajime; Tsuyama, Naohiro; Masujima, Tsutomu

    2015-09-01

    Live single-cell mass spectrometry (live MS) provides a mass spectrum that shows thousands of metabolite peaks from a single live plant cell within minutes. By using an optical microscope, a cell is chosen for analysis and a metal-coated nanospray microcapillary tip is used to remove the cell's contents. After adding a microliter of ionization solvent to the opposite end of the tip, the trapped contents are directly fed into the mass spectrometer by applying a high voltage between the tip and the inlet port of the spectrometer to induce nanospray ionization. Proteins are not detected because of insufficient sensitivity. Metabolite peaks are identified by exact mass or tandem mass spectrometry (MS/MS) analysis, and isomers can be separated by combining live MS with ion-mobility separation. By using this approach, spectra can be acquired in 10 min. In combination with metabolic maps and/or molecular databases, the data can be annotated into metabolic pathways; the data analysis takes 30 min to 4 h, depending on the MS/MS data availability from databases. This method enables the analysis of a number of metabolites from a single cell with rapid sampling at sub-attomolar-level sensitivity.

  12. Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower

    Energy Technology Data Exchange (ETDEWEB)

    Lemouari, M. [Department of Processes Engineering, Faculty of Sciences and Engineering, University of Bejaia (Algeria); Boumaza, M. [Department of Chemical Engineering, College of Engineering - King Saud University, P.O. Box 800, Riyadh (Saudi Arabia); Kaabi, A. [Department of Genie Climatique, Faculty of Engineering, University of Constantine, Constantine (Algeria)

    2009-06-15

    This paper deals with an experimental analysis of simultaneous heat and mass transfer phenomena between water and air by direct contact in a packed cooling tower. The tower is filled with a ''VGA.'' (Vertical Grid Apparatus) type packing. The packing is 0.42 m high and consists of four (04) galvanised sheets having a zigzag form, between which are disposed three (03) metallic vertical grids in parallel with a cross-sectional test area of 0.15 m x 0.148 m. This study investigates the effect of the air and water flow rates on the global heat and mass transfer coefficient as well as the evaporation rate of water into the air stream, for different inlet water temperatures. Two operating regimes were observed during the air/water contact inside the tower, a Pellicular Regime (PR) and a Bubble and Dispersion Regime (BDR). These two regimes can determine the best way to promote the heat and mass transfer phenomena in such device. The BDR regime seems to be more efficient than the Pellicular Regime, as it enables to achieve relatively higher values of the global heat and mass transfer coefficient and larger water evaporation rates. The comparison between the obtained results and some of those available in the literature for other types of packing indicates that this type possesses good heat and mass transfer characteristics. (author)

  13. The Gaia-ESO Survey: Hydrogen lines in red giants directly trace stellar mass

    Science.gov (United States)

    Bergemann, Maria; Serenelli, Aldo; Schönrich, Ralph; Ruchti, Greg; Korn, Andreas; Hekker, Saskia; Kovalev, Mikhail; Mashonkina, Lyudmila; Gilmore, Gerry; Randich, Sofia; Asplund, Martin; Rix, Hans-Walter; Casey, Andrew R.; Jofre, Paula; Pancino, Elena; Recio-Blanco, Alejandra; de Laverny, Patrick; Smiljanic, Rodolfo; Tautvaisiene, Grazina; Bayo, Amelia; Lewis, Jim; Koposov, Sergey; Hourihane, Anna; Worley, Clare; Morbidelli, Lorenzo; Franciosini, Elena; Sacco, Germano; Magrini, Laura; Damiani, Francesco; Bestenlehner, Joachim M.

    2016-10-01

    Red giant stars are perhaps the most important type of stars for Galactic and extra-galactic archaeology: they are luminous, occur in all stellar populations, and their surface temperatures allow precise abundance determinations for many different chemical elements. Yet, the full star formation and enrichment history of a galaxy can be traced directly only if two key observables can be determined for large stellar samples: age and chemical composition. While spectroscopy is a powerful method to analyse the detailed abundances of stars, stellar ages are the missing link in the chain, since they are not a direct observable. However, spectroscopy should be able to estimate stellar masses, which for red giants directly infer ages provided their chemical composition is known. Here we establish a new empirical relation between the shape of the hydrogen line in the observed spectra of red giants and stellar mass determined from asteroseismology. The relation allows determining stellar masses and ages with an accuracy of 10-15%. The method can be used with confidence for stars in the following range of stellar parameters: 4000 < Teff < 5000 K, 0.5 < log g< 3.5, -2.0 < [Fe/H] < 0.3, and luminosities log L/LSun < 2.5. Our analysis provides observational evidence that the Hα spectral characteristics of red giant stars are tightly correlated with their mass and therefore their age. We also show that the method samples well all stellar populations with ages above 1 Gyr. Targeting bright giants, the method allows obtaining simultaneous age and chemical abundance information far deeper than would be possible with asteroseismology, extending the possible survey volume to remote regions of the Milky Way and even to neighbouring galaxies such as Andromeda or the Magellanic Clouds even with current instrumentation, such as the VLT and Keck facilities.

  14. In situ direct sampling mass spectrometric study on formation of polycyclic aromatic hydrocarbons in toluene pyrolysis.

    Science.gov (United States)

    Shukla, Bikau; Susa, Akio; Miyoshi, Akira; Koshi, Mitsuo

    2007-08-30

    The gas-phase reaction products of toluene pyrolysis with and without acetylene addition produced in a flow tube reactor at pressures of 8.15-15.11 Torr and temperatures of 1136-1507 K with constant residence time (0.56 s) have been detected in an in situ direct sampling mass spectrometric study by using a vacuum ultraviolet single-photon ionization time-of-flight mass spectrometry technique. Those products range from methyl radical to large polycyclic aromatic hydrocarbons (PAHs) of mass 522 amu (C(42)H(18)) including smaller species, radicals, polyynes, and PAHs, together with ethynyl, methyl, and phenyl PAHs. On the basis of observed mass spectra, the chemical kinetic mechanisms of the formation of products are discussed. Especially, acetylene is mixed with toluene to understand the effect of the hydrogen abstraction and acetylene addition (HACA) mechanism on the formation pathways of products in toluene pyrolysis. The most prominent outputs of this work are the direct detection of large PAHs and new reaction pathways for the formation of PAHs with the major role of cyclopenta-fused radicals. The basis of this new reaction route is the appearance of different sequences of mass spectra that well explain the major role of aromatic radicals mainly cyclopenta fused radicals of PAHs resulting from their corresponding methyl PAHs, with active participation of c-C(5)H(5), C(6)H(5), C(6)H(5)CH(2) ,and C(9)H(7) in the formation of large PAHs. The role of the HACA only seemed important for the formation of stable condensed PAHs from unstable primary PAHs with zigzag structure (having triple fusing sites) in one step by ring growth with two carbon atoms.

  15. Iberian ham typification by direct infusion electrospray and photospray ionization mass spectrometry fingerprinting.

    Science.gov (United States)

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

    2012-04-15

    Iberian ham is a product of high commercial value whose quality mainly depends on breeding and feeding of pigs in an authorized way. Simple, fast, simple, reliable and high-throughput analytical methods are necessary to assure the quality of ham and for fraud prevention. Tandem mass spectrometry (MS/MS) is proposed as an advantageous alternative over other analytical techniques commonly used in this industry for product authentication. The analytical approach is based on direct infusion electrospray mass spectrometry (ESI(+)-MS) of dichloromethane/methanol (60:40) extracts of ham intramuscular fat. Similarly, atmospheric pressure photoionization ionization mass spectrometry (APPI(+)-MS) was used with a flow injection analysis system for sample introduction with methanol/water (50%) as the mobile phase and toluene as the dopant. All experiments were performed on an API QSTAR® XL Hybrid system using both ESI and APPI sources. The ESI(+)-MS mass spectra present several clusters of peaks attributed to ammonium adducts [M + NH(4) (+) ] of lipid compounds (mono-, di- and triacylglycerols - MGs, DGs, TGs, and free fatty acids - FFAs), that can be identified by MS/MS spectra. On the other hand, the APPI(+)-MS spectra present [M + H(+) ] ions and reflect a higher fragmentation of the sample. Five different types of Iberian ham samples were successfully classified using partial least-squares discriminant analysis (PLS-DA) of data from these samples. The application of direct infusion tandem mass spectrometry to dichloromethane/methanol extracts from intramuscular fat ham allows the simple, fast and reliable fingerprinting typification of different Iberian ham samples from pigs with different diets. With the proposed method, sample handling is minimal and chromatographic separation is not necessary, which represents an evident advantage over other analytical procedures usually used for this purpose. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Direct Analysis in Real Time (DART) of an Organothiophosphate at Ultrahigh Resolution by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and Tandem Mass Spectrometry.

    Science.gov (United States)

    Prokai, Laszlo; Stevens, Stanley M

    2016-01-16

    Direct analysis in real time (DART) is a recently developed ambient ionization technique for mass spectrometry to enable rapid and sensitive analyses with little or no sample preparation. After swab-based field sampling, the organothiophosphate malathion was analyzed using DART-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Mass resolution was documented to be over 800,000 in full-scan MS mode and over 1,000,000 for an MS/MS product ion produced by collision-induced dissociation of the protonated analyte. Mass measurement accuracy below 1 ppm was obtained for all DART-generated ions that belonged to the test compound in the mass spectra acquired using only external mass calibration. This high mass measurement accuracy, achievable at present only through FTMS, was required for unequivocal identification of the corresponding molecular formulae.

  17. A 125 GeV Higgs boson mass and gravitino dark matter in R-invariant direct gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Ibe, Masahiro [ICRR, University of Tokyo, Kashiwa 277-8582 (Japan); Kavli IPMU, University of Tokyo, Kashiwa 277-8583 (Japan); Sato, Ryosuke, E-mail: rsato@hep-th.phys.s.u-tokyo.ac.jp [Kavli IPMU, University of Tokyo, Kashiwa 277-8583 (Japan); Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

    2012-10-22

    We discuss the Standard Model-like Higgs boson mass in the Supersymmetric Standard Model in an R-invariant direct gauge mediation model with the gravitino mass in the O(1) keV range. The gravitino dark matter scenario in this mass range is a good candidate for a slightly warm dark matter. We show that the Higgs boson mass around 125 GeV suggested by the ATLAS and CMS experiments can be easily achieved in R-invariant direct gauge mediation models with the gravitino mass in this range.

  18. The characteristic black hole mass resulting from direct collapse in the early universe

    CERN Document Server

    Latif, M A; Schmidt, W; Niemeyer, J C

    2013-01-01

    Black holes of a billion solar masses are observed in the infant universe a few hundred million years after the Big Bang. The direct collapse of protogalactic gas clouds in primordial halos with $\\rm T_{vir} \\geq 10^{4} K$ provides the most promising way to assemble massive black holes. In this study, we aim to determine the characteristic mass scale of seed black holes and the time evolution of the accretion rates resulting from the direct collapse model. We explore the formation of supermassive black holes via cosmological large eddy simulations (LES) by employing sink particles and following their evolution for twenty thousand years after the formation of the first sink. As the resulting protostars were shown to have cool atmospheres in the presence of strong accretion, we assume here that UV feedback is negligible during this calculation. We confirm this result in a comparison run without sinks. Our findings show that black hole seeds with characteristic mass of $\\rm 10^{5} M_{\\odot}$ are formed in the pr...

  19. Direct mass measurements of Cd isotopes show strong shell gap at N=82

    CERN Document Server

    Knöbel, R; Bosch, F; Boutin, D; Chen, L; Dimopoulou, C; Dolinskii, A; Franczak, B; Franzke, B; Geissel, H; Hausmann, M; Kozhuharov, C; Kurcewicz, J; Litvinova, S A; Martínez-Pinedo, G; Matoš, M; Mazzocco, M; Münzenberg, G; Nakajima, S; Nociforo, C; Nolden, F; Ohtsubo, T; Ozawa, A; Patyk, Z; Plaß, W R; Scheidenberger, C; Stadlmann, J; Steck, M; Sun, B; Suzuki, T; Walker, P; Weick, H; Wu, M -R; Winkler, M; Yamaguchi, T

    2015-01-01

    A $^{238}$U projectile beam was used to create cadmium isotopes via abrasion-fission at 410 MeV/u in a beryllium target at the entrance of the in-flight separator FRS at GSI. The fission fragments were separated with the FRS and injected into the isochronous storage ring ESR for mass measurements. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B$\\rho$-tagging at the dispersive central focal plane of the FRS. In the experiment with B$\\rho$-tagging the magnetic rigidity of the injected fragments was determined by an accuracy of $2\\times 10^{-4}$. A new method of data analysis, using a correlation matrix for the combined data set from both experiments, has provided mass values for 25 different isotopes for the first time. The high selectivity and sensitivity of the experiment and analysis has given access even to rare isotopes detected with a few atoms per week. In this letter we present for the $^{129,130,131}$Cd isotopes mass values directly ...

  20. Restoration of the N=82 Shell Gap from Direct Mass Measurements of $^{132,134}$Sn

    CERN Document Server

    Dworschak, M; Blaum, K; Delahaye, P; George, S; Hager, U; Herfurth, F; Herlert, A; Kellerbauer, A G; Kluge, H J; Lunney, D; Schweikhard, L; Yazidjian, C

    2008-01-01

    A high-precision direct Penning trap mass measurement has revealed a 0.5-MeV deviation of the binding energy of $^{134}$Sn from the currently accepted value. The corrected mass assignment of this neutron-rich nuclide restores the neutron-shell gap at N=82, previously considered to be a case of “shell quenching.” In fact, the new shell gap value for the short-lived $^{132}$Sn is larger than that of the doubly-magic $^{48}$Ca which is stable. The N=82 shell gap has considerable impact on fission recycling during the $r$ process. More generally, the new finding has important consequences for microscopic mean-field theories which systematically deviate from the measured binding energies of closed-shell nuclides.

  1. Direct mass spectrometry of prebiotically-relevant molecules in irradiated astrophysical ices

    Science.gov (United States)

    Henderson, Bryana; Gudipati, Murthy

    2016-10-01

    Despite overwhelming evidence of complex chemistry in space from ground and space-based observations, much is still unknown about radiation-induced chemistry icy grains. While significant laboratory efforts have been made to understand these reactions, radiation chemistry in ice has so far been studied mainly either by spectroscopic methods or by analyzing the reaction products during warm-up of the ices.To directly probe these reactions in situ with mass spectrometry, we use a two-step (two-color) laser ablation and ionization (2S-LAI) mass spectrometry method, recently developed in our lab [1]. This method enables direct mass spectrometric detection of organic species of prebiotic importance in energetically-processed comet or planetary ice analogs in situ, without the need for sample warming or processing. With this method, we have previously successfully identified reactive intermediates and photoproducts in energetically processed ices with 2S-LAI mass spectrometry [2][3] at temperatures as low as 5 K. Low-temperature electron irradiation of cometary ice analogs generated CHNO species of potential prebiotic importance (i.e. formamide, methylamine). Our work suggests that complex chemistry may be ubiquitous throughout the universe, and aligns with the current observation of glycine in a cometary coma [4] and theories involving delivery of prebiotically-important molecules through comet and asteroid impacts to the early Earth.References[1] M.S. Gudipati & R. Yang, Astrophysical Journal Letters 756, L24 (2012)[2] B.L. Henderson & M.S. Gudipati, Journal of Physical Chemistry A 118.29, 5454 (2014)[3] B.L. Henderson & M.S. Gudipati, The Astrophysical Journal 800.1, 66 (2015)[4] K. Altwegg, et al., Science Advances 2.5 (2016): e1600285.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jing [School of Science, China University of Geosciences (Beijing), Beijing 100083 (China); Wang, Shiqi; Chen, Qiushui [Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084 (China); Jiang, Hao; Liang, Shuping [School of Science, China University of Geosciences (Beijing), Beijing 100083 (China); Lin, Jin-Ming, E-mail: jmlin@mail.tsinghua.edu.cn [Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, Tsinghua University, Beijing 100084 (China)

    2015-09-10

    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{sup 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.

  3. 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…

  4. Theory Meets Theatre Practice: Making a Difference to Public Health Programmes in Southern Africa. Professor Lynn Dalrymple--South African Scholar, Activist, Educator

    Science.gov (United States)

    Durden, Emma; Tomaselli, Keyan

    2012-01-01

    Lynn Dalrymple is a pioneer in the field of communication about HIV and AIDS in South Africa. Her work has influenced practitioners, researchers and thinkers in South Africa and beyond. This review explores Dalrymple's background as a teacher in the rural areas of Zululand in South Africa, and how she came to apply theatre theory for one of the…

  5. Analysis of boronic acids by nano liquid chromatography-direct electron ionization mass spectrometry.

    Science.gov (United States)

    Flender, Cornelia; Leonhard, Peter; Wolf, Christian; Fritzsche, Matthias; Karas, Michael

    2010-05-15

    A new method, based on a direct-electron ionization (EI) interface, is presented for the analysis of compounds insufficiently amenable to usual MS methods. The instrumentation is composed of a nano liquid chromatograph (LC) and a mass spectrometer (MS) directly coupled by a transfer capillary. The eluent is directly introduced into the heated electron impact ion source of the MS. Significant advantages are the generation of reproducible spectra and the ability to ionize highly polar compounds. Boronic acids are used as coupling reagents to produce drugs, agrochemicals, or herbicides. The purity of educts is of high importance because impurities in the educt are directly associated with impurities in the product. Because of their high polarity and tendency to form boroxines, boronic acids require derivatization for GC analysis. The presented nano-LC-EI/MS method is easily applicable for a broad range of boronic acids. The method shows good detection limits for boronic acids up to 200 pg, is perfectly linear, and shows a very high robustness and reproducibility. A mixture of compounds could easily be separated on a monolithic RP18e column. The method represents a new, simple, robust, and reproducible approach for the detection of polar analytes. It is a good candidate to become a standard method for industrial applications.

  6. Thin layer chromatography coupled with electrospray ionization mass spectrometry for direct analysis of raw samples.

    Science.gov (United States)

    Hu, Bin; Xin, Gui-zhong; So, Pui-Kin; Yao, Zhong-Ping

    2015-10-09

    Conventional mass spectrometric analysis of raw samples commonly requires sample pretreatment and chromatographic separation using high performance liquid chromatography or gas chromatography, which could be time-consuming and laborious. In this study, thin layer chromatography (TLC) coupled with electrospray ionization mass spectrometry (ESI-MS) was developed for direct analysis of raw samples. The sorbent material of the TLC plate was found to be able to retain the interfering compounds and allow interested analytes to be extracted, ionized and detected by ESI-MS with much reduced matrix interference. Our results showed that this method could be effectively applied in direct analysis of samples containing common interfering compounds, e.g., salts and detergents, and rapid detection and quantitation of target analytes in raw samples. Offline and online separation and detection of different components in mixture samples, e.g., plant extracts, using TLC-ESI-MS were also demonstrated. Overall, this study revealed that TLC-ESI-MS could be a simple, rapid and efficient method for analysis of raw samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Direct sampling ion trap mass spectrometry (DSITMS). Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This report describes the cost, performance, and other key characteristics of an innovative technology for determining the presence or absence, and measuring the concentration, of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in groundwater and soil, and in gaseous remediation process streams at hazardous waste sites. This new technology is Direct Sampling Ion Trap Mass Spectrometry (DSITMS). DSITMS introduces sample materials directly into an ion trap mass spectrometer by means of a very simple interface, such as a capillary restrictor or a polymer membrane. There is typically very little, if any, sample preparation and no chromatographic separation of the sample constituents. This means that the response of the instrument to the analytes or contaminants in a sample is nearly instantaneous, and that analytical methods based on DSITMS are fast. Analyses are typically completed in less than five minutes, and the analysis cost is generally 50% or less than the amount charged by commercial laboratories using Environmental Protection Agency (EPA) analysis methods.

  8. 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.

  9. Stability of the directly imaged multiplanet system HR 8799: resonance and masses

    CERN Document Server

    Fabrycky, Daniel C

    2008-01-01

    A new era of directly imaged extrasolar planets has produced a three-planet system (Marois et al. 2008), where the masses of the planets have been estimated by untested cooling models. We point out that the nominal circular, face-on orbits of the planets lead to a dynamical instability in ~1e5 yr, a factor of at least 100 shorter than the estimated age of the star. Relaxing the face-on assumption, but still requiring circular orbits while fitting the observed positions, makes the problem even worse. Keeping the nominal orbits, but reducing the planetary masses, allows stability only for unreasonably small (0.04) and that its current velocity is smaller than the nominal circular orbit, which can be confirmed with several more years of observations. That the resonance has lasted until now, in spite of the perturbations of the outer planet, leads to a limit <~10 MJup on the masses of the outer two planets. This constraint rules out certain versions of the core accretion hypothesis, and favors hot-start coolin...

  10. A direct method for determining the mass of gases in ICF shell

    Institute of Scientific and Technical Information of China (English)

    杨传路; 朱正和; 汪蓉; 谭明亮; 蒋刚; 王明达; 郑永铭; 唐永建; 郑志坚; 赵永宽

    2002-01-01

    In the present paper, the defects of dew point method for measuring the mass of gas filled in ICF shells are analyzed. An accurate state equation for gas D2 is deduced from Benedict-Webb-Rubin (BWR) equation and experimental data in planar phase. A direct method to determine gas mass in ICF shells via measuring the temperature and pressure outside the shells and solving the equation of state by numerical method is proposed. It overcomes the theoretical defects of dew point method and the complexities of equipment. In the present method, the state equation can be improved by more accurately measuring P-V-T values of gas D2, so the measuring precision of the mass of gas in the shells can also be improved. The present method is effective for treating mix gases filled in the shells as well. The errors between the computational results and experimental data are very small. Some cases in the filling process are predicted, and the proper temperature and pressure for filling gases effectively are also suggested.

  11. Quality by design study of the direct analysis in real time mass spectrometry response.

    Science.gov (United States)

    Wang, Lu; Chen, Teng; Zeng, Shanshan; Qu, Haibin

    2014-02-01

    A mass spectrometry method has been developed using the Quality by Design (QbD) principle. Direct analysis in real time mass spectrometry (DART-MS) was adopted to analyze a pharmaceutical preparation. A fishbone diagram for DART-MS and the Plackett-Burman design were utilized to evaluate the impact of a number of factors on the method performance. Multivariate regression and Pareto ranking analysis indicated that the temperature, determined distance, and sampler speed were statistically significant (P design combined with response surface analysis was then employed to study the relationships between these three factors and the quality of the DART-MS analysis. The analytical design space of DART-MS was thus constructed and its robustness was validated. In this presented approach, method performance was mathematically described as a composite desirability function of the critical quality attributes (CQAs). Two terms of method validation, including analytical repeatability and method robustness, were carried out at an operating work point. Finally, the validated method was successfully applied to the pharmaceutical quality assurance in different manufacturing batches. These results revealed that the QbD concept was practical in DART-MS method development. Meanwhile, the determined quality was controlled by the analytical design space. This presented strategy provided a tutorial to the development of a robust QbD-compliant mass spectrometry method for industrial quality control.

  12. Quality by Design Study of the Direct Analysis in Real Time Mass Spectrometry Response

    Science.gov (United States)

    Wang, Lu; Chen, Teng; Zeng, Shanshan; Qu, Haibin

    2013-12-01

    A mass spectrometry method has been developed using the Quality by Design (QbD) principle. Direct analysis in real time mass spectrometry (DART-MS) was adopted to analyze a pharmaceutical preparation. A fishbone diagram for DART-MS and the Plackett-Burman design were utilized to evaluate the impact of a number of factors on the method performance. Multivariate regression and Pareto ranking analysis indicated that the temperature, determined distance, and sampler speed were statistically significant (P < 0.05). Furthermore, the Box-Behnken design combined with response surface analysis was then employed to study the relationships between these three factors and the quality of the DART-MS analysis. The analytical design space of DART-MS was thus constructed and its robustness was validated. In this presented approach, method performance was mathematically described as a composite desirability function of the critical quality attributes (CQAs). Two terms of method validation, including analytical repeatability and method robustness, were carried out at an operating work point. Finally, the validated method was successfully applied to the pharmaceutical quality assurance in different manufacturing batches. These results revealed that the QbD concept was practical in DART-MS method development. Meanwhile, the determined quality was controlled by the analytical design space. This presented strategy provided a tutorial to the development of a robust QbD-compliant mass spectrometry method for industrial quality control.

  13. 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...

  14. Direct Measurement of the Mass Difference of Ho163 and Dy163 Solves the Q-Value Puzzle for the Neutrino Mass Determination

    CERN Document Server

    Eliseev, S; Block, M; Chenmarev, S; Dorrer, H; Duellmann, Ch E; Enss, C; Filianin, P E; Gastaldo, L; Goncharov, M; Koester, U; Lautenschlaeger, F; Novikov, Yu N; Rischka, A; Schuessler, R X; Schweikhard, L; Tuerler, A

    2016-01-01

    The atomic mass difference of 163Ho and 163Dy has been directly measured with the Penning trap mass spectrometer SHIPTRAP applying the novel phase imaging ion cyclotron resonance technique. Our measurement has solved the long standing problem of large discrepancies in the Q value of the electron capture in 163Ho determined by different techniques. Our measured mass difference shifts the current Q value of 2555(16) eV evaluated in the Atomic Mass Evaluation 2012 [G. Audi et al., Chin. Phys. C 36, 1157 (2012)] by more than 7 sigma to 2833(30stat)(15sys) eV/c2. With the new mass difference it will be possible, e.g., to reach in the first phase of the ECHo experiment a statistical sensitivity to the neutrino mass below 10 eV, which will reduce its present upper limit by more than an order of magnitude.

  15. Direct quantitative analysis of nicotine alkaloids from biofluid samples using paper spray mass spectrometry.

    Science.gov (United States)

    Wang, He; Ren, Yue; McLuckey, Morgan N; Manicke, Nicholas E; Park, Jonghyuck; Zheng, Lingxing; Shi, Riyi; Cooks, R Graham; Ouyang, Zheng

    2013-12-03

    The determination of tobacco derived nicotine alkaloids in biofluid samples is of great importance to testing for tobacco use, tobacco cessation treatment, and studies on exposure to secondhand smoke. Paper spray mass spectrometry (MS) has been adapted for direct, quantitative analysis of tobacco alkaloids from biofluid samples, such as blood, urine, and saliva in liquid and dried form. Limits of quantitation as low as several nanograms per milliliter were obtained for nicotine, cotinine, trans-3'-hydroxycotinine, and anabasine. Direct analysis of fresh blood samples has also been achieved with improved sensitivity using print paper substrates of high density. Quantitation of the cotinine in the blood of a rat was performed with both direct analysis using paper spray and a traditional analysis protocol using liquid chromatography MS. Comparable results were obtained and the precision of the two methods was similar. The paper spray MS method is rapid and shows potential for significantly improved analytical efficiency in clinical laboratories as well as for point-of-care tobacco use assessment.

  16. 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 (GC

  17. Direct Measurement of Free Estradiol in Human Serum and Plasma by Equilibrium Dialysis-Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Ray, Julie A; Kushnir, Mark M; Rockwood, Alan L; Meikle, A Wayne

    2016-01-01

    We describe a direct method of measurement of free estradiol using equilibrium dialysis followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Serum aliquots and internal standards are extracted by liquid-liquid extraction using methyl-tert-butyl ether (MTBE) followed by derivatization with dansyl chloride. An API 5500 mass spectrometer operated in positive electrospray mode is used for detection.

  18. Identifying Ca2+-Binding Sites in Proteins by Liquid Chromatography-Mass Spectrometry Using Ca2+-Directed Dissociations

    NARCIS (Netherlands)

    Jamalian, Azadeh; Sneekes, Evert-Jan; Wienk, Hans; Dekker, Lennard J. M.; Ruttink, Paul J. A.; Ursem, Mario; Luider, Theo M.; Burgers, Peter C.

    2014-01-01

    Here we describe a new method to identify calcium-binding sites in proteins using high-resolution liquid chromatography-mass spectrometry in concert with calcium-directed collision-induced dissociations. Our method does not require any modifications to the liquid chromatography-mass spectrometry app

  19. 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.

  20. 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.

  1. A new mass spectrometry based bioassay for the direct assessment of hyaluronidase activity and inhibition.

    Science.gov (United States)

    Britton, Emily R; Ibberson, Carolyn B; Horswill, Alexander R; Cech, Nadja B

    2015-12-01

    The development of drug resistance by bacterial pathogens is a growing threat. Drug resistant infections have high morbidity and mortality rates, and treatment of these infections is a major burden on the health care system. One potential strategy to prevent the development of drug resistance would be the application of therapeutic strategies that target bacterial virulence. Hyaluronidase is virulence factor that plays a role in the ability of Gram-positive bacteria such as Staphyloccus aureus and Streptococcus agalactiae to spread in tissue. As such, this enzyme could be a target for the development of future anti-virulence therapies. To facilitate the identification of hyaluronidase inhibitors, quantitative and reproducible assays of hyaluronidase activity are required. In the present study, we developed a new mass spectrometry based bioassay for this purpose. This assay directly measures the quantity of a degradation product (3-(4-deoxy-β-D-gluc-4-enuronosyl)-N-acetyl-D-glucosamine) produced by the hyaluronidase enzyme. Validation parameters for the new assay are as follows: repeatability, <7%; intermediate precision, <10%; range, 0.78-50 μM; limit of detection, 0.29 μM; and limit of quantification, 0.78 μM. Using the new assay, the IC50 value for a published inhibitor of S. agalactiae hyaluronidase, ascorbic acyl 6-palmitate, was 8.0±1.0 μM. We also identified a new hyaluronidase inhibitor, n-cyclohexanecarbonylpentadecylamine, with an IC50 of 30.4±9.8 μM. In conclusion, we describe a new, direct, and reproducible method for assessing hyaluronidase activity using mass spectrometry that can facilitate the discovery of inhibitors.

  2. Direct quantitation of peptide mixtures without standards using clusters formed by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Leib, Ryan D; Flick, Tawnya G; Williams, Evan R

    2009-05-15

    In electrospray ionization mass spectrometry, ion abundances depend on a number of different factors, including analyte surface activity, competition between analytes for charge, analyte concentration, as well as instrumental factors, including mass-dependent ion transmission and detection. Here, a novel method for obtaining quantitative information about solution-phase concentrations of peptide mixtures is described and demonstrated for five different peptide mixtures with relative concentrations ranging from 0.05% to 50%. In this method, the abundances of large clusters containing anywhere from 0 to 13 impurity molecules are measured and directly related to the relative solution-phase concentration of the peptides. For clusters containing approximately 15 or more peptides, the composition of the clusters approaches the statistical value indicating that these clusters are formed nonspecifically and that any differences in ion detection or ionization efficiency are negligible at these large cluster sizes. This method is accurate to within approximately 20% or better, even when the relative ion intensities of the protonated monomers can differ by over an order of magnitude compared to their solution-phase concentrations. Although less accurate than other quantitation methods that employ internal standards, this method does have the key advantages of speed, simplicity, and the ability to quantitate components in solution even when the identities of the components are unknown.

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

    CERN Document Server

    Bateman, James; Merle, Alexander; Morris, Tim R; Ulbricht, Hendrik

    2014-01-01

    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 $\\chi$ 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...

  4. 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.

  5. Rapid determination of nicotine in urine by direct thermal desorption ion trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wise, M.B.; Ilgner, R.H.; Guerin, M.R.

    1990-01-01

    The measurement of nicotine and cotinine in physiological fluids (urine, blood serum, and saliva) is widely used as a means of assessing human exposure to environmental tobacco smoke (ETS). Although numerous analytical methods exist for these measurements, they generally involve extensive sample preparation which increases cost and decreases sample throughput. We report the use of thermal desorption directly into an ion trap mass spectrometer (ITMS) for the rapid determination of nicotine and cotinine in urine. A 1{mu}L aliquot of urine is injected into a specially designed inlet and flash vaporized directly into an ITMS through an open-split capillary restrictor interface. Isobutane chemical ionization is used to generate (M+H){sup +} ions of the analytes and collision induced dissociation is used to generate characteristic fragment ions which are used to confirm their identity. Quantification is achieved by integrating the ion current for the characteristic ions and comparing with an external working curve. Detection limits are approximately 50 pg per analyte and the sample turnaround time is approximately 3 minutes without the need for extensive sample preparation. 12 refs., 5 figs.

  6. Rapid extraction of melamine in powdered milk for direct electrospray ionization tandem mass spectrometry analysis.

    Science.gov (United States)

    Domingo, Elisângela do Carmo; Tireli, Aline Auxiliadora; Nunes, Cleiton Antonio; Batista, Alexandre Vieira; Guerreiro, Mário César; Pinto, Sandra Maria

    2015-01-01

    A combination of a simple pretreatment for melamine extraction and direct analysis in electrospray ionization tandem mass spectrometry (ESI-MS/MS) is proposed. Three pretreatments were evaluated. The first was based on suppressing interference using acetonitrile. The second used sulphuric acid and trichloroacetic acid to suppress interference and for melamine extraction, respectively. The third used sulphuric acid to suppress milk interference, trichloroacetic acid for melamine precipitation, and ethyl acetate for melamine extraction. However, only the last pretreatment suppressed milk interference in melamine detection and a good linearity (R(2)=0.99) was obtained. The presence of MS/MS 85 on melamine fragmentation spectrum showed the selectivity of this method. The limit of detection and limit of quantification were 0.269 µg L(-1) and 0.897 µg L(-1), respectively. The recoveries and relative standard deviation (RDS) of method were lower than 114% and 7.86%, respectively. Further, the research was extended to elucidate the nature of the melamine in the extract through infrared spectroscopy and microscopy analyses. The precipitate was characterized as melaminium bis(trichloroacetate) dihydrate, which is generated through hydrogen bound formation in an interaction between melamine and trichloroacetic acid. Therefore, a simple, fast, and easy method for melamine extraction and direct ESI-MS/MS analysis was developed.

  7. Dark Matter Mass Constrained by the Relic Abundance, Direct Detections, and Colliders

    CERN Document Server

    Tsai, Ho-Chin

    2013-01-01

    We take into account a generic form of a Dirac fermionic dark matter (DM), which communicates with the Standard Model quarks via a scalar mediator, in a model-independent way. Four special interaction scenarios are investigated, where one is parity conserving and the other three are parity violating. Three of them result in the $v$ suppressed DM-nucleon cross sections, where $v \\sim 10^{-3} c$ is the velocity of the DM in the laboratory frame. We constrain the masses of the dark matter and mediator as well as the couplings from the thermal relic abundance, and the recent results of the XENON100 direct detection and collider experiments involving the two channels: (i) monojet plus large missing transverse energy, and (ii) dijet. The current monojet constraint is not stronger than that from the requirement of the correct relic density and the null result by the XENON100 direct detection. We find that the dijet resonance measurements can exclude a large portion of the parameter space $(m_\\chi, m_Y)$, where the c...

  8. Direct electrospray ionization mass spectrometry quantitative analysis of sebacic and terephthalic acids in biodegradable polymers.

    Science.gov (United States)

    Rizzarelli, Paola; Zampino, Daniela; Ferreri, Loredana; Impallomeni, Giuseppe

    2011-02-01

    A direct, rapid, and easy electrospray ionization mass spectrometry (ESI-MS) method to determine concentrations of sebacic acid (SA) and terephthalic acid (TA) residues in biodegradable copolymers was developed. Copolyester samples were synthesized from 1,4-butanediol and sebacic and terephthalic acids by melt polymerization. Extraction of monomers was performed in methanol. Their concentrations were determined by direct infusion ESI-MS, without chromatographic separation, using 1,12-dodecanedioic acid (DDA) as an internal standard. Calibration curves were obtained by plotting the ratio of the areas of the peaks relative to monomers and DDA standard as a function of their concentration ratio. We validated the method by determining the concentration of TA residue using both the ESI-MS protocol and high-performance liquid chromatography (HPLC) analysis with UV detection. The linearity range and the detection limit of this assay were 0.1-5.0 and 0.01 ppm for SA and 0.1-6.0 and 0.03 ppm for TA. This assay represents a useful alternative to conventional methods currently employed for acid quantification, resulting advantageous for its speed and high sensitivity.

  9. 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

    2015-01-27

    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.

  10. 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.

  11. 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

  12. Direct or indirect composite veneers in anterior teeth: which method causes higher tooth mass loss? An in vitro study.

    Science.gov (United States)

    Machado, Alessandra Nunes; Coelho-de-Souza, Fabio Herrmann; Rolla, Juliana Nunes; Erhardt, Maria Carolina Guilherme; Demarco, Flavio Fernando

    2014-01-01

    There is little information in the literature regarding the relationship between preparations made for direct and indirect veneers and the loss of tooth structure required for each technique. This in vitro study sought to quantify the different mass losses from preparation techniques used for direct and indirect veneers. Thirty artificial teeth were weighted using a digital balance and placed in a dental manikin in the position corresponding to the right maxillary central incisor. Five clinicians-all experts in esthetic dentistry-were asked to perform conventional preparations for both a direct composite resin veneer and an indirect ceramic veneer. After preparations, specimens were weighted again in the same digital balance. Teeth undergoing veneer preparations demonstrated a statistically significant mass loss compared to unprepared teeth. Indirect ceramic veneer preparations produced more mass loss than direct composite veneer preparations (P < 0.01).

  13. 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 u...... of the isolates stored according to classical taxonomic criteria. Mass profiles collected in previous studies could be identified by a search in the database. (C) 1997 Elsevier Science Ltd....

  14. Direct Photon Shine: Direct Photon And Neutral Pion Production In Center Of Mass Energy = 200 Gev Gold+gold Collisions

    CERN Document Server

    Frantz, J

    2005-01-01

    With substantial additional statistics due to the inclusion of a new Run2 trigger data sample, the PHENIX Collaboration has measured the first positive direct photon (γdirect) signal in Au+Au collisions at sNN = 200 GeV and midrapidity (|y| ≤ 0.35). The measurement is made in 10 centrality bins covering 0–92% of the full geometric cross section. Additionally, the new data has extended the previous PHENIX π 0 measurement [70] by 4 GeV/c in its pT range, matching the γdirect measurement with a pT range of 1–14 GeV/c which make them the highest pT measurements yet in RHIC Au+Au. The γdirect yields are compared amongst themselves, with references, and with the π 0. The suppression in meson hard scattering previously discovered at RHIC [70] is found to be absent in the direct photons. Specifically, using the NLO perturbative QCD prediction of γdirect as a reference, the nuclear modification factor RAA is found to be consistent wit...

  15. The International Deep Planet Survey. II. The frequency of directly imaged giant exoplanets with stellar mass

    Science.gov (United States)

    Galicher, R.; Marois, C.; Macintosh, B.; Zuckerman, B.; Barman, T.; Konopacky, Q.; Song, I.; Patience, J.; Lafrenière, D.; Doyon, R.; Nielsen, E. L.

    2016-10-01

    Context. Radial velocity and transit methods are effective for the study of short orbital period exoplanets but they hardly probe objects at large separations for which direct imaging can be used. Aims: We carried out the international deep planet survey of 292 young nearby stars to search for giant exoplanets and determine their frequency. Methods: We developed a pipeline for a uniform processing of all the data that we have recorded with NIRC2/Keck II, NIRI/Gemini North, NICI/Gemini South, and NACO/VLT for 14 yr. The pipeline first applies cosmetic corrections and then reduces the speckle intensity to enhance the contrast in the images. Results: The main result of the international deep planet survey is the discovery of the HR 8799 exoplanets. We also detected 59 visual multiple systems including 16 new binary stars and 2 new triple stellar systems, as well as 2279 point-like sources. We used Monte Carlo simulations and the Bayesian theorem to determine that 1.05+2.80-0.70% of stars harbor at least one giant planet between 0.5 and 14 MJ and between 20 and 300 AU. This result is obtained assuming uniform distributions of planet masses and semi-major axes. If we consider power law distributions as measured for close-in planets instead, the derived frequency is 2.30+5.95-1.55%, recalling the strong impact of assumptions on Monte Carlo output distributions. We also find no evidence that the derived frequency depends on the mass of the hosting star, whereas it does for close-in planets. Conclusions: The international deep planet survey provides a database of confirmed background sources that may be useful for other exoplanet direct imaging surveys. It also puts new constraints on the number of stars with at least one giant planet reducing by a factor of two the frequencies derived by almost all previous works. Tables 11-15 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  16. Passive mass transport for direct and quantitative SERS detection using purified silica encapsulated metal nanoparticles

    Science.gov (United States)

    Shrestha, Binaya Kumar

    This thesis focuses on understanding implications of nanomaterial quality control and mass transport through internally etched silica coated nanoparticles for direct and quantitative molecular detection using surface enhanced Raman scattering (SERS). Prior to use, bare nanoparticles (partially or uncoated with silica) are removal using column chromatography to improve the quality of these nanomaterials and their SERS reproducibility. Separation of silica coated nanoparticles with two different diameters is achieved using Surfactant-free size exclusion chromatography with modest fractionation. Next, selective molecular transport is modeled and monitored using SERS and evaluated as a function of solution ionic strength, pH, and polarity. Molecular detection is achieved when the analytes first partition through the silica membrane then interact with the metal surface at short distances (i.e., less than 2 nm). The SERS intensities of unique molecular vibrational modes for a given molecule increases as the number of molecules that bind to the metal surface increases and are enhanced via both chemical and electromagnetic enhancement mechanisms as long as the vibrational mode has a component of polarizability tensor along the surface normal. SERS signals increase linearly with molecular concentration until the three-dimensional SERS-active volume is saturated with molecules. Implications of molecular orientation as well as surface selection rules on SERS intensities of molecular vibrational modes are studied to improve quantitative and reproducible SERS detection using internally etched Ag Au SiO2 nanoparticles. Using the unique vibrational modes, SERS intensities for p-aminothiophenol as a function of metal core compositions and plasmonics are studied. By understanding molecular transport mechanisms through internally etched silica matrices coated on metal nanoparticles, important experimental and materials design parameters are learned, which can be subsequently applied

  17. The coupling of direct analysis in real time ionization to Fourier transform ion cyclotron resonance mass spectrometry for ultrahigh-resolution mass analysis.

    Science.gov (United States)

    Rummel, Julia L; McKenna, Amy M; Marshall, Alan G; Eyler, John R; Powell, David H

    2010-03-01

    Direct Analysis in Real Time (DART) is an ambient ionization technique for mass spectrometry that provides rapid and sensitive analyses with little or no sample preparation. DART has been reported primarily for mass analyzers of low to moderate resolving power such as quadrupole ion traps and time-of-flight (TOF) mass spectrometers. In the current work, a custom-built DART source has been successfully coupled to two different Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers for the first time. Comparison of spectra of the isobaric compounds, diisopropyl methylphosphonate and theophylline, acquired by 4.7 T FT-ICR MS and TOF MS, demonstrates that the TOF resolving power can be insufficient for compositionally complex samples. 9.4 T FT-ICR MS yielded the highest mass resolving power yet reported with DART ionization for 1,2-benzanthracene and 9,10-diphenylanthracene. Polycyclic aromatic hydrocarbons exhibit a spatial dependence in ionization mechanisms between the DART source and the mass spectrometer. The feasibility of analyzing a variety of samples was established with the introduction and analysis of food products and crude oil samples. DART FT-ICR MS provides complex sample analysis that is rapid, highly selective and information-rich, but limited to relatively low-mass analytes.

  18. 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.

  19. 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.

  20. Detection and confirmation of serum lipid biomarkers for preeclampsia using direct infusion mass spectrometry[S

    Science.gov (United States)

    Anand, Swati; Young, SydneyA.; Esplin, M. Sean; Peaden, Benjamin; Tolley, H. Dennis; Porter, T. Flint; Varner, Michael W.; D’Alton, Mary E.; Jackson, Bruce J.; Graves, Steven W.

    2016-01-01

    Despite substantial research, the early diagnosis of preeclampsia remains elusive. Lipids are now recognized to be involved in regulation and pathophysiology of some disease. Shotgun lipidomic studies were undertaken to determine whether serum lipid biomarkers exist that predict preeclampsia later in the same in pregnancy. A discovery study was performed using sera collected at 12–14 weeks pregnancy from 27 controls with uncomplicated pregnancies and 29 cases that later developed preeclampsia. Lipids were extracted and analyzed by direct infusion into a TOF mass spectrometer. MS signals, demonstrating apparent differences were selected, their abundances determined, and statistical differences tested. Statistically significant lipid markers were reevaluated in a second confirmatory study having 43 controls and 37 preeclampsia cases. Multi-marker combinations were developed using those lipid biomarkers confirmed in the second study. The initial study detected 45 potential preeclampsia markers. Of these, 23 markers continued to be statistically significant in the second confirmatory set. Most of these markers, representing several lipid classes, were chemically characterized, typically providing lipid class and potential molecular components using MS2. Several multi-marker panels with areas under the curve >0.85 and high predictive values were developed. Developed panels of serum lipidomic biomarkers appear to be able to identify most women at risk for preeclampsia in a given pregnancy at 12–14 weeks gestation. PMID:26891737

  1. Direct mass measurements of cadmium and palladium isotopes and their double-beta transition $Q$-values

    CERN Document Server

    Smorra, C; Blaum, K; Block, M; Düllmann, Ch E; Eberhardt, K; Eibach, M; Eliseev, S; Nagy, Sz; Nörtershäuser, W; Renisch, D

    2012-01-01

    The $Q$-value of the double-electron capture in $^{108}$Cd has been determined to be (272.04 $\\pm$ 0.55) keV in a direct measurement with the double-Penning trap mass spectrometer TRIGA-TRAP. Based on this result a resonant enhancement of the decay rate of $^{108}$Cd is excluded. We have confirmed the double-beta transition $Q$-values of $^{106}$Cd and $^{110}$Pd recently measured with the Penning-trap mass spectrometers SHIPTRAP and ISOLTRAP, respectively. Furthermore, the atomic masses of the involved nuclides ($^{106, 108, 110}$Cd, $^{106, 108, 110}$Pd) have been directly linked to the atomic mass standard.

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

    OpenAIRE

    Elaff Ganim Salih; Hardev Kaur; Wan Roselezam Wan Yahya

    2016-01-01

    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 sh...

  3. 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

    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 (C...... to known secondary metabolites were, however, found in all mass profiles. (C) 1997 Elsevier Science Ltd....

  4. Direct Analysis of Textile Fabrics and Dyes Using IR Matrix-Assisted Laser Desorption Electrospray Ionization (MALDESI) Mass Spectrometry

    OpenAIRE

    Cochran, Kristin H.; Barry, Jeremy A.; Muddiman, David C.; Hinks, David

    2012-01-01

    The forensic analysis of textile fibers uses a variety of techniques from microscopy to spectroscopy. One such technique that is often used to identify the dye(s) within the fiber is mass spectrometry (MS). In the traditional MS method, the dye must be extracted from the fabric and the dye components are separated by chromatography prior to mass spectrometric analysis. Direct analysis of the dye from the fabric allows the omission of the lengthy sample preparation involved in extraction, ther...

  5. 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.

  6. Latent feature representation with depth directional long-term recurrent learning for breast masses in digital breast tomosynthesis

    Science.gov (United States)

    Kim, Dae Hoe; Kim, Seong Tae; Chang, Jung Min; Ro, Yong Man

    2017-02-01

    Characterization of masses in computer-aided detection systems for digital breast tomosynthesis (DBT) is an important step to reduce false positive (FP) rates. To effectively differentiate masses from FPs in DBT, discriminative mass feature representation is required. In this paper, we propose a new latent feature representation boosted by depth directional long-term recurrent learning for characterizing malignant masses. The proposed network is designed to encode mass characteristics in two parts. First, 2D spatial image characteristics of DBT slices are encoded as a slice feature representation by convolutional neural network (CNN). Then, depth directional characteristics of masses among the slice feature representations are encoded by the proposed depth directional long-term recurrent learning. In addition, to further improve the class discriminability of latent feature representation, we have devised three objective functions aiming to (a) minimize classification error, (b) minimize intra-class variation within the same class, and (c) preserve feature representation consistency in a central slice. Experimental results have demonstrated that the proposed latent feature representation achieves a higher level of classification performance in terms of receiver operating characteristic (ROC) curves and the area under the ROC curve values compared to performance with feature representation learned by conventional CNN and hand-crafted features.

  7. Latent feature representation with depth directional long-term recurrent learning for breast masses in digital breast tomosynthesis.

    Science.gov (United States)

    Kim, Dae Hoe; Kim, Seong Tae; Chang, Jung Min; Ro, Yong Man

    2017-02-07

    Characterization of masses in computer-aided detection systems for digital breast tomosynthesis (DBT) is an important step to reduce false positive (FP) rates. To effectively differentiate masses from FPs in DBT, discriminative mass feature representation is required. In this paper, we propose a new latent feature representation boosted by depth directional long-term recurrent learning for characterizing malignant masses. The proposed network is designed to encode mass characteristics in two parts. First, 2D spatial image characteristics of DBT slices are encoded as a slice feature representation by convolutional neural network (CNN). Then, depth directional characteristics of masses among the slice feature representations are encoded by the proposed depth directional long-term recurrent learning. In addition, to further improve the class discriminability of latent feature representation, we have devised three objective functions aiming to (a) minimize classification error, (b) minimize intra-class variation within the same class, and (c) preserve feature representation consistency in a central slice. Experimental results have demonstrated that the proposed latent feature representation achieves a higher level of classification performance in terms of receiver operating characteristic (ROC) curves and the area under the ROC curve values compared to performance with feature representation learned by conventional CNN and hand-crafted features.

  8. Rapid High-throughput Species Identification of Botanical Material Using Direct Analysis in Real Time High Resolution Mass Spectrometry.

    Science.gov (United States)

    Lesiak, Ashton D; Musah, Rabi A

    2016-10-02

    We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, and that these chemical fingerprints can be used for plant species identification. The mass spectral data can be acquired rapidly and in a high throughput manner without the need for sample extraction, derivatization or pH adjustment steps. The use of this technique bypasses challenges presented by more conventional techniques including lengthy chromatography analysis times and resource intensive methods. The high throughput capabilities of the direct analysis in real time-high resolution mass spectrometry protocol, coupled with multivariate statistical analysis processing of the data, provide not only class characterization of plants, but also yield species and varietal information. Here, the technique is demonstrated with two psychoactive plant products, Mitragyna speciosa (Kratom) and Datura (Jimsonweed), which were subjected to direct analysis in real time-high resolution mass spectrometry followed by statistical analysis processing of the mass spectral data. The application of these tools in tandem enabled the plant materials to be rapidly identified at the level of variety and species.

  9. Rapid High-throughput Species Identification of Botanical Material Using Direct Analysis in Real Time High Resolution Mass Spectrometry

    Science.gov (United States)

    Lesiak, Ashton D.; Musah, Rabi A.

    2016-01-01

    We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, and that these chemical fingerprints can be used for plant species identification. The mass spectral data can be acquired rapidly and in a high throughput manner without the need for sample extraction, derivatization or pH adjustment steps. The use of this technique bypasses challenges presented by more conventional techniques including lengthy chromatography analysis times and resource intensive methods. The high throughput capabilities of the direct analysis in real time-high resolution mass spectrometry protocol, coupled with multivariate statistical analysis processing of the data, provide not only class characterization of plants, but also yield species and varietal information. Here, the technique is demonstrated with two psychoactive plant products, Mitragyna speciosa (Kratom) and Datura (Jimsonweed), which were subjected to direct analysis in real time-high resolution mass spectrometry followed by statistical analysis processing of the mass spectral data. The application of these tools in tandem enabled the plant materials to be rapidly identified at the level of variety and species. PMID:27768072

  10. Direct Mass Measurements in the Light Neutron-Rich Region Using a Combined Energy and Time-of-Flight Technique

    Science.gov (United States)

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

    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 (BETA)-stability. Mass measurements for several neutron-rich light nuclei ranging from C-17 to NE-26 have been performed. In all cases these measurements agree with the latest mass compilation of Wapstra and Audi. The masses of N-20 N and F-24 have been determined for the first time.

  11. 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.

  12. Capabilities and limitations of direct analysis in real time orbitrap mass spectrometry and tandem mass spectrometry for the analysis of synthetic and natural polymers.

    Science.gov (United States)

    Bridoux, Maxime C; Machuron-Mandard, Xavier

    2013-09-30

    Despite the widespread use of direct analysis in real time mass spectrometry (DART-MS), its capabilities in terms of accessible mass range and the types of polymers that can be analysed are not well known. The goal of this work was to evaluate the capabilities and limitations of this ionization technique combined with orbitrap mass spectrometry and tandem mass spectrometry, for the characterization (structural and polydispersity metrics) of various synthetic and natural polymers. The capabilities and limitations of DART-MS (and -MS(2)), using an orbitrap mass spectrometer, for polymer analysis were evaluated using various industrial synthetic polymers and biopolymers. Stainless steel mesh screens secured on a movable rail were used as the sampling surface, onto which 5 μL of various polymers dissolved in tetrahydrofuran were added. Assignment of spectral features and calculation of molecular weight and polydispersity metrics were performed using Polymerix™ software and the results were compared with those obtained by gel-permeation chromatography (GPC). Protonated oligomers and ammonium adducts were instantaneously detected as the major ionisation products in positive ion mode. Only perfluoropolyethers (PFPEs) were ionised in negative mode and detected as [M](-·) ions. Only singly charged molecular species were observed for all oligomers under study, allowing for a rapid determination of the molecular weight and polydispersity metrics of polymers. At elevated DART gas temperatures (400-500°C) the molecular weight and polydispersity metrics compared fairly well with those obtained by GPC, with polymers whose masses ranged from 200 g x mol(-1) to 4000 g x mol(-1). DART-MS allowed the direct and rapid analysis (mass spectra and tandem mass spectra of all the polymers were acquired in seconds) based on the exact masses of their [M+H](+) and [M+NH4](+) ions (in the positive mode) or [M](-·) ions (for polymers having a high sensitivity toward electron

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

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Ruffmann, B.; Vetter, S.; Nunes, S.P. [GKSS Research Centre, Max-Planck Str., 21502 Geesthacht (Germany)

    2006-05-05

    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{sup (R)} 112 was used as reference material. DMFC tests were also performed at 50{sup o}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{sup (R)} 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{sup (R)} 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD=52%. (author)

  14. 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

  15. 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.

  16. Thermal desorption counter-flow introduction atmospheric pressure chemical ionization for direct mass spectrometry of ecstasy tablets.

    Science.gov (United States)

    Inoue, Hiroyuki; Hashimoto, Hiroaki; Watanabe, Susumu; Iwata, Yuko T; Kanamori, Tatsuyuki; Miyaguchi, Hajime; Tsujikawa, Kenji; Kuwayama, Kenji; Tachi, Noriyuki; Uetake, Naohito

    2009-09-01

    A novel approach to the analysis of ecstasy tablets by direct mass spectrometry coupled with thermal desorption (TD) and counter-flow introduction atmospheric pressure chemical ionization (CFI-APCI) is described. Analytes were thermally desorbed with a metal block heater and introduced to a CFI-APCI source with ambient air by a diaphragm pump. Water in the air was sufficient to act as the reactive reagent responsible for the generation of ions in the positive corona discharge. TD-CFI-APCI required neither a nebulizing gas nor solvent flow and the accompanying laborious optimizations. Ions generated were sent in the direction opposite to the air flow by an electric field and introduced into an ion trap mass spectrometer. The major ions corresponding to the protonated molecules ([M + H](+)) were observed with several fragment ions in full scan mass spectrometry (MS) mode. Collision-induced dissociation of protonated molecules gave characteristic product-ion mass spectra and provided identification of the analytes within 5 s. The method required neither sample pretreatment nor a chromatographic separation step. The effectiveness of the combination of TD and CFI-APCI was demonstrated by application to the direct mass spectrometric analysis of ecstasy tablets and legal pharmaceutical products.

  17. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    van Steenbergen, H.; Hrnčiřík, K.; Ermacora, A.; de Koning, S.; Janssen, H.-G.

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  18. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    van Steenbergen, H.; Hrnčiřík, K.; Ermacora, A.; de Koning, S.; Janssen, H.-G.

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  19. 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.

  20. Direct mass limits for chiral fourth-generation quarks in all mixing scenarios.

    Science.gov (United States)

    Flacco, Christian J; Whiteson, Daniel; Tait, Tim M P; Bar-Shalom, Shaouly

    2010-09-10

    Present limits on chiral fourth-generation quark masses mb' and mt' are broadly generalized and strengthened by combining both t' and b' decays and considering a full range of t' and b' flavor-mixing scenarios with the lighter generations (to 1-‖V44‖2≈10(-13)). Various characteristic mass-splitting choices are considered. With mt'>mb' we find that CDF Collaboration limits on the b' mass vary by no more than 10%-20% with any choice of flavor mixing, while for the t' mass, we typically find stronger bounds, in some cases up to mt'>430  GeV. For mb'>mt', we find mb'>380-430  GeV, depending on the flavor mixing and the size of the mt'-mb' mass splitting.

  1. Direct determination of the atomic mass difference of Re187 and Os187 for neutrino physics and cosmochronology

    CERN Document Server

    Nesterenko, D A; Blaum, K; Block, M; Chenmarev, S; Doerr, A; Droese, C; Filianin, P E; Goncharov, M; Ramirez, E Minaya; Novikov, Yu N; Schweikhard, L; Simon, V V

    2016-01-01

    For the first time a direct determination of the atomic mass difference of 187Re and 187Os has been performed with the Penning-trap mass spectrometer SHIPTRAP applying the novel phase-imaging ion-cyclotron-resonance technique. The obtained value of 2492(30stat)(15sys) eV is in excellent agreement with the Q values determined indirectly with microcalorimetry and thus resolves a long-standing discrepancy with older proportional counter measurements. This is essential for the determination of the neutrino mass from the beta-decay of 187Re as planned in future microcalorimetric measurements. In addition, an accurate mass difference of 187Re and 187Os is also important for the assessment of 187Re for cosmochronology.

  2. 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.

  3. The use of low temperature detectors for direct measurements of the mass of the electron neutrino

    CERN Document Server

    Nucciotti, Angelo

    2015-01-01

    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 have been tremendous technical progresses: 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 a calorimetric measurements with sub-eV neutrino mass sensitivity using low temperature detectors.

  4. 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.

  5. 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...

  6. Directed Sample Interrogation Utilizing an Accurate Mass Exclusion-Based Data-Dependent Acquisition Strategy (AMEx)

    OpenAIRE

    Rudomin, Emily L.; Carr, Steven A.; Jaffe, Jacob D.

    2009-01-01

    The ability to perform thorough sampling is of critical importance when using mass spectrometry to characterize complex proteomic mixtures. A common approach is to re-interrogate a sample multiple times by LC-MS/MS. However, the conventional data-dependent acquisition methods that are typically used in proteomics studies will often redundantly sample high-intensity precursor ions while failing to sample low-intensity precursors entirely. We describe a method wherein the masses of successfully...

  7. Direct Quantitation of Peptide Mixtures without Standards using Clusters Formed by Electrospray Ionization Mass Spectrometry

    OpenAIRE

    Leib, Ryan D.; Flick, Tawnya G.; Williams, Evan R.

    2009-01-01

    In electrospray ionization mass spectrometry, ion abundances depend on a number of different factors, including analyte surface activity, competition between analytes for charge, analyte concentration, as well as instrumental factors, including mass-dependent ion transmission and detection. Here, a novel method for obtaining quantitative information about solution-phase concentrations of peptide mixtures is described and demonstrated for five different peptide mixtures with relative concentra...

  8. Direct analysis of steviol glycosides from Stevia leaves by ambient ionization mass spectrometry performed on whole leaves.

    Science.gov (United States)

    Zhang, J Isabella; Li, Xin; Ouyang, Zheng; Cooks, R Graham

    2012-07-07

    Leaf spray mass spectrometry is explored as a fast and simple way for direct analysis of sweet glycosides in fresh untreated Stevia leaves without sample pretreatment. In this technique, a fresh triangular piece of Stevia leaf serves as both sample and substrate. Application of a butanol : methanol : water mixture and a high voltage to intact leaf material produces a high electric field at the tip of the leaf. This results in field emission of charged droplets containing the glycosides. The resulting dry ions are detected by mass spectrometry and confirmed by tandem mass spectrometry and exact mass measurements. A comparison between leaf spray and other ambient ionization methods which are successful for screening glycosides in Stevia leaves--desorption electrospray ionization, low temperature plasma and paper spray--shows that leaf spray produces the highest quality spectra. It is also extremely easy to implement with no need for nebulizing gas or sample preparation and is suited to semi-quantitative determinations. The potential for the application of leaf spray mass spectrometry to direct and rapid screening of plant materials is here realized in the case of Stevia sweet glycosides.

  9. 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

    2017-08-30

    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 was used to differentiate between different classes of samples RESULTS: 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 principal component analysis 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. This article is protected by

  10. When navigating wood ants use the centre of mass of a shape to extract directional information from a panoramic skyline.

    Science.gov (United States)

    Woodgate, Joseph L; Buehlmann, Cornelia; Collett, Thomas S

    2016-06-01

    Bees and ants can control their direction of travel within a familiar landscape using the information available in the surrounding visual scene. To learn more about the visual cues that contribute to this directional control, we have examined how wood ants obtain direction from a single shape that is presented in an otherwise uniform panorama. Earlier experiments revealed that when an ant's goal is aligned with a point within a prominent shape, the ant is guided by a global property of the shape: it learns the relative areas of the shape that lie to its left and right when facing the goal and sets its path by keeping the proportions at the memorised value. This strategy cannot be applied when the direction of the goal lies outside the shape. To see whether a different global feature of the shape might guide ants under these conditions, we trained ants to follow a direction to a point outside a single shape and then analysed their direction of travel when they were presented with different shapes. The tests indicate that ants learn the retinal position of the centre of mass of the training shape when facing the goal and can then guide themselves by placing the centre of mass of training and test shapes in this learnt position. © 2016. Published by The Company of Biologists Ltd.

  11. 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.

  12. Direct evidence of hierarchical assembly at low masses from isolated dwarf galaxy groups

    Science.gov (United States)

    Stierwalt, S.; Liss, S. E.; Johnson, K. E.; Patton, D. R.; Privon, G. C.; Besla, G.; Kallivayalil, N.; Putman, M.

    2017-01-01

    The demographics of dwarf galaxy populations have long been in tension with predictions from the Λ cold dark matter (ΛCDM) paradigm 1-4 . If primordial density fluctuations were scale-free as predicted, dwarf galaxies should themselves host dark-matter subhaloes 5 , the most massive of which may have undergone star formation resulting in dwarf galaxy groups. Ensembles of dwarf galaxies are observed as sate­llites of more massive galaxies 6-9 , and there is observational 10 and theoretical 11 evidence to suggest that these satellites at redshift z = 0 were captured by the massive host halo as a group. However, the evolution of dwarf galaxies is highly susceptible to environment 12-14 , making these satellite groups imperfect probes of ΛCDM in the low-mass regime. Here we report one of the clearest examples yet of hierarchical structure formation at low masses: using deep multi-wavelength data, we identify seven isolated, spectroscopically confirmed groups of only dwarf galaxies. Each group hosts three to five known members, has a baryonic mass of ~4.4 × 109 to 2 × 1010 solar masses (M ⊙), and requires a mass-to-light ratio of <100 to be gravitationally bound. Such groups are predicted to be rare theoretically and found to be rare observationally at the current epoch, and thus provide a unique window into the possible formation mechanism of more massive, isolated galaxies.

  13. From direct to absolute mass measurements a study of the accuracy of ISOLTRAP

    CERN Document Server

    Kellerbauer, A G; Bollen, G; Herfurth, F; Kluge, H J; Kuckein, M; Sauvan, E; Scheidenberger, C; Schweikhard, L

    2003-01-01

    For a detailed study of the accuracy of the Penning trap mass spectrometer ISOLTRAP all expected sources of uncertainty were investigated with respect to their contributions to the uncertainty of the final result. In the course of these investigations, cross-reference measurements with singly charged carbon clusters $^{12}$C$^{+}_{n}$ were carried out. The carbon cluster ions were produced by use of laser-induced desorption, fragmentation, and ionization of C$_{60}$ fullerenes and injected into and stored in the Penning trap system. The comparison of the cyclotron frequencies of different carbon clusters has provided detailed insight into the residual systematic uncertainty of \\acro{ISOLTRAP} and yielded a value of $8 \\cdot 10^{-9}$. This also represents the current limit of mass accuracy of the apparatus. Since the unified atomic mass unit is defined as 1/12 of the mass of the $^{12}$C atom, it will be possible to carry out absolute mass measurements with \\acro{ISOLTRAP} in the future.\\\\[1\\baselineskip] PACS...

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

    Science.gov (United States)

    Knöbel, R.; Diwisch, M.; Bosch, F.; Boutin, D.; Chen, L.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S. A.; Martinez-Pinedo, G.; Matoš, M.; Mazzocco, M.; Münzenberg, G.; Nakajima, S.; Nociforo, C.; Nolden, F.; Ohtsubo, T.; Ozawa, A.; Patyk, Z.; Plaß, W. R.; Scheidenberger, C.; Stadlmann, J.; Steck, M.; Sun, B.; Suzuki, T.; Walker, P. M.; Weick, H.; Wu, M.-R.; Winkler, M.; Yamaguchi, T.

    2016-03-01

    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 ṡ10-4. 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.

  15. Differentiating samples and experimental protocols by direct comparison of tandem mass spectra

    DEFF Research Database (Denmark)

    van der Plas-Duivesteijn, Suzanne J.; Wulff, Tune; Klychnikov, Oleg;

    2016-01-01

    compares spectra between liquid chromatography/tandem mass spectrometry (LC/MS/MS) datasets to determine the shared spectral content, and demonstrated how this can be applied in a molecular phylogenetic study using sera from human and non-human primates. We will here explore if such a method have other...... protein digests in different types of experiments. There is no reason to assume that our instance of this method is optimal in any of these situations, as it makes limited or no use of accurate mass and chromatographic retention time. We propose that with further improvement and refinement, this type...... of analysis can be applied as a simple but informative first step in many pipelines for bottom-up tandem mass spectrometry data analysis in proteomics and other fields, comparing or analysing large numbers of samples or datasets....

  16. Direct observation of the mass renormalization in SrVO3 by angle resolved photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, t.

    2010-05-03

    We have performed an angle-resolved photoemission study of the three-dimensional perovskite-type SrVO{sub 3}. Observed spectral weight distribution of the coherent part in the momentum space shows cylindrical Fermi surfaces consisting of the V 3d t{sub 2g} orbitals as predicted by local-density approximation (LDA) band-structure calculation. The observed energy dispersion shows a moderately enhanced effective mass compared to the LDA results, corresponding to the effective mass enhancement seen in the thermodynamic properties. Contributions from the bulk and surface electronic structures to the observed spectra are discussed based on model calculations.

  17. Mediating relationship between body mass index and the direct measures of the Theory of Planned Behaviour on physical activity intention.

    Science.gov (United States)

    Caperchione, Cristina M; Duncan, Mitch J; Mummery, Kerry; Steele, Rebekah; Schofield, Grant

    2008-03-01

    This research examines (a) the interrelationships between body mass index (BMI), the direct measures of the Theory of Planned Behaviour (TPB) and physical activity intention and (b) the potential mediation effects of the direct measures of the TPB in the relationship between BMI and physical activity intention in a sample of Australian adults. A total sample of 1,062 respondents participated in a computer-assisted telephone-interview (CATI) survey comprised of a standardised introduction; questions regarding TPB and physical activity; and standard demographic questions. BMI for each participant was calculated from self-reported height and weight. Separate regression analyses were performed to examine the mediating effects of each of the direct measures of the TPB on the predictive relationship between the BMI and physical activity intention, as proposed by Baron and Kenny (Journal of Personality and Social Psychology, 51(6), 1173 - 1182, 1986). Findings indicated that the direct measure of attitude and perceived behavioural control mediated the relationship between BMI and physical activity intention. However, the direct measure of subjective norm failed to act as a mediating mechanism. To date there has been no research that has examined the mechanism by which body mass may affect physical activity behaviour. Given the current focus for health promotion specialists on promoting physical activity as a strategy for reducing overweight and obesity, a theoretical understanding of weight-related barriers to physical activity may aid in the development of future interventions and community physical activity programs, particularly those targeting overweight and obese populations.

  18. Direct Chemical Analysis of Solids by Laser Ablation in an Ion-Storage Time-of-Flight Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Klunder, G L; Grant, P M; Andresen, B D; Russo, R E

    2003-09-29

    A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows direct viewing and selected analysis of the sample. Measurements identified trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Resolution (m/{micro}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.

  19. Direct tandem mass spectrometric analysis of amino acids in plasma using fluorous derivatization and monolithic solid-phase purification.

    Science.gov (United States)

    Tamashima, Erina; Hayama, Tadashi; Yoshida, Hideyuki; Imakyure, Osamu; Yamaguchi, Masatoshi; Nohta, Hitoshi

    2015-11-10

    In this study, we developed a novel direct tandem mass spectrometric method for rapid and accurate analysis of amino acids utilizing a fluorous derivatization and purification technique. Amino acids were perfluoroalkylated with 2H,2H,3H,3H-perfluoroundecan-1-al in the presence of 2-picoline borane via reductive amination. The derivatives were purified by perfluoroalkyl-modified silica-based monolithic solid-phase extraction (monolithic F-SPE), and directly analyzed by tandem mass spectrometry using electrospray ionization without liquid chromatographic separation. The perfluoroalkyl derivatives could be sufficiently distinguished from non-fluorous compounds, i.e. the biological matrix, due to their fluorous interaction. Thus, rapid and accurate determination of amino acids was accomplished. The method was validated with human plasma samples and applied to the analysis of amino acids in the plasma of mice with maple syrup urine disease or phenylketonuria.

  20. Detection of white dwarf companions to blue stragglers in the open cluster NGC 188: direct evidence for recent mass transfer

    CERN Document Server

    Gosnell, Natalie M; Geller, Aaron M; Sills, Alison; Leigh, Nathan; Knigge, Christian

    2014-01-01

    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 ACS/SBC 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.

  1. Enzyme kinetics by directly imaging a porous silicon microfluidic reactor using desorption/ionization on silicon mass spectrometry.

    Science.gov (United States)

    Nichols, Kevin P; Azoz, Seyla; Gardeniers, Han J G E

    2008-11-01

    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 desorption/ionization mass spectrometry (MALDI-MS) laser source. The porous silicon of the channel walls functions in a manner analogous to the matrix in MALDI-MS, and is referred to as a desorption/ionization on silicon mass spectrometry (DIOS-MS) target when used in this configuration. Mass spectrometry signal intensity of substrate residue correlates with relative concentration, and position in the microchannel correlates with time, thus allowing determination of kinetic parameters. The system is especially suitable for initial reaction velocity determination. This microreactor is broadly applicable to time-resolved kinetic assays as long as at least one substrate or product of the reaction is ionizable by DIOS-MS.

  2. The Sloan Lens ACS Survey. VII. Elliptical Galaxy Scaling Laws from Direct Observational Mass Measurements

    CERN Document Server

    Bolton, Adam S; Koopmans, Leon V E; Gavazzi, Raphael; Moustakas, Leonidas A; Burles, Scott; Schlegel, David J; Wayth, Randall

    2008-01-01

    We use a sample of 53 massive early-type strong gravitational lens galaxies with well-measured redshifts (ranging from z=0.06 to 0.36) and stellar velocity dispersions (between 175 and 400 km/s) from the Sloan Lens ACS (SLACS) Survey to derive numerous empirical scaling relations. The ratio between central stellar velocity dispersion and isothermal lens-model velocity dispersion is nearly unity within errors. The SLACS lenses define a fundamental plane (FP) that is consistent with the FP of the general population of early-type galaxies. We measure the relationship between strong-lensing mass M_lens within one-half effective radius (R_e/2) and the dimensional mass variable M_dim = G^-1 sigma_e2^2 R_e/2 to be log_10 [M_lens/10^11 M_Sun] = (1.03 +/- 0.04) log_10 [M_dim/10^11 M_Sun] + (0.54 +/- 0.02) (where sigma_e2 is the projected stellar velocity dispersion within R_e/2). The near-unity slope indicates that the mass-dynamical structure of massive elliptical galaxies is independent of mass, and that the "tilt" ...

  3. Directed sample interrogation utilizing an accurate mass exclusion-based data-dependent acquisition strategy (AMEx).

    Science.gov (United States)

    Rudomin, Emily L; Carr, Steven A; Jaffe, Jacob D

    2009-06-01

    The ability to perform thorough sampling is of critical importance when using mass spectrometry to characterize complex proteomic mixtures. A common approach is to reinterrogate a sample multiple times by LC-MS/MS. However, the conventional data-dependent acquisition methods that are typically used in proteomics studies will often redundantly sample high-intensity precursor ions while failing to sample low-intensity precursors entirely. We describe a method wherein the masses of successfully identified peptides are used to generate an accurate mass exclusion list such that those precursors are not selected for sequencing during subsequent analyses. We performed multiple concatenated analytical runs to sample a complex cell lysate, using either accurate mass exclusion-based data-dependent acquisition (AMEx) or standard data-dependent acquisition, and found that utilization of AMEx on an ESI-Orbitrap instrument significantly increases the total number of validated peptide identifications relative to a standard DDA approach. The additional identified peptides represent precursor ions that exhibit low signal intensity in the sample. Increasing the total number of peptide identifications augmented the number of proteins identified, as well as improved the sequence coverage of those proteins. Together, these data indicate that using AMEx is an effective strategy to improve the characterization of complex proteomic mixtures.

  4. Direct analysis of dithiocarbamate fungicides in fruit by ambient mass spectrometry

    NARCIS (Netherlands)

    Cajka, T.; Riddelova, K.; Zomer, P.; Mol, J.G.J.; Hajslova, J.

    2011-01-01

    Dithiocarbamates (DTCs) are fungicides that require a specific single-residue method for detection and verification of compliance with maximum residue limits (MRLs) as established for fruit and vegetables in the EU. In this study, the use of ambient mass spectrometry was investigated for specific de

  5. Deformation gradients imprint the direction and speed of en masse fibroblast migration for fast healing

    Science.gov (United States)

    Pan, Zhi; Ghosh, Kaustabh; Hung, Victoria; Macri, Lauren; Einhorn, Justin; Bhatnagar, Divya; Simon, Marcia; Clark, Richard A.F.; Rafailovich, Miriam H.

    2013-01-01

    En masse cell migration is more relevant than single cell migration in physiological processes of tissue formation, such as embryogenesis, morphogenesis and wound healing. In these situations, cells are influenced by the proximity of other cells including interactions facilitated by substrate mechanics. Here we found that when fibroblasts migrated en masse over a hydrogel, they established a well-defined deformation field by traction forces and migrated along a trajectory defined by field gradients. The mechanics of the hydrogel determined the magnitude of the gradient. For materials stiff enough to withstand deformation related to cellular traction forces, such patterns did not form. Furthermore, migration patterns functioned poorly on very soft matrices where only a minimal traction gradient could be established. The largest degree of alignment and migration velocity occurred on the gels with the largest gradients. Granulation tissue formation in punch wounds of juvenile pigs was correlated strongly with the modulus of the implanted gel in agreement with in vitro en masse cell migration studies. These findings provide basic insight into the biomechanical influences on fibroblast movement in early wounds and relevant design criteria for development of tissue-engineered constructs that aim to stimulate en masse cell recruitment for rapid wound healing. PMID:23594599

  6. Differentiating samples and experimental protocols by direct comparison of tandem mass spectra

    NARCIS (Netherlands)

    Plas-Duivesteijn, Van Der Suzanne J.; Wulff, Tune; Klychnikov, Oleg; Keijzer, De Jeroen; Nessen, Merel A.

    2016-01-01

    Rationale Peptide tandem mass spectra can be analyzed by a number of means. They can be compared against predicted spectra of peptides derived from genome sequences, compared against previously acquired and identified spectra, or - sometimes - sequenced de novo. We recently introduced another met

  7. Constraining the Z' mass in 331 models using direct dark matter detection

    Energy Technology Data Exchange (ETDEWEB)

    Profumo, Stefano; Queiroz, Farinaldo S. [University of California, Department of Physics, Santa Cruz Institute for Particle Physics, Santa Cruz, CA (United States)

    2014-07-15

    We investigate a so-called 331 extension of the Standard Model gauge sector which accommodates neutrino masses and where the lightest of the new neutral fermions in the theory is a viable particle dark matter candidate. In this model, processes mediated by the additional Z' gauge boson set both the dark matter relic abundance and the scattering cross section off of nuclei. We calculate with unprecedented accuracy the dark matter relic density, including the important effect of coannihilation across the heavy fermion sector, and show that indeed the candidate particle has the potential of having the observed dark matter density. We find that the recent LUX results put very stringent bounds on the mass of the extra gauge boson, M{sub Z'} >or similar TeV, independently of the dark matter mass. We also comment on the regime where our bounds on the Z' mass may apply to generic 331-like models, and on implications for LHC phenomenology. (orig.)

  8. MODEL FOR REVELATION OF UNFRIENDLY INFORMATION IMPACTS IN MASS-MEDIA WHICH ARE DIRECTED ON CHANGE OF PUBLIC OPINION

    OpenAIRE

    Victor BOCHARNIKOV; Sergey SVESHNIKOV; Voznyak, Stepan; Yuzefovich, Vladimir

    2010-01-01

    In this article we proposes the mathematical model for revelation of deliberate unfriendly information impacts which are fulfilled by means of specially prepared information messages (news, reviews and others) in mass-media. The model calculates the quantitative measure for fact determination of purposeful information impact and evaluation of potential damage to interests of state (party, corporation) from impact fulfilment. The model use the following data: intensity and direction of informa...

  9. 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.

  10. Direct analysis of textile fabrics and dyes using infrared matrix-assisted laser desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Cochran, Kristin H; Barry, Jeremy A; Muddiman, David C; Hinks, David

    2013-01-15

    The forensic analysis of textile fibers uses a variety of techniques from microscopy to spectroscopy. One such technique that is often used to identify the dye(s) within the fiber is mass spectrometry (MS). In the traditional MS method, the dye must be extracted from the fabric and the dye components are separated by chromatography prior to mass spectrometric analysis. Direct analysis of the dye from the fabric allows the omission of the lengthy sample preparation involved in extraction, thereby significantly reducing the overall analysis time. Herein, a direct analysis of dyed textile fabric was performed using the infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) source for MS. In MALDESI, an IR laser with wavelength tuned to 2.94 μm is used to desorb the dye from the fabric sample with the aid of water as the matrix. The desorbed dye molecules are then postionized by electrospray ionization (ESI). A variety of dye classes were analyzed from various fabrics with little to no sample preparation allowing for the identification of the dye mass and in some cases the fiber polymer. Those dyes that were not detected using MALDESI were also not observed by direct infusion ESI of the dye standard.

  11. The direct cooling tail method for X-ray burst analysis to constrain neutron star masses and radii

    Science.gov (United States)

    Suleimanov, Valery F.; Poutanen, Juri; Nättilä, Joonas; Kajava, Jari J. E.; Revnivtsev, Mikhail G.; Werner, Klaus

    2017-04-01

    Determining neutron star (NS) radii and masses can help to understand the properties of matter at supra-nuclear densities. Thermal emission during thermonuclear X-ray bursts from NSs in low-mass X-ray binaries provides a unique opportunity to study NS parameters, because of the high fluxes, large luminosity variations and the related changes in the spectral properties. The standard cooling tail method uses hot NS atmosphere models to convert the observed spectral evolution during cooling stages of X-ray bursts to the Eddington flux FEdd and the stellar angular size Ω. These are then translated to the constraints on the NS mass M and radius R. Here we present the improved, direct cooling tail method that generalizes the standard approach. First, we adjust the cooling tail method to account for the bolometric correction to the flux. Then, we fit the observed dependence of the blackbody normalization on flux with a theoretical model directly on the M-R plane by interpolating theoretical dependences to a given gravity, hence ensuring only weakly informative priors for M and R instead of FEdd and Ω. The direct cooling method is demonstrated using a photospheric radius expansion burst from SAX J1810.8-2609, which has happened when the system was in the hard state. Comparing to the standard cooling tail method, the confidence regions are shifted by 1σ towards larger radii, giving R = 11.5-13.0 km at M = 1.3-1.8 M⊙ for this NS.

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

    Science.gov (United States)

    Chapline, George F.; Frampton, Paul H.

    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 > 15Msolar 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.

  13. Direct observations of magnetic flux rope formation during a solar coronal mass ejection

    OpenAIRE

    Song, Hongqiang; Zhang, Jie; Chen, Yao; Cheng, Xin

    2014-01-01

    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, \\textit{e.g.}, filaments, coronal cavities, sigmoid structures and hot channels (or hot blobs), are proposed as MFRs and observed before the eruption, which suppor...

  14. 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

    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...... 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...... or a petal. In order to enable direct imaging of such plant materials, a new ternary solvent system is introduced, providing a higher and more stable signal from soft plant materials than the binary solvent systems typically used in DESI. With this ternary solvent system, it was possible to image a number...

  15. 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.

  16. Direct determinations of the nucleon and pion σ terms at nearly physical quark masses

    Science.gov (United States)

    Bali, Gunnar S.; Collins, Sara; Richtmann, Daniel; Schäfer, Andreas; Söldner, Wolfgang; Sternbeck, André; RQCD Collaboration

    2016-05-01

    We present a high statistics study of the pion and nucleon light and strange quark sigma terms using Nf=2 dynamical nonperturbatively improved clover fermions with a range of pion masses down to mπ˜150 MeV and several volumes, L mπ=3.4 up to 6.7, and lattice spacings, a =0.06 - 0.08 fm , enabling a study of finite volume and discretization effects for mπ≳260 MeV . Systematics are found to be reasonably under control. For the nucleon we obtain σπ N=35 (6 ) MeV and σs=35 (12 ) MeV , or equivalently in terms of the quark fractions, fTu=0.021 (4 ) , fTd=0.016 (4 ) and fTs=0.037 (13 ) , where the errors include estimates of both the systematic and statistical uncertainties. These values, together with perturbative matching in the heavy quark limit, lead to fTc=0.075(4 ), fT b=0.072 (2 ) and fT t=0.070 (1 ). In addition, through the use of the (inverse) Feynman-Hellmann theorem our results for σπ N are shown to be consistent with the nucleon masses determined in the analysis. For the pion we implement a method which greatly reduces excited state contamination to the scalar matrix elements from states traveling across the temporal boundary. This enables us to demonstrate the Gell-Mann-Oakes-Renner expectation σπ=mπ/2 over our range of pion masses.

  17. Reverse the force direction at long distance by quantum corrections with a mass

    CERN Document Server

    Chen, X S

    2005-01-01

    We demonstrate that quantum corrections can possibly reverse the sign of the one-particle-exchange potential (OPEP) at long distance if (and under general assumptions, only if) the exchanged particle has a mass $m$, either intrinsic or effective. Such phenomenon requires a running coupling constant $\\alpha(q^2)$ satisfying $\\alpha (-m^2)<0$ in the off-shell renormalization scheme. Reversal of the OPEP sign at long distance (and hence attraction transits to repulsion, or vice versa) may have important implications for gravity and cosmic acceleration, particle and nuclear physics, and also condensed matter properties such as superconductivity.

  18. Direct measurement of the top quark mass by the DØ Collaboration

    Science.gov (United States)

    Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Coney, L.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M. K.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Geld, T. L.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Greenlee, H.; Grim, G.; Grinstein, S.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Lander, R.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Manankov, V.; Mani, S.; Mao, H. S.; Markeloff, R.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Norman, D.; Oesch, L.; Oguri, V.; Oliveira, E.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Pawlik, B.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Steinbrück, G.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stichelbaut, F.; Stoianova, D. A.; Stoker, D.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1998-09-01

    We determine the top quark mass mt using tt¯ pairs produced in the DØ detector by s=1.8 TeV pp¯ collisions in a 125 pb-1 exposure at the Fermilab Tevatron. We make a two constraint fit to mt in tt¯-->bW+b¯W- final states with one W boson decaying to qq¯ and the other to eν or μν. Likelihood fits to the data yield mt(l+jets)=173.3+/-5.6 (stat) +/- 5.5 (syst) GeV/c2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain mt=172.1+/-5.2 (stat) +/- 4.9 (syst) GeV/c2. An alternate analysis, using three constraint fits to fixed top quark masses, gives mt(l+jets)=176.0+/-7.9 (stat)+/- 4.8 (syst) GeV/c2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented. 14.65.Ha, 13.85.Ni, 13.85.Qk

  19. Direct profiling of myelinated and demyelinated regions in mouse brain by imaging mass spectrometry

    Science.gov (United States)

    Ceuppens, Ruben; Dumont, Debora; van Brussel, Leen; van de Plas, Babs; Daniels, Ruth; Noben, Jean-Paul; Verhaert, Peter; van der Gucht, Estel; Robben, Johan; Clerens, Stefan; Arckens, Lutgarde

    2007-02-01

    One of the newly developed imaging mass spectrometry (IMS) technologies utilizes matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to map proteins in thin tissue sections. In this study, we evaluated the power of MALDI IMS as we developed it in our (Bruker) MALDI TOF (Reflex IV) and TOF-TOF (Ultraflex II) systems to study myelin patterns in the mouse central nervous system under normal and pathological conditions. MALDI IMS was applied to assess myelin basic protein (MBP) isoform-specific profiles in different regions throughout the mouse brain. The distribution of ions of m/z 14,144 and 18,447 displayed a striking resemblance with white matter histology and were identified as MBP isoform 8 and 5, respectively. In addition, we demonstrated a significant reduction of the MBP-8 peak intensity upon MALDI IMS analysis of focal ethidium bromide-induced demyelinated brain areas. Our MS images were validated by immunohistochemistry using MBP antibodies. This study underscores the potential of MALDI IMS to study the contribution of MBP to demyelinating diseases.

  20. Modelling of heat and mass transfer in the laser cladding during direct metal deposition

    Science.gov (United States)

    Bedenko, D. V.; Kovalev, O. B.

    2013-06-01

    A physical and mathematical model has been proposed for computing the thermal state and shape of the individual deposited track at the laser powder cladding. A three-dimensional statement of the two-phase problem of Stefan type with curved moving boundaries is considered. One of the boundaries is the melting-crystallization boundary, and the other is the boundary of the deposited layer, where the conservation laws are written from the condition of the inflow of the additional mass and energy. To describe the track shape the equation of kinematic compatibility of the points of a surface is used, the motion of which occurs at the expense of the mass of powder particles supplied to the radiation spot. An explicit finite difference scheme on a rectangular nonuniform grid is used for numerical solution of equations. The computations are carried out by through computation without an explicit identification of curved boundaries by using a modification of the immersed boundary method. The computational results are presented for the thermal state and the shape of the surface of the forming individual track depending on physical parameters: the substrate initial temperature, laser radiation intensity, scanning speed, powder feeding rate, etc.

  1. The direct cooling tail method for X-ray burst analysis to constrain neutron star masses and radii

    CERN Document Server

    Suleimanov, Valery F; Nättilä, Joonas; Kajava, Jari J E; Revnivtsev, Mikhail G; Werner, Klaus

    2016-01-01

    Determining neutron star (NS) radii and masses can help to understand the properties of matter at supra-nuclear densities. Thermal emission during thermonuclear X-ray bursts from NSs in low-mass X-ray binaries provides a unique opportunity to study NS parameters, because of the high fluxes, large luminosity variations and the related changes in the spectral properties. The standard cooling tail method uses hot NS atmosphere models to convert the observed spectral evolution during cooling stages of X-ray bursts to the Eddington flux F_Edd and the stellar angular size \\Omega. These are then translated to the constraints on the NS mass M and radius R. Here we present the improved, direct cooling tail method that generalises the standard approach. First, we adjust the cooling tail method to account for the bolometric correction to the flux. Then, we fit the observed dependence of the blackbody normalization on flux with a theoretical model directly on the M-R plane by interpolating theoretical dependences to a gi...

  2. Star on the horizon: The emergence of the direct broadcast satellite in American mass communications

    Science.gov (United States)

    Thomas, J. H.

    1984-12-01

    The purpose of this thesis is to describe the concept of broadcasting from satellites directly to the viewer equipped with a small, inexpensive receiving antenna, and the evolution of this technology as a means of commercial broadcast. Emphasis is placed on the problems of developing a regulatory framework for DBS by the Federal Communications Commission. The opposition of the existing broadcasters to the unregulated development of direct broadcast satellite (DBS) is explored in light of the possible effect that DBS may have on the economic base, audience, and advertising revenue of existing broadcasters. The information for this study was obtained from government documents, legal journals, books and the popular press. Two basic conclusions are drawn from this study: First, that the existing broadcasters have opposed the marketplace development of DBS, and second, that DBS does not pose as great a threat, at least in the near term, as the broadcasters fear.

  3. Demountable direct injection high efficiency nebulizer for inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Montaser, Akbar; Westphal, Craig S.; Kahen, Kaveh; Rutkowski, William F.; Acon, Billy W.

    2006-12-05

    A nebulizer adapted for adjusting a position of a capillary tube contained within the nebulizer is provided. The nebulizer includes an elongated tubular shell having a gas input port and a gas output port, a capillary adjustment adapter for displacing the capillary tube in a lateral direction via a rotational force, and a connector for connecting the elongated tubular shell, the capillary adjustment adapter and the capillary tube.

  4. Probing of Metabolites in Finely Powdered Plant Material by Direct Laser Desorption Ionization Mass Spectrometry

    Science.gov (United States)

    Musharraf, Syed Ghulam; Ali, Arslan; Choudhary, M. Iqbal; Atta-ur-Rahman

    2014-04-01

    Natural products continue to serve as an important source of novel drugs since the beginning of human history. High-throughput techniques, such as MALDI-MS, can be techniques of choice for the rapid screening of natural products in plant materials. We present here a fast and reproducible matrix-free approach for the direct detection of UV active metabolites in plant materials without any prior sample preparation. The plant material is mechanically ground to a fine powder and then sieved through different mesh sizes. The collected plant material is dispersed using 1 μL solvent on a target plate is directly exposed to Nd:YAG 335 nm laser. The strategy was optimized for the analysis of plant metabolites after study of the different factors affecting the reproducibility and effectiveness of the analysis, including particle sizes effects, types of solvents used to disperse the sample, and the part of the plant analyzed. Moreover, several plant species, known for different classes of metabolites, were screened to establish the generality of the approach. The developed approach was validated by the characterization of withaferin A and nicotine in the leaves of Withania somnifera and Nicotiana tabacum, respectively, through comparison of its MS/MS data with the standard compound. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques were used for the tissue imaging purposes. This approach can be used to directly probe small molecules in plant materials as well as in herbal and pharmaceutical formulations for fingerprinting development.

  5. Optimization of an acoustic rectifier for uni-directional wave propagation in periodic mass-spring lattices

    Science.gov (United States)

    Ma, Chu; Parker, Robert G.; Yellen, Benjamin B.

    2013-09-01

    We perform optimization studies on the construction of acoustic rectifiers, which allow uni-directional propagation of acoustic waves, from a periodic array of masses and springs arranged in one- and two- dimensions. An acoustic rectifier is achieved by pairing a nonlinear material, which can up-convert an input excitation frequency to a higher harmonic, with a bandgap material whose dispersion relation has a bandgap region for the input frequency range but a bandpass region at the higher harmonic. First, we analyze the mass and stiffness parameters that lead to acoustic rectification in infinite mass-spring arrays with the largest possible range of working frequencies. A combination of analytical techniques, numerical simulations, and particle swarm optimization is used to identify the optimal acoustic rectifier. Next, we study the practical working range of acoustic rectifiers of finite size and examine how the rectification properties change as a function of the lattice size and damping. Finally, we perform numerical simulations of an acoustic rectification device in which a Duffing oscillator is attached to the end of a tri-atomic mass-spring chain.

  6. 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)

  7. 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.

  8. Direct imaging of elemental distributions in tissue sections by laser ablation mass spectrometry.

    Science.gov (United States)

    Shariatgorji, Mohammadreza; Nilsson, Anna; Bonta, Maximilian; Gan, Jinrui; Marklund, Niklas; Clausen, Fredrik; Källback, Patrik; Loden, Henrik; Limbeck, Andreas; Andrén, Per E

    2016-07-15

    We present a strategy for imaging of elements in biological tissues using laser ablation (LA) mass spectrometry (MS), which was compared to laser ablation inductively coupled plasma (LA-ICP) MS. Both methods were adopted for quantitative imaging of elements in mouse kidney, as well as traumatic brain injury model tissue sections. MS imaging (MSI) employing LA provides quantitative data by comparing signal abundances of sodium from tissues to those obtained by imaging quantitation calibration standards of the target element applied to adjacent control tissue sections. LA-ICP MSI provided quantitative data for several essential elements in both brain and kidney tissue sections using a dried-droplet approach. Both methods were used to image a rat model of traumatic brain injury, revealing accumulations of sodium and calcium in the impact area and its peripheral regions. LA MSI is shown to be a viable option for quantitative imaging of specific elements in biological tissue sections.

  9. Mass transport and direction dependent battery modeling for accurate on-line power capability prediction

    Energy Technology Data Exchange (ETDEWEB)

    Wiegman, H.L.N. [General Electric Corporate Research and Development, Schenectady, NY (United States)

    2000-07-01

    Some recent advances in battery modeling were discussed with reference to on-line impedance estimates and power performance predictions for aqueous solution, porous electrode cell structures. The objective was to determine which methods accurately estimate a battery's internal state and power capability while operating a charge and sustaining a hybrid electric vehicle (HEV) over a wide range of driving conditions. The enhancements to the Randles-Ershler equivalent electrical model of common cells with lead-acid, nickel-cadmium and nickel-metal hydride chemistries were described. This study also investigated which impedances are sensitive to boundary layer charge concentrations and mass transport limitations. Non-linear impedances were shown to significantly affect the battery's ability to process power. The main advantage of on-line estimating a battery's impedance state and power capability is that the battery can be optimally sized for any application. refs., tabs., figs., append.

  10. Direct and Sensitive Detection of CWA Simulants by Active Capillary Plasma Ionization Coupled to a Handheld Ion Trap Mass Spectrometer

    Science.gov (United States)

    Wolf, Jan-Christoph; Etter, Raphael; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2016-07-01

    An active capillary plasma ionization (ACI) source was coupled to a handheld mass spectrometer (Mini 10.5; Aston Labs, West Lafayette, IN, USA) and applied to the direct gas-phase detection and quantification of chemical warfare agent (CWA) related chemicals. Complementing the discontinuous atmospheric pressure interface (DAPI) of the Mini 10.5 mass spectrometer with an additional membrane pump, a quasi-continuous sample introduction through the ACI source was achieved. Nerve agent simulants (three dialkyl alkylphosphonates, a dialkyl phosporamidate, and the pesticide dichlorvos) were detected at low gas-phase concentrations with limits of detection ranging from 1.0 μg/m3 to 6.3 μg/m3. Our results demonstrate a sensitivity enhancement for portable MS-instrumentation by using an ACI source, enabling direct, quantitative measurements of volatile organic compounds. Due to its high sensitivity, selectivity, low power consumption (<80 W) and weight (<13 kg), this instrumentation has the potential for direct on-site CWA detection as required by military or civil protection.

  11. Direct and Sensitive Detection of CWA Simulants by Active Capillary Plasma Ionization Coupled to a Handheld Ion Trap Mass Spectrometer.

    Science.gov (United States)

    Wolf, Jan-Christoph; Etter, Raphael; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2016-07-01

    An active capillary plasma ionization (ACI) source was coupled to a handheld mass spectrometer (Mini 10.5; Aston Labs, West Lafayette, IN, USA) and applied to the direct gas-phase detection and quantification of chemical warfare agent (CWA) related chemicals. Complementing the discontinuous atmospheric pressure interface (DAPI) of the Mini 10.5 mass spectrometer with an additional membrane pump, a quasi-continuous sample introduction through the ACI source was achieved. Nerve agent simulants (three dialkyl alkylphosphonates, a dialkyl phosporamidate, and the pesticide dichlorvos) were detected at low gas-phase concentrations with limits of detection ranging from 1.0 μg/m(3) to 6.3 μg/m(3). Our results demonstrate a sensitivity enhancement for portable MS-instrumentation by using an ACI source, enabling direct, quantitative measurements of volatile organic compounds. Due to its high sensitivity, selectivity, low power consumption (<80 W) and weight (<13 kg), this instrumentation has the potential for direct on-site CWA detection as required by military or civil protection. Graphical Abstract ᅟ.

  12. Surface desorption atmospheric pressure chemical ionization mass spectrometry for direct ambient sample analysis without toxic chemical contamination.

    Science.gov (United States)

    Chen, Huanwen; Zheng, Jian; Zhang, Xie; Luo, Mingbiao; Wang, Zhichang; Qiao, Xiaolin

    2007-08-01

    Ambient mass spectrometry, pioneered with desorption electrospray ionization (DESI) technique, is of increasing interest in recent years. In this study, a corona discharge ionization source is adapted for direct surface desorption chemical ionization of compounds on various surfaces at atmospheric pressure. Ambient air, with about 60% relative humidity, is used as a reagent to generate primary ions such as H(3)O(+), which is then directed to impact the sample surface for desorption and ionization. Under experimental conditions, protonated or deprotonated molecules of analytes present on various samples are observed using positive or negative corona discharge. Fast detection of trace amounts of analytes present in pharmaceutical preparations, viz foods, skins and clothes has been demonstrated without any sample pretreatment. Taking the advantage of the gasless setup, powder samples such as amino acids and mixtures of pharmaceutical preparations are rapidly analyzed. Impurities such as sudan dyes in tomato sauce are detected semiquantitatively. Molecular markers (e.g. putrescine) for meat spoilage are successfully identified from an artificially spoiled fish sample. Chemical warfare agent stimulants, explosives and herbicides are directly detected from the skin samples and clothing exposed to these compounds. This provides a detection limit of sub-pg (S/N > or = 3) range in MS2. Metabolites and consumed chemicals such as glucose are detected successfully from human skins. Conclusively, surface desorption atmospheric pressure chemical ionization (DAPCI) mass spectrometry, without toxic chemical contamination, detects various compounds in complex matrices, showing promising applications for analyses of human related samples.

  13. Solvent Separating Secondary Metabolites Directly from Biosynthetic Tissue for Surface-Assisted Laser Desorption Ionisation Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    David Rudd

    2015-03-01

    Full Text Available Marine bioactive metabolites are often heterogeneously expressed in tissues both spatially and over time. Therefore, traditional solvent extraction methods benefit from an understanding of the in situ sites of biosynthesis and storage to deal with heterogeneity and maximize yield. Recently, surface-assisted mass spectrometry (MS methods namely nanostructure-assisted laser desorption ionisation (NALDI and desorption ionisation on porous silicon (DIOS surfaces have been developed to enable the direct detection of low molecular weight metabolites. Since direct tissue NALDI-MS or DIOS-MS produce complex spectra due to the wide variety of other metabolites and fragments present in the low mass range, we report here the use of “on surface” solvent separation directly from mollusc tissue onto nanostructured surfaces for MS analysis, as a mechanism for simplifying data annotation and detecting possible artefacts from compound delocalization during the preparative steps. Water, ethanol, chloroform and hexane selectively extracted a range of choline esters, brominated indoles and lipids from Dicathais orbita hypobranchial tissue imprints. These compounds could be quantified on the nanostructured surfaces by comparison to standard curves generated from the pure compounds. Surface-assisted MS could have broad utility for detecting a broad range of secondary metabolites in complex marine tissue samples.

  14. Direct electrospray tandem mass spectrometry of the unstable hydroperoxy bishemiacetal product derived from cholesterol ozonolysis.

    Science.gov (United States)

    Pulfer, Melissa K; Harrison, Kathleen; Murphy, Robert C

    2004-02-01

    Cholesterol is the most abundant neutral lipid in the epithelial lining fluid of the lower airways of the lung also known as pulmonary surfactant and a potential target for reaction with ambient ozone when inspired into the human lung. The isolated double bond of cholesterol has been shown to be susceptible to attack by ozone, but the major reaction product from cholesterol ozonolysis had been remarkably difficult to structurally characterize. Recently, NMR and X-ray crystallography have been used to suggest the formation of a hydroperoxy, hydroxy hemiacetal product, using various derivatives and models of cholesterol to stabilize this chemically reactive product. Electrospray ionization mass spectrometry was used to study the somewhat unstable ozonolysis product of cholesterol which was found to display unique ionization and fragmentation properties when collisionally activated. The electron-deficient carbon atoms of this highly oxygenated product permitted covalent attachment of an acetate anion during negative ion electrospray ionization, leading to the formation of abundant adduct ions at m/z 511. Surprisingly, positive ions were not readily formed. Collision induced dissociation of the adduct anion yielded a major ion at m/z 477, corresponding to the loss of hydrogen peroxide. The most abundant fragment ion following collisional activation was observed at m/z 93, resulting from a complex rearrangement subsequent to the attack of the hydroperoxide anion on the carbon center of the acetate adduct. Based on the interpretation of the tandem mass spectral data, the major cholesterol ozonization product was characterized as a hydroperoxy, hydroxy hemiacetal derivative, which was consistent with the NMR and X-ray crystallographic studies which were carried out on the more stable methyl ether derivative.

  15. Direct identification of prohibited substances in cosmetics and foodstuffs using ambient ionization on a miniature mass spectrometry system.

    Science.gov (United States)

    Ma, Qiang; Bai, Hua; Li, Wentao; Wang, Chao; Li, Xinshi; Cooks, R Graham; Ouyang, Zheng

    2016-03-17

    Significantly simplified work flows were developed for rapid analysis of various types of cosmetic and foodstuff samples by employing a miniature mass spectrometry system and ambient ionization methods. A desktop Mini 12 ion trap mass spectrometer was coupled with paper spray ionization, extraction spray ionization and slug-flow microextraction for direct analysis of Sudan Reds, parabens, antibiotics, steroids, bisphenol and plasticizer from raw samples with complex matrices. Limits of detection as low as 5 μg/kg were obtained for target analytes. On-line derivatization was also implemented for analysis of steroid in cosmetics. The developed methods provide potential analytical possibility for outside-the-lab screening of cosmetics and foodstuff products for the presence of illegal substances.

  16. Rapid detection of hazardous chemicals in textiles by direct analysis in real-time mass spectrometry (DART-MS).

    Science.gov (United States)

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

    2016-07-01

    Residues of chemicals on clothing products were examined by direct analysis in real-time (DART) mass spectrometry. Our experiments have revealed the presence of more than 40 chemicals in 15 different clothing items. The identification was confirmed by DART tandem mass spectrometry (MS/MS) experiments for 14 compounds. The most commonly detected hazardous substances were nonylphenol ethoxylates (NPEs), phthalic acid esters (phthalates), amines released by azo dyes, and quinoline derivates. DART-MS was able to detect NPEs on the skin of the person wearing the clothing item contaminated by NPE residuals. Automated data acquisition and processing method was developed and tested for the recognition of NPE residues thereby reducing the analysis time.

  17. Comparative Study of Three Methods for Affinity Measurements: Capillary Electrophoresis Coupled with UV Detection and Mass Spectrometry, and Direct Infusion Mass Spectrometry

    Science.gov (United States)

    Mironov, Gleb G.; Logie, Jennifer; Okhonin, Victor; Renaud, Justin B.; Mayer, Paul M.; Berezovski, Maxim V.

    2012-07-01

    We present affinity capillary electrophoresis and mass spectrometry (ACE-MS) as a comprehensive separation technique for label-free solution-based affinity analysis. The application of ACE-MS for measuring affinity constants between eight small molecule drugs [ibuprofen, s-flurbiprofen, diclofenac, phenylbutazone, naproxen, folic acid, resveratrol, and 4,4'-(propane-1,3-diyl) dibenzoic acid] and β-cyclodextrin is described. We couple on-line ACE with MS to combine the separation and kinetic capability of ACE together with the molecular weight and structural elucidation of MS in one system. To understand the full potential of ACE-MS, we compare it with two other methods: Direct infusion mass spectrometry (DIMS) and ACE with UV detection (ACE-UV). After the evaluation, DIMS provides less reliable equilibrium dissociation constants than separation-based ACE-UV and ACE-MS, and cannot be used solely for the study of noncovalent interactions. ACE-MS determines apparent dissociation constants for all reacting small molecules in a mixture, even in cases when drugs overlap with each other during separation. The ability of ACE-MS to interact, separate, and rapidly scan through m/z can facilitate the simultaneous affinity analysis of multiple interacting pairs, potentially leading to the high-throughput screening of drug candidates.

  18. 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.

  19. Evaluating the physiological state of maize (Zea mays L.) plants by direct-injection electrospray mass spectrometry (DIESI-MS).

    Science.gov (United States)

    García-Flores, Martín; Juárez-Colunga, Sheila; Montero-Vargas, Josaphat Miguel; López-Arciniega, Janet Ana Isabel; Chagolla, Alicia; Tiessen, Axel; Winkler, Robert

    2012-06-01

    Climatic change is an increasing challenge for agriculture that is driving the development of suitable crops in order to ensure supply for both human nutrition and animal feed. In this context, it is increasingly important to understand the biochemical responses of cells to environmental cues at the whole system level, an aim that is being brought closer by advances in high throughput, cost-efficient plant metabolomics. To support molecular breeding activities, we have assessed the economic, technical and statistical feasibility of using direct mass spectrometry methods to evaluate the physiological state of maize (Zea mays L.) plants grown under different stress conditions.

  20. Competitive ion kinetics in direct mass spectrometric organic speciation. 1994 Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sieck, L.W.

    1994-12-31

    The experimental work on the gas phase proton affinity (PA) scale, discussed in some detail in last year`s Progress Report, will be completed within the next few weeks. Basically this effort involves the development of a precise and accurate interlocking ladder of relative PA`s derived from the temperature dependence of proton transfer equilibria incorporating a variety of reactant pairs using the technique of pulsed high pressure mass spectrometry (NIST has the only US facility). The PA subset under investigation was expanded from the original list to cover the region between CH{sub 3}CHO and (CH{sub 3}){sub 2}CO, which spans a PA range of approximately 12 kcal/mol. More than 300 separate equilibrium measurements have been carried out to date over the temperature range 240--395 C. The thermochemical region under study creates a bridge between the so-called upper and lower PA scales, and includes two primary reference standards, CH{sub 3}CHO and i-C{sub 4}H{sub 8}, with PA`s independently defined elsewhere via photoionization techniques.

  1. 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.

  2. Multiple Reaction Monitoring for Direct Quantitation of Intact Proteins Using a Triple Quadrupole Mass Spectrometer.

    Science.gov (United States)

    Wang, Evelyn H; Combe, Peter C; Schug, Kevin A

    2016-05-01

    Methods that can efficiently and effectively quantify proteins are needed to support increasing demand in many bioanalytical fields. Triple quadrupole mass spectrometry (QQQ-MS) is sensitive and specific, and it is routinely used to quantify small molecules. However, low resolution fragmentation-dependent MS detection can pose inherent difficulties for intact proteins. In this research, we investigated variables that affect protein and fragment ion signals to enable protein quantitation using QQQ-MS. Collision induced dissociation gas pressure and collision energy were found to be the most crucial variables for optimization. Multiple reaction monitoring (MRM) transitions for seven standard proteins, including lysozyme, ubiquitin, cytochrome c from both equine and bovine, lactalbumin, myoglobin, and prostate-specific antigen (PSA) were determined. Assuming the eventual goal of applying such methodology is to analyze protein in biological fluids, a liquid chromatography method was developed. Calibration curves of six standard proteins (excluding PSA) were obtained to show the feasibility of intact protein quantification using QQQ-MS. Linearity (2-3 orders), limits of detection (0.5-50 μg/mL), accuracy (protein. Sensitivities for different proteins varied considerably. Biological fluids, including human urine, equine plasma, and bovine plasma were used to demonstrate the specificity of the approach. The purpose of this model study was to identify, study, and demonstrate the advantages and challenges for QQQ-MS-based intact protein quantitation, a largely underutilized approach to date.

  3. Multiple Reaction Monitoring for Direct Quantitation of Intact Proteins Using a Triple Quadrupole Mass Spectrometer

    Science.gov (United States)

    Wang, Evelyn H.; Combe, Peter C.; Schug, Kevin A.

    2016-05-01

    Methods that can efficiently and effectively quantify proteins are needed to support increasing demand in many bioanalytical fields. Triple quadrupole mass spectrometry (QQQ-MS) is sensitive and specific, and it is routinely used to quantify small molecules. However, low resolution fragmentation-dependent MS detection can pose inherent difficulties for intact proteins. In this research, we investigated variables that affect protein and fragment ion signals to enable protein quantitation using QQQ-MS. Collision induced dissociation gas pressure and collision energy were found to be the most crucial variables for optimization. Multiple reaction monitoring (MRM) transitions for seven standard proteins, including lysozyme, ubiquitin, cytochrome c from both equine and bovine, lactalbumin, myoglobin, and prostate-specific antigen (PSA) were determined. Assuming the eventual goal of applying such methodology is to analyze protein in biological fluids, a liquid chromatography method was developed. Calibration curves of six standard proteins (excluding PSA) were obtained to show the feasibility of intact protein quantification using QQQ-MS. Linearity (2-3 orders), limits of detection (0.5-50 μg/mL), accuracy (protein. Sensitivities for different proteins varied considerably. Biological fluids, including human urine, equine plasma, and bovine plasma were used to demonstrate the specificity of the approach. The purpose of this model study was to identify, study, and demonstrate the advantages and challenges for QQQ-MS-based intact protein quantitation, a largely underutilized approach to date.

  4. Direct stimulation of bone mass by increased GH signalling in the osteoblasts of Socs2-/- mice.

    Science.gov (United States)

    Dobie, R; MacRae, V E; Huesa, C; van't Hof, R; Ahmed, S F; Farquharson, C

    2014-10-01

    The suppressor of cytokine signalling (Socs2(-/-))-knockout mouse is characterised by an overgrowth phenotype due to enhanced GH signalling. The objective of this study was to define the Socs2(-/-) bone phenotype and determine whether GH promotes bone mass via IGF1-dependent mechanisms. Despite no elevation in systemic IGF1 levels, increased body weight in 4-week-old Socs2(-/-) mice following GH treatment was associated with increased cortical bone area (Ct.Ar) (PGH. Indeed, male Socs2(-/-) mice had increased Ct.Ar (PGH action. Mechanistic studies showed that in osteoblasts and bone of Socs2(-/-) mice, STAT5 phosphorylation was significantly increased in response to GH. Conversely, overexpression of SOCS2 decreased GH-induced STAT5 signalling. Although an increase in Igf1 expression was observed in Socs2(-/-) osteoblasts following GH, it was not evident in vivo. Igf1 expression levels were not elevated in response to GH in 4-week-old mice and no alterations in expression was observed in bone samples of 6-week-old Socs2(-/-) mice. These studies emphasise the critical role of SOCS2 in controlling the local GH anabolic bone effects. We provide compelling evidence implicating SOCS2 in the regulation of GH osteoblast signalling and ultimately bone accrual, which maybe via mechanisms that are independent of IGF1 production in vivo.

  5. Direct observations of magnetic flux rope formation during a solar coronal mass ejection

    CERN Document Server

    Song, Hongqiang; Chen, Yao; Cheng, Xin

    2014-01-01

    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, \\textit{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 letter, we present an intriguing observation of a solar eruptive event occurred on 2013 November 21 with the Atmospheric Imaging Assembly on board the \\textit{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-fo...

  6. Direct numerical simulation of fluid-particle mass, momentum, and heat tranfers in reactive systems.

    Science.gov (United States)

    Hammouti, Abdelkader; Wachs, Anthony

    2015-11-01

    Many industrial processes like coal combustion, catalytic cracking, gas phase polymerization reactors and more recently biomass gasification and chemical looping involve two-phase reactive flows in which the continuous phase is a fluid and the dispersed phase consists of rigid particles. Improving both the design and the operating conditions of these processes represents a major scientific and industrial challenge in a context of markedly rising energy cost and sustainable development. Thus, it is above all important to better understand the coupling of hydrodynamic, chemical and thermal phenomena in those flows in order to be able to predict them reliably. The aim of our work is to build up a multi-scale modelling approach of reactive particulate flows and at first to focus on the development of a microscopic-scale including heat and mass transfers and chemical reactions for the prediction of particle-laden flows in dense and dilute regimes. A first step is the upgrading and the validation of our numerical tools via analytical solutions or empirical correlations when it is feasible. These couplings are implemented in a massively parallel numerical code that already enable to take a step towards the enhanced design of semi-industrial processes.

  7. Direct determinations of the nucleon and pion $\\sigma$ terms at nearly physical quark masses

    CERN Document Server

    Bali, Gunnar S; Richtmann, Daniel; Schäfer, Andreas; Söldner, Wolfgang; Sternbeck, André

    2016-01-01

    We present a high statistics study of the pion and nucleon light and strange quark sigma terms using $N_f=2$ dynamical non-perturbatively improved clover fermions with a range of pion masses down to $m_\\pi\\sim 150$ MeV and several volumes, $Lm_\\pi=3.4$ up to $6.7$, and lattice spacings, $a=0.06-0.08$ fm, enabling a study of finite volume and discretisation effects for $m_\\pi\\gtrsim 260$ MeV. Systematics are found to be reasonably under control. For the nucleon we obtain $\\sigma_{\\pi N}=35(6)$ MeV and $\\sigma_s=35(12)$ MeV, or equivalently in terms of the quark fractions, $f_{T_u}=0.021(4)$, $f_{T_d}=0.016(4)$ and $f_{T_s}=0.037(13)$, where the errors include estimates of both the systematic and statistical uncertainties. These values, together with perturbative matching in the heavy quark limit, lead to $f_{T_c}=0.075(4)$, $f_{T_b}=0.072(2)$ and $f_{T_t}=0.070(1)$. In addition, through the use of the (inverse) Feynman-Hellmann theorem our results for $\\sigma_{\\pi N}$ are shown to be consistent with the nucleo...

  8. Membrane inlet proton transfer reaction mass spectrometry (MI-PTRMS) for direct measurements of VOCs in water

    Science.gov (United States)

    Boscaini, Elena; Alexander, Michael L.; Prazeller, Peter; Märk, Tilmann D.

    2004-12-01

    The use of a membrane inlet proton transfer reaction mass spectrometry (MI-PTRMS) system was investigated for the quantitative analysis of VOCs directly from water. Compounds playing an important role in environmental, biological and health issues such as methanol, acetonitrile, acetone, dimethylsulfide (DMS), isoprene, benzene, and toluene have been analyzed both in fresh and salty water. The system shows very good sensitivity, reproducibility, and a linear response of up to five orders of magnitude. The detection limit for DMS is about 100 ppt and for methanol is about 10 ppb both in fresh and salty water. The response time of the various compounds across the membrane is on the order of a few minutes. This fast response and the fact that the PTRMS can perform absolute measurements without the necessity of calibration make the system suitable for on-line and -site measurements of VOCs directly from water.

  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.

  10. Direct Analysis in Real Time-Mass Spectrometry for the Rapid Detection of Metabolites of Aconite Alkaloids in Intestinal Bacteria

    Science.gov (United States)

    Li, Xue; Hou, Guangyue; Xing, Junpeng; Song, Fengrui; Liu, Zhiqiang; Liu, Shuying

    2014-12-01

    In the present work, direct analysis of real time ionization combined with multi-stage tandem mass spectrometry (DART-MSn) was used to investigate the metabolic profile of aconite alkaloids in rat intestinal bacteria. A total of 36 metabolites from three aconite alkaloids were identified by using DART-MSn, and the feasibility of quantitative analysis of these analytes was examined. Key parameters of the DART ion source, such as helium gas temperature and pressure, the source-to-MS distance, and the speed of the autosampler, were optimized to achieve high sensitivity, enhance reproducibility, and reduce the occurrence of fragmentation. The instrument analysis time for one sample can be less than 10 s for this method. Compared with ESI-MS and UPLC-MS, the DART-MS is more efficient for directly detecting metabolic samples, and has the advantage of being a simple, high-speed, high-throughput method.

  11. Holocene age of the Yuha burial: Direct radiocarbon determinations by accelerator mass spectrometry

    Science.gov (United States)

    Stafford, Thomas W.; Jull, A.J.T.; Zabel, T.H.; Donahue, D.J.; Duhamel, R.C.; Brendel, K.; Haynes, C.V.; Bischoff, J.L.; Payen, L.A.; Taylor, R.E.

    1984-01-01

    The view that human populations may not have arrived in the Western Hemisphere before about 12,000 radiocarbon yr BP1,2 has been challenged by claims of much greater antiquity for a small number of archaeological sites and human skeleton samples. One such site is the Homo sapiens sapiens cairn burial excavated in 1971 from the Yuha desert, Imperial County, California3-5. Radiocarbon analysis of caliche coating one of the bones of the skeleton yielded a radiocarbon age of 21,500??1,000 yr BP4, while radiocarbon and uranium series analyses of caliche coating a cairn boulder yielded ages of 22,125??400 and 19,000??3,000 yr BP, respectively5. The late Pleistocene age assignment to the Yuha burial has been challenged by comparing the cultural context of the burial with other cairn burials in the same region6, on the basis of the site's geomorphological context and from radiocarbon analyses of soil caliches. 7,8 In rebuttal, arguments in defence of the original age assignment have been presented9,10 as well as an amino acid racemization analysis on the Yuha skeleton indicating an age of 23,600??2,600 yr BP11. The tandem accelerator mass spectrometer at the University of Arizona has now been used to measure the ratio of 14C/13C in several organic and inorganic fractions of post-cranial bone from the Yuha H. sapiens sapiens skeleton. Isotope ratios from six chemical fractions all yielded radiocarbon ages for the skeleton of less than 4,000 yr BP. These results indicate that the Yuha skeleton is of Holocene age, in agreement with the cultural context of the burial, and in disagreement with the previously assigned Pleistocene age of 19,000-23,000 yr. ?? 1984 Nature Publishing Group.

  12. 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)

  13. 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.

  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. Overview of Methods for the Direct Molar Mass Determination of Cellulose

    Directory of Open Access Journals (Sweden)

    Josua Timotheus Oberlerchner

    2015-06-01

    Full Text Available The purpose of this article is to provide the reader with an overview of the methods used to determine the molecular weights of cellulose. Methods that employ direct dissolution of the cellulose polymer are described; hence methods for investigating the molecular weight of cellulose in derivatized states, such as ethers or esters, only form a minor part of this review. Many of the methods described are primarily of historical interest since they have no use in modern cellulose chemistry. However, older methods, such as osmometry or ultracentrifuge experiments, were the first analytical methods used in polymer chemistry and continue to serve as sources of fundamental information (such as the cellulose structure in solution. The first part of the paper reviews methods, either absolute or relative, for the estimation of average molecular weights. Regardless of an absolute or relative approach, the outcome is a molecular weight average (MWA. In the final section, coupling methods are described. The primary benefit of performing a pre-separation step on the molecules is the discovery of the molecular weight distribution (MWD. Here, size exclusion chromatography (SEC is unquestionably the most powerful and most commonly-applied method in modern laboratories and industrial settings.

  16. Overview of Methods for the Direct Molar Mass Determination of Cellulose.

    Science.gov (United States)

    Oberlerchner, Josua Timotheus; Rosenau, Thomas; Potthast, Antje

    2015-06-04

    The purpose of this article is to provide the reader with an overview of the methods used to determine the molecular weights of cellulose. Methods that employ direct dissolution of the cellulose polymer are described; hence methods for investigating the molecular weight of cellulose in derivatized states, such as ethers or esters, only form a minor part of this review. Many of the methods described are primarily of historical interest since they have no use in modern cellulose chemistry. However, older methods, such as osmometry or ultracentrifuge experiments, were the first analytical methods used in polymer chemistry and continue to serve as sources of fundamental information (such as the cellulose structure in solution). The first part of the paper reviews methods, either absolute or relative, for the estimation of average molecular weights. Regardless of an absolute or relative approach, the outcome is a molecular weight average (MWA). In the final section, coupling methods are described. The primary benefit of performing a pre-separation step on the molecules is the discovery of the molecular weight distribution (MWD). Here, size exclusion chromatography (SEC) is unquestionably the most powerful and most commonly-applied method in modern laboratories and industrial settings.

  17. The International Deep Planet Survey II: The frequency of directly imaged giant exoplanets with stellar mass

    CERN Document Server

    Galicher, Raphael; Macintosh, Bruce; Zuckerman, Ben; Barman, Travis; Konopacky, Quinn; Song, Inseok; Patience, Jenny; Lafreniere, David; Doyon, Rene; Nielsen, Eric L

    2016-01-01

    Radial velocity and transit methods are effective for the study of short orbital period exoplanets but they hardly probe objects at large separations for which direct imaging can be used. We carried out the international deep planet survey of 292 young nearby stars to search for giant exoplanets and determine their frequency. We developed a pipeline for a uniform processing of all the data that we have recorded with NIRC2/Keck II, NIRI/Gemini North, NICI/Gemini South, and NACO/VLT for 14 years. The pipeline first applies cosmetic corrections and then reduces the speckle intensity to enhance the contrast in the images. The main result of the international deep planet survey is the discovery of the HR 8799 exoplanets. We also detected 59 visual multiple systems including 16 new binary stars and 2 new triple stellar systems, as well as 2,279 point-like sources. We used Monte Carlo simulations and the Bayesian theorem to determine that 1.05[+2.80-0.70]% of stars harbor at least one giant planet between 0.5 and 14...

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

    Science.gov (United States)

    Manfredi, Marcello; Robotti, Elisa; Bearman, Greg; France, Fenella; Barberis, Elettra; Shor, Pnina; Marengo, Emilio

    2016-01-01

    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.

  19. Direct infussion Electrospray Mass Spectrometry as a new non-invasive tool for serum metabolomics in induced-stress subjects

    Directory of Open Access Journals (Sweden)

    Mónica Lorenzo-Tejedor

    2015-12-01

    Full Text Available Background and Objectives: Nanotechnology is becoming a tool for the study of changes in the metabolome of patients in different states of disease. Analytical techniques such as Electrospray Mass Spectrometry, allow to find biomarkers by determination of metabolites. Nowadays, there is not an objective analytical approach for diagnosis of stress. Thus, the objectives of this pilot work are: Describing the development of a fast, direct and non-invasive analytical protocol, applied for the first time, to study the metabolomic profile of patient´s different states through a disease. Testing the protocol in a pilot sample with non-stressed and stress-induced subjects. Methods: High resolution direct infusion electrospray mass spectrometry has been used to analyse the metabolome of blood samples (0.3 ml from six subjects. Results: Data prove a clear discrimination between non-stressed and stressed states in the metabolome. Data showed different predominant metabolites in both states. Results allow objective characterization of the state of the patient. Conclusions: Although this is a pilot study, the method was successful in discriminating different metabolites in non-stressed and stress-induced subjects.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Qualitative and quantitative analysis of the anthelmintic fenbendazole and its metabolites in biological matrices by direct exposure probe mass spectrometry.

    Science.gov (United States)

    Barker, S A; Hsieh, L C; McDowell, T R; Short, C R

    1987-04-01

    Methodology for the qualitative and quantitative analysis of the anthelmintic fenbendazole and its metabolites in goat feces using electron impact (EI)/direct exposure probe (DEP)/mass spectrometric (MS) and tandem mass spectrometric (MS/MS) techniques is presented. Analyses were conducted on extracts from spiked feces and feces from animals treated per os with 5 mg fenbendazole/kg, with samples being collected at zero time and at twelve hour intervals for 144 h. The results of the EI/DEP/MS quantitation of these samples are compared to those for the same samples analysed by high pressure liquid chromatography (HPLC). Mass spectral data for fenbendazole and its metabolites are presented and the advantages of the use of EI/DEP/MS and/or DEP/MS/MS over HPLC are discussed. This methodology may be used as a confirmatory method for the HPLC analysis of fenbendazole and its metabolites or may be used as a method in its own right for the rapid qualitative and quantitative analysis of these compounds.

  5. 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.

    2016-10-01

    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.

  6. Unambiguous identification and discovery of bacterial siderophores by direct injection 21 Tesla Fourier transform ion cyclotron resonance mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Lawrence R.; Tfaily, Malak M.; Shaw, Jared B.; Hess, Nancy J.; Pasa Tolic, Ljiljana; Koppenaal, David W.

    2017-01-01

    Under iron-limiting conditions, bacteria produce low molecular mass Fe(III) binding molecules known as siderophores to sequester the Fe(III), along with other elements, increasing their bioavailibility. Siderophores are thought to influence iron cycling and biogeochemistry in both marine and terrestrial ecosystems and hence the need for rapid, confident characterization of these compounds has increased. In this study, the type of siderophores produced by two marine bacterial species, Synechococcus sp. PCC 7002 and Vibrio cyclitrophicus 1F53, were characterized using a newly developed 21T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR MS) with direct injection electrospray ionization. This technique allowed for the rapid detection of synechobactins from Synechococcus sp. PCC 7002 as well as amphibactins from Vibrio cyclitrophicus 1F53 based on high mass accuracy and resolution allowing for observation of specific Fe isotopic peaks and fine isotopic structure enables highly confident identification of these sideropohores. When combined with molecular network analysis two new amphibactins were discovered and verified by tandem MS. These results show that high-field FTICR MS is a powerful technique that will greatly improve the ability to rapidly identify and discover metal binding species in the environment.

  7. New insights into atmospherically relevant reaction systems using direct analysis in real-time mass spectrometry (DART-MS)

    Science.gov (United States)

    Zhao, Yue; Fairhurst, Michelle C.; Wingen, Lisa M.; Perraud, Véronique; Ezell, Michael J.; Finlayson-Pitts, Barbara J.

    2017-04-01

    The application of direct analysis in real-time mass spectrometry (DART-MS), which is finding increasing use in atmospheric chemistry, to two different laboratory model systems for airborne particles is investigated: (1) submicron C3-C7 dicarboxylic acid (diacid) particles reacted with gas-phase trimethylamine (TMA) or butylamine (BA) and (2) secondary organic aerosol (SOA) particles from the ozonolysis of α-cedrene. The diacid particles exhibit a clear odd-even pattern in their chemical reactivity toward TMA and BA, with the odd-carbon diacid particles being substantially more reactive than even ones. The ratio of base to diacid in reacted particles, determined using known diacid-base mixtures, was compared to that measured by high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS), which vaporizes the whole particle. Results show that DART-MS probes ˜ 30 nm of the surface layer, consistent with other studies on different systems. For α-cedrene SOA particles, it is shown that varying the temperature of the particle stream as it enters the DART-MS ionization region can distinguish between specific components with the same molecular mass but different vapor pressures. These results demonstrate the utility of DART-MS for (1) examining reactivity of heterogeneous model systems for atmospheric particles and (2) probing components of SOA particles based on volatility.

  8. Automated analysis of sequence polymorphism in STR alleles by PCR and direct electrospray ionization mass spectrometry.

    Science.gov (United States)

    Planz, John V; Sannes-Lowery, Kristen A; Duncan, David D; Manalili, Sheri; Budowle, Bruce; Chakraborty, Ranajit; Hofstadler, Steven A; Hall, Thomas A

    2012-09-01

    Short tandem repeats (STRs) are the primary genetic markers used for the analysis of biological samples in forensic and human identity testing. The discrimination power of a combination of STRs is sufficient in many human identity testing comparisons unless the evidence is substantially compromised and/or there are insufficient relatives or a potential mutation may have arisen in kinship analyses. An automated STR assay system that is based on electrospray ionization mass spectrometry (ESI-MS) has been developed that can increase the discrimination power of some of the CODIS core STR loci and thus provide more information in typical and challenged samples and cases. Data from the ESI-MS STR system is fully backwards compatible with existing STR typing results generated by capillary electrophoresis. In contrast, however, the ESI-MS analytical system also reveals nucleotide polymorphisms residing within the STR alleles. The presence of these polymorphisms expands the number of alleles at a locus. Population studies were performed on the 13 core CODIS STR loci from African Americans, Caucasians and Hispanics capturing both the length of the allele, as well as nucleotide variations contained within repeat motifs or flanking regions. Such additional polymorphisms were identified in 11 of the 13 loci examined whereby several nominal length alleles were subdivided. A substantial increase in heterozygosity was observed, with close to or greater than 5% of samples analyzed being heterozygous with equal-length alleles in at least one of five of the core CODIS loci. This additional polymorphism increases discrimination power significantly, whereby the seven most polymorphic STR loci have a discrimination power equivalent to the 10 most discriminating of the CODIS core loci. An analysis of substructure among the three population groups revealed a higher θ than would be observed compared with using alleles designated by nominal length, i.e., repeats solely. Two loci, D3S1358

  9. Field-testing of a Passive Surface Water Flux Meter for the Direct Measurement of Water and Solute Mass Fluxes

    Science.gov (United States)

    Atkinson, E. C.; Jawitz, J. W.; Annable, M. D.; Klammler, H.; Hatfield, K.

    2007-05-01

    The measurement of water and solute mass discharges in surface water flow systems is a fundamental hydrologic task for ecological and economic decision making. However, due to the extensive monetary, labor, and time costs of traditional monitoring devices and methods, many water quality monitoring programs lack the resources necessary to provide comprehensive descriptions of surface water impairments. The Passive Surface Water Flux Meter (PSFM) is a recently developed passive sampling device that measures water and solute fluxes within flowing surface water bodies. Devoid of mechanical components and power supply requirements, the relatively low-maintenance, low-cost design of the PSFM gives it considerable potential as a tool for extensive, large-scale surface water quality characterization and monitoring. The novelty of the PSFM extends to its direct mass-based approach to solute flux measurement, as compared to conventional, indirect concentration-based approaches. During this field-testing campaign, the PSFM was deployed in flowing surface water bodies of north- central Florida. The device contained a dual-packed porous media cartridge that performed simultaneous ion exchange to determine phosphate mass flux and equilibrium tracer desorption to determine water flux within the stream. The PSFM demonstrated accurate measurement of steady-state water and phosphate mass fluxes to within 15% over a range of stream velocities, solute concentrations, and deployment durations. The PSFM design described here was found to perform well in steady-flow conditions. The device was also shown to be effective under transient conditions of limited variability, but full transient testing remains for future work.

  10. Determination of Dicyandiamide in Powdered Milk Using Direct Analysis in Real Time Quadrupole Time-of-Flight Tandem Mass Spectrometry

    Science.gov (United States)

    Zhang, Liya; Yong, Wei; Liu, Jiahui; Wang, Sai; Chen, Qilong; Guo, Tianyang; Zhang, Jichuan; Tan, Tianwei; Su, Haijia; Dong, Yiyang

    2015-08-01

    The direct analysis in real time (DART) ionization source coupled with quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) system has the capability to desorb analytes directly from samples without sample cleanup or chromatographic separation. In this work, a method based on DART/Q-TOF MS/MS has been developed for rapid identification of dicyandiamide (DCD) present in powdered milk. Simple sample extraction procedure employing acetonitrile-water (80:20, v/v) mixture was followed by direct, high-throughput determination of sample extracts spread on a steel mesh of the transmission module by mass spectrometry under ambient conditions. The method has been evaluated for both qualitative and quantitative analysis of DCD in powdered milk. Variables including experimental apparatus, DART gas heater temperature, sample presentation speed, and vacuum pressure were investigated. The quantitative method was validated with respect to linearity, sensitivity, repeatability, precision, and accuracy by using external standards. After optimization of these parameters, a limit of detection (LOD) of 100 μg kg-1 was obtained for DCD with a linear working range from 100 to 10000 μg kg-1 and a satisfactory correlation coefficient (R2) of 0.9997. Good recovery (80.08%-106.47%) and repeatability (RSD = 3.0%-5.4%) were achieved for DCD. The DART/Q-TOF MS/MS-based method provides a rapid, efficient, and powerful scheme to analyze DCD in powdered milk with limited sample preparation, thus reducing time and complexity of quality control.

  11. Characterization of direct-current atmospheric-pressure discharges useful for ambient desorption/ionization mass spectrometry.

    Science.gov (United States)

    Shelley, Jacob T; Wiley, Joshua S; Chan, George C Y; Schilling, Gregory D; Ray, Steven J; Hieftje, Gary M

    2009-05-01

    Two relatively new ambient ionization sources, direct analysis in real time (DART) and the flowing atmospheric-pressure afterglow (FAPA), use direct current, atmospheric-pressure discharges to produce reagent ions for the direct ionization of a sample. Although at a first glance these two sources appear similar, a fundamental study reveals otherwise. Specifically, DART was found to operate with a corona-to-glow transition (C-G) discharge whereas the FAPA was found to operate with a glow-to-arc transition (G-A) discharge. The characteristics of both discharges were evaluated on the basis of four factors: reagent-ion production, response to a model analyte (ferrocene), infrared (IR) thermography of the gas used for desorption and ionization, and spatial emission characteristics. The G-A discharge produced a greater abundance and a wider variety of reagent ions than the C-G discharge. In addition, the discharges yielded different adducts and signal strengths for ferrocene. It was also found that the gas exiting the discharge chamber reached a maximum of 235 degrees C and 55 degrees C for the G-A and C-G discharges, respectively. Finally, spatially resolved emission maps of both discharges showed clear differences for N(2)(+) and O(I). These findings demonstrate that the discharges used by FAPA and DART are fundamentally different and should have different optimal applications for ambient desorption/ionization mass spectrometry (ADI-MS).

  12. Direct determination of arsenic in fresh and saline waters by electrothermal vaporization inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Conrad Grégoire, D.; de Lourdes Ballinas, Maria

    1997-01-01

    A method is described for the direct determination of arsenic in fresh and saline waters by electrothermal vaporization inductively coupled plasma mass spectrometry. Arsenic could be determined directly in waters containing up to 10 000 μg ml -1 NaCl without interference from the formation of 75ArCl +. For non-saline waters, arsenic was determined directly with the addition to both aqueous calibration standards and samples of 0.1 μg each of Pd and Mg to act as physical carriers. For the analysis of highly saline waters, the use of Pd and Mg chemical modifier served to thermally stabilize arsenic up to a temperature of 1000°C, while the separate addition of 8 mg of ammonium nitrate was used to remove chloride from the sample. This eliminated serious spectral interference on 75As + from 75ArCl +. Although the ArCl + spectral interference was completely eliminated, residual Na co-volatilized with As caused signal suppression, requiring the use of the method of standard additions for calibration. An absolute limit of detection limit for As of 0.069 pg was obtained corresponding to 6.9 pg ml -1 in a 10 μl sample.

  13. 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.

  14. 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 statistic...

  15. 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 statistic...

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

    NARCIS (Netherlands)

    Miglio, A.; Brogaard, K.; Stello, D.; Chaplin, W.J.; D'Antona, F.; Montalbán, J.; Basu, S.; Bressan, A.; Grundahl, F.; Pinsonneault, M.; Serenelli, A.M.; Elsworth, Y.; Hekker, S.; Kallinger, T.; Mosser, B.; Ventura, P.; Bonanno, A.; Noels, A.; Silva Aguirre, V.; Szabo, R.; Li, J.; McCauliff, S.; Middour, C.K.; Kjeldsen, H.

    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 statisticall

  17. 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.

  18. Matrix assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) for direct visualization of plant metabolites in situ.

    Science.gov (United States)

    Sturtevant, Drew; Lee, Young-Jin; Chapman, Kent D

    2016-02-01

    Direct visualization of plant tissues by matrix assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has revealed key insights into the localization of metabolites in situ. Recent efforts have determined the spatial distribution of primary and secondary metabolites in plant tissues and cells. Strategies have been applied in many areas of metabolism including isotope flux analyses, plant interactions, and transcriptional regulation of metabolite accumulation. Technological advances have pushed achievable spatial resolution to subcellular levels and increased instrument sensitivity by several orders of magnitude. It is anticipated that MALDI-MSI and other MSI approaches will bring a new level of understanding to metabolomics as scientists will be encouraged to consider spatial heterogeneity of metabolites in descriptions of metabolic pathway regulation.

  19. 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.

  20. 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.

    2016-03-01

    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.

  1. 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

  2. Directly coupled high-performance liquid chromatography-accelerator mass spectrometry measurement of chemically modified protein and peptides.

    Science.gov (United States)

    Thomas, Avi T; Stewart, Benjamin J; Ognibene, Ted J; Turteltaub, Kenneth W; Bench, Graham

    2013-04-02

    Quantitation of low-abundance protein modifications involves significant analytical challenges, especially in biologically important applications, such as studying the role of post-translational modifications in biology and measurement of the effects of reactive drug metabolites. (14)C labeling combined with accelerator mass spectrometry (AMS) provides exquisite sensitivity for such experiments. Here, we demonstrate real-time (14)C quantitation of high-performance liquid chromatography (HPLC) separations by liquid sample accelerator mass spectrometry (LS-AMS). By enabling direct HPLC-AMS coupling, LS-AMS overcomes several major limitations of conventional HPLC-AMS, where individual HPLC fractions must be collected and converted to graphite before measurement. To demonstrate LS-AMS and compare the new technology to traditional solid sample AMS (SS-AMS), reduced and native bovine serum albumin (BSA) was modified by (14)C-iodoacetamide, with and without glutathione present, producing adducts on the order of 1 modification in every 10(6) to 10(8) proteins. (14)C incorporated into modified BSA was measured by solid carbon AMS and LS-AMS. BSA peptides were generated by tryptic digestion. Analysis of HPLC-separated peptides was performed in parallel by LS-AMS, fraction collection combined with SS-AMS, and (for peptide identification) electrospray ionization and tandem mass spectrometry (ESI-MS/MS). LS-AMS enabled (14)C quantitation from ng sample sizes and was 100 times more sensitive to (14)C incorporated in HPLC-separated peptides than SS-AMS, resulting in a lower limit of quantitation of 50 zmol (14)C/peak. Additionally, LS-AMS turnaround times were minutes instead of days, and HPLC trace analyses required 1/6th the AMS instrument time required for analysis of graphite fractions by SS-AMS.

  3. 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.)

  4. 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

  5. Mapping the lipoylation site of Arabidopsis thaliana plastidial dihydrolipoamide S-acetyltransferase using mass spectrometry and site-directed mutagenesis.

    Science.gov (United States)

    Casteel, Jill; Miernyk, Ján A; Thelen, Jay J

    2011-11-01

    Catalytic enhancement achieved by the pyruvate dehydrogenase complex (PDC) results from a combination of substrate channeling plus active-site coupling. The mechanism for active-site coupling involves lipoic acid prosthetic groups covalently attached to Lys in the primary sequence of the dihydrolipoyl S-acetyltransferase (E2) component. Arabidopsis thaliana plastidial E2 (AtplE2-1A-His(6)) was expressed in Escherichia coli. Analysis of recombinant protein by SDS-PAGE revealed a Mr 59,000 band. Supplementation of bacterial culture medium with l-lipoic acid (LA) shifted the band to Mr 57,000. Intact mass determinations using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) revealed the faster migrating E2 species was 189 Da larger than the slower migrating form, exactly the difference that would result from addition of a single lipoamide group. Results from systematic MALDI-TOF analysis of Lys-containing tryptic peptides derived from purified recombinant AtplE2-1A indicate that Lys96 is the site of lipoyl-addition. Analysis of Lys96 site-directed mutant proteins showed that they migrated as single species during SDS-PAGE when expressed in either the absence or presence of supplemental LA. Results from both intact and tryptic peptide mass determinations by MALDI-TOF MS confirmed that the mutant proteins were not lipoylated. The A. thaliana plastidial E2 subunit includes a single lipoyl-prosthetic group covalently attached to Lys96. Despite low primary sequence identity with bacterial E2, the plant E2 protein was recognized and modified by E. coli E2 lipoyl-addition system. Results from meta-genomic analysis suggest a β-turn is more important in defining the site for LA addition than a conserved sequence motif.

  6. Proteomic-based prognosis of brain tumor patients using direct-tissue matrix-assisted laser desorption ionization mass spectrometry.

    Science.gov (United States)

    Schwartz, Sarah A; Weil, Robert J; Thompson, Reid C; Shyr, Yu; Moore, Jason H; Toms, Steven A; Johnson, Mahlon D; Caprioli, Richard M

    2005-09-01

    Clinical diagnosis and treatment decisions for a subset of primary human brain tumors, gliomas, are based almost exclusively on tissue histology. Approaches for glioma diagnosis can be highly subjective due to the heterogeneity and infiltrative nature of these tumors and depend on the skill of the neuropathologist. There is therefore a critical need to develop more precise, non-subjective, and systematic methods to classify human gliomas. To this end, mass spectrometric analysis has been applied to these tumors to determine glioma-specific protein patterns. Protein profiles have been obtained from human gliomas of various grades through direct analysis of tissue samples using matrix-assisted laser desorption ionization mass spectrometry (MS). Statistical algorithms applied to the MS profiles from tissue sections identified protein patterns that correlated with tumor histology and patient survival. Using a data set of 108 glioma patients, two patient populations, a short-term and a long-term survival group, were identified based on the tissue protein profiles. In addition, a subset of 57 patients diagnosed with high-grade, grade IV, malignant gliomas were analyzed and a novel classification scheme that segregated short-term and long-term survival patients based on the proteomic profiles was developed. The protein patterns described served as an independent indicator of patient survival. These results show that this new molecular approach to monitoring gliomas can provide clinically relevant information on tumor malignancy and is suitable for high-throughput clinical screening.

  7. 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.

  8. Production of High-Mass Pairs of Direct Photons and Neutral Mesons in a Tevatron Fixed-Target Experiment

    CERN Document Server

    Begel, M

    1999-01-01

    The production of high-mass pairs of direct photons, π 0's, and η's has been measured by Fermilab experiment E706. The experimental apparatus included a large, finely segmented lead-liquid argon electromagnetic calorimeter and a charged particle spectrometer consisting of silicon microstrip detectors in the target region and multiwire proportional chambers and straw tube drift chambers downstream of an analysis magnet. The experiment triggered on localized high- pT depositions in the electromagnetic calorimeter; the high-mass pair data required two depositions on opposite sides of the calorimeter. Correlations between high-pT particles are used to extract information about the transverse momentum of partons (k T). Comparisons are made between the diphoton data and the results of next-to-leading order perturbative Quantum Chromodynamic (NLO pQCD) calculations. The shapes of the NLO pQCD results are inconsistent with the data distributions. A resummed NLO pQCD calculation, which incorporates the ...

  9. Characterizing and classifying water-based lubricants using direct analysis in real time(®)-time of flight mass spectrometry.

    Science.gov (United States)

    Maric, Mark; Bridge, Candice

    2016-09-01

    Lubricant analysis is a relatively recent addition to the examination protocol in sexual assault cases by the forensic science community. Currently, lubricants cannot be unequivocally identified, although their presence can be determined based on the detection of a few chemical components, i.e. polydimethylsiloxane, polyethylene glycol, glycerol or nonoxynol-9. Confirmation of their presence typically requires that an authentic reference sample be submitted and compared to the unknown sample to determine if they potentially came from the same source. In this study, 33 individual personal water-based lubricants were characterized by direct analysis in real time-time of flight mass spectroscopy (DART-TOFMS). The resultant mass spectral data were evaluated using well-established multivariate statistical techniques, such as principal component and linear discriminant analysis. Statistical analysis revealed six different groupings within the data that could be correlated to sub-categories of water-based lubricants that contain additives in the form of anesthetics, sensation enhancers and flavorings. This variability in the personal lubricant sources can be utilized to aid in identifying the specific type of lubricant when only a questioned sample is available.

  10. Use of fiber interface direct mass spectrometry for the determination of volatile flavor release from model food systems.

    Science.gov (United States)

    Springett, M B; Rozier, V; Bakker, J

    1999-03-01

    Described in this paper is a fiber interface direct headspace mass spectrometric system for the real-time measurement of flavor release. The system was optimized for the detection of the garlic aroma volatile, diallyl disulfide, from water. Parameters investigated included interface temperature, flow rate through the fiber, flow rate through the sample vessel, and sample stir rate. The delay time for detection of sample after introduction into the sample vessel was determined as 43 s. The system proved to be reliable and robust with no loss in sensitivity or contamination of the mass spectrometer over a 6 month period. The technique was applied to a homologous series of aliphatic alcohols from C(2) to C(7). Results showed that as polarity decreased with increasing chain length the release of volatile into the headspace was faster and gave a higher maximum intensity. Release of the garlic aroma volatile from different commercial mayonnaise products clearly showed a decrease in the release of diallyl disulfide as fat content increased. These results demonstrate the potential of using this technique as a tool for understanding the complex interactions that occur between flavor compounds and the bulk food matrix.

  11. Direct Sampling and Analysis from Solid Phase Extraction Cards using an Automated Liquid Extraction Surface Analysis Nanoelectrospray Mass Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Walworth, Matthew J [ORNL; ElNaggar, Mariam S [ORNL; Stankovich, Joseph J [ORNL; WitkowskiII, Charles E. [Protein Discovery, Inc.; Norris, Jeremy L [ORNL; Van Berkel, Gary J [ORNL

    2011-01-01

    Direct liquid extraction based surface sampling, a technique previously demonstrated with continuous flow and autonomous pipette liquid microjunction surface sampling probes, has recently been implemented as the Liquid Extraction Surface Analysis (LESA) mode on the commercially available Advion NanoMate chip-based infusion nanoelectrospray ionization system. In the present paper, the LESA mode was applied to the analysis of 96-well format custom solid phase extraction (SPE) cards, with each well consisting of either a 1 or 2 mm diameter monolithic hydrophobic stationary phase. These substrate wells were conditioned, loaded with either single or multi-component aqueous mixtures, and read out using the LESA mode of a TriVersa NanoMate or a Nanomate 100 coupled to an ABI/Sciex 4000QTRAPTM hybrid triple quadrupole/linear ion trap mass spectrometer and a Thermo LTQ XL linear ion trap mass spectrometer. Extraction conditions, including extraction/nanoESI solvent composition, volume, and dwell times, were optimized in the analysis of targeted compounds. Limit of detection and quantitation as well as analysis reproducibility figures of merit were measured. Calibration data was obtained for propranolol using a deuterated internal standard which demonstrated linearity and reproducibility. A 10x increase in signal and cleanup of micromolar Angiotensin II from a concentrated salt solution was demonstrated. Additionally, a multicomponent herbicide mixture at ppb concentration levels was analyzed using MS3 spectra for compound identification in the presence of isobaric interferences.

  12. 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.

  13. Broad-Range Detection of Microorganisms Directly from Bronchoalveolar Lavage Specimens by PCR/Electrospray Ionization-Mass Spectrometry

    Science.gov (United States)

    Ullberg, Måns; Lüthje, Petra; Mölling, Paula; Strålin, Kristoffer

    2017-01-01

    The clinical demand on rapid microbiological diagnostic is constantly increasing. PCR coupled to electrospray ionization-mass spectrometry, PCR/ESI-MS, offers detection and identification of over 750 bacteria and Candida species directly from clinical specimens within 6 hours. In this study, we investigated the clinical performance of the IRIDICA BAC LRT Assay for detection of bacterial pathogens in 121 bronchoalveolar lavage (BAL) samples that were received consecutively at our bacterial laboratory for BAL culture. Commensal or pathogenic microorganisms were detected in 118/121 (98%) BAL samples by PCR/ESI-MS, while in 104/121 (86%) samples by routine culture (PPCR/ESI-MS was evaluated in comparison with conventional culture-based or molecular methods. The agreement between positive findings was overall good. Most Staphylococcus aureus-positive PCR/ESI-MS results were confirmed by culture or species-specific PCR (27/33, 82%). The identity of Streptococcus pneumoniae could however be confirmed for only 6/17 (35%) PCR/ESI-MS-positive samples. Non-cultivable and fastidious pathogens, which were not covered by standard culture procedures were readily detected by PCR/ESI-MS, including Legionella pneumophila, Bordetella pertussis, Norcadia species and Mycoplasma pneumoniae. In conclusion, PCR/ESI-MS detected a broad range of potential pathogens with equal or superior sensitivity compared to conventional methods within few hours directly from BAL samples. This novel method might thus provide a relevant tool for diagnostics in critically ill patients. PMID:28085931

  14. Sample preparation and direct electrospray ionization on a tip column for rapid mass spectrometry analysis of complex samples.

    Science.gov (United States)

    Huang, Yun-Qing; You, Jin-Qing; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-10-07

    A handheld pipette tip column electrospray ionization source (PTC-ESI source) was developed for rapid mass spectrometry analysis at ambient pressure. The PTC-ESI source was made up of three main component parts including a micro DC high voltage (HV) power supply, a micropipette and a disposable micropipette tip filled with a plug of adsorbent. A DC high voltage was applied to the sharp point of the micropipette tip column to induce electrospray ionization. The PTC-ESI source was successfully used for direct analysis of basic organic compounds, organic acids and peptides in a simple matrix. In the case of complex samples, micro-extraction based on the adsorbent phase filled in the pipette tip was used to remove impurities and concentrate target analytes prior to ionization. The eluting solution was not pipetted out, but directly dispersed in the form of electrospray from the pipette tip for ionization. The effectiveness of the PTC-ESI source has been further demonstrated by fast analysis of therapeutic compounds and endogenous bioactive chemicals in complex biological samples.

  15. Laser desorption ionization-time-of-flight mass analysis of perfluoropolyether monolayer directly from hard disk medium surface.

    Science.gov (United States)

    Kudo, Toshiji; Macht, Marcus; Kuroda, Masami

    2011-07-15

    Modern life is dependent on computer technology, and because the volume of digital data in the world is increasing rapidly, the importance of data storage devices is also increasing rapidly. Among them, demands for magnetic disk drive well-known as hard disk drives is quite huge and information recording density on the disk media is continuing to grow dramatically. For the research and development of the magnetic disk media, it is critical to investigate and characterize the lubricant layer formed on the disk media surface. However, it is difficult because the layer is only a monolayer which has only approximately 1 nm thickness in many cases. Although matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) measurements of monolayers have already been reported (Su, J.; Mrksich, M. Langmuir, 2003, 19, 4867-4870), lubricants used here are (co)polymers which have molecular weight distributions and are mixtures of various degrees of polymerization. This can reduce the sensitivity of MS measurement because the number (or density) of distinct single molecular species is lower than for homogeneous samples. In this report, direct measurement and characterization of lubricant monolayers using the LDI-TOF-MS instrument is performed to gain insight into detailed information like average molecular weight, polymer distribution, and two-dimensional mapping directly from magnetic disk monolayers. To our knowledge, this is the first time such information was acquired directly from hard disk media. The technique reported here might open up new possibilities also for investigations of various electronic devices other than magnetic hard disks.

  16. 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.)

  17. Plant seed species identification from chemical fingerprints: a high-throughput application of direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Lesiak, Ashton D; Cody, Robert B; Dane, A John; Musah, Rabi A

    2015-09-01

    Plant species identification based on the morphological features of plant parts is a well-established science in botany. However, species identification from seeds has largely been unexplored, despite the fact that the seeds contain all of the genetic information that distinguishes one plant from another. Using seeds of genus Datura plants, we show here that the mass spectrum-derived chemical fingerprints for seeds of the same species are similar. On the other hand, seeds from different species within the same genus display distinct chemical signatures, even though they may contain similar characteristic biomarkers. The intraspecies chemical signature similarities on the one hand, and interspecies fingerprint differences on the other, can be processed by multivariate statistical analysis methods to enable rapid species-level identification and differentiation. The chemical fingerprints can be acquired rapidly and in a high-throughput manner by direct analysis in real time mass spectrometry (DART-MS) analysis of the seeds in their native form, without use of a solvent extract. Importantly, knowledge of the identity of the detected molecules is not required for species level identification. However, confirmation of the presence within the seeds of various characteristic tropane and other alkaloids, including atropine, scopolamine, scopoline, tropine, tropinone, and tyramine, was accomplished by comparison of the in-source collision-induced dissociation (CID) fragmentation patterns of authentic standards, to the fragmentation patterns observed in the seeds when analyzed under similar in-source CID conditions. The advantages, applications, and implications of the chemometric processing of DART-MS derived seed chemical signatures for species level identification and differentiation are discussed.

  18. Detection of illicit drugs on surfaces using direct analysis in real time (DART) time-of-flight mass spectrometry.

    Science.gov (United States)

    Grange, Andrew H; Sovocool, G Wayne

    2011-05-15

    Methamphetamine (meth) from meth syntheses or habitual meth smoking deposited on household surfaces poses human health hazards. The U.S. State Departments of Health require decontamination of sites where meth was synthesized (meth labs) before they are sold. National Institute for Occupational Safety and Health (NIOSH) methods for meth analysis require wipe sampling, extraction, clean-up, solvent exchange, derivatization, and/or mass spectral analysis using selected ion monitoring. Rapid and inexpensive analyses could screen for drug-contamination within structures with greater spatial resolution, provide real-time analyses during decontamination, and provide thorough documentation of successful clean ups. Herein an autosampler/open-air ion source time-of-flight mass spectrometric technique is described that required only direct sampling using cotton-swab wipes. Each wipe sample collection required 2 min and data acquisition required only 13 s per sample. Optimum collision-induced dissociation voltages, desorption gas temperatures, and wipe sample solvents were determined for 11 drugs. Peaks were observed in analyte-ion traces for 0.025 µg/100 cm(2) of meth and seven other drugs. This level is half the detection limit of NIOSH methods and one-fourth of the lowest U.S. state decontamination limit for meth. Dynamic ranges of 100 in concentration were demonstrated for eight drugs, which is sufficient for a screening technique. The volatilities of 11 drugs deposited on glass were determined. The pick up of the drugs by solvent-soaked cotton-swab wipes from glass relative to acrylic latex paint was also compared.

  19. 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.

  20. 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

  1. Mass spectrometry of planetary exospheres at high relative velocity: direct comparison of open- and closed-source measurements

    Science.gov (United States)

    Meyer, Stefan; Tulej, Marek; Wurz, Peter

    2017-01-01

    The exploration of habitable environments on or inside icy moons around the gas giants in the solar system is of major interest in upcoming planetary missions. Exactly this theme is addressed by the JUpiter ICy moons Explorer (JUICE) mission of ESA, which will characterise Ganymede, Europa and Callisto as planetary objects and potential habitats. We developed a prototype of the Neutral Gas and Ion Mass spectrometer (NIM) of the Particle Environment Package (PEP) for the JUICE mission intended for composition measurements of neutral gas and thermal plasma. NIM/PEP will be used to measure the chemical composition of the exospheres of the icy Jovian moons. Besides direct ion measurement, the NIM instrument is able to measure the inflowing neutral gas in two different modes: in neutral mode, where the gas enters directly the ion source (open source), and in thermal mode, where the gas gets thermally accommodated to the wall temperature by several collisions inside an equilibrium sphere, called antechamber, before entering the ion source (closed source). We performed measurements with the prototype NIM using a neutral gas beam of 1 up to 4.5 km s-1 velocity in the neutral and thermal mode. The current trajectory of JUICE foresees a flyby velocity of 4 km s-1 at Europa; other flybys are in the range of 1 up to 7 km s-1 and orbital velocity in Ganymede orbits is around 2 km s-1. Different species are used for the gas beam, such as noble gases Ne, Ar, Kr as well as molecules like H2, methane, ethane, propane and more complex ones. The NIM prototype was successfully tested under realistic JUICE mission conditions. In addition, we find that the antechamber (closed source) behaves as expected with predictable density enhancement over the specified mass range and within the JUICE mission phase velocities. Furthermore, with the open source and the closed source we measure almost the same composition for noble gases, as well as for molecules, indicating no additional

  2. Remote and In Situ Observations of an Unusual Earth-Directed Coronal Mass Ejection from Multiple Viewpoints

    Science.gov (United States)

    Nieves-Chinchilla, T.; Colaninno, R.; Vourlidas, A.; Szabo, A.; Lepping, R. P.; Boardsen, S. A.; Anderson, B. J.; Korth, H.

    2012-01-01

    During June 16-21, 2010, an Earth-directed Coronal Mass Ejection (CME) event was observed by instruments onboard STEREO, SOHO, MESSENGER and Wind. This event was the first direct detection of a rotating CME in the middle and outer corona. Here, we carry out a comprehensive analysis of the evolution of the CME in the interplanetary medium comparing in-situ and remote observations, with analytical models and three-dimensional reconstructions. In particular, we investigate the parallel and perpendicular cross section expansion of the CME from the corona through the heliosphere up to 1 AU. We use height-time measurements and the Gradual Cylindrical Shell (GCS) technique to model the imaging observations, remove the projection effects, and derive the 3-dimensional extent of the event. Then, we compare the results with in-situ analytical Magnetic Cloud (MC) models, and with geometrical predictions from past works. We nd that the parallel (along the propagation plane) cross section expansion agrees well with the in-situ model and with the Bothmer & Schwenn [1998] empirical relationship based on in-situ observations between 0.3 and 1 AU. Our results effectively extend this empirical relationship to about 5 solar radii. The expansion of the perpendicular diameter agrees very well with the in-situ results at MESSENGER ( 0:5 AU) but not at 1 AU. We also find a slightly different, from Bothmer & Schwenn [1998], empirical relationship for the perpendicular expansion. More importantly, we find no evidence that the CME undergoes a significant latitudinal over-expansion as it is commonly assumed

  3. 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.

  4. Direct analysis of pharmaceutical tablet formulations using Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging.

    Science.gov (United States)

    Earnshaw, Caroline J; Carolan, Vikki A; Richards, Don S; Clench, Malcolm R

    2010-06-15

    Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging (MALDI MSI) has been used to directly analyse a range of tablets in order to assess the homogeneity of the active drug compound throughout the excipients contained within the tablets studied. The information gained from the imaging experiments can be used to improve and gain a greater understanding of the manufacturing process; such knowledge will enable improvements in finished product quality to make safer and more efficacious tablet formulations. Commercially available and prescription tablet formulations have been analysed, including aspirin, paracetamol, sildenafil citrate (Viagra(R)) and a batch of tablets in development (tablet X: placebo; 1 mg; 3 mg and 6 mg). MALDI MSI provides semi-quantitative information that is related to ion abundance, therefore Principal Component Analysis (PCA), a multivariate analysis technique, has been used to differentiate between tablets containing different amounts of active drug ingredient. Aspects of sample preparation have also been investigated with regard to tablet shape and texture. The results obtained indicate that MALDI MSI can be used effectively to analyse the spatial distribution of the active pharmaceutical component (API) in pharmaceutical tablet formulations.

  5. Direct determination of melamine in dairy products by gas chromatography/mass spectrometry with coupled column separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xiaomin [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, 310028 (China); Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Ren Yiping [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Zhu Yun [Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention, Urumchi, 830002 (China); Cai Zengxuan; Han Jianlong; Huang Baifen [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Zhu Yan, E-mail: zhuyan@zju.edu.cn [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, 310028 (China)

    2009-09-14

    A coupled capillary column system was developed for the qualitative and quantitative determination of melamine with isotope internal standard in dairy products by gas chromatography/mass spectrometry (GC/MS) without derivatization. A 30 m of DB-5ms ((5%-phenyl)-methylpolysiloxane, 0.25 mm i.d., 0.25 {mu}m df) coupled with a 1.5 m of Innowax (polyethylene glycol, 0.32 mm i.d., 0.25 {mu}m df) by a quartz capillary column connector was introduced as separation column. Three advantages were discussed for the coupled system. The sample was fortified with a ring-labeled {sup 13}C{sub 3}{sup 15}N{sub 3}-melamine as an isotope internal standard and extracted by 1% of trichloroacetic acid aqueous solution. 2.2% of lead acetate solution was then added to deposit protein in the sample matrix. After purification by cation exchange cartridge, the sample solution was directly injected and detected by GC/MS. A six-point calibration curve ranging from 0.05 to 2 mg kg{sup -1} of melamine in sample was used to establish instrument response. The recovery was 93.9-102% with relative standard deviation from 3.1 to 8.7% when isotope internal standard used. The calculated method detection limit was 0.01 mg kg{sup -1}.

  6. Direct and comprehensive analysis of ginsenosides and diterpene alkaloids in Shenfu injection by combinatory liquid chromatography-mass spectrometric techniques.

    Science.gov (United States)

    Yang, Hua; Liu, Lei; Gao, Wen; Liu, Ke; Qi, Lian-Wen; Li, Ping

    2014-04-01

    Shenfu injection (SFI) is a widely used Chinese herbal formulation for cardiac diseases prepared from red ginseng and processed aconite root. Clinical observations and pharmacological effects on SFI have been well investigated. Chemical analysis and quality control studies of this formulation, however, are relatively limited, especially regarding toxic aconite alkaloids. In this work, a high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) method was applied to comprehensive analysis of constituents in SFI. Highly sensitive MS allows direct analysis of injections without additional sample pretreatment required. Using diagnostic ions and fragmentation rules, we identified 23 trace diterpene alkaloids, nineteen ginseng saponins, one panaxytriol, and one 5-hydroxymethylfurfural in SFI. A LC-MS method with selected ion monitoring was then used to quantify 24 major alkaloids and ginsenosides. The method was validated in terms of linearity, accuracy and precision. Especially, the limits of quantification were low to 0.4-18ng/mL for diterpene alkaloids. The total concentrations of saponins and alkaloids were about 676-742μg/mL and 3-7μg/mL in five batches of SFI samples, respectively. Finally, cosine ratio and euclidean distance were introduced to evaluate the batch-to-batch reproducibility of SFI samples, and the results demonstrated high quality consistency. Global identification and quantification of complex constituents based on LC-MS promises wide applications in quality control and batch monitoring for herbal products.

  7. Differential electrochemical mass spectrometry study of Pt and PtSn nanocatalysts for direct ethanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saidani, F.; Bommersbach, P.; Guay, D.; Mohamedi, M. [Quebec Univ., Institut National de la Recherche Scientifique, Varennes, PQ (Canada). Centre de l' Energie, Materiaux et Telecommunications; Rochefort, D. [Montreal Univ., PQ (Canada). Dept. of Chemistry

    2008-07-01

    This paper reported on a study that investigated Platinum (Pt) and Pt with tin (Sn) nanoparticles prepared under vacuum and under 2 Torr of He by pulsed laser ablation. This method was chosen because it is possible to control size of nanoparticles, structure and morphology of films by varying deposition conditions. The influence of deposition conditions on the electrocatalytic behaviour was determined. In particular, the objective of the study was to better understand the reaction mechanism involved during ethanol oxidation at Pt and PtSn catalysts by means of cyclic voltammetry combined with Differential Electrochemical Mass Spectrometry (DEMS), a powerful technique to elucidate the Ethanol Oxidation Reaction (EOR) mechanism. Ethanol was shown to be a very attractive liquid biofuel for direct-fuelled systems, since its partial oxidation products are less toxic than other alcohols. During pulsed laser ablation, the interaction between an intense laser and a target material resulted in the creation of plasma. This plasma enabled the transfer of matter from the target to the substrate. Highly nanocrystalline films can be prepared when deposition is performed into a moderate pressure gas. The electrochemical investigations showed that Pt deposited under 2 torr have a beneficial effect on the electrocatalytic activity towards ethanol oxidation. 5 refs., 1 fig.

  8. Gas purge microsyringe extraction for quantitative direct gas chromatographic-mass spectrometric analysis of volatile and semivolatile chemicals.

    Science.gov (United States)

    Yang, Cui; Piao, Xiangfan; Qiu, Jinxue; Wang, Xiaoping; Ren, Chunyan; Li, Donghao

    2011-03-25

    Sample pretreatment before chromatographic analysis is the most time consuming and error prone part of analytical procedures, yet it is a key factor in the final success of the analysis. A quantitative and fast liquid phase microextraction technique termed as gas purge microsyringe extraction (GP-MSE) has been developed for simultaneous direct gas chromatography-mass spectrometry (GC-MS) analysis of volatile and semivolatile chemicals without cleanup process. Use of a gas flowing system, temperature control and a conventional microsyringe greatly increased the surface area of the liquid phase micro solvent, and led to quantitative recoveries of both volatile and semivolatile chemicals within short extraction time of only 2 min. Recoveries of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and alkylphenols (APs) determined were 85-107%, and reproducibility was between 2.8% and 8.5%. In particular, the technique shows high sensitivity for semivolatile chemicals which is difficult to achieve in other sample pretreatment techniques such as headspace-liquid phase microextraction. The variables affecting extraction efficiency such as gas flow rate, extraction time, extracting solvent type, temperature of sample and extracting solvent were investigated. Finally, the technique was evaluated to determine PAHs, APs and OCPs from plant and soil samples. The experimental results demonstrated that the technique is economic, sensitive to both volatile and semivolatile chemicals, is fast, simple to operate, and allows quantitative extraction. On-site monitoring of volatile and semivolatile chemicals is now possible using this technique due to the simplification and speed of sample treatment.

  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. Validation of Direct Analysis Real Time source/Time-of-Flight Mass Spectrometry for organophosphate quantitation on wafer surface.

    Science.gov (United States)

    Hayeck, Nathalie; Ravier, Sylvain; Gemayel, Rachel; Gligorovski, Sasho; Poulet, Irène; Maalouly, Jacqueline; Wortham, Henri

    2015-11-01

    Microelectronic wafers are exposed to airborne molecular contamination (AMC) during the fabrication process of microelectronic components. The organophosphate compounds belonging to the dopant group are one of the most harmful groups. Once adsorbed on the wafer surface these compounds hardly desorb and could diffuse in the bulk of the wafer and invert the wafer from p-type to n-type. The presence of these compounds on wafer surface could have electrical effect on the microelectronic components. For these reasons, it is of importance to control the amount of these compounds on the surface of the wafer. As a result, a fast quantitative and qualitative analytical method, nondestructive for the wafers, is needed to be able to adjust the process and avoid the loss of an important quantity of processed wafers due to the contamination by organophosphate compounds. Here we developed and validated an analytical method for the determination of organic compounds adsorbed on the surface of microelectronic wafers using the Direct Analysis in Real Time-Time of Flight-Mass Spectrometry (DART-ToF-MS) system. Specifically, the developed methodology concerns the organophosphate group.

  11. 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.

  12. Improvement in ionization efficiency of direct analysis in real time-mass spectrometry (DART-MS) by corona discharge.

    Science.gov (United States)

    Sekimoto, Kanako; Sakakura, Motoshi; Kawamukai, Takatomo; Hike, Hiroshi; Shiota, Teruhisa; Usui, Fumihiko; Bando, Yasuhiko; Takayama, Mitsuo

    2016-08-02

    Herein it is shown that a combination of direct analysis in real time (DART) with a corona discharge system consisting of only a needle electrode easily improves DART ionization efficiency. Positive and negative DC corona discharges led to a formation of abundant excited helium atoms as well as the reactant ions H3O(+)(H2O)n and O2˙(-) in the DART analyte ionization area. These phenomena resulted in an increase in the absolute intensities of (de)protonated analytes by a factor of 2-20 over conventional DART. The other analyte ions detected in this corona-DART system (i.e., molecular ions, fragment ions, oxygenated (de)protonated analytes, dehydrogenated deprotonated analytes, and negative ion adducts) were quite similar to those obtained from DART alone. This indicates a lack of side reactions due to the corona discharge. The change in the relative intensities of individual analyte-related ions due to the combination of a corona discharge system with DART suggests that there is no effect of the abundant excited helium in the analyte ionization area on the fragmentation processes or enhancement of oxidation due to hydroxyl radicals HO˙. Furthermore, it was found that the corona-DART combination can be applied to the highly sensitive analysis of n-alkanes, in which the alkanes are ionized as positive ions via hydride abstraction and oxidation, independent of the type of alkane or the mass spectrometer used.

  13. Mass spectrometry of planetary exospheres at high relative velocity: direct comparison of open- and closed source measurements

    Science.gov (United States)

    Meyer, Stefan; Tulej, Marek; Wurz, Peter

    2016-04-01

    The exploration of habitable worlds around the gas giants in the Solar System is of major interest in upcoming planetary missions. Exactly this theme is addressed by the Jupiter Icy Moons Explorer (JUICE) mission of ESA, which will characterise Ganymede, Europa and Callisto as planetary objects and potential habitats [1], [2]. We developed a prototype of the Neutral gas and Ion Mass spectrometer (NIM) of the Particle Environment Package (PEP) for the JUICE mission intended for composition measurements of neutral gas and thermal plasma. NIM/PEP will be used to measure the chemical composition of the exospheres of the icy Jovian moons. Besides direct ion measurement, the NIM instrument is able to measure the inflowing neutral gas in two different modes: in neutral mode the gas enters directly the ion source (open source) and in thermal mode, the gas gets thermally accommodated to wall temperature by several collisions inside an equilibrium sphere before entering the ion source (closed source). We performed measurements with the prototype NIM using a neutral gas beam of 1 up to 5 km/s velocity in the neutral and thermal mode. The current trajectory of JUICE foresees a flyby velocity of 4 km/s at Europa, other flybys are in the range of 1 up to 7 km/s and velocity in Ganymede orbits is around 2 km/s. Different species are used for gas beam, such as noble gases Ne, Ar, Kr as well as molecules like H2, Methane, Ethane, Propane and more complex ones. We will present the results of these measurements with respect to fragmentation and density enhancements in the closed source mode. Furthermore, we will give a direct comparison between open and closed source mode measurements. References: [1] ESA, "JUICE assessment study report (Yellow Book)", ESA/SRE(2011)18, 2012. [2] O. Grasset, M.K. Dougherty, A. Coustenis, E.J. Bunce, C. Erd, D. Titov, M. Blanc, A. Coates, P. Drossart, L.N. Fletcher, H. Hussmann, R. Jaumann, N. Krupp, J.-P. Lebreton, O. Prieto-Ballesteros, P. Tortora, F

  14. 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\

  15. Effects of uniaxial strain on electron effective mass and tunneling capability of direct gap Ge{sub 1−x}Sn{sub x} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Liang, Renrong, E-mail: liangrr@tsinghua.edu.cn; Wang, Jing; Xu, Jun [Tsinghua National Laboratory for Information Science and Technology, Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2016-01-15

    Direct gap Ge{sub 1−x}Sn{sub x} alloys under [100] and [110] uniaxial strain are comprehensively investigated by theoretical calculations using the nonlocal empirical pseudopotential method (EPM). It is shown that [100] uniaxial tensile strain aids indirect-to-direct gap transition in Ge{sub 1−x}Sn{sub x} alloys. The Γ electron effective mass along the optimal direction under [110] uniaxial strain is smaller than those under [100] uniaxial strain and (001) biaxial strain. Additionally, the direct tunneling gap is smallest along the strain-perpendicular direction under [110] uniaxial tensile strain, resulting in a maximum direct band-to-band tunneling generation rate. An optimal [110] uniaxial tensile strain is favorable for high-performance direct gap Ge{sub 1−x}Sn{sub x} electronic devices.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

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

    Science.gov (United States)

    Dunovská, Lenka; Cajka, Tomás; Hajslová, Jana; Holadová, Katerina

    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 (d3-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 microg kg(-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(-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 (Food Analysis Performance Assessment Scheme) interlaboratory proficiency tests.

  2. 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.

  3. Interactions of Intact Unfractionated Heparin with Its Client Proteins Can Be Probed Directly Using Native Electrospray Ionization Mass Spectrometry.

    Science.gov (United States)

    Zhao, Yunlong; Abzalimov, Rinat R; Kaltashov, Igor A

    2016-02-01

    Heparin and related members of the glycosaminoglycan (GAG) family are highly polyanionic linear saccharides that play important roles in a variety of physiological processes ranging from blood coagulation to embryo- and oncogenesis, tissue regeneration, and immune response regulation. These diverse functions are executed via a variety of mechanisms, including protein sequestration, activation, and facilitation of their interactions with cell-surface receptors, but deciphering the specific molecular mechanisms is frequently impossible due to the extremely high degree of GAG heterogeneity. As a result, the vast majority of studies of heparin (or related GAGs) interactions with its client proteins use synthetically produced heparin mimetics with defined structure or short heparin fragments. In this work we use native electrospray ionization mass spectrometry (ESI MS) in combination with limited charge reduction in the gas phase to obtain meaningful information on noncovalent complexes formed by intact unfractionated heparin and antithrombin-III, interaction which is central to preventing blood clotting. Complexes of different stoichiometries are observed ranging from 1:1 to 1:3 (heparin/protein ratio). In addition to binding stoichiometry, the measurements allow the range of heparin chain lengths to be obtained for each complex and the contribution of each complex to the total ionic signal to be calculated. Incorporation of ion mobility measurements in the experimental workflow allows the total analysis time to be shortened very significantly and the charge state assignment for the charge-reduced species to be verified. The possibility to study interactions of intact unfractionated heparin with a client protein carried out directly by native ESI MS without the need to use relatively homogeneous surrogates demonstrated in this work opens up a host of new exciting opportunities and goes a long way toward ameliorating the persistent but outdated view of the

  4. Hydrolysis of VX on Concrete: Rate of Degradation by Direct Surface Interrogation using an Ion Trap Secondary Ion Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Groenewold, Gary Steven; Appelhans, Anthony David; Gresham, Garold Linn; Olson, John Eric; Rowland, B.; Williams, j.; Jeffery, M. T.

    2002-09-01

    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 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 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.

  5. 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 oi

  6. Charge and frequency resolved isochronous mass spectrometry in storage rings: First direct mass measurement of the short-lived neutron-deficient $^{51}$Co nuclide

    CERN Document Server

    Shuai, P; Tu, X L; Zhang, Y H; Sun, B H; Litvinov, Yu A; Yan, X L; Blaum, K; Wang, M; Zhou, X H; He, J J; Sun, Y; Kaneko, K; Yuan, Y J; Xia, J W; Yang, J C; Audi, G; Chen, X C; Jia, G B; Hu, Z G; Ma, X W; Mao, R S; Mei, B; Sun, Z Y; Wang, S T; Xiao, G Q; Xu, X; Yamaguchi, T; Yamaguchi, Y; Zang, Y D; Zhao, H W; Zhao, T C; Zhang, W; Zhan, W L

    2014-01-01

    Revolution frequency measurements of individual ions in storage rings require sophisticated timing detectors. One of common approaches for such detectors is the detection of secondary electrons released from a thin foil due to penetration of the stored ions. A new method based on the analysis of intensities of secondary electrons was developed which enables determination of the charge of each ion simultaneously with the measurement of its revolution frequency. Although the mass-over-charge ratios of $^{51}$Co$^{27+}$ and $^{34}$Ar$^{18+}$ ions are almost identical, and therefore, the ions can not be resolved in a storage ring, by applying the new method the mass excess of the short-lived $^{51}$Co is determined for the first time to be ME($^{51}$Co)=-27342(48) keV. Shell-model calculations in the $fp$-shell nuclei compared to the new data indicate the need to include isospin-nonconserving forces.

  7. Direct mass measurements of neutron-rich $^{86}$Kr projectile fragments and the persistence of neutron magic number $N$ = 32 in Sc isotopes

    CERN Document Server

    Xu, Xing; Zhang, Yu-hu; Xu, Hu-shan; Shuai, Peng; Tu, Xiao-lin; Litvinov, Yuri A; Zhou, Xiao-hong; Sun, Bao-hua; Yuan, You-jin; Xia, Jia-wen; Yang, Jian-cheng; Blaum, KLaus; Chen, Rui-jiu; Chen, Xiang-cheng; Fu, Chao-yi; Ge, Zhuang; Hu, Zheng-guo; Huang, Wen-jia; Liu, Da-wei; Lam, Yi-hua; Ma, Xin-wen; Mao, Rui-shi; Uesaka, T; Xiao, Guo-ging; Xing, Yuan-ming; Yamaguchi, T; Yamaguchi, Y; Zeng, Qi; Yan, Xin-liang; Zhao, Hong-wei; Zhao, Tie-cheneg; Zhang, Wei; Zhan, Wen-long

    2016-01-01

    In this paper, we present direct mass measurements of neutron-rich $^{86}$Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of $^{52-54}$Sc nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, $^{53}$Sc and $^{54}$Sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number $N$ = 32 in Sc isotopes.

  8. Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space

    Science.gov (United States)

    Monson, D. J.

    1978-01-01

    Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

  9. 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.

  10. 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

  11. Liquid chromatography tandem mass spectrometric quantitation of sulfamethazine and its metabolites: direct analysis of swine urine by triple quadrupole and by ion trap mass spectrometry.

    Science.gov (United States)

    Bartolucci, G; Pieraccini, G; Villanelli, F; Moneti, G; Triolo, A

    2000-01-01

    This work describes a new method for the quantitation of trace amounts of sulfamethazine (SMZ) and its main metabolite, N4-acetylsulfamethazine (Ac-SMZ), in swine urine, using high-performance liquid chromatography (HPLC) tandem mass spectrometric analysis of crude urine after addition of internal standard and simple dilution with water. The aim was to determine whether residues of this sulfamidic drug, normally administered to swine in order to prevent infectious diseases, were present in urine at levels lower than those permitted by regulatory authorities before human consumption (EU Project SMT, contract number CT 96-2092). A 10 microL volume of diluted urine was injected into a very short, narrow-bore chromatographic column (Zorbax SB-C18 2.1 i. d. x30 mm length, 3.5 microm pore size). Elution of the analytes of interest was achieved in less than seven minutes using a rapid gradient (from 20 to 80% methanol in 3 minutes). Either a PE Sciex API 365 triple quadrupole (QqQ), operated in the selected reaction monitoring (SRM) mode, or a Finnigan LCQ ion trap (IT) mass spectrometer, operated in narrow-range product ion scan, was used as the final detector. Electrospray (ESI) was used as the ionization technique. A comparison of the two tandem mass spectrometers was performed by analyzing the same set of test samples, at three concentration levels, on three different days. Linearity of responses of the calibration standards, intra- and inter-assay precision of the samples, specificity and limits of detection were evaluated for both systems. Both the QqQ and the IT instrument was suitable for rapid, sensitive and specific determination of the analytes, although the overall performance of the QqQ was slightly superior in terms of linearity, precision and sensitivity.

  12. Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel

    Science.gov (United States)

    Toward, M. G. R.; Griffin, M. J.

    2010-04-01

    The apparent mass of the seated human body influences the vibration transmitted through a car seat. The apparent mass of the body is known to be influenced by sitting posture but the influence of the position of the hands and the feet is not well understood. This study was designed to quantify the influence of steering wheel location and the position of a footrest on the vertical apparent mass of the human body. The influences of the forces applied by the hands to a steering wheel and by the feet to a footrest were also investigated. Twelve subjects were exposed to whole-body vertical random vibration (1.0 m s -2 rms over the frequency range 0.13-40.0 Hz) while supported by a rigid seat with a backrest reclined to 15°. The apparent mass of the body was measured with five horizontal positions and three vertical positions of a steering wheel and also with hands in the lap, and with five horizontal positions of a footrest. The influence of five forward forces (0, 50, 100, 150, 200 N) applied separately to the 'steering wheel' and the footrest were also investigated as well as a 'no backrest' condition. With their hands in their laps, subjects exhibited a resonance around 6.7 Hz, compared to 4.8 Hz when sitting upright with no backrest. In the same posture holding a steering wheel, the mass supported on the seat surface decreased and there was an additional resonance at 4 Hz. Moving the steering wheel away from the body reduced the apparent mass at the primary resonance frequency and increased the apparent mass around the 4 Hz resonance. As the feet moved forward, the mass supported on the seat surface decreased, indicating that the backrest and footrest supported a greater proportion of the subject weight. Applying force to either the steering wheel or the footrest reduced the apparent mass at resonance and decreased the mass supported on the seat surface. It is concluded that the positions and contact conditions of the hands and the feet affect the biodynamic

  13. 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

  14. Analysis, design, and testing of a low cost, direct force command linear proof mass actuator for structural control

    Science.gov (United States)

    Slater, G. L.; Shelley, Stuart; Jacobson, Mark

    1993-01-01

    In this paper, the design, analysis, and test of a low cost, linear proof mass actuator for vibration control is presented. The actuator is based on a linear induction coil from a large computer disk drive. Such disk drives are readily available and provide the linear actuator, current feedback amplifier, and power supply for a highly effective, yet inexpensive, experimental laboratory actuator. The device is implemented as a force command input system, and the performance is virtually the same as other, more sophisticated, linear proof mass systems.

  15. Detecting Free-Mass Common-Mode Motion Induced by Incident Gravitational Waves: Testing General Relativity and Source Direction via Fox-Smith and Michelson Interferometers

    CERN Document Server

    Tobar, Michael Edmund; Kuroda, Kazuaki

    2009-01-01

    In this paper we show that information on both the differential and common mode free-mass response to a gravitational wave can provide important information on discriminating the direction of the gravitational wave source and between different theories of gravitation. The conventional Michelson interferometer scheme only measures the differential free-mass response. By changing the orientation of the beam splitter, it is possible to configure the detector so it is sensitive to the common-mode of the free-mass motion. The proposed interferometer is an adaptation of the Fox-Smith interferometer. A major limitation to the new scheme is its enhanced sensitivity to laser frequency fluctuations over the conventional, and we propose a method of canceling these fluctuations. The configuration could be used in parallel to the conventional differential detection scheme with a significant sensitivity and bandwidth.

  16. Direct detection of Mycobacterium tuberculosis in sputum using combined solid phase extraction-gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Dang, N.A.; Mourão, M.; Kuijper, S.; Walters, E.; Janssen, H.-G.; Kolk, A.H.J.

    2015-01-01

    Recently, thermally-assisted hydrolysis and methylation followed by gas chromatography-mass spectrometry (THM-GC-MS) in combination with chemometrics has been used to develop a 20-compound model for fast differentiation of Mycobacterium tuberculosis (MTB) from Non-tuberculous mycobacteria (NTM) in b

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

    NARCIS (Netherlands)

    Duvivier, W.F.; Beek, van T.A.; Pennings, E.J.M.; Nielen, M.W.F.

    2014-01-01

    RATIONALE - 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

  18. A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for direct and on-line measurements of pharmaceuticals and contaminants in small, complex samples.

    Science.gov (United States)

    Duncan, Kyle D; Willis, Megan D; Krogh, Erik T; Gill, Christopher G

    2013-06-15

    High-throughput, automated analytical measurements are desirable in many analytical scenarios, as are rapid sample pre-screening techniques to identify 'positive' samples for subsequent measurements using more time-consuming conventional methodologies (e.g., liquid chromatography/mass spectrometry (LC/MS)). A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for the direct and continuous, on-line measurement of pharmaceuticals and environmental contaminants in small, complex samples is presented. A miniature polydimethylsiloxane hollow fibre membrane (PDMS-HFM) probe is coupled with an electrospray ionization (ESI) triple quadrupole mass spectrometer. Analytes are transported from the probe to the ESI source by a methanol acceptor phase. The probe can be autosampler mounted and directly inserted in small samples (≥400 μL) allowing continuous and simultaneous pptr-ppb level detection of target analytes (chlorophenols, triclosan, gemfibrozil, nonylphenol) in complex samples (artificial urine, beer, natural water, waste water, plant tissue). The probe has been characterized and optimized for acceptor phase flow rate, sample mixing and probe washing. Signal response times, detection limits and calibration data are given for selected ion monitoring (SIM) and tandem mass spectrometry (MS/MS) measurements of target analytes at trace levels. Comparisons with flow cell type CP-MIMS systems are given. Analyte depletion effects are evaluated for small samples (≥400 μL). On-line measurements in small volumes of complex samples, temporally resolved reaction monitoring and in situ/in vivo demonstrations are presented. The miniature CP-MIMS probe developed was successfully used for the direct, on-line detection of target analytes in small volumes (40 mL to 400 μL) of complex samples at pptr to low ppb levels. The probe can be readily automated as well as deployed for in situ/in vivo monitoring, including reaction monitoring, small sample

  19. The DODO Survey II: A Gemini Direct Imaging Search for Substellar and Planetary Mass Companions around Nearby Equatorial and Northern Hemisphere White Dwarfs

    CERN Document Server

    Hogan, E; Clarke, F J

    2009-01-01

    The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions would allow the spectroscopic investigation of objects with temperatures much lower ( T8.5 and so could belong to the proposed Y dwarf spectral sequence. The detection of a planet around a white dwarf would prove that such objects can survive the final stages of stellar evolution and place constraints on the frequency of planetary systems around their progenitors (with masses between 1.5 - 8 solar masses, i.e., early B to mid F). This paper presents the results of a multi-epoch J band common proper motion survey of 23 nearby equatorial and northern hemisphere white dwarfs. We rule out the presence of any common proper motion companions, with limiting masses determined from the completeness limit of each observation, to 18 white dwarfs. For the remaining five targets, the motion...

  20. Direct analysis in real time - high resolution mass spectrometry (DART-HRMS): a high throughput strategy for identification and quantification of anabolic steroid esters.

    Science.gov (United States)

    Doué, Mickael; Dervilly-Pinel, Gaud; Pouponneau, Karinne; Monteau, Fabrice; Le Bizec, Bruno

    2015-07-01

    High throughput screening is essential for doping, forensic, and food safety laboratories. While hyphenated chromatography-mass spectrometry (MS) remains the approach of choice, recent ambient MS techniques, such as direct analysis in real time (DART), offer more rapid and more versatile strategies and thus gain in popularity. In this study, the potential of DART hyphenated with Orbitrap-MS for fast identification and quantification of 21 anabolic steroid esters has been evaluated. Direct analysis in high resolution scan mode allowed steroid esters screening by accurate mass measurement (Resolution = 60 000 and mass error  0.99), dynamic range (from 1 to 1000 ng mL(-1) ), bias (<10%), sensitivity (1 ng mL(-1) ), repeatability and reproducibility (RSD < 20%) were evaluated as similar to those obtained with hyphenated chromatography-mass spectrometry techniques. This innovative high throughput approach was successfully applied for the characterization of oily commercial preparations, and thus fits the needs of the competent authorities in the fight against forbidden or counterfeited substances.

  1. Gas chromatography – mass spectrometry of JWH-018 metabolites in urine samples with direct comparison to analytical standards

    Science.gov (United States)

    Emerson, Beth; Durham, Bill; Gidden, Jennifer; Lay, Jackson O.

    2013-01-01

    JWH-018 (1-pentyl-3-(1-naphthoyl)indole) is one of numerous potential aminoalkylindoles contained in products marketed as ‘K2’ or ‘Spice’. Investigation of the urinary metabolites from consumption of these compounds is important because they are banned in the United States and many European countries. An efficient extraction procedure and gas chromatography – mass spectrometry (GC-MS) method were developed for detection of ‘K2’ metabolites in urine from individuals suspected of using these products. Analytical standards were used to elucidate the structure-specific mass spectral fragmentations and retention properties to confirm proposed identifications and support quantitative studies. A procedure for the synthesis of one of these metabolites (5-hydroxypentyl JWH-018) was also developed. Results are comparable to existing LC-MS/MS methods, with the same primary metabolites detected. The specific metabolite hydrolysis products include 4-hydroxpentyl, 5-hydroxypentyl, and N-pentanoic acid derivatives. PMID:23683902

  2. Photometric and H-alpha studies of two extreme mass-ratio short period contact binaries in the direction of open cluster Praesepe

    CERN Document Server

    Rukmini, J

    2016-01-01

    We present the high precession photometric studies in V band and spectroscopic studies centered around H-alpha line for two extreme mass-ratio short period contact binaries ASAS J082243+1927.0 (V1) and ASAS J085710+1856.8 (V2). The variables in study are in the direction of open cluster Praesepe. From the light curve analysis V1 was found to be a low mass-ratio over-contact binary of A-type, with a mass ratio q 0.121 and fill-out factor f 72%, and V2 was found to be a low mass contact binary of W-type, with a mass-ratio q 1.29 and fill-out factor f 11% (marginal contact). The study of H-alpha absorption line profile of both the variables shows variation in equivalent widths (EWs) with orbital phases. The mean EWs of the H-alpha line were obtained as 1.6+or-0.13 A and 1.18+or-0.12 A for V1 and V2 respectively. The variation of H-alpha absorption with respect to phase is explained to be due to chromospheric activity in V1, as evident from the O Connell effect and that due to chromospheric flares, winds or photo...

  3. An improved method for the determination of 5-hydroxymethylfurfural in Shenfu injection by direct analysis in real time-quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Gao, Wen; Qi, Lian-Wen; Liu, Charles C; Wang, Rui; Li, Ping; Yang, Hua

    2016-07-01

    The emergence of direct analysis in real time (DART) ion source provides the great possibility for rapid analysis of hazardous substance in drugs. DART mass spectrometry (DART-MS) enabled the conducting of a fast and non-contact analysis of various samples, including solid or liquid ones, without complex sample preparation or chromatographic separation. In this study, a modified DART-quadrupole time-of-flight mass spectrometry (DART-QTOF-MS) method was developed for identification and determination of 5-hydroxymethylfurfural (5-HMF) in Shenfu (SF) injection. The quantitative transfer of sample solution was introduced to the glass tips of DIP-it sampler at a fixed volume, which significantly increases the repeatability and accuracy of analytical results. The protonated ion of dibutyl phthalate in the atmosphere was used as the reference mass for TOF-MS recalibration during the data acquisition for constant high accuracy mass measurements. Finally, the developed DART-MS method was used to determine 5-HMF in seven batches of SF injection, and the contents of 5-HMF were not higher than 100 µg/mL. The results obtained were further confirmed by an ultra-high performance liquid chromatography combined with triple quadrupole mass spectrometer (UHPLC-QQQ-MS). The overall results demonstrated that the DART-QTOF-MS method could be applied as an alternative technique for rapid monitoring 5-HMF in herbal medicine injection. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Valuing customer portfolios with endogenous mass-and-direct-marketing interventions using a stochastic dynamic programming decomposition

    OpenAIRE

    YILDIRIM, Gökhan; Vidal-Sanz, Jose M.; Esteban-Bravo, Mercedes

    2012-01-01

    Customer Relationship Management generally uses the value of customers to allocate marketing budget. But marketing interventions generally change the customer behavior, turning upside-down the customers ranking based on their initial valuations and making the budget allocation suboptimal. Rational Managers should allocate the marketing budget to maximize the expected net present value of future profits drawn from each customer, simultaneously planning mass marketing interventio...

  5. Processing Doppler Lidar and Cloud Radar Observations for Analysis of Convective Mass Flux Parameterizations Using DYNAMO Direct Observations

    Science.gov (United States)

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Processing Doppler Lidar and Cloud Radar Observations...campaign the data gathered from the High Resolution Doppler Lidar (HRDL) and the 94-GHz cloud Doppler radar Report Documentation Page Form ApprovedOMB No...00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Processing Doppler Lidar and Cloud Radar Observations for Analysis of Convective Mass Flux

  6. Valuing customer portfolios with endogenous mass-and-direct-marketing interventions using a stochastic dynamic programming decomposition

    OpenAIRE

    YILDIRIM, Gökhan; Vidal-Sanz, Jose M.; Esteban-Bravo, Mercedes

    2012-01-01

    Customer Relationship Management generally uses the value of customers to allocate marketing budget. But marketing interventions generally change the customer behavior, turning upside-down the customers ranking based on their initial valuations and making the budget allocation suboptimal. Rational Managers should allocate the marketing budget to maximize the expected net present value of future profits drawn from each customer, simultaneously planning mass marketing interventio...

  7. Direct analysis of silica gel extracts from immunostained glycosphingolipids by nanoelectrospray ionization quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Meisen, Iris; Peter-Katalinić, Jasna; Müthing, Johannes

    2004-04-15

    A combined strategy of preparative high-performance thin-layer chromatography overlay assay and mass spectrometry was established for the structural characterization of immunostained glycosphingolipids (GSLs) in silica gel extracts. Crude chloroform/methanol/water (30/60/8, v/v/v) extracts of immunostained TLC bands were analyzed by nanoelectrospray low-energy CID mass spectrometry without further purification. The GSL species investigated were isomeric monosialogangliosides of the neolacto series from a ganglioside preparation of human granulocytes, the disialoganglioside GD3 from a human melanoma lipid extract, and ganglio series Gg3Cer of a neutral GSL preparation from murine lymphoreticular MDAY-D2 cells. For the specific detection of lipid-bound oligosaccharides, polyclonal chicken IgY, murine monoclonal IgG3, and IgM antibodies were used. The resulting mass spectra show that only analytical quantities of approximately 1 microg of a single GSL within a complex mixture are required for the structure determination of immunostained GSLs by MS and MS/MS. All species investigated were detected as singly charged deprotonated molecular ions, and neither buffer-derived salt adducts nor coextracted contaminants from the immunostaining procedure or the silica gel layer were observed. This effective HPTLC-MS-joined procedure offers a wide range of applications for any carbohydrate binding agents such as bacterial toxins, plant lectins, and others.

  8. Direct matrix-assisted laser desorption/ionization mass spectrometric imaging of cellulose and hemicellulose in Populus tissue.

    Science.gov (United States)

    Lunsford, Kyle Ann; Peter, Gary F; Yost, Richard A

    2011-09-01

    Imaging applied toward lignocellulosic materials requires high molecular specificity to map specific compounds within intact tissue. Although secondary ionization mass spectrometry (SIMS) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) with a single stage of MS have been used to image lignocellulosic biomass, the complexity of the plant tissue requires tandem MS, which limits the interpretation of simple MS. MALDI linear ion trap (LIT) tandem MS offers the high molecular specificity needed for lignocellulosic analyses. MALDI-LIT MS analyses of cellulose and xylan (hemicellulose) standards were performed to determine mass-to-charge ratios and fragmentation pathways for identification of these compounds in intact tissue. The MALDI-LIT-MS images of young Populus wood stem showed even distribution of both cellulose and hemicellulose ions; in contrast, the tandem MS images of cellulose and hemicellulose generated by plotting characteristic fragment ions resulted in drastically different images. This demonstrates that isobaric ions are present during MALDI-LIT-MS analyses of wood tissue and tandem MS is necessary to distinguish between isobaric species for selective imaging of carbohydrates in biomass.

  9. 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

    2010-04-13

    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 CO(2). 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 CO(2) 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.

  10. Direct analysis of Salvia divinorum leaves for salvinorin A by thin layer chromatography and desorption electrospray ionization multi-stage tandem mass spectrometry.

    Science.gov (United States)

    Kennedy, Joseph H; Wiseman, Justin M

    2010-05-15

    Salvia divinorum is widely cultivated in the US, Mexico, Central and South America and Europe and is consumed for its ability to produce hallucinogenic effects similar to those of other scheduled hallucinogenic drugs, such as LSD. Salvinorin A (SA), a kappa opiod receptor agonist and psychoactive constituent, is found primarily in the leaves and to a lesser extent in the stems of the plant. Herein, the analysis of intact S. divinorum leaves for SA and of acetone extracts separated using thin layer chromatography (TLC) is demonstrated using desorption electrospray ionization (DESI) mass spectrometry. The detection of SA using DESI in the positive ion mode is characterized by several ions associated with the compound - [M+H](+), [M+NH(4)](+), [M+Na](+), [2M+NH(4)](+), and [2M+Na](+). Confirmation of the identity of these ions is provided through exact mass measurements using a time-of-flight (ToF) mass spectrometer. The presence of SA in the leaves was confirmed by multi-stage tandem mass spectrometry (MS(n)) of the [M+H](+) ion using a linear ion trap mass spectrometer. Direct analysis of the leaves revealed several species of salvinorin in addition to SA as confirmed by MS(n), including salvinorin B, C, D/E, and divinatorin B. Further, the results from DESI imaging of a TLC separation of a commercial leaf extract and an acetone extract of S. divinorum leaves were in concordance with the TLC/DESI-MS results of an authentic salvinorin A standard. The present study provides an example of both the direct analysis of intact plant materials for screening illicit substances and the coupling of TLC and DESI-MS as a simple method for the examination of natural products.

  11. 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.

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

    NARCIS (Netherlands)

    Nichols, Kevin P.; Azoz, Seyla; Gardeniers, Han J.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. 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.

  14. Extinction of the N=20 neutron-shell closure for 32Mg examined by direct mass measurements

    CERN Document Server

    Chaudhuri, A; Brunner, T; Chowdhury, U; Ettenauer, S; Gallant, A T; Gwinner, G; Kwiatkowski, A A; Lennarz, A; Lunney, D; Macdonald, T D; Schultz, B E; Simon, M C; Simon, V V; Dilling, J

    2013-01-01

    The 'island of inversion' around $^{32}$Mg is one of the most important paradigm for studying the disappearance of the stabilizing 'magic' of a shell closure. We present the first Penning-trap mass measurements of the exotic nuclides $^{29-31}$Na and $^{30-34}$Mg, which allow a precise determination of the empirical shell gap for $^{32}$Mg. The new value of 1.10(3) MeV is the lowest observed shell gap for any nuclide with a canonical magic number.

  15. Comparison of five methods for direct extraction of surface proteins from Listeria monocytogenes for proteomic analysis by orbitrap mass spectrometry.

    Science.gov (United States)

    Tiong, Hung King; Hartson, Steven; Muriana, Peter M

    2015-03-01

    Extracts of surface proteins, with minimal artifacts from contaminating cytosolic components, are highly desirable for investigating surface factors involved in the attachment and formation of biofilms by bacteria that are problematic in commercial food processing facilities. In this study, we compared the protein profiles of the food pathogen, Listeria monocytogenes, recovered after applying different surface protein extraction methods compiled from the literature: trypsin-enzymatic shaving with BICAM/sucrose or Tris/sucrose buffers (Tryp B+S, Tryp T+S), Tris-buffered urea (UB), lithium chloride (LiCl) and Tris-buffered urea applied with hypotonic-stressed cells (UB-Ghost), and subjected them to liquid chromatography tandem mass spectrometry and protein identification. The data indicate that the UB-Ghost extraction method provides a cleaner extract of surface proteins including the predicted (this study and the literature) or validated members (literature) from L. monocytogenes. This was determined by an accumulative lower unique peptide number exhibited by mass spectrometry for total cytoplasmic proteins among different surface extracts, with a majority of proteins demonstrating hydrophilic properties. The extracted proteins were from different functional categories and have associations with the cell surface, intermediary metabolism, information pathways, or functionally unknown proteins as suggested by in silico analyses performed by other groups (Leger and ListiList). The utilization of an optimized method for surface protein extraction should greatly facilitate identification by LC-MS/MS that could be useful to anyone working on molecular proteomics of bacterial surfaces.

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

    CERN Document Server

    Möstl, C; Hall, J R; Liewer, P C; De Jong, E M; Colaninno, R C; Veronig, A M; Rollett, T; Temmer, M; Peinhart, V; Davies, J A; Lugaz, N; Liu, Y D; Farrugia, C J; Luhmann, J G; Vršnak, B; Harrison, R A; Galvin, A B

    2014-01-01

    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 $2700 \\: km \\: s^{-1}$). We track the CMEs to $34.9 \\pm 7.1$ degrees elongation from the Sun with J-maps constructed using the SATPLOT tool, resulting in prediction lead times of $-26.4 \\pm 15.3$ hours. The geometrical models we use assume different CME front shapes (Fixed-$\\Phi$, Harmonic Mean, S...

  17. 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.

  18. Nanoporous GaN-Ag composite materials prepared by metal-assisted electroless etching for direct laser desorption-ionization mass spectrometry.

    Science.gov (United States)

    Nie, Bei; Duan, Barrett K; Bohn, Paul W

    2013-07-10

    Three-dimensional nanoporous gallium nitride(PGaN) produced by metal-assisted electroless etching is chemically embedded with silver nanoparticles via electroless deposition, forming a metallized semiconductor membrane with large surface area and nanoscale metal features. A new application utilizing the unique chemical and morphological features of these composite nanostructures is described here, laser induced desorption-ionization(LDI) of biomolecules(e.g., cholesterol and nucleotides) for direct mass analysis, without use of additional organic matrix. Although PGaN itself is a poor matrix for direct LDI mass spectrometry, the combination of Ag and PGaN greatly improves ion signals relative to PGaN or Ag nanostructure surfaces alone. This behavior is attributed to the combination of strong UV absorption, enhanced surface area, and favorable thermal properties of PGaN. Importantly, Ag-PGaN is shown to facilitate the formation of Ag adduct ions in some cases, for example adenine, where adducts are not observed from either porous anodic aluminum membranes or surfaces presenting Ag nanoparticles in isolation. Nanopore-embedded Ag nanostructures serve a dual role: as cationization agents and to assist thermal desorption under UV laser irradiation. The results reported here suggest that the combination of Ag nanostructures embedded in PGaN has the capacity for high quality matrix-free LDI mass analysis.

  19. The DODO survey - II. A Gemini direct imaging search for substellar and planetary mass companions around nearby equatorial and Northern hemisphere white dwarfs

    Science.gov (United States)

    Hogan, E.; Burleigh, M. R.; Clarke, F. J.

    2009-07-01

    The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low-mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions would allow the spectroscopic investigation of objects with temperatures much lower (T8.5, and so could belong to the proposed Y dwarf spectral sequence. The detection of a planet around a white dwarf would prove that such objects can survive the final stages of stellar evolution and place constraints on the frequency of planetary systems around their progenitors (with masses between 1.5 and 8Msolar, i.e. early B to mid-F). This paper presents the results of a multi epoch J band common proper motion survey of 23 nearby equatorial and Northern hemisphere white dwarfs. We rule out the presence of any common proper motion companions, with limiting masses determined from the completeness limit of each observation, to 18 white dwarfs. For the remaining five targets, the motion of the white dwarf is not sufficiently separated from the non-moving background objects in each field. These targets require additional observations to conclusively rule out the presence of any common proper motion companions. From our completeness limits, we tentatively suggest that ~ 500 K between projected physical separations of 60-200 au.

  20. 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.

  1. Direct identification of trypanosomatids by matrix-assisted laser desorption ionization-time of flight mass spectrometry (DIT MALDI-TOF MS).

    Science.gov (United States)

    Avila, C C; Almeida, F G; Palmisano, G

    2016-08-01

    Accurate and rapid determination of trypanosomatids is essential in epidemiological surveillance and therapeutic studies. Matrix-assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF MS) has been shown to be a useful and powerful technique to identify bacteria, fungi, metazoa and human intact cells with applications in clinical settings. Here, we developed and optimized a MALDI-TOF MS method to profile trypanosomatids. trypanosomatid cells were deposited on a MALDI target plate followed by addition of matrix solution. The plate was then subjected to MALDI-TOF MS measurement to create reference mass spectra library and unknown samples were identified by pattern matching using the BioTyper software tool. Several m/z peaks reproducibly and uniquely identified trypanosomatids species showing the potentials of direct identification of trypanosomatids by MALDI-TOF MS. Moreover, this method discriminated different life stages of Trypanosoma cruzi, epimastigote and bloodstream trypomastigote and Trypanosoma brucei, procyclic and bloodstream. T. cruzi Discrete Typing Units (DTUs) were also discriminated in three clades. However, it was not possible to achieve enough resolution and software-assisted identification at the strain level. Overall, this study shows the importance of MALDI-TOF MS for the direct identification of trypanosomatids and opens new avenues for mass spectrometry-based detection of parasites in biofluids. Copyright © 2016 John Wiley & Sons, Ltd.

  2. 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.

  3. Mass Spectrometry-Based Strategy for Direct Detection and Quantification of Some Mycotoxins Produced by Stachybotrys and Aspergillus spp. in Indoor Environments▿

    Science.gov (United States)

    Bloom, Erica; Bal, Karol; Nyman, Eva; Must, Aime; Larsson, Lennart

    2007-01-01

    Dampness in buildings has been linked to adverse health effects, but the specific causative agents are unknown. Mycotoxins are secondary metabolites produced by molds and toxic to higher vertebrates. In this study, mass spectrometry was used to demonstrate the presence of mycotoxins predominantly produced by Aspergillus spp. and Stachybotrys spp. in buildings with either ongoing dampness or a history of water damage. Verrucarol and trichodermol, hydrolysis products of macrocyclic trichothecenes (including satratoxins), and trichodermin, predominately produced by Stachybotrys chartarum, were analyzed by gas chromatography-tandem mass spectrometry, whereas sterigmatocystin (mainly produced by Aspergillus versicolor), satratoxin G, and satratoxin H were analyzed by high-performance liquid chromatography-tandem mass spectrometry. These mycotoxin analytes were demonstrated in 45 of 62 building material samples studied, in three of eight settled dust samples, and in five of eight cultures of airborne dust samples. This is the first report on the use of tandem mass spectrometry for demonstrating mycotoxins in dust settled on surfaces above floor level in damp buildings. The direct detection of the highly toxic sterigmatocystin and macrocyclic trichothecene mycotoxins in indoor environments is important due to their potential health impacts. PMID:17483261

  4. Direct monitoring of the liquid and gas phases during a fermentation in a computer-mass-spectrometer-fermentor system

    Energy Technology Data Exchange (ETDEWEB)

    Pungor, E. Jr.; Schaefer, E.J.; Cooney, C.L.; Weaver, J.C.

    1983-01-01

    Measurement of chemical concentrations is a weak link in the monitoring of fermentations. The use of a computer-controlled mass-spectrometer (MS) has made possible the measurement of one or more volatile compounds on an essentially continuous basis, both in the liquid (broth) and the gas (headspace) phases. For our purposes, the MS was used, not as a spectrometer for chemical identification, but as a programmable detector for measuring concentrations of different compounds. Specifically, a computer-controlled MS was employed during the fermentation of Saccharomyces italicus, to monitor N/sub 2/, O/sub 2/, and CO/sub 2/ concentration in the gas phase, and N/sub 2/, O/sub 2/, CO/sub 2/, and ethanol in the liquid phase. The performance of the MS was carefully analyzed.

  5. Direct detection of free fatty acids in edible oils using supercritical fluid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Qu, Shuping; Du, Zhenxia; Zhang, Yun

    2015-03-01

    Determination of free fatty acids (FFAs) in food products is of enormous interest mainly because they are related to the quality and authenticity of the oils. In this study, supercritical fluid chromatography (SFC), followed by an electrospray ionisation triple-quadrupole mass spectrometry (ESI-MS), is shown to provide a novel method for the separation and detection of FFAs in edible oils without any pretreatment. Eight FFAs were separated on a HSS C18 SB column with gradient elution within 3 min. Effects of different columns, modifiers and column temperature changes were evaluated. The results indicated the feasibility of this method for the high-throughput determination of individual FFAs with satisfactory correlation coefficients (R(2)>0.994) and good reproducibility of RSDoil were successfully distinguished into several categories, showing a potential application for the determination of oil quality or authenticity.

  6. Direct measurement of the glucuronide conjugate of 1-hydroxypyrene in human urine by using liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Kakimoto, Kensaku; Toriba, Akira; Ohno, Takanori; Ueno, Mariko; Kameda, Takayuki; Tang, Ning; Hayakawa, Kazuichi

    2008-05-15

    To evaluate human exposure to polycyclic aromatic hydrocarbons (PAHs), we developed a rapid, simple and sensitive method for determining 1-hydroxypyrene-glucuronide (1-OHP-G) in human urine. To improve precision, a deuterated glucuronide was used as an internal standard. The method requires only 1 mL of urine. The urine was treated with a mixed-mode anion-exchange and reversed-phase solid-phase extraction cartridge (Oasis MAX). The analytes were analyzed with a C(18) reversed-phase column with a gradient elution, followed by tandem mass spectrometry with electrospray ionization in negative ion mode. The detection limit of 1-OHP-G (corresponding to a signal-to-noise ratio of 3) was 0.13 fmol/injection. Urinary concentrations of 1-OHP-G determined by this method were strongly correlated (r(2)=0.961) with concentrations of 1-hydroxypyrene by conventional HPLC with fluorescence detection.

  7. Direct Determination of Trace Impurities in High Purity Zinc Oxide by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; NIE Xidu; LI Libo; SONG Chuhua

    2006-01-01

    The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was investigated. To overcome some potentially problematic spectral interference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02 μg/g to 6 μg/g depending on the elements.The experimental results for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.

  8. 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.

  9. Rapid screening and distribution of bioactive compounds in different parts of Berberis petiolaris using direct analysis in real time mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Awantika Singh; Vikas Bajpai; Mukesh Srivastava; Kamal Ram Arya; Brijesh Kumar

    2015-01-01

    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 dis-criminated each part of B. petiolaris plant.

  10. Direct Mass Measurements on the Superallowed Emitter $^{74}$Rb and its Daughter $^{74}$Kr Isospin-Symmetry-Breaking Correction for Standard-Model Tests

    CERN Document Server

    Kellerbauer, A G; Beck, D; Blaum, K; Bollen, G; Brown, B A; Delahaye, P; Guénaut, C; Herfurth, F; Kluge, H J; Lunney, M D; Schwarz, S; Schweikhard, L; Yazidjian, C

    2004-01-01

    The decay energy of the superallowed $\\beta$-decay $^{74}$Rb($\\beta^{+}$)$^{74}$Kr was determined by direct Penning trap mass measurements on both the mother and the daughter nuclide using the time-of-flight resonance technique and found to be $Q = 10416.8(4.5)$ keV. The exotic nuclide $^{74}$Rb, with a half-life of only 65 ms, is the shortest-lived nuclide on which a high-precision mass measurement in a Penning trap has been carried out. Together with existing data for the partial half-life as well as theoretical corrections, the decay energy yields a comparative half-life of $Ft$ = 3084(15) s for this decay, in agreement with the mean value for the series of the lighter nuclides from $^{10}$C to $^{54}$Co. Assuming conserved vector current, this result allows for an experimental determination of the isospin-symmetry-breaking correction $\\delta$C.

  11. A direct temperature-resolved tandem mass spectrometry study of cholesterol oxidation products in light-aged egg tempera paints with examples from works of art

    Science.gov (United States)

    van den Brink, Oscar F.; Ferreira, Ester S. B.; van der Horst, Jerre; Boon, Jaap J.

    2009-07-01

    Cholesterol (1) constitutes approximately 5% of the lipid fraction of eggs. The compound is therefore abundant in fresh egg tempera paints. The fate of cholesterol upon light ageing of egg tempera paint binding medium was investigated by direct temperature resolved mass spectrometry (DTMS) and tandem mass spectrometry (DTMSMS). Cholesterol oxidation products (COPs) such as 5,6-epoxycholestan-3-ol (2) and 3-hydroxycholest-5-en-7-one (3) were positively identified in light-aged egg binding medium. Given the fast rate of oxidation of cholesterol, the corresponding oxidation products are better markers for egg tempera than the cholesterol molecule itself. Cholesterol and COPs were discovered in paints on German baroque altar pieces from the 16th and 18th C and in a 20th C glaze on a Mark Rothko Seagram Mural painting at Tate by DTMS fingerprinting analysis of paint microsamples.

  12. 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.

  13. 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.

  14. Effect-directed analysis of cold-pressed hemp, flax and canola seed oils by planar chromatography linked with (bio)assays and mass spectrometry.

    Science.gov (United States)

    Teh, Sue-Siang; Morlock, Gertrud E

    2015-11-15

    Cold-pressed hemp, flax and canola seed oils are healthy oils for human consumption as these are rich in polyunsaturated fatty acids and bioactive phytochemicals. However, bioactive information on the food intake side is mainly focused on target analysis. For more comprehensive information with regard to effects, single bioactive compounds present in the seed oil extracts were detected by effect-directed assays, like bioassays or an enzymatic assay, directly linked with chromatography and further characterized by mass spectrometry. This effect-directed analysis is a streamlined method for the analysis of bioactive compounds in the seed oil extracts. All effective compounds with regard to the five assays or bioassays applied were detected in the samples, meaning also bioactive breakdown products caused during oil processing, residues or contaminants, aside the naturally present bioactive phytochemicals. The investigated cold-pressed oils contained compounds that exert antioxidative, antimicrobial, acetylcholinesterase inhibitory and estrogenic activities. This effect-directed analysis can be recommended for bioactivity profiling of food to obtain profound effect-directed information on the food intake side.

  15. Direct analysis of pharmaceutical drug formulations using ion mobility spectrometry/quadrupole-time-of-flight mass spectrometry combined with desorption electrospray ionization.

    Science.gov (United States)

    Weston, Daniel J; Bateman, Robert; Wilson, Ian D; Wood, Tim R; Creaser, Colin S

    2005-12-01

    A novel approach to the rapid analysis of pharmaceutical drug formulations using hyphenated ion mobility spectrometry (IMS) and time-of-flight mass spectrometry (ToF-MS) that requires no sample pretreatment or chromatographic separation is described. A modified quadrupole time-of-flight mass spectrometer containing an ion mobility drift cell was used for gas-phase electrophoretic separation of ions prior to ToF-MS detection. The generation of sample ions directly from tablets and cream formulations was effected by desorption electrospray ionization (DESI) using a modified electrospray ion source. The analysis of a range of over-the-counter and prescription tablet formulations is described, including histamine H2 receptor antagonist (ranitidine), analgesic (paracetamol), opiate (codeine), and aromatase inhibitor anticancer (anastrozole) drugs. The successful determination of active drugs from soft formulations, such as an antiseptic cream (chlorhexidine) and a nicotine-containing skin patch, is also presented. Limits of detection for the active drugs using the DESI/IMS/ToF-MS method fell within the high-picomole to nanomole range. In all cases, the use of ion mobility drift tube separation showed increased selectivity for active drug responses (present as low as 0.14% w/w) over excipient responses such as poly(ethylene glycol). Tandem mass spectrometric analysis of precursor ions separated by IMS allowed positive confirmation of active drugs with little loss of ion mobility efficiency. The ability to analyze hard or soft pharmaceutical formulations directly by DESI combined with ion mobility spectrometry/mass spectrometry in approximately 2 min demonstrates the potential applicability of this novel method to pharmaceutical screening of low-molecular-weight drug formulations with high selectivity over the formulation vehicle.

  16. Direct analysis of volatile fatty acids in marine sediment porewater by two-dimensional ion chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Pedersen, Jeanette; Røy, Hans

    2014-01-01

    Volatile fatty acids (VFAs) are key intermediates in the microbial food web. However, the analysis of low concentrations of VFAs in marine porewater is hampered by interference from high concentrations of inorganic ions. Published methods often use sample pretreatment, including distillation...... or derivatization, to overcome this problem. This is not only labor intensive but also increases the risk of contamination. We have developed an analytical procedure that enables the direct quantification of several VFAs (formate, acetate, propionate, butyrate, valerate, pyruvate, and lactate) in marine porewater...

  17. Search for Mu's K(0)'s or Characteristic Hadron Signatures and Masses in Coincidence with Single Directly Produced Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Barton, D.; Bolon, C.; Brandenburg, G.; Butler, J.; Busza, W.; Fiedman, J.; Frisch, D.; Garbincius, P.; Kendall, H.; Luckey, D.; Nelson, B.; /MIT /Bari U.

    1975-01-01

    The authors propose to investigate the anomalous production of leptons in hadron reactions using the FNAL cyclotron magnet facility in conjunction with a direct electron trigger. The large aperture of the magnet plus the existing detector array will make it possible to study the topology of the anomalous events for distinctive signatures such as invariant mass peaks or accompanying {mu}'s or K{sup o}'s. The use of an electron trigger instead of a muon trigger allows better offline noise suppression as well as overall event reconstructability.

  18. Modeling the gas flow upstream and in the sampling nozzle of the inductively coupled plasma mass spectrometer via the Direct Simulation Monte Carlo algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Ross L. [Brigham Young University (United States)], E-mail: ross_spencer@byu.edu; Krogel, Jaron; Palmer, Jamie; Payne, Adam; Sampson, Andrew; Somers, William; Woods, Charles N. [Brigham Young University (United States)

    2009-03-15

    The Direct Simulation Monte Carlo algorithm has been applied to the flow of neutral argon gas through the first vacuum stage of the Inductively Coupled Plasma Mass Spectrometer. Good agreement is found between the simulation results and the equations of fluid dynamics, including the approximate hemispherical sink model of Douglas and French. The simulation reveals details of boundary layer formation in the nozzle, including a reduction in the total flow through the nozzle of about 15% from the ideal value calculated by Douglas and French.

  19. Rapid characterization of trace aflatoxin B1 in groundnuts, wheat and maize by dispersive liquid-liquid microextraction followed by direct electrospray probe tandem mass spectrometry.

    Science.gov (United States)

    Satarpai, Thiphol; Siripinyanond, Atitaya; Su, Hung; Shiea, Jentaie

    2017-04-30

    Aflatoxins are poisonous and cancer-related chemical compounds commonly found in crops and plants. Aflatoxin B1 is the most toxic compound among aflatoxins and has been classified as group 1 carcinogenic to humans, especially in liver cancer. Herein, an ambient mass spectrometric method was developed for rapid characterization of trace aflatoxin B1 in peanuts. Direct electrospray probe tandem mass spectrometry (DEP-MS/MS) was used to detect aflatoxin B1 in peanuts. To avoid the matrix effect, the aflatoxin B1 in the samples was extracted and concentrated by dispersive liquid-liquid microextraction. The mass spectrometer was operated in the positive ion mode to monitor the intact molecular ion (m/z 313, MH(+) ) and product ion (m/z 241) of aflatoxin B1 using multiple reaction monitoring. Since no clean-up procedure of the sample was required, the sampling step and the subsequent mass spectrometric detection of the aflatoxin B1 was completed in less than 5 min. The limit of detection of aflatoxin B1 is at the sub-ppb level. The results obtained by DEP-MS/MS were also validated by liquid chromatography/tandem mass spectrometry (LC/MS/MS). Recovery of aflatoxin B1 in the sample was evaluated by analyzing spiked aflatoxin B1 with LC/MS/MS to be 85% and DEP-MS/MS to be 84%. DEP-MS/MS combined with a simple dispersive liquid-liquid microextraction procedure was successfully used for the quantitative analysis of AFB1 in nut samples. Due to its high efficiency, it is promising in providing important toxicological information for food safety in the real world. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Simultaneous determination of fluoroquinolones in environmental water by liquid chromatography-tandem mass spectrometry with direct injection: A green approach.

    Science.gov (United States)

    Denadai, Marina; Cass, Quezia Bezerra

    2015-10-30

    This work describes an on-line multi-residue method for simultaneous quantification of ciprofloxacin, enrofloxacin, gemifloxacin, moxifloxacin, norfloxacin and ofloxacin in superficial and wastewater samples. For that, an octyl restricted-access media bovine serum albumin column (RAM-BSA C8) was used for sample clean-up, enrichment and analysis with quantitation carried out by tandem mass spectrometry. For water samples volumes of only 500μL the method provided good selectivity, extraction efficiency, accuracy, and precision with quantification limits in the order of 20-150ngL(-1). Out of the six fluoroquinolones only ciprofloxacin (195ngL(-1)) and norfloxacin (270ngL(-1)) were quantified in an influent sample of the wastewater treatment plant (WWTP) of São Carlos (SP, Brazil). None were found in the superficial water samples analyzed. The capability of injecting native sample in an automated mode provides high productivity and represents a greener approach in environmental sample analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. 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.

  2. 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.

  3. 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.

  4. Kinetic measurements of phosphoglucose isomerase and phosphomannose isomerase by direct analysis of phosphorylated aldose-ketose isomers using tandem mass spectrometry

    Science.gov (United States)

    Gao, Hong; Chen, Ye; Leary, Julie A.

    2005-02-01

    A mass spectrometry based method for the direct determination of kinetic constants for phosphoglucose isomerase (PGI) and phosphomannose isomerase (PMI) is described. PGI catalyzes the interconversion between glucose-6-phosphate (Glc6P) and fructose-6-phosphate (Fru6P) and PMI performs the same function between mannose-6-phosphate (Man6P) and Fru6P. These two enzymes are essential in the pathways of glycolytic or oxidative metabolism of carbohydrates and have been considered as potential therapeutic targets. Traditionally, they are assayed either by spectrophotometric detection of Glc6P with one or more coupling enzymes or by a colorimetric detection of Fru6P. However, no suitable assay for Man6P has been developed yet to study the reaction of PMI in the direction from Fru6P to Man6P. In the work presented herein, a general assay for the isomeric substrate-product pair between Glc6P and Fru6P or between Man6P and Fru6P was developed, with the aim of directly studying the kinetics of PGI and PMI in both directions. The 6-phosphorylated aldose and ketose isomers were distinguished based on their corresponding tandem mass spectra (MS2) obtained on a quadrupole ion trap mass spectrometer, and a multicomponent quantification method was utilized to determine the composition of binary mixtures. Using this method, the conversion between Fru6P and Glc6P and that between Fru6P and Man6P are directly monitored. The equilibrium constants for the reversible reactions catalyzed by PGI and PMI are measured to be 0.3 and 1.1, respectively, and the kinetic parameters for both substrates of PGI and PMI are also determined. The values of KM and Vmax for Fru6P as substrate of PMI are reported to be 0.15 mM and 7.78 [mu]mol/(min mg), respectively. All other kinetic parameters measured correlate well with those obtained using traditional methods, demonstrating the accuracy and reliability of this assay.

  5. 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.

  6. Effect of supervised, periodized exercise training vs. self-directed training on lean body mass and other fitness variables in health club members.

    Science.gov (United States)

    Storer, Thomas W; Dolezal, Brett A; Berenc, Matthew N; Timmins, John E; Cooper, Christopher B

    2014-07-01

    Conventional wisdom suggests that exercise training with a personal trainer (PTr) is more beneficial for improving health-related fitness than training alone. However, there are no published data that confirm whether fitness club members who exercise with a PTr in the fitness club setting obtain superior results compared with self-directed training. We hypothesized that club members randomized to receive an evidence-based training program would accrue greater improvements in lean body mass (LBM) and other fitness measures than members randomized to self-training. Men, aged 30-44 years, who were members of a single Southern California fitness club were randomized to exercise with a PTr administering a nonlinear periodized training program (TRAINED, N = 17) or to self-directed training (SELF, N = 17); both groups trained 3 days per week for 12 weeks. Lean body mass was determined by dual-energy x-ray absorptiometry. Secondary outcomes included muscle strength 1 repetition maximum (1RM), leg power (vertical jump), and aerobic capacity (V[Combining Dot Above]O2max). TRAINED individuals increased LBM by 1.3 (0.4) kg, mean (SEM) vs. no change in SELF, p = 0.029. Similarly, significantly greater improvements were seen for TRAINED vs. SELF in chest press strength (42 vs. 19%; p = 0.003), peak leg power (6 vs. 0.6%; p members whose training is directed by well-qualified PTrs administering evidence-based training regimens achieve significantly greater improvements in LBM and other dimensions of fitness than members who direct their own training.

  7. Interplanetary Coronal Mass Ejections Resulting from Earth-Directed CMEs Using SOHO and ACE Combined Data During Solar Cycle 23

    Science.gov (United States)

    Paouris, Evangelos; Mavromichalaki, Helen

    2017-02-01

    In this work a total of 266 interplanetary coronal mass ejections observed by the Solar and Heliospheric Observatory/ Large Angle and Spectrometric Coronagraph (SOHO/LASCO) and then studied by in situ observations from Advanced Composition Explorer (ACE) spacecraft, are presented in a new catalog for the time interval 1996 - 2009 covering Solar Cycle 23. Specifically, we determine the characteristics of the CME which is responsible for the upcoming ICME and the associated solar flare, the initial/background solar wind plasma and magnetic field conditions before the arrival of the CME, the conditions in the sheath of the ICME, the main part of the ICME, the geomagnetic conditions of the ICME's impact at Earth and finally we remark on the visual examination for each event. Interesting results revealed from this study include the high correlation coefficient values of the magnetic field Bz component against the Ap index (r = 0.84), as well as against the Dst index (r = 0.80) and of the effective acceleration against the CME linear speed (r = 0.98). We also identify a north-south asymmetry for X-class solar flares and an east-west asymmetry for CMEs associated with strong solar flares (magnitude ≥ M1.0) which finally triggered intense geomagnetic storms (with Ap ≥179). The majority of the geomagnetic storms are determined to be due to the ICME main part and not to the extreme conditions which dominate inside the sheath. For the intense geomagnetic storms the maximum value of the Ap index is observed almost 4 hours before the minimum Dst index. The amount of information makes this new catalog the most comprehensive ICME catalog for Solar Cycle 23.

  8. 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

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Andrew W.; McAulay, Edith A.J. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Nordon, Alison, E-mail: alison.nordon@strath.ac.uk [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Littlejohn, David, E-mail: d.littlejohn@strath.ac.uk [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lynch, Thomas P. [WestCHEM, Department of Pure and Applied Chemistry and CPACT, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL (United Kingdom); Lancaster, J. Steven [Hull Research and Technology Centre, BP Chemicals, Hull, HU12 8DS (United Kingdom); Wright, Robert G. [Thermo Fisher Scientific, Winsford, Cheshire, CW7 3GA (United Kingdom)

    2014-11-07

    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{sup −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

  9. Simultaneous determination of bromine and chlorine in coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis.

    Science.gov (United States)

    de Gois, Jefferson S; Pereira, Éderson R; Welz, Bernhard; Borges, Daniel L G

    2014-12-10

    A new method for the direct analysis of coal using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis was developed, aiming at the determination of Br and Cl. The procedure does not require any significant sample pretreatment and allows simultaneous determination of both elements to be carried out, requiring small mass aliquots of sample (about 0.5 mg). All operating parameters, including carrier gas flow-rate and RF power, were optimized for maximum sensitivity. The use of modifiers/aerosol carriers (Pd, Pd+Al and Pd+Ca) was evaluated, and the mixture of Pd and Ca was chosen, allowing pyrolysis and vaporization temperatures of 700°C and 1900°C, respectively. Chlorine was accurately determined using calibration against solid standards, whereas Br could also be determined using calibration against aqueous standard solutions. The limits of quantification were 0.03 μg g(-1) for Br and 7 μg g(-1) for Cl, and no spectral interferences were observed.

  10. Direct probe atmospheric pressure photoionization/atmospheric pressure chemical ionization high-resolution mass spectrometry for fast screening of flame retardants and plasticizers in products and waste.

    Science.gov (United States)

    Ballesteros-Gómez, A; Brandsma, S H; de Boer, J; Leonards, P E G

    2014-04-01

    In this study, we develop fast screening methods for flame retardants and plasticizers in products and waste based on direct probe (DP) atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) coupled to a high-resolution (HR) time-of-flight mass spectrometer. DP-APPI is reported for the first time in this study, and DP-APCI that has been scarcely exploited is optimized for comparison. DP-APPI was more selective than DP-APCI and also more sensitive for the most hydrophobic compounds. No sample treatment was necessary, and only a minimal amount of sample (few milligrams) was used for analysis that was performed within a few minutes. Both methods were applied to the analysis of plastic products, electronic waste, and car interiors. Polybrominated diphenylethers, new brominated flame retardants, and organophosphorus flame retardants were present in most of the samples. The combination of DP with HR mass spectra and data processing based on mass accuracy and isotopic patterns allowed the unambiguous identification of chemicals at low levels of about 0.025 % (w/w). Under untargeted screening, resorcinol bis(biphenylphosphate) and bisphenol A bis(bisphenylphosphate) were identified in many of the consumer products of which literature data are still very limited.

  11. Detection of gaseous compounds by needle trap sampling and direct thermal-desorption photoionization mass spectrometry: concept and demonstrative application to breath gas analysis.

    Science.gov (United States)

    Kleeblatt, Juliane; Schubert, Jochen K; Zimmermann, Ralf

    2015-02-01

    A fast detection method to analyze gaseous organic compounds in complex gas mixtures was developed, using a needle trap device (NTD) in conjunction with thermal-desorption photoionization time-of-flight mass spectrometry (TD-PI-TOFMS). The mass spectrometer was coupled via a deactivated fused silica capillary to an injector of a gas chromatograph. In the hot injector, the analytes collected on the NTD were thermally desorbed and directly transferred to the PI-TOFMS ion source. The molecules are softly ionized either by single photon ionization (SPI, 118 nm) or by resonance enhanced multiphoton ionization (REMPI, 266 nm), and the molecular ion signals are detected in the TOF mass analyzer. Analyte desorption and the subsequent PI-TOFMS detection step only lasts ten seconds. The specific selectivity of REMPI (i.e., aromatic compounds) and universal ionization characteristics render PI-MS as a promising detection system. As a first demonstrative application, the alveolar phase breath gas of healthy, nonsmoking subjects was sampled on NTDs. While smaller organic compounds such as acetone, acetaldehyde, isoprene, or cysteamine can be detected in the breath gas with SPI, REMPI depicts the aromatic substances phenol and indole at 266 nm. In the breath gas of a healthy, smoking male subject, several xenobiotic substances such as benzene, toluene, styrene, and ethylbenzene can be found as well. Furthermore, the NTD-REMPI-TOFMS setup was tested for breath gas taken from a mechanically ventilated pig under continuous intravenous propofol (2,6-diisopropylphenol, narcotic drug) infusion.

  12. 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.

  13. Characterization of Dissolved Organic Matter in River Water by Conventional Methods and Direct Sample Analysis-Time of Flight-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    T. Garrido Reyes

    2016-01-01

    Full Text Available The dissolved organic matter in surface waters is composed of fractions of different molecular weight and polarity, characteristics that determine their capacity for complexing different types of pollutants and their environmental impact. In this study, the dissolved organic matter in the surface water of the Bio-Bio River (Central Region of Chile was characterized chemically and spectroscopically after fractionating by molecular weight and polarity. The technique of direct sample analysis-time of flight-mass spectrometry (DSA-TOF-MS was used to obtain more information on the composition of dissolved organic matter. It is concluded that dissolved organic matter found in the water of the river from the site of minor human impact (Rucalhue has a predominantly natural origin, with a high content of aromatic carbon, in contrast to dissolved organic matter found in the waters of the sites that have higher human impact (Laja and Concepción, characterized by a greater molecular size and higher organic carbon content. These results are consistent with those obtained from DSA-TOF-MS, where higher correlation was observed between the mass spectrum of the standard commercial humic acid and dissolved organic matter found in the sectors of Laja and Concepción, unlike the spectrum mass of lignin which is more like dissolved organic matter found in the sector Rucalhue.

  14. A temperature compensation procedure for performance improvement of mass-produced MEMS gyroscopes based on direct parameter measurement

    Science.gov (United States)

    Straube, Timothy Milton

    Micro Electro Mechanical Systems gyroscopes are an enabling technology for many rate sensing applications that require low cost, mass and volume, including the class of spacecraft known as nano- or pico-satellites. The weakness of these types of gyroscopes to date has been limited performance capabilities, especially over a varying temperature range. This thesis presents a methodology for correcting the gyroscope output signal for variations over temperature based on measurements of specific internal gyro parameters, namely, drive and sense axis resonant frequency, and off-axis electrostatic forcing function. The thesis presents the development of the full analytical equations of motion for a translating type MEMS gyro. The equations are simplified, numerically validated, and decomposed for gyro scale factor and bias expressions. Employing gyroscope parameters obtained from open literature sources as a function of temperature, a reference model of gyro scale factor and bias voltage as a function of temperature is developed. The research also includes the empirical testing of two types of gyro, and ten total individual devices, including eight ADXRS150 automotive grade gyroscopes from Analog Devices. Device outputs at temperatures from -35°C to +75°C and across a range of rotation rate were measured and processed to calculate individual gyro scale factor and bias. Data from all gyros were analyzed using a principal component methodology to extract the dominant structures in the gyro behavior. The final correction model is individualized for each gyro using ambient scale factor and bias data from that gyro. This model is used to compensate the individual raw gyro output taken during testing. Compositing the compensated output from all gyro provides a final rate estimate, which can be compared against the known testing inputs. The results demonstrate considerable improvement over manufacturer-provided scale factor and bias correction values. With the linkage between

  15. The mass of planet GJ 676A b from ground-based astrometry. A planetary system with two mature gas giants suitable for direct imaging

    Science.gov (United States)

    Sahlmann, J.; Lazorenko, P. F.; Ségransan, D.; Astudillo-Defru, N.; Bonfils, X.; Delfosse, X.; Forveille, T.; Hagelberg, J.; Lo Curto, G.; Pepe, F.; Queloz, D.; Udry, S.; Zimmerman, N. T.

    2016-11-01

    The star GJ 676A is an M0 dwarf hosting both gas-giant and super-Earth-type planets that were discovered with radial-velocity measurements. Using FORS2/VLT, we obtained position measurements of the star in the plane of the sky that tightly constrain its astrometric reflex motion caused by the super-Jupiter planet "b" in a 1052-day orbit. This allows us to determine the mass of this planet to be , which is 40% higher than the minimum mass inferred from the radial-velocity orbit. Using new HARPS radial-velocity measurements, we improve upon the orbital parameters of the inner low-mass planets "d" and "e" and we determine the orbital period of the outer giant planet "c" to be Pc = 7340 days under the assumption of a circular orbit. The preliminary minimum mass of planet "c" is Mcsini = 6.8 MJ with an upper limit of 39 MJ that we set using NACO/VLT high-contrast imaging. We also determine precise parallaxes and relative proper motions for both GJ 676A and its wide M3 companion GJ 676B. Although the system is probably quite mature, the masses and projected separations ( 0.̋1-0.̋4) of planets "b" and "c" make them promising targets for direct imaging with future instruments in space and on extremely large telescopes. In particular, we estimate that GJ 676A b and GJ 676A c are promising targets for directly detecting their reflected light with the WFIRST space mission. Our study demonstrates the synergy of radial-velocity and astrometric surveys that is necessary to identify the best targets for such a mission. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 385.C-0416 (A,B), 086.C-0515(A), 089.C-0115(D,E), 072.C-0488(E), 180.C-0886(A), 183.C-0437(A), 085.C-0019(A), 091.C-0034(A), 095.C-0551(A), 096.C-0460(A).Full Table A.2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A77

  16. Towards Direct Numerical Simulation of mass and energy fluxes at the soil-atmospheric interface with advanced Lattice Boltzmann methods

    Science.gov (United States)

    Wang, Ying; Krafczyk, Manfred; Geier, Martin; Schönherr, Martin

    2014-05-01

    The quantification of soil evaporation and of soil water content dynamics near the soil surface are critical in the physics of land-surface processes on many scales and are dominated by multi-component and multi-phase mass and energy fluxes between the ground and the atmosphere. Although it is widely recognized that both liquid and gaseous water movement are fundamental factors in the quantification of soil heat flux and surface evaporation, their computation has only started to be taken into account using simplified macroscopic models. As the flow field over the soil can be safely considered as turbulent, it would be natural to study the detailed transient flow dynamics by means of Large Eddy Simulation (LES [1]) where the three-dimensional flow field is resolved down to the laminar sub-layer. Yet this requires very fine resolved meshes allowing a grid resolution of at least one order of magnitude below the typical grain diameter of the soil under consideration. In order to gain reliable turbulence statistics, up to several hundred eddy turnover times have to be simulated which adds up to several seconds of real time. Yet, the time scale of the receding saturated water front dynamics in the soil is on the order of hours. Thus we are faced with the task of solving a transient turbulent flow problem including the advection-diffusion of water vapour over the soil-atmospheric interface represented by a realistic tomographic reconstruction of a real porous medium taken from laboratory probes. Our flow solver is based on the Lattice Boltzmann method (LBM) [2] which has been extended by a Cumulant approach similar to the one described in [3,4] to minimize the spurious coupling between the degrees of freedom in previous LBM approaches and can be used as an implicit LES turbulence model due to its low numerical dissipation and increased stability at high Reynolds numbers. The kernel has been integrated into the research code Virtualfluids [5] and delivers up to 30% of the

  17. Comprehensive analysis of oil sands processed water by direct-infusion Fourier-transform ion cyclotron resonance mass spectrometry with and without offline UHPLC sample prefractionation.

    Science.gov (United States)

    Nyakas, Adrien; Han, Jun; Peru, Kerry M; Headley, John V; Borchers, Christoph H

    2013-05-07

    Oil sands processed water (OSPW) is the main byproduct of the large-scale bitumen extraction activity in the Athabasca oil sands region (Alberta, Canada). We have investigated the acid-extractable fraction (AEF) of OSPW by extraction-only (EO) direct infusion (DI) negative-ion mode electrospray ionization (ESI) on a 12T-Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS), as well as by offline ultrahigh performance liquid chromatography (UHPLC) followed by DI-FTICR-MS. A preliminary offline UHPLC separation into 8 fractions using a reversed-phase C4 column led to approximately twice as many detected peaks and identified compounds (973 peaks versus 2231 peaks, of which 856 and 1734 peaks, respectively, could be assigned to chemical formulas based on accurate mass measurements). Conversion of these masses to the Kendrick mass scale allowed the straightforward recognition of homologues. Naphthenic (CnH2n+zO2) and oxy-naphthenic (CnH2n+zOx) acids represented the largest group of molecules with assigned formulas (64%), followed by sulfur-containing compounds (23%) and nitrogen-containing compounds (8%). Pooling of corresponding fractions from two consecutive offline UHPLC runs prior to MS analysis resulted in ~50% more assignments than a single injection, resulting in 3-fold increase of identifications compared to EO-DI-FTICR-MS using the same volume of starting material. Liquid-liquid extraction followed by offline UHPLC fractionation thus holds enormous potential for a more comprehensive profiling of OSPW, which may provide a deeper understanding of its chemical nature and environmental impact.

  18. (Un)targeted Scanning of Locks of Hair for Drugs of Abuse by Direct Analysis in Real Time-High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Duvivier, Wilco F; van Putten, Marc R; van Beek, Teris A; Nielen, Michel W F

    2016-02-16

    Forensic hair evidence can be used to obtain retrospective timelines of drug use by analysis of hair segments. However, this is a laborious and time-consuming process, and mass spectrometric (MS) imaging techniques, which show great potential for single-hair targeted analysis, are less useful due to differences in hair growth rate between individual hairs. As an alternative, a fast untargeted analysis method was developed that uses direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) to longitudinally scan intact locks of hair without extensive sample preparation or segmentation. The hair scan method was validated for cocaine against an accredited liquid chromatography/tandem mass spectrometry (LC/MS/MS) method. The detection limit for cocaine in hair was found to comply with the cutoff value of 0.5 ng/mg recommended by the Society of Hair Testing; that is, the DART hair scan method is amenable to forensic cases. Under DART conditions, no significant thermal degradation of cocaine occurred. The standard DART spot size of 5.1 ± 1.1 mm could be improved to 3.3 ± 1.0 mm, corresponding to approximately 10 days of hair growth, by using a high spatial resolution exit cone. By use of data-dependent product ion scans, multiple drugs of abuse could be detected in a single drug user hair scan with confirmation of identity by both exact mass and MS/HRMS fragmentation patterns. Furthermore, full-scan high-resolution data were retrospectively interrogated versus a list of more than 100 compounds and revealed additional hits and temporal profiles in good correlation with reported drug use.

  19. Direct quantification of chemical warfare agents and related compounds at low ppt levels: comparing active capillary dielectric barrier discharge plasma ionization and secondary electrospray ionization mass spectrometry.

    Science.gov (United States)

    Wolf, Jan-Christoph; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2015-01-06

    A novel active capillary dielectric barrier discharge plasma ionization (DBDI) technique for mass spectrometry is applied to the direct detection of 13 chemical warfare related compounds, including sarin, and compared to secondary electrospray ionization (SESI) in terms of selectivity and sensitivity. The investigated compounds include an intact chemical warfare agent and structurally related molecules, hydrolysis products and/or precursors of highly toxic nerve agents (G-series, V-series, and "new" nerve agents), and blistering and incapacitating warfare agents. Well-defined analyte gas phase concentrations were generated by a pressure-assisted nanospray with consecutive thermal evaporation and dilution. Identification was achieved by selected reaction monitoring (SRM). The most abundant fragment ion intensity of each compound was used for quantification. For DBDI and SESI, absolute gas phase detection limits in the low ppt range (in MS/MS mode) were achieved for all compounds investigated. Although the sensitivity of both methods was comparable, the active capillary DBDI sensitivity was found to be dependent on the applied AC voltage, thus enabling direct tuning of the sensitivity and the in-source fragmentation, which may become a key feature in terms of field applicability. Our findings underline the applicability of DBDI and SESI for the direct, sensitive detection and quantification of several CWA types and their degradation products. Furthermore, they suggest the use of DBDI in combination with hand-held instruments for CWAs on-site monitoring.

  20. 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.

  1. 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 CH3 COONH4 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

    2015-09-01

    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.

  6. Target-guided separation of Bougainvillea glabra betacyanins by direct coupling of preparative ion-pair high-speed countercurrent chromatography and electrospray ionization mass-spectrometry.

    Science.gov (United States)

    Jerz, Gerold; Wybraniec, Sławomir; Gebers, Nadine; Winterhalter, Peter

    2010-07-02

    In this study, preparative ion-pair high-speed countercurrent chromatography was directly coupled to an electrospray ionization mass-spectrometry device (IP-HSCCC/ESI-MS-MS) for target-guided fractionation of high molecular weight acyl-oligosaccharide linked betacyanins from purple bracts of Bougainvillea glabra (Nyctaginaceae). The direct identification of six principal acyl-oligosaccharide linked betacyanins in the mass range between m/z 859 and m/z 1359 was achieved by positive ESI-MS ionization and gave access to the genuine pigment profile already during the proceeding of the preparative separation. Inclusively, all MS/MS-fragmentation data were provided during the chromatographic run for a complete analysis of substitution pattern. On-line purity evaluation of the recovered fractions is of high value in target-guided screening procedures and for immediate decisions about suitable fractions used for further structural analysis. The applied preparative hyphenation was shown to be a versatile screening method for on-line monitoring of countercurrent chromatographic separations of polar crude pigment extracts and also traced some minor concentrated compounds. For the separation of 760mg crude pigment extract the biphasic solvent system tert.-butylmethylether/n-butanol/acetonitrile/water 2:2:1:5 (v/v/v/v) was used with addition of ion-pair forming reagent trifluoroacetic acid. The preparative HSCCC-eluate had to be modified by post-column addition of a make-up solvent stream containing formic acid to reduce ion-suppression caused by trifluoroacetic acid and later significantly maximized response of ESI-MS/MS detection of target substances. A variable low-pressure split-unit guided a micro-eluate to the ESI-MS-interface for sensitive and direct on-line detection, and the major volume of the effluent stream was directed to the fraction collector for preparative sample recovery. The applied make-up solvent mixture significantly improved smoothness of the continuously

  7. Simultaneous enantioselective quantification of fluoxetine and norfluoxetine in human milk by direct sample injection using 2-dimensional liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alvim-Jr, Joel; Lopes, Bianca Rebelo; Cass, Quezia Bezerra

    2016-06-17

    A two-dimensional liquid chromatography system coupled to triple quadrupole tandem mass spectrometer (2D LC-MS/MS) was employed for the simultaneously quantification of fluoxetine (FLX) and norfluoxetine (NFLX) enantiomers in human milk by direct injection of samples. A restricted access media of bovine serum albumin octadecyl column (RAM-BSAC18) was used in the first dimension for the milk proteins depletion, while an antibiotic-based chiral column was used in the second dimension. The results herein described show good selectivity, extraction efficiency, accuracy, and precision with limits of quantification in the order of 7.5ngmL(-1)for the FLX enantiomers and 10.0ngmL(-1) for NFLX enantiomers. Furthermore, it represents a practical tool in terms of sustainability for the sample preparation of such a difficult matrix.

  8. An extraction method of positive blood cultures for direct identification of Candida species by Vitek MS matrix-assisted laser desorption ionization time of flight mass spectrometry.

    Science.gov (United States)

    Lavergne, Rose-Anne; Chauvin, Pamela; Valentin, Alexis; Fillaux, Judith; Roques-Malecaze, Christine; Arnaud, Sylvie; Menard, Sandie; Magnaval, Jean-François; Berry, Antoine; Cassaing, Sophie; Iriart, Xavier

    2013-08-01

    Candida spp. are an important cause of nosocomial bloodstream infections. Currently, complete identification of yeasts with conventional methods takes several days. We report here the first evaluation of an extraction method associated with the Vitek MS matrix-assisted laser desorption ionization time of flight mass spectrometry for direct identification of Candida species from positive blood cultures. We evaluated this protocol with blood cultures that were inoculated with reference and routine isolates (eight reference strains, 30 patients isolates and six mixed cultures containing two strains of different Candida species), or from patients with candidemia (28 isolates). This method performed extremely well (97% correct identification) with blood cultures of single Candida spp. and significantly reduced the time of diagnosis. Nevertheless, subculture remains indispensable to test fungal resistance and to detect mixed infections.

  9. Direct Separation of Pregabalin Enantiomers Using a Zwitterionic Chiral Selector by High Performance Liquid Chromatography Coupled to Mass Spectrometry and Ultraviolet Detection

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana Chennuru

    2016-11-01

    Full Text Available The chromatographic resolution of pregabalin enantiomers has been often achieved by derivatization of the molecule, in order to reach enough sensitivity at low concentrations of the minor enantiomer present in the active principle. In the present article, the development and optimization of two liquid chromatographic methods are presented for the direct resolution of pregabalin enantiomers on a chiral stationary phase (CSP containing a zwitterionic selector derived from cinchona alkaloid and sulfonic acid (CHIRALPAK ZWIX. The key parameters for the separation as well as the compatibility of chromatographic conditions with different detection modes (ultraviolet and mass spectrometry were investigated. The resulting methods were found to be selective, of high performance and low limits of detection (2 µg/mL by UV and 1 ng/mL by MS, respectively and quantification (6 µg/mL by UV and 5 ng/mL by MS, respectively for the minor enantiomer which is considered as a chiral impurity.

  10. 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.

  11. Direct isotope ratio analysis of individual uranium-plutonium mixed particles with various U/Pu ratios by thermal ionization mass spectrometry.

    Science.gov (United States)

    Suzuki, Daisuke; Esaka, Fumitaka; Miyamoto, Yutaka; Magara, Masaaki

    2015-02-01

    Uranium and plutonium isotope ratios in individual uranium-plutonium (U-Pu) mixed particles with various U/Pu atomic ratios were analyzed without prior chemical separation by thermal ionization mass spectrometry (TIMS). Prior to measurement, micron-sized particles with U/Pu ratios of 1, 5, 10, 18, and 70 were produced from uranium and plutonium certified reference materials. In the TIMS analysis, the peaks of americium, plutonium, and uranium ion signals were successfully separated by continuously increasing the evaporation filament current. Consequently, the uranium and plutonium isotope ratios, except the (238)Pu/(239)Pu ratio, were successfully determined for the particles at all U/Pu ratios. This indicates that TIMS direct analysis allows for the measurement of individual U-Pu mixed particles without prior chemical separation.

  12. Direct demonstration of tissue uptake of an inhaled drug: proof-of-principle study using matrix-assisted laser desorption ionization mass spectrometry imaging.

    Science.gov (United States)

    Fehniger, Thomas E; Végvári, Akos; Rezeli, Melinda; Prikk, Kaiu; Ross, Peeter; Dahlbäck, Magnus; Edula, Goutham; Sepper, Ruth; Marko-Varga, György

    2011-11-01

    Drug therapy is often directed to specific organ and tissue compartments where the mode of action of the compound affects specifically targeted biological processes. However, the direct measurement of drug uptake in terms of a time kinetic and concentrations attained at the local sites has not been readily available as a clinical index for most drugs. A proof-of-principle study was conducted to test the utility of applying matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) to demonstrate the qualitative distribution pattern of a locally administered drug within tissue sites of targeted action. Here we have measured the occurrence of an inhaled bronchodilator, the muscarinic receptor antagonist ipratropium, within human bronchial biopsies obtained by fiber optic bronchoscopy shortly after dosing exposure. Cryo-preserved biopsy samples from five subjects being evaluated for airway obstruction or potential tumor development were prepared as thin frozen sections. Samples coated with a MALDI matrix were analyzed by a MALDI LTQ Orbitrap XL mass spectrometer at large (100 μm) and small (30 μm) raster sizes. Our results demonstrate that ipratropium is rapidly absorbed into the airway wall. Ipratropium parent ion (m/z 332.332) and daughter ions (m/z 166.2 and 290.2) were coincidently partitioned within submucosal spaces containing targeted airway smooth muscle in four out of five subjects. The signal intensity of ipratropium fragment ions provided estimates that local drug concentrations between 3 and 80 nM were achieved within the airway wall. To our knowledge, this is the first reported study in applying MALDI-MSI to demonstrate the localization of a drug administered at therapeutic levels. The study highlights the potential benefit of MALDI-MSI to provide important measurements of drug efficacy in clinical settings.

  13. Direct measurement of free estradiol in human serum by equilibrium dialysis-liquid chromatography-tandem mass spectrometry and reference intervals of free estradiol in women.

    Science.gov (United States)

    Ray, Julie A; Kushnir, Mark M; Bunker, Ashley; Rockwood, Alan L; Meikle, A Wayne

    2012-06-14

    Measurement of free estradiol offers a better representation of the bioactive fraction of the hormone. We describe a direct equilibrium dialysis-liquid chromatography-tandem mass spectrometry (ED-LC-MS/MS) method for serum free estradiol. Two hundred fifty microliter aliquots of serum were dialyzed for 22h followed by liquid-liquid extraction and derivatization with dansyl chloride. Free estradiol was measured using LC-MS/MS with an AB SCIEX 5500 mass spectrometer in positive ion and multiple reaction monitoring (MRM) mode. The limits of detection and quantification for free estradiol were 0.25 and 0.5pg/ml (0.9 and 1.8pmol/l) respectively. Total imprecision was less than 10%. Results of method comparison showed 3 times overestimation using indirect methods of measurement. Reference intervals in pre-menopausal women in follicular, mid-cycle, and luteal phases of cycle were <2.4, <3.1 and <2.6pg/ml (8.8, 11.4, 9.5pmol/l) respectively; in post menopausal women the concentrations were ≤0.5pg/ml (1.8pmol/l). ED-LC-MS/MS is a direct method for accurately measuring free estradiol, independent of total estradiol or sex hormone binding globulin concentrations. Imprecision and sensitivity of the method are adequate for clinical diagnostic applications. The degree of variation observed in the method comparison reinforces the relevance of method specific reference ranges. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. 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.

    Science.gov (United States)

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

    2015-04-15

    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 various recipes and baking conditions. Information-rich mass spectral fingerprints were obtained by analysis of biscuit extracts for preparation of which aqueous methanol was used. The principal component analysis (PCA) of the acquired data revealed an apparent clustering of samples according to the extent of heat-treatment applied during the baking of the biscuits. The regression model for prediction of acrylamide in biscuits was obtained by partial least square regression (PLSR) analysis of the data matrix representing combined positive and negative ionization mode fingerprints. The model provided a least root mean square error of cross validation (RMSECV) equal to an acrylamide concentration of 5.4 μg kg(-1) and standard error of prediction (SEP) of 14.8 μg kg(-1). The results obtained indicate that this strategy can be used to accurately predict the amounts of acrylamide formed during baking of biscuits. Such rapid estimation of acrylamide concentration can become a useful tool in evaluation of the effectivity of processes aiming at mitigation of this food processing contaminant. However, the robustness this approach with respect to variability in the chemical composition of ingredients used for preparation of biscuits should be tested further. Copyright © 2014. Published by Elsevier Ltd.

  15. 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.

  16. A Direct Measurement of the High-Mass End of the Velocity Dispersion Function at z~0.55 from SDSS-III/BOSS

    CERN Document Server

    Montero-Dorta, Antonio D; Shu, Yiping

    2016-01-01

    We report the first direct spectroscopic measurement of the velocity dispersion function (VDF) for the high-mass red sequence (RS) galaxy population at redshift $z \\sim 0.55$. We achieve high precision by using a sample of 600,000 massive galaxies with spectra from the Baryon Oscillation Spectroscopic Survey (BOSS) of the third Sloan Digital Sky Survey (SDSS-III), covering stellar masses $M_* \\gtrsim 10^{11} M_{\\odot}$. We determine the VDF by projecting the joint probability-density function (PDF) of luminosity $L$ and velocity dispersion $\\sigma$, i.e. $p(L, \\sigma)$, defined by our previous measurements of the RS luminosity function (LF) and $L-\\sigma$ relation for this sample. These measurements were corrected from red--blue galaxy population confusion, photometric blurring, incompleteness and selection effects within a forward-modeling framework that furthermore correctly accommodates the low spectroscopic signal-to-noise ratio of the individual BOSS spectra. The $z\\sim0.55$ RS VDF is in agreement with t...

  17. Direct detection of exoplanet host star companion gamma Cep B and revised masses for both stars and the sub-stellar object

    CERN Document Server

    Neuhäuser, R; Fukagawa, M; Torres, G; Schmidt, T; Neuhaeuser, Ralph; Mugrauer, Markus; Fukagawa, Misato; Torres, Guillermo; Schmidt, Tobias

    2006-01-01

    The star gamma Cep is known as a single-lined spectroscopic triple system at a distance of 13.8 pc, composed of a K1 III-IV primary star with V = 3.2 mag, a stellar-mass companion in a 66--67 year orbit (Torres 2006), and a substellar companion with M_p sin i = 1.7 M_Jup that is most likely a planet (Hatzes et al. 2003). We aim to obtain a first direct detection of the stellar companion, to determine its current orbital position (for comparison with the spectroscopic and astrometric data), its infrared magnitude and, hence, mass. We use the Adaptive Optics camera CIAO at the Japanese 8m telescope Subaru on Mauna Kea, Hawaii, with the semi-transparent coronograph to block most of the light from the bright primary gamma Cep A, and to detect at the same time the faint companion B. In addition, we also used the IR camera Omega-Cass at the Calar Alto 3.5m telescope, Spain, to image gamma Cep A and B by adding up many very short integrations (without AO). gamma Cep B is clearly detected on our CIAO and Omega-Cass i...

  18. 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

    2017-07-31

    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.

  19. Profiling and classification of French propolis by combined multivariate data analysis of planar chromatograms and scanning direct analysis in real time mass spectra.

    Science.gov (United States)

    Chasset, Thibaut; Häbe, Tim T; Ristivojevic, Petar; Morlock, Gertrud E

    2016-09-23

    Quality control of propolis is challenging, as it is a complex natural mixture of compounds, and thus, very difficult to analyze and standardize. Shown on the example of 30 French propolis samples, a strategy for an improved quality control was demonstrated in which high-performance thin-layer chromatography (HPTLC) fingerprints were evaluated in combination with selected mass signals obtained by desorption-based scanning mass spectrometry (MS). The French propolis sample extracts were separated by a newly developed reversed phase (RP)-HPTLC method. The fingerprints obtained by two different detection modes, i.e. after (1) derivatization and fluorescence detection (FLD) at UV 366nm and (2) scanning direct analysis in real time (DART)-MS, were analyzed by multivariate data analysis. Thus, RP-HPTLC-FLD and RP-HPTLC-DART-MS fingerprints were explored and the best classification was obtained using both methods in combination with pattern recognition techniques, such as principal component analysis. All investigated French propolis samples were divided in two types and characteristic patterns were observed. Phenolic compounds such as caffeic acid, p-coumaric acid, chrysin, pinobanksin, pinobanksin-3-acetate, galangin, kaempferol, tectochrysin and pinocembrin were identified as characteristic marker compounds of French propolis samples. This study expanded the research on the European poplar type of propolis and confirmed the presence of two botanically different types of propolis, known as the blue and orange types. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Distinguishing between the metabolome and xenobiotic exposome in environmental field samples analysed by direct-infusion mass spectrometry based metabolomics and lipidomics.

    Science.gov (United States)

    Southam, Andrew D; Lange, Anke; Al-Salhi, Raghad; Hill, Elizabeth M; Tyler, Charles R; Viant, Mark R

    2014-01-01

    Environmental metabolomics is increasingly used to investigate organismal responses to complex chemical mixtures, including waste water effluent (WWE). In parallel, increasingly sensitive analytical methods are being used in metabolomics studies, particularly mass spectrometry. This introduces a considerable, yet overlooked, challenge that high analytical sensitivity will not only improve the detection of endogenous metabolites in biological specimens but also exogenous chemicals. If these often unknown xenobiotic features are not removed from the "biological" dataset, they will bias the interpretation and could lead to incorrect conclusions about the biotic response. Here we illustrate and validate a novel workflow classifying the origin of peaks detected in biological samples as: endogenous, xenobiotics, or metabolised xenobiotics. The workflow is demonstrated using direct infusion mass spectrometry-based metabolomic analysis of testes from roach exposed to different concentrations of a complex WWE. We show that xenobiotics and their metabolic products can be detected in roach testes (including triclosan, chloroxylenol and chlorophene), and that these compounds have a disproportionately high level of statistical significance within the total (bio)chemical changes induced by the WWE. Overall we have demonstrated that this workflow extracts more information from an environmental metabolomics study of complex mixture exposures than was possible previously.

  1. Neutrino Masses

    CERN Document Server

    Weinheimer, Christian

    2013-01-01

    The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double $\\beta$-decay and the direct neutrino mass search by investigating single $\\beta$-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments with different techniques are being constructed, commissioned or are even running, which aim for a sensitivity on the neutrino ...

  2. Rapid detection by direct analysis in real time-mass spectrometry (DART-MS) of psychoactive plant drugs of abuse: the case of Mitragyna speciosa aka "Kratom".

    Science.gov (United States)

    Lesiak, Ashton D; Cody, Robert B; Dane, A John; Musah, Rabi A

    2014-09-01

    Mitragyna speciosa, also known commonly as "Kratom" or "Ketum", is a plant with psychoactive properties that have been attributed to the presence of various indole alkaloids such as mitragynine and 7-hydroxymitragynine. M. speciosa use is gaining popularity internationally as a natural and legal alternative to narcotics. As a drug of abuse, its detection and identification are not straightforward, since M. speciosa plant material is not particularly distinctive. Here, we show that direct analysis in real time-mass spectrometry (DART-MS) can be used not only to rapidly identify M. speciosa plant material and distinguish it from other plants, but also to distinguish between M. speciosa plant varieties, based on differences between their chemical profiles. The method is rapid and the analysis expeditious. Plant material such as that found at a crime scene can be analyzed directly with no sample pre-preparation steps. Furthermore, we show that the basis set of principal components that permit characterization of the plant material can be used to positively identify M. speciosa.

  3. Rapid screening for the adulterants of Berberis aristata using direct analysis in real-time mass spectrometry and principal component analysis for discrimination.

    Science.gov (United States)

    Bajpai, Vikas; Singh, Awantika; Arya, Kamal Ram; Srivastava, Mukesh; Kumar, Brijesh

    2015-01-01

    Adulteration or substitution of commercial Berberis aristata and its herbal products with inferior-quality substituents is very common. Metabolic profiling of B. aristata, along with its common adulterants/contaminants/substituents such as B. asiatica, Mahonia borealis and Coscinium fenestratum, was rapidly carried out using direct analysis in real-time mass spectrometry (DART MS) to generate the chemical fingerprints for the differentiation of these species. Phytochemical analysis showed the presence of mainly alkaloids. The identified alkaloids were berberrubine, berberine, jatrorrhizine, ketoberberine, palmatine, dihydropalmatine or 7,8-dihydro-8-hydroxyberberine, berbamine and pakistanamine. Berberine, which was mainly reported from the root and stem bark of B. aristata, was also identified in the leaf along with chlorogenic acid. The DART MS data have been subjected to principal component analysis (PCA). The resulting score plots showed clustering and clear differentiation of the species and plant parts. It is thus apparent that the technique of DART MS followed by PCA is a quick and reliable method for the direct profiling of B. aristata and its adulterant plants and plant parts. The study reports the rapid analytical method to identify the possibility of illegal adulteration/contamination/substitution in potential plant materials and herbal extracts.

  4. Direct Imaging Mass Spectrometry of Plant Leaves Using Surface-assisted Laser Desorption/Ionization with Sputter-deposited Platinum Film.

    Science.gov (United States)

    Ozawa, Tomoyuki; Osaka, Issey; Hamada, Satoshi; Murakami, Tatsuya; Miyazato, Akio; Kawasaki, Hideya; Arakawa, Ryuichi

    2016-01-01

    Plant leaves administered with systemic insecticides as agricultural chemicals were analyzed using imaging mass spectrometry (IMS). Matrix-assisted laser desorption/ionization (MALDI) is inadequate for the detection of insecticides on leaves because of the charge-up effect that occurs on the non-conductive surface of the leaves. In this study, surface-assisted laser desorption/ionization with a sputter-deposited platinum film (Pt-SALDI) was used for direct analysis of chemicals in plant leaves. Sputter-deposited platinum (Pt) films were prepared on leaves administered with the insecticides. A sputter-deposited Pt film with porous structure was used as the matrix for Pt-SALDI. Acephate and acetamiprid contained in the insecticides on the leaves could be detected using Pt-SALDI-MS, but these chemical components could not be adequately detected using MALDI-MS because of the charge-up effect. Enhancement of ion yields for the insecticides was achieved using Pt-SALDI, accompanied by prevention of the charge-up effect by the conductive Pt film. The movement of systemic insecticides in plants could be observed clearly using Pt-SALDI-IMS. The distribution and movement of components of systemic insecticides on leaves could be analyzed directly using Pt-SALDI-IMS. Additionally, changes in the properties of the chemicals with time, as an indicator of the permeability of the insecticides, could be evaluated.

  5. 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.

  6. Solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the direct determination of Hg in different materials using isotope dilution with a gaseous phase for calibration

    Science.gov (United States)

    Resano, M.; Gelaude, I.; Dams, R.; Vanhaecke, F.

    2005-03-01

    This paper evaluates the potential of electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICPMS) for the direct determination of Hg in solid samples, using a 200Hg-enriched gaseous phase for calibration based on isotope dilution. Three different samples were studied, BCR CRM 320 River sediment, IAEA-086 Hair and a real (wet) freshwater fish sample (M1). The samples selected show important differences in their matrix composition, and especially the fish sample constitutes a challenge as a result of its high water content (≈80%). The main conclusion of the work is that the calibration approach investigated succesfully corrects for all the matrix effects (suppression) observed during Hg vaporization, allowing accurate values to be obtained in all cases. Moreover, practically the same operating conditions could be used for all sample types. The method finally proposed presents interesting features for the direct determination of this challenging element in solid samples, such as: a low sample consumption (a few milligrams), a high sample throughput (10 min/sample), a low limit of detection (6 ng g -1) and a reduced risk of analyte losses or contamination. Precision values depend on the homogeneity of the sample studied, and are typically in the vicinity of 10% RSD, except for the more inhomogenous river sediment (18% RSD).

  7. On-line coupling of macroporous resin column chromatography with direct analysis in real time mass spectrometry utilizing a surface flowing mode sample holder.

    Science.gov (United States)

    Zeng, Shanshan; Wang, Lu; Chen, Teng; Qu, Haibin

    2014-02-06

    A surface flowing mode sample holder was designed as an alternative sampling strategy for direct analysis in real time mass spectrometry (DART-MS). With the sample holder, the on-line coupling of macroporous resin column chromatography with DART-MS was explored and the new system was employed to monitor the column chromatography elution process of Panax notoginseng. The effluent from macroporous resin column was first diluted and mixed with a derivatization reagent on-line, and the mixture was then directly transferred into the ionization region of DART-MS by the sample holder. Notoginsenosides were methylated and ionized in a metastable helium gas stream, and was introduced into MS for detection. The on-line system showed reasonable repeatability with a relative standard deviation of 12.3% for the peak area. Three notoginsenosides, i.e. notoginsenoside R1, ginsenoside Rb1 and ginsenoside Rg1, were simultaneously determined during the eluting process. The alteration of the chemical composition in the effluent was accurately identified in 9 min, agreeing well with the off-line analysis. The presented technique is more convenient compared to the traditional UPLC method. These results suggest that the surface flowing mode DART-MS has a good potential for the on-line process monitoring in the pharmaceutical industry.

  8. 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

  9. Direct shear strength model of rock mass with coplanar intermittent joints%共面断续节理岩体直剪强度特性模型

    Institute of Scientific and Technical Information of China (English)

    胡波; 王思敬; 刘晓丽

    2012-01-01

    采用理论分析和模型试验相结合方法,对共面闭合断续节理岩体直剪强度特性进行分析和研究.引入法向变形协调条件,基于Mohr-Coulomb理论,推导共面断续节理岩体模型的直剪强度公式.模型试验表明:全应力-应变曲线主要经历了线弹性增长、节理面错动、次生裂纹起裂稳态扩展、节理面贯通破坏和残余强度5个阶段;剪切应力峰值和残余强度都随正应力的增大而增大,而变形特性随正应力的变化规律性不强;抗剪峰值强度随节理连通率的增大而减小,低连通率时强度下降速度慢;节理分布形态对强度也有影响,节理在两边分布的试样强度普遍高于节理在中间的;理论计算结果与试验值吻合较好,能较好描述共面断续节理岩体的直剪强度特征.%According to theoretical analysis and model test, the direct shear strength behavior of rock mass with coplanar close intermittent joints was investigated. Through introducing deformation compatibility equation at normal direction, the direct shear strength formulation was deduced based on the Mohr-Coulomb theory. According to the complete stress strain curve obtained from model tests, there are five typical stages in the failure process with linear elastic increment, slippage of the joints, steady development of post-cracking, the coalescence failure of discontinuous joints and the residual strength. The peak and residual strength are increased by the increase of normal stress with poor relationship between deformation property and normal stress. The peak strength decreases with the increase of the joint connectivity rate, and the drop velocity is slow at low connectivity rate. The joint distribution has influence on the strength of rock mass, and the strength of model with joints on edge is bigger than that of the model with joints in the middle. The theoretical calculation results are in good consistency with experimental results to give

  10. Sensitivity of a direct computer-aided detection system in full-field digital mammography for detection of microcalcifications not associated with mass or architectural distortion.

    Science.gov (United States)

    Scaranelo, Anabel M; Crystal, Pavel; Bukhanov, Karina; Helbich, Thomas H

    2010-06-01

    The purpose of this study was to evaluate the sensitivity of a direct computer-aided detection (CAD) system (d-CAD) in full-field digital mammography (FFDM) for the detection of microcalcifications not associated with mass or architectural distortion. A database search of 1063 consecutive stereotactic core biopsies performed between 2002 and 2005 identified 196 patients with Breast Imaging-Reporting and Data System (BI-RADS) 4 and 5 microcalcifications not associated with mass or distortion detected exclusively by bilateral FFDM. A commercially available CAD system (Second Look, version 7.2) was retrospectively applied to the craniocaudal and mediolateral oblique views in these patients (mean age, 59 years; range, 35-84 years). Breast density, location and mammographic size of the lesion, distribution, and tumour histology were recorded and analysed by using chi(2), Fisher exact, or McNemar tests, when applicable. When using d-CAD, 71 of 74 malignant microcalcification cases (96%) and 101 of 122 benign microcalcifications (83%) were identified. There was a significant difference (P < .05) between CAD sensitivity on the craniocaudal view, 91% (68 of 75), vs CAD sensitivity on the mediolateral oblique view, 80% (60 of 75). The d-CAD sensitivity for dense breast tissue (American College of Radiology [ACR] density 3 and 4) was higher (97%) than d-CAD sensitivity (95%) for nondense tissue (ACR density 1 and 2), but the difference was not statically significant. All 28 malignant calcifications larger than 10 mm were detected by CAD, whereas the sensitivity for lesions small than or equal to 10 mm was 94%. D-CAD had a high sensitivity in the depiction of asymptomatic breast cancers, which were seen as microcalcifications on FFDM screening, with a sensitivity of d-CAD on the craniocaudal view being significantly better. All malignant microcalcifications larger than 10 mm were detected by d-CAD. Copyright 2010 Canadian Association of Radiologists. Published by Elsevier Inc

  11. Direct and efficient liquid chromatographic-tandem mass spectrometric method for opiates in urine drug testing - importance of 6-acetylmorphine and reduction of analytes.

    Science.gov (United States)

    Andersson, Maria; Stephanson, Nikolai; Ohman, Inger; Terzuoli, Tommy; Lindh, Jonatan D; Beck, Olof

    2014-04-01

    Opiates comprise a class of abused drugs that is of primary interest in clinical and forensic urine drug testing. Determination of heroin, codeine, or a multi-drug ingestion is complicated since both heroin and codeine can lead to urinary excretion of free and conjugated morphine. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers advantage over gas chromatography-mass spectrometry by simplifying sample preparation but increases the number of analytes. A method based on direct injection of five-fold diluted urine for confirmation of morphine, morphine-3-glucuronide, morphine-6-glucuronide, codeine, codeine-6-glucuronide and 6-acetylmorphine was validated using LC-MS/MS in positive electrospray mode monitoring two transitions using selected reaction monitoring. The method was applied for the analysis of 3155 unknown urine samples which were positive for opiates in immunochemical screening. A linear response was observed for all compounds in the calibration curves covering more than three orders of magnitude. Cut off was set to 2 ng/ml for 6-acetylmorphine and 150 ng/ml for the other analytes. 6-Acetylmorphine was found to be effective (sensitivity 82%) in detecting samples as heroin intake. Morphine-3-glucuronide and codeine-6-glucuronide was the predominant components of total morphine and codeine, 84% and 93%, respectively. The authors have validated a robust LC-MS/MS method for rapid qualitative and quantitative analysis of opiates in urine. 6-Acetylmorphine has been demonstrated as a sensitive and important parameter for a heroin intake. A possible interpretation strategy to conclude the source of detected analytes was proposed. The method might be further developed by reducing the number of analytes to morphine-3-glucuronide, codeine-6-glucuronide and 6-acetylmorphine without compromising test performance.

  12. Mass Spectrometry for Profiling LOS and Lipid A Structures from Whole-Cell Lysates: Directly from a Few Bacterial Colonies or from Liquid Broth Cultures.

    Science.gov (United States)

    Kocsis, Béla; Kilár, Anikó; Péter, Szandra; Dörnyei, Ágnes; Sándor, Viktor; Kilár, Ferenc

    2017-01-01

    Lipopolysaccharides (LPSs, endotoxins) are components of the outer cell membrane of most Gram-negative bacteria and can play an important role in a number of diseases of bacteria, including Gram-negative sepsis. The hydrophilic carbohydrate part of LPSs consists of a core oligosaccharide (in the case of an R-type LPS or lipooligosaccharide, LOS) linked to an O-polysaccharide chain (in the case of an S-type LPS), which is responsible for O-specific immunogenicity. The hydrophobic lipid A anchor is composed of a phosphorylated diglucosamine backbone to which varying numbers of ester- and amide-linked fatty acids are attached and this part of the LPSs is associated with endotoxicity. The detailed chemical characterization of endotoxins requires long-lasting large-scale isolation procedures, by which high-purity LPSs can be obtained. However, when a large number of bacterial samples and their LPS content are to be compared prompt, small-scale isolation methods are used for the preparation of endotoxins directly from bacterial cell cultures. The purity of the endotoxins extracted by these methods may not be high, but it is sufficient for analysis.Here, we describe a fast and easy micromethod suitable for extracting small quantities of LOS and a slightly modified micromethod for the detection of the lipid A constituents of the LPSs from bacteria grown in different culture media and evaluate the structures with mass spectrometry. The cellular LOS and lipid A were obtained from crude isolates of heat-killed cells, which were then subjected to matrix-assisted laser desorption/ionization mass spectrometry analysis. The observed ions in the 10-colony samples were similar to those detected for purified samples. The total time for the sample preparation and the MS analysis is less than 3 h.

  13. Rapid on-site detection of explosives on surfaces by ambient pressure laser desorption and direct inlet single photon ionization or chemical ionization mass spectrometry.

    Science.gov (United States)

    Ehlert, S; Hölzer, J; Rittgen, J; Pütz, M; Schulte-Ladbeck, R; Zimmermann, R

    2013-09-01

    Considering current security issues, powerful tools for detection of security-relevant substances such as traces of explosives and drugs/drug precursors related to clandestine laboratories are required. Especially in the field of detection of explosives and improvised explosive devices, several relevant compounds exhibit a very low vapor pressure. Ambient pressure laser desorption is proposed to make these substances available in the gas phase for the detection by adapted mass spectrometers or in the future with ion-mobility spectrometry as well. In contrast to the state-of-the-art thermal desorption approach, by which the sample surface is probed for explosive traces by a wipe pad being transferred to a thermal desorber unit, by the ambient pressure laser desorption approach presented here, the sample is directly shockwave ablated from the surface. The laser-dispersed molecules are sampled by a heated sniffing capillary located in the vicinity of the ablation spot into the mass analyzer. This approach has the advantage that the target molecules are dispersed more gently than in a thermal desorber unit where the analyte molecules may be decomposed by the thermal intake. In the technical realization, the sampling capillary as well as the laser desorption optics are integrated in the tip of an endoscopic probe or a handheld sampling module. Laboratory as well as field test scenarios were performed, partially in cooperation with the Federal Criminal Police Office (Bundeskriminalamt, BKA, Wiesbaden, Germany), in order to demonstrate the applicability for various explosives, drugs, and drug precursors. In this work, we concentrate on the detection of explosives. A wide range of samples and matrices have been investigated successfully.

  14. 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.

  15. Comparison of direct infusion and on-line liquid chromatography/electrospray ionization mass spectrometry for the analysis of nucleic acids.

    Science.gov (United States)

    Huber, C G; Krajete, A

    2000-07-01

    The applicability of ion-pair reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (IP-RP-HPLC/ESI-MS) and direct infusion/ESI-MS to the characterization of nucleic acid mixtures was evaluated by the analysis of the reaction products obtained from solid-phase synthesis of a 39-mer oligonucleotide. IP-RP-HPLC/ESI-MS was performed using 200 microm i.d. capillary columns packed with octadecylated, micropellicular poly(styrene-divinylbenzene) particles and applying gradients of acetonitrile in 50 mM triethylammonium bicarbonate (TEAB). Three different solvent systems were utilized for direct infusion/ESI-MS with removal of metal cations by on-line cation exchange: (1) 10 mM triethylamine (TEA) in 50% aqueous acetonitrile, (2) 2.2 mM TEA, 400 mM hexafluoro-2-propanol (HFIP) in 20% aqueous methanol and (3) 50 mM TEAB in 10% aqueous acetonitrile. Owing to its separation capability, the highest selectivity and specificity were achieved with IP-RP-HPLC/ESI-MS, which, apart form the 39-mer target sequence, allowed the identification of two isobutyryl-protected target sequences and a 10-mer and 20-mer failure sequence. Direct infusion/ESI-MS with TEA-acetonitrile or TEA-HFIP-methanol as solvent revealed signals for the 39-mer in the m/z range 700-1600. The presence of derivatives containing one, two, three and four isobutyryl groups indicated that the hydrolysis of the protecting groups after solid-phase synthesis was not complete. Failure sequences could not be identified by direct infusion/ESI-MS under conditions favoring multiple charging of the analytes owing to the high chemical background and coincidental overlapping of m/z signals. However, efficient charge state reduction upon addition of carbonic acid to the electrosprayed solvent shifted the signals of the 39-mer and derivatives to m/z values >2400 and allowed the detection of seven different failure sequences, ranging from the 8-mer to the 23-mer, in the mixture.

  16. Coal liquefaction process streams characterization and evaluation: The application of {sup 252}Cf-plasma desorption mass spectrometry to analysis of direct coal liquefaction heavy products

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, J.W.; Lapucha, A.R.

    1992-10-01

    This study demonstrated the feasibility of using {sup 252}Cf PDMS, GPC, and MPLC for the examination of the tetrahydrofuran (THF)-soluble portion of distillation resid materials derived from direct coal liquefaction. The {sup 252}Cf-PDMS technique was used to determine molecular weight distributions of twenty-five THF-soluble resids. In order to detemine if {sup 252}Cf-PDMS responds differently to different chemical classes of compounds, Lehigh separated five of the samples into chemically distinct fractions by MPLC, then analyzed the parent samples, their fractions, and the re-mixed fractions by {sup 252}Cf-PDMS and GPC. Irreversible alteration of the samples upon separation was noted by Lehigh. This was confirmed by use of gas chromatographic (GC) analyses. The noted irreversible alterations prevented a direct comparison of the remixed materials and the original samples. Thus, the selective response of {sup 252}Cf-PDMS to different chemical classes of compounds could not be confirmed or ruled out. The number average molecular weights (M{sub n}) obtained by {sup 252}Cf-PDMS and GPC agreed well. However, the weight average molecular weights (M{sub w}) obtained by GPC are always higher than the corresponding {sup 252}Cf-PDMS results. Number average molecular weights and weight average molecular weights obtained with {sup 252}Cf-PDMS and GPC were compared with those obtained by field ionization mass spectrometry (FIMS), previously reported by SRI International for the parent resid samples from which the Lehigh THF-soluble samples were derived.

  17. Coal liquefaction process streams characterization and evaluation: The application of [sup 252]Cf-plasma desorption mass spectrometry to analysis of direct coal liquefaction heavy products

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, J.W.; Lapucha, A.R.

    1992-10-01

    This study demonstrated the feasibility of using [sup 252]Cf PDMS, GPC, and MPLC for the examination of the tetrahydrofuran (THF)-soluble portion of distillation resid materials derived from direct coal liquefaction. The [sup 252]Cf-PDMS technique was used to determine molecular weight distributions of twenty-five THF-soluble resids. In order to detemine if [sup 252]Cf-PDMS responds differently to different chemical classes of compounds, Lehigh separated five of the samples into chemically distinct fractions by MPLC, then analyzed the parent samples, their fractions, and the re-mixed fractions by [sup 252]Cf-PDMS and GPC. Irreversible alteration of the samples upon separation was noted by Lehigh. This was confirmed by use of gas chromatographic (GC) analyses. The noted irreversible alterations prevented a direct comparison of the remixed materials and the original samples. Thus, the selective response of [sup 252]Cf-PDMS to different chemical classes of compounds could not be confirmed or ruled out. The number average molecular weights (M[sub n]) obtained by [sup 252]Cf-PDMS and GPC agreed well. However, the weight average molecular weights (M[sub w]) obtained by GPC are always higher than the corresponding [sup 252]Cf-PDMS results. Number average molecular weights and weight average molecular weights obtained with [sup 252]Cf-PDMS and GPC were compared with those obtained by field ionization mass spectrometry (FIMS), previously reported by SRI International for the parent resid samples from which the Lehigh THF-soluble samples were derived.

  18. 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.

  19. Analysis of iodinated haloacetic acids in drinking water by reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry with large volume direct aqueous injection.

    Science.gov (United States)

    Li, Yongtao; Whitaker, Joshua S; McCarty, Christina L

    2012-07-01

    A large volume direct aqueous injection method was developed for the analysis of iodinated haloacetic acids in drinking water by using reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry in the negative ion mode. Both the external and internal standard calibration methods were studied for the analysis of monoiodoacetic acid, chloroiodoacetic acid, bromoiodoacetic acid, and diiodoacetic acid in drinking water. The use of a divert valve technique for the mobile phase solvent delay, along with isotopically labeled analogs used as internal standards, effectively reduced and compensated for the ionization suppression typically caused by coexisting common inorganic anions. Under the optimized method conditions, the mean absolute and relative recoveries resulting from the replicate fortified deionized water and chlorinated drinking water analyses were 83-107% with a relative standard deviation of 0.7-11.7% and 84-111% with a relative standard deviation of 0.8-12.1%, respectively. The method detection limits resulting from the external and internal standard calibrations, based on seven fortified deionized water replicates, were 0.7-2.3 ng/L and 0.5-1.9 ng/L, respectively.

  20. Reduction of aflatoxin B1 during tortilla production and identification of degradation by-products by direct-injection electrospray mass spectrometry

    Directory of Open Access Journals (Sweden)

    Abigail Moreno-Pedraza

    2015-01-01

    Full Text Available Objective. To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1 during the tortilla making process as well as the degradative molecules generated. Materials and methods. Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degradative products were analyzed by direct injection electrospray mass spectometry (DIESI-MS. Results. The alkaline pH of the maize-dough after nixtamalización between 10.2, and 30-40 minutes of resting at room temperature allows the 100% reduction of AFB1. DIESI-MS analysis of the extracts indicated the presence of two degradation molecules from AFB1. Conclusion. The alkaline pH of maize-dough and resting time are the principal factors involved in diminishing AFB1 levels in tortillas. A procedure to the tortilla making process is proposed, which allows the reduction of remnant AFB1, avoiding the accumulative effect over consumers.

  1. 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.

  2. 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.

  3. Direct analysis in real time-mass spectrometry (DART-MS) for rapid qualitative screening of toxic glycols in glycerin-containing products.

    Science.gov (United States)

    Self, Randy L

    2013-06-01

    In 2007, the United States Food and Drug Administration released guidance recommending testing of glycerin used in regulated consumer products, such as cough syrup preparations, toothpaste, and other pharmaceutical and food products, for the toxic compounds ethylene glycol and diethylene glycol. Regulatory laboratories routinely test glycerin, and products containing glycerin or related compounds for these toxic glycols, using an official gas chromatographic method, to ensure the safety of these products. The current work describes a companion technique to compliment this GC-FID method utilizing Orbitrap mass spectrometry with direct analysis in real time ionization to rapidly screen these samples qualitatively, with results in as little as five seconds, with no sample preparation required. This allows the more time and resource intensive method to be reserved for those rare cases when these compounds are detected, potentially greatly improving laboratory efficiency. The technique was evaluated for qualitative sensitivity and repeatability, and compared against the GC-FID method. The method appears to perform well against these metrics.

  4. 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...

  5. Combined multivariate data analysis of high-performance thin-layer chromatography fingerprints and direct analysis in real time mass spectra for profiling of natural products like propolis.

    Science.gov (United States)

    Morlock, Gertrud E; Ristivojevic, Petar; Chernetsova, Elena S

    2014-02-07

    Sophisticated statistical tools are required to extract the full analytical power from high-performance thin-layer chromatography (HPTLC). Especially, the combination of HPTLC fingerprints (image) with chemometrics is rarely used so far. Also, the newly developed, instantaneous direct analysis in real time mass spectrometry (DART-MS) method is perspective for sample characterization and differentiation by multivariate data analysis. This is a first novel study on the differentiation of natural products using a combination of fast fingerprint techniques, like HPTLC and DART-MS, for multivariate data analysis. The results obtained by the chemometric evaluation of HPTLC and DART-MS data provided complementary information. The complexity, expense, and analysis time were significantly reduced due to the use of statistical tools for evaluation of fingerprints. The approach allowed categorizing 91 propolis samples from Germany and other locations based on their phenolic compound profile. A high level of confidence was obtained when combining orthogonal approaches (HPTLC and DART-MS) for ultrafast sample characterization. HPTLC with selective post-chromatographic derivatization provided information on polarity, functional groups and spectral properties of marker compounds, while information on possible elemental formulae of principal components (phenolic markers) was obtained by DART-MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Direct coupling of thin-layer chromatography-bioautography with electrostatic field induced spray ionization-mass spectrometry for separation and identification of lipase inhibitors in lotus leaves.

    Science.gov (United States)

    Zhang, Lei; Shi, Jiyao; Tang, Jihe; Cheng, Zhihong; Lu, Xiaohui; Kong, Yao; Wu, Tao

    2017-05-15

    In situ profiling compounds in complex matrices is important technology to develop in analytic chemistry. The aim of this study is to develop a direct coupling method of thin layer chromatography (TLC) to mass spectrometry (MS) via electrostatic field induced spray ionization (EFISI). We proposed a surface treatment method of normal-phase thin layer chromatography (TLC) plates with dimethyl silicone oil coating which successfully allowed TLC to couple to MS via EFISI. Different parameters affecting the ionization efficiency were investigated and optimized, including silicone oil concentrations, air-drying times, applied voltages, and TLC plate types. This optimized TLC-EFISI-MS method was successfully applied to examine lipase inhibitory components present in lotus leaves. Six active alkaloids including three aporphines and three benzylisoquinolines were profiled with their MS(n) (n = 4) data, or with a comparison with reference substances. This is the first report on the coupling EFISI-MS to TLC or TLC bioautography for in situ identification of active natural products. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Direct identification of phenolic constituents in Boldo Folium (Peumus boldus Mol.) infusions by high-performance liquid chromatography with diode array detection and electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Simirgiotis, M J; Schmeda-Hirschmann, G

    2010-01-22

    A very simple and direct method was developed for the qualitative analysis of polyphenols in boldo (Peumus boldus Mol., Monimiaceae) leaves infusions by high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization tandem mass spectrometry (HPLC-MS(n)). The phenolic constituents identified in infusions of the crude drug Boldo Folium were mainly proanthocyanidins and flavonol glycosides. In the infusions, 41 compounds were detected in male and 43 compounds in female leaf samples, respectively. Nine quercetin glycosides, eight kaempferol derivatives, nine isorhamnetin glycosides, three phenolic acids, one caffeoylquinic acid glycoside and twenty one proanthocyanidins were identified by HPLC-DAD and ESI-MS for the first time in the crude drug. Isorhamnetin glucosyl-di-rhamnoside was the most abundant flavonol glycoside in the male boldo sample, whereas isorhamnetin di-glucosyl-di-rhamnoside was the main phenolic compound in female boldo leaves infusion. The results suggest that the medicinal properties reported for this popular infusion should be attributed not only to the presence of catechin and boldine but also to several phenolic compounds with known antioxidant activity. The HPLC fingerprint obtained can be useful in the authentication of the crude drug Boldo Folium as well as for qualitative analysis and differentiation of plant populations in the tree distribution range. Copyright 2009 Elsevier B.V. All rights reserved.

  8. 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.

  9. 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.

  10. 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.

  11. Gold upgrading in metamorphosed massive sulfide ore deposits: Direct evidence from laser-ablation-inductively coupled plasma-mass spectrometry analysis of invisible gold

    Science.gov (United States)

    Wagner, Thomas; Klemd, Reiner; Wenzel, Thomas; Mattsson, Benny

    2007-09-01

    The metamorphosed Boliden volcanic-hosted massive sulfide (VHMS) ore deposit, northern Sweden, is characterized by an abundance of massive arsenopyrite ore and unusually high gold enrichments (up to 300-600 g/t) in crosscutting veins and fracture zones. The ore textures observed record progressive recrystallization and porphyroblast growth during meta morphism. We conducted a systematic laser-ablation-inductively coupled plasma-mass spectrom etry (LA-ICP-MS) study on the gold distribution in fine-grained massive arseno-pyrite and pyrite ore, partially recrystallized arsenopyrite ore, and both arsenopyrite and pyrite porphyroblasts found in gold-rich veins. The gold concentrations in massive arseno-pyrite are highest (30-50 ppm on average) and systematically decrease to 0-2.7 ppm with increasing degree of recrystallization. By contrast, gold concentrations in pyrite ore are much lower and do not exceed 0.2 ppm. The LA-ICP-MS data, coupled with textural data, provide the first direct conclusive evidence that gold is progressively liberated from massive sulfide ores during metamorphism and reprecipitated in veins and other low-strain sites. We suggest that such upgrading is the principal mechanism responsible for significant gold enrichment observed in many metamorphosed VHMS deposits worldwide.

  12. 2-D numerical modeling and experimental investigation of electrochemical mechanisms coupled with heat and mass transfer in a planar direct carbon fuel cell

    Science.gov (United States)

    Elleuch, Amal; Sahraoui, Melik; Boussetta, Ahlem; Halouani, Kamel; Li, Yongdan

    2014-02-01

    A two-dimensional modeling of a lab-scale planar Direct Carbon Fuel Cell (DCFC) of 20 mm in diameter is developed by taking into account of the electrochemical mechanisms and mass and heat transfer phenomena in all regions of the cell simultaneously. The electrodes and the electrolyte of the DCFC are both considered as distinct regions with different local properties such as permeability, conductivity and diffusivity. An improved packed bed anodic structure with a finite thickness is also adopted. General boundary conditions are implemented by taking into consideration the species concentrations at the DCFC inlet such as oxygen concentration which is a very important parameter to determine the cell efficiency. The effects of the main operating parameters such as temperature, inlet gas flow velocity and porosity of the electrolyte matrix on the DCFC efficiency are investigated. A sensitivity analysis based on numerical simulations of the effects of cathode kinetic parameters and the anode specific surface area is also performed. Good agreement is obtained between numerical results and experimental data with an absolute average deviation of about 9%.

  13. Discriminating the indistinguishable sapwood from heartwood in discolored ancient wood by direct molecular mapping of specific extractives using time-of-flight secondary ion mass spectrometry.

    Science.gov (United States)

    Saito, Kaori; Mitsutani, Takumi; Imai, Takanori; Matsushita, Yasuyuki; Fukushima, Kazuhiko

    2008-03-01

    A new method that can chemically discriminate the visually indistinguishable sapwood from heartwood in discolored woods is presented in this paper. Discriminating between sapwood and heartwood, which are normally recognized by color in cross sections of stems of tress, is important in dendrochronological dating, as well as in evaluating qualities of woods such as durability. In tree-ring chronology, the felling date, which affects the construction date of architectures, can be estimated only in woods that have a recognizable sapwood/heartwood boundary. However, the felling date cannot be estimated in discolored woods because it has indistinguishable sapwood. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of specific chemical substances retained for approximately 1300 years after felling demonstrated the presence of sapwood in a discolored ancient architectural wood of Hinoki cypress (Chamaecyparis obtusa). Direct molecular mapping by TOF-SIMS clearly indicated that the specific substances, hinokinin, hinokiresinol, hinokione, and hinokiol, started to accumulate at the sapwood/heartwood boundary where only hinokinin was localized and retained predominantly in ray parenchyma cells. The result allowed the determination of the felling date of the discolored wood. TOF-SIMS has shown to be useful for investigating the distribution of minute amounts of chemical components in woods.

  14. Arabica and robusta coffees: identification of major polar compounds and quantification of blends by direct-infusion electrospray ionization-mass spectrometry.

    Science.gov (United States)

    Garrett, Rafael; Vaz, Boniek G; Hovell, Ana Maria C; Eberlin, Marcos N; Rezende, Claudia M

    2012-05-02

    Considering that illegal admixture of robusta coffee into high-quality arabica coffee is an important task in coffee analysis, we evaluated the use of direct-infusion electrospray ionization-mass spectrometry (ESI-MS) data combined with the partial least-squares (PLS) multivariate calibration technique as a fast way to detect and quantify arabica coffee adulterations by robusta coffee. A total of 16 PLS models were built using ESI± quadrupole time-of-flight (QTOF) and ESI± Fourier transform ion cyclotron resonance (FT-ICR) MS data from hot aqueous extracts of certified coffee samples. The model using the 30 more abundant ions detected by ES+ FT-ICR MS produced the most accurate coffee blend percentage prediction, and thus, it was later successfully employed to predict the blend composition of commercial robusta and arabica coffee. In addition, ESI± FT-ICR MS analysis allowed for the identification of 22 compounds in the arabica coffee and 20 compounds in the robusta coffee, mostly phenolics.

  15. Direct and sensitive determination of glyphosate and aminomethylphosphonic acid in environmental water samples by high performance liquid chromatography coupled to electrospray tandem mass spectrometry.

    Science.gov (United States)

    Guo, Hongyue; Riter, Leah S; Wujcik, Chad E; Armstrong, Daniel W

    2016-04-22

    A novel method based on high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) was developed for the sensitive determination of glyphosate and its major degradation product, AMPA in environmental water samples. The method involves the use of MS compatible mobile phases (0.1% formic acid in water and acetonitrile) for HPLC and direct analysis of water samples without sample derivatization. The method has been validated in different types of water matrices (drinking, surface and groundwater) by accuracy and precision studies with samples spiked at 0.1, 7.5 and 90 ppb. All mean accuracy values ranged from 85% to 112% for glyphosate and AMPA using both primary and secondary quantitative ion transitions (RSD ≤ 10%). Moreover, both primary and secondary ion transitions for glyphosate and AMPA can achieve the quantitation limits at 0.1 ppb. The linear dynamic range of the calibration curves were from 0.1 to 100 ppb for each analyte at each ion transitions with correlation coefficient higher than 0.997.

  16. Identification of in vivo nitrosylated phytochelatins in Arabidopsis thaliana cells by liquid chromatography-direct electrospray-linear ion trap-mass spectrometry.

    Science.gov (United States)

    Elviri, L; Speroni, F; Careri, M; Mangia, A; di Toppi, L Sanità; Zottini, M

    2010-06-18

    Reversed-phase liquid chromatography (RPLC) and electrospray (ESI)-linear ion trap (LIT) mass spectrometry was applied to the direct characterization of in vivo S-nitrosylated (SNO) phytochelatins (PCs) expressed in cadmium-stressed Arabidopsis thaliana cells. Cys-nitrosylation is under discussion as in vivo redox-based post-translational modification of proteins and peptides in plants in which the -NO group is involved as signal molecule in different biological functions. The gas-phase ion chemistry of in vivo and in vitro generated SNO-PC(s) was compared with the aim of evaluating NO binding stability and improving MS knowledge about peptide nitrosation. Using RPLC separation and ESI-LIT-MS, mono-nitrosylated PCs were identified in in vivo cadmium treated A. thaliana cells without derivatization. The in vivo binding of the NO group to PC(2), PC(3) and PC(4) resulted to occur selectively on only one cystein residue. The fragmentation pathway energies of the in vitro GSNO-generated NO-PCs with respect to the in vivo NO-PCs were investigated, suggesting the presence of a different internal stability for these molecules. By carrying out MS(2) experiments on these quasi-symmetric peptides, the different stability degree of the NO group was demonstrated to be correlated with the PC chain length. In addition, the data obtained highlight a putative role of the adjacent Glu/Cys motif in the gas-phase stability of the NO-containing molecule.

  17. Rapid and nondestructive analysis of phthalic acid esters in toys made of poly(vinyl chloride) by direct analysis in real time single-quadrupole mass spectrometry.

    Science.gov (United States)

    Rothenbacher, Thorsten; Schwack, Wolfgang

    2009-09-01

    In the European Community, selected phthalic acid esters (PAE) are restricted in their use for the manufacture of toys and childcare articles to a content of 0.1% by weight. As PAE are mainly used as plasticisers for poly(vinyl chloride) (PVC), a rapid screening method for PVC samples with direct analysis in real time ionisation and single-quadrupole mass spectrometry (DART-MS) was developed. Using the ions for the protonated molecules, a limit of detection (LOD) of 0.05% was obtained for benzyl butyl phthalate, bis(2-ethylhexyl) phthalate and diisononyl phthalate, while for dibutyl phthalate, di-n-octyl phthalate and diisodecyl phthalate the LOD was 0.1%. Validation of identification by the presence of ammonium adducts and characteristic fragment ions was possible to a content of >or=1% for all PAE, except for benzyl butyl phthalate (>or=5%). Based on the fragment ions, bis(2-ethylhexyl) phthalate could clearly be distinguished from di-n-octyl phthalate, if the concentrations were >r=5% and >or=1% at measured DART helium temperatures of 130 and 310 degrees C, respectively. The complete analysis of one sample only took about 8 min. At the generally used gas temperature of 130 degrees C, most toy and childcare samples did not sustain damage if their shape fitted into the DART source. Copyright (c) 2009 John Wiley & Sons, Ltd.

  18. 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.

  19. 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.

  20. 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.

  1. Determination of As, Cd, Pb, and Hg in urine using inductively coupled plasma mass spectrometry with the direct injection high efficiency nebulizer

    Science.gov (United States)

    Minnich, Michael G.; Miller, Derek C.; Parsons, Patrick J.

    2008-03-01

    The application of the large-bore direct injection high efficiency nebulizer (LB-DIHEN) for the determination of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine by inductively coupled plasma mass spectrometry (ICP-MS) is described. The LB-DIHEN is compared with the standard method using a concentric pneumatic nebulizer and cyclonic spray chamber. In addition to the toxicological significance of As, Cd, Pb, and Hg, these elements represent a cross-section of analytical issues including spectral interferences (e.g., 40Ar 35Cl + on 75As + and 98Mo 16O + on 114Cd +) and memory effects (Hg). In this study, the low sample consumption of the LB-DIHEN is used to reduce the volume of urine needed for analysis, and to reduce the volume of final diluted sample required for analysis. Eliminating the spray chamber and reducing the dead volume of the nebulizer reduces memory effects, especially for analytes such as Hg. The Dynamic Reaction Cell (DRC) is used in this study to attenuate the background level of ArCl + in spite of the increase in the solvent load and, in turn, the urine matrix (chloride) delivered to the plasma by the LB-DIHEN. This is the first report on coupling the LB-DIHEN to a standard autosampler for unattended sample analysis. The robustness of direct injection nebulization for routine analysis and the issues associated with automation of the sample introduction process are discussed. Although the figures of merit (sensitivity, limit of detection, and precision) determined for both nebulizers are slightly poorer for the LB-DIHEN than for the concentric pneumatic nebulizer, there is not a clinically significant difference between the results for both sample introduction systems. The accuracy of results is assessed using archived urine materials that are circulated by several different proficiency testing (PT) programs and external quality assessment schemes (EQAS). Results obtained using the LB-DIHEN were within the acceptable range

  2. Determination of Nilestriol in Fish by Coupling Direct Insertion Probe With Mass Spectrometer%直接进样质谱法检测鱼肉中尼尔雌醇

    Institute of Scientific and Technical Information of China (English)

    谢增瑞; 庞立新; 赵亚敏

    2004-01-01

    A method for determination of nilestriol in the fish by coupling direct insertion probe with mass spectrometer was established. When the fish be dewatered, nilestriol can be drawed with chloroform and the analysis can be made by coupling direct insertion probe with mass spectrometer as the primary temperature at 100℃ and maintains for 30s, then the temperation rised to 300℃ at the rate of 150℃ · min-1 and kept for 30s. The ratio of signal to noise(S/N) of nilestriol is 14 : 1 as the sample content is lng. The method issimple in operation and sensitive.

  3. National Difference in Intelligence: A Review of the Work of Lynn and Vanhanen%国民智商:有关智力国别差异的研究

    Institute of Scientific and Technical Information of China (English)

    Lynn R.; Vanhanen T; 周静; 谢天(译)

    2012-01-01

    国民智商是某国家或地区民众智商的平均值。RichardLynn与TatuVanhanen教授调查了近两百个国家,给出了全球的国民智商。他们发现,国民智商与国家经济、文化、政治,及国民健康等均呈正高度正相关,并以一个两阶因果模型解释该现象。%National Intelligence is the average intelligence in a country or region. Richard Lynn and Tatu Vanhanen surveyed almost 200 countries in the world, and reported the national intelligence differences in the world. They found that the national IQs correlated highly and positively with national economics, cultural, politics, and national health. They also proposed a two-stage causal model to account for these phenomena.

  4. Characterization of cigarette tobacco by direct electrospray ionization-ion trap mass spectrometry (ESI-ITMS) analysis of the aqueous extract--a novel and simple approach.

    Science.gov (United States)

    Ng, Lay-Keow; Lafontaine, Pierre; Vanier, Micheline

    2004-12-01

    In support of the efforts to combat smuggling, as well as illegal sale and distribution of cigarettes, an analytical approach for the characterization of tobacco has been proposed and evaluated. It involves aqueous extraction of the filler tobaccos followed by direct analysis of the extracts by electrospray ionization-ion trap mass spectrometry (ESI-ITMS) in the negative mode. Typically, the deprotonated ions, [M - H](-), of organic acids (malic, citric, caffeic, quinic acid) and polyphenols (chlorogenic acid, rutin, scopoletin) were detected. MS/MS spectra of the ion at m/z 191, which is the [M - H](-) of quinic acid, citric acid, and scopoletin, and a fragment ion of chlorogenic acid were acquired. Significant differences in the MS and MS/MS spectra were observed between counterfeit samples and the corresponding authentic brand name cigarettes. Analysis of 25 commercial cigarettes showed that straight Virginia blends were readily distinguished from the blended products containing different tobacco types (Virginia, burley, and Oriental). The former exhibited consistently higher relative abundances of m/z 353 (chlorogenic acid) to m/z 133 (malic acid) in the MS spectra (0.9-1.2 vs 0.4-0.6) and higher intensity ratios of m/z 176 (scopoletin) to m/z 173 (0.4-0.8 vs 0.1-0.3) and of m/z 127 (quinic acid) to m/z 173 (0.7-1.0 vs 0.3-0.5) in the MS/MS spectra. Evidence is presented to demonstrate that the spectral differences were related not only to the tobacco type (Virginia, burley and Oriental) but also to the tobacco part (stem, lamina) used in the manufacture of the cigarettes.

  5. Application of direct-fitting, mass-integral, and multi-ratemethods to analysis of flowing fluid electric conductivity logs fromHoronobe, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, C.; Tsang, C.-F.; Hatanaka, K.; Yabuuchi, S.; Kurikami, H.

    2007-08-01

    The flowing fluid electric conductivity (FFEC) loggingmethod is an efficient way to provide information on the depths,salinities, and transmissivities of individual conductive featuresintercepted by a borehole, without the use of specialized probes. Usingit in a multiple-flow-rate mode allows, in addition, an estimate of theinherent "far-field" pressure heads in each of the conductive features.The multi-rate method was successfully applied to a 500-m borehole in agranitic formation and reported recently. The present paper presents theapplication of the method to two zones within a 1000-m borehole insedimentary rock, which produced, for each zone, three sets of logs atdifferent pumping rates, each set measured over a period of about oneday. The data sets involve a number of complications, such as variablewell diameter, free water table decline in the well, and effects ofdrilling mud. To analyze data from this borehole, we apply varioustechniques that have been developed for analyzing FFEC logs:direct-fitting, mass-integral, and the multi-rate method mentioned above.In spite of complications associated with the tests, analysis of the datais able to identify 44 hydraulically conducting fractures distributedover the depth interval 150-775 meters below ground surface. Thesalinities (in FEC), and transmissivities and pressure heads (indimensionless form) of these 44 features are obtained and found to varysignificantly among one another. These results are compared with datafrom eight packer tests with packer intervals of 10-80 m, which wereconducted in this borehole over the same depth interval. They are foundto be consistent with these independent packer-test data, thusdemonstrating the robustness of the FFEC logging method under non-idealconditions.

  6. 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.

  7. Office Chromatography: Precise printing of sample solutions on miniaturized thin-layer phases and utilization for scanning Direct Analysis in Real Time mass spectrometry.

    Science.gov (United States)

    Häbe, Tim T; Morlock, Gertrud E

    2015-09-25

    Office Chromatography combines achievements in office technologies with miniaturized planar chromatography. In the life sciences, printing of materials became an accepted technique, whereas in separation science, the use of printers for chromatography is at its infancy. A bubble-jet printer was modified for exact application on miniaturized plates. Technical modifications included the removal of all unnecessary parts and the improvement of the positioning system, purge unit and sample supply system. Evaluation was performed via a slide scanner and image evaluation software. Printing of a food dye mixture solution (n=5) led to a calculated mean deposition volume of 13±1nL/mm(2) per print-cycle. A mean determination coefficient (R(2); n=5) of 0.9990 was obtained for application of increasing volumes, executed via increasing band widths of 50-200μm (corresponding to 2-8nL). Using larger band widths and multiple print jobs, deposition volumes of up to the microliter scale represented an alternative to cost-intensive standard equipment. After print, separation, detection and digital evaluation of five food dyes, mean R(2) (n=5) were obtained between 0.9977 and 0.9995. The accuracy of printing was proven by mean recovery rates of 101-105% with repeatabilities of 3-7% (%RSD, n=5). The transfer to nanostructured ultrathin-layer plates proved the synergetic potential of these fields of research. First, this modified printer was suited for printing of finely graduated scales of three preservatives for determination of the spatial resolution of scanning Direct Analysis in Real Time mass spectrometry. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. 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

    Science.gov (United States)

    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 chemotherapies received treatment. Methods. Coverage of community-directed treatment with praziquantel (PZQ) and albendazole (ALB) was analyzed in 17 villages of Mayuge District, Uganda. National drug registers, household questionnaires, and parasitological surveys were collected to track 935 individuals before and after MDA. Multilevel logistic regressions, including household and village effects, were specified with a comprehensive set of socioeconomic and parasitological variables. The factors predicting who did not receive PZQ and ALB from community medicine distributors were identified. Results. Drug receipt was correlated among members within a household, and nonrecipients of PZQ or ALB were profiled by household-level socioeconomic factors. Individuals were less likely to receive either PZQ or ALB if they had a Muslim household head or low home quality, belonged to the minority tribe, or had settled for more years in their village. Untreated individuals were also more likely to belong to households that did not purify drinking water, had no home latrine, and had no members who were part of the village government. Conclusions. The findings demonstrate how to locate and target individuals who are not treated in MDA. Infection risk factors were not informative. In particular, age, gender, and occupation were unable to identify non-recipients, although World Health Organization guidelines rely on these factors. Individuals of low socioeconomic status, minority religions, and minority tribes can be targeted to expand MDA coverage. PMID:26409064

  9. Direct determination of flavor relevant and further branched-chain fatty acids from sheep subcutaneous adipose tissue by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Kaffarnik, Stefanie; Preuß, Siegfried; Vetter, Walter

    2014-07-11

    4-Methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid are key-flavor compounds of sheep and goat. Yet, the low amounts of these volatile branched-chain fatty acids (vBCFAs) in the fat of the ruminants hampered their determination on a routine basis. In this work we developed a gas chromatography/mass spectrometry selected ion monitoring (GC/MS-SIM) method for the direct determination of the vBCFAs as methyl esters, which were obtained after transesterification of subcutaneous adipose tissue of sheep. The excellent sensitivity of the GC/MS-SIM method (limit of quantification, LOQ, 3.6-4.8μg/g; limit of detection, LOD, 1.1-1.4μg/g for 4-Me-8:0, 4-Et-8:0 and 4-Me-9:0) enabled us to determine the three vBCFAs without an enrichment step. Subcutaneous adipose sheep tissue of three different breeds contained 23-88μg/g 4-methyloctanoic acid, 13-26μg/g 4-ethyloctanoic acid and ∼2.9-18μg/g 4-methylnonanoic acid. Since all fatty acids were present in the FAME fraction, the samples could be screened for further branched-chain FAMEs. After elimination of unsaturated fatty acids by hydrogenation (the presence of some unsaturated fatty acids could be verified by this measure), additional measurements in SIM and full scan modes of methyl esters and picolinyl esters enabled the determination of further 97 saturated fatty acids in the samples with eight to 20 carbons. The method is suited for routine analysis and may be useful to investigate the reasons for the abundance/absence of 4-methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid and further branched-chain fatty acids in sheep and goat.

  10. High-performance liquid chromatography coupled to direct analysis in real time mass spectrometry: investigations on gradient elution and influence of complex matrices on signal intensities.

    Science.gov (United States)

    Beissmann, Susanne; Buchberger, Wolfgang; Hertsens, Robert; Klampfl, Christian W

    2011-08-01

    Direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) has been tested for its suitability as a detector for gradient elution HPLC. Thereby a strong dependency of signal intensity on the amount of organic solvent present in the eluent could be observed. Adding a make-up liquid (iso-propanol) post-column to the HPLC effluent greatly enhanced detection limits for early eluting compounds. Limits of detection achieved employing this approach were in the range of 7-27 μg L(-1) for the parabene test mixture and 15-87 μg L(-1) for the pharmaceuticals. In further investigations DART ionization was compared to several other widely used atmospheric pressure ionization methods with respect to signal suppression phenomena occurring in when samples with problematic matrices are analyzed. For this purpose extracts from environmental and waste water samples were selected as model matrices which were subsequently spiked with a set of six substances commonly present in personal care products as well as six pharmaceuticals at concentration levels between 100 μg L(-1) and 500 μg L(-1) corresponding to 100 ng L(-1) and 500 ng L(-1) respectively in the original sample. With ionization suppression of less than 11% for most analytes investigated, DART ionization showed similar to even somewhat superior behavior compared to atmospheric pressure chemical ionization (APCI) and atmospheric pressure photo ionization (APPI) for the Danube river water extract; for the more challenging matrix of the sewage plant effluent extract DART provided better results with ion suppression being less than 11% for 9 out of 12 analytes while values for APCI were lying between 20% and >90%. Electrospray ionization (ESI) was much more affected by suppression effects than DART with values between 26% and 80% for Danube river water; in combination with the sewage plant effluent matrix suppression >50% was observed for all analytes.

  11. Factors Associated with Non-Participation and Non-Adherence in Directly Observed Mass Drug Administration for Malaria in The Gambia.

    Directory of Open Access Journals (Sweden)

    Susan Dierickx

    Full Text Available The potential benefits of Mass Drug Administration (MDA for malaria elimination are being considered in several malaria endemic countries where a decline in malaria transmission has been reported. For this strategy to work, it is important that a large proportion of the target population participates, requiring an in-depth understanding of factors that may affect participation and adherence to MDA programs.This social science study was ancillary to a one-round directly observed MDA campaign with dihydroartemisinin-piperaquine, carried out in 12 villages in rural Gambia between June and August 2014. The social science study employed a mixed-methods approach combining qualitative methods (participant observation and in-depth interviewing and quantitative methods (structured follow-up interviews among non-participating and non-adhering community members.Of 3942 people registered in the study villages, 67.9% adhered to the three consecutive daily doses. For the remaining villagers, 12.6% did not attend the screening, 3.5% was not eligible and 16% did not adhere to the treatment schedule. The main barriers for non-participation and adherence were long and short-term mobility of individuals and specific subgroups, perceived adverse drug reactions and rumors, inconveniences related to the logistics of MDA (e.g. waiting times and the perceived lack of information about MDA.While, there was no fundamental resistance from the target communities, adherence was 67.9%. This shows the necessity of understanding local perceptions and barriers to increase its effectiveness. Moreover, certain of the constraining factors were socio-spatially clustered which might prove problematic since focal areas of residual malaria transmission may remain allowing malaria to spread to adjacent areas where transmission had been temporarily interrupted.

  12. Quantitative real-time monitoring of multi-elements in airborne particulates by direct introduction into an inductively coupled plasma mass spectrometer

    Science.gov (United States)

    Suzuki, Yoshinari; Sato, Hikaru; Hiyoshi, Katsuhiro; Furuta, Naoki

    2012-10-01

    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.

  13. 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.

  14. A method for rapid sampling and characterization of smokeless powder using sorbent-coated wire mesh and direct analysis in real time - mass spectrometry (DART-MS).

    Science.gov (United States)

    Li, Frederick; Tice, Joseph; Musselman, Brian D; Hall, Adam B

    2016-09-01

    Improvised explosive devices (IEDs) are often used by terrorists and criminals to create public panic and destruction, necessitating rapid investigative information. However, backlogs in many forensic laboratories resulting in part from time-consuming GC-MS and LC-MS techniques prevent prompt analytical information. Direct analysis in real time - mass spectrometry (DART-MS) is a promising analytical technique that can address this challenge in the forensic science community by permitting rapid trace analysis of energetic materials. Therefore, we have designed a qualitative analytical approach that utilizes novel sorbent-coated wire mesh and dynamic headspace concentration to permit the generation of information rich chemical attribute signatures (CAS) for trace energetic materials in smokeless powder with DART-MS. Sorbent-coated wire mesh improves the overall efficiency of capturing trace energetic materials in comparison to swabbing or vacuuming. Hodgdon Lil' Gun smokeless powder was used to optimize the dynamic headspace parameters. This method was compared to traditional GC-MS methods and validated using the NIST RM 8107 smokeless powder reference standard. Additives and energetic materials, notably nitroglycerin, were rapidly and efficiently captured by the Carbopack X wire mesh, followed by detection and identification using DART-MS. This approach has demonstrated the capability of generating comparable results with significantly reduced analysis time in comparison to GC-MS. All targeted components that can be detected by GC-MS were detected by DART-MS in less than a minute. Furthermore, DART-MS offers the advantage of detecting targeted analytes that are not amenable to GC-MS. The speed and efficiency associated with both the sample collection technique and DART-MS demonstrate an attractive and viable potential alternative to conventional techniques.

  15. 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

  16. 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...

  17. Quantitation of aflatoxins from corn and other food related materials by direct analysis in real time - mass spectrometry (DART-MS)

    Science.gov (United States)

    Ambient ionization coupled to mass spectrometry continues to be applied to new analytical problems, facilitating the rapid and convenient analysis of a variety of analytes. Recently, demonstrations of ambient ionization mass spectrometry applied to quantitative analysis of mycotoxins have been shown...

  18. 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 r...

  19. 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

  20. Thin-layer chromatography/direct analysis in real time time-of-flight mass spectrometry and isotope dilution to analyze organophosphorus insecticides in fatty foods.

    Science.gov (United States)

    Kiguchi, Osamu; Oka, Kazuko; Tamada, Masafumi; Kobayashi, Takashi; Onodera, Jun

    2014-11-28

    To assess food safety emergencies caused by highly hazardous chemical-tainted foods, simultaneous analysis of organophosphorus insecticides in fatty foods such as precooked foods was conducted using thin-layer chromatography/direct analysis in real time time-of-flight mass spectrometry (TLC/DART-TOFMS) and isotope dilution technique. Polar (methamidophos and acephate) and nonpolar organophosphorus insecticides (fenitrothion, diazinon, and EPN) were studied. Experiments to ascertain chromatographic patterns using TLC/DART-TOFMS reveal that it was more useful than GC/MS or GC/MS/MS for the simultaneous analyses of polar and nonpolar pesticides, while obviating the addition of a protective agent for tailing effects of polar pesticides. Lower helium gas temperature (260°C) for DART-TOFMS was suitable for the simultaneous analysis of target pesticides. Linearities were achieved respectively at a lower standard concentration range (0.05-5 μg) for diazinon and EPN and at a higher standard concentration range (2.5-25 μg) for methamidophos, acephate, and fenitrothion. Their respective coefficients of determination were ≥ 0.9989 and ≥ 0.9959. A few higher repeatabilities (RSDs) for diazinon and EPN were found (>20%), although isotope dilution technique was used. Application to the HPTLC plate without an automatic TLC sampler might be inferred as a cause of their higher RSDs. Detection limits were estimated in the higher picogram range for diazinon and EPN, and in the lower nanogram range for methamidophos, acephate, and fenitrothion. Aside from methamidophos, recovery results (n=3) obtained using a highly insecticide-tainted fatty food (dumpling) and raw food (grapefruit) samples (10mg/kg) using TLC/DART-TOFMS with both complex and simpler cleanups were not as susceptible to matrix effects (95-121%; RSD, 1.3-14%) as those using GC/MS/MS (102-117%; RSD, 0.4-8.5%), although dumpling samples using GC/MS were remarkably susceptible to matrix effects. The coupled method of

  1. Exploiting simultaneous observational constraints on mass and absorption to estimate the global direct radiative forcing of black carbon and brown carbon

    Science.gov (United States)

    Wang, X.; Heald, C. L.; Ridley, D. A.; Schwarz, J. P.; Spackman, J. R.; Perring, A. E.; Coe, H.; Liu, D.; Clarke, A. D.

    2014-10-01

    Atmospheric black carbon (BC) is a leading climate warming agent, yet uncertainties on the global direct radiative forcing (DRF) remain large. Here we expand a global model simulation (GEOS-Chem) of BC to include the absorption enhancement associated with BC coating and separately treat both the aging and physical properties of fossil-fuel and biomass-burning BC. In addition we develop a global simulation of brown carbon (BrC) from both secondary (aromatic) and primary (biomass burning and biofuel) sources. The global mean lifetime of BC in this simulation (4.4 days) is substantially lower compared to the AeroCom I model means (7.3 days), and as a result, this model captures both the mass concentrations measured in near-source airborne field campaigns (ARCTAS, EUCAARI) and surface sites within 30%, and in remote regions (HIPPO) within a factor of 2. We show that the new BC optical properties together with the inclusion of BrC reduces the model bias in absorption aerosol optical depth (AAOD) at multiple wavelengths by more than 50% at AERONET sites worldwide. However our improved model still underestimates AAOD by a factor of 1.4 to 2.8 regionally, with the largest underestimates in regions influenced by fire. Using the RRTMG model integrated with GEOS-Chem we estimate that the all-sky top-of-atmosphere DRF of BC is +0.13 Wm-2 (0.08 Wm-2 from anthropogenic sources and 0.05 Wm-2 from biomass burning). If we scale our model to match AERONET AAOD observations we estimate the DRF of BC is +0.21 Wm-2, with an additional +0.11 Wm-2 of warming from BrC. Uncertainties in size, optical properties, observations, and emissions suggest an overall uncertainty in BC DRF of -80%/+140%. Our estimates are at the lower end of the 0.2-1.0 Wm-2 range from previous studies, and substantially less than the +0.6 Wm-2 DRF estimated in the IPCC 5th Assessment Report. We suggest that the DRF of BC has previously been overestimated due to the overestimation of the BC lifetime (including the

  2. Combined use of direct analysis in real-time/Orbitrap mass spectrometry and micro-Raman spectroscopy for the comprehensive characterization of real explosive samples.

    Science.gov (United States)

    Bridoux, Maxime C; Schwarzenberg, Adrián; Schramm, Sébastien; Cole, Richard B

    2016-08-01

    Direct Analysis in Real Time (DART™) high-resolution Orbitrap™ mass spectrometry (HRMS) in combination with Raman microscopy was used for the detailed molecular level characterization of explosives including not only the charge but also the complex matrix of binders, plasticizers, polymers, and other possible organic additives. A total of 15 defused military weapons including grenades, mines, rockets, submunitions, and mortars were examined. Swabs and wipes were used to collect trace (residual) amounts of explosives and their organic constituents from the defused military weapons and micrometer-size explosive particles were transferred using a vacuum suction-impact collection device (vacuum impactor) from wipe and swap samples to an impaction plate made of carbon. The particles deposited on the carbon plate were then characterized using micro-Raman spectroscopy followed by DART-HRMS providing fingerprint signatures of orthogonal nature. The optical microscope of the micro-Raman spectrometer was first used to localize and characterize the explosive charge on the impaction plate which was then targeted for identification by DART-HRMS analysis in both the negative and positive modes. Raman spectra of the explosives TNT, RDX and PETN were acquired from micrometer size particles and characterized by the presence of their characteristic Raman bands obtained directly at the surface of the impaction plate nondestructively without further sample preparation. Negative mode DART-HRMS confirmed the types of charges contained in the weapons (mainly TNT, RDX, HMX, and PETN; either as individual components or as mixtures). These energetic compounds were mainly detected as deprotonated species [M-H](-), or as adduct [M + (35)Cl](-), [M + (37)Cl](-), or [M + NO3](-) anions. Chloride adducts were promoted in the heated DART reagent gas by adding chloroform vapors to the helium stream using an "in-house" delivery method. When the polarity was switched to positive mode

  3. 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, S.

    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. Tabs, figs, refs.

  4. Oxygenated fraction and mass of organic aerosol from direct emission and atmospheric processing measured on the R/V Ronald Brown during TEXAQS/GoMACCS 2006

    Science.gov (United States)

    Russell, L. M.; Takahama, S.; Liu, S.; Hawkins, L. N.; Covert, D. S.; Quinn, P. K.; Bates, T. S.

    2009-04-01

    Submicron particles collected on Teflon filters aboard the R/V Ronald Brown during the Texas Air Quality Study and Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) 2006 in and around the port of Houston, Texas, were measured by Fourier transform infrared (FTIR) and X-ray fluorescence for organic functional groups and elemental composition. Organic mass (OM) concentrations (1-25 μg m-3) for ambient particle samples measured by FTIR showed good agreement with measurements made with an aerosol mass spectrometer. The fractions of organic mass identified as alkane and carboxylic acid groups were 47% and 32%, respectively. Three different types of air masses were identified on the basis of the air mass origin and the radon concentration, with significantly higher carboxylic acid group mass fractions in air masses from the north (35%) than the south (29%) or Gulf of Mexico (26%). Positive matrix factorization analysis attributed carboxylic acid fractions of 30-35% to factors with mild or strong correlations (r > 0.5) to elemental signatures of oil combustion and 9-24% to wood smoke, indicating that part of the carboxylic acid fraction of OM was formed by the same sources that controlled the metal emissions, namely the oil and wood combustion activities. The implication is that a substantial part of the measured carboxylic acid contribution was formed independently of traditionally "secondary" processes, which would be affected by atmospheric (both photochemical and meteorological) conditions and other emission sources. The carboxylic acid group fractions in the Gulf of Mexico and south air masses (GAM and SAM, respectively) were largely oil combustion emissions from ships as well as background marine sources, with only limited recent land influences (based on radon concentrations). Alcohol groups accounted for 14% of OM (mostly associated with oil combustion emissions and background sources), and amine groups accounted for 4% of OM in all air

  5. Evaluation of a direct high-capacity target screening approach for urine drug testing using liquid chromatography-time-of-flight mass spectrometry.

    Science.gov (United States)

    Saleh, Aljona; Stephanson, Niclas Nikolai; Granelli, Ingrid; Villén, Tomas; Beck, Olof

    2012-11-15

    In this study a rapid liquid chromatography-time-of-flight mass spectrometry method was developed, validated and applied in order to evaluate the potential of this technique for routine urine drug testing. Approximately 800 authentic patient samples were analyzed for amphetamines (amphetamine and methamphetamine), opiates (morphine, morphine-3-glucuronide, morphine-6-glucuronide, codeine and codeine-6-glucuronide) and buprenorphines (buprenorphine and buprenorphine-glucuronide) using immunochemical screening assays and mass spectrometry confirmation methods for comparison. The chromatographic application utilized a rapid gradient with high flow and a reversed phase column with 1.8 μm particles. Total analysis time was 4 min. The mass spectrometer operated with an electrospray interface in positive mode with a resolution power of >10,000 at m/z 956. The applied reporting limits were 100 ng/mL for amphetamines and opiates, and 5 ng/mL for buprenorphines, with lower limits of quantification were 2.8-41 ng/mL. Calibration curves showed a linear response with coefficients of correlation of 0.97-0.99. The intra- and interday imprecision in quantification at the reporting limits were amphetamines and opiates; 3.2% for buprenorphines) and negatives (1.8% for amphetamines; 0.6% for opiates; 0% for buprenorphines). The overall agreement between the two screening methods was between 94.2 and 97.4%. Comparison of data with the confirmation (LC-MS) results for all individual 9 analytes showed that most deviating results were produced in samples with low levels of analytes. False negatives were mainly related to failure of detected peak to meet mass accuracy criteria (±20 mDa). False positives was related to presence of interfering peaks meeting mass accuracy and retention time criteria and occurred mainly at low levels. It is concluded that liquid chromatography-time-of-flight mass spectrometry has potential both as a complement and as replacement of immunochemical screening

  6. Observation of free electron cyclotron resonance in NaAlSi3O8 feldspar: Direct determination of the effective electron mass

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Nicholis, J.E.; Bøtter-Jensen, L.;

    2001-01-01

    We report the first observation of cyclotron resonances in alkali feldspars, using highly sensitive optical detection methods. In Na-feldspar (NaAlSi3O8). a near isotropic effective electron mass value of m(c)(*) = 0.79m, has been determined. The significance of this measurement in terms of the o......We report the first observation of cyclotron resonances in alkali feldspars, using highly sensitive optical detection methods. In Na-feldspar (NaAlSi3O8). a near isotropic effective electron mass value of m(c)(*) = 0.79m, has been determined. The significance of this measurement in terms...

  7. Prospects for a search for direct pair production of top squarks in scenarios with compressed mass spectra at the high luminosity LHC with the ATLAS Detector

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    The current searches at the LHC have yielded a limited sensitivity to top squark pair production in scenarios with compressed mass spectra, where the top squark decays via $\\tilde{t}_{1} \\rightarrow t \\tilde{\\chi}_{1}^{0}$. The reach at the high-luminosity phase of the LHC is expected to significantly extend beyond the current limits. This document presents benchmark studies targeting dileptonic final states with a parameterised simulation of the ATLAS detector, considering proton-proton collisions at a centre-of-mass energy of 14~TeV. Results are shown for an integrated luminosity of 3000 fb$^{-1}$.

  8. 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.

  9. 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

    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...

  10. The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets

    CERN Document Server

    Liu, Michael C; Deacon, Niall R; Allers, Katelyn N; Dupuy, Trent J; Kotson, Michael C; Aller, Kimberly M; Burgett, W S; Chambers, K C; Draper, P W; Hodapp, K W; Jedicke, R; Kudritzki, R -P; Metcalfe, N; Morgan, J S; Kaiser, N; Price, P A; Tonry, J L; Wainscoat, R J

    2013-01-01

    We have used Pan-STARRS1 to discover an extremely red late-L dwarf, which has (J-K)_MKO = 2.84 and (J-K)_2MASS = 2.78, making it the reddest known field dwarf and second only to 2MASS J1207-39b among substellar companions. Near-IR spectroscopy shows a spectral type of L7 and reveals a triangular H-band continuum and weak alkali (K I and Na I) lines, hallmarks of low surface gravity. Near-IR astrometry from the Hawaii Infrared Parallax Program gives a distance of 24.6+/-1.4 pc and indicates a much fainter J-band absolute magnitude than field L dwarfs. The position and kinematics of PSO J318-22 point to membership in the beta Pictoris moving group. Evolutionary models give a temperature of 1160 (-40,+30) K and a mass of 6.5 (-1.0, +1.3) Mjup, making PSO J318-22 one of the lowest mass free-floating objects in the solar neighborhood. This object adds to the growing list of low-gravity field L dwarfs and is the first to be strongly deficient in methane relative to its estimated temperature. Comparing their spectra...

  11. Estimating rates of denitrification enzyme activity in wetland soils and direct simultaneous quantification of nitrogen and nitrous oxide by membrane inlet mass spectrometry

    Science.gov (United States)

    Denitrification enzyme activity (DEA) was measured in short-term (4 h) anaerobic assays using Membrane Inlet Mass Spectrometry (MIMS) and electron capture gas chromatography (GC-ECD). Using MIMS, modifications of the instrument and sample handling allowed for the simultaneous me...

  12. Estimating rates of denitrification enzyme activity in wetland soils and direct simultaneous quantification of nitrogen and nitrous oxide by membrane inlet mass spectrometry

    Science.gov (United States)

    Denitrification enzyme activity (DEA) was measured in short-term (4 h) anaerobic assays using Membrane Inlet Mass Spectrometry (MIMS) and electron capture gas chromatography (GC-ECD). Using MIMS, modifications of the instrument and sample handling allowed for the simultaneous me...

  13. 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), 3,4-methylene

  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, 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 chemotherapi

  15. The mass of planet GJ676A b from ground-based astrometry: A planetary system with two mature gas giants suitable for direct imaging

    CERN Document Server

    Sahlmann, J; Ségransan, D; Astudillo-Defru, N; Bonfils, X; Delfosse, X; Forveille, T; Hagelberg, J; Curto, G Lo; Pepe, F; Queloz, D; Udry, S; Zimmerman, N T

    2016-01-01

    GJ676A is an M0 dwarf hosting both gas-giant and super-Earth-type planets discovered with radial-velocity measurements. Using FORS2/VLT, we obtained position measurements of the star in the plane of the sky that tightly constrain its astrometric reflex motion caused by the super-Jupiter planet `b` in a 1052-day orbit. This allows us to determine the mass of this planet to $M_\\mathrm{b} = 6.7^{+1.8}_{-1.5}\\,M_\\mathrm{J}$, which is $\\sim$40 \\% higher than the minimum mass inferred from the radial-velocity orbit. Using new HARPS radial-velocity measurements, we improve upon the orbital parameters of the inner low-mass planets `d` and `e` and we determine the orbital period of the outer giant planet `c` to $P_\\mathrm{c}=7340$ days under the assumption of a circular orbit. The preliminary minimum mass of planet `c` is $M_\\mathrm{c} \\sin i = 6.8\\,M_\\mathrm{J}$ with an upper limit of $\\sim$$39\\,M_\\mathrm{J}$ that we set using NACO/VLT high-contrast imaging. We also determine precise parallaxes and relative proper mo...

  16. (Un)targeted scanning of locks of hair for drugs of abuse by direct analysis in real time-high-resolution mass spectrometry

    NARCIS (Netherlands)

    Duvivier, W.F.; Rutten, van Marc; Beek, van T.A.; Nielen, M.W.F.

    2016-01-01

    Forensic hair evidence can be used to obtain retrospective timelines of drug use by analysis of hair segments. However, this is a laborious and time-consuming process, and mass spectrometric (MS) imaging techniques, which show great potential for single-hair targeted analysis, are less useful due to

  17. (Un)targeted scanning of locks of hair for drugs of abuse by direct analysis in real time-high-resolution mass spectrometry

    NARCIS (Netherlands)

    Duvivier, W.F.; Rutten, van Marc; Beek, van T.A.; Nielen, M.W.F.

    2016-01-01

    Forensic hair evidence can be used to obtain retrospective timelines of drug use by analysis of hair segments. However, this is a laborious and time-consuming process, and mass spectrometric (MS) imaging techniques, which show great potential for single-hair targeted analysis, are less useful due to

  18. Direct Analysis of Leucine and Its Metabolites β-Hydroxy-β-methylbutyric Acid, α-Ketoisocaproic Acid, and α-Hydroxyisocaproic Acid in Human Breast Milk by Liquid Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Ehling, Stefan; Reddy, Todime M

    2015-09-02

    A direct, quantitative, and confirmatory method based on stable isotope dilution liquid chromatography-mass spectrometry was developed and validated for the analysis of leucine and metabolites β-hydroxy-β-methylbutyric acid (HMB), α-ketoisocaproic acid (KIC), and α-hydroxyisocaproic acid (HICA) in human breast milk. Chromatographic resolution was achieved between isobaric leucine and isoleucine. Accuracy and intermediate precision were 89-117% and breast milk composition and its effect on protein turnover in developing infants.

  19. Development of "Laser Ablation Direct Analysis in Real Time Imaging" Mass Spectrometry: Application to Spatial Distribution Mapping of Metabolites Along the Biosynthetic Cascade Leading to Synthesis of Atropine and Scopolamine in Plant Tissue.

    Science.gov (United States)

    Fowble, Kristen L; Teramoto, Kanae; Cody, Robert B; Edwards, David; Guarrera, Donna; Musah, Rabi A

    2017-03-21

    Methods for the accomplishment of small-molecule imaging by mass spectrometry are challenged by the need for sample pretreatment steps, such as cryo-sectioning, dehydration, chemical fixation, or application of a matrix or solvent, that must be performed to obtain interpretable spatial distribution data. Furthermore, these steps along with requirements of the mass analyzer such as high vacuum, can severely limit the range of sample types that can be analyzed by this powerful method. Here, we report the development of a laser ablation-direct analysis in real time imaging mass spectrometry approach which couples a 213 nm Nd:YAG solid state UV laser to a direct analysis in a real time ion source and high-resolution time-of-flight mass spectrometer. This platform enables facile determination of the spatial distribution of small-molecules spanning a range of polarities in a diversity of sample types and requires no matrix, vacuum, solvent, or complicated sample pretreatment steps. It furnishes high-resolution data, can be performed under ambient conditions on samples in their native form, and results in little to no fragmentation of analytes. We demonstrate its application through determination of the spatial distribution of molecules involved in the biosynthetic cascade leading to formation of the clinically relevant alkaloids atropine and scopolamine in Datura leichhardtii seed tissue.

  20. "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/

  1. “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

  2. 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

  3. 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

  4. K2 Discovery of Young Eclipsing Binaries in Upper Scorpius: Direct Mass and Radius Determinations for the Lowest Mass Stars and Initial Characterization of an Eclipsing Brown Dwarf Binary

    CERN Document Server

    David, Trevor J; Cody, Ann Marie; Carpenter, John M; Howard, Andrew W

    2015-01-01

    We report the discovery of three low-mass double-lined eclipsing binaries in the pre-main sequence Upper Scorpius association, revealed by $K2$ photometric monitoring of the region over $\\sim$ 78 days. The orbital periods of all three systems are $<$5 days. We use the $K2$ photometry plus multiple Keck/HIRES radial velocities and spectroscopic flux ratios to determine fundamental stellar parameters for both the primary and secondary components of each system, along with the orbital parameters. We present tentative evidence that EPIC 203868608 is a hierarchical triple system comprised of an eclipsing pair of $\\sim$25 $M_\\mathrm{Jup}$ brown dwarfs with a wide M-type companion. If confirmed, it would constitute only the second double-lined eclipsing brown dwarf binary system discovered to date. The double-lined system EPIC 203710387 is composed of nearly identical M4.5-M5 stars with fundamentally determined masses and radii measured to better than 3% precision ($M_1=0.1169\\pm0.0031 M_\\odot$, $M_2=0.1065\\pm0.0...

  5. 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

  6. 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