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Sample records for high-resolution mass spectra

  1. A new matching algorithm for high resolution mass spectra

    DEFF Research Database (Denmark)

    Hansen, Michael Edberg; Smedsgaard, Jørn

    2004-01-01

    We present a new matching algorithm designed to compare high-resolution spectra. Whereas existing methods are bound to compare fixed intervals of ion masses, the accurate mass spectrum (AMS) distance method presented here is independent of any alignment. Based on the Jeffreys-Matusitas (JM......) distance, a difference between observed peaks across pairs of spectra can be calculated, and used to find a unique correspondence between the peaks. The method takes into account that there may be differences in resolution of the spectra. The algorithm is used for indexing in a database containing 80...... accurate mass spectra from an analysis of extracts of 80 isolates representing the nine closely related species in the Penicillium series Viridicata. Using this algorithm we can obtain a retrieval performance of approximate to97-98% that is comparable with the best of the existing methods (e.g., the dot...

  2. Automated data processing of high-resolution mass spectra

    DEFF Research Database (Denmark)

    Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn

    There has been an almost explosive growth in performance and applications of Electrospray Ionization (ESI) Time of Flight (TOF) mass spectrometry, which today is one of the most efficient tools for screening of metabolites in complex bio-samples. Most efficiently ESI-MS can be used by directly...... infusion of crude extracts into the source taking advantage of the high sensitivity, high mass resolution and accuracy and the limited fragmentation. Unfortunately, there has not been a comparable development in the data processing techniques to fully exploit gain in high resolution and accuracy...... and mass axis on to a fixed one-dimensional array, we obtain a vector that can be used directly as input in multivariate statistics or library search methods. We demonstrate that both cluster- and discriminant analysis as well as PCA (and related methods) can be applied directly on mass spectra from direct...

  3. “Lossless” compression of high resolution mass spectra of small molecules

    Science.gov (United States)

    Blanckenburg, Bo; van der Burgt, Yuri E. M.; Deelder, André M.

    2010-01-01

    Fourier transform ion cyclotron resonance (FTICR) provides the highest resolving power of any commercially available mass spectrometer. This advantage is most significant for species of low mass-to-charge ratio (m/z), such as metabolites. Unfortunately, FTICR spectra contain a very large number of data points, most of which are noise. This is most pronounced at the low m/z end of spectra, where data point density is the highest but peak density low. We therefore developed a filter that offers lossless compression of FTICR mass spectra from singly charged metabolites. The filter relies on the high resolving power and mass measurement precision of FTICR and removes only those m/z channels that cannot contain signal from singly charged organic species. The resulting pseudospectra still contain the same signal as the original spectra but less uninformative background. The filter does not affect the outcome of standard downstream chemometric analysis methods, such as principal component analysis, but use of the filter significantly reduces memory requirements and CPU time for such analyses. We demonstrate the utility of the filter for urinary metabolite profiling using direct infusion electrospray ionization and a 15 tesla FTICR mass spectrometer. Electronic supplementary material The online version of this article (doi:10.1007/s11306-010-0202-2) contains supplementary material, which is available to authorized users. PMID:20676216

  4. Accurate proteome-wide protein quantification from high-resolution 15N mass spectra.

    Science.gov (United States)

    Khan, Zia; Amini, Sasan; Bloom, Joshua S; Ruse, Cristian; Caudy, Amy A; Kruglyak, Leonid; Singh, Mona; Perlman, David H; Tavazoie, Saeed

    2011-12-19

    In quantitative mass spectrometry-based proteomics, the metabolic incorporation of a single source of 15N-labeled nitrogen has many advantages over using stable isotope-labeled amino acids. However, the lack of a robust computational framework for analyzing the resulting spectra has impeded wide use of this approach. We have addressed this challenge by introducing a new computational methodology for analyzing 15N spectra in which quantification is integrated with identification. Application of this method to an Escherichia coli growth transition reveals significant improvement in quantification accuracy over previous methods.

  5. Retrieval of Precise Radial Velocities from Near-Infrared High Resolution Spectra of Low Mass Stars

    CERN Document Server

    Gao, Peter; Gagné, Jonathan; Furlan, Elise; Bottom, Michael; Anglada-Escudé, Guillem; White, Russel; Davison, Cassy; Beichman, Charles; Brinkworth, Carolyn; Johnson, John; Ciardi, David; Wallace, James; Mennesson, Bertrand; von Braun, Kaspar; Vasisht, Gautam; Prato, Lisa; Kane, Stephen; Tanner, Angelle; Crawford, Timothy; Latham, David; Rougeot, Raphaël; Geneser, Claire; Catanzarite, Joseph

    2016-01-01

    Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this work we describe and test a novel RV extraction pipeline dedicated to retrieving RVs from low mass stars using NIR spectra taken by the CSHELL spectrograph at the NASA Infrared Telescope Facility, where a methane isotopologue gas cell is used for wavelength calibration. The pipeline minimizes the residuals between the observations and a spectral model composed of templates for the target star, the gas cell, and atmospheric telluric absorption; models of the line spread function, continuum curvature, and sinusoidal fringing; and a parameterization of the wavelength solution. The stellar template is derived iteratively from the science observations themselves without a need for separate observations dedicated to retrieving it. Despite limitations from CSHELL's narrow wavelen...

  6. Factor analysis of combined organic and inorganic aerosol mass spectra from high resolution aerosol mass spectrometer measurements

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2012-05-01

    Full Text Available The high resolution mass spectra of organic and inorganic aerosols from aerosol mass spectrometer (AMS measurements were first combined into positive matrix factorization (PMF analysis to investigate the sources and evolution processes of atmospheric aerosols. The new approach is able to study the mixing of organic aerosols (OA and inorganic species, the acidity of OA factors, and the fragment ion patterns related to photochemical processing. In this study, PMF analysis of the unified AMS spectral matrices resolved 8 factors for the submicron aerosols measured at Queens College in New York City in summer 2009. The hydrocarbon-like OA (HOA and cooking OA (COA contain very minor inorganic species, indicating the different sources and mixing characteristics between primary OA and secondary species. The two factors that are primarily ammonium sulfate (SO4-OA and ammonium nitrate (NO3-OA, respectively, are overall neutralized, of which the OA in SO4-OA shows the highest oxidation state (O/C = 0.69 among OA factors. The semi-volatile oxygenated OA comprises two components, i.e., a less oxidized (LO-OOA and a more oxidized (MO-OOA. The MO-OOA represents a local photochemical product with the diurnal profile exhibiting a pronounced noon peak, consistent with those of formaldehyde (HCHO and Ox (= O3+NO2. The much higher NO+/NO2+ fragment ion ratio in MO-OOA than that from ammonium nitrate alone provides evidence for the formation of organic nitrates. The amine-related nitrogen-enriched OA (NOA contains ~25% of acidic inorganic salts, elucidating the formation of secondary OA from amines in acidic environments. The size distributions derived from 3-dimensional size-resolved mass spectra show distinct diurnal evolving behaviors for different OA factors, but overall a progressing evolution from smaller to larger particle mode as a function of oxidation states

  7. A new method to discriminate secondary organic aerosols from different sources using high-resolution aerosol mass spectra

    Science.gov (United States)

    Heringa, M. F.; Decarlo, P. F.; Chirico, R.; Tritscher, T.; Clairotte, M.; Mohr, C.; Crippa, M.; Slowik, J. G.; Pfaffenberger, L.; Dommen, J.; Weingartner, E.; Prévôt, A. S. H.; Baltensperger, U.

    2012-02-01

    Organic aerosol (OA) represents a significant and often major fraction of the non-refractory PM1 (particulate matter with an aerodynamic diameter da car and a two-stroke Euro 2 scooter were characterized with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and compared to SOA from α-pinene. The emissions were sampled from the chimney/tailpipe by a heated inlet system and filtered before injection into a smog chamber. The gas phase emissions were irradiated by xenon arc lamps to initiate photo-chemistry which led to nucleation and subsequent particle growth by SOA production. Duplicate experiments were performed for each SOA type, with the averaged organic mass spectra showing Pearson's r values >0.94 for the correlations between the four different SOA types after five hours of aging. High-resolution mass spectra (HR-MS) showed that the dominant peaks in the MS, m/z 43 and 44, are dominated by the oxygenated ions C2H3O+ and CO2+, respectively, similarly to the relatively fresh semi-volatile oxygenated OA (SV-OOA) observed in the ambient aerosol. The atomic O:C ratios were found to be in the range of 0.25-0.55 with no major increase during the first five hours of aging. On average, the diesel SOA showed the lowest O:C ratio followed by SOA from wood burning, α-pinene and the scooter emissions. Grouping the fragment ions revealed that the SOA source with the highest O:C ratio had the largest fraction of small ions. The HR data of the four sources could be clustered and separated using principal component analysis (PCA). The model showed a significant separation of the four SOA types and clustering of the duplicate experiments on the first two principal components (PCs), which explained 79% of the total variance. Projection of ambient SV-OOA spectra resolved by positive matrix factorization (PMF) showed that this approach could be useful to identify large contributions of the tested SOA sources to SV-OOA. The first results from this

  8. Structure of high-resolution NMR spectra

    CERN Document Server

    Corio, PL

    2012-01-01

    Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

  9. Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

    Directory of Open Access Journals (Sweden)

    L.-Y. He

    2010-09-01

    Full Text Available Aerosol Mass Spectrometer (AMS has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS collected worldwide by AMS demonstrates that submicron organic aerosol (OA is usually composed of several major components, such as oxygenated (OOA, hydrocarbon-like (HOA, biomass burning (BBOA, and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurement of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS measurement, which performs improved characterization by separating the ions of different elemental compositions at each m/z in comparison with unit mass resolution MS (UMR-MS measurement. In this study, primary emissions from four types of Chinese cooking (CC and six types of biomass burning (BB were simulated systemically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS. The MS of the CC emissions show high similarity with m/z 41 and m/z 55 being the highest signals; the MS of the BB emissions also show high similarity with m/z 29 and m/z 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions while from 0.18 to 0.26 for the BB emissions. The ions of m/z 43, m/z 44, m/z 57, and m/z 60, usually used as tracer ions in AMS measurement, were examined for their HR-MS characteristics in the CC and BB emissions. Moreover, the MS of the CC and BB emissions are also used to compare with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS

  10. A new method to discriminate secondary organic aerosols from different sources using high-resolution aerosol mass spectra

    Directory of Open Access Journals (Sweden)

    M. F. Heringa

    2012-02-01

    Full Text Available Organic aerosol (OA represents a significant and often major fraction of the non-refractory PM1 (particulate matter with an aerodynamic diameter da < 1 μm mass. Secondary organic aerosol (SOA is an important contributor to the OA and can be formed from biogenic and anthropogenic precursors. Here we present results from the characterization of SOA produced from the emissions of three different anthropogenic sources. SOA from a log wood burner, a Euro 2 diesel car and a two-stroke Euro 2 scooter were characterized with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS and compared to SOA from α-pinene.

    The emissions were sampled from the chimney/tailpipe by a heated inlet system and filtered before injection into a smog chamber. The gas phase emissions were irradiated by xenon arc lamps to initiate photo-chemistry which led to nucleation and subsequent particle growth by SOA production.

    Duplicate experiments were performed for each SOA type, with the averaged organic mass spectra showing Pearson's r values >0.94 for the correlations between the four different SOA types after five hours of aging. High-resolution mass spectra (HR-MS showed that the dominant peaks in the MS, m/z 43 and 44, are dominated by the oxygenated ions C2H3O+ and CO2+, respectively, similarly to the relatively fresh semi-volatile oxygenated OA (SV-OOA observed in the ambient aerosol. The atomic O:C ratios were found to be in the range of 0.25–0.55 with no major increase during the first five hours of aging. On average, the diesel SOA showed the lowest O:C ratio followed by SOA from wood burning, α-pinene and the scooter emissions. Grouping the fragment ions revealed that the SOA source with the highest O:C ratio had the largest fraction of small ions.

    The HR data of the four sources could be clustered and separated using

  11. A new method to discriminate secondary organic aerosols from different sources using high-resolution aerosol mass spectra

    Directory of Open Access Journals (Sweden)

    M. F. Heringa

    2011-10-01

    Full Text Available Organic aerosol (OA represents a significant and often major fraction of the non-refractory PM1 (particulate matter with an aerodynamic diameter da < 1 μm mass. Secondary organic aerosol (SOA is an important contributor to the OA and can be formed from biogenic and anthropogenic precursors. Here we present results from the characterization of SOA produced from the emissions of three different anthropogenic sources. SOA from a log wood burner, a Euro 2 diesel car and a two-stroke Euro 2 scooter were characterized with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS and compared to SOA from α-pinene.

    The emissions were sampled from the chimney/tailpipe by a heated inlet system and filtered before injection into a smog chamber. The gas phase emissions were irradiated by xenon arc lamps to initiate photo-chemistry which led to nucleation and subsequent particle growth by SOA production.

    Duplicate experiments were performed for each SOA type, with the averaged organic mass spectra in the m/z range 12–250 showing Pearson's r values >0.94 for the correlations between the different SOA types after 5 h of aging. High-resolution mass spectra (HR-MS showed that the dominant peaks in the MS, m/z 43 and 44, are dominated by the oxygenated ions C2H3O+ and CO2+, respectively, similarly to the relatively fresh semi-volatile oxidized OA (SV-OOA observed in the ambient aerosol. The atomic O : C ratios were found to be in the range of 0.25–0.55 with no major increase during the first 5 h of aging. On average, the diesel SOA showed the lowest O : C ratio followed by SOA from wood burning, α-pinene and the scooter emissions. Grouping the fragment ions based on their carbon number revealed that the SOA source with the highest O : C ratio had the largest fraction of small ions. Fragment ions

  12. Applying 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) for systematic toxicological analysis with liquid chromatography-high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Arnhard, Kathrin; Gottschall, Anna; Pitterl, Florian; Oberacher, Herbert

    2015-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become an indispensable analytical technique in clinical and forensic toxicology for detection and identification of potentially toxic or harmful compounds. Particularly, non-target LC-MS/MS assays enable extensive and universal screening requested in systematic toxicological analysis. An integral part of the identification process is the generation of information-rich product ion spectra which can be searched against libraries of reference mass spectra. Usually, 'data-dependent acquisition' (DDA) strategies are applied for automated data acquisition. In this study, the 'data-independent acquisition' (DIA) method 'Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectra' (SWATH) was combined with LC-MS/MS on a quadrupole-quadrupole-time-of-flight (QqTOF) instrument for acquiring informative high-resolution tandem mass spectra. SWATH performs data-independent fragmentation of all precursor ions entering the mass spectrometer in 21m/z isolation windows. The whole m/z range of interest is covered by continuous stepping of the isolation window. This allows numerous repeat analyses of each window during the elution of a single chromatographic peak and results in a complete fragment ion map of the sample. Compounds and samples typically encountered in forensic casework were used to assess performance characteristics of LC-MS/MS with SWATH. Our experiments clearly revealed that SWATH is a sensitive and specific identification technique. SWATH is capable of identifying more compounds at lower concentration levels than DDA does. The dynamic range of SWATH was estimated to be three orders of magnitude. Furthermore, the >600,000 SWATH spectra matched led to only 408 incorrect calls (false positive rate = 0.06 %). Deconvolution of generated ion maps was found to be essential for unravelling the full identification power of LC-MS/MS with SWATH. With the available software, however, only semi

  13. High-Resolution Mass Spectrometers

    Science.gov (United States)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  14. Physical Properties of Young Brown Dwarfs and Very Low-Mass Stars Inferred from High-Resolution Model Spectra

    CERN Document Server

    Rice, Emily L; McLean, Ian S; Prato, L; Kirkpatrick, J Davy

    2009-01-01

    By comparing near-infrared spectra with atmosphere models, we infer the effective temperature, surface gravity, projected rotational velocity, and radial velocity for 21 very-low-mass stars and brown dwarfs. The unique sample consists of two sequences in spectral type from M6-M9, one of 5-10 Myr objects and one of >1 Gyr field objects. A third sequence is comprised of only ~M6 objects with ages ranging from 1 Gyr. Spectra were obtained in the J band at medium (R~2,000) and high (R~20,000) resolutions with NIRSPEC on the Keck II telescope. Synthetic spectra were generated from atmospheric structures calculated with the PHOENIX model atmosphere code. Using multi-dimensional least-squares fitting and Monte Carlo routines we determine the best-fit model parameters for each observed spectrum and note which spectral regions provide consistent results. We identify successes in the reproduction of observed features by atmospheric models, including pressure-broadened KI lines, and investigate deficiencies in the model...

  15. Automatic abundance analysis of high resolution spectra

    CERN Document Server

    Bonifacio, P; Bonifacio, Piercarlo; Caffau, Elisabetta

    2003-01-01

    We describe an automatic procedure for determining abundances from high resolution spectra. Such procedures are becoming increasingly important as large amounts of data are delivered from 8m telescopes and their high-multiplexing fiber facilities, such as FLAMES on ESO-VLT. The present procedure is specifically targeted for the analysis of spectra of giants in the Sgr dSph; however, the procedure may be, in principle, tailored to analyse stars of any type. Emphasis is placed on the algorithms and on the stability of the method; the external accuracy rests, ultimately, on the reliability of the theoretical models (model-atmospheres, synthetic spectra) used to interpret the data. Comparison of the results of the procedure with the results of a traditional analysis for 12 Sgr giants shows that abundances accurate at the level of 0.2 dex, comparable with that of traditional analysis of the same spectra, may be derived in a fast and efficient way. Such automatic procedures are not meant to replace the traditional ...

  16. Retrieval of Precise Radial Velocities from Near-infrared High-resolution Spectra of Low-mass Stars

    Science.gov (United States)

    Gao, Peter; Plavchan, P.; Gagné, J.; Furlan, E.; Bottom, M.; Anglada-Escudé, G.; White, R.; Davison, C. L.; Beichman, C.; Brinkworth, C.; Johnson, J.; Ciardi, D.; Wallace, K.; Mennesson, B.; von Braun, K.; Vasisht, G.; Prato, L.; Kane, S. R.; Tanner, A.; Crawford, T. J.; Latham, D.; Rougeot, R.; Geneser, C. S.; Catanzarite, J.

    2016-10-01

    Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this work, we describe and test a novel RV extraction pipeline dedicated to retrieving RVs from low-mass stars using NIR spectra taken by the CSHELL spectrograph at the NASA Infrared Telescope Facility, where a methane isotopologue gas cell is used for wavelength calibration. The pipeline minimizes the residuals between the observations and a spectral model composed of templates for the target star, the gas cell, and atmospheric telluric absorption; models of the line-spread function, continuum curvature, and sinusoidal fringing; and a parameterization of the wavelength solution. The stellar template is derived iteratively from the science observations themselves without a need for separate observations dedicated to retrieving it. Despite limitations from CSHELL’s narrow wavelength range and instrumental systematics, we are able to (1) obtain an RV precision of 35 m s-1 for the RV standard star GJ 15 A over a time baseline of 817 days, reaching the photon noise limit for our attained signal-to-noise ratio; (2) achieve ˜3 m s-1 RV precision for the M giant SV Peg over a baseline of several days and confirm its long-term RV trend due to stellar pulsations, as well as obtain nightly noise floors of ˜2-6 m s-1 and (3) show that our data are consistent with the known masses, periods, and orbital eccentricities of the two most massive planets orbiting GJ 876. Future applications of our pipeline to RV surveys using the next generation of NIR spectrographs, such as iSHELL, will enable the potential detection of super-Earths and mini-Neptunes in the habitable zones of M dwarfs.

  17. A Simple Approach for Obtaining High Resolution, High Sensitivity ¹H NMR Metabolite Spectra of Biofluids with Limited Mass Supply

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Zhi; Rommereim, Donald N.; Wind, Robert A.; Minard, Kevin R.; Sears, Jesse A.

    2006-11-01

    A simple approach is reported that yields high resolution, high sensitivity ¹H NMR spectra of biofluids with limited mass supply. This is achieved by spinning a capillary sample tube containing a biofluid at the magic angle at a frequency of about 80Hz. A 2D pulse sequence called ¹H PASS is then used to produce a high-resolution ¹H NMR spectrum that is free from magnetic susceptibility induced line broadening. With this new approach a high resolution ¹H NMR spectrum of biofluids with a volume less than 1.0 µl can be easily achieved at a magnetic field strength as low as 7.05T. Furthermore, the methodology facilitates easy sample handling, i.e., the samples can be directly collected into inexpensive and disposable capillary tubes at the site of collection and subsequently used for NMR measurements. In addition, slow magic angle spinning improves magnetic field shimming and is especially suitable for high throughput investigations. In this paper first results are shown obtained in a magnetic field of 7.05T on urine samples collected from mice using a modified commercial NMR probe.

  18. Highly accurate chemical formula prediction tool utilizing high-resolution mass spectra, MS/MS fragmentation, heuristic rules, and isotope pattern matching.

    Science.gov (United States)

    Pluskal, Tomáš; Uehara, Taisuke; Yanagida, Mitsuhiro

    2012-05-15

    Mass spectrometry is commonly applied to qualitatively and quantitatively profile small molecules, such as peptides, metabolites, or lipids. Modern mass spectrometers provide accurate measurements of mass-to-charge ratios of ions, with errors as low as 1 ppm. Even such high mass accuracy, however, is not sufficient to determine the unique chemical formula of each ion, and additional algorithms are necessary. Here we present a universal software tool for predicting chemical formulas from high-resolution mass spectrometry data, developed within the MZmine 2 framework. The tool is based on the use of a combination of heuristic techniques, including MS/MS fragmentation analysis and isotope pattern matching. The performance of the tool was evaluated using a real metabolomic data set obtained with the Orbitrap MS detector. The true formula was correctly determined as the highest-ranking candidate for 79% of the tested compounds. The novel isotope pattern-scoring algorithm outperformed a previously published method in 64% of the tested Orbitrap spectra. The software described in this manuscript is freely available and its source code can be accessed within the MZmine 2 source code repository.

  19. SPIRAL2/DESIR high resolution mass separator

    Energy Technology Data Exchange (ETDEWEB)

    Kurtukian-Nieto, T., E-mail: kurtukia@cenbg.in2p3.fr [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver B.C., V6T 2A3 (Canada); Blank, B.; Chiron, T. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Davids, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Delalee, F. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Duval, M. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); El Abbeir, S.; Fournier, A. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Lunney, D. [CSNSM-IN2P3-CNRS, Université de Paris Sud, F-91405 Orsay (France); Méot, F. [BNL, Upton, Long Island, New York (United States); Serani, L. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Stodel, M.-H.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); and others

    2013-12-15

    DESIR is the low-energy part of the SPIRAL2 ISOL facility under construction at GANIL. DESIR includes a high-resolution mass separator (HRS) with a designed resolving power m/Δm of 31,000 for a 1 π-mm-mrad beam emittance, obtained using a high-intensity beam cooling device. The proposed design consists of two 90-degree magnetic dipoles, complemented by electrostatic quadrupoles, sextupoles, and a multipole, arranged in a symmetric configuration to minimize aberrations. A detailed description of the design and results of extensive simulations are given.

  20. High-resolution x-ray photoemission spectra of silver

    DEFF Research Database (Denmark)

    Barrie, A.; Christensen, N. E.

    1976-01-01

    An electron spectrometer fitted with an x-ray monochromator for Al Kα1,2 radiation (1486.6 eV) has been used to record high-resolution x-ray photoelectron spectra for the 4d valence band as well as the 3d spin doublet in silver. The core-level spectrum has a line shape that can be described...

  1. Understanding reconstructed Dante spectra using high resolution spectroscopy

    Science.gov (United States)

    May, M. J.; Weaver, J.; Widmann, K.; Kemp, G. E.; Thorn, D.; Colvin, J. D.; Schneider, M. B.; Moore, A.; Blue, B. E.

    2016-11-01

    The Dante is an 18 channel filtered diode array used at the National Ignition Facility (NIF) to measure the spectrally and temporally resolved radiation flux between 50 eV and 20 keV from various targets. The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and a reconstruction algorithm applied to the recorded voltages from each channel. The reconstructed spectra are very low resolution with features consistent with the instrument response and are not necessarily consistent with the spectral emission features from the plasma. Errors may exist between the reconstructed spectra and the actual emission features due to assumptions in the algorithm. Recently, a high resolution convex crystal spectrometer, VIRGIL, has been installed at NIF with the same line of sight as the Dante. Spectra from L-shell Ag and Xe have been recorded by both VIRGIL and Dante. Comparisons of these two spectroscopic measurements yield insights into the accuracy of the Dante reconstructions.

  2. Understanding reconstructed Dante spectra using high resolution spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    May, M. J., E-mail: may13@llnl.gov; Widmann, K.; Kemp, G. E.; Thorn, D.; Colvin, J. D.; Schneider, M. B.; Moore, A.; Blue, B. E. [L-170 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551 (United States); Weaver, J. [Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States)

    2016-11-15

    The Dante is an 18 channel filtered diode array used at the National Ignition Facility (NIF) to measure the spectrally and temporally resolved radiation flux between 50 eV and 20 keV from various targets. The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and a reconstruction algorithm applied to the recorded voltages from each channel. The reconstructed spectra are very low resolution with features consistent with the instrument response and are not necessarily consistent with the spectral emission features from the plasma. Errors may exist between the reconstructed spectra and the actual emission features due to assumptions in the algorithm. Recently, a high resolution convex crystal spectrometer, VIRGIL, has been installed at NIF with the same line of sight as the Dante. Spectra from L-shell Ag and Xe have been recorded by both VIRGIL and Dante. Comparisons of these two spectroscopic measurements yield insights into the accuracy of the Dante reconstructions.

  3. High Resolution Studies of Mass Loss from Massive Binary Stars

    Science.gov (United States)

    Corcoran, Michael F.; Gull, Theodore R.; Hamaguchi, Kenji; Richardson, Noel; Madura, Thomas; Post Russell, Christopher Michael; Teodoro, Mairan; Nichols, Joy S.; Moffat, Anthony F. J.; Shenar, Tomer; Pablo, Herbert

    2017-01-01

    Mass loss from hot luminous single and binary stars has a significant, perhaps decisive, effect on their evolution. The combination of X-ray observations of hot shocked gas embedded in the stellar winds and high-resolution optical/UV spectra of the cooler mass in the outflow provides unique ways to study the unstable process by which massive stars lose mass both through continuous stellar winds and rare, impulsive, large-scale mass ejections. The ability to obtain coordinated observations with the Hubble Space Telescope Imaging Spectrograph (HST/STIS) and the Chandra High-Energy Transmission Grating Spectrometer (HETGS) and other X-ray observatories has allowed, for the first time, studies of resolved line emisssion over the temperature range of 104- 108K, and has provided observations to confront numerical dynamical models in three dimensions. Such observations advance our knowledge of mass-loss asymmetries, spatial and temporal variabilities, and the fundamental underlying physics of the hot shocked outflow, providing more realistic constraints on the amount of mass lost by different luminous stars in a variety of evolutionary stages. We discuss the impact that these joint observational studies have had on our understanding of dynamical mass outflows from massive stars, with particular emphasis on two important massive binaries, Delta Ori Aa, a linchpin of the mass luminosity relation for upper HRD main sequence stars, and the supermassive colliding wind binary Eta Carinae.

  4. High Resolution Optical and NIR Spectra of HBC 722

    CERN Document Server

    Lee, Jeong-Eun; Green, Joel D; Cochran, William D; Kang, Wonseok; Lee, Sang-Gak; Sung, Hyun-Il

    2015-01-01

    We present the results of high resolution (R$\\ge$30,000) optical and near-IR spectroscopic monitoring observations of HBC 722, a recent FU Orionis object that underwent an accretion burst in 2010. We observed HBC 722 in optical/near-IR with the BOES, HET-HRS, and IGRINS spectrographs, at various points in the outburst. We found atomic lines with strongly blueshifted absorption features or P Cygni profiles, both evidence of a wind driven by the accretion. Some lines show a broad double-peaked absorption feature, evidence of disk rotation. However, the wind-driven and disk-driven spectroscopic features are anti-correlated in time; the disk features became strong as the wind features disappeared. This anti-correlation might indicate that the rebuilding of the inner disk was interrupted by the wind pressure during the first two years. The Half-Width at Half-Depth (HWHD) of the double-peaked profiles decreases with wavelength, indicative of the Keplerian rotation; the optical spectra with the disk feature are fitt...

  5. HIGH RESOLUTION OPTICAL AND NIR SPECTRA OF HBC 722

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong-Eun; Park, Sunkyung [School of Space Research, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Green, Joel D.; Cochran, William D. [Department of Astronomy, University of Texas at Austin, TX (United States); Kang, Wonseok; Lee, Sang-Gak [National Youth Space Center, 200 Deokheungyangjjok-gil, Dongil-myeon, Goheung-gun, Jeollanam-do 548-951 (Korea, Republic of); Sung, Hyun-Il, E-mail: jeongeun.lee@khu.ac.kr, E-mail: sunkyung@khu.ac.kr, E-mail: joel@astro.as.utexas.edu, E-mail: wdc@astro.as.utexas.edu, E-mail: wskang@kywa.or.kr, E-mail: sanggak@kywa.or.kr, E-mail: hisung@kasi.re.kr [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

    2015-07-01

    We present the results of high resolution (R ≥ 30,000) optical and near-IR spectroscopic monitoring observations of HBC 722, a recent FU Orionis object that underwent an accretion burst in 2010. We observed HBC 722 in the optical/near-IR with the Bohyunsan Optical Echelle Spectrograph, Hobby–Eberly Telescope-HRS, and Immersion Grating Infrared Spectrograph, at various points in the outburst. We found atomic lines with strongly blueshifted absorption features or P Cygni profiles, both evidence of a wind driven by the accretion. Some lines show a broad double-peaked absorption feature, evidence of disk rotation. However, the wind-driven and disk-driven spectroscopic features are anti-correlated in time; the disk features became strong as the wind features disappeared. This anti-correlation might indicate that the rebuilding of the inner disk was interrupted by the wind pressure during the first 2 years. The half-width at half-depth of the double-peaked profiles decreases with wavelength, indicative of the Keplerian rotation; the optical spectra with the disk feature are fitted by a G5 template stellar spectrum convolved with a rotation velocity of 70 km s{sup −1} while the near-IR disk features are fitted by a K5 template stellar spectrum convolved with a rotation velocity of 50 km s{sup −1}. Therefore, the optical and near-IR spectra seem to trace the disk at 39 and 76 R{sub ⊙}, respectively. We fit a power-law temperature distribution in the disk, finding an index of 0.8, comparable to optically thick accretion disk models.

  6. Intact MicroRNA Analysis Using High Resolution Mass Spectrometry

    Science.gov (United States)

    Kullolli, Majlinda; Knouf, Emily; Arampatzidou, Maria; Tewari, Muneesh; Pitteri, Sharon J.

    2014-01-01

    MicroRNAs (miRNAs) are small single-stranded non-coding RNAs that post-transcriptionally regulate gene expression, and play key roles in the regulation of a variety of cellular processes and in disease. New tools to analyze miRNAs will add understanding of the physiological origins and biological functions of this class of molecules. In this study, we investigate the utility of high resolution mass spectrometry for the analysis of miRNAs through proof-of-concept experiments. We demonstrate the ability of mass spectrometry to resolve and separate miRNAs and corresponding 3' variants in mixtures. The mass accuracy of the monoisotopic deprotonated peaks from various miRNAs is in the low ppm range. We compare fragmentation of miRNA by collision-induced dissociation (CID) and by higher-energy collisional dissociation (HCD) which yields similar sequence coverage from both methods but additional fragmentation by HCD versus CID. We measure the linear dynamic range, limit of detection, and limit of quantitation of miRNA loaded onto a C18 column. Lastly, we explore the use of data-dependent acquisition of MS/MS spectra of miRNA during online LC-MS and demonstrate that multiple charge states can be fragmented, yielding nearly full sequence coverage of miRNA on a chromatographic time scale. We conclude that high resolution mass spectrometry allows the separation and measurement of miRNAs in mixtures and a standard LC-MS setup can be adapted for online analysis of these molecules.

  7. Spectroscopic Characterisation of CARMENES Target Candidates from FEROS, CAFE and HRS High-Resolution Spectra

    Science.gov (United States)

    Passegger, Vera Maria; Reiners, Ansgar; Jeffers, Sandra V.; Wende, Sebastian; Schöfer, Patrick; Amado, Pedro J.; Caballero, Jose A.; Montes, David; Mundt, Reinhard; Ribas, Ignasi; Quirrenbach, Andreas

    2016-07-01

    CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible and near-infrared at Calar Alto Observatory. They will perform high-accuracy radial-velocity measurements (goal 1 m s-1) of about 300 M-dwarfs with the aim to detect low-mass planets within habitable zones. We characterised the candidate sample for CARMENES and provide fundamental parameters for these stars in order to constrain planetary properties and understand star-planet systems. Using state-of-the-art model atmospheres (PHOENIX-ACES) and χ2-minimization with a downhill-simplex method we determine effective temperature, surface gravity and metallicity [Fe/H] for high-resolution spectra of around 480 stars of spectral types M0.0-6.5V taken with FEROS, CAFE and HRS. We find good agreement between the models and our observed high-resolution spectra. We show the performance of the algorithm, as well as results, parameter and spectral type distributions for the CARMENES candidate sample, which is used to define the CARMENES target sample. We also present first preliminary results obtained from CARMENES spectra.

  8. Spectroscopic characterisation of CARMENES target candidates from FEROS, CAFE and HRS high-resolution spectra

    CERN Document Server

    Passegger, V M; Jeffers, S V; Wende, S; Schöfer, P; Amado, P J; Caballero, J A; Montes, D; Mundt, R; Ribas, I; Quirrenbach, A

    2016-01-01

    CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible and near-infrared at Calar Alto Observatory. They will perform high-accuracy radial-velocity measurements (goal 1 m s-1) of about 300 M-dwarfs with the aim to detect low-mass planets within habitable zones. We characterised the candidate sample for CARMENES and provide fundamental parameters for these stars in order to constrain planetary properties and understand star-planet systems. Using state-of-the-art model atmospheres (PHOENIX-ACES) and chi2-minimization with a downhill-simplex method we determine effective temperature, surface gravity and metallicity [Fe/H] for high-resolution spectra of around 480 stars of spectral types M0.0-6.5V taken with FEROS, CAFE and HRS. We find good agreement between the models and our observed high-resolution spectra. We sh...

  9. High Resolution Optical Spectra of HBC 722 after Outburst

    CERN Document Server

    Lee, Jeong-Eun; Lee, Sang-Gak; Sung, Hyun-Il; Lee, Byeong-Cheol; Sung, Hwankyung; Green, Joel D; Jeon, Young-Beom

    2011-01-01

    We report the results of our high resolution optical spectroscopic monitoring campaign ($\\lambda$ = 3800 -- 8800 A, R = 30000 -- 45000) of the new FU Orionis-type object HBC 722. We observed HBC 722 with the BOES 1.8-m telescope between 2010 November 26 and 2010 December 29 and FU Orionis itself on 2011 January 26. We detect a number of previously unreported high-resolution K I and Ca II lines beyond 7500 A. We resolve the H$\\alpha$ and Ca II line profiles into three velocity components, which we attribute to both disk and outflow. The increased accretion during outburst can heat the disk to produce the relatively narrow absorption feature and launch outflows appearing as high velocity blue and redshifted broad features.

  10. LSD-based analysis of high-resolution stellar spectra

    Science.gov (United States)

    Tsymbal, V.; Tkachenko, A.; Van, Reeth T.

    2014-11-01

    We present a generalization of the method of least-squares deconvolution (LSD), a powerful tool for extracting high S/N average line profiles from stellar spectra. The generalization of the method is effected by extending it towards the multiprofile LSD and by introducing the possibility to correct the line strengths from the initial mask. We illustrate the new approach by two examples: (a) the detection of astroseismic signatures from low S/N spectra of single stars, and (b) disentangling spectra of multiple stellar objects. The analysis is applied to spectra obtained with 2-m class telescopes in the course of spectroscopic ground-based support for space missions such as CoRoT and Kepler. Usually, rather high S/N is required, so smaller telescopes can only compete successfully with more advanced ones when one can apply a technique that enables a remarkable increase in the S/N of the spectra which they observe. Since the LSD profiles have a potential for reconstruction what is common in all the spectral profiles, it should have a particular practical application to faint stars observed with 2-m class telescopes and whose spectra show remarkable LPVs.

  11. Yeast expression proteomics by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Walther, Tobias C; Olsen, Jesper Velgaard; Mann, Matthias

    2010-01-01

    -translational controls contribute majorly to regulation of protein abundance, for example in heat shock stress response. The development of new sample preparation methods, high-resolution mass spectrometry and novel bioinfomatic tools close this gap and allow the global quantitation of the yeast proteome under different...... conditions. Here, we provide background information on proteomics by mass-spectrometry and describe the practice of a comprehensive yeast proteome analysis....

  12. 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...

  13. TES/Aura L1B Spectra Special Observation High Resolution V004

    Data.gov (United States)

    National Aeronautics and Space Administration — A L1B High Resolution granule consists of radiometrically calibrated spectra & associated NESR, observed at 0.025 cm-1 resolution for a Special Observation &...

  14. High-resolution spectra of the planetary nebula NGC 6803

    Science.gov (United States)

    Lee, S.-J.; Hyung, S.

    2013-01-01

    We present the high-dispersion spectra of the elliptical ring shaped planetary nebula NGC 6803, secured with the Hamilton Echelle Spectrograph attached to the 3-m Shane telescope of Lick Observatory. Numerous lines from neutral to quadruply ionized ions are presented in the wavelength region from 3650 to 9900 Å. We also use the low dispersion UV spectral data obtained with the 60-cm interstellar ultraviolet explorer. In spite of its simplistic symmetrical bilateral shape, the diagnostics imply that the physical condition of the nebular shell is very complex with a huge density range of 1300-80 000 cm-3. A comparison of the 1995 and 2001 [Ar iv] data suggests that the density increase occurred near the inner shell boundary. In spite of a huge ionization potential range, the average electron temperature indicated by primary diagnostic lines is relatively low, i.e., Te ≤ 9500 K, except for [Cl iv], from which we derive a temperature that is around 11 500 K. We derived the chemical abundances of He, C, N, O, Ne, S, Ar, Cl, and K, based on the physical condition suggested by diagnostics and photo-ionization analysis. The chemical abundances of NGC 6803 are mostly enhanced when compared with the average Galactic planetary nebula. The effective temperature of its central star appears to be about 90 000 K and its luminosity about 2400 L⊙, assuming a distance of 3000 pc. The evolutionary track implies that NGC 6803 might have been evolved from a companion star of about 1.0 M⊙ in a binary system, or from a single progenitor of about 1.5 M⊙, born in a metal-rich zone near the Galactic plane. Table 2 is available in electronic form at http://www.aanda.org

  15. VizieR Online Data Catalog: High-resolution NIR spectra of local giants (Feuillet+, 2016)

    Science.gov (United States)

    Feuillet, D. K.; Bovy, J.; Holtzman, J.; Girardi, L.; MacDonald, N.; Majewski, S. R.; Nidever, D. L.

    2016-04-01

    We present a sample of 705 local giant stars observed using the New Mexico State University 1m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R~22500), near infrared (1.51-1.7μm) APOGEE spectra provide measurements of stellar atmospheric parameters (temperature, surface gravity, [M/H], and [α/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 30%. For giants, the relatively rapid evolution up the red giant branch allows the age to be constrained by the mass. We examine methods of estimating age using both the mass-age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant SFH. To improve the SFH prior, we use a hierarchical modeling approach to constrain the parameters of the model SFH using the age probability distribution functions of the data. The results of an α-dependent Gaussian SFH model show a clear age-[α/M] relation at all ages. Using this SFH model as the prior for an empirical Bayesian analysis, we determine ages for individual stars. The resulting age-metallicity relation is flat, with a slight decrease in [M/H] at the oldest ages and a ~0.5 dex spread in metallicity across most ages. For stars with ages <~1Gyr we find a smaller spread, consistent with radial migration having a smaller effect on these young stars than on the older stars. (1 data file).

  16. Total lineshape analysis of high-resolution NMR spectra powered by simulated annealing

    Science.gov (United States)

    Cheshkov, D. A.; Sinitsyn, D. O.; Sheberstov, K. F.; Chertkov, V. A.

    2016-11-01

    The novel algorithm for a total lineshape analysis of high-resolution NMR spectra has been developed. A global optimization by simulated annealing has been applied that has allowed to overcome the main trouble of common approaches which had frequently returned solutions for local minima rather than for global ones. The algorithm has been verified for the four-spin test systems ABCD, and has been successfully used for analysis of experimental NMR spectra of proline. The approach has allowed to avoid a sophisticated manual setup of initial parameters and to conduct the analysis of complicated high-resolution NMR spectra nearly automatically.

  17. Fragmentation reactions of labeled and untabeled Rhodamine B in a high-resolution Fourier transform ion cyclotron resonance mass spectrometer.

    Science.gov (United States)

    Clemen, Martin; Gernert, Claus; Peters, Jonathan; Grotemeyer, Jürgen

    2013-01-01

    The fragmentation reactions of Rhodamine B have been investigated by the use of electrospray ionization mass spectra in a high mass resolving ion cyclotron resonance mass spectrometer. Using high resolution, it could be shown that the loss of 44 mass units from the molecular ion is due to propane; the measured masses were inconsistent with loss of carbon dioxide. These conclusions are supported using deuterium-labeled Rhodamine B. This sample again only shows the loss of fully-deuterated propane verifying the high-resolution data. These findings illustrate very clearly that the conclusions based solely on low resolution spectra were false. The general implication on fragmentations of aromatic acids is discussed.

  18. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    Science.gov (United States)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias; Helmus, Rick; Knepper, Thomas P.; de Voogt, Pim

    2016-02-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.

  19. A high-resolution record of Greenland mass balance

    Science.gov (United States)

    McMillan, Malcolm; Leeson, Amber; Shepherd, Andrew; Briggs, Kate; Armitage, Thomas W. K.; Hogg, Anna; Kuipers Munneke, Peter; Broeke, Michiel; Noël, Brice; Berg, Willem Jan; Ligtenberg, Stefan; Horwath, Martin; Groh, Andreas; Muir, Alan; Gilbert, Lin

    2016-07-01

    We map recent Greenland Ice Sheet elevation change at high spatial (5 km) and temporal (monthly) resolution using CryoSat-2 altimetry. After correcting for the impact of changing snowpack properties associated with unprecedented surface melting in 2012, we find good agreement (3 cm/yr bias) with airborne measurements. With the aid of regional climate and firn modeling, we compute high spatial and temporal resolution records of Greenland mass evolution, which correlate (R = 0.96) with monthly satellite gravimetry and reveal glacier dynamic imbalance. During 2011-2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland's area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.

  20. The First High-Resolution Spectra of 1.3 L Subdwarfs

    CERN Document Server

    Reiners, A; Basri, Gibor; Reiners, Ansgar

    2005-01-01

    We present the first high-resolution (R ~ 31,000) spectra of the cool sdL 2MASS0532, and what was originally identified as an early-type L subdwarf (sdL) LSR1610-0040. Our work, in combination with contemporaneous work by Cushing and Vacca, makes it clear that the latter object is more probably a mid-M dwarf with an unusual composition that gives it some sub-dwarf spectral features. We use the data to derive precise radial velocities for both objects and to estimate space motion; both are consistent with halo kinematics. We measure the projected rotational velocities, revealing very slow rotation for the old sd?M6 object \\lsr. \\twom exhibits rapid rotation of vsini = 65 +- 15km/s, consistent with the behavior of L dwarfs. This means that the braking time for L dwarfs is extremely long, or that perhaps they never slow down. A detailed comparison of the atomic Rb and Cs lines to spectra of field L dwarfs shows the spectral type \\twom is consistent with being mid- to late-L. The Rb I and K I lines of \\lsr\\ are l...

  1. HCN Polymers: Toward Structure Comprehension Using High Resolution Mass Spectrometry

    Science.gov (United States)

    Bonnet, Jean-Yves; Thissen, Roland; Frisari, Ma; Vuitton, Veronique; Quirico, Eric; Le Roy, Léna; Fray, Nicolas; Cottin, Hervé; Horst, Sarah; Yelle, Roger

    A lot of solar system materials, including cometary ices and Titan aerosols, contain dark matter that can be interpreted as complex nitrogen bearing organic matter [1]. In laboratory experi-ments, HCN polymers are thus analogs of great interest. In fact they may be present in Titan atmosphere and in comet nuclei and then reprocessed as a CN distributed source [2], when ices began to sublimate and ejects from the nucleus organic matter grains [3]. The presence of HCN polymers is suggested because HCN molecule has been directly observed in 1P/Halley comet [4] and others. HCN polymers are also of prebiotic interest [5] as it can form amino acid under hydrolysis conditions. Even if they have been studied during the last decades, their chemical composition and structure are still poorly understood, and a great analytical effort has to be continued. In this way we present a high resolution mass spectrometry (HRMS) and a high resolution tandem mass spectrometry (MS/HRMS) analysis of HCN polymers. It was shown [6] that this is a suitable technique to elucidate composition and structure of the soluble part of tholins analogs of Titan's atmosphere aerosols. HCN polymers have never been studied by HRMS, thus we used a LTQ-Orbitrap XL high resolution mass spectrometer to analyse the HCN polymers. These are produced at LISA by direct polymerisation of pure liquid HCN, catalyzed by ammonia. HCN polymers have been completely dissolved in methanol and then injected in the mass spectrometer by ElectroSpray Ionization (ESI). This atmospheric pressure ionization process produces protonated or deprotonated ions, but it does not fragment molecules. Thus HRMS, allows a direct access to the stoechiometry of all the ionizable molecules present in the samples. Fragmentation analyses (MS/MS) of selected ions have also been performed. Thess analysis provide information about the different chemical fonctionnalities present in HCN poly-mers and also about their structure. Thus we are able to

  2. Determination of Total Ozone over Mauna Loa Using Very High Resolution Infrared Solar Spectra

    Science.gov (United States)

    David, Shelle J.; Beaton, Sheryl A.; Anderberg, Mary H.; Murcray, Frank J.

    1993-01-01

    A very high resolution infrared Fourier transform spectrometer has been used to record solar spectra at the Mauna Loa Observatory in Hawaii. Spectra are normally taken one day a week at sunrise. These spectra have been analyzed for ozone and N2O total columns, and the ozone column compared with the value reported by tile Mauna Loa Dobson spectrophotometer. Aside from the FTIR reporting about 5% lower values than the Dobson (which may be due to a systematic difference in the treatment of tropospheric ozone), the FTIR and Dobson agree to within 2.7% (RMS) during this period.

  3. VO-compliant libraries of high resolution spectra of cool stars

    Science.gov (United States)

    Montes, D.

    2008-10-01

    In this contribution we describe a Virtual Observatory (VO) compliant version of the libraries of high resolution spectra of cool stars described by Montes et al. (1997; 1998; and 1999). Since their publication the fully reduced spectra in FITS format have been available via ftp and in the World Wide Web. However, in the VO all the spectra will be accessible using a common web interface following the standards of the International Virtual Observatory Alliance (IVOA). These libraries include F, G, K and M field stars, from dwarfs to giants. The spectral coverage is from 3800 to 10000 Å, with spectral resolution ranging from 0.09 to 3.0 Å.

  4. Proteogenomic analysis of Mycobacterium smegmatis using high resolution mass spectrometry

    Directory of Open Access Journals (Sweden)

    Matthys Gerhardus Potgieter

    2016-04-01

    Full Text Available AbstractBiochemical evidence is vital for accurate genome annotation. The integration of experimental data collected at the proteome level using high resolution mass spectrometry allows for improvements in genome annotation by providing evidence for novel gene models, while validating or modifying others. Here we report the results of a proteogenomic analysis of a reference strain of Mycobacterium smegmatis (mc2155, a fast growing model organism for the pathogenic Mycobacterium tuberculosis - the causative agent for Tuberculosis. By integrating high throughput LC/MS/MS proteomic data with genomic six frame translation and ab initio gene prediction databases, a total of 2887 ORFs were identified, including 2810 ORFs annotated to a Reference protein, and 63 ORFs not previously annotated to a Reference protein. Further, the translational start site (TSS was validated for 558 Reference proteome gene models, while upstream translational evidence was identified for 81. In addition, N-terminus derived peptide identifications allowed for downstream TSS modification of a further 24 gene models. We validated the existence of 6 previously described interrupted coding sequences at the peptide level, and provide evidence for 4 novel frameshift positions. Analysis of peptide posterior error probability (PEP scores indicates high-confidence novel peptide identifications and shows that the genome of M. smegmatis mc2155 is not yet fully annotated. Data are available via ProteomeXchange with identifier PXD003500.

  5. Determination of phosphorus using high-resolution diphosphorus molecular absorption spectra produced in the graphite furnace

    Science.gov (United States)

    Huang, Mao Dong; Becker-Ross, Helmut; Okruss, Michael; Geisler, Sebastian; Florek, Stefan

    2016-01-01

    Molecular absorption of diphosphorus was produced in a graphite furnace and evaluated in view of its suitability for phosphorus determination. Measurements were performed with two different high-resolution continuum source absorption spectrometers. The first system is a newly in-house developed simultaneous broad-range spectrograph, which was mainly used for recording overview absorption spectra of P2 between 193 nm and 245 nm. The region covers the main part of the C 1Σu+ ← X 1Σg+ electronic transition and shows a complex structure with many vibrational bands, each consisting of a multitude of sharp rotational lines. With the help of molecular data available for P2, an assignment of the vibrational bands was possible and the rotational structure could be compared with simulated spectra. The second system is a commercial sequential continuum source spectrometer, which was used for the basic analytical measurements. The P2 rotational line at 204.205 nm was selected and systematically evaluated with regard to phosphorus determination. The conditions for P2 generation were optimized and it was found that the combination of a ZrC modified graphite tube and borate as a chemical modifier were essential for a good production of P2. Serious interferences were found in the case of nitrate and sulfuric acid, although the nitrate interference can be eliminated by a higher pyrolysis temperature. The reliability of the method was proved by analysis of certified samples. Using standard tubes, a characteristic mass of 10 ng and a limit of detection of 7 ng were found. The values could further be improved by a factor of ten using a miniaturized tube with an internal diameter of 2 mm. Compared to the conventional method based on the phosphorus absorption line at 213.618 nm, the advantages of using P2 are the gentle temperature conditions and the potential of performing a simultaneous multi-line evaluation to further improve the limit of detection.

  6. Stars at high resolution: a library of synthetic spectra from 850 to 7000 Å

    Science.gov (United States)

    Bertone, E.; Buzzoni, A.; Rodríguez-Merino, L. H.; Chávez, M.

    We present a new theoretical library of about 2500 high-resolution spectra of stars covering a wide wavelength range from 850 to 7000 Å. The set consists of an ultraviolet grid (1690 spectra), at an inverse resolution R=50 000, and an optical grid (832 spectra), at R=500 000, and spans a large volume in the fundamental parameters space (i.e. Teff, log {g}, [M/H]). The synthetic spectra, based on the ATLAS 9 model atmospheres, have been computed with the SYNTHE code developed by R.L. Kurucz. These properties make the library an updated tool, especially suitable to match high-quality observing data from the new-generation telescopes.

  7. A high-throughput de novo sequencing approach for shotgun proteomics using high-resolution tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Banfield Jillian F

    2010-03-01

    Full Text Available Abstract Background High-resolution tandem mass spectra can now be readily acquired with hybrid instruments, such as LTQ-Orbitrap and LTQ-FT, in high-throughput shotgun proteomics workflows. The improved spectral quality enables more accurate de novo sequencing for identification of post-translational modifications and amino acid polymorphisms. Results In this study, a new de novo sequencing algorithm, called Vonode, has been developed specifically for analysis of such high-resolution tandem mass spectra. To fully exploit the high mass accuracy of these spectra, a unique scoring system is proposed to evaluate sequence tags based primarily on mass accuracy information of fragment ions. Consensus sequence tags were inferred for 11,422 spectra with an average peptide length of 5.5 residues from a total of 40,297 input spectra acquired in a 24-hour proteomics measurement of Rhodopseudomonas palustris. The accuracy of inferred consensus sequence tags was 84%. According to our comparison, the performance of Vonode was shown to be superior to the PepNovo v2.0 algorithm, in terms of the number of de novo sequenced spectra and the sequencing accuracy. Conclusions Here, we improved de novo sequencing performance by developing a new algorithm specifically for high-resolution tandem mass spectral data. The Vonode algorithm is freely available for download at http://compbio.ornl.gov/Vonode.

  8. The INES System; 2, Ripple Correction and Absolute Calibration for IUE High Resolution Spectra

    CERN Document Server

    Cassatella, A; González-Riestra, R; Ponz, J D; Barbero, J F G; Talavera, A; Wamsteker, W

    1999-01-01

    In this paper we document the results of the study which led to the ripple correction and absolute calibration algorithms applied to the high resolution spectra processed with the NEWSIPS software for the Final Archive of the IUE Project. In this analysis, based on a very large number of spectra, we find that both K and the alpha parameters (not only the former as previously believed) vary with order number. This fact, together with the finding that the central peaks of the blaze function vary also as a function of the THDA temperature (for the SWP camera) and of the date of observations (for the LWP and LWR cameras), makes the ripple correction algorithm more complex than previously considered but, at the same time, considerably more reliable. As for the high resolution absolute calibration, the method followed is similar to the one implemented in IUESIPS. The internal accuracy of the high resolution calibration is about 4%. We note that the ripple correction and absolute calibration algorithms here describe...

  9. High-resolution photoelectron spectra of the pyrimidine-type nucleobases.

    Science.gov (United States)

    Fulfer, K D; Hardy, D; Aguilar, A A; Poliakoff, E D

    2015-06-14

    High-resolution photoelectron spectra of the gas phase pyrimidine-type nucleobases, thymine, uracil, and cytosine, were collected using synchrotron radiation over the photon energy range 17 ≤ hν ≤ 150 eV. These data provide the highest resolution photoelectron spectra of thymine, uracil, and cytosine published to date. By comparing integrated regions of the energy dependent photoelectron spectra of thymine, the ionization potentials of the first four ionic states of thymine were estimated to be 8.8, 9.8, 10.3, and 10.8 eV. The thymine data also show evidence for low energy shape resonances in three of the outermost valence electronic states. Comparing the uracil spectrum with the thymine spectrum, the four outermost valence electronic states of uracil likely begin at binding energies 9.3, 9.9, 10.5, and 11.0 eV. High-resolution spectra indicate only one tautomeric form of cytosine contributes significantly to the spectrum with the four outermost valence electronic states beginning at binding energies 8.9, 9.9, 10.4, and 10.85 eV.

  10. High-resolution photoelectron spectra of the pyrimidine-type nucleobases

    Energy Technology Data Exchange (ETDEWEB)

    Fulfer, K. D.; Hardy, D.; Poliakoff, E. D., E-mail: epoliak@lsu.edu [Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Aguilar, A. A. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2015-06-14

    High-resolution photoelectron spectra of the gas phase pyrimidine-type nucleobases, thymine, uracil, and cytosine, were collected using synchrotron radiation over the photon energy range 17 ≤ hν ≤ 150 eV. These data provide the highest resolution photoelectron spectra of thymine, uracil, and cytosine published to date. By comparing integrated regions of the energy dependent photoelectron spectra of thymine, the ionization potentials of the first four ionic states of thymine were estimated to be 8.8, 9.8, 10.3, and 10.8 eV. The thymine data also show evidence for low energy shape resonances in three of the outermost valence electronic states. Comparing the uracil spectrum with the thymine spectrum, the four outermost valence electronic states of uracil likely begin at binding energies 9.3, 9.9, 10.5, and 11.0 eV. High-resolution spectra indicate only one tautomeric form of cytosine contributes significantly to the spectrum with the four outermost valence electronic states beginning at binding energies 8.9, 9.9, 10.4, and 10.85 eV.

  11. kspectrum: an open-source code for high-resolution molecular absorption spectra production

    Science.gov (United States)

    Eymet, V.; Coustet, C.; Piaud, B.

    2016-01-01

    We present the kspectrum, scientific code that produces high-resolution synthetic absorption spectra from public molecular transition parameters databases. This code was originally required by the atmospheric and astrophysics communities, and its evolution is now driven by new scientific projects among the user community. Since it was designed without any optimization that would be specific to any particular application field, its use could also be extended to other domains. kspectrum produces spectral data that can subsequently be used either for high-resolution radiative transfer simulations, or for producing statistic spectral model parameters using additional tools. This is a open project that aims at providing an up-to-date tool that takes advantage of modern computational hardware and recent parallelization libraries. It is currently provided by Méso-Star (http://www.meso-star.com) under the CeCILL license, and benefits from regular updates and improvements.

  12. Accurate Gravities of F, G, and K stars from High Resolution Spectra Without External Constraints

    CERN Document Server

    Brewer, John M; Basu, Sarbani; Valenti, Jeff A; Piskunov, Nikolai

    2015-01-01

    We demonstrate a new procedure to derive accurate and precise surface gravities from high resolution spectra without the use of external constraints. Our analysis utilizes Spectroscopy Made Easy (SME) with robust spectral line constraints and uses an iterative process to mitigate degeneracies in the fitting process. We adopt an updated radiative transfer code, a new treatment for neutral perturber broadening, a line list with multiple gravity constraints and separate fitting for global stellar properties and abundance determinations. To investigate the sources of temperature dependent trends in determining log g noted in previous studies, we obtained Keck HIRES spectra of 42 Kepler asteroseismic stars. In comparison to asteroseismically determined log g our spectroscopic analysis has a constant offset of 0.01 dex with a root mean square (RMS) scatter of 0.05 dex. We also analyzed 30 spectra which had published surface gravities determined using the $a/R_*$ technique from planetary transits and found a constan...

  13. A high-resolution neutron spectra unfolding method using the Genetic Algorithm technique

    CERN Document Server

    Mukherjee, B

    2002-01-01

    The Bonner sphere spectrometers (BSS) are commonly used to determine the neutron spectra within various nuclear facilities. Sophisticated mathematical tools are used to unfold the neutron energy distribution from the output data of the BSS. This paper highlights a novel high-resolution neutron spectra-unfolding method using the Genetic Algorithm (GA) technique. The GA imitates the biological evolution process prevailing in the nature to solve complex optimisation problems. The GA method was utilised to evaluate the neutron energy distribution, average energy, fluence and equivalent dose rates at important work places of a DIDO class research reactor and a high-energy superconducting heavy ion cyclotron. The spectrometer was calibrated with a sup 2 sup 4 sup 1 Am/Be (alpha,n) neutron standard source. The results of the GA method agreed satisfactorily with the results obtained by using the well-known BUNKI neutron spectra unfolding code.

  14. The high resolution vacuum ultraviolet absorption spectra of the group VI dihydrides and deuterides Rydberg series

    CERN Document Server

    Mayhew, C A

    1984-01-01

    The high resolution absorption spectra of the important group VI dihydrides and deuterides in the vacuum ultraviolet below, and up to, their first ionisation potentials are presented. These spectra were recorded using synchrotron radiation as the background light source in conjunction with a 3m normal incidence vacuum spectrograph, equipped with holographic gratings. Due to the nature of the originating orbital for the majority of optical transitions in the VUV well developed Rydberg series are observed. One particular series can be followed up to fairly high n, so that accurate values of the first ionisation potential are determined. The identifications of the Rydberg series are made from arguments relating to their oscillator strengths, quantum defects, symmetries and from comparisons with the spectra of the corresponding united atoms i.e. the inert gases. Examples of the symmetry assignments for Rydberg series from rotational band contour analyses of the lower Rydberg members for the H sub 2 S, H sub 2 Se ...

  15. Time variations of narrow absorption lines in high resolution quasar spectra

    CERN Document Server

    Boissé, P; Prochaska, J X; Péroux, C; York, D G

    2015-01-01

    Aims. We have searched for temporal variations of narrow absorption lines in high resolution quasar spectra. A sample of 5 distant sources have been assembled, for which 2 spectra - VLT/UVES or Keck/HIRES - taken several years apart are available. Methods. We first investigate under which conditions variations in absorption line profiles can be detected reliably from high resolution spectra, and discuss the implications of changes in terms of small-scale structure within the intervening gas or intrinsic origin. The targets selected allow us to investigate the time behavior of a broad variety of absorption line systems, sampling diverse environments: the vicinity of active nuclei, galaxy halos, molecular-rich galaxy disks associated with damped Lya systems, as well as neutral gas within our own Galaxy. Results. Absorption lines from MgII, FeII or proxy species with lines of lower opacity tracing the same kind of gas appear to be remarkably stable (1 sigma upper limits as low as 10 % for some components on scal...

  16. CRIRES-POP: A library of high resolution spectra in the near-infrared

    CERN Document Server

    Lebzelter, T; Uttenthaler, S; Ramsay, S; Hartman, H; Nieva, M -F; Przybilla, N; Smette, A; Wahlgren, G M; Wolff, B; Hussain, G A J; Kaeufl, H U; Seemann, U

    2012-01-01

    New instrumental capabilities and the wealth of astrophysical information extractable from the near-infrared wavelength region have led to a growing interest in the field of high resolution spectroscopy at 1-5 mu. We aim to provide a library of observed high-resolution and high signal-to-noise-ratio near-infrared spectra of stars of various types throughout the Hertzsprung-Russell diagram. This is needed for the exploration of spectral features in this wavelength range and for comparison of reference targets with observations and models. High quality spectra were obtained using the CRIRES near-infrared spectrograph at ESO's VLT covering the range from 0.97 to 5.3 mu at high spectral resolution. Accurate wavelength calibration and correction for of telluric lines were performed by fitting synthetic transmission spectra for the Earth's atmosphere to each spectrum individually. We describe the observational strategy and the current status and content of the library which includes 13 objects. The first examples o...

  17. SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, W; Laura Tovo, L

    2008-07-08

    The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms

  18. Analysis of the high resolution Mg XI x-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Siarkowski, M.; Sylwester, J. (Polska Akademia Nauk, Wroclaw. Centrum Badan Kosmicznych); Bromboszcz, G. (Wrolaw Univ. (Poland). Astronomical Inst.); Korneev, V.V.; Mandelshtam, S.L.; Oparin, S.N.; Urnov, A.M.; Zhitnik, I.A. (AN SSSR, Moscow. Fizicheskij Inst.); Vasha, S. (Mongolian Academy of Sciences, Ulan Bator (USSR). Inst. of Physics and Technics)

    1982-04-01

    In this paper, the second in a series dealing with high-resolution spectra (9.14-9.33 A) measured on board the INTERCOSMOS-16 satellite, the analysis of the physical conditions in the coronal part of the McMath 14352 active regions is performed. The temperature structure of the emitting plasma is investigated on the basis of the photon fluxes measured in six selected wavelength bands involving the resonance, intercombination, and forbidden lines of the Mg XI ion and a number of satellite lines. Relative line intensities are discussed in terms of the active region plasma density.

  19. Modelling High Resolution Absorption Spectra with ExoMolLine Lists: NH3and CH4

    DEFF Research Database (Denmark)

    Barton, E. J.; Yurchenko, S. N.; Tennyson, J.;

    The conditions, chemical reactions and gas mixing in industrial progresses involving gasification or combustion can be monitored by in situ measurement of gas temperature and gas composition. This can be done spectroscopically, though the result is highly dependent on the quality of reference data...... [1]. For this reason, a smart collaboration has been established between Optical Diagnostics Group at DTU and ExoMol, to combine high resolution spectra measured at elevated temperatures and empirically tuned ab initio methods to produce suitable molecular line lists for modelling molecules...

  20. Quantitation of Acrylamide in Foods by High-Resolution Mass Spectrometry

    NARCIS (Netherlands)

    Troise, A.D.; Fogliano, Vincenzo

    2016-01-01

    The use of liquid chromatography high-resolution mass spectrometry (LC-HRMS) and direct analysis real-time high-resolution mass spectrometry (DART-HRMS) defines a new scenario in the analysis of thermal-induced toxicants, such as acrylamide. Several factors contribute to the definition of the

  1. Quantitation of Acrylamide in Foods by High-Resolution Mass Spectrometry

    NARCIS (Netherlands)

    Troise, A.D.; Fogliano, Vincenzo

    2016-01-01

    The use of liquid chromatography high-resolution mass spectrometry (LC-HRMS) and direct analysis real-time high-resolution mass spectrometry (DART-HRMS) defines a new scenario in the analysis of thermal-induced toxicants, such as acrylamide. Several factors contribute to the definition of the com

  2. Fundamental M-dwarf parameters from high-resolution spectra using PHOENIX ACES models: I. Parameter accuracy and benchmark stars

    CERN Document Server

    Passegger, Vera Maria; Reiners, Ansgar

    2016-01-01

    M-dwarf stars are the most numerous stars in the Universe; they span a wide range in mass and are in the focus of ongoing and planned exoplanet surveys. To investigate and understand their physical nature, detailed spectral information and accurate stellar models are needed. We use a new synthetic atmosphere model generation and compare model spectra to observations. To test the model accuracy, we compared the models to four benchmark stars with atmospheric parameters for which independent information from interferometric radius measurements is available. We used $\\chi^2$ -based methods to determine parameters from high-resolution spectroscopic observations. Our synthetic spectra are based on the new PHOENIX grid that uses the ACES description for the equation of state. This is a model generation expected to be especially suitable for the low-temperature atmospheres. We identified suitable spectral tracers of atmospheric parameters and determined the uncertainties in $T_{\\rm eff}$, $\\log{g}$, and [Fe/H] resul...

  3. High-resolution field desorption/ionization fourier transform ion cyclotron resonance mass analysis of nonpolar molecules.

    Science.gov (United States)

    Schaub, Tanner M; Hendrickson, Christopher L; Qian, Kuangnan; Quinn, John P; Marshall, Alan G

    2003-05-01

    We report the first field desorption ionization broadband high-resolution (m/Deltam(50%) approximately 65 000) mass spectra. We have interfaced a field ionization/field desorption source to a home-built 9.4-T FT-ICR mass spectrometer. The instrumental configuration employs convenient sample introduction (in-source liquid injection) and external ion accumulation. We demonstrate the utility of this configuration by generating high-resolution positive-ion mass spectra of C(60) and a midboiling crude oil distillate. The latter contains species not accessible by common soft-ionization methods, for example, low-voltage electron ionization, electrospray ionization, and matrix-assisted laser desorption/ionization. The present work demonstrates significant advantages of FI/FD FT-ICR MS for analysis of nonpolar molecules in complex mixtures.

  4. Assessment of meat authenticity using bioinformatics, targeted peptide biomarkers and high-resolution mass spectrometry.

    Science.gov (United States)

    Ruiz Orduna, Alberto; Husby, Erik; Yang, Charles T; Ghosh, Dipankar; Beaudry, Francis

    2015-01-01

    In recent years a significant increase of food fraud has been observed, ranging from false label claims to the use of additives and fillers to increase profitability. Recently in 2013 horse and pig DNAs were detected in beef products sold from several retailers. Mass spectrometry (MS) has become the workhorse in protein research, and the detection of marker proteins could serve for both animal species and tissue authentication. Meat species authenticity is performed in this paper using a well-defined proteogenomic annotation, carefully chosen surrogate tryptic peptides and analysis using a hybrid quadrupole-Orbitrap MS. Selected mammalian meat samples were homogenised and proteins were extracted and digested with trypsin. The samples were analysed using a high-resolution MS. Chromatography was achieved using a 30-min linear gradient along with a BioBasic C8 100 × 1 mm column at a flow rate of 75 µl min(-1). The MS was operated in full-scan high resolution and accurate mass. MS/MS spectra were collected for selected proteotypic peptides. Muscular proteins were methodically analysed in silico in order to generate tryptic peptide mass lists and theoretical MS/MS spectra. Following a comprehensive bottom-up proteomic analysis, we detected and identified a proteotypic myoglobin tryptic peptide (120-134) for each species with observed m/z below 1.3 ppm compared with theoretical values. Moreover, proteotypic peptides from myosin-1, myosin-2 and β-haemoglobin were also identified. This targeted method allowed comprehensive meat speciation down to 1% (w/w) of undesired product.

  5. De Novo Peptide Sequencing: Deep Mining of High-Resolution Mass Spectrometry Data.

    Science.gov (United States)

    Islam, Mohammad Tawhidul; Mohamedali, Abidali; Fernandes, Criselda Santan; Baker, Mark S; Ranganathan, Shoba

    2017-01-01

    High resolution mass spectrometry has revolutionized proteomics over the past decade, resulting in tremendous amounts of data in the form of mass spectra, being generated in a relatively short span of time. The mining of this spectral data for analysis and interpretation though has lagged behind such that potentially valuable data is being overlooked because it does not fit into the mold of traditional database searching methodologies. Although the analysis of spectra by de novo sequences removes such biases and has been available for a long period of time, its uptake has been slow or almost nonexistent within the scientific community. In this chapter, we propose a methodology to integrate de novo peptide sequencing using three commonly available software solutions in tandem, complemented by homology searching, and manual validation of spectra. This simplified method would allow greater use of de novo sequencing approaches and potentially greatly increase proteome coverage leading to the unearthing of valuable insights into protein biology, especially of organisms whose genomes have been recently sequenced or are poorly annotated.

  6. Marvel Analysis of the Measured High-resolution Rovibronic Spectra of TiO

    Science.gov (United States)

    McKemmish, Laura K.; Masseron, Thomas; Sheppard, Samuel; Sandeman, Elizabeth; Schofield, Zak; Furtenbacher, Tibor; Császár, Attila G.; Tennyson, Jonathan; Sousa-Silva, Clara

    2017-02-01

    Accurate, experimental rovibronic energy levels, with associated labels and uncertainties, are reported for 11 low-lying electronic states of the diatomic {}48{{Ti}}16{{O}} molecule, determined using the Marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. All levels are based on lines corresponding to critically reviewed and validated high-resolution experimental spectra taken from 24 literature sources. The transition data are in the 2-22,160 cm-1 region. Out of the 49,679 measured transitions, 43,885 are triplet-triplet, 5710 are singlet-singlet, and 84 are triplet-singlet transitions. A careful analysis of the resulting experimental spectroscopic network (SN) allows 48,590 transitions to be validated. The transitions determine 93 vibrational band origins of {}48{{Ti}}16{{O}}, including 71 triplet and 22 singlet ones. There are 276 (73) triplet-triplet (singlet-singlet) band-heads derived from Marvel experimental energies, 123(38) of which have never been assigned in low- or high-resolution experiments. The highest J value, where J stands for the total angular momentum, for which an energy level is validated is 163. The number of experimentally derived triplet and singlet {}48{{Ti}}16{{O}} rovibrational energy levels is 8682 and 1882, respectively. The lists of validated lines and levels for {}48{{Ti}}16{{O}} are deposited in the supporting information to this paper.

  7. A computational method to help identify and measure metal lines in high resolution QSO spectra

    Institute of Scientific and Technical Information of China (English)

    Xi-Heng Shi; David Tytler; Jin-Liang Hou; David Kirkman; Jeffery Lee; Benjamin Ou

    2011-01-01

    A computational code is developed to help identify metal absorption lines in high resolution QSO spectra,especially in the Lyα forest.The input to the code includes a list of line central wavelengths,column densities and Doppler widths.The code then searches for candidate metal absorption systems and assesses the probability that each system could be real.The framework of the strategy we employ is described in detail and we discuss how to estimate the errors in line profile fitting that are essential to identification.A series of artificial spectra is constructed to calibrate the performance of the code.Due to the effects of blending and noise on Voigt profile fitting,the completeness of the identification depends on the column density of absorbers.For intermediate and strong artificial metal absorbers,more than 90% could be confirmed by the code.The results of applying the code to the real spectra of QSOs HS0757+5218 and Q0100+1300 are also presented.

  8. NLTE Analysis of High Resolution H-band Spectra. I. Neutral Silicon

    CERN Document Server

    Zhang, Junbo; Pan, Kaike; Prieto, Carlos Allende; Liu, Chao

    2016-01-01

    We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si I) lines in the near-infrared (near-IR) H-band. We derived the differential Si abundances for 13 sample stars with high-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE), as well as from optical spectra, both under local thermodynamical equilibrium (LTE) and NLTE conditions. We found that the differences between the Si abundances derived from the H-band and from optical lines for the same stars are less than 0.1 dex when the NLTE effects included, and that NLTE reduces the line-to-line scatter in the H-band spectra for most sample stars. These results suggest that our Si atomic model is appropriate for studying the formation of H-band Si lines. Our calculations show that the NLTE corrections of the Si I H-band lines are negative, i.e. the final Si abundances will be overestimated in LTE. The correc...

  9. COSMIC-LAB: Unexpected Results from High-resolution Spectra of AGB Stars in Globular Clusters

    CERN Document Server

    Lapenna, Emilio

    2016-01-01

    This thesis is aimed at clarifying one of the least studied phases of stellar evolution: the asymptotic giant branch (AGB). Recent results obtained for Galactic globular clusters (GCs) suggest that the AGB stage may contain crucial information about the evolutionary history of exotic stars (Beccari et al. 2006) and multiple-populations (Campbell et al. 2013) in the parent cluster. The thesis presents the analysis of a large sample of high-resolution spectra of AGB stars in four Galactic GCs, acquired at the Very Large Telescope (ESO) and the 2.2 meter telescope (MPG). The obtained results provide evidence of a previously unknown physical mechanism affecting the neutral species of some chemical elements in the atmosphere of most AGB stars: because of it, the abundances derived from neutral lines are systematically underestimated, while those measured from ionized lines remain unaffected. Such a behaviour exactly corresponds to what expected in the case of non-local thermodynamic equilibrium (NLTE) conditions i...

  10. Quantitative proteomics using the high resolution accurate mass capabilities of the quadrupole-orbitrap mass spectrometer.

    Science.gov (United States)

    Gallien, Sebastien; Domon, Bruno

    2014-08-01

    High resolution/accurate mass hybrid mass spectrometers have considerably advanced shotgun proteomics and the recent introduction of fast sequencing capabilities has expanded its use for targeted approaches. More specifically, the quadrupole-orbitrap instrument has a unique configuration and its new features enable a wide range of experiments. An overview of the analytical capabilities of this instrument is presented, with a focus on its application to quantitative analyses. The high resolution, the trapping capability and the versatility of the instrument have allowed quantitative proteomic workflows to be redefined and new data acquisition schemes to be developed. The initial proteomic applications have shown an improvement of the analytical performance. However, as quantification relies on ion trapping, instead of ion beam, further refinement of the technique can be expected.

  11. Chemical Diversity and Complexity of Scotch Whisky as Revealed by High-Resolution Mass Spectrometry

    Science.gov (United States)

    Kew, Will; Goodall, Ian; Clarke, David; Uhrín, Dušan

    2017-01-01

    Scotch Whisky is an important product, both culturally and economically. Chemically, Scotch Whisky is a complex mixture, which comprises thousands of compounds, the nature of which are largely unknown. Here, we present a thorough overview of the chemistry of Scotch Whisky as observed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Eighty-five whiskies, representing the majority of Scotch Whisky produced and sold, were analyzed by untargeted high-resolution mass spectrometry. Thousands of chemical formulae were assigned for each sample based on parts-per-billion mass accuracy of FT-ICR MS spectra. For the first time, isotopic fine structure analysis was used to confirm the assignment of high molecular weight CHOS species in Scotch Whisky. The assigned spectra were compared using a number of visualization techniques, including van Krevelen diagrams, double bond equivalence (DBE) plots, as well as heteroatomic compound class distributions. Additionally, multivariate analysis, including PCA and OPLS-DA, was used to interpret the data, with key compounds identified for discriminating between types of whisky (blend or malt) or maturation wood type. FT-ICR MS analysis of Scotch Whisky was shown to be of significant potential in further understanding of the complexity of mature spirit drinks and as a tool for investigating the chemistry of the maturation processes.

  12. A new, high-resolution global mass coral bleaching database.

    Science.gov (United States)

    Donner, Simon D; Rickbeil, Gregory J M; Heron, Scott F

    2017-01-01

    Episodes of mass coral bleaching have been reported in recent decades and have raised concerns about the future of coral reefs on a warming planet. Despite the efforts to enhance and coordinate coral reef monitoring within and across countries, our knowledge of the geographic extent of mass coral bleaching over the past few decades is incomplete. Existing databases, like ReefBase, are limited by the voluntary nature of contributions, geographical biases in data collection, and the variations in the spatial scale of bleaching reports. In this study, we have developed the first-ever gridded, global-scale historical coral bleaching database. First, we conducted a targeted search for bleaching reports not included in ReefBase by personally contacting scientists and divers conducting monitoring in under-reported locations and by extracting data from the literature. This search increased the number of observed bleaching reports by 79%, from 4146 to 7429. Second, we employed spatial interpolation techniques to develop annual 0.04° × 0.04° latitude-longitude global maps of the probability that bleaching occurred for 1985 through 2010. Initial results indicate that the area of coral reefs with a more likely than not (>50%) or likely (>66%) probability of bleaching was eight times higher in the second half of the assessed time period, after the 1997/1998 El Niño. The results also indicate that annual maximum Degree Heating Weeks, a measure of thermal stress, for coral reefs with a high probability of bleaching increased over time. The database will help the scientific community more accurately assess the change in the frequency of mass coral bleaching events, validate methods of predicting mass coral bleaching, and test whether coral reefs are adjusting to rising ocean temperatures.

  13. High resolution weak lensing mass mapping combining shear and flexion

    Science.gov (United States)

    Lanusse, F.; Starck, J.-L.; Leonard, A.; Pires, S.

    2016-06-01

    Aims: We propose a new mass mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to increase the sensitivity to substructures and the overall resolution of the convergence map without relying on strong lensing constraints. Methods: To preserve all available small scale information, we avoid any binning of the irregularly sampled input shear and flexion fields and treat the mass mapping problem as a general ill-posed inverse problem, which is regularised using a robust multi-scale wavelet sparsity prior. The resulting algorithm incorporates redshift, reduced shear, and reduced flexion measurements for individual galaxies and is made highly efficient by the use of fast Fourier estimators. Results: We tested our reconstruction method on a set of realistic weak lensing simulations corresponding to typical HST/ACS cluster observations and demonstrate our ability to recover substructures with the inclusion of flexion, which are otherwise lost if only shear information is used. In particular, we can detect substructures on the 15'' scale well outside of the critical region of the clusters. In addition, flexion also helps to constrain the shape of the central regions of the main dark matter halos. Our mass mapping software, called Glimpse2D, is made freely available at http://www.cosmostat.org/software/glimpse

  14. Ozone vertical distribution retrieval from ground-based high resolution infrared solar spectra

    Science.gov (United States)

    Pougatchev, N. S.; Connor, B. J.; Rinsland, C. P.

    1995-01-01

    A practical procedure for the retrieval of ozone vertical profiles from ground-based high resolution Fourier transform infrared solar spectra has been developed. The analysis is based on a multilayer line-by-line forward model and a semi-empirical version of the optimal estimation inversion method of Rodgers. The 1002.6-1003.2 cm(exp -1) spectral interval has been selected for the analysis on the basis of synthetic spectrum calculations. This interval contains numerous ozone lines covering a range of intensities and providing retrieval sensitivity from ground level to about 35 km. Characterization of the method and an error analysis have been performed. For a spectral resolution of 0.05-0.01 cm(exp -1) and a signal-to-noise ratio greater than or equal to 100 the retrieval is stable with a vertical resolution of approximately 5 km attainable near the surface degrading to approximately 10 km in the stratosphere. Synthetic spectra studies show that the a priori profile and weak constraints selected for the retrievals introduce no significant biases for a wide range of ozone profiles.

  15. NLTE Analysis of High Resolution H-band Spectra. II. Neutral Magnesium

    CERN Document Server

    Zhang, Junbo; Pan, Kaike; Prieto, Carlos Allende; Liu, Chao

    2016-01-01

    Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H-band neutral magnesium lines, we derive the differential Mg abundances from selected transitions for 13 stars either adopting or relaxing the assumption of local thermodynamical equilibrium (LTE). Our analysis is based on high-resolution and high signal-to-noise ratio H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and optical spectra from several instruments. The absolute differences between the Mg abundances derived from the two wavelength bands are always less than 0.1 dex in the NLTE analysis, while they are slightly larger for the LTE case. This suggests that our Mg atomic model is appropriate for investigating the NLTE formation of the H-band Mg lines. The NLTE corrections for the Mg I H-band lines are sensitive to the surface gravity, becoming larger for smaller log g values, and strong lines are more...

  16. N to K Uranium PIXE spectra obtained at the high resolution high energy PIXE setup

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, P.C., E-mail: cchaves@ctn.ist.utl.pt [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal); Taborda, A. [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal); Marques, J.P. [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Dept. Física da Fac. Ciências da Universidade de Lisboa, Campo Grande, Ed. C8, 1749-016 Lisboa (Portugal); Reis, M.A. [Centro de Física Atómica da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); IST/ITN, Instituto Superior Técnico, Universidade Técnica de Lisboa, Campus Tecnológico e Nuclear, EN10, 2686-953 Sacavém (Portugal)

    2014-01-01

    The CTN (previous ITN) high resolution high energy (HRHE) PIXE set-up facility was set in operation on July 2008 and upgrades were being implemented until late in 2011. The study of a pure UO{sub 2} sample and the mapping of geological sample are the first results where the whole range of possibilities has been exploited, namely the possibility of obtaining simultaneous spectra covering a very wide energy range of more than 100 keV. In this paper, the N-shell to K-shell spectra of Uranium is presented and discussed, as well as the details on the characteristics and capacities of the setup, including the automated X–Y positioning systems installed in the X–Y–Z sample support unit, which allows for the possibility of making macroscopic mappings of geological samples (Chaves et al. (2013) [1]). As for the N-shell lines in the X-ray Microcalorimeter Spectrometer (XMS) spectrum, due to the lack of data (Zschornack (2007) [2]), transition energies were determined using ab initio calculations assuming a closed shell U{sup 4+} electronic structure for Uranium prior to the ionisation by proton impact.

  17. MARVEL analysis of the measured high-resolution spectra of 14NH3

    Science.gov (United States)

    Al Derzi, Afaf R.; Furtenbacher, Tibor; Tennyson, Jonathan; Yurchenko, Sergei N.; Császár, Attila G.

    2015-08-01

    Accurate, experimental rotational-vibrational energy levels and line positions, with associated labels and uncertainties, are reported for the ground electronic state of the symmetric-top 14NH3 molecule. All levels and lines are based on critically reviewed and validated high-resolution experimental spectra taken from 56 literature sources. The transition data are in the 0.7-17 000 cm-1 region, with a large gap between 7000 and 15 000 cm-1. The MARVEL (Measured Active Rotational-Vibrational Energy Levels) algorithm is used to determine the energy levels. Out of the 29 450 measured transitions 10 041 and 18 947 belong to ortho- and para-14NH3, respectively. A careful analysis of the related experimental spectroscopic network (SN) allows 28 530 of the measured transitions to be validated, 18 178 of these are unique, while 462 transitions belong to floating components. Despite the large number of spectroscopic measurements published over the last 80 years, the transitions determine only 30 vibrational band origins of 14NH3, 8 for ortho- and 22 for para-14NH3. The highest J value, where J stands for the rotational quantum number, for which an energy level is validated is 31. The number of experimental-quality ortho- and para-14NH3 rovibrational energy levels is 1724 and 3237, respectively. The MARVEL energy levels are checked against ones in the BYTe first-principles database, determined previously. The lists of validated lines and levels for 14NH3 are deposited in the Supporting Information to this paper. Combination of the MARVEL energy levels with first-principles absorption intensities yields a huge number of experimental-quality rovibrational lines, which should prove to be useful for the understanding of future complex high-resolution spectroscopy on 14NH3; these lines are also deposited in the Supporting Information to this paper.

  18. UVBLUE: A New High-Resolution Theoretical Library of Ultraviolet Stellar Spectra

    Science.gov (United States)

    Rodríguez-Merino, L. H.; Chavez, M.; Bertone, E.; Buzzoni, A.

    2005-06-01

    We present an extended ultraviolet-blue (850-4700 Å) library of theoretical stellar spectral energy distributions computed at high resolution, λ/Δλ=50,000. The UVBLUE grid, as we named the library, is based on LTE calculations carried out with ATLAS9 and SYNTHE codes developed by R. L. Kurucz and consists of nearly 1800 entries that cover a large volume of the parameter space. It spans a range in Teff from 3000 to 50,000 K, the surface gravity ranges from logg=0.0 to 5.0 with Δlogg=0.5 dex, while seven chemical compositions are considered: [M/H]=-2.0,-1.5,-1.0,-0.5,+0.0,+0.3, and +0.5 dex. For its coverage across the Hertzsprung-Russell diagram, this library is the most comprehensive one ever computed at high resolution in the short-wavelength spectral range, and useful application can be foreseen for both the study of single stars and in population synthesis models of galaxies and other stellar systems. We briefly discuss some relevant issues for a safe application of the theoretical output to ultraviolet observations, and a comparison of our LTE models with the non-LTE (NLTE) ones from the TLUSTY code is also carried out. NLTE spectra are found, on average, to be slightly ``redder'' compared to the LTE ones for the same value of Teff, while a larger difference could be detected for weak lines, which are nearly wiped out by the enhanced core emission component in case of NLTE atmospheres. These effects seem to be magnified at low metallicity (typically [M/H]<~-1). A match with a working sample of 111 stars from the IUE atlas, with available atmosphere parameters from the literature, shows that UVBLUE models provide an accurate description of the main mid- and low-resolution spectral features for stars along the whole sequence from the B to ~G5 type. The comparison sensibly degrades for later spectral types, with supergiant stars that are in general more poorly reproduced than dwarfs. As a possible explanation of this overall trend, we partly invoke the

  19. Modelling the Emission And/or Absorption Features in the High Resolution Spectra of the Southern Binary System: HH Car

    Science.gov (United States)

    Koseoglu, Dogan; Bakış, Hicran

    2016-07-01

    High-resolution spectra (R=48000) of the southern close binary system, HH Car, has been analyzed with modern analysis techniques. Precise absolute parameters were derived from the simultaneous solution of the radial velocity, produced in this study and the light curves, published. According to the results of these analyses, the primary component is an O9 type main sequence star while the secondary component is a giant/subgiant star with a spectral type of B0. Hα emissions can be seen explicitly in the spectra of HH Car. These features were modelled using the absolute parameters of the components. Since components of HH Car are massive early-type stars, mass loss through stellar winds can be expected. This study revealed that the components of HH Car have stellar winds and the secondary component loses mass to the primary. Stellar winds and the gas stream between the components were modelled as a hot shell around the system. It is determined that the interaction between the winds and the gas stream leads to formation of a high temperature impact region.

  20. Atmospheric Oxidation of Squalene: Molecular Study Using COBRA Modeling and High-Resolution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fooshee, David R.; Aiona, Paige K.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey; Baldi, Pierre

    2015-10-22

    Squalene is a major component of skin and plant surface lipids, and is known to be present at high concentrations in indoor dust. Its high reactivity toward ozone makes it an important ozone sink and a natural protectant against atmospheric oxidizing agents. While the volatile products of squalene ozonolysis are known, the condensed-phase products have not been characterized. We present an analysis of condensed-phase products resulting from an extensive oxidation of squalene by ozone probed by electrospray ionization (ESI) high-resolution mass spectrometry (HR-MS). A complex distribution of nearly 1,300 peaks assignable to molecular formulas is observed in direct infusion positive ion mode ESI mass spectra. The distribution of peaks in the mass spectra suggests that there are extensive cross-coupling reactions between hydroxy-carbonyl products of squalene ozonolysis. To get additional insights into the mechanism, we apply a Computational Brewing Application (COBRA) to simulate the oxidation of squalene in the presence of ozone, and compare predicted results with those observed by the HR-MS experiments. The system predicts over one billion molecular structures between 0-1450 Da, which correspond to about 27,000 distinct elemental formulas. Over 83% of the squalene oxidation products inferred from the mass spectrometry data are matched by the simulation. Simulation indicates a prevalence of peroxy groups, with hydroxyl and ether groups being the second-most important O-containing functional groups formed during squalene oxidation. These highly oxidized products of squalene ozonolysis may accumulate on indoor dust and surfaces, and contribute to their redox capacity.

  1. High-resolution vacuum-ultraviolet photoabsorption spectra of 1-butyne and 2-butyne

    Energy Technology Data Exchange (ETDEWEB)

    Jacovella, U. [Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich (Switzerland); Holland, D. M. P. [STFC, Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD (United Kingdom); Boyé-Péronne, S.; Gans, B. [Institut des Sciences Moléculaires d’Orsay, UMR 8214, CNRS and Université Paris-Sud, F-91405 Orsay (France); Oliveira, N. de; Joyeux, D.; Archer, L. E. [Synchrotron Soleil, L’Orme des Merisiers, F-91192 Gif-sur-Yvette (France); Lucchese, R. R. [Department of Chemistry, Texas A& M University, College Station, Texas 77843 (United States); Xu, H.; Pratt, S. T. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-07-21

    The absolute photoabsorption cross sections of 1- and 2-butyne have been recorded at high resolution by using the vacuum-ultraviolet Fourier-Transform spectrometer at the SOLEIL Synchrotron. Both spectra show more resolved structure than previously observed, especially in the case of 2-butyne. In this work, we assess the potential importance of Rydberg states with higher values of orbital angular momentum, l, than are typically observed in photoabsorption experiments from ground state molecules. We show how the character of the highest occupied molecular orbitals in 1- and 2-butyne suggests the potential importance of transitions to such high-l (l = 3 and 4) Rydberg states. Furthermore, we use theoretical calculations of the partial wave composition of the absorption cross section just above the ionization threshold and the principle of continuity of oscillator strength through an ionization threshold to support this conclusion. The new absolute photoabsorption cross sections are discussed in light of these arguments, and the results are consistent with the expectations. This type of argument should be valuable for assessing the potential importance of different Rydberg series when sufficiently accurate direct quantum chemical calculations are difficult, for example, in the n ≥ 5 manifolds of excited states of larger molecules.

  2. Reference-free, high-resolution measurement method of timing jitter spectra of optical frequency combs

    Science.gov (United States)

    Kwon, Dohyeon; Jeon, Chan-Gi; Shin, Junho; Heo, Myoung-Sun; Park, Sang Eon; Song, Youjian; Kim, Jungwon

    2017-01-01

    Timing jitter is one of the most important properties of femtosecond mode-locked lasers and optical frequency combs. Accurate measurement of timing jitter power spectral density (PSD) is a critical prerequisite for optimizing overall noise performance and further advancing comb applications both in the time and frequency domains. Commonly used jitter measurement methods require a reference mode-locked laser with timing jitter similar to or lower than that of the laser-under-test, which is a demanding requirement for many laser laboratories, and/or have limited measurement resolution. Here we show a high-resolution and reference-source-free measurement method of timing jitter spectra of optical frequency combs using an optical fibre delay line and optical carrier interference. The demonstrated method works well for both mode-locked oscillators and supercontinua, with 2 × 10−9 fs2/Hz (equivalent to −174 dBc/Hz at 10-GHz carrier frequency) measurement noise floor. The demonstrated method can serve as a simple and powerful characterization tool for timing jitter PSDs of various comb sources including mode-locked oscillators, supercontinua and recently emerging Kerr-frequency combs; the jitter measurement results enabled by our method will provide new insights for understanding and optimizing timing noise in such comb sources. PMID:28102352

  3. High-resolution CCD spectra of stars in globular clusters. I - Oxygen in M13

    Science.gov (United States)

    Leep, E. M.; Wallerstein, G.; Oke, J. B.

    1986-01-01

    High-resolution (0.3 A) CCD spectra obtained at the 200 in. coude spectrograph have been analyzed for the abundances of O, Sc, Fe, and La in four stars in the globular cluster M13. Fe/H abundance is found to be = -1.6, as found by many other observers of this cluster. For three stars O/Fe abundance is found to be = +0.3 + or - 0.1, which is similar to O/Fe ratios in other globular clusters and metal-poor field stars. For star II-67, no oxygen line is visible at 6300 A and O/Fe abundance is found to be not greater than -0.4 (for a high carbon content) and not greater than -0.7 (for a low carbon content). The latter is more likely to be correct. Two possible explanations of the oxygen deficiency in II-67 are discussed: primordial deficiency, and CNO cycling at or above a temperature of 25,000,000 K.

  4. Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene

    Energy Technology Data Exchange (ETDEWEB)

    Fronzoni, Giovanna; Baseggio, Oscar; Stener, Mauro, E-mail: stener@univ.trieste.it [Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Unita’ di Trieste, I-34127 Trieste (Italy); Hua, Weijie; Tian, Guangjun [Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Luo, Yi [Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm (Sweden); National Synchrotron Radiation Laboratory and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Apicella, Barbara; Alfé, Michela [Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli (Italy); Simone, Monica de; Kivimäki, Antti [CNR-IOM, Laboratorio TASC, 34149 Trieste (Italy); Coreno, Marcello [CNR-IMIP, 00016 Montelibretti (Italy)

    2014-07-28

    We performed a combined experimental and theoretical study of the C1s Near-Edge X-ray Absorption Fine-Structure (NEXAFS) spectroscopy and X-ray Photoelectron Spectroscopy in the gas phase of two polycyclic aromatic hydrocarbons (phenanthrene and coronene), typically formed in combustion reactions. In the NEXAFS of both molecules, a double-peak structure appears in the C1s → LUMO region, which differ by less than 1 eV in transition energies. The vibronic coupling is found to play an important role in such systems. It leads to weakening of the lower-energy peak and strengthening of the higher-energy one because the 0 − n (n > 0) vibrational progressions of the lower-energy peak appear in nearly the same region of the higher-energy peak. Vibrationally resolved theoretical spectra computed within the Frank-Condon (FC) approximation and linear coupling model agree well with the high-resolution experimental results. We find that FC-active normal modes all correspond to in-plane vibrations.

  5. Mass defect filter technique and its applications to drug metabolite identification by high-resolution mass spectrometry.

    Science.gov (United States)

    Zhang, Haiying; Zhang, Donglu; Ray, Kenneth; Zhu, Mingshe

    2009-07-01

    Identification of drug metabolites by liquid chromatography/mass spectrometry (LC/MS) involves metabolite detection in biological matrixes and structural characterization based on product ion spectra. Traditionally, metabolite detection is accomplished primarily on the basis of predicted molecular masses or fragmentation patterns of metabolites using triple-quadrupole and ion trap mass spectrometers. Recently, a novel mass defect filter (MDF) technique has been developed, which enables high-resolution mass spectrometers to be utilized for detecting both predicted and unexpected drug metabolites based on narrow, well-defined mass defect ranges for these metabolites. This is a new approach that is completely different from, but complementary to, traditional molecular mass- or MS/MS fragmentation-based LC/MS approaches. This article reviews the mass defect patterns of various classes of drug metabolites and the basic principles of the MDF approach. Examples are given on the applications of the MDF technique to the detection of stable and chemically reactive metabolites in vitro and in vivo. Advantages, limitations, and future applications are also discussed on MDF and its combinations with other data mining techniques for the detection and identification of drug metabolites.

  6. High-resolution far ultraviolet emission spectra of electron-excited molecular deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Abgrall, H.; Roueff, E. [Observatoire de Paris, Section de Meudon, DAEC and CNRS UMR 8631, 92195 Meudon Cedex (France); Xianming Liu; Shemansky, D.E. [Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA 90089 (United States); James, G.K. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    1999-08-14

    The high-resolution (full width at half maximum {delta} {lambda} = 0.11 A) emission spectrum of the deuterium molecule produced by electron-impact excitation at 100 eV has been measured in the wavelength range 1200-1660 A. In conjunction with the experimental measurement, transition probabilities of B{sup 1}{sigma}{sub u}{sup +}-X{sup 1}{sigma}{sub g}{sup +}, C{sup 1}{pi}{sub u}-X{sup 1}{sigma}{sub g}{sup +}, B'{sup 1}{sigma}{sub u}{sup +}-X{sup 1}{sigma}{sub g}{sup +} and D{sup 1}{pi}{sub u}-X{sup 1}{sigma}{sub g}{sup -} band systems are calculated. Synthetic spectra based on the calculated transition probabilities are in very good agreement with the optically thin experimental spectra. While centrifugal effects on the overall Lyman band emission intensity in D{sub 2} and H{sub 2} are similar, the effect of rotation-vibrational perturbations between the B{sup 1}{sigma}{sub u}{sup +} and C{sup 1}{pi}{sub u}{sup +} states on spectral intensities is found to be less significant in D{sub 2}. Excitations via isotropic ({delta} J = 0) and anisotropic ({delta}J = {+-} 2, and 0) interactions for the dipole forbidden E, F{sup 1}{sigma}{sub g}{sup +}-X{sup 1}{sigma}{sub g}{sup +} transition are inferred from the measured spectra. Excitation cross sections of the B{sup 1}{sigma}{sub u}{sup +}-X{sup 1}{sigma}{sub g}{sup +} and C{sup 1}{pi}{sub u}-X{sup 1}{sigma}{sub g}{sup +} bands, along with the estimated E, F{sup 1}{sigma}{sub g}{sup +}-B{sup 1}{sigma}{sub u}{sup +} cascade cross section, for D{sub 2} are obtained. (author)

  7. High-Resolution Mass Spectroscopic Analysis of Secondary Organic Aerosol Generated by Ozonolysis of Isoprene

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Tran B; Bateman, Adam P; Bones, David L; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2010-02-01

    The chemical composition of secondary organic aerosol (SOA) generated from the ozonolysis of isoprene (C5H8) in the presence of an OH scavenger was examined using high-resolution electrospray ionization mass spectrometry (ESI-MS). The chemical composition of SOA is complex, with more than 1000 assigned peaks observed in the positive and negative ion mode spectra. Only a small fraction of peaks corresponds to known products of isoprene oxidation, such as pyruvic acid, glycolic acid, methylglyoxal, etc. The absolute majority of the detected peaks correspond to highly oxidized oligomeric constituents of SOA, with an average O:C molar ratio of ~0.6. The corresponding organic mass (OM) to organic oxygen (OO) ratio is OM/OO ~2.4. Approximately 8% of oxygen atoms in SOA are in the form of peroxides as quantified with an iodide test. Double bond equivalency (DBE) factors, representing the sum of all double bonds and rings, increase by 1 for every 2-3 additional carbon atoms in the molecule. The prevalent oligomer building blocks are therefore carbonyls or carboxylic acids with a C2-C3 skeleton. Kendrick analysis suggests that simple aldehydes, specifically formaldehyde, acetaldehyde, and methylglyoxal can serve as monomeric building blocks in the observed oligomers. The large number of reactive functional groups, especially organic peroxides and carbonyls, suggests that isoprene/O3 SOA should be prone to chemical and photochemical aging.

  8. High resolution ultrasound characterization of soft tissue masses in children. [Comparison with CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Glasier, C.M.; Seibert, J.J.; Williamson, S.L.; Seibert, R.W.; Lange, T.A.; Corbitt, S.L.; Rodgers, A.B.

    1987-03-01

    Forty-two soft tissue masses in infants and children were examined with high resolution ultrasonography. Sonography was diagnostically specific in 17/42 (40%), useful but not diagnostic in 24/42 (58%), and misleading in 1/42 (2%) of soft tissue masses. Lesions with diagnostic sonographic features included cystic hygroma, fibromatosis colli, lymphadenopathy with abscess formation, and one case of osteomyelitis.

  9. Screening new psychoactive substances in urban wastewater using high resolution mass spectrometry.

    Science.gov (United States)

    González-Mariño, Iria; Gracia-Lor, Emma; Bagnati, Renzo; Martins, Claudia P B; Zuccato, Ettore; Castiglioni, Sara

    2016-06-01

    Analysis of drug residues in urban wastewater could complement epidemiological studies in detecting the use of new psychoactive substances (NPS), a continuously changing group of drugs hard to monitor by classical methods. We initially selected 52 NPS potentially used in Italy based on seizure data and consumption alerts provided by the Antidrug Police Department and the National Early Warning System. Using a linear ion trap-Orbitrap high resolution mass spectrometer, we designed a suspect screening and a target method approach and compared them for the analysis of 24 h wastewater samples collected at the treatment plant influents of four Italian cities. This highlighted the main limitations of these two approaches, so we could propose requirements for future research. A library of MS/MS spectra of 16 synthetic cathinones and 19 synthetic cannabinoids, for which analytical standards were acquired, was built at different collision energies and is available on request. The stability of synthetic cannabinoids was studied in analytical standards and wastewater, identifying the best analytical conditions for future studies. To the best of our knowledge, these are the first stability data on NPS. Few suspects were identified in Italian wastewater samples, in accordance with recent epidemiological data reporting a very low prevalence of use of NPS in Italy. This study outlines an analytical approach for NPS identification and measurement in urban wastewater and for estimating their use in the population.

  10. Gold finger formation studied by high-resolution mass spectrometry and in silico methods

    NARCIS (Netherlands)

    Laskay, Ü.A.; Garino, C.; Tsybin, Y.O.; Salassa, L.; Casini, A.

    2015-01-01

    High-resolution mass spectrometry and quantum mechanics/molecular mechanics studies were employed for characterizing the formation of two gold finger (GF) domains from the reaction of zinc fingers (ZF) with gold complexes. The influence of both the gold oxidation state and the ZF coordination sphere

  11. Gold finger formation studied by high-resolution mass spectrometry and in silico methods

    NARCIS (Netherlands)

    Laskay, Ü.A.; Garino, C.; Tsybin, Y.O.; Salassa, L.; Casini, A.

    2015-01-01

    High-resolution mass spectrometry and quantum mechanics/molecular mechanics studies were employed for characterizing the formation of two gold finger (GF) domains from the reaction of zinc fingers (ZF) with gold complexes. The influence of both the gold oxidation state and the ZF coordination sphere

  12. Physical Properties of the Interstellar Medium Using High-resolution Chandra Spectra: O K-edge Absorption

    Science.gov (United States)

    Gatuzz, E.; García, J.; Mendoza, C.; Kallman, T. R.; Bautista, M. A.; Gorczyca, T. W.

    2014-08-01

    Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the accuracy of the atomic data. Hydrogen column densities are derived with a broadband fit that takes into account pileup effects, and in general are in good agreement with previous results. The dominant features in the oxygen-edge region are O I and O II Kα absorption lines whose simultaneous fits lead to average values of the ionization parameter of log ξ = -2.90 and oxygen abundance of A O = 0.70. The latter is given relative to the standard by Grevesse & Sauval, but rescaling with the revision by Asplund et al. would lead to an average abundance value fairly close to solar. The low average oxygen column density (N O = 9.2 × 1017 cm-2) suggests a correlation with the low ionization parameters, the latter also being in evidence in the column density ratios N(O II)/N(O I) and N(O III)/N(O I) that are estimated to be less than 0.1. We do not find conclusive evidence for absorption by any other compound but atomic oxygen in our oxygen-edge region analysis.

  13. Thin Layer Chromatography-Autography-High Resolution Mass Spectrometry Analysis: Accelerating the Identification of Acetylcholinesterase Inhibitors.

    Science.gov (United States)

    Ramallo, I Ayelen; Salazar, Mario O; Furlan, Ricardo L E

    2015-01-01

    The prevailing treatment for Alzheimer's disease is the use of acetylcholinesterase (AChE) inhibitors. Natural extracts are the principal source of AChE's inhibitors. However, their chemical complexity demands for simple, selective and rapid assays. To develop a strategy for identification of AChE inhibitors present in mixtures employing high resolution mass spectrometry (HRMS) and thin layer chromatography (TLC)-biological staining. The strategy uses an autographic assay based on the α-naphthyl acetate - fast blue B system for the detection of AChE activity. The immobilisation of AChE in agar allowed the extraction of the compounds for analysis by HRMS. Three TLC experiments employing different solvent systems were used in parallel and the mass spectra of the compounds extracted from the inhibition halos, were compared. The analysis was performed under MatLab environment. The strategy was used to detect the presence of physostigmine in an extract of Brassica rapa L. spiked with the inhibitor. Similarly, caffeine was straightforwardly spotted as responsible for the inhibitory properties of an extract of Ilex paraguariensis Saint-Hilaire. Comparison of the HRMS profiles lead to the facile identification of the [M+H](+) and [M+Na](+) of the compounds responsible for the inhibition. The proposed methodology, coupling TLC-AChE autography-HRMS, illustrates the feasibility of assigning molecular formulas of active compounds present in complex mixtures directly from autography. The new AChE agar-immobilised assay presented a more homogenous colour and a better definition than direct spraying methods, reducing the cost of the assay and improving its sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Masayoshi Tamura

    2014-08-01

    Full Text Available Fumonisin A-series (FAs in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS. Peaks for fumonisin B1 (FB1, fumonisin B2 (FB2, and fumonisin B3 (FB3, in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1 synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1, A2 (FA2, and A3 (FA3. The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  15. Urinary antihypertensive drug metabolite screening using molecular networking coupled to high-resolution mass spectrometry fragmentation

    OpenAIRE

    2016-01-01

    Introduction Mass spectrometry is the current technique of choice in studying drug metabolism. High-resolution mass spectrometry in combination with MS/MS gas-phase experiments has the potential to contribute to rapid advances in this field. However, the data emerging from such fragmentation spectral files pose challenges to downstream analysis, given their complexity and size. Objectives This study aims to detect and visualize antihypertensive drug metabolites in untargeted metabolomics expe...

  16. FluTyper-an algorithm for automated typing and subtyping of the influenza virus from high resolution mass spectral data

    Directory of Open Access Journals (Sweden)

    Schwahn Alexander B

    2010-05-01

    Full Text Available Abstract Background High resolution mass spectrometry has been employed to rapidly and accurately type and subtype influenza viruses. The detection of signature peptides with unique theoretical masses enables the unequivocal assignment of the type and subtype of a given strain. This analysis has, to date, required the manual inspection of mass spectra of whole virus and antigen digests. Results A computer algorithm, FluTyper, has been designed and implemented to achieve the automated analysis of MALDI mass spectra recorded for proteolytic digests of the whole influenza virus and antigens. FluTyper incorporates the use of established signature peptides and newly developed naïve Bayes classifiers for four common influenza antigens, hemagglutinin, neuraminidase, nucleoprotein, and matrix protein 1, to type and subtype the influenza virus based on their detection within proteolytic peptide mass maps. Theoretical and experimental testing of the classifiers demonstrates their applicability at protein coverage rates normally achievable in mass mapping experiments. The application of FluTyper to whole virus and antigen digests of a range of different strains of the influenza virus is demonstrated. Conclusions FluTyper algorithm facilitates the rapid and automated typing and subtyping of the influenza virus from mass spectral data. The newly developed naïve Bayes classifiers increase the confidence of influenza virus subtyping, especially where signature peptides are not detected. FluTyper is expected to popularize the use of mass spectrometry to characterize influenza viruses.

  17. Development of high resolution simulations of the atmospheric environment using the MASS model

    Science.gov (United States)

    Kaplan, Michael L.; Zack, John W.; Karyampudi, V. Mohan

    1989-01-01

    Numerical simulations were performed with a very high resolution (7.25 km) version of the MASS model (Version 4.0) in an effort to diagnose the vertical wind shear and static stability structure during the Shuttle Challenger disaster which occurred on 28 January 1986. These meso-beta scale simulations reveal that the strongest vertical wind shears were concentrated in the 200 to 150 mb layer at 1630 GMT, i.e., at about the time of the disaster. These simulated vertical shears were the result of two primary dynamical processes. The juxtaposition of both of these processes produced a shallow (30 mb deep) region of strong vertical wind shear, and hence, low Richardson number values during the launch time period. Comparisons with the Cape Canaveral (XMR) rawinsonde indicates that the high resolution MASS 4.0 simulation more closely emulated nature than did previous simulations of the same event with the GMASS model.

  18. Early developmental stages of Ascaris lumbricoides featured by high-resolution mass spectrometry.

    Science.gov (United States)

    Melo, Carlos Fernando Odir Rodrigues; Esteves, Cibele Zanardi; de Oliveira, Rosimeire Nunes; Guerreiro, Tatiane Melina; de Oliveira, Diogo Noin; Lima, Estela de Oliveira; Miné, Júlio César; Allegretti, Silmara Marques; Catharino, Rodrigo Ramos

    2016-11-01

    Ascaris lumbricoides is responsible for a highly disseminated helminth parasitic disease, ascariosis, a relevant parasitosis that responds for great financial burden on the public health system of developing countries. In this work, metabolic fingerprinting using high-resolution mass spectrometry (HRMS) was employed to identify marker molecules from A. lumbricoides in different development stages. We have identified nine biomarkers, such as pheromones and steroidal prohormones in early stages, among other molecules in late development stages, making up four molecules for fertilized eggs, four marker molecules for first larvae (L1) and one marker molecule for third larvae (L3). Therefore, our findings indicate that this approach is suitable for biochemical characterization of A. lumbricoides development stages. Moreover, the straightforward analytical method employed, with almost no sample preparation from a complex matrix (feces) using high-resolution mass spectrometry, suggests that it is possible to seek for an easier and faster way to study animal molding processes.

  19. Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry

    Science.gov (United States)

    Souda, Puneet; Ryan, Christopher M.; Cramer, William A.; Whitelegge, Julian

    2011-01-01

    Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein’s native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electroncapture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

  20. Analysis of High-Resolution Spectra From a Hybrid Interferometric/Dispersive Spectrometer

    CERN Document Server

    Ko, P; Jovanovic, I

    2015-01-01

    To more fully take advantage of a low-cost, small footprint hybrid interferometric/dispersive spectrometer, a mathematical reconstruction technique was developed to accurately capture the high-resolution and relative peak intensities from complex spectral patterns. A Fabry-Perot etalon was coupled to a Czerny-Turner spectrometer, leading to increased spectral resolution by more than an order of magnitude without the commensurate increase in spectrometer size. Measurement of the industry standard Hg 313.1555/313.1844 nm doublet yielded a ratio of 0.682, which agreed well with an independent measurement and literature values. The doublet separation (29 pm) is similar to the U isotope shift (25 pm) at 424.437 nm that is of interest to monitoring nuclear nonproliferation activities. Additionally, the technique was applied to LIBS measurement of the mineral cinnabar (HgS) and resulted in a ratio of 0.682. This reconstruction method could enable significantly smaller, portable high-resolution instruments with isoto...

  1. UVBLUE: a new high-resolution theoretical library of ultraviolet stellar spectra

    CERN Document Server

    Rodríguez-Merino, L H; Bertone, E; Buzzoni, A

    2005-01-01

    We present an extended ultraviolet-blue (850-4700 AA) library of theoretical stellar spectral energy distributions (SEDs) computed at high resolution, R= 50,000. The UVBLUE grid, as we named the library, is based on LTE calculations carried out with ATLAS9 and SYNTHE codes developed by R. L. Kurucz and consists of nearly 1800 entries that cover a large volume of the parameter space. It spans a range in effective temperature from 3000 to 50,000 K, the surface gravity ranges from log g= 0.0 to 5.0 with a step of 0.5 dex, while seven chemical compositions are considered: [Fe/H]= -2.0, -1.5, -1.0, -0.5, +0.0, +0.3 and +0.5 dex. For its coverage across the H-R diagram, this library is the most comprehensive one ever computed at high resolution in the short-wavelength spectral range, and useful application can be foreseen both for the study of single stars and in population synthesis models of galaxies and other stellar systems.

  2. High-resolution NMR spectra of n-alkanes penetrating into carbon fibers and of protons in carbon fibers.

    Science.gov (United States)

    Yamazaki, Yuya; Kobayashi, Nobuaki; Nikki, Kunio; Kuwahara, Daisuke

    2008-08-01

    We present a simple NMR method for microscopically exploring the local environment in carbon fibers. The method utilizes n-alkanes as probe molecules, where the n-alkanes penetrate carbon fibers of interest. The high-resolution (1)H NMR spectra for a mixture of a carbon fiber and n-alkanes acquired by this method show a shift of the resonance line, which is due to the local structure of the fiber. The utility of this method is discussed on the basis of the (1)H NMR spectra obtained. In addition, the (1)H distribution and the local motion in the structure of the carbon fiber are revealed in view of the (1)H NMR spectra.

  3. Time-Resolved Molecular Characterization of Limonene/Ozone Aerosol using High-Resolution Electrospray Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2009-09-09

    Molecular composition of limonene/O3 secondary organic aerosol (SOA) was investigated using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) as a function of reaction time. SOA was generated by ozonation of D-limonene in a reaction chamber and sampled at different time intervals using a cascade impactor. The SOA samples were extracted into acetonitrile and analyzed using a HR-ESI-MS instrument with a resolving power of 100,000 (m/Δm). The resulting mass spectra provided detailed information about the extent of oxidation inferred from the O:C ratios, double bond equivalency (DBE) factors, and aromaticity indexes (AI) in hundreds of identified individual SOA species.

  4. Determination of Trace Elements in High Purity Gold by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; HUANG Kelong; NIE Xidu; FU Liang

    2009-01-01

    Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).Sample were decomposed by aqua regia.To overcome some potentially problematic spectral interference,measurements were acquired in both medium and high resolution modes.The matrix effects due to the presence of excessive HCl and Au were evaluated.The optimum conditions for the determination was tested and discussed.The standard addition method was employed for quantitative analysis.The detection limits range from 0.01 μg/g to 0.28 μg/g depending on the elements.The method is accurate,quick and convenient.It has been applied to the determination of trace elements in high purity gold with satisfactory results.

  5. High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2010-10-01

    This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

  6. Analysis of the high resolution Mg XI X-ray spectra. Pt. 3. Non-thermal interpretation of some spectra

    Energy Technology Data Exchange (ETDEWEB)

    Siarkowski, M.; Sylwester, J. (Polska Akademia Nauk, Wroclaw. Centrum Badan Kosmicznych); Bromboszcs, G. (Wroclaw Univ. (Poland). Obserwatorium Astronomiczne); Korneev, V.V.; Mandelshtam, S.L.; Oparin, S.N.; Urnov, A.M.; Zhitnik, I.A. (AN SSSR, Moscow. Fizicheskij Inst.)

    1982-11-01

    In part III of the paper containing the analysis of the INTERCOSMOS 16 ADP spectra, it is shown that by assuming the existence of a small admixture (1%) of non-thermal electrons in the active-region plasma it is possible to improve the agreement between measured and calculated fluxes for some spectra. The analysis follows the suggestion contained in the paper by Karev et al. (1980).

  7. Modelling high-resolution spatially-resolved Supernova Remnant spectra with the Sardinia Radio Telescope

    CERN Document Server

    Loru, Sara; Egron, Elise; Iacolina, Noemi; Righini, Simona; Marongiu, Marco; Mulas, Sara; Murtas, Giulia; Simeone, Davide; Pilia, Maura; Bachetti, Matteo; Trois, Alessio; Ricci, Roberto; Melis, Andrea; Concu, Raimondo

    2016-01-01

    Supernova Remnants (SNRs) exhibit spectra featured by synchrotron radio emission arising from the relativistic electrons, and high-energy emission from both leptonic (Bremsstrahlung and Inverse Compton) and hadronic processes (${\\pi}^0$ mesons decay) which are a direct signature of cosmic rays acceleration. Thanks to radio single-dish imaging observations obtained in three frequency bands (1.6, 7, 22 GHz) with the Sardinia Radio Telescope (www.srt.inaf.it), we can model different SNR regions separately. Indeed, in order to disentangle interesting and peculiar hadron contributions in the high-energy spectra (gamma-ray band) and better constrain SNRs as cosmic rays emitters, it is crucial to fully constrain lepton contributions first through radio-observed parameters. In particular, the Bremsstrahlung and Inverse Compton bumps observed in gamma-rays are bounded to synchrotron spectral slope and cut-off in the radio domain. Since these parameters vary for different SNR regions and electron populations, spatially...

  8. Modeling Stellar Parameters for High Resolution Late-M and Early-L Dwarf SDSS/APOGEE Spectra

    Science.gov (United States)

    Birky, Jessica L.; Aganze, Christian; Burgasser, Adam J.; Theissen, Christopher; Schmidt, Sarah J.; Teske, Johanna K.; Stassun, Keivan G.; Bird, Jonathan C.; UCSD FAST Team

    2017-01-01

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) of the Sloan Digital Sky Survey IV has measured high resolution (R~22,500), near-infrared (1.51-1.70 µm) spectra for nearly 100,000 stars within the Milky Way Galaxy. While the APOGEE experiment was designed to research Galactic structure by targeting bright stellar populations in the disk, we have focused attention on the lesser-studied subset of faint and low-temperature late-M and early-L dwarfs, with the objective of characterizing their chemical abundances. Using spectral synthesis routines from the Starfish package, we report preliminary determinations of Teff, logg, and [Fe/H] for a small sample of spectra using PHOENIX models ranging in the 2,300 to 3,000K temperature grids.This work is supported by the SDSS Faculty and Student (FAST) initiative, funded by the Alfred P. Sloan Foundation.

  9. 13C high resolution solid state NMR spectra of Chinese coals

    Institute of Scientific and Technical Information of China (English)

    陈德玉; 胡建治; 叶朝辉

    1997-01-01

    Several typical exinites in China including alginite, cultinite, suberinite and bituminite are analysed by means of 13C high solution solid state CP MAS TOSS NMR spectra to determine their chemical structures and hydrocarbon potential. Thermal simulation solid products (TSSP) of hydrogen-rich coals arc studied to discuss the generation and expulsion mechanism of coal-generating hydrocarbon. The preliminary results are quite encouraging, containing useful information about genesis of coal-generating oil and gases.

  10. High-resolution Absorption Spectra of Acetylene in 142.8-152.3 nm

    Institute of Scientific and Technical Information of China (English)

    Ya-hua Hu; Chen Zhen; Jing-hua Dai; Xiao-guo Zhou; Shi-lin Liu

    2008-01-01

    The absorption spectra of acetylene molecules was measured under jet-cooled conditions in the wavelength range of 142.8-152.3 nm, with a tunable and highly resolved vacuum ultraviolet (VUV) laser generated by two-photon resonant four wave difference frequency mixing processes. Due to the sufficient vibrational and rotational cooling effect of the molecular beam and the higher resolution VUV laser, the observed absorption spectra exhibit more distinct spectral features than the previous works measured at room temperature. The major three vibrational bands are assigned as a C-C symmetry stretching vibrational progress (v2=0-2) of the C~Ⅱu state of acetylene. The observed shoulder peak at 148.2 nm is assigned to the first overtone band of the trans-bending mode v4 of the C~Ⅱu state of acetylene. Additionally, the two components, 42 (μ1 Ⅱu) and 42(K1Ⅱu), are suggested to exhibit in the present absorption spectra, due to their Penner-Teller effect and transition selection rule. All band origins and bandwidths are obtained subsequently, and it is found that bandwidths are broadened and lifetimes decrease gradually with the excitation of vibration.

  11. High-resolution Absorption Spectra of Acetylene in 142.8-152.3 nm

    Science.gov (United States)

    Hu, Ya-hua; Zhen, Chen; Dai, Jing-hua; Zhou, Xiao-guo; Liu, Shi-lin

    2008-10-01

    The absorption spectra of acetylene molecules was measured under jet-cooled conditions in the wavelength range of 142.8-152.3 nm, with a tunable and highly resolved vacuum ultraviolet (VUV) laser generated by two-photon resonant four wave difference frequency mixing processes. Due to the sufficient vibrational and rotational cooling effect of the molecular beam and the higher resolution VUV laser, the observed absorption spectra exhibit more distinct spectral features than the previous works measured at room temperature. The major three vibrational bands are assigned as a C-C symmetry stretching vibrational progress (u2 = 0-2) of the tilde C1 IIu state of acetylene. The observed shoulder peak at 148.2 nm is assigned to the first overtone band of the trans-bending mode u4 of the tilde C1 IIustate of acetylene. Additionally, the two components, 4o2(μ1IIu) and 4o2(κ1 IIuare suggested to exhibit in the present absorption spectra, due to their Renner-Teller effect and transition selection rule. All band origins and bandwidths are obtained subsequently, and it is found that bandwidths are broadened and lifetimes decrease gradually with the excitation of vibration.

  12. The NIRSPEC Brown Dwarf Spectroscopic Survey II: High-Resolution J-Band Spectra of M, L and T Dwarfs

    CERN Document Server

    McLean, I S; McGovern, M R; Burgasser, A J; Kirkpatrick, J D; Rice, E L; Kim, S S; Lean, Ian S. Mc; Govern, Mark R. Mc; Burgasser, Adam J.; Rice, Emily L.; Kim, Sungsoo S.

    2006-01-01

    We present a sequence of high resolution (R~20,000 or 15 km/s) infrared spectra of stars and brown dwarfs spanning spectral types M2.5 to T6. Observations of 16 objects were obtained using eight echelle orders to cover part of the J-band from 1.165-1.323 micron with NIRSPEC on the Keck II telescope. By comparing opacity plots and line lists, over 200 weak features in the J-band are identified with either FeH or H2O transitions. Absorption by FeH attains maximum strength in the mid-L dwarfs, while H2O absorption becomes systematically stronger towards later spectral types. Narrow resolved features broaden markedly after the M to L transition. Our high resolution spectra also reveal that the disappearance of neutral Al lines at the boundary between M and L dwarfs is remarkably abrupt, presumably because of the formation of grains. Neutral Fe lines can be traced to mid-L dwarfs before Fe is removed by condensation. The neutral potassium (K I) doublets that dominate the J-band have pressure broadened wings that c...

  13. 13C labeling analysis of sugars by high resolution-mass spectrometry for metabolic flux analysis.

    Science.gov (United States)

    Acket, Sébastien; Degournay, Anthony; Merlier, Franck; Thomasset, Brigitte

    2017-02-14

    Metabolic flux analysis is particularly complex in plant cells because of highly compartmented metabolism. Analysis of free sugars is interesting because it provides data to define fluxes around hexose, pentose, and triose phosphate pools in different compartment. In this work, we present a method to analyze the isotopomer distribution of free sugars labeled with carbon 13 using a liquid chromatography-high resolution mass spectrometry, without derivatized procedure, adapted for Metabolic flux analysis. Our results showed a good sensitivity, reproducibility and better accuracy to determine isotopic enrichments of free sugars compared to our previous methods [5, 6].

  14. Seed oil polyphenols: rapid and sensitive extraction method and high resolution-mass spectrometry identification.

    Science.gov (United States)

    Koubaa, Mohamed; Mhemdi, Houcine; Vorobiev, Eugène

    2015-05-01

    Phenolic content is a primary parameter for vegetables oil quality evaluation, and directly involved in the prevention of oxidation and oil preservation. Several methods have been reported in the literature for polyphenols extraction from seed oil but the approaches commonly used remain manually handled. In this work, we propose a rapid and sensitive method for seed oil polyphenols extraction and identification. For this purpose, polyphenols were extracted from Opuntia stricta Haw seed oil, using high frequency agitation, separated, and then identified using a liquid chromatography-high resolution mass spectrometry method. Our results showed good sensitivity and reproducibility of the developed methods.

  15. Program Package for the Analysis of High Resolution High Signal-To-Noise Stellar Spectra

    Science.gov (United States)

    Piskunov, N.; Ryabchikova, T.; Pakhomov, Yu.; Sitnova, T.; Alekseeva, S.; Mashonkina, L.; Nordlander, T.

    2017-06-01

    The program package SME (Spectroscopy Made Easy), designed to perform an analysis of stellar spectra using spectral fitting techniques, was updated due to adding new functions (isotopic and hyperfine splittins) in VALD and including grids of NLTE calculations for energy levels of few chemical elements. SME allows to derive automatically stellar atmospheric parameters: effective temperature, surface gravity, chemical abundances, radial and rotational velocities, turbulent velocities, taking into account all the effects defining spectral line formation. SME package uses the best grids of stellar atmospheres that allows us to perform spectral analysis with the similar accuracy in wide range of stellar parameters and metallicities - from dwarfs to giants of BAFGK spectral classes.

  16. Investigation Jet Rotation in Young Stars via High Resolution UV Spectra

    Science.gov (United States)

    Bacciotti, Francesca

    2009-07-01

    In recent years we have successfully harnessed the high resolution of STIS in the optical to reveal asymmetries in Doppler shifts transverse to the flow direction in 8 T Tauri jets {Bacciotti ea 2002; Woitas ea 2005; Coffey ea 2004; 2007}. We interpret the findings, just 100 AU above the disk, as signatures of jet rotation. The significance of these results is considerable. They form the only existing observational indications supporting the theory that jets extract angular momentum from star-disk systems. Furthermore, they hold the potential to discriminate between the main model contenders: X-wind and Disk-wind {Ferreira ea 2006}. Although our results are encouraging, it is evident that we are only marginally resolving the effects of rotation because of the limiting resolution {spatially and spectrally} of STIS in the optical. Therefore, in Cycle 12 we proposed to extend this study into the near-ultraviolet {NUV}, giving double the spatial and spectral resolution {proposal ID 9807}. Unfortunately, only 3 targets in our survey were observed before the failure of STIS {Coffey ea 2007}. Nevertheless, the results were very exciting. Agreement was found between the optical and NUV results in terms of the magnitude and sense of the Doppler shift gradient across the jet. Furthermore, the NUV lines indicated that the observed high velocity gas was launched from about 0.2-0.5 AU, compared to the lower velocity gas traced in optical lines which originates from as far as 2 AU. This puts a strong contraint on MHD launch models, and indeed holds the potential to differentiate between them. Given that the strength of a rotation argument lies in the survey nature of the findings, we need to resume this program in order to see if the same rotation signatures are commonly seen in the NUV, as they are in the optical. Furthermore, the higher spatial and spectral resolution of STIS in the NUV will allow us to more accurately quantify the variation in toroidal velocity as a function

  17. A High-Resolution Time-of-Flight Mass Spectrometer for Experiments with Ultracold Gases

    CERN Document Server

    Kraft, S D; Staanum, P; Fioretti, A; Lange, J; Wester, R; Weidemüller, M; Kraft, Stephan D.; Mikosch, Jochen; Staanum, Peter; Fioretti, Andrea; Lange, Joerg; Wester, Roland; Weidemueller, Matthias

    2005-01-01

    We have realized a high-resolution time-of-flight mass spectrometer combined with a magneto-optical trap. The spectrometer enables excellent optical access to the trapped atomic cloud using properly devised acceleration and deflection electrodes. The ions are extracted along a laser axis and deflected onto an off axis detector. The setup is applied to detect atoms and molecules photoassociated from ultracold atoms. The detection is based on resonance-enhanced multi-photon ionization. The versatile setup can easily be implemented in more complex experiments with ultracold atomic and molecular gases. Mass resolution up to $m/\\Delta m_{rms} = 1000$ at the mass of $^{133}$Cs is achieved.

  18. Structural characterization of suppressor lipids by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

    2016-01-01

    RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

  19. Synthetic High-Resolution Line Spectra of Star-Forming Galaxies Below 1200A

    CERN Document Server

    Robert, C; Aloisi, A; Leitherer, C; Hoopes, C; Heckman, T M; Robert, Carmelle; Pellerin, Anne; Aloisi, Alessandra; Leitherer, Claus; Hoopes, Charles; Heckman, Timothy M.

    2002-01-01

    We have generated a set of far-ultraviolet stellar libraries using spectra of OB and Wolf-Rayet stars in the Galaxy and the Large and Small Magellanic Cloud. The spectra were collected with the Far Ultraviolet Spectroscopic Explorer and cover a wavelength range from 1003.1 to 1182.7A at a resolution of 0.127A. The libraries extend from the earliest O- to late-O and early-B stars for the Magellanic Cloud and Galactic libraries, respectively. Attention is paid to the complex blending of stellar and interstellar lines, which can be significant, especially in models using Galactic stars. The most severe contamination is due to molecular hydrogen. Using a simple model for the H$_2$ line strength, we were able to remove the molecular hydrogen lines in a subset of Magellanic Cloud stars. Variations of the photospheric and wind features of CIII 1176, OVI 1032, 1038, PV 1118, 1128, and SIV 1063, 1073, 1074 are discussed as a function of temperature and luminosity class. The spectral libraries were implemented into the...

  20. Chlorophyll Fluorescence Emissions of Vegetation Canopies From High Resolution Field Reflectance Spectra

    Science.gov (United States)

    Middleton, E. M.; Corp, L. A.; Daughtry, C. S. T.; Campbell, P. K. Entcheva

    2006-01-01

    A two-year experiment was performed on corn (Zea mays L.) crops under nitrogen (N) fertilization regimes to examine the use of hyperspectral canopy reflectance information for estimating chlorophyll fluorescence (ChlF) and vegetation production. Fluorescence of foliage in the laboratory has proven more rigorous than reflectance for correlation to plant physiology. Especially useful are emissions produced from two stable red and far-red chlorophyll ChlF peaks centered at 685V10 nm and 735V5 nm. Methods have been developed elsewhere to extract steady state solar induced fluorescence (SF) from apparent reflectance of vegetation canopies/landscapes using the Fraunhofer Line Depth (FLD) principal. Our study utilized these methods in conjunction with field-acquired high spectral resolution canopy reflectance spectra obtained in 2004 and 2005 over corn crops, as part of an ongoing multi-year experiment at the USDA/Agriculture Research Service in Beltsville, MD. A spectroradiometer (ASD-FR Fieldspec Pro, Analytical Spectral Devices, Inc., Boulder, CO) was used to measure canopy radiances 1 m above plant canopies with a 22deg field of view and a 0deg nadir view zenith angle. Canopy and plant measurements were made at the R3 grain fill reproductive stage on 3-4 replicate N application plots provided seasonal inputs of 280, 140, 70, and 28 kg N/ha. Leaf level measurements were also made which included ChlF, photosynthesis, and leaf constituents (photosynthetic pigment, carbon (C), and N contents). Crop yields were determined at harvest. SIF intensities for ChlF were derived directly from canopy reflectance spectra in specific narrowband regions associated with atmospheric oxygen absorption features centered at 688 and 760 nm. The red/far-red S F ratio derived from these field reflectance spectra successfully discriminated foliar pigment levels (e.g., total chlorophyll, Chl) associated with N application rates in both corn crops. This canopy-level spectral ratio was also

  1. Time-Varying Potassium in High-Resolution Spectra of the Type Ia Supernova 2014J

    CERN Document Server

    Graham, M L; Fulton, B J; Weiss, L M; Shen, K J; Kelly, P L; Zheng, W; Filippenko, A V; Marcy, G W; Howell, D A; Burt, J; Rivera, E J

    2014-01-01

    We present a time series of the highest resolution spectra yet published for the nearby Type Ia supernova (SN) 2014J in M82. They were obtained at 11 epochs over 33 days around peak brightness with the Levy Spectrograph (resolution R~110,000) on the 2.4m Automated Planet Finder telescope at Lick Observatory. We identify multiple Na I D and K I absorption features, as well as absorption by Ca I H & K and several of the more common diffuse interstellar bands (DIBs). We see no evolution in any component of Na I D, Ca I, or in the DIBs, but do establish the dissipation/weakening of the two most blueshifted components of K I. We present several potential physical explanations, finding the most plausible to be photoionization of circumstellar material, and discuss the implications of our results with respect to the progenitor scenario of SN 2014J.

  2. Isotopic abundances of stratospheric ozone from balloon-borne high-resolution infrared solar spectra

    Science.gov (United States)

    Goldman, A.; Murcray, F. J.; Murcray, D. G.; Kosters, J. J.; Rinsland, C. P.

    1989-01-01

    IR solar absorption spectra at 0.002-0.0003/cm resolution in the 10-micron region obtained during two balloon flights near 32 deg N latitude are examined to determine the isotopic ratios of (O-16)(O-16)(O-18) and (O-16)(O-18)(O-16) relative to normal ozone in the stratosphere. For November 18, 1987, the results show column-averaged isotopic enhancement ratios of 1.20 + or - 0.14 and 1.40 + or - 0.18 for (O-16)(O-18)(O-16)/(O-16)(O-16)(O-16) and (O-16)(O-16)(O-18)/(O-16)(O-16)(O-16), respectively. The corresponding values for June 6, 1988, show ratios of 1.16 + or - 0.08 and 1.25 + or - 0.12. The results are compared with heavy-to-normal O3 ratios obtained using other techniques.

  3. New insights in high-resolution spectroscopy a wide theoretical library of R=500000 stellar spectra

    CERN Document Server

    Bertone, E; Rodríguez-Merino, L H; Chavez, M

    2002-01-01

    We present an extended theoretical library of over 800 synthetic stellar spectra, covering energy distribution in the optical range (lambda = 3500-7000 angstrom), at inverse resolution R=500000. The library, based on the ATLAS9 model atmospheres, has been computed with the SYNTHE code developed by R.L. Kurucz. The grid spans a large volume in the fundamental parameter space (i.e. effective temperature, surface gravity, metallicity), and can be profitably applied to different research fields dealing both with the study of single stars and stellar aggregates, through population synthesis models. A complementary project, in progress, will extend the wavelength range to the ultraviolet, down to 850 angstrom, at an inverse resolution of R=50000.

  4. New Insights in High-Resolution Spectroscopy: a Wide Theoretical Library of R=500000 Stellar Spectra

    Science.gov (United States)

    Bertone, E.; Buzzoni, A.; Rodríguez-Merino, L. H.; Chávez, M.

    We present an extended theoretical library of over 800 synthetic stellar spectra, covering energy distribution in the optical range (lambda = 3500-7000 angstrom), at inverse resolution R=500000. The library, based on the ATLAS9 model atmospheres, has been computed with the SYNTHE code developed by R.L. Kurucz. The grid spans a large volume in the fundamental parameter space (i.e. effective temperature, surface gravity, metallicity), and can be profitably applied to different research fields dealing both with the study of single stars and stellar aggregates, through population synthesis models. A complementary project, in progress, will extend the wavelength range to the ultraviolet, down to 850 angstrom, at an inverse resolution of R=50000.

  5. Ion Mobility Spectrometry - High Resolution LTQ-Orbitrap Mass Spectrometry for Analysis of Homemade Explosives

    Science.gov (United States)

    Hagan, Nathan; Goldberg, Ilana; Graichen, Adam; St. Jean, Amanda; Wu, Ching; Lawrence, David; Demirev, Plamen

    2017-08-01

    The detailed chemical characterization of homemade explosives (HMEs) and other chemicals that can mimic or mask the presence of explosives is important for understanding and improving the performance of commercial instrumentation used for explosive detection. To that end, an atmospheric-pressure drift tube ion mobility spectrometry (IMS) instrument has been successfully coupled to a commercial tandem mass spectrometry (MS) system. The tandem MS system is comprised of a linear ion trap and a high resolution Orbitrap analyzer. This IMS-MS combination allows extensive characterization of threat chemical compounds, including HMEs, and complex real-world background chemicals that can interfere with detection. Here, the composition of ion species originating from a specific HME, erythritol tetranitrate, has been elucidated using accurate mass measurements, isotopic ratios, and tandem MS. Gated IMS-MS and high-resolution MS have been used to identify minor impurities that can be indicative of the HME source and/or synthesis route. Comparison between data obtained on the IMS/MS system and on commercial stand-alone IMS instruments used as explosive trace detectors (ETDs) has also been performed. Such analysis allows better signature assignments of threat compounds, modified detection algorithms, and improved overall ETD performance.

  6. High-resolution mass models of dwarf galaxies from LITTLE THINGS

    CERN Document Server

    Oh, Se-Heon; Brinks, Elias; Elmegreen, Bruce G; Schruba, Andreas; Walter, Fabian; Rupen, Michael P; Young, Lisa M; Simpson, Caroline E; Johnson, Megan; Herrmann, Kimberly A; Ficut-Vicas, Dana; Cigan, Phil; Heesen, Volker; Ashley, Trisha; Zhang, Hong-Xin

    2015-01-01

    We present high-resolution rotation curves and mass models of 26 dwarf galaxies from LITTLE THINGS. LITTLE THINGS is a high-resolution Very Large Array HI survey for nearby dwarf galaxies in the local volume within 11 Mpc. The rotation curves of the sample galaxies derived in a homogeneous and consistent manner are combined with Spitzer archival 3.6 micron and ancillary optical U, B, and V images to construct mass models of the galaxies. We decompose the rotation curves in terms of the dynamical contributions by baryons and dark matter halos, and compare the latter with those of dwarf galaxies from THINGS as well as Lambda CDM SPH simulations in which the effect of baryonic feedback processes is included. Being generally consistent with THINGS and simulated dwarf galaxies, most of the LITTLE THINGS sample galaxies show a linear increase of the rotation curve in their inner regions, which gives shallower logarithmic inner slopes alpha of their dark matter density profiles. The mean value of the slopes of the 2...

  7. Evaluation of data compression techniques for the inference of stellar atmospheric parameters from high-resolution spectra

    Science.gov (United States)

    González-Marcos, A.; Sarro, L. M.; Ordieres-Meré, J.; Bello-García, A.

    2017-03-01

    The determination of stellar atmospheric parameters from spectra suffers the so-called curse-of-dimensionality problem, which is related to the higher number of input variables (flux values) compared to the number of spectra available to fit a regression model (this collection of examples is known as the training set). This work evaluates the utility of several techniques for alleviating this problem in regression tasks where the objective is to estimate the effective temperature (Teff), the surface gravity (log g), the metallicity ([M/H]) and/or the alpha-to-iron ratio ([α/Fe]). The goal of the techniques analysed here is to achieve data compression by representing the spectra with a number of variables much lower than the initially available set of fluxes. The experiments were performed with high-resolution spectra of stars in the 4000-8000 K range for different signal-to-noise ratio (SNR) regimes. We conclude that independent component analysis (ICA) performs better than the rest of techniques evaluated for all SNR regimes. We also assess the necessity to adapt the SNR of the spectra used to fit a regression model (training set) to the SNR of the spectra for which the atmospheric parameters are needed (evaluation set). Within the conditions of our experiments, we conclude that at most only two such regression models are needed (in the case of regression models for effective temperatures, those corresponding to SNR = 50 and 10) to cover the entire SNR range. Finally, we also compare the prediction accuracy of effective temperature regression models for increasing values of the training grid density and the same compression techniques.

  8. Fundamental stellar parameters and metallicities from Bayesian spectroscopy: application to low- and high-resolution spectra

    Science.gov (United States)

    Schönrich, Ralph; Bergemann, Maria

    2014-09-01

    We present a unified framework to derive fundamental stellar parameters by combining all available observational and theoretical information for a star. The algorithm relies on the method of Bayesian inference, which for the first time directly integrates the spectroscopic analysis pipeline based on the global spectrum synthesis and allows for comprehensive and objective error calculations given the priors. Arbitrary input data sets can be included into our analysis and other stellar quantities, in addition to stellar age, effective temperature, surface gravity, and metallicity, can be computed on demand. We lay out the mathematical framework of the method and apply it to several observational data sets, including high- and low-resolution spectra (UVES, NARVAL, HARPS, SDSS/SEGUE). We find that simpler approximations for the spectroscopic probability distribution function, which are inherent to past Bayesian approaches, lead to deviations of several standard deviations and unreliable errors on the same data. By its flexibility and the simultaneous analysis of multiple independent measurements for a star, it will be ideal to analyse and cross-calibrate the large ongoing and forthcoming surveys, like Gaia-European Southern Observatory (ESO), SDSS, Gaia and LSST.

  9. High resolution infrared spectra of NGC 6440 and NGC 6441: two massive Bulge Globular Clusters

    CERN Document Server

    Origlia, L; Rich, R M

    2008-01-01

    Using the NIRSPEC spectrograph at Keck II, we have obtained infrared echelle spectra covering the 1.5-1.8 micron range for giant stars in the massive bulge globular clusters NGC6440 and NGC6441. We report the first high dispersion abundance for NGC6440, [Fe/H]=-0.56+/-0.02 and we find [Fe/H]=-0.50+/-0.02 for the blue HB cluster NGC6441. We measure an average $\\alpha$-enhancement of ~+0.3 dex in both clusters, consistent with previous measurements of other metal rich bulge clusters, and favoring the scenario of a rapid bulge formation and chemical enrichment. We also measure very low 12C/13C isotopic ratios (~5+/- 1), suggesting that extra-mixing mechanisms are at work during evolution along the Red Giant Branch also in the high metallicity regime. We also measure Al abundances, finding average [Al/Fe]=0.45+/-0.02 and [Al/Fe]=0.52+/-0.02 in NGC6440 and NGC6441, respectively, and some Mg-Al anti-correlation in NGC6441. We also measure radial velocities vr=-76+/-3 km/s and vr=+14+/-3 km/s and velocity dispersion...

  10. Absorption line indices from high resolution spectra. I. New Response Functions

    CERN Document Server

    Tantalo, R; Munari, U; Piovan, L; Sordo, R

    2004-01-01

    Basing on the huge library of 1A resolution spectra calculated by Munari et al. (2004) over a large range of atmospheric parameters (log Teff, log g, [Fe/H]) and both for solar and alpha-enhanced abundance ratios, we present theoretical absorption line indices on the Lick system. Firstly we derive the so-called Response Functions (RFs) of Tripicco & Bell (1995, TB95) for a wide range of atmospheric parameters, and [a/Fe]=+0.4. The RFs are commonly used to correct indices with solar [a/Fe] ratios to indices with [a/Fe]>0. Not only the RFs vary with the type of star but also with the metallicity. Secondly, with the aid of this and the Fitting Functions (FFs) of Worthey et al. (1994), we derive the indices for SSPs and compare them with those obtained by previous authors. The new RFs not only supersede the old ones by TB95, but also confirm that method adopted by Tantalo & Chiosi (2004a) to include the effect of alpha-enhancement was correct, and clearly show that also Hb increases with the degree of enh...

  11. CHEMICAL ABUNDANCES IN FIELD RED GIANTS FROM HIGH-RESOLUTION H-BAND SPECTRA USING THE APOGEE SPECTRAL LINELIST

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Verne V.; Cunha, Katia [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Shetrone, Matthew D. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Meszaros, Szabolcs; Allende Prieto, Carlos [Instituto d' Astrofisica de Canarias, E-38205, La Laguna, Tenerife (Spain); Bizyaev, Dmitry [Apache Point Observatory, Sunspot, NM 88349 (United States); Garcia Perez, Ana; Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Schiavon, Ricardo [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5UX (United Kingdom); Holtzman, Jon [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Johnson, Jennifer A., E-mail: vsmith@noao.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2013-03-01

    High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory Fourier transform spectrometer, are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the Sloan Digital Sky Survey III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. The red giant sample studied here was chosen to probe which chemical elements can be derived reliably from the H-band APOGEE spectral region. These red giants consist of two K-giants ({alpha} Boo and {mu} Leo), two M-giants ({beta} And and {delta} Oph), and one thermally pulsing asymptotic giant branch (TP-AGB) star of spectral type MS (HD 199799). Measured chemical abundances include the cosmochemically important isotopes {sup 12}C, {sup 13}C, {sup 14}N, and {sup 16}O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. The K and M giants exhibit the abundance signature of the first dredge-up of CN-cycle material, while the TP-AGB star shows clear evidence of the addition of {sup 12}C synthesized during {sup 4}He-burning thermal pulses and subsequent third dredge-up. A comparison of the abundances derived here with published values for these stars reveals consistent results to {approx}0.1 dex. The APOGEE spectral region and linelist is thus well suited for probing both Galactic chemical evolution, as well as internal nucleosynthesis and mixing in populations of red giants via high-resolution spectroscopy.

  12. New high-resolution electrostatic ion mass analyzer using time of flight

    Science.gov (United States)

    Hamilton, D. C.; Gloeckler, G.; Ipavich, F. M.; Lundgren, R. A.; Sheldon, R. B.

    1990-01-01

    The design of a high-resolution ion-mass analyzer is described, which is based on an accurate measurement of the time of flight (TOF) of ions within a region configured to produce a harmonic potential. In this device, the TOF, which is independent of ion energy, is determined from a start pulse from secondary electrons produced when the ion passes through a thin carbon foil at the entrance of the TOF region and at a stop pulse from the ion striking a microchannel plate upon exciting the region. A laboratory prototype instrument called 'VMASS' was built and was tested at the Goddard Space Flight Center electrostatic accelerator, showing a good mass resolution of the instrument. Sensors of the VMASS type will form part of the WIND Solar Wind and Suprathermal Ion experiment, the Soho mission, and the Advanced Composition Explorer.

  13. Glycation promoted by dynamic high pressure microfluidisation pretreatment revealed by high resolution mass spectrometry.

    Science.gov (United States)

    Huang, Xiaoqin; Tu, Zongcai; Wang, Hui; Zhang, Qiuting; Hu, Yueming; Zhang, Lan; Niu, Peipei; Shi, Yan; Xiao, Hui

    2013-12-01

    The effect of dynamic high pressure microfluidisation (DHPM) pretreatment on the glycation of bovine serum albumin (BSA) was investigated. A detailed glycation map was obtained from high resolution mass spectrometry. Without DHPM pretreatment, only 7 glycation sites were identified, whereas the numbers were increased to 10, 11 and 11 when BSA-glucose was pretreated with DHPM at 50, 100 and 200 MPa, respectively, suggesting that DHPM pretreatment can significantly promote the Maillard reaction. Average degree of substitution per peptide molecule BSA (DSP) was used to further evaluate the glycation level under various DHPM conditions. All the DHPM pretreated samples exhibited elevated glycation level compared to the un-pretreated sample. With 100 MPa DHPM pretreatment, the protein showed the most significantly enhanced glycation extent. In addition, our results suggest that Maillard-type glycation followed by mass spectrometry analysis can be used to study the conformational changes when proteins are disturbed by external forces.

  14. High-Resolution Mass Spectrometry and Molecular Characterization of Aqueous Photochemistry Products of Common Types of Secondary Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Romonosky, Dian E.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-03-19

    A significant fraction of atmospheric organic compounds is predominantly found in condensed phases, such as aerosol particles and cloud droplets. Many of these compounds are photolabile and can degrade through direct photolysis or indirect photooxidation processes on time scales that are comparable to the typical lifetimes of aqueous droplets (hours) and particles (days). This paper presents a systematic investigation of the molecular level composition and the extent of aqueous photochemical processing in different types of secondary organic aerosol (SOA) from biogenic and anthropogenic precursors including α-pinene, β-pinene, β-myrcene, d- limonene, α-humulene, 1,3,5-trimethylbenzene, and guaiacol, oxidized by ozone (to simulate a remote atmosphere) or by OH in the presence of NOx (to simulate an urban atmosphere). Chamber- and flow tube-generated SOA samples were collected, extracted in a methanol/water solution, and photolyzed for 1 h under identical irradiation conditions. In these experiments, the irradiation was equivalent to about 3-8 h of exposure to the sun in its zenith. The molecular level composition of the dissolved SOA was probed before and after photolysis with direct-infusion electrospray ionization high-resolution mass spectrometry (ESI-HR-MS). The mass spectra of unphotolyzed SOA generated by ozone oxidation of monoterpenes showed qualitatively similar features, and contained largely overlapping subsets of identified compounds. The mass spectra of OH/NOx generated SOA had more unique visual appearance, and indicated a lower extent of products overlap. Furthermore, the fraction of nitrogen containing species (organonitrates and nitroaromatics) was highly sensitive to the SOA precursor. These observations suggest that attribution of high-resolution mass spectra in field SOA samples to specific SOA precursors should be more straightforward under OH/NOx oxidation conditions compared to the ozone driven oxidation. Comparison of the SOA constituents

  15. Chemical Abundances in Field Red Giants from High-Resolution H-Band Spectra using the APOGEE Spectral Linelist

    CERN Document Server

    Smith, Verne V; Shetrone, Matthew D; Meszaros, Szabolcs; Prieto, Carlos Allende; Bizyaev, Dmitry; Perez, Ana Garcia; Majewski, Steven R; Schiavon, Ricardo; Holtzman, Jon; Johnson, Jennifer A

    2012-01-01

    High-resolution H-band spectra of five bright field K, M, and MS giants, obtained from the archives of the Kitt Peak National Observatory (KPNO) Fourier Transform Spectrometer (FTS), are analyzed to determine chemical abundances of 16 elements. The abundances were derived via spectrum synthesis using the detailed linelist prepared for the SDSS III Apache Point Galactic Evolution Experiment (APOGEE), which is a high-resolution near-infrared spectroscopic survey to derive detailed chemical abundance distributions and precise radial velocities for 100,000 red giants sampling all Galactic stellar populations. Measured chemical abundances include the cosmochemically important isotopes 12C, 13C, 14N, and 16O, along with Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. A comparison of the abundances derived here with published values for these stars reveals consistent results to ~0.1 dex. The APOGEE spectral region and linelist is, thus, well-suited for probing both Galactic chemical evolution, as well as inter...

  16. MAINTAINING HIGH RESOLUTION MASS SPECTROMETRY CAPABILITIES FOR NATIONAL NUCLEAR SECURITY ADMINISTRATION APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Wyrick, S.; Cordaro, J.; Reeves, G.; Mcintosh, J.; Mauldin, C.; Tietze, K.; Varble, D.

    2011-06-06

    The Department of Energy (DOE) National Nuclear Security Administration (NNSA) has a specialized need for analyzing low mass gas species at very high resolutions. The currently preferred analytical method is electromagnetic sector mass spectrometry. This method allows the NNSA Nuclear Security Enterprise (NSE) to resolve species of similar masses down to acceptable minimum detection limits (MDLs). Some examples of these similar masses are helium-4/deuterium and carbon monoxide/nitrogen. Through the 1980s and 1990s, there were two vendors who supplied and supported these instruments. However, with declining procurements and down turns in the economy, the supply of instruments, service and spare parts from these vendors has become less available, and in some cases, nonexistent. The largest NSE user of this capability is the Savannah River Site (SRS), located near Aiken, South Carolina. The Research and Development Engineering (R&DE) Group in the Savannah River National Laboratory (SRNL) investigated the areas of instrument support that were needed to extend the life cycle of these aging instruments. Their conclusions, as to the focus areas of electromagnetic sector mass spectrometers to address, in order of priority, were electronics, software and hardware. Over the past 3-5 years, the R&DE Group has designed state of the art electronics and software that will allow high resolution legacy mass spectrometers, critical to the NNSA mission, to be operated for the foreseeable future. The funding support for this effort has been from several sources, including the SRS Defense Programs, NNSA Readiness Campaign, Pantex Plant and Sandia National Laboratory. To date, electronics systems have been upgraded on one development system at SRNL, two production systems at Pantex and one production system at Sandia National Laboratory. An NSE working group meets periodically to review strategies going forward. The R&DE Group has also applied their work to the electronics for a

  17. Electronic Wave Packet Interferometry of Gas Phase Samples: High Resolution Spectra and Collective Effects

    Science.gov (United States)

    Stienkemeier, Frank

    2017-06-01

    Time-resolved coherent spectroscopy has opened many new directions to study ultrafast dynamics in complex quantum systems. While most applications have been achieved in the condensed phase, we are focusing on dilute gas phase samples, in particular, on doped helium droplet beams. Isolation in such droplets at millikelvin temperatures provides unique opportunities to synthesize well-defined complexes, to prepare specific ro-vibronic states, and study their dynamics. To account for the small densities in our samples, we apply a phase modulation technique in order to reach enough sensitivity and a high spectral resolution in electronic wave packet interferometry experiments. The combination with mass-resolved ion detection enabled us e.g. to characterize vibrational structures of excimer molecules. By extending this technique we have observed collective resonances in samples of very low density (10^8 cm^{-3}). With a variant of this method, we are currently elaborating the implementation of nonlinear all-XUV spectroscopy.

  18. Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan)] [and others

    1997-03-01

    High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

  19. Quantification of several atmospheric gases from high resolution infrared solar spectra obtained at the South Pole in 1980 and 1986

    Science.gov (United States)

    Goldman, Aaron; Murcray, Frank J.; Murcray, Frank H.; Murcray, David G.; Rinsland, Curtis P.

    1988-01-01

    High-resolution solar absorption spectra recorded at the Amundsen-Scott South Pole Station were analyzed to obtain total column amounts of O3, N2O, HNO3, CO2, CH4, and CF2Cl2, and to investigate the differences in the values obtained in December 1980 with those obtained in December 1986. In addition, vertical column amounts for HCl, NO, NO2, and C2H6 were derived for December 1986. One interesting feature of these results is that the total column amounts of HCl measured for several days at the South Pole (/6.4 + or - 0.8/ x 10 to the 15th molecules/sq cm) were high compared with the HCl column amounts reported for lower latitudes.

  20. High Resolution Studies of the Origins of Polyatomic Ions in Inductively Coupled Plasma-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Jill Wisnewski [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    The inductively coupled plasma (ICP) is an atmospheric pressure ionization source. Traditionally, the plasma is sampled via a sampler cone. A supersonic jet develops behind the sampler, and this region is pumped down to a pressure of approximately one Torr. A skimmer cone is located inside this zone of silence to transmit ions into the mass spectrometer. The position of the sampler and skimmer cones relative to the initial radiation and normal analytical zones of the plasma is key to optimizing the useful analytical signal [1]. The ICP both atomizes and ionizes the sample. Polyatomic ions form through ion-molecule interactions either in the ICP or during ion extraction [l]. Common polyatomic ions that inhibit analysis include metal oxides (MO+), adducts with argon, the gas most commonly used to make up the plasma, and hydride species. While high resolution devices can separate many analytes from common interferences, this is done at great cost in ion transmission efficiency--a loss of 99% when using high versus low resolution on the same instrument [2]. Simple quadrupole devices, which make up the bulk of ICP-MS instruments in existence, do not present this option. Therefore, if the source of polyatomic interferences can be determined and then manipulated, this could potentially improve the figures of merit on all ICP-MS devices, not just the high resolution devices often utilized to study polyatomic interferences.

  1. A high-resolution x-ray spectrometer for a kaon mass measurement

    Science.gov (United States)

    Phelan, Kevin; Suzuki, Ken; Zmeskal, Johann; Tortorella, Daniele; Bühler, Matthias; Hertrich, Theo

    2017-02-01

    The ASPECT consortium (Adaptable Spectrometer Enabled by Cryogenic Technology) is currently constructing a generalised cryogenic platform for cryogenic detector work which will be able to accommodate a wide range of sensors. The cryogenics system is based on a small mechanical cooler with a further adiabatic demagnetisation stage and will work with cryogenic detectors at sub-Kelvin temperatures. The commercial aim of the consortium is to produce a compact, user-friendly device with an emphasis on reliability and portability which can easily be transported for specialised on-site work, such as beam-lines or telescope facilities. The cryogenic detector platform will accommodate a specially developed cryogenic sensor, either a metallic magnetic calorimeter or a magnetic penetration-depth thermometer. The detectors will be designed to work in various temperatures regions with an emphasis on optimising the various detector resolutions for specific temperatures. One resolution target is of about 10 eV at the energies range typically created in kaonic atoms experiments (soft x-ray energies). A following step will see the introduction of continuous, high-power, sub-Kelvin cooling which will bring the cryogenic basis for a high resolution spectrometer system to the market. The scientific goal of the project will produce an experimental set-up optimised for kaon-mass measurements performing high-resolution x-ray spectroscopy on a beam-line provided foreseeably by the J-PARC (Tokai, Japan) or DAΦNE (Frascati, Italy) facilities.

  2. High-resolution Orbitrap™-based mass spectrometry for rapid detection of peanuts in nuts.

    Science.gov (United States)

    Monaci, Linda; De Angelis, Elisabetta; Bavaro, Simona L; Pilolli, Rosa

    2015-01-01

    Peanut represents one of the most harmful allergenic foods capable of triggering severe and sometimes lethal reactions in allergic consumers upon ingestion of even small amounts. Several proteins capable of inducing allergic reactions that have been recognised by patients' IgE antibodies have been identified from this nut source. Methods mainly based on ELISA assays have been developed in order to detect peanuts in several food commodities. In addition LC-MS/MS methods based on different mass analysers have also been devised for tracing peanut contamination in different foods achieving low limits of detection. The applicability of a benchtop high-resolution Exactive™ mass spectrometer has never been investigated for the rapid screening of peanut contamination in complex food matrices like mixtures of nuts. We report in this paper the design of suitable peanut markers and the development of an high-resolution Orbitrap™ mass spectrometer-based method for peanut detection in a mixture of nuts species. With this aim, different types of samples were prepared: (1) nuts-based powder made up of a mixture of hazelnuts, pistachios, almonds and walnuts; and (2) nuts powder fortified with peanuts. Different levels of fortifications were produced and the applicability of the method was tested. Finally, a subset of six peptides fulfilling specific analytical requirements was chosen to check the suitability of the method tailored to the detection of peanuts in nuts-based products, and two of them, peptides VYD and WLG, were selected as quantitative markers. The method proved to be a suitable screening tool to assess the presence of traces of peanuts in other tree nuts with a limit of detection as low as 4 µg of peanuts proteins or 26 µg of peanuts in 1 g of matrix.

  3. Amino acid analysis in micrograms of meteorite sample by nanoliquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Callahan, Michael P; Martin, Mildred G; Burton, Aaron S; Glavin, Daniel P; Dworkin, Jason P

    2014-03-07

    Amino acids and their enantiomers in a 360 microgram sample of Murchison meteorite were unambiguously identified and quantified using chemical derivatization and nanoliquid chromatography coupled to nanoelectrospray ionization high resolution orbitrap mass spectrometry techniques. The distribution and abundance of amino acids were similar to past studies of Murchison meteorite but the samples used here were three orders of magnitude lower. The analytical method was also highly sensitive, and some amino acid reference standards were successfully detected at a level of ∼200 attomoles (on column). These results may open up the possibility for investigating other less studied, sample-limited extraterrestrial samples (e.g., micrometeorites, interplanetary dust particles, and cometary particles) for biologically-relevant organic molecules.

  4. Saffron authentication based on liquid chromatography high resolution tandem mass spectrometry and multivariate data analysis.

    Science.gov (United States)

    Rubert, Josep; Lacina, Ondrej; Zachariasova, Milena; Hajslova, Jana

    2016-08-01

    Saffron is one of the oldest and most expensive spices, which is often target of fraudulent activities. In this research, a new strategy of saffron authentication based on metabolic fingerprinting was developed. In the first phase, a solid liquid extraction procedure was optimized, the main aim was to isolate as maximal representation of small molecules contained in saffron as possible. In the second step, a detection method based on liquid chromatography coupled with high-resolution mass spectrometry was developed. Initially, principal component analysis (PCA) revealed clear differences between saffron cultivated and packaged in Spain, protected designation of origin (PDO), and saffron packaged in Spain of unknown origin, labeled Spanish saffron. Afterwards, orthogonal partial least square discriminant analysis (OPLS-DA) was favorably used to discriminate between Spanish saffron. The tentative identification of markers showed glycerophospholipids and their oxidized lipids were significant markers according to their origin.

  5. Detection and quantification of proteins in clinical samples using high resolution mass spectrometry.

    Science.gov (United States)

    Gallien, Sebastien; Domon, Bruno

    2015-06-15

    Quantitative proteomics has benefited from the recent development of mass spectrometers capable of high-resolution and accurate-mass (HR/AM) measurements. While targeted experiments are routinely performed on triple quadrupole instruments in selected reaction monitoring (SRM; often referred as multiple reaction monitoring, MRM) mode, the quadrupole-orbitrap mass spectrometers allow quantification in MS/MS mode, also known as parallel reaction monitoring (PRM). This technique is characterized by higher selectivity and better confidence in the assignment of the precursor and fragment ions, and thus translates into an improved analytical performance. More fundamentally, PRM introduces a change of the overall paradigm of targeted experiments, by the decoupling of the acquisition and data processing. They rely on two distinct steps, with a simplified acquisition method in conjunction with a flexible, iterative, post-acquisition data processing. This account describes in detail the different steps of a PRM experiment, which include the design of the acquisition method, the confirmation of the identity of the analytes founded upon a full MS/MS fragmentation pattern, and the quantification based on the extraction of specific fragment ions (selected post-acquisition) using tight mass tolerance. The different types of PRM experiments, defined as large-scale screening or precise targeted quantification using calibrated internal standards, together with the considerations on the selection of experimental parameters are discussed.

  6. [The rapid analysis of polychlorinated quaterphenyls in blood using different diameter capillary column with the high-resolution gas chromatograph high-resolution mass spectrometer].

    Science.gov (United States)

    Yasutake, Daisuke; Ashizuka, Yuki; Hori, Tsuguhide; Kurokawa, Youichi; Kajiwara, Jumboku; Hirata, Teruaki; Ishiguro, Yasuhisa; Iida, Takao; Uchi, Hiroshi; Furue, Masutaka

    2011-04-01

    The polychlorinated quaterphenyl (PCQ) concentrations in blood are important discriminative parameters in yusho patient. In this study, a rapid analytical method for PCQ using different diameter capillary column (rapid-Rtx65TG) with high-resolution gas chromatograph high-resolution mass spectrometer (HRGC/HRMS) instead of the gas chromatograph electron capture detector (ECD/GC) was developed. Using different diameter capillary columns, the analysis time of the HRGC/HRMS was drastically shortened, and the detection sensitivity was improved. In the rapid-Rtx65TG column, a small-bore capillary column (length 1m, I.D. 0.1mm) was connected with the inlet side of the GC, and behind that column, a large-bore capillary column (length 15mm, I.D. 0.53mm) for octadecachloroquaterphenyl (ODCQ) analysis was connected. In the HRGC/HRMS measurement of ODCQ by the rapid-Rtx65TG column, the minimum limit of detection for the apparatus was 0.4 pg, and the minimum limit of determination for the blood was 0.008 ppb. On ECD/GC in the conventional method and HRGC/HRMS in this study, the PCQ concentration in blood including yusho patients and yusho suspected persons was almost equivalent.

  7. Reference Standardization for Mass Spectrometry and High-resolution Metabolomics Applications to Exposome Research.

    Science.gov (United States)

    Go, Young-Mi; Walker, Douglas I; Liang, Yongliang; Uppal, Karan; Soltow, Quinlyn A; Tran, ViLinh; Strobel, Frederick; Quyyumi, Arshed A; Ziegler, Thomas R; Pennell, Kurt D; Miller, Gary W; Jones, Dean P

    2015-12-01

    The exposome is the cumulative measure of environmental influences and associated biological responses throughout the lifespan, including exposures from the environment, diet, behavior, and endogenous processes. A major challenge for exposome research lies in the development of robust and affordable analytic procedures to measure the broad range of exposures and associated biologic impacts occurring over a lifetime. Biomonitoring is an established approach to evaluate internal body burden of environmental exposures, but use of biomonitoring for exposome research is often limited by the high costs associated with quantification of individual chemicals. High-resolution metabolomics (HRM) uses ultra-high resolution mass spectrometry with minimal sample preparation to support high-throughput relative quantification of thousands of environmental, dietary, and microbial chemicals. HRM also measures metabolites in most endogenous metabolic pathways, thereby providing simultaneous measurement of biologic responses to environmental exposures. The present research examined quantification strategies to enhance the usefulness of HRM data for cumulative exposome research. The results provide a simple reference standardization protocol in which individual chemical concentrations in unknown samples are estimated by comparison to a concurrently analyzed, pooled reference sample with known chemical concentrations. The approach was tested using blinded analyses of amino acids in human samples and was found to be comparable to independent laboratory results based on surrogate standardization or internal standardization. Quantification was reproducible over a 13-month period and extrapolated to thousands of chemicals. The results show that reference standardization protocol provides an effective strategy that will enhance data collection for cumulative exposome research. In principle, the approach can be extended to other types of mass spectrometry and other analytical methods.

  8. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Xu, J.; Zhang, Q.; Chen, M.; Ge, X.; Ren, J.; Qin, D.

    2014-06-01

    An aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed along with a Scanning Mobility Particle Sizer (SMPS) and a Multi Angle Absorption Photometers (MAAP) to measure the temporal variations of the mass loading, chemical composition, and size distribution of sub-micrometer particulate matter (PM1) in Lanzhou, northwest China, during 12 July-7 August 2012. The average PM1 mass concentration including non-refractory PM1 (NR-PM1) measured by HR-ToF-AMS and black carbon (BC) measured by MAAP during this study was 24.5 μg m-3 (ranging from 0.86 to 105μg m-3), with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. The organics was consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C) of 0.33 and organic mass-to-carbon ratio (OM / OC) of 1.58. Positive matrix factorization (PMF) of the high-resolution mass spectra of organic aerosols (OA) identified four distinct factors which represent, respectively, two primary OA (POA) emission sources (traffic and food cooking) and two secondary OA (SOA) types - a fresher, semi-volatile oxygenated OA (SV-OOA) and a more aged, low-volatility oxygenated OA (LV-OOA). Traffic-related hydrocarbon-like OA (HOA) and BC displayed distinct diurnal patterns both with peak at ~07:00-11:00 (BJT: UTC +8) corresponding to the morning rush hours, while cooking OA (COA) peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ∼07:00-15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak at ~08:00-13:00. The later morning and early afternoon peak in the diurnal profiles of secondary aerosol species was likely caused by mixing down of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during night time. The mass spectrum of SV-OOA also showed similarity with that of

  9. Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars

    CERN Document Server

    Smiljanic, R; Bergemann, M; Frasca, A; Magrini, L; Masseron, T; Pancino, E; Ruchti, G; Roman, I San; Sbordone, L; Sousa, S G; Tabernero, H; Tautvaisiene, G; Valentini, M; Weber, M; Worley, C C; Adibekyan, V Zh; Prieto, C Allende; Barisevicius, G; Biazzo, K; Blanco-Cuaresma, S; Bonifacio, P; Bragaglia, A; Caffau, E; Cantat-Gaudin, T; Chorniy, Y; de Laverny, P; Delgado-Mena, E; Donati, P; Duffau, S; Franciosini, E; Friel, E; Geisler, D; Hernandez, J I Gonzalez; Gruyters, P; Guiglion, G; Hansen, C J; Heiter, U; Hill, V; Jacobson, H R; Jofre, P; Jonsson, H; Lanzafame, A C; Lardo, C; Ludwig, H G; Maiorca, E; Mikolaitis, S; Montes, D; Morel, T; Mucciarelli, A; Munoz, C; Nordlander, T; Pasquini, L; Puzeras, E; Recio-Blanco, A; Ryde, N; Sacco, G; Santos, N C; Serenelli, A M; Sordo, R; Soubiran, C; Spina, L; Steffen, M; Vallenari, A; Van Eck, S; Villanova, S; Gilmore, G; Randich, S; Asplund, M; Binney, J; Drew, J; Feltzing, S; Ferguson, A; Jeffries, R; Micela, G; Negueruela, I; Prusti, T; Rix, H-W; Alfaro, E; Babusiaux, C; Bensby, T; Blomme, R; Flaccomio, E; Francois, P; Irwin, M; Koposov, S; Walton, N; Bayo, A; Carraro, G; Costado, M T; Damiani, F; Edvardsson, B; Hourihane, A; Jackson, R; Lewis, J; Lind, K; Marconi, G; Martayan, C; Monaco, L; Morbidelli, L; Prisinzano, L; Zaggia, S

    2014-01-01

    The Gaia-ESO Survey is obtaining high-quality spectroscopic data for about 10^5 stars using FLAMES at the VLT. UVES high-resolution spectra are being collected for about 5000 FGK-type stars. These UVES spectra are analyzed in parallel by several state-of-the-art methodologies. Our aim is to present how these analyses were implemented, to discuss their results, and to describe how a final recommended parameter scale is defined. We also discuss the precision (method-to-method dispersion) and accuracy (biases with respect to the reference values) of the final parameters. These results are part of the Gaia-ESO 2nd internal release and will be part of its 1st public release of advanced data products. The final parameter scale is tied to the one defined by the Gaia benchmark stars, a set of stars with fundamental atmospheric parameters. A set of open and globular clusters is used to evaluate the physical soundness of the results. Each methodology is judged against the benchmark stars to define weights in three diff...

  10. Simultaneous determination of 40 novel psychoactive stimulants in urine by liquid chromatography-high resolution mass spectrometry and library matching.

    Science.gov (United States)

    Concheiro, Marta; Castaneto, Marisol; Kronstrand, Robert; Huestis, Marilyn A

    2015-06-05

    The emergence of novel psychoactive substances is an ongoing challenge for analytical toxicologists. Different analogs are continuously introduced in the market to circumvent legislation and to enhance their pharmacological activity. Although detection of drugs in blood indicates recent exposure and link intoxication to the causative agent, urine is still the most preferred testing matrix in clinical and forensic settings. We developed a method for the simultaneous quantification of 8 piperazines, 4 designer amphetamines and 28 synthetic cathinones and 4 metabolites, in urine by liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Data were acquired in full scan and data dependent MS(2) mode. Compounds were quantified by precursor ion exact mass, and confirmed by product ion spectra library matching, taking into account product ions' exact mass and intensities. One-hundred μL urine was subjected to solid phase cation exchange extraction (SOLA SCX). The chromatographic reverse-phase separation was achieved with gradient mobile phase of 0.1% formic acid in water and in acetonitrile in 20 min. The assay was linear from 2.5 or 5 to 500 μg/L. Imprecision (n=15) was urine specimens (n=62) were analyzed with the method that provides a comprehensive confirmation for 40 new stimulant drugs with specificity and sensitivity.

  11. Rock Mass Characterization by High-Resolution Sonic and GSI Borehole Logging

    Science.gov (United States)

    Agliardi, F.; Sapigni, M.; Crosta, G. B.

    2016-11-01

    We investigate the relationships between the in situ P-wave velocity (Vp) of rock masses, measured by borehole acoustic logging, and their Geological Strength Index (GSI), to support a reliable assessment of equivalent continuum rock mass properties at depth. We quantified both Vp and GSI in three deep boreholes drilled in a crystalline core complex of the central Italian Alps. The boreholes were driven up to 400 m in depth and provided high-quality drill cores in gneiss, schist and metasedimentary rocks with variable lithology. Geological and geomechanical logging was carried out for over 800 m of cores, and acoustic logging was performed for more than 600 m of borehole length. High-resolution core logging in terms of GSI was obtained using an original quantitative approach. Candidate empirical correlation functions linking Vp and GSI were tested by a two-step statistical analysis of the experimental dataset, including outlier removal and nonlinear regression analysis. We propose a sigmoid Vp-GSI equation valid over a depth range between 100 and 400 m. This accounts for extremely variable lithological, weathering and rock mass damage conditions, complementing existing shallow-depth approaches and showing potential for practical applications in different engineering settings.

  12. Elemental analysis of aerosol organic nitrates with electron ionization high-resolution mass spectrometry

    Directory of Open Access Journals (Sweden)

    A. W. Rollins

    2009-10-01

    Full Text Available Four hydroxynitrates (R(OHR'ONO2 representative of atmospheric volatile organic compound (VOC oxidation products were synthesized, nebulized and sampled into an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS. The resulting mass spectrum was used to evaluate calibration factors for elemental analysis of organic nitrates by AMS, and to determine the distribution of nitrogen in the detected fragments in a search for an AMS signature of organic nitrates. We find that 30% of the detected nitrogen mass is in the NO+ and NO2+ fragments, 12% at NHx+ fragments, 5% at CxHyOzN+ fragments, and 53% at various CxHyN+ fragments. Elemental analysis indicated that nitrogen was detected with higher efficiency than carbon and hydrogen, but oxygen was detected with reduced efficiency compared to previously reported results for a suite of organics which did not include organic nitrates. The results are used to suggest the maximum corrections to ambient O:C and N:C ratios based on AMS measurements.

  13. Advances in high-resolution mass spectrometry based on metabolomics studies for food--a review.

    Science.gov (United States)

    Rubert, Josep; Zachariasova, Milena; Hajslova, Jana

    2015-01-01

    Food authenticity becomes a necessity for global food policies, since food placed in the market without fail has to be authentic. It has always been a challenge, since in the past minor components, called also markers, have been mainly monitored by chromatographic methods in order to authenticate the food. Nevertheless, nowadays, advanced analytical methods have allowed food fingerprints to be achieved. At the same time they have been also combined with chemometrics, which uses statistical methods in order to verify food and to provide maximum information by analysing chemical data. These sophisticated methods based on different separation techniques or stand alone have been recently coupled to high-resolution mass spectrometry (HRMS) in order to verify the authenticity of food. The new generation of HRMS detectors have experienced significant advances in resolving power, sensitivity, robustness, extended dynamic range, easier mass calibration and tandem mass capabilities, making HRMS more attractive and useful to the food metabolomics community, therefore becoming a reliable tool for food authenticity. The purpose of this review is to summarise and describe the most recent metabolomics approaches in the area of food metabolomics, and to discuss the strengths and drawbacks of the HRMS analytical platforms combined with chemometrics.

  14. Molecular Chemistry of Organic Aerosols Through the Application of High Resolution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2011-01-05

    Understanding of molecular composition and fundamental chemical transformations of organic aerosols (OA) during their formation and aging is both a major challenge and the area of greatest uncertainty in atmospheric research. Particularly little is known about fundamental relationship between the chemical composition and physicochemical properties of OA, their atmospheric history, evolution, and impact on the environment. Ambient soft-ionization methods combined with high-resolution mass spectrometry (HR-MS) analysis provide detailed information on the molecular content of OA that is pivotal for improved understanding of their complex composition, multi-phase aging chemistry, direct (light absorption and scattering) and indirect (aerosol-cloud interactions) effects on atmospheric radiation and climate, and health effects. The HR-MS methods can detect thousands of individual OA constituents at once, provide their elemental formulae from accurate mass measurements, and provide structural information based on tandem mass spectrometry. Integration with additional analytical tools, such as chromatography and UV/Vis absorption spectroscopy, makes it possible to further separate OA compounds by their polarity and ability to absorb solar radiation. The goal of this perspective is to describe modern HR-MS methods, review recent applications to field and laboratory studies of OA, and explain how the information obtained from HR-MS methods can be translated into improved understanding of OA chemistry.

  15. [Determination of mono- to tri-chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry].

    Science.gov (United States)

    Tang, Chen; Liu, Qipeng; Tian, Zhenyu; Xie, Huiting; Wang, Mengjing; Liu, Wenbin

    2014-09-01

    A method for the determination of mono- to tri-chlorinated dibenzo-p-dioxins and dibenzofurans (mono- to tri-CDD/Fs) in stack gas using isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed. The sam- ples were extracted by Soxhlet extraction, and then the extracts were concentrated and purified using a multilayer silica gel column and a basic alumina column. The analytes were separated by HRGC on a DB-5MS column (30 m x 0.25 mm x 0.25 μm) and determined by HRMS. The identi- fication of mono- to tri-CDD/Fs was based on the retention times of 13C-labelled standard and the abundance ratios of the two exacted mass-to-charge ratios. The quantitative analysis was performed using the ratios of the integrated areas of the 13C-labelled standards. This method had the recoveries ranging from 66.6% to 112.5% and the relative standard deviations (RSD) ranging from 19.9% to 40.5% (n = 5). The limits of detection (LODs) of this method for the mono- to tri-CDD/Fs were ranging from 0.027 to 0.485 μg/L. Three stack gas samples from waste incinerators were measured using this method, with the recoveries ranging from 85.7% to 137.0% and the concentrations ranging from 11.4 to 9,183 pg/Nm3. The results indicated that the method can be applied to the precise determination of mono- to tri-CDD/Fs at trace level in stack gas.

  16. Molecular composition of organic aerosols in central Amazonia: an ultra-high-resolution mass spectrometry study

    Science.gov (United States)

    Kourtchev, Ivan; Godoi, Ricardo H. M.; Connors, Sarah; Levine, James G.; Archibald, Alex T.; Godoi, Ana F. L.; Paralovo, Sarah L.; Barbosa, Cybelli G. G.; Souza, Rodrigo A. F.; Manzi, Antonio O.; Seco, Roger; Sjostedt, Steve; Park, Jeong-Hoo; Guenther, Alex; Kim, Saewung; Smith, James; Martin, Scot T.; Kalberer, Markus

    2016-09-01

    The Amazon Basin plays key role in atmospheric chemistry, biodiversity and climate change. In this study we applied nanoelectrospray (nanoESI) ultra-high-resolution mass spectrometry (UHRMS) for the analysis of the organic fraction of PM2.5 aerosol samples collected during dry and wet seasons at a site in central Amazonia receiving background air masses, biomass burning and urban pollution. Comprehensive mass spectral data evaluation methods (e.g. Kendrick mass defect, Van Krevelen diagrams, carbon oxidation state and aromaticity equivalent) were used to identify compound classes and mass distributions of the detected species. Nitrogen- and/or sulfur-containing organic species contributed up to 60 % of the total identified number of formulae. A large number of molecular formulae in organic aerosol (OA) were attributed to later-generation nitrogen- and sulfur-containing oxidation products, suggesting that OA composition is affected by biomass burning and other, potentially anthropogenic, sources. Isoprene-derived organosulfate (IEPOX-OS) was found to be the most dominant ion in most of the analysed samples and strongly followed the concentration trends of the gas-phase anthropogenic tracers confirming its mixed anthropogenic-biogenic origin. The presence of oxidised aromatic and nitro-aromatic compounds in the samples suggested a strong influence from biomass burning especially during the dry period. Aerosol samples from the dry period and under enhanced biomass burning conditions contained a large number of molecules with high carbon oxidation state and an increased number of aromatic compounds compared to that from the wet period. The results of this work demonstrate that the studied site is influenced not only by biogenic emissions from the forest but also by biomass burning and potentially other anthropogenic emissions from the neighbouring urban environments.

  17. Decon2LS: An open-source software package for automated processing and visualization of high resolution mass spectrometry data

    Directory of Open Access Journals (Sweden)

    Anderson Gordon A

    2009-03-01

    Full Text Available Abstract Background Data generated from liquid chromatography coupled to high-resolution mass spectrometry (LC-MS-based studies of a biological sample can contain large amounts of biologically significant information in the form of proteins, peptides, and metabolites. Interpreting this data involves inferring the masses and abundances of biomolecules injected into the instrument. Because of the inherent complexity of mass spectral patterns produced by these biomolecules, the analysis is significantly enhanced by using visualization capabilities to inspect and confirm results. In this paper we describe Decon2LS, an open-source software package for automated processing and visualization of high-resolution MS data. Drawing extensively on algorithms developed over the last ten years for ICR2LS, Decon2LS packages the algorithms as a rich set of modular, reusable processing classes for performing diverse functions such as reading raw data, routine peak finding, theoretical isotope distribution modelling, and deisotoping. Because the source code is openly available, these functionalities can now be used to build derivative applications in relatively fast manner. In addition, Decon2LS provides an extensive set of visualization tools, such as high performance chart controls. Results With a variety of options that include peak processing, deisotoping, isotope composition, etc, Decon2LS supports processing of multiple raw data formats. Deisotoping can be performed on an individual scan, an individual dataset, or on multiple datasets using batch processing. Other processing options include creating a two dimensional view of mass and liquid chromatography (LC elution time features, generating spectrum files for tandem MS data, creating total intensity chromatograms, and visualizing theoretical peptide profiles. Application of Decon2LS to deisotope different datasets obtained across different instruments yielded a high number of features that can be used to

  18. An Automated Platform for High-Resolution Tissue Imaging Using Nanospray Desorption Electrospray Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lanekoff, Ingela T.; Heath, Brandi S.; Liyu, Andrey V.; Thomas, Mathew; Carson, James P.; Laskin, Julia

    2012-10-02

    An automated platform has been developed for acquisition and visualization of mass spectrometry imaging (MSI) data using nanospray desorption electrospray ionization (nano-DESI). The new system enables robust operation of the nano-DESI imaging source over many hours. This is achieved by controlling the distance between the sample and the probe by mounting the sample holder onto an automated XYZ stage and defining the tilt of the sample plane. This approach is useful for imaging of relatively flat samples such as thin tissue sections. Custom software called MSI QuickView was developed for visualization of large data sets generated in imaging experiments. MSI QuickView enables fast visualization of the imaging data during data acquisition and detailed processing after the entire image is acquired. The performance of the system is demonstrated by imaging rat brain tissue sections. High resolution mass analysis combined with MS/MS experiments enabled identification of lipids and metabolites in the tissue section. In addition, high dynamic range and sensitivity of the technique allowed us to generate ion images of low-abundance isobaric lipids. High-spatial resolution image acquired over a small region of the tissue section revealed the spatial distribution of an abundant brain metabolite, creatine, in the white and gray matter that is consistent with the literature data obtained using magnetic resonance spectroscopy.

  19. Advances in liquid chromatography-high-resolution mass spectrometry for quantitative and qualitative environmental analysis.

    Science.gov (United States)

    Aceña, Jaume; Stampachiacchiere, Serena; Pérez, Sandra; Barceló, Damià

    2015-08-01

    This review summarizes the advances in environmental analysis by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) during the last decade and discusses different aspects of their application. LC-HRMS has become a powerful tool for simultaneous quantitative and qualitative analysis of organic pollutants, enabling their quantitation and the search for metabolites and transformation products or the detection of unknown compounds. LC-HRMS provides more information than low-resolution (LR) MS for each sample because it can accurately determine the mass of the molecular ion and its fragment ions if it can be used for MS-MS. Another advantage is that the data can be processed using either target analysis, suspect screening, retrospective analysis, or non-target screening. With the growing popularity and acceptance of HRMS analysis, current guidelines for compound confirmation need to be revised for quantitative and qualitative purposes. Furthermore, new commercial software and user-built libraries are required to mine data in an efficient and comprehensive way. The scope of this critical review is not to provide a comprehensive overview of the many studies performed with LC-HRMS in the field of environmental analysis, but to reveal its advantages and limitations using different workflows.

  20. In-depth glycoproteomic characterization of γ-conglutin by high-resolution accurate mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Silvia Schiarea

    Full Text Available The molecular characterization of bioactive food components is necessary for understanding the mechanisms of their beneficial or detrimental effects on human health. This study focused on γ-conglutin, a well-known lupin seed N-glycoprotein with health-promoting properties and controversial allergenic potential. Given the importance of N-glycosylation for the functional and structural characteristics of proteins, we studied the purified protein by a mass spectrometry-based glycoproteomic approach able to identify the structure, micro-heterogeneity and attachment site of the bound N-glycan(s, and to provide extensive coverage of the protein sequence. The peptide/N-glycopeptide mixtures generated by enzymatic digestion (with or without N-deglycosylation were analyzed by high-resolution accurate mass liquid chromatography-multi-stage mass spectrometry. The four main micro-heterogeneous variants of the single N-glycan bound to γ-conglutin were identified as Man2(Xyl (Fuc GlcNAc2, Man3(Xyl (Fuc GlcNAc2, GlcNAcMan3(Xyl (Fuc GlcNAc2 and GlcNAc 2Man3(Xyl (Fuc GlcNAc2. These carry both core β1,2-xylose and core α1-3-fucose (well known Cross-Reactive Carbohydrate Determinants, but corresponding fucose-free variants were also identified as minor components. The N-glycan was proven to reside on Asn131, one of the two potential N-glycosylation sites. The extensive coverage of the γ-conglutin amino acid sequence suggested three alternative N-termini of the small subunit, that were later confirmed by direct-infusion Orbitrap mass spectrometry analysis of the intact subunit.

  1. In-Depth Glycoproteomic Characterization of γ-Conglutin by High-Resolution Accurate Mass Spectrometry

    Science.gov (United States)

    Schiarea, Silvia; Arnoldi, Lolita; Fanelli, Roberto; De Combarieu, Eric; Chiabrando, Chiara

    2013-01-01

    The molecular characterization of bioactive food components is necessary for understanding the mechanisms of their beneficial or detrimental effects on human health. This study focused on γ-conglutin, a well-known lupin seed N-glycoprotein with health-promoting properties and controversial allergenic potential. Given the importance of N-glycosylation for the functional and structural characteristics of proteins, we studied the purified protein by a mass spectrometry-based glycoproteomic approach able to identify the structure, micro-heterogeneity and attachment site of the bound N-glycan(s), and to provide extensive coverage of the protein sequence. The peptide/N-glycopeptide mixtures generated by enzymatic digestion (with or without N-deglycosylation) were analyzed by high-resolution accurate mass liquid chromatography–multi-stage mass spectrometry. The four main micro-heterogeneous variants of the single N-glycan bound to γ-conglutin were identified as Man2(Xyl) (Fuc) GlcNAc2, Man3(Xyl) (Fuc) GlcNAc2, GlcNAcMan3(Xyl) (Fuc) GlcNAc2 and GlcNAc 2Man3(Xyl) (Fuc) GlcNAc2. These carry both core β1,2-xylose and core α1-3-fucose (well known Cross-Reactive Carbohydrate Determinants), but corresponding fucose-free variants were also identified as minor components. The N-glycan was proven to reside on Asn131, one of the two potential N-glycosylation sites. The extensive coverage of the γ-conglutin amino acid sequence suggested three alternative N-termini of the small subunit, that were later confirmed by direct-infusion Orbitrap mass spectrometry analysis of the intact subunit. PMID:24069245

  2. Determination of stimulants using gas chromatography/high-resolution time-of-flight mass spectrometry and a soft ionization source.

    Science.gov (United States)

    Lopez-Avila, Viorica; Cooley, James; Urdahl, Randall; Thevis, Mario

    2012-12-15

    The aim of this study was to investigate the mass spectral fragmentation of a small set of stimulants in a high-resolution time-of-flight mass spectrometer equipped with a soft ionization source using vacuum ultraviolet (VUV) photons emitted from different plasma gases. It was postulated that the use of a plasma gas such as Xe, which emits photons at a lower energy than Kr or Ar, would lead to softer ionization of the test compounds, and thus to less fragmentation. A set of nine stimulants: cocaine, codeine, nicotine, methadone, phenmetrazine, pentylenetetrazole, niketamide, fencamfamine, and caffeine, was analyzed by gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) in positive ion mode with this soft ionization source, using either Xe, Kr, or Ar as plasma gases. Working solutions of the test compounds at 0.1 to 100 ng/μL were used to establish instrument sensitivity and linearity. All test compounds, except methadone and pentylenetetrazole, exhibited strong molecular ions and no fragmentation with Xe-microplasma photoionization (MPPI). Methadone exhibited significant fragmentation not only with Xe, but also with Kr and Ar, and pentylenetetrazole could not be ionized with Xe, probably because its ionization energy is above 8.44 eV. The Kr- and Ar-MPPI mass spectra of the test compounds showed that the relative intensity of the molecular ion decreased as the photon energy increased. When coupled to a TOF mass spectrometer this soft ionization source has demonstrated signal-to-noise (S/N) ratios from 7 to 730 at 100 pg per injection (depending on the compound), and a dynamic range of three orders of magnitude (100 pg to 100 ng) for some of the test compounds. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Ambient Observations of Organic Nitrogen Compounds in Submicrometer Aerosols in New York Using High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Zhou, S.; Ge, X.; Xu, J.; Sun, Y.; Zhang, Q.

    2015-12-01

    Organic nitrogen (ON) compounds, which include amines, nitriles, organic nitrates, amides, and N-containing aromatic heterocycles, are an important class of compounds ubiquitously detected in atmospheric particles and fog and cloud droplets. Previous studies indicate that these compounds can make up a significant fraction (20-80%) of the total nitrogen (N) content in atmospheric condensed phases and play important roles in new particle formation and growth and affecting the optical and hygroscopicity of aerosols. In this study, we report the observation of ON compounds in submicrometer particles (PM1) at two locations in New York based on measurements using Aerodyne high-resolution time-of-flight mass spectrometer (HR-ToF-AMS). One study was conducted as part of the US Department of Energy funded Aerosol Lifecyle - Intensive Operation Period (ALC-IOP) campaign at Brookhaven National Lab (BNL, 40.871˚N, 72.89˚W) in summer, 2011 and the other was conducted at the Queen's College (QC) in New York City (NYC) in summer, 2009. We observed a notable amount of N-containing organic fragment ions, CxHyNp+ and CxHyOzNp+, in the AMS spectra of organic aerosols at both locations and found that they were mainly associated with amino functional groups. Compared with results from lab experiments, the C3H8N+ at m/z = 58 was primarily attributed to trimethylamine. In addition, a significant amount of organonitrates was observed at BNL. Positive matrix factorization (PMF) analysis of the high resolution mass spectra (HRMS) of organic aerosols identified a unique nitrogen-enriched OA (NOA) factor with elevated nitrogen-to-carbon (N/C) at both BNL and QC. Analysis of the size distributions, volatility profiles, and correlations with external tracer indicates that acid-base reactions of amino compounds with sulfate and acidic gas were mainly responsible for the formation of amine salts. Photochemical production was also observed to play a role in the formation of NOA. Bivariate polar

  4. The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars

    Science.gov (United States)

    Smiljanic, R.; Korn, A. J.; Bergemann, M.; Frasca, A.; Magrini, L.; Masseron, T.; Pancino, E.; Ruchti, G.; San Roman, I.; Sbordone, L.; Sousa, S. G.; Tabernero, H.; Tautvaišienė, G.; Valentini, M.; Weber, M.; Worley, C. C.; Adibekyan, V. Zh.; Allende Prieto, C.; Barisevičius, G.; Biazzo, K.; Blanco-Cuaresma, S.; Bonifacio, P.; Bragaglia, A.; Caffau, E.; Cantat-Gaudin, T.; Chorniy, Y.; de Laverny, P.; Delgado-Mena, E.; Donati, P.; Duffau, S.; Franciosini, E.; Friel, E.; Geisler, D.; González Hernández, J. I.; Gruyters, P.; Guiglion, G.; Hansen, C. J.; Heiter, U.; Hill, V.; Jacobson, H. R.; Jofre, P.; Jönsson, H.; Lanzafame, A. C.; Lardo, C.; Ludwig, H.-G.; Maiorca, E.; Mikolaitis, Š.; Montes, D.; Morel, T.; Mucciarelli, A.; Muñoz, C.; Nordlander, T.; Pasquini, L.; Puzeras, E.; Recio-Blanco, A.; Ryde, N.; Sacco, G.; Santos, N. C.; Serenelli, A. M.; Sordo, R.; Soubiran, C.; Spina, L.; Steffen, M.; Vallenari, A.; Van Eck, S.; Villanova, S.; Gilmore, G.; Randich, S.; Asplund, M.; Binney, J.; Drew, J.; Feltzing, S.; Ferguson, A.; Jeffries, R.; Micela, G.; Negueruela, I.; Prusti, T.; Rix, H.-W.; Alfaro, E.; Babusiaux, C.; Bensby, T.; Blomme, R.; Flaccomio, E.; François, P.; Irwin, M.; Koposov, S.; Walton, N.; Bayo, A.; Carraro, G.; Costado, M. T.; Damiani, F.; Edvardsson, B.; Hourihane, A.; Jackson, R.; Lewis, J.; Lind, K.; Marconi, G.; Martayan, C.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Zaggia, S.

    2014-10-01

    Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 105 stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already observed 1447 FGK-type stars. Aims: These UVES spectra are analyzed in parallel by several state-of-the-art methodologies. Our aim is to present how these analyses were implemented, to discuss their results, and to describe how a final recommended parameter scale is defined. We also discuss the precision (method-to-method dispersion) and accuracy (biases with respect to the reference values) of the final parameters. These results are part of the Gaia-ESO second internal release and will be part of its first public release of advanced data products. Methods: The final parameter scale is tied to the scale defined by the Gaia benchmark stars, a set of stars with fundamental atmospheric parameters. In addition, a set of open and globular clusters is used to evaluate the physical soundness of the results. Each of the implemented methodologies is judged against the benchmark stars to define weights in three different regions of the parameter space. The final recommended results are the weighted medians of those from the individual methods. Results: The recommended results successfully reproduce the atmospheric parameters of the benchmark stars and the expected Teff-log g relation of the calibrating clusters. Atmospheric parameters and abundances have been determined for 1301 FGK-type stars observed with UVES. The median of the method-to-method dispersion of the atmospheric parameters is 55 K for Teff, 0.13 dex for log g and 0.07 dex for [Fe/H]. Systematic biases are estimated to be between 50-100 K for Teff, 0.10-0.25 dex for log g and 0.05-0.10 dex for [Fe/H]. Abundances for 24 elements were derived: C, N, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, Nd, and Eu. The typical method

  5. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    NARCIS (Netherlands)

    Mol, Hans G.J.; Tienstra, Marc; Zomer, Paul

    2016-01-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS

  6. Current use of high-resolution mass spectrometry in the environmental sciences

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, F.; Sancho, J.V.; Ibanez, M.; Portoles, T. [University Jaume I, Research Institute for Pesticides and Water, Castellon (Spain); Abad, E.; Mattioli, L. [IDAEA-CSIC, Laboratory of Dioxins, Department of Environmental Chemistry, Barcelona (Spain)

    2012-05-15

    During the last two decades, mass spectrometry (MS) has been increasingly used in the environmental sciences with the objective of investigating the presence of organic pollutants. MS has been widely coupled with chromatographic techniques, both gas chromatography (GC) and liquid chromatography (LC), because of their complementary nature when facing a broad range of organic pollutants of different polarity and volatility. A clear trend has been observed, from the very popular GC-MS with a single quadrupole mass analyser, to tandem mass spectrometry (MS-MS) and, more recently, high-resolution mass spectrometry (HRMS). For years GC has been coupled to HR magnetic sector instruments, mostly for dioxin analysis, although in the last ten years there has been growing interest in HRMS with time-of-flight (TOF) and Orbitrap mass analyzers, especially in LC-MS analysis. The increasing interest in the use of HRMS in the environmental sciences is because of its suitability for both targeted and untargeted analysis, owing to its sensitivity in full-scan acquisition mode and high mass accuracy. With the same instrument one can perform a variety of tasks: pre- and post-target analysis, retrospective analysis, discovery of metabolite and transformation products, and non-target analysis. All these functions are relevant to the environmental sciences, in which the analyst encounters thousands of different organic contaminants. Thus, wide-scope screening of environmental samples is one of the main applications of HRMS. This paper is a critical review of current use of HRMS in the environmental sciences. Needless to say, it is not the intention of the authors to summarise all contributions of HRMS in this field, as in classic descriptive reviews, but to give an overview of the main characteristics of HRMS, its strong potential in environmental mass spectrometry and the trends observed over the last few years. Most of the literature has been acquired since 2005, coinciding with the

  7. Predicting the stellar and non-equilibrium dust emission spectra of high-resolution simulated galaxies with DART-Ray

    CERN Document Server

    Natale, Giovanni; Tuffs, Richard J; Debattista, Victor P; Fischera, Jörg; Grootes, Meiert W

    2015-01-01

    We describe the calculation of the stochastically heated dust emission using the 3D ray-tracing dust radiative transfer code DART-Ray, which is designed to solve the dust radiative transfer problem for galaxies with arbitrary geometries. In order to reduce the time required to derive the non-equilibrium dust emission spectra from each volume element within a model, we implemented an adaptive SED library approach, which we tested for the case of axisymmetric galaxy geometries. To show the capabilities of the code, we applied DART-Ray to a high-resolution N-body+SPH galaxy simulation to predict the appearance of the simulated galaxy at a set of wavelengths from the UV to the sub-mm. We analyse the results to determine the effect of dust on the observed radial and vertical profiles of the stellar emission as well as on the attenuation and scattering of light from the constituent stellar populations. We also quantify the proportion of dust re-radiated stellar light powered by young and old stellar populations, bo...

  8. Predicting the stellar and non-equilibrium dust emission spectra of high-resolution simulated galaxies with DART-RAY

    Science.gov (United States)

    Natale, Giovanni; Popescu, Cristina C.; Tuffs, Richard. J.; Debattista, Victor P.; Fischera, Jörg; Grootes, Meiert W.

    2015-05-01

    We describe the calculation of the stochastically heated dust emission using the 3D ray-tracing dust radiative transfer code DART-RAY, which is designed to solve the dust radiative transfer problem for galaxies with arbitrary geometries. In order to reduce the time required to derive the non-equilibrium dust emission spectra from each volume element within a model, we implemented an adaptive spectral energy distribution library approach, which we tested for the case of axisymmetric galaxy geometries. To show the capabilities of the code, we applied DART-RAY to a high-resolution N-body+SPH galaxy simulation to predict the appearance of the simulated galaxy at a set of wavelengths from the UV to the sub-mm. We analyse the results to determine the effect of dust on the observed radial and vertical profiles of the stellar emission as well as on the attenuation and scattering of light from the constituent stellar populations. We also quantify the proportion of dust re-radiated stellar light powered by young and old stellar populations, both bolometrically and as a function of infrared wavelength.

  9. Spatially resolved spectroscopy across stellar surfaces. II. High-resolution spectra across HD 209458 (G0 V)

    Science.gov (United States)

    Dravins, Dainis; Ludwig, Hans-Günter; Dahlén, Erik; Pazira, Hiva

    2017-09-01

    Context. High-resolution spectroscopy across spatially resolved stellar surfaces aims at obtaining spectral-line profiles that are free from rotational broadening; the gradual changes of these profiles from disk center toward the stellar limb reveal properties of atmospheric fine structure, which are possible to model with 3D hydrodynamics. Aims: Previous such studies have only been carried out for the Sun but are now extended to other stars. In this work, profiles of photospheric spectral lines are retrieved across the disk of the planet-hosting star HD 209458 (G0 V). Methods: During exoplanet transit, stellar surface portions successively become hidden and differential spectroscopy provides spectra of small surface segments temporarily hidden behind the planet. The method was elaborated in Paper I, with observable signatures quantitatively predicted from hydrodynamic simulations. Results: From observations of HD 209458 with spectral resolution λ/ Δλ 80 000, photospheric Fe I line profiles are obtained at several center-to-limb positions, reaching adequately high S/N after averaging over numerous similar lines. Conclusions: Retrieved line profiles are compared to synthetic line profiles. Hydrodynamic 3D models predict, and current observations confirm, that photospheric absorption lines become broader and shallower toward the stellar limb, reflecting that horizontal velocities in stellar granulation are greater than vertical velocities. Additional types of 3D signatures will become observable with the highest resolution spectrometers at large telescopes.

  10. Processing of high resolution magic angle spinning spectra of breast cancer cells by the filter diagonalization method.

    Science.gov (United States)

    Maria, Roberta Manzano; Moraes, Tiago Bueno; Magon, Claudio José; Venâncio, Tiago; Altei, Wanessa Fernanda; Andricopulo, Adriano Defini; Colnago, Luiz Alberto

    2012-10-01

    Proton nuclear magnetic resonance ((1)H NMR) spectroscopy for detection of biochemical changes in biological samples is a successful technique. However, the achieved NMR resolution is not sufficiently high when the analysis is performed with intact cells. To improve spectral resolution, high resolution magic angle spinning (HR-MAS) is used and the broad signals are separated by a T(2) filter based on the CPMG pulse sequence. Additionally, HR-MAS experiments with a T(2) filter are preceded by a water suppression procedure. The goal of this work is to demonstrate that the experimental procedures of water suppression and T(2) or diffusing filters are unnecessary steps when the filter diagonalization method (FDM) is used to process the time domain HR-MAS signals. Manipulation of the FDM results, represented as a tabular list of peak positions, widths, amplitudes and phases, allows the removal of water signals without the disturbing overlapping or nearby signals. Additionally, the FDM can also be used for phase correction and noise suppression, and to discriminate between sharp and broad lines. Results demonstrate the applicability of the FDM post-acquisition processing to obtain high quality HR-MAS spectra of heterogeneous biological materials.

  11. High resolution catalogue of emission lines in the spectra of comet C/2002 C1 Ikeya-Zhang

    Science.gov (United States)

    Capria, M. T.; Cremonese, G.; de Sanctis, M. C.; Buzzoni, A.

    2003-04-01

    The comet C/2002 C1 Ikeya-Zhang was observed at the Telescopio Nazionale Galileo in Canary Islands with the echelle spectrograph SARG during the night 19-20 of April 2002. One echelle spectrum composed by 55 orders covering the spectral range from 462 to 792 nm with R=57000 was acquired. The observations were performed in the frame of a program aimed to collect, catalogue and identify cometary emission lines in the optical part of the spectral range. In this range many important lines of daughters molecules and ions can be found; most of these lines were detected many times with low resolution spectroscopy, but the cataloguing with high resolution spectroscopy was done until now for few comets, and many lines still remain unidentified. We present here a first version of our catalogue, in which the line identification, based on wavelength coincidence only, is made using as starting line lists the ones compiled by Brown et al. [1] and Cochran and Cochran [2]. The O(1S) and O(1D) metastable lines are also clearly visible in our spectra and well separated from the other cometary and telluric lines, so we present also a preliminary estimate of the ratio of the green and red lines. [1] M.E. Brown et al. (1996) AJ, 112. [2] A. Cochran and D. Cochran (2002) Icarus, 157.

  12. Analysis of the hyperfine structures and Λ doubling of high-resolution LMR spectra of 15N16O (X2Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    From the theories of the nuclear hyperfine structure (HFS) and Λ doubling of diatomic molecules, several brief algebraic equations for interpretation of HFS and Λ doubling of transitions of diatomic molecule have been developed. A few important parameters of HFS and Λ doubling of 15N16O have been efficiently and accurately obtained from the analysis of the high resolution spectra of 15N16O (X2Ⅱ) observed in our experiments with these equations. This method can provide an effective approach to obtain important hyperfine parameters of novel radicals from their high resolution laser magnetic resonance spectra.

  13. Identification of novel metabolites from Aspergillus flavus by high resolution and multiple stage mass spectrometry.

    Science.gov (United States)

    Malysheva, Svetlana V; Arroyo-Manzanares, Natalia; Cary, Jeffrey W; Ehrlich, Kenneth C; Vanden Bussche, Julie; Vanhaecke, Lynn; Bhatnagar, Deepak; Di Mavungu, José Diana; De Saeger, Sarah

    2014-01-01

    The filamentous fungus Aspergillus flavus is one of the most important species in the Aspergillus genus and is distributed worldwide as a prevalent aflatoxin-producing food and feed contaminant. A. flavus contains more than 55 gene clusters that are predicted to encode proteins involved in secondary metabolite production. One of these, cluster 27, contains a polyketide synthase (pks27) gene that encodes a protein that is highly homologous to the aflatoxin cluster PKS. Comparative metabolomics, using ultra-high performance liquid chromatography (UHPLC) coupled to high resolution Orbitrap mass spectrometry (MS) was used to detect metabolites differentially expressed in the A. flavus wild-type and ∆pks27 mutant strains. Metabolite profiling was aided by a statistical differential analysis of MS data using SIEVE software. This differential analysis combined with accurate mass data from the Orbitrap and ion trap multiple stage MS allowed four metabolites to be identified that were produced only by the wild-type culture. These included asparasone A (358 Da), an anthraquinone pigment, and related anthraquinones with masses of 316, 340 and 374 Da. These latter three compounds had similar fragmentation patterns to that of asparasone A. The 316 Da anthraquinone is particularly interesting because it is most likely formed by incorporation of seven malonyl-CoA units rather than the eight units required for the formation of asparasone A. The 340 and 374 Da metabolites are the dehydration and an oxy-derivative of asparasone A, respectively. Asparasone A was also identified in extracts from several other Aspergillus species.

  14. Enlightening the Mechanism of Copper Mediated PhotoRDRP via High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Frick, Elena; Anastasaki, Athina; Haddleton, David M; Barner-Kowollik, Christopher

    2015-06-03

    The initiation mechanism of photochemically mediated Cu-based reversible-deactivation radical polymerization (photoRDRP) was investigated using pulsed-laser polymerization (PLP) and high-resolution mass spectrometry. The variation of the catalyst composition and ESI-MS analysis of the resulting products provided information on how initiator, ligand, copper species, and monomer are interacting upon irradiation with UV light. A discussion of the results allows for a new postulation of the mechanism of photoRDRP and-for the first time-the unambiguous identification of the initiating species and their interactions within the reaction mixture. One pathway for radical generation proceeds via UV light-induced C-Br bond scission of the initiator, giving rise to propagating radicals. The generation of copper(I) species from copper(II) can occur via several pathways, including, among others, via reduction by free amine ligand in its excited as well as from its ground state via the irradiation with UV light. The amine ligand serves as a strong reducing agent and is likely the main participant in the generation of copper(I) species.

  15. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Benjamin F.; Chen, Hong-Mei; Herndon, Elizabeth M.; Chu, Rosalie K.; Tolic, Nikola; Portier, Evan; Chowdhury, Taniya R.; Robinson, Errol W.; Callister, Stephen J.; Wullschleger, Stan D.; Graham, David E.; Liang, Liyuan; Gu, Baohua

    2015-06-12

    Microbial degradation of soil organic matter (SOM) is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between –1 and 0 in a water-soluble fraction (WSF) demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF) did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions.

  16. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry.

    Directory of Open Access Journals (Sweden)

    Benjamin F Mann

    Full Text Available Microbial degradation of soil organic matter (SOM is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between -1 and 0 in a water-soluble fraction (WSF demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions.

  17. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry

    Science.gov (United States)

    Herndon, Elizabeth M.; Chu, Rosalie K.; Tolic, Nikola; Portier, Evan F.; Roy Chowdhury, Taniya; Robinson, Errol W.; Callister, Stephen J.; Wullschleger, Stan D.; Graham, David E.; Liang, Liyuan; Gu, Baohua

    2015-01-01

    Microbial degradation of soil organic matter (SOM) is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between –1 and 0 in a water-soluble fraction (WSF) demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF) did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions. PMID:26068586

  18. Protein profile of exhaled breath condensate determined by high resolution mass spectrometry.

    Science.gov (United States)

    Muccilli, Vera; Saletti, Rosaria; Cunsolo, Vincenzo; Ho, Jenny; Gili, Elisa; Conte, Enrico; Sichili, Stefania; Vancheri, Carlo; Foti, Salvatore

    2015-02-01

    A method based on liquid chromatography/high resolution tandem mass spectrometry coupled with electrophoretic separation, for determination and relative quantification of the protein composition of exhaled breath condensate (EBC), was developed. Application of the procedure to a sample of EBC, pooled from nine healthy subjects, resulted in the identification of 167 unique gene products, 113 of which not previously reported in EBC samples. The abundance of the protein identified was estimated by means of the exponentially modified protein abundance index protocol (emPAI). Cytokeratins were by far the most abundant proteins in EBC samples. Many of the identified proteins were associated with multiple cellular location with cytoplasm constituting the largest group. Cytosol, nucleus, membrane, cytoskeleton and extracellular were other abundantly represented locations. No amylase was detected, suggesting the absence of saliva protein contamination. The profile obtained represents the most comprehensive protein characterization of EBC so far reported and demonstrates that this approach provides a powerful tool for investigating the protein profile of EBC samples. Compared with analogous investigations, this study also shows that the protein profile of EBC is strongly affected by the sampling method adopted.

  19. Method Development for the Detection of Human Myostatin by High-Resolution and Targeted Mass Spectrometry.

    Science.gov (United States)

    Peiris, Hassendrini Nileishika; Ashman, Keith; Vaswani, Kanchan; Kvaskoff, David; Rice, Gregory Edward; Mitchell, Murray David

    2014-06-30

    Myostatin, a highly conserved secretory protein, negatively regulates muscle development, affecting both the proliferation and differentiation of muscle cells. Proteolytic processing of the myostatin precursor protein generates a myostatin pro-peptide and mature protein. Dimerization of the mature myostatin protein creates the active form of myostatin. Myostatin dimer activity can be inhibited by noncovalent binding of two monomeric myostatin pro-peptides. This ability for myostatin to self-regulate as well as the altered expression of myostatin in states of abnormal health (e.g., muscle wasting) support the need for specific detection of myostatin forms. Current protein detection methods (e.g., Western blot) rely greatly on antibodies and are semiquantitative at best. Tandem mass spectometry (as in this study) provides a highly specific method of detection, enabling the characterization of myostatin protein forms through the analysis of discrete peptides fragments. Utilizing the scheduled high-resolution multiple reaction monitoring paradigm (sMRM(HR); AB SCIEX 5600 TripleTOF) we identified the lower limit of quantitation (LLOQ) of both mature (DFGLDCDEHSTESR) and pro-peptide regions (ELIDQYDVQR) as 0.19 nmol/L. Furthermore, scheduled multiple reaction monitoring (sMRM; AB SCIEX QTRAP 5500) identified a LLOQ for a peptide of the pro-peptide region (LETAPNISK) as 0.16 nmol/L and a peptide of the mature region (EQIIYGK) as 0.25 nmol/L.

  20. Indexing Permafrost Soil Organic Matter Degradation Using High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Mann, Benjamin F; Chen, Hongmei; Herndon, Elizabeth M; Chu, Rosalie K; Tolic, Nikola; Portier, Evan F; Roy Chowdhury, Taniya; Robinson, Errol W; Callister, Stephen J; Wullschleger, Stan D; Graham, David E; Liang, Liyuan; Gu, Baohua

    2015-01-01

    Microbial degradation of soil organic matter (SOM) is a key process for terrestrial carbon cycling, although the molecular details of these transformations remain unclear. This study reports the application of ultrahigh resolution mass spectrometry to profile the molecular composition of SOM and its degradation during a simulated warming experiment. A soil sample, collected near Barrow, Alaska, USA, was subjected to a 40-day incubation under anoxic conditions and analyzed before and after the incubation to determine changes of SOM composition. A CHO index based on molecular C, H, and O data was utilized to codify SOM components according to their observed degradation potentials. Compounds with a CHO index score between -1 and 0 in a water-soluble fraction (WSF) demonstrated high degradation potential, with a highest shift of CHO index occurred in the N-containing group of compounds, while similar stoichiometries in a base-soluble fraction (BSF) did not. Additionally, compared with the classical H:C vs O:C van Krevelen diagram, CHO index allowed for direct visualization of the distribution of heteroatoms such as N in the identified SOM compounds. We demonstrate that CHO index is useful not only in characterizing arctic SOM at the molecular level but also enabling quantitative description of SOM degradation, thereby facilitating incorporation of the high resolution MS datasets to future mechanistic models of SOM degradation and prediction of greenhouse gas emissions.

  1. Analytical strategy to investigate 3,4-methylenedioxypyrovalerone (MDPV) metabolites in consumers' urine by high-resolution mass spectrometry.

    Science.gov (United States)

    Ibáñez, María; Pozo, Óscar J; Sancho, Juan V; Orengo, Teresa; Haro, Gonzalo; Hernández, Félix

    2016-01-01

    The potential of high-resolution mass spectrometry (HRMS) for the investigation of human in vivo metabolism of 3,4-methylenedioxypyrovalerone (MDPV) using urine collected from a consumer (this is, in non-controlled experiments) has been investigated. As a control sample was not available, the common approach based on the comparison of a control/blank sample and samples collected after drug intake could not be used. Alternatively, an investigation based on common fragmentation pathways was applied, assuming that most metabolites share some fragments with the parent drug. An extension of this approach was also applied based on the fragmentation pathway of those metabolites identified in urine samples in the first step. The use of MS(E) experiments (sequential acquisition of mass spectra at low and high collision energy) has been crucial to this aim as it allowed promoting fragmentation in the collision cell without any previous precursor ion selection. MDPV belongs to the group of new psychoactive substances (NPS), being known as the "cannibal drug". This substance is being abused more and more and is associated with dangerous side effects. The human metabolites (both phase I and phase II) were detected and tentatively identified by accurate mass full-spectrum measurements using ultra-high performance liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). Following this strategy, up to 10 phase I metabolites, together with some glucuronides and sulphates, were detected and tentative structures were proposed. Several compounds identified in this work have not been previously reported in the literature.

  2. High-resolution mass-selective UV spectroscopy of pseudoephedrine: evidence for conformer-specific fragmentation.

    Science.gov (United States)

    Karaminkov, R; Chervenkov, S; Delchev, V; Neusser, H J

    2011-09-01

    Using resonance-enhanced two-photon ionization spectroscopy with mass resolution of jet-cooled molecules, a low-resolution S(1) ← S(0) vibronic spectrum of pseudoephedrine was recorded at the mass channels of three distinct fragments with m/z = 58, 71, and 85. Two of the fragments, with m/z = 71 and 85, are observed for the first time for this molecule. The vibronic spectra recorded at different mass channels feature different patterns, implying that they originate from different conformers in the cold molecular beam, following conformer-specific fragmentation pathways. Highly resolved spectra of all prominent vibronic features were measured, and from their analysis based on genetic algorithms, the molecular parameters of the conformers giving rise to the respective bands have been determined. Comparing the experimental results with those obtained from high-level ab initio quantum chemistry calculations, the observed prominent vibronic bands have been assigned to originate from four distinct conformers. The conformers are separated into two groups that have different fragmentation pathways determined by the different intramolecular interactions.

  3. Environmental forensics in groundwater coupling passive sampling and high resolution mass spectrometry for screening.

    Science.gov (United States)

    Soulier, Coralie; Coureau, Charlotte; Togola, Anne

    2016-09-01

    One of the difficulties encountered when monitoring groundwater quality is low and fluctuating concentration levels and complex mixtures of micropollutants, including emerging substances or transformation products. Combining passive sampling techniques with analysis by high resolution mass spectrometry (HRMS) should improve environmental metrology. Passive samplers accumulate compounds during exposure, which improves the detection of organic compounds and integrates pollution fluctuations. The Polar Organic Chemical Integrative Sampler (POCIS) were used in this study to sequester polar to semi-polar compounds. The methodology described here improves our knowledge of environmental pollution by highlighting and identifying pertinent compounds to be monitored in groundwater. The advantage of combining these two approaches is demonstrated on two different sites impacted by agricultural and/or urban pollution sources where groundwater was sampled for several months. Grab and passive sampling were done and analyzed by liquid chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer (LC-QTOF). Various data processing approaches were used (target, suspect and non-target screening). Target screening was based on research from compounds listed in a homemade database and suspect screening used a database compiled using literature data. The non-target screening was done using statistical tools such as principal components analysis (PCA) with direct connections between original chromatograms and ion intensity. Trend plots were used to highlight relevant compounds for their identification. The advantage of using POCIS to improve screening of polar organic compounds was demonstrated. Compounds undetected in water samples were detected with these tools. The subsequent data processing identified sentinel molecules, molecular clusters as compounds never revealed in these sampling sites, and molecular fingerprints. Samples were compared and multidimensional

  4. Comprehensive Characterization of Atmospheric Organic Carbon using Multiple High-Resolution Mass Spectrometric Instruments

    Science.gov (United States)

    Kroll, J. H.; Hunter, J. F.; Isaacman-VanWertz, G. A.

    2015-12-01

    Accurate modeling of major atmospheric chemical processes (oxidant cycling, aerosol formation, etc.) requires understanding the identity, chemistry, and lifecycle (emission, reaction, and deposition) of atmospheric organic species. Such an understanding is generally limited by the wide diversity in chemical structure, properties, and reactivity of atmospheric organics, posing major challenges in detection and quantification. However the last several years have seen the development of several new techniques for the measurement of a wide range of carbon-containing compounds, including low-volatility, oxidized species that have traditionally been difficult to measure. Many of these new techniques are based on high-resolution mass spectrometry, enabling the unambiguous identification of individual ions, and hence the elemental ratios and carbon oxidation state of the organic species; most also provide information on volatility and/or carbon number distributions of the molecular species. While a single instrument can generally measure only species of a particular class (occupying a localized region of "chemical space"), here we show that the combined measurements from multiple instruments can provide a comprehensive picture of the chemical composition of the entire organic mixture. From these combined measurements, the organic species can be described not only in terms of organic carbon mass but also in terms of distributions of key ensemble properties (such as oxidation state and volatility), and thus can be used to populate and constrain the various reduced-dimensionality chemical spaces that have been put forth as frameworks for describing atmospheric organic chemistry. We apply this general measurement approach both to field data, providing information on ambient organic species, and to laboratory (chamber) studies, providing insight into the chemical transformations that organic species undergo upon atmospheric oxidation.

  5. High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments

    Directory of Open Access Journals (Sweden)

    K. Junge

    2008-05-01

    Full Text Available Even though studies of Arctic ice forming particles suggest that a bacterial or viral source derived from open leads could be important for ice formation in Arctic clouds (Bigg and Leck, 2001, the ice nucleation potential of most polar marine psychrophiles or viruses has not been examined under conditions more closely resembling those in the atmosphere. In this paper, we examined the ice nucleation activity (INA of several representative Arctic and Antarctic sea-ice bacterial isolates and a polar Colwellia phage virus. High-resolution ice nucleation spectra were obtained for droplets containing bacterial cells or virus particles using a free-fall freezing tube technique. The fraction of frozen droplets at a particular droplet temperature was determined by measuring the depolarized light scattering intensity from solution droplets in free-fall. Our experiments revealed that all sea-ice isolates and the virus nucleated ice at temperatures very close to the homogeneous nucleation temperature for the nucleation medium – which for artificial seawater was –42.2±0.3°C. Our results suggest that immersion freezing of these marine psychro-active bacteria and viruses would not be important for heterogeneous ice nucleation processes in polar clouds or to the formation of sea ice. These results also suggested that avoidance of ice formation in close proximity to cell surfaces might be one of the cold-adaptation and survival strategies for sea-ice bacteria. The fact that INA occurs at such low temperature could constitute one factor that explains the persistence of metabolic activities at temperatures far below the freezing point of seawater.

  6. High-resolution ice nucleation spectra of sea-ice bacteria: implications for cloud formation and life in frozen environments

    Directory of Open Access Journals (Sweden)

    K. Junge

    2007-11-01

    Full Text Available Even though studies of Arctic ice forming particles suggest that a bacterial or viral source derived from open leads could be important for cloud formation in the Arctic (Bigg and Leck, 2001, the ice nucleation potential of most polar marine psychrophiles or viruses has not been examined under conditions more closely resembling those in the atmosphere. In this paper, we examined the ice nucleation activity (INA of several representative Arctic and Antarctic sea-ice bacterial isolates and a polar Colwellia phage virus. High-resolution ice nucleation spectra were obtained for droplets containing bacterial cells or virus particles using a free-fall freezing tube technique. The fraction of frozen droplets at a particular droplet temperature was determined by measuring the depolarized light scattering intensity from solution droplets in free-fall. Our experiments revealed that all sea-ice isolates and the virus nucleated ice at temperatures very close to the homogeneous nucleation temperature for the nucleation medium – which for artificial seawater was −42.2±0.3°C. Our results indicated that these marine psychro-active bacteria and viruses are not important for heterogeneous ice nucleation processes in sea ice or polar clouds. These results also suggested that avoidance of ice formation in close proximity to cell surfaces might be one of the cold-adaptation and survival strategies for sea-ice bacteria. The fact that INA occurs at such low temperature could constitute one factor that explains the persistence of metabolic activities at temperatures far below the freezing point of seawater.

  7. Advanced Characterization of Soil Organic Matter Using Ultra High Resolution Mass Spectrometry

    Science.gov (United States)

    Tfaily, M. M.; Chu, R.; Tolic, N.; Roscioli, K.; Robinson, E. R.; Paša-Tolić, L.; Hess, N. J.

    2014-12-01

    The focus on ecosystem stress and climate change is currently relevant as researchers and policymakers strive to understand the feedbacks between soil C dynamics and climate change. Successful development of molecular profiles that link soil microbiology with soil carbon (C) to ascertain soil vulnerability and resilience to climate change would have great impact on assessments of soil ecosystems in response to climate change. Additionally, better understanding of the dynamics of soil organic matter (SOM) plays a central role to climate modeling, and fate and transport of carbon. The use of ultra-high resolution mass spectrometry (UHR MS) has enabled the examination of molecules, directly from mixtures, with ultrahigh mass resolution and sub-ppm mass accuracy. In this study, EMSL's extensive expertise and capabilities in UHR MS proteomics were leveraged to develop extraction protocols for the characterization of carbon compounds in SOM, thereby providing the chemical and structural detail needed to develop mechanistic descriptions of soil carbon flow processes. Our experiments have allowed us to identify thousands of individual compounds in complex soil mixtures with a wide range of C content representing diverse ecosystems within the USA. The yield of the chemical extraction was dependent on (1) the type of solvent used and its polarity, (2) sample-to-solvent ratios and (3) the chemical and physical nature of the samples including their origins. Hexane, a non-polar organic solvent, was efficient in extracting lipid-like compounds regardless of soil origin or organic carbon %. For samples with high organic carbon %, acetonitrile extracted a wide range of compounds characterized with high O/C ratios, identified as polyphenolic compounds that were not observed with methanol extraction. Soils extracted with pyridine showed a similar molecular distribution to those extracted by methanol. Solvent extraction followed by UHR MS is a promising tool to understand the

  8. Molecular characterization of dissolved organic matter through a desalination process by high resolution mass spectrometry.

    Science.gov (United States)

    Cortés-Francisco, Nuria; Caixach, Josep

    2013-09-01

    The effect of different water treatments such as ultrafiltration (UF) and reverse osmosis (RO) on dissolved organic matter (DOM) is still unknown. Electrospray ionization Fourier transform orbitrap mass spectrometry has been used to provide valuable information of marine DOM evolution through a desalination process on a molecular scale. In the present manuscript, the characterization of four real composite water samples from a desalination pilot plant installed in the coast of Barcelona (Spain) has been carried out. The sampling was performed on each point of the pilot plant: raw seawater (RSW), UF effluent, brine RO and permeate RO. The mass spectra of the different samples show several thousand peaks, however for the present screening study, only the mass range m/z 200-500 and the main signals in this mass range (relative intensities ≥1%) have been considered. The analysis of RSW and UF samples reveal that there is little effect on DOM by the UF pilot. However, when the water is treated on the RO an important change on DOM has been observed. The recurring periodical patterns found in RSW and UF are lost in Permeate RO sample. Compounds with more aliphatic character, with higher H/C ratio (H/Cav 1.72) are present in the Permeate and some of them have been tentatively identified as fatty acids.

  9. High-resolution mass spectrometry driven discovery of peptidic danger signals in insect immunity.

    Science.gov (United States)

    Berisha, Arton; Mukherjee, Krishnendu; Vilcinskas, Andreas; Spengler, Bernhard; Römpp, Andreas

    2013-01-01

    The 'danger model' is an alternative concept for immune response postulating that the immune system reacts to entities that do damage (danger associated molecular patterns, DAMP) and not only to entities that are foreign (pathogen-associated molecular patterns, PAMP) as proposed by classical immunology concepts. In this study we used Galleria mellonella to validate the danger model in insects. Hemolymph of G. mellonella was digested with thermolysin (as a representative for virulence-associated metalloproteinases produced by humanpathogens) followed by chromatographic fractionation. Immune-stimulatory activity was tested by measuring lysozyme activity with the lytic zone assays against Micrococcus luteus cell wall components. Peptides were analyzed by nano-scale liquid chromatography coupled to high-resolution Fourier transform mass spectrometers. Addressing the lack of a genome sequence we complemented the rudimentary NCBI protein database with a recently established transcriptome and de novo sequencing methods for peptide identification. This approach led to identification of 127 peptides, 9 of which were identified in bioactive fractions. Detailed MS/MS experiments in comparison with synthetic analogues confirmed the amino acid sequence of all 9 peptides. To test the potential of these putative danger signals to induce immune responses we injected the synthetic analogues into G. mellonella and monitored the anti-bacterial activity against living Micrococcus luteus. Six out of 9 peptides identified in the bioactive fractions exhibited immune-stimulatory activity when injected. Hence, we provide evidence that small peptides resulting from thermolysin-mediated digestion of hemolymph proteins function as endogenous danger signals which can set the immune system into alarm. Consequently, our study indicates that the danger model also plays a role in insect immunity.

  10. Signal Enhancement with Stacked Magnets for High-Resolution Radio Frequency Glow Discharge Mass Spectrometry.

    Science.gov (United States)

    Wei, Juan; Dong, Jiangli; Zhuo, Shangjun; Qian, Rong; Fang, Yuanxing; Chen, Qiao; Patel, Ekbal

    2017-01-17

    A method for signal enhancement utilizing stacked magnets was introduced into high-resolution radio frequency glow discharge-mass spectrometry (rf-GD-MS) for significantly improved analysis of inorganic materials. Compared to the block magnet, the stacked magnets method was able to achieve 50-59% signal enhancement for typical elements in Y2O3, BSO, and BTN samples. The results indicated that signal was enhanced as the increase of discharge pressure from 1.3 to 8.0 mPa, the increase of rf-power from 10 to 50 W with a frequency of 13.56 MHz, the decrease of sample thickness, and the increase of number of stacked magnets. The possible mechanism for the signal enhancement was further probed using the software "Mechanical APDL (ANSYS) 14.0". It was found that the distinct oscillated magnetic field distribution from the stacked magnets was responsible for signal enhancement, which could extend the movement trajectories of electrons and increase the collisions between the electrons and neutral particles to increase the ionization efficiency. Two NIST samples were used for the validation of the method, and the results suggested that relative errors were within 13% and detection limit for six transverse stacked magnets could reach as low as 0.0082 μg g(-1). Additionally, the stability of the method was also studied. RSD within 15% of the elements in three nonconducting samples could be obtained during the sputtering process. Together, the results showed that the signal enhancement method with stacked magnets could offer great promises in providing a sensitive, stable, and facile solution for analyzing the nonconducting materials.

  11. Environmental Chemistry Compound Identification Using High Resolution Mass Spectrometry Data Integrated to the EPA Chemistry Dashboard (EAS)

    Science.gov (United States)

    There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chromatograph...

  12. Fabrication of transistors on flexible substrates: from mass-printing to high-resolution alternative lithography strategies

    NARCIS (Netherlands)

    Moonen, P.; Yakimets, I.; Huskens, J.

    2012-01-01

    In this report, the development of conventional, mass-printing strategies into high-resolution, alternative patterning techniques is reviewed with the focus on large-area patterning of flexible thin-film transistors (TFTs) for display applications. In the first part, conventional and digital printin

  13. The EPA iCSS Chemistry Dashboard to Support Compound Identification Using High Resolution Mass Spectrometry Data (ACS Fall meeting)

    Science.gov (United States)

    Abstract: There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chr...

  14. Screening of plant toxins in food,feed and botanicals using full-scan high-resolution (Orbitrap) mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Dam, van R.C.J.; Zomer, P.; Mulder, P.P.J.

    2011-01-01

    A generic method based on LC with full-scan high-resolution (Orbitrap) mass spectrometry (MS) was systematically investigated for the simultaneous detection of a wide range of plant toxins in a variety of food and feed matrices. For a selection of 150 substances, representing various chemical classe

  15. Screening of plant toxins in food,feed and botanicals using full-scan high-resolution (Orbitrap) mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Dam, van R.C.J.; Zomer, P.; Mulder, P.P.J.

    2011-01-01

    A generic method based on LC with full-scan high-resolution (Orbitrap) mass spectrometry (MS) was systematically investigated for the simultaneous detection of a wide range of plant toxins in a variety of food and feed matrices. For a selection of 150 substances, representing various chemical classe

  16. The EPA iCSS Chemistry Dashboard to Support Compound Identification Using High Resolution Mass Spectrometry Data (ACS Fall meeting)

    Science.gov (United States)

    Abstract: There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chr...

  17. Environmental Chemistry Compound Identification Using High Resolution Mass Spectrometry Data Integrated to the EPA Chemistry Dashboard (EAS)

    Science.gov (United States)

    There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chromatograph...

  18. Targeted metabolite profile of food bioactive compounds by Orbitrap high resolution mass spectrometry: The 'FancyTiles' approach

    NARCIS (Netherlands)

    Troise, A.D.; Ferracane, R.; Palermo, M.; Fogliano, V.

    2014-01-01

    In this paper a new targeted metabolic profile approach using Orbitrap high resolution mass spectrometry was described. For each foodmatrix various classes of bioactive compounds and some specificmetabolites of interest were selected on the basis of the existing knowledge creating an easy-to-read fi

  19. Linking high resolution mass spectrometry data with exposure and toxicity forecasts to advance high-throughput environmental monitoring

    Science.gov (United States)

    There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and analysis platforms, based on high resolution mass spectrometry (HRMS), now exist to meet this need. Here we describe r...

  20. Aerosol Composition in the Los Angeles Basin Studied by High Resolution Aerosol Mass Spectrometry

    Science.gov (United States)

    Hayes, P. L.; Ortega, A. M.; Cubison, M.; Hu, W.; Toohey, D. W.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; Alvarez, S. L.; Rappenglueck, B.; Allan, J. D.; Taylor, J.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; De Gouw, J. A.; Massoli, P.; Zhang, X.; Weber, R.; Zhao, Y.; Cliff, S. S.; Wexler, A. S.; Isaacman, G. A.; Worton, D. R.; Kreisberg, N. M.; Hering, S. V.; Goldstein, A. H.; Jimenez, J. L.

    2011-12-01

    Atmospheric aerosols impact climate and health, but their sources and composition are poorly understood. To address this knowledge gap, a high-resolution aerosol mass spectrometer (AMS) and complementary instrumentation were deployed during the 2010 CalNex campaign to characterize aerosol composition in the Los Angeles (LA) area. Total mass concentrations as well as the species concentrations measured by the AMS compare well with most other instruments. Nitrate dominates in the mornings, but its concentration is reduced in the afternoon when organic aerosols (OA) increase and dominate. The diurnal variations in concentrations are strongly influenced by emission transport from the source-rich western basin. The average OA to enhanced CO ratio increases with photochemical age from 25 to 80 μg m-3 ppm-1, which indicates significant secondary OA (SOA) production and that a large majority of OA is secondary in aged air. The ratio values are similar to those from Mexico City as well as New England and the Mid-Atlantic States. Positive matrix factorization (PMF) is used to assess the concentrations of different OA components. The major OA classes are oxygenated OA (OOA, a surrogate for total SOA), and hydrocarbon-like OA (HOA, a surrogate for primary combustion OA). Several subclasses of OA are identified as well including diesel-influenced HOA (DI-HOA) and non-diesel HOA. DI-HOA exhibits low concentrations on Sundays consistent with the well-known weekday/weekend effect in LA. PMF analysis finds that OOA is 67% of the total OA concentration. A strong correlation between OOA and Ox (O3 + NO2) concentrations is observed with a slope of 0.15 that suggests the production of fresh SOA in Pasadena. Plotting the OA elemental ratios in a Van Krevelen diagram (H:C vs. O:C) yields a slope of -0.6, which is less steep than that observed in Riverside during the SOAR-2005 campaign. The difference in slopes may be attributed to the highly oxidized HOA present in Pasadena that is

  1. Chemical composition, sources, and processes of urban aerosols during summertime in Northwest China: insights from High Resolution Aerosol Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Xu

    2014-06-01

    Full Text Available An aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed along with a Scanning Mobility Particle Sizer (SMPS and a Multi Angle Absorption Photometers (MAAP to measure the temporal variations of the mass loading, chemical composition, and size distribution of sub-micrometer particulate matter (PM1 in Lanzhou, northwest China, during 12 July–7 August 2012. The average PM1 mass concentration including non-refractory PM1 (NR-PM1 measured by HR-ToF-AMS and black carbon (BC measured by MAAP during this study was 24.5 μg m−3 (ranging from 0.86 to 105μg m−3, with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. The organics was consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C of 0.33 and organic mass-to-carbon ratio (OM / OC of 1.58. Positive matrix factorization (PMF of the high-resolution mass spectra of organic aerosols (OA identified four distinct factors which represent, respectively, two primary OA (POA emission sources (traffic and food cooking and two secondary OA (SOA types – a fresher, semi-volatile oxygenated OA (SV-OOA and a more aged, low-volatility oxygenated OA (LV-OOA. Traffic-related hydrocarbon-like OA (HOA and BC displayed distinct diurnal patterns both with peak at ~07:00–11:00 (BJT: UTC +8 corresponding to the morning rush hours, while cooking OA (COA peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ∼07:00–15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak at ~08:00–13:00. The later morning and early afternoon peak in the diurnal profiles of secondary aerosol species was likely caused by mixing down of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during night time. The mass spectrum of SV-OOA also showed similarity

  2. High-resolution mid-infrared spectra of Co II, Ni I, and Fe II in SN 1987A

    Science.gov (United States)

    Jennings, D. E.; Boyle, R. J.; Wiedemann, G. R.; Moseley, S. H.

    1993-01-01

    Ground-based infrared observations of SN 1987A on day 612 after the explosion have yielded resolved line profiles of Co II, Ni I, Fe II at 10.52, 11.31, and 17.94 micron, respectively. The spectra were taken at a resolving power of about 1000 with an array grating spectrometer on the 4 m telescope of Cerro Tololo Inter-American Observatory. Based on the observed line intensities we have estimated the minimum mass of each ion: M(Co II) = (6.0 +/- 1.8) x 10 exp -5 solar mass; M(Ni I) = (1.1 +/- 0.1) x 10 exp -3 solar mass; and M(Fe II) = (8.0 +/- 1.5) x 10 exp -3 solar mass. From these we infer total masses for cobalt, nickel, and iron in the ejecta. The nickel and iron line profiles are markedly asymmetric. We interpret these as arising from two components, one centered on the stellar rest velocity with an approximately 3250 km/s full width, and the second at about +1200 km/s with an approximately 1100 km/s full width. The asymmetry may represent a large-scale fracturing of the ejecta by Rayleigh-Taylor instabilities.

  3. Non-target screening with high-resolution mass spectrometry: critical review using a collaborative trial on water analysis.

    Science.gov (United States)

    Schymanski, Emma L; Singer, Heinz P; Slobodnik, Jaroslav; Ipolyi, Ildiko M; Oswald, Peter; Krauss, Martin; Schulze, Tobias; Haglund, Peter; Letzel, Thomas; Grosse, Sylvia; Thomaidis, Nikolaos S; Bletsou, Anna; Zwiener, Christian; Ibáñez, María; Portolés, Tania; de Boer, Ronald; Reid, Malcolm J; Onghena, Matthias; Kunkel, Uwe; Schulz, Wolfgang; Guillon, Amélie; Noyon, Naïke; Leroy, Gaëla; Bados, Philippe; Bogialli, Sara; Stipaničev, Draženka; Rostkowski, Pawel; Hollender, Juliane

    2015-08-01

    In this article, a dataset from a collaborative non-target screening trial organised by the NORMAN Association is used to review the state-of-the-art and discuss future perspectives of non-target screening using high-resolution mass spectrometry in water analysis. A total of 18 institutes from 12 European countries analysed an extract of the same water sample collected from the River Danube with either one or both of liquid and gas chromatography coupled with mass spectrometry detection. This article focuses mainly on the use of high resolution screening techniques with target, suspect, and non-target workflows to identify substances in environmental samples. Specific examples are given to emphasise major challenges including isobaric and co-eluting substances, dependence on target and suspect lists, formula assignment, the use of retention information, and the confidence of identification. Approaches and methods applicable to unit resolution data are also discussed. Although most substances were identified using high resolution data with target and suspect-screening approaches, some participants proposed tentative non-target identifications. This comprehensive dataset revealed that non-target analytical techniques are already substantially harmonised between the participants, but the data processing remains time-consuming. Although the objective of a "fully-automated identification workflow" remains elusive in the short term, important steps in this direction have been taken, exemplified by the growing popularity of suspect screening approaches. Major recommendations to improve non-target screening include better integration and connection of desired features into software packages, the exchange of target and suspect lists, and the contribution of more spectra from standard substances into (openly accessible) databases. Graphical Abstract Matrix of identification approach versus identification confidence.

  4. Investigation of high-resolution absorption spectra of diatomic sulfides of group 14 elements in graphite furnace and the comparison of their performance for sulfur determination

    Science.gov (United States)

    Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Abad, Carlos; Okruss, Michael

    2017-09-01

    For the purpose of finding suitable molecules applicable to sulfur determination and to compare their analytical sensitivity systematically, high-resolution overview molecular absorption spectra of sulfides of group 14 elements produced in a graphite furnace were investigated. To that end a modular simultaneous echelle spectrograph (MOSES) was used, which allows recording sub-ranges of spectra out of a total wavelength range from 190 nm to 735 nm. The combined overview spectra show a complex structure with many vibrational bands, each of them consisting of a multitude of sharp rotational lines. The absorption of rotational lines of SiS (282.910 nm), GeS (295.209 nm), SnS (271.578 nm), and PbS (335.085 nm) has been analyzed for optimizing the particular experimental conditions regarding to the sulfur determination. Using the commercial CS AAS instrument contrAA 600 under optimized conditions such as the temperature program, the modification of the platform with Zr and the use of chemical modifiers, the achieved characteristic masses for sulfur are 12 ng (CS), 15.7 ng (SiS), 9.4 ng (GeS), 20 ng (SnS), and 220 ng (PbS). The first four sulfides provide an analytical sensitivity at roughly the same level, but the GeS molecule seems to be the best one with respect to analytical sensitivity and flexibility in molecular formation control. The PbS molecule provides the lowest analytical sensitivity, and together with its low bond strength it is not recommended for sulfur determination.

  5. Aerosol Organic Matter-Trace Metal Relationships Revealed by Ultra-High Resolution Mass Spectrometry

    Science.gov (United States)

    Wozniak, A. S.; Sleighter, R. L.; Morton, P. L.; Landing, W. M.; Shelley, R. U.; Hatcher, P. G.

    2011-12-01

    Atmospheric delivery of aerosols is important for the biogeochemical cycling of organic matter (OM) and trace elements in marine environments. Aerosols over marine environments can be derived from marine sources or transported from continental regions of variable vegetative cover and anthropogenic influence. These different sources are key determinants of aerosol OM composition, as well as trace metal amounts and characteristics. Dust-influenced aerosols typically contain higher amounts of Fe than anthropogenic-influenced aerosols but have lesser % of soluble Fe (%FeS), believed to be the bioavailable form of Fe for marine phytoplankton. Four samples from the 2008 GEOTRACES intercalibration experiments (Miami, FL, USA) were analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and related to both air mass back trajectories and %FeS. Three samples showed aerosol sources from the east consistent with Saharan dust inputs, while the fourth sample was derived in part from air masses to the north, influenced by the North American continent. This North American-influenced sample was collected following the 3 day period with the highest %FeS (1.3-1.7%) of the 11 day intercalibration experiment (mean = 0.4-1.1%). FT-ICR mass spectra showed 795 peaks common to the dust-influenced samples but absent from the North American-influenced sample. These peaks were assigned molecular formulas characterized by CHO and CHON compounds with lower H/C and O/C ratios than the 1257 formulas common to all 4 samples, suggesting that the dust-influenced aerosols carry OM that is less oxygenated and more condensed in structure along with Fe of lesser solubility. Air mass trajectory analyses revealed samples collected during a 2010 cruise in the North Atlantic Ocean to be characterized by European-influenced (anthropogenic), African-influenced (dust), and primarily marine air masses, making them ideal for further exploration of the

  6. A detailed analysis of the high-resolution X-ray spectra of NGC 3516: variability of the ionized absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Huerta, E. M.; Krongold, Y.; Jimenez-Bailon, E. [Departamento de Astronomia Extragalactica y Cosmologia, Instituto de Astronomia, Universidad Nacional Autonoma de Mexico (UNAM), Apartado Postal 70-264, 04510 Mexico D.F. (Mexico); Nicastro, F. [Osservatorio Astronomico di Roma-INAF, Via di Frascati 33, I-00040 Monte Porzio Catone, RM (Italy); Mathur, S. [Astronomy Department, The Ohio State University, Enarson Hall, 140 West 18th Avenue, Columbus, OH 43210 (United States); Longinotti, A. L. [European Space Astronomy Centre of ESA, E-28691, Madrid (Spain)

    2014-09-20

    The 1.5 Seyfert galaxy NGC 3516 presents a strong time variability in X-rays. We re-analyzed the nine observations performed in 2006 October by XMM-Newton and Chandra in the 0.3 to 10 keV energy band. An acceptable model was found for the XMM-Newton data fitting the EPIC-PN and RGS spectra simultaneously; later, this model was successfully applied to the contemporary Chandra high-resolution data. The model consists of a continuum emission component (power law + blackbody) absorbed by four ionized components (warm absorbers), and 10 narrow emission lines. Three absorbing components are warm, producing features only in the soft X-ray band. The fourth ionization component produces Fe XXV and Fe XXVI in the hard-energy band. We study the time response of the absorbing components to the well-detected changes in the X-ray luminosity of this source and find that the two components with the lower ionization state show clear opacity changes consistent with gas close to photoionization equilibrium. These changes are supported by the models and by differences in the spectral features among the nine observations. On the other hand, the two components with higher ionization state do not seem to respond to continuum variations. The response time of the ionized absorbers allows us to constrain their electron density and location. We find that one component (with intermediate ionization) must be located within the obscuring torus at a distance 2.7 × 10{sup 17} cm from the central engine. This outflowing component likely originated in the accretion disk. The three remaining components are at distances larger than 10{sup 16}-10{sup 17} cm. Two of the absorbing components in the soft X-rays have similar outflow velocities and locations. These components may be in pressure equilibrium, forming a multi-phase medium, if the gas has metallicity larger than the solar one (≳ 5 Z {sub ☉}). We also search for variations in the covering factor of the ionized absorbers (although partial

  7. 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.

  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.

    2016-01-01

    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

  9. Ambient Aerosol in Southeast Asia: High Resolution Aerosol Mass Spectrometer Measurements Over Oil Palm (Elaeis guineensis)

    Science.gov (United States)

    Phillips, G.; Dimarco, C.; Misztal, P.; Nemitz, E.; Farmer, D.; Kimmel, J.; Jimenez, J.

    2008-12-01

    The emission of organic compounds in the troposphere is important factor in the formation of secondary organic aerosol (SOA). A very large proportion of organic material emitted globally is estimated to arise from biogenic sources, with almost half coming from tropical and sub-tropical forests. Preliminary analyses of leave cuvette emission studies suggest that oil palm (Elaeis guineensis) is a significantly larger source of isoprene than tropical forest. Much larger sources of isoprene over oil palm allied with a larger anthropogenic component of local emissions contrast greatly with the remote tropical forest environment and therefore the character of SOA formed may differ significantly. These issues, allied with the high price of palm oil on international markets leading to increased use of land for oil palm production, could give rise to rapidly changing chemical and aerosol regimes in the tropics. It is therefore important to understand the current emissions and composition of organic aerosol over all important land-uses in the tropical environment. This in turn will lead to a greater understanding of the present, and to an improvement in predictive capacity for the future system. To help address these issues, a high resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) was deployed in the Sabahmas (PPB OIL) oil palm plantation near Lahad Datu, in Eastern Sabah, as part of the field component of the Aerosol Coupling in the Earth System (ACES) project, part of the UK NERC APPRAISE program. This project was allied closely with measurements made of similar chemical species and aerosol components at a forest site in the Danum Valley as part of the UK Oxidant and Particle Photochemical Processes above a Southeast Asian tropical rainforest (OP3) project. Measurements of submicron non- refractory aerosol composition are presented along with some preliminary analysis of chemically resolved aerosol fluxes made with a new eddy covariance system, based on the

  10. Sequential extraction protocol for organic matter from soils and sediments using high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Toyoda, Jason; Toli?, Nikola; Robinson, Errol W.; Pa?a-Toli?, Ljiljana; Hess, Nancy J.

    2017-03-31

    A vast number of organic compounds are present in soil organic matter (SOM) and play an important role in the terrestrial carbon cycle, facilitate interactions between organisms, and represent a sink for atmospheric CO2. The diversity of different SOM compounds and their molecular characteristics is a function of the organic source material and biogeochemical history. By understanding how SOM composition changes with sources and the processes by which it is biogeochemically altered in different terrestrial ecosystems, it may be possible to predict nutrient and carbon cycling, response to system perturbations, and impact of climate change will have on SOM composition. In this study, a sequential chemical extraction procedure was developed to reveal the diversity of organic matter (OM) in different ecosystems and was compared to the previously published protocol using parallel solvent extraction (PSE). We compared six extraction methods using three sample types, peat soil, spruce forest soil and river sediment, so as to select the best method for extracting a representative fraction of organic matter from soils and sediments from a wide range of ecosystems. We estimated the extraction yield of dissolved organic carbon (DOC) by total organic carbon analysis, and measured the composition of extracted OM using high resolution mass spectrometry. This study showed that OM composition depends primarily on soil and sediment characteristics. Two sequential extraction protocols, progressing from polar to non-polar solvents, were found to provide the highest number and diversity of organic compounds extracted from the soil and sediments. Water (H2O) is the first solvent used for both protocols followed by either co-extraction with methanol-chloroform (MeOH-CHCl3) mixture, or acetonitrile (ACN) and CHCl3 sequentially. The sequential extraction protocol developed in this study offers improved sensitivity, and requires less sample compared to the PSE workflow where a new sample

  11. I Search of Narrow Proton-Antiproton Bound States: High Resolution Gamma and Charged Flow Pion Spectra from Protonium.

    Science.gov (United States)

    Petridou, Chariclia I.

    We studied the pp annihilations at rest looking for narrow bound states in the proton-antiproton system. We looked, with high energy resolution, for radiative and pionic transitions in the gamma and charged pion spectra. The detector for the (gamma)(--->)e+e- and the (pi)('(+OR-)) was a magnetic pair spectrometer. The directions of the incident particles (e(+OR-) and (pi)(+OR-)) were determined by a drift chamber module in front of the magnet and the final directions of the particles, if reflected in the magnet, by the same chamber; if transversing the magnet, by an identical module at the rear of the magnet. The momentum was calculated from the directions of the particle. The following gamma spectra were obtained. Gammas with both e+, e- reflected in the magnet at a field of about 6 Kgauss (RR-gammas). That covers the region between 80 and 180 MeV, corresponding to a missing mass 1794 to 1686 MeV/c. The energy resolution is about 2.5 MeV ((sigma)) at 129 MeV (confirmed by the observed Panofsky gammas from stopping (pi)('-)p data) and 5 MeV ((sigma)) at 80 MeV. We have no evidence for narrow peaks except for the Panofsky gamma produced with a branching ratio of 3.3 x 10('-3) from (pi)('-) stops in the target. Upper limits for (gamma) -transitions in the region between 80 to 180 MeV were set at about 10('-3). Gammas with one e+(e-) reflected and the other transversing the magnet (RP-gammas) for fields of about 6 and 12 Kgauss, covering the region (GREATERTHEQ) 200 MeV, which corresponds to missing mass (LESSTHEQ) 1664 MeV/c('2). The gamma energy resolution in MeV is 51(.)E('2) (GeV) and 25.5(.)E('2)(GeV) for the low and high field respectively. Finally the charged pion spectra for those transversing the magnet are given for both magnet settings and as a function of charge multiplicity, covering the momentum region from (GREATERTHEQ) 150 MeV/c. The momentum resolution is the same as that for the RP-gammas. The two body annihilations (pi)('+)(pi)('-) and (pi

  12. Features-Based Deisotoping Method for Tandem Mass Spectra

    Directory of Open Access Journals (Sweden)

    Zheng Yuan

    2011-01-01

    Full Text Available For high-resolution tandem mass spectra, the determination of monoisotopic masses of fragment ions plays a key role in the subsequent peptide and protein identification. In this paper, we present a new algorithm for deisotoping the bottom-up spectra. Isotopic-cluster graphs are constructed to describe the relationship between all possible isotopic clusters. Based on the relationship in isotopic-cluster graphs, each possible isotopic cluster is assessed with a score function, which is built by combining nonintensity and intensity features of fragment ions. The non-intensity features are used to prevent fragment ions with low intensity from being removed. Dynamic programming is adopted to find the highest score path with the most reliable isotopic clusters. The experimental results have shown that the average Mascot scores and F-scores of identified peptides from spectra processed by our deisotoping method are greater than those by YADA and MS-Deconv software.

  13. High-resolution Fourier transform ion cyclotron resonance mass spectrometry with increased throughput for biomolecular analysis.

    Science.gov (United States)

    Nagornov, Konstantin O; Gorshkov, Mikhail V; Kozhinov, Anton N; Tsybin, Yury O

    2014-09-16

    A multielectrode ion cyclotron resonance (ICR) cell, herein referred to as the "4X cell", for signal detection at the quadruple frequency multiple was implemented and characterized on a commercial 10 T Fourier transform ICR mass spectrometer (FT-ICR MS). Notably, with the 4X cell operating at a 10 T magnetic field we achieved a 4-fold increase in MS acquisition rate per unit of resolving power for signal detection periods typically employed in FTMS, viz., shorter than 6 s. Effectively, the obtained resolution performance represents the limit of the standard measurement principle with dipolar signal detection and FT signal processing at an equivalent magnetic field of 40 T. In other words, the achieved resolving powers are 4 times higher than those provided by 10 T FT-ICR MS with a standard ICR cell. For example, resolving powers of 170,000 and 70,000 were obtained in magnitude-mode Fourier spectra of 768 and 192 ms apodized transient signals acquired for a singly charged fluorinated phosphazine (m/z 1422) and a 19-fold charged myoglobin (MW 16.9 kDa), respectively. In peptide analysis, the baseline-resolved isotopic fine structures were obtained with as short as 768 ms transients. In intact protein analysis, the average resolving power of 340,000 across the baseline-resolved (13)C isotopic pattern of multiply charged ions of bovine serum albumin was obtained with 1.5 s transients. The dynamic range and the mass measurement accuracy of the 4X cell were found to be comparable to the ones obtained for the standard ICR cell on the same mass spectrometer. Overall, the reported results validate the advantages of signal detection at frequency multiples for increased throughput in FT-ICR MS, essential for numerous applications with time constraints, including proteomics.

  14. Fast Airborne Aerosol Size and Chemistry Measurements with the High Resolution Aerosol Mass Spectrometer during the MILAGRO Campaign

    Science.gov (United States)

    DeCarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; Zhou, J.; Tomlinson, J.; Collins,D. R.; Knapp, D.; Weinheimer, A. J.; Montzka,D. D.; Campos,T.; Jimenez, J. L.

    2007-01-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM(sub l)) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS. During the campaign the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM(sub l) mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 microg/cubic m (STP) ppm(exp -1). This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2008). The stability of the OA/CO while O/C increases with photochemical age implies a net loss of carbon from the OA. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major regional source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city

  15. Fast airborne aerosol size and chemistry measurements with the high resolution aerosol mass spectrometer during the MILAGRO Campaign

    Science.gov (United States)

    Decarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; Zhou, J.; Tomlinson, J.; Collins, D. R.; Knapp, D.; Weinheimer, A. J.; Montzka, D. D.; Campos, T.; Jimenez, J. L.

    2007-12-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM1) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS, in which the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM1 mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 μg m-3 (STP) ppm-1. This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2007b). BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city likely due to evaporation. BB does not appear to be a strong source of nitrate despite its high emissions of nitrogen oxides, presumably due to low ammonia

  16. Fast airborne aerosol size and chemistry measurements with the high resolution aerosol mass spectrometer during the MILAGRO Campaign

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2007-12-01

    Full Text Available The concentration, size, and composition of non-refractory submicron aerosol (NR-PM1 was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS, in which the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA species dominate the NR-PM1 mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA and biomass burning (BB are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 μg m−3 (STP ppm−1. This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006 and Kleinman et al. (2007b. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city likely due to evaporation. BB does not appear to be a strong source of nitrate

  17. Triple Quadrupole Versus High Resolution Quadrupole-Time-of-Flight Mass Spectrometry for Quantitative LC-MS/MS Analysis of 25-Hydroxyvitamin D in Human Serum

    Science.gov (United States)

    Geib, Timon; Sleno, Lekha; Hall, Rabea A.; Stokes, Caroline S.; Volmer, Dietrich A.

    2016-08-01

    We describe a systematic comparison of high and low resolution LC-MS/MS assays for quantification of 25-hydroxyvitamin D3 in human serum. Identical sample preparation, chromatography separations, electrospray ionization sources, precursor ion selection, and ion activation were used; the two assays differed only in the implemented final mass analyzer stage; viz. high resolution quadrupole-quadrupole-time-of-flight (QqTOF) versus low resolution triple quadrupole instruments. The results were assessed against measured concentration levels from a routine clinical chemiluminescence immunoassay. Isobaric interferences prevented the simple use of TOF-MS spectra for extraction of accurate masses and necessitated the application of collision-induced dissociation on the QqTOF platform. The two mass spectrometry assays provided very similar analytical figures of merit, reflecting the lack of relevant isobaric interferences in the MS/MS domain, and were successfully applied to determine the levels of 25-hydroxyvitamin D for patients with chronic liver disease.

  18. Using radiative transfer models to study the atmospheric water vapor content and to eliminate telluric lines from high-resolution optical spectra

    CERN Document Server

    Gardini, A; Pérez, E; Quesada, J A; Funke, B

    2012-01-01

    The Radiative Transfer Model (RTM) and the retrieval algorithm, incorporated in the SCIATRAN 2.2 software package developed at the Institute of Remote Sensing/Institute of Enviromental Physics of Bremen University (Germany), allows to simulate, among other things, radiance/irradiance spectra in the 2400-24 000 {\\AA} range. In this work we present applications of RTM to two case studies. In the first case the RTM was used to simulate direct solar irradiance spectra, with different water vapor amounts, for the study of the water vapor content in the atmosphere above Sierra Nevada Observatory. Simulated spectra were compared with those measured with a spectrometer operating in the 8000-10 000 {\\AA} range. In the second case the RTM was used to generate telluric model spectra to subtract the atmospheric contribution and correct high-resolution stellar spectra from atmospheric water vapor and oxygen lines. The results of both studies are discussed.

  19. Identification of Microorganisms by High Resolution Tandem Mass Spectrometry with Accurate Statistical Significance

    Science.gov (United States)

    Alves, Gelio; Wang, Guanghui; Ogurtsov, Aleksey Y.; Drake, Steven K.; Gucek, Marjan; Suffredini, Anthony F.; Sacks, David B.; Yu, Yi-Kuo

    2016-02-01

    Correct and rapid identification of microorganisms is the key to the success of many important applications in health and safety, including, but not limited to, infection treatment, food safety, and biodefense. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is challenging correct microbial identification because of the large number of choices present. To properly disentangle candidate microbes, one needs to go beyond apparent morphology or simple `fingerprinting'; to correctly prioritize the candidate microbes, one needs to have accurate statistical significance in microbial identification. We meet these challenges by using peptidome profiles of microbes to better separate them and by designing an analysis method that yields accurate statistical significance. Here, we present an analysis pipeline that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using MS/MS data of 81 samples, each composed of a single known microorganism, that the proposed pipeline can correctly identify microorganisms at least at the genus and species levels. We have also shown that the proposed pipeline computes accurate statistical significances, i.e., E-values for identified peptides and unified E-values for identified microorganisms. The proposed analysis pipeline has been implemented in MiCId, a freely available software for Microorganism Classification and Identification. MiCId is available for download at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html.

  20. Measurement of pyrethroid, organophosphorus, and carbamate insecticides in human plasma using isotope dilution gas chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Pérez, José J; Williams, Megan K; Weerasekera, Gayanga; Smith, Kimberly; Whyatt, Robin M; Needham, Larry L; Barr, Dana Boyd

    2010-10-01

    We have developed a gas chromatography-high resolution mass spectrometry method for measuring pyrethroid, organophosphorus, carbamate and fipronil pesticides and the synergist piperonyl butoxide in human plasma. Plasma samples were extracted using solid phase extraction and were then concentrated for injection and analysis using isotope dilution gas chromatography-high resolution mass spectrometry. The limits of detection ranged from 10 to 158 pg/mL with relative recoveries at concentrations near the LODs (e.g., 25 or 250 pg/mL) ranging from 87% to 156% (9 of the 16 compounds were within ±15% of 100%). The extraction recoveries ranged from 20% to 98% and the overall method relative standard deviations were typically less than 20% with some exceptions. Analytical characteristics were determined at 25, 250, and 1000 pg/mL.

  1. Chemical evolution of fluorine in the bulge. High-resolution K-band spectra of giants in three fields

    Science.gov (United States)

    Jönsson, H.; Ryde, N.; Harper, G. M.; Cunha, K.; Schultheis, M.; Eriksson, K.; Kobayashi, C.; Smith, V. V.; Zoccali, M.

    2014-04-01

    Context. Possible main formation sites of fluorine in the Universe include asymptotic giant branch (AGB) stars, the ν-process in Type II supernova, and/or Wolf-Rayet stars. The importance of the Wolf-Rayet stars has theoretically been questioned and they are probably not needed in modeling the chemical evolution of fluorine in the solar neighborhood. It has, however, been suggested that Wolf-Rayet stars are indeed needed to explain the chemical evolution of fluorine in the bulge. The molecular spectral data, needed to determine the fluorine abundance, of the often used HF-molecule has not been presented in a complete and consistent way and has recently been debated in the literature. Aims: We intend to determine the trend of the fluorine-oxygen abundance ratio as a function of a metallicity indicator in the bulge to investigate the possible contribution from Wolf-Rayet stars. Additionally, we present here a consistent HF line list for the K- and L-bands including the often used 23 358.33 Å line. Methods: High-resolution near-infrared spectra of eight K giants were recorded using the spectrograph CRIRES mounted at the VLT. A standard setting was used that covered the HF molecular line at 23 358.33 Å. The fluorine abundances were determined using spectral fitting. We also re-analyzed five previously published bulge giants observed with the Phoenix spectrograph on Gemini using our new HF molecular data. Results: We find that the fluorine-oxygen abundance in the bulge probably cannot be explained with chemical evolution models that only include AGB stars and the ν-process in supernovae Type II, that is a significant amount of fluorine production in Wolf-Rayet stars is most likely needed to explain the fluorine abundance in the bulge. For the HF line data, we find that a possible reason for the inconsistencies in the literature, where two different excitation energies were used, is two different definitions of the zero-point energy for the HF molecule and therefore

  2. Atmospheric-Pressure Chemical Ionization Tandem Mass Spectrometry (APGC/MS/MS) an Alternative to High-Resolution Mass Spectrometry (HRGC/HRMS) for the Determination of Dioxins

    NARCIS (Netherlands)

    Bavel, Van Bert; Geng, Dawei; Cherta, Laura; Nácher-Mestre, Jaime; Portolés, Tania; Ábalos, Manuela; Sauló, Jordi; Abad, Esteban; Dunstan, Jody; Jones, Rhys; Kotz, Alexander; Winterhalter, Helmut; Malisch, Rainer; Traag, Wim; Hagberg, Jessika; Ericson Jogsten, Ingrid; Beltran, Joaquim; Hernández, Félix

    2015-01-01

    The use of a new atmospheric-pressure chemical ionization source for gas chromatography (APGC) coupled with a tandem quadrupole mass spectrometry (MS/MS) system, as an alternative to high-resolution mass spectrometry (HRMS), for the determination of PCDDs/PCDFs is described. The potential of usin

  3. High-resolution CCD spectra of stars in globular clusters. III - M4, M13, and M22

    Science.gov (United States)

    Wallerstein, George; Leep, E. Myckky; Oke, J. B.

    1987-01-01

    Spectra of 0.3 and 0.6 A resolution of stars in M4, M13 and M22 to derive abundances of various atomic species and the CN molecule. For M13, the usual Fe/H ratio and a surprisingly high aluminum abundance is found. The CN lines indicate a larger column density in the oxygen-rich star III-63 than in the oxygen-poor star II-67 by a factor of 10. It appears that II-67 is deficient in C, N, and O by about a factor 3 relative to iron for all three elements. For M4, Fe/H = -1.2 using solar f values derived via the Bell et al. (1976) model. This Fe abundance lies between earlier echelle values and photometric values. For two stars, CN data are obtained that can be understood if there was a slight excess of C/Fe and N/Fe prior to CN cycling and mixing. For M22, a large difference in CN is found between stars III-3 and IV-102. The origin of the CNO elements is discussed in terms of mass loss from an early generation of red giants and possibly Wolf-Rayet stars.

  4. Non-target screening with high-resolution mass spectrometry : critical review using a collaborative trial on water analysis

    OpenAIRE

    Emma L. Schymanski; Singer, Heinz P.; Slobodnik, Jaroslav; Onghena, Matthias; et al

    2015-01-01

    Abstract: In this article, a dataset from a collaborative non-target screening trial organised by the NORMAN Association is used to review the state-of-the-art and discuss future perspectives of non-target screening using high-resolution mass spectrometry in water analysis. A total of 18 institutes from 12 European countries analysed an extract of the same water sample collected from the River Danube with either one or both of liquid and gas chromatography coupled with mass spectrometry detec...

  5. High-resolution methods for preserving the sum of mass fractions: improved χ-scheme and an alternative

    Energy Technology Data Exchange (ETDEWEB)

    Syamial, Madhava [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Benyahia, Sofiane [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2013-11-20

    When high resolution convection schemes are used for discretizing chemical species mass balance equations, the mass fractions are not guaranteed to add to one. We show that a proposed remedy called χ-scheme (Darwish and Moukalled, Comput.Methods Appl.Mech. Engrg. 192 (2003): 1711) will degrade to a diffusive first-order scheme when a chemical species vanishes from the mixture, for example, because of chemical reactions. We propose an improvement to the χ-scheme to overcome this problem. Furthermore, a computationally efficient alternative scheme is proposed and evaluated with several examples, to quantify the improvements in the accuracy and the computational time.

  6. 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.

  7. Deriving the extinction to young stellar objects using [FeII] near-infrared emission lines. Prescriptions from GIANO high-resolution spectra

    CERN Document Server

    Pecchioli, Tommaso; Massi, Fabrizio; Oliva, Ernesto

    2016-01-01

    The near-infrared emission lines of Fe$^{+}$ at 1.257, 1.321, and 1.644 $\\mu$m share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission coefficients are known. This is commonly done, normally from low-resolution spectra, in observations of shocked gas from jets driven by Young Stellar Objects. In this paper we review this method, provide the relevant equations, and test it by analyzing high-resolution ($R \\sim 50000$) near-infrared spectra oftwo young stars, namely the Herbig Be star HD 200775 and the Be star V1478 Cyg, which exhibit intense emission lines. The spectra were obtained with the new GIANO echelle spectrograph at the Telescopio Nazionale Galileo. Notably, the high-resolution spectra allowed checking the effects of overlapping telluric absorption lines. A set of various determinations of the Einstein coefficients are compared to show how much the available computations affect extinction derivation. The m...

  8. Structural Characterization of a Thrombin-Aptamer Complex by High Resolution Native Top-Down Mass Spectrometry

    Science.gov (United States)

    Zhang, Jiang; Loo, Rachel R. Ogorzalek; Loo, Joseph A.

    2017-09-01

    Native mass spectrometry (MS) with electrospray ionization (ESI) has evolved as an invaluable tool for the characterization of intact native proteins and non-covalently bound protein complexes. Here we report the structural characterization by high resolution native top-down MS of human thrombin and its complex with the Bock thrombin binding aptamer (TBA), a 15-nucleotide DNA with high specificity and affinity for thrombin. Accurate mass measurements revealed that the predominant form of native human α-thrombin contains a glycosylation mass of 2205 Da, corresponding to a sialylated symmetric biantennary oligosaccharide structure without fucosylation. Native MS showed that thrombin and TBA predominantly form a 1:1 complex under near physiological conditions (pH 6.8, 200 mM NH4OAc), but the binding stoichiometry is influenced by the solution ionic strength. In 20 mM ammonium acetate solution, up to two TBAs were bound to thrombin, whereas increasing the solution ionic strength destabilized the thrombin-TBA complex and 1 M NH4OAc nearly completely dissociated the complex. This observation is consistent with the mediation of thrombin-aptamer binding through electrostatic interactions and it is further consistent with the human thrombin structure that contains two anion binding sites on the surface. Electron capture dissociation (ECD) top-down MS of the thrombin-TBA complex performed with a high resolution 15 Tesla Fourier transform ion cyclotron resonance (FTICR) mass spectrometer showed the primary binding site to be at exosite I located near the N-terminal sequence of the heavy chain, consistent with crystallographic data. High resolution native top-down MS is complementary to traditional structural biology methods for structurally characterizing native proteins and protein-DNA complexes. [Figure not available: see fulltext.

  9. Desorption electrospray ionization-high resolution mass spectrometry for the screening of veterinary drugs in cross-contaminated feedstuffs.

    Science.gov (United States)

    Seró, Raquel; Núñez, Oscar; Bosch, Jaume; Grases, José M; Rodríguez, Pilar; Moyano, Encarnacion; Galceran, Martia Teresa

    2015-09-01

    In this study, a desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) screening method was developed for fast identification of veterinary drugs in cross-contaminated feedstuffs. The reliable detection was performed working at high resolution (70,000 full width half maximum, FWHM) using an orbitrap mass analyzer. Among the optimized DESI parameters, the solvent (acetonitrile/water, 80:20, v/v) and the sample substrate (poly-tetrafluoroethylene, PTFE) were critical to obtain the best sensitivity. To analyze the solid feed samples, different approaches were tested and a simple solid-liquid extraction and the direct analysis of an aliquot (2 μL) of the extract after letting it dry on the PTFE printed spot provided the best results. The identification of the veterinary drugs (target and non-target) in the cross-contaminated feedstuffs based on the accurate mass measurement and the isotopic pattern fit was performed automatically using a custom-made database. The positive cross-contaminated feed samples were quantified by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results obtained demonstrate that DESI-HRMS can be proposed as a fast and suitable screening method to identify positive cross-contaminated feedstuffs reducing the number of samples to be subsequently quantified by UHPLC-MS/MS, thus improving the productivity in quality control laboratories.

  10. Characterization of submicron aerosols at a rural site in Pearl River Delta of China using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-11-01

    Full Text Available The Pearl River Delta (PRD region in South China is one of the most economically developed regions in China, but it is also noted for its severe air pollution due to industrial/metropolitan emissions. In order to continuously improve the understanding and quantification of air pollution in this region, an intensive campaign was executed in PRD during October–November 2008. Here, we report and analyze Aerodyne High-Resolution Aerosol Mass Spectrometer measurements at Kaiping, a rural site downwind of the highly-polluted central PRD area, to characterize the general features of submicron particulate pollution in the regional air. The mean measured PM1 mass concentration was 33.1 ± 18.1 μg m−3 during the campaign and composed of organic matter (33.8%, sulfate (33.7%, ammonium (14.0%, nitrate (10.7%, black carbon (6.7%, and chloride (1.1%, which is characterized by high fractions of inorganic ions due to huge emissions of SO2 and NOx in PRD. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at ~450 nm in vacuum aerodynamic diameter. Calculations based on high-resolution organic mass spectra indicate that C, H, O, and N on average contributed 56.6, 7.0, 35.1, and 1.3% to the total organic mass, respectively, corresponding to an organic matter mass to organic carbon mass ratio (OM/OC of 1.77 ± 0.08. Based on the high-resolution organic mass spectral dataset observed, Positive Matrix Factorization (PMF analysis differentiated the organic aerosol into three components, i.e., biomass burning (BBOA and two oxygenated (LV-OOA and SV-OOA organic aerosols, which on average accounted for 24.5, 39.6 and 35.8% of the total organic mass, respectively. The BBOA showed strong features of biomass burning emissions and has been mainly attributed to field rice straw burning after harvest. The LV-OOA and SV-OOA were found to correspond to more aged (and thus

  11. Deriving the Extinction to Young Stellar Objects using [Fe II] Near-infrared Emission Lines: Prescriptions from GIANO High-resolution Spectra

    Science.gov (United States)

    Pecchioli, T.; Sanna, N.; Massi, F.; Oliva, E.

    2016-07-01

    The near-infrared (NIR) emission lines of Fe+ at 1.257, 1.321, and 1.644 μm share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission coefficients are known. This is commonly done, normally from low-resolution spectra, in observations of shocked gas from jets driven by Young Stellar Objects. In this paper we review this method, provide the relevant equations, and test it by analyzing high-resolution (R ∼ 50,000) NIR spectra of two young stars, namely the Herbig Be star HD 200775 and the Be star V1478 Cyg, which exhibit intense emission lines. The spectra were obtained with the new GIANO echelle spectrograph at the Telescopio Nazionale Galileo. Notably, the high-resolution spectra allowed checking the effects of overlapping telluric absorption lines. A set of various determinations of the Einstein coefficients are compared to show how much the available computations affect extinction derivation. The most recently obtained values are probably good enough to allow reddening determination within 1 visual mag of accuracy. Furthermore, we show that [Fe ii] line ratios from low-resolution pure emission-line spectra in general are likely to be in error due to the impossibility to properly account for telluric absorption lines. If low-resolution spectra are used for reddening determinations, we advice that the ratio 1.644/1.257, rather than 1.644/1.321, should be used, being less affected by the effects of telluric absorption lines.

  12. A High Resolution Orbitrap Mass Spectrometer for In-Situ Analysis in Planetary Science

    Science.gov (United States)

    Briois, C.; Thirkell, L.; Boukrara, A.; Lebreton, J. P.; Thissen, R.; Puget, P.; Cottin, H.; Grand, N.; Pennanech, C.; Zapf, P.; Szopa, C.; Carrasco, N.; Chapuis, C.; Bouabdellah, A.; Berthelier, J. J.; Engrand, C.; Makarov, A.

    2012-04-01

    Solar System exploration is dealing more and more with chemically complex matter, potentially associated with astrobiology or prebiotic questions, requiring optimized methods of analysis. Due to its ability to reveal quantitatively almost any chemical element, mass spectrometry has served as an invaluable scientific analytical instruments. Nevertheless the best mass resolution (M/deltaM) currently achieved by mass spectrometers in space is about 3000 at mass 28 (ROSINA's DFMS on board ESA's comet chaser Rosetta). This resolution allows separation of peaks for only a limited number of isobaric species (e.g. N2 / CO at 28 Da). Yet, purely electrostatic orbital traps in laboratory are showing mass resolution above 100 000 for m/z <= 400 [1, 2], that provides separation for each detected isobaric species. Therefore it opens new opportunity for molecular characterization, isotopic abundance evaluation, and more generally environmental characterization. Our French consortium of laboratories, in collaboration with ThermoFischer Scientific, is currently working on the adaptation of this type of mass spectrometer for space instrumentation. We present here this innovative concept of mass analyzer for space that is lightweight, uses DC voltages, and provides ultra high resolving power capabilities. A mass resolution of 140,000 at mass 56 has been recently achieved with our prototype.

  13. High-resolution MALDI mass spectrometry imaging of gallotannins and monoterpene glucosides in the root of Paeonia lactiflora

    DEFF Research Database (Denmark)

    Li, Bin; Bhandari, Dhaka Ram; Römpp, Andreas

    2016-01-01

    High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) at 10 μm pixel size was performed to unravel the spatio-chemical distribution of major secondary metabolites in the root of Paeonia lactiflora. The spatial...... distributions of two major classes of bioactive components, gallotannins and monoterpene glucosides, were investigated and visualized at the cellular level in tissue sections of P. lactiflora roots. Accordingly, other primary and secondary metabolites were imaged, including amino acids, carbohydrates, lipids...

  14. Metabolite Identification Using Automated Comparison of High-Resolution Multistage Mass Spectral Trees

    NARCIS (Netherlands)

    Rojas-Cherto, M.; Peironcely, J.E.; Kasper, P.T.; Hooft, van der J.J.J.; Vos, de R.C.H.; Vreeken, R.; Hankemeier, T.; Reijmers, T.

    2012-01-01

    Multistage mass spectrometry (MSn) generating so-called spectral trees is a powerful tool in the annotation and structural elucidation of metabolites and is increasingly used in the area of accurate mass LC/MS-based metabolomics to identify unknown, but biologically relevant, compounds. As a consequ

  15. Accurate correction of magnetic field instabilities for high-resolution isochronous mass measurements in storage rings

    CERN Document Server

    Shuai, P; Zhang, Y H; Litvinov, Yu A; Wang, M; Tu, X L; Blaum, K; Zhou, X H; Yuan, Y J; Audi, G; Yan, X L; Chen, X C; Xu, X; Zhang, W; Sun, B H; Yamaguchi, T; Chen, R J; Fu, C Y; Ge, Z; Huang, W J; Liu, D W; Xing, Y M; Zeng, Q

    2014-01-01

    Isochronous mass spectrometry (IMS) in storage rings is a successful technique for accurate mass measurements of short-lived nuclides with relative precision of about $10^{-5}-10^{-7}$. Instabilities of the magnetic fields in storage rings are one of the major contributions limiting the achievable mass resolving power, which is directly related to the precision of the obtained mass values. A new data analysis method is proposed allowing one to minimise the effect of such instabilities. The masses of the previously measured at the CSRe $^{41}$Ti, $^{43}$V, $^{47}$Mn, $^{49}$Fe, $^{53}$Ni and $^{55}$Cu nuclides were re-determined with this method. An improvement of the mass precision by a factor of $\\sim 1.7$ has been achieved for $^{41}$Ti and $^{43}$V. The method can be applied to any isochronous mass experiment irrespective of the accelerator facility. Furthermore, the method can be used as an on-line tool for checking the isochronous conditions of the storage ring.

  16. Transformation products of emerging contaminants in the environment and high-resolution mass spectrometry: a new horizon.

    Science.gov (United States)

    Picó, Yolanda; Barceló, Damià

    2015-08-01

    It is crucial to study the presence of transformation products (TPs) of emerging contaminants that can be potentially found in the environment after biological or chemical degradation. This review focuses on the potential and shortcomings of high-resolution mass spectrometry (HRMS) to identify these TPs, with emphasis on recent developments in mass analyzers, data evaluation, and compound identification workflows and applications. Advances in HRMS technologies, including direct introduction or in-line chromatographic separation modes, ionization techniques, mass analyzers, and detection methods, have led to powerful tools to assess the molecular changes and the opening of new horizons to identify unknown molecules. Advances in HRMS pertaining to the generation of analytical data for the main methods to identify TPs, including nontargeted and targeted approaches as they are applied to elucidate the structure of TPs, are also discussed.

  17. Expanding the linear dynamic range for quantitative liquid chromatography-high resolution mass spectrometry utilizing natural isotopologue signals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hanghui, E-mail: Hanghui.Liu@senomyx.com [Senomyx Inc. 4767 Nexus Centre Dr., San Diego, CA 92121 (United States); Lam, Lily; Yan, Lin; Chi, Bert [Senomyx Inc. 4767 Nexus Centre Dr., San Diego, CA 92121 (United States); Dasgupta, Purnendu K., E-mail: Dasgupta@uta.edu [Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019-0065 (United States)

    2014-11-19

    Highlights: • Less abundant isotopologue ions were utilized to decrease detector saturation. • A 25–50 fold increase in the upper limit of dynamic range was demonstrated. • Linear dynamic range was expanded without compromising mass resolution. - Abstract: The linear dynamic range (LDR) for quantitative liquid chromatography–mass spectrometry can be extended until ionization saturation is reached by using a number of target isotopologue ions in addition to the normally used target ion that provides the highest sensitivity. Less abundant isotopologue ions extend the LDR: the lower ion abundance decreases the probability of ion detector saturation. Effectively the sensitivity decreases and the upper limit of the LDR increases. We show in this paper that the technique is particularly powerful with a high resolution time of flight mass spectrometer because the data for all ions are automatically acquired, and we demonstrated this for four small organic molecules; the upper limits of LDRs increased by 25–50 times.

  18. High resolution photoassociation spectra of an ultracold Cs2 long-range 0u+ (6S1/2 + 6P1/2) state

    Science.gov (United States)

    Chen, Peng; Li, Yu-Qing; Zhang, Yi-Chi; Wu, Ji-Zhou; Ma, Jie; Xiao, Lian-Tuan; Jia, Suo-Tang

    2013-09-01

    In this paper, ultracold cesium molecules are formed through photoassociation technology, which is carried out in a magneto-optical trap. High resolution photoassociaion spectra with the rotational progressions up to J = 7 are obtained. Three rovibrational levels of the long-range 0u+ state of Cs2 below the (6S1/2 + 6P1/2) dissociation limit are specifically investigated. By fitting their binding energy intervals to the non-rigid rotational model, the rotational constant of the long-range 0u+ state is determined. A proportional dependence of the value of the rotational constant on the vibrational quantum number is demonstrated.

  19. Quantification of HCl from High Resolution Infrared Solar Spectra Obtained at the South Pole in December 1986

    Science.gov (United States)

    Goldman, A.; Murcray, F. J.; Murcray, F. H.; Murcray, D. G.

    1987-01-01

    Ground-based infrared solar spectra at 0.02/ cm resolution obtained at the Amundsen-Scott South Pole station in December 1986 have been analysed for the atmospheric content of HCl. Nonlinear least-squares spectral fitting applied to the spectra yields a total HCl column amount of (6.4 +/- 0.8) x 10(exp 15) molec/sq cm, most being stratospheric. This amount is larger than that extrapolated from earlier results on the latitudinal distribution of atmospheric HCl.

  20. CRIRES-POP: a library of high resolution spectra from 1 to 5 microns II. Data reduction and the spectrum of the K giant 10 Leo

    CERN Document Server

    Nicholls, C P; Smette, A; Wolff, B; Hartman, H; Käufl, H -U; Przybilla, N; Ramsay, S; Uttenthaler, S; Wahlgren, G M; Bagnulo, S; Hussain, G A J; Nieva, M -F; Seeman, U; Seifahrt, A

    2016-01-01

    Context. High resolution stellar spectral atlases are valuable resources to astronomy. They are rare in the $1 - 5\\,\\mu$m region for historical reasons, but once available, high resolution atlases in this part of the spectrum will aid the study of a wide range of astrophysical phenomena. Aims. The aim of the CRIRES-POP project is to produce a high resolution near-infrared spectral library of stars across the H-R diagram. The aim of this paper is to present the fully reduced spectrum of the K giant 10 Leo that will form the basis of the first atlas within the CRIRES-POP library, to provide a full description of the data reduction processes involved, and to provide an update on the CRIRES-POP project. Methods. All CRIRES-POP targets were observed with almost 200 different observational settings of CRIRES on the ESO Very Large Telescope, resulting in a basically complete coverage of its spectral range as accessible from the ground. We reduced the spectra of 10 Leo with the CRIRES pipeline, corrected the waveleng...

  1. Investigation of slow collisions for (quasi) symmetric heavy systems: what can be extracted from high resolution X-ray spectra

    CERN Document Server

    Trassinelli, Martino; Lamour, Emily; Mezdari, Férid; Merot, Jacques; Reuschl, Regina; Rozet, Jean-Pierre; Steydli, S; Vernhet, Dominique

    2012-01-01

    We present a new experiment on (quasi) symmetric collision systems at low-velocity, namely Ar$^{17+}$ ions ($v=0.53$ a.u.) on gaseous Ar and N$_2$ targets, using low- and high-resolution X-ray spectroscopy. Thanks to an accurate efficiency calibration of the spectrometers, we extract absolute X-ray emission cross sections combining low-resolution X-ray spectroscopy and a complete determination of the ion beam - gas jet target overlap. Values with improved uncertainty are found in agreement with previous results \\cite{Tawara2001}. Resolving the whole He-like Ar$^{16+}$ Lyman series from $n=2$ to 10 with our crystal spectrometer enables to determine precisely the distribution ${\\mathcal{P}_n}$ of the electron capture probability and the preferential $n_{pref}$ level of the selective single-electron capture. Evaluation of cross sections for this process as well as for the contribution of multiple-capture is carried out. Their sensitivity to the $\\ell$-distribution of $n$ levels populated by single-electron captu...

  2. Phase I and phase II reductive metabolism simulation of nitro aromatic xenobiotics with electrochemistry coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Bussy, Ugo; Chung-Davidson, Yu-Wen; Li, Ke; Li, Weiming

    2014-11-01

    Electrochemistry combined with (liquid chromatography) high resolution mass spectrometry was used to simulate the general reductive metabolism of three biologically important nitro aromatic molecules: 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide, and nilutamide. TFM is a pesticide used in the Laurential Great Lakes while niclosamide and nilutamide are used in cancer therapy. At first, a flow-through electrochemical cell was directly connected to a high resolution mass spectrometer to evaluate the ability of electrochemistry to produce the main reduction metabolites of nitro aromatic, nitroso, hydroxylamine, and amine functional groups. Electrochemical experiments were then carried out at a constant potential of -2.5 V before analysis of the reduction products by LC-HRMS, which confirmed the presence of the nitroso, hydroxylamine, and amine species as well as dimers. Dimer identification illustrates the reactivity of the nitroso species with amine and hydroxylamine species. To investigate xenobiotic metabolism, the reactivity of nitroso species to biomolecules was also examined. Binding of the nitroso metabolite to glutathione was demonstrated by the observation of adducts by LC-ESI(+)-HRMS and the characteristics of their MSMS fragmentation. In conclusion, electrochemistry produces the main reductive metabolites of nitro aromatics and supports the observation of nitroso reactivity through dimer or glutathione adduct formation.

  3. Preprocessing significantly improves the peptide/protein identification sensitivity of high-resolution isobarically labeled tandem mass spectrometry data.

    Science.gov (United States)

    Sheng, Quanhu; Li, Rongxia; Dai, Jie; Li, Qingrun; Su, Zhiduan; Guo, Yan; Li, Chen; Shyr, Yu; Zeng, Rong

    2015-02-01

    Isobaric labeling techniques coupled with high-resolution mass spectrometry have been widely employed in proteomic workflows requiring relative quantification. For each high-resolution tandem mass spectrum (MS/MS), isobaric labeling techniques can be used not only to quantify the peptide from different samples by reporter ions, but also to identify the peptide it is derived from. Because the ions related to isobaric labeling may act as noise in database searching, the MS/MS spectrum should be preprocessed before peptide or protein identification. In this article, we demonstrate that there are a lot of high-frequency, high-abundance isobaric related ions in the MS/MS spectrum, and removing isobaric related ions combined with deisotoping and deconvolution in MS/MS preprocessing procedures significantly improves the peptide/protein identification sensitivity. The user-friendly software package TurboRaw2MGF (v2.0) has been implemented for converting raw TIC data files to mascot generic format files and can be downloaded for free from https://github.com/shengqh/RCPA.Tools/releases as part of the software suite ProteomicsTools. The data have been deposited to the ProteomeXchange with identifier PXD000994.

  4. Mobile high-resolution time-of-flight mass spectrometer for in-situ analytics

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Johannes; Ebert, Jens [II. Physikalisches Institut, JLU, Giessen (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [II. Physikalisches Institut, JLU, Giessen (Germany); GSI, Darmstadt (Germany)

    2011-07-01

    A compact multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed. For the first time it allows for mass measurements with a resolving power exceeding 100000 and sub ppm accuracy in a mobile device. Thus it allows to resolve isobars and enables to accurately determine the composition and structure of biomolecules. The MR-TOF-MS consists of an atmospheric pressure interface for DESI and REIMS, ion cooler, ion trap, time-of-flight analyzer, MCP detector and DAQ. Vacuum system components, power supplies as well as electronics are mounted together with the ion optical spectrometer parts on a single frame with a total volume of 0.8 m{sup 3}. Applications of the device within the AmbiProbe research program include in-situ mass spectrometry such as real-time tissue recognition in electrosurgery, identification of mycotoxins and analysis of soil samples for environmental studies.

  5. Methods for Identification of CA125 from Ovarian Cancer Ascites by High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Florian Weiland

    2012-08-01

    Full Text Available CA125 is the most widely used tumour marker in ovarian cancer with unsatisfactory sensitivity and specificity especially at early stage. It is quantified by antibody-based immunoassays; however different molecular weight isoforms have been described in the literature which have never been validated by mass spectrometry, potentially affecting the diagnostic accuracy and clinical reliability of the test. In this study, CA125 was detected by Western blot and its identity confirmed by mass spectrometry. Two-dimensional (2D gel electrophoresis in combination with mass spectrometry revealed that positive Western blot signals up to 500 kDa are most likely false-positive interactions of M11-like and OC125-like antibodies. Fibronectin, identified as one of these false-positive interaction partners, increased the reading for CA125 in a first generation ELISA significantly (p = 0.02. The existence of low-molecular weight isoforms of CA125 is therefore questionable and is most likely reflecting cross-reactivity of the antibodies with other proteins. This would explain the conflicting reports on the molecular structure of CA125 and also the inconsistency of CA125 levels by different ELISAs. Our results are also the first steps towards a mass spectrometric assay for CA125 quantification, which would improve sensitivity and reliability.

  6. ION COMPOSITION ELUCIDATION (ICE): A HIGH RESOLUTION MASS SPECTROMETRIC TECHNIQUE FOR IDENTIFYING COMPOUNDS IN COMPLEX MIXTURES

    Science.gov (United States)

    When tentatively identifying compounds in complex mixtures using mass spectral libraries, multiple matches or no plausible matches due to a high level of chemical noise or interferences can occur. Worse yet, most analytes are not in the libraries. In each case, Ion Composition El...

  7. A high-resolution mass spectrometer to measure atmospheric ion composition

    Directory of Open Access Journals (Sweden)

    H. Junninen

    2010-02-01

    Full Text Available In this paper we present recent achievements on developing and testing a tool to detect the composition of ambient ions in the mass/charge range up to 2000 Th. The instrument is an Atmospheric Pressure Interface Time-of-Flight Mass Spectrometer (APi-TOF, Tofwerk AG. Its mass accuracy is better than 0.002%, and the mass resolving power is 3000 Th/Th. In the data analysis, a new efficient Matlab based set of programs (tofTools were developed, tested and used. The APi-TOF was tested both in laboratory conditions and applied to outdoor air sampling in Helsinki at the SMEAR III station. Transmission efficiency calibrations showed a throughput of 0.1–0.5% in the range 100–1300 Th for positive ions, and linearity over 3 orders of magnitude in concentration was determined. In the laboratory tests the APi-TOF detected sulphuric acid-ammonia clusters in high concentration from a nebulised sample illustrating the potential of the instrument in revealing the role of sulphuric acid clusters in atmospheric new particle formation. The APi-TOF features a high enough accuracy, resolution and sensitivity for the determination of the composition of atmospheric small ions although the total concentration of those ions is typically only 400–2000 cm-3. The atmospheric ions were identified based on their exact masses, utilizing Kendrick analysis and correlograms as well as narrowing down the potential candidates based on their proton affinities as well isotopic patterns. In Helsinki during day-time the main negative ambient small ions were inorganic acids and their clusters. The positive ions were more complex, the main compounds were (polyalkyl pyridines and – amines. The APi-TOF provides a near universal interface for atmospheric pressure sampling, and this key feature will be utilized in future laboratory and field studies.

  8. Screening of environmental contaminants in honey bee wax comb using gas chromatography-high-resolution time-of-flight mass spectrometry.

    Science.gov (United States)

    Gómez-Ramos, M M; García-Valcárcel, A I; Tadeo, J L; Fernández-Alba, A R; Hernando, M D

    2016-03-01

    This study reports an analytical approach intended to be used for investigation of non-targeted environmental contaminants and to characterize the organic pollution pattern of bee wax comb samples. The method comprises a generic extraction followed by detection with gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-TOF-MS), operated in electron impact ionization (EI) mode. The screening approach for the investigation of non-targeted contaminants consisted of initial peak detection by deconvolution and matching the first-stage mass spectra EI-MS(1) with a nominal mass spectral library. To gain further confidence in the structural characterization of the contaminants under investigation, the molecular formula of representative ions (molecular ion when present in the EI spectrum) and, for at least other two fragment ions, was provided for those with an accurate mass scoring (mass error bee wax comb. This approach has allowed the tentative identification of some GC-amenable contaminants belonging to different chemical groups, among them, phthalates and polycyclic aromatic hydrocarbons (PAHs), along with residues of veterinary treatments used in apiculture.

  9. High Resolution Spectroscopy of Halo Stars in the Near UV and Blue Region I. Spectra in the Wavelength Region 3550-5000(A)

    Institute of Scientific and Technical Information of China (English)

    V. G. Klochkova; Gang Zhao; S. V. Ermakov; V. E. Panchuk

    2006-01-01

    An atlas of high resolution (R = 60 000) CCD-spectra in the wavelength range 3500-5000(A) is presented for four objects in metallicity range -3.0 < [Fe/H] < -0.6,temperature range 4750 < Teff < 5900K, and surface gravity range 1.6 < lgg < 5.0.We describe the calibration of the stellar atmospheric parameters using Alonso's formula based on the method of infrared flux and outline the determination of the abundances of a total number of 25 chemical elements. An analysis of the abundance determination errors for different chemical elements is carried out, and a method is provided for the observations and reduction of spectral material. Properties of the method of producing an atlas of spectra and line identifications are described.

  10. VizieR Online Data Catalog: Boo-127 and Boo-980 high-resolution spectra (Frebel+, 2016)

    Science.gov (United States)

    Frebel, A.; Norris, J. E.; Gilmore, G.; Wyse, R. F. G.

    2016-09-01

    We observed Boo-980 and Boo-127 stars with the MIKE spectrograph on the Magellan-Clay telescope in 2010 March and 2011 March. Details of the MIKE observations and photometry taken from Norris et al. (2008ApJ...689L.113N) are given in Table 1. MIKE spectra have nearly full optical wavelength coverage over the range ~3500-9000Å (R~22000 in the red and ~28000 in the blue wavelength regime). (2 data files).

  11. Kea: a new tool to obtain stellar parameters from low to moderate signal/noise and high-resolution Echelle spectra

    CERN Document Server

    Endl, Michael

    2016-01-01

    In this paper we describe Kea a new spectroscopic fitting method to derive stellar parameters from moderate to low signal/noise, high-resolution spectra. We developed this new tool to analyze the massive data set of the Kepler mission reconnaissance spectra that we have obtained at McDonald Observatory. We use Kea to determine effective temperatures (T_eff), metallicity ([Fe/H]), surface gravity (log g) and projected rotational velocity (v sin i). Kea compares the observations to a large library of synthetic spectra that covers a wide range of different T_eff, [Fe/H] and log g values. We calibrated Kea on observations of well-characterized standard stars (the Kepler field "platinum" sample) which range in T_eff from 5000 to 6500 K, in [Fe/H] from -0.5 to +0.4 dex and in log g from 3.2 to 4.6 dex. We then compared the Kea results from reconnaissance spectra of 45 KOIs (Kepler Object of Interest) to stellar parameters derived from higher signal/noise spectra obtained with Keck/HIRES. We find typical uncertainti...

  12. Broad Separation of Isomeric Lipids by High-Resolution Differential Ion Mobility Spectrometry with Tandem Mass Spectrometry

    Science.gov (United States)

    Bowman, Andrew P.; Abzalimov, Rinat R.; Shvartsburg, Alexandre A.

    2017-08-01

    Maturation of metabolomics has brought a deeper appreciation for the importance of isomeric identity of lipids to their biological role, mirroring that for proteoforms in proteomics. However, full characterization of the lipid isomerism has been thwarted by paucity of rapid and effective analytical tools. A novel approach is ion mobility spectrometry (IMS) and particularly differential or field asymmetric waveform IMS (FAIMS) at high electric fields, which is more orthogonal to mass spectrometry. Here we broadly explore the power of FAIMS to separate lipid isomers, and find a 75% success rate across the four major types of glycero- and phospho- lipids ( sn, chain length, double bond position, and cis/ trans). The resolved isomers were identified using standards, and (for the first two types) tandem mass spectrometry. These results demonstrate the general merit of incorporating high-resolution FAIMS into lipidomic analyses.

  13. High Resolution Weak Lensing Mass-Mapping Combining Shear and Flexion

    CERN Document Server

    Lanusse, Francois; Leonard, Adrienne; Pires, Sandrine

    2016-01-01

    We propose a new mass-mapping algorithm, specifically designed to recover small-scale information from a combination of gravitational shear and flexion. Including flexion allows us to supplement the shear on small scales in order to increase the sensitivity to substructures and the overall resolution of the convergence map without relying on strong lensing constraints. In order to preserve all available small scale information, we avoid any binning of the irregularly sampled input shear and flexion fields and treat the mass-mapping problem as a general ill-posed inverse problem, regularised using a robust multi-scale wavelet sparsity prior. The resulting algorithm incorporates redshift, reduced shear, and reduced flexion measurements for individual galaxies and is made highly efficient by the use of fast Fourier estimators. We test our reconstruction method on a set of realistic weak lensing simulations corresponding to typical HST/ACS cluster observations and demonstrate our ability to recover substructures ...

  14. DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY - HIGH RESOLUTION MASS SPECTROMETRY.

    Science.gov (United States)

    Nikcevic, Irena; Wyrzykiewicz, Tadeusz K; Limbach, Patrick A

    2011-07-01

    An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described.Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3'-terminal phosphate monoester and 3'-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N(3) (2-cyanoethyl) adducts of the full

  15. Ice Mass Changes in the Russian High Arctic from Repeat High Resolution Topography.

    Science.gov (United States)

    Willis, Michael; Zheng, Whyjay; Pritchard, Matthew; Melkonian, Andrew; Morin, Paul; Porter, Claire; Howat, Ian; Noh, Myoung-Jong; Jeong, Seongsu

    2016-04-01

    We use a combination of ASTER and cartographically derived Digital Elevation Models (DEMs) supplemented with WorldView DEMs, the ArcticDEM and ICESat lidar returns to produce a time-series of ice changes occurring in the Russian High Arctic between the mid-20th century and the present. Glaciers on the western, Barents Sea coast of Novaya Zemlya are in a state of general retreat and thinning, while those on the eastern, Kara Sea coast are retreating at a slower rate. Franz Josef Land has a complicated pattern of thinning and thickening, although almost all the thinning is associated with rapid outlet glaciers feeding ice shelves. Severnaya Zemlya is also thinning in a complicated manner. A very rapid surging glacier is transferring mass into the ocean from the western periphery of the Vavilov Ice Cap on October Revolution Island, while glaciers feeding the former Matusevich Ice Shelf continue to thin at rates that are faster than those observed during the operational period of ICESat, between 2003 and 2009. Passive microwave studies indicate the total number of melt days is increasing in the Russian Arctic, although much of the melt may refreeze within the firn. It is likely that ice dynamic changes will drive mass loss for the immediate future. The sub-marine basins beneath several of the ice caps in the region suggest the possibility that mass loss rates may accelerate in the future.

  16. Matrix-assisted ionization vacuum for high-resolution Fourier transform ion cyclotron resonance mass spectrometers.

    Science.gov (United States)

    Wang, Beixi; Tisdale, Evgenia; Trimpin, Sarah; Wilkins, Charles L

    2014-07-15

    Matrix-assisted ionization vacuum (MAIV) produces charge states similar to electrospray ionization (ESI) from the solid state without requiring high voltage or added heat. MAIV differs from matrix-assisted laser desorption/ionization (MALDI) in that no laser is needed and abundant multiply charged ions are produced from molecules having multiple basic sites such as proteins. Here we introduce simple modifications to the commercial vacuum MALDI and ESI sources of a 9.4 T Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer to perform MAIV from both intermediate and atmospheric pressure. The multiply charged ions are shown for the proteins bovine insulin, ubiquitin, and lysozyme using 3-nitrobenzonitrile as matrix. These are the first examples of MAIV operating at pressures as low as 10(-6) mbar in an FT-ICR mass spectrometer source, and the expected mass resolving power of 100000 to 400000 is achieved. Identical protein charge states are observed with and without laser ablation indicating minimal, if any, role of photochemical ionization for the compounds studied.

  17. Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography-high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Karen M.; McNichol, Jesse; McGinn, Patrick J.; O' Leary, Stephen J.B.; Melanson, Jeremy E. [Institute for Marine Biosciences, National Research Council of Canada, Halifax, NS (Canada)

    2011-11-15

    Biofuels from photosynthetic microalgae are quickly gaining interest as a viable carbon-neutral energy source. Typically, characterization of algal feedstock involves breaking down triacylglycerols (TAG) and other intact lipids, followed by derivatization of the fatty acids to fatty acid methyl esters prior to analysis by gas chromatography (GC). However, knowledge of the intact lipid profile could offer significant advantages for discovery stage biofuel research such as the selection of an algal strain or the optimization of growth and extraction conditions. Herein, lipid extracts from microalgae were directly analyzed by ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) using a benchtop Orbitrap mass spectrometer. Phospholipids, glycolipids, and TAGs were analyzed in the same chromatographic run, using a combination of accurate mass and diagnostic fragment ions for identification. Using this approach, greater than 100 unique TAGs were identified over the six algal strains studied and TAG profiles were obtained to assess their potential for biofuel applications. Under the growth conditions employed, Botryococcus braunii and Scenedesmus obliquus yielded the most comprehensive TAG profile with a high abundance of TAGs containing oleic acid. (orig.)

  18. High-resolution quantitative imaging of mammalian and bacterial cells using stable isotope mass spectrometry

    Directory of Open Access Journals (Sweden)

    Park Kwon

    2006-10-01

    Full Text Available Abstract Background Secondary-ion mass spectrometry (SIMS is an important tool for investigating isotopic composition in the chemical and materials sciences, but its use in biology has been limited by technical considerations. Multi-isotope imaging mass spectrometry (MIMS, which combines a new generation of SIMS instrument with sophisticated ion optics, labeling with stable isotopes, and quantitative image-analysis software, was developed to study biological materials. Results The new instrument allows the production of mass images of high lateral resolution (down to 33 nm, as well as the counting or imaging of several isotopes simultaneously. As MIMS can distinguish between ions of very similar mass, such as 12C15N- and 13C14N-, it enables the precise and reproducible measurement of isotope ratios, and thus of the levels of enrichment in specific isotopic labels, within volumes of less than a cubic micrometer. The sensitivity of MIMS is at least 1,000 times that of 14C autoradiography. The depth resolution can be smaller than 1 nm because only a few atomic layers are needed to create an atomic mass image. We illustrate the use of MIMS to image unlabeled mammalian cultured cells and tissue sections; to analyze fatty-acid transport in adipocyte lipid droplets using 13C-oleic acid; to examine nitrogen fixation in bacteria using 15N gaseous nitrogen; to measure levels of protein renewal in the cochlea and in post-ischemic kidney cells using 15N-leucine; to study DNA and RNA co-distribution and uridine incorporation in the nucleolus using 15N-uridine and 81Br of bromodeoxyuridine or 14C-thymidine; to reveal domains in cultured endothelial cells using the native isotopes 12C, 16O, 14N and 31P; and to track a few 15N-labeled donor spleen cells in the lymph nodes of the host mouse. Conclusion MIMS makes it possible for the first time to both image and quantify molecules labeled with stable or radioactive isotopes within subcellular compartments.

  19. Line Identifications and Preliminary Synthesis of High-resolution Infrared Spectra of CP and Herbig Ae Stars

    Science.gov (United States)

    Cowley, Charles R.; Castelli, F.; Hubrig, S.; Wolff, B.; Elkin, V.

    2012-01-01

    We report on surveys of infrared spectra of chemically peculiar and Herbig Ae stars based on CRIRES (Kaufl, et al. SPIE, 5492, 1218 2004). We discuss the magnetic CP stars Gamma Equ and HD 154708, and multiple-phase observations of the Herbig Ae star HD 101412. The Be star HR 4537 and HgMn HR 6620 were also examined. The primary emphasis of the present work is on line identifications primarily in four regions, 1065-1091, 1084-1109,1550-1587, and 2276-2313nm (with order gaps). Observations were reduced with recipes available from the ESO CRIRES data reduction pipeline. Wavelength calibration is determined from daytime ThAr arc lamp exposures. Generally speaking, this is not rich in atomic lines. The strongest features are the Paschen line P6 (1093.81nm), and He I (108.30nm). The latter shows phase variations indicative of a more complex magnetic field than that of a pure dipole. No individual molecular lines were found in these early stars, though CO emission from circumstellar material is likely present in HR 4537 and HD 101412. We used atomic line lists from Kurucz's site (kurucz.harvard.edu) and VALD (http://vald.astro.univie.ac.at/ cf. Kupka et al. 1999, A&AS, 138, 119), supplemented by Outred (J. Phys. Chem. Ref. Data 7, 1, 1978). The following spectra were identified in Gamma Equ: C I, Si I, Ca I, Mg I, II, Cr I, Fe I, Sr II, and Ce III (1584.75nm). The Ap star spectra show broad Zeeman patterns compatible with published models and field strengths. Synthetic calculations used SYNTHE and SYNTHMAG (Piskunov N. E., 1999, in Astrophys. Space Sci. Library Vol. 243, Solar polarization. Kluwer, p 515). The γ Equ model is from Heiter et al. (2002, A&A, 392, 619). and the line list from VALD.

  20. Site-specific glycosylation of donkey milk lactoferrin investigated by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Gallina, Serafina; Saletti, Rosaria; Cunsolo, Vincenzo;

    2016-01-01

    A comprehensive monosaccharide composition of the N-glycans of donkey milk lactoferrin, isolated by ion exchange chromatography from an individual milk sample, was obtained by means of chymotryptic digestion, TiO2 and HILIC enrichment, reversed-phase high-performance liquid chromatography......, electrospray mass spectrometry, and high collision dissociation fragmentation. The results obtained allowed identifying 26 different glycan structures, including high mannose, complex and hybrid N-glycans, linked to the protein backbone via an amide bond to asparagine residues located at the positions 137, 281...

  1. A hybrid approach to urine drug testing using high-resolution mass spectrometry and select immunoassays.

    Science.gov (United States)

    McMillin, Gwendolyn A; Marin, Stephanie J; Johnson-Davis, Kamisha L; Lawlor, Bryan G; Strathmann, Frederick G

    2015-02-01

    The major objective of this research was to propose a simplified approach for the evaluation of medication adherence in chronic pain management patients, using liquid chromatography time-of-flight (TOF) mass spectrometry, performed in parallel with select homogeneous enzyme immunoassays (HEIAs). We called it a "hybrid" approach to urine drug testing. The hybrid approach was defined based on anticipated positivity rates, availability of commercial reagents for HEIAs, and assay performance, particularly analytical sensitivity and specificity for drug(s) of interest. Subsequent to implementation of the hybrid approach, time to result was compared with that observed with other urine drug testing approaches. Opioids, benzodiazepines, zolpidem, amphetamine-like stimulants, and methylphenidate metabolite were detected by TOF mass spectrometry to maximize specificity and sensitivity of these 37 drug analytes. Barbiturates, cannabinoid metabolite, carisoprodol, cocaine metabolite, ethyl glucuronide, methadone, phencyclidine, propoxyphene, and tramadol were detected by HEIAs that performed adequately and/or for which positivity rates were very low. Time to result was significantly reduced compared with the traditional approach. The hybrid approach to urine drug testing provides a simplified and analytically specific testing process that minimizes the need for secondary confirmation. Copyright© by the American Society for Clinical Pathology.

  2. Photolysis of Antibiotics under Simulated Sunlight Irradiation: Identification of Photoproducts by High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Baena-Nogueras, Rosa María; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2017-02-28

    There is growing concern regarding the widespread use of antibiotics and their presence in the aqueous environment. Their removal in the water column is mediated by different types of degradation processes for which the mechanisms are still unclear. This research is focused on characterizing the photodegradation kinetics and pathways of two largely employed antibiotics families: sulfonamides (9 SDs) and fluoroquinolones (6 FQs). Degradation percentages and rates were measured in pure water exposed to simulated natural sunlight at a constant irradiance value (500 W m(-2)) during all the experiments, and the main photoproducts formed were characterized through accurate mass measurement using ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-QToF-MS). Over 200 different phototransformation products were identified for SDs and FQs, 66% of them, to the best of our knowledge, have not been described before. Their sequential formation and disappearance over the course of the experiments reveals the existence of several pathways for the degradation of target antibiotics. Occurrence of new photoproducts derived from desulfonation and/or denitrification, as well as hydroxylation of photo-oxidized heterocyclic rings, have been identified during photodegradation of SDs, whereas a new pathway yielding oxidation of the benzene ring after the cleavage of the piperazine ring (e.g., CIP product with m/z 280) is described for FQs.

  3. High Resolution, Long - Slit Spectroscopy of VY CMa: The Evidence for Localized High Mass Loss Events

    CERN Document Server

    Humphreys, R M; Ruch, G; Wallerstein, G; Humphreys, Roberta M.; Davidson, Kris; Ruch, Gerald; Wallerstein, George

    2004-01-01

    High spatial and spectral resolution spectroscopy of the OH/IR supergiant VY CMa and its circumstellar ejecta reveals evidence for high mass loss events from localized regions on the star occurring over the past 1000 years. The reflected absorption lines and the extremely strong K I emission lines show a complex pattern of velocities in the ejecta. We show that the large, dusty NW arc, expanding at 50 km/sec with respect to the embedded star, is kinematically distinct from the surrounding nebulosity and was ejected about 400 years ago. Other large, more filamentary loops were probably expelled as much as 800 to 1000 years ago while knots and small arcs close to the star resulted from more recent events 100 to 200 years ago. The more diffuse, uniformly distributed gas and dust is surprisingly stationary with little or no velocity relative to the star. This is not what we would expect for the circumstellar material from an evolved red supergiant with a long history of mass loss. We therefore suggest that the hi...

  4. The Physical Properties of the RW Aur Bipolar Jet from HST/STIS High-Resolution Spectra

    Science.gov (United States)

    Melnikov, Stanislav; Eislöffel, Jochen; Bacciotti, Francesca; Woitas, Jens; Ray, Tom

    A well-collimated bipolar jet emanating from the classic T Tauri star RW Aur A (HH 229) has been traced out to 15″ in the redshifted [2] and over 100″ in the blueshifted lobe [3]. Long-slit spectra of the RW Aur jet were taken on 10. Dec. 2000 with the STIS spectrograph on board the HST. The spectrographslit of width 0″:1 and length 10″ was moved across the jet in seven positions from NW to SE, keeping it parallel to the jet axis. As a result, seven spectra covering the jet in both dimensions were obtained. The observations taken with the G750M grating cover the three prominent forbidden emission doublets - [O I] (λλ 6300,6363, [N II] λλ 6548,6583, and [S II] λλ 6716,6731. The current study presents a continuation of the analysis of the HST/STIS spectroscopy of the RW Aur jet started in Woitas et al. [5]. For extraction of the physical quantities we followed the well-established method described in Bacciotti and Eislöffel [1].

  5. High-Resolution Ultraviolet Spectra of the Dwarf Seyfert 1 Galaxy NGC 4395: Evidence for Intrinsic Absorption

    CERN Document Server

    Crenshaw, D M; Gabel, J R; Schmitt, H R; Filippenko, A V; Ho, L C; Shields, J C; Turner, T J

    2004-01-01

    We present ultraviolet spectra of the dwarf Seyfert 1 nucleus of NGC 4395, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope's Space Telescope Imaging Spectrograph at velocity resolutions of 7 to 15 km/sec. We confirm our earlier claim of C IV absorption in low-resolution UV spectra and detect a number of other absorption lines with lower ionization potentials. In addition to the Galactic lines, we identify two kinematic components of absorption that are likely to be intrinsic to NGC 4395. We consider possible origins of the absorption, including the interstellar medium (ISM) of NGC 4395, the narrow-line region (NLR), outflowing UV absorbers, and X-ray ``warm absorbers.'' Component 1, at a radial velocity of -770 km/sec with respect to the nucleus, is only identified in the C IV 1548.2 line. It most likely represents an outflowing UV absorber, similar to those seen in a majority of Seyfert 1 galaxies, although additional observations are needed to confirm the reali...

  6. High-resolution MALDI mass spectrometry imaging of gallotannins and monoterpene glucosides in the root of Paeonia lactiflora

    Science.gov (United States)

    Li, Bin; Bhandari, Dhaka Ram; Römpp, Andreas; Spengler, Bernhard

    2016-10-01

    High-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) at 10 μm pixel size was performed to unravel the spatio-chemical distribution of major secondary metabolites in the root of Paeonia lactiflora. The spatial distributions of two major classes of bioactive components, gallotannins and monoterpene glucosides, were investigated and visualized at the cellular level in tissue sections of P. lactiflora roots. Accordingly, other primary and secondary metabolites were imaged, including amino acids, carbohydrates, lipids and monoterpenes, indicating the capability of untargeted localization of metabolites by using high-resolution MSI platform. The employed AP-SMALDI MSI system provides significant technological advancement in the visualization of individual molecular species at the cellular level. In contrast to previous histochemical studies of tannins using unspecific staining reagents, individual gallotannin species were accurately localized and unequivocally discriminated from other phenolic components in the root tissues. High-quality ion images were obtained, providing significant clues for understanding the biosynthetic pathway of gallotannins and monoterpene glucosides and possibly helping to decipher the role of tannins in xylem cells differentiation and in the defence mechanisms of plants, as well as to investigate the interrelationship between tannins and lignins.

  7. Artificial Neural Network for Probabilistic Feature Recognition in Liquid Chromatography Coupled to High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Woldegebriel, Michael; Derks, Eduard

    2017-01-17

    In this work, a novel probabilistic untargeted feature detection algorithm for liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) using artificial neural network (ANN) is presented. The feature detection process is approached as a pattern recognition problem, and thus, ANN was utilized as an efficient feature recognition tool. Unlike most existing feature detection algorithms, with this approach, any suspected chromatographic profile (i.e., shape of a peak) can easily be incorporated by training the network, avoiding the need to perform computationally expensive regression methods with specific mathematical models. In addition, with this method, we have shown that the high-resolution raw data can be fully utilized without applying any arbitrary thresholds or data reduction, therefore improving the sensitivity of the method for compound identification purposes. Furthermore, opposed to existing deterministic (binary) approaches, this method rather estimates the probability of a feature being present/absent at a given point of interest, thus giving chance for all data points to be propagated down the data analysis pipeline, weighed with their probability. The algorithm was tested with data sets generated from spiked samples in forensic and food safety context and has shown promising results by detecting features for all compounds in a computationally reasonable time.

  8. Evaluation of Rock Mass Responses Using High Resolution Water-level Tiltmeter Arrays

    Science.gov (United States)

    Roberts, J. S.; Wang, H. F.; Fratta, D.; Stetler, L. D.; Volk, J. T.; Geox^Tm

    2010-12-01

    External forces act on the surface of the earth and produce deformation across all spatial and temporal scales. This research study focuses on the deformation evaluation of the rock-mass subjected to tidal, earthquake and surface forces. The events are monitored over horizontal distances of over 100 meters with tilt measurement arrays with a resolution of 10-8 radians. These measurements are obtained from hydrostatic leveling system (HLS) arrays that have been installed in the LaFarge mine in North Aurora, IL by Fermilab. Each sensor in the array is equipped with a water-filled reservoir beneath a capacitor. The amount of water in the reservoir is calculated as a function of the measured capacitance. Individual sensors are connected in a closed system via a water and air line. As the host rock expands and contracts sensors are raised relative to another and water is displaced. The water level in each reservoir is sent to a computer in the mine and recorded. In order to measure the tilt of the rock between two points, the difference in water levels between adjacent sensors is computed. The difference between the end sensors is also calculated to determine the larger-scale tilt of the array. The tiltmeters in LaFarge mine are supported by concrete pedestals installed on the floor of the drift. In the Homestake mine the tiltmeters are placed on similar pedestals, as well as platforms made of artificial wood decking. These platforms are fixed to the wall of the drift with a rock bolt. Time and frequency domain analyses were performed on time series ranging from hours to six months to capture relevant time scales including the response to the 2010 Chile Earthquake (hour-long scale), the stages of the moon (month scale), Fox River floods (flooding week long scales and pressure dissipation month-long scales). By monitoring tiltmeter array responses to different forces, we aim at making predictions about the material properties of rock masses.

  9. Analysis of bromotryptophan and hydroxyproline modifications by high-resolution, high-accuracy precursor ion scanning utilizing fragment ions with mass-deficient mass tags.

    Science.gov (United States)

    Steen, Hanno; Mann, Matthias

    2002-12-15

    Protein modifications are often detected by precursor ion scanning. When quadrupole TOF mass spectrometers are used for precursor ion scanning with high-resolution, high-accuracy fragment ion selection, "reporter" ions are required to have a unique mass within +/-0.04 Da or less instead of +/-0.5 Da on triple quadrupole mass spectrometers, the traditional instrument used for precursor ion scanning. Thus, characteristic fragment ions can be utilized even if other fragment ions have the same nominal mass as long as the characteristic fragment ions are slightly mass deficient as compared to the other fragments, i.e., when they have an inherent mass-deficient mass tag. Here, the immonium ions of bromotryptophan and hydroxyproline are described as two fragment ions characteristic for tryptophan-brominated and proline-hydroxylated peptides, respectively. The "reporter" ion of trytophan-brominated peptides is highly mass deficient due to the presence of bromine, thereby allowing the selective detection of these species and the distinction from other dipeptidic a-, b-, and y-fragment ions by high-resolution, high-accuracy precursor ion scanning. This strategy also enables the differentiation between precursors giving rise to the oxygen-containing immonium ion of hydroxyproline and precursors of the immonium ions of near-ubiquitous leucine/isoleucine. Both immonium ions have the same nominal mass of 86 Da, but the exact masses differ by less than 0.04 Da. High-resolution, high-accuracy precursor ion scanning enabled the identification of proline-hydroxylated and tryptophan-brominated species and the directed analysis of species carrying these modifications in a highly complex Conus textile conotoxin mixture. This lead to the characterization of one novel C. textile conotoxin containing a bromotryptophan residue and one novel C. textile conotoxin carrying two hydroxyproline residues.

  10. CRIRES-POP: a library of high resolution spectra in the near-infrared. II. Data reduction and the spectrum of the K giant 10 Leonis

    Science.gov (United States)

    Nicholls, C. P.; Lebzelter, T.; Smette, A.; Wolff, B.; Hartman, H.; Käufl, H.-U.; Przybilla, N.; Ramsay, S.; Uttenthaler, S.; Wahlgren, G. M.; Bagnulo, S.; Hussain, G. A. J.; Nieva, M.-F.; Seemann, U.; Seifahrt, A.

    2017-02-01

    Context. High resolution stellar spectral atlases are valuable resources to astronomy. They are rare in the 1-5 μm region for historical reasons, but once available, high resolution atlases in this part of the spectrum will aid the study of a wide range of astrophysical phenomena. Aims: The aim of the CRIRES-POP project is to produce a high resolution near-infrared spectral library of stars across the H-R diagram. The aim of this paper is to present the fully reduced spectrum of the K giant 10 Leo that will form the basis of the first atlas within the CRIRES-POP library, to provide a full description of the data reduction processes involved, and to provide an update on the CRIRES-POP project. Methods: All CRIRES-POP targets were observed with almost 200 different observational settings of CRIRES on the ESO Very Large Telescope, resulting in a basically complete coverage of its spectral range as accessible from the ground. We reduced the spectra of 10 Leo with the CRIRES pipeline, corrected the wavelength solution and removed telluric absorption with Molecfit, then resampled the spectra to a common wavelength scale, shifted them to rest wavelengths, flux normalised, and median combined them into one final data product. Results: We present the fully reduced, high resolution, near-infrared spectrum of 10 Leo. This is also the first complete spectrum from the CRIRES instrument. The spectrum is available online. Conclusions: The first CRIRES-POP spectrum has exceeded our quality expectations and will form the centre of a state-of-the-art stellar atlas. This first CRIRES-POP atlas will soon be available, and further atlases will follow. All CRIRES-POP data products will be freely and publicly available online. The spectrum 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/598/A79

  11. A New Theoretical Library of High-resolution Stellar Spectra for UV-Optical Population Synthesis Models

    Science.gov (United States)

    Bertone, E.; Rodriguez-Merino, L.; Chavez, M.; Buzzoni, A.

    2003-06-01

    We present a new theoretical library of stellar spectra covering the wavelength interval from 850 to 7000 Å. The library consists of two datasets, one including the far UV-blue spectral region from 850 to 4750 Å at inverse spectral resolution R = 50000, and the latter spanning the range 3500-7000 Å at R = 500000. Both sets are based on the SYNTHE series of codes developed by R.L. Kurucz. For its comprehensive range of physical parameters (i.e. T[eff], logg and [M/H]) and higher spectral resolution, this is the most advanced spectral library currently available in the literature, and could profitably be used for population synthesis models and abundance studies of single stars.

  12. Selective extraction of halogenated compounds from data measured by comprehensive multidimensional gas chromatography/high resolution time-of-flight mass spectrometry for non-target analysis of environmental and biological samples.

    Science.gov (United States)

    Hashimoto, Shunji; Zushi, Yasuyuki; Fushimi, Akihiro; Takazawa, Yoshikatsu; Tanabe, Kiyoshi; Shibata, Yasuyuki

    2013-03-22

    We developed a method that selectively extracts a subset from comprehensive 2D gas chromatography (GC×GC) and high-resolution time-of-flight mass spectrometry (HRTOFMS) data to detect and identify trace levels of organohalogens. The data were obtained by measuring several environmental and biological samples, namely fly ash, soil, sediment, the atmosphere, and human urine. For global analysis, some samples were measured without purification. By using our novel software, the mass spectra of organochlorines or organobromines were then extracted into a data subset under high mass accuracy conditions that were approximately equivalent to a mass resolution of 6000 for some samples. Mass defect filtering as pre-screening for the data extraction was very effective in removing the mass spectra of hydrocarbons. Those results showed that data obtained with HRTOFMS are valuable for global analysis of organohalogens, and probably of other compounds if specific data extraction methods can be devised.

  13. Ultrafast High-Resolution Mass Spectrometric Finger Pore Imaging in Latent Finger Prints

    Science.gov (United States)

    Elsner, Christian; Abel, Bernd

    2014-11-01

    Latent finger prints (LFPs) are deposits of sweat components in ridge and groove patterns, left after human fingers contact with a surface. Being important targets in biometry and forensic investigations they contain more information than topological patterns. With laser desorption mass spectrometry imaging (LD-MSI) we record `three-dimensional' finger prints with additional chemical information as the third dimension. Here we show the potential of fast finger pore imaging (FPI) in latent finger prints employing LD-MSI without a classical matrix in a high- spatial resolution mode. Thin films of gold rapidly sputtered on top of the sample are used for desorption. FPI employing an optical image for rapid spatial orientation and guiding of the desorption laser enables the rapid analysis of individual finger pores, and the chemical composition of their excretions. With this approach we rapidly detect metabolites, drugs, and characteristic excretions from the inside of the human organism by a minimally-invasive strategy, and distinguish them from chemicals in contact with fingers without any labeling. The fast finger pore imaging, analysis, and screening approach opens the door for a vast number of novel applications in such different fields as forensics, doping and medication control, therapy, as well as rapid profiling of individuals.

  14. Nontargeted modification-specific metabolomics study based on liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Dai, Weidong; Yin, Peiyuan; Zeng, Zhongda; Kong, Hongwei; Tong, Hongwei; Xu, Zhiliang; Lu, Xin; Lehmann, Rainer; Xu, Guowang

    2014-09-16

    Modifications of genes and proteins have been extensively studied in systems biology using comprehensive analytical strategies. Although metabolites are frequently modified, these modifications have not been studied using -omics approaches. Here a general strategy for the nontargeted profiling of modified metabolites, which we call "nontargeted modification-specific metabolomics", is reported. A key aspect of this strategy was the combination of in-source collision-induced dissociation liquid chromatography-mass spectrometry (LC-MS) and global nontargeted LC-MS-based metabolomics. Characteristic neutral loss fragments that are specific for acetylation, sulfation, glucuronidation, glucosidation, or ribose conjugation were reproducibly detected using human urine as a model specimen for method development. The practical application of this method was demonstrated by profiling urine samples from liver cirrhosis patients. Approximately 900 features were identified as modified endogenous metabolites and xenobiotics. Moreover, this strategy supports the identification of compounds not included in traditional metabolomics databases (HMDB, Metlin, and KEGG), which are currently referred to as "unknowns" in metabolomics projects. Nontargeted modification-specific metabolomics opens a new perspective in systems biology.

  15. Determination of plastic additives in packaging by liquid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Moreta, Cristina; Tena, María-Teresa

    2015-10-02

    A simple and sensitive analytical method for the determination of several plastic additives in multilayer packaging based on solid-liquid extraction (SLE) and ultra-high performance liquid chromatography (UHPLC) coupled to variable wavelength (VWD) and time of flight mass spectrometry (TOF-MS) detectors is presented. The proposed method allows the simultaneous determination of fourteen additives belonging to different families such as antioxidants, slip agents and light stabilizers, as well as two oxidation products in only 9min. The developed method was validated in terms of linearity, matrix effect error, detection and quantification limits, repeatability and intermediate precision. The instrumental method showed satisfactory repeatability and intermediate precision at concentrations closed to LOQ with RSDs less than 7 and 20%, respectively, and LODs until 5000 times more sensitive than other GC-FID and HPLC-VWD methods previously reported. Also, focused ultrasound solid-liquid extraction (FUSLE) was optimized and evaluated to extract plastic additives from packaging. Extraction results obtained by FUSLE and SLE were compared to those obtained by pressurized liquid extraction (PLE). All extraction methods showed excellent extraction efficiency for slip agents, however quantitative recovery of all analytes was achieved only by SLE with just 5ml of hexane for 10h. Finally, the selected method was applied to the analysis of packaging samples where erucamide, Irgafos 168, oxidized Irgafos 168, Irganox 1076 and Irganox 1010 were detected and quantified. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Five Micron High Resolution MALDI Mass Spectrometry Imaging with Simple, Interchangeable, Multi-Resolution Optical System

    Science.gov (United States)

    Feenstra, Adam D.; Dueñas, Maria Emilia; Lee, Young Jin

    2017-01-01

    High-spatial resolution mass spectrometry imaging (MSI) is crucial for the mapping of chemical distributions at the cellular and subcellular level. In this work, we improved our previous laser optical system for matrix-assisted laser desorption ionization (MALDI)-MSI, from 9 μm practical laser spot size to a practical laser spot size of 4 μm, thereby allowing for 5 μm resolution imaging without oversampling. This is accomplished through a combination of spatial filtering, beam expansion, and reduction of the final focal length. Most importantly, the new laser optics system allows for simple modification of the spot size solely through the interchanging of the beam expander component. Using 10×, 5×, and no beam expander, we could routinely change between 4, 7, and 45 μm laser spot size, in less than 5 min. We applied this multi-resolution MALDI-MSI system to a single maize root tissue section with three different spatial resolutions of 5, 10, and 50 μm and compared the differences in imaging quality and signal sensitivity. We also demonstrated the difference in depth of focus between the optical systems with 10× and 5× beam expanders.

  17. Exploring the Behaviour of Emerging Contaminants in the Water Cycle using the Capabilities of High Resolution Mass Spectrometry.

    Science.gov (United States)

    Hollender, Juliane; Bourgin, Marc; Fenner, Kathrin B; Longrée, Philipp; Mcardell, Christa S; Moschet, Christoph; Ruff, Matthias; Schymanski, Emma L; Singer, Heinz P

    2014-11-01

    To characterize a broad range of organic contaminants and their transformation products (TPs) as well as their loads, input pathways and fate in the water cycle, the Department of Environmental Chemistry (Uchem) at Eawag applies and develops high-performance liquid chromatography (LC) methods combined with high-resolution tandem mass spectrometry (HRMS/MS). In this article, the background and state-of-the-art of LC-HRMS/MS for detection of i) known targets, ii) suspected compounds like TPs, and iii) unknown emerging compounds are introduced briefly. Examples for each approach are taken from recent research projects conducted within the department. These include the detection of trace organic contaminants and their TPs in wastewater, pesticides and their TPs in surface water, identification of new TPs in laboratory degradation studies and ozonation experiments and finally the screening for unknown compounds in the catchment of the river Rhine.

  18. Liquid chromatography-high-resolution mass spectrometry for pesticide residue analysis in fruit and vegetables: screening and quantitative studies.

    Science.gov (United States)

    Gómez-Ramos, M M; Ferrer, C; Malato, O; Agüera, A; Fernández-Alba, A R

    2013-04-26

    This work reviews the current state-of-the-art of liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) techniques applied to the analysis of pesticides in fruit-based and vegetable-based matrices. Nowadays, simultaneous trace analysis of hundreds of pesticides from different classes is required, preferably in just one run. The most commonly used QqQ-MS technology presents certain limitations in its application in a cost and effective way when analyzing a large number of pesticides. Thus, this review includes HRMS technology as a reliable complementary alternative allowing the analysis of a wide range of pesticides in food. Its capabilities and limitations in identifying, confirming and quantifying pesticides are discussed. HRMS instruments can adequately address such issues; however, the main drawbacks are as a result of insufficient prior optimization of the operational parameters during non-target analysis in full-scan mode and due to software shortcomings.

  19. Atmospheric-pressure chemical ionization tandem mass spectrometry (APGC/MS/MS) an alternative to high-resolution mass spectrometry (HRGC/HRMS) for the determination of dioxins.

    Science.gov (United States)

    van Bavel, Bert; Geng, Dawei; Cherta, Laura; Nácher-Mestre, Jaime; Portolés, Tania; Ábalos, Manuela; Sauló, Jordi; Abad, Esteban; Dunstan, Jody; Jones, Rhys; Kotz, Alexander; Winterhalter, Helmut; Malisch, Rainer; Traag, Wim; Hagberg, Jessika; Ericson Jogsten, Ingrid; Beltran, Joaquim; Hernández, Félix

    2015-09-01

    The use of a new atmospheric-pressure chemical ionization source for gas chromatography (APGC) coupled with a tandem quadrupole mass spectrometry (MS/MS) system, as an alternative to high-resolution mass spectrometry (HRMS), for the determination of PCDDs/PCDFs is described. The potential of using atmospheric-pressure chemical ionization (APCI) coupled to a tandem quadrupole analyzer has been validated for the identification and quantification of dioxins and furans in different complex matrices. The main advantage of using the APCI source is the soft ionization at atmospheric pressure, which results in very limited fragmentation. APCI mass spectra are dominated by the molecular ion cluster, in contrast with the high energy ionization process under electron ionization (EI). The use of the molecular ion as the precursor ion in MS/MS enhances selectivity and, consequently, sensitivity by increasing the signal-to-noise ratios (S/N). For standard solutions of 2,3,7,8-TCDD, injections of 10 fg in the splitless mode on 30- or 60-m-length, 0.25 mm inner diameter (id), and 25 μm film thickness low-polarity capillary columns (DB5MS type), signal-to-noise (S/N) ratios of >10:1 were routinely obtained. Linearity was achieved in the region (correlation coefficient of r(2) > 0.998) for calibration curves ranging from 100 fg/μL to 1000 pg/μL. The results from a wide variety of complex samples, including certified and standard reference materials and samples from several QA/QC studies, which were previously analyzed by EI HRGC/HRMS, were compared with the results from the APGC/MS/MS system. Results between instruments showed good agreement both in individual congeners and toxic equivalence factors (TEQs). The data show that the use of APGC in combination with MS/MS for the analysis of dioxins has the same potential, in terms of sensitivity and selectivity, as the traditional HRMS instrumentation used for this analysis. However, the APCI/MS/MS system, as a benchtop system, is

  20. Identification of codon-specific serine to asparagine mistranslation in recombinant monoclonal antibodies by high-resolution mass spectrometry.

    Science.gov (United States)

    Yu, X Christopher; Borisov, Oleg V; Alvarez, Melissa; Michels, David A; Wang, Yajun Jennifer; Ling, Victor

    2009-11-15

    Translation errors in protein biosynthesis may result in low level amino acid misincorporation and contribute to product heterogeneity of recombinant protein therapeutics. We report the use of peptide map analysis by reversed-phase high-performance liquid chromatography and high-resolution mass spectrometry to detect and identify mistranslation events in recombinant monoclonal antibodies expressed in mammalian cell lines including Chinese hamster ovary (CHO) cells. Misincorporation of an asparagine residue at multiple serine positions was detected as earlier-eluting peptides with masses 27.01 Da higher than expected. The exact positions at which misincorporation occurred were identified by tandem mass spectrometry of the asparagine-containing variant peptides. The identified asparagine misincorporation sites correlated with the use of codon AGC but with none of the other five serine codons. The relative levels of misincorporation ranged from 0.01%-0.2% among multiple serine positions detected across three different antibodies by targeted analysis of expected and variant peptides. The low levels of misincorporation are consistent with published predictions for in vivo translation error rates. Our results demonstrate that state-of-the-art mass spectrometry with a combination of high sensitivity, accuracy, and dynamic range provides a new ability to discover and characterize low level protein variants that arise from mistranslation events.

  1. Dereplication of known nucleobase and nucleoside compounds in natural product extracts by capillary electrophoresis-high resolution mass spectrometry.

    Science.gov (United States)

    Chen, Junhui; Shi, Qian; Wang, Yanlong; Li, Zhaoyong; Wang, Shuai

    2015-03-26

    Nucleobase and nucleoside compounds exist widely in various organisms. An often occurring problem in the discovery of new bioactive compounds from natural products is reisolation of known nucleobase and nucleoside compounds. To resolve this problem, a capillary electrophoresis-high resolution mass spectrometry (CE-HR-MS) method providing both rapid separation and accurate mass full-scan MS data was developed for the first time to screen and dereplicate known nucleobase and nucleoside compounds in crude extracts of natural products. Instrumental parameters were optimized to obtain optimum conditions for CE separation and electrospray ionization-time-of-flight mass spectrometry (ESI-TOF/MS) detection. The proposed method was verified to be precise, reproducible, and sensitive. Using this method, known nucleobase and nucleoside compounds in different marine medicinal organisms including Syngnathus acus Linnaeus; Hippocampus japonicus Kaup and Anthopleura lanthogrammica Berkly were successfully observed and identified. This work demonstrates that CE-HR-MS combined with an accurate mass database may be used as a powerful tool for dereplicating known nucleobase and nucleoside compounds in different types of natural products. Rapid dereplication of known nucleobase and nucleoside compounds allows researchers to focus on other leads with greater potential to yield new substances.

  2. Dereplication of Known Nucleobase and Nucleoside Compounds in Natural Product Extracts by Capillary Electrophoresis-High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Junhui Chen

    2015-03-01

    Full Text Available Nucleobase and nucleoside compounds exist widely in various organisms. An often occurring problem in the discovery of new bioactive compounds from natural products is reisolation of known nucleobase and nucleoside compounds. To resolve this problem, a capillary electrophoresis-high resolution mass spectrometry (CE-HR-MS method providing both rapid separation and accurate mass full-scan MS data was developed for the first time to screen and dereplicate known nucleobase and nucleoside compounds in crude extracts of natural products. Instrumental parameters were optimized to obtain optimum conditions for CE separation and electrospray ionization-time-of-flight mass spectrometry (ESI-TOF/MS detection. The proposed method was verified to be precise, reproducible, and sensitive. Using this method, known nucleobase and nucleoside compounds in different marine medicinal organisms including Syngnathus acus Linnaeus; Hippocampus japonicus Kaup and Anthopleura lanthogrammica Berkly were successfully observed and identified. This work demonstrates that CE-HR-MS combined with an accurate mass database may be used as a powerful tool for dereplicating known nucleobase and nucleoside compounds in different types of natural products. Rapid dereplication of known nucleobase and nucleoside compounds allows researchers to focus on other leads with greater potential to yield new substances.

  3. The weakly bound He-HCCCN complex: High-resolution microwave spectra and intermolecular potential-energy surface

    Science.gov (United States)

    Topic, Wendy C.; Jäger, Wolfgang

    2005-08-01

    Rotational spectra of the weakly bound He-HCCCN and He-DCCCN van der Waals complexes were observed using a pulsed-nozzle Fourier-transform microwave spectrometer in the 7-26-GHz frequency region. Nuclear quadrupole hyperfine structures due to the N14 and D nuclei (both with nuclear-spin quantum number I =1) were resolved and assigned. Both strong a and weaker b-type transitions were observed and the assigned transitions were used to fit the parameters of a distortable asymmetric rotor model. The dimers are floppy, near T-shaped complexes. Three intermolecular potential-energy surfaces were calculated using the coupled-cluster method with single and double excitations and noniterative inclusion of triple excitations. Bound-state rotational energy levels supported by these surfaces were determined. The quality of the potential-energy surfaces was assessed by comparing the experimental and calculated transition frequencies and also the corresponding spectroscopic parameters. Simple scaling of the surfaces improved both the transition frequencies and spectroscopic constants. Five other recently reported surfaces [O. Akin-Ojo, R. Bukowski, and K. Szalewicz, J. Chem. Phys. 119, 8379 (2003)], calculated using a variety of methods, and their agreement with spectroscopic properties of He-HCCCN are discussed.

  4. Chemical composition, sources, and processes of urban aerosols during summertime in northwest China: insights from high-resolution aerosol mass spectrometry

    Science.gov (United States)

    Xu, J.; Zhang, Q.; Chen, M.; Ge, X.; Ren, J.; Qin, D.

    2014-12-01

    An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed along with a scanning mobility particle sizer (SMPS) and a multi-angle absorption photometer (MAAP) to measure the temporal variations of the mass loading, chemical composition, and size distribution of submicron particulate matter (PM1) in Lanzhou, northwest China, during 11 July-7 August 2012. The average (PM1 mass concentration including non-refractory (PM1 (NR-(PM1) measured by HR-ToF-AMS and black carbon (BC) measured by MAAP during this study was 24.5 μg m-3 (ranging from 0.86 to 105 μg m-3), with a mean composition consisting of 47% organics, 16% sulfate, 12% BC, 11% ammonium, 10% nitrate, and 4% chloride. Organic aerosol (OA) on average consisted of 70% carbon, 21% oxygen, 8% hydrogen, and 1% nitrogen, with the average oxygen-to-carbon ratio (O / C) of 0.33 and organic mass-to-carbon ratio (OM / OC) of 1.58. Positive matrix factorization (PMF) of the high-resolution organic mass spectra identified four distinct factors which represent, respectively, two primary OA (POA) emission sources (traffic and food cooking) and two secondary OA (SOA) types - a fresher, semi-volatile oxygenated OA (SV-OOA) and a more aged, low-volatility oxygenated OA (LV-OOA). Traffic-related hydrocarbon-like OA (HOA) and BC displayed distinct diurnal patterns, both with peak at ~ 07:00-11:00 (BJT: UTC +8), corresponding to the morning rush hours, while cooking-emission related OA (COA) peaked during three meal periods. The diurnal profiles of sulfate and LV-OOA displayed a broad peak between ~ 07:00 and 15:00, while those of nitrate, ammonium, and SV-OOA showed a narrower peak between ~ 08:00-13:00. The later morning and early afternoon maximum in the diurnal profiles of secondary aerosol species was likely caused by downward mixing of pollutants aloft, which were likely produced in the residual layer decoupled from the boundary layer during nighttime. The mass spectrum of SV-OOA was

  5. A Sounding Rocket Mission Concept to Acquire High-Resolution Radiometric Spectra Spanning the 9 nm - 31 nm Wavelength Range

    Science.gov (United States)

    Krause, L. Habash; Cirtain, Jonathan; McGuirck, Michael; Pavelitz, Steven; Weber, Ed.; Winebarger, Amy

    2012-01-01

    When studying Solar Extreme Ultraviolet (EUV) emissions, both single-wavelength, two- dimensional (2D) spectroheliograms and multi-wavelength, one-dimensional (1D) line spectra are important, especially for a thorough understanding of the complex processes in the solar magnetized plasma from the base of the chromosphere through the corona. 2D image data are required for a detailed study of spatial structures, whereas radiometric (i.e., spectral) data provide information on relevant atomic excitation/ionization state densities (and thus temperature). Using both imaging and radiometric techniques, several satellite missions presently study solar dynamics in the EUV, including the Solar Dynamics Observatory (SDO), Hinode, and the Solar-Terrestrial Relations Observatory (STEREO). The EUV wavelengths of interest typically span 9 nm to 31 nm, with the shorter wavelengths being associated with the hottest features (e.g., intense flares and bright points) and the longer wavelengths associated with cooler features (e.g., coronal holes and filaments). Because the optical components of satellite instruments degrade over time, it is not uncommon to conduct sounding rocket underflights for calibration purposes. The authors have designed a radiometric sounding rocket payload that could serve as both a calibration underflight for and a complementary scientific mission to the upcoming Solar Ultraviolet Imager (SUVI) mission aboard the GOES-R satellite (scheduled for a 2015 launch). The challenge to provide quality radiometric line spectra over the 9-31 nm range covered by SUVI was driven by the multilayer coatings required to make the optical components, including mirrors and gratings, reflective over the entire range. Typically, these multilayers provide useful EUV reflectances over bandwidths of a few nm. Our solution to this problem was to employ a three-telescope system in which the optical components were coated with multilayers that spanned three wavelength ranges to cover

  6. High resolution CCD spectra of stars in globular clusters. Part 2: Metals and CNO in M71

    Science.gov (United States)

    Leep, E. M.; Oke, J. B.; Wallerstein, G.

    1986-01-01

    Palomar coude CCD spectra of resolution 0.3 and 0.6 has been used to redetermine abundances in five stars of the relatively metal rich globular cluster M71. The (Fe/H) value is restricted to the limits of -0.6 to -1.0. The largest source of uncertainty is a systematic difference in f-values between those derived via the Holweger-Muller (1974) solar model and the Bell et al. (1976) solar model. If we use absolute f-values measured by the Oxford group (Blackwell et al. 1982) we find Fe/H to lie in the range of -0.6 to -0.75, i.e., as given by using the Bell et al. solar model. The relative abundances of the light elements, i.e., Na through Ca and probably including Ti show an average excess relative to iron of 0.4 dex. The effect of this difference on metal indices derived from broad- and narrow- band photometry is discussed. For three stars we find O/H = -0.6 using absolute f-values. For CN an analysis of individual rotational lines of the 2-0 band of the red system yields lines in the (C/H,N/H) plane that are consistent with either an original C/Fe = N/Fe = 0 or a modest increase in N relative to C due to CN burning and mixing. A search for C-13N was not successful and an uncertain lower limit of C-12/C-13 near 10 was obtained.

  7. High-resolution CCD spectra of stars in globular clusters. II - Metals and CNO in M71

    Science.gov (United States)

    Leep, E. Myckky; Wallerstein, George; Oke, J. B.

    1987-01-01

    Palomar coude CCD spectra of resolution 0.3 and 0.6 has been used to redetermine abundances in five stars of the relatively metal rich globular cluster M71. The (Fe/H) value is restricted to the limits of -0.6 to -1.0. The largest source of uncertainty is a systematic difference in f-values between those derived via the Holweger-Muller (1974) solar model and the Bell et al. (1976) solar model. If we use absolute f-values measured by the Oxford group (Blackwell et al. 1982) we find Fe/H to lie in the range of -0.6 to -0.75, i.e., as given by using the Bell et al. solar model. The relative abundances of the light elements, i.e., Na through Ca and probably including Ti show an average excess relative to iron of 0.4-dex. The effect of this difference on metal indices derived from broad- and narrow- band photometry is discussed. For three stars we find O/H = -0.6 using absolute f-values. For CN an analysis of individual rotational lines of the 2-0 band of the red system yields lines in the (C/H, N/H) plane that are consistent with either an original C/Fe = N/Fe = 0 or a modest increase in N relative to C due to CN burning and mixing. A search for C-13N was not successful and an uncertain lower limit of C-12/C-13 near 10 was obtained.

  8. A software application for comparing large numbers of high resolution MALDI-FTICR MS spectra demonstrated by searching candidate biomarkers for glioma blood vessel formation

    NARCIS (Netherlands)

    M.K. Titulaer (Mark); D.A.M. Mustafa (Dana); I. Siccama (Ivar); M. Konijnenburg (Marco); P.C. Burgers (Peter); A.C. Andeweg (Arno); P.A. Smitt (Peter); J.M. Kros (Johan); T.M. Luider (Theo)

    2008-01-01

    textabstractBackground: A Java™ application is presented, which compares large numbers (n > 100) of raw FTICR mass spectra from patients and controls. Two peptide profile matrices can be produced simultaneously, one with occurrences of peptide masses in samples and another with the intensity of comm

  9. 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.

  10. Structural characterization of reaction products of caftaric acid and bisulfite present in a commercial wine using high resolution mass spectrometric and nuclear magnetic resonance techniques.

    Science.gov (United States)

    Hayasaka, Yoji; Black, Cory A; Hack, Jeremy; Smith, Paul

    2017-09-01

    Reaction products of bisulfite and caftaric acid were found in wines containing sulfites as a preservative. Acidic compounds were separated from wine and analyzed by HPLC combined with DAD and QTOF mass spectrometer. HPLC chromatograms of the expected [M-H](-) ion and UV absorption revealed the presence of five possible reaction products (a-e). These compounds were isolated then characterized by NMR and confirmed to be the reaction products as follows; 5-sulfo-(E)-caftaric acid (a), 2-sulfo-(Z)-caftaric acid (b), 2-sulfo-(E)-caftaric acid (c), (E)-caftaric acid-4-O-sulfate (d) and (E)-caftaric acid-3-O-sulfate (e). UV spectra and high resolution product ion spectra of the five compounds also supported their identity. The reaction products were confirmed to be commonly present in commercial wines across four vintages and two varieties. Their concentration was found to be as much as that of 2-S-glutathionyl caftaric acid, suggesting that bisulfite consistently competes as a nucleophile with glutathione for the o-quinone of caftaric acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Clustering, methodology, and mechanistic insights into acetate chemical ionization using high-resolution time-of-flight mass spectrometry

    Science.gov (United States)

    Brophy, Patrick; Farmer, Delphine K.

    2016-08-01

    We present a comprehensive characterization of cluster control and transmission through the Tofwerk atmospheric pressure interface installed on various chemical ionization time-of-flight mass spectrometers using authentic standards. This characterization of the atmospheric pressure interface allows for a detailed investigation of the acetate chemical ionization mechanisms and the impact of controlling these mechanisms on sensitivity, selectivity, and mass spectral ambiguity with the aim of non-targeted analysis. Chemical ionization with acetate reagent ions is controlled by a distribution of reagent ion-neutral clusters that vary with relative humidity and the concentration of the acetic anhydride precursor. Deprotonated carboxylic acids are primarily detected only if sufficient declustering is employed inside the atmospheric pressure interface. The configuration of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-TOF-CIMS) using an acetate chemical ionization source for non-targeted analysis is discussed. Recent approaches and studies characterizing acetate chemical ionization as it applies to the HR-TOF-CIMS are evaluated in light of the work presented herein.

  12. Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zachariasova, M.; Lacina, O.; Malachova, A.; Kostelanska, M.; Poustka, J. [Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Godula, M. [Thermo Fisher Scientific, Czech Republic, Slunecna 27, 100 00 Prague 10 (Czech Republic); Hajslova, J., E-mail: jana.hajslova@vscht.cz [Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)

    2010-03-03

    Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. {sup 13}C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.

  13. Rapid in situ identification of bioactive compounds in plants by in vivo nanospray high-resolution mass spectrometry.

    Science.gov (United States)

    Chang, Qing; Peng, Yue'e; Dan, Conghui; Shuai, Qin; Hu, Shenghong

    2015-03-25

    A method for the rapid in situ identification of bioactive compounds in fresh plants has been developed using in vivo nanospray coupled to high-resolution mass spectrometry (HR-MS). Using a homemade in vivo nanospray ion source, the plant liquid was drawn out from a target region and ionized in situ. The ionized bioactive compounds were then identified using Q-Orbitrap HR-MS. The accurate mass measurements of these bioactive compounds were performed by full-scan or selected ion monitoring (SIM), and tandem mass spectrometry (MS/MS) was used in the structural elucidation. Without sample pretreatment, 12 bioactive compounds in 7 different plant species were identified, namely, isoalliin in onion; butylphthalide in celery; N-methylpelletierine, pelletierine, and pseudopelletierine in pomegranate; chlorogenic acid in crabapple; solamargine, solasonine, and solasodine in nightshade; aloin and aloe-emodin in aloe; and menthone in mint. This work demonstrates that in vivo nanospray HR-MS is a good method for rapid in situ identification of bioactive compounds in plants.

  14. Analysis of the Fusarium mycotoxin moniliformin in cereal samples using 13C2-moniliformin and high-resolution mass spectrometry.

    Science.gov (United States)

    von Bargen, Katharina Walburga; Lohrey, Lilia; Cramer, Benedikt; Humpf, Hans-Ulrich

    2012-04-11

    Moniliformin is a mycotoxin produced by fungi of the Fusarium genus and occurs as a contaminant of different cereals worldwide. This study describes the first application of isotopically labeled (13)C(2)-moniliformin for the analysis of moniliformin in cereals. Moniliformin is a small and ionic molecule that forms only a single sensitive fragment ion in the collision cell of a tandem mass spectrometer. Therefore, the methods described in the literature for this kind of instrument observe only a single mass transition and show a relatively poor sensitivity. The use of high-resolution mass spectrometry was described to be a suitable alternative technique for the detection of this compound and was therefore applied in this study. The developed method is based on the use of strong anion exchange columns for cleanup prior to HPLC analysis and has a recovery rate of 75.3%, a limit of detection (LOD) of 0.7 μg/kg, and a limit of quantitation (LOQ) of 2.5 μg/kg. Twenty-three different cereal samples were analyzed for their moniliformin content. Twenty of them showed positive results with levels up to 126 ± 12.2 μg/kg.

  15. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-09-01

    Full Text Available As part of Campaigns of Air Quality Research in Beijing and Surrounding Region-2008 (CAREBeijing-2008, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralympic Games (24 July to 20 September 2008. The campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m−3; the mean composition consisted of organics (37.9%, sulfate (26.7%, ammonium (15.9%, nitrate (15.8%, black carbon (3.1%, and chloride (0.87%. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA, cooking-related (COA, and two oxygenated organic aerosols (OOA-1 and OOA-2, which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum and diurnal pattern showed similar characteristics to that measured for cooking emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. Aerosol particles in southern airmasses were especially rich in inorganic and oxidized organic species. Aerosol particles in northern airmasses

  16. Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    X.-F. Huang

    2010-05-01

    Full Text Available As part of Campaigns of Air Quality Research in Beijing and Surrounding Region–2008 (CAREBeijing-2008, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralytic Games (24 July to 20 September 2008. The campaign mean PM1 mass concentration was 63.1±39.8 μg m−3; the mean composition consisted of organics (37.9%, sulfate (26.7%, ammonium (15.9%, nitrate (15.8%, black carbon (3.1%, and chloride (0.87%. The average size distributions of the species (except BC were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA, cooking-related (COA, and two oxygenated organic aerosols (OOA-1 and OOA-2, which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum showed high similarity to that measured from cooking aerosol emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. This result is similar to observations made in the summer of 2006, although the average PM1 concentration level for the southerly air flows is 31% lower than

  17. Size-resolved aerosol chemistry on Whistler Mountain, Canada with a High-Resolution Aerosol Mass Spectrometer during INTEX-B

    Directory of Open Access Journals (Sweden)

    Y. Sun

    2008-12-01

    Full Text Available An Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed at the peak of Whistler Mountain (elevation 2182 m-MSL, British Columbia, from 19 April to 16 May 2006, as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B campaign. The mass concentrations and size distributions of non-refractory submicron particle (NR-PM1 species (i.e., sulfate, nitrate, ammonium, chloride, and organics were measured in situ every 5 min. The HR-ToF-AMS results agreed well with collocated measurements. The average concentration of non-refractory submicron particulate matter (NR-PM1; 1.9 μg m−3 is similar to those observed at other remote, high elevation sites in North America. Episodes of enhanced aerosol loadings were observed, due to influences of regional and trans-Pacific transport of air pollution. Organics and sulfate were the dominant species, on average accounting for 55% and 30%, respectively, of the NR-PM1 mass. The average size distributions of sulfate and ammonium both showed a~large accumulation mode peaking around 500–600 nm in Dva while those of organic aerosol (OA and nitrate peaked at ~300 nm. The size differences suggest that sulfate and OA were mostly present in external mixtures from different source origins. We also quantitatively determined the elemental composition of OA using the high resolution mass spectra. Overall, OA at Whistler Peak was highly oxygenated, with an average organic-mass-to-organic-carbon ratio (OM/OC of 2.28±0.23 and an atomic ratio of oxygen-to-carbon (O/C of 0.83±0.17. The nominal formula for OA was C1H1.66N0.03O0.83 for the entire study. Two significant trans-Pacific dust events originated from Asia were observed at Whistler Peak during this study. While both events were characterized with significant enhancements of coarse mode particles and mineral

  18. High Resolution Mass Spectrometry of Seasonal Aerosol Samples From an Urban Location in the Italian Po Valley

    Science.gov (United States)

    Mahon, Brendan; Giorio, Chiara; Gallimore, Peter J.; Zielinski, Arthur T.; Tapparo, Andrea; Kalberer, Markus

    2016-04-01

    The Po Valley in Northern Italy represents one of the most polluted environments in Europe, with PM2.5 and ozone concentrations regularly exceeding 100μg/m3 and 50ppb respectively. Particularly during winter, prolonged inversion conditions together with biomass burning and anthropogenic emissions regularly lead to severe air pollution events. Over the course of several months in 2013-14, we carried out a sampling program at a city-centre site in Padova, Italy, collecting 24-hour high-volume aerosol filter samples, 18 in winter (mid December - mid March) and 20 in summer (late May - late July). Utilising high-resolution Orbitrap mass spectrometry techniques, we have characterised these sample sets to examine the long-term variation in aerosol composition over the sampling campaign and to determine the effect of anthropogenic gaseous pollutants such as NOx and SO2 on the composition of organic particle components. The results showed that between ca. 450-700 ions were measured in each sample in both the summer and winter sample sets, however the majority (90%) of ions in the winter samples were below 300m/z and below 380m/z in the summer samples. A much higher percentage of CHO-only ions were found in winter (ca. 27%) compared to the summer samples (ca. 6%), indicating a higher degree of photochemical reactions taking place involving pollutants such as NOx and SO2 in summer. Our results represent the first long term data set of high-resolution measurements of aerosol composition and demonstrate that this technique is an important tool in evaluating the composition of aerosol particles in complex polluted urban areas.

  19. Screening for exogenous androgen anabolic steroids in human hair by liquid chromatography/orbitrap-high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Strano-Rossi, Sabina, E-mail: sabina.stranorossi@rm.unicatt.it [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Castrignanò, Erika; Anzillotti, Luca; Odoardi, Sara; De-Giorgio, Fabio [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy); Bermejo, Ana [Institute of Legal Medicine, University of Santiago de Compostela, Av S. Francisco s/n, Santiago de Compostela (Spain); Pascali, Vincenzo L. [Institute of Legal Medicine, Catholic University of Sacred Heart, L.go F. Vito, 1, 00168 Rome (Italy)

    2013-09-02

    Graphical abstract: -- Highlights: •LC–HRMS screening method for the detection of a variety of anabolics in hair. •Detection of unmetabolized anabolic steroids and their esters in hair matrix by simple keratin pretreatment. •Identification of target compounds by retention time, accurate mass and isotopic cluster. •Quantitative determination of detected compounds. •Possibility to a retrospective re-analysis of the acquired datafile in case a further analyte is to be screened. -- Abstract: A method for the screening of various anabolic steroids and their esters in human hair, based on liquid-chromatography–high resolution mass spectrometry using an Exactive benchtop Orbitrap mass spectrometer, has been set up and validated. This method involved methanolic incubation of 30 mg of hair and analysis of the relevant extract in HPLC using a C18 column. The mass detector, with nominal resolving power of 100,000, operated in full scan mode in APCI under positive ionization mode. Analytes were identified by exact mass, correspondence of isotopic cluster and retention times. The limits of detection obtained varied from 10 to 50 pg mg{sup −1}, and limits of quantitation were 0.5 ng mg{sup −1} for all compounds. The method was linear for all analytes in the ranges from the LOQ to 6 ng mg{sup −1}, giving correlation coefficients >0.99 for all analytes. Also accuracy (intended as %E) and repeatability (%CV) were always lower than 15%. Specificity was assessed by analysing ten blank samples and fifteen samples from polidrug abusers. This method was applied to a real-life case, resulting in the identification of testosterone undecanoate in the hair of a suspect. The analyte identity was confirmed by the analysis of its in-source fragmentation and comparison to a certified standard. Thanks to the scan acquisition, this method also enables retrospective re-analysis of the acquired datafile in case a further analyte needs to be screened.

  20. A two stage algorithm for target and suspect analysis of produced water via gas chromatography coupled with high resolution time of flight mass spectrometry.

    Science.gov (United States)

    Samanipour, Saer; Langford, Katherine; Reid, Malcolm J; Thomas, Kevin V

    2016-09-09

    Gas chromatography coupled with high resolution time of flight mass spectrometry (GC-HR-TOFMS) has gained popularity for the target and suspect analysis of complex samples. However, confident detection of target/suspect analytes in complex samples, such as produced water, remains a challenging task. Here we report on the development and validation of a two stage algorithm for the confident target and suspect analysis of produced water extracts. We performed both target and suspect analysis for 48 standards, which were a mixture of 28 aliphatic hydrocarbons and 20 alkylated phenols, in 3 produced water extracts. The two stage algorithm produces a chemical standard database of spectra, in the first stage, which is used for target and suspect analysis during the second stage. The first stage is carried out through five steps via an algorithm here referred to as unique ion extractor (UIE). During the first step the m/z values in the spectrum of a standard that do not belong to that standard are removed in order to produce a clean spectrum and then during the last step the cleaned spectrum is calibrated. The Dot-product algorithm, during the second stage, uses the cleaned and calibrated spectra of the standards for both target and suspect analysis. We performed the target analysis of 48 standards in all 3 samples via conventional methods, in order to validate the two stage algorithm. The two stage algorithm was demonstrated to be more robust, reliable, and less sensitive to the signal-to-noise ratio (S/N), when compared to the conventional method. The Dot-product algorithm showed lower potential in producing false positives compared to the conventional methods, when dealing with complex samples. We also evaluated the effect of the mass accuracy on the performances of Dot-product algorithm. Our results indicated the crucial importance of HR-MS data and the mass accuracy for confident suspect analysis in complex samples.

  1. Quantification of Trace Amounts of Impurities in High Purity Cobalt by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    Hua Lin XIE; Xi Du NIE; You Gen TANG

    2006-01-01

    An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to thc presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%- 111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.

  2. Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; HUANG Kelong; NIE Xidu; TANG Yougen

    2007-01-01

    An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn,Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects because of the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 μg.g-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.

  3. Optimized ultra performance liquid chromatography tandem high resolution mass spectrometry method for the quantification of paraquat in plasma and urine.

    Science.gov (United States)

    Lu, Haihua; Yu, Jing; Wu, Linlin; Xing, Jingjing; Wang, Jun; Huang, Peipei; Zhang, Jinsong; Xiao, Hang; Gao, Rong

    2016-08-01

    A simple, sensitive and specific ultra performance liquid chromatography coupled to electrospray tandem high resolution mass spectrometry (UPLC-ESI-HRMS/MS) method has been developed and validated for quantification of paraquat in plasma and urine. The sample preparation was carried out by one-step protein precipitation with acetonitrile. The paraquat was separated with a HILIC column in 10min. Detection was performed using Q Exactive Orbitrap mass spectrometer by Targeted-MS/MS scan mode. Methodological parameters, such as ammonium formate concentration, formic acid concentration, spray voltage, capillary temperature, heater temperature and normalized collision energy were optimized to achieve the highest sensitivity. The calibration curve was linear over the concentration range of LOQ-1000ng/mL. LOD was 0.1 and 0.3ng/mL, LOQ was 0.3 and 0.8ng/mL for urine and plasma, respectively. The intra- and inter-day precisions were paraquat concentration in plasma samples with hemoperfusion from 5 suspected paraquat poisoning patients.

  4. Oligomers, organosulfates, and nitrooxy organosulfates in rainwater identified by ultra-high resolution electrospray ionization FT-ICR mass spectrometry

    Science.gov (United States)

    Altieri, K. E.; Turpin, B. J.; Seitzinger, S. P.

    2009-04-01

    Wet deposition is an important removal mechanism for atmospheric organic matter, and a potentially important input for receiving ecosystems, yet less than 50% of rainwater organic matter is considered chemically characterized. Precipitation samples collected in New Jersey, USA, were analyzed by negative ion ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Elemental compositions of 552 unique molecular species were determined in the mass range 50-500 Da in the rainwater. Four main groups of organic compounds were identified: compounds containing carbon, hydrogen, and oxygen (CHO) only, sulfur (S) containing CHOS compounds, nitrogen (N) containing CHON compounds, and S- and N- containing CHONS compounds. Organic acids commonly identified in precipitation were detected in the rainwater. Within the four main groups of compounds detected in the rainwater, oligomers, organosulfates, and nitrooxy-organosulfates were assigned based on elemental formula comparisons. The majority of the compounds identified are products of atmospheric reactions and are known contributors to secondary organic aerosol (SOA) formed from gas phase, aerosol phase, and in-cloud reactions in the atmosphere. It is suggested that the large uncharacterized component of SOA is the main contributor to the large uncharacterized component of rainwater organic matter.

  5. Investigation of pharmaceuticals in processed animal by-products by liquid chromatography coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    Nácher-Mestre, Jaime; Ibáñez, María; Serrano, Roque; Boix, Clara; Bijlsma, Lubertus; Lunestad, Bjørn Tore; Hannisdal, Rita; Alm, Martin; Hernández, Félix; Berntssen, Marc H G

    2016-07-01

    There is an on-going trend for developing more sustainable salmon feed in which traditionally applied marine feed ingredients are replaced with alternatives. Processed animal products (PAPs) have been re-authorized as novel high quality protein ingredients in 2013. These PAPs may harbor undesirable substances such as pharmaceuticals and metabolites which are not previously associated with salmon farming, but might cause a potential risk for feed and food safety. To control these contaminants, an analytical strategy based on a generic extraction followed by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS) using quadrupole time-of-flight mass analyzer (QTOF MS) was applied for wide scope screening. Quality control samples, consisting of PAP commodities spiked at 0.02, 0.1 and 0.2 mg/kg with 150 analytes, were injected in every sample batch to verify the overall method performance. The methodology was applied to 19 commercially available PAP samples from six different types of matrices from the EU animal rendering industry. This strategy allows assessing possible emergent risk exposition of the salmon farming industry to 1005 undesirables, including pharmaceuticals, several dyes and relevant metabolites.

  6. Retrospective screening of pesticide metabolites in ambient air using liquid chromatography coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    López, Antonio; Yusà, Vicent; Millet, Maurice; Coscollà, Clara

    2016-04-01

    A new methodology for the retrospective screening of pesticide metabolites in ambient air was developed, using liquid chromatography coupled to Orbitrap high-resolution mass spectrometry (UHPLC-HRMS), including two systematic workflows (i) post-run target screening (suspect screening) and (ii) non-target screening. An accurate-mass database was built and used for the post-run screening analysis. The database contained 240 pesticide metabolites found in different matrixes such as air, soil, water, plants, animals and humans. For non-target analysis, a "fragmentation-degradation" relationship strategy was selected. The proposed methodology was applied to 31 air samples (PM10) collected in the Valencian Region (Spain). In the post-target analysis 34 metabolites were identified, of which 11 (3-ketocarburan, carbofuran-7-phenol, carbendazim, desmethylisoproturon, ethiofencarb-sulfoxide, malaoxon, methiocarb-sulfoxide, N-(2-ethyl-6-methylphenyl)-L-alanine, omethoate, 2-hydroxy-terbuthylazine, and THPAM) were confirmed using analytical standards. The semiquantitative estimated concentration ranged between 6.78 and 198.31 pg m(-3). Likewise, two unknown degradation products of malaoxon and fenhexamid were elucidated in the non-target screening.

  7. Retrospective analysis of pesticide metabolites in urine using liquid chromatography coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    López, Antonio; Dualde, Pablo; Yusà, Vicent; Coscollà, Clara

    2016-11-01

    A comprehensive retrospective analysis of pesticide metabolites in urine was developed, using liquid chromatography coupled to Orbitrap high-resolution mass spectrometry (UHPLC-HRMS) that includes both post-run target (suspect screening) and non-target screening. An accurate-mass database comprising 263 pesticide metabolites was built and used for the post-run screening analysis. For non-target analysis, a "fragmentation-degradation" relationship strategy was selected. The proposed methodology was applied to 49 real urine samples from pregnant women. In the post-target analysis 26 pesticide metabolites were tentatively identified, 8 of which (2-diethylamino-6-methyl-pyrimidinol; 3-ketocarbofuran; 4,6-dimethoxy-2-pyrimidinamine; 4-hydroxy-2-isporopyl-6-methylpyrimidine; diethyl malate; diethyl maleate; N-(2-Ethyl-6-methylphenyl)-2-hydroxyacetamide and propachlor oxanilic acid ) were confirmed using analytical standards. Likewise, one unknown degradation product, methyl-N-phenylcarbamate was elucidated in the non-target screening. Finally, the real urine samples were grouped according to their origin applying a metabolomic approach.

  8. Very high resolution surface mass balance over Greenland modeled by the regional climate model MAR with a downscaling technique

    Science.gov (United States)

    Kittel, Christoph; Lang, Charlotte; Agosta, Cécile; Prignon, Maxime; Fettweis, Xavier; Erpicum, Michel

    2016-04-01

    This study presents surface mass balance (SMB) results at 5 km resolution with the regional climate MAR model over the Greenland ice sheet. Here, we use the last MAR version (v3.6) where the land-ice module (SISVAT) using a high resolution grid (5km) for surface variables is fully coupled while the MAR atmospheric module running at a lower resolution of 10km. This online downscaling technique enables to correct near-surface temperature and humidity from MAR by a gradient based on elevation before forcing SISVAT. The 10 km precipitation is not corrected. Corrections are stronger over the ablation zone where topography presents more variations. The model has been force by ERA-Interim between 1979 and 2014. We will show the advantages of using an online SMB downscaling technique in respect to an offline downscaling extrapolation based on local SMB vertical gradients. Results at 5 km show a better agreement with the PROMICE surface mass balance data base than the extrapolated 10 km MAR SMB results.

  9. Oligomers, organosulfates, and nitrooxy organosulfates in rainwater identified by ultra-high resolution electrospray ionization FT-ICR mass spectrometry

    Directory of Open Access Journals (Sweden)

    K. E. Altieri

    2009-04-01

    Full Text Available Wet deposition is an important removal mechanism for atmospheric organic matter, and a potentially important input for receiving ecosystems, yet less than 50% of rainwater organic matter is considered chemically characterized. Precipitation samples collected in New Jersey, USA, were analyzed by negative ion ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS. Elemental compositions of 552 unique molecular species were determined in the mass range 50–500 Da in the rainwater. Four main groups of organic compounds were identified: compounds containing carbon, hydrogen, and oxygen (CHO only, sulfur (S containing CHOS compounds, nitrogen (N containing CHON compounds, and S- and N- containing CHONS compounds. Organic acids commonly identified in precipitation were detected in the rainwater. Within the four main groups of compounds detected in the rainwater, oligomers, organosulfates, and nitrooxy-organosulfates were assigned based on elemental formula comparisons. The majority of the compounds identified are products of atmospheric reactions and are known contributors to secondary organic aerosol (SOA formed from gas phase, aerosol phase, and in-cloud reactions in the atmosphere. It is suggested that the large uncharacterized component of SOA is the main contributor to the large uncharacterized component of rainwater organic matter.

  10. First characterization of AKB-48 metabolism, a novel synthetic cannabinoid, using human hepatocytes and high-resolution mass spectrometry.

    Science.gov (United States)

    Gandhi, Adarsh S; Zhu, Mingshe; Pang, Shaokun; Wohlfarth, Ariane; Scheidweiler, Karl B; Liu, Hua-Fen; Huestis, Marilyn A

    2013-10-01

    Since the federal authorities scheduled the first synthetic cannabinoids, JWH-018 and JWH-073, new synthetic cannabinoids were robustly marketed. N-(1-Adamantyl)-1-pentylindazole-3-carboxamide (AKB-48), also known as APINACA, was recently observed in Japanese herbal smoking blends. The National Forensic Laboratory Information System registered 443 reports of AKB-48 cases in the USA from March 2010 to January 2013. In May 2013, the Drug Enforcement Administration listed AKB-48 as a Schedule I drug. Recently, AKB-48 was shown to have twice the CB1 receptor binding affinity than CB2. These pharmacological effects and the difficulty in detecting the parent compound in urine highlight the importance of metabolite identification for developing analytical methods for clinical and forensic investigations. Using human hepatocytes and TripleTOF mass spectrometry, we identified 17 novel phase I and II AKB-48 metabolites, products of monohydroxylation, dihydroxylation, or trihydroxylation on the aliphatic adamantane ring or N-pentyl side chain. Glucuronide conjugation of some mono- and dihydroxylated metabolites also occurred. Oxidation and dihydroxylation on the adamantane ring and N-pentyl side chain formed a ketone. More metabolites were identified after 3 h of incubation than at 1 h. For the first time, we present a AKB-48 metabolic scheme obtained from human hepatocytes and high-resolution mass spectrometry. These data are needed to develop analytical methods to identify AKB-48 consumption in clinical and forensic testing.

  11. Orbitrap technology for comprehensive metabolite-based liquid chromatographic–high resolution-tandem mass spectrometric urine drug screening – Exemplified for cardiovascular drugs

    Energy Technology Data Exchange (ETDEWEB)

    Helfer, Andreas G.; Michely, Julian A.; Weber, Armin A.; Meyer, Markus R.; Maurer, Hans H., E-mail: hans.maurer@uks.eu

    2015-09-03

    LC–high resolution (HR)-MS well established in proteomics has become more and more important in bioanalysis of small molecules over the last few years. Its high selectivity and specificity provide best prerequisites for its use in broad screening approaches. Therefore, Orbitrap technology was tested for developing a general metabolite-based LC–HR-MS/MS screening approach for urinalysis of drugs necessary in clinical and forensic toxicology. After simple urine precipitation, the drugs and their metabolites were separated within 10 min and detected by a Q-Exactive mass spectrometer in full scan with positive/negative switching, and subsequent data dependent acquisition (DDA) mode. Identification criteria were the presence of accurate precursor ions, isotopic patterns, five most intense fragment ions, and comparison with full HR-MS/MS library spectra. The current library contains over 1900 parent drugs and 1200 metabolites. The method was validated for typical drug representatives and metabolites concerning recovery, matrix effects, process efficiency, and limits showed acceptable results. The applicability was tested first for cardiovascular drugs, which should be screened for in poisoning cases and for medication adherence of hypertension patients. The novel LC–HR-MS/MS method allowed fast, simple, and robust urine screening, particularly for cardiovascular drugs showing the usefulness of Orbitrap technology for drug testing. - Highlights: • First study on the application of Orbitrap technology for comprehensive drug screening in clinical and forensic toxicology. • Simple workup, sufficient separation, and powerful screening and identification using modern high resolution MS. • Validation of the assay according to guidelines for qualitative approaches. • Elucidation of the power of new data evaluation software in combination with a new reference drug and metabolite library. • Great relevance for science and practice in clinical and forensic

  12. High Resolution Imaging of Very Low Mass Spectral Binaries: Three Resolved Systems and Detection of Orbital Motion in an L/T Transition Binary

    CERN Document Server

    Gagliuffi, Daniella C Bardalez; Burgasser, Adam J

    2015-01-01

    We present high resolution Laser Guide Star Adaptive Optics imaging of 43 late-M, L and T dwarf systems with Keck/NIRC2. These include 17 spectral binary candidates, systems whose spectra suggest the presence of a T dwarf secondary. We resolve three systems: 2MASS J1341$-$3052, SDSS J1511+0607 and SDSS J2052$-$1609; the first two are resolved for the first time. All three have projected separations $<8$ AU and estimated periods of $14-80$ years. We also report a preliminary orbit determination for SDSS J2052$-$1609 based on six epochs of resolved astrometry between 2005$-$2010. Among the 14 unresolved spectral binaries, 5 systems were confirmed binaries but remained unresolved, implying a minimum binary fraction of $47^{+12}_{-11}\\%$ for this sample. Our inability to resolve most of the spectral binaries, including the confirmed binaries, supports the hypothesis that a large fraction of very low mass systems have relatively small separations and are missed with direct imaging.

  13. Submicron aerosol analysis and organic source apportionment in an urban atmosphere in Pearl River Delta of China using high-resolution aerosol mass spectrometry

    Science.gov (United States)

    He, Ling-Yan; Huang, Xiao-Feng; Xue, Lian; Hu, Min; Lin, Yun; Zheng, Jun; Zhang, Renyi; Zhang, Yuan-Hang

    2011-06-01

    The Pearl River Delta (PRD) region in South China is one of the most economically developed regions in China while also noted for its severe air pollution, especially in the urban environments. In order to understand in depth the aerosol chemistry and the emission sources in PRD, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site in the Hong Kong-Shenzhen metropolitan area between 25 October and 2 December 2009. Ten minute-resolved measurement data were analyzed, and an average mass concentration of 44.5 ± 34.0 μg m-3 was calculated for the entire campaign. On average, organic matter was the most abundant PM1 component accounting for 39.7% of the total mass, followed by sulfate (24.5%), black carbon (measured by aethalometer, 14.0%), ammonium (10.2%), nitrate (10.0%), and chloride (1.6%). Moreover, organic matter comprised an increasing fraction of the PM1 loading as the PM1 loading increased, denoting its key role in particulate pollution in this region. Calculations of organic elemental composition based on the high-resolution organic mass spectra obtained indicated that C, H, O, and N on average contributed 33.8%, 55.1%, 10.2%, and 0.9%, respectively, to the total atomic numbers of organic aerosol (OA), which corresponded to an OM/OC ratio (the ratio of organic matter mass/organic carbon mass) of 1.57 ± 0.08. Positive matrix factorization analysis was then conducted on the high-resolution organic mass spectral data set. Four OA components were identified, including a hydrocarbon-like (HOA), a biomass burning (BBOA), and two oxygenated (LV-OOA and SV-OOA) components, which on average accounted for 29.5%, 24.1%, 18.8%, and 27.6%, respectively, of the total organic mass. The HOA was found to have contributions from both fossil fuel combustion and cooking emissions, while the BBOA was well correlated with acetonitrile, a known biomass burning marker. The LV-OOA and SV-OOA corresponded to more aged and

  14. High-resolution high-performance liquid chromatography with electrospray ionization mass spectrometry and tandem mass spectrometry characterization of a new isoform of human salivary acidic proline-rich proteins named Roma-Boston Ser22(Phos) → Phe variant

    Science.gov (United States)

    Iavarone, Federica; D’Alessandro, Alfredo; Tian, Na; Cabras, Tiziana; Messana, Irene; Helmerhorst, Eva J.; Oppenheim, Frank G.; Castagnola, Massimo

    2015-01-01

    During a survey of human saliva by a top-down reversed-phase high-performance liquid chromatography with electrospray ionization mass spectrometry approach, two proteins eluting at 27.4 and 28.4 min, with average masses of 15 494 ± 1 and 11 142 ± 1 Da, were detected in a subject from Boston. The Δmass value (4352 Da) of the two proteins was similar to the difference in mass values between intact (150 amino acids, [a.a.]) and truncated acidic proline-rich proteins (aPRPs; 106 a.a.) suggesting an a.a. substitution in the first 106 residues resulting in a strong reduction in polarity, since under the same experimental conditions aPRPs eluted at ~22.5 min (intact) and 23.5 min (truncated forms). Manual inspection of the high-resolution high-performance liquid chromatography with electrospray ionization tandem mass spectra of the truncated isoform showed the replacement of the phosphorylated Ser-22 in PRP-3 with a Phe residue. Inspection of the tandem mass spectra of the intact isoform confirmed the substitution, which is allowed by the code transition TCT→TTT and is in agreement with the dramatic increase in elution time. The isoform was also detected in two other subjects, one from Boston (unrelated to the previous) and one from Rome. For this reason we propose to name this variant PRP-1 (PRP-3) RB (Roma-Boston) Ser22(phos)→Phe. PMID:24771659

  15. Feasibility of the detection of trace elements in particulate matter using online High-Resolution Aerosol Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo, D.; Laskin, Alexander; Shutthanandan, V.; Jimenez, Jose L.

    2012-08-10

    The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign, where relatively high concentrations of trace elements have been reported. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in PM. The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600oC in this instrument. Operation of the AMS vaporizer at higher temperatures is likely to improve trace element detection. The detection limit is estimated at approximately 0.3 ng m-3 for 5-min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple

  16. “Profiling Sterols in Cerebrotendinous Xanthomatosis: Utility of Girard Derivatization and High Resolution Exact Mass LC-ESI-MSn Analysis”

    Science.gov (United States)

    Sandlers, Yana; Pappu, Anuradha S.; Merkens, Louise S.; Duell, Barton; Lear, Steven R.; Erickson, Sandra K.; Steiner, Robert D.

    2011-01-01

    In this study we profile free 3-oxo sterols present in plasma from patients affected with the neurodegenerative disorder of sterol and bile acid metabolism cerebrotendinous xanthomatosis (CTX), utilizing a combination of charge-tagging and LC-ESI-MSn performed with an LTQ-Orbitrap Discovery instrument. In addition, we profile sterols in plasma from 24 month old cyp27A1 gene knockout mice lacking the enzyme defective in CTX. Charge-tagging was accomplished by reaction with cationic Girard's P (GP) reagent 1-(carboxymethyl) pyridinium chloride hydrazide, an approach uniquely suited to studying the 3-oxo sterols that accumulate in CTX, as Girard's reagent reacts with the sterol oxo moiety to form charged hydrazone derivatives. The ability to selectively generate GP-tagged 3-oxo-4-ene and 3-oxo-5(H) saturated plasma sterols enabled ESI-MSn analysis of these sterols in the presence of a large excess (3 orders of magnitude) of cholesterol. Often cholesterol detected in biological samples makes it challenging to quantify minor sterols, with cholesterol frequently removed prior to analysis. We derivatized plasma (10μl) without SPE removal of cholesterol to ensure detection of all sterols - present in plasma. We were able to measure 4-cholesten-3-one in plasma from untreated CTX patients (1207 ± 302 ng/ml, mean ± SD, n=4), as well as other intermediates in a proposed pathway to 5αa-cholestanol. In addition, a number of bile acid precursors were identified in plasma using this technique. GP-tagged sterols were identified utilizing high resolution exact mass spectra (± 5 ppm), as well as MS2 ([M]+→) spectra that possessed characteristic neutral loss of 79 Da (pyridine) fragment ions, and MS3 ([M]+→[M-79]+→) spectra that provided additional structurally informative fragment ions. PMID:21168372

  17. The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high resolution observations

    CERN Document Server

    Rosotti, Giovanni P; Booth, Richard A; Clarke, Cathie J

    2016-01-01

    We investigate the minimum planet mass that produces observable signatures in infrared scattered light and submm continuum images and demonstrate how these images can be used to measure planet masses to within a factor of about two. To this end we perform multi-fluid gas and dust simulations of discs containing low mass planets, generating simulated observations at $1.65 \\mu$m, $10 \\mu$m and $850 \\mu$m. We show that the minimum planet mass that produces a detectable signature is $\\sim 15 M_\\oplus$: this value is strongly dependent on disc temperature and changes slightly with wavelength (favouring the submm). We also confirm previous results that there is a minimum planet mass of $\\sim 20 M_\\oplus$ that produces a pressure maximum in the disc: only planets above this threshold mass generate a dust trap that can eventually create a hole in the submm dust. Below this mass, planets produce annular enhancements in dust outward of the planet and a reduction in the vicinity of the planet. These features are in stea...

  18. Abundances of disk and bulge giants from high-resolution optical spectra. I. O, Mg, Ca, and Ti in the solar neighborhood and Kepler field samples

    Science.gov (United States)

    Jönsson, H.; Ryde, N.; Nordlander, T.; Pehlivan Rhodin, A.; Hartman, H.; Jönsson, P.; Eriksson, K.

    2017-02-01

    Context. The Galactic bulge is an intriguing and significant part of our Galaxy, but it is hard to observe because it is both distant and covered by dust in the disk. Therefore, there are not many high-resolution optical spectra of bulge stars with large wavelength coverage, whose determined abundances can be compared with nearby, similarly analyzed stellar samples. Aims: We aim to determine the diagnostically important alpha elements of a sample of bulge giants using high-resolution optical spectra with large wavelength coverage. The abundances found are compared to similarly derived abundances from similar spectra of similar stars in the local thin and thick disks. In this first paper we focus on the solar neighborhood reference sample. Methods: We used spectral synthesis to derive the stellar parameters as well as the elemental abundances of both the local and bulge samples of giants. We took special care to benchmark our method of determining stellar parameters against independent measurements of effective temperatures from angular diameter measurements and surface gravities from asteroseismology. Results: In this first paper we present the method used to determine the stellar parameters and elemental abundances, evaluate them, and present the results for our local disk sample of 291 giants. Conclusions: When comparing our determined spectroscopic temperatures to those derived from angular diameter measurements, we reproduce these with a systematic difference of +10 K and a standard deviation of 53 K. The spectroscopic gravities reproduce those determined from asteroseismology with a systematic offset of +0.10 dex and a standard deviation of 0.12 dex. When it comes to the abundance trends, our sample of local disk giants closely follows trends found in other works analyzing solar neighborhood dwarfs, showing that the much brighter giant stars are as good abundance probes as the often used dwarfs. Based on observations made with the Nordic Optical Telescope

  19. High Resolution STIS/HST and HIRES/Keck Spectra of Three Weak MgII Absorbers Toward PG 1634+706

    CERN Document Server

    Charlton, J C; Zonak, S G; Churchill, C W; Bond, N A; Rigby, J R

    2003-01-01

    High resolution optical (HIRES/Keck) and UV (STIS/HST) spectra, covering a large range of chemical transitions, are analyzed for three single-cloud weak MgII absorption systems along the line of sight toward the quasar PG 1634+706. Weak MgII absorption lines in quasar spectra trace metal-enriched environments that are rarely closely associated with the most luminous galaxies (>0.05L^*). The two weak MgII systems at z=0.81 and z=0.90 are constrained to have >=solar metallicity, while the metallicity of the z=0.65 system is not as well-constrained, but is consistent with >1/10th solar. These weak MgII clouds are likely to be local pockets of high metallicity in a lower metallicity environment. All three systems have two phases of gas, a higher density region that produces narrower absorption lines for low ionization transitions, such as MgII, and a lower density region that produces broader absorption lines for high ionization transitions, such as CIV. The CIV profile for one system (at z=0.81) can be fit with ...

  20. High-Resolution Spectra of the 10B18O and 11B18O: Rotational Analysis of the B-X Bands

    Institute of Scientific and Technical Information of China (English)

    V.Bojovic; A.Anti6-Jovanovi(c); M.Kuzmanovi(c)

    2005-01-01

    @@ Emission spectra of 10B18O and 11 B18O isotopomers in the 230-330 nm region have been investigated by means of conventional high-resolution spectroscopy.The molecules were produced in a low-pressure arc by discharging 8 Torr of mixture containing argon and oxygen 18 in the ratio of 4:1 and the spectra have been recorded using Ebert-type spectrograph.The boron needed to produce BO has been present in the system as amorphous powder with natural abundance of 10B and 11 B.Rotational analysis of the 0, 0 and 0, 1 bands has been performed and spectroscopic constants have been extracted.The results have allowed first determination of the equilibrium rotational constants Be and De for both isotope species 10B18O and 11B18O in their lower electronic state.Assuming a linear dependence of Be on (v + 1/2), the value of equilibrium distance re in the lower state has been derived.

  1. Characterization of the sources and processes of organic and inorganic aerosols in New York City with a high-resolution time-of-flight aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    Y.-L. Sun

    2010-10-01

    Full Text Available Submicron aerosol particles (PM1 were measured in-situ using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS during the summer 2009 Field Intensive Study at Queens College in New York City. Organic aerosol (OA and sulfate are the two dominant species, accounting for 54% and 24%, respectively, of total PM1 mass on average. The average mass size distribution of OA presents a small mode peaking at ~150 nm (Dva in addition to an accumulation mode (~550 nm that is internally mixed with sulfate, nitrate, and ammonium. The diurnal cycles of sulfate and OA both show pronounced peaks between 01:00–02:00 p.m. EST due to photochemical production. The average (±1σ oxygen-to-carbon (O/C, hydrogen-to-carbon (H/C, and nitrogen-to-carbon (N/C ratios of OA in NYC are 0.36 (±0.09, 1.49 (±0.08, and 0.012(±0.005, respectively, corresponding to an average organic mass-to-carbon (OM/OC ratio of 1.62(±0.11. Positive matrix factorization (PMF of the high resolution mass spectra identified five OA components: a hydrocarbon-like OA (HOA, two types of oxygenated OA (OOA including a low-volatility OOA (LV-OOA and a semi-volatile OOA (SV-OOA, a cooking-emission related OA (COA, and a unique nitrogen-enriched OA (NOA. HOA appears to represent primary OA (POA from urban traffic emissions. It comprises primarily of reduced species (H/C=1.83; O/C=0.06 and shows a mass spectral pattern very similar to those of POA from fossil fuel combustion, and correlates tightly with traffic emission tracers including elemental carbon and NOx. LV-OOA, which is highly oxidized (O/C=0.63 and correlates well with sulfate, appears to be representative for regional, aged secondary OA (SOA. SV-OOA, which is less oxidized (O/C=0.38 and correlates well with non-refractory chloride, likely represents less photo-chemically aged, semi-volatile SOA. COA shows a similar spectral pattern to the reference spectra of POA from

  2. The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high-resolution observations

    Science.gov (United States)

    Rosotti, Giovanni P.; Juhasz, Attila; Booth, Richard A.; Clarke, Cathie J.

    2016-07-01

    We investigate the minimum planet mass that produces observable signatures in infrared scattered light and submillimetre (submm) continuum images and demonstrate how these images can be used to measure planet masses to within a factor of about 2. To this end, we perform multi-fluid gas and dust simulations of discs containing low-mass planets, generating simulated observations at 1.65, 10 and 850 μm. We show that the minimum planet mass that produces a detectable signature is ˜15 M⊕: this value is strongly dependent on disc temperature and changes slightly with wavelength (favouring the submm). We also confirm previous results that there is a minimum planet mass of ˜20 M⊕ that produces a pressure maximum in the disc: only planets above this threshold mass generate a dust trap that can eventually create a hole in the submm dust. Below this mass, planets produce annular enhancements in dust outwards of the planet and a reduction in the vicinity of the planet. These features are in steady state and can be understood in terms of variations in the dust radial velocity, imposed by the perturbed gas pressure radial profile, analogous to a traffic jam. We also show how planet masses can be derived from structure in scattered light and submm images. We emphasize that simulations with dust need to be run over thousands of planetary orbits so as to allow the gas profile to achieve a steady state and caution against the estimation of planet masses using gas-only simulations.

  3. The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high-resolution observations.

    Science.gov (United States)

    Rosotti, Giovanni P; Juhasz, Attila; Booth, Richard A; Clarke, Cathie J

    2016-07-01

    We investigate the minimum planet mass that produces observable signatures in infrared scattered light and submillimetre (submm) continuum images and demonstrate how these images can be used to measure planet masses to within a factor of about 2. To this end, we perform multi-fluid gas and dust simulations of discs containing low-mass planets, generating simulated observations at 1.65, 10 and 850 μm. We show that the minimum planet mass that produces a detectable signature is ∼15 M⊕: this value is strongly dependent on disc temperature and changes slightly with wavelength (favouring the submm). We also confirm previous results that there is a minimum planet mass of ∼20 M⊕ that produces a pressure maximum in the disc: only planets above this threshold mass generate a dust trap that can eventually create a hole in the submm dust. Below this mass, planets produce annular enhancements in dust outwards of the planet and a reduction in the vicinity of the planet. These features are in steady state and can be understood in terms of variations in the dust radial velocity, imposed by the perturbed gas pressure radial profile, analogous to a traffic jam. We also show how planet masses can be derived from structure in scattered light and submm images. We emphasize that simulations with dust need to be run over thousands of planetary orbits so as to allow the gas profile to achieve a steady state and caution against the estimation of planet masses using gas-only simulations.

  4. High-resolution Orbitrap mass spectrometry for the analysis of carotenoids in tomato fruit: validation and comparative evaluation towards UV-VIS and tandem mass spectrometry.

    Science.gov (United States)

    Van Meulebroek, Lieven; Vanden Bussche, Julie; Steppe, Kathy; Vanhaecke, Lynn

    2014-04-01

    In this study, a generic extraction protocol and full-scan high-resolution Orbitrap-mass spectrometry (MS) detection method were developed, enabling the metabolomic screening for carotenoids in tomato fruit tissue. To this end, the carotenoids lutein, zeaxanthin, α-carotene, β-carotene, and lycopene (representing both xanthofylls and carotenes) were considered. The extraction procedure was optimized by means of a D-optimal design and consisted of a liquid-liquid extraction with methanol/tert-butyl methyl ether (1:1, v/v). The considered compounds were detected by a single-stage Exactive(TM) mass spectrometer, operating at a mass resolution of 100,000 full width at half maximum. The validation study demonstrated excellent performance in terms of linearity (R (2) > 0.99), repeatability (CV ≤ 10.6 %), within-laboratory reproducibility (CV ≤ 12.2 %), and mean corrected recovery (ranging from 85 to 106 %). Additionally, a comparative evaluation towards well-established detection techniques, i.e., tandem mass spectrometry (MS/MS) and ultraviolet-visible spectroscopy (UV-VIS) photodiode array, indicated superior performance of high-resolution Orbitrap-MS with regard to specificity/selectivity and sensitivity (with limits of detection ranging from 1.0 to 3.8 pg μL(-1)). As a result, it may be concluded that high-resolution Orbitrap-MS is a suited alternative for UV-VIS or MS/MS in analyzing carotenoids and may offer significant value in carotenoid research because of the metabolomic screening possibilities.

  5. Comprehensive characterisation of flame retardants in textile furnishings by ambient high resolution mass spectrometry, gas chromatography-mass spectrometry and environmental forensic microscopy.

    Science.gov (United States)

    Ionas, Alin C; Ballesteros Gómez, Ana; Uchida, Natsuyo; Suzuki, Go; Kajiwara, Natsuko; Takata, Kyoko; Takigami, Hidetaka; Leonards, Pim E G; Covaci, Adrian

    2015-10-01

    The presence and levels of flame retardants (FRs), such as polybrominated diphenyl ethers (PBDEs) and organophosphate flame retardants (PFRs), was determined in textile home furnishings, such as carpets and curtains from stores in Belgium. A comprehensive characterisation of FRs in textile was done by ambient high resolution mass spectrometry (qualitative screening), gas chromatography-mass spectrometry (GC-MS) (quantitation), and environmental forensic microscopy (surface distribution). Ambient ionisation coupled to a time-of-flight (TOF) high resolution mass spectrometer (direct probe-TOF-MS) was investigated for the rapid screening of FRs. Direct probe-TOF-MS proved to be useful for a first screening step of textiles to detect FRs below the levels required to impart flame retardancy and to reduce, in this way, the number of samples for further quantitative analysis. Samples were analysed by GC-MS to confirm the results obtained by ambient mass spectrometry and to obtain quantitative information. The levels of PBDEs and PFRs were typically too low to impart flame retardancy. Only high levels of BDE-209 (11-18% by weight) were discovered and investigated in localised hotspots by employing forensic microscopy techniques. Most of the samples were made of polymeric materials known to be inherently flame retarded to some extent, so it is likely that other alternative and halogen-free FR treatments/solutions are preferred for the textiles on the Belgian market. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Balancing the false negative and positive rates in suspect screening with high-resolution Orbitrap mass spectrometry using multivariate statistics.

    Science.gov (United States)

    Vergeynst, Leendert; Van Langenhove, Herman; Demeestere, Kristof

    2015-02-17

    Modern high-resolution mass spectrometry (HRMS) enables full-spectrum trace level analysis of emerging environmental organic contaminants. This raises the opportunity for post-acquisition suspect screening when no reference standards are a priori available. When setting up a conventional screening identification train based on successively different identification criteria including mass error and isotope fit, the false negative rate typically accumulates upon advancing through the decision tree. The challenge is thus to elaborate a well-balanced screening, in which the different criteria are equally stringent, leading to a controllable number of false negatives. Presented is a novel suspect screening approach using liquid-chromatography Orbitrap HRMS. Based on a multivariate statistical model, the screening takes into account the accurate mass error of the mono isotopic ion and up to three isotopes, isotope ratios, and a peak/noise filter. As such, for the first time, controlling the overall false negative rate of the screening algorithm to a desired level (5% in this study) is achieved. Simultaneously, a well-balanced identification decision is guaranteed taking the different identification criteria as a whole in a holistic statistical approach. Taking into account 1, 2, and 3 isotopes decreases the false positive rate from 22, 2.8 to <0.3%, but the cost of increasing the median limits of identification from 200, 2000 to 2062 ng L(-1), respectively, should also be considered. As proof of concept, 7 biologically treated wastewaters were screened toward 77 suspect pharmaceuticals resulting in the indicative identification of 25 suspects. Subsequently obtained reference standards allowed confirmation for 19 out of these 25 pharmaceutical contaminants.

  7. High-Resolution Live-Cell Imaging and Analysis by Laser Desorption/Ionization Droplet Delivery Mass Spectrometry.

    Science.gov (United States)

    Lee, Jae Kyoo; Jansson, Erik T; Nam, Hong Gil; Zare, Richard N

    2016-05-17

    We have developed a new ambient-ionization mass spectrometric technique named laser desorption/ionization droplet delivery mass spectrometry (LDIDD-MS). LDIDD-MS permits high-resolution, high-sensitivity imaging of tissue samples as well as measurements of both single-cell apoptosis and live-cell exocytosis. A pulsed (15 Hz) UV laser beam (266 nm) is focused on a surface covered with target analytes to trigger their desorption and ionization. A spray of liquid droplets is simultaneously directed onto the laser-focused surface region to capture the ionized analytes and deliver them to a mass spectrometer. The approach of rapid and effective capturing of molecules after laser desorption/ionization allows the limit of detection for the amino acid lysine to be as low as 2 amol under ambient ionization conditions. Two-dimensional maps of the desorbed/ionized species are recorded by moving the sample on an XY translational stage. The spatial resolution for imaging with LDIDD-MS was determined to be 2.4 μm for an ink-printed pattern and 3 μm for mouse brain tissue. We applied LDIDD-MS to single-cell analysis of apoptotic HEK cells. Differences were observed in the profiles of fatty acids and lipids between healthy HEK cells and those undergoing apoptosis. We observed upregulation of phosphatidylcholine (PC) with a relatively shorter carbon chain length and downregulation of PC with a relatively longer carbon chain length. We also applied LDIDD-MS for a real-time direct measurements of live-cell exocytosis. The catecholamine dopamine and trace amines (phenethylamine and tyramine) were detected from live PC12 cells without damaging them.

  8. Present and Future Surface Mass Budget of Small Arctic Ice Caps in a High Resolution Regional Climate Model

    Science.gov (United States)

    Mottram, Ruth; Langen, Peter; Koldtoft, Iben; Midefelt, Linnea; Hesselbjerg Christensen, Jens

    2016-04-01

    Globally, small ice caps and glaciers make a substantial contribution to sea level rise; this is also true in the Arctic. Around Greenland small ice caps are surprisingly important to the total mass balance from the island as their marginal coastal position means they receive a large amount of precipitation and also experience high surface melt rates. Since small ice caps and glaciers have had a disproportionate number of long-term monitoring and observational schemes in the Arctic, likely due to their relative accessibility, they can also be a valuable source of data. However, in climate models the surface mass balance contributions are often not distinguished from the main ice sheet and the presence of high relief topography is difficult to capture in coarse resolution climate models. At the same time, the diminutive size of marginal ice masses in comparison to the ice sheet makes modelling their ice dynamics difficult. Using observational data from the Devon Ice Cap in Arctic Canada and the Renland Ice Cap in Eastern Greenland, we assess the success of a very high resolution (~5km) regional climate model, HIRHAM5 in capturing the surface mass balance (SMB) of these small ice caps. The model is forced with ERA-Interim and we compare observed mean SMB and the interannual variability to assess model performance. The steep gradient in topography around Renland is challenging for climate models and additional statistical corrections are required to fit the calculated surface mass balance to the high relief topography. Results from a modelling experiment at Renland Ice Cap shows that this technique produces a better fit between modelled and observed surface topography. We apply this statistical relationship to modelled SMB on the Devon Ice Cap and use the long time series of observations from this glacier to evaluate the model and the smoothed SMB. Measured SMB values from a number of other small ice caps including Mittivakkat and A.P. Olsen ice cap are also compared

  9. Very High Resolution 2.5km Surface Mass balance Modelling Forced with Non-Hydrostatic HARMONIE-AROME

    Science.gov (United States)

    Mottram, Ruth; Langen, Peter; Pagh Nielsen, Kristian; Yang, Xiaohua; Gleeson, Emily

    2017-04-01

    The numerical weather prediction (NWP) model system HARMONIE, developed in collaboration between 26 European and Mediterranean countries by the ALADIN-HIRLAM consortium, offers an opportunity for extraordinarily high resolution surface mass balance (SMB) modelling. We present some initial experimental simulations where HARMONIE-AROME output from the DMI's operational NWP system, is used to force an offline SMB model for the whole of Greenland. The output from HARMONIE-AROME is compared with automatic weather station data from the PROMICE network on the ice sheet to evaluate its performance. We find the HARMONIE-AROME to represents the surface weather over the ice sheet very well, in particular 2m temperature, surface temperature and wind speeds are well reproduced. Ongoing work to assess precipitation is complicated by the difficulties of measuring solid precipitation in Greenland. The SURFEX model provides the surface scheme for HARMONIE-AROME and output from this part of the model is compared with that from the offline SMB model to assess the comparability of HARMONIE-AROME with the HIRHAM5 regional climate model. Improved SMB modelling is crucial in Greenland and Iceland not just to assess the rate of glacier change and sea level rise but also to facilitate infrastructural considerations such as communal water supplies, hydropower development and mineral extraction. The model evaluation here suggests that HARMONIE may be helpful in existing NWP domains that cover for example the Svalbard archipelago, the Alps and the Scandinavian mountain glaciers, in order to assess glacier runoff and change.

  10. Chemical dereplication of marine actinomycetes by liquid chromatography-high resolution mass spectrometry profiling and statistical analysis.

    Science.gov (United States)

    Forner, David; Berrué, Fabrice; Correa, Hebelin; Duncan, Katherine; Kerr, Russell G

    2013-12-17

    Discovery of novel bioactive metabolites from marine bacteria is becoming increasingly challenging, and the development of novel approaches to improve the efficiency of early steps in the microbial drug discovery process is therefore of interest. For example, current protocols for the taxonomic dereplication of microbial strains generally use molecular tools which do not take into consideration the ability of these selected bacteria to produce secondary metabolites. As the identification of novel chemical entities is one of the key elements driving drug discovery programs, this study reports a novel methodology to dereplicate microbial strains by a metabolomics approach using liquid chromatography-high resolution mass spectrometry (LC-HRMS). In order to process large and complex three dimensional LC-HRMS datasets, the reported method uses a bucketing and presence-absence standardization strategy in addition to statistical analysis tools including principal component analysis (PCA) and cluster analysis. From a closely related group of Streptomyces isolated from geographically varied environments, we demonstrated that grouping bacteria according to the chemical diversity of produced metabolites is reproducible and provides greatly improved resolution for the discrimination of microbial strains compared to current molecular dereplication techniques. Importantly, this method provides the ability to identify putative novel chemical entities as natural product discovery leads. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Localization of iron in rice grain using synchrotron X-ray fluorescence microscopy and high resolution secondary ion mass spectrometry

    KAUST Repository

    Kyriacou, Bianca

    2014-03-01

    Cereal crops accumulate low levels of iron (Fe) of which only a small fraction (5-10%) is bioavailable in human diets. Extensive co-localization of Fe in outer grain tissues with phytic acid, a strong chelator of metal ions, results in the formation of insoluble complexes that cannot be digested by humans. Here we describe the use of synchrotron X-ray fluorescence microscopy (XFM) and high resolution secondary ion mass spectrometry (NanoSIMS) to map the distribution of Fe, zinc (Zn), phosphorus (P) and other elements in the aleurone and subaleurone layers of mature grain from wild-type and an Fe-enriched line of rice (Oryza sativa L.). The results obtained from both XFM and NanoSIMS indicated that most Fe was co-localized with P (indicative of phytic acid) in the aleurone layer but that a small amount of Fe, often present as "hotspots", extended further into the subaleurone and outer endosperm in a pattern that was not co-localized with P. We hypothesize that Fe in subaleurone and outer endosperm layers of rice grain could be bound to low molecular weight chelators such as nicotianamine and/or deoxymugineic acid. © 2014.

  12. Comprehensive Characterization of Glycosylation and Hydroxylation of Basement Membrane Collagen IV by High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Basak, Trayambak; Vega-Montoto, Lorenzo; Zimmerman, Lisa J; Tabb, David L; Hudson, Billy G; Vanacore, Roberto M

    2016-01-04

    Collagen IV is the main structural protein that provides a scaffold for assembly of basement membrane proteins. Posttranslational modifications such as hydroxylation of proline and lysine and glycosylation of lysine are essential for the functioning of collagen IV triple-helical molecules. These modifications are highly abundant posing a difficult challenge for in-depth characterization of collagen IV using conventional proteomics approaches. Herein, we implemented an integrated pipeline combining high-resolution mass spectrometry with different fragmentation techniques and an optimized bioinformatics workflow to study posttranslational modifications in mouse collagen IV. We achieved 82% sequence coverage for the α1 chain, mapping 39 glycosylated hydroxylysine, 148 4-hydroxyproline, and seven 3-hydroxyproline residues. Further, we employed our pipeline to map the modifications on human collagen IV and achieved 85% sequence coverage for the α1 chain, mapping 35 glycosylated hydroxylysine, 163 4-hydroxyproline, and 14 3-hydroxyproline residues. Although lysine glycosylation heterogeneity was observed in both mouse and human, 21 conserved sites were identified. Likewise, five 3-hydroxyproline residues were conserved between mouse and human, suggesting that these modification sites are important for collagen IV function. Collectively, these are the first comprehensive maps of hydroxylation and glycosylation sites in collagen IV, which lay the foundation for dissecting the key role of these modifications in health and disease.

  13. [Characterization of pyrolysis of waste printed circuit boards by high-resolution pyrolysis gas chromatography-mass spectrometry].

    Science.gov (United States)

    Zhang, Yanhong; Huang, Hong; Xia, Zhengbin; Chen, Huanqin

    2008-07-01

    Thermal degradation of pyrolysis of waste circuit boards was investigated by high-resolution pyrolysis gas chromatography-mass spectrometry (PyGC-MS) and thermogravimetry (TG). In helium atmosphere, the products of FR-4 waste printed circuit board were pyrolyzed at 350, 450, 550, 650, and 750 degrees degrees C, separately, and the pyrolysis products were identified by online MS. The results indicated that the pyrolysis products of the FR-4 waste circuit board were three kinds of substances, such as the low boiling point products, phenol, bisphenol and their related products. Moreover, under 300 degrees degrees C, only observed less pyrolysis products. As the increase of pyrolysis temperature, the relative content of the low boiling point products increased. In the range of 450-650 degrees degrees C, the qualitative analysis and character were similar, and the relative contents of phenol and bisphenol were higher. The influence of pyrolysis temperature on pyrolyzate yields was studied. On the basis of the pyrolyzate profile and the dependence of pyrolyzate yields on pyrolysis temperature, the thermal degradation mechanism of brominated epoxy resin was proposed.

  14. Tracing nitrogenous disinfection byproducts after medium pressure UV water treatment by stable isotope labeling and high resolution mass spectrometry.

    Science.gov (United States)

    Kolkman, Annemieke; Martijn, Bram J; Vughs, Dennis; Baken, Kirsten A; van Wezel, Annemarie P

    2015-04-07

    Advanced oxidation processes are important barriers for organic micropollutants (e.g., pharmaceuticals, pesticides) in (drinking) water treatment. Studies indicate that medium pressure (MP) UV/H2O2 treatment leads to a positive response in Ames mutagenicity tests, which is then removed after granulated activated carbon (GAC) filtration. The formed potentially mutagenic substances were hitherto not identified and may result from the reaction of photolysis products of nitrate with (photolysis products of) natural organic material (NOM). In this study we present an innovative approach to trace the formation of disinfection byproducts (DBPs) of MP UV water treatment, based on stable isotope labeled nitrate combined with high resolution mass spectrometry. It was shown that after MP UV treatment of artificial water containing NOM and nitrate, multiple nitrogen containing substances were formed. In total 84 N-DBPs were detected at individual concentrations between 1 to 135 ng/L bentazon-d6 equivalents, with a summed concentration of 1.2 μg/L bentazon-d6 equivalents. The chemical structures of three byproducts were confirmed. Screening for the 84 N-DBPs in water samples from a full-scale drinking water treatment plant based on MP UV/H2O2 treatment showed that 22 of the N-DBPs found in artificial water were also detected in real water samples.

  15. Application of Holistic Liquid Chromatography-High Resolution Mass Spectrometry Based Urinary Metabolomics for Prostate Cancer Detection and Biomarker Discovery.

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    Full Text Available Human exhibit wide variations in their metabolic profiles because of differences in genetic factors, diet and lifestyle. Therefore in order to detect metabolic differences between individuals robust analytical methods are required. A protocol was produced based on the use of Liquid Chromatography- High Resolution Mass Spectrometry (LC-HRMS in combination with orthogonal Hydrophilic Interaction (HILIC and Reversed Phase (RP liquid chromatography methods for the analysis of the urinary metabolome, which was then evaluated as a diagnostic tool for prostate cancer (a common but highly heterogeneous condition. The LC-HRMS method was found to be robust and exhibited excellent repeatability for retention times (0.9. In addition, using the receiver operator characteristics (ROC test, the area under curve (AUC for the combination of the four best characterised biomarker compounds was 0.896. The four biomarker compounds were also found to differ significantly (P<0.05 between an independent patient cohort and controls. This is the first time such a rigorous test has been applied to this type of model. If validated, the established protocol provides a robust approach with a potentially wide application to metabolite profiling of human biofluids in health and disease.

  16. Genetic engineering, high resolution mass spectrometry and nuclear magnetic resonance spectroscopy elucidate the bikaverin biosynthetic pathway in Fusarium fujikuroi.

    Science.gov (United States)

    Arndt, Birgit; Studt, Lena; Wiemann, Philipp; Osmanov, Helena; Kleigrewe, Karin; Köhler, Jens; Krug, Isabel; Tudzynski, Bettina; Humpf, Hans-Ulrich

    2015-11-01

    Secondary metabolites of filamentous fungi can be highly bioactive, ranging from antibiotic to cancerogenic properties. In this study we were able to identify a new, yet unknown metabolite produced by Fusarium fujikuroi, an ascomycetous rice pathogen. With the help of genomic engineering and high-performance liquid chromatography (HPLC) coupled to high resolution mass spectrometry (HRMS) followed by isolation and detailed structure elucidation, the new substance could be designated as an unknown bikaverin precursor, missing two methyl- and one hydroxy group, hence named oxo-pre-bikaverin. Though the bikaverin gene cluster has been extensively studied in the past, elucidation of the biosynthetic pathway remained elusive due to a negative feedback loop that regulates the genes within the cluster. To decipher the bikaverin biosynthetic pathway and to overcome these negative regulation circuits, the structural cluster genes BIK2 and BIK3 were overexpressed independently in the ΔΔBIK2/BIK3+OE::BIK1 mutant background by using strong constitutive promoters. Using the software tool MZmine 2, the metabolite profile of the generated mutants obtained by HPLC-HRMS was compared, revealing further intermediates.

  17. Comprehensive characterization and identification of antioxidants in Folium Artemisiae Argyi using high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Han, Binsong; Xin, Zhongquan; Ma, Shasha; Liu, Wenbin; Zhang, Bingyang; Ran, Lu; Yi, Lunzhao; Ren, Dabing

    2017-09-15

    Antioxidants from natural sources, such as vegetables and fruits, are attracting more and more interest. In this work, we evaluated the antioxidant potential of Folium Artemisia Argyi, a traditional Chinese herb medicine and food supplement. The total phenolic content, total flavonoid content, and antioxidant ability of the crude extracts and fractions obtained from consecutively partition of n-hexane, ethyl acetate, and n-butanol were measured and compared. Ethyl acetate fraction shows the highest total phenolic and flavonoid contents and highest antioxidant capability with regard to DPPH, ABTS, superoxide anion free radical scavenging ability, and ferric-reducing antioxidant power. In addition, the potential antioxidant components were screened by DPPH-UHPLC-MS experiments and subsequently characterized by using high-resolution tandem mass spectrometry. This work finally identified 45 antioxidants, including organic acids, phenolic compounds, flavonoids, and methoxylated flavonoids. The results suggested that Folium Artemisiae Argyi is a potential inexpensive resource of natural antioxidants. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    Science.gov (United States)

    Altieri, K. E.; Hastings, M. G.; Peters, A. J.; Sigman, D. M.

    2012-04-01

    Atmospheric water soluble organic nitrogen (WSON) is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W), which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2281 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+), CHON compounds that contained sulfur (CHONS+), CHON compounds that contained phosphorus (CHONP+), CHON compounds that contained both sulfur and phosphorus (CHONSP+), and compounds that contained only carbon, hydrogen, and nitrogen (CHN+). Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Despite their prevalence in continental rainwater, no organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March) which have anthropogenic air mass origins and samples collected during the warm season (April to September) with remote marine air mass origins. This, in

  19. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    K. E. Altieri

    2011-11-01

    Full Text Available Atmospheric water soluble organic nitrogen (WSON is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties, and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W, which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2455 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+, CHON compounds that contained sulfur (CHONS+, CHON compounds that contained phosphorous (CHONP+, CHON compounds that contained both sulfur and phosphorous (CHONSP+, and compounds that contained only carbon, hydrogen, and nitrogen (CHN+. No organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March which have anthropogenic air mass origins and samples collected during the warm season (April to September with remote marine air mass origins. This, in conjunction with patterns

  20. Application of high resolution Chemical Ionization Mass Spectrometry (CI-ToFMS to study SOA composition: focus on formation of oxygenated species via aqueous phase processing

    Directory of Open Access Journals (Sweden)

    D. Aljawhary

    2013-07-01

    Full Text Available This paper demonstrates the capabilities of Chemical Ionization Mass Spectrometry (CIMS to study secondary organic aerosol (SOA composition with a high resolution (HR time-of-flight mass analyzer (aerosol-CI-ToFMS. In particular, by studying aqueous oxidation of Water Soluble Organic Compounds (WSOC extracted from α-pinene ozonolysis SOA, we assess the capabilities of three common CIMS reagent ions: (a protonated water clusters (H2OnH+, (b acetate CH3C(OO− and (c iodide water clusters I(H2On− to monitor SOA composition. As well, we report the relative sensitivity of these reagent ions to a wide range of common organic aerosol constituents. We find that (H2OnH+ is more selective to the detection of less oxidized species, so that the range of O/C and OSC (carbon oxidation state in the SOA spectra is considerably lower than those measured using CH3C(OO− and I(H2On−. Specifically, (H2OnH+ ionizes organic compounds with OSC ≤ 1.3, whereas CH3C(OO− and I(H2On− both ionize highly oxygenated organics with OSC up to 4 with I(H2On− being more selective towards multi-functional organic compounds. In the bulk O/C and H/C space, i.e. in a Van Krevelen plot, there is a remarkable agreement in both absolute magnitude and oxidation trajectory between CI-ToFMS data and those from a high resolution aerosol mass spectrometer (HR-AMS. This indicates that the CI-ToFMS data captures much of the chemical change occurring in the particle and that gas phase species, which are not detected by the HR-AMS, do not dominate the overall ion signal. Finally, the data illustrate the capability of aerosol-CI-ToFMS to monitor specific chemical change, including the fragmentation and functionalization reactions that occur during organic oxidation, and the oxidative conversion of dimeric SOA species into monomers. Overall, aerosol-CI-ToFMS is a valuable, selective complement to some common SOA characterization methods, such as AMS and spectroscopic techniques. Both

  1. Skin imprinting in silica plates: a potential diagnostic methodology for leprosy using high-resolution mass spectrometry.

    Science.gov (United States)

    Lima, Estela de Oliveira; de Macedo, Cristiana Santos; Esteves, Cibele Zanardi; de Oliveira, Diogo Noin; Pessolani, Maria Cristina Vidal; Nery, José Augusto da Costa; Sarno, Euzenir Nunes; Catharino, Rodrigo Ramos

    2015-04-07

    Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which primarily infects macrophages and Schwann cells, affecting skin and peripheral nerves. Clinically, the most common form of identification is through the observation of anesthetic lesions on skin; however, up to 30% of infected patients may not present this clinical manifestation. Currently, the gold standard diagnostic test for leprosy is based on skin lesion biopsy, which is invasive and presents low sensibility for suspect cases. Therefore, the development of a fast, sensible and noninvasive method that identifies infected patients would be helpful for assertive diagnosis. The aim of this work was to identify lipid markers in leprosy patients directly from skin imprints, using a mass spectrometric analytical strategy. For skin imprint samples, a 1 cm(2) silica plate was gently pressed against the skin of patients or healthy volunteers. Imprinted silica lipids were extracted and submitted to direct-infusion electrospray ionization high-resolution mass spectrometry (ESI-HRMS). All samples were differentiated using a lipidomics-based data workup employing multivariate data analysis, which helped electing different lipid markers, for example, mycobacterial mycolic acids, inflammatory and apoptotic molecules were identified as leprosy patients' markers. Otherwise, phospholipids and gangliosides were pointed as healthy volunteers' skin lipid markers, according to normal skin composition. Results indicate that silica plate skin imprinting associated with ESI-HRMS is a promising fast and sensible leprosy diagnostic method. With a prompt leprosy diagnosis, an early and effective treatment could be feasible and thus the chain of leprosy transmission could be abbreviated.

  2. Very high resolution modelling of the Surface Mass Balance of the Greenland Ice Sheet: Present day conditions and future prospects.

    Science.gov (United States)

    Mottram, Ruth; Aðalgeirsdóttir, Guðfinna; Boberg, Fredrik; Hesselbjerg Christensen, Jens; Bøssing Christensen, Ole; Langen, Peter; Rodehacke, Christian; Stendel, Martin; Yang, Shuting

    2014-05-01

    Recent experiments with the Regional Climate Model (RCM) HIRHAM5 have produced new surface mass balance (SMB) estimates at the unprecedented high horizontal resolution of 0.05 degrees (~5.5km). These simulations indicate a present day SMB of 347 ± 98 Gt/year over the whole ice sheet averaged over the period 1989 - 2012 driven by the ERA-Interim reanalysis dataset. We validate accumulation rates over the ice sheet using estimates from shallow firn cores to confirm the importance of resolution to accurate estimates of accumulation. Comparison with PROMICE and GC-Net automatic weather station observations shows the model represents present day climate and climate variability well when driven by the ERA-Interim reanalysis dataset. Comparison with a simulation at 0.25 degrees (~27km) resolution from the same model shows a significantly different calculated SMB over the whole ice sheet, largely due to changes in precipitation distribution over Greenland. The very high resolution requires a more sophisticated treatment of sub-grid scale processes in the snow pack including meltwater retention and refreezing and an enhanced albedo scheme. Our results indicate retention processes account for a significant proportion of the total surface budget based on a new parameterization scheme in the model. SMB projections, driven by the EC-Earth Global Climate Model (GCM) at the boundaries for the RCP 4.5 scenario indicate a declining surface mass balance over the 21st century with some compensation for warmer summer temperatures and enhanced melt in the form of increased precipitation. A cold bias in the driving GCM for present day conditions suggests that this simulation likely underestimates the change in SMB. However, the downscaled precipitation fields compare well with those in the reanalysis driven simulations. A soon-to-be complete simulation uses driving fields from the GCM running the RCP8.5 scenario.

  3. On-sky Doppler performance of TOU optical very high-resolution spectrograph for detecting low-mass planets

    Science.gov (United States)

    Ge, Jian; Ma, Bo; Sithajan, Sirinrat; Singer, Michael A.; Powell, Scott; Varosi, Frank; Zhao, Bo; Schofield, Sidney; Liu, Jian; Grieves, Nolan; Cassette, Anthony; Avner, Louis; Jakeman, Hali; Muterspaugh, Matthew; Williamson, Michael; Barnes, Rory

    2016-08-01

    The TOU robotic, compact very high resolution optical spectrograph (R=100,000, 0.38-0.9 microns) has been fully characterized at the 2 meter Automatic Spectroscopy Telescope (AST) at Fairborn Observatory in Arizona during its pilot survey of 12 bright FGK dwarfs in 2015. This instrument has delivered sub m/s Doppler precision for bright reference stars (e.g., 0.7 m/s for Tau Ceti over 60 days) with 5-30 min exposures and 0.7 m/s long-term instrument stability, which is the best performance among all of the known Doppler spectrographs to our knowledge. This performance was achieved by maintaining the instrument in a very high vacuum of 1 micron torr and about 0.5 mK (RMS) long-term temperature stability through an innovative close-loop instrument bench temperature control. It has discovered a 21 Earth-mass planet (P=43days) around a bright K dwarf and confirmed three super-Earth planetary systems, HD 1461, 190360 and HD 219314. This instrument will be used to conduct the Dharma Planet Survey (DPS) in 2016-2019 to monitor 100 nearby very bright FGK dwarfs (most of them brighter than V=8) at the dedicated 50-inch Robotic Telescope on Mt. Lemmon. With very high RV precision and high cadence ( 100 observations per target randomly spread over 450 days), a large number of rocky planets, including possible habitable ones, are expected to be detected. The survey also provides the largest single homogenous high precision RV sample of nearby stars for studying low mass planet populations and constraining various planet formation models. Instrument on-sky performance is summarized.

  4. Identification of Putative Steroid Receptor Antagonists in Bottled Water: Combining Bioassays and High-Resolution Mass Spectrometry

    Science.gov (United States)

    Wagner, Martin; Schlüsener, Michael P.; Ternes, Thomas A.; Oehlmann, Jörg

    2013-01-01

    Endocrine disrupting chemicals (EDCs) are man-made compounds interfering with hormone signaling and thereby adversely affecting human health. Recent reports provide evidence for the presence of EDCs in commercially available bottled water, including steroid receptor agonists and antagonists. However, since these findings are based on biological data the causative chemicals remain unidentified and, therefore, inaccessible for toxicological evaluation. Thus, the aim of this study is to assess the antiestrogenic and antiandrogenic activity of bottled water and to identify the causative steroid receptor antagonists. We evaluated the antiestrogenic and antiandrogenic activity of 18 bottled water products in reporter gene assays for human estrogen receptor alpha and androgen receptor. Using nontarget high-resolution mass spectrometry (LTQ-Orbitrap Velos), we acquired corresponding analytical data. We combined the biological and chemical information to determine the exact mass of the tentative steroid receptor antagonist. Further MSn experiments elucidated the molecule’s structure and enabled its identification. We detected significant antiestrogenicity in 13 of 18 products. 16 samples were antiandrogenic inhibiting the androgen receptor by up to 90%. Nontarget chemical analysis revealed that out of 24520 candidates present in bottled water one was consistently correlated with the antagonistic activity. By combining experimental and in silico MSn data we identified this compound as di(2-ethylhexyl) fumarate (DEHF). We confirmed the identity and biological activity of DEHF and additional isomers of dioctyl fumarate and maleate using authentic standards. Since DEHF is antiestrogenic but not antiandrogenic we conclude that additional, yet unidentified EDCs must contribute to the antagonistic effect of bottled water. Applying a novel approach to combine biological and chemical analysis this is the first study to identify so far unknown EDCs in bottled water. Notably

  5. Identification of putative steroid receptor antagonists in bottled water: combining bioassays and high-resolution mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Martin Wagner

    Full Text Available Endocrine disrupting chemicals (EDCs are man-made compounds interfering with hormone signaling and thereby adversely affecting human health. Recent reports provide evidence for the presence of EDCs in commercially available bottled water, including steroid receptor agonists and antagonists. However, since these findings are based on biological data the causative chemicals remain unidentified and, therefore, inaccessible for toxicological evaluation. Thus, the aim of this study is to assess the antiestrogenic and antiandrogenic activity of bottled water and to identify the causative steroid receptor antagonists. We evaluated the antiestrogenic and antiandrogenic activity of 18 bottled water products in reporter gene assays for human estrogen receptor alpha and androgen receptor. Using nontarget high-resolution mass spectrometry (LTQ-Orbitrap Velos, we acquired corresponding analytical data. We combined the biological and chemical information to determine the exact mass of the tentative steroid receptor antagonist. Further MS(n experiments elucidated the molecule's structure and enabled its identification. We detected significant antiestrogenicity in 13 of 18 products. 16 samples were antiandrogenic inhibiting the androgen receptor by up to 90%. Nontarget chemical analysis revealed that out of 24520 candidates present in bottled water one was consistently correlated with the antagonistic activity. By combining experimental and in silico MS(n data we identified this compound as di(2-ethylhexyl fumarate (DEHF. We confirmed the identity and biological activity of DEHF and additional isomers of dioctyl fumarate and maleate using authentic standards. Since DEHF is antiestrogenic but not antiandrogenic we conclude that additional, yet unidentified EDCs must contribute to the antagonistic effect of bottled water. Applying a novel approach to combine biological and chemical analysis this is the first study to identify so far unknown EDCs in bottled water

  6. Hydrophilic interaction liquid chromatography coupled to high-resolution mass spectrometry to determine artificial sweeteners in environmental waters.

    Science.gov (United States)

    Salas, Daniela; Borrull, Francesc; Fontanals, Núria; Marcé, Rosa Maria

    2015-06-01

    Artificial sweeteners are food additives employed as sugar substitutes which are now considered to be emerging organic contaminants. In the present study, a method is developed for the determination of a group of artificial sweeteners in environmental waters. Considering the polar and hydrophilic character of these compounds, hydrophilic interaction liquid chromatography is proposed for their separation as an alternative to traditional reversed-phase liquid chromatography. Two stationary phases with different chemistry were compared for this purpose. For the detection of the analytes, high-resolution mass spectrometry (Orbitrap) was employed to take advantage of its benefits in terms of reliable quantification and confirmation for the measurement of accurate masses. Solid-phase extraction was chosen as the sample treatment, in which the extract in a mixture of NH4OH:MeOH:ACN (1:4:15) was directly injected into the chromatographic system, simplifying the analytical procedure. The optimized method was validated on river and waste water samples. For example, in the case of effluent water samples, limits of detection ranged from 0.002 to 0.7 μg/L and limits of quantification ranged from 0.004 to 1.5 μg/L. Apparent (whole method) recoveries ranged from 57 to 74% with intra-day precision (%RSD, n = 5) ranging from 6 to 25%. The method was successfully applied to water samples from different rivers in Catalonia and different waste water treatment plants in Tarragona. Acesulfame, cyclamate, saccharine and sucralose were found in several samples.

  7. High-Resolution spectroscopy of the low-mass X-ray binary EXO 0748-67

    CERN Document Server

    Cottam, J; Brinkman, A C; Den Herder, J M; Erd, Christian

    2001-01-01

    We present initial results from observations of the low-mass X-ray binary EXO 0748-67 with the Reflection Grating Spectrometer on board the XMM-Newton Observatory. The spectra exhibit discrete structure due to absorption and emission from ionized neon, oxygen, and nitrogen. We use the quantitative constraints imposed by the spectral features to develop an empirical model of the circumsource material. This consists of a thickened accretion disk with emission and absorption in the plasma orbiting high above the binary plane. This model presents challenges to current theories of accretion in X-ray binary systems.

  8. Characterization of submicron particles influenced by mixed biogenic and anthropogenic emissions using high-resolution aerosol mass spectrometry: results from CARES

    Directory of Open Access Journals (Sweden)

    A. Setyan

    2012-09-01

    Full Text Available An Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS was deployed during the Carbonaceous Aerosols and Radiative Effects Study (CARES that took place in northern California in June 2010. We present results obtained at Cool (denoted as the T1 site of the project in the foothills of the Sierra Nevada Mountains, where intense biogenic emissions are periodically mixed with urban outflow transported by daytime southwesterly winds from the Sacramento metropolitan area. During this study, the average mass loading of submicrometer particles (PM1 was 3.0 μg m−3, dominated by organics (80% and sulfate (9.9%. The organic aerosol (OA had a nominal formula of C1H1.38N0.004OM0.44, thus an average organic mass-to-carbon (OM/OC ratio of 1.70. Two distinct oxygenated OA factors were identified via Positive matrix factorization (PMF of the high-resolution mass spectra of organics. The more oxidized MO-OOA (O/C = 0.54 was interpreted as a surrogate for secondary OA (SOA influenced by biogenic emissions whereas the less oxidized LO-OOA (O/C = 0.42 was found to represent SOA formed in photochemically processed urban emissions. LO-OOA correlated strongly with ozone and MO-OOA correlated well with two 1st generation isoprene oxidation products (methacrolein and methyl vinyl ketone, indicating that both SOAs were relatively fresh. A hydrocarbon like OA (HOA factor was also identified, representing primary emissions mainly due to local traffic. On average, SOA (= MO-OOA + LO-OOA accounted for 91% of the total OA mass and 72% of the PM1 mass observed at Cool. Twenty three periods of urban plumes from T0 (Sacramento to T1 (Cool were identified using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem. The average PM1 mass loading was considerably higher in urban plumes than in air masses dominated by biogenic SOA. The change in OA

  9. Interpreting peptide mass spectra by VEMS

    DEFF Research Database (Denmark)

    Mathiesen, Rune; Lundsgaard, M.; Welinder, Karen G.;

    2003-01-01

    of peptide MS/MS spectra imported in text file format. Peaks are annotated, the monoisotopic peaks retained, and the b-and y-ion series identified in an interactive manner. The called peptide sequence is searched against a local protein database for sequence identity and peptide mass. The report compares...... the calculated and the experimental mass spectrum of the called peptide. The program package includes four accessory programs. VEMStrans creates protein databases in FASTA format from EST or cDNA sequence files. VEMSdata creates a virtual peptide database from FASTA files. VEMSdist displays the distribution...... of masses up to 5000 Da. VEMSmaldi searches singly charged peptide masses against the local database....

  10. A Computational Drug Metabolite Detection Using the Stable Isotopic Mass-Shift Filtering with High Resolution Mass Spectrometry in Pioglitazone and Flurbiprofen

    Directory of Open Access Journals (Sweden)

    Yohei Miyamoto

    2013-09-01

    Full Text Available The identification of metabolites in drug discovery is important. At present, radioisotopes and mass spectrometry are both widely used. However, rapid and comprehensive identification is still laborious and difficult. In this study, we developed new analytical software and employed a stable isotope as a tool to identify drug metabolites using mass spectrometry. A deuterium-labeled compound and non-labeled compound were both metabolized in human liver microsomes and analyzed by liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS. We computationally aligned two different MS data sets and filtered ions having a specific mass-shift equal to masses of labeled isotopes between those data using our own software. For pioglitazone and flurbiprofen, eight and four metabolites, respectively, were identified with calculations of mass and formulas and chemical structural fragmentation analysis. With high resolution MS, the approach became more accurate. The approach detected two unexpected metabolites in pioglitazone, i.e., the hydroxypropanamide form and the aldehyde hydrolysis form, which other approaches such as metabolite-biotransformation list matching and mass defect filtering could not detect. We demonstrated that the approach using computational alignment and stable isotopic mass-shift filtering has the ability to identify drug metabolites and is useful in drug discovery.

  11. Characterization of lemon (Citrus limon) polar extract by liquid chromatography-tandem mass spectrometry in high resolution mode.

    Science.gov (United States)

    Ledesma-Escobar, C A; Priego-Capote, F; Luque de Castro, M D

    2015-11-01

    Eighty four metabolites (32 flavonoids, 15 amino acids, nine carboxylic acids, six coumarins, six sugars, five phenolic acids and 11 unclassified compounds) have been tentatively identified in a polar extract from lemon, without reference standards, based on their liquid chromatography-quadrupole-time-of-flight MS/MS spectra and the comparison with databases. Despite information in databases for some families of plant compounds is poor, tentative identification based on MS/MS information (mass of the precursor ion and their fragments, together with neutral mass loss) was possible with the help of known fragmentation patterns for the given families of compounds. Both positive and negative ionization modes and at least two collision energies were always applied to obtain as much information as possible from each molecular entity, thus helping for identification. As the tentatively identified metabolites are the same regardless of the organism they belong, their fragmentation patterns are useful for identification with independence of the sample nature.

  12. Carbon Abundances of Three Carbon-Enhanced Metal-Poor Stars from High-Resolution Gemini-S/bHROS Spectra of the 8727A [C I] Line

    CERN Document Server

    Schuler, S C; Sivarani, T; Asplund, M; Smith, V V; Cunha, K; Beers, T C

    2008-01-01

    We present the results from an analysis of the 8727ang forbidden [C I] line in high-resolution Gemini-S/bHROS spectra of three CEMP stars. We find the [C/Fe] ratios based on the [C I] abundances of the two most Fe-rich stars in our sample (HIP 0507-1653: [Fe/H] = -1.42 and HIP 0054-2542: [Fe/H] = -2.66) to be in good agreement with previously determined CH and C_2 line-based values. For the most Fe-deficient star in our sample (HIP 1005-1439: [Fe/H] = -3.08), however, the [C/Fe] ratio is found to be 0.34 dex lower than the published molecular-based value. We have carried out 3D local thermodynamic equilibrium (LTE) calculations for [C I], and the resulting corrections are found to be modest for all three stars, suggesting that the discrepancy between the [C I] and molecular-based C abundances of HIP 1005-1439 is due to more severe 3D effects on the molecular lines. Carbon abundances are also derived from C I high-excitation lines and are found to be 0.45-0.64 dex higher than the [C I]-based abundances. Previo...

  13. Analysis of Rotational Structure in the High-Resolution Infrared Spectra of the TRANS-HEXATRIENE-1,1-D2 and -CIS-1-D1 Species

    Science.gov (United States)

    Craig, Norman C.; Fuson, Hannah A.; Tian, Hengfeng; Blake, Thomas A.

    2011-06-01

    Hexatriene-1,1-D2 with some admixture of the cis-1-D1 and trans-1-D1 species was synthesized by reaction of 2,4-pentadienal and (methyl-D3)-triphenylphosphonium iodide (Wittig reagent). The trans isomer was isolated by preparative gas chromatography, and the high-resolution (0.0015 Cm-1) infrared spectrum was recorded on a Bruker IFS 125HR instrument. The rotational structure in two C-type bands for the 1,1-D2 species was analyzed. For this species the bands at 902.043 and 721.864 Cm-1 yielded composite ground state rotational constants of A0 = 0.801882(1), B0 = 0.041850(2), and C0 = 0.039804(1) Cm-1. For the cis-1-D1 species the C-type band at 803.018 Cm-1 gave A0 = 0.809384(2), B0 = 0.043530(3), and C0 = 0.041321(2) Cm-1. By iodine-catalyzed isomerization, we have obtained some of the much less favored cis isomer and hope to obtain microwave spectra for its three deuterium-substituted species. The rotational constants reported here contribute to data needed for determining a semi-experimental structure for trans-hexatriene, which should show that the structural consequences of pi-electron delocalization increase with the chain length of polyenes.

  14. Analysis of the rotational structure in the high-resolution infrared spectra of trans-hexatriene-1,1-d2 and -cis-1-d1

    Science.gov (United States)

    Craig, Norman C.; Fuson, Hannah A.; Tian, Hengfeng; Blake, Thomas A.

    2012-09-01

    Mixtures of trans-hexatriene-1,1-d2, -cis-1-d1, and -trans-1-d1 have been synthesized. Anharmonic frequencies and harmonic intensities were predicted with the B3LYP/cc-pVTZ model for the out-of-plane (a″) modes of the three isotopologues. Assignments are proposed for most of the a″ vibrational modes above 500 cm-1. Ground state (GS) rotational constants have been determined for the 1,1-d2 and cis-1-d1 species from the analysis of rotational structure of C-type bands in the high-resolution (0.0015 cm-1) infrared spectra in a mixture of the three isotopologues. The GS constants for the 1,1-d2 species are A0 = 0.8018850(6), B0 = 0.0418540(6), and C0 = 0.0397997(4) cm-1. The GS constants for the cis-1-d1 species are A0 = 0.809388(1), B0 = 0.043532(2), and C0 = 0.041320(1) cm-1. Small inertial defects confirm planarity for both species. These ground state rotational constants are intended for use in determining a semiexperimental equilibrium structure and evaluating the influence of chain length on π-electron delocalization in polyenes.

  15. Application of high-resolution photoelectron spectroscopy: Vibrational resolved C 1s and O 1s spectra of CO adsorbed on Ni(100)

    Energy Technology Data Exchange (ETDEWEB)

    Foehlisch, A.; Nilsson, A.; Martensson, N. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    There are various effects which determine the line shape of a core-level electron spectrum. These are due to the finite life-time of the core hole, inelastic scattering of the outgoing photoelectron, electronic shake-up and shake-off processes and vibrational excitations. For free atoms and molecules the different contributions to the observed line shapes can often be well separated. For solids, surfaces and adsorbates the line shapes are in general much broader and it has in the past been assumed that no separation of the various contributions can be made. In the present report the authors will show that this is indeed not the case. Surprisingly, the vibrational fine structure of CO adsorbed on Ni(100) can be resolved in the C 1s and O 1s electron spectra. This was achieved by the combination of highly monochromatized soft X-rays from B18.0 with a high resolution Scienta 200 mm photoelectron spectrometer. X-ray photoelectron spectroscopy (XPS) with tunable excitation energy yields as a core level spectroscopy atomic and site-specific information. The presented measurements allow for a determination of internuclear distances and potential energy curves in corehole ionized adsorbed molecules. The authors analysis of the c(2x2) phase CO/Ni(100) on {open_quotes}top{close_quotes} yielded a vibrational splitting of 217 +/- 2 meV for C 1s ionization. For O 1s ionization a splitting of 173 +/- 8 meV was found.

  16. Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gallart-Ayala, H., E-mail: laberca@oniris-nantes.fr [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Courant, F.; Severe, S.; Antignac, J.-P. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France); Morio, F.; Abadie, J. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), Cancers Animaux, Modèles pour la Recherche en Oncologie Comparée (AMaROC), Site de la Chantrerie–CS50707, 44307 Nantes cedex 3 (France); Le Bizec, B. [LUNAM, Ecole Nationale Vétérinaire, Agroalimentaire et de l’Alimentation Nantes Atlantique (Oniris), USC 1329 INRA Laboratoire d’Etude des résidus et Contaminants dans les Aliments (LABERCA), Site de la Chantrerie – CS50707, 44307 Nantes cedex 3 (France)

    2013-09-24

    Graphical abstract: -- Highlights: •Lipidomics, high resolution mass spectrometry, polarity switching, serum, canine mammary cancer. -- Abstract: Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale.

  17. Analyzing high resolution topography for advancing the understanding of mass and energy transfer through landscapes: A review

    Science.gov (United States)

    Passaiacquaa, Paola; Belmont, Patrick; Staley, Dennis M.; Simley, Jeffery; Arrowsmith, J. Ramon; Bode, Collin A.; Crosby, Christopher; DeLong, Stephen; Glenn, Nancy; Kelly, Sara; Lague, Dimitri; Sangireddy, Harish; Schaffrath, Keelin; Tarboton, David; Wasklewicz, Thad; Wheaton, Joseph

    2015-01-01

    The study of mass and energy transfer across landscapes has recently evolved to comprehensive considerations acknowledging the role of biota and humans as geomorphic agents, as well as the importance of small-scale landscape features. A contributing and supporting factor to this evolution is the emergence over the last two decades of technologies able to acquire high resolution topography (HRT) (meter and sub-meter resolution) data. Landscape features can now be captured at an appropriately fine spatial resolution at which surface processes operate; this has revolutionized the way we study Earth-surface processes. The wealth of information contained in HRT also presents considerable challenges. For example, selection of the most appropriate type of HRT data for a given application is not trivial. No definitive approach exists for identifying and filtering erroneous or unwanted data, yet inappropriate filtering can create artifacts or eliminate/distort critical features. Estimates of errors and uncertainty are often poorly defined and typically fail to represent the spatial heterogeneity of the dataset, which may introduce bias or error for many analyses. For ease of use, gridded products are typically preferred rather than the more information-rich point cloud representations. Thus many users take advantage of only a fraction of the available data, which has furthermore been subjected to a series of operations often not known or investigated by the user. Lastly, standard HRT analysis work-flows are yet to be established for many popular HRT operations, which has contributed to the limited use of point cloud data.In this review, we identify key research questions relevant to the Earth-surface processes community within the theme of mass and energy transfer across landscapes and offer guidance on how to identify the most appropriate topographic data type for the analysis of interest. We describe the operations commonly performed from raw data to raster products and

  18. 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.

  19. 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.

  20. High resolution mass spectrometry coupled with multivariate data analysis revealing plasma lipidomic alteration in ovarian cancer in Asian women.

    Science.gov (United States)

    Zhang, Yangyang; Liu, Yingying; Li, Lin; Wei, Jinchao; Xiong, Shaoxiang; Zhao, Zhenwen

    2016-04-01

    Ovarian cancer (OC) is the most common cause of death from gynecologic malignancies in women. The identification of reliable diagnostic biomarkers for the early detection of this deadly disease is critical for reducing the mortality rate of OC. Plasma lysophosphatidic acid (LPA) levels were increased from OC patients vs. healthy controls. Therefore, lipidomics may represent an excellent developing prospect for the discovery of diagnostic biomarkers of OC. In this study, a nontargeted lipidomics approach based on ultra performance liquid chromatography-electrospray ionization-QTOF-mass spectrometry (UPLC-ESI-QTOF-MS) combined with multivariate data analysis, including principal component analysis (PCA) and (orthogonal) partial least squared discriminant analysis [(O)PLS-DA] was applied for the investigation of potential diagnostic biomarkers in plasma of OC patients. Patients with OC could be distinguished from healthy individuals and patients with benign gynecological tumor disease by this method, which shows a significant lipid perturbation in this disease. With the assistance of high resolution and high accuracy of MS and MS/MS data, the potential markers including lysophosphatidylcholines (LPCs), phosphatidylcholines (PCs) and triacylglycerols (TGs) with specific fatty acid chains, were identified. Interestingly, LPCs were up-regulated and PCs and TGs were down-regulated, compared OC group with benign tumor and normal control groups, and the glycerophospholipid metabolism emerged as a key pathway, in particular, the phospholipase A2 (PLA2) enzyme activity, that was disregulated in the disease. This study may provide new insight into underlying mechanisms for OC and proves that MS-based lipidomics is a powerful method in discovering new potential clinical biomarkers for diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. High-resolution mass spectrometric identification and quantification of glucocorticoid compounds in various wastewaters in the Netherlands.

    Science.gov (United States)

    Schriks, Merijn; van Leerdam, Jan A; van der Linden, Sander C; van der Burg, Bart; van Wezel, Annemarie P; de Voogt, Pim

    2010-06-15

    In the past two decades much research effort has focused on the occurrence, effects, and risks of estrogenic compounds. However, increasing emissions of new emerging compounds may also affect the action of hormonal pathways other than the estrogenic hormonal axis. Recently, a suite of novel CALUX bioassays has become available that enables looking further than estrogenic effects only. By employing these bioassays, we recently showed high glucocorticogenic activity in wastewaters collected at various sites in The Netherlands. However, since bioassays provide an integrated biological response, the identity of the responsible biological compounds remained unknown. Therefore, our current objective was to elucidate the chemical composition of the wastewater extracts used in our previous study by means of LC-high-resolution Orbitrap MS/MS and to determine if the compounds quantified could account for the observed glucocorticoid responsive (GR) CALUX bioassay response. The mass spectrometric analysis revealed the presence of various glucocorticoids in the range of 13-1900 ng/L. In extracts of hospital wastewater-collected prior to sewage treatment-several glucocorticoids were identified (cortisol 275-301 ng/L, cortisone 381-472 ng/L, prednisone 117-545 ng/L, prednisolone 315-1918 ng/L, and triamcinolone acetonide 14-41 ng/L) which are used to treat a great number of human pathologies. A potency balance calculation based on the instrumental analyses and relative potencies (REPs) of the individual glucocorticoids supports the conclusion that triamcinolone acetonide (REP = 1.3), dexamethasone (REP = 1), and prednisolone (REP = 0.2) are the main contributors to the glucocorticogenic activity in the investigated wastewater extracts. The action of these compounds is concentration additive and the overall glucocorticogenic activity can be explained to a fairly large extent by their contribution.

  2. Determination of 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and -furans at the part per trillion level in United States beef fat using high-resolution gas chromatography/high-resolution mass spectrometry

    Science.gov (United States)

    Ferrario, J.; Byrne, C.; McDaniel, D.; Dupuy, A. Jr; Harless, R.

    1996-01-01

    As part of the U.S. EPA Dioxin Reassessment Program, the 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and furans were measured at part per trillion (ppt) levels in beef fat collected from slaughter facilities in the United States. This is the first statistically designed national survey of these compounds in the U.S. beef supply. Analyte concentrations were determined by high-resolution gas chromatography/high-resolution mass spectrometry, using isotope dilution methodology. Method limits of detection on a whole weight basis were 0.05 ppt for TCDD and 0.10 ppt for TCDF, 0.50 ppt for the pentas (PeCDDs/PeCDFs)/hexas (HxCDDs/HxCDFs)/heptas (HpCDDs/HpCDFs), and 3.00 ppt for the octas (OCDD/OCDF). Method detection and quantitation limits were established on the basis of demonstrated performance criteria utilizing fortified samples rather than by conventional signal-to-noise or variability of response methods. The background subtraction procedures developed for this study minimized the likelihood of false positives and increased the confidence associated with reported values near the detection limits. Mean and median values for each of the 2,3,7,8-Cl-substituted dioxins and furans are reported, along with the supporting information required for their interpretation. The mean toxic equivalence values for the samples are 0.35 ppt (nondetects = 0) and 0.89 ppt (nondetects = 1/2 LOD).

  3. Multi-detection of corticosteroids in sports doping and veterinary control using high-resolution liquid chromatography/time-of-flight mass spectrometry

    NARCIS (Netherlands)

    Touber, M.E.; Engelen, M.C.; Georgakopoulus, C.; Rhijn, van J.A.; Nielen, M.W.F.

    2007-01-01

    A liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) method was developed using the latest high-resolution LC column technology, the ultra performance liquid chromatography (UPLC (TM)), and electrospray ionization (ESI) in the positive ion mode. Gradient UPLC separation conditions wer

  4. Qualitative aspects and validation of a screening method for pesticides in vegetables and fruits based on liquid chromatography coupled to full scan high resolution (Orbitrap) mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Zomer, P.; Koning, de A.

    2012-01-01

    The analytical capabilities of liquid chromatography with single-stage high-resolution mass spectrometry have been investigated with emphasis on qualitative aspects related to selective detection during screening and to identification. The study involved 21 different vegetable and fruit commodities,

  5. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, Rick|info:eu-repo/dai/nl/357286081; Jilbert, Tom|info:eu-repo/dai/nl/304835714; Mason, Paul R D|info:eu-repo/dai/nl/304829331; de Lange, Gert J.|info:eu-repo/dai/nl/073930962; Reichart, Gert Jan|info:eu-repo/dai/nl/165599081

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (μm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  6. High-resolution line-scan analysis of resin-embedded sediments using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)

    NARCIS (Netherlands)

    Hennekam, R.; Jilbert, T.; de Lange, G.J.; Reichart, G.J.

    2015-01-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) line-scanning is a promising technique for producing high-resolution (µm-scale) geochemical records on resin-embedded sediments. However, this approach has not yet been thoroughly tested on sediment samples of known elemental

  7. Molecular composition of rainwater and aerosol during rain events in León, Spain, using high resolution mass spectrometry.

    Science.gov (United States)

    Fee, Anna

    2017-04-01

    Anna Fee (1), Markus Kalberer (1), Roberto Fraile (2), Amaya Castro (2), Ana. I. Calvo (2), Carlos Blanco-Alegre (2), Fernanda Oduber (2) and Mário Cerqueira (3). 1 Department of Chemistry, University of Cambridge, UK. 2 Department of Applied Chemistry and Physics, IMARENAB, University of León, Spain. 3 Department of Environmental Planning, University of Aveiro, Portugal. A wide range of atmospheric compounds which are present in rainwater are often also present in aerosol. They can be taken up during cloud droplet formation (in-cloud scavenging) or washed out during precipitation (below-cloud scavenging). Such compounds including aromatic hydrocarbons and organic nitrogen containing compounds are hazardous to health. In this study, the organic chemical composition of rainwater and aerosol from rain events in León, Spain, is being analysed using high resolution mass spectrometry. Collected rainwater along with high volume and low volume filters from rain events which occurred during spring, summer and winter of 2016 have been selected for analysis. Rainwater samples were prepared using Polymeric Reversed Phase Solid Phase Extraction (SPE) and filters have been extracted in water with and without SPE. Three different SPE polymer based sorbents were tested; one for extracting neutral compounds and two which are more suitable for extracting organic compounds containing sulphate and other polar functional groups. The sorbent for extracting neutral compounds was found to yield a higher number of compounds from the sample extraction than the other two varieties. Kendrick masses, Van Krevelen plots and carbon oxidation states have been investigated to identify compounds and patterns. Preliminary results show a predominance in peaks with O/C ratios between 0.2 and 0.7 and H/C ratios between 1 and 2 in both rain and aerosol samples which indicates substituted aromatic compounds. Cellulose material and fatty acids may also be present. The rain samples also have a

  8. Characterization of Organic Nitrate Formation in Limonene Secondary Organic Aerosol using High-Resolution Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Faxon, Cameron; Hammes, Julia; Peng, Jianfei; Hallquist, Mattias; Pathak, Ravi

    2016-04-01

    Previous work has shown that organic nitrates (RONO2) are prevalent in the boundary layer, and can contribute significantly to secondary organic aerosol formation. Monoterpenes, including limonene, have been shown to be precursors for the formation of these organic nitrates. Limonene has two double bonds, either of which may be oxidized by NO3 or O3. This leads to the generation of products that can subsequently condense or partition into the particle phase, producing secondary organic aerosol. In order to further elucidate the particle and gas phase product distribution of organic nitrates forming from the reactions of limonene and the nitrate radical (NO3), a series of experiments were performed in the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures (G-FROST), described by previous work. N2O5 was used as the source for NO3 and NO2, and a characterized diffusion source was used to introduce limonene into the flow reactor. All experiments were conducted in the absence of light, and the concentration of limonene was increased step-wise throughout each experiment to modify the ratio of N2O5to limonene. The experiments were conducted such that both limonene- and N2O5-limited regimes were present. Gas and particle phase products were measured using an iodide High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-CIMS) coupled to a Filter Inlet for Gases and AEROsols (FIGAERO, and particle size and SOA mass concentrations were derived using a Scanning Mobility Particle Sizer (SMPS). CIMS measurement techniques have previously been employed for the measurement of organic nitrate products of such compounds using multiple reagent ions. The use of this instrumentation allowed for the identification of chemical formulas for gas and particle phase species. The findings from the experiments will be presented in terms of the relative gas-particle partitioning of major products and the effects of N2O5/limonene ratios on product distributions. Additionally, a

  9. Development of High Resolution Resonance Ionization Mass Spectrometry for Neutron Dosimetry Technique with93Nb(n,n'93mNb Reaction

    Directory of Open Access Journals (Sweden)

    Tomita Hideki

    2016-01-01

    Full Text Available We have proposed an advanced technique to measure the 93mNb yield precisely by Resonance Ionization Mass Spectrometry, instead of conventional characteristic X-ray spectroscopy. 93mNb-selective resonance ionization is achievable by distinguishing the hyperfine splitting of the atomic energy levels between 93Nb and 93mNb at high resolution. In advance of 93mNb detection, we could successfully demonstrate high resolution resonant ionization spectroscopy of stable 93Nb using an all solid-state, narrow-band and tunable Ti:Sapphire laser system operated at 1 kHz repetition rate.

  10. Bioprospecting of microalgae: Proper extraction followed by high performance liquid chromatographic-high resolution mass spectrometric fingerprinting as key tools for successful metabolom characterization.

    Science.gov (United States)

    Stranska-Zachariasova, Milena; Kastanek, Petr; Dzuman, Zbynek; Rubert, Josep; Godula, Michal; Hajslova, Jana

    2016-03-15

    Currently, the interest in microalgae as a source of biologically active components exploitable as supplementary ingredients to food/feed or in cosmetics continues to increase. Existing research mainly aims to focus on revealing and recovering the rare, cost competitive components of the algae metabolom. Because these components could be of very different physicochemical character, a universal approach for their isolation and characterization should be developed. This study demonstrates the systematic development of the extraction strategy that represents one of the key challenges in effective algae bioprospecting, which predefines their further industrial application. By using of Trachydiscus minutus as a model microalgae biomass, following procedures were tested and critically evaluated in order to develop the generic procedure for microalgae bioprospecting: (i) various ways of mechanical disintegration of algae cells enabling maximum extraction efficiency, (ii) the use of a wide range of extraction solvents/solvent mixtures suitable for optimal extraction yields of polar, medium-polar, and non-polar compounds, (iii) the use of consecutive extractions as a fractionation approach. Within the study, targeted screening of selected compounds representing broad range of polarities was realized by ultra-high performance liquid chromatography coupled with high resolution tandem mass spectrometric detection (UHPLC-HRMS/MS), to assess the effectiveness of undertaken isolation steps. As a result, simple and high-throughput extraction-fractionation strategy based on consecutive extraction with water-aqueous methanol-hexane/isopropanol was developed. Moreover, to demonstrate the potential of the UHPLC-HRMS/MS for the retrospective non-target screening and compounds identification, the collected mass spectra have been evaluated to characterize the pattern of extracted metabolites. Attention was focused on medium-/non-polar extracts and characterization of lipid species

  11. Electrospray Ionization Mass Spectra of Dipeptide Derivatives

    Institute of Scientific and Technical Information of China (English)

    LUO, Zaigang; ZENG, Chengchu; YANG, Daoshan; HUANG, Yali; WANG, Fang; DU, Hongguang; HU, Liming

    2009-01-01

    Based on the structure of the HIV integrase core domain, dipeptide derivatives, as a type of HIV integrase in- hibitor, were synthesized, and their fragmentation pathways were investigated by electrospray ionization mass spec- trometry (ESI-MSN) in conjunction with tandem mass spectrometry (MS/MS). In order to better understand the fragmentation pathways, the MS2 and MS3 spectra of the title compound were obtained. The main fragmentation pathways occur by the cleavage of the C-CO bonds between N-(benzothiazol-2-yl)aminocarbonyl and methylene, NH-CO bonds between the NH groups and carbonyl groups. Electrospray ionization was proven to be a good method for the structural characterization and identification of this kind of compound.

  12. Practical considerations for the rapid screening for pesticides using ambient pressure desorption ionisation with high-resolution mass spectrometry.

    Science.gov (United States)

    Edison, S E; Lin, L A; Parrales, L

    2011-10-01

    A rapid screening method for pesticides has been developed to streamline the processing of produce entering the United States. Foam swabs were used to recover multi-class mixtures of 240, 140, 132 and 60 pesticides from the surfaces of apples, kiwis, peaches and tomatoes. The mixtures were selected to span a large range of chemical classes, polarities, solubilities and sizes to provide a broad look at how this technique will perform for a variety of analytes. The swabs were analysed using direct analysis in real-time (DART) ionisation coupled with a high-resolution Exactive Orbitrap™ mass spectrometer. This study expands the types of commodities analysed using this method and explores the feasibility of compositing multiple units of produce per batch to analyse a representative sample. It was established that whilst smooth-skinned produce, such as apples, maintained a high detection rate for the pesticide mixtures even when ten apples are swabbed with one foam disk, commodities with rougher surfaces, such as peaches, suffered a decrease in detection rate when ten peaches are swabbed with one foam disk. In order to maintain some consistency across the sample preparation process, a composite size of three units was selected. The varying topography of the commodities necessitated minor modifications to the method; for example, analysis of kiwi required that the hair on the surface be shaved prior to swabbing to achieve good recovery. Additionally, the effect of storage conditions on detection rate was analysed by spiking the surface of tomatoes at levels of 5 and 10 ng g(-1) for each pesticide, storing them under refrigeration and ambient conditions for 3 and 8 days, and then analysing the surface using this method. After 8 days of storage under both conditions more than 80% of the pesticides in the mixture were detected. Also, analysis of the multi-class mixtures was performed in both positive- and negative-ion mode and many classes were detected in both modes

  13. High Resolution Infrared Spectra of Plasma Jet-Cooled - and Triacetylene in the C-H Stretch Region by CW Cavity Ring-Down Spectroscopy

    Science.gov (United States)

    Zhao, D.; Guss, J.; Walsh, A.; Doney, K.; Linnartz, H.

    2013-06-01

    Polyacetylenes form an important series of unsaturated hydrocarbons that are of astrophysical interest. Small polyacetylenes have been detected from infrared observations in dense atmosphere of Titan and in a protoplanetary nebula CRL 618. We present here high-resolution mid-infrared spectra of diacetylene (HC_{4}H) and triacetylene (HC_{6}H) that are recorded in a supersonically expanded pulsed planar plasma using an ultra-sensitive detection technique. This method uses an all fiber-laser-based optical parametric oscillator (OPO), in combination with continuous wave cavity ring-down spectroscopy (cw-CRDS) as a direct absorption detection tool. A hardware-based multi-trigger concept is developed to apply cw-CRDS to pulsed plasmas. Vibrationally hot but rotationally cold HC_{4}H and HC_{6}H are produced by discharging a C_{2}H_{2}/He/Ar gas mixture which is supersonically expanded into a vacuum chamber through a slit discharge nozzle. Experimental spectra are recorded at a resolution of ˜100 MHz in the 3305-3340 cm^{-1} region, which is characteristic of the C-H stretch vibrations of HC_{4}H and HC_{6}H. Jet-cooling in our experiment reduces the rotational temperature of both HC_{4}H and HC_{6}H to <20 K. In total, ˜2000 lines are measured. More than fourteen (vibrationally hot) bands for HC_{4}H and four bands for HC_{6}H are assigned based on Loomis-Wood diagrams, and nearly half of these bands are analyzed for the first time. For both molecules improved and new molecular constants of a series of vibrational levels are presented. The accurate molecular data reported here, particularly those for low-lying (bending) vibrational levels may be used to interpret the ro-vibrational transitions in the FIR and submillimeter/THz region. D. Zhao, J. Guss, A. Walsh, H. Linnartz Chem. Phys. Lett., {dx.doi.org/10.1016/j.cplett.2013.02.025}, in press, 2013.

  14. Global distributions of CO2 volume mixing ratio in the middle and upper atmosphere from daytime MIPAS high-resolution spectra

    Science.gov (United States)

    Aythami Jurado-Navarro, Á.; López-Puertas, Manuel; Funke, Bernd; García-Comas, Maya; Gardini, Angela; González-Galindo, Francisco; Stiller, Gabriele P.; von Clarmann, Thomas; Grabowski, Udo; Linden, Andrea

    2016-12-01

    Global distributions of the CO2 vmr (volume mixing ratio) in the mesosphere and lower thermosphere (from 70 up to ˜ 140 km) have been derived from high-resolution limb emission daytime MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) spectra in the 4.3 µm region. This is the first time that the CO2 vmr has been retrieved in the 120-140 km range. The data set spans from January 2005 to March 2012. The retrieval of CO2 has been performed jointly with the elevation pointing of the line of sight (LOS) by using a non-local thermodynamic equilibrium (non-LTE) retrieval scheme. The non-LTE model incorporates the new vibrational-vibrational and vibrational-translational collisional rates recently derived from the MIPAS spectra by [Jurado-Navarro et al.(2015)]. It also takes advantage of simultaneous MIPAS measurements of other atmospheric parameters (retrieved in previous steps), such as the kinetic temperature (derived up to ˜ 100 km from the CO2 15 µm region of MIPAS spectra and from 100 up to 170 km from the NO 5.3 µm emission of the same MIPAS spectra) and the O3 measurements (up to ˜ 100 km). The latter is very important for calculations of the non-LTE populations because it strongly constrains the O(3P) and O(1D) concentrations below ˜ 100 km. The estimated precision of the retrieved CO2 vmr profiles varies with altitude ranging from ˜ 1 % below 90 km to 5 % around 120 km and larger than 10 % above 130 km. There are some latitudinal and seasonal variations of the precision, which are mainly driven by the solar illumination conditions. The retrieved CO2 profiles have a vertical resolution of about 5-7 km below 120 km and between 10 and 20 km at 120-140 km. We have shown that the inclusion of the LOS as joint fit parameter improves the retrieval of CO2, allowing for a clear discrimination between the information on CO2 concentration and the LOS and also leading to significantly smaller systematic errors. The retrieved CO2 has an improved

  15. A software application for comparing large numbers of high resolution MALDI-FTICR MS spectra demonstrated by searching candidate biomarkers for glioma blood vessel formation

    Directory of Open Access Journals (Sweden)

    Smitt Peter

    2008-03-01

    Full Text Available Abstract Background A Java™ application is presented, which compares large numbers (n > 100 of raw FTICR mass spectra from patients and controls. Two peptide profile matrices can be produced simultaneously, one with occurrences of peptide masses in samples and another with the intensity of common peak masses in all the measured samples, using the peak- and background intensities of the raw data. In latter way, more significantly differentially expressed peptides are found between groups than just using the presence or absence in samples of common peak masses. The software application is tested by searching angiogenesis related proteins in glioma by comparing laser capture micro dissected- and enzymatic by trypsin digested tissue sections. Results By hierarchical clustering of the presence-absence matrix, it appears that proteins, such as hemoglobin alpha and delta subunit, fibrinogen beta and gamma chain precursor, tubulin specific chaperone A, epidermal fatty acid binding protein, neutrophil gelatinase-associated lipocalin precursor, peptidyl tRNA hydrolase 2 mitochondrial precursor, placenta specific growth hormone, and zinc finger CCHC domain containing protein 13 are significantly different expressed in glioma vessels. The up-regulated proteins in the glioma vessels with respect to the normal vessels determined by the Wilcoxon-Mann-Whitney test on the intensity matrix are vimentin, glial fibrillary acidic protein, serum albumin precursor, annexin A5, alpha cardiac and beta actin, type I cytoskeletal 10 keratin, calcium binding protein p22, and desmin. Peptide masses of calcium binding protein p22, Cdc42 effector protein 3, fibronectin precursor, and myosin-9 are exclusively present in glioma vessels. Some peptide fragments of non-muscular myosin-9 at the C-terminus are strongly up-regulated in the glioma vessels with respect to the normal vessels. Conclusion The less rigorous than in general used commercial propriety software de

  16. Iron in the Fire: Searching for Fire's Magnetic Fingerprint using Controlled Heating Experiments, High-Resolution FORCs, IRM Coercivity Spectra, and Low-Temperature Remanence Experiments

    Science.gov (United States)

    Lippert, P. C.; Reiners, P. W.

    2014-12-01

    Evidence for recent climate-wildfire linkages underscores the need for better understanding of relationships between wildfire and major climate shifts in Earth history, which in turn offers the potential for prognoses for wildfire and human adaptations to it. In particular, what are the links between seasonality and wildfire frequency and severity, and what are the feedbacks between wildfire, landscape evolution, and biogeochemical cycles, particularly the carbon and iron cycles? A key first step in addressing these questions is recovering well-described wildfire records from a variety of paleolandscapes and paleoclimate regimes. Although charcoal and organic biomarkers are commonly used indicators of fire, taphonomic processes and time-consuming analytical preparations often preclude their routine use in some environments and in high-stratigraphic resolution paleowildfire surveying. The phenomenological relationship between fire and magnetic susceptibility can make it a useful surveying tool, but increased magnetic susceptibility in sediments is not unique to fire, and thus limits its diagnostic power. Here we utilize component-specific rock magnetic methods and analytical techniques to identify the rock magnetic fingerprint of wildfire. We use a custom-designed air furnace, a series of iron-free laboratory soils, natural saprolites and soils, and fuels from Arizona Ponderosa pine forests and grasslands to simulate wildfire in a controlled and monitored environment. Soil-ash residues and soil and fuel controls were then characterized using First Order Reversal Curve (FORC) patterns, DC backfield IRM coercivity spectra, low-temperature SIRM demagnetization behavior, and low-temperature cycling of room-temperature SIRM behavior. We will complement these magnetic analyses with high-resolution TEM of magnetic extracts. Here we summarize the systematic changes to sediment magnetism as pyrolitized organic matter is incorporated into artificial and natural soils. These

  17. Optimized approach to retrieve information on the tropospheric and stratospheric carbonyl sulfide (OCS) vertical distributions above Jungfraujoch from high-resolution FTIR solar spectra.

    Science.gov (United States)

    Lejeune, Bernard; Mahieu, Emmanuel; Servais, Christian; Duchatelet, Pierre; Demoulin, Philippe

    2010-05-01

    Carbonyl sulfide (OCS), which is produced in the troposphere from both biogenic and anthropogenic sources, is the most abundant gaseous sulfur species in the unpolluted atmosphere. Due to its low chemical reactivity and water solubility, a significant fraction of OCS is able to reach the stratosphere where it is converted to SO2 and ultimately to H2SO4 aerosols (Junge layer). These aerosols have the potential to amplify stratospheric ozone destruction on a global scale and may influence Earth's radiation budget and climate through increasing solar scattering. The transport of OCS from troposphere to stratosphere is thought to be the primary mechanism by which the Junge layer is sustained during nonvolcanic periods. Because of this, long-term trends in atmospheric OCS concentration, not only in the troposphere but also in the stratosphere, are of great interest. A new approach has been developed and optimized to retrieve atmospheric abundance of OCS from high-resolution ground-based infrared solar spectra by using the SFIT-2 (v3.91) algorithm, including a new model for solar lines simulation (solar lines often produce significant interferences in the OCS microwindows). The strongest lines of the ν3 fundamental band of OCS at 2062 cm-1 have been systematically evaluated with objective criteria to select a new set of microwindows, assuming the HITRAN 2004 spectroscopic parameters with an increase in the OCS line intensities of the ν3band main isotopologue 16O12C32S by 15.79% as compared to HITRAN 2000 (Rothman et al., 2008, and references therein). Two regularization schemes have further been compared (deducted from ATMOS and ACE-FTS measurements or based on a Tikhonov approach), in order to select the one which optimizes the information content while minimizing the error budget. The selected approach has allowed us to determine updated OCS long-term trend from 1988 to 2009 in both the troposphere and the stratosphere, using spectra recorded on a regular basis with

  18. Phase-modulated electronic wave-packet interferometry reveals high resolution vibronic spectra of free Rb atoms and Rb*He molecules

    CERN Document Server

    Bruder, Lukas; Stienkemeier, Frank

    2015-01-01

    Phase-modulated wave-packet interferometry is combined with mass-resolved photoion detection to investigate rubidium atoms attached to helium nanodroplets in a molecular beam experiment. The spectra of atomic Rb electronic states show a vastly enhanced sensitivity and spectral resolution when compared to conventional pump-probe wave-packet interferometry. Furthermore, the formation of Rb*He exciplex molecules is probed and for the first time a fully resolved vibrational spectrum for transitions between the lowest excited $5\\Pi_{3/2}$ and the high-lying electronic states $2^2\\Pi$, $4^2\\Delta$, $6^2\\Sigma$ is obtained and compared to theory. The feasibility of applying coherent multidimensional spectroscopy to dilute cold gas phase samples is demonstrated in these experiments.

  19. First retrievals of HCFC-142b from ground-based high-resolution FTIR solar observations: application to high-altitude Jungfraujoch spectra

    Science.gov (United States)

    Mahieu, Emmanuel; O'Doherty, Simon; Reimann, Stefan; Vollmer, Martin; Bader, Whitney; Bovy, Benoît; Lejeune, Bernard; Demoulin, Philippe; Roland, Ginette; Servais, Christian; Zander, Rodolphe

    2013-04-01

    Hydrofluorocarbons (HCFCs) are the first substitutes to the long-lived ozone depleting halocarbons, in particular the chlorofluorocarbons (CFCs). Given the complete ban of the CFCs by the Montreal Protocol, its Amendments and Adjustments, HCFCs are on the rise, with current rates of increase substantially larger than at the beginning of the 21st century. HCFC-142b (CH3CClF2) is presently the second most abundant HCFCs, after HCFC-22 (CHClF2). It is used in a wide range of applications, including as a blowing foam agent, in refrigeration and air-conditioning. Its concentration will soon reach 25 ppt in the northern hemisphere, with mixing ratios increasing at about 1.1 ppt/yr [Montzka et al., 2011]. The HCFC-142b lifetime is estimated at 18 years. With a global warming potential of 2310 on a 100-yr horizon, this species is also a potent greenhouse gas [Forster et al., 2007]. First space-based retrievals of HCFC-142b have been reported by Dufour et al. [2005]. 17 occultations recorded in 2004 by the Canadian ACE-FTS instrument (Atmospheric Chemistry Experiment - Fourier Transform Spectrometer, onboard SCISAT-1) were analyzed, using two microwindows (1132.5-1135.5 and 1191.5-1195.5 cm-1). In 2009, Rinsland et al. determined the HCFC-142b trend near the tropopause, from the analysis of ACE-FTS observations recorded over the 2004-2008 time period. The spectral region used in this study extended from 903 to 905.5 cm-1. In this contribution, we will present the first HCFC-142b measurements from ground-based high-resolution Fourier Transform Infrared (FTIR) solar spectra. We use observations recorded at the high altitude station of the Jungfraujoch (46.5°N, 8°E, 3580 m asl), with a Bruker 120HR instrument, in the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). The retrieval of HCFC-142b is very challenging, with simulations indicating only weak absorptions, lower than 1% for low sun spectra and current

  20. Targeting high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance analysis with high-resolution radical scavenging profiles - bioactive secondary metabolites from the endophytic fungus Penicillium namyslowskii

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Nyberg, Nils; Tejesvi, Mysore V.

    2013-01-01

    -HRMS-SPE-NMR, for identification of anti-oxidative secondary metabolites. This revealed the two chromatographic peaks with the highest relative response in the radical scavenging profile to be griseophenone C and peniprequinolone. The HPLC-HRMS-SPE-NMR analysis was performed in the tube-transfer mode using a cryogenically cooled.......e., dechlorogriseofulvin, dechlorodehydrogriseofulvin, griseofulvin, dehydrogriseofulvin, mevastatin acid, and mevastatin. The high mass sensitivity of the 1.7-mm cryogenically cooled NMR probe allowed for the first time acquisition of direct detected 13C NMR spectra of fungal metabolites, i.e., dechlorogriseofulvin...

  1. Confirmation of pinnatoxins and spirolides in shellfish and passive samplers from Catalonia (Spain) by liquid chromatography coupled with triple quadrupole and high-resolution hybrid tandem mass spectrometry.

    Science.gov (United States)

    García-Altares, María; Casanova, Alexis; Bane, Vaishali; Diogène, Jorge; Furey, Ambrose; de la Iglesia, Pablo

    2014-06-01

    Cyclic imines are lipophilic marine toxins that bioaccumulate in seafood. Their structure comprises a cyclic-imino moiety, responsible for acute neurotoxicity in mice. Cyclic imines have not been linked yet to human poisonings and are not regulated in Europe, although the European Food Safety Authority requires more data to perform a conclusive risk assessment for consumers. This work presents the first detection of pinnatoxin G (PnTX-G) in Spain and 13-desmethyl spirolide C (SPX-1) in shellfish from Catalonia (Spain, NW Mediterranean Sea). Cyclic imines were found at low concentrations (2 to 60 µg/kg) in 13 samples of mussels and oysters (22 samples analyzed). Pinnatoxin G has been also detected in 17 seawater samples (out of 34) using solid phase adsorption toxin tracking devices (0.3 to 0.9 µg/kg-resin). Pinnatoxin G and SPX-1 were confirmed with both low and high resolution (<2 ppm) mass spectrometry by comparison of the response with that from reference standards. For other analogs without reference standards, we applied a strategy combining low resolution MS with a triple quadrupole mass analyzer for a fast and reliable screening, and high resolution MS LTQ Orbitrap® for unambiguous confirmation. The advantages and limitations of using high resolution MS without reference standards were discussed.

  2. Application of high-resolution electrospray mass spectrometry for the elucidation of the disproportionation reaction of iodobenzene diacetate

    Science.gov (United States)

    Silva, Luiz F., Jr.; Vasconcelos, Ramon S.; Lopes, Norberto P.

    2008-09-01

    Disproportionation reactions take place in solution of (diacetoxyiodo)benzene (DIB) in acetonitrile in the presence of water, giving iodine(V) and iodine(I) species. This redox reaction is accelerated by the presence of water and by increasing the temperature. Several species of the solution of DIB were identified by high-resolution ESI-MS/MS, which allowed the elucidation of the mechanisms of disproportionation for DIB in gas phase and in solution. Key species in the process are the dimers [PhI(OH)OIPh]+ at m/z 440.8864, [PhI(OAc)OIPh]+ at m/z 482.8947, and [PhI(O)(OAc)OIPh]+ at m/z 498.8887.

  3. Fe- and Cu-complex formation with artificial ligands investigated by ultra-high resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS: Implications for natural metal-organic complex studies

    Directory of Open Access Journals (Sweden)

    Hannelore Waska

    2016-07-01

    Full Text Available In recent years, electrospray-ionization mass spectrometry (ESI-MS has been increasingly used to complement the bulk determination of metal-ligand equilibria, for example via competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV. However, ESI-MS speciation analyses may be impacted by instrumental artefacts such as reduction reactions, fragmentation, and adduct formation at the ESI source, changes in the ionization efficiencies of the detected species in relation to sample matrix, and peak overlaps in response to increasing sample complexity. In our study, equilibria of the known artificial ligands citrate, ethylenediaminetetraacetic acid (EDTA, 1-nitroso-2-naphthol (NN, and salicylaldoxime (SA with iron (Fe and copper (Cu were investigated by ultra-high resolution ESI-MS, Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS, under a variety of sample matrix and ionization settings. The acquired mass spectra were compared with metal-ligand equilibrium data from the literature as well as an adapted speciation model. Overall, the mass spectra produced representative species mentioned in previous reports and predicted by the speciation calculations, such as Fe(Cit, Cu(Cit2, Fe(EDTA, Cu(EDTA, Fe(NN3, and Cu(SA2. The analyses furthermore revealed new species which had been hypothesized but not measured directly using other methods, for example ternary complexes of citrate with Fe and Cu, Cu(SA monomers, and the dimer Fe(SA2. Finally, parallel measurements of a Cu+SA calibration series and a Cu+SA+EDTA competition series indicated that FT-ICR-MS can produce linear responses and low detection limits analogous to those of ACSV. We propose that ultra-high resolution FT-ICR-MS can be used as a representative tool to study interactions of trace metals with artificial as well as natural, unknown ligands at the molecular level.

  4. Performance of the High Resolution, Multi-collector Helix MC Plus Noble Gas Mass Spectrometer at the Australian National University

    Science.gov (United States)

    Zhang, Xiaodong; Honda, Masahiko; Hamilton, Doug

    2016-12-01

    Performance of the Helix MC Plus noble gas mass spectrometer installed at the Australian National University (ANU) is reported. Results for sensitivity, mass discrimination and their linearity against partial pressure of noble gases, and mass resolution of the mass spectrometer are presented, and the results are compared with those of conventional noble gas mass spectrometers. The application of the five detectors on the Helix MC Plus in measuring various noble gas isotopes in multi-collector modes and the integration of the software drivers of peripheral hardware devices into the controlling program Qtegra of the mass spectrometer are discussed. High mass resolution (>1800) and mass resolving power (>8000) make this mass spectrometer unique in noble gas cosmo-geochemistry. It provides the capability to measure isobaric interference-free noble gas isotopes in multi-collector mode, significantly improves the accuracy to determine isotopic ratios, and greatly increases the efficiency of data acquisition.

  5. Performance of the High Resolution, Multi-collector Helix MC Plus Noble Gas Mass Spectrometer at the Australian National University

    Science.gov (United States)

    Zhang, Xiaodong; Honda, Masahiko; Hamilton, Doug

    2016-09-01

    Performance of the Helix MC Plus noble gas mass spectrometer installed at the Australian National University (ANU) is reported. Results for sensitivity, mass discrimination and their linearity against partial pressure of noble gases, and mass resolution of the mass spectrometer are presented, and the results are compared with those of conventional noble gas mass spectrometers. The application of the five detectors on the Helix MC Plus in measuring various noble gas isotopes in multi-collector modes and the integration of the software drivers of peripheral hardware devices into the controlling program Qtegra of the mass spectrometer are discussed. High mass resolution (>1800) and mass resolving power (>8000) make this mass spectrometer unique in noble gas cosmo-geochemistry. It provides the capability to measure isobaric interference-free noble gas isotopes in multi-collector mode, significantly improves the accuracy to determine isotopic ratios, and greatly increases the efficiency of data acquisition.

  6. Versatile lipid profiling by liquid chromatography-high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer.

    Science.gov (United States)

    Gallart-Ayala, H; Courant, F; Severe, S; Antignac, J-P; Morio, F; Abadie, J; Le Bizec, B

    2013-09-24

    Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC-HRMS or LC-MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and "all ion fragmentation" (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale.

  7. [Application of gas chromatography-high resolution quadrupole time of flight mass spectrometry to the analysis of benzaldehyde, benzyl alcohol acetophenone and phenylacetaldehyde in complex aromatic samples].

    Science.gov (United States)

    Liu, Junyan; Cao, Zhe; Li, Jiwen; Wang, Zheming; Wang, Chuan; Gu, Songyuan

    2015-02-01

    The study focuses on the quantitative analytical characterization of benzaldehyde, benzyl alcohol, acetophenone and phenylacetaldehyde in complex aromatic samples by gas chromatography-high resolution quadrupole time of flight mass spectrometry (GC-QTOF MS). The four compounds in real sample were accurately qualified and quantified through a comprehensive analysis of the GC retention times and the accurate masses of the ion fragments obtained by the high resolution MS. The new method therefore effectively avoids the interference of the real sample substrate, which reduces the accuracy of the analysis results. The peak area of the characteristic ion fragment for each compound was used for quantitation calculation. The MS signal responses of the four compounds showed good linear relationships with the corresponding mass concentrations and the linear regression coefficients were greater than 0. 99. The method recoveries were 87. 97% - 103.01%. The limits of detection (LODs) were 0. 01, 0. 03, 0. 02 and 0. 01 mg/L for benzaldehyde, benzyl alcohol, acetophenone and phenylacetaldehyde respectively. The contents of the four compounds in three real samples were analyzed. The study provided a new strategy for oxygenate analysis in complex aromatic samples using GC-QTOF MS. By measuring the accurate masses, the new method reduces the reliance on chromatographic separation ability and makes up the shortcomings of the traditional GC-MS methods.

  8. Biodegradation of carbamazepine and clarithromycin by Trichoderma harzianum and Pleurotus ostreatus investigated by liquid chromatography - high-resolution tandem mass spectrometry (FTICR MS-IRMPD).

    Science.gov (United States)

    Buchicchio, Alessandro; Bianco, Giuliana; Sofo, Adriano; Masi, Salvatore; Caniani, Donatella

    2016-07-01

    In this study, the capability of pharmaceutical biodegradation of fungus Trichoderma harzianum was evaluated through the comparison with the well-known biodegradation capability of white-rot fungus Pleurotus ostreatus. The study was performed in aqueous phase under aerobic conditions, using two of the most frequently detected drugs in water bodies: carbamazepine and clarithromycin, with concentrations commonly found in treated wastewater (4μg/l and 0.03μg/l respectively). For the first time, we demonstrated that T. harzianum is able to remove carbamazepine and clarithromycin. The analyses were performed by reversed-phase liquid chromatography/mass spectrometry, using high-resolution Fourier-transform ion cyclotron resonance mass spectrometry upon electrospray ionization in positive ion mode. The high selectivity and mass accuracy provided by high-resolution mass spectrometry, allowed us to identify some unknown metabolites. On the basis of our study, the major metabolites detected in liquid culture treated by T. harzianum were: 14-hydroxy-descladinosyl- and descladinosyl-clarithromycin, which are pharmacologically inactive products not dangerous for the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Proteome Scale-Protein Turnover Analysis Using High Resolution Mass Spectrometric Data from Stable-Isotope Labeled Plants.

    Science.gov (United States)

    Fan, Kai-Ting; Rendahl, Aaron K; Chen, Wen-Ping; Freund, Dana M; Gray, William M; Cohen, Jerry D; Hegeman, Adrian D

    2016-03-04

    Protein turnover is an important aspect of the regulation of cellular processes for organisms when responding to developmental or environmental cues. The measurement of protein turnover in plants, in contrast to that of rapidly growing unicellular organismal cultures, is made more complicated by the high degree of amino acid recycling, resulting in significant transient isotope incorporation distributions that must be dealt with computationally for high throughput analysis to be practical. An algorithm in R, ProteinTurnover, was developed to calculate protein turnover with transient stable isotope incorporation distributions in a high throughput automated manner using high resolution MS and MS/MS proteomic analysis of stable isotopically labeled plant material. ProteinTurnover extracts isotopic distribution information from raw MS data for peptides identified by MS/MS from data sets of either isotopic label dilution or incorporation experiments. Variable isotopic incorporation distributions were modeled using binomial and beta-binomial distributions to deconvolute the natural abundance, newly synthesized/partial-labeled, and fully labeled peptide distributions. Maximum likelihood estimation was performed to calculate the distribution abundance proportion of old and newly synthesized peptides. The half-life or turnover rate of each peptide was calculated from changes in the distribution abundance proportions using nonlinear regression. We applied ProteinTurnover to obtain half-lives of proteins from enriched soluble and membrane fractions from Arabidopsis roots.

  10. Non-targeted analysis of electronics waste by comprehensive two-dimensional gas chromatography combined with high-resolution mass spectrometry: Using accurate mass information and mass defect analysis to explore the data.

    Science.gov (United States)

    Ubukata, Masaaki; Jobst, Karl J; Reiner, Eric J; Reichenbach, Stephen E; Tao, Qingping; Hang, Jiliang; Wu, Zhanpin; Dane, A John; Cody, Robert B

    2015-05-22

    Comprehensive two-dimensional gas chromatography (GC×GC) and high-resolution mass spectrometry (HRMS) offer the best possible separation of their respective techniques. Recent commercialization of combined GC×GC-HRMS systems offers new possibilities for the analysis of complex mixtures. However, such experiments yield enormous data sets that require new informatics tools to facilitate the interpretation of the rich information content. This study reports on the analysis of dust obtained from an electronics recycling facility by using GC×GC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. New software tools for (non-traditional) Kendrick mass defect analysis were developed in this research and greatly aided in the identification of compounds containing chlorine and bromine, elements that feature in most persistent organic pollutants (POPs). In essence, the mass defect plot serves as a visual aid from which halogenated compounds are recognizable on the basis of their mass defect and isotope patterns. Mass chromatograms were generated based on specific ions identified in the plots as well as region of the plot predominantly occupied by halogenated contaminants. Tentative identification was aided by database searches, complementary electron-capture negative ionization experiments and elemental composition determinations from the exact mass data. These included known and emerging flame retardants, such as polybrominated diphenyl ethers (PBDEs), hexabromobenzene, tetrabromo bisphenol A and tris (1-chloro-2-propyl) phosphate (TCPP), as well as other legacy contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated terphenyls (PCTs).

  11. Wide-Scope Screening Method for Multiclass Veterinary Drug Residues in Fish, Shrimp, and Eel Using Liquid Chromatography-Quadrupole High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Turnipseed, Sherri B; Storey, Joseph M; Lohne, Jack J; Andersen, Wendy C; Burger, Robert; Johnson, Aaron S; Madson, Mark R

    2017-01-13

    A screening method for veterinary drug residues in fish, shrimp, and eel using LC with a high-resolution MS instrument has been developed and validated. The method was optimized for over 70 test compounds representing a variety of veterinary drug classes. Tissues were extracted by vortex mixing with acetonitrile acidified with 2% acetic acid and 0.2% p-toluenesulfonic acid. A centrifuged portion of the extract was passed through a novel solid phase extraction cartridge designed to remove interfering matrix components from tissue extracts. The eluent was then evaporated and reconstituted for analysis. Data were collected with a quadrupole-Orbitrap high-resolution mass spectrometer using both nontargeted and targeted acquisition methods. Residues were detected on the basis of the exact mass of the precursor and a product ion along with isotope pattern and retention time matching. Semiquantitative data analysis compared MS(1) signal to a one-point extracted matrix standard at a target testing level. The test compounds were detected and identified in salmon, tilapia, catfish, shrimp, and eel extracts fortified at the target testing levels. Fish dosed with selected analytes and aquaculture samples previously found to contain residues were also analyzed. The screening method can be expanded to monitor for an additional >260 veterinary drugs on the basis of exact mass measurements and retention times.

  12. [Rapid screening and confirming carcinogenic banned azo colorants in textiles by high performance liquid chromatography-linear ion trap/orbitrap high-resolution mass spectrometry].

    Science.gov (United States)

    Yun, Huan; Liu, Xin; Wang, Jing; Yan, Hua; Cui, Fengyun; Zhang, Zhaohui

    2013-09-01

    A method of high performance liquid chromatography-linear ion trap/orbitrap highresolution mass spectrometry (HPLC-LTP/Orbitrap MS) was ued to screen and confirm-banned azo colorants in textiles rapidly. The analytes were reduced to carcinogenic aromatic amines with sodium dithionite in citrate buffer solution. The reduced solution was extracted bydiatomite, and loadd onto an Acquity UPLC BEH C18 column (50 mm x 2.1 MM. 1.7 microm) with a gradient elution of methanol and 0.1% (v/v) methane acid aqueous solution, and finally detected by linear ion trap/orbitrap high-resolution mass spectrometry in positive ESI mode. In mass spectrometry method, the MS spectrum of high-resolution and the collision induced dissociation (CID) spectrum of data-dependent scan mode were used for screening analysis and conformation, respectively. The calibration curves showed a good linearity in the range of 0.05 -2.00 mg/b, and the correlation coefficients (r) were higher than 0.99. By detecting spiked samples, the limits of quantification were 0.08 mg/kg for all the residues and the recoveries were in the range of 65.5% - 111.5% with the relative standard deviations (RSDs) between 0.87% and 2.49%. The results indicate that the method is simple, rapid, sensitive and suitable for the qualitative and quantitative analysis of carcinogenic aromatic amines in textiles.

  13. General strategies to increase the repeatability in non-target screening by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Bader, Tobias; Schulz, Wolfgang; Kümmerer, Klaus; Winzenbacher, Rudi

    2016-09-01

    This article focuses on the data evaluation of non-target high-resolution LC-MS profiles of water samples. Taking into account multiple technical replicates, the difficulties in peak recognition and the related problems of false positive and false negative findings are systematically demonstrated. On the basis of a combinatorial approach, different models involving sophisticated workflows are evaluated, particularly with regard to the repeatability. In addition, the improvement resulting from data processing was systematically taken into consideration where the recovery of spiked standards emphasized that real peaks of interest were barely or not removed by the derived filter criteria. The comprehensive evaluation included different matrix types spiked with up to 263 analytical standards which were analyzed repeatedly leading to a total number of more than 250 injections that were incorporated in the assessment of different models of data processing. It was found that the analysis of multiple replicates is the key factor as, on the one hand, it provides the option of integrating valuable filters in order to minimize the false positive rate and, on the other hand, allows correcting partially false negative findings occurring during the peak recognition. The developed processing strategies including replicates clearly point to an enhanced data quality since both the repeatability as well as the peak recognition could be considerably improved. As proof of concept, four different matrix types, including a wastewater treatment plant (WWTP) effluent, were spiked with 130 isotopically labeled standards at different concentration levels. Despite the stringent filter criteria, at 100 ng L(-1) recovery rates of up to 93% were reached in the positive ionization mode. The proposed model, comprising three technical replicates, filters less than 5% and 2% of the standards recognized at 100 and 500 ng L(-1), respectively and thus indicates the general applicability of the

  14. High resolution LC-ESI-TOF-mass spectrometry method for fast separation, identification, and quantification of 12 isoflavones in soybeans and soybean products.

    Science.gov (United States)

    Lee, Mi Jin; Chung, Ill-Min; Kim, Hunjung; Jung, Mun Yhung

    2015-06-01

    A high resolution LC-ESI-TOF-MS analytical method was established for the rapid isolation, identification, and quantification of 12 isoflavones in soybean and soybean products. Individual isoflavones were identified on the basis of the accurate mass data of their respective protonated mass ions, Na or K adduct ions, fragment ions, and isotope ion patterns. The protonated mass ions of isoflavones were extracted for their quantification in soybean products. Twelve different isoflavones in the soybean products were fully separated, identified and quantified within 12min separation time. The established LC-TOF/MS was an effective analytical method for the simultaneous characterization and quantification of isoflavones with exceptionally short analytical time, high selectivity, a high linearity (r(2)>0.992) in a wide range, low LOD and LOQ, high precision, inter-and intra-day repeatability, and no significant matrix effect. Furthermore, it requires simple sample preparation procedure (solvent extraction, dilution, and syringe filtration).

  15. Dynamic Cluster Analysis: An Unbiased Method for Identifying A+2 Element Containing Compounds in Liquid Chromatographic High-Resolution TOF Mass Spectrometric Data

    DEFF Research Database (Denmark)

    Andersen, Aaron John Christian; Hansen, Per Juel; Jørgensen, Kevin

    2016-01-01

    Dynamic Cluster Analysis (DCA) is an automated, unbiased technique which can identify Cl, Br, S, and other A+2 element containing metabolites in liquid chromatographic high resolution mass spectrometric data. DCA is based on three features, primarily the previously unutilised A+1 to A+2 isotope...... cluster spacing which is a strong classifier in itself, but improved with the addition of the monoisotopic mass, and the well-known A:A+2 intensity ratio. Utilizing only the A+1 to A+2 isotope cluster spacing and the monoisotopic mass it was possible to filter a chromatogram for metabolites which contain...... Cl, Br, and S. Screening simulated isotope patterns of the Antibase Natural Products Database it was determined that the A+1 to A+2 isotope cluster spacing can be used to correctly classify 97.4% of molecular formulas containing these elements, only misclassifying a few metabolites which were either...

  16. Rapid Detection of Gas Hazards and Leaks with an Atmospheric Sampling, High Resolution, Mass Spectrometer with Low Pumping Requirements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Miniaturization of mass spectrometers is restricted almost exclusively by the ability of small vacuum pumps to remove gas loads during operation of the instrument....

  17. Determination of anxiolytic veterinary drugs from biological fertilizer blood meal using liquid chromatography high-resolution mass spectrometry.

    Science.gov (United States)

    Choi, Jeong-Heui; Lamshöft, Marc; Zühlke, Sebastian; Park, Jong-Hyouk; Rahman, Md Musfiqur; Abd El-Aty, A M; Spiteller, Michael; Shim, Jae-Han

    2014-06-01

    A liquid environment-friendly agricultural material originating from animal blood, blood meal, was employed to detect anxiolytic veterinary drugs using a combination of liquid-liquid extraction (LLE) and positive electrospray ionization Orbitrap mass spectrometry. Every positive ion of the analytes was consistent with [M+H](+) , and the accurate mass analysis and mass spectral filtration with a 2-ppm mass tolerance window were applied to identify and quantitate the analytes and metabolites. The developed LLE method was validated with the lowest calibrated level, linearity (r(2) ), recovery, repeatability and the within-laboratory reproducibility, which were in the ranges of 0.3-1 µg/L, 0.9963-0.9995, 48.3-117.5%, 1.1-12.6% and 2.3-15.7%, respectively. The LLE method was compared with a solid-phase extraction (SPE) method; however, its recoveries were liquid blood meal samples, and none of the targeted compounds were observed.

  18. Optimization of Search Engines and Postprocessing Approaches to Maximize Peptide and Protein Identification for High-Resolution Mass Data.

    Science.gov (United States)

    Tu, Chengjian; Sheng, Quanhu; Li, Jun; Ma, Danjun; Shen, Xiaomeng; Wang, Xue; Shyr, Yu; Yi, Zhengping; Qu, Jun

    2015-11-06

    The two key steps for analyzing proteomic data generated by high-resolution MS are database searching and postprocessing. While the two steps are interrelated, studies on their combinatory effects and the optimization of these procedures have not been adequately conducted. Here, we investigated the performance of three popular search engines (SEQUEST, Mascot, and MS Amanda) in conjunction with five filtering approaches, including respective score-based filtering, a group-based approach, local false discovery rate (LFDR), PeptideProphet, and Percolator. A total of eight data sets from various proteomes (e.g., E. coli, yeast, and human) produced by various instruments with high-accuracy survey scan (MS1) and high- or low-accuracy fragment ion scan (MS2) (LTQ-Orbitrap, Orbitrap-Velos, Orbitrap-Elite, Q-Exactive, Orbitrap-Fusion, and Q-TOF) were analyzed. It was found combinations involving Percolator achieved markedly more peptide and protein identifications at the same FDR level than the other 12 combinations for all data sets. Among these, combinations of SEQUEST-Percolator and MS Amanda-Percolator provided slightly better performances for data sets with low-accuracy MS2 (ion trap or IT) and high accuracy MS2 (Orbitrap or TOF), respectively, than did other methods. For approaches without Percolator, SEQUEST-group performs the best for data sets with MS2 produced by collision-induced dissociation (CID) and IT analysis; Mascot-LFDR gives more identifications for data sets generated by higher-energy collisional dissociation (HCD) and analyzed in Orbitrap (HCD-OT) and in Orbitrap Fusion (HCD-IT); MS Amanda-Group excels for the Q-TOF data set and the Orbitrap Velos HCD-OT data set. Therefore, if Percolator was not used, a specific combination should be applied for each type of data set. Moreover, a higher percentage of multiple-peptide proteins and lower variation of protein spectral counts were observed when analyzing technical replicates using Percolator

  19. Estimating mass-wasting processes in active earth slides – earth flows with time-series of High-Resolution DEMs from photogrammetry and airborne LiDAR

    Directory of Open Access Journals (Sweden)

    A. Corsini

    2009-03-01

    Full Text Available This paper deals with the use of time-series of High-Resolution Digital Elevation Models (HR DEMs obtained from photogrammetry and airborne LiDAR coupled with aerial photos, to analyse the magnitude of recently reactivated large scale earth slides – earth flows located in the northern Apennines of Italy. The landslides underwent complete reactivation between 2001 and 2006, causing civil protection emergencies. With the final aim to support hazard assessment and the planning of mitigation measures, high-resolution DEMs are used to identify, quantify and visualize depletion and accumulation in the slope resulting from the reactivation of the mass movements. This information allows to quantify mass wasting, i.e. the amount of landslide material that is wasted during reactivation events due to stream erosion along the slope and at its bottom, resulting in sediment discharge into the local fluvial system, and to assess the total volumetric magnitude of the events. By quantifying and visualising elevation changes at the slope scale, results are also a valuable support for the comprehension of geomorphological processes acting behind the evolution of the analysed landslides.

  20. Qualitative and quantitative determination of YiXinShu Tablet using ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometry.

    Science.gov (United States)

    Sun, Zhi; Li, Zhuolun; Zuo, Lihua; Wang, Zhenhui; Zhou, Lin; Shi, Yingying; Kang, Jian; Zhu, Zhenfeng; Zhang, Xiaojian

    2017-08-24

    To clarify and quantify the chemical profile of YiXinShu Tablet rapidly, a feasible and accurate strategy was developed by applying ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometry. A total of 105 components were identified, including 25 phenanthraquinones, 11 lactones, 19 lignans, 24 acids and 26 other compounds. Among them, 26 major compounds were unambiguously detected by comparing with reference standards. And 19 of these compounds in three batches of YiXinShu Tablet were selected for quantitative determination. (Z)-Ligustilide, salvianic acid A, salvianolic acid A, salvianolic acid B and rosmarinic acid were abundant in these three batches with contents over 1.000 mg/g. The established analysis methods were examined to be accurate and feasible. The results show that the ultra high performance liquid chromatography with Q Exactive hybrid quadrupole orbitrap high-resolution accurate mass spectrometry method has a powerful qualitative ability and promising quantitative application. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Setting up of a liquid chromatography-high resolution tandem mass spectrometry method for the detection of caseins in food. A comparison with ELISA method

    Directory of Open Access Journals (Sweden)

    Daniela Gastaldi

    2013-06-01

    Full Text Available Determination of caseins in food matrices is usually performed by using the competitiveenzyme- linked immunosorbent assay (ELISA technique. However such a technique suffers from a number of limitations. Among these, the applicability to a narrow concentration range, a non linear (logarithmic response, a non-negligible cross-reactivity and a high cost per kit. At the time of the completion of this study, in case of ELISA positive feedback, there was poor availability in the literature of finding reliable instrumental methods able to determine both qualitatively and quantitatively this class of substances. In the present study, a liquid chromatography-high resolution tandem mass spectrometry (HPLC-HRMS/MS instrumental method was developed with a high resolution mass spectrometer (Orbitrap. Real samples of sausages in which caseins were detected by ELISA technique were analysed. A casein-free sample of ham was used as a blank. The analytical characteristics of the instrumental method were compared with those of a commercial ELISA test, declared specific for α- and β-casein.

  2. Phase I and II metabolites of speciogynine, a diastereomer of the main Kratom alkaloid mitragynine, identified in rat and human urine by liquid chromatography coupled to low- and high-resolution linear ion trap mass spectrometry.

    Science.gov (United States)

    Philipp, Anika A; Wissenbach, Dirk K; Weber, Armin A; Zapp, Josef; Maurer, Hans H

    2010-11-01

    Mitragyna speciosa (Kratom in Thai), a Thai medical plant, is misused as herbal drug of abuse. Besides the most abundant alkaloids mitragynine (MG) and paynantheine (PAY), several other alkaloids were isolated from Kratom leaves, among them the third abundant alkaloid is speciogynine (SG), a diastereomer of MG. The aim of this present study was to identify the phase I and II metabolites of SG in rat urine after the administration of a rather high dose of the pure alkaloid and then to confirm these findings using human urine samples after Kratom use. The applied liquid chromatography coupled to low- and high-resolution mass spectrometry (LC-HRMS-MS) provided detailed information on the structure in the MS(n) mode particularly with high resolution. For the analysis of the human samples, the LC separation had to be improved markedly allowing the separation of SG and its metabolites from its diastereomer MG and its metabolites. In analogy to MG, besides SG, nine phase I and eight phase II metabolites could be identified in rat urine, but only three phase I and five phase II metabolites in human urine. These differences may be caused by the lower SG dose applied by the user of Kratom preparations. SG and its metabolites could be differentiated in the human samples from the diastereomeric MG and its metabolites comparing the different retention times determined after application of the single alkaloids to rats. In addition, some differences in MS(2) and/or MS(3) spectra of the corresponding diastereomers were observed.

  3. Mexico City Aerosol Analysis during MILAGRO using High Resolution Aerosol Mass Spectrometry at the Urban Supersite (T0). Part 2: Analysis of the Biomass Burning Contribution and the Modern Carbon Fraction

    Energy Technology Data Exchange (ETDEWEB)

    Aiken, Allison; de Foy, B.; Wiedinmyer, Christine; DeCarlo, Peter; Ulbrich, Ingrid M.; Wehrli, M. N.; Szidat, S.; Prevot, A. S. H.; Noda, J.; Wacker, L.; Volkamer, Rainer M.; Fortner, Edward; Wang, J. X.; Laskin, Alexander; Shutthanandan, V.; Zheng, J.; Zhang, Renyi; Paredes-Miranda, Guadalupe L.; Arnott, W. P.; Molina, Luis; Sosa, G.; Querol, X.; Jimenez, J. L.

    2010-06-16

    Submicron aerosol was analyzed during the MILAGRO field campaign in March 2006 at the T0 urban supersite in Mexico City with a High-Resolution Aerosol Mass Spectrometer (AMS) and complementary instrumentation. Positive Matrix Factorization (PMF) of high resolution AMS spectra identified a biomass burning OA (BBOA) component, which includes several large plumes that appear to be from forest fires within the region. Here, we show that the AMS BBOA concentration at T0 correlates with fire counts in the vicinity of Mexico City and that most of the BBOA variability is captured when the FLEXPART model is used for the dispersion of fire emissions as estimated from satellite fire counts. The resulting FLEXPART fire impact index correlates well with the observed BBOA, CH3CN, levoglucosan, and potassium, indicating that wildfires in the region surrounding Mexico City are the dominant source of BBOA at T0 during MILAGRO. The impact of distant BB sources such as the Yucatan is very small during this period. All fire tracers are correlated, with BBOA and levoglucosan showing little background, acetonitrile having a well-known tropospheric background of ~100-150 ppt, and PM2.5 potassium having a background of ~160 ng m-3 (two-thirds of its average concentration), which does not appear to be related to BB sources.

  4. Multicomponent mixed dopant optimization for rapid screening of polycyclic aromatic hydrocarbons using ultra high performance liquid chromatography coupled to atmospheric pressure photoionization high-resolution mass spectrometry

    KAUST Repository

    Sioud, Salim

    2012-05-04

    RATIONALE To enhance the ionization efficiencies in atmospheric pressure photoionization mass spectrometry a dopant with favorable ionization energy such as chlorobenzene is typically used. These dopants are typically toxic and difficult to mix with water-soluble organic solvents. In order to achieve a more efficient and less toxic dopant, a multicomponent mixed dopant was explored. METHODS A multicomponent mixed dopant for non-targeted rapid screening of polycyclic aromatic hydrocarbons (PAHs) was developed and optimized using ultra high performance liquid chromatography (UPLC) coupled to atmospheric pressure photoionization high-resolution mass spectrometry. Various single and multicomponent mixed dopants consisting of ethanol, chlorobenzene, bromobenzene, anisole and toluene were evaluated. RESULTS Fourteen out of eighteen PAHs were successfully separated and detected at low pg/μL levels within 5 min with high mass accuracy ≤4 ppm. The optimal mixed multicomponent dopant consisted of ethanol/chlorobenzene/bromobenzene/anisole (98.975:0.1:0.9:0.025, v/v %) and it improved the limit of detection (LOD) by 2- to 10-fold for the tested PAHs compared to those obtained with pure chlorobenzene. CONCLUSIONS A novel multicomponent dopant that contains 99% ethanol and 1% mixture of chlorobenzene, bromobenzene and anisole was found to be an effective dopant mixture to ionize PAHs. The developed UPLC multicomponent dopant assisted atmospheric pressure photoionization high-resolution mass spectrometry offered a rapid non targeted screening method for detecting the PAHs at low pg/;μL levels within a 5 min run time with high mass accuracy a;circ4 ppm. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Elucidation and identification of amino acid containing membrane lipids using liquid chromatography/high-resolution mass spectrometry

    NARCIS (Netherlands)

    Moore, E.K.; Hopmans, E.C.; Rijpstra, W.I.C.; Villanueva, L.; Sinninghe Damsté, J.S.

    2016-01-01

    RATIONALE: Intact polar lipids (IPLs) are the building blocks of cell membranes, and amino acid containing IPLs havebeen observed to be involved in response to changing environmental conditions in various species of bacteri a. High-performance liquid chromatography/mass spectrometry (HPLC/MS) has be

  6. Accurate and precise 40Ar/39Ar dating by high-resolution, multi-collection, mass spectrometry

    DEFF Research Database (Denmark)

    Storey, Michael; Rivera, Tiffany; Flude, Stephanie

    -Instruments multi-collector Noblesse noble gas mass spectrometer configured with a faraday detector and three ion-counting electron multipliers. The instrument has the capability to measure several noble gas isotopes simultaneously and to change measurement configurations instantaneously by the use of QUAD lenses...

  7. Close range photogrammetry in soil erosion monitoring: Mass loss comparison between runoff plots and high resolution DEMs

    Science.gov (United States)

    Ahner, Mario; Seitz, Steffen; Scholten, Thomas; Song, Zhengshan; Schmidt, Karsten

    2017-04-01

    Soil erosion is a major environmental problem and can lead to severe negative impacts on terrestrial ecosystems. When raindrops hit a bare soil surface, the applied kinetic energy successively detaches soil particles. This rainsplash effect marks the initial stage of soil erosion, which can result in serious sediment losses with beginning surface runoff. Mini-runoff plots are often used to monitor soil erosion rates in comparative field experiments. However, this method is time-consuming, the sampling of detached soil is difficult and the accuracy heavily depends on thorough maintenance and control of the measurement setup. To optimize the acquisition of soil erosion data from splash and interrill processes, a digital method using close range photogrammetry was tested in 2015. Therefore, a photogrammetric workflow was applied to process high resolution digital elevation models (DEMs) from overlapping stereo-images. By calculating the differences between multi-temporal DEMs with a sub-millimetre resolution, the volume of detached sediment was assessed. We performed rainfall simulations with a single nozzle rainfall simulator and a light weight tent. Micro-scale runoff plots (ROPs, 0.4 m x 0.4 m) were used with two different treatments, namely a Hortic Anthrosol and sand (grain size 0.10-0.45 mm). Five repetitions of rainfall-exposure with an intensity of 60 mm h-1 were performed and each repetition divided into three intervals (0-15 min, 15-30 min and 30-60 min). Before the first and every following interval, a block of 25 stereo-images was acquired with a single lens reflex camera system and processed in Agisoft PhotoScan for DEM-generation. After every interval, the discharged sediment was dried and weighed in order to derive the ground-truth validation data for comparison. Results show that ROPs with the sand treatment generally showed a larger volume of detached sediment than the garden soil treatment. As sediment discharge increased, the modelled and measured

  8. Interpretation of Tandem Mass Spectrometry (MSMS) Spectra for Peptide Analysis

    DEFF Research Database (Denmark)

    Hjernø, Karin; Højrup, Peter

    2015-01-01

    The aim of this chapter is to give a short introduction to peptide analysis by mass spectrometry (MS) and interpretation of fragment mass spectra. Through examples and guidelines we demonstrate how to understand and validate search results and how to perform de novo sequencing based on the often...... very complex fragmentation pattern obtained by tandem mass spectrometry (also referred to as MSMS). The focus is on simple rules for interpretation of MSMS spectra of tryptic as well as non-tryptic peptides....

  9. Impurity profiling of liothyronine sodium by means of reversed phase HPLC, high resolution mass spectrometry, on-line H/D exchange and UV/Vis absorption.

    Science.gov (United States)

    Ruggenthaler, M; Grass, J; Schuh, W; Huber, C G; Reischl, R J

    2017-09-05

    For the first time, a comprehensive investigation of the impurity profile of the synthetic thyroid API (active pharmaceutical ingredient) liothyronine sodium (LT3Na) was performed by using reversed phase HPLC and advanced structural elucidation techniques including high resolution tandem mass spectrometry (HRMS/MS) and on-line hydrogen-deuterium (H/D) exchange. Overall, 39 compounds were characterized and 25 of these related substances were previously unknown to literature. The impurity classification system recently developed for the closely related API levothyroxine sodium (LT4Na) could be applied to the newly characterized liothyronine sodium impurities resulting in a wholistic thyroid API impurity classification system. Furthermore, the mass-spectrometric CID-fragmentation of specific related substances was discussed and rationalized by detailed fragmentation pathways. Moreover, the UV/Vis absorption characteristics of the API and selected impurities were investigated to corroborate chemical structure assignments derived from MS data. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The relation between gas density and velocity power spectra in galaxy clusters: high-resolution hydrodynamic simulations and the role of conduction

    CERN Document Server

    Gaspari, M; Nagai, D; Lau, E T; Zhuravleva, I

    2014-01-01

    Exploring the ICM power spectrum can help us to probe the physics of galaxy clusters. Using high-resolution 3D plasma simulations, we study the statistics of the velocity field and its relation with the thermodynamic perturbations. The normalization of the ICM spectrum (density, entropy, or pressure) is linearly tied to the level of large-scale motions, which excite both gravity and sound waves due to stratification. For low 3D Mach number M~0.25, gravity waves mainly drive entropy perturbations, traced by preferentially tangential turbulence. For M>0.5, sound waves start to significantly contribute, passing the leading role to compressive pressure fluctuations, associated with isotropic turbulence (or a slight radial bias). Density and temperature fluctuations are then characterized by the dominant process: isobaric (low M), adiabatic (high M), or isothermal (strong conduction). Most clusters reside in the intermediate regime, showing a mixture of gravity and sound waves, hence drifting towards isotropic vel...

  11. DOTS: A High Resolution Orbitrap Mass Spectrometer for In Situ Analysis of the surface samples of Airless Planetary Bodies

    Science.gov (United States)

    Briois, Christelle; Thissen, Roland; Engrand, Cécile; Altwegg, Kathrin; Bouabdellah, Abdel; Boukrara, Amirouche; Carrasco, Nathalie; Chapuis, Claude; Cottin, Hervé; Grün, Eberhard; Grand, Noel; Henkel, Hartmut; Kempf, Sascha; Lebreton, Jean-Pierre; Makarov, Alexander A.; Postber, Frank; Srama, Ralf; Schmidt, Jürgen; Szopa, Cyril; Thirkell, Laurent; Tobie, Gabriel; Wurz, Peter; Zolotov, Mikhail Yu

    2013-04-01

    The dust detectors on board the Ulysses and Galileo spacecraft have shown that the Galilean satellites are surrounded by clouds of sub-micrometer size grains generated by impacts of interplanetary (micro-) meteoroids [1, 2]. In situ chemical analysis from orbit of these ballistic grains ejected from the surface of airless bodies provides a unique opportunity to remotely access the chemical composition of the Jovian moons' surface and subsurface. For Saturn, in situ identification by the Cassini Dust Analyzer (CDA) of sodium in icy grains in the E-Ring and in Enceladus plumes have proven a subsurface liquid water reservoir inside Enceladus [3, 4]. Noticeably, this was not accessible to other in situ or traditional remote sensing techniques. In situ measurements, either during a flyby or from orbit, of grains ejected from the surface, or emerging from the subsurface, of an airless body is a powerful tool to remotely study its surface composition and the nature of its geological activity. Crucial constraints on habitability can thus be determined. Our consortium of laboratories, in collaboration with Thermo Fischer Scientific [5, 6], is currently developing a high mass resolution Fourier Transform (FT) Orbitrap-based mass spectrometer optimized for in situ analysis of dust and icy grains in the environment of Solar System airless bodies. This new generation of dust mass spectrometer was studied in the framework of the Europa Jupiter System Mission (EJSM) instrument study in 2010-2012 and proposed in response to ESA's AO for the JUpiter ICy moons Explorer (JUICE) mission [7]. This mass analyser can provide very high mass resolution analysis (M/ΔM reaching 50 000 at m/z 50 Da). DOTS would allow identification of elemental and molecular species with excellent accuracy, in the 20-1000 Da mass range. In the context of the JUICE mission, DOTS would provide decisive information on the surface composition and on the putative liquid oceans in the subsurface of Ganymede

  12. Analytical Characterization of two new related impurities of Diltiazem by High Resolution Mass spectrometry and NMR techniques096

    Directory of Open Access Journals (Sweden)

    Jagadeesh Narkedimilli

    2015-09-01

    Full Text Available Diltiazem (DTZ is an optically active calcium channel blocker having a benzodiazepine structure. Two impurities (referred as DTZ-I and DTZ-II were detected with area percentages ranging from 0.1% to 0.15% during the impurity profile study of Diltiazem hydrochloride drug substance. A simple isocratic high performance liquid chromatographic method (HPLC and liquid chromatography–mass spectrometry (LC–MS were used for the detection. The impurities were isolated by preparative column chromatography. Analytical information from nuclear magnetic resonance and mass spectral data of the potential impurities revealed their structures as 2-(4-methoxyphenyl-5-methyl-4-oxo-2,3,4,5-tetrahydrobenzo[b][1,4]thiazepin-3-yl acetate (DTZ-I and 2-(4-methoxyphenyl-4-oxo-5-vinyl-2,3,4,5-tetrahydrobenzo[b][1,4]thiazepin-3-yl acetate (DTZ-II. Impurity identification, isolation and structure elucidation were discussed.

  13. High resolution spectroscopy of six new extreme helium stars

    Science.gov (United States)

    Heber, U.; Jones, G.; Drilling, J. S.

    1986-01-01

    High resolution spectra of six newly discovered extreme helium stars are presented. LSS 5121 is shown to be a spectroscopical twin of the hot extreme helium star HD 160641. A preliminary LTE analysis of LSS 3184 yielded an effective temperature of 22,000 K and a surface gravity of log g = 3.2. Four stars form a new subgroup, classified by sharp-lined He I spectra and pronounced O II spectra, and it is conjectured that these lie close to the Eddington limit. The whole group of extreme helium stars apparently is inhomogeneous with respect to luminosity to mass ratio and chemical composition.

  14. Comparison of peak-picking workflows for untargeted liquid chromatography/high-resolution mass spectrometry metabolomics data analysis.

    Science.gov (United States)

    Rafiei, Atefeh; Sleno, Lekha

    2015-01-15

    Data analysis is a key step in mass spectrometry based untargeted metabolomics, starting with the generation of generic peak lists from raw liquid chromatography/mass spectrometry (LC/MS) data. Due to the use of various algorithms by different workflows, the results of different peak-picking strategies often differ widely. Raw LC/HRMS data from two types of biological samples (bile and urine), as well as a standard mixture of 84 metabolites, were processed with four peak-picking softwares: Peakview®, Markerview™, MetabolitePilot™ and XCMS Online. The overlaps between the results of each peak-generating method were then investigated. To gauge the relevance of peak lists, a database search using the METLIN online database was performed to determine which features had accurate masses matching known metabolites as well as a secondary filtering based on MS/MS spectral matching. In this study, only a small proportion of all peaks (less than 10%) were common to all four software programs. Comparison of database searching results showed peaks found uniquely by one workflow have less chance of being found in the METLIN metabolomics database and are even less likely to be confirmed by MS/MS. It was shown that the performance of peak-generating workflows has a direct impact on untargeted metabolomics results. As it was demonstrated that the peaks found in more than one peak detection workflow have higher potential to be identified by accurate mass as well as MS/MS spectrum matching, it is suggested to use the overlap of different peak-picking workflows as preliminary peak lists for more rugged statistical analysis in global metabolomics investigations. Copyright © 2014 John Wiley & Sons, Ltd.

  15. (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.

  16. The Mass Function of Main Sequence Stars in NGC6397 from Near IR and Optical High Resolution HST Observations

    CERN Document Server

    De Marchi, G; Pulonen, L E; Marchi, Guido De; Paresce, Francesco; Pulone, Luigi

    1999-01-01

    We have investigated the properties of the stellar mass function in the globular cluster NGC6397 using a large set of HST observations that include WFPC2 images in V and I, obtained at ~4' and 10' radial distances, and a series of deep images in the J and H bands obtained with the NIC2 and NIC3 cameras of NICMOS pointed to regions located ~4.5' and ~3.2' from the center. These observations span the region from ~1 to ~3 times the cluster's half-light radius. All luminosity functions, derived from color magniutde diagrams, increase with decreasing luminosity up to a peak at M_I~8.5 or M_H~7 and then precipitously drop well before photometric incompleteness becomes significant. Within the observational uncertainties, at M_I~12 or M_H~10.5 (~0.09 Msun) the luminosity functions are compatible with zero. By applying the best available mass- luminosity relation appropriate to the metallicity of NGC6397 to both the optical and IR data, we obtain a mass function that shows a break in slope at data, regardless of the v...

  17. Semi-targeted analysis of metabolites using capillary-flow ion chromatography coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    Burgess, Karl; Creek, Darren; Dewsbury, Paul; Cook, Ken; Barrett, Michael P

    2011-11-30

    This work describes a novel application of capillary-flow ion chromatography mass spectrometry for metabolomic analysis, and comparison of the technique to octadecyl silica and hydrophilic interaction chromatography (HILIC)-based mass spectrometry. While liquid chromatography/mass spectrometry (LC/MS) is rapidly becoming the standard technique for metabolomic analysis, metabolomic samples are extremely heterogeneous, leading to a requirement for multiple methods of analysis and separation techniques to perform a 'global' metabolomic analysis. While C18 is suitable for hydrophobic metabolites and has been used extensively in pharmaceutical drug metabolism studies, HILIC is, in general, efficient at separating polar metabolites. Phosphorylated species and organic acids are challenging to analyse and effectively quantitate on both systems. There is therefore a requirement for an MS-compatible analytical technique that can separate negatively charged compounds, such as ion-exchange chromatography. Evaluation of capillary flow ion chromatography with electrolytic suppression was performed on a library of metabolite standards and was shown to effectively separate organic acids and sugar di- and tri-phosphates. Limits of detection for these compounds range from 0.01 to 100 pmol on-column. Application of capillary ion chromatography to a comparative analysis of energy metabolism in procyclic forms of the parasitic protozoan Trypanosoma brucei where cells were grown on glucose or proline as a carbon source was demonstrated to be more effective than HILIC for detection of the organic acids that comprise glucose central metabolism and the tricarboxylic acid (TCA) cycle.

  18. Ozone-induced dissociation on a traveling wave high-resolution mass spectrometer for determination of double-bond position in lipids.

    Science.gov (United States)

    Vu, Ngoc; Brown, Jeffery; Giles, Kevin; Zhang, Qibin

    2017-09-15

    The position of C=C within fatty acyl chains affects the biological function of lipids. Ozone-induced dissociation mass spectrometry (OzID-MS) has great potential in determination of lipid double-bond position, but has generally been implemented on low-resolution ion trap mass spectrometers. In addition, most of the OzID-MS experiments carried out so far were focused on the sodiated adducts of lipids; fragmentation of the most commonly observed protonated ions generated in LC/MS-based lipidomics workflow has been less explored. Ozone generated in line from an ozone generator was connected to the trap and transfer gas supply line of a Synapt G2 high-resolution mass spectrometer. Protonated ions of different phosphatidylcholines (PC) were generated by electrospray ionization through direct infusion. Different parameters, including traveling wave height and velocity, trap entrance and DC potential, were adjusted to maximize the OzID efficiency. sn-positional isomers and cis/trans isomers of lipids were compared for their reactivity with ozone. Traveling wave height and velocity were tuned to prolong the encounter time between lipid ions and ozone, and resulted in improved OzID efficiency, as did increasing trapping region DC and entrance potential. Under optimized settings, at least 1000 times enhancement in OzID efficiency was achieved compared to that under default settings for monounsaturated PC standards. Monounsaturated C=C in the sn-2 PC isomer reacted faster with ozone than the sn-1 isomer. Similarly, the C=C in trans PC reacted faster than in cis PC. This is the first implementation of OzID in the trap and transfer region of a traveling wave enabled high-resolution mass spectrometer. The OzID reaction efficiency is significantly improved by slowing down ions in the trap region for their prolonged interaction with ozone. This will facilitate application of high-resolution OzID-MS in lipidomics. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Exploring the frontiers of synthetic eumelanin polymers by high-resolution matrix-assisted laser/desorption ionization mass spectrometry.

    Science.gov (United States)

    Reale, Samantha; Crucianelli, Marcello; Pezzella, Alessandro; d'Ischia, Marco; De Angelis, Francesco

    2012-01-01

    New trends in material science and nanotechnologies have spurred growing interest in eumelanins black insoluble biopolymers derived by tyrosinase-catalysed oxidation of tyrosine via 5,6-dihydroxyindole (DHI) and its 2-carboxylic acid (DHICA). Efficient antioxidant and photoprotective actions, associated with peculiar optoelectronic properties, are recognised as prominent functions of eumelanin macromolecules within the human and mammalian pigmentary system, making them unique candidates for the realisation of innovative bio-inspired functional soft materials, with structure-based physical-chemical properties. An unprecedented breakthrough into the mechanism of synthetic eumelanin buildup has derived from a detailed investigation of the oxidative polymerization of DHI and its N-methyl derivative (NMDHI) by linear and reflectron matrix-assisted laser/desorption ionization mass spectrometry. Regular collections of oligomers of increasing masses, spanning the entire m/z ranges up to 5000 Da (>30-mer) and 8000 Da (> 50-mer) for the two building blocks, respectively, were disclosed. It is the first time that the in vitro polymerisation of dihydroxyindoles to form synthetic eumelanins is explored up to its high mass limits, giving at the same time information on the polymerisation mode, whether it follows a stepwise pattern (being this the conclusion in our case) or a staking sequencing of small-sized entities. It also highlighted the influence of the N-methyl substituent on the polymerization process; this opens the way to the production of N-functionalized, synthetic eumelanin-inspired soft materials, for possible future technological applications. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Electromechanical model of a resonating nano-cantilever-based sensor for high-resolution and high-sensitivity mass detection

    DEFF Research Database (Denmark)

    Abadal, G.; Davis, Zachary James; Helbo, Bjarne;

    2001-01-01

    A simple linear electromechanical model for an electrostatically driven resonating cantilever is derived. The model has been developed in order to determine dynamic quantities such as the capacitive current flowing through the cantilever-driver system at the resonance frequency, and it allows us...... to calculate static magnitudes such as position and voltage of collapse or the voltage versus deflection characteristic. The model is used to demonstrate the theoretical sensitivity on the attogram scale of a mass sensor based on a nanometre-scale cantilever, and to analyse the effect of an extra feedback loop...

  1. A comprehensive characterisation of beer polyphenols by high resolution mass spectrometry (LC-ESI-LTQ-Orbitrap-MS).

    Science.gov (United States)

    Quifer-Rada, Paola; Vallverdú-Queralt, Anna; Martínez-Huélamo, Miriam; Chiva-Blanch, Gemma; Jáuregui, Olga; Estruch, Ramon; Lamuela-Raventós, Rosa

    2015-02-15

    Beer is the second most consumed alcoholic beverage in Europe and shown by the European Prospective Investigation into Cancer and Nutrition cohort study to be the main food contributor to hydroxybenzoic acid intake. About 70-80% of the total polyphenol content in beer comes from malt, and the remaining 30-20% from hops. In this work, liquid chromatography coupled with an electrospray ionization hybrid linear ion trap quadrupole Orbitrap mass spectrometry technique has been used for an accurate identification of beer polyphenols. 47 phenolic compounds were identified using high mass accuracy and confirmed by MS(2) experiments, including simple phenolic acids, hydroxycinnamoylquinics, flavanols, flavonols, flavones, alkylmethoxyphenols, alpha- and iso-alpha-acids, hydroxyphenylacetic acids and prenylflavonoids. As far as we know, 7 of these compounds have been recognised in beer for the first time: feruloylquinic acid, caffeic acid-O-hexoside, coumaric acid-O-hexoside, sinapic acid-O-hexoside, catechin-O-dihexoside, kaempferol-O-hexoside, and apigenin-C-hexoside-pentoside.

  2. Profiling of Histone Post-Translational Modifications in Mouse Brain with High-Resolution Top-Down Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Mowei; Paša-Tolić, Ljiljana; Stenoien, David L.

    2016-12-21

    Histones play central roles in most chromosomal functions and both their basic biology and roles in disease have been the subject of intense study. Since multiple PTMs along the entire protein sequence are potential regulators of histones, a top-down approach, where intact proteins are analyzed, is ultimately required for complete characterization of proteoforms. However, significant challenges remain for top-down histone analysis primarily because of deficiencies in separation/resolving power and effective identification algorithms. Here, we used state of the art mass spectrometry and a bioinformatics workflow for targeted data analysis and visualization. The workflow uses ProMex for intact mass deconvolution, MSPathFinder as search engine, and LcMsSpectator as a data visualization tool. ProMex sums across retention time to maximize sensitivity and accuracy for low abundance species in MS1deconvolution. MSPathFinder searches the MS2 data against protein sequence databases with user-defined modifications. LcMsSpectator presents the results from ProMex and MSPathFinder in a format that allows quick manual evaluation of critical attributes for high-confidence identifications. When complemented with the open-modification tool TopPIC, this workflow enabled identification of novel histone PTMs including tyrosine bromination on histone H4 and H2A, H3 glutathionylation, and mapping of conventional PTMs along the entire protein for many histone subunits.

  3. High-resolution simulations of the surface mass balance of Greenland at the end of this century

    Directory of Open Access Journals (Sweden)

    G. Krinner

    2007-09-01

    Full Text Available We present atmospheric general circulation model simulations of the present (1981–2005 and future (2081–2100 climate according to the SRES A1B greenhouse gas scenario. Focusing on Greenland, we use a stretched grid in the global model, thereby reaching a horizontal grid spacing of 60 km in the region of interest. This allows to capture reasonably the escarpment zone of the ice sheet. For the end of this century, the model suggests a precipitation increase in the central region of Greenland, which is overcompensated for by a strong increase of meltwater production in the lower areas. We calculate the changes of water fluxes into the adjacent seas according the simulated surface mass balances changes. The calculated freshwater flux at the end of the 21st century appears too weak to induce a significant reduction of the meridional overturning circulation in the North Atlantic. The resulting surface mass balance decrease between the last decades of the 20th and 21st centuries is equivalent to a positive contribution of 0.8 mm yr−1 to global eustatic sea-level rise.

  4. Orbital parameters, masses and distance to Beta Centauri determined with the Sydney University Stellar Interferometer and high resolution spectroscopy

    CERN Document Server

    Davis, J; Seneta, E B; Tango, W J; Booth, A J; O'Byrne, J W; Thorvaldson, E D; Ausseloos, M; Aerts, C; Uytterhoeven, K

    2004-01-01

    The bright southern binary star beta Centauri (HR 5267) has been observed with the Sydney University Stellar Interferometer (SUSI) and spectroscopically with the ESO CAT and Swiss Euler telescopes at La Silla. The interferometric observations have confirmed the binary nature of the primary component and have enabled the determination of the orbital parameters of the system. At the observing wavelength of 442 nm the two components of the binary system have a magnitude difference of 0.15. The combination of interferometric and spectroscopic data gives the following results: orbital period 357 days, semi-major axis 25.30 mas, inclination 67.4 degrees, eccentricity 0.821, distance 102.3 pc, primary and secondary masses M1 = M2 = 9.1 solar masses and absolute visual magnitudes of the primary and secondary M1V = -3.85 and M2V = -3.70. The high accuracy of the results offers a fruitful starting point for future asteroseismic modelling of the pulsating binary components.

  5. Burn-Up Determination by High Resolution Gamma Spectrometry: Spectra from Slightly-Irradiated Uranium and Plutonium between 400-830 keV

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R.S.; Ronqvist, N.

    1966-08-15

    Previously published studies of the short-cooled fission product spectra of irradiated uranium have been severely restricted by the poor energy resolution of the sodium iodide detectors used. In this report are presented fission product spectra of irradiated uranium and plutonium obtained by means of a lithium-drifted germanium detector. The resolved gamma peaks have been assigned to various fission products by correlation of measured energy and half-life values with published data. By simultaneous study of the spectra of two irradiated mixtures of plutonium and uranium, the possibility of using the activities of Ru-103 and Ru-106 as a measure of the relative fission rate in U-235 and Pu-239 has been briefly examined.

  6. High-resolution spectroscopy in superfluid helium droplets. Investigation of vibrational fine structures in electronic spectra of phthalocyanine and porphyrin derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Riechers, Ricarda Eva Friederike Elisabeth

    2011-03-22

    Since a considerably large variety of substituted compounds is commercially available and the electronic excitation spectra fit well into the spectral range covered by the continuous wave dye laser used for this study several porphyrin and phthalocyanine derivatives substituted with different types and numbers of alkyl and aryl groups were chosen as molecular probes. Recording fluorescence excitation and dispersed emission spectra revealed exclusively sharp transitions for all species. A change of the molecule's electrostatic moments, primarily and most effectively, a change of the molecular dipole moment regarding both magnitude and orientation, was identified as the main contribution for line broadening effects. Apart from the sharp lines presented in their fluorescence excitation spectra, the phthalocyanine derivatives investigated for this study, namely chloro-aluminium-phthalocyanine (AlClPc) and tetra-tertbutyl-phthalocyanine (TTBPc), exhibited more than one emission spectrum.

  7. Characterization of submicron aerosols during a serious pollution month in Beijing (2013 using an aerodyne high-resolution aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    J. K. Zhang

    2013-07-01

    Full Text Available In January 2013, Beijing experienced several serious haze events. To achieve a better understanding of the characteristics, sources and processes of aerosols during this month, an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS was deployed at an urban site between 1 January and 1 February 2013 to obtain the size-resolved chemical composition of non-refractory submicron particles (NR-PM1. During this period, the mean measured NR-PM1 mass concentration was 87.4 μg m-3 and was composed of organics (49.8%, sulfate (21.4%, nitrate (14.6%, ammonium (10.4%, and chloride (3.8%. Moreover, inorganic matter, such as sulfate and nitrate comprised an increasing fraction of the NR-PM1 load as NR-PM1 loading increased, denoting their key roles in particulate pollution during this month. The average size distributions of the species were all dominated by an accumulation mode peaking at approximately 600 nm in vacuum aerodynamic diameter and organics characterized by an additional smaller size (∼200 nm. Elemental analyses showed that the average O/C, H/C, and N/C (molar ratio of organic matter were 0.34, 1.44 and 0.015, respectively, corresponding to an OM/OC ratio (mass ratio of organic matter to organic carbon of 1.60. Positive matrix factorization (PMF analyses of the high-resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., oxygenated organic aerosols (OOA, cooking-related (COA, nitrogen-containing (NOA and hydrocarbon-like (HOA, which on average accounted for 40.0, 23.4, 18.1 and 18.5% of the total organic mass, respectively. Back trajectory clustering analyses indicated that the WNW air masses were associated with the highest NR-PM1 pollution during the campaign. Aerosol particles in southern air masses were especially rich in inorganic and oxidized organic species, whereas northern air masses contained a large fraction of primary species.

  8. Dynamics of explosive paroxysms at open andesitic systems: high-resolution mass distribution analyses of 2006 tephra from Tungurahua volcano (Ecuador)

    Science.gov (United States)

    Le Pennec, J.; Eychenne, J.; Ramon, P.; Yepes, H.

    2012-12-01

    Many andesitic volcanoes at subduction plate margins can experience in the course of their evolution periods of sub-continuous eruption during years, decades, or centuries. Such long-lived periods may embrace more or less intense outgassing events, extrusion of viscous lava flows and domes (e.g. Colima in Mexico, Merapi in Indonesia, Arenal in Costa Rica), and explosive activity of uneven intensity (e.g. Semeru in Indonesia, Sakurajima in Japan, Sangay in Ecuador). In addition, strong explosive events of short duration may occur, with potential generation of pyroclastic flows on the flanks and beyond, which can pose significant hazards in populated regions. The origin and dynamics of such violent eruptions remain poorly known and may involve a combination of different factors. Tungurahua volcano, Ecuador, reawaken in 1999 and is an example of such open-system behaviour that experienced a strong and deadly andesitic pyroclastic flow-forming event in August 2006. Inspection of the deposits suggested that the event could have been triggered by magma mixing (silicic pumices in the tephra), magma-water interaction (presence of xenolithic clasts) or deep andesitic magma reinjection (based on mineral chemistry). Here we investigate these options by performing a high-resolution mass budget analysis of the scoria fall deposit. This is achieved by analysing componentry compositions and their mass distribution pattern in the layer, which allow us to document and integrate exponential and power laws mass decay rates over wide areas. The results yield a total mass for the tephra layer of ~2 x 1010kg. The pumice mass fraction is far too small (< 0.4 %) to account for the high explosivity of the 2006 event. Similarly, the xenoclastic mass fraction is small (0.2%) and suggests limited magma-water interaction. Instead, we interpret these xenoclasts as a result of upper conduit erosion at a rate of ~30 cm/hour during the paroxysm. Altogether our results support an explosive event

  9. Eddy covariance measurements with high-resolution time-of-flight aerosol mass spectrometry: a new approach to chemically-resolved aerosol fluxes

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2010-12-01

    Full Text Available Although laboratory studies show that biogenic volatile organic compounds (VOCs yield substantial secondary organic aerosol (SOA, production of biogenic SOA as indicated by upward fluxes has not been conclusively observed over forests. Further, while aerosols are known to deposit to surfaces, few techniques exist to provide chemically-resolved particle deposition fluxes. To better constrain aerosol sources and sinks, we have developed a new technique to directly measure fluxes of chemically-resolved submicron aerosols using the high-resolution time-of-flight aerosol mass spectrometer (HR-AMS in a new, fast eddy covariance mode. This approach takes advantage of the instrument's ability to quantitatively identify both organic and inorganic components, including ammonium, sulphate and nitrate, at a temporal resolution of several Hz. The new approach has been successfully deployed over a temperate ponderosa pine plantation in California during the BEARPEX-2007 campaign, providing both total and chemically resolved non-refractory (NR PM1 fluxes. Average deposition velocity for total NR-PM1 aerosol at noon was 2.05 ± 0.04 mm/s. Using a high resolution measurement of the NH2+ and NH3+ fragments, we demonstrate the first eddy covariance flux measurements of particulate ammonium, which show a noon-time deposition velocity of 1.9 ± 0.7 mm/s and are dominated by deposition of ammonium sulphate.

  10. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation

    Energy Technology Data Exchange (ETDEWEB)

    Borràs, S. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain); Kaufmann, A., E-mail: anton.kaufmann@klzh.ch [Official Food Control Authority, Fehrenstrasse 15, 8032 Zürich (Switzerland); Companyó, R. [Departament de Química Analítica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain)

    2013-04-15

    Highlights: ► We are describing a technique to spot ions which are derived from each other. ► Single stage high resolution data is used. ► This “in silicon” technique is compared to conventional precursor scan. ► Some applications for this technique are presented. -- Abstract: Monitoring of common diagnostic fragments is essential for recognizing molecules which are members of a particular compound class. Up to now, unit resolving tandem quadrupole mass spectrometers, operating in the precursor ion scan mode, have been typically used to perform such analysis. By means of high-resolution mass spectrometry (HRMS) a much more sensitive and selective detection can be achieved. However, using a single-stage HRMS instrument, there is no unequivocal link to the corresponding precursor ion, since such instrumentation does not permit a previous precursor selection. Thus, to address this limitation, an in silico approach to locate precursor ions, based on diagnostic fragments, was developed. Implemented as an Excel macro, the algorithm rapidly assembles and surveys exact mass data to provide a list of feasible precursor candidates according to the correlation of the chromatographic peak shape profile and other additional filtering criteria (e.g. neutral losses and isotopes). The macro was tested with two families of veterinary drugs, sulfonamides and penicillins, which are known to yield diagnostic product ions when fragmented. Data sets obtained from different food matrices (fish and liver), both at high and low concentration of the target compounds, were investigated in order to evaluate the capabilities and limitations of the reported approach. Finally, other possible applications of this technique, such as the elucidation of elemental compositions based on product ions and corresponding neutral losses, were also presented and discussed.

  11. Identification and quantification of the phosphorylated ovalbumin by high resolution mass spectrometry under dry-heating treatment.

    Science.gov (United States)

    Wang, Hui; Tu, Zong-Cai; Liu, Guang-Xian; Zhang, Lu; Chen, Yuan

    2016-11-01

    The specific phosphorylation sites and degree of phosphorylation (DP) at each site are directly related to protein's structure and functional properties. Thus, characterizing the introduced phosphate groups is of great importance. This study was to monitor the phosphorylation sites, DP and the number of phosphorylation sites in P-Oval achieved by dry heating in the presence of pyrophosphate for 1, 2 and 5days by using Fourier transform ion cyclotron mass spectrometry (FTICR MS). Two phosphorylation sites were found in natural ovalbumin, but the number of phosphorylation sites increased to 8, 8 and 10 after dry-heating phosphorylation for 1, 2 and 5days, respectively. In addition, dual-phosphorylated peptides were detected for samples without extensive heating. The phosphorylation sites were found to be mainly on Ser residues, which could be the preferred phosphorylation site for dry heating in the presence of pyrophosphate.

  12. Liquid extraction surface analysis (LESA) of hydrophobic TLC plates coupled to chip-based nanoelectrospray high-resolution mass spectrometry.

    Science.gov (United States)

    Himmelsbach, Markus; Varesio, Emmanuel; Hopfgartner, Gérard

    2014-01-01

    Direct identification and structural characterization of analyte spots on TLC plates have always been of great interest and the development of interfaces that allow TLC to be combined with MS is making steady progress. The recently introduced liquid extraction surface analysis (LESA) approach has the potential to hyphenate TLC with MS. A mixture of lipid standards was separated on HPTLC RP-18 glass plates using chloroform:methanol :acetonitrile 2:1:1 (v:v:v) as mobile phase. After visualization with primuline dye (0.02% in acetone:water 8:2 (v:v)), LESA was performed, followed by a chip-based nanoflow infusion in combination with FTICRMS. The optimized extraction solvent composition was methanol:chloroform:water:formic acid 52:24:24:0.2 (v:v:v:v). A nanoelectrospray voltage of 1.6 kV and a gas pressure of 0.2 psi were applied in all experiments. All phospholipids were extracted successfully and detected unambiguously using the optimized TLC-LESA-FTICRMS procedure. Sampling the tricaprylin spot gave the most intense signals and also tricaprin was detected. Three other triacylglycerols of higher molecular mass have logP values between 15.5 and 21.6, which are the highest among all investigated compounds and are not detected from their corresponding spots, due to the fact that the solubility of very apolar lipids is not high enough in the extraction solvent. It was demonstrated that TLC can be elegantly combined with mass spectrometry based on the LESA approach. In general, apart from the analysis of lipids, TLC-LESA-MS has a high potential for medium-polar compounds separated on reversed-phase TLC plates, but limitations are present when very apolar compounds have to be extracted.

  13. An iodide-adduct high-resolution time-of-flight chemical-ionization mass spectrometer: application to atmospheric inorganic and organic compounds.

    Science.gov (United States)

    Lee, Ben H; Lopez-Hilfiker, Felipe D; Mohr, Claudia; Kurtén, Theo; Worsnop, Douglas R; Thornton, Joel A

    2014-06-03

    A high-resolution time-of-flight chemical-ionization mass spectrometer (HR-ToF-CIMS) using Iodide-adducts has been characterized and deployed in several laboratory and field studies to measure a suite of organic and inorganic atmospheric species. The large negative mass defect of Iodide, combined with soft ionization and the high mass-accuracy (5500) of the time-of-flight mass spectrometer, provides an additional degree of separation and allows for the determination of elemental compositions for the vast majority of detected ions. Laboratory characterization reveals Iodide-adduct ionization generally exhibits increasing sensitivity toward more polar or acidic volatile organic compounds. Simultaneous retrieval of a wide range of mass-to-charge ratios (m/Q from 25 to 625 Th) at a high frequency (>1 Hz) provides a comprehensive view of atmospheric oxidative chemistry, particularly when sampling rapidly evolving plumes from fast moving platforms like an aircraft. We present the sampling protocol, detection limits and observations from the first aircraft deployment for an instrument of this type, which took place aboard the NOAA WP-3D aircraft during the Southeast Nexus (SENEX) 2013 field campaign.

  14. A new generation of high resolution mass analyzer to study organic and mineral matters simulating those of Titan and Enceladus: the Cosmorbitrap project

    Science.gov (United States)

    Selliez-Vandernotte, Laura; Briois, Christelle; Carrasco, Nathalie; Thirkell, Laurent; Cosmorbitrap Team

    2016-10-01

    Cassini mission highlighted for the first time, among many discoveries, the chemistry occurring in Titan atmosphere (with the detection of positive and negative ions at very high masses) and the presence of organic matter hidden in Enceladus plumes (1; 2). Can you imagine which results would have been obtained with a better resolution?Today, in lab, a new generation of high resolution mass analyzer called OrbitrapTM can reach a resolution of 106 at m/z=200 (3; 4). It gives a precise reading of the mass on charge, using a purely electric field and applying a Fourier transform. A project named Cosmorbitrap is trying to incorporate an OrbitrapTM analyzer, as a part of a mass spectrometer instrument, in order to propose it for a future mission toward the Saturn moons but also toward many other objects in the Solar System (5).Among the various tests required, we are optimizing the analysis of mineral and organic matter. This includes mass precision, resolution, isotopic detection, isotopic ratios and identification of unknown molecules. Starting with simple molecules, we will study more and more complex molecules and mixtures like Titan and Enceladus analogs. This meeting could be a great opportunity to explain our last results, to present benefits and limits of this instrument.(1) Waite et al, 2007, Science(2) Waite et al, 2009, Nature(3) Makarov, 2000(4) Denisov et al, 2012(5) Briois et al, 2016, Planetary and Space Science (in press)

  15. Environmental screening of acidic compounds based on capillary zone electrophoresis/laser-induced fluorescence detection with identification by gas chromatography/mass spectrometry and gas chromatography/high-resolution mass spectrometry.

    Science.gov (United States)

    Brumley, W C; Grange, A H; Kelliher, V; Patterson, D B; Montcalm, A; Glassman, J; Farley, J W

    2000-01-01

    This paper describes the application of capillary zone electrophoresis/laser-induced fluorescence detection (CZE/LIF) to the discovery of acidic compounds in environmental matrixes or the screening of extracts for acidic components. Published studies indicate that coal-derived materials contain a significant fraction of acidic compounds relative to materials derived from petroleum and shales. Such compounds may be useful as marker compounds for site assessment and source apportionment issues, and their identification may be important in toxicological and other health issues. We used deep-UV light from the frequency-doubled Ar ion laser at 244 and 257 nm to study extracts of samples. The CZE/LIF technique possesses good sensitivity and therefore overcomes one of the limitations of CZE with UV detection. The present work depends on high pressure/temperature solvent extraction of polynuclear aromatic hydrocarbon (PNA)-contaminated soil, followed by separation using CZE. The anionic analytes were separated by using borate or phosphate buffer (pH 9.2-12.3) after a chemical class separation. Samples were also characterized by gas chromatography/mass spectrometry (GC/MS) using full scans at low resolution, and elemental compositions were determined unequivocally by GC/high-resolution MS (GC/HRMS) using mass peak profiling (MPP). The similarity of low-resolution electron ionization mass spectra for a standard, 1-hydroxypyrene, and for a series of compounds in a contaminated-soil extract suggested that several types of phenolic and hydroxy-PNAs were present, including hydroxylated derivatives of fluorenes, fluoranthenes, and pyrenes. GC/HRMS using MPP confirmed the elemental compositions of the hydroxyfluorenes and hydroxypyrenes (and presumably hydroxyfluoranthenes) as [C13H10O] and [C16H10O], respectively. A new version of the MPP software was written for the Finnigan-MAT 900S-Trap and was similar to that developed previously for the VG 250SE. Inclusion of a calibration

  16. Detailed Structural Characterization of Sphingolipids via 193 nm Ultraviolet Photodissociation and Ultra High Resolution Tandem Mass Spectrometry

    Science.gov (United States)

    Ryan, Eileen; Nguyen, Catherine Quynh Nhu; Shiea, Christopher; Reid, Gavin E.

    2017-07-01

    Sphingolipids serve not only as components of cellular membranes but also as bioactive mediators of numerous cellular functions. As the biological activities of these lipids are dependent on their structures, and due to the limitations of conventional ion activation methods employed during tandem mass spectrometry (MS/MS), there is a recognized need for the development of improved structure-specific methods for their comprehensive identification and characterization. Here, positive-ionization mode 193 nm ultraviolet photodissociation (UVPD)-MS/MS has been implemented for the detailed structural characterization of lipid species from a range of sphingolipid classes introduced to the mass spectrometer via electrospray ionization as their lithiated or protonated adducts. These include sphingosine d18:1(4E), dihydrosphingosine (sphinganine) d18:0, sphingadiene d18:2(4E,11Z), the isomeric sphingolipids ceramide d18:1(4E)/18:0 and dihydroceramide d18:0/18:1(9Z), ceramide-1-phosphate d18:1(4Z)/16:0, sphingomyelin d18:1(4E)/18:1(9Z) the glycosphingolipids galactosyl ceramide d18:1(4E)/24:1(15Z) and lactosyl ceramide d18:1(4E)/24:0, and several endogenous lipids present within a porcine brain total lipid extract. In addition to the product ions formed by higher energy collision dissociation (HCD), UVPD is shown to yield a series of novel structurally diagnostic product ions resulting from cleavage of both sphingosine carbon-carbon and acyl chain carbon-carbon double bonds for direct localization of site(s) of unsaturation, as well as via diagnostic cleavages of the sphingosine backbone and N-C amide bond linkages. With activation timescales and dissociation efficiencies similar to those found in conventional MS/MS strategies, this approach is therefore a promising new tool in the arsenal of ion activation techniques toward providing complete structural elucidation in automated, high-throughput lipid analysis workflows.

  17. Facilitating high resolution mass spectrometry data processing for screening of environmental water samples: An evaluation of two deconvolution tools.

    Science.gov (United States)

    Bade, Richard; Causanilles, Ana; Emke, Erik; Bijlsma, Lubertus; Sancho, Juan V; Hernandez, Felix; de Voogt, Pim

    2016-11-01

    A screening approach was applied to influent and effluent wastewater samples. After injection in a LC-LTQ-Orbitrap, data analysis was performed using two deconvolution tools, MsXelerator (modules MPeaks and MS Compare) and Sieve 2.1. The outputs were searched incorporating an in-house database of >200 pharmaceuticals and illicit drugs or ChemSpider. This hidden target screening approach led to the detection of numerous compounds including the illicit drug cocaine and its metabolite benzoylecgonine and the pharmaceuticals carbamazepine, gemfibrozil and losartan. The compounds found using both approaches were combined, and isotopic pattern and retention time prediction were used to filter out false positives. The remaining potential positives were reanalysed in MS/MS mode and their product ions were compared with literature and/or mass spectral libraries. The inclusion of the chemical database ChemSpider led to the tentative identification of several metabolites, including paraxanthine, theobromine, theophylline and carboxylosartan, as well as the pharmaceutical phenazone. The first three of these compounds are isomers and they were subsequently distinguished based on their product ions and predicted retention times. This work has shown that the use deconvolution tools facilitates non-target screening and enables the identification of a higher number of compounds.

  18. Metabolism of clofibric acid in zebrafish embryos (Danio rerio) as determined by liquid chromatography-high resolution-mass spectrometry.

    Science.gov (United States)

    Brox, Stephan; Seiwert, Bettina; Haase, Nora; Küster, Eberhard; Reemtsma, Thorsten

    2016-01-01

    The zebrafish embryo (ZFE) is increasingly used in ecotoxicology research but detailed knowledge of its metabolic potential is still limited. This study focuses on the xenobiotic metabolism of ZFE at different life-stages using the pharmaceutical compound clofibric acid as study compound. Liquid chromatography with quadrupole-time-of-flight mass spectrometry (LC-QToF-MS) is used to detect and to identify the transformation products (TPs). In screening experiments, a total of 18 TPs was detected and structure proposals were elaborated for 17 TPs, formed by phase I and phase II metabolism. Biotransformation of clofibric acid by the ZFE involves conjugation with sulfate or glucuronic acid, and, reported here for the first time, with carnitine, taurine, and aminomethanesulfonic acid. Further yet unknown cyclization products were identified using non-target screening that may represent a new detoxification pathway. Sulfate containing TPs occurred already after 3h of exposure (7hpf), and from 48h of exposure (52hpf) onwards, all TPs were detected. The detection of these TPs indicates the activity of phase I and phase II enzymes already at early life-stages. Additionally, the excretion of one TP into the exposure medium was observed. The results of this study outline the high metabolic potential of the ZFE with respect to the transformation of xenobiotics. Similarities but also differences to other test systems were observed. Biotransformation of test chemicals in toxicity testing with ZFE may therefore need further consideration.

  19. Data on endogenous chicken sperm peptides and small proteins obtained through Top-Down High Resolution Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    L. Soler

    2016-09-01

    Full Text Available The endogenous peptides and small proteins present in chicken sperm were identified in the context of the characterization of a fertility-diagnostic method based on the use of ICM-MS (Intact Cell Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. The interpretation and description of these data can be found in a research article, “Intact cell MALDI-TOF MS on sperm: a molecular test for male fertility diagnosis” (Soler et al., 2016 [1], and raw data derived from this analysis have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PRIDE: PXD002768. Here, we describe the inventory of all the molecular species identified, along with their biochemical features and functional analysis. This peptide/protein catalogue can be further employed as reference for other studies and reveal that the use of proteomics allows for a global evaluation of sperm cells functions.

  20. High-resolution laser ablation-inductively coupled plasma-mass spectrometry imaging of cisplatin-induced nephrotoxic side effects.

    Science.gov (United States)

    Van Acker, Thibaut; Van Malderen, Stijn J M; Van Heerden, Marjolein; McDuffie, James Eric; Cuyckens, Filip; Vanhaecke, Frank

    2016-11-16

    Two-dimensional elemental mapping (bioimaging) via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was performed on 5 μm thick formalin-fixed, paraffin-embedded kidney tissue sections from Cynomolgus monkeys administered with increasing pharmacological doses of cisplatin. Laterally resolved pixels of 1 μm were achieved, enabling elemental analysis on a (sub-)cellular level. Zones of high Pt response were observed in the renal cortex, where proximal tubules are present, the epithelium of which is responsible for partial reabsorption of cisplatin. Histopathological evaluation, of hematoxylin and eosin-stained serial sections, adjacent to the sections probed via LA-ICP-MS, revealed minimal to mild cisplatin-related lesions (<100 μm) in the renal cortex. Necrotic proximal tubules with sloughed epithelial cells in their lumen could be linked directly to the areas with the highest accumulation of cisplatin, indicating a direct link between cellular concentration and toxicity, thereby providing more insight into the mechanisms through which renal damage occurs.

  1. Insights into the Binding Sites of Organometallic Ruthenium Anticancer Compounds on Peptides Using Ultra-High Resolution Mass Spectrometry

    Science.gov (United States)

    Wills, Rebecca H.; Habtemariam, Abraha; Lopez-Clavijo, Andrea F.; Barrow, Mark P.; Sadler, Peter J.; O'Connor, Peter B.

    2014-04-01

    The binding sites of two ruthenium(II) organometallic complexes of the form [(η6-arene)Ru( N, N)Cl]+, where arene/ N, N = biphenyl (bip)/bipyridine (bipy) for complex AH076, and biphenyl (bip)/ o-phenylenediamine ( o-pda) for complex AH078, on the peptides angiotensin and bombesin have been investigated using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Fragmentation was performed using collisionally activated dissociation (CAD), with, in some cases, additional data being provided by electron capture dissociation (ECD). The primary binding sites were identified as methionine and histidine, with further coordination to phenylalanine, potentially through a π-stacking interaction, which has been observed here for the first time. This initial peptide study was expanded to investigate protein binding through reaction with insulin, on which the binding sites proposed are histidine, glutamic acid, and tyrosine. Further reaction of the ruthenium complexes with the oxidized B chain of insulin, in which two cysteine residues are oxidized to cysteine sulfonic acid (Cys-SO3H), and glutathione, which had been oxidized with hydrogen peroxide to convert the cysteine to cysteine sulfonic acid, provided further support for histidine and glutamic acid binding, respectively.

  2. A new measure of Δα/α at redshift z = 1.84 from very high resolution spectra of Q 1101-264

    Science.gov (United States)

    Levshakov, S. A.; Molaro, P.; Lopez, S.; D'Odorico, S.; Centurión, M.; Bonifacio, P.; Agafonova, I. I.; Reimers, D.

    2007-05-01

    Aims:We probe the evolution of the fine-structure constant α with cosmic time. Methods: Accurate positions of the Fe II lines λ1608, λ2382, and λ2600 are measured in the z_abs = 1.84 absorption system from a high-resolution (FWHM ~ 3.8 km s-1) and high signal-to-noise (S/N ⪆ 100) spectrum of the quasar Q 1101-264 (z_em = 2.15, V = 16.0), integrated for 15.4 h. The Single Ion Differential α Measurement (SIDAM) procedure and the Δ χ2 method are used to set constraints on Δα/α. Results: We have found a relative radial velocity shift between the λ1608 and λλ2382,2600 lines of Δ v = -180 ± 85 m s-1 (both random and systematic errors are included), which, if real, would correspond to Δα/α = (5.4±2.5) × 10-6 (1σ C.L.). Considering the strong implications of a such variability, additional observations with comparable accuracy at redshift z ˜ 1.8 are required to confirm this result. Based on observations performed at the VLT Kueyen telescope (ESO, Paranal, Chile), the ESO programme No. 076.A-0463.

  3. Normalization to specific gravity prior to analysis improves information recovery from high resolution mass spectrometry metabolomic profiles of human urine.

    Science.gov (United States)

    Edmands, William M B; Ferrari, Pietro; Scalbert, Augustin

    2014-11-04

    Extraction of meaningful biological information from urinary metabolomic profiles obtained by liquid-chromatography coupled to mass spectrometry (MS) necessitates the control of unwanted sources of variability associated with large differences in urine sample concentrations. Different methods of normalization either before analysis (preacquisition normalization) through dilution of urine samples to the lowest specific gravity measured by refractometry, or after analysis (postacquisition normalization) to urine volume, specific gravity and median fold change are compared for their capacity to recover lead metabolites for a potential future use as dietary biomarkers. Twenty-four urine samples of 19 subjects from the European Prospective Investigation into Cancer and nutrition (EPIC) cohort were selected based on their high and low/nonconsumption of six polyphenol-rich foods as assessed with a 24 h dietary recall. MS features selected on the basis of minimum discriminant selection criteria were related to each dietary item by means of orthogonal partial least-squares discriminant analysis models. Normalization methods ranked in the following decreasing order when comparing the number of total discriminant MS features recovered to that obtained in the absence of normalization: preacquisition normalization to specific gravity (4.2-fold), postacquisition normalization to specific gravity (2.3-fold), postacquisition median fold change normalization (1.8-fold increase), postacquisition normalization to urinary volume (0.79-fold). A preventative preacquisition normalization based on urine specific gravity was found to be superior to all curative postacquisition normalization methods tested for discovery of MS features discriminant of dietary intake in these urinary metabolomic datasets.

  4. Advanced solvent based methods for molecular characterization of soil organic matter by high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Tolic, Nikola; Roscioli, Kristyn M.; Anderton, Christopher R.; Pasa-Tolic, Ljiljana; Robinson, Errol W.; Hess, Nancy J.

    2015-05-19

    Soil organic matter (SOM) a complex, heterogeneous mixture of above and belowground plant litter and animal and microbial residues at various degrees of decomposition, is a key reservoir for carbon (C) and nutrient biogeochemical cycling in soil based ecosystems. A limited understanding of the molecular composition of SOM limits the ability to routinely decipher chemical processes within soil and predict accurately how terrestrial carbon fluxes will response to changing climatic conditions and land use. To elucidate the molecular-level structure of SOM, we selectively extracted a broad range of intact SOM compounds by a combination of different organic solvents from soils with a wide range of C content. Our use of Electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and a suite of solvents with varying polarity significantly expands the inventory of the types of organic molecules present in soils. Specifically, we found that hexane is selective for lipid-like compounds with very low O:C ratios; water was selective for carbohydrates with high O:C ratios; acetonitrile preferentially extracts lignin, condensed structures, and tannin poly phenolic compounds with O:C > 0.5; methanol has higher selectivity towards compounds characterized with low O:C < 0.5; and hexane, MeOH, ACN and water solvents increase the number and types of organic molecules extracted from soil for a broader range of chemically diverse soil types. Our study of SOM molecules by ESI-FTICR MS revealed new insight into the molecular-level complexity of organics contained in soils.

  5. Multi-class methodology to determine pesticides and mycotoxins in green tea and royal jelly supplements by liquid chromatography coupled to Orbitrap high resolution mass spectrometry.

    Science.gov (United States)

    Martínez-Domínguez, Gerardo; Romero-González, Roberto; Garrido Frenich, Antonia

    2016-04-15

    A multi-class methodology was developed to determine pesticides and mycotoxins in food supplements. The extraction was performed using acetonitrile acidified with formic acid (1%, v/v). Different clean-up sorbents were tested, and the best results were obtained using C18 and zirconium oxide for green tea and royal jelly, respectively. The compounds were determined using ultra high performance liquid chromatography (UHPLC) coupled to Exactive-Orbitrap high resolution mass spectrometry (HRMS). The recovery rates obtained were between 70% and 120% for most of the compounds studied with a relative standard deviation green tea (10) and royal jelly (8) samples. Nine (eight of green tea and one of royal jelly) samples were found to be positive for pesticides at concentrations ranging from 10.6 (cinosulfuron) to 47.9 μg/kg (paclobutrazol). The aflatoxin B1 (5.4 μg/kg) was also found in one of the green tea samples.

  6. Micro-solid-phase extraction coupled to desorption electrospray ionization-high-resolution mass spectrometry for the analysis of explosives in soil.

    Science.gov (United States)

    Bianchi, Federica; Gregori, Adolfo; Braun, Gabriele; Crescenzi, Carlo; Careri, Maria

    2015-01-01

    Home-made micro-solid-phase extraction (SPE) cartridges using different adsorbent materials were tested for the desorption electrospray ionization-high-resolution mass spectrometry (DESI-HRMS) determination of explosives like 2,4,6-trinitrotoluene, cyclotrimethylene-trinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, and trinitrophenylmethylnitramine in soil samples. Quantitation limits in the low nanogram per kilogram range proved the reliability of the method for the detection of explosives at ultra-trace levels. The reduced sample preparation allowed for low costs and high-throughput analyses. Finally, the superior extraction capability of the method was proved by obtaining DESI-HRMS responses at least five times higher than those achieved by performing DESI-HRMS analyses of solid-liquid extracts spotted onto commercial polytetrafluoroethylene slides.

  7. Ultra high-performance liquid chromatography with high-resolution mass spectrometry analysis of African mango (Irvingia gabonensis) seeds, extract, and related dietary supplements.

    Science.gov (United States)

    Sun, Jianghao; Chen, Pei

    2012-09-05

    Dietary supplements based on an extract from Irvingia gabonensis (African mango, AM) seeds are one of the popular herbal weight loss dietary supplements in the U.S. market. The extract is believed to be a natural and healthy way to lose weight and improve overall health. However, the chemical composition of AM-based dietary supplements (AMDSs) has never been reported. In this study, the chemical constituents of AM seeds, AM seeds extract (AMSE), and different kinds of commercially available AMDSs have been investigated using an ultra high-performance liquid chromatography with high resolution mass spectrometry method. Ellagic acid, mono-, di-, and tri-O-methyl-ellagic acids, and their glycosides were found as major components in AM seeds. These compounds may be used for quality control of AM extract and related dietary supplements.

  8. Conformational ordering of biomolecules in the gas phase: nitrogen collision cross sections measured on a prototype high resolution drift tube ion mobility-mass spectrometer.

    Science.gov (United States)

    May, Jody C; Goodwin, Cody R; Lareau, Nichole M; Leaptrot, Katrina L; Morris, Caleb B; Kurulugama, Ruwan T; Mordehai, Alex; Klein, Christian; Barry, William; Darland, Ed; Overney, Gregor; Imatani, Kenneth; Stafford, George C; Fjeldsted, John C; McLean, John A

    2014-02-18

    Ion mobility-mass spectrometry measurements which describe the gas-phase scaling of molecular size and mass are of both fundamental and pragmatic utility. Fundamentally, such measurements expand our understanding of intrinsic intramolecular folding forces in the absence of solvent. Practically, reproducible transport properties, such as gas-phase collision cross-section (CCS), are analytically useful metrics for identification and characterization purposes. Here, we report 594 CCS values obtained in nitrogen drift gas on an electrostatic drift tube ion mobility-mass spectrometry (IM-MS) instrument. The instrument platform is a newly developed prototype incorporating a uniform-field drift tube bracketed by electrodynamic ion funnels and coupled to a high resolution quadrupole time-of-flight mass spectrometer. The CCS values reported here are of high experimental precision (±0.5% or better) and represent four chemically distinct classes of molecules (quaternary ammonium salts, lipids, peptides, and carbohydrates), which enables structural comparisons to be made between molecules of different chemical compositions for the rapid "omni-omic" characterization of complex biological samples. Comparisons made between helium and nitrogen-derived CCS measurements demonstrate that nitrogen CCS values are systematically larger than helium values; however, general separation trends between chemical classes are retained regardless of the drift gas. These results underscore that, for the highest CCS accuracy, care must be exercised when utilizing helium-derived CCS values to calibrate measurements obtained in nitrogen, as is the common practice in the field.

  9. [Screening and confirmation of 24 hormones in cosmetics by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

    Science.gov (United States)

    Li, Zhaoyong; Wang, Fengmei; Niu, Zengyuan; Luo, Xin; Zhang, Gang; Chen, Junhui

    2014-05-01

    A method of ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was established to screen and confirm 24 hormones in cosmetics. Various cosmetic samples were extracted with methanol. The extract was loaded onto a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) using a gradient elution of acetonitrile/water containing 0.1% (v/v) formic acid for the separation. The accurate mass of quasi-molecular ion was acquired by full scanning of electrostatic field orbitrap. The rapid screening was carried out by the accurate mass of quasi-molecular ion. The confirmation analysis for targeted compounds was performed with the retention time and qualitative fragments obtained by data dependent scan mode. Under the optimal conditions, the 24 hormones were routinely detected with mass accuracy error below 3 x 10(-6) (3 ppm), and good linearities were obtained in their respective linear ranges with correlation coefficients higher than 0.99. The LODs (S/N = 3) of the 24 compounds were hormones in 50 cosmetic samples. The results demonstrate that the method is a useful tool for the rapid screening and identification of the hormones in cosmetics.

  10. Measurement of Surface Displacement and Deformation of Mass Movements Using Least Squares Matching of Repeat High Resolution Satellite and Aerial Images

    Directory of Open Access Journals (Sweden)

    Misganu Debella-Gilo

    2012-01-01

    Full Text Available Displacement and deformation are fundamental measures of Earth surface mass movements such as glacier flow, rockglacier creep and rockslides. Ground-based methods of monitoring such mass movements can be costly, time consuming and limited in spatial and temporal coverage. Remote sensing techniques, here matching of repeat optical images, are increasingly used to obtain displacement and deformation fields. Strain rates are usually computed in a post-processing step based on the gradients of the measured velocity field. This study explores the potential of automatically and directly computing velocity, rotation and strain rates on Earth surface mass movements simultaneously from the matching positions and the parameters of the geometric transformation models using the least squares matching (LSM approach. The procedures are exemplified using bi-temporal high resolution satellite and aerial images of glacier flow, rockglacier creep and land sliding. The results show that LSM matches the images and computes longitudinal strain rates, transverse strain rates and shear strain rates reliably with mean absolute deviations in the order of 10−4 (one level of significance below the measured values as evaluated on stable grounds. The LSM also improves the accuracy of displacement estimation of the pixel-precision normalized cross-correlation by over 90% under ideal (simulated circumstances and by about 25% for real multi-temporal images of mass movements.

  11. Target analysis and retrospective screening of veterinary drugs, ergot alkaloids, plant toxins and other undesirable substances in feed using liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    León, Nuria; Pastor, Agustín; Yusà, Vicent

    2016-01-01

    A comprehensive strategy combining a quantitative method for 77 banned veterinary drugs, mycotoxins, ergot alkaloids and plant toxins, and a post-target screening for 425 substances including pesticides and environmental contaminants in feed were developed using a QuEChERS-based extraction and an ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS). The quantitative method was validated after previous statistical optimisation of the main parameters governing ionisation, and presented recoveries ranging, in general, from 80 to 120%, with a precision in terms of Relative Standard Deviation (RSD) lower than 20%. The full-scan accurate mass data were acquired with a resolving power of 50000 FWHM and a mass accuracy lower than 5ppm. The method LOQ was lower than 12.5µgkg(-1) for the majority of the veterinary drugs and plant toxins and 20µgkg(-1) for ergot alkaloids. For post-target screening a customised theoretical database including the exact mass, the polarity of acquisition and the expected adducts was built and used for post-run retrospective screening. The analytical strategy was applied to 32 feed samples collected from farms of the Valencia Region (Spain). Florfenicol, zearalenone and atropine were identified and quantified at concentrations around 10µgkg(-1). In the post-target screening of the real samples, Sulfadiazine, Thrimetoprin and Pirimiphosmethyl were tentatively identified.

  12. 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.

  13. [Determination of 18 pesticide residues in red wine by ultra high performance liquid chromatography-high resolution mass spectrometry with isotope dilution technique].

    Science.gov (United States)

    Chen, Dawei; Lü, Bing; Ding, Hao; Zou, Jianhong; Yang, Xin; Zhao, Yunfeng; Miao, Hong

    2014-05-01

    A method for the simultaneous determination of 18 pesticide residues in red wine was developed using ultra high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) with isotope dilution technique. The red wine samples were extracted with acetonitrile, and the extracts were cleaned up with dispersive solid phase extraction (dSPE) using the mixture of N-propyl ethylene diamine (PSA) and C18 powder as sorbent. The extracted components were separated on a BEH C18 column by gradient elution. The qualitative and quantitative analyses were operated under full scan/data dependent MS/MS (ddms2) and targeted selective ion monitoring (tSIM) by high resolution mass spectrometry, respectively. Carbendazim-D4, chlorpyrifos-D10, imidacloprid-D4, methoxyfenozide-D9, pyrimethanil-D5 and tebuconazole-D6 were used as the internal standards to reduce the matrix effects. The response of each pesticide showed a good linearity in the range of 0.5-50 microg/kg with the correlation coefficient more than 0.999. The limits of detection and quantification for the 18 pesticides in the spiked blank red wine were 0.5 microg/kg and 1.0 microg/kg, respectively. The recovery results with spiked blank red wine samples at the levels of 1 to 40 microg/kg were satisfactory with average recoveries of 85.4% - 117.9% and the RSDs of 0.5%-6.1%. The method was applied for the determination of the red wine real samples from the market. Carbendazim, imidacloprid, pyrimethanil, tebuconazole and triadimenol were detected in the samples. The results show that the method is suitable for the rapid screening and quantitative analysis of pesticide residues in red wine.

  14. Extending a Tandem Mass Spectral Library to Include MS2 Spectra of Fragment Ions Produced In-Source and MSn Spectra

    Science.gov (United States)

    Yang, Xiaoyu; Neta, Pedatsur; Stein, Stephen E.

    2017-07-01

    Tandem mass spectral library searching is finding increased use as an effective means of determining chemical identity in mass spectrometry-based omics studies. We previously reported on constructing a tandem mass spectral library that includes spectra for multiple precursor ions for each analyte. Here we report our method for expanding this library to include MS2 spectra of fragment ions generated during the ionization process (in-source fragment ions) as well as MS3 and MS4 spectra. These can assist the chemical identification process. A simple density-based clustering algorithm was used to cluster all significant precursor ions from MS1 scans for an analyte acquired during an infusion experiment. The MS2 spectra associated with these precursor ions were grouped into the same precursor clusters. Subsequently, a new top-down hierarchical divisive clustering algorithm was developed for clustering the spectra from fragmentation of ions in each precursor cluster, including the MS2 spectra of the original precursors and of the in-source fragments as well as the MSn spectra. This algorithm starts with all the spectra of one precursor in one cluster and then separates them into sub-clusters of similar spectra based on the fragment patterns. Herein, we describe the algorithms and spectral evaluation methods for extending the library. The new library features were demonstrated by searching the high resolution spectra of E. coli extracts against the extended library, allowing identification of compounds and their in-source fragment ions in a manner that was not possible before.

  15. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speakin