WorldWideScience

Sample records for accurate mass determination

  1. Accurate mass measurements on neutron-deficient krypton isotopes

    CERN Document Server

    Rodríguez, D.; Äystö, J.; Beck, D.; Blaum, K.; Bollen, G.; Herfurth, F.; Jokinen, A.; Kellerbauer, A.; Kluge, H.-J.; Kolhinen, V.S.; Oinonen, M.; Sauvan, E.; Schwarz, S.

    2006-01-01

    The masses of $^{72–78,80,82,86}$Kr were measured directly with the ISOLTRAP Penning trap mass spectrometer at ISOLDE/CERN. For all these nuclides, the measurements yielded mass uncertainties below 10 keV. The ISOLTRAP mass values for $^{72–75}$Kr being more precise than the previous results obtained by means of other techniques, and thus completely determine the new values in the Atomic-Mass Evaluation. Besides the interest of these masses for nuclear astrophysics, nuclear structure studies, and Standard Model tests, these results constitute a valuable and accurate input to improve mass models. In this paper, we present the mass measurements and discuss the mass evaluation for these Kr isotopes.

  2. An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope

    Science.gov (United States)

    Haywood, Raphaëlle D.; Vanderburg, Andrew; Mortier, Annelies; Giles, Helen A. C.; López-Morales, Mercedes; Lopez, Eric D.; Malavolta, Luca; Charbonneau, David; Collier Cameron, Andrew; Coughlin, Jeffrey L.; Dressing, Courtney D.; Nava, Chantanelle; Latham, David W.; Dumusque, Xavier; Lovis, Christophe; Molinari, Emilio; Pepe, Francesco; Sozzetti, Alessandro; Udry, Stéphane; Bouchy, François; Johnson, John A.; Mayor, Michel; Micela, Giusi; Phillips, David; Piotto, Giampaolo; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Watson, Chris; Affer, Laura; Bonomo, Aldo S.; Buchhave, Lars A.; Ciardi, David R.; Fiorenzano, Aldo F.; Harutyunyan, Avet

    2018-05-01

    We present the confirmation of a small, moderately irradiated (F = 155 ± 7 F ⊕) Neptune with a substantial gas envelope in a P = 11.8728787 ± 0.0000085 day orbit about a quiet, Sun-like G0V star Kepler-1655. Based on our analysis of the Kepler light curve, we determined Kepler-1655b’s radius to be 2.213 ± 0.082 R ⊕. We acquired 95 high-resolution spectra with Telescopio Nazionale Galileo/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0{+/- }2.83.1 {M}\\oplus via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655b falls on the upper edge of the evaporation valley, in the relatively sparsely occupied transition region between rocky and gas-rich planets. It is therefore part of a population of planets that we should actively seek to characterize further.

  3. Accurate isotope ratio mass spectrometry. Some problems and possibilities

    International Nuclear Information System (INIS)

    Bievre, P. de

    1978-01-01

    The review includes reference to 190 papers, mainly published during the last 10 years. It covers the following: important factors in accurate isotope ratio measurements (precision and accuracy of isotope ratio measurements -exemplified by determinations of 235 U/ 238 U and of other elements including 239 Pu/ 240 Pu; isotope fractionation -exemplified by curves for Rb, U); applications (atomic weights); the Oklo natural nuclear reactor (discovered by UF 6 mass spectrometry at Pierrelatte); nuclear and other constants; isotope ratio measurements in nuclear geology and isotope cosmology - accurate age determination; isotope ratio measurements on very small samples - archaeometry; isotope dilution; miscellaneous applications; and future prospects. (U.K.)

  4. The Effect of Starspots on Accurate Radius Determination of the Low-Mass Double-Lined Eclipsing Binary Gu Boo

    Science.gov (United States)

    Windmiller, G.; Orosz, J. A.; Etzel, P. B.

    2010-04-01

    GU Boo is one of only a relatively small number of well-studied double-lined eclipsing binaries that contain low-mass stars. López-Morales & Ribas present a comprehensive analysis of multi-color light and radial velocity curves for this system. The GU Boo light curves presented by López-Morales & Ribas had substantial asymmetries, which were attributed to large spots. In spite of the asymmetry, López-Morales & Ribas derived masses and radii accurate to sime2%. We obtained additional photometry of GU Boo using both a CCD and a single-channel photometer and modeled the light curves with the ELC software to determine if the large spots in the light curves give rise to systematic errors at the few percent level. We also modeled the original light curves from the work of López-Morales & Ribas using models with and without spots. We derived a radius of the primary of 0.6329 ± 0.0026 R sun, 0.6413 ± 0.0049 R sun, and 0.6373 ± 0.0029 R sun from the CCD, photoelectric, and López-Morales & Ribas data, respectively. Each of these measurements agrees with the value reported by López-Morales & Ribas (R 1 = 0.623 ± 0.016 R sun) at the level of ≈2%. In addition, the spread in these values is ≈1%-2% from the mean. For the secondary, we derive radii of 0.6074 ± 0.0035 R sun, 0.5944 ± 0.0069 R sun, and 0.5976 ± 0.0059 R sun from the three respective data sets. The López-Morales & Ribas value is R 2 = 0.620 ± 0.020 R sun, which is ≈2%-3% larger than each of the three values we found. The spread in these values is ≈2% from the mean. The systematic difference between our three determinations of the secondary radius and that of López-Morales & Ribas might be attributed to differences in the modeling process and codes used. Our own fits suggest that, for GU Boo at least, using accurate spot modeling of a single set of multi-color light curves results in radii determinations accurate at the ≈2% level.

  5. THE EFFECT OF STARSPOTS ON ACCURATE RADIUS DETERMINATION OF THE LOW-MASS DOUBLE-LINED ECLIPSING BINARY GU Boo

    International Nuclear Information System (INIS)

    Windmiller, G.; Orosz, J. A.; Etzel, P. B.

    2010-01-01

    GU Boo is one of only a relatively small number of well-studied double-lined eclipsing binaries that contain low-mass stars. Lopez-Morales and Ribas present a comprehensive analysis of multi-color light and radial velocity curves for this system. The GU Boo light curves presented by Lopez-Morales and Ribas had substantial asymmetries, which were attributed to large spots. In spite of the asymmetry, Lopez-Morales and Ribas derived masses and radii accurate to ≅2%. We obtained additional photometry of GU Boo using both a CCD and a single-channel photometer and modeled the light curves with the ELC software to determine if the large spots in the light curves give rise to systematic errors at the few percent level. We also modeled the original light curves from the work of Lopez-Morales and Ribas using models with and without spots. We derived a radius of the primary of 0.6329 ± 0.0026 R sun , 0.6413 ± 0.0049 R sun , and 0.6373 ± 0.0029 R sun from the CCD, photoelectric, and Lopez-Morales and Ribas data, respectively. Each of these measurements agrees with the value reported by Lopez-Morales and Ribas (R 1 = 0.623 ± 0.016 R sun ) at the level of ∼2%. In addition, the spread in these values is ∼1%-2% from the mean. For the secondary, we derive radii of 0.6074 ± 0.0035 R sun , 0.5944 ± 0.0069 R sun , and 0.5976 ± 0.0059 R sun from the three respective data sets. The Lopez-Morales and Ribas value is R 2 = 0.620 ± 0.020 R sun , which is ∼2%-3% larger than each of the three values we found. The spread in these values is ∼2% from the mean. The systematic difference between our three determinations of the secondary radius and that of Lopez-Morales and Ribas might be attributed to differences in the modeling process and codes used. Our own fits suggest that, for GU Boo at least, using accurate spot modeling of a single set of multi-color light curves results in radii determinations accurate at the ∼2% level.

  6. Negative chemical ionization gas chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry and automated accurate mass data processing for determination of pesticides in fruit and vegetables.

    Science.gov (United States)

    Besil, Natalia; Uclés, Samanta; Mezcúa, Milagros; Heinzen, Horacio; Fernández-Alba, Amadeo R

    2015-08-01

    Gas chromatography coupled to high resolution hybrid quadrupole time-of-flight mass spectrometry (GC-QTOF MS), operating in negative chemical ionization (NCI) mode and combining full scan with MSMS experiments using accurate mass analysis, has been explored for the automated determination of pesticide residues in fruit and vegetables. Seventy compounds were included in this approach where 50 % of them are not approved by the EU legislation. A global 76 % of the analytes could be identified at 1 μg kg(-1). Recovery studies were developed at three concentration levels (1, 5, and 10 μg kg(-1)). Seventy-seven percent of the detected pesticides at the lowest level yielded recoveries within the 70 %-120 % range, whereas 94 % could be quantified at 5 μg kg(-1), and the 100 % were determined at 10 μg kg(-1). Good repeatability, expressed as relative standard deviation (RSD home-made database was developed and applied to an automatic accurate mass data processing. Measured mass accuracies of the generated ions were mainly less than 5 ppm for at least one diagnostic ion. When only one ion was obtained in the single-stage NCI-MS, a representative product ion from MSMS experiments was used as identification criterion. A total of 30 real samples were analyzed and 67 % of the samples were positive for 12 different pesticides in the range 1.0-1321.3 μg kg(-1).

  7. A new approach for accurate mass assignment on a multi-turn time-of-flight mass spectrometer.

    Science.gov (United States)

    Hondo, Toshinobu; Jensen, Kirk R; Aoki, Jun; Toyoda, Michisato

    2017-12-01

    A simple, effective accurate mass assignment procedure for a time-of-flight mass spectrometer is desirable. External mass calibration using a mass calibration standard together with an internal mass reference (lock mass) is a common technique for mass assignment, however, using polynomial fitting can result in mass-dependent errors. By using the multi-turn time-of-flight mass spectrometer infiTOF-UHV, we were able to obtain multiple time-of-flight data from an ion monitored under several different numbers of laps that was then used to calculate a mass calibration equation. We have developed a data acquisition system that simultaneously monitors spectra at several different lap conditions with on-the-fly centroid determination and scan law estimation, which is a function of acceleration voltage, flight path, and instrumental time delay. Less than 0.9 mDa mass errors were observed for assigned mass to charge ratios ( m/z) ranging between 4 and 134 using only 40 Ar + as a reference. It was also observed that estimating the scan law on-the-fly provides excellent mass drift compensation.

  8. Mass and position determination in MEMS mass sensors: a theoretical and an experimental investigation

    KAUST Repository

    Bouchaala, Adam M.; Nayfeh, Ali H.; Jaber, Nizar; Younis, Mohammad I.

    2016-01-01

    We present a method to determine accurately the position and mass of an entity attached to the surface of an electrostatically actuated clamped-clamped microbeam implemented as a mass sensor. In the theoretical investigation, the microbeam

  9. Leg mass characteristics of accurate and inaccurate kickers--an Australian football perspective.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Cochrane, Jodie L; Newton, Robert U

    2013-01-01

    Athletic profiling provides valuable information to sport scientists, assisting in the optimal design of strength and conditioning programmes. Understanding the influence these physical characteristics may have on the generation of kicking accuracy is advantageous. The aim of this study was to profile and compare the lower limb mass characteristics of accurate and inaccurate Australian footballers. Thirty-one players were recruited from the Western Australian Football League to perform ten drop punt kicks over 20 metres to a player target. Players were separated into accurate (n = 15) and inaccurate (n = 16) groups, with leg mass characteristics assessed using whole body dual energy x-ray absorptiometry (DXA) scans. Accurate kickers demonstrated significantly greater relative lean mass (P ≤ 0.004) and significantly lower relative fat mass (P ≤ 0.024) across all segments of the kicking and support limbs, while also exhibiting significantly higher intra-limb lean-to-fat mass ratios for all segments across both limbs (P ≤ 0.009). Inaccurate kickers also produced significantly larger asymmetries between limbs than accurate kickers (P ≤ 0.028), showing considerably lower lean mass in their support leg. These results illustrate a difference in leg mass characteristics between accurate and inaccurate kickers, highlighting the potential influence these may have on technical proficiency of the drop punt.

  10. Accurate determination of selected pesticides in soya beans by liquid chromatography coupled to isotope dilution mass spectrometry.

    Science.gov (United States)

    Huertas Pérez, J F; Sejerøe-Olsen, B; Fernández Alba, A R; Schimmel, H; Dabrio, M

    2015-05-01

    A sensitive, accurate and simple liquid chromatography coupled with mass spectrometry method for the determination of 10 selected pesticides in soya beans has been developed and validated. The method is intended for use during the characterization of selected pesticides in a reference material. In this process, high accuracy and appropriate uncertainty levels associated to the analytical measurements are of utmost importance. The analytical procedure is based on sample extraction by the use of a modified QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction and subsequent clean-up of the extract with C18, PSA and Florisil. Analytes were separated on a C18 column using gradient elution with water-methanol/2.5 mM ammonium acetate mobile phase, and finally identified and quantified by triple quadrupole mass spectrometry in the multiple reaction monitoring mode (MRM). Reliable and accurate quantification of the analytes was achieved by means of stable isotope-labelled analogues employed as internal standards (IS) and calibration with pure substance solutions containing both, the isotopically labelled and native compounds. Exceptions were made for thiodicarb and malaoxon where the isotopically labelled congeners were not commercially available at the time of analysis. For the quantification of those compounds methomyl-(13)C2(15)N and malathion-D10 were used respectively. The method was validated according to the general principles covered by DG SANCO guidelines. However, validation criteria were set more stringently. Mean recoveries were in the range of 86-103% with RSDs lower than 8.1%. Repeatability and intermediate precision were in the range of 3.9-7.6% and 1.9-8.7% respectively. LODs were theoretically estimated and experimentally confirmed to be in the range 0.001-0.005 mg kg(-1) in the matrix, while LOQs established as the lowest spiking mass fractionation level were in the range 0.01-0.05 mg kg(-1). The method reliably identifies and quantifies the

  11. High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

    CERN Multimedia

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  12. A Method To Determine Adhesion Of Suppository Mass On Excised ...

    African Journals Online (AJOL)

    A method to determine adhesion of suppository mass to intestinal tissue was developed using excised pig intestine. The method which employs the principe of drainage unto and subsequent detachment from the mucosa, of an adherent suppository mass is simple, inexpensive and accurate. Fully optimised, it can be used ...

  13. Determination of nuclear fuel burn-up using mass spectrometric techniques

    International Nuclear Information System (INIS)

    Saha, B.; Bagyalakshmi, R.; Periaswami, G.; Kavimandan, V.D.; Chitambar, S.A.; Jain, H.C.; Mathews, C.K.

    1977-01-01

    Determination of burn-up using a stable fission product monitor such as 148 Nd and heavy elements, determined by isotope dilution mass spectrometry gives the most accurate data. This report describes the work carried out to standardise the conditions for burn-up determination. Some typical results are given. (author)

  14. Accurate determination of non-metallic impurities in high purity tetramethylammonium hydroxide using inductively coupled plasma tandem mass spectrometry

    Science.gov (United States)

    Fu, Liang; Xie, Hualin; Shi, Shuyun; Chen, Xiaoqing

    2018-06-01

    The content of non-metallic impurities in high-purity tetramethylammonium hydroxide (HPTMAH) aqueous solution has an important influence on the yield, electrical properties and reliability of the integrated circuit during the process of chip etching and cleaning. Therefore, an efficient analytical method to directly quantify the content of non-metallic impurities in HPTMAH aqueous solutions is necessary. The present study was aimed to develop a novel method that can accurately determine seven non-metallic impurities (B, Si, P, S, Cl, As, and Se) in an aqueous solution of HPTMAH by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). The samples were measured using a direct injection method. In the MS/MS mode, oxygen and hydrogen were used as reaction gases in the octopole reaction system (ORS) to eliminate mass spectral interferences during the analytical process. The detection limits of B, Si, P, S, Cl, As, and Se were 0.31, 0.48, 0.051, 0.27, 3.10, 0.008, and 0.005 μg L-1, respectively. The samples were analyzed by the developed method and the sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) was used for contrastive analysis. The values of these seven elements measured using ICP-MS/MS were consistent with those measured by SF-ICP-MS. The proposed method can be utilized to analyze non-metallic impurities in HPTMAH aqueous solution. Table S2 Multiple potential interferences on the analytes. Table S3 Parameters of calibration curve and the detection limit (DL). Table S4 Results obtained for 25% concentration high-purity grade TMAH aqueous solution samples (μg L-1, mean ± standard deviation, n = 10).

  15. Characterization of photo-transformation products of the antibiotic drug Ciprofloxacin with liquid chromatography-tandem mass spectrometry in combination with accurate mass determination using an LTQ-Orbitrap.

    Science.gov (United States)

    Haddad, Tarek; Kümmerer, Klaus

    2014-11-01

    The presence of pharmaceuticals, especially antibiotics, in the aquatic environment is of growing concern. Several studies have been carried out on the occurrence and environmental risk of these compounds. Ciprofloxacin (CIP), a broad-spectrum anti-microbial second-generation fluoroquinolone, is widely used in human and veterinary medicine. In this work, photo-degradation of CIP in aqueous solution using UV and xenon lamps was studied. The transformation products (TPs), created from CIP, were initially analyzed by an ion trap in the MS, MS/MS and MS(3) modes. These data were used to clarify the structures of the degradation products. Furthermore, the proposed products were confirmed by accurate mass measurement and empirical formula calculation for the molecular ions of TPs using LTQ-Orbitrap XL mass spectrometer. The degree of mineralization, the abundance of detected TPs and degradation pathways were determined. Eleven TPs were detected in the present study. TP1, which was never detected before, was structurally characterized in this work. All TPs still retained the core quinolone structure, which is responsible for the biological activity. As mineralization of CIP and its transformation products did not happen, the formation of stable TPs can be expected in waste water treatment and in surface water with further follow-up problems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Accurate mass and velocity functions of dark matter haloes

    Science.gov (United States)

    Comparat, Johan; Prada, Francisco; Yepes, Gustavo; Klypin, Anatoly

    2017-08-01

    N-body cosmological simulations are an essential tool to understand the observed distribution of galaxies. We use the MultiDark simulation suite, run with the Planck cosmological parameters, to revisit the mass and velocity functions. At redshift z = 0, the simulations cover four orders of magnitude in halo mass from ˜1011M⊙ with 8783 874 distinct haloes and 532 533 subhaloes. The total volume used is ˜515 Gpc3, more than eight times larger than in previous studies. We measure and model the halo mass function, its covariance matrix w.r.t halo mass and the large-scale halo bias. With the formalism of the excursion-set mass function, we explicit the tight interconnection between the covariance matrix, bias and halo mass function. We obtain a very accurate (function. We also model the subhalo mass function and its relation to the distinct halo mass function. The set of models obtained provides a complete and precise framework for the description of haloes in the concordance Planck cosmology. Finally, we provide precise analytical fits of the Vmax maximum velocity function up to redshift z publicly available in the Skies and Universes data base.

  17. THE MEGAMASER COSMOLOGY PROJECT. III. ACCURATE MASSES OF SEVEN SUPERMASSIVE BLACK HOLES IN ACTIVE GALAXIES WITH CIRCUMNUCLEAR MEGAMASER DISKS

    International Nuclear Information System (INIS)

    Kuo, C. Y.; Braatz, J. A.; Condon, J. J.; Impellizzeri, C. M. V.; Lo, K. Y.; Zaw, I.; Schenker, M.; Henkel, C.; Reid, M. J.; Greene, J. E.

    2011-01-01

    Observations of H 2 O masers from circumnuclear disks in active galaxies for the Megamaser Cosmology Project (MCP) allow accurate measurement of the mass of supermassive black holes (BH) in these galaxies. We present the Very Long Baseline Interferometry images and kinematics of water maser emission in six active galaxies: NGC 1194, NGC 2273, NGC 2960 (Mrk 1419), NGC 4388, NGC 6264 and NGC 6323. We use the Keplerian rotation curves of these six megamaser galaxies, plus a seventh previously published, to determine accurate enclosed masses within the central ∼0.3 pc of these galaxies, smaller than the radius of the sphere of influence of the central mass in all cases. We also set lower limits to the central mass densities of between 0.12 x 10 10 and 61 x 10 10 M sun pc -3 . For six of the seven disks, the high central densities rule out clusters of stars or stellar remnants as the central objects, and this result further supports our assumption that the enclosed mass can be attributed predominantly to a supermassive BH. The seven BHs have masses ranging between 0.75 x 10 7 and 6.5 x 10 7 M sun , with the mass errors dominated by the uncertainty of the Hubble constant. We compare the megamaser BH mass determination with BH mass measured from the virial estimation method. The virial estimation BH mass in four galaxies is consistent with the megamaser BH mass, but the virial mass uncertainty is much greater. Circumnuclear megamaser disks allow the best mass determination of the central BH mass in external galaxies and significantly improve the observational basis at the low-mass end of the M-σ * relation. The M-σ * relation may not be a single, low-scatter power law as originally proposed. MCP observations continue and we expect to obtain more maser BH masses in the future.

  18. Accurate determination and certification of bromine in plastic by isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Ohata, Masaki; Miura, Tsutomu

    2014-01-01

    Highlights: • Accurate analytical method of Br in plastic was studied by isotope dilution ICPMS. • A microwave acid digestion using quartz vessel was suitable for Br analysis. • Sample dilution by NH 3 solution could remove memory effect for ICPMS measurement. • The analytical result of the ID-ICPMS showed consistency with that of INAA. • The ID-ICPMS developed could apply to certification of Br in candidate plastic CRM. - Abstract: The accurate analytical method of bromine (Br) in plastic was developed by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The figures of merit of microwave acid digestion procedures using polytetrafluoroethylene (PTFE) or quartz vessels were studied and the latter one was suitable for Br analysis since its material was free from Br contamination. The sample dilution procedures using Milli-Q water or ammonium (NH 3 ) solution were also studied to remove memory effect for ICPMS measurement. Although severe memory effect was observed on Milli-Q water dilution, NH 3 solution could remove it successfully. The accuracy of the ID-ICPMS was validated by a certified reference material (CRM) as well as the comparison with the analytical result obtained by an instrumental neutron activation analysis (INAA) as different analytical method. From these results, the ID-ICPMS developed in the present study could be evaluated as accurate analytical method of Br in plastic materials and it could apply to certification of Br in candidate plastic CRM with respect to such regulations related to RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive

  19. Comparison of STIM and particle backscattering spectrometry mass determination for quantitative microanalysis of cultured cells

    International Nuclear Information System (INIS)

    Deves, G.; Ortega, R.

    2001-01-01

    In biological sample microanalysis, a mass-normalisation method is commonly used as a quantitative index of elemental concentrations determined by particle-induced X-ray emission (PIXE). The organic mass can either be determined using particle backscattering spectrometry (BS) or scanning transmission ion microscopy (STIM). However, the accuracy of quantitative microanalysis in samples such as cultured cells is affected by beam-induced loss of organic mass during analysis. The aim of this paper is to compare mass measurements determined by particle BS or by STIM. In order to calibrate STIM and BS analyses, we measured by both techniques the thickness of standard foils of polycarbonate (3 and 6 μm), Mylar[reg] (4 μm), Kapton[reg] (7.5 μm) and Nylon[reg] (15 μm), as well as biological samples of mono-layered cultured cells. Non-damaging STIM analysis of samples before PIXE irradiation is certainly one of the most accurate ways to determine the sample mass, however, this requires strong experimental handling. On the other hand, BS performed simultaneously to PIXE is the simplest method to determine the local mass in polymer foils, but appears less accurate in the case of cultured cells

  20. Mass and Position Determination in MEMS Resonant Mass Sensors: Theoretical and Experimental Investigation

    KAUST Repository

    Bouchaala, Adam M.

    2016-12-05

    We present a method to determine accurately the position and mass of an entity attached to the surface of an electrostatically actuated clamped-clamped microbeam implemented as a mass sensor. In the theoretical investigation, the microbeam is modeled as a nonlinear Euler-Bernoulli beam and a perturbation technique is used to develop a closed-form expression for the frequency shift due to an added mass at a specific location on the microbeam surface. The experimental investigation was conducted on a microbeam made of Polyimide with a special lower electrode to excite both of the first and second modes of vibration. Using an ink-jet printer, we deposited droplets of polymers with a defined mass and position on the surface of the microbeam and we measured the shifts in its resonance frequencies. The theoretical predictions of the mass and position of the deposited droplets match well with the experimental measurements.

  1. Mass and Position Determination in MEMS Resonant Mass Sensors: Theoretical and Experimental Investigation

    KAUST Repository

    Bouchaala, Adam M.; Nayfeh, Ali H.; Jaber, Nizar; Younis, Mohammad I.

    2016-01-01

    We present a method to determine accurately the position and mass of an entity attached to the surface of an electrostatically actuated clamped-clamped microbeam implemented as a mass sensor. In the theoretical investigation, the microbeam is modeled as a nonlinear Euler-Bernoulli beam and a perturbation technique is used to develop a closed-form expression for the frequency shift due to an added mass at a specific location on the microbeam surface. The experimental investigation was conducted on a microbeam made of Polyimide with a special lower electrode to excite both of the first and second modes of vibration. Using an ink-jet printer, we deposited droplets of polymers with a defined mass and position on the surface of the microbeam and we measured the shifts in its resonance frequencies. The theoretical predictions of the mass and position of the deposited droplets match well with the experimental measurements.

  2. Empirical Accurate Masses and Radii of Single Stars with TESS and Gaia

    Science.gov (United States)

    Stassun, Keivan G.; Corsaro, Enrico; Pepper, Joshua A.; Gaudi, B. Scott

    2018-01-01

    We present a methodology for the determination of empirical masses of single stars through the combination of three direct observables with Gaia and Transiting Exoplanet Survey Satellite (TESS): (i) the surface gravity via granulation-driven variations in the TESS light curve, (ii) the bolometric flux at Earth via the broadband spectral energy distribution, and (iii) the distance via the Gaia parallax. We demonstrate the method using 525 Kepler stars for which these measures are available in the literature, and show that the stellar masses can be measured with this method to a precision of ∼25%, limited by the surface-gravity precision of the granulation “flicker” method (∼0.1 dex) and by the parallax uncertainties (∼10% for the Kepler sample). We explore the impact of expected improvements in the surface gravity determinations—through the application of granulation background fitting and the use of recently published granulation-metallicity relations—and improvements in the parallaxes with the arrival of the Gaia second data release. We show that the application of this methodology to stars that will be observed by TESS should yield radii good to a few percent and masses good to ≈10%. Importantly, the method does not require the presence of an orbiting, eclipsing, or transiting body, nor does it require spatial resolution of the stellar surface. Thus, we can anticipate the determination of fundamental, accurate stellar radii and masses for hundreds of thousands of bright single stars—across the entire sky and spanning the Hertzsprung–Russell diagram—including those that will ultimately be found to host planets.

  3. Accurate determination and certification of bromine in plastic by isotope dilution inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ohata, Masaki, E-mail: m-oohata@aist.go.jp; Miura, Tsutomu

    2014-07-21

    Highlights: • Accurate analytical method of Br in plastic was studied by isotope dilution ICPMS. • A microwave acid digestion using quartz vessel was suitable for Br analysis. • Sample dilution by NH{sub 3} solution could remove memory effect for ICPMS measurement. • The analytical result of the ID-ICPMS showed consistency with that of INAA. • The ID-ICPMS developed could apply to certification of Br in candidate plastic CRM. - Abstract: The accurate analytical method of bromine (Br) in plastic was developed by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The figures of merit of microwave acid digestion procedures using polytetrafluoroethylene (PTFE) or quartz vessels were studied and the latter one was suitable for Br analysis since its material was free from Br contamination. The sample dilution procedures using Milli-Q water or ammonium (NH{sub 3}) solution were also studied to remove memory effect for ICPMS measurement. Although severe memory effect was observed on Milli-Q water dilution, NH{sub 3} solution could remove it successfully. The accuracy of the ID-ICPMS was validated by a certified reference material (CRM) as well as the comparison with the analytical result obtained by an instrumental neutron activation analysis (INAA) as different analytical method. From these results, the ID-ICPMS developed in the present study could be evaluated as accurate analytical method of Br in plastic materials and it could apply to certification of Br in candidate plastic CRM with respect to such regulations related to RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive.

  4. Chemical preparation of biological materials for accurate chromium determination by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Dunstan, L.P.; Garner, E.L.

    1977-01-01

    The current interest in trace elements in biological materials has created a need for accurate methods of analysis. The source of discrepancies and variations in chromium concentration determinations is often traceable to inadequate methods of sample preparation. Any method of Cr analysis that requires acid digestion of a biological matrix must take into consideration the existence or formation of a volatile Cr component. In addition, because Cr is often present at concentrations less than 1 μg/g, the analytical blank becomes a potential source of error. Chemical procedures have been developed for the digestion of the biological matrix and the separation of Cr without either large analytical blanks or significant losses by volatilization. These procedures have been used for the analysis of NBS Standard Reference Material (SRM) 1569 Brewers Yeast; SRM 1577 Bovine Liver; SRM 1570 Spinach and other biological materials including human hair and nails. At this time, samples containing 1 μg of Cr can be determined with an estimated accuracy of 2 percent

  5. Heat-And-Mass Transfer Relationship to Determine Shear Stress in Tubular Membrane Systems

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Nopens, Ingmar

    2012-01-01

    The main drawback of Membrane Bioreactors (MBRs) is the fouling of the membrane. One way to reduce this fouling is through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. It has been proven in literature that the slug flow pattern has a higher scouring effect...... to remove particulates due to the high shear rates and high mass transfer between the membrane surface and the bulk region. However, to calculate the mass transfer coefficient in an efficient and accurate way is not straightforward. Indeed, for accurate determination, numerous complex experimental...

  6. Accurate determination of light elements by charged particle activation analysis

    International Nuclear Information System (INIS)

    Shikano, K.; Shigematsu, T.

    1989-01-01

    To develop accurate determination of light elements by CPAA, accurate and practical standardization methods and uniform chemical etching are studied based on determination of carbon in gallium arsenide using the 12 C(d,n) 13 N reaction and the following results are obtained: (1)Average stopping power method with thick target yield is useful as an accurate and practical standardization method. (2)Front surface of sample has to be etched for accurate estimate of incident energy. (3)CPAA is utilized for calibration of light element analysis by physical method. (4)Calibration factor of carbon analysis in gallium arsenide using the IR method is determined to be (9.2±0.3) x 10 15 cm -1 . (author)

  7. Mass and position determination in MEMS mass sensors: a theoretical and an experimental investigation

    KAUST Repository

    Bouchaala, Adam M.

    2016-08-31

    We present a method to determine accurately the position and mass of an entity attached to the surface of an electrostatically actuated clamped-clamped microbeam implemented as a mass sensor. In the theoretical investigation, the microbeam is modeled as a nonlinear Euler-Bernoulli beam and a perturbation technique is used to develop a closed-form expression for the frequency shift due to an added mass at a specific location on the microbeam surface. The experimental investigation was conducted on a microbeam made of Polyimide with a special lower electrode to excite both of the first and second modes of vibration. Using an ink-jet printer, we deposited droplets of polymers with a defined mass and position on the surface of the microbeam and we measured the shifts in its resonance frequencies. The theoretical predictions of the mass and position of the deposited droplets match well with the experimental measurements.

  8. Accurate EPR radiosensitivity calibration using small sample masses

    Science.gov (United States)

    Hayes, R. B.; Haskell, E. H.; Barrus, J. K.; Kenner, G. H.; Romanyukha, A. A.

    2000-03-01

    We demonstrate a procedure in retrospective EPR dosimetry which allows for virtually nondestructive sample evaluation in terms of sample irradiations. For this procedure to work, it is shown that corrections must be made for cavity response characteristics when using variable mass samples. Likewise, methods are employed to correct for empty tube signals, sample anisotropy and frequency drift while considering the effects of dose distribution optimization. A demonstration of the method's utility is given by comparing sample portions evaluated using both the described methodology and standard full sample additive dose techniques. The samples used in this study are tooth enamel from teeth removed during routine dental care. We show that by making all the recommended corrections, very small masses can be both accurately measured and correlated with measurements of other samples. Some issues relating to dose distribution optimization are also addressed.

  9. Accurate EPR radiosensitivity calibration using small sample masses

    International Nuclear Information System (INIS)

    Hayes, R.B.; Haskell, E.H.; Barrus, J.K.; Kenner, G.H.; Romanyukha, A.A.

    2000-01-01

    We demonstrate a procedure in retrospective EPR dosimetry which allows for virtually nondestructive sample evaluation in terms of sample irradiations. For this procedure to work, it is shown that corrections must be made for cavity response characteristics when using variable mass samples. Likewise, methods are employed to correct for empty tube signals, sample anisotropy and frequency drift while considering the effects of dose distribution optimization. A demonstration of the method's utility is given by comparing sample portions evaluated using both the described methodology and standard full sample additive dose techniques. The samples used in this study are tooth enamel from teeth removed during routine dental care. We show that by making all the recommended corrections, very small masses can be both accurately measured and correlated with measurements of other samples. Some issues relating to dose distribution optimization are also addressed

  10. Asteroids mass determination

    International Nuclear Information System (INIS)

    Hoffmann, M.

    1989-01-01

    Basic methods for asteroid mass determinations and their errors are discussed. New results and some current developments in the astrometric method are reviewed. New methods and techniques, such as electronic imaging, radar ranging and space probes are becoming important for asteroid mass determinations. Mass and density estimations on rotational properties and possible satelites are also discussed

  11. Search for new candidates for the neutrino-oriented mass determination by electron-capture

    CERN Multimedia

    Herfurth, F; Boehm, C; Blaum, K; Beck, D

    2008-01-01

    This proposal is part of an extended program dedicated to the neutrino-mass determination in the electron-capture sector, which aims at ultra-precise mass measurements by Penning traps in combination with cryogenic micro-calorimetry for atomic de-excitation measurements. Here, precise mass measurements with ISOLTRAP are proposed for the orbital electron-capture nuclides $^{194}$Hg and $^{202}$Pb, as well as their daughters, with the goal to determine accurately their Q-values. These values are expected to be the smallest ones among a great variety of known electron-capture precursors. Therefore, these nuclides are strong candidates for an improved electron-neutrino mass determination. We ask for 8 shifts of on-line beam at ISOLDE for mass measurements of $^{194}$Hg, $^{194}$ Au, $^{202}$Pb, and $^{202}$Tl at ISOLTRAP.

  12. Accurate determination of 3-alkyl-2-methoxypyrazines in wines by gas chromatography quadrupole time-of-flight tandem mass spectrometry following solid-phase extraction and dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Fontana, Ariel; Rodríguez, Isaac; Cela, Rafael

    2017-09-15

    A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06mL carbon tetrachloride (CCl 4 ) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1ngL -1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25ngL -1 ) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Accurate mass measurements of very short-lived nuclei. Prerequisites for high-accuracy investigations of superallowed β-decays

    International Nuclear Information System (INIS)

    Herfurth, F.; Kellerbauer, A.; Sauvan, E.; Ames, F.; Engels, O.; Audi, G.; Lunney, D.; Beck, D.; Blaum, K.; Kluge, H.J.; Scheidenberger, C.; Sikler, G.; Weber, C.; Bollen, G.; Schwarz, S.; Moore, R.B.; Oinonen, M.

    2002-01-01

    Mass measurements of 34 Ar, 73-78 Kr, and 74,76 Rb were performed with the Penning-trap mass spectrometer ISOLTRAP. Very accurate Q EC -values are needed for the investigations of the Ft-value of 0 + → 0 + nuclear β-decays used to test the standard model predictions for weak interactions. The necessary accuracy on the Q EC -value requires the mass of mother and daughter nuclei to be measured with δm/m ≤ 3 . 10 -8 . For most of the measured nuclides presented here this has been reached. The 34 Ar mass has been measured with a relative accuracy of 1.1 .10 -8 . The Q EC -value of the 34 Ar 0 + → 0 + decay can now be determined with an uncertainty of about 0.01%. Furthermore, 74 Rb is the shortest-lived nuclide ever investigated in a Penning trap. (orig.)

  14. Semiquantitative dynamic contrast-enhanced MRI for accurate classification of complex adnexal masses.

    Science.gov (United States)

    Kazerooni, Anahita Fathi; Malek, Mahrooz; Haghighatkhah, Hamidreza; Parviz, Sara; Nabil, Mahnaz; Torbati, Leila; Assili, Sanam; Saligheh Rad, Hamidreza; Gity, Masoumeh

    2017-02-01

    To identify the best dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) descriptive parameters in predicting malignancy of complex ovarian masses, and develop an optimal decision tree for accurate classification of benign and malignant complex ovarian masses. Preoperative DCE-MR images of 55 sonographically indeterminate ovarian masses (27 benign and 28 malignant) were analyzed prospectively. Four descriptive parameters of the dynamic curve, namely, time-to-peak (TTP), wash-in-rate (WIR), relative signal intensity (SI rel ), and the initial area under the curve (IAUC 60 ) were calculated on the normalized curves of specified regions-of-interest (ROIs). A two-tailed Student's t-test and two automated classifiers, linear discriminant analysis (LDA) and support vector machines (SVMs), were used to compare the performance of the mentioned parameters individually and in combination with each other. TTP (P = 6.15E-8) and WIR (P = 5.65E-5) parameters induced the highest sensitivity (89% for LDA, and 97% for SVM) and specificity (93% for LDA, and 100% for SVM), respectively. Regarding the high sensitivity of TTP and high specificity of WIR and through their combination, an accurate and simple decision-tree classifier was designed using the line equation obtained by LDA classification model. The proposed classifier achieved an accuracy of 89% and area under the ROC curve of 93%. In this study an accurate decision-tree classifier based on a combination of TTP and WIR parameters was proposed, which provides a clinically flexible framework to aid radiologists/clinicians to reach a conclusive preoperative diagnosis and patient-specific therapy plan for distinguishing malignant from benign complex ovarian masses. 2 J. Magn. Reson. Imaging 2017;45:418-427. © 2016 International Society for Magnetic Resonance in Medicine.

  15. Accurate determination of antenna directivity

    DEFF Research Database (Denmark)

    Dich, Mikael

    1997-01-01

    The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...

  16. Identification and accurate quantification of structurally related peptide impurities in synthetic human C-peptide by liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Li, Ming; Josephs, Ralf D; Daireaux, Adeline; Choteau, Tiphaine; Westwood, Steven; Wielgosz, Robert I; Li, Hongmei

    2018-06-04

    Peptides are an increasingly important group of biomarkers and pharmaceuticals. The accurate purity characterization of peptide calibrators is critical for the development of reference measurement systems for laboratory medicine and quality control of pharmaceuticals. The peptides used for these purposes are increasingly produced through peptide synthesis. Various approaches (for example mass balance, amino acid analysis, qNMR, and nitrogen determination) can be applied to accurately value assign the purity of peptide calibrators. However, all purity assessment approaches require a correction for structurally related peptide impurities in order to avoid biases. Liquid chromatography coupled to high resolution mass spectrometry (LC-hrMS) has become the key technique for the identification and accurate quantification of structurally related peptide impurities in intact peptide calibrator materials. In this study, LC-hrMS-based methods were developed and validated in-house for the identification and quantification of structurally related peptide impurities in a synthetic human C-peptide (hCP) material, which served as a study material for an international comparison looking at the competencies of laboratories to perform peptide purity mass fraction assignments. More than 65 impurities were identified, confirmed, and accurately quantified by using LC-hrMS. The total mass fraction of all structurally related peptide impurities in the hCP study material was estimated to be 83.3 mg/g with an associated expanded uncertainty of 3.0 mg/g (k = 2). The calibration hierarchy concept used for the quantification of individual impurities is described in detail. Graphical abstract ᅟ.

  17. One-photon mass-analyzed threshold ionization (MATI) spectroscopy of pyridine: Determination of accurate ionization energy and cationic structure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yu Ran; Kang, Do Won; Kim, Hong Lae, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr; Kwon, Chan Ho, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr [Department of Chemistry and Institute for Molecular Science and Fusion Technology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2014-11-07

    Ionization energies and cationic structures of pyridine were intensively investigated utilizing one-photon mass-analyzed threshold ionization (MATI) spectroscopy with vacuum ultraviolet radiation generated by four-wave difference frequency mixing in Kr. The present one-photon high-resolution MATI spectrum of pyridine demonstrated a much finer and richer vibrational structure than that of the previously reported two-photon MATI spectrum. From the MATI spectrum and photoionization efficiency curve, the accurate ionization energy of the ionic ground state of pyridine was confidently determined to be 73 570 ± 6 cm{sup −1} (9.1215 ± 0.0007 eV). The observed spectrum was almost completely assigned by utilizing Franck-Condon factors and vibrational frequencies calculated through adjustments of the geometrical parameters of cationic pyridine at the B3LYP/cc-pVTZ level. A unique feature unveiled through rigorous analysis was the prominent progression of the 10 vibrational mode, which corresponds to in-plane ring bending, and the combination of other totally symmetric fundamentals with the ring bending overtones, which contribute to the geometrical change upon ionization. Notably, the remaining peaks originate from the upper electronic state ({sup 2}A{sub 2}), as predicted by high-resolution photoelectron spectroscopy studies and symmetry-adapted cluster configuration interaction calculations. Based on the quantitatively good agreement between the experimental and calculated results, it was concluded that upon ionization the pyridine cation in the ground electronic state should have a planar structure of C{sub 2v} symmetry through the C-N axis.

  18. Accurate determination of silver nanoparticles in animal tissues by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Veverková, Lenka [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Hradilová, Šárka [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Milde, David, E-mail: david.mlde@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Panáček, Aleš [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Skopalová, Jana [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Kvítek, Libor [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Petrželová, Kamila [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); National Reference Laboratory for Chemical Elements, Department of Residues in Kroměříž, State Veterinary Institute Olomouc, Hulínská 2286, CZ 767 60 Kroměříž (Czech Republic); and others

    2014-12-01

    This study examined recoveries of silver determination in animal tissues after wet digestion by inductively coupled plasma mass spectrometry. The composition of the mineralization mixture for microwave assisted digestion was optimized and the best recoveries were obtained for mineralization with HNO{sub 3} and addition of HCl promptly after digestion. The optimization was performed on model samples of chicken meat spiked with silver nanoparticles and a solution of ionic silver. Basic calculations of theoretical distribution of Ag among various silver-containing species were implemented and the results showed that most of the silver is in the form of soluble complexes AgCl{sub 2}{sup −} and AgCl{sub 3}{sup 2−} for the optimized composition of the mineralization mixture. Three animal tissue certified reference materials were then analyzed to verify the trueness and precision of the results. - Highlights: • We performed detailed optimization of microwave assisted digestion procedure of animal tissue used prior to Ag determination by ICP-MS. • We provide basic equilibrium calculations to give theoretical explanation of results from optimization of tested mineralization mixtures. • Results from method validation that was done by analysis of several matrix CRMs are presented.

  19. 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.

  20. Isotope determination of sulfur by mass spectrometry in soil samples

    Directory of Open Access Journals (Sweden)

    Alexssandra Luiza Rodrigues Molina Rossete

    2012-12-01

    Full Text Available Sulphur plays an essential role in plants and is one of the main nutrients in several metabolic processes. It has four stable isotopes (32S, 33S, 34S, and 36S with a natural abundance of 95.00, 0.76, 4.22, and 0.014 in atom %, respectively. A method for isotopic determination of S by isotope-ratio mass spectrometry (IRMS in soil samples is proposed. The procedure involves the oxidation of organic S to sulphate (S-SO4(2-, which was determined by dry combustion with alkaline oxidizing agents. The total S-SO4(2- concentration was determined by turbidimetry and the results showed that the conversion process was adequate. To produce gaseous SO2 gas, BaSO4 was thermally decomposed in a vacuum system at 900 ºC in the presence of NaPO3. The isotope determination of S (atom % 34S atoms was carried out by isotope ratio mass spectrometry (IRMS. In this work, the labeled material (K2(34SO4 was used to validate the method of isotopic determination of S; the results were precise and accurate, showing the viability of the proposed method.

  1. Determination of La and Nd by thermal ionization mass spectrometry (TIMS) pre-separated by high performance liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Jaison, P.G.; Raut, N.M.; Parab, A.R.; Khodade, P.S.; Govindan, R.; Aggarwal, S.K.

    2003-01-01

    Determination of La and Nd by TIMS is required for accurate determination of burn-up of nuclear fuels. During their thermal ionization mass spectrometric (TIMS) analysis, 138 Ce and 142 Ce show spectroscopic isobaric interferences at 138 La and 142 Nd, respectively. Hence, it is essential to remove Ce from La and Nd for their accurate isotopic composition determination. Reversed phase high performance liquid chromatography (HPLC) is a promising technique for rapid and effective separation

  2. Screening in veterinary drug analysis and sports doping control based on full-scan, accurate-mass spectrometry

    NARCIS (Netherlands)

    Peters, R.J.B.; Stolker, A.A.M.; Mol, J.G.J.; Lommen, A.; Lyris, E.; Angelis, Y.S.; Vonaparti, A.; Stamou, M.; Georgakopoulos, C.G.; Nielen, M.W.F.

    2010-01-01

    A common trend in food contaminants and sports doping control is towards a limited number of targeted, full-scan, accurate-mass spectrometry (MS) methods based on time-of-flight (TOF) or Fourier-transform orbital trap (Orbitrap) mass analyzers. Retrospective analysis of the full-scan datasets of

  3. Development of isotope dilution-liquid chromatography/mass spectrometry combined with standard addition techniques for the accurate determination of tocopherols in infant formula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joonhee; Jang, Eun-Sil; Kim, Byungjoo, E-mail: byungjoo@kriss.re.kr

    2013-07-17

    Graphical abstract: -- Highlights: •ID-LC/MS method showed biased results for tocopherols analysis in infant formula. •H/D exchange of deuterated tocopherols in sample preparation was the source of bias. •Standard addition (SA)-ID-LC/MS was developed as an alternative to ID-LC/MS. •Details of calculation and uncertainty evaluation of the SA-IDMS were described. •SA-ID-LC/MS showed a higher-order metrological quality as a reference method. -- Abstract: During the development of isotope dilution-liquid chromatography/mass spectrometry (ID-LC/MS) for tocopherol analysis in infant formula, biased measurement results were observed when deuterium-labeled tocopherols were used as internal standards. It turned out that the biases came from intermolecular H/D exchange and intramolecular H/D scrambling of internal standards in sample preparation processes. Degrees of H/D exchange and scrambling showed considerable dependence on sample matrix. Standard addition-isotope dilution mass spectrometry (SA-IDMS) based on LC/MS was developed in this study to overcome the shortcomings of using deuterium-labeled internal standards while the inherent advantage of isotope dilution techniques is utilized for the accurate recovery correction in sample preparation processes. Details of experimental scheme, calculation equation, and uncertainty evaluation scheme are described in this article. The proposed SA-IDMS method was applied to several infant formula samples to test its validity. The method was proven to have a higher-order metrological quality with providing very accurate and precise measurement results.

  4. Development of accurate mass spectrometric routine and reference methods for the determination of trace amounts of iridium and rhodium in photographic emulsionsf

    NARCIS (Netherlands)

    Krystek, Petra; Heumann, Klaus G.

    1999-01-01

    For the determination of trace amounts of iridium and rhodium in photographic emulsions different sample treatment procedures were coupled with inductively coupled plasma mass spectrometry (ICP-MS) and, for iridium, also with negative thermal ionisation isotope dilution mass spectrometry (NTI-IDMS)

  5. Accurate screening for synthetic preservatives in beverage using high performance liquid chromatography with time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Li Xiuqin; Zhang Feng; Sun Yanyan; Yong Wei; Chu Xiaogang; Fang Yanyan; Zweigenbaum, Jerry

    2008-01-01

    In this study, liquid chromatography time-of-flight mass spectrometry (HPLC/TOF-MS) is applied to qualitation and quantitation of 18 synthetic preservatives in beverage. The identification by HPLC/TOF-MS is accomplished with the accurate mass (the subsequent generated empirical formula) of the protonated molecules [M + H]+ or the deprotonated molecules [M - H]-, along with the accurate mass of their main fragment ions. In order to obtain sufficient sensitivity for quantitation purposes (using the protonated or deprotonated molecule) and additional qualitative mass spectrum information provided by the fragments ions, segment program of fragmentor voltages is designed in positive and negative ion mode, respectively. Accurate mass measurements are highly useful in the complex sample analyses since they allow us to achieve a high degree of specificity, often needed when other interferents are present in the matrix. The mass accuracy typically obtained is routinely better than 3 ppm. The 18 compounds behave linearly in the 0.005-5.0 mg.kg -1 concentration range, with correlation coefficient >0.996. The recoveries at the tested concentrations of 1.0 mg.kg -1 -100 mg.kg -1 are 81-106%, with coefficients of variation -1 , which are far below the required maximum residue level (MRL) for these preservatives in foodstuff. The method is suitable for routine quantitative and qualitative analyses of synthetic preservatives in foodstuff

  6. Ion Mass Determination

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (100) is described for determining the mass of ions, the apparatus configured to hold a plasma (101 ) having a plasma potential. The apparatus (100) comprises an electrode (102) having a surface extending in a surface plane and an insulator (104) interfacing with the electrode (102......, and a processing unit (108) configured to interpret the detected impact locations in terms of the mass of the impacting ions....

  7. Formic acid hydrolysis/liquid chromatography isotope dilution mass spectrometry: An accurate method for large DNA quantification.

    Science.gov (United States)

    Shibayama, Sachie; Fujii, Shin-Ichiro; Inagaki, Kazumi; Yamazaki, Taichi; Takatsu, Akiko

    2016-10-14

    Liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) with formic acid hydrolysis was established for the accurate quantification of λDNA. The over-decomposition of nucleobases in formic acid hydrolysis was restricted by optimizing the reaction temperature and the reaction time, and accurately corrected by using deoxynucleotides (dNMPs) and isotope-labeled dNMPs as the calibrator and the internal standard, respectively. The present method could quantify λDNA with an expanded uncertainty of 4.6% using 10fmol of λDNA. The analytical results obtained with the present method were validated by comparing with the results of phosphate-base quantification by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed good agreement with each other. We conclude that the formic acid hydrolysis/LC-IDMS method can quantify λDNA accurately and is promising as the primary method for the certification of DNA as reference material. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Accurate determination of 41Ca concentrations in spent resins from the nuclear industry by Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bourlès, Didier; Bienvenu, Philippe; Labet, Alexandre; Arnold, Maurice; Bertaux, Maité

    2013-01-01

    The radiological characterisation of nuclear waste is essential for managing storage sites. Determining the concentration of Long‐Lived RadioNuclides (LLRN) is fundamental for their long-term management. This paper focuses on the measurement of low 41 Ca concentrations in ions exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). 41 Ca concentrations were successfully measured by Accelerator Mass Spectrometry (AMS) after the acid digestion of resin samples, followed by radioactive decontamination and isobaric suppression through successive hydroxide, carbonate, nitrate and final CaF 2 precipitations. Measured 41 Ca concentrations ranged from 0.02 to 0.03 ng/g, i.e. from 0.06 to 0.09 Bq/g. The 41 Ca/ 60 Co activity ratios obtained were remarkably reproducible and in good agreement with the current ratio used for resins management. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 41 Ca in spent resins using Accelerator Mass Spectrometry. • A chemical treatment procedure was developed to quantitatively recover calcium in solution and selectively extract it. • Developed firstly on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • Accelerator mass spectrometry allowed measuring concentrations of 41 Ca in spent resins as low as 0.02 ng/g of dry resin. • Final results are in agreement with current data used for spent resins management

  9. Toward Accurate On-Ground Attitude Determination for the Gaia Spacecraft

    Science.gov (United States)

    Samaan, Malak A.

    2010-03-01

    The work presented in this paper concerns the accurate On-Ground Attitude (OGA) reconstruction for the astrometry spacecraft Gaia in the presence of disturbance and of control torques acting on the spacecraft. The reconstruction of the expected environmental torques which influence the spacecraft dynamics will be also investigated. The telemetry data from the spacecraft will include the on-board real-time attitude, which is of order of several arcsec. This raw attitude is the starting point for the further attitude reconstruction. The OGA will use the inputs from the field coordinates of known stars (attitude stars) and also the field coordinate differences of objects on the Sky Mapper (SM) and Astrometric Field (AF) payload instruments to improve this raw attitude. The on-board attitude determination uses a Kalman Filter (KF) to minimize the attitude errors and produce a more accurate attitude estimation than the pure star tracker measurement. Therefore the first approach for the OGA will be an adapted version of KF. Furthermore, we will design a batch least squares algorithm to investigate how to obtain a more accurate OGA estimation. Finally, a comparison between these different attitude determination techniques in terms of accuracy, robustness, speed and memory required will be evaluated in order to choose the best attitude algorithm for the OGA. The expected resulting accuracy for the OGA determination will be on the order of milli-arcsec.

  10. Hybrid quadrupole-orbitrap mass spectrometry analysis with accurate-mass database and parallel reaction monitoring for high-throughput screening and quantification of multi-xenobiotics in honey.

    Science.gov (United States)

    Li, Yi; Zhang, Jinzhen; Jin, Yue; Wang, Lin; Zhao, Wen; Zhang, Wenwen; Zhai, Lifei; Zhang, Yaping; Zhang, Yongxin; Zhou, Jinhui

    2016-01-15

    This study reports a rapid, automated screening and quantification method for the determination of multi-xenobiotic residues in honey using ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-Q-Orbitrap) with a user-built accurate-mass database plus parallel reaction monitoring (PRM). The database contains multi-xenobiotic information including formulas, adduct types, theoretical exact mass and retention time, characteristic fragment ions, ion ratios, and mass accuracies. A simple sample preparation method was developed to reduce xenobiotic loss in the honey samples. The screening method was validated based on retention time deviation, mass accuracy via full scan-data-dependent MS/MS (full scan-ddMS2), multi-isotope ratio, characteristic ion ratio, sensitivity, and positive/negative switching performance between the spiked sample and corresponding standard solution. The quantification method based on the PRM mode is a promising new quantitative tool which we validated in terms of selectivity, linearity, recovery (accuracy), repeatability (precision), decision limit (CCα), detection capability (CCβ), matrix effects, and carry-over. The optimized methods proposed in this study enable the automated screening and quantification of 157 compounds in less than 15 min in honey. The results of this study, as they represent a convenient protocol for large-scale screening and quantification, also provide a research approach for analysis of various contaminants in other matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Non-targeted screening for contaminants in paper and board food-contact materials using effect-directed analysis and accurate mass spectrometry

    DEFF Research Database (Denmark)

    Bengtström, Linda; Rosenmai, Anna Kjerstine; Trier, Xenia

    2016-01-01

    Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including......R) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries...... in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven...

  12. Method and apparatus for simultaneous determination of fluid mass flow rate, mean velocity and density

    International Nuclear Information System (INIS)

    Hamel, W.R.

    1984-01-01

    This invention relates to a new method and new apparatus for determining fluid mass flow rate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flow rate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flow rate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flow rate and density are determined from the required change in power input. The invention provides stable, rapid, and accurate measurements. It does not require bending of the fluid flow

  13. Screening and confirmation criteria for hormone residue analysis using liquid chromatography accurate mass time-of-flight, Fourier transform ion cyclotron resonance and orbitrap mass spectrometry techniques

    NARCIS (Netherlands)

    Nielen, M.W.F.; Engelen, M.C. van; Zuiderent, R.; Ramaker, R.

    2007-01-01

    An emerging trend is recognised in hormone and veterinary drug residue analysis from liquid chromatography tandem mass spectrometry (LC/MS/MS) based screening and confirmation towards accurate mass alternatives such as LC coupled with time-of-flight (TOF), Fourier transform ion cyclotron resonance

  14. Accurate determination of Curium and Californium isotopic ratios by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 248Cm samples for transmutation studies

    Energy Technology Data Exchange (ETDEWEB)

    Gourgiotis, A.; Isnard, H.; Aubert, M.; Dupont, E.; AlMahamid, I.; Cassette, P.; Panebianco, S.; Letourneau, A.; Chartier, F.; Tian, G.; Rao, L.; Lukens, W.

    2011-02-01

    The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in {sup 248}Cm ({approx}97 %) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides formations ranged from 0.3% to 1.3%. This uncertainties range is quite acceptable for the nuclear data to be used in transmutation studies.

  15. In-vivo determination of total body water and lean body mass in subjects by deuterium dilution

    International Nuclear Information System (INIS)

    Blagojevic, N.; Allen, B.J.; Baur, L.; Gaskin, K.

    1988-01-01

    Total body water (TBW) estimation is one of a number of basic techniques required for the determination of body composition in normal and malnourished subjects. When combined with total body nitrogen (TBN) analysis by prompt gamma neutron activation, an accurate compartmental model of in vivo body composition can be formed, providing valuable nutritional and other data. This study examines the role of TBW on its own in evaluating lean body mass. Total body water was studied in six male and five female subjects using deuterium oxide and a Fourier transform infrared spectrometer. The lean body mass calculated from the results was compared with the lean body mass deduced from established total body nitrogen measurements. A four-compartment model was also used to calculate lean body mass. Excellent agreement was shown between lean body mass derived from TBW, the four-compartment model and TBN. Hence, TBW can provide a fast, cost-efficient method for evaluating normal subjects. However, for disease-induced malnutrition, or highly developed athletes, both TBN and TBW measurements are essential to establish an accurate picture of their body composition. TBW measurements alone can monitor the hydration state of patients and as such have a useful diagnostic value

  16. In-vivo determination of total body water and lean body mass in subjects by deuterium dilution

    Energy Technology Data Exchange (ETDEWEB)

    Blagojevic, N; Allen, B J; Baur, L; Gaskin, K

    1988-12-01

    Total body water (TBW) estimation is one of a number of basic techniques required for the determination of body composition in normal and malnourished subjects. When combined with total body nitrogen (TBN) analysis by prompt gamma neutron activation, an accurate compartmental model of in vivo body composition can be formed, providing valuable nutritional and other data. This study examines the role of TBW on its own in evaluating lean body mass. Total body water was studied in six male and five female subjects using deuterium oxide and a Fourier transform infrared spectrometer. The lean body mass calculated from the results was compared with the lean body mass deduced from established total body nitrogen measurements. A four-compartment model was also used to calculate lean body mass. Excellent agreement was shown between lean body mass derived from TBW, the four-compartment model and TBN. Hence, TBW can provide a fast, cost-efficient method for evaluating normal subjects. However, for disease-induced malnutrition, or highly developed athletes, both TBN and TBW measurements are essential to establish an accurate picture of their body composition. TBW measurements alone can monitor the hydration state of patients and as such have a useful diagnostic value.

  17. Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry

    Science.gov (United States)

    Thurman, E.M.; Ferrer, I.; Parry, R.

    2002-01-01

    Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750??0.0049 amu and 270.0786??0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098??0.0061 amu and 314.1153??0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.

  18. Novel insight into neutrophil immune responses by dry mass determination of Candida albicans morphotypes.

    Directory of Open Access Journals (Sweden)

    Ava Hosseinzadeh

    Full Text Available The common fungal pathogen Candida albicans has the ability to grow as a yeast or as a hypha and can alternate between these morphotypes. The overall biomass of both morphotypes increases with growth. However, only yeasts, but not hyphae, exist as discrete cellular entities. Multiplicity of infection (MOI is a useful parameter to determine the initial inoculum of yeasts for in vitro infection assays. Since the amount of hyphae is difficult to quantify, comparable starting conditions in such assays cannot be determined accurately for yeasts and hyphae using MOI. To circumvent this problem, we have established a set of correlation coefficients to convert fungal metabolic activity and optical density to dry mass. Using these correlations, we were able to accurately compare ROS production and IL-8 release by polymorphonuclear neutrophils upon infection with equal dry mass amounts of yeast and hyphal morphotypes. Neutrophil responses depended on the initial form of infection, irrespective of C. albicans wild-type yeasts transforming to hyphal growth during the assay. Infection with a high mass of live C. albicans yeasts resulted in lower neutrophil ROS and this decrease stems from efficient ROS detoxification by C. albicans without directly affecting the phagocyte ROS machinery. Moreover, we show that dead C. albicans induces significantly less ROS and IL-8 release than live fungi, but thimerosal-killed C. albicans were still able to detoxify neutrophil ROS. Thus, the dry mass approach presented in this study reveals neutrophil responses to different amounts and morphotypes of C. albicans and serves as a template for studies that aim to identify morphotype-specific responses in a variety of immune cells.

  19. REFINED NEUTRON STAR MASS DETERMINATIONS FOR SIX ECLIPSING X-RAY PULSAR BINARIES

    International Nuclear Information System (INIS)

    Rawls, Meredith L.; Orosz, Jerome A.; McClintock, Jeffrey E.; Torres, Manuel A. P.; Bailyn, Charles D.; Buxton, Michelle M.

    2011-01-01

    We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply the method to six systems, namely, Vela X-1, 4U 1538-52, SMC X-1, LMC X-4, Cen X-3, and Her X-1. In previous studies to determine neutron star mass, the X-ray eclipse duration has been approximated analytically by assuming that the companion star is spherical with an effective Roche lobe radius. We use a numerical code based on Roche geometry with various optimizers to analyze the published data for these systems, which we supplement with new spectroscopic and photometric data for 4U 1538-52. This allows us to model the eclipse duration more accurately and thus calculate an improved value for the neutron star mass. The derived neutron star mass also depends on the assumed Roche lobe filling factor β of the companion star, where β = 1 indicates a completely filled Roche lobe. In previous work a range of β between 0.9 and 1.0 was usually adopted. We use optical ellipsoidal light-curve data to constrain β. We find neutron star masses of 1.77 ± 0.08 M sun for Vela X-1, 0.87 ± 0.07 M sun for 4U 1538-52 (eccentric orbit), 1.00 ± 0.10 M sun for 4U 1538-52 (circular orbit), 1.04 ± 0.09 M sun for SMC X-1, 1.29 ± 0.05 M sun for LMC X-4, 1.49 ± 0.08 M sun for Cen X-3, and 1.07 ± 0.36 M sun for Her X-1. We discuss the limits of the approximations that were used to derive the earlier mass determinations, and we comment on the implications our new masses have for observationally refining the upper and lower bounds of the neutron star mass distribution.

  20. Limitation of secondary electron multiplier non-linearity on accurate U-Th isotopic determination by MC-ICP-MS

    Science.gov (United States)

    Shen, C.; Wu, C.; Gallet, S.; Cheng, H.; Edwards, R.; Hsieh, Y.; Lin, K.

    2008-12-01

    Contemporary multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS) with discrete dynode secondary electron multipliers (SEMs) can offer U-Th isotopic determinations with subpermil-permil- level precision in femtogram quantities. However, accurate isotopic measurement requires fully understanding SEM mass and intensity biases. In additional to dead-time effect, Richter et al (2001, Int. J. Mass Spectrom., 206, 105-127) reported a nonlinearity on SEMs produced by ETP and MasCom for count rates > 20 thousand counts per second (cps). We evaluated the possible biases for ion beams of 500- 1,600,000 cps on a latest MasCom SEM, SEV TE-Z/17, with more effective ion optical acceptance area (>50%) and better peak shape than previous models, used in a MC-ICP-MS, Thermo Fisher NEPTUNE. With the retarding potential quadruple lens (RPQ) turned off, ion beam intensity can be biased by only dead- time effect, which can be precisely corrected online or offline. With the RPQ on, two additional biases, an exponential-like increase of ion beam intensity from 100-100,000 s cps and an apparent dead-time effect (-2 to 2 ns) at high count rates, are observed. They are likely caused by the slightly defocused ions with a wide kinetic energy spread of ~5 eV, 10 times worse than that with thermal source, passing through the RPQ lens to the SEM, which is installed behind the focal plane. Fortunately, the two biases, which are stable during the daily measurements with the same settings of inlet system, source lenses, zoom optics, and RPQ, can be corrected effectively offline to earn accurate U-Th isotopic measurement.

  1. A highly accurate method for determination of dissolved oxygen: Gravimetric Winkler method

    International Nuclear Information System (INIS)

    Helm, Irja; Jalukse, Lauri; Leito, Ivo

    2012-01-01

    Highlights: ► Probably the most accurate method available for dissolved oxygen concentration measurement was developed. ► Careful analysis of uncertainty sources was carried out and the method was optimized for minimizing all uncertainty sources as far as practical. ► This development enables more accurate calibration of dissolved oxygen sensors for routine analysis than has been possible before. - Abstract: A high-accuracy Winkler titration method has been developed for determination of dissolved oxygen concentration. Careful analysis of uncertainty sources relevant to the Winkler method was carried out and the method was optimized for minimizing all uncertainty sources as far as practical. The most important improvements were: gravimetric measurement of all solutions, pre-titration to minimize the effect of iodine volatilization, accurate amperometric end point detection and careful accounting for dissolved oxygen in the reagents. As a result, the developed method is possibly the most accurate method of determination of dissolved oxygen available. Depending on measurement conditions and on the dissolved oxygen concentration the combined standard uncertainties of the method are in the range of 0.012–0.018 mg dm −3 corresponding to the k = 2 expanded uncertainty in the range of 0.023–0.035 mg dm −3 (0.27–0.38%, relative). This development enables more accurate calibration of electrochemical and optical dissolved oxygen sensors for routine analysis than has been possible before.

  2. Accurate and precise determination of small quantity uranium by means of automatic potentiometric titration

    International Nuclear Information System (INIS)

    Liu Quanwei; Luo Zhongyan; Zhu Haiqiao; Wu Jizong

    2007-01-01

    For high radioactivity level of dissolved solution of spent fuel and the solution of uranium product, radioactive hazard must be considered and reduced as low as possible during accurate determination of uranium. In this work automatic potentiometric titration was applied and the sample only 10 mg of uranium contained was taken in order to reduce the harm of analyzer suffered from the radioactivity. RSD<0.06%, at the same time the result can be corrected for more reliable and accurate measurement. The determination method can effectively reduce the harm of analyzer suffered from the radioactivity, and meets the requirement of reliable accurate measurement of uranium. (authors)

  3. Efficient mass calibration of magnetic sector mass spectrometers

    International Nuclear Information System (INIS)

    Roddick, J.C.

    1996-01-01

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A·Mass 1/2 + B·(Mass) p where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs

  4. Accurate evolutions of inspiralling and magnetized neutron stars: Equal-mass binaries

    International Nuclear Information System (INIS)

    Giacomazzo, Bruno; Rezzolla, Luciano; Baiotti, Luca

    2011-01-01

    By performing new, long and numerically accurate general-relativistic simulations of magnetized, equal-mass neutron-star binaries, we investigate the role that realistic magnetic fields may have in the evolution of these systems. In particular, we study the evolution of the magnetic fields and show that they can influence the survival of the hypermassive neutron star produced at the merger by accelerating its collapse to a black hole. We also provide evidence that, even if purely poloidal initially, the magnetic fields produced in the tori surrounding the black hole have toroidal and poloidal components of equivalent strength. When estimating the possibility that magnetic fields could have an impact on the gravitational-wave signals emitted by these systems either during the inspiral or after the merger, we conclude that for realistic magnetic-field strengths B 12 G such effects could be detected, but only marginally, by detectors such as advanced LIGO or advanced Virgo. However, magnetically induced modifications could become detectable in the case of small-mass binaries and with the development of gravitational-wave detectors, such as the Einstein Telescope, with much higher sensitivities at frequencies larger than ≅2 kHz.

  5. Accurate determination of process variables in a solid-state fermentation system

    NARCIS (Netherlands)

    Smits, J.P.; Rinzema, A.; Tramper, J.; Schlösser, E.E.; Knol, W.

    1996-01-01

    The solid-state fermentation (SSF) method described enabled accurate determination of variables related to biological activity. Growth, respiratory activity and production of carboxymethyl-cellulose-hydrolysing enzyme (CMC-ase) activity by Trichoderma reesei QM9414 on wheat bran was used as a model

  6. Non-targeted screening for contaminants in paper and board food-contact materials using effect-directed analysis and accurate mass spectrometry.

    Science.gov (United States)

    Bengtström, Linda; Rosenmai, Anna Kjerstine; Trier, Xenia; Jensen, Lisbeth Krüger; Granby, Kit; Vinggaard, Anne Marie; Driffield, Malcolm; Højslev Petersen, Jens

    2016-06-01

    Due to large knowledge gaps in chemical composition and toxicological data for substances involved, paper and board food-contact materials (P&B FCM) have been emerging as a FCM type of particular concern for consumer safety. This study describes the development of a step-by-step strategy, including extraction, high-performance liquid chromatography (HPLC) fractionation, tentative identification of relevant substances and in vitro testing of selected tentatively identified substances. As a case study, we used two fractions from a recycled pizza box sample which exhibited aryl hydrocarbon receptor (AhR) activity. These fractions were analysed by gas chromatography (GC) and ultra-HPLC (UHPLC) coupled to quadrupole time-of-flight mass spectrometers (QTOF MS) in order tentatively to identify substances. The elemental composition was determined for peaks above a threshold, and compared with entries in a commercial mass spectral library for GC-MS (GC-EI-QTOF MS) analysis and an in-house built library of accurate masses for substances known to be used in P&B packaging for UHPLC-QTOF analysis. Of 75 tentatively identified substances, 15 were initially selected for further testing in vitro; however, only seven were commercially available and subsequently tested in vitro and quantified. Of these seven, the identities of three pigments found in printing inks were confirmed by UHPLC tandem mass spectrometry (QqQ MS/MS). Two pigments had entries in the database, meaning that a material relevant accurate mass database can provide a fast tentative identification. Pure standards of the seven tentatively identified substances were tested in vitro but could not explain a significant proportion of the AhR-response in the extract. Targeted analyses of dioxins and PCBs, both well-known AhR agonists, was performed. However, the dioxins could explain approximately 3% of the activity observed in the pizza box extract indicating that some very AhR active substance(s) still remain to be

  7. Total cholesterol in serum determined by isotope dilution/mass spectrometry, with liquid-chromatographic separation

    International Nuclear Information System (INIS)

    Takatsu, Akiko; Nishi, Sueo

    1988-01-01

    We describe an accurate, precise method for determination of total serum cholesterol by isotope dilution/mass spectrometry (IDMS) with liquid chromatographic separation. After adding [3,4- 13 C] cholesterol to serum and hydrolyzing the cholesterol esters, we extract the total cholesterol. High-performance liquid chromatography (HPLC) is used to separate the extracted cholesterol for measurement by electron-impact mass spectrometry with use of a direct-insertion device. To evaluate the specificity and the accuracy of this method, we also studied the conventional IDMS method, which involves converting cholesterol to the trimethylsilyl ether and assay by gas chromatography-mass spectrometry with use of a capillary column. The coefficient of variation for the HPLC method was a little larger than for the conventional method, but mean values by each method agreed within 1% for all sera tested. (author)

  8. Burnup determination of mass spectrometry for nuclear fuels

    International Nuclear Information System (INIS)

    Zhang Chunhua.

    1987-01-01

    The various methods currently being used in burnup determination of nuclear fuels are studied and reviewed. The mass spectrometry method of destructive testing is discussed emphatically. The burnup determination of mass spectrometry includes heavy isotopic abundance ratio method and isotope dilution mass spectrometry used as burnup indicator for the fission products. The former is applied to high burnup level, but the later to various burnup level. According to experiences, some problems which should be noticed in burnup determination of mass spectrometry are presented

  9. Accurate light-time correction due to a gravitating mass

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, Neil [Department of Physics, University of Colorado, Boulder, CO (United States); Bertotti, Bruno, E-mail: ashby@boulder.nist.go [Dipartimento di Fisica Nucleare e Teorica, Universita di Pavia (Italy)

    2010-07-21

    This technical paper of mathematical physics arose as an aftermath of the 2002 Cassini experiment (Bertotti et al 2003 Nature 425 374-6), in which the PPN parameter {gamma} was measured with an accuracy {sigma}{sub {gamma}} = 2.3 x 10{sup -5} and found consistent with the prediction {gamma} = 1 of general relativity. The Orbit Determination Program (ODP) of NASA's Jet Propulsion Laboratory, which was used in the data analysis, is based on an expression (8) for the gravitational delay {Delta}t that differs from the standard formula (2); this difference is of second order in powers of m-the gravitational radius of the Sun-but in Cassini's case it was much larger than the expected order of magnitude m{sup 2}/b, where b is the distance of the closest approach of the ray. Since the ODP does not take into account any other second-order terms, it is necessary, also in view of future more accurate experiments, to revisit the whole problem, to systematically evaluate higher order corrections and to determine which terms, and why, are larger than the expected value. We note that light propagation in a static spacetime is equivalent to a problem in ordinary geometrical optics; Fermat's action functional at its minimum is just the light-time between the two end points A and B. A new and powerful formulation is thus obtained. This method is closely connected with the much more general approach of Le Poncin-Lafitte et al (2004 Class. Quantum Grav. 21 4463-83), which is based on Synge's world function. Asymptotic power series are necessary to provide a safe and automatic way of selecting which terms to keep at each order. Higher order approximations to the required quantities, in particular the delay and the deflection, are easily obtained. We also show that in a close superior conjunction, when b is much smaller than the distances of A and B from the Sun, say of order R, the second-order correction has an enhanced part of order m{sup 2}R/b{sup 2}, which

  10. Accurate determination of ultra-trace levels of Ti in blood serum using ICP-MS/MS

    International Nuclear Information System (INIS)

    Balcaen, Lieve; Bolea-Fernandez, Eduardo; Resano, Martín; Vanhaecke, Frank

    2014-01-01

    Graphical abstract: -- Highlights: •Novel method for determination of Ti at ultra-trace levels in clinical samples (serum). •Novel method based on Ti(NH 3 ) 6 + reaction product ion formation and double mass selection using recently introduced ICP-QQQ instrumentation. •Lowest limits of detection ever obtained using quadrupole-based instrumentation for Ti. •Accurate determination of basal levels of Ti in blood serum. -- Abstract: Ti is frequently used in implants and prostheses and it has been shown before that the presence of these in the human body can lead to elevated Ti concentrations in body fluids such as serum and urine. As identification of the exact mechanisms responsible for this increase in Ti concentrations, and the risks associated with it, are not fully understood, it is important to have sound analytical methods that enable straightforward quantification of Ti levels in body fluids (for both implanted and non-implanted individuals). Until now, only double-focusing sector field ICP-mass spectrometry (SF-ICP-MS) offered limits of detection that are good enough to deal with the very low basal levels of Ti in human serum. This work reports on the development of a novel method for the accurate and precise determination of trace levels of Ti in human serum samples, based on the use of ICP-MS/MS. O 2 and NH 3 /He have been compared as reaction gases. While the use of O 2 did not enable to overcome all spectral interferences, it has been shown that conversion of Ti + ions into Ti(NH 3 ) 6 + cluster ions by using NH 3 /He as a reaction gas in an ICP-QQQ-MS system, operated in MS/MS mode, provided interference-free conditions and sufficiently low limits of detection, down to 3 ng L −1 (instrumental detection limit obtained for the most abundant Ti isotope). The accuracy of the method proposed was evaluated by analysis of a Seronorm Trace Elements Serum L-1 reference material and by comparing the results obtained with those achieved by means of SF

  11. Atomic spectroscopy and highly accurate measurement: determination of fundamental constants

    International Nuclear Information System (INIS)

    Schwob, C.

    2006-12-01

    This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm -1 ). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10 -9 began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is α -1 = 137.03599884 (91) with a relative uncertainty of 6.7*10 -9 . The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)

  12. Analytical method comparisons for the accurate determination of PCBs in sediments

    Energy Technology Data Exchange (ETDEWEB)

    Numata, M.; Yarita, T.; Aoyagi, Y.; Yamazaki, M.; Takatsu, A. [National Metrology Institute of Japan, Tsukuba (Japan)

    2004-09-15

    National Metrology Institute of Japan in National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has been developing several matrix reference materials, for example, sediments, water and biological tissues, for the determinations of heavy metals and organometallic compounds. The matrix compositions of those certified reference materials (CRMs) are similar to compositions of actual samples, and those are useful for validating analytical procedures. ''Primary methods of measurements'' are essential to obtain accurate and SI-traceable certified values in the reference materials, because the methods have the highest quality of measurement. However, inappropriate analytical operations, such as incomplete extraction of analytes or crosscontamination during analytical procedures, will cause error of analytical results, even if one of the primary methods, isotope-dilution, is utilized. To avoid possible procedural bias for the certification of reference materials, we employ more than two analytical methods which have been optimized beforehand. Because the accurate determination of trace POPs in the environment is important to evaluate their risk, reliable CRMs are required by environmental chemists. Therefore, we have also been preparing matrix CRMs for the determination of POPs. To establish accurate analytical procedures for the certification of POPs, extraction is one of the critical steps as described above. In general, conventional extraction techniques for the determination of POPs, such as Soxhlet extraction (SOX) and saponification (SAP), have been characterized well, and introduced as official methods for environmental analysis. On the other hand, emerging techniques, such as microwave-assisted extraction (MAE), pressurized fluid extraction (PFE) and supercritical fluid extraction (SFE), give higher recovery yields of analytes with relatively short extraction time and small amount of solvent, by reasons of the high

  13. Determination of the neutron mass

    International Nuclear Information System (INIS)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R.

    2005-01-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, 1 0 n + 1 1 H → 2 1 D + γ. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source 239 PuBe whose activity is of 3.7 x 10 10 Bq. (Author)

  14. Efficient mass calibration of magnetic sector mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Roddick, J C

    1997-12-31

    Magnetic sector mass spectrometers used for automatic acquisition of precise isotopic data are usually controlled with Hall probes and software that uses polynomial equations to define and calibrate the mass-field relations required for mass focusing. This procedure requires a number of reference masses and careful tuning to define and maintain an accurate mass calibration. A simplified equation is presented and applied to several different magnetically controlled mass spectrometers. The equation accounts for nonlinearity in typical Hall probe controlled mass-field relations, reduces calibration to a linear fitting procedure, and is sufficiently accurate to permit calibration over a mass range of 2 to 200 amu with only two defining masses. Procedures developed can quickly correct for normal drift in calibrations and compensate for drift during isotopic analysis over a limited mass range such as a single element. The equation is: Field A{center_dot}Mass{sup 1/2} + B{center_dot}(Mass){sup p} where A, B, and p are constants. The power value p has a characteristic value for a Hall probe/controller and is insensitive to changing conditions, thus reducing calibration to a linear regression to determine optimum A and B. (author). 1 ref., 1 tab., 6 figs.

  15. MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING

    International Nuclear Information System (INIS)

    Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M.; Backer, D. C.; Bailes, M.; Bhat, N. D. R.; Van Straten, W.; Coles, W.; Demorest, P. B.; Ferdman, R. D.; Purver, M. B.; Folkner, W. M.; Hotan, A. W.; Kramer, M.; Lommen, A. N.; Nice, D. J.; Stairs, I. H.

    2010-01-01

    High-precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2) x10 -4 M sun , being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.

  16. MS2Analyzer: A Software for Small Molecule Substructure Annotations from Accurate Tandem Mass Spectra

    Science.gov (United States)

    2015-01-01

    Systematic analysis and interpretation of the large number of tandem mass spectra (MS/MS) obtained in metabolomics experiments is a bottleneck in discovery-driven research. MS/MS mass spectral libraries are small compared to all known small molecule structures and are often not freely available. MS2Analyzer was therefore developed to enable user-defined searches of thousands of spectra for mass spectral features such as neutral losses, m/z differences, and product and precursor ions from MS/MS spectra in MSP/MGF files. The software is freely available at http://fiehnlab.ucdavis.edu/projects/MS2Analyzer/. As the reference query set, 147 literature-reported neutral losses and their corresponding substructures were collected. This set was tested for accuracy of linking neutral loss analysis to substructure annotations using 19 329 accurate mass tandem mass spectra of structurally known compounds from the NIST11 MS/MS library. Validation studies showed that 92.1 ± 6.4% of 13 typical neutral losses such as acetylations, cysteine conjugates, or glycosylations are correct annotating the associated substructures, while the absence of mass spectra features does not necessarily imply the absence of such substructures. Use of this tool has been successfully demonstrated for complex lipids in microalgae. PMID:25263576

  17. Accurate Mass GC/LC-Quadrupole Time of Flight Mass Spectrometry Analysis of Fatty Acids and Triacylglycerols of Spicy Fruits from the Apiaceae Family

    Directory of Open Access Journals (Sweden)

    Thao Nguyen

    2015-12-01

    Full Text Available The triacylglycerol (TAG structure and the regio-stereospecific distribution of fatty acids (FA of seed oils from most of the Apiaceae family are not well documented. The TAG structure ultimately determines the final physical properties of the oils and the position of FAs in the TAG molecule affects the digestion; absorption and metabolism; and physical and technological properties of TAGs. Fixed oils from the fruits of dill (Anethum graveolens, caraway (Carum carvi, cumin (Cuminum cyminum, coriander (Coriandrum sativum, anise (Pimpinella anisum, carrot (Daucus carota, celery (Apium graveolens, fennel (Foeniculum vulgare, and Khella (Ammi visnaga, all from the Apiaceae family, were extracted at room temperature in chloroform/methanol (2:1 v/v using percolators. Crude lipids were fractionated by solid phase extraction to separate neutral triacylglycerols (TAGs from other lipids components. Neutral TAGs were subjected to transesterification process to convert them to their corresponding fatty acids methyl esters (FAMES using 1% boron trifluoride (BF3 in methanol. FAMES were analyzed by gas chromatography-quadrupole time of flight (GC-QTOF mass spectrometry. Triglycerides were analyzed using high performance liquid chromatography-quadrupole time of flight (LC-QTOF mass spectrometry. Petroselinic acid was the major fatty acid in all samples ranging from 57% of the total fatty acids in caraway up to 82% in fennel. All samples contained palmitic (16:0, palmitoleic (C16:1n-9, stearic (C18:0, petroselinic (C18:1n-12, linoleic (C18:2n-6, linolinic (18:3n-3, and arachidic (C20:0 acids. TAG were analyzed using LC-QTOF for accurate mass identification and mass spectrometry/mass spectrometry (MS/MS techniques for regiospesific elucidation of the identified TAGs. Five major TAGs were detected in all samples but with different relative concentrations in all of the tested samples. Several other TAGs were detected as minor components and were present in some

  18. Cluster abundance in chameleon f ( R ) gravity I: toward an accurate halo mass function prediction

    Energy Technology Data Exchange (ETDEWEB)

    Cataneo, Matteo; Rapetti, David [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen (Denmark); Lombriser, Lucas [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Li, Baojiu, E-mail: matteoc@dark-cosmology.dk, E-mail: drapetti@dark-cosmology.dk, E-mail: llo@roe.ac.uk, E-mail: baojiu.li@durham.ac.uk [Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom)

    2016-12-01

    We refine the mass and environment dependent spherical collapse model of chameleon f ( R ) gravity by calibrating a phenomenological correction inspired by the parameterized post-Friedmann framework against high-resolution N -body simulations. We employ our method to predict the corresponding modified halo mass function, and provide fitting formulas to calculate the enhancement of the f ( R ) halo abundance with respect to that of General Relativity (GR) within a precision of ∼< 5% from the results obtained in the simulations. Similar accuracy can be achieved for the full f ( R ) mass function on the condition that the modeling of the reference GR abundance of halos is accurate at the percent level. We use our fits to forecast constraints on the additional scalar degree of freedom of the theory, finding that upper bounds competitive with current Solar System tests are within reach of cluster number count analyses from ongoing and upcoming surveys at much larger scales. Importantly, the flexibility of our method allows also for this to be applied to other scalar-tensor theories characterized by a mass and environment dependent spherical collapse.

  19. PDF uncertainties in the determination of the W boson mass and of the effective lepton mixing angle at the LHC

    CERN Document Server

    Rojo, Juan

    2013-01-01

    The precision measurement of the W boson mass allows to perform stringent consistency tests of the Standard Model by means of global electroweak fits. The accurate determination of the W boson mass is one of the legacy results of the Tevatron, where the experimental accuracy is such that $M_W$ is now limited by theoretical uncertainties related to the parton distributions of the proton. In this contribution, we show how to quantify the impact of PDF uncertainties in the measurement of $M_W$ at the Tevatron and the LHC by means of a template method, and study both the use of the W transverse mass and the lepton pT kinematical distributions to generate these templates. We also present preliminary results on the quantification of the PDF uncertainties in the determination of the effective lepton mixing angle at the LHC, based on the same template method as for the W mass determination

  20. τ lepton mass determination at KEDR

    International Nuclear Information System (INIS)

    Eidelman, S.I.; Anashin, V.V.; Aulchenko, V.M.; Baldin, E.M.; Barladyan, A.K.; Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baru, S.E.; Basok, I.Yu.; Bedny, I.V.; Beloborodova, O.L.; Blinov, A.E.; Blinov, V.E.; Bobrov, A.V.; Bobrovnikov, V.S.; Bogomyagkov, A.V.; Bondar, A.E.; Buzykaev, A.R.; Eidelman, S.I.; Glukhovchenko, Yu.M.

    2011-01-01

    We present preliminary results of a new high-precision determination of the τ lepton mass performed with the KEDR detector at the VEPP-4M e + e - collider. These results are compared to two recent τ lepton mass measurements at Belle and BaBar.

  1. Position and mass determination of multiple particles using cantilever based mass sensors

    International Nuclear Information System (INIS)

    Dohn, Soeren; Schmid, Silvan; Boisen, Anja; Amiot, Fabien

    2010-01-01

    Resonant microcantilevers are highly sensitive to added masses and have the potential to be used as mass-spectrometers. However, making the detection of individual added masses quantitative requires the position determination for each added mass. We derive expressions relating the position and mass of several added particles to the resonant frequencies of a cantilever, and an identification procedure valid for particles with different masses is proposed. The identification procedure is tested by calculating positions and mass of multiple microparticles with similar mass positioned on individual microcantilevers. Excellent agreement is observed between calculated and measured positions and calculated and theoretical masses.

  2. Standard addition strip for quantitative electrostatic spray ionization mass spectrometry analysis: determination of caffeine in drinks.

    Science.gov (United States)

    Tobolkina, Elena; Qiao, Liang; Roussel, Christophe; Girault, Hubert H

    2014-12-01

    Standard addition strips were prepared for the quantitative determination of caffeine in different beverages by electrostatic spray ionization mass spectrometry (ESTASI-MS). The gist of this approach is to dry spots of caffeine solutions with different concentrations on a polymer strip, then to deposit a drop of sample mixed with an internal standard, here theobromine on each spot and to measure the mass spectrometry signals of caffeine and theobromine by ESTASI-MS. This strip approach is very convenient and provides quantitative analyses as accurate as the classical standard addition method by MS or liquid chromatography. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Accurate determination of the oxidative phosphorylation affinity for ADP in isolated mitochondria.

    Directory of Open Access Journals (Sweden)

    Gilles Gouspillou

    Full Text Available BACKGROUND: Mitochondrial dysfunctions appear strongly implicated in a wide range of pathologies. Therefore, there is a growing need in the determination of the normal and pathological integrated response of oxidative phosphorylation to cellular ATP demand. The present study intends to address this issue by providing a method to investigate mitochondrial oxidative phosphorylation affinity for ADP in isolated mitochondria. METHODOLOGY/PRINCIPAL FINDINGS: The proposed method is based on the simultaneous monitoring of substrate oxidation (determined polarographically and phosphorylation (determined using the glucose-hexokinase glucose-6-phosphate dehydrogenase-NADP(+ enzymatic system rates, coupled to the determination of actual ADP and ATP concentrations by bioluminescent assay. This enzymatic system allows the study of oxidative phosphorylation during true steady states in a wide range of ADP concentrations. We demonstrate how the application of this method allows an accurate determination of mitochondrial affinity for ADP from both oxidation (K(mVox and phosphorylation (K(mVp rates. We also demonstrate that determination of K(mVox leads to an important overestimation of the mitochondrial affinity for ADP, indicating that mitochondrial affinity for ADP should be determined using phosphorylation rate. Finally, we show how this method allows the direct and precise determination of the mitochondrial coupling efficiency. Data obtained from rat skeletal muscle and liver mitochondria illustrate the discriminating capabilities of this method. CONCLUSIONS/SIGNIFICANCE: Because the proposed method allows the accurate determination of mitochondrial oxidative phosphorylation affinity for ADP in isolated mitochondria, it also opens the route to a better understanding of functional consequences of mitochondrial adaptations/dysfunctions arising in various physiological/pathophysiological conditions.

  4. Accurate prediction of the ammonia probes of a variable proton-to-electron mass ratio

    Science.gov (United States)

    Owens, A.; Yurchenko, S. N.; Thiel, W.; Špirko, V.

    2015-07-01

    A comprehensive study of the mass sensitivity of the vibration-rotation-inversion transitions of 14NH3, 15NH3, 14ND3 and 15ND3 is carried out variationally using the TROVE approach. Variational calculations are robust and accurate, offering a new way to compute sensitivity coefficients. Particular attention is paid to the Δk = ±3 transitions between the accidentally coinciding rotation-inversion energy levels of the ν2 = 0+, 0-, 1+ and 1- states, and the inversion transitions in the ν4 = 1 state affected by the `giant' l-type doubling effect. These transitions exhibit highly anomalous sensitivities, thus appearing as promising probes of a possible cosmological variation of the proton-to-electron mass ratio μ. Moreover, a simultaneous comparison of the calculated sensitivities reveals a sizeable isotopic dependence which could aid an exclusive ammonia detection.

  5. Hot vacuum extraction-isotopic dilution mass spectrometry for determination of hydrogen isotopes in zircaloys

    International Nuclear Information System (INIS)

    Shi, Y.; Leeson, P.K.; Wilkin, D.; Britton, A.; Macleod, R.

    2016-01-01

    A hot vacuum extraction-isotope dilution mass spectrometry (HVE-IDMS) was studied for determination of hydrogen isotopes in zirconium metal and alloys as nuclear reactor materials. A theoretical assessment of the completeness of the extraction of hydrogen isotopes under the chosen condition was carried out based on the hydrogen and deuterium solubility data for zirconium. The optimal isotopic spiking condition for conventional IDMS was further explored for the special case IDMS where the isotope abundance of the samples is varied and non-natural. Applying the optimal conditions, the accurate IDMS determination was realized. The agreement between the measured values and the certified or prepared values of standard reference materials and homemade standard materials validate the method developed. (author)

  6. Accurate determination of rates from non-uniformly sampled relaxation data

    Energy Technology Data Exchange (ETDEWEB)

    Stetz, Matthew A.; Wand, A. Joshua, E-mail: wand@upenn.edu [University of Pennsylvania Perelman School of Medicine, Johnson Research Foundation and Department of Biochemistry and Biophysics (United States)

    2016-08-15

    The application of non-uniform sampling (NUS) to relaxation experiments traditionally used to characterize the fast internal motion of proteins is quantitatively examined. Experimentally acquired Poisson-gap sampled data reconstructed with iterative soft thresholding are compared to regular sequentially sampled (RSS) data. Using ubiquitin as a model system, it is shown that 25 % sampling is sufficient for the determination of quantitatively accurate relaxation rates. When the sampling density is fixed at 25 %, the accuracy of rates is shown to increase sharply with the total number of sampled points until eventually converging near the inherent reproducibility of the experiment. Perhaps contrary to some expectations, it is found that accurate peak height reconstruction is not required for the determination of accurate rates. Instead, inaccuracies in rates arise from inconsistencies in reconstruction across the relaxation series that primarily manifest as a non-linearity in the recovered peak height. This indicates that the performance of an NUS relaxation experiment cannot be predicted from comparison of peak heights using a single RSS reference spectrum. The generality of these findings was assessed using three alternative reconstruction algorithms, eight different relaxation measurements, and three additional proteins that exhibit varying degrees of spectral complexity. From these data, it is revealed that non-linearity in peak height reconstruction across the relaxation series is strongly correlated with errors in NUS-derived relaxation rates. Importantly, it is shown that this correlation can be exploited to reliably predict the performance of an NUS-relaxation experiment by using three or more RSS reference planes from the relaxation series. The RSS reference time points can also serve to provide estimates of the uncertainty of the sampled intensity, which for a typical relaxation times series incurs no penalty in total acquisition time.

  7. A new method of accurate determination of isotopic composition and concentration of strontium in a spike solution used for geochronological works

    International Nuclear Information System (INIS)

    Yanagi, Takeru

    1990-01-01

    A new method of accurate determination of isotopic composition and concentration of a strontium-84 spike solution was devised for simultaneous determination of strontium contents and isotopic compositions in rocks and minerals by measuring strontium isotopic ratios in spiked samples. In this method, the isotopic composition of strontium in the spike were determined so as to minimize the sum of squares of deviations of spike strontium-84 concentrations which were calculated from measured isotopic ratios of strontium in five different mixtures of the spike and the standard solution. The method can eliminate all mass discriminations occurred during the measurements on a surface ionization mass spectrometer. The results were tested by measuring 87 Sr/ 86 Sr ratios of Eimer and Amend SrCO 3 and JB-1 geochemical reference material, and by determining the strontium content in JB-1. The measurements of strontium isotope ratios in spiked samples give average values of 0.708007±0.000052 and 0.70417±0.00004 for 87 Sr/ 86 Sr ratios of E and A SrCO 3 and JB-1, respectively. The strontium content in JB-1 was estimated at 457.1±1.3 ppm. These values are very close to reported respective values. (author)

  8. Accurate determination of 129I concentrations and 129I/137Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-01-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low 129 I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO 3 /HClO 4 , (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured 129 I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of 129 I/ 137 Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 129 I in spent resins using accelerator mass spectrometry. • The treatment procedure included microwave acid digestion of samples, iodine extraction by CL resins and AgI precipitation. • Developed first on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • 129 I concentrations ranged from 4 to 12 ng/g of dry resin. • Results are in agreement with previous measurements and support reference values currently used for nuclear resin management

  9. Accurate Rapid Lifetime Determination on Time-Gated FLIM Microscopy with Optical Sectioning.

    Science.gov (United States)

    Silva, Susana F; Domingues, José Paulo; Morgado, António Miguel

    2018-01-01

    Time-gated fluorescence lifetime imaging microscopy (FLIM) is a powerful technique to assess the biochemistry of cells and tissues. When applied to living thick samples, it is hampered by the lack of optical sectioning and the need of acquiring many images for an accurate measurement of fluorescence lifetimes. Here, we report on the use of processing techniques to overcome these limitations, minimizing the acquisition time, while providing optical sectioning. We evaluated the application of the HiLo and the rapid lifetime determination (RLD) techniques for accurate measurement of fluorescence lifetimes with optical sectioning. HiLo provides optical sectioning by combining the high-frequency content from a standard image, obtained with uniform illumination, with the low-frequency content of a second image, acquired using structured illumination. Our results show that HiLo produces optical sectioning on thick samples without degrading the accuracy of the measured lifetimes. We also show that instrument response function (IRF) deconvolution can be applied with the RLD technique on HiLo images, improving greatly the accuracy of the measured lifetimes. These results open the possibility of using the RLD technique with pulsed diode laser sources to determine accurately fluorescence lifetimes in the subnanosecond range on thick multilayer samples, providing that offline processing is allowed.

  10. Determinism and mass-media portrayals of genetics.

    Science.gov (United States)

    Condit, C M; Ofulue, N; Sheedy, K M

    1998-01-01

    Scholars have expressed concern that the introduction of substantial coverage of "medical genetics" in the mass media during the past 2 decades represents an increase in biological determinism in public discourse. To test this contention, we analyzed the contents of a randomly selected, structured sample of American public newspapers (n=250) and magazines (n=722) published during 1919-95. Three coders, using three measures, all with intercoder reliability >85%, were employed. Results indicate that the introduction of the discourse of medical genetics is correlated with both a statistically significant decrease in the degree to which articles attribute human characteristics to genetic causes (P<.001) and a statistically significant increase in the differentiation of attributions to genetic and other causes among various conditions or outcomes (P<. 016). There has been no statistically significant change in the relative proportions of physical phenomena attributed to genetic causes, but there has been a statistically significant decrease in the number of articles assigning genetic causes to mental (P<.002) and behavioral (P<.000) characteristics. These results suggest that the current discourse of medical genetics is not accurately described as more biologically deterministic than its antecedents. PMID:9529342

  11. Toward a Determination of the Proton-Electron Mass Ratio from the Lamb-Dip Measurement of HD

    Science.gov (United States)

    Tao, L.-G.; Liu, A.-W.; Pachucki, K.; Komasa, J.; Sun, Y. R.; Wang, J.; Hu, S.-M.

    2018-04-01

    Precision spectroscopy of the hydrogen molecule is a test ground of quantum electrodynamics (QED), and it may serve for the determination of fundamental constants. Using a comb-locked cavity ring-down spectrometer, for the first time, we observed the Lamb-dip spectrum of the R (1 ) line in the overtone of hydrogen deuteride (HD). The line position was determined to be 217 105 182.79 ±0.03stat±0.08syst MHz (δ ν /ν =4 ×10-10 ), which is the most accurate rovibrational transition ever measured in the ground electronic state of molecular hydrogen. Moreover, from calculations including QED effects up to the order meα6, we obtained predictions for this R (1 ) line as well as for the HD dissociation energy, which are less accurate but signaling the importance of the complete treatment of nonadiabatic effects. Provided that the theoretical calculation reaches the same accuracy, the present measurement will lead to a determination of the proton-to-electron mass ratio with a precision of 1.3 parts per billion.

  12. Simultaneous determination of 13 carbohydrates using high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry.

    Science.gov (United States)

    Zhao, Dan; Feng, Feng; Yuan, Fei; Su, Jin; Cheng, Yan; Wu, Hanqiu; Song, Kun; Nie, Bo; Yu, Lian; Zhang, Feng

    2017-04-01

    A simple, accurate, and highly sensitive method was developed for the determination of 13 carbohydrates in polysaccharide of Spirulina platensis based on high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry. Samples were extracted with deionized water using ultrasonic-assisted extraction, and the ultrasound-assisted extraction conditions were optimized by Box-Behnken design. Then the extracted polysaccharide was hydrolyzed by adding 1 mol/L trifluoroacetic acid before determination by high-performance anion-exchange chromatography coupled with pulsed amperometric detection and confirmed by high-performance anion-exchange chromatography coupled with mass spectrometry. The high-performance anion-exchange chromatography coupled with pulsed amperometric detection method was performed on a CarboPac PA20 column by gradient elution using deionized water, 0.1 mol/L sodium hydroxide solution, and 0.4 mol/L sodium acetate solution. Excellent linearity was observed in the range of 0.05-10 mg/L. The average recoveries ranged from 80.7 to 121.7%. The limits of detection and limits of quantification for 13 carbohydrates were 0.02-0.10 and 0.2-1.2  μg/kg, respectively. The developed method has been successfully applied to ambient samples, and the results indicated that high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry could provide a rapid and accurate method for the simultaneous determination of carbohydrates. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Precision determination of the top-quark mass

    International Nuclear Information System (INIS)

    Moch, Sven-Olaf

    2014-08-01

    Precision determinations of the top-quark mass require theory predictions with a well-defined mass parameter in a given renormalization scheme. The top-quark's running mass in the MS scheme can be extracted with good precision from the total cross section at next-to-next-to-leading order in QCD. The Monte Carlo top-quark mass parameter measured from comparison to events with top-quark decay products is not identical with the pole mass. Its translation to the pole mass scheme introduces an additional uncertainty of the order of 1 GeV.

  14. Evolution of Mass Functions of Coeval Stars through Wind Mass Loss and Binary Interactions

    NARCIS (Netherlands)

    Schneider, F.R.N.; Izzard, R.G.; Langer, N.; de Mink, S.E.

    2015-01-01

    Accurate determinations of stellar mass functions and ages of stellar populations are crucial to much of astrophysics. We analyze the evolution of stellar mass functions of coeval main-sequence stars, including all relevant aspects of single and binary star evolution. We show that the slope of the

  15. Accurate Determination of the Values of Fundamental Physical Constants: The Basis of the New "Quantum" SI Units

    Science.gov (United States)

    Karshenboim, S. G.

    2018-03-01

    The metric system appeared as the system of units designed for macroscopic (laboratory scale) measurements. The progress in accurate determination of the values of quantum constants (such as the Planck constant) in SI units shows that the capabilities in high-precision measurement of microscopic and macroscopic quantities in terms of the same units have increased substantially recently. At the same time, relative microscopic measurements (for example, the comparison of atomic transition frequencies or atomic masses) are often much more accurate than relative measurements of macroscopic quantities. This is the basis for the strategy to define units in microscopic phenomena and then use them on the laboratory scale, which plays a crucial role in practical methodological applications determined by everyday life and technologies. The international CODATA task group on fundamental constants regularly performs an overall analysis of the precision world data (the so-called Adjustment of the Fundamental Constants) and publishes their recommended values. The most recent evaluation was based on the data published by the end of 2014; here, we review the corresponding data and results. The accuracy in determination of the Boltzmann constant has increased, the consistency of the data on determination of the Planck constant has improved; it is these two dimensional constants that will be used in near future as the basis for the new definition of the kelvin and kilogram, respectively. The contradictions in determination of the Rydberg constant and the proton charge radius remain. The accuracy of determination of the fine structure constant and relative atomic weight of the electron has improved. Overall, we give a detailed review of the state of the art in precision determination of the values of fundamental constants. The mathematical procedure of the Adjustment, the new data and results are considered in detail. The limitations due to macroscopic properties of material

  16. Incentives Increase Participation in Mass Dog Rabies Vaccination Clinics and Methods of Coverage Estimation Are Assessed to Be Accurate.

    Directory of Open Access Journals (Sweden)

    Abel B Minyoo

    2015-12-01

    Full Text Available In this study we show that incentives (dog collars and owner wristbands are effective at increasing owner participation in mass dog rabies vaccination clinics and we conclude that household questionnaire surveys and the mark-re-sight (transect survey method for estimating post-vaccination coverage are accurate when all dogs, including puppies, are included. Incentives were distributed during central-point rabies vaccination clinics in northern Tanzania to quantify their effect on owner participation. In villages where incentives were handed out participation increased, with an average of 34 more dogs being vaccinated. Through economies of scale, this represents a reduction in the cost-per-dog of $0.47. This represents the price-threshold under which the cost of the incentive used must fall to be economically viable. Additionally, vaccination coverage levels were determined in ten villages through the gold-standard village-wide census technique, as well as through two cheaper and quicker methods (randomized household questionnaire and the transect survey. Cost data were also collected. Both non-gold standard methods were found to be accurate when puppies were included in the calculations, although the transect survey and the household questionnaire survey over- and under-estimated the coverage respectively. Given that additional demographic data can be collected through the household questionnaire survey, and that its estimate of coverage is more conservative, we recommend this method. Despite the use of incentives the average vaccination coverage was below the 70% threshold for eliminating rabies. We discuss the reasons and suggest solutions to improve coverage. Given recent international targets to eliminate rabies, this study provides valuable and timely data to help improve mass dog vaccination programs in Africa and elsewhere.

  17. Incentives Increase Participation in Mass Dog Rabies Vaccination Clinics and Methods of Coverage Estimation Are Assessed to Be Accurate

    Science.gov (United States)

    Steinmetz, Melissa; Czupryna, Anna; Bigambo, Machunde; Mzimbiri, Imam; Powell, George; Gwakisa, Paul

    2015-01-01

    In this study we show that incentives (dog collars and owner wristbands) are effective at increasing owner participation in mass dog rabies vaccination clinics and we conclude that household questionnaire surveys and the mark-re-sight (transect survey) method for estimating post-vaccination coverage are accurate when all dogs, including puppies, are included. Incentives were distributed during central-point rabies vaccination clinics in northern Tanzania to quantify their effect on owner participation. In villages where incentives were handed out participation increased, with an average of 34 more dogs being vaccinated. Through economies of scale, this represents a reduction in the cost-per-dog of $0.47. This represents the price-threshold under which the cost of the incentive used must fall to be economically viable. Additionally, vaccination coverage levels were determined in ten villages through the gold-standard village-wide census technique, as well as through two cheaper and quicker methods (randomized household questionnaire and the transect survey). Cost data were also collected. Both non-gold standard methods were found to be accurate when puppies were included in the calculations, although the transect survey and the household questionnaire survey over- and under-estimated the coverage respectively. Given that additional demographic data can be collected through the household questionnaire survey, and that its estimate of coverage is more conservative, we recommend this method. Despite the use of incentives the average vaccination coverage was below the 70% threshold for eliminating rabies. We discuss the reasons and suggest solutions to improve coverage. Given recent international targets to eliminate rabies, this study provides valuable and timely data to help improve mass dog vaccination programs in Africa and elsewhere. PMID:26633821

  18. Structural determination of intact proteins using mass spectrometry

    Science.gov (United States)

    Kruppa, Gary [San Francisco, CA; Schoeniger, Joseph S [Oakland, CA; Young, Malin M [Livermore, CA

    2008-05-06

    The present invention relates to novel methods of determining the sequence and structure of proteins. Specifically, the present invention allows for the analysis of intact proteins within a mass spectrometer. Therefore, preparatory separations need not be performed prior to introducing a protein sample into the mass spectrometer. Also disclosed herein are new instrumental developments for enhancing the signal from the desired modified proteins, methods for producing controlled protein fragments in the mass spectrometer, eliminating complex microseparations, and protein preparatory chemical steps necessary for cross-linking based protein structure determination.Additionally, the preferred method of the present invention involves the determination of protein structures utilizing a top-down analysis of protein structures to search for covalent modifications. In the preferred method, intact proteins are ionized and fragmented within the mass spectrometer.

  19. Review of clinically accessible methods to determine lean body mass for normalization of standardized uptake values

    International Nuclear Information System (INIS)

    DEVRIESE, Joke; POTTEL, Hans; BEELS, Laurence; MAES, Alex; VAN DE WIELE, Christophe; GHEYSENS, Olivier

    2016-01-01

    With the routine use of 2-deoxy-2-[ 18 F]-fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scans, metabolic activity of tumors can be quantitatively assessed through calculation of SUVs. One possible normalization parameter for the standardized uptake value (SUV) is lean body mass (LBM), which is generally calculated through predictive equations based on height and body weight. (Semi-)direct measurements of LBM could provide more accurate results in cancer populations than predictive equations based on healthy populations. In this context, four methods to determine LBM are reviewed: bioelectrical impedance analysis, dual-energy X-ray absorptiometry. CT, and magnetic resonance imaging. These methods were selected based on clinical accessibility and are compared in terms of methodology, precision and accuracy. By assessing each method’s specific advantages and limitations, a well-considered choice of method can hopefully lead to more accurate SUVLBM values, hence more accurate quantitative assessment of 18F-FDG PET images.

  20. Metabolic profiling of yeast culture using gas chromatography coupled with orthogonal acceleration accurate mass time-of-flight mass spectrometry: application to biomarker discovery.

    Science.gov (United States)

    Kondo, Elsuida; Marriott, Philip J; Parker, Rhiannon M; Kouremenos, Konstantinos A; Morrison, Paul; Adams, Mike

    2014-01-07

    Yeast and yeast cultures are frequently used as additives in diets of dairy cows. Beneficial effects from the inclusion of yeast culture in diets for dairy mammals have been reported, and the aim of this study was to develop a comprehensive analytical method for the accurate mass identification of the 'global' metabolites in order to differentiate a variety of yeasts at varying growth stages (Diamond V XP, Yea-Sacc and Levucell). Microwave-assisted derivatization for metabolic profiling is demonstrated through the analysis of differing yeast samples developed for cattle feed, which include a wide range of metabolites of interest covering a large range of compound classes. Accurate identification of the components was undertaken using GC-oa-ToFMS (gas chromatography-orthogonal acceleration-time-of-flight mass spectrometry), followed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) for data reduction and biomarker discovery. Semi-quantification (fold changes in relative peak areas) was reported for metabolites identified as possible discriminative biomarkers (p-value 2), including D-ribose (four fold decrease), myo-inositol (five fold increase), L-phenylalanine (three fold increase), glucopyranoside (two fold increase), fructose (three fold increase) and threitol (three fold increase) respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Peptide Mass Fingerprinting of Egg White Proteins

    Science.gov (United States)

    Alty, Lisa T.; LaRiviere, Frederick J.

    2016-01-01

    Use of advanced mass spectrometry techniques in the undergraduate setting has burgeoned in the past decade. However, relatively few undergraduate experiments examine the proteomics tools of protein digestion, peptide accurate mass determination, and database searching, also known as peptide mass fingerprinting. In this experiment, biochemistry…

  2. Higgs mass determination in supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Javier Pardo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy); SISSA International School for Advanced Studies and INFN Trieste, Via Bonomea 265, 34136, Trieste (Italy); Villadoro, Giovanni [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy)

    2015-07-29

    We present the state-of-the-art of the effective field theory computation of the MSSM Higgs mass, improving the existing ones by including extra threshold corrections. We show that, with this approach, the theoretical uncertainty is within 1 GeV in most of the relevant parameter space. We confirm the smaller value of the Higgs mass found in the EFT computations, which implies a slightly heavier SUSY scale. We study the large tan β region, finding that sbottom thresholds might relax the upper bound on the scale of SUSY. We present SUSYHD, a fast computer code that computes the Higgs mass and its uncertainty for any SUSY scale, from the TeV to the Planck scale, even in Split SUSY, both in the (DR)-bar and in the on-shell schemes. Finally, we apply our results to derive bounds on some well motivated SUSY models, in particular we show how the value of the Higgs mass allows to determine the complete spectrum in minimal gauge mediation.

  3. Determination of iodine to compliment mass spectrometric measurements

    International Nuclear Information System (INIS)

    Hohorst, F.A.

    1994-11-01

    The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples

  4. A method of accurate determination of voltage stability margin

    Energy Technology Data Exchange (ETDEWEB)

    Wiszniewski, A.; Rebizant, W. [Wroclaw Univ. of Technology, Wroclaw (Poland); Klimek, A. [AREVA Transmission and Distribution, Stafford (United Kingdom)

    2008-07-01

    In the process of developing power system disturbance, voltage instability at the receiving substations often contributes to deteriorating system stability, which eventually may lead to severe blackouts. The voltage stability margin at receiving substations may be used to determine measures to prevent voltage collapse, primarily by operating or blocking the transformer tap changing device, or by load shedding. The best measure of the stability margin is the actual load to source impedance ratio and its critical value, which is unity. This paper presented an accurate method of calculating the load to source impedance ratio, derived from the Thevenin's equivalent circuit of the system, which led to calculation of the stability margin. The paper described the calculation of the load to source impedance ratio including the supporting equations. The calculation was based on the very definition of voltage stability, which says that system stability is maintained as long as the change of power, which follows the increase of admittance is positive. The testing of the stability margin assessment method was performed in a simulative way for a number of power network structures and simulation scenarios. Results of the simulations revealed that this method is accurate and stable for all possible events occurring downstream of the device location. 3 refs., 8 figs.

  5. Determination of test methods for the prediction of the behavior of mass concrete

    Science.gov (United States)

    Ferraro, Christopher C.

    Hydration at early ages results from chemical and physical processes that take place between Portland cement and water, and is an exothermic process. The resultant heat evolution and temperature rise for massive concrete placements can be so great that the temperature differentials between the internal concrete core and outer concrete stratum can cause cracking due to thermal gradients. Accurate prediction of temperature distribution and stresses in mass concrete is needed to determine if a given concrete mixture design may have problems in the field, so that adjustments to the design can be made prior to its use. This research examines calorimetric, strength, and physical testing methods in an effort to predict the thermal and physical behavior of mass concrete. Four groups of concrete mixture types containing different cementitious materials are examined. One group contains Portland cement, while the other three groups incorporate large replacements of supplementary cementitious materials: granulated blast furnace slag, fly ash, and a ternary blend (combining Portland cement, fly ash, and slag).

  6. Precise determination of sodium in serum by simulated isotope dilution method of inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Yan Ying; Zhang Chuanbao; Zhao Haijian; Chen Wenxiang; Shen Ziyu; Wang Xiaoru; Chen Dengyun

    2007-01-01

    A new precise and accurate method for the determination of sodium in serum by inductively coupled plasma mass spectrometry (ICP-MS) was developed. Since 23 Na is the single isotope element, 27 Al is selected as simulated isotope of Na. Al is spiked into serum samples and Na standard solution. 23 Na/ 27 Al ratio in the Na standard solution is determined to assume the natural Na isotope ratio. The serums samples are digested by purified HNO 3 /H 2 O 2 and diluted to get about 0.6 μg·g -1 Al solutions, and the 23 Na/ 27 Al ratios of the serum samples are obtained to calculate the accurate Na concentrations basing on the isotope dilution method. When the simulated isotope dilution method of ICP-MS is applied and Al is selected as the simulated isotope of Na, the precise and accurate Na concentrations in the serums are determined. The inter-day precision of CV<0.13% for one same serum sample is obtained during 3 days 4 measurements. The spike recoveries are between 99.69% and 100.60% for 4 different serum samples and 3 days multi-measurements. The results of measuring standard reference materials of serum sodium are agree with the certified value. The relative difference between 3 days is 0.22%-0.65%, and the relative difference in one bottle is 0.15%-0.44%. The ICP-MS and Al simulated isotope dilution method is proved to be not only precise and accurate, but also quick and convenient for measuring Na in serum. It is promising to be a reference method for precise determination of Na in serum. Since Al is a low cost isotope dilution reagent, the method is possible to be widely applied for serum Na determination. (authors)

  7. Accurate particle speed prediction by improved particle speed measurement and 3-dimensional particle size and shape characterization technique

    DEFF Research Database (Denmark)

    Cernuschi, Federico; Rothleitner, Christian; Clausen, Sønnik

    2017-01-01

    Accurate particle mass and velocity measurement is needed for interpreting test results in erosion tests of materials and coatings. The impact and damage of a surface is influenced by the kinetic energy of a particle, i.e. particle mass and velocity. Particle mass is usually determined with optic...

  8. The effect of nuclear gas distribution on the mass determination of supermassive black holes

    Science.gov (United States)

    Mejía-Restrepo, J. E.; Lira, P.; Netzer, H.; Trakhtenbrot, B.; Capellupo, D. M.

    2018-01-01

    Supermassive black holes reside in the nuclei of most galaxies. During their active episodes, black holes are powered by accretion discs where gravitational energy is converted into radiation1. Accurately determining black hole masses is key to understand how the population evolves over time and how the black holes relate to their host galaxies2-4. Beyond the local universe, z ≳ 0.2, the mass is commonly estimated assuming a virialized motion of gas in the close vicinity of the active black holes, traced through broad emission lines5,6. However, this procedure has uncertainties associated with the unknown distribution of the gas clouds. Here, we show that the black hole masses derived from the properties of the accretion disk and virial mass estimates differ by a factor that is inversely proportional to the width of the broad emission lines. This leads to virial mass misestimations up to a factor of six. Our results suggest that a planar gas distribution that is inclined with respect to the line of sight may account for this effect. However, radiation pressure effects on the distribution of gas can also reproduce our results. Regardless of the physical origin, our findings contribute to mitigating the uncertainties in current black hole mass estimations and, in turn, will help us to better understand the evolution of distant supermassive black holes and their host galaxies.

  9. Measurement of the x-ray mass-attenuation coefficients of gold, derived quantities between 14 keV and 21 keV and determination of the bond lengths of gold

    International Nuclear Information System (INIS)

    Glover, J L; Chantler, C T; Barnea, Z; Rae, N A; Tran, C Q

    2010-01-01

    The x-ray mass-attenuation coefficients of gold are measured at 91 energies between 14 keV and 21 keV using synchrotron radiation. The measurements are accurate to between 0.08% and 0.1%. The photoelectric mass-absorption coefficients and the imaginary component of the form factors of gold are also determined. The results include the L I edge and are the most accurate and extensive gold dataset available in this energy range. An analysis of the L I edge XAFS showed excellent agreement between the measured and simulated XAFS and yielded highly accurate values of the bond lengths of gold. When our results are compared with earlier measurements and with predictions of major theoretical tabulations, significant discrepancies are noted. The comparison raises questions about the nature of discrepancies between experimental and theoretical values of mass-attenuation coefficients.

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

    Science.gov (United States)

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

  11. STELLAR LOCUS REGRESSION: ACCURATE COLOR CALIBRATION AND THE REAL-TIME DETERMINATION OF GALAXY CLUSTER PHOTOMETRIC REDSHIFTS

    International Nuclear Information System (INIS)

    High, F. William; Stubbs, Christopher W.; Rest, Armin; Stalder, Brian; Challis, Peter

    2009-01-01

    We present stellar locus regression (SLR), a method of directly adjusting the instrumental broadband optical colors of stars to bring them into accord with a universal stellar color-color locus, producing accurately calibrated colors for both stars and galaxies. This is achieved without first establishing individual zero points for each passband, and can be performed in real-time at the telescope. We demonstrate how SLR naturally makes one wholesale correction for differences in instrumental response, for atmospheric transparency, for atmospheric extinction, and for Galactic extinction. We perform an example SLR treatment of Sloan Digital Sky Survey data over a wide range of Galactic dust values and independently recover the direction and magnitude of the canonical Galactic reddening vector with 14-18 mmag rms uncertainties. We then isolate the effect of atmospheric extinction, showing that SLR accounts for this and returns precise colors over a wide range of air mass, with 5-14 mmag rms residuals. We demonstrate that SLR-corrected colors are sufficiently accurate to allow photometric redshift estimates for galaxy clusters (using red sequence galaxies) with an uncertainty σ(z)/(1 + z) = 0.6% per cluster for redshifts 0.09 < z < 0.25. Finally, we identify our objects in the 2MASS all-sky catalog, and produce i-band zero points typically accurate to 18 mmag using only SLR. We offer open-source access to our IDL routines, validated and verified for the implementation of this technique, at http://stellar-locus-regression.googlecode.com.

  12. [Determination of Heavy Metal Elements in Diatomite Filter Aid by Inductively Coupled Plasma Mass Spectrometry].

    Science.gov (United States)

    Nie, Xi-du; Fu, Liang

    2015-11-01

    This study established a method for determining Be, Cr, Ni, As, Cd, Sb, Sn, Tl, Hg and Pb, total 10 heavy metals in diatomite filter aid. The diatomite filter aid was digested by using the mixture acid of HNO₃ + HF+ H₃PO₄ in microwave system, 10 heavy metals elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The interferences of mass spectrometry caused by the high silicon substrate were optimized, first the equipment parameters and isotopes of test metals were selected to eliminate these interferences, the methane was selected as reactant gas, and the mass spectral interferences were eliminated by dynamic reaction cell (DRC). Li, Sc, Y, In and Bi were selected as the internal standard elements to correct the interferences caused by matrix and the drift of sensitivity. The results show that the detection limits for analyte is in the range of 3.29-15.68 ng · L⁻¹, relative standard deviations (RSD) is less than 4.62%, and the recovery is in the range of 90.71%-107.22%. The current method has some advantages such as, high sensitivity, accurate, and precision, which can be used in diatomite filter aid quality control and safety estimations.

  13. Determination of fluspirilene in human plasma by liquid chromatography-tandem mass spectrometry with electrospray ionisation.

    Science.gov (United States)

    Swart, K J; Sutherland, F C; van Essen, G H; Hundt, H K; Hundt, A F

    1998-12-18

    An ultra-sensitive method for the determination of fluspirilene in plasma was established, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted with hexane/isoamyl alcohol, separated on a Phenomenex Luna C18 5 mu 150 x 2.1 mm column with a mobile phase consisting of methanol-water-acetic acid (600:400:1) at a flow-rate of 0.3 ml/min. Detection was achieved by a Finnigan Matt mass spectrometer (LCQ) at unit resolution in full scan mode scanning the product ion spectrum from m/z 130-500 and monitoring the transition of the protonated molecular ion at m/z 476.2, to the sum of the largest product ions m/z 371, 342 and 274 (MS-MS). Electrospray ionisation was used for ion production. The mean recovery for fluspirilene was 90% with a lower limit of quantification of 21.50 pg/ml using 1 ml plasma for extraction. This is the first chromatographic method described for the determination of fluspirilene in plasma that is accurate and sensitive enough to be used in pharmacokinetic studies.

  14. Electrochemical separation and isotopic determination of thallium at the nanogram level by surface ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Arden, J.W.

    1983-01-01

    A rapid low-blank procedure is described for the co-separation of thallium and lead by sequential cathodic and anodic electrodeposition from natural samples, especially complex natural silicates, for subsequent mass spectrometry. A micro anion-exchange procedure is also described for the separation of thallium and lead. Ion currents of 10 - 10 A can be obtained from 1 ng of thallium. The isotopic composition of 1 ng of thallium can be measured on a Faraday detector with a precision of 0.05-0.1%. The total procedural blank is 3 pg. By using stable isotope dilution, 0.2 ng of thallium can be measured with a precision of 0.6% with only a 2% blank correction. This allows the accurate determination of thallium in natural samples down to concentration levels of about 50 pg g - 1 . The detection limit is 50 fg. This procedure has been applied to meteorites and terrestrial rocks. The stable isotope dilution technique is suitable for geochemical, environmental and toxicological studies requiring a highly sensitive, accurate and precise method for the determination of thallium. (Auth.)

  15. A method for the accurate determination of the polarization of a neutron beam using a polarized 3He spin filter

    International Nuclear Information System (INIS)

    Greene, G.L.; Thompson, A.K.; Dewey, M.S.

    1995-01-01

    A new method for the accurate determination of the degree of polarization of a neutron beam which has been polarized by transmission through a spin polarized 3 He cell is given. The method does not require the use of an analyzer or spin flipper nor does it require an accurate independent determination of the 3 He polarization. The method provides a continuous on-line determination of the neutron polarization. The method may be of use in the accurate determination of correlation coefficients in neutron beta decay which provide a test of the standard model for the electroweak interaction. The method may also provide an accurate procedure for the calibration of polarized 3 He targets used in medium and high energy scattering experiments. ((orig.))

  16. Automated gravimetric sample pretreatment using an industrial robot for the high-precision determination of plutonium by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Surugaya, Naoki; Hiyama, Toshiaki; Watahiki, Masaru

    2008-01-01

    A robotized sample-preparation method for the determination of Pu, which is recovered by extraction reprocessing of spent nuclear fuel, by isotope dilution mass spectrometry (IDMS) is described. The automated system uses a six-axis industrial robot, whose motility is very fast, accurate, and flexible, installed in a glove box. The automation of the weighing and dilution steps enables operator-unattended sample pretreatment for the high-precision analysis of Pu in aqueous solutions. Using the developed system, the Pu concentration in a HNO 3 medium was successfully determined using a set of subsequent mass spectrometric measurements. The relative uncertainty in determining the Pu concentration by IDMS using this system was estimated to be less than 0.1% (k=2), which is equal to that expected of a talented analysis. The operation time required was the same as that for a skilled operator. (author)

  17. On canonical cylinder sections for accurate determination of contact angle in microgravity

    Science.gov (United States)

    Concus, Paul; Finn, Robert; Zabihi, Farhad

    1992-01-01

    Large shifts of liquid arising from small changes in certain container shapes in zero gravity can be used as a basis for accurately determining contact angle. Canonical geometries for this purpose, recently developed mathematically, are investigated here computationally. It is found that the desired nearly-discontinuous behavior can be obtained and that the shifts of liquid have sufficient volume to be readily observed.

  18. Accurate donor electron wave functions from a multivalley effective mass theory.

    Science.gov (United States)

    Pendo, Luke; Hu, Xuedong

    Multivalley effective mass (MEM) theories combine physical intuition with a marginal need for computational resources, but they tend to be insensitive to variations in the wavefunction. However, recent papers suggest full Bloch functions and suitable central cell donor potential corrections are essential to replicating qualitative and quantitative features of the wavefunction. In this talk, we consider a variational MEM method that can accurately predict both spectrum and wavefunction of isolated phosphorus donors. As per Gamble et. al, we employ a truncated series representation of the Bloch function with a tetrahedrally symmetric central cell correction. We use a dynamic dielectric constant, a feature commonly seen in tight-binding methods. Uniquely, we use a freely extensible basis of either all Slater- or all Gaussian-type functions. With a large basis able to capture the influence of higher energy eigenstates, this method is well positioned to consider the influence of external perturbations, such as electric field or applied strain, on the charge density. This work is supported by the US Army Research Office (W911NF1210609).

  19. Kinetic determinations of accurate relative oxidation potentials of amines with reactive radical cations.

    Science.gov (United States)

    Gould, Ian R; Wosinska, Zofia M; Farid, Samir

    2006-01-01

    Accurate oxidation potentials for organic compounds are critical for the evaluation of thermodynamic and kinetic properties of their radical cations. Except when using a specialized apparatus, electrochemical oxidation of molecules with reactive radical cations is usually an irreversible process, providing peak potentials, E(p), rather than thermodynamically meaningful oxidation potentials, E(ox). In a previous study on amines with radical cations that underwent rapid decarboxylation, we estimated E(ox) by correcting the E(p) from cyclic voltammetry with rate constants for decarboxylation obtained using laser flash photolysis. Here we use redox equilibration experiments to determine accurate relative oxidation potentials for the same amines. We also describe an extension of these experiments to show how relative oxidation potentials can be obtained in the absence of equilibrium, from a complete kinetic analysis of the reversible redox kinetics. The results provide support for the previous cyclic voltammetry/laser flash photolysis method for determining oxidation potentials.

  20. A new approach to determine accurately minority-carrier lifetime

    International Nuclear Information System (INIS)

    Idali Oumhand, M.; Mir, Y.; Zazoui, M.

    2009-01-01

    Electron or proton irradiations introduce recombination centers, which tend to affect solar cell parameters by reducing the minority-carrier lifetime (MCLT). Because this MCLT plays a fundamental role in the performance degradation of solar cells, in this work we present a new approach that allows us to get accurate values of MCLT. The relationship between MCLT in p-region and n-region both before and after irradiation has been determined by the new method. The validity and accuracy of this approach are justified by the fact that the degradation parameters that fit the experimental data are the same for both short-circuit current and the open-circuit voltages. This method is applied to the p + /n-InGaP solar cell under 1 MeV electron irradiation

  1. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide.

    Science.gov (United States)

    Ross, Charles W; Simonsick, William J; Bogusky, Michael J; Celikay, Recep W; Guare, James P; Newton, Randall C

    2016-06-28

    Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI), sheath flow electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and high-field nuclear magnetic resonance (NMR) analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  2. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide

    Directory of Open Access Journals (Sweden)

    Charles W. Ross

    2016-06-01

    Full Text Available Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI, sheath flow electrospray ionization (ESI Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS and high-field nuclear magnetic resonance (NMR analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  3. Determination of accurate metal silicide layer thickness by RBS

    International Nuclear Information System (INIS)

    Kirchhoff, J.F.; Baumann, S.M.; Evans, C.; Ward, I.; Coveney, P.

    1995-01-01

    Rutherford Backscattering Spectrometry (RBS) is a proven useful analytical tool for determining compositional information of a wide variety of materials. One of the most widely utilized applications of RBS is the study of the composition of metal silicides (MSi x ), also referred to as polycides. A key quantity obtained from an analysis of a metal silicide is the ratio of silicon to metal (Si/M). Although compositional information is very reliable in these applications, determination of metal silicide layer thickness by RBS techniques can differ from true layer thicknesses by more than 40%. The cause of these differences lies in how the densities utilized in the RBS analysis are calculated. The standard RBS analysis software packages calculate layer densities by assuming each element's bulk densities weighted by the fractional atomic presence. This calculation causes large thickness discrepancies in metal silicide thicknesses because most films form into crystal structures with distinct densities. Assuming a constant layer density for a full spectrum of Si/M values for metal silicide samples improves layer thickness determination but ignores the underlying physics of the films. We will present results of RBS determination of the thickness various metal silicide films with a range of Si/M values using a physically accurate model for the calculation of layer densities. The thicknesses are compared to scanning electron microscopy (SEM) cross-section micrographs. We have also developed supporting software that incorporates these calculations into routine analyses. (orig.)

  4. Device for accurately measuring mass flow of gases

    Science.gov (United States)

    Hylton, James O.; Remenyik, Carl J.

    1994-01-01

    A device for measuring mass flow of gases which utilizes a substantially buoyant pressure vessel suspended within a fluid/liquid in an enclosure. The pressure vessel is connected to a weighing device for continuously determining weight change of the vessel as a function of the amount of gas within the pressure vessel. In the preferred embodiment, this pressure vessel is formed from inner and outer right circular cylindrical hulls, with a volume between the hulls being vented to the atmosphere external the enclosure. The fluid/liquid, normally in the form of water typically with an added detergent, is contained within an enclosure with the fluid/liquid being at a level such that the pressure vessel is suspended beneath this level but above a bottom of the enclosure. The buoyant pressure vessel can be interconnected with selected valves to an auxiliary pressure vessel so that initial flow can be established to or from the auxiliary pressure vessel prior to flow to or from the buoyant pressure vessel.

  5. ACCURATE UNIVERSAL MODELS FOR THE MASS ACCRETION HISTORIES AND CONCENTRATIONS OF DARK MATTER HALOS

    International Nuclear Information System (INIS)

    Zhao, D. H.; Jing, Y. P.; Mo, H. J.; Boerner, G.

    2009-01-01

    A large amount of observations have constrained cosmological parameters and the initial density fluctuation spectrum to a very high accuracy. However, cosmological parameters change with time and the power index of the power spectrum dramatically varies with mass scale in the so-called concordance ΛCDM cosmology. Thus, any successful model for its structural evolution should work well simultaneously for various cosmological models and different power spectra. We use a large set of high-resolution N-body simulations of a variety of structure formation models (scale-free, standard CDM, open CDM, and ΛCDM) to study the mass accretion histories, the mass and redshift dependence of concentrations, and the concentration evolution histories of dark matter halos. We find that there is significant disagreement between the much-used empirical models in the literature and our simulations. Based on our simulation results, we find that the mass accretion rate of a halo is tightly correlated with a simple function of its mass, the redshift, parameters of the cosmology, and of the initial density fluctuation spectrum, which correctly disentangles the effects of all these factors and halo environments. We also find that the concentration of a halo is strongly correlated with the universe age when its progenitor on the mass accretion history first reaches 4% of its current mass. According to these correlations, we develop new empirical models for both the mass accretion histories and the concentration evolution histories of dark matter halos, and the latter can also be used to predict the mass and redshift dependence of halo concentrations. These models are accurate and universal: the same set of model parameters works well for different cosmological models and for halos of different masses at different redshifts, and in the ΛCDM case the model predictions match the simulation results very well even though halo mass is traced to about 0.0005 times the final mass, when

  6. SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Lelli, Federico; McGaugh, Stacy S. [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Schombert, James M., E-mail: federico.lelli@case.edu [Department of Physics, University of Oregon, Eugene, OR 97403 (United States)

    2016-12-01

    We introduce SPARC ( Spitzer Photometry and Accurate Rotation Curves): a sample of 175 nearby galaxies with new surface photometry at 3.6  μ m and high-quality rotation curves from previous H i/H α studies. SPARC spans a broad range of morphologies (S0 to Irr), luminosities (∼5 dex), and surface brightnesses (∼4 dex). We derive [3.6] surface photometry and study structural relations of stellar and gas disks. We find that both the stellar mass–H i mass relation and the stellar radius–H i radius relation have significant intrinsic scatter, while the H i   mass–radius relation is extremely tight. We build detailed mass models and quantify the ratio of baryonic to observed velocity ( V {sub bar}/ V {sub obs}) for different characteristic radii and values of the stellar mass-to-light ratio (ϒ{sub ⋆}) at [3.6]. Assuming ϒ{sub ⋆} ≃ 0.5 M {sub ⊙}/ L {sub ⊙} (as suggested by stellar population models), we find that (i) the gas fraction linearly correlates with total luminosity; (ii) the transition from star-dominated to gas-dominated galaxies roughly corresponds to the transition from spiral galaxies to dwarf irregulars, in line with density wave theory; and (iii)  V {sub bar}/ V {sub obs} varies with luminosity and surface brightness: high-mass, high-surface-brightness galaxies are nearly maximal, while low-mass, low-surface-brightness galaxies are submaximal. These basic properties are lost for low values of ϒ{sub ⋆} ≃ 0.2 M {sub ⊙}/ L {sub ⊙} as suggested by the DiskMass survey. The mean maximum-disk limit in bright galaxies is ϒ{sub ⋆} ≃ 0.7 M {sub ⊙}/ L {sub ⊙} at [3.6]. The SPARC data are publicly available and represent an ideal test bed for models of galaxy formation.

  7. OSM-Classic : An optical imaging technique for accurately determining strain

    Science.gov (United States)

    Aldrich, Daniel R.; Ayranci, Cagri; Nobes, David S.

    OSM-Classic is a program designed in MATLAB® to provide a method of accurately determining strain in a test sample using an optical imaging technique. Measuring strain for the mechanical characterization of materials is most commonly performed with extensometers, LVDT (linear variable differential transistors), and strain gauges; however, these strain measurement methods suffer from their fragile nature and it is not particularly easy to attach these devices to the material for testing. To alleviate these potential problems, an optical approach that does not require contact with the specimen can be implemented to measure the strain. OSM-Classic is a software that interrogates a series of images to determine elongation in a test sample and hence, strain of the specimen. It was designed to provide a graphical user interface that includes image processing with a dynamic region of interest. Additionally, the stain is calculated directly while providing active feedback during the processing.

  8. Accurate Mass Measurements for Planetary Microlensing Events Using High Angular Resolution Observations

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Beaulieu

    2018-04-01

    Full Text Available The microlensing technique is a unique method to hunt for cold planets over a range of mass and separation, orbiting all varieties of host stars in the disk of our galaxy. It provides precise mass-ratio and projected separations in units of the Einstein ring radius. In order to obtain the physical parameters (mass, distance, orbital separation of the system, it is necessary to combine the result of light curve modeling with lens mass-distance relations and/or perform a Bayesian analysis with a galactic model. A first mass-distance relation could be obtained from a constraint on the Einstein ring radius if the crossing time of the source over the caustic is measured. It could then be supplemented by secondary constraints such as parallax measurements, ideally by using coinciding ground and space-born observations. These are still subject to degeneracies, like the orbital motion of the lens. A third mass-distance relation can be obtained thanks to constraints on the lens luminosity using high angular resolution observations with 8 m class telescopes or the Hubble Space Telescope. The latter route, although quite inexpensive in telescope time is very effective. If we have to rely heavily on Bayesian analysis and limited constraints on mass-distance relations, the physical parameters are determined to 30–40% typically. In a handful of cases, ground-space parallax is a powerful route to get stronger constraint on masses. High angular resolution observations will be able to constrain the luminosity of the lenses in the majority of the cases, and in favorable circumstances it is possible to derive physical parameters to 10% or better. Moreover, these constraints will be obtained in most of the planets to be discovered by the Euclid and WFIRST satellites. We describe here the state-of-the-art approaches to measure lens masses and distances with an emphasis on high angular resolution observations. We will discuss the challenges, recent results and

  9. Simultaneous Mass Determination for Gravitationally Coupled Asteroids

    Energy Technology Data Exchange (ETDEWEB)

    Baer, James [Private address, 3210 Apache Road, Pittsburgh, PA 15241 (United States); Chesley, Steven R., E-mail: jimbaer1@earthlink.net [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2017-08-01

    The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid, or that the encounter’s precise geometry may be entangled with encounters involving other asteroids. After reviewing the conventional algorithm, we use it to calculate the masses of 30 main-belt asteroids. Compared to our previous results, we find new mass estimates for eight asteroids (11 Parthenope, 27 Euterpe, 51 Neimausa, 76 Freia, 121 Hermione, 324 Bamberga, 476 Hedwig, and 532 Herculina) and significantly more precise estimates for six others (2 Pallas, 3 Juno, 4 Vesta, 9 Metis, 16 Psyche, and 88 Thisbe). However, we also find that the conventional algorithm yields questionable results in several gravitationally coupled cases. To address such cases, we describe a new algorithm that allows the epoch state vectors of the subject asteroids to be included as solve-for parameters, allowing for the simultaneous solution of the masses and epoch state vectors of multiple subject and test asteroids. We then apply this algorithm to the same 30 main-belt asteroids and conclude that mass determinations resulting from current and future high-precision astrometric sources (such as Gaia ) should conduct a thorough search for possible gravitational couplings and account for their effects.

  10. Simultaneous Mass Determination for Gravitationally Coupled Asteroids

    Science.gov (United States)

    Baer, James; Chesley, Steven R.

    2017-08-01

    The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid, or that the encounter’s precise geometry may be entangled with encounters involving other asteroids. After reviewing the conventional algorithm, we use it to calculate the masses of 30 main-belt asteroids. Compared to our previous results, we find new mass estimates for eight asteroids (11 Parthenope, 27 Euterpe, 51 Neimausa, 76 Freia, 121 Hermione, 324 Bamberga, 476 Hedwig, and 532 Herculina) and significantly more precise estimates for six others (2 Pallas, 3 Juno, 4 Vesta, 9 Metis, 16 Psyche, and 88 Thisbe). However, we also find that the conventional algorithm yields questionable results in several gravitationally coupled cases. To address such cases, we describe a new algorithm that allows the epoch state vectors of the subject asteroids to be included as solve-for parameters, allowing for the simultaneous solution of the masses and epoch state vectors of multiple subject and test asteroids. We then apply this algorithm to the same 30 main-belt asteroids and conclude that mass determinations resulting from current and future high-precision astrometric sources (such as Gaia) should conduct a thorough search for possible gravitational couplings and account for their effects.

  11. Simultaneous Mass Determination for Gravitationally Coupled Asteroids

    International Nuclear Information System (INIS)

    Baer, James; Chesley, Steven R.

    2017-01-01

    The conventional least-squares asteroid mass determination algorithm allows us to solve for the mass of a large subject asteroid that is perturbing the trajectory of a smaller test asteroid. However, this algorithm is necessarily a first approximation, ignoring the possibility that the subject asteroid may itself be perturbed by the test asteroid, or that the encounter’s precise geometry may be entangled with encounters involving other asteroids. After reviewing the conventional algorithm, we use it to calculate the masses of 30 main-belt asteroids. Compared to our previous results, we find new mass estimates for eight asteroids (11 Parthenope, 27 Euterpe, 51 Neimausa, 76 Freia, 121 Hermione, 324 Bamberga, 476 Hedwig, and 532 Herculina) and significantly more precise estimates for six others (2 Pallas, 3 Juno, 4 Vesta, 9 Metis, 16 Psyche, and 88 Thisbe). However, we also find that the conventional algorithm yields questionable results in several gravitationally coupled cases. To address such cases, we describe a new algorithm that allows the epoch state vectors of the subject asteroids to be included as solve-for parameters, allowing for the simultaneous solution of the masses and epoch state vectors of multiple subject and test asteroids. We then apply this algorithm to the same 30 main-belt asteroids and conclude that mass determinations resulting from current and future high-precision astrometric sources (such as Gaia ) should conduct a thorough search for possible gravitational couplings and account for their effects.

  12. Technical developments for accurate determination of amount of samples used for TOF measurements

    Directory of Open Access Journals (Sweden)

    Terada Kazushi

    2017-01-01

    Full Text Available Activity determination of 241,243Am samples has been performed with two separate methods of calorimetry and gamma-ray spectroscopy. Decay heat measurements of the samples were carried out by using a calorimeter, and activities of the samples were accurately determined with uncertainties less than 0.45%. The primary source of uncertainty in the calorimetric method is the accuracy of available half-life data. Gamma-ray detection efficiencies of a HPGe detector were determined with uncertainties of 1.5% by combining measured efficiencies and Monte Carlo simulation. Activities of the samples were determined with uncertainties less than 2.0% by gamma-ray spectroscopy and were concordant with those of the calorimetry.

  13. Accurate determination of renal function in patients with intestinal urinary diversions

    International Nuclear Information System (INIS)

    McDougal, W.S.; Koch, M.O.

    1986-01-01

    The regular determination of renal function is a critical part of the management of patients who have had the urinary tract reconstructed with intestinal segments. These intestinal segments reabsorb urinary solutes and, thereby, complicate the determination of renal function by conventional methods. Urinary clearances of urea, creatinine and inulin were performed in patients with intestinal segments in the urinary tract and controls under varying diuretic conditions. Patients with intestinal diversions also underwent radioisotopic determination of renal function. The urinary clearances of urea, creatinine and inulin are highly dependent on the rate of urine flow in patients with intestinal segments in the urinary tract. Diuresis maximizes the urinary clearances of these solutes by minimizing intestinal reabsorption. Creatinine clearance prediction from the serum creatinine underestimates true glomerular filtration rate. Radioisotopic determination of renal function correlates poorly with true glomerular filtration rate. Only creatinine clearance measured under diuretic conditions correlates well with true renal function. Urine concentrating ability cannot be assessed accurately in patients with intestinal segments in the urinary tract, since osmolality rapidly equilibrates across the segments

  14. On accurate determination of contact angle

    Science.gov (United States)

    Concus, P.; Finn, R.

    1992-01-01

    Methods are proposed that exploit a microgravity environment to obtain highly accurate measurement of contact angle. These methods, which are based on our earlier mathematical results, do not require detailed measurement of a liquid free-surface, as they incorporate discontinuous or nearly-discontinuous behavior of the liquid bulk in certain container geometries. Physical testing is planned in the forthcoming IML-2 space flight and in related preparatory ground-based experiments.

  15. Neutrino mass matrices with vanishing determinant

    International Nuclear Information System (INIS)

    Chauhan, Bhag C.; Pulido, Joao; Picariello, Marco

    2006-01-01

    We investigate the prospects for neutrinoless double beta decay, texture zeros. and equalities between neutrino mass matrix elements in scenarios with vanishing determinant mass matrices for vanishing and finite θ 13 mixing angles in normal and inverse mass hierarchies. For normal hierarchy and both zero and finite θ 13 it is found that neutrinoless double beta decay cannot be observed by any of the present or next generation experiments, while for inverse hierarchy it is, on the contrary, accessible to experiments. Regarding texture zeros and equalities between mass matrix elements, we find that in both normal and inverse hierarchies with θ 13 =0 no texture zeros nor any such equalities can exist apart from the obvious ones. For θ 13 ≠0 some texture zeros become possible. In normal hierarchy two texture zeros occur if 8.1x10 -2 ≤sinθ 13 ≤9.1x10 -2 while in inverse hierarchy three are possible, one with sinθ 13 ≥7x10 -3 and two others with sinθ 13 ≥0.18. All equalities between mass matrix elements are impossible with θ 13 ≠0

  16. Accurate masses of unstable rare earth isotopes by ISOLTRAP

    International Nuclear Information System (INIS)

    Beck, D.; Ames, F.; Audi, G.

    2000-05-01

    Direct mass measurements of neutron-deficient rare earth isotopes in the vicinity of 146 Gd were performed with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. This paper reports on the measurement of more than 40 isotopes of the elements Pr, Nd, Pm, Sm, Eu, Dy and Ho, that have been measured with a typical accuracy of δm ∼ 14 keV. An atomic mass evaluation has been performed taking into account other experimental mass values via a least-squares adjustment. The results of the adjustment are discussed. (orig.)

  17. Determination of the X-ray mass absorption coefficient by measurement of the intensity of AgKα Compton scattered radiation

    International Nuclear Information System (INIS)

    Franzini, M.; Leoni, L.; Saitta, M.

    1976-01-01

    By utilizing a reflection geometry, an accurate mass absorption coefficient of a sample can be determined by measuring the Ag Kα Compton intensity. Intensities of Ag Kα Compton scattered radiation have been collected by using either the usual reflection geometry of a Philips PW 1450 automatic x-ray spectrometer or a more refined reflection geometry, achieved on a Philips PW 1540/10A manual x-ray spectrometer. The experimental results have shown that the relationship between the Ag Kα Compton intensity and the mass absorption is a logarithmic function. The experimental results are not in agreement with those reported in literature, but a theoretical explanation to account for this fact has not been achieved as yet. (author)

  18. Determination of reactor thermal power using a more accurate method

    International Nuclear Information System (INIS)

    Papuga, J.; Madron, F.; Pliska, J.

    2005-01-01

    Reactor thermal power is an important operational parameter in many respects such as nuclear safety, reactor physics or evaluation of turbine thermal performance. Thermal power of a pressurized water reactor is determined on the basis of the steam generator thermal balance. The balance can be made in several variants differing from one another by the selection of different measuring circuits whose data are used in the balancing. In principle, no one such variant gives the true value of the thermal power. Among the variant values, the one nearest to the unknown true value of reactor thermal power is probably the value calculated with the lowest uncertainty. The determination of such uncertainty is not easy and its value can make even several percent, which has significant economic consequences. This paper presents the method of data reconciliation and its application to the data of the third of Dukovany NPP. The data reconciliation method allows to exploit all the information which process data contain. It is based on the statistical adjustment of the redundant data in such a way that the adjusted data obey generally valid laws of nature (e.g. conservation laws). Mass and energy balances based on the data not yet reconciled do not obey those laws because of measurement errors. For data reconciliation in Dukovany, a detailed model of mass and energy flows describing the 3rd unit from steam generators to alternator and condenser was set up. Laws of mass and energy conservation and phase equilibrium in water-steam systems are thus fulfilled. Moreover, the user can model momentum balances in pipelines and create other equations, which are respected during calculation. The data reconciliation is done regularly for hourly averages (Authors)

  19. Accurate determination of bromine and iodine in medicinal plants by inductively coupled plasma-mass spectrometry after microwave-induced combustion

    Science.gov (United States)

    Nascimento, Mariele S.; Mendes, Ana Luiza G.; Henn, Alessandra S.; Picoloto, Rochele S.; Mello, Paola A.; Flores, Erico M. M.

    2017-12-01

    In this work, a method for the determination of bromine and iodine in medicinal plants by inductively coupled plasma mass spectrometry (ICP-MS) after digestion by microwave-induced combustion (MIC) was developed. Medicinal plants were pressed as pellets and combusted at 20 bar of oxygen. The suitability of absorbing solution (water, 50 mmol L- 1 (NH4)2CO3, 10 mmol L- 1, 25 mmol L- 1, 50 mmol L- 1 or 100 mmol L- 1 NH4OH) was evaluated and a reflux step of 5 min was applied after combustion. The accuracy of the proposed method was evaluated by using certified reference materials (CRMs) of apple leaves and peach leaves and also by spiked samples. Using 50 mmol L- 1 NH4OH as absorbing solution, recoveries close to 100% for bromine and iodine were obtained as well as a low relative standard deviation (5%). No statistical difference (t-test, 95% of confidence level) was observed between the values obtained by ICP-MS after MIC digestion and the certified values. One of the important advantages of the proposed method is that it allowed the use of a relatively high sample mass (1000 mg) of medicinal plant resulting in low limits of quantification (0.033 μg g- 1 and 0.003 μg g- 1 for Br and I, respectively). Blanks were always negligible and only diluted solutions were used, in agreement with current recommendations for analytical methods. A high digestion efficiency was achieved (> 99%) assuring quantitative results. The concentration of analytes in medicinal plants was in the range of 0.17 μg g- 1 to 53.1 μg g- 1 for Br and medicinal plants (125 μg g- 1).

  20. Determination of vanillin, ethyl vanillin, and coumarin in infant formula by liquid chromatography-quadrupole linear ion trap mass spectrometry.

    Science.gov (United States)

    Shen, Yan; Han, Chao; Liu, Bin; Lin, Zhengfeng; Zhou, Xiujin; Wang, Chengjun; Zhu, Zhenou

    2014-02-01

    A simple, precise, accurate, and validated liquid chromatography-quadrupole linear ion trap mass spectrometry method was developed for the determination of vanillin, ethyl vanillin, and coumarin in infant formula samples. Following ultrasonic extraction with methanol/water (1:1, vol/vol), and clean-up on an HLB solid-phase extraction cartridge (Waters Corp., Milford, MA), samples were separated on a Waters XSelect HSS T3 column (150 × 2.1-mm i.d., 5-μm film thickness; Waters Corp.), with 0.1% formic acid solution-acetonitrile as mobile phase at a flow rate of 0.25 mL/min. Quantification of the target was performed by the internal standard approach, using isotopically labeled compounds for each chemical group, to correct matrix effects. Data acquisition was carried out in multiple reaction monitoring transitions mode, monitoring 2 multiple reaction monitoring transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus of the linear ion trap. The novel liquid chromatography-quadrupole linear ion trap mass spectrometry platform offers the best sensitivity and specificity for characterization and quantitative determination of vanillin, ethyl vanillin, and coumarin in infant formula and fulfills the quality criteria for routine laboratory application. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Building phytochemical mass spec identification protocols and database libraries

    Science.gov (United States)

    An optimized single LC-MS evaluation that would accurately determine the elemental composition of as many compounds present in an extract would greatly aid in the evaluation of plant tissues. For phytochemicals, we have used accurate mass analysis to quickly characterize the potential chemical formu...

  2. The effect of virtual mass on the prediction of critical flow

    International Nuclear Information System (INIS)

    Cheng, L.; Lahey, R.T.; Drew, D.A.

    1983-01-01

    By observing the results in Fig. 4 and Fig. 5 we can see that virtual mass effects are important in predicting critical flow. However, as seen in Fig. 7a, in which all three flows are predicted to be critical (Δ=0), it is difficult to distinguish one set of conditions from the other by just considering the pressure profile. Clearly more detailed data, such as the throat void fraction, is needed for discrimination between these calculations. Moreover, since the calculated critical flows have been found to be sensitive to initial mass flux, and void fraction, careful measurements of those parameters are needed before accurate virtual mass parameters can be determined from these data. It can be concluded that the existing Moby Dick data is inadequate to allow one to deduce accurate values of the virtual mass parameters C/sub VM/ and λ. Nevertheless, more careful experiments of this type are uniquely suited for the determination of these important parameters. It appears that the use of a nine equation model, such as that discussed herein, coupled with more detailed accurate critical flow data is an effective means of determining the parameters in interfacial momentum transfer models, such as virtual mass effects, which are only important during strong spatial accelerations. Indeed, there are few other methods available which can be used for such determinations

  3. Volumetric determination of tumor size abdominal masses. Problems -feasabilities

    International Nuclear Information System (INIS)

    Helmberger, H.; Bautz, W.; Sendler, A.; Fink, U.; Gerhardt, P.

    1995-01-01

    The most important indication for clinically reliable volumetric determination of tumor size in the abdominal region is monitoring liver metastases during chemotherapy. Determination of volume can be effectively realized using 3D reconstruction. Therefore, the primary data set must be complete and contiguous. The mass should be depicted strongly enhanced and free of artifacts. At present, this prerequisite can only be complied with using thin-slice spiral CT. Phantom studies have proven that a semiautomatic reconstruction algorithm is recommendable. The basic difficulties involved in volumetric determination of tumor size are the problems in differentiating active malignant mass and changes in the surrounding tissue, as well as the lack of histomorphological correlation. Possible indications for volumetry of gastrointestinal masses in the assessment of neoadjuvant therapeutic concepts are under scientific evaluation. (orig./MG) [de

  4. Determination of 230Th/232Th and correct methods by High Resolution Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    Xie Shengkai; Guo Dongfa; Tan Jing; Zhang Yanhui; Huang Qiuhong; Gao Aiguo

    2013-01-01

    It is very important for the rapid and reliable determination of 230 Th/ 232 Th in the thorium-230 dating. A method of measuring 230 Th/ 232 Th in natural samples by high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) was developed on the base of our former work. The precise and accurate of natural 230 Th in geology samples is challenging, as the peak tailing to the high intensity of neighboring peak at 232 Th and the mass discrimination of the instrument. The peak tailing of 238 U to 236 U was used to decrease the peak tailing effect of 232 Th to 230 Th. The mass discrimination factor K between ture and measured isotope ratio was calculated after measuring different 230 Th/ 232 Th ratio solutions. Lab used standard samples was digested in mixed acids of HN0 3 -HF-HCI-HCl0 4 , and separated by the Bio-rad AG 1 × 8 Cl - resin. The measurement method of blank-standard-blank-sample procession was used to determinate the 230 Th/ 232 Th. The measured result of 230 Th/ 232 Th was at (7.29 ± 0.34) × 10 -6 , which agreed with the reference value of (7.33 ± 0.17) × 10 -6 . (authors)

  5. Application of the mass spectrometry-isotope dilution technique for the determination of uranium contents in rocks

    International Nuclear Information System (INIS)

    Kakazu, M.H.; Iyer, S.S.

    1980-01-01

    Application of the spectrometric isotope dilution technique for the accurate determination of parts per million range of uranium in rock samples is described. The various aspects of the method like sample dissolution, ion exchange separation, mass spectrometric procedures are discussed. A single filament ionization source was employed for the isotope analysis. A carbon reduction method was used to reduce uranium oxide ions to uranium metal ions. The tracer solution for isotope dilution was prepared from National Bureau of Standards uranium isotopic Standard NBS U-970. Uranium contents are meassured for nine rock samples and the values obtained are compared with the uranium values measured by others workers. Errors caused in the uranium determination due to sample splitting problems as well as the incomplete acid digestion of the samples are discussed. (Author) [pt

  6. Accurate determination of the charge transfer efficiency of photoanodes for solar water splitting.

    Science.gov (United States)

    Klotz, Dino; Grave, Daniel A; Rothschild, Avner

    2017-08-09

    The oxygen evolution reaction (OER) at the surface of semiconductor photoanodes is critical for photoelectrochemical water splitting. This reaction involves photo-generated holes that oxidize water via charge transfer at the photoanode/electrolyte interface. However, a certain fraction of the holes that reach the surface recombine with electrons from the conduction band, giving rise to the surface recombination loss. The charge transfer efficiency, η t , defined as the ratio between the flux of holes that contribute to the water oxidation reaction and the total flux of holes that reach the surface, is an important parameter that helps to distinguish between bulk and surface recombination losses. However, accurate determination of η t by conventional voltammetry measurements is complicated because only the total current is measured and it is difficult to discern between different contributions to the current. Chopped light measurement (CLM) and hole scavenger measurement (HSM) techniques are widely employed to determine η t , but they often lead to errors resulting from instrumental as well as fundamental limitations. Intensity modulated photocurrent spectroscopy (IMPS) is better suited for accurate determination of η t because it provides direct information on both the total photocurrent and the surface recombination current. However, careful analysis of IMPS measurements at different light intensities is required to account for nonlinear effects. This work compares the η t values obtained by these methods using heteroepitaxial thin-film hematite photoanodes as a case study. We show that a wide spread of η t values is obtained by different analysis methods, and even within the same method different values may be obtained depending on instrumental and experimental conditions such as the light source and light intensity. Statistical analysis of the results obtained for our model hematite photoanode show good correlation between different methods for

  7. Using MALDI-TOF mass spectrometry as a rapid and accurate diagnostic tool in infective endocarditis: a case report of a patient with mitral valve infective endocarditis caused by Abiotrophia defectiva

    DEFF Research Database (Denmark)

    Holler, Jon Gitz; Pedersen, Line; Calum, Henrik

    2011-01-01

    A case of infective endocarditis caused by Abiotrophia defectiva is presented. The use of MALDI-TOF mass spectrometry as a rapid and accurate diagnostic tool in infective endocarditis is discussed.......A case of infective endocarditis caused by Abiotrophia defectiva is presented. The use of MALDI-TOF mass spectrometry as a rapid and accurate diagnostic tool in infective endocarditis is discussed....

  8. Rapid and accurate determination of radiochemical purity of sup(99m)Tc compounds

    International Nuclear Information System (INIS)

    Tamat, S.R.

    1977-01-01

    The wide spread use of sup(99m)Tc-labelled radiopharmaceuticals and limitation of the short half-life of the isotope, is associated with an urgent need for a rapid, simple but accurate method for determining the radiochemical purity of the compound. A short paper chromatographic (KK) or thin layer chromatographic (KLT) method using 95% methanol or 0.9% saline solution as solvents, has solved the problem. With these methods, the amount of free sup(99m)Tc pertechnetate in a compound, can be determined in only a few minutes. These methods compare satisfactorily with lengtheir procedures. (author)

  9. Saponification reaction system: a detailed mass transfer coefficient determination.

    Science.gov (United States)

    Pečar, Darja; Goršek, Andreja

    2015-01-01

    The saponification of an aromatic ester with an aqueous sodium hydroxide was studied within a heterogeneous reaction medium in order to determine the overall kinetics of the selected system. The extended thermo-kinetic model was developed compared to the previously used simple one. The reaction rate within a heterogeneous liquid-liquid system incorporates a chemical kinetics term as well as mass transfer between both phases. Chemical rate constant was obtained from experiments within a homogeneous medium, whilst the mass-transfer coefficient was determined separately. The measured thermal profiles were then the bases for determining the overall reaction-rate. This study presents the development of an extended kinetic model for considering mass transfer regarding the saponification of ethyl benzoate with sodium hydroxide within a heterogeneous reaction medium. The time-dependences are presented for the mass transfer coefficient and the interfacial areas at different heterogeneous stages and temperatures. The results indicated an important role of reliable kinetic model, as significant difference in k(L)a product was obtained with extended and simple approach.

  10. Improving mass measurement accuracy in mass spectrometry based proteomics by combining open source tools for chromatographic alignment and internal calibration.

    Science.gov (United States)

    Palmblad, Magnus; van der Burgt, Yuri E M; Dalebout, Hans; Derks, Rico J E; Schoenmaker, Bart; Deelder, André M

    2009-05-02

    Accurate mass determination enhances peptide identification in mass spectrometry based proteomics. We here describe the combination of two previously published open source software tools to improve mass measurement accuracy in Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The first program, msalign, aligns one MS/MS dataset with one FTICRMS dataset. The second software, recal2, uses peptides identified from the MS/MS data for automated internal calibration of the FTICR spectra, resulting in sub-ppm mass measurement errors.

  11. The determination of polycyclic aromatic hydrocarbons in human urine by high-resolution gas chromatography-mass spectrometry.

    Science.gov (United States)

    Cho, Sung-Hee; Lee, Sun-Kyung; Kim, Chong Hyeak

    2018-05-01

    Polycyclic aromatic hydrocarbons (PAHs), organic compounds formed by at least two condensed aromatic rings, are ubiquitous environmental pollutants that are produced by incomplete combustion of organic materials. PAHs have been classified as carcinogenIC to humans by the International Agency for Research on Cancer, because they can bind to DNA, causing mutations. Therefore, the levels of PAHs in human urine can be used as an indicator for potential carcinogenesis and cell mutation. An analytical method was developed for the accurate measurement of PAHs in urine using high-resolution gas chromatography-mass spectrometry. Urine samples were extracted by an Oasis HLB extraction cartridge after enzymatic hydrolysis with a β-glucuronidase/arylsulfatase cocktail. The 18 PAHs were separated using an Agilent DB-5 MS capillary column (30 m × 0.25 mm, 0.25 μm) and monitored by time-of-flight mass spectrometry. Under the optimized method, the linearity of calibration curves was >0.994. The limits of detection at a signal-to-noise ratio of 3 were 10-100 ng/L. The coefficients of variation were in the range of 0.4-9.0%. The present method was highly accurate for simultaneous determination of 18 PAHs in human urine and could be applied to monitoring and biomedical investigations to check exposure of PAHs. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Dynamic weighing for accurate fertilizer application and monitoring

    NARCIS (Netherlands)

    Bergeijk, van J.; Goense, D.; Willigenburg, van L.G.; Speelman, L.

    2001-01-01

    The mass flow of fertilizer spreaders must be calibrated for the different types of fertilizers used. To obtain accurate fertilizer application manual calibration of actual mass flow must be repeated frequently. Automatic calibration is possible by measurement of the actual mass flow, based on

  13. Development of an extraction method for the determination of dissolved organic radiocarbon in seawater by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Tanaka, Takayuki; Otosaka, Shigeyoshi; Togawa, Orihiko; Amano, Hikaru

    2009-01-01

    We developed an extraction method for accurately and reproducibly determining dissolved organic radiocarbon in seawater by ultraviolet oxidation of dissolved organic carbon and subsequent accelerator mass spectrometry. We determined the irradiation time required for oxidation of the dissolved organic carbon. By modifying the experimental apparatus, we decreased contamination by dead carbon, which came mainly from petrochemical products in the apparatus and from the incursion of carbon dioxide from the atmosphere. The modifications decreased the analytical blank level to less than 1% of sample size, a percentage that had not previously been achieved. The recovery efficiency was high, 95±1%. To confirm both the accuracy and reproducibility of the method, we tested it by analyzing an oxalic acid radiocarbon reference material and by determining the dissolved organic carbon in surface seawater samples. (author)

  14. Accurate Determination of the Frequency Response Function of Submerged and Confined Structures by Using PZT-Patches†

    Directory of Open Access Journals (Sweden)

    Alexandre Presas

    2017-03-01

    Full Text Available To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs, which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the

  15. Accurate Determination of the Frequency Response Function of Submerged and Confined Structures by Using PZT-Patches†.

    Science.gov (United States)

    Presas, Alexandre; Valentin, David; Egusquiza, Eduard; Valero, Carme; Egusquiza, Mònica; Bossio, Matias

    2017-03-22

    To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF) for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs), which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force) has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the structure vibrating

  16. Calculating Cluster Masses via the Sunyaev-Zel'dovich Effect

    Science.gov (United States)

    Lindley, Ashley; Landry, D.; Bonamente, M.; Joy, M.; Bulbul, E.; Carlstrom, J. E.; Culverhouse, T. L.; Gralla, M.; Greer, C.; Hawkins, D.; Lamb, J. W.; Leitch, E. M.; Marrone, D. P.; Miller, A.; Mroczkowski, T.; Muchovej, S.; Plagge, T.; Woody, D.

    2012-05-01

    Accurate measurements of the total mass of galaxy clusters are key for measuring the cluster mass function and therefore investigating the evolution of the universe. We apply two new methods to measure cluster masses for five galaxy clusters contained within the Brightest Cluster Sample (BCS), an X-ray luminous statistically complete sample of 35 clusters at z=0.15-0.30. These methods distinctively use only observations of the Sunyaev-Zel'dovich (SZ) effect, for which the brightness is redshift independent. At the low redshifts of the BCS, X-ray observations can easily be used to determine cluster masses, providing convenient calibrators for our SZ mass calculations. These clusters have been observed with the Sunyaev-Zel'dovich Array (SZA), an interferometer that is part of the Combined Array for Research in Millimeter-wave Astronomy (CARMA) that has been optimized for accurate measurement of the SZ effect in clusters of galaxies at 30 GHz. One method implements a scaling relation that relates the integrated pressure, Y, as determined by the SZ observations to the mass of the cluster calculated via optical weak lensing. The second method makes use of the Virial theorem to determine the mass given the integrated pressure of the cluster. We find that masses calculated utilizing these methods within a radius r500 are consistent with X-ray masses, calculated by manipulating the surface brightness and temperature data within the same radius, thus concluding that these are viable methods for the determination of cluster masses via the SZ effect. We present preliminary results of our analysis for five galaxy clusters.

  17. Workshop on Top mass: challenges in definition and determination

    CERN Document Server

    2015-01-01

    The top-quark mass definition and determination is a major subject of debate in both theoretical and experimental communities. Different strategies to relate the measured and theoretical quantities have been envisaged. The aim of this 3-day meeting is to convene experts on this topic to stimulate an informal discussion on different aspects of the issue. We plan to have only three or four talks each day, and plenty of time to discuss the connection between the experimentally reconstructed top mass relying on Monte Carlo generators and different theoretical mass definitions, including the most advanced strategies. Implications of the top-mass determination for physics beyond the standard model will be also covered. The general approach and format will be pedagogical, the audience ranging from top-quark physics experts to graduate students, and should favour extended discussion among participants.

  18. Model-independent X-ray Mass Determinations for Clusters of Galaxies

    Science.gov (United States)

    Nulsen, Paul

    2005-09-01

    We propose to use high quality X-ray data from the Chandra archive to determine the mass distributions of about 60 clusters of galaxies over the largest possible range of radii. By avoiding unwarranted assumptions, model-independent methods make best use of high quality data. We will employ two model-independent methods. That used by Nulsen & Boehringer (1995) to determine the mass of the Virgo Cluster and a new method, that will be developed as part of the project. The new method will fit a general mass model directly to the X-ray spectra, making best possible use of the fitting errors to constrain mass profiles.

  19. Rapid yet accurate measurement of mass diffusion coefficients by phase shifting interferometer

    CERN Document Server

    Guo Zhi Xiong; Komiya, A

    1999-01-01

    The technique of using a phase-shifting interferometer is applied to the study of diffusion in transparent liquid mixtures. A quick method is proposed for determining the diffusion coefficient from the measurements of the location of fringes on a grey level picture. The measurement time is very short (within 100 s) and a very small transient diffusion field can be observed and recorded accurately with a rate of 30 frames per second. The measurement can be completed using less than 0.12 cc of solutions. The influence of gravity on the measurement of the diffusion coefficient is eliminated in the present method. Results on NaCl-water diffusion systems are presented and compared with the reference data. (author)

  20. Rapid Classification and Identification of Multiple Microorganisms with Accurate Statistical Significance via High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

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

    2018-06-05

    Rapid and accurate identification and classification of microorganisms is of paramount importance to public health and safety. With the advance of mass spectrometry (MS) technology, the speed of identification can be greatly improved. However, the increasing number of microbes sequenced is complicating correct microbial identification even in a simple sample due to the large number of candidates present. To properly untwine candidate microbes in samples containing one or more 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 peptide-centric representations of microbes to better separate them and by augmenting our earlier analysis method that yields accurate statistical significance. Here, we present an updated analysis workflow that uses tandem MS (MS/MS) spectra for microbial identification or classification. We have demonstrated, using 226 MS/MS publicly available data files (each containing from 2500 to nearly 100,000 MS/MS spectra) and 4000 additional MS/MS data files, that the updated workflow can correctly identify multiple microbes at the genus and often the species level for samples containing more than one microbe. We have also shown that the proposed workflow computes accurate statistical significances, i.e., E values for identified peptides and unified E values for identified microbes. Our updated analysis workflow MiCId, a freely available software for Microorganism Classification and Identification, is available for download at https://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads.html . Graphical Abstract ᅟ.

  1. Highly sensitive capillary electrophoresis-mass spectrometry for rapid screening and accurate quantitation of drugs of abuse in urine.

    Science.gov (United States)

    Kohler, Isabelle; Schappler, Julie; Rudaz, Serge

    2013-05-30

    The combination of capillary electrophoresis (CE) and mass spectrometry (MS) is particularly well adapted to bioanalysis due to its high separation efficiency, selectivity, and sensitivity; its short analytical time; and its low solvent and sample consumption. For clinical and forensic toxicology, a two-step analysis is usually performed: first, a screening step for compound identification, and second, confirmation and/or accurate quantitation in cases of presumed positive results. In this study, a fast and sensitive CE-MS workflow was developed for the screening and quantitation of drugs of abuse in urine samples. A CE with a time-of-flight MS (CE-TOF/MS) screening method was developed using a simple urine dilution and on-line sample preconcentration with pH-mediated stacking. The sample stacking allowed for a high loading capacity (20.5% of the capillary length), leading to limits of detection as low as 2 ng mL(-1) for drugs of abuse. Compound quantitation of positive samples was performed by CE-MS/MS with a triple quadrupole MS equipped with an adapted triple-tube sprayer and an electrospray ionization (ESI) source. The CE-ESI-MS/MS method was validated for two model compounds, cocaine (COC) and methadone (MTD), according to the Guidance of the Food and Drug Administration. The quantitative performance was evaluated for selectivity, response function, the lower limit of quantitation, trueness, precision, and accuracy. COC and MTD detection in urine samples was determined to be accurate over the range of 10-1000 ng mL(-1) and 21-1000 ng mL(-1), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Determination of balloon gas mass and revised estimates of drag and virtual mass coefficients

    Science.gov (United States)

    Robbins, E.; Martone, M.

    1993-01-01

    In support of the NASA Balloon Program, small-scale balloons were flown with varying lifting gas and total system mass. Instrument packages were developed to measure and record acceleration and temperature data during these tests. Top fitting and instrument payload accelerations were measured from launch to steady state ascent and through ballast drop transients. The development of the small lightweight self-powered Stowaway Special instrument packages is discussed along with mathematical models developed to determine gas mass, drag and virtual mass coefficients.

  3. Accurate Determination of Tunneling-Affected Rate Coefficients: Theory Assessing Experiment.

    Science.gov (United States)

    Zuo, Junxiang; Xie, Changjian; Guo, Hua; Xie, Daiqian

    2017-07-20

    The thermal rate coefficients of a prototypical bimolecular reaction are determined on an accurate ab initio potential energy surface (PES) using ring polymer molecular dynamics (RPMD). It is shown that quantum effects such as tunneling and zero-point energy (ZPE) are of critical importance for the HCl + OH reaction at low temperatures, while the heavier deuterium substitution renders tunneling less facile in the DCl + OH reaction. The calculated RPMD rate coefficients are in excellent agreement with experimental data for the HCl + OH reaction in the entire temperature range of 200-1000 K, confirming the accuracy of the PES. On the other hand, the RPMD rate coefficients for the DCl + OH reaction agree with some, but not all, experimental values. The self-consistency of the theoretical results thus allows a quality assessment of the experimental data.

  4. Fast and accurate automated cell boundary determination for fluorescence microscopy

    Science.gov (United States)

    Arce, Stephen Hugo; Wu, Pei-Hsun; Tseng, Yiider

    2013-07-01

    Detailed measurement of cell phenotype information from digital fluorescence images has the potential to greatly advance biomedicine in various disciplines such as patient diagnostics or drug screening. Yet, the complexity of cell conformations presents a major barrier preventing effective determination of cell boundaries, and introduces measurement error that propagates throughout subsequent assessment of cellular parameters and statistical analysis. State-of-the-art image segmentation techniques that require user-interaction, prolonged computation time and specialized training cannot adequately provide the support for high content platforms, which often sacrifice resolution to foster the speedy collection of massive amounts of cellular data. This work introduces a strategy that allows us to rapidly obtain accurate cell boundaries from digital fluorescent images in an automated format. Hence, this new method has broad applicability to promote biotechnology.

  5. Precise mass determination of single cell with cantilever-based microbiosensor system.

    Directory of Open Access Journals (Sweden)

    Bogdan Łabędź

    Full Text Available Having determined the mass of a single cell of brewer yeast Saccharomyces cerevisiae by means of a microcantilever-based biosensor Cantisens CSR-801 (Concentris, Basel, Switzerland, it was found that its dry mass is 47,65 ± 1,05 pg. Found to be crucial in this mass determination was the cell position along the length of the cantilever. Moreover, calculations including cells positions on the cantilever provide a threefold better degree of accuracy than those which assume uniform mass distribution. We have also examined the influence of storage time on the single cell mass. Our results show that after 6 months there is an increase in the average mass of a single yeast cell.

  6. Precise mass determination of single cell with cantilever-based microbiosensor system.

    Science.gov (United States)

    Łabędź, Bogdan; Wańczyk, Aleksandra; Rajfur, Zenon

    2017-01-01

    Having determined the mass of a single cell of brewer yeast Saccharomyces cerevisiae by means of a microcantilever-based biosensor Cantisens CSR-801 (Concentris, Basel, Switzerland), it was found that its dry mass is 47,65 ± 1,05 pg. Found to be crucial in this mass determination was the cell position along the length of the cantilever. Moreover, calculations including cells positions on the cantilever provide a threefold better degree of accuracy than those which assume uniform mass distribution. We have also examined the influence of storage time on the single cell mass. Our results show that after 6 months there is an increase in the average mass of a single yeast cell.

  7. Quark mass relations to four-loop order

    International Nuclear Information System (INIS)

    Marquard, Peter; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias

    2015-02-01

    We present results for the relation between a heavy quark mass defined in the on-shell and MS scheme to four-loop order. The method to compute the four-loop on-shell integral is briefly described and the new results are used to establish relations between various short-distance masses and the MS quark mass to next-to-next-to-next-to-leading order accuracy. These relations play an important role in the accurate determination of the MS heavy quark masses.

  8. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Patterson, K.Y.; Veillon, Claude

    1992-01-01

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g -1 . The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  9. A new determination of the pion mass

    International Nuclear Information System (INIS)

    Anagnastopoulos, D.; Belmiloud, D.; El-Khoury, P.; Indelicato, P.; Borchert, G.; Gorke, H.; Gotta, D.; Lenz, S.; Siems, T.; Daum, M.; Frosch, R.; Hauser, P.; Kirch, K.; Simons, L.M.

    1996-01-01

    Initial measurements concerning the feasibility of a new pion mass determination are described. In a first step, a high-resolution crystal spectrometer was coupled to a cyclotron trap which provides a high pion stopping density, sufficient to check predictions for the cascade process and to measure the stability of the apparatus. A comparison with the measured Cu K α fluorescence line resolves an ambiguity in the value of the pion mass. The preliminary result from this experiment is m π -=(139.57040±0.00045) MeV/c 2 . (orig.)

  10. How accurate is ultrasound in evaluating palpable breast masses ...

    African Journals Online (AJOL)

    Methods: Eighty palpable breast masses were evaluated at ultrasound and information about the characteristic features of the masses was recorded. An impression about the diagnosis was made and results were correlated with histology findings. Results: The overall sensitivity of ultrasound in detecting breast lumps was ...

  11. Determination of the masses of electrical weak gauge bosons with L3

    CERN Document Server

    Rosenbleck, Christian

    2006-01-01

    This thesis presents the measurement of the masses of the carriers of the weak force in the Standard Model of Particle Physics, the gauge bosons W and Z. The masses are determined using the kinematics of the bosons' decay products. The data were collected by the L3 experiment at the Large Electron Positron Collider (LEP) at centre-of-mass energies, sqrt(s), between 183 GeV and 209 GeV in the years 1997 to 2000. The mass of the Z-boson, mZ, is already known very precisely: The L3 collaboration determined it to be mZ = 91.1898 +- 0.0031 GeV from a scan of the Z resonance. Therefore the main aim of this analysis is not the determination of the numerical value of mZ; instead the analysis is used to cross-check the measurement of the W boson mass since the methods are similar. Alternatively, the analysis can be used to measure the mean centre-of-mass energy at the L3 interaction point. The Z-boson mass is determined to be mZ = 91.272 +- 0.046 GeV. If interpreted as measurement of the centre-of-mass energy, this va...

  12. The determination of the pressure-viscosity coefficient of a lubricant through an accurate film thickness formula and accurate film thickness measurements : part 2 : high L values

    NARCIS (Netherlands)

    Leeuwen, van H.J.

    2011-01-01

    The pressure-viscosity coefficient of a traction fluid is determined by fitting calculation results on accurate film thickness measurements, obtained at different speeds, loads, and temperatures. Through experiments, covering a range of 5.6

  13. Masses of the components of SB2 binaries observed with Gaia - IV. Accurate SB2 orbits for 14 binaries and masses of three binaries*

    Science.gov (United States)

    Kiefer, F.; Halbwachs, J.-L.; Lebreton, Y.; Soubiran, C.; Arenou, F.; Pourbaix, D.; Famaey, B.; Guillout, P.; Ibata, R.; Mazeh, T.

    2018-02-01

    The orbital motion of non-contact double-lined spectroscopic binaries (SB2s), with periods of a few tens of days to several years, holds unique, accurate information on individual stellar masses, which only long-term monitoring can unlock. The combination of radial velocity measurements from high-resolution spectrographs and astrometric measurements from high-precision interferometers allows the derivation of SB2 component masses down to the percent precision. Since 2010, we have observed a large sample of SB2s with the SOPHIE spectrograph at the Observatoire de Haute-Provence, aiming at the derivation of orbital elements with sufficient accuracy to obtain masses of components with relative errors as low as 1 per cent when the astrometric measurements of the Gaia satellite are taken into account. In this paper, we present the results from 6 yr of observations of 14 SB2 systems with periods ranging from 33 to 4185 days. Using the TODMOR algorithm, we computed radial velocities from the spectra and then derived the orbital elements of these binary systems. The minimum masses of the 28 stellar components are then obtained with an average sample accuracy of 1.0 ± 0.2 per cent. Combining the radial velocities with existing interferometric measurements, we derived the masses of the primary and secondary components of HIP 61100, HIP 95995 and HIP 101382 with relative errors for components (A,B) of, respectively, (2.0, 1.7) per cent, (3.7, 3.7) per cent and (0.2, 0.1) per cent. Using the CESAM2K stellar evolution code, we constrained the initial He abundance, age and metallicity for HIP 61100 and HIP 95995.

  14. Metabolite signal identification in accurate mass metabolomics data with MZedDB, an interactive m/z annotation tool utilising predicted ionisation behaviour 'rules'

    Directory of Open Access Journals (Sweden)

    Snowdon Stuart

    2009-07-01

    Full Text Available Abstract Background Metabolomics experiments using Mass Spectrometry (MS technology measure the mass to charge ratio (m/z and intensity of ionised molecules in crude extracts of complex biological samples to generate high dimensional metabolite 'fingerprint' or metabolite 'profile' data. High resolution MS instruments perform routinely with a mass accuracy of Results Metabolite 'structures' harvested from publicly accessible databases were converted into a common format to generate a comprehensive archive in MZedDB. 'Rules' were derived from chemical information that allowed MZedDB to generate a list of adducts and neutral loss fragments putatively able to form for each structure and calculate, on the fly, the exact molecular weight of every potential ionisation product to provide targets for annotation searches based on accurate mass. We demonstrate that data matrices representing populations of ionisation products generated from different biological matrices contain a large proportion (sometimes > 50% of molecular isotopes, salt adducts and neutral loss fragments. Correlation analysis of ESI-MS data features confirmed the predicted relationships of m/z signals. An integrated isotope enumerator in MZedDB allowed verification of exact isotopic pattern distributions to corroborate experimental data. Conclusion We conclude that although ultra-high accurate mass instruments provide major insight into the chemical diversity of biological extracts, the facile annotation of a large proportion of signals is not possible by simple, automated query of current databases using computed molecular formulae. Parameterising MZedDB to take into account predicted ionisation behaviour and the biological source of any sample improves greatly both the frequency and accuracy of potential annotation 'hits' in ESI-MS data.

  15. Determination of absolute neutrino masses from Z-bursts

    International Nuclear Information System (INIS)

    Fodor, Z.

    2001-05-01

    Ultrahigh energy neutrinos (UHEν) scatter on cosmological relic neutrinos (Rν) producing Z bosons, which can decay hadronically producing protons (Z-burst). We compare the predicted proton spectrum with the observed ultrahigh energy cosmic ray (UHECR) spectrum and determine the mass of the heaviest Rν via a maximum likelihood analysis. Our mass prediction depends on the origin of the power-like part of the UHECR spectrum: m ν = 2.34 -0.84 +1.29 eV for Galactic halo and 0.26 -0.14 +0.20 eV for extragalactic (EG) origin. The second mass, with a lower bound of 0.06 eV on the 95% confidence level (CL), is compatible with a hierarchical ν mass scenario with the largest mass suggested by the atmospheric ν oscillation. The necessary UHEν flux is compatible with present upper limits and should be detected in the near future. (orig.)

  16. A radioactive tracer dilution method to determine the mass of molten salt

    International Nuclear Information System (INIS)

    Lei Cao; Jarrell, Josh; Hardtmayer, D.E.; White, Susan; Herminghuysen, Kevin; Kauffman, Andrew; Sanders, Jeff; Li, Shelly

    2017-01-01

    A new technique for molten salt mass determination, termed radioactive tracer dilution, that uses 22 Na as a tracer was validated at bench scale. It has been a challenging problem to determine the mass of molten salt in irregularly shaped containers, where a highly radioactive, high-temperature molten salt was used to process nuclear spent/used fuel during electrochemical recycling (pyro-processing) or for coolant/fuel salt from molten salt reactors. A radioactive source with known activity is dissolved into the salt. After a complete mixture, a small amount of the salt is sampled and measured in terms of its mass and radioactivity. By finding the ratio of the mass to radioactivity, the unknown salt mass in the original container can be precisely determined. (author)

  17. A new method of determining the ejected mass of novae

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, W.M.

    1994-12-31

    A new method of determining the ejected mass of novae based on simple, reasonable assumptions is presented. This method assumes that the remnant mass on the white dwarf is the same as that from the previous nova outburst. The hydrogen, helium, and metal abundances of the accreted material from the secondary must also be known or assumed. The white dwarf`s mass has a small effect because the amount of hydrogen consumed during the thermonuclear runaway only depends weakly upon this mass. If the composition of the ejecta and the time of the remnant shell burnout are determined from observations, then the ejected and remnant masses can be deduced. At present only a sharp decrease in the X-rays observed by ROSAT has been attributed to this remnant burnout and only for two novae: GQ Mus and V1974 Cyg. The ejected and remnant masses for these two novae are calculated. If other indicators of nova remnant burnout, such as a rapid decrease in high-ionization lines, can be identified, then this method could be applied to additional novae.

  18. Precision determination of pion mass using X-ray CCD spectroscopy

    CERN Document Server

    Nelms, N; Augsburger, M A; Borchert, G; Chatellard, D; Daum, M; Egger, J P; Gotta, D; Hauser, P; Indelicato, P J; Jeannet, E; Kirch, K; Schult, O W B; Siems, T; Simons, L M; Wells, A

    2002-01-01

    An experiment is described which aims to determine the charged pion mass to 1 ppm or better, from which a new determination of the upper limit of the muon neutrino mass is anticipated. The experimental approach uses a high-intensity negative pion beam (produced at the PSI 590 MeV proton cyclotron), injected into a cyclotron trap and stopped inside a gas-filled target chamber, to form highly excited exotic atoms of pionic nitrogen and muonic oxygen. The energy of photons, emitted during de-excitation, is directly proportional to the mass of the pion or muon. These soft X-ray emission spectra are measured using a high-precision crystal spectrometer, with an array of six, high quantum efficiency X-ray position resolving CCDs at the focus. To achieve sub-ppm accuracy, simultaneous calibration of the pionic nitrogen line is provided by measurement of an adjacent muonic oxygen line, whose energy is known to 0.3 ppm. The high precision of the experiment offers a new opportunity to determine the pion mass to the leve...

  19. High-Precision Direct Mass Determination of Unstable Isotopes

    CERN Multimedia

    2002-01-01

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

  20. Evaluation of left ventricular mass in vitro and in vivo with MR imaging

    International Nuclear Information System (INIS)

    Mogelvang, J.; Thomsen, C.; Mehisen, J.; Henriksen, O.; Horn, T.

    1986-01-01

    The left ventricular (LV) mass was determined by MR multisection imaging in ten unopened postmortem human hearts and compared with the true weight of the isolated LV. In addition, the LV mass in 14 patients was determined by MR imaging. LV myocardial volume determined from acquisitions at end diastole were compared with the volume determined from acquisitions at end systole. The LV masses as determined on MR imaging showed excellent correlation with reference values (r = .99, P < .001). There was fine correlation between myocardial volume (mass) estimated in vivo in diastole and systole (r = .95, P < .0001). These results suggest that MR imaging is accurate for the determination of LV mass in vivo

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

    Science.gov (United States)

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

    2011-01-01

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

  2. Rapid Screening of Bovine Milk Oligosaccharides in a Whey Permeate Product and Domestic Animal Milks by Accurate Mass Database and Tandem Mass Spectral Library

    Science.gov (United States)

    Lee, Hyeyoung; Cuthbertson, Daniel J.; Otter, Don E.; Barile, Daniela

    2018-01-01

    A bovine milk oligosaccharide (BMO) library, prepared from cow colostrum, with 34 structures was generated and used to rapidly screen oligosaccharides in domestic animal milks and a whey permeate powder. The novel library was entered into a custom Personal Compound Database and Library (PCDL) and included accurate mass, retention time, and tandem mass spectra. Oligosaccharides in minute-sized samples were separated using nanoliquid chromatography (nanoLC) coupled to a high resolution and sensitive quadrupole-Time of Flight (Q-ToF) MS system. Using the PCDL, 18 oligosaccharides were found in a BMO-enriched product obtained from whey permeate processing. The usefulness of the analytical system and BMO library was further validated using milks from domestic sheep and buffaloes. Through BMO PCDL searching, 15 and 13 oligosaccharides in the BMO library were assigned in sheep and buffalo milks, respectively, thus demonstrating significant overlap between oligosaccharides in bovine (cow and buffalo) and ovine (sheep) milks. This method was shown to be an efficient, reliable, and rapid tool to identify oligosaccharide structures using automated spectral matching. PMID:27428379

  3. Testing substellar models with dynamical mass measurements

    Directory of Open Access Journals (Sweden)

    Liu M.C.

    2011-07-01

    Full Text Available We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical models. We have identified three specific problems with theory: (1 We find that model color–magnitude diagrams cannot be reliably used to infer masses as they do not accurately reproduce the colors of ultracool dwarfs of known mass. (2 Effective temperatures inferred from evolutionary model radii are typically inconsistent with temperatures derived from fitting atmospheric models to observed spectra by 100–300 K. (3 For the only known pair of field brown dwarfs with a precise mass (3% and age determination (≈25%, the measured luminosities are ~2–3× higher than predicted by model cooling rates (i.e., masses inferred from Lbol and age are 20–30% larger than measured. To make progress in understanding the observed discrepancies, more mass measurements spanning a wide range of luminosity, temperature, and age are needed, along with more accurate age determinations (e.g., via asteroseismology for primary stars with brown dwarf binary companions. Also, resolved optical and infrared spectroscopy are needed to measure lithium depletion and to characterize the atmospheres of binary components in order to better assess model deficiencies.

  4. Determining the dark matter mass with DeepCore

    Energy Technology Data Exchange (ETDEWEB)

    Das, Chitta R. [Centro de Física Teórica de Partículas, Instituto Superior Técnico (CFTP), Universidade Tćnica de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Palomares-Ruiz, Sergio, E-mail: sergio.palomares.ruiz@ist.utl.pt [Centro de Física Teórica de Partículas, Instituto Superior Técnico (CFTP), Universidade Tćnica de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Pascoli, Silvia [IPPP, Department of Physics, Durham University, Durham DH1 3LE (United Kingdom)

    2013-10-01

    Cosmological and astrophysical observations provide increasing evidence of the existence of dark matter in our Universe. Dark matter particles with a mass above a few GeV can be captured by the Sun, accumulate in the core, annihilate, and produce high energy neutrinos either directly or by subsequent decays of Standard Model particles. We investigate the prospects for indirect dark matter detection in the IceCube/DeepCore neutrino telescope and its capabilities to determine the dark matter mass.

  5. A method for determination mass absorption coefficient of gamma rays by Compton scattering

    International Nuclear Information System (INIS)

    El Abd, A.

    2014-01-01

    A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. - Highlights: • Compton scattering of γ−rays was used for determining mass absorption coefficient. • Scattered intensities were determined by the MCSHAPE software. • Mass absorption coefficients were determined for some compounds, mixtures and alloys. • Mass absorption coefficients were calculated by Winxcom software. • Good agreements were found between determined and calculated results

  6. Accurate and sensitive determination of molar fractions of "1"3C-Labeled intracellular metabolites in cell cultures grown in the presence of isotopically-labeled glucose

    International Nuclear Information System (INIS)

    Fernández-Fernández, Mario; Rodríguez-González, Pablo; Hevia Sánchez, David; González-Menéndez, Pedro; Sainz Menéndez, Rosa M.; García Alonso, J. Ignacio

    2017-01-01

    This work describes a methodology based on multiple linear regression and GC-MS for the determination of molar fractions of isotopically-labeled intracellular metabolites in cell cultures. Novel aspects of this work are: i) the calculation of theoretical isotopic distributions of the different isotopologues from an experimentally measured value of % 13C enrichment of the labeled precursor ii) the calculation of the contribution of lack of mass resolution of the mass spectrometer and different fragmentation mechanism such as the loss or gain of hydrogen atoms in the EI source to measure the purity of the selected cluster for each metabolite and iii) the validation of the methodology not only by the analysis of gravimetrically prepared mixtures of isotopologues but also by the comparison of the obtained molar fractions with experimental values obtained by GC-Combustion-IRMS based on "1"3C/"1"2C isotope ratio measurements. The method is able to measure molar fractions for twenty-eight intracellular metabolites derived from glucose metabolism in cell cultures grown in the presence of "1"3C-labeled Glucose. The validation strategies demonstrate a satisfactory accuracy and precision of the proposed procedure. Also, our results show that the minimum value of "1"3C incorporation that can be accurately quantified is significantly influenced by the calculation of the spectral purity of the measured cluster and the number of "1"3C atoms of the labeled precursor. The proposed procedure was able to accurately quantify gravimetrically prepared mixtures of natural and labeled glucose molar fractions of 0.07% and mixtures of natural and labeled glycine at molar fractions down to 0.7%. The method was applied to initial studies of glucose metabolism of different prostate cancer cell lines. - Highlights: • Determination of molar fractions of "1"3C-labeled metabolites in cell cultures. • The method is based on multiple linear regression and GC-MS. • Validation of the method by

  7. Accurate and sensitive determination of molar fractions of {sup 13}C-Labeled intracellular metabolites in cell cultures grown in the presence of isotopically-labeled glucose

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Fernández, Mario [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain); Rodríguez-González, Pablo, E-mail: rodriguezpablo@uniovi.es [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain); Hevia Sánchez, David; González-Menéndez, Pedro; Sainz Menéndez, Rosa M. [University Institute of Oncology (IUOPA), University of Oviedo, Julián Clavería 6, 33006 Oviedo (Spain); García Alonso, J. Ignacio [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain)

    2017-05-29

    This work describes a methodology based on multiple linear regression and GC-MS for the determination of molar fractions of isotopically-labeled intracellular metabolites in cell cultures. Novel aspects of this work are: i) the calculation of theoretical isotopic distributions of the different isotopologues from an experimentally measured value of % 13C enrichment of the labeled precursor ii) the calculation of the contribution of lack of mass resolution of the mass spectrometer and different fragmentation mechanism such as the loss or gain of hydrogen atoms in the EI source to measure the purity of the selected cluster for each metabolite and iii) the validation of the methodology not only by the analysis of gravimetrically prepared mixtures of isotopologues but also by the comparison of the obtained molar fractions with experimental values obtained by GC-Combustion-IRMS based on {sup 13}C/{sup 12}C isotope ratio measurements. The method is able to measure molar fractions for twenty-eight intracellular metabolites derived from glucose metabolism in cell cultures grown in the presence of {sup 13}C-labeled Glucose. The validation strategies demonstrate a satisfactory accuracy and precision of the proposed procedure. Also, our results show that the minimum value of {sup 13}C incorporation that can be accurately quantified is significantly influenced by the calculation of the spectral purity of the measured cluster and the number of {sup 13}C atoms of the labeled precursor. The proposed procedure was able to accurately quantify gravimetrically prepared mixtures of natural and labeled glucose molar fractions of 0.07% and mixtures of natural and labeled glycine at molar fractions down to 0.7%. The method was applied to initial studies of glucose metabolism of different prostate cancer cell lines. - Highlights: • Determination of molar fractions of {sup 13}C-labeled metabolites in cell cultures. • The method is based on multiple linear regression and GC-MS.

  8. Decision peptide-driven: a free software tool for accurate protein quantification using gel electrophoresis and matrix assisted laser desorption ionization time of flight mass spectrometry.

    Science.gov (United States)

    Santos, Hugo M; Reboiro-Jato, Miguel; Glez-Peña, Daniel; Nunes-Miranda, J D; Fdez-Riverola, Florentino; Carvallo, R; Capelo, J L

    2010-09-15

    The decision peptide-driven tool implements a software application for assisting the user in a protocol for accurate protein quantification based on the following steps: (1) protein separation through gel electrophoresis; (2) in-gel protein digestion; (3) direct and inverse (18)O-labeling and (4) matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI analysis. The DPD software compares the MALDI results of the direct and inverse (18)O-labeling experiments and quickly identifies those peptides with paralleled loses in different sets of a typical proteomic workflow. Those peptides are used for subsequent accurate protein quantification. The interpretation of the MALDI data from direct and inverse labeling experiments is time-consuming requiring a significant amount of time to do all comparisons manually. The DPD software shortens and simplifies the searching of the peptides that must be used for quantification from a week to just some minutes. To do so, it takes as input several MALDI spectra and aids the researcher in an automatic mode (i) to compare data from direct and inverse (18)O-labeling experiments, calculating the corresponding ratios to determine those peptides with paralleled losses throughout different sets of experiments; and (ii) allow to use those peptides as internal standards for subsequent accurate protein quantification using (18)O-labeling. In this work the DPD software is presented and explained with the quantification of protein carbonic anhydrase. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  9. Determination of fission products and actinides by inductively coupled plasma-mass spectrometry using isotope dilution analysis. A study of random and systematic errors

    International Nuclear Information System (INIS)

    Ignacio Garcia Alonso, Jose

    1995-01-01

    The theory of the propagation of errors (random and systematic) for isotope dilution analysis (IDA) has been applied to the analysis of fission products and actinide elements by inductively coupled plasma-mass spectrometry (ICP-MS). Systematic errors in ID-ICP-MS arising from mass-discrimination (mass bias), detector non-linearity and isobaric interferences in the measured isotopes have to be corrected for in order to achieve accurate results. The mass bias factor and the detector dead-time can be determined by using natural elements with well-defined isotope abundances. A combined method for the simultaneous determination of both factors is proposed. On the other hand, isobaric interferences for some fission products and actinides cannot be eliminated using mathematical corrections (due to the unknown isotope abundances in the sample) and a chemical separation is necessary. The theory for random error propagation in IDA has been applied to the determination of non-natural elements by ICP-MS taking into account all possible sources of uncertainty with pulse counting detection. For the analysis of fission products, the selection of the right spike isotope composition and spike to sample ratio can be performed by applying conventional random propagation theory. However, it has been observed that, in the experimental determination of the isotope abundances of the fission product elements to be determined, the correction for mass-discrimination and the correction for detector dead-time losses contribute to the total random uncertainty. For the instrument used in the experimental part of this study, it was found that the random uncertainty on the measured isotope ratios followed Poisson statistics for low counting rates whereas, for high counting rates, source instability was the main source of error

  10. Interlaboratory determinations of isotopically enriched metals by field desorption mass spectroscopy

    International Nuclear Information System (INIS)

    Bahr, U.; Schulten, H.R.; Achenbach, C.; Ziskoven, R.

    1982-01-01

    The isotopic distribution of stable isotopes in six enriched metals (calcium, copper, barium, rubidium, strontium and thallium) has been determined by field desorption mass spectrometry. A first evaluation of the interlaboratory reproducibility of the application of this method for trace determination of metals was made using three different types of mass spectrometers in three different laboratories. The standard deviations for the most abundant isotopes of the metals investigated are between +-0.1 and +-0.5%. Within these standard deviations, the values obtained by the three mass spectrometry groups are the same. To support the accuracy of our quantification, thermal ionization mass spectrometry has been employed and confirms the results of the field desorption method. (orig.) [de

  11. Atomic spectroscopy and highly accurate measurement: determination of fundamental constants; Spectroscopie atomique et mesures de grande precision: determination de constantes fonfamentales

    Energy Technology Data Exchange (ETDEWEB)

    Schwob, C

    2006-12-15

    This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm{sup -1}). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10{sup -9} began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is {alpha}{sub -1} = 137.03599884 (91) with a relative uncertainty of 6.7*10{sup -9}. The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)

  12. 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.

  13. Higher order and heavy quark mass effects in the determination of parton distribution functions

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Valerio

    2013-07-01

    The present thesis was devoted to the study of the inclusion of higher-order corrections and heavy quark mass effects in a PDF determination. This has been carried out in the NNPDF framework resulting originally in the NNPDF2.1 sets, which were at a later stage supplemented by the first LHC data leading to the most recent NNPDF2.3 sets. In Chapter 1 the concept of Parton Distribution Function (PDF) was introduced. We have shown how the analytical computation of the Deep-Inelastic-Scattering (DIS) process at order α{sub s} in QCD leads to initial-stale collinear divergences which, using the factorization theorem, can be reabsorbed into the PDFs. The energy dependence of PDFs is fully determined and the task is then reduced to the determination of the x (Bjorken variable) dependence. In Chapter 2 a detailed discussion of the factorization schemes presently available to include heavy quark mass effects into DIS structure functions has been given. It emerged that there are two possible basic approaches to the calculation of the DIS structure functions. In the first approach, the so-called Fixed-Flavour-Number Scheme (FFNS), the calculation is performed retaining the quark mass of the heavy flavours which provide a ''natural'' regulator for the infrared divergences. In the second approach, called Zero-Mass Variable-Flavour-Number Scheme (ZM-VFNS), the heavy quark masses are instead set to zero and this gives rise to the usual final-state collinear divergences that are absorbed into the PDFs. In addition, in the ZM-VFNS, the number of active flavours is assumed to increase by one unity as the energy of the process crosses the energy threshold of a given heavy quark. In order to obtain a factorization scheme that is accurate both at large and low energies, several prescriptions that interpolate between FFNS at low energy and ZM-VFNS at large energy have been proposed and implemented in as many PDF fits. In Chapter 2 they have been described showing how they behave for

  14. Higher order and heavy quark mass effects in the determination of parton distribution functions

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Valerio

    2013-07-01

    The present thesis was devoted to the study of the inclusion of higher-order corrections and heavy quark mass effects in a PDF determination. This has been carried out in the NNPDF framework resulting originally in the NNPDF2.1 sets, which were at a later stage supplemented by the first LHC data leading to the most recent NNPDF2.3 sets. In Chapter 1 the concept of Parton Distribution Function (PDF) was introduced. We have shown how the analytical computation of the Deep-Inelastic-Scattering (DIS) process at order α{sub s} in QCD leads to initial-stale collinear divergences which, using the factorization theorem, can be reabsorbed into the PDFs. The energy dependence of PDFs is fully determined and the task is then reduced to the determination of the x (Bjorken variable) dependence. In Chapter 2 a detailed discussion of the factorization schemes presently available to include heavy quark mass effects into DIS structure functions has been given. It emerged that there are two possible basic approaches to the calculation of the DIS structure functions. In the first approach, the so-called Fixed-Flavour-Number Scheme (FFNS), the calculation is performed retaining the quark mass of the heavy flavours which provide a ''natural'' regulator for the infrared divergences. In the second approach, called Zero-Mass Variable-Flavour-Number Scheme (ZM-VFNS), the heavy quark masses are instead set to zero and this gives rise to the usual final-state collinear divergences that are absorbed into the PDFs. In addition, in the ZM-VFNS, the number of active flavours is assumed to increase by one unity as the energy of the process crosses the energy threshold of a given heavy quark. In order to obtain a factorization scheme that is accurate both at large and low energies, several prescriptions that interpolate between FFNS at low energy and ZM-VFNS at large energy have been proposed and implemented in as many PDF fits. In Chapter 2 they have been described showing

  15. Higher order and heavy quark mass effects in the determination of parton distribution functions

    International Nuclear Information System (INIS)

    Bertone, Valerio

    2013-01-01

    The present thesis was devoted to the study of the inclusion of higher-order corrections and heavy quark mass effects in a PDF determination. This has been carried out in the NNPDF framework resulting originally in the NNPDF2.1 sets, which were at a later stage supplemented by the first LHC data leading to the most recent NNPDF2.3 sets. In Chapter 1 the concept of Parton Distribution Function (PDF) was introduced. We have shown how the analytical computation of the Deep-Inelastic-Scattering (DIS) process at order α s in QCD leads to initial-stale collinear divergences which, using the factorization theorem, can be reabsorbed into the PDFs. The energy dependence of PDFs is fully determined and the task is then reduced to the determination of the x (Bjorken variable) dependence. In Chapter 2 a detailed discussion of the factorization schemes presently available to include heavy quark mass effects into DIS structure functions has been given. It emerged that there are two possible basic approaches to the calculation of the DIS structure functions. In the first approach, the so-called Fixed-Flavour-Number Scheme (FFNS), the calculation is performed retaining the quark mass of the heavy flavours which provide a ''natural'' regulator for the infrared divergences. In the second approach, called Zero-Mass Variable-Flavour-Number Scheme (ZM-VFNS), the heavy quark masses are instead set to zero and this gives rise to the usual final-state collinear divergences that are absorbed into the PDFs. In addition, in the ZM-VFNS, the number of active flavours is assumed to increase by one unity as the energy of the process crosses the energy threshold of a given heavy quark. In order to obtain a factorization scheme that is accurate both at large and low energies, several prescriptions that interpolate between FFNS at low energy and ZM-VFNS at large energy have been proposed and implemented in as many PDF fits. In Chapter 2 they have been described showing how

  16. An accurate method for the determination of unlike potential parameters from thermal diffusion data

    International Nuclear Information System (INIS)

    El-Geubeily, S.

    1997-01-01

    A new method is introduced by means of which the unlike intermolecular potential parameters can be determined from the experimental measurements of the thermal diffusion factor as a function of temperature. The method proved to be easy, accurate, and applicable two-, three-, and four-parameter potential functions whose collision integrals are available. The potential parameters computed by this method are found to provide a faith full representation of the thermal diffusion data under consideration. 3 figs., 4 tabs

  17. Experimental conditions for determination of the neutrino mass hierarchy with reactor antineutrinos

    Directory of Open Access Journals (Sweden)

    Myoung Youl Pac

    2016-01-01

    Full Text Available This article reports the optimized experimental requirements to determine neutrino mass hierarchy using electron antineutrinos (ν¯e generated in a nuclear reactor. The features of the neutrino mass hierarchy can be extracted from the |Δm312| and |Δm322| oscillations by applying the Fourier sine and cosine transforms to the L/E spectrum. To determine the neutrino mass hierarchy above 90% probability, the requirements on the energy resolution as a function of the baseline are studied at sin2⁡2θ13=0.1. If the energy resolution of the neutrino detector is less than 0.04/Eν and the determination probability obtained from Bayes' theorem is above 90%, the detector needs to be located around 48–53 km from the reactor(s to measure the energy spectrum of ν¯e. These results will be helpful for setting up an experiment to determine the neutrino mass hierarchy, which is an important problem in neutrino physics.

  18. Determination of ash content of coal by mass absorption coefficient measurements at two X-ray energies

    International Nuclear Information System (INIS)

    Fookes, R.A.; Gravitis, V.L.; Watt, J.S.

    1977-01-01

    A method for determining the ash content of coal is proposed. It involves measurements proportional to mass absorption coefficients of coal at two X-ray energies. These measurements can be made using X-ray transmission or scatter techniques. Calculations based on transmission of narrow beams of X-rays have shown that ash can be determined to about 1wt%(1 sigma) in coal of widely varying ash content and composition. Experimentally, ash content was determined to 0.67wt% by transmission techniques and 1.0wt% by backscatter techniques in coal samples from the Bulli seam, NSW, Australia, having ash in the range 11-34wt%. For samples with a much wider range of coal composition (7-53wt% ash and 0-25wt% iron in the ash), ash content was determined by backscatter measurements to 1.62wt%. The method produced ash determinations at least as accurate as those produced by the established technique which compensates for variation in iron content of the ash by X-ray fluorescence analysis for iron. Compared with the established technique, it has the advantage of averaging analysis over much larger volumes of coal, but the disadvantage that much more precise measurements of X-ray intensities are required. (author)

  19. [Determination of the distribution of relative molecular mass of organic matter by high pressure size exclusion chromatography with UV and TOC detectors].

    Science.gov (United States)

    Zhang, Han; Dong, Bing-Zhi

    2012-09-01

    An on-line high pressure size exclusion chromatography (HPSEC) with UV and TOC detectors was adapted to examine the distribution of relative molecular mass of natural organic matter (NOM). Through synchronous determination of UV254 and TOC responses in a wide range of relative molecular mass, it was possible to accurately characterize the structure of NOM, especially for some non-aromatic and non-conjugated double bond organics which have low response to UV. It was found that, TOC detector was capable of detecting all kinds of organic matters, including sucrose, sodium alginate and other hydrophilic organic compounds. The sample volume had a positively linear correlation with the TOC response, indicating that the larger volume would produce stronger responses. The effect of ion strength was relatively low, shown by the small decrease of peak area (1.2% ) from none to 0.2 mol x L(-1) NaCl. The pH value of tested samples should be adjusted to neutral or acidic because when the samples were alkaline, the results might be inaccurate. Compared to the sample solvents adopted as ultrapure water, the samples prepared by mobile phase solvents had less interference to salt boundary peak. The on-line HPSEC-UV-TOC can be used accurately to characterize the distribution of relative molecular mass and its four fractions in River Xiang.

  20. Mass Spectrometric Analysis for Nuclear Safeguards

    International Nuclear Information System (INIS)

    Boulyga, S.

    2013-01-01

    The release of man-made radionuclides into the environment results in contamination that carries specific isotopic signatures according to the release scenarios and the previous usage of materials and facilities. In order to trace the origin of such contamination and/or to assess the potential impact on the public and environmental health, it is necessary to determine the isotopic composition and activity concentrations of radionuclides in environmental samples in an accurate and timely fashion. Mass spectrometric techniques, such as thermal ionization mass spectrometry (TIMS), secondary ion mass spectrometry (SIMS), and inductively coupled plasma mass spectrometry (ICP-MS) belong to the most powerful methods for analysis of nuclear and related samples in nuclear safeguards, forensics, and environmental monitoring. This presentation will address the potential of mass spectrometric analysis of actinides at ultra-trace concentration levels, isotopic analysis of micro-samples, age determination of nuclear materials as well as identification and quantification of elemental and isotopic signatures of nuclear samples in general. (author)

  1. An accurate determination of the flux within a slab

    International Nuclear Information System (INIS)

    Ganapol, B.D.; Lapenta, G.

    1993-01-01

    During the past decade, several articles have been written concerning accurate solutions to the monoenergetic neutron transport equation in infinite and semi-infinite geometries. The numerical formulations found in these articles were based primarily on the extensive theoretical investigations performed by the open-quotes transport greatsclose quotes such as Chandrasekhar, Busbridge, Sobolev, and Ivanov, to name a few. The development of numerical solutions in infinite and semi-infinite geometries represents an example of how mathematical transport theory can be utilized to provide highly accurate and efficient numerical transport solutions. These solutions, or analytical benchmarks, are useful as open-quotes industry standards,close quotes which provide guidance to code developers and promote learning in the classroom. The high accuracy of these benchmarks is directly attributable to the rapid advancement of the state of computing and computational methods. Transport calculations that were beyond the capability of the open-quotes supercomputersclose quotes of just a few years ago are now possible at one's desk. In this paper, we again build upon the past to tackle the slab problem, which is of the next level of difficulty in comparison to infinite media problems. The formulation is based on the monoenergetic Green's function, which is the most fundamental transport solution. This method of solution requires a fast and accurate evaluation of the Green's function, which, with today's computational power, is now readily available

  2. Accurate product ion mass spectra of galanthamine derivatives

    Czech Academy of Sciences Publication Activity Database

    Jegorov, A.; Buchta, M.; Sedmera, Petr; Kuzma, Marek; Havlíček, Vladimír

    2006-01-01

    Roč. 41, - (2006), s. 544-548 ISSN 1076-5174 R&D Projects: GA MŠk LC545 Grant - others:XE(XE) MTKD-CT-2004-014407 Institutional research plan: CEZ:AV0Z50200510 Keywords : mass spectrometry * galanthamine Subject RIV: EE - Microbiology, Virology Impact factor: 2.945, year: 2006

  3. Using gravimetric measurement for determination of the mass fraction PM10

    Directory of Open Access Journals (Sweden)

    Nicolae Chirilă

    2011-12-01

    Full Text Available In this paper, we tried to determinate the air pollution level with mass fraction PM10 from Targu Mures area. For this purpose, determinations were made in University Petru Maior’s laboratory, using ADR 1200 S device and in Targu Mures Environmental Department’s laboratory. The results that we obtained show a low level of air pollution with mass fraction PM10 in Targu Mures area.

  4. Screening of 439 Pesticide Residues in Fruits and Vegetables by Gas Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry Based on TOF Accurate Mass Database and Q-TOF Spectrum Library.

    Science.gov (United States)

    Li, Jian-Xun; Li, Xiao-Ying; Chang, Qiao-Ying; Li, Yan; Jin, Ling-He; Pang, Guo-Fang; Fan, Chun-Lin

    2018-05-03

    Because of its unique characteristics of accurate mass full-spectrum acquisition, high resolution, and fast acquisition rates, GC-quadrupole-time-of-flight MS (GC-Q-TOF/MS) has become a powerful tool for pesticide residue analysis. In this study, a TOF accurate mass database and Q-TOF spectrum library of 439 pesticides were established, and the parameters of the TOF database were optimized. Through solid-phase extraction (SPE), whereby pesticides are extracted from fruit and vegetable substrates by using 40 mL 1% acetic acid in acetonitrile (v/v), purified by the Carbon/NH₂ SPE cartridge, and finally detected by GC-Q-TOF/MS, the rapid analysis of 439 pesticides in fruits and vegetables can be achieved. The methodology verification results show that more than 70 and 91% of pesticides, spiked in fruits and vegetables with concentrations of 10 and 100 μg/kg, respectively, saw recoveries that conform to the European Commission's criterion of between 70 and 120% with RSD ≤20%. Eighty-one percent of pesticides have screening detection limits lower than 10 μg/kg, which makes this a reliable analysis technology for the monitoring of pesticide residues in fruits and vegetables. This technology was further validated for its characteristics of high precision, high speed, and high throughput through successful detection of 9817 samples during 2013-2015.

  5. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

    The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated--therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129 Xe + for the determination of 129 I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass

  6. Determination of fusarium mycotoxins in wheat, maize and animal feed using on-line clean-up with high resolution mass spectrometry.

    Science.gov (United States)

    Ates, E; Mittendorf, K; Stroka, J; Senyuva, H

    2013-01-01

    An automated method involving on-line clean-up and analytical separation in a single run using TurboFlow™ reversed phase liquid chromatography coupled to a high resolution mass spectrometer has been developed for the simultaneous determination of deoxynivalenol, T2 toxin, HT2 toxin, zearalenone and fumonisins B1 and B2 in maize, wheat and animal feed. Detection was performed in full scan mode at a resolution of R = 100,000 full width at half maximum with high energy collision cell dissociation for the determination of fragment ions with a mass accuracy below 5 ppm. The extract from homogenised samples, after blending with a 0.1% aqueous mixture of 0.1% formic acid/acetonitrile (43:57) for 45 min, was injected directly onto the TurboFlow™ (TLX) column for automated on-line clean-up followed by analytical separation and accurate mass detection. The TurboFlow™ column enabled specific binding of target mycotoxins, whereas higher molecular weight compounds, like fats, proteins and other interferences with different chemical properties, were removed to waste. Single laboratory method validation was performed by spiking blank materials with mycotoxin standards. The recovery and repeatability was determined by spiking at three concentration levels (50, 100 and 200% of legislative limits) with six replicates. Average recovery, relative standard deviation and intermediate precision values were 71 to 120%, 1 to 19% and 4 to 19%, respectively. The method accuracy was confirmed with certified reference materials and participation in proficiency testing.

  7. Technical Note: Using experimentally determined proton spot scanning timing parameters to accurately model beam delivery time.

    Science.gov (United States)

    Shen, Jiajian; Tryggestad, Erik; Younkin, James E; Keole, Sameer R; Furutani, Keith M; Kang, Yixiu; Herman, Michael G; Bues, Martin

    2017-10-01

    To accurately model the beam delivery time (BDT) for a synchrotron-based proton spot scanning system using experimentally determined beam parameters. A model to simulate the proton spot delivery sequences was constructed, and BDT was calculated by summing times for layer switch, spot switch, and spot delivery. Test plans were designed to isolate and quantify the relevant beam parameters in the operation cycle of the proton beam therapy delivery system. These parameters included the layer switch time, magnet preparation and verification time, average beam scanning speeds in x- and y-directions, proton spill rate, and maximum charge and maximum extraction time for each spill. The experimentally determined parameters, as well as the nominal values initially provided by the vendor, served as inputs to the model to predict BDTs for 602 clinical proton beam deliveries. The calculated BDTs (T BDT ) were compared with the BDTs recorded in the treatment delivery log files (T Log ): ∆t = T Log -T BDT . The experimentally determined average layer switch time for all 97 energies was 1.91 s (ranging from 1.9 to 2.0 s for beam energies from 71.3 to 228.8 MeV), average magnet preparation and verification time was 1.93 ms, the average scanning speeds were 5.9 m/s in x-direction and 19.3 m/s in y-direction, the proton spill rate was 8.7 MU/s, and the maximum proton charge available for one acceleration is 2.0 ± 0.4 nC. Some of the measured parameters differed from the nominal values provided by the vendor. The calculated BDTs using experimentally determined parameters matched the recorded BDTs of 602 beam deliveries (∆t = -0.49 ± 1.44 s), which were significantly more accurate than BDTs calculated using nominal timing parameters (∆t = -7.48 ± 6.97 s). An accurate model for BDT prediction was achieved by using the experimentally determined proton beam therapy delivery parameters, which may be useful in modeling the interplay effect and patient throughput. The model may

  8. Tracer test method and process data reconciliation based on VDI 2048. Comparison of two methods for highly accurate determination of feedwater massflow at NPP Beznau

    International Nuclear Information System (INIS)

    Hungerbuehler, T.; Langenstein, M.

    2007-01-01

    The feedwater mass flow is the key measured variable used to determine the thermal reactor output in a nuclear power plant. Usually this parameter is recorded via venturi nozzles of orifice plates. The problem with both principles of measurement, however, is that an accuracy of below 1% cannot be reached. In order to make more accurate statements about the feedwater amounts recirculated in the water-steam cycle, tracer measurements that offer an accuracy of up to 0.2% are used. In the NPP Beznau both methods have been used in parallel to determine the feedwater flow rates in 2004 (unit 1) and 2005 (unit 2). Comparison of the results shows that a high level of agreement is obtained between the results of the reconciliation and the results of the tracer measurements. As a result of the findings of this comparison, a high level of acceptance of process data reconciliation based on VDI 2048 was achieved. (orig.)

  9. The determination of low level trace elements in coals by laser ablation-inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Booth, C.A.; Spears, D.A.; Krause, P.; Cox, A.G. [University of Sheffield, Sheffield (United Kingdom). Dept. of Earth Sciences

    1999-11-01

    The rapid determination of elements present in low level concentrations in bituminous coals is possible using laser abalation-inductively coupled plasma-mass spectrometry (l.a.-i.c.p.-m.s.). A wide range of trace elements can routinely be determined using this technique but it is for environmentally sensitive elements, such as As, Cd, Mo, Sb, Se and Hg, that it is of most use due to the low levels of detection. Calibration of the i.c.p.-m.s. was achieved using a series of uncertified coals and the method evaluated using the South African certified coals, Sarm 18, 19 and 20. A critical evaluation of the data obtained shows that for many of the elements studied the results obtained are both accurate and precise, even at very low concentrations, with the limits of detection for all of the elements being in the {mu}g/kg (parts per billion) range. 6 refs., 3 figs., 9 tabs.

  10. Precise determination of 40Ti mass by measuring the 40Sc isospin analogue state

    International Nuclear Information System (INIS)

    Liu Weiping; Hellstroem, M.; Collatz, R.; Benlliure, J.; Cortina, G.D.; Farget, F.; Grawe, H.; Hu, Z.; Iwasa, N.; Pfuetzner, M.; Roeckl, E.; Chulkov, L.; Piechaczek, A.; Raabe, R.; Reusen, I.; Vancraeynest, G.; Woehr, A.

    2001-01-01

    The mass of 40 Ti has been determined by using the isobaric multiplet mass equation method. The experimental data of the 40 Ti β-decay were used to determine the level of the isospin analogue state of 40 Sc. The ground-state mass excess and the Q EC value for 40 Ti were determined to be -9060 +- 12 keV and 11466 +- 13 keV, respectively

  11. Penning trap mass measurements on nobelium isotopes

    International Nuclear Information System (INIS)

    Dworschak, M.; Block, M.; Ackermann, D.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Vorobyev, G. K.; Audi, G.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Eliseev, S.; Ketter, J.; Fleckenstein, T.; Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ketelaer, J.; Kluge, H.-J.

    2010-01-01

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt allows accurate mass measurements of radionuclides, produced in fusion-evaporation reactions and separated by the velocity filter SHIP from the primary beam. Recently, the masses of the three nobelium isotopes 252-254 No were determined. These are the first direct mass measurements of transuranium elements, which provide new anchor points in this region. The heavy nuclides were produced in cold-fusion reactions by irradiating a PbS target with a 48 Ca beam, resulting in production rates of the nuclei of interest of about one atom per second. In combination with data from decay spectroscopy our results are used to perform a new atomic-mass evaluation in this region.

  12. Precision and accuracy of β gauge for aerosol mass determinations

    International Nuclear Information System (INIS)

    Courtney, W.J.; Shaw, R.W.; Dzabay, T.G.

    1982-01-01

    Results of an experimental determination of the precision and the accuracy of a β-ray attenuation method for measurement of aerosol mass are presented. The instrumental precision for a short-term experiment was 25 μg for a 6.5-cm 2 deposit collected on approximately 1 mg/cm 2 Teflon filters; for a longer-term experiment the precision was 27 μg. The precision of the gravimetric determinations of aerosol deposits was 22 μg for Teflon filters weighed to 1 μg. Filter reorientation and air density changes that were able adversely to affect the β-ray attenuation results are discussed. β-ray attenuation results are in good agreement with gravimetric measurements on the same filter-collected aerosols. Using dichotomous samplers in Durham, NC, we collected 136 aerosol samples on Teflon filters in two size ranges. A regression line was calculated implicitly assuming errors in both measurements of mass. The 90% confidence intervals lay within 21 μg of the regression line for mean fine fraction aerosol mass loadings of 536 μg and within 19 μg of the regression line for mean coarse fraction aerosol mass loadings of 349 μg. Any bias between gravimetric and β-gauge mass measurements was found to be less than 5%

  13. [Determination of 21 fragrance allergens in toys by gas chromatography-ion trap mass spectrometry].

    Science.gov (United States)

    Lü, Qing; Zang, Qing; Bai, Hua; Li, Haiyu; Kang, Suyuan; Wang, Chao

    2012-05-01

    A method of gas chromatography-ion trap mass spectrometry (GC-IT-MS) was developed for the determination of 21 fragrance allergens in sticker toys, plush toys and plastic toys. The experimental conditions, such as sample pretreatment conditions, and the analytical conditions of GC-IT-MS, were optimized. The sticker toy samples and plush toy samples were extracted with acetone by ultrasonic wave, and the extracts were separated on an Agilent HP-1 MS column (50 m x 0.2 mm x 0.5 microm), then determined by IT-MS and quantified by external standard method. The plastic toy samples were extracted by the dissolution-precipitation approach, cleaned up with an Envi-carb solid phase extraction column and concentrated by rotary evaporation and nitrogen blowing, then determined by GC-IT-MS and quantified by external standard method. The calibration curves showed good linearity in the range of 0.002-50 mg/L with the correlation coefficients greater than 0.996 8. The limits of quantification (LOQ, S/N > 10) were 0.02-40 mg/kg. The average recoveries of the target compounds spiked in the sample at three concentration levels were in the range of 82.2%-110.8% with the relative standard deviations (RSDs) of 0.6%-10.5%. These results show that this method is accurate and sensitive for the qualitative and quantitative determination of the 21 fragrance allergens in the 3 types of toys.

  14. Comprehensive and accurate tracking of carbon origin of LC-tandem mass spectrometry collisional fragments for 13C-MFA.

    Science.gov (United States)

    Kappelmann, Jannick; Klein, Bianca; Geilenkirchen, Petra; Noack, Stephan

    2017-03-01

    In recent years the benefit of measuring positionally resolved 13 C-labeling enrichment from tandem mass spectrometry (MS/MS) collisional fragments for improved precision of 13 C-Metabolic Flux Analysis ( 13 C-MFA) has become evident. However, the usage of positional labeling information for 13 C-MFA faces two challenges: (1) The mass spectrometric acquisition of a large number of potentially interfering mass transitions may hamper accuracy and sensitivity. (2) The positional identity of carbon atoms of product ions needs to be known. The present contribution addresses the latter challenge by deducing the maximal positional labeling information contained in LC-ESI-MS/MS spectra of product anions of central metabolism as well as product cations of amino acids. For this purpose, we draw on accurate mass spectrometry, selectively labeled standards, and published fragmentation pathways to structurally annotate all dominant mass peaks of a large collection of metabolites, some of which with a complete fragmentation pathway. Compiling all available information, we arrive at the most detailed map of carbon atom fate of LC-ESI-MS/MS collisional fragments yet, comprising 170 intense and structurally annotated product ions with unique carbon origin from 76 precursor ions of 72 metabolites. Our 13 C-data proof that heuristic fragmentation rules often fail to yield correct fragment structures and we expose common pitfalls in the structural annotation of product ions. We show that the positionally resolved 13 C-label information contained in the product ions that we structurally annotated allows to infer the entire isotopomer distribution of several central metabolism intermediates, which is experimentally demonstrated for malate using quadrupole-time-of-flight MS technology. Finally, the inclusion of the label information from a subset of these fragments improves flux precision in a Corynebacterium glutamicum model of the central carbon metabolism.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-17

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

  16. Determining mass-to-light ratios in elliptical galaxies

    International Nuclear Information System (INIS)

    Mathews, W.G.

    1988-01-01

    If the endstate of cooling hot gas in elliptical galaxies is a population of optically dark, low-mass stars near the galactic cores, the mass-to-light ratio could be expected to vary significantly with projected radius. No strong variation in M/L is observed. To investigate the sensitivity and reliability of observational mass-to-light determinations for a variety of galactic parameters, model galaxies having de Vaucouleurs profiles (but with central cores and outer cutoffs), variable velocity ellipsoid structure, and extended dark halos are constructed. Spurious radial variations in M/L can occur when none are present if the properties of the galactic models are processed similar to observational data. Conversely, when a population of diffuse dark stellar matter is added near the galactic cores, large gradients in M/L can escape detection. However, the magnitude of the central velocity dispersion and its variation with projected radius within the effective radius both suggest that a component of dark stars is unlikely to be more massive than about 30 times the core mass of luminous stars. This restriction is important in establishing the initial mass function of stars in elliptical galaxies and the history of winds and cooling inflows in the interstellar medium. 35 references

  17. Using ab initio 'data' to accurately determine the fourth density virial coefficient of helium

    International Nuclear Information System (INIS)

    Moldover, Michael R.; McLinden, Mark O.

    2010-01-01

    We combine accurate ab initio calculations of the second and third density virial coefficients, B(T) and C(T), of 4 He with measurements of its (p-ρ-T) behavior to determine the fourth density virial coefficient D(T). The measurements were made with a two-sinker, magnetic-suspension densimeter at pressures up to 38 MPa. The measurements on isotherms from T = 223 K to T = 323 K were previously published; new measurements from T = 323 K to T = 500 K are presented here. On each isotherm, a regression of the virial expansion was constrained to the ab initio values of B(T) and C(T); the regression determined D(T) as well as two apparatus-dependent parameters that compensated for systematic errors in the measurements. The percentage uncertainties of D(T) ranged from 2.6% at T = 223 K to 9.5% at T = 400 K to 24.7% at T = 500 K, where these uncertainties are expanded uncertainties with coverage factor of k = 2 corresponding to a 95% confidence interval. These uncertainties are 1/6th of the uncertainty obtained without the ab initio values of B(T) and C(T). The apparatus-dependent parameters can be used to calibrate the densimeter, and this will reduce the uncertainty of other measurements made with this two-sinker densimeter. The new values of D(T) will find applications in accurate gas metrology, such as a primary pressure standard based on the refractive index of helium.

  18. Accurate determination of 129I, 41Ca and 10Be long-lived radionuclides concentrations in spent resins from the nuclear industry by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Nottoli-Lepage, E.

    2013-01-01

    Radiological characterization of nuclear waste is essential for the management of storage sites. More particularly, determining the concentration of Long-Lived Radionuclides (LLRN) is fundamental for their long term management. This study focuses on the determination of three LLRN concentrations, i.e. 129 I (T 1/2 = 15.7*10 6 a), 41 Ca (T 1/2 = 9.94*10 4 a) and 10 Be (T 1/2 = 1.387*10 6 a), in ion exchange resins used for primary fluid purification in Pressurized Water Reactors (PWR). To benefit from the Accelerator Mass Spectrometry (AMS) technique allowing to measure extremely low levels of nuclide concentrations, analytical procedures including: 1) sample dissolution; 2) selective and quantitative extraction of the analyte; and, 3) analyte conditioning for AMS measurements, were developed. Applied on spent resin samples collected at a 900 MW PWR, the procedures developed for each studied LLRN allowed their quantitative recovery and their selective extraction from β-γ emitters and isobars. The concentration measurements of the LLRN of interest were then performed on the Accelerator Mass Spectrometry national facility ASTER housed by the Centre Europeen de Recherche et d'Enseignement des Geosciences de l'Environnement (CEREGE, Aix-en-Provence). 129 I, 41 Ca and 10 Be concentrations in spent resins were measured to be about 10 ng/g, 20 pg/g and 4 ng/g of dry resin, respectively. Considering 129 I and 41 Ca, the measured concentrations agree with those assessed from scaling factors established relatively to easily measured gamma emitters ( 137 Cs and 60 Co). For 10 Be, the presented results are significantly different from expected values but are in agreement with previous ICP-MS results. (author) [fr

  19. Can tritiated water-dilution space accurately predict total body water in chukar partridges

    International Nuclear Information System (INIS)

    Crum, B.G.; Williams, J.B.; Nagy, K.A.

    1985-01-01

    Total body water (TBW) volumes determined from the dilution space of injected tritiated water have consistently overestimated actual water volumes (determined by desiccation to constant mass) in reptiles and mammals, but results for birds are controversial. We investigated potential errors in both the dilution method and the desiccation method in an attempt to resolve this controversy. Tritiated water dilution yielded an accurate measurement of water mass in vitro. However, in vivo, this method yielded a 4.6% overestimate of the amount of water (3.1% of live body mass) in chukar partridges, apparently largely because of loss of tritium from body water to sites of dissociable hydrogens on body solids. An additional source of overestimation (approximately 2% of body mass) was loss of tritium to the solids in blood samples during distillation of blood to obtain pure water for tritium analysis. Measuring tritium activity in plasma samples avoided this problem but required measurement of, and correction for, the dry matter content in plasma. Desiccation to constant mass by lyophilization or oven-drying also overestimated the amount of water actually in the bodies of chukar partridges by 1.4% of body mass, because these values included water adsorbed onto the outside of feathers. When desiccating defeathered carcasses, oven-drying at 70 degrees C yielded TBW values identical to those obtained from lyophilization, but TBW was overestimated (0.5% of body mass) by drying at 100 degrees C due to loss of organic substances as well as water

  20. Preoperative core needle biopsy is accurate in determining molecular subtypes in invasive breast cancer

    International Nuclear Information System (INIS)

    Chen, Xiaosong; Yuan, Ying; Fei, Xiaochun; Jin, Xiaolong; Shen, Kunwei; Sun, Long; Mao, Yan; Zhu, Siji; Wu, Jiayi; Huang, Ou; Li, Yafen; Chen, Weiguo; Wang, Jianhua

    2013-01-01

    Estrogen receptor (ER), progesterone receptor (PgR), HER2, and Ki67 have been increasingly evaluated by core needle biopsy (CNB) and are recommended for classifying breast cancer into molecular subtypes. However, the concordance rate between CNB and open excision biopsy (OEB) has not been well documented. Patients with paired CNB and OEB samples from Oct. 2009 to Feb. 2012 in Ruijin Hospital were included. ER, PgR, HER2, and Ki67 were determined by immunohistochemistry (IHC). Patients with HER2 IHC 2+ were further examined by FISH. Cutoff value for Ki67 high expression was 14%. Molecular subtypes were constructed as follows: Luminal A, Luminal B, Triple Negative, and HER2 positive. There were 298 invasive breast cancer patients analyzed. Concordance rates for ER, PgR, and HER2 were 93.6%, 85.9%, and 96.3%, respectively. Ki67 expression was slightly higher in OEB than in CNB samples (29.3% vs. 26.8%, P = 0.046). Good agreement (κ = 0.658) was demonstrated in evaluating molecular subtypes between CNB and OEB, with a concordance rate of 77.2%. We also used a different Ki67 cutoff value (20%) for determining Luminal A and B subtypes in HR (hormone receptor) +/HER2- diseases and the overall concordance rate was 79.2%. However, using a cut-point of Ki67 either 14% or 20% for both specimens, there will be about 14% of HR+/HER2- specimens that are called Luminal A on CNB and Luminal B on OEB. CNB was accurate in determining ER, PgR, and HER2 status as well as non-Luminal molecular subtypes in invasive breast cancer. Ki67 should be retested on OEB samples in HR+/HER2- patients to accurately distinguish Luminal A from B tumors

  1. Determination of the mass-ratio distribution, I: single-lined spectroscopic binary stars

    NARCIS (Netherlands)

    Hogeveen, S.J.

    1992-01-01

    For single-lined spectroscopic binary stars (sbi), the mass ratio q = Msec=Mprim is calculated from the mass function f(m), which is determined from observations. For statistical investigations of the mass-ratio distribution, the term sin^3 i, that remains in the cubic equation from which q is

  2. Determining Energies and Cross Sections of Individual Ions Using Higher-Order Harmonics in Fourier Transform Charge Detection Mass Spectrometry (FT-CDMS).

    Science.gov (United States)

    Harper, Conner C; Elliott, Andrew G; Lin, Haw-Wei; Williams, Evan R

    2018-06-02

    A general method for in situ measurements of the energy of individual ions trapped and weighed using charge detection mass spectrometry (CDMS) is described. Highly charged (> 300 e), individual polyethylene glycol (PEG) ions are trapped and oscillate within an electrostatic trap, producing a time domain signal. A segmented Fourier transform (FT) of this signal yields the temporal evolution of the fundamental and harmonic frequencies of ion motion throughout the 500-ms trap time. The ratio of the fundamental frequency and second harmonic (HAR) depends on the ion energy, which is an essential parameter for measuring ion mass in CDMS. This relationship is calibrated using simulated ion signals, and the calibration is compared to the HAR values measured for PEG ion signals where the ion energy was also determined using an independent method that requires that the ions be highly charged (> 300 e). The mean error of 0.6% between the two measurements indicates that the HAR method is an accurate means of ion energy determination that does not depend on ion size or charge. The HAR is determined dynamically over the entire trapping period, making it possible to observe the change in ion energy that takes place as solvent evaporates from the ion and collisions with background gas occur. This method makes it possible to measure mass changes, either from solvent evaporation or from molecular fragmentation (MS n ), as well as the cross sections of ions measured using CDMS. Graphical Abstract.

  3. Determination of naphthalene-derived compounds in apples by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Esparza, X; Moyano, E; Cosialls, J R; Galceran, M T

    2013-06-11

    Naphthylacetic acid, naphthyloxy acetic acid and naphthylacetamide belong to a group of synthetic substances known as "auxin-like" compounds which are used as growth regulators in vegetables and fruits due to their structure similarities with the indoleacetic acid, the most important plant auxin. This paper reports a selective, sensitive and fast ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of naphthylacetamide (NAD) and the isomers (α and β) of naphthylacetic acid (NAA) and naphthyloxy acetic (NOA) acid in apple samples. A baseline separation between the respective isomers was achieved using an RP-Amide column with gradient elution. The UHPLC-MS/MS method developed, using electrospray and selected reaction monitoring (SRM) acquisition mode led to a reliable determination of these family of compounds in apple samples at low quantitation levels, down to 1.0 μg kg(-1) and 0.25 μg kg(-1) respectively. For confirmation of NAA accurate mass measurement is proposed giving at these conditions quantitation limits of 10 μg kg(-1) for this compound. The UHPLC-MS/MS method developed was used for the analysis of apple samples harvested in three different apple fields from Lleida (Spain) during the blooming period. NAD and NAA were found in samples collected during 4-5 weeks after application at concentrations between the quantification limits and 43 μg kg(-1) and 24 μg kg(-1), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Determination of B and Li in nuclear materials by secondary-ion mass spectrometry

    International Nuclear Information System (INIS)

    Eby, R.E.; Christie, W.H.

    1981-01-01

    Secondary ion mass spectrometry (SIMS) was used to perform mass and isotopic analysis for B and Li in samples that are not readily amenable to more conventional mass spectrometric techniques (e.g., surface ionization, electron impact, etc.). In this paper three specific applications of SIMS analysis to nuclear materials are discussed: first, the quantitative determination of B and its isotopic composition in borosilicate glasses; second, the determination of the isotopic composition of B and Li in irradiated nuclear-grade aluminum oxide/boron carbide composite pellets, and, lastly, the quantitative and isotopic determination of B and Li in highly radioactive solutions of unknown composition

  5. Dispersive liquid-liquid microextraction and gas chromatography accurate mass spectrometry for extraction and non-targeted profiling of volatile and semi-volatile compounds in grape marc distillates.

    Science.gov (United States)

    Fontana, Ariel; Rodríguez, Isaac; Cela, Rafael

    2018-04-20

    The suitability of dispersive liquid-liquid microextraction (DLLME) and gas chromatography accurate mass spectrometry (GC-MS), based on a time-of-flight (TOF) MS analyzer and using electron ionization (EI), for the characterization of volatile and semi-volatile profiles of grape marc distillates (grappa) are evaluated. DLLME conditions are optimized with a selection of compounds, from different chemical families, present in the distillate spirit. Under final working conditions, 2.5 mL of sample and 0.5 mL of organic solvents are consumed in the sample preparation process. The absolute extraction efficiencies ranged from 30 to 100%, depending on the compound. For the same sample volume, DLLME provided higher responses than solid-phase microextraction (SPME) for most of the model compounds. The GC-EI-TOF-MS records of grappa samples were processed using a data mining non-targeted search algorithm. In this way, chromatographic peaks and accurate EI-MS spectra of sample components were linked. The identities of more than 140 of these components are proposed from comparison of their accurate spectra with those in a low resolution EI-MS database, accurate masses of most intense fragment ions of known structure, and available chromatographic retention index. The use of chromatographic and spectral data, associated to the set of components mined from different grappa samples, for multivariate analysis purposes is also illustrated in the study. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Physical consequences of the alpha/beta rule which accurately calculates particle masses

    Energy Technology Data Exchange (ETDEWEB)

    Greulich, Karl Otto [Fritz Lipmann Institute, Beutenbergstr.11, D07745 Jena (Germany)

    2015-07-01

    Using the fine structure constant α (=1/137.036), the proton vs. electron mass ratio β (= 1836.2) and the integers m and n, the α/β rule: m{sub particle} = α{sup -n} x β m x 27.2 eV/c{sup 2} allows almost exact calculation of particle masses. (K.O.Greulich, DPG Spring meeting 2014, Mainz, T99.4) With n=2, m=0 the electron mass becomes 510.79 keV/c{sup 2} (experimental 511 keV/c{sup 2}) With n=2, m=1 the proton mass is 937.9 MeV/c{sup 2} (literature 938.3 MeV/c{sup 2}). For n=3 and m=1 a particle with 128.6 GeV/c{sup 2} close to the reported Higgs mass, is expected. For n=14 and m=-1 the Planck mass results. The calculated masses for gauge bosons and for quarks have similar accuracy. All masses fit into the same scheme (the alpha/beta rule), indicating that non of these particle masses play an extraordinary role. Particularly, the Higgs Boson, often termed the *God particle* plays in this sense no extraordinary role. In addition, particle masses are intimately correlated with the fine structure constant α. If particle masses have been constant over all times, α must have been constant over these times. In addition, the ionization energy of the hydrogen atom (13.6 eV) needs to have been constant if particle masses have been unchanged or vice versa. In conclusion, the α/β rule needs to be taken into account when cosmological models are developed.

  7. Screening of 485 Pesticide Residues in Fruits and Vegetables by Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry Based on TOF Accurate Mass Database and QTOF Spectrum Library.

    Science.gov (United States)

    Pang, Guo-Fang; Fan, Chun-Lin; Chang, Qiao-Ying; Li, Jian-Xun; Kang, Jian; Lu, Mei-Ling

    2018-03-22

    This paper uses the LC-quadrupole-time-of-flight MS technique to evaluate the behavioral characteristics of MSof 485 pesticides under different conditions and has developed an accurate mass database and spectra library. A high-throughput screening and confirmation method has been developed for the 485 pesticides in fruits and vegetables. Through the optimization of parameters such as accurate mass number, time of retention window, ionization forms, etc., the method has improved the accuracy of pesticide screening, thus avoiding the occurrence of false-positive and false-negative results. The method features a full scan of fragments, with 80% of pesticide qualitative points over 10, which helps increase pesticide qualitative accuracy. The abundant differences of fragment categories help realize the effective separation and qualitative identification of isomer pesticides. Four different fruits and vegetables-apples, grapes, celery, and tomatoes-were chosen to evaluate the efficiency of the method at three fortification levels of 5, 10, and 20 μg/kg, and satisfactory results were obtained. With this method, a national survey of pesticide residues was conducted between 2012 and 2015 for 12 551 samples of 146 different fruits and vegetables collected from 638 sampling points in 284 counties across 31 provincial capitals/cities directly under the central government, which provided scientific data backup for ensuring pesticide residue safety of the fruits and vegetables consumed daily by the public. Meanwhile, the big data statistical analysis of the new technique also further proves it to be of high speed, high throughput, high accuracy, high reliability, and high informatization.

  8. Validation of a new noniterative method for accurate position determination of a scanning laser vibrometer

    Science.gov (United States)

    Pauwels, Steven; Boucart, Nick; Dierckx, Benoit; Van Vlierberghe, Pieter

    2000-05-01

    The use of a scanning laser Doppler vibrometer for vibration testing is becoming a popular instrument. The scanning laser Doppler vibrometer is a non-contacting transducer that can measure many points at a high spatial resolution in a short time. Manually aiming the laser beam at the points that need to be measured is very time consuming. In order to use it effectively, the position of the laser Doppler vibrometer needs to be determined relative to the structure. If the position of the laser Doppler vibrometer is known, any visible point on the structure can be hit and measured automatically. A new algorithm for this position determination is developed, based on a geometry model of the structure. After manually aiming the laser beam at 4 or more known points, the laser position and orientation relative to the structure is determined. Using this calculated position and orientation a list with the mirror angles for every measurement point is generated, which is used during the measurement. The algorithm is validated using 3 practical cases. In the first case a plate is used of which the points are measured very accurately, so the geometry model is assumed to be perfect. The second case is a brake disc. Here the geometry points are measured with a ruler, thus not so accurate. The final validation is done on a body in white of a car. A reduced finite element model is used as geometry model. This calibration shows that the new algorithm is very effective and practically usable.

  9. Determination of the LEP centre-of-mass energy from Z$\\gamma$ events

    CERN Document Server

    Barate, R.; Ghez, Philippe; Goy, C.; Jezequel, S.; Lees, J.P.; Martin, F.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Przysiezniak, H.; Alemany, R.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Juste, A.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Morawitz, P.; Pacheco, A.; Park, I.C.; Riu, I.; Colaleo, A.; Creanza, D.; De Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Becker, U.; Boix, G.; Cattaneo, M.; Cerutti, F.; Ciulli, V.; Dissertori, G.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Greening, T.C.; Halley, A.W.; Hansen, J.B.; Harvey, John; Janot, P.; Jost, B.; Lehraus, I.; Leroy, O.; Loomis, C.; Maley, P.; Mato, P.; Minten, A.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schmitt, M.; Schneider, O.; Spagnolo, P.; Tejessy, W.; Teubert, F.; Tomalin, I.R.; Tournefier, E.; Wright, A.E.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Dessagne, S.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Rensch, B.; Waananen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Blondel, A.; Brient, J.C.; Machefert, F.; Rouge, A.; Swynghedauw, M.; Tanaka, R.; Valassi, A.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Cavanaugh, R.; Corden, M.; Georgiopoulos, C.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Chalmers, M.; Curtis, L.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raeven, B.; Raine, C.; Smith, D.; Teixeira-Dias, P.; Thompson, A.S.; Ward, J.J.; Buchmuller, O.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Goodsir, S.; Marinelli, N.; Martin, E.B.; Nash, J.; Nowell, J.; Sciaba, A.; Sedgbeer, J.K.; Thomson, Evelyn J.; Williams, M.D.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C.K.; Buck, P.G.; Ellis, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Robertson, N.A.; Smizanska, M.; Williams, M.I.; Giehl, I.; Holldorfer, F.; Jakobs, K.; Kleinknecht, K.; Krocker, M.; Muller, A.S.; Nurnberger, H.A.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Aubert, J.J.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Ealet, A.; Fouchez, D.; Motsch, F.; Payre, P.; Rousseau, D.; Talby, M.; Thulasidas, M.; Tilquin, A.; Aleppo, M.; Antonelli, M.; Gilardoni, Simone S.; Ragusa, F.; Buescher, Volker; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Schael, S.; Settles, R.; Seywerd, H.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Azzurri, P.; Boucrot, J.; Callot, O.; Chen, S.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Jacholkowska, A.; Kado, M.; Lefrancois, J.; Serin, L.; Veillet, J.J.; Videau, I.; de Viviede Regie, J.B.; Zerwas, D.; Bagliesi, Giuseppe; Bettarini, S.; Boccali, T.; Bozzi, C.; Calderini, G.; Dell'Orso, R.; Ferrante, I.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P.S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sguazzoni, G.; Tenchini, R.; Vannini, C.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Coles, J.; Cowan, G.; Green, M.G.; Hutchcroft, D.E.; Jones, L.T.; Medcalf, T.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Botterill, D.R.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Thompson, J.C.; Bloch-Devaux, Brigitte; Colas, P.; Fabbro, B.; Faif, G.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Rosowsky, A.; Trabelsi, A.; Tuchming, B.; Vallage, B.; Black, S.N.; Dann, J.H.; Kim, H.Y.; Konstantinidis, N.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Hodgson, P.N.; Kelly, M.S.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Hess, J.; Misiejuk, A.; Prange, G.; Sieler, U.; Giannini, G.; Gobbo, B.; Putz, J.; Rothberg, J.; Wasserbaech, S.; Williams, R.W.; Armstrong, S.R.; Elmer, P.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; McNamara, P.A., III; Nielsen, J.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

    1999-01-01

    Radiative returns to the Z resonance (Z\\gamma events) are used to determine the LEP2 centre-of-mass energy from the data collected with the ALEPH detector in 1997. The average centre-of-mass energy is measured to be: E_CM = 182.50 +- 0.19 (stat.) +- 0.08 (syst.) GeV in good agreement with the precise determination by the LEP energy working group of 182.652 +- 0.050 GeV. If applied to the measurement of the W mass, its precision translates into a systematic error on M_W which is smaller than the statistical error achieved from the corresponding dataset.

  10. Prediction of collision cross section and retention time for broad scope screening in gradient reversed-phase liquid chromatography-ion mobility-high resolution accurate mass spectrometry

    DEFF Research Database (Denmark)

    Mollerup, Christian Brinch; Mardal, Marie; Dalsgaard, Petur Weihe

    2018-01-01

    artificial neural networks (ANNs). Prediction was based on molecular descriptors, 827 RTs, and 357 CCS values from pharmaceuticals, drugs of abuse, and their metabolites. ANN models for the prediction of RT or CCS separately were examined, and the potential to predict both from a single model......Exact mass, retention time (RT), and collision cross section (CCS) are used as identification parameters in liquid chromatography coupled to ion mobility high resolution accurate mass spectrometry (LC-IM-HRMS). Targeted screening analyses are now more flexible and can be expanded for suspect...

  11. Determination of rare earth elements in environmental matrices by sector-field inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Riondato, J; Vanhaecke, F; Moens, L; Dams, R

    2001-07-01

    In the framework of an international certification campaign, sector-field inductively coupled plasma mass spectrometry (sector-field ICP-MS) was used for the accurate determination of the rare earth elements in five candidate reference materials: aquatic plant, calcareous soil, mussel tissue, river sediment, and tuna muscle. All samples were taken into solution by use of microwave-assisted or mixed microwave-assisted / open beaker acid digestion. Subsequently, the samples were appropriately diluted and subjected to ICP-MS analysis. Except for Sc, all the elements involved were determined at low mass resolution (R = 300). For Sc, application of a higher resolution setting (R = 3,000) was required to separate the analyte signal from those of several molecular ions which gave rise to spectral overlap at low mass resolution. Some of the heavier REE can also suffer from spectral overlap attributed to the occurrence of oxide ions (MO+) of the lighter REE and Ba. This spectral overlap could be successfully overcome by mathematical correction. Matrix effects were overcome by use of two carefully selected internal standards, such that external calibration could be used. On each occasion, a geological reference material was analyzed as a quality-control sample and the reliability of all results obtained was additionally checked by means of chondrite normalization. For tuna muscle the content of all REE was below the limit of detection. For calcareous soil and river sediment, low to sub microg g(-1) values were observed, whereas the REE content of aquatic plant and mussel tissue was considerably lower (low to sub ng g(-1)). Overall, the results obtained were in excellent agreement with the average values, calculated on the basis of all "accepted" values, obtained in different laboratories using different techniques.

  12. Histamine quantification in human plasma using high resolution accurate mass LC-MS technology.

    Science.gov (United States)

    Laurichesse, Mathieu; Gicquel, Thomas; Moreau, Caroline; Tribut, Olivier; Tarte, Karin; Morel, Isabelle; Bendavid, Claude; Amé-Thomas, Patricia

    2016-01-01

    Histamine (HA) is a small amine playing an important role in anaphylactic reactions. In order to identify and quantify HA in plasma matrix, different methods have been developed but present several disadvantages. Here, we developed an alternative method using liquid chromatography coupled with an ultra-high resolution and accurate mass instrument, Q Exactive™ (Thermo Fisher) (LCHRMS). The method includes a protein precipitation of plasma samples spiked with HA-d4 as internal standard (IS). LC separation was performed on a C18 Accucore column (100∗2.1mm, 2.6μm) using a mobile phase containing nonafluoropentanoic acid (3nM) and acetonitrile with 0.1% (v/v) formic acid on gradient mode. Separation of analytes was obtained within 10min. Analysis was performed from full scan mode and targeted MS2 mode using a 5ppm mass window. Ion transitions monitored for targeted MS2 mode were 112.0869>95.0607m/z for HA and 116.1120>99.0855m/z for HA-d4. Calibration curves were obtained by adding standard calibration dilution at 1 to 180nM in TrisBSA. Elution of HA and IS occurred at 4.1min. The method was validated over a range of concentrations from 1nM to 100nM. The intra- and inter-run precisions were <15% for quality controls. Human plasma samples from 30 patients were analyzed by LCHRMS, and the results were highly correlated with those obtained using the gold standard radioimmunoassay (RIA) method. Overall, we demonstrate here that LCHRMS is a sensitive method for histamine quantification in biological human plasmas, suitable for routine use in medical laboratories. In addition, LCHRMS is less time-consuming than RIA, avoids the use of radioactivity, and could then be considered as an alternative quantitative method. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  13. Evaluation difference between mass of received cargo and mass of handed over the cargo in the determination of the masses by draft survey

    Directory of Open Access Journals (Sweden)

    Yakuta I. V.

    2016-12-01

    Full Text Available The paper provides the analysis of problems associated with the evaluation of difference between the mass of received and handed over cargo in determining the masses by draft survey and due to the difference in the measurement conditions at the loading and unloading ports (due to the change errors in various stages of the measurement procedures. The errors that may arise in determining the mass of the cargo due to roughness when measuring draft, due to using the inclinometer to determine the draft from one of boards, due to instrumental errors in the determination of the density of seawater, due to other possible errors have been investigated and evaluated. To estimate the errors of draft due to heaving and errors of inclinometer some formula are to be applied, their derivation has been done in this paper. It has been recommended to use the traditional formula of high-speed drawdown with the replacement of vessel speed on current rate to calculate the error of precipitation arising from the drawdowns ship on a current. The value per unit displacement draft from loading scale has been used to evaluate the error of the displacement appearing in the presence of draft errors. As a result two similar criteria (rigorous and statistical of allowable discrepancies calculated by draft survey mass of cargo in the port of loading and port of discharge have been substantiated. These criteria require the calculation and accumulation in a table of all the errors and calculate the total error of displacement. Criteria will allow the consignee and the carrier come to a reasonable and agreed decision about the significance of differences of the masses taking into account the indifference of conditions and measuring instruments.

  14. Determination of the System Mass and the Individual Masses of Pluto and Charon from New Horizons Radio Tracking

    Science.gov (United States)

    Hahn, M.; Paetzold, M.; Andert, T.; Bird, M. K.; Tyler, G. L.; Hinson, D. P.; Linscott, I.; Stern, A.; Weaver, H. A., Jr.; Young, L. A.; Ennico Smith, K.; Olkin, C.

    2016-12-01

    One objective of the New Horizons Radio Science Experiment REX is the direct determination of the system mass and the individual masses of Pluto and Charon. About four weeks of two-way radio tracking centered around the closest approach of New Horizons to the Pluto system were processed. Major problems during the processing were the changes in spacecraft attitude by thrusters which applied extra Δv to the spacecraft motion masking partially the continuously perturbed motion caused by the attracting forces of the Pluto system members. The times of the spacecraft thruster activity are known but the applied Δv magnitude needed to be specifically adjusted. No two-way tracking was available during the flyby day on 14th July but slots of the REX one-way uplink observations cover the most important time near closest approach, these are for example the Pluto and Charon Earth occultation entries and exits. The REX data during the flyby day allowed to extract the individual masses of Pluto and Charon from the system mass at high precision. The relative errors of the mass determinations are below 0.02% and 0.2%, respectively. The masses of the 4 small satellites in the Pluto system could not be resolved.

  15. A Simple yet Accurate Method for Students to Determine Asteroid Rotation Periods from Fragmented Light Curve Data

    Science.gov (United States)

    Beare, R. A.

    2008-01-01

    Professional astronomers use specialized software not normally available to students to determine the rotation periods of asteroids from fragmented light curve data. This paper describes a simple yet accurate method based on Microsoft Excel[R] that enables students to find periods in asteroid light curve and other discontinuous time series data of…

  16. Accurate Determination of Platinum, Palladium, and Rhodium in Ryegrass using Collision Cell Inductively Coupled Plasma Mass Spectrometry with Xenon as Collision Gas

    International Nuclear Information System (INIS)

    Amr, M.A.

    2011-01-01

    Inductively coupled plasma mass spectrometry with an octupole collision cell was used for determination of Pt, Pd and Rh in ryegrass (Lolium multiflorum) which was grown hydroponically. Xenon was used as a collision gas to reduce serious polyatomic interferences formed by combination of matrix elements such as CI, Cu, Hf, Sr, Zn, Zr, Y and REE with O, N, C, and Ar. The detection limits for Pt, Pd and Rh in spiked ryegrass are 1.8, 4.2, and 0.8 ppt, respectively. The results for Pt, Pd and Rh in reference materials (NIST SRM 2557, recycled monolith auto catalyst) are in agreement with the certified values. The bioaccumulation of Pt, Pd and Rh by ryegrass grown hydroponically with nutrient solutions containing Pt, Pd and Rh was studied. The obtained results showed that most of the studied metals were accumulated in roots, and only a small fraction was metabolized and transported to leaves. The highest bioaccumulation factors were obtained for Pd and Rh in roots and for Pt in leaves

  17. Determination of subjective similarity for pairs of masses and pairs of clustered microcalcifications on mammograms: Comparison of similarity ranking scores and absolute similarity ratings

    International Nuclear Information System (INIS)

    Muramatsu, Chisako; Li Qiang; Schmidt, Robert A.; Shiraishi, Junji; Suzuki, Kenji; Newstead, Gillian M.; Doi, Kunio

    2007-01-01

    The presentation of images that are similar to that of an unknown lesion seen on a mammogram may be helpful for radiologists to correctly diagnose that lesion. For similar images to be useful, they must be quite similar from the radiologists' point of view. We have been trying to quantify the radiologists' impression of similarity for pairs of lesions and to establish a ''gold standard'' for development and evaluation of a computerized scheme for selecting such similar images. However, it is considered difficult to reliably and accurately determine similarity ratings, because they are subjective. In this study, we compared the subjective similarities obtained by two different methods, an absolute rating method and a 2-alternative forced-choice (2AFC) method, to demonstrate that reliable similarity ratings can be determined by the responses of a group of radiologists. The absolute similarity ratings were previously obtained for pairs of masses and pairs of microcalcifications from five and nine radiologists, respectively. In this study, similarity ranking scores for eight pairs of masses and eight pairs of microcalcifications were determined by use of the 2AFC method. In the first session, the eight pairs of masses and eight pairs of microcalcifications were grouped and compared separately for determining the similarity ranking scores. In the second session, another similarity ranking score was determined by use of mixed pairs, i.e., by comparison of the similarity of a mass pair with that of a calcification pair. Four pairs of masses and four pairs of microcalcifications were grouped together to create two sets of eight pairs. The average absolute similarity ratings and the average similarity ranking scores showed very good correlations in the first study (Pearson's correlation coefficients: 0.94 and 0.98 for masses and microcalcifications, respectively). Moreover, in the second study, the correlations between the absolute ratings and the ranking scores were also

  18. Rare earth elements determined in Antarctic ice by inductively coupled plasma-Time of flight, quadrupole and sector field-mass spectrometry: An inter-comparison study

    International Nuclear Information System (INIS)

    Dick, D.; Wegner, A.; Gabrielli, P.; Ruth, U.; Barbante, C.; Kriews, M.

    2008-01-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is a suitable tool for multi-element analysis at low concentration levels. Rare earth element (REE) determinations in standard reference materials and small volumes of molten ice core samples from Antarctica have been performed with an ICP-time of flight-MS (ICP-TOF-MS) system. Recovery rates for REE in e.g. SPS-SW1 amounted to ∼103%, and the relative standard deviations were 3.4% for replicate analysis at REE concentrations in the lower ng L -1 range. Analyses of REE concentrations in Antarctic ice core samples showed that the ICP-TOF-MS technique meets the demands of restricted sample mass. The data obtained are in good agreement with ICP-Quadrupole-MS (ICP-Q-MS) and ICP-Sector Field-MS (ICP-SF-MS) results. The ICP-TOF-MS system determines accurately and precisely REE concentrations exceeding 5 ng L -1 while between 0.5 and 5 ng L -1 accuracy and precision are element dependent

  19. A hybrid solution using computational prediction and measured data to accurately determine process corrections with reduced overlay sampling

    Science.gov (United States)

    Noyes, Ben F.; Mokaberi, Babak; Mandoy, Ram; Pate, Alex; Huijgen, Ralph; McBurney, Mike; Chen, Owen

    2017-03-01

    Reducing overlay error via an accurate APC feedback system is one of the main challenges in high volume production of the current and future nodes in the semiconductor industry. The overlay feedback system directly affects the number of dies meeting overlay specification and the number of layers requiring dedicated exposure tools through the fabrication flow. Increasing the former number and reducing the latter number is beneficial for the overall efficiency and yield of the fabrication process. An overlay feedback system requires accurate determination of the overlay error, or fingerprint, on exposed wafers in order to determine corrections to be automatically and dynamically applied to the exposure of future wafers. Since current and future nodes require correction per exposure (CPE), the resolution of the overlay fingerprint must be high enough to accommodate CPE in the overlay feedback system, or overlay control module (OCM). Determining a high resolution fingerprint from measured data requires extremely dense overlay sampling that takes a significant amount of measurement time. For static corrections this is acceptable, but in an automated dynamic correction system this method creates extreme bottlenecks for the throughput of said system as new lots have to wait until the previous lot is measured. One solution is using a less dense overlay sampling scheme and employing computationally up-sampled data to a dense fingerprint. That method uses a global fingerprint model over the entire wafer; measured localized overlay errors are therefore not always represented in its up-sampled output. This paper will discuss a hybrid system shown in Fig. 1 that combines a computationally up-sampled fingerprint with the measured data to more accurately capture the actual fingerprint, including local overlay errors. Such a hybrid system is shown to result in reduced modelled residuals while determining the fingerprint, and better on-product overlay performance.

  20. Determination of the Relative Atomic Masses of Metals by Liberation of Molecular Hydrogen

    Science.gov (United States)

    Waghorne, W. Earle; Rous, Andrew J.

    2009-01-01

    Students determine the relative atomic masses of calcium, magnesium, and aluminum by reaction with hydrochloric acid and measurement of the volume of hydrogen gas liberated. The experiment demonstrates stoichiometry and illustrates clearly that mass of the reagent is not the determinant of the amounts in chemical reactions. The experiment is…

  1. Species specific isotope dilution for the accurate and SI traceable determination of arsenobetaine and methylmercury in cuttlefish and prawn

    International Nuclear Information System (INIS)

    Kumkrong, Paramee; Thiensong, Benjaporn; Le, Phuong Mai; McRae, Garnet; Windust, Anthony; Deawtong, Suladda; Meija, Juris; Maxwell, Paulette; Yang, Lu; Mester, Zoltán

    2016-01-01

    Methods based on species specific isotope dilution were developed for the accurate and SI traceable determination of arsenobetaine (AsBet) and methylmercury (MeHg) in prawn and cuttlefish tissues by LC-MS/MS and SPME GC-ICPMS. Quantitation of AsBet and MeHg were achieved by using a "1"3C-enriched AsBet spike (NRC CRM CBET-1) and an enriched spike of Me"1"9"8Hg (NRC CRM EMMS-1), respectively, wherein analyte mass fractions in enriched spikes were determined by reverse isotope dilution using natural abundance AsBet and MeHg primary standards. Purity of these primary standards were characterized by quantitative "1H-NMR with the use of NIST SRM 350b benzoic acid as a primary calibrator, ensuring the final measurement results traceable to SI. Validation of employed methods of ID LC-MS/MS and ID SPME GC-ICPMS was demonstrated by analysis of several biological CRMs (DORM-4, TORT-3, DOLT-5, BCR-627 and BCR-463) with satisfying results. The developed methods were applied for the determination of AsBet and MeHg in two new certified reference materials (CRMs) prawn (PRON-1) and cuttlefish (SQID-1) produced jointly by Thailand Institute of Scientific and Technological Research (TISTR) and National Research Council Canada (NRC). With additional measurements of AsBet using LC-ICPMS with standard additions calibration and external calibration at NRC and TISTR, respectively, certified values of 1.206 ± 0.058 and 13.96 ± 0.54 mg kg"−"1 for AsBet as As (expanded uncertainty, k = 2) were obtained for the new CRMs PRON-1 and SQID-1, respectively. The reference value of 0.324 ± 0.028 mg kg"−"1 as Hg (expanded uncertainty, k = 2) for MeHg was obtained for the SQID-1 based on the results obtained by ID SPME GC-ICPMS method only, whereas MeHg in PRON-1 was found to be < 0.015 mg kg"−"1. It was found that AsBet comprised 69.7% and 99.0% of total As in the prawn and cuttlefish, respectively, whereas MeHg comprised 94.5% of total Hg in cuttlefish. - Highlights:

  2. Quark mass relations to four-loop order in perturbative QCD.

    Science.gov (United States)

    Marquard, Peter; Smirnov, Alexander V; Smirnov, Vladimir A; Steinhauser, Matthias

    2015-04-10

    We present results for the relation between a heavy quark mass defined in the on-shell and minimal subtraction (MS[over ¯]) scheme to four-loop order. The method to compute the four-loop on-shell integral is briefly described and the new results are used to establish relations between various short-distance masses and the MS[over ¯] quark mass to next-to-next-to-next-to-leading order accuracy. These relations play an important role in the accurate determination of the MS[over ¯] heavy quark masses.

  3. Mass determination of heavy nuclei by the (α, 8He) reaction

    International Nuclear Information System (INIS)

    Kato, S.; Kubono, S.; Tanaka, M.H.

    1991-07-01

    The atomic mass excesses of 86 Zr, 88 Mo, 181 Re, 193 Au, and 200 Pb were determined from the Q-value measurements of the (α, 8 He) reaction on 90 Zr, 92 Mo, 185 Re, 197 Au, and 204 Pb. Further, the mass excesses of 181 Os, 193 Hg, 204 Po, 208 Rn, 212 Ra, and 216 Th were deduced from the measured mass excesses and the known Q values of alpha and beta decays. (author)

  4. Determination and correlation of mass transfer coefficients in a stirred cell

    International Nuclear Information System (INIS)

    Herranz, J.; Bloxom, S.R.; Keeler, J.B.; Roth, S.R.

    1975-01-01

    In the proposed Molten Salt Breeder Reactor flowsheet, a fraction of the rare earth fission products is removed from the fuel salt in mass transfer cells. To obtain design parameters for this extraction, the effect of cell size, blade diameter, phase volume, and agitation rate on the mass transfer for a high density ratio system (mercury/water) in nondispersing square cross section contactors was determined. Aqueous side mass transfer coefficients were measured by polarography over a wide range of operating conditions. Correlations for the experimental mass transfer coefficients as functions of the operating parameters are presented. Several techniques for measuring mercury-side mass transfer coefficients were evaluated and a new one is recommended

  5. A new model for the determination of limb segment mass in children.

    Science.gov (United States)

    Kuemmerle-Deschner, J B; Hansmann, S; Rapp, H; Dannecker, G E

    2007-04-01

    The knowledge of limb segment masses is critical for the calculation of joint torques. Several methods for segment mass estimation have been described in the literature. They are either inaccurate or not applicable to the limb segments of children. Therefore, we developed a new cylinder brick model (CBM) to estimate segment mass in children. The aim of this study was to compare CBM and a model based on a polynomial regression equation (PRE) to volume measurement obtained by the water displacement method (WDM). We examined forearms, hands, lower legs, and feet of 121 children using CBM, PRE, and WDM. The differences between CBM and WDM or PRE and WDM were calculated and compared using a Bland-Altman plot of differences. Absolute limb segment mass measured by WDM ranged from 0.16+/-0.04 kg for hands in girls 5-6 years old, up to 2.72+/-1.03 kg for legs in girls 11-12 years old. The differences of normalised segment masses ranged from 0.0002+/-0.0021 to 0.0011+/-0.0036 for CBM-WDM and from 0.0023+/-0.0041 to 0.0127+/-0.036 for PRE-WDM (values are mean+/-2 S.D.). The CBM showed better agreement with WDM than PRE for all limb segments in girls and boys. CBM is accurate and superior to PRE for the estimation of individual limb segment mass of children. Therefore, CBM is a practical and useful tool for the analysis of kinetic parameters and the calculation of resulting forces to assess joint functionality in children.

  6. Increasing the productivity of glycopeptides analysis by using higher-energy collision dissociation-accurate mass-product-dependent electron transfer dissociation.

    Science.gov (United States)

    Saba, Julian; Dutta, Sucharita; Hemenway, Eric; Viner, Rosa

    2012-01-01

    Currently, glycans are attracting attention from the scientific community as potential biomarkers or as posttranslational modifications (PTMs) of therapeutic proteins. However, structural characterization of glycoproteins and glycopeptides remains analytically challenging. Here, we report on the implementation of a novel acquisition strategy termed higher-energy collision dissociation-accurate mass-product-dependent electron transfer dissociation (HCD-PD-ETD) on a hybrid linear ion trap-orbitrap mass spectrometer. This acquisition strategy uses the complementary fragmentations of ETD and HCD for glycopeptides analysis in an intelligent fashion. Furthermore, the approach minimizes user input for optimizing instrumental parameters and enables straightforward detection of glycopeptides. ETD spectra are only acquired when glycan oxonium ions from MS/MS HCD are detected. The advantage of this approach is that it streamlines data analysis and improves dynamic range and duty cycle. Here, we present the benefits of HCD-PD-ETD relative to the traditional alternating HCD/ETD for a trainer set containing twelve-protein mixture with two glycoproteins: human serotransferrin, ovalbumin and contaminations of two other: bovine alpha 1 acid glycoprotein (bAGP) and bovine fetuin.

  7. Imaging of fetal chest masses

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Richard A. [Lucile Packard Children' s Hospital, Stanford University School of Medicine, Department of Radiology, Stanford, CA (United States)

    2012-01-15

    Prenatal imaging with high-resolution US and rapid acquisition MRI plays a key role in the accurate diagnosis of congenital chest masses. Imaging has enhanced our understanding of the natural history of fetal lung masses, allowing for accurate prediction of outcome, parental counseling, and planning of pregnancy and newborn management. This paper will focus on congenital bronchopulmonary malformations, which account for the vast majority of primary lung masses in the fetus. In addition, anomalies that mimic masses and less common causes of lung masses will be discussed. (orig.)

  8. Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors

    International Nuclear Information System (INIS)

    Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Mehta, Poonam; Sankar, S Uma; Shalgar, Shashank

    2008-01-01

    The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle θ 13 is about 10 deg. (close to CHOOZ upper bound), the hierarchy sensitivity is essentially determined by resonant matter effects. To maximize the potential of these effects in atmospheric neutrinos, charge discrimination capability in the detector is desirable. Hence, detectors with this capability have an advantage in hierarchy determination. We compare and contrast the performance of the above three detectors in this respect. We perform a realistic analysis of the above future detectors for atmospheric neutrinos and show that it is possible to achieve a significant hierarchy sensitivity if the detector characteristics are favourable. Note: The abstract has been modified from its original form to incorporate suggestions received during the conference. The poster is being submitted in its original form.

  9. First on-line mass measurements at SHIPTRAP and mass determinations of neutron-rich Fr and Ra isotopes at ISOLTRAP

    CERN Document Server

    Rahaman, Saidu

    SHIPTRAP is an ion trap facility behind the velocity filter SHIP at GSI/Darmstadt. Its aim are precision studies of transuranium nuclides produced in a fusion reaction and separated by SHIP. The current set-up for high-precision mass measurements consists of three main functional parts: (i) a gas cell for stopping the energetic ions from SHIP, (ii) radiofrequency quadrupole structures to cool and to bunch the ions extracted from the gas cell, and (iii) a superconducting magnet with two cylindrical Penning traps at a field strength of 7 T. In this work the Penning trap system has been installed and extensively characterized. The first on-line mass measurements of short-lived nuclides were carried out and the masses of $^{147}$Er and $^{148}$Er could be experimentally determined for the first time. Here a relative mass uncertainty of $\\delta$ m/m of about 1$\\times$ 10$^{-6}$ was achieved. Furthermore the masses of heavy neutron-rich $^{229-232}$Ra and $^{230}$Fr isotopes have been determined with a relative m...

  10. Determination of external and internal mass transfer limitation in nitrifying microbial aggregates.

    Science.gov (United States)

    Wilén, Britt-Marie; Gapes, Daniel; Keller, Jürg

    2004-05-20

    In this article we present a study of the effects of external and internal mass transfer limitation of oxygen in a nitrifying system. The oxygen uptake rates (OUR) were measured on both a macro-scale with a respirometric reactor using off-gas analysis (Titrimetric and Off-Gas Analysis (TOGA) sensor) and on a micro-scale with microsensors. These two methods provide independent, accurate measurements of the reaction rates and concentration profiles around and in the granules. The TOGA sensor and microsensor measurements showed a significant external mass transfer effect at low dissolved oxygen (DO) concentrations in the bulk liquid while it was insignificant at higher DO concentrations. The oxygen distribution with anaerobic or anoxic conditions in the center clearly shows major mass transfer limitation in the aggregate interior. The large drop in DO concentration of 22-80% between the bulk liquid and aggregate surface demonstrates that the external mass transfer resistance is also highly important. The maximum OUR even for floccular biomass was only attained at much higher DO concentrations (approximately 8 mg/L) than typically used in such systems. For granules, the DO required for maximal activity was estimated to be >20 mg/L, clearly indicating the effects of the major external and internal mass transfer limitations on the overall biomass activity. Smaller aggregates had a larger volumetric OUR indicating that the granules may have a lower activity in the interior part of the aggregate. Copyright 2004 Wiley Periodicals, Inc.

  11. Application of fast Fourier transform cross-correlation and mass spectrometry data for accurate alignment of chromatograms.

    Science.gov (United States)

    Zheng, Yi-Bao; Zhang, Zhi-Min; Liang, Yi-Zeng; Zhan, De-Jian; Huang, Jian-Hua; Yun, Yong-Huan; Xie, Hua-Lin

    2013-04-19

    Chromatography has been established as one of the most important analytical methods in the modern analytical laboratory. However, preprocessing of the chromatograms, especially peak alignment, is usually a time-consuming task prior to extracting useful information from the datasets because of the small unavoidable differences in the experimental conditions caused by minor changes and drift. Most of the alignment algorithms are performed on reduced datasets using only the detected peaks in the chromatograms, which means a loss of data and introduces the problem of extraction of peak data from the chromatographic profiles. These disadvantages can be overcome by using the full chromatographic information that is generated from hyphenated chromatographic instruments. A new alignment algorithm called CAMS (Chromatogram Alignment via Mass Spectra) is present here to correct the retention time shifts among chromatograms accurately and rapidly. In this report, peaks of each chromatogram were detected based on Continuous Wavelet Transform (CWT) with Haar wavelet and were aligned against the reference chromatogram via the correlation of mass spectra. The aligning procedure was accelerated by Fast Fourier Transform cross correlation (FFT cross correlation). This approach has been compared with several well-known alignment methods on real chromatographic datasets, which demonstrates that CAMS can preserve the shape of peaks and achieve a high quality alignment result. Furthermore, the CAMS method was implemented in the Matlab language and available as an open source package at http://www.github.com/matchcoder/CAMS. Copyright © 2013. Published by Elsevier B.V.

  12. A fast algorithm for determining bounds and accurate approximate p-values of the rank product statistic for replicate experiments.

    Science.gov (United States)

    Heskes, Tom; Eisinga, Rob; Breitling, Rainer

    2014-11-21

    The rank product method is a powerful statistical technique for identifying differentially expressed molecules in replicated experiments. A critical issue in molecule selection is accurate calculation of the p-value of the rank product statistic to adequately address multiple testing. Both exact calculation and permutation and gamma approximations have been proposed to determine molecule-level significance. These current approaches have serious drawbacks as they are either computationally burdensome or provide inaccurate estimates in the tail of the p-value distribution. We derive strict lower and upper bounds to the exact p-value along with an accurate approximation that can be used to assess the significance of the rank product statistic in a computationally fast manner. The bounds and the proposed approximation are shown to provide far better accuracy over existing approximate methods in determining tail probabilities, with the slightly conservative upper bound protecting against false positives. We illustrate the proposed method in the context of a recently published analysis on transcriptomic profiling performed in blood. We provide a method to determine upper bounds and accurate approximate p-values of the rank product statistic. The proposed algorithm provides an order of magnitude increase in throughput as compared with current approaches and offers the opportunity to explore new application domains with even larger multiple testing issue. The R code is published in one of the Additional files and is available at http://www.ru.nl/publish/pages/726696/rankprodbounds.zip .

  13. Neutrino mass hierarchy determination for θ13 = 0

    International Nuclear Information System (INIS)

    Gandhi, Raj; Ghoshal, Pomita; Goswami, Srubabati; Sankar, S. Uma

    2010-01-01

    We examine the possibility of determining the neutrino mass hierarchy in the limit θ 13 = 0 using atmospheric neutrinos as the source. In this limit, θ 13 driven matter effects are absent so independent measurements of Δ 31 and Δ 32 can, in principle, lead to hierarchy determination. Since their difference is Δ 21 , one needs an experimental arrangement where Δ 21 L/E > or approx. 1 can be achieved. This can be satisfied by atmospheric neutrinos which have a large range of L and E. Still, we find that hierarchy determination in the θ 13 = 0 limit with atmospheric neutrinos is not a realistic possibility, even in conjunction with a beam experiment like T2K or NOνA. We discuss why, and also reiterate the general conditions for hierarchy determination if θ 13 = 0.

  14. [Determination of bisphenol A from toys and food contact materials by derivatization and gas chromatography-mass spectrometry].

    Science.gov (United States)

    Gao, Yonggang; Zhang, Yanyan; Gao, Jianguo; Zhang, Huiling; Zheng, Lisha; Chen, Jing

    2012-10-01

    A method was developed for the determination of bisphenol A (BPA) in toys and food contact materials. The BPA was extracted with Soxhlet extraction method from the sample and reacted with acetic anhydride. The final product was determined by gas chromatography-mass spectrometry (GC-MS). To achieve the optimum derivatization performance, the derivatization time and dosage of derivatization reagent etc. were investigated. Under the optimized experimental conditions, the final product was stable and the peak shape was good. The linearity of the derivative was good in the range of 0.05 to 50 mg/L with the correlation coefficient (r2) above 0.999. The recoveries ranged from 80% to 93% at the spiked levels of 0.05, 1.00, 10.00 mg/kg with the relative standard deviations (RSDs) less than 3.7%. The limit of detection (S/N = 3) was 10 microg/kg. The method is accurate and has high recovery. The method is suitable for the inspection of bisphenol A in toys and food contact materials.

  15. Precision Timing of PSR J0437-4715: An Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton's Gravitational Constant

    Science.gov (United States)

    Verbiest, J. P. W.; Bailes, M.; van Straten, W.; Hobbs, G. B.; Edwards, R. T.; Manchester, R. N.; Bhat, N. D. R.; Sarkissian, J. M.; Jacoby, B. A.; Kulkarni, S. R.

    2008-05-01

    Analysis of 10 years of high-precision timing data on the millisecond pulsar PSR J0437-4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, dot Pb , determined at the 1.5% level of precision (Dk = 157.0 +/- 2.4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy between this measurement and a previously published parallax distance estimate is attributed to errors in the DE200 solar system ephemerides. The precise measurement of dot Pb allows a limit on the variation of Newton's gravitational constant, |Ġ/G| <= 23 × 10-12 yr-1. We also constrain any anomalous acceleration along the line of sight to the pulsar to |a⊙/c| <= 1.5 × 10-18 s-1 at 95% confidence, and derive a pulsar mass, mpsr = 1.76 +/- 0.20 M⊙, one of the highest estimates so far obtained.

  16. Determination of Coefficient of Thermal Expansion (CTE) of 20MPa Mass Concrete Using Granite Aggregate

    Science.gov (United States)

    Chee Siang, GO

    2017-07-01

    Experimental test was carried out to determine the coefficient of thermal expansion (CTE) value of 20MPa mass concrete using granite aggregate. The CTE value was established using procedure proposed by Kada et al. 2002 in determining the magnitude of early-ages CTE through laboratory test which is a rather accurate way by eliminating any possible superimposed effect of others early-age thermal deformation shrinkages such as autogenous, carbonation, plastic and drying shrinkage. This was done by submitting granite concrete block samples instrumented with ST4 vibrating wire extensometers to thermal shocks. The response of the concrete samples to this shock results in a nearly instantaneous deformation, which are measured by the sensor. These deformations, as well as the temperature signal, are used to calculate the CTE. By repeating heat cycles, the variation in the early-ages of concrete CTE over time was monitored and assessed for a period of upto 7 days. The developed CTE value facilitating the verification and validation of actual maximum permissible critical temperature differential limit (rather than arbitrarily follow published value) of cracking potential. For thick sections, internal restraint is dominant and this is governed by differentials mainly. Of the required physical properties for thermal modelling, CTE is of paramount importance that with given appropriate internal restraint factor the condition of cracking due to internal restraint is governs by equation, ΔTmax= 3.663ɛctu / αc. Thus, it can be appreciated that an increase in CTE will lower the maximum allowable differential for cracking avoidance in mass concrete while an increase of tensile strain capacity will increase the maximum allowable temperature differential.

  17. First one-line mass measurements at SHIPTRAP and mass determinations of neutron-rich Fr and Ra isotopes at ISOLTRAP

    International Nuclear Information System (INIS)

    Rahaman, M.S.

    2005-01-01

    SHIPTRAP is an ion trap facility behind the velocity lter SHIP at GSI/Darmstadt. Its aim are precision studies of transuranium nuclides produced in a fusion reaction and separated by SHIP. The current set-up for high-precision mass measurements consists of three main functional parts: (i) a gas cell for stopping the energetic ions from SHIP, (ii) radiofrequency quadrupole structures to cool and to bunch the ions extracted from the gas cell, and (iii) a superconducting magnet with two cylindrical Penning traps at a eld strength of 7 T. In this work the Penning trap system has been installed and extensively characterized. The rst on-line mass measurements of short-lived nuclides were carried out and the masses of 147 Er and 148 Er could be experimentally determined for the rst time. Here a relative mass uncertainty of δm/m of about 1 x 10 -6 was achieved. Furthermore the masses of heavy neutron-rich 229-232 Ra and 230 Fr isotopes have been determined with a relative mass uncertainty of about 1 x 10 -7 with the ISOLTRAP mass spectometer at ISOLDE/CERN. The isotope 232 Ra is the heaviest unstable nuclide ever investigated with a Penning trap. Underlying nuclear structure effects of these nuclides far from β-stability were studied by a comparison of the resulting two-neutron separation energies S 2n with those given by the theoretical Infinite Nuclear Mass model. (orig.)

  18. Gravimetric gas determinations for volume calibration

    International Nuclear Information System (INIS)

    Gibbs, P.W.

    1991-01-01

    Gravimetric measurements of gases is one of the methods available for calibrating gas volumes. By inputting a known quantity of gas and measuring the resulting pressure and temperature, the system volume can be calculated using gas law principles. Historically, this method has been less accurate due to the difficulty in the mass determination. This difficulty comes from several sources. Two examples are the large tare weight of the gas container relative to the weight of gas and the external volume of the gas container relative to the standards. The application of a gravimetric gas determination to tank volume calibrations at the savannah River Site is discussed. Mass determinations on a 25,00 gram gas container were such that a 1500 gram quantity of gas was routinely determined to within ±0.2 gram at the 99% confidence level. In this paper the weighting design and the methods used to address the difficulties of the mass determination are detailed

  19. Relationship of Muscle Mass Determined by DEXA with Spirometric Results in Healthy Individuals.

    Science.gov (United States)

    Martín Holguera, Rafael; Turrión Nieves, Ana Isabel; Rodríguez Torres, Rosa; Alonso, María Concepción

    2017-07-01

    Muscle mass maybe a determining factor in the variability of spirometry results in individuals of the same sex and age who have similar anthropometric characteristics. The aim of this study was to determine the association between spirometric results from healthy individuals and their muscle mass assessed by dual energy X-ray absorptiometry (DEXA). A sample of 161 women and 144 men, all healthy non-smokers, was studied. Ages ranged from18 to77years. For each subject, spirometry results and total and regional lean mass values obtained by full body DEXA were recorded. A descriptive analysis of the variables and a regression analysis were performed to study the relationship between spirometric variables and lean body mass, correcting for age and body mass index (BMI). In both sexes all muscle mass variables correlated positively and significantly with spirometric variables, and to a greater extent in men. After partial adjustment of correlations by age and BMI, the factor which best explains the spirometric variables is the total lean body mass in men, and trunk lean body mass in women. In men, muscle mass in the lower extremities is most closely associated with spirometric results. In women, it is the muscle mass of the trunk. In both sexes muscle mass mainly affects FEV 1 . Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Precision electron-capture energy in {sup 202}Pb and its relevance for neutrino mass determination

    Energy Technology Data Exchange (ETDEWEB)

    Welker, A. [CERN, Geneva (Switzerland); Technische Universitaet Dresden, Dresden (Germany); Filianin, P. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Althubiti, N.A.S. [The University of Manchester, School of Physics and Astronomy, Manchester (United Kingdom); Atanasov, D.; Blaum, K.; Eliseev, S.; Kreim, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Cocolios, T.E. [The University of Manchester, School of Physics and Astronomy, Manchester (United Kingdom); KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Herfurth, F.; Neidherr, D. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Lunney, D. [CSNSM-IN2P3-CNRS, Universite Paris-Sud, Orsay (France); Manea, V. [CERN, Geneva (Switzerland); Novikov, Yu. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Physics Faculty, St. Petersburg State University (Russian Federation); Rosenbusch, M.; Schweikhard, L.; Wienholtz, F. [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, Greifswald (Germany); Wolf, R.N. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); The University of Sydney, ARC Centre of Excellence for Engineered Quantum Systems, Sydney (Australia); Zuber, K. [Technische Universitaet Dresden, Dresden (Germany)

    2017-07-15

    Within the framework of an extensive programme devoted to the search for alternative candidates for the neutrino mass determination, the atomic mass difference between {sup 202}Pb and {sup 202}Tl has been measured with the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. The obtained value Q{sub EC} = 38.8(43) keV is three times more precise than the AME2012 value. While it will probably not lead to a replacement of {sup 163}Ho in modern experiments on the determination of the electron-neutrino mass, the electron capture in {sup 202}Pb would however allow a determination of the electron-neutrino mass on the few-eV level using a cryogenic micro-calorimeter. (orig.)

  1. Calculation of isotopic mass and energy production by a matrix operator method

    International Nuclear Information System (INIS)

    Lee, C.E.

    1976-08-01

    The Volterra method of the multiplicative integral is used to determine the isotopic density, mass, and energy production in linear systems. The solution method, assumptions, and limitations are discussed. The method allows a rapid accurate calculation of the change in isotopic density, mass, and energy production independent of the magnitude of the time steps, production or decay rates, or flux levels

  2. Proposed thermodynamic method to determine the vortex mass in layered superconductors

    International Nuclear Information System (INIS)

    Moler, K.A.; Fetter, A.L.; Kapitulnik, A.

    1995-01-01

    The authors describe a simple method to study vortex dynamics that can determine or set an upper limit on the vortex mass. The specific heat of the vortex lattice in layered superconductors has a classical limit of 1 k B per pancake vortex if the vortex mass is zero. If the vortex mass m v is finite, a new Einstein branch of normal modes will appear with a crossover temperature Θ E ∝ m v -1 , and the specific heat will saturate at a new classical limit of 2 k B per pancake vortex

  3. Determination of burn-up of irradiated nuclear fuels using mass spectrometry

    International Nuclear Information System (INIS)

    Jagadish Kumar, S.; Telmore, V.M.; Shah, R.V.; Sasi Bhushan, K.; Paul, Sumana; Kumar, Pranaw; Rao, Radhika M.; Jaison, P.G.

    2017-01-01

    Burn-up defined as the atom percent fission, is a vital parameter used for assessing the performance of nuclear fuel during its irradiation in the reactor. Accurate data on the actinide isotopes are also essential for the reliable accountability of nuclear materials and for nuclear safeguards. Both destructive and non-destructive methods are employed in the post-irradiation analysis for the burn-up measurements. Though non-destructive methods are preferred from the point view of remote handling of irradiated fuels with high radioactivity, they do not provide the high accuracy as achieved by the chemical analysis methods. Thus destructive radiochemical and chemical analyses are still the established reference methods for accurate and reliable burn-up determination of irradiated nuclear fuels. In the destructive method, burn-up of irradiated nuclear fuel is determined by correlating the amount of a fission product formed during irradiation with that of heavy elements. Thus the destructive experimental determination of burn-up involves the dissolution of irradiated fuel samples followed by the separation and determination of heavy elements and fission product(s) to be used as burn-up monitor(s). Another approach for the experimental determination of burn-up is based on the changes in the abundances of the heavy element isotopes. A widely accepted method for burn-up determination is based on stable "1"4"8Nd and "1"3"9La as burn-up monitors. Several properties such as non-volatility, nearly same yields for thermal fissions of "2"3"5U and "2"3"9Pu etc justifies the selection of "1"4"8Nd as a burn-up monitor

  4. [Determination of olive oil content in olive blend oil by headspace gas chromatography-mass spectrometry].

    Science.gov (United States)

    Jiang, Wanfeng; Zhang, Ning; Zhang, Fengyan; Yang, Zhao

    2017-07-08

    A method for the determination of the content of olive oil in olive blend oil by headspace gas chromatography-mass spectrometry (SH-GC/MS) was established. The amount of the sample, the heating temperature, the heating time, the amount of injection, the injection mode and the chromatographic column were optimized. The characteristic compounds of olive oil were found by chemometric method. A sample of 1.0 g was placed in a 20 mL headspace flask, and heated at 180℃ for 2700 s. Then, 1.0 mL headspace gas was taken into the instrument. An HP-88 chromatographic column was used for the separation and the analysis was performed by GC/MS. The results showed that the linear range was 0-100%(olive oil content). The linear correlation coefficient ( r 2 ) was more than 0.995, and the limits of detection were 1.26%-2.13%. The deviations of olive oil contents in the olive blend oil were from -0.65% to 1.02%, with the relative deviations from -1.3% to 6.8% and the relative standard deviations from 1.18% to 4.26% ( n =6). The method is simple, rapid, environment friendly, sensitive and accurate. It is suitable for the determination of the content of olive oil in olive blend oil.

  5. Determination of the neutron mass; Determinacion de la masa del neutron

    Energy Technology Data Exchange (ETDEWEB)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: paus2281@yahoo.com.mx

    2005-07-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, {sup 1}{sub 0} n + {sup 1}{sub 1} H {yields}{sup 2}{sub 1} D + {gamma}. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source {sup 239} PuBe whose activity is of 3.7 x 10{sup 10} Bq. (Author)

  6. Determining the REV for Fracture Rock Mass Based on Seepage Theory

    Directory of Open Access Journals (Sweden)

    Lili Zhang

    2017-01-01

    Full Text Available Seepage problems of the fractured rock mass have always been a heated topic within hydrogeology and engineering geology. The equivalent porous medium model method is the main method in the study of the seepage of the fractured rock mass and its engineering application. The key to the method is to determine a representative elementary volume (REV. The FractureToKarst software, that is, discrete element software, is a main analysis tool in this paper and developed by a number of authors. According to the standard of rock classification established by ISRM, this paper aims to discuss the existence and the size of REV of fractured rock masses with medium tractility and provide a general method to determine the existence of REV. It can be gleaned from the study that the existence condition of fractured rock mass with medium tractility features average fracture spacing smaller than 0.6 m. If average fracture spacing is larger than 0.6 m, there is no existence of REV. The rationality of the model is verified by a case study. The present research provides a method for the simulation of seepage field in fissured rocks.

  7. Detection and quantitation of trace phenolphthalein (in pharmaceutical preparations and in forensic exhibits) by liquid chromatography-tandem mass spectrometry, a sensitive and accurate method.

    Science.gov (United States)

    Sharma, Kakali; Sharma, Shiba P; Lahiri, Sujit C

    2013-01-01

    Phenolphthalein, an acid-base indicator and laxative, is important as a constituent of widely used weight-reducing multicomponent food formulations. Phenolphthalein is an useful reagent in forensic science for the identification of blood stains of suspected victims and for apprehending erring officials accepting bribes in graft or trap cases. The pink-colored alkaline hand washes originating from the phenolphthalein-smeared notes can easily be determined spectrophotometrically. But in many cases, colored solution turns colorless with time, which renders the genuineness of bribe cases doubtful to the judiciary. No method is known till now for the detection and identification of phenolphthalein in colorless forensic exhibits with positive proof. Liquid chromatography-tandem mass spectrometry had been found to be most sensitive, accurate method capable of detection and quantitation of trace phenolphthalein in commercial formulations and colorless forensic exhibits with positive proof. The detection limit of phenolphthalein was found to be 1.66 pg/L or ng/mL, and the calibration curve shows good linearity (r(2) = 0.9974). © 2012 American Academy of Forensic Sciences.

  8. Accurate determination of the Boltzmann constant by Doppler spectroscopy: Towards a new definition of the kelvin

    International Nuclear Information System (INIS)

    Darquie, B.; Mejri, S.; Sow, P. L. T.; Lemarchand, C.; Triki, M.; Tokunaga, S. K.; Borde, C. J.; Chardonnet, C.; Daussy, C.

    2013-01-01

    Accurate molecular spectroscopy in the mid-infrared region allows precision measurements of fundamental constants. For instance, measuring the linewidth of an isolated Doppler-broadened absorption line of ammonia around 10 μm enables a determination of the Boltzmann constant k B . We report on our latest measurements. By fitting this lineshape to several models which include Dicke narrowing or speed-dependent collisional effects, we find that a determination of k B with an uncertainty of a few ppm is reachable. This is comparable to the best current uncertainty obtained using acoustic methods and would make a significant contribution to any new value of k B determined by the CODATA. Furthermore, having multiple independent measurements at these accuracies opens the possibility of defining the kelvin by fixing k B , an exciting prospect considering the upcoming redefinition of the International System of Units. (authors)

  9. Electrospray Ionization Mass Spectrometric Analysis of Highly Reactive Glycosyl Halides

    Directory of Open Access Journals (Sweden)

    Lajos Kovács

    2012-07-01

    Full Text Available Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]+, [2M+Li]+ etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass determination of these highly sensitive compounds.

  10. Accurate determination of the composition of Y-Ba-Cu-O superconductor by spectrophotometry, gravimetry and flame AAS

    International Nuclear Information System (INIS)

    Bruneel, E; Verbauwhede, D; Vyver, D Van de; Schaubroeck, J; Hoste, S; Driessche, I Van

    2005-01-01

    A procedure for the accurate analytical determination of yttrium, barium and copper in an YBa 2 Cu 3 O x superconductor is described. After dissolution of the material the concentration of Y and Cu was spectrophotometrically determined as an Y-Arsenazo III and a Cu-Nitroso-R-salt complex, respectively. Ba was determined either gravimetrically as BaCrO 4 , after precipitation using a K 2 CrO 4 solution or using flame atomic absorption spectroscopy (AAS). An accuracy better than 0.7% and a coefficient of variation better then 1.2% are obtained. It is illustrated that this analytical procedure can be used to determine the composition of a bulk superconducting YBa 2 Cu 3 O x sample. For determination of Ba in thin films we suggest the use of flame AAS, with an accuracy of 0.03% and a coefficient of variation of 1.7%

  11. Myofiber metabolic type determination by mass spectrometry imaging

    OpenAIRE

    Théron, Laetitia; Vénien, Annie; Pujos-Guillot, Estelle; Astruc, Thierry; Chambon, Christophe

    2017-01-01

    In muscle imaging, myofiber type determination is of great importance to better understand biological mechanisms related to skeletal muscle changes associated with pathologies. However, reference methods (histo-enzymology and immunohistochemistry) require serial-cross sections, and several days from the sampling to the results of image analysis. In this work, a strategy based on MALDI-Mass Spectrometry Imaging was developed as an alternative to the classical methods for myofiber metabolic typ...

  12. An accurate method for determining residual stresses with magnetic non-destructive techniques in welded ferromagnetic steels

    International Nuclear Information System (INIS)

    Vourna, P

    2016-01-01

    The scope of the present research work was to investigate the proper selection criteria for developing a suitable methodology for the accurate determination of residual stresses existing in welded parts. Magnetic non-destructive testing took place by the use of two magnetic non-destructive techniques: by the measurement of the magnetic Barkhausen noise and by the evaluation of the magnetic hysteresis loop parameters. The spatial distribution of residual stresses in welded metal parts by both non-destructive magnetic methods and two diffraction methods was determined. The conduction of magnetic measurements required an initial calibration of ferromagnetic steels. Based on the examined volume of the sample, all methods used were divided into two large categories: the first one was related to the determination of surface residual stress, whereas the second one was related to bulk residual stress determination. The first category included the magnetic Barkhausen noise and the X-ray diffraction measurements, while the second one included the magnetic permeability and the neutron diffraction data. The residual stresses determined by the magnetic techniques were in a good agreement with the diffraction ones. (paper)

  13. Species specific isotope dilution for the accurate and SI traceable determination of arsenobetaine and methylmercury in cuttlefish and prawn

    Energy Technology Data Exchange (ETDEWEB)

    Kumkrong, Paramee [National Research Council Canada, 1200 Montreal Rd, Ottawa, Ontario, K1A 0R6 (Canada); Thailand Institute of Scientific and Technological Research, 35 Mu 3 Tambon Khlong Ha, Amphoe Khlong Luang, Pathum Thani, 12120 (Thailand); Thiensong, Benjaporn [Thailand Institute of Scientific and Technological Research, 35 Mu 3 Tambon Khlong Ha, Amphoe Khlong Luang, Pathum Thani, 12120 (Thailand); Le, Phuong Mai; McRae, Garnet; Windust, Anthony [National Research Council Canada, 1200 Montreal Rd, Ottawa, Ontario, K1A 0R6 (Canada); Deawtong, Suladda [Thailand Institute of Scientific and Technological Research, 35 Mu 3 Tambon Khlong Ha, Amphoe Khlong Luang, Pathum Thani, 12120 (Thailand); Meija, Juris; Maxwell, Paulette [National Research Council Canada, 1200 Montreal Rd, Ottawa, Ontario, K1A 0R6 (Canada); Yang, Lu, E-mail: Lu.yang@nrc-cnrc.gc.ca [National Research Council Canada, 1200 Montreal Rd, Ottawa, Ontario, K1A 0R6 (Canada); Mester, Zoltán [National Research Council Canada, 1200 Montreal Rd, Ottawa, Ontario, K1A 0R6 (Canada)

    2016-11-02

    Methods based on species specific isotope dilution were developed for the accurate and SI traceable determination of arsenobetaine (AsBet) and methylmercury (MeHg) in prawn and cuttlefish tissues by LC-MS/MS and SPME GC-ICPMS. Quantitation of AsBet and MeHg were achieved by using a {sup 13}C-enriched AsBet spike (NRC CRM CBET-1) and an enriched spike of Me{sup 198}Hg (NRC CRM EMMS-1), respectively, wherein analyte mass fractions in enriched spikes were determined by reverse isotope dilution using natural abundance AsBet and MeHg primary standards. Purity of these primary standards were characterized by quantitative {sup 1}H-NMR with the use of NIST SRM 350b benzoic acid as a primary calibrator, ensuring the final measurement results traceable to SI. Validation of employed methods of ID LC-MS/MS and ID SPME GC-ICPMS was demonstrated by analysis of several biological CRMs (DORM-4, TORT-3, DOLT-5, BCR-627 and BCR-463) with satisfying results. The developed methods were applied for the determination of AsBet and MeHg in two new certified reference materials (CRMs) prawn (PRON-1) and cuttlefish (SQID-1) produced jointly by Thailand Institute of Scientific and Technological Research (TISTR) and National Research Council Canada (NRC). With additional measurements of AsBet using LC-ICPMS with standard additions calibration and external calibration at NRC and TISTR, respectively, certified values of 1.206 ± 0.058 and 13.96 ± 0.54 mg kg{sup −1} for AsBet as As (expanded uncertainty, k = 2) were obtained for the new CRMs PRON-1 and SQID-1, respectively. The reference value of 0.324 ± 0.028 mg kg{sup −1} as Hg (expanded uncertainty, k = 2) for MeHg was obtained for the SQID-1 based on the results obtained by ID SPME GC-ICPMS method only, whereas MeHg in PRON-1 was found to be < 0.015 mg kg{sup −1}. It was found that AsBet comprised 69.7% and 99.0% of total As in the prawn and cuttlefish, respectively, whereas MeHg comprised 94.5% of total Hg in

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

    Science.gov (United States)

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

    2017-12-01

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

  15. Accurate calibration of test mass displacement in the LIGO interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, E [University of Michigan, Ann Arbor, MI 48109 (United States); Savage, R L Jr; Garofoli, J; Kawabe, K; Landry, M [LIGO Hanford Observatory, Richland, WA 99352 (United States); Gonzalez, G; Kissel, J; Sung, M [Louisiana State University, Baton Rouge, LA 70803 (United States); Hirose, E [Syracuse University, Syracuse, NY 13244 (United States); Kalmus, P [Columbia University, New York, NY 10027 (United States); O' Reilly, B; Stuver, A [LIGO Livingston Observatory, Livingston, LA 70754 (United States); Siemens, X, E-mail: egoetz@umich.ed, E-mail: savage_r@ligo-wa.caltech.ed [University of Wisconsin-Milwaukee, Milwaukee, WI 53201 (United States)

    2010-04-21

    We describe three fundamentally different methods we have applied to calibrate the test mass displacement actuators to search for systematic errors in the calibration of the LIGO gravitational-wave detectors. The actuation frequencies tested range from 90 Hz to 1 kHz and the actuation amplitudes range from 10{sup -6} m to 10{sup -18} m. For each of the four test mass actuators measured, the weighted mean coefficient over all frequencies for each technique deviates from the average actuation coefficient for all three techniques by less than 4%. This result indicates that systematic errors in the calibration of the responses of the LIGO detectors to differential length variations are within the stated uncertainties.

  16. Accurate calibration of test mass displacement in the LIGO interferometers

    International Nuclear Information System (INIS)

    Goetz, E; Savage, R L Jr; Garofoli, J; Kawabe, K; Landry, M; Gonzalez, G; Kissel, J; Sung, M; Hirose, E; Kalmus, P; O'Reilly, B; Stuver, A; Siemens, X

    2010-01-01

    We describe three fundamentally different methods we have applied to calibrate the test mass displacement actuators to search for systematic errors in the calibration of the LIGO gravitational-wave detectors. The actuation frequencies tested range from 90 Hz to 1 kHz and the actuation amplitudes range from 10 -6 m to 10 -18 m. For each of the four test mass actuators measured, the weighted mean coefficient over all frequencies for each technique deviates from the average actuation coefficient for all three techniques by less than 4%. This result indicates that systematic errors in the calibration of the responses of the LIGO detectors to differential length variations are within the stated uncertainties.

  17. Applicability of hydraulic dynamometer for measuring load mass on forwarders

    Directory of Open Access Journals (Sweden)

    Pandur Zdravko

    2015-01-01

    Full Text Available In the last few years, with the start of wood biomass production from wood residues, the need for determining the quantity of extracted wood residuals on a landing site has appeared. The beginning of intensive usage of wood residues for wood biomass starts in lowland forest where all wood residues are extracted with forwarders. There are several ways to determine load mass on a forwarder, first and probably most accurate is the use of load cells which are installed between forwarder undercarriage and loading space. In Croatia, as far as it is known, there is no forwarder with such equipment, although manufacturers offer the installation of such equipment when buying a new forwarder. The second option is using a portable measuring platform (axle scale which was already used for research of axle loads of trucks and forwarders. The data obtained with the measuring platform are very accurate, while its deficiency is relatively great mass, large dimensions and high price. The third option is determining mass by using hydraulic dynamometer which is installed on crane between the rotator and the telescopic boom. The production and installation of such a system is very simple, and with the price it can easily compete with previously described measuring systems. The main deficiency of this system is its unsatisfying accuracy. The results of assortment mass measuring with hydraulic dynamometer installed on a hydraulic crane and discussion on factors influencing obtained results will be presented in this paper.

  18. Lean body mass as a determinant of thyroid size

    NARCIS (Netherlands)

    Wesche, M. F.; Wiersinga, W. M.; Smits, N. J.

    1998-01-01

    Males have a larger thyroid gland than females, and this has been related to the difference in body weight. In view of the different body composition of men and women, we hypothesized that lean body mass is a better determinant of thyroid volume than body weight. A cross-sectional study in an area

  19. Simultaneous determination of three pesticide adjuvant residues in plant-derived agro-products using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Li, Hui; Jiang, Zejun; Cao, Xiaolin; Su, Hang; Shao, Hua; Jin, Fen; Abd El-Aty, A M; Wang, Jing

    2017-12-15

    Herein, an accurate and reliable isotope-labelled internal standard method was developed and validated for simultaneous determination of three polar pesticide adjuvants, namely 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone in plant-derived agro-products. Matrices, including apple, cabbage, tomato, cucumber, rice, and wheat were extracted with a modified quick, easy, cheap, effective, rugged, and safe "QuEChERS" method and purified with a new clean-up sorbent (Z-Sep). A hydrophilic interaction liquid chromatography column (HILIC), exhibiting a lipophilic-hydrophilic character, was used to separate the three analytes over 10min using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Matrix effects in various matrices were evaluated and an isotope-labelled internal standard method was employed to compensate for ion enhancement/suppression effects. At three fortification levels (2.0, 5.0, and 20.0μg/kg), the mean recoveries ranged from 78.5 to 112.1% with relative standard deviations (RSDs)determination of the three tested pesticide adjuvant residues in agro-products of plant origin. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Determination of the top mass with exclusive events t->Wb->lvJPsiX

    CERN Document Server

    Chierici, Roberto

    2006-01-01

    This note presents a realistic estimate of the CMS potential for determining the top quark mass via indirect reconstruction using leptonic W decays and from the fragmentation of the b quark. The top quark mass is determined via its correlation with the invariant mass of the and the lepton from the W decay coming from the sametop. This measurement is expected to strongly reduce the systematic errors coming from the hadronic sector, which is known to be dominant indirect reconstruction methods. This analysis also presents many innovations with respect to previously published methods on the subject, and takes into account both physics and combinatorial background. The expected error on from this measurement will be presented as a function of the collected luminosity, and emphasis will be given to the determination of systematic errors, studied in great detail.

  1. Determination of the distribution of uranium and the transuranic elements in the environment by thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Chastagner, P.

    1987-01-01

    Protection of the world population from releases of uranium, plutonium, and other transuranic materials requires, among other things, a knowledge of the sources, transport, and distribution of these elements in the environment. Both isotopic and quantitative analytical data are required in the determination of these factors. Also, the analyses must be precise and accurate enough to distinguish newly released material from older material such as the worldwide deposits from atmospheric weapons testing. For this reason, uranium, neptunium, and plutonium and other transuranic elements in the environment are routinely determined by high-sensitivity thermal ionization mass spectrometric techniques. With current instrumentation and techniques, routine isotope dilution and isotopic analyses are made with purified elemental samples as small as 2 x 10 -14 g. The detection limit for uranium and most of the transuranic isotopes is ∼ 5 x 10 18 g (∼ 13,000 atoms), which is at least an order of magnitude better than the detection limits of the radiometric counting techniques normally employed. The mass spectral sensitivities are equal for all of the isotopes of a given element but vary from element to element. Thus, each elemental sample must be highly purified. Separation techniques recover ∼ 80% of the uranium and the transuranic material from soils and other materials. Interelement separation factors > 10 5 are achieved with advanced ion exchange methods. Results of recent application of these techniques at the Savannah River Lab. and other laboratories are include

  2. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football.

    Science.gov (United States)

    Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

    2016-06-01

    Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2) each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15) and inaccurate (n = 16) kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701). Relative lean mass was positively correlated with kicking accuracy (r = 0.631), while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083). Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy. Key pointsAccurate kickers expressed a very strong inverse relationship between leg mass and foot velocity. Inaccurate kickers were unable to replicate this, with greater volatility in their performance, indicating an ability of accurate kickers to mediate foot velocity to compensate for leg mass in order to deliver the ball over the required distance.Accurate kickers exhibited larger quantities of relative lean mass and lower quantities

  3. Determination of endocrine-disrupting compounds in drinking waters by fast liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Magi, Emanuele; Scapolla, Carlo; Di Carro, Marina; Liscio, Camilla

    2010-09-01

    Growing attention has been recently paid to safety of food and drinking water, making necessary the adoption of policies for water sources protection and the development of sensitive and rapid analytical methods to identify micropollutants. Endocrine-disrupting compounds (EDCs) have emerged as a major issue as they alter the functioning of the endocrine system. Since ingestion of EDCs via food is considered the major exposure route, there is a growing interest in understanding EDC fate during drinking water treatment and in monitoring potential contamination of surface waters and groundwaters. In this work, a fast liquid chromatography-electrospray ionization-tandem mass spectrometry method was developed for the determination of 4-n-nonylphenol (NP), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in drinking waters. In the literature analytical articles seldom provide details regarding fragmentation pathways. In this paper spectra of the five EDCs in negative ESI were interpreted with the support of accurate mass spectra acquired by a quadrupole time-of-flight instrument; fragmentation pathways were also proposed. The chromatographic separation of EDCs was optimized on a Pinnacle DB Biphenylic column with a water-acetonitrile gradient. Quantitative analysis was performed in multiple reaction monitoring (MRM) mode using bisphenol A-d(16) (BPA-d(16)) as internal standard; calibration curves showed good correlation coefficients (0.9989-0.9997). All figures of merit of the method were satisfactory; limits of detection were in the range 0.2-0.4 ng/ml. The method was applied to the determination of the analytes in waters sampled by polar organic chemical integrative samplers in a drinking water treatment plant. Rather low concentration of BPA, NP and E1 were measured in the inlet, while none of the considered EDCs was detected in the outlet. 2010 John Wiley & Sons, Ltd.

  4. Determination of Ultralow Level 129I/127I in Natural Samples by Separation of Microgram Carrier Free Iodine and Accelerator Mass Spectrometry Detection

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Zhou, Weijian; Chen, Ning

    2010-01-01

    of 129I/127I, and a detection limit of this method for 129I is calculated to be 105 atoms. This will allow us to accurately determine 129I in prenuclear geological samples of low iodine concentration with 129I/127I of 10−12, such as loess, soil, coral, rock, sediment, and groundwater. Some samples......Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level 129I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced 129I. In this work, we present...... a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass...

  5. Direct Measurement of Initial 230TH/ 232TH Ratios in Central Texas Speleothems for More Accurate Age Determination

    Science.gov (United States)

    Wortham, B. E.; Banner, J. L.; James, E.; Loewy, S. L.

    2013-12-01

    Speleothems, calcite deposits in caves, preserve a record of climate in their growth rate, isotope ratios and trace element concentrations. These variables must be tied to precise ages to produce pre-instrumental records of climate. The 238U-234U- 230Th disequilibrium method of dating can yield precise ages if the amount of 230Th from the decay of radiogenic 238U can be constrained. 230Th in a speleothem calcite growth layer has two potential sources - 1) decay of radioactive 238U since the time of growth of the calcite layer; and 2) initial detrital 230Th, incorporated along with detrital 232Th, into the calcite layer at the time it grew. Although the calcite lattice does not typically incorporate Th, samples can contain impurities with relatively high Th contents. Initial 230Th/232Th is commonly estimated by assuming a source with bulk-Earth U/Th values in a state of secular equilibrium in the 238U-decay chain. The uncertainty in this 230Th/232Th estimate is also assumed, typically at +/-100%. Both assumptions contribute to uncertainty in ages determined for young speleothems. If the amount of initial detrital 230Th can be better quantified for samples or sites, then U-series ages will have smaller uncertainties and more precisely define the time series of climate proxies. This study determined the initial 230Th/232Th of modern calcite to provide more precise dates for central Texas speleothems. Calcite was grown on glass-plate substrates placed under active drips in central Texas caves. The 230Th/232Th of this modern calcite was determined using thermal ionization mass spectrometry. Results show that: 1) initial 230Th/232Th ratios can be accurately determined in these young samples and 2) measuring 230Th/232Th reduces the uncertainties in previously-determined ages on stalagmites from under the same drips. For example, measured initial 230Th/232Th in calcite collected on substrates from different locations in the cave at Westcave Preserve are 15.3 × 0.67 ppm

  6. Controlling quark mass determinations non-perturbatively in three-flavour QCD

    CERN Document Server

    Campos, Isabel

    2017-01-01

    The determination of quark masses from lattice QCD simulations requires a non-perturbative renormalization procedure and subsequent scale evolution to high energies, where a conversion to the commonly used MS-bar scheme can be safely established. We present our results for the non-perturbative running of renormalized quark masses in Nf=3 QCD between the electroweak and a hadronic energy scale, where lattice simulations are at our disposal. Recent theoretical advances in combination with well-established techniques allows to follow the scale evolution to very high statistical accuracy, and full control of systematic effects.

  7. Determination of chlormequat in pears by liquid chromatography/mass spectrometry

    NARCIS (Netherlands)

    Mol, H.G.J.; Dam, R.C.J. van; Vreeken, R.J.; Steijger, O.M.

    2000-01-01

    A straightforward and reliable method was developed for the determination of chlormequat in pears by liquid chromatography/mass spectrometry (LC/MS). Water and methanol were compared as extraction solvents. Because no significant differences in extraction efficiency or repeatability were found,

  8. Surface-MALDI mass spectrometry in biomaterials research

    DEFF Research Database (Denmark)

    Griesser, H.J.; Kingshott, P.; McArthur, S.L.

    2004-01-01

    Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for over a decade for the determination of purity and accurate molecular masses of macromolecular analytes, such as proteins, in solution. In the last few years the technique has been adapted to become a new...... surfaces and detecting their molecular ions with high mass resolution and at levels much below monolayer coverage. Thus, Surface-MALDI-MS offers unique means of addressing biomaterial surface analysis needs, such as identification of the proteins and lipids that adsorb from multicomponent biological...... solutions in vitro and in vivo, the study of interactions between biomaterial surfaces and biomolecules, and identification of surface-enriched additives and contaminants. Surface-MALDI-MS is rapid, experimentally convenient, overcomes limitations in mass resolution and sensitivity of established...

  9. Identifying modifications in RNA by MALDI mass spectrometry

    DEFF Research Database (Denmark)

    Douthwaite, Stephen; Kirpekar, Finn

    2007-01-01

    as RNA modifications added in cell-free in vitro systems. MALDI-MS is particularly useful in cases in which other techniques such as those involving primer extension or chromatographic analyses are not practicable. To date, MALDI-MS has been used to localize rRNA modifications that are involved......Posttranscriptional modifications on the base or sugar of ribonucleosides generally result in mass increases that can be measured by mass spectrometry. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a direct and accurate means of determining the masses of RNAs. Mass...... spectra produced by MALDI are relatively straightforward to interpret, because they are dominated by singly charged ions, making it possible to analyze complex mixtures of RNA oligonucleotides ranging from trinucleotides up to 20-mers. Analysis of modifications within much longer RNAs, such as ribosomal...

  10. Accurate determination of the composition of Y-Ba-Cu-O superconductor by spectrophotometry, gravimetry and flame AAS

    Energy Technology Data Exchange (ETDEWEB)

    Bruneel, E [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281(S3), 9000 Ghent (Belgium); Verbauwhede, D [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281(S3), 9000 Ghent (Belgium); Vyver, D Van de [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281(S3), 9000 Ghent (Belgium); Schaubroeck, J [Departement Industriele Wetenschappen, Hogeschool Gent, Schoonmeerstraat 52 9000 Ghent (Belgium); Hoste, S [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281(S3), 9000 Ghent (Belgium); Driessche, I Van [Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281(S3), 9000 Ghent (Belgium)

    2005-06-01

    A procedure for the accurate analytical determination of yttrium, barium and copper in an YBa{sub 2}Cu{sub 3}O{sub x} superconductor is described. After dissolution of the material the concentration of Y and Cu was spectrophotometrically determined as an Y-Arsenazo III and a Cu-Nitroso-R-salt complex, respectively. Ba was determined either gravimetrically as BaCrO{sub 4}, after precipitation using a K{sub 2}CrO{sub 4} solution or using flame atomic absorption spectroscopy (AAS). An accuracy better than 0.7% and a coefficient of variation better then 1.2% are obtained. It is illustrated that this analytical procedure can be used to determine the composition of a bulk superconducting YBa{sub 2}Cu{sub 3}O{sub x} sample. For determination of Ba in thin films we suggest the use of flame AAS, with an accuracy of 0.03% and a coefficient of variation of 1.7%.

  11. Determination of ion mobility collision cross sections for unresolved isomeric mixtures using tandem mass spectrometry and chemometric deconvolution

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Brett [Institute of Biomedical Studies, Baylor University, Waco, TX 76798 (United States); Neumann, Elizabeth K. [Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798 (United States); Stow, Sarah M.; May, Jody C.; McLean, John A. [Department of Chemistry, Vanderbilt University, Nashville, TN 37235 (United States); Vanderbilt Institute of Chemical Biology, Nashville, TN 37235 (United States); Vanderbilt Institute for Integrative Biosystems Research and Education, Nashville, TN 37235 (United States); Center for Innovative Technology, Nashville, TN 37235 (United States); Solouki, Touradj, E-mail: Touradj_Solouki@baylor.edu [Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76798 (United States)

    2016-10-05

    Ion mobility (IM) is an important analytical technique for determining ion collision cross section (CCS) values in the gas-phase and gaining insight into molecular structures and conformations. However, limited instrument resolving powers for IM may restrict adequate characterization of conformationally similar ions, such as structural isomers, and reduce the accuracy of IM-based CCS calculations. Recently, we introduced an automated technique for extracting “pure” IM and collision-induced dissociation (CID) mass spectra of IM overlapping species using chemometric deconvolution of post-IM/CID mass spectrometry (MS) data [J. Am. Soc. Mass Spectrom., 2014, 25, 1810–1819]. Here we extend those capabilities to demonstrate how extracted IM profiles can be used to calculate accurate CCS values of peptide isomer ions which are not fully resolved by IM. We show that CCS values obtained from deconvoluted IM spectra match with CCS values measured from the individually analyzed corresponding peptides on uniform field IM instrumentation. We introduce an approach that utilizes experimentally determined IM arrival time (AT) “shift factors” to compensate for ion acceleration variations during post-IM/CID and significantly improve the accuracy of the calculated CCS values. Also, we discuss details of this IM deconvolution approach and compare empirical CCS values from traveling wave (TW)IM-MS and drift tube (DT)IM-MS with theoretically calculated CCS values using the projected superposition approximation (PSA). For example, experimentally measured deconvoluted TWIM-MS mean CCS values for doubly-protonated RYGGFM, RMFGYG, MFRYGG, and FRMYGG peptide isomers were 288.{sub 8} Å{sup 2}, 295.{sub 1} Å{sup 2}, 296.{sub 8} Å{sup 2}, and 300.{sub 1} Å{sup 2}; all four of these CCS values were within 1.5% of independently measured DTIM-MS values.

  12. Determination of ion mobility collision cross sections for unresolved isomeric mixtures using tandem mass spectrometry and chemometric deconvolution

    International Nuclear Information System (INIS)

    Harper, Brett; Neumann, Elizabeth K.; Stow, Sarah M.; May, Jody C.; McLean, John A.; Solouki, Touradj

    2016-01-01

    Ion mobility (IM) is an important analytical technique for determining ion collision cross section (CCS) values in the gas-phase and gaining insight into molecular structures and conformations. However, limited instrument resolving powers for IM may restrict adequate characterization of conformationally similar ions, such as structural isomers, and reduce the accuracy of IM-based CCS calculations. Recently, we introduced an automated technique for extracting “pure” IM and collision-induced dissociation (CID) mass spectra of IM overlapping species using chemometric deconvolution of post-IM/CID mass spectrometry (MS) data [J. Am. Soc. Mass Spectrom., 2014, 25, 1810–1819]. Here we extend those capabilities to demonstrate how extracted IM profiles can be used to calculate accurate CCS values of peptide isomer ions which are not fully resolved by IM. We show that CCS values obtained from deconvoluted IM spectra match with CCS values measured from the individually analyzed corresponding peptides on uniform field IM instrumentation. We introduce an approach that utilizes experimentally determined IM arrival time (AT) “shift factors” to compensate for ion acceleration variations during post-IM/CID and significantly improve the accuracy of the calculated CCS values. Also, we discuss details of this IM deconvolution approach and compare empirical CCS values from traveling wave (TW)IM-MS and drift tube (DT)IM-MS with theoretically calculated CCS values using the projected superposition approximation (PSA). For example, experimentally measured deconvoluted TWIM-MS mean CCS values for doubly-protonated RYGGFM, RMFGYG, MFRYGG, and FRMYGG peptide isomers were 288._8 Å"2, 295._1 Å"2, 296._8 Å"2, and 300._1 Å"2; all four of these CCS values were within 1.5% of independently measured DTIM-MS values.

  13. Experimental determination of airplane mass and inertial characteristics

    Science.gov (United States)

    Wolowicz, C. H.; Yancey, R. B.

    1974-01-01

    Current practices are evaluated for experimentally determining airplane center of gravity, moments of inertia, and products of inertia. The techniques discussed are applicable to bodies other than airplanes. In pitching- and rolling-moment-of-inertia investigations with the airplane mounted on and pivoted about knife edges, the nonlinear spring moments that occur at large amplitudes of oscillation can be eliminated by using the proper spring configuration. The single-point suspension double-pendulum technique for obtaining yawing moments of inertia, products of inertia, and the inclination of the principal axis provides accurate results from yaw-mode oscillation data, provided that the sway-mode effects are minimized by proper suspension rig design. Rocking-mode effects in the data can be isolated.

  14. Mass Measurement of Very Short Half-Lived Nuclei

    CERN Document Server

    Duma, M; Iacob, V E; Thibault, C

    2002-01-01

    The MISTRAL (Mass measurements at ISolde with a Transmission RAdiofrequency spectrometer on-Line) experiment exploits a rapid measurement technique to make accurate mass determinations of very short-lived nuclei. The physics goals are to elucidate new nuclear structure effects and constrain nuclear mass models in regions of interest to nuclear astrophysics.\\\\ \\\\The spectrometer, installed in May 97, performed as promised in the proposal with mass resolution exceeding 100,000. In its first experiment in July 1998, neutron-rich Na isotopes having half-lives as short as 31 ms were measured. A second experiment in November 1998 enabled us to improve the measurement precision of the isotopes $^{26-30}$Na to about 20 keV. The measurement program continues as experiment IS 373.

  15. Water vapor mass balance method for determining air infiltration rates in houses

    Science.gov (United States)

    David R. DeWalle; Gordon M. Heisler

    1980-01-01

    A water vapor mass balance technique that includes the use of common humidity-control equipment can be used to determine average air infiltration rates in buildings. Only measurements of the humidity inside and outside the home, the mass of vapor exchanged by a humidifier/dehumidifier, and the volume of interior air space are needed. This method gives results that...

  16. New Beta-delayed Neutron Measurements in the Light-mass Fission Group

    Energy Technology Data Exchange (ETDEWEB)

    Agramunt, J. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); García, A.R. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Algora, A. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Äystö, J. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Caballero-Folch, R.; Calviño, F. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Cano-Ott, D. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Cortés, G. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Domingo-Pardo, C. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Eronen, T. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Gelletly, W. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Gómez-Hornillos, M.B. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); and others

    2014-06-15

    A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for {sup 91}Br, {sup 86}As, {sup 85}As, and {sup 85}Ge nuclei.

  17. Reduction of determinate errors in mass bias-corrected isotope ratios measured using a multi-collector plasma mass spectrometer

    International Nuclear Information System (INIS)

    Doherty, W.

    2015-01-01

    A nebulizer-centric instrument response function model of the plasma mass spectrometer was combined with a signal drift model, and the result was used to identify the causes of the non-spectroscopic determinate errors remaining in mass bias-corrected Pb isotope ratios (Tl as internal standard) measured using a multi-collector plasma mass spectrometer. Model calculations, confirmed by measurement, show that the detectable time-dependent errors are a result of the combined effect of signal drift and differences in the coordinates of the Pb and Tl response function maxima (horizontal offset effect). If there are no horizontal offsets, then the mass bias-corrected isotope ratios are approximately constant in time. In the absence of signal drift, the response surface curvature and horizontal offset effects are responsible for proportional errors in the mass bias-corrected isotope ratios. The proportional errors will be different for different analyte isotope ratios and different at every instrument operating point. Consequently, mass bias coefficients calculated using different isotope ratios are not necessarily equal. The error analysis based on the combined model provides strong justification for recommending a three step correction procedure (mass bias correction, drift correction and a proportional error correction, in that order) for isotope ratio measurements using a multi-collector plasma mass spectrometer

  18. Community air monitoring for pesticides-part 2: multiresidue determination of pesticides in air by gas chromatography, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Hengel, Matt; Lee, P

    2014-03-01

    Two multiresidue methods were developed to determine pesticides in air collected in California. Pesticides were trapped using XAD-4 resin and extracted with ethyl acetate. Based on an analytical method from the University of California Davis Trace Analytical Laboratory, pesticides were detected by analyzing the extract by gas chromatography-mass spectrometry (GC-MS) to determine chlorothalonil, chlorthal-dimethyl, cycloate, dicloran, dicofol, EPTC, ethalfluralin, iprodione, mefenoxam, metolachlor, PCNB, permethrin, pronamide, simazine, trifluralin, and vinclozolin. A GC with a flame photometric detector was used to determine chlorpyrifos, chlorpyrifos oxon, diazinon, diazinon oxon, dimethoate, dimethoate oxon, fonophos, fonophos oxon, malathion, malathion oxon, naled, and oxydemeton. Trapping efficiencies ranged from 78 to 92 % for low level (0.5 μg) and 37-104 % for high level (50 and 100 μg) recoveries. Little to no degradation of compounds occurred over 31 days; recoveries ranged from 78 to 113 %. In the California Department of Food and Agriculture (CDFA) method, pesticides were detected by analyzing the extract by GC-MS to determine chlorothalonil, chlorpyrifos, cypermethrin, dichlorvos, dicofol, endosulfan 1, endosulfan sulfate, oxyfluorfen, permethrin, propargite, and trifluralin. A liquid chromatograph coupled to a MS was used to determine azinphos-methyl, chloropyrifos oxon, DEF, diazinon, diazinon oxon, dimethoate, dimethoate oxon, diuron, EPTC, malathion, malathion oxon, metolachlor, molinate, norflurazon, oryzalin, phosmet, propanil, simazine and thiobencarb. Trapping efficiencies for compounds determined by the CDFA method ranged from 10 to 113, 22 to 114, and 56 to 132 % for 10, 5, and 2 μg spikes, respectively. Storage tests yielded 70-170 % recovery for up to 28 days. These multiresidue methods represent flexible, sensitive, accurate, and cost-effective ways to determine residues of various pesticides in ambient air.

  19. Determination of W boson mass from the four quark decay in the DELPHI experiment at LEP; Mesure de la masse du boson W dans la desintegration a quatre quarks dans l'experience DELPHI au LEP

    Energy Technology Data Exchange (ETDEWEB)

    Duperrin, Arnaud [Universite Claude Bernard, 69 - Lyon (France)

    1999-04-20

    The accurate determination of W boson mass allows testing the coherence of standard model and imposing new constrains upon some of its parameters as for instance the Higgs boson mass. The W mass obtained by direct reconstruction of WW{yields}qq-bar qq-bar, was measured by means of the data recorded in 1997 and 1998 by DELPHI experimentat the center-of-mass energies 183 GeV and 189 GeV, for a total luminosity of 212 pb{sup -1} at the LEP collider of CERN. A neural network was used to label the signal what led to an efficiency and a selection accuracy of 86% and 80%, respectively. The number of the selected events among the data was 1710. By mass reconstruction, the jet multiplicity was let to vary free between four and eight jets. A new fast algorithm of kinematic fitting of the jets was developed to improve the mass resolution of the multi-jet events, by imposing the energy and momentum conservation. The association of jets has been carried out also by means of a neural network. The W boson mass was extracted starting from a probability fitting of the two-dimensional distribution provided by complete simulation and formed by the mean and the difference of two masses of W reconstructs. A technique of Monte Carlo re-weighting has been developed to obtain the simulation spectra for arbitrary M{sub W} values. The leading systematic uncertainties are studied by gathering a large number of e{sup +}e{sup -}{yields}Z{yields}qq-bar events and by merging them for obtaining events similar to the W pairs. The value of the W mass obtained from the data based on this probability is M{sub W} = 80.350{+-}0.099 (stat.) {+-} 0.038 (exp.) {+-} 0.056 (th.) {+-} 0.018 (LEP) GeV/c{sup 2}. This result is competitive and in good agreement with other determinations. The current world average mass of W boson is M{sub W} = 80.394 {+-} 0.042 GeV/c{sup 2}. This result, included in a global fitting of the electroweak data, constraints the standard Higgs boson to a mass lower than 262 Ge

  20. Mass determination based on electron scattering in electron probe X-ray microanalysis of thin biological specimens

    International Nuclear Information System (INIS)

    Linders, P.W.J.

    1984-01-01

    This thesis describes the development of a method for mass determination of thin biological objects by quantitative electron microscopy. The practical realization of the mass determination consists of photographical recording with subsequent densitometry. (Auth.)

  1. StarHorse: a Bayesian tool for determining stellar masses, ages, distances, and extinctions for field stars

    Science.gov (United States)

    Queiroz, A. B. A.; Anders, F.; Santiago, B. X.; Chiappini, C.; Steinmetz, M.; Dal Ponte, M.; Stassun, K. G.; da Costa, L. N.; Maia, M. A. G.; Crestani, J.; Beers, T. C.; Fernández-Trincado, J. G.; García-Hernández, D. A.; Roman-Lopes, A.; Zamora, O.

    2018-05-01

    Understanding the formation and evolution of our Galaxy requires accurate distances, ages, and chemistry for large populations of field stars. Here, we present several updates to our spectrophotometric distance code, which can now also be used to estimate ages, masses, and extinctions for individual stars. Given a set of measured spectrophotometric parameters, we calculate the posterior probability distribution over a given grid of stellar evolutionary models, using flexible Galactic stellar-population priors. The code (called StarHorse) can accommodate different observational data sets, prior options, partially missing data, and the inclusion of parallax information into the estimated probabilities. We validate the code using a variety of simulated stars as well as real stars with parameters determined from asteroseismology, eclipsing binaries, and isochrone fits to star clusters. Our main goal in this validation process is to test the applicability of the code to field stars with known Gaia-like parallaxes. The typical internal precisions (obtained from realistic simulations of an APOGEE+Gaia-like sample) are {˜eq } 8 {per cent} in distance, {˜eq } 20 {per cent} in age, {˜eq } 6 {per cent} in mass, and ≃ 0.04 mag in AV. The median external precision (derived from comparisons with earlier work for real stars) varies with the sample used, but lies in the range of {˜eq } [0,2] {per cent} for distances, {˜eq } [12,31] {per cent} for ages, {˜eq } [4,12] {per cent} for masses, and ≃ 0.07 mag for AV. We provide StarHorse distances and extinctions for the APOGEE DR14, RAVE DR5, GES DR3, and GALAH DR1 catalogues.

  2. Gas chromatography–triple quadrupole mass spectrometry for the determination of atmospheric polychlorinated naphthalenes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fang [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Jing [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Sun, Xiaoli [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Xueli; Li, Yun; Shah, Syed Mazhar [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China)

    2014-09-15

    Highlights: • Atmospheric PCNs were detected by isotope-dilution GC–MS/MS. • The pollution levels of PCNs covering from mono- to octa-CNs were investigated comprehensively in air samples. • The dioxin-like toxicity and human exposure levels of PCNs in air samples were estimated. - Abstract: Atmospheric polychlorinated naphthalenes (PCNs) ranging from mono-CNs to octa-CNs were detected using isotope-dilution gas chromatography coupled with triple quadrupole mass spectrometry (GC–MS/MS). The developed instrumental method was successfully applied to the determination of PCNs in technical products. It was observed that there were significant differences in concentrations, homologue profiles, chlorinated contents and total toxic equivalents (∑TEQs) of PCNs for four Halowax products. Subsequently, the validation of the analytical method was evaluated for the determination of PCNs in air samples in terms of method detection limit (MDL), recovery and matrix effect. The results demonstrated that this method could provide satisfactory sensitivity and adequate selectivity with lower cost. It was conducted to comprehensively evaluate the levels, composition patterns, ∑TEQs, and daily intake exposure of PCNs in indoor and outdoor air samples. Concentrations and ∑TEQs of PCNs in air samples ranged 47.7–832.7 pg m{sup −3} and 1.31–5.99 fg m{sup −3}, respectively, and the predominant homologues were di- and tri-CNs in the gas phase. The results indicated that this analytical method was useful for the accurate and specific evaluation of dioxin-like toxicity and human exposure levels of PCNs in the atmosphere.

  3. arXiv Mass-improvement of the vector current in three-flavor QCD

    CERN Document Server

    Fritzsch, Patrick

    2018-06-04

    We determine two improvement coefficients which are relevant to cancel mass-dependent cutoff effects in correlation functions with operator insertions of the non-singlet local QCD vector current. This determination is based on degenerate three-flavor QCD simulations of non-perturbatively O(a) improved Wilson fermions with tree-level improved gauge action. Employing a very robust strategy that has been pioneered in the quenched approximation leads to an accurate estimate of a counterterm cancelling dynamical quark cutoff effects linear in the trace of the quark mass matrix. To our knowledge this is the first time that such an effect has been determined systematically with large significance.

  4. Molecular effects in the neutrino mass determination from beta-decay of the tritium molecule

    International Nuclear Information System (INIS)

    Fackler, O.; Jeziorski, B.; Kolos, W.; Szalewicz, K.; Monkhorst, H.J.; Mugge, M.

    1986-03-01

    Molecular final state energies and transition probabilities have been computed for beta-decay of the tritium molecule. The results are of sufficient accuracy to make a determination of the electron neutrino rest mass with an error not exceeding a few tenths of an electron volt. Effects of approximate models of tritium beta-decay on the neutrino mass determination are discussed. 14 refs., 3 figs., 1 tab

  5. Accurate and approximate thermal rate constants for polyatomic chemical reactions

    International Nuclear Information System (INIS)

    Nyman, Gunnar

    2007-01-01

    In favourable cases it is possible to calculate thermal rate constants for polyatomic reactions to high accuracy from first principles. Here, we discuss the use of flux correlation functions combined with the multi-configurational time-dependent Hartree (MCTDH) approach to efficiently calculate cumulative reaction probabilities and thermal rate constants for polyatomic chemical reactions. Three isotopic variants of the H 2 + CH 3 → CH 4 + H reaction are used to illustrate the theory. There is good agreement with experimental results although the experimental rates generally are larger than the calculated ones, which are believed to be at least as accurate as the experimental rates. Approximations allowing evaluation of the thermal rate constant above 400 K are treated. It is also noted that for the treated reactions, transition state theory (TST) gives accurate rate constants above 500 K. TST theory also gives accurate results for kinetic isotope effects in cases where the mass of the transfered atom is unchanged. Due to neglect of tunnelling, TST however fails below 400 K if the mass of the transferred atom changes between the isotopic reactions

  6. Determination of plutonium-241 half-life by mass spectrometric measurement

    International Nuclear Information System (INIS)

    Hiyama, Takashi; Wada, Yukio; Onishi, Koichi

    1982-01-01

    Much data for Pu-241 half-life have been reported, but these values range from 13.8 years to 15.1 years depending on investigators. In order to define the half-life of Pu-241, the half-life was calculated by analyzing the mass spectrometry data obtained in the author's laboratory over the past six years on Plutonium Isotopic Standard Reference Materials prepared at the National Bureau of Standards (NBS). The sample used for this work consisted of SRM-947 and SRM-948 prepared at NBS. Before mass spectrometric analysis, the plutonium aliquot was separated from its Am-241 daughter by anion exchange chromatography, since Am-241 is not distinguished from Pu-241 in the mass spectrometer. 241 Pu/ 239 Pu and 241 Pu/ 240 Pu ratios were calculated from the values of mass spectrometric measurement. From the relation of log N to time, the half-life of Pu-241 was determined, based on the slope using a least squares fit. The half-life of Pu-241 was estimated to be 14.29+-0.15 years. (Yoshitake, I.)

  7. Higgs-boson contributions to gauge-boson mass shifts in extended electroweak models

    International Nuclear Information System (INIS)

    Moore, S.R.

    1985-01-01

    The author analyzed the mass shifts for models with a more complicated Higgs sector. He uses the on-shell renormalization scheme, in which the parameters of the theory are the physical masses and couplings. The author has considered the 2-doublet, n-doublet, triplet and doublet-triplet models. He has found that the Z-boson mass prediction has a strong dependence on the charged-Higgs mass. In the limit that the charged Higgs is much heavier than the gauge bosons, the Higgs-dependent terms become significant, and may even cancel the light-fermion terms. If the author uses the Z mass as input in determining the parameters of the theory, a scenario which will become attractive as the mass of the Z is accurately measured in the next few years, it is found that the W-boson mass shift exhibits the same sort of behavior, differing from the minimal model for the case of the charged Higgs being heavy. The author has found that when the radiative corrections are taken into account, models with extended Higgs sectors may differ significantly from the minimal standard model in this predictions for the gauge-boson masses. Thus, an accurate measurement of the masses will help shed light on the structure of the Higgs sector

  8. [Determination of lidocaine and its metabolites in human plasma by liquid chromatography in combination with tandem mass spectrometry].

    Science.gov (United States)

    Xiang, Jin; Zhang, Cheng; Yu, Qin; Liang, Mao-Zhi; Qin, Yong-Ping; Nan, Feng

    2010-07-01

    To establish a liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method for the determination of lidocaine (LDC) and its metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), in human plasma. METHODS; The assay was conducted with an API 3000 HPLC-MS/MS system consisted of a Ultimate C18 column (50 x 4.6 mm, 5 microm). The mobile phase consisted of methanol: 5 mmol/ L ammonium acetate (50:50, pH was adjusted to 5.0 by formic acid) and the flow rate was set at 0.2 mL/min. The alkalinized sample was extracted with ethyl acetate. After evaporation of the organic layer, the residue was dissolved in mobile phase and the drug was determined by HPLC-MS/MS using electrospray ionization. The calibration curve was linear in a range from 15.625 to 2000 ng/mL for LDC. Linear calibration curves were obtained in the range of 1.5625 to 200 ng/mL for both for MEGX and GX. The limit of quantification for LDC, MEGX and GX was set at 15.625, 1.5625 and 1.5625 ng/mL. This method for the quantitative determination of lidocaine and its metabolites in human plasma is simple, rapid, sensitive and accurate. Therefore it can be used for the determination of lidocaine and its metabolites in clinical practice.

  9. SYSTEMATIC UNCERTAINTIES IN BLACK HOLE MASSES DETERMINED FROM SINGLE-EPOCH SPECTRA

    International Nuclear Information System (INIS)

    Denney, Kelly D.; Peterson, Bradley M.; Dietrich, Matthias; Bentz, Misty C.; Vestergaard, Marianne

    2009-01-01

    We explore the nature of systematic errors that can arise in measurement of black hole masses from single-epoch (SE) spectra of active galactic nuclei (AGNs) by utilizing the many epochs available for NGC 5548 and PG1229+204 from reverberation mapping (RM) databases. In particular, we examine systematics due to AGN variability, contamination due to constant spectral components (i.e., narrow lines and host galaxy flux), data quality (i.e., signal-to-noise ratio (S/N)), and blending of spectral features. We investigate the effect that each of these systematics has on the precision and accuracy of SE masses calculated from two commonly used line width measures by comparing these results to recent RM studies. We calculate masses by characterizing the broad Hβ emission line by both the full width at half maximum and the line dispersion, and demonstrate the importance of removing narrow emission-line components and host starlight. We find that the reliability of line width measurements rapidly decreases for S/N lower than ∼ 10-20 (per pixel), and that fitting the line profiles instead of direct measurement of the data does not mitigate this problem but can, in fact, introduce systematic errors. We also conclude that a full spectral decomposition to deblend the AGN and galaxy spectral features is unnecessary, except to judge the contribution of the host galaxy to the luminosity and to deblend any emission lines that may inhibit accurate line width measurements. Finally, we present an error budget which summarizes the minimum observable uncertainties as well as the amount of additional scatter and/or systematic offset that can be expected from the individual sources of error investigated. In particular, we find that the minimum observable uncertainty in SE mass estimates due to variability is ∼ 20 pixel -1 ) spectra.

  10. Determination of plutonium in soils by mass spectrometry

    International Nuclear Information System (INIS)

    Storms, H.A.; Carlson, D.C.; Hunter, F.F.

    1974-01-01

    A procedure is described in which mass spectrometry is utilized for the determination of plutonium in soils. Using this procedure we have measured plutonium isotopic compositions at concentrations as low as 2 x 10 -14 grams Pu per gram soil. A thermal ionization source with canoe-shaped rhenium filament, is utilized in the mass spectrometer. The plutonium, when loaded onto the filament, is contained in a single Dowex-1 resin bead which is about 350 micrometers in diameter. Concentrating the plutonium within this single bead is a key step in the procedure and produces a relatively clean plutonium fraction. The resin bead also serves as an effective diffusion barrier such that the plutonium is prevented from being removed with the lower boiling impurities. The Pu remains in the bead until the temperature is sufficiently high for efficient production of Pu + ions. Plutonium ionization efficiencies as high as 2.5 percent have been measured

  11. A method for determination mass absorption coefficient of gamma rays by Compton scattering.

    Science.gov (United States)

    El Abd, A

    2014-12-01

    A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Determination of ultra-low levels of uranium using resonance ionization mass spectrometry

    International Nuclear Information System (INIS)

    Kiran Kumar, P.V.; Acharyulu, G.V.S.G.

    2015-01-01

    The determination of isotopic composition of actinides like U and Pu is important, due to their distribution in the environment as a result of nuclear weapons testing, fuel reprocessing, reactor operations and to a smaller extent from accidental releases. The analytical methods like fission track analysis (FTA), thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICPMS) and resonance ionization mass spectrometry (RIMS) have evolved as sensitive techniques. Resonance Ionization Mass Spectrometry yields rapid isotopic signature data for material containing actinides without requiring time-consuming sample preparation and chemical separation procedures. In this paper, authors presented the details of the methodology and results for low-level detection of uranium using RIMS

  13. Chiral recognition and determination of enantiomeric excess by mass spectrometry: A review

    International Nuclear Information System (INIS)

    Yu, Xiangying; Yao, Zhong-Ping

    2017-01-01

    Chiral analysis is of great importance to fundamental and applied research in chemical, biological and pharmaceutical sciences. Due to the superiority of mass spectrometry (MS) over other analytical methods in terms of speed, specificity and sensitivity, chiral analysis by MS has attracted much interest in recent years. Chiral analysis by MS typically involves introduction of a chiral selector to form diastereomers with analyte enantiomers, and comparison of the behaviors of diastereomers in MS. Chiral differentiation can be achieved by comparing the relative abundances of diastereomers, the thermodynamic or kinetic constants of ion-molecule reactions of diastereomers in the gas phase, the dissociation of diastereomers in MS/MS, or the mobility of diastereomers in ion mobility mass spectrometry. In this review, chiral recognition and determination of enantiomeric excess by these chiral MS methods were summarized, and the prospects of chiral analysis by MS were discussed. - Highlights: • Both chiral recognition and determination of enantiomeric excess by mass spectrometry are systematically reviewed. • Classification is based on the behavioral differences of diastereomers formed between chiral analytes and chiral selectors. • Development of ion mobility mass spectrometry for chiral differentiation is covered. • Various methods are highlighted and compared.

  14. Chiral recognition and determination of enantiomeric excess by mass spectrometry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiangying [College of Pharmacy, Jinan University, Guangzhou 510632, Guangdong (China); State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation) and Shenzhen Key Laboratory of Food Biological Safety Control, Shenzhen Research Institute of Hong Kong Polytechnic University, Shenzhen 518057 (China); Yao, Zhong-Ping, E-mail: zhongping.yao@polyu.edu.hk [State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation) and Shenzhen Key Laboratory of Food Biological Safety Control, Shenzhen Research Institute of Hong Kong Polytechnic University, Shenzhen 518057 (China); Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules (Yanbian University), Ministry of Education, Yanji 133002, Jilin (China); State Key Laboratory of Chirosciences, Food Safety and Technology Research Centre and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region (China)

    2017-05-22

    Chiral analysis is of great importance to fundamental and applied research in chemical, biological and pharmaceutical sciences. Due to the superiority of mass spectrometry (MS) over other analytical methods in terms of speed, specificity and sensitivity, chiral analysis by MS has attracted much interest in recent years. Chiral analysis by MS typically involves introduction of a chiral selector to form diastereomers with analyte enantiomers, and comparison of the behaviors of diastereomers in MS. Chiral differentiation can be achieved by comparing the relative abundances of diastereomers, the thermodynamic or kinetic constants of ion-molecule reactions of diastereomers in the gas phase, the dissociation of diastereomers in MS/MS, or the mobility of diastereomers in ion mobility mass spectrometry. In this review, chiral recognition and determination of enantiomeric excess by these chiral MS methods were summarized, and the prospects of chiral analysis by MS were discussed. - Highlights: • Both chiral recognition and determination of enantiomeric excess by mass spectrometry are systematically reviewed. • Classification is based on the behavioral differences of diastereomers formed between chiral analytes and chiral selectors. • Development of ion mobility mass spectrometry for chiral differentiation is covered. • Various methods are highlighted and compared.

  15. Performance results of a mobile high-resolution MR-TOF mass spectrometer for in-situ analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lippert, Wayne; Lang, Johannes [Justus-Liebig-Universitaet Giessen (Germany); Ayet San Andres, Samuel [GSI, Darmstadt (Germany); Dickel, Timo; Geissel, Hans; Plass, Wolfgang; Scheidenberger, Christoph [Justus-Liebig-Universitaet Giessen (Germany); GSI, Darmstadt (Germany); Yavor, Mikhail [RAS St. Petersburg (Russian Federation)

    2014-07-01

    A mobile multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been developed which provides a mass resolving power exceeding 250,000 and sub-ppm mass accuracy in a transportable format. Thus it allows resolving isobars and enables accurate determination of the composition and structure of biomolecules. Furthermore the device offers high mass resolving MS/MS capability via selective ion re-trapping and collisional-induced dissociation (CID). An atmospheric pressure interface (API) provides for routine measurements with various atmospheric ion sources. All supply electronics, DAQ and control system are mounted with the spectrometer into a single frame with a total volume of only 0.8 m{sup 3}. With the current system many applications like waste water monitoring at hot spots, mass-based classification of biomolecules and breath analysis are possible. In addition the mass spectrometer is readily scalable and can be adopted and simplified for even more specific use like in space science for instance. A characterization and first performance results are shown, and the implementation of MS/MS in combination with CID is discussed.

  16. Accurate quantification of polycyclic aromatic hydrocarbons in dust samples using microwave-assisted solvent extraction combined with isotope-dilution mass spectrometry

    International Nuclear Information System (INIS)

    Itoh, Nobuyasu; Fushimi, Akihiro; Yarita, Takashi; Aoyagi, Yoshie; Numata, Masahiko

    2011-01-01

    Highlights: → We applied MAE-IDMS for accurate quantification of PAHs in dust samples. → Both partitioning and isotopic equilibria can be achieved using this technique. → MAE-IDMS can provide accurate concentrations even if extraction efficiencies were low. → Characteristics of samples strongly affected for low extraction efficiencies of PAHs. - Abstract: For accurate quantification of polycyclic aromatic hydrocarbons (PAHs) in dust samples, we investigated the use of microwave-assisted solvent extraction (MAE) combined with isotope-dilution mass spectrometry (IDMS) using deuterium-labelled PAHs (D-PAHs). Although MAE with a methanol/toluene mixture (1:3 by volume) at 160 deg. C for 40 min was best for extracting PAHs from tunnel dust among examined, the recovery yields of D-PAHs decreased with increasing molecular weight (<40% for MW ≥ 264; that of deuterium-labelled indeno[123-cd]pyrene (D-IcdP) was only 7.1%). Although the residues were extracted a second time, the observed concentrations did not change dramatically (<5%), and the recovery yields of heavier D-PAHs (i.e., MW ≥ 264) were approximately half of those of the first extract, including D-IcdP (3.4%). These results suggest that both partitioning and isotopic equilibria of PAHs and D-PAHs between sample and solvent were achieved for extractable heavier PAHs under the condition. Thus, the observed concentrations of PAHs obtained by MAE-IDMS were reasonable, even though recovery yields of D-PAHs were <50%. From the results of carbon analyses and extractable contents, lower recovery yields of D-PAHs from the tunnel dust were due to a large content of char with low extractable contents.

  17. Determination of mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal.

    Science.gov (United States)

    Soluch, Waldemar; Brzozowski, Ernest; Lysakowska, Magdalena; Sadura, Jolanta

    2011-11-01

    Mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal were determined. Mass density was obtained from the measured ratio of mass to volume of a cuboid. The dielectric constants were determined from the measured capacitances of an interdigital transducer (IDT) deposited on a Z-cut plate and from a parallel plate capacitor fabricated from this plate. The elastic and piezoelectric constants were determined by comparing the measured and calculated SAW velocities and electromechanical coupling coefficients on the Z- and X-cut plates. The following new constants were obtained: mass density p = 5986 kg/m(3); relative dielectric constants (at constant strain S) ε(S)(11)/ε(0) = 8.6 and ε(S)(11)/ε(0) = 10.5, where ε(0) is a dielectric constant of free space; elastic constants (at constant electric field E) C(E)(11) = 349.7, C(E)(12) = 128.1, C(E)(13) = 129.4, C(E)(33) = 430.3, and C(E)(44) = 96.5 GPa; and piezoelectric constants e(33) = 0.84, e(31) = -0.47, and e(15) = -0.41 C/m(2).

  18. Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200

    Science.gov (United States)

    Knezevic, David; Jovancevic, Nikola; Sukhovoj, Anatoly M.; Mitsyna, Ludmila V.; Krmar, Miodrag; Cong, Vu D.; Hambsch, Franz-Josef; Oberstedt, Stephan; Revay, Zsolt; Stieghorst, Christian; Dragic, Aleksandar

    2018-03-01

    The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei Eex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.

  19. Mass determination of U-233 and Pu-239 by gamma spectrometry technique

    International Nuclear Information System (INIS)

    Moraes, M.A.P.V. de; Pugliesi, R.

    1988-09-01

    The gamma spectrometry technique has been used for masses determinations of uranium-233 and plutonium-239, granted by AERE-HARWELL. A high purity Ge semicondutor detector was used and the total efficiency curve was obtained for the counting system in the energy range 13 KeV to 135 KeV. The calculated values for the masses compared with that obtained by means of gravimetry technique. (author) [pt

  20. Perpendicular eν mass from W decay

    International Nuclear Information System (INIS)

    Barger, V.; Martin, A.G.; Phillips, R.J.N.

    1983-01-01

    Properties of the perpendicular eν mass, defined in terms of transverse momenta p-vectorsub(T) by Msub(T)sup(2)(eν) = 2|p-vectorsub(eT)| |p-vectorsub(νT)| - 2p-vectorsub(eT).p-vectorsub(νT), that make it particularly well suited to W mass and width determinations are examined. An analytic expression for its distribution in W production and subsequent W → eν decay at p-barp colliders, accurate to order approximately equal to 1% is given. A maximum likelihood fit of this formula to the five UA1 events gives Msub(W) = 80.3 +- 3 6 GeV. (author)

  1. Ultrasensitive mass sensing with nonlinear optics in a doubly clamped suspended carbon nanotube resonator

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Jun; Zhu, Ka-Di [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai 2 00240 (China)

    2013-12-07

    Nanomechanical resonator makes itself as an ideal system for ultrasensitive mass sensing due to its ultralow mass and high vibrational frequency. The mass sensing principle is due to the linear relationship of the frequency-shift and mass-variation. In this work, we will propose a nonlinear optical mass sensor based on a doubly clamped suspended carbon nanotube resonator in all-optical domain. The masses of external particles (such as nitric oxide molecules) landing onto the surface of carbon nanotube can be determined directly and accurately via using the nonlinear optical spectroscopy. This mass sensing proposed here may provide a nonlinear optical measurement technique in quantum measurements and environmental science.

  2. Linear signal noise summer accurately determines and controls S/N ratio

    Science.gov (United States)

    Sundry, J. L.

    1966-01-01

    Linear signal noise summer precisely controls the relative power levels of signal and noise, and mixes them linearly in accurately known ratios. The S/N ratio accuracy and stability are greatly improved by this technique and are attained simultaneously.

  3. Mass spectrometric determination of magnesium isotopic ratios and its corrections for electron multiplier discrimination and mass fractionation

    International Nuclear Information System (INIS)

    Deng Zhongguo

    1989-01-01

    The mass spectrometric determination of magnesium isotopic ratios by the use of uranyl nitrate added to magnesium samples to act as a binding agent is reported. Prebaking empty filaments and preheating filaments with deposited magnesium samples on its surface in a vacuum are employed to reduce the Na signal from the thenium-ribbon. Methods for correcting magnesium isotopic ratios for electron multiplier discrimination and mass fractionation are described in detail. The results of the determination of natural magnesium isotopic ratios are 25 Mg/ 24 Mg = 0.12660 (1±0.01%) and 26 Mg/ 24 Mg = 0.13938 (1±0.10%). The magnesium isotopic ratios of rich - 26 Mg-2 sample and rich- 25 Mg-1 sample are 24 Mg/ 26 Mg = 0.003463 (1±0.2%), 25 Mg/ 26 Mg = 0.001656 (±0.2%) and 24 Mg/ 25 Mg = 0.006716 (1±0.2%), 26 Mg/ 25 Mg = 0.007264 (1±0.2%) respectively

  4. The angular momentum-mass relation: a fundamental law from dwarf irregulars to massive spirals

    Science.gov (United States)

    Posti, Lorenzo; Fraternali, Filippo; Di Teodoro, Enrico M.; Pezzulli, Gabriele

    2018-05-01

    In a Λ CDM Universe, the specific stellar angular momentum (j*) and stellar mass (M*) of a galaxy are correlated as a consequence of the scaling existing for dark matter haloes (jh ∝2/3). The shape of this law is crucial to test galaxy formation models, which are currently discrepant especially at the lowest masses, allowing to constrain fundamental parameters, such as, for example, the retained fraction of angular momentum. In this study, we accurately determine the empirical j*-M* relation (Fall relation) for 92 nearby spiral galaxies (from S0 to Irr) selected from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample in the unprecedented mass range 7 ≲ log M*/M⊙≲ 11.5. We significantly improve all previous estimates of the Fall relation by determining j* profiles homogeneously for all galaxies, using extended HI rotation curves, and selecting only galaxies for which a robust j* could be measured (converged j*(http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/L6

  5. An on-spot internal standard addition approach for accurately determining colistin A and colistin B in dried blood spots using ultra high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tsai, I-Lin; Kuo, Ching-Hua; Sun, Hsin-Yun; Chuang, Yu-Chung; Chepyala, Divyabharathi; Lin, Shu-Wen; Tsai, Yun-Jung

    2017-10-25

    Outbreaks of multidrug-resistant Gram-negative bacterial infections have been reported worldwide. Colistin, an antibiotic with known nephrotoxicity and neurotoxicity, is now being used to treat multidrug-resistant Gram-negative strains. In this study, we applied an on-spot internal standard addition approach coupled with an ultra high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify colistin A and B from dried blood spots (DBSs). Only 15μL of whole blood was required for each sample. An internal standard with the same yield of extraction recoveries as colistin was added to the spot before sample extraction for accurate quantification. Formic acid in water (0.15%) with an equal volume of acetonitrile (50:50v/v) was used as the extraction solution. With the optimized extraction process and LC-MS/MS conditions, colistin A and B could be quantified from a DBS with respective limits of quantification of 0.13 and 0.27μgmL -1 , and the retention times were spot internal standard addition approach which benefited the precision and accuracy. Results showed that DBS sampling coupled with the sensitive LC-MS/MS method has the potential to be an alternative approach for colistin quantification, where the bias of prodrug hydrolysis in liquid samples is decreased. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Accurate dipole moment curve and non-adiabatic effects on the high resolution spectroscopic properties of the LiH molecule

    Science.gov (United States)

    Diniz, Leonardo G.; Kirnosov, Nikita; Alijah, Alexander; Mohallem, José R.; Adamowicz, Ludwik

    2016-04-01

    A very accurate dipole moment curve (DMC) for the ground X1Σ+ electronic state of the 7LiH molecule is reported. It is calculated with the use of all-particle explicitly correlated Gaussian functions with shifted centers. The DMC - the most accurate to our knowledge - and the corresponding highly accurate potential energy curve are used to calculate the transition energies, the transition dipole moments, and the Einstein coefficients for the rovibrational transitions with ΔJ = - 1 and Δv ⩽ 5 . The importance of the non-adiabatic effects in determining these properties is evaluated using the model of a vibrational R-dependent effective reduced mass in the rovibrational calculations introduced earlier (Diniz et al., 2015). The results of the present calculations are used to assess the quality of the two complete linelists of 7LiH available in the literature.

  7. Determination of rivaroxaban in patient’s plasma samples by anti-Xa chromogenic test associated to High Performance Liquid Chromatography tandem Mass Spectrometry (HPLC-MS/MS)

    Science.gov (United States)

    Derogis, Priscilla Bento Matos; Sanches, Livia Rentas; de Aranda, Valdir Fernandes; Colombini, Marjorie Paris; Mangueira, Cristóvão Luis Pitangueira; Katz, Marcelo; Faulhaber, Adriana Caschera Leme; Mendes, Claudio Ernesto Albers; Ferreira, Carlos Eduardo dos Santos; França, Carolina Nunes; Guerra, João Carlos de Campos

    2017-01-01

    Rivaroxaban is an oral direct factor Xa inhibitor, therapeutically indicated in the treatment of thromboembolic diseases. As other new oral anticoagulants, routine monitoring of rivaroxaban is not necessary, but important in some clinical circumstances. In our study a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was validated to measure rivaroxaban plasmatic concentration. Our method used a simple sample preparation, protein precipitation, and a fast chromatographic run. It was developed a precise and accurate method, with a linear range from 2 to 500 ng/mL, and a lower limit of quantification of 4 pg on column. The new method was compared to a reference method (anti-factor Xa activity) and both presented a good correlation (r = 0.98, p highly correlated and should be used as clinical tools for drug monitoring. The method was applied successfully in a group of 49 real-life patients, which allowed an accurate determination of rivaroxaban in peak and trough levels. PMID:28170419

  8. [Rapid determination of 8 urinary carbamate pesticides by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Hualiang; Wang, Yuan; Zhu, Baoli

    2015-11-01

    To establish a method for simultaneously determining the urinary concentrations of 8 carbamate pesticides. After being purified by acetonitrile precipitation, urine samples were transferred to a liquid chromatography-tandem mass spectrometry system, and the concentrations of 8 carbamate pesticides were determined by external standard method. A C18 column was used for ultra-high-performance liquid chromatography; methanol/ammonium acetate solution was used as the mobile phase for gradient elution; the mass spectrometer was operated in a multi-reaction monitoring mode. The calibration curves were linear when the urinary concentrations of these carbamate pesticides were 20~800 µg/L, and the recovery rates were 61.0%~121% at spiked levels of 20, 200 and 800 µg/L, with a relative standard deviation of 1.7%~5.5%. This determination method meets the Guide for establishing occupational health standards-part 5: Determination methods of chemicals in biological materials, and can be used for simultaneous determination of 8 carbamate pesticides in the urine of poisoning patients.

  9. Accurate and Simple Calibration of DLP Projector Systems

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus

    2014-01-01

    does not rely on an initial camera calibration, and so does not carry over the error into projector calibration. A radial interpolation scheme is used to convert features coordinates into projector space, thereby allowing for a very accurate procedure. This allows for highly accurate determination...

  10. Method for accurate determination of dissociation constants of optical ratiometric systems: chemical probes, genetically encoded sensors, and interacting molecules.

    Science.gov (United States)

    Pomorski, Adam; Kochańczyk, Tomasz; Miłoch, Anna; Krężel, Artur

    2013-12-03

    Ratiometric chemical probes and genetically encoded sensors are of high interest for both analytical chemists and molecular biologists. Their high sensitivity toward the target ligand and ability to obtain quantitative results without a known sensor concentration have made them a very useful tool in both in vitro and in vivo assays. Although ratiometric sensors are widely used in many applications, their successful and accurate usage depends on how they are characterized in terms of sensing target molecules. The most important feature of probes and sensors besides their optical parameters is an affinity constant toward analyzed molecules. The literature shows that different analytical approaches are used to determine the stability constants, with the ratio approach being most popular. However, oversimplification and lack of attention to detail results in inaccurate determination of stability constants, which in turn affects the results obtained using these sensors. Here, we present a new method where ratio signal is calibrated for borderline values of intensities of both wavelengths, instead of borderline ratio values that generate errors in many studies. At the same time, the equation takes into account the cooperativity factor or fluorescence artifacts and therefore can be used to characterize systems with various stoichiometries and experimental conditions. Accurate determination of stability constants is demonstrated utilizing four known optical ratiometric probes and sensors, together with a discussion regarding other, currently used methods.

  11. CLASH-VLT: INSIGHTS ON THE MASS SUBSTRUCTURES IN THE FRONTIER FIELDS CLUSTER MACS J0416.1–2403 THROUGH ACCURATE STRONG LENS MODELING

    International Nuclear Information System (INIS)

    Grillo, C.; Suyu, S. H.; Umetsu, K.; Rosati, P.; Caminha, G. B.; Mercurio, A.; Balestra, I.; Munari, E.; Nonino, M.; De Lucia, G.; Borgani, S.; Biviano, A.; Girardi, M.; Lombardi, M.; Gobat, R.; Coe, D.; Koekemoer, A. M.; Postman, M.; Zitrin, A.; Halkola, A.

    2015-01-01

    We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1–2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of our CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems and to select a sample of 175 plausible cluster members to a limiting stellar mass of log (M * /M ☉ ) ≅ 8.6. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0.''3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. The latter have total mass-to-light ratios increasing with the galaxy HST/WFC3 near-IR (F160W) luminosities. The measurement of the total enclosed mass within the Einstein radius is accurate to ∼5%, including the systematic uncertainties estimated from six distinct mass models. We emphasize that the use of multiple-image systems with spectroscopic redshifts and knowledge of cluster membership based on extensive spectroscopic information is key to constructing robust high-resolution mass maps. We also produce magnification maps over the central area that is covered with HST observations. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. When compared with the outcomes of cosmological N-body simulations, our results point to a lack of massive subhalos in the inner regions of simulated clusters with total masses similar to that of MACS J0416.1–2403. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide intriguing

  12. CLASH-VLT: INSIGHTS ON THE MASS SUBSTRUCTURES IN THE FRONTIER FIELDS CLUSTER MACS J0416.1–2403 THROUGH ACCURATE STRONG LENS MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Suyu, S. H.; Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Rosati, P.; Caminha, G. B. [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, I-44122 Ferrara (Italy); Mercurio, A. [INAF - Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Balestra, I.; Munari, E.; Nonino, M.; De Lucia, G.; Borgani, S.; Biviano, A.; Girardi, M. [INAF - Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34143, Trieste (Italy); Lombardi, M. [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy); Gobat, R. [Laboratoire AIM-Paris-Saclay, CEA/DSM-CNRS-Universitè Paris Diderot, Irfu/Service d' Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif sur Yvette (France); Coe, D.; Koekemoer, A. M.; Postman, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Zitrin, A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Halkola, A., E-mail: grillo@dark-cosmology.dk; and others

    2015-02-10

    We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1–2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of our CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems and to select a sample of 175 plausible cluster members to a limiting stellar mass of log (M {sub *}/M {sub ☉}) ≅ 8.6. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0.''3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. The latter have total mass-to-light ratios increasing with the galaxy HST/WFC3 near-IR (F160W) luminosities. The measurement of the total enclosed mass within the Einstein radius is accurate to ∼5%, including the systematic uncertainties estimated from six distinct mass models. We emphasize that the use of multiple-image systems with spectroscopic redshifts and knowledge of cluster membership based on extensive spectroscopic information is key to constructing robust high-resolution mass maps. We also produce magnification maps over the central area that is covered with HST observations. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. When compared with the outcomes of cosmological N-body simulations, our results point to a lack of massive subhalos in the inner regions of simulated clusters with total masses similar to that of MACS J0416.1–2403. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide

  13. The mass angular scattering power method for determining the kinetic energies of clinical electron beams

    International Nuclear Information System (INIS)

    Blais, N.; Podgorsak, E.B.

    1992-01-01

    A method for determining the kinetic energy of clinical electron beams is described, based on the measurement in air of the spatial spread of a pencil electron beam which is produced from the broad clinical electron beam. As predicted by the Fermi-Eyges theory, the dose distribution measured in air on a plane, perpendicular to the incident direction of the initial pencil electron beam, is Gaussian. The square of its spatial spread is related to the mass angular scattering power which in turn is related to the kinetic energy of the electron beam. The measured spatial spread may thus be used to determine the mass angular scattering power, which is then used to determine the kinetic energy of the electron beam from the known relationship between mass angular scattering power and kinetic energy. Energies obtained with the mass angular scattering power method agree with those obtained with the electron range method. (author)

  14. Determination of organophosphorus acids by thermo-spray liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Wils, E.R.J.; Hulst, A.G.

    1988-01-01

    The determination of thirteen organophosphorus acids, hydrolysis products of nerve agents and pesticides, by a combination of ion-pair liquid chromatography on a reversed-phase C18 column and thermospray mass spectrometry was investigated. Ammonium acetate and three tetraalkylammonium salts with

  15. Determination of trace elements by resonant ionization mass spectrometry (RIMS)

    International Nuclear Information System (INIS)

    Ruster, W.; Ames, F.; Rehklau, D.; Mang, M.; Muehleck, C.; Rimke, H.; Sattelberger, P.; Herrmann, G.; Trautmann, N.; Kluge, H.J.; Otten, E.W.

    1988-01-01

    A resonant ionization mass spectrometer has been developed as an analytical tool for the detection of trace elements, especially of plutonium and other radionuclides. The sample, deposited on a rhenium filament, is evaporated by electrical heating and the atoms of the element under investigation are selectively ionized by laser light delivered from three dye lasers pumped by a copper vapour laser. The resulting photoions are detected in a time-of-flight spectrometer with a channelplate detector. For plutonium a mass resolution of M/ΔM=1500 was obtained and an overall detection efficiency of 4x10 -6 was determined for stepwise excitation and ionization via autoionizing states. With a laser light bandwidth of 3-5 GHz neighbouring isotopes could be suppressed by a factor of 20 due to isotope shifts in the excitation transitions. The isotope composition of synthetic samples was measured and good agreement was found with mass spectroscopic results. The influence of the hyperfine structure on the isotope ratios is discussed. (orig.)

  16. Assessing the accuracy of body mass estimation equations from pelvic and femoral variables among modern British women of known mass.

    Science.gov (United States)

    Young, Mariel; Johannesdottir, Fjola; Poole, Ken; Shaw, Colin; Stock, J T

    2018-02-01

    Femoral head diameter is commonly used to estimate body mass from the skeleton. The three most frequently employed methods, designed by Ruff, Grine, and McHenry, were developed using different populations to address different research questions. They were not specifically designed for application to female remains, and their accuracy for this purpose has rarely been assessed or compared in living populations. This study analyzes the accuracy of these methods using a sample of modern British women through the use of pelvic CT scans (n = 97) and corresponding information about the individuals' known height and weight. Results showed that all methods provided reasonably accurate body mass estimates (average percent prediction errors under 20%) for the normal weight and overweight subsamples, but were inaccurate for the obese and underweight subsamples (average percent prediction errors over 20%). When women of all body mass categories were combined, the methods provided reasonable estimates (average percent prediction errors between 16 and 18%). The results demonstrate that different methods provide more accurate results within specific body mass index (BMI) ranges. The McHenry Equation provided the most accurate estimation for women of small body size, while the original Ruff Equation is most likely to be accurate if the individual was obese or severely obese. The refined Ruff Equation was the most accurate predictor of body mass on average for the entire sample, indicating that it should be utilized when there is no knowledge of the individual's body size or if the individual is assumed to be of a normal body size. The study also revealed a correlation between pubis length and body mass, and an equation for body mass estimation using pubis length was accurate in a dummy sample, suggesting that pubis length can also be used to acquire reliable body mass estimates. This has implications for how we interpret body mass in fossil hominins and has particular relevance

  17. Special features of the isotope ratio determination using mass-spectrometer with induction-bound plasma

    International Nuclear Information System (INIS)

    Stepanov, A.I.; Ramendik, G.I.; Fatyushina, E.V.

    2000-01-01

    The origin of the errors arising upon measuring relative abundance of Nd, Yb, and Gd isotopes on a HP-4500 mass-spectrometer (USA) is studied. It is shown that the main origin of the error is the different sensitivity of the mass-spectrometer to ions of different masses. Optimal content of the elements in the solutions is established upon determination of their isotopic abundance [ru

  18. The isobaric multiplet mass equation for A≤71 revisited

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Yi Hua, E-mail: lamyihua@gmail.com [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Blank, Bertram, E-mail: blank@cenbg.in2p3.fr [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Smirnova, Nadezda A. [CENBG (UMR 5797 — Université Bordeaux 1 — CNRS/IN2P3), Chemin du Solarium, Le Haut Vigneau, BP 120, 33175 Gradignan Cedex (France); Bueb, Jean Bernard; Antony, Maria Susai [IPHC, Université de Strasbourg, CNRS/UMR7178, 23 Rue du Loess, 67037 Strasbourg Cedex (France)

    2013-11-15

    Accurate mass determination of short-lived nuclides by Penning-trap spectrometers and progress in the spectroscopy of proton-rich nuclei have triggered renewed interest in the isobaric multiplet mass equation (IMME). The energy levels of the members of T=1/2,1,3/2, and 2 multiplets and the coefficients of the IMME are tabulated for A≤71. The new compilation is based on the most recent mass evaluation (AME2011) and it includes the experimental results on energies of the states evaluated up to end of 2011. Taking into account the error bars, a significant deviation from the quadratic form of the IMME for the A=9,35 quartets and the A=32 quintet is observed.

  19. Accurate and rapid modeling of iron-bleomycin-induced DNA damage using tethered duplex oligonucleotides and electrospray ionization ion trap mass spectrometric analysis.

    Science.gov (United States)

    Harsch, A; Marzilli, L A; Bunt, R C; Stubbe, J; Vouros, P

    2000-05-01

    Bleomycin B(2)(BLM) in the presence of iron [Fe(II)] and O(2)catalyzes single-stranded (ss) and double-stranded (ds) cleavage of DNA. Electrospray ionization ion trap mass spectrometry was used to monitor these cleavage processes. Two duplex oligonucleotides containing an ethylene oxide tether between both strands were used in this investigation, allowing facile monitoring of all ss and ds cleavage events. A sequence for site-specific binding and cleavage by Fe-BLM was incorporated into each analyte. One of these core sequences, GTAC, is a known hot-spot for ds cleavage, while the other sequence, GGCC, is a hot-spot for ss cleavage. Incubation of each oligo-nucleotide under anaerobic conditions with Fe(II)-BLM allowed detection of the non-covalent ternary Fe-BLM/oligonucleotide complex in the gas phase. Cleavage studies were then performed utilizing O(2)-activated Fe(II)-BLM. No work-up or separation steps were required and direct MS and MS/MS analyses of the crude reaction mixtures confirmed sequence-specific Fe-BLM-induced cleavage. Comparison of the cleavage patterns for both oligonucleotides revealed sequence-dependent preferences for ss and ds cleavages in accordance with previously established gel electrophoresis analysis of hairpin oligonucleotides. This novel methodology allowed direct, rapid and accurate determination of cleavage profiles of model duplex oligonucleotides after exposure to activated Fe-BLM.

  20. Molar mass determination of lignins by size-exclusion chromatography: towards standardisation of the method

    NARCIS (Netherlands)

    Baumberger, S.; Abaecherli, A.; Fasching, M.; Gellerstedt, G.; Gosselink, R.J.A.; Hortling, B.; Li, J.; Saake, B.; Jong, de E.

    2007-01-01

    The reactivity and physicochemical properties of lignins are partly governed by their molar mass distribution. The development of reliable standard methods for determination of the molar mass distribution is not only relevant for designing technical lignins for specific applications, but also for

  1. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    Energy Technology Data Exchange (ETDEWEB)

    Montes, R.; Garcia-Lopez, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Rodriguez, I., E-mail: isaac.rodriguez@usc.es [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain); Cela, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Instituto de Investigacion y Analisis Alimentario, Universidad de Santiago de Compostela, Santiago de Compostela 15782 (Spain)

    2010-07-12

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL{sup -1} and linear responses for concentrations up to 2.5 {mu}g mL{sup -1}, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL{sup -1}. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  2. Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

    International Nuclear Information System (INIS)

    Montes, R.; Garcia-Lopez, M.; Rodriguez, I.; Cela, R.

    2010-01-01

    This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL -1 and linear responses for concentrations up to 2.5 μg mL -1 , referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL -1 . Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.

  3. Accurate and precise determination of critical properties from Gibbs ensemble Monte Carlo simulations

    International Nuclear Information System (INIS)

    Dinpajooh, Mohammadhasan; Bai, Peng; Allan, Douglas A.; Siepmann, J. Ilja

    2015-01-01

    Since the seminal paper by Panagiotopoulos [Mol. Phys. 61, 813 (1997)], the Gibbs ensemble Monte Carlo (GEMC) method has been the most popular particle-based simulation approach for the computation of vapor–liquid phase equilibria. However, the validity of GEMC simulations in the near-critical region has been questioned because rigorous finite-size scaling approaches cannot be applied to simulations with fluctuating volume. Valleau [Mol. Simul. 29, 627 (2003)] has argued that GEMC simulations would lead to a spurious overestimation of the critical temperature. More recently, Patel et al. [J. Chem. Phys. 134, 024101 (2011)] opined that the use of analytical tail corrections would be problematic in the near-critical region. To address these issues, we perform extensive GEMC simulations for Lennard-Jones particles in the near-critical region varying the system size, the overall system density, and the cutoff distance. For a system with N = 5500 particles, potential truncation at 8σ and analytical tail corrections, an extrapolation of GEMC simulation data at temperatures in the range from 1.27 to 1.305 yields T c = 1.3128 ± 0.0016, ρ c = 0.316 ± 0.004, and p c = 0.1274 ± 0.0013 in excellent agreement with the thermodynamic limit determined by Potoff and Panagiotopoulos [J. Chem. Phys. 109, 10914 (1998)] using grand canonical Monte Carlo simulations and finite-size scaling. Critical properties estimated using GEMC simulations with different overall system densities (0.296 ≤ ρ t ≤ 0.336) agree to within the statistical uncertainties. For simulations with tail corrections, data obtained using r cut = 3.5σ yield T c and p c that are higher by 0.2% and 1.4% than simulations with r cut = 5 and 8σ but still with overlapping 95% confidence intervals. In contrast, GEMC simulations with a truncated and shifted potential show that r cut = 8σ is insufficient to obtain accurate results. Additional GEMC simulations for hard-core square-well particles with various

  4. Accurate label-free reaction kinetics determination using initial rate heat measurements

    Science.gov (United States)

    Ebrahimi, Kourosh Honarmand; Hagedoorn, Peter-Leon; Jacobs, Denise; Hagen, Wilfred R.

    2015-01-01

    Accurate label-free methods or assays to obtain the initial reaction rates have significant importance in fundamental studies of enzymes and in application-oriented high throughput screening of enzyme activity. Here we introduce a label-free approach for obtaining initial rates of enzyme activity from heat measurements, which we name initial rate calorimetry (IrCal). This approach is based on our new finding that the data recorded by isothermal titration calorimetry for the early stages of a reaction, which have been widely ignored, are correlated to the initial rates. Application of the IrCal approach to various enzymes led to accurate enzyme kinetics parameters as compared to spectroscopic methods and enabled enzyme kinetic studies with natural substrate, e.g. proteases with protein substrates. Because heat is a label-free property of almost all reactions, the IrCal approach holds promise in fundamental studies of various enzymes and in use of calorimetry for high throughput screening of enzyme activity. PMID:26574737

  5. The Interplay Between Fat Mass and Fat Distribution as Determinants of the Metabolic Syndrome Is Sex-Dependent.

    Science.gov (United States)

    Lind, Lars; Ärnlöv, Johan; Lampa, Erik

    2017-09-01

    Fat mass and fat distribution are major determinants of the metabolic syndrome (MetS), but the interplay between them has not been thoroughly investigated. In addition, fat mass and fat distribution are generally different in men than in women. We aimed to determine whether the interplay between fat mass and fat distribution regarding MetS and its components is sex-dependent using data from the large-scale population-based sample EpiHealth. Occurrence of MetS and its components was determined together with fat mass by bioimpedance in 19,094 participants in the EpiHealth sample [mean age 61 years (SD 8.5), 56% females]. MetS was defined by the NCEP/ATPIII-criteria. MetS prevalence was 23.0%. Fat mass (percent of body weight) was more strongly related to MetS (and the number of MetS components) in men than in women (P distribution on the fat mass versus MetS-relationship is stronger in women.

  6. [Determination of five arsenic species in rice by liquid chromatography-inductively coupled plasma-mass spectrometry].

    Science.gov (United States)

    Gong, Jiadi; Cao, Xiaolin; Cao, Zhaoyun; Bian, Yingfang; Yu, Shasha; Chen, Mingxue

    2014-07-01

    A method was developed for the simultaneous determination of arsenic acid [As (V)], arsenious acid [As (III)], arsenobetaine (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in rice by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). The extraction reagent was 0.3 mol/L nitric acid with heat-assistant condition for 1.5 h at 95 degrees C. Then, the five arsenic species were separated by an anion exchange column (Dionex IonPac AS19, 250 mm x 4 mm) and detected by ICP-MS. Four kinds of extracted solutions were compared through the extraction efficiency. The concentration of nitric acid, the temperature and the extraction time were optimized. The recoveries of the five arsenic species spiked in rice at two levels ranged from 89.6% to 99.5% with the relative standard deviations (RSDs, n = 5) of 0.6% - 3.6%. The measured values of the arsenic species in standard rice materials were consistent with their standard values. The linear ranges were 0.05 - 200 microg/L for AsB and DMA, 0.10-400 microg/L for As (III) and MMA, 0.15-600 microg/L for As (V). The limits of detection for the five arsenic species were 0.15-0.45 microg/kg. The results showed that the method is much more precise for the risk assessment of the rice. This method is simple, accurate and durable for the determination of arsenic species in rice.

  7. Rapid determination of anti-estrogens by gas chromatography/mass spectrometry in urine: Method validation and application to real samples.

    Science.gov (United States)

    Gerace, E; Salomone, A; Abbadessa, G; Racca, S; Vincenti, M

    2012-02-01

    A fast screening protocol was developed for the simultaneous determination of nine anti-estrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone) plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid-liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/mass spectrometry (fast-GC/MS) after derivatization. The use of a short column, high-flow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MS-sampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration.

  8. Fuzzy Reasoning to More Accurately Determine Void Areas on Optical Micrographs of Composite Structures

    Science.gov (United States)

    Dominquez, Jesus A.; Tate, Lanetra C.; Wright, M. Clara; Caraccio, Anne

    2013-01-01

    Accomplishing the best-performing composite matrix (resin) requires that not only the processing method but also the cure cycle generate low-void-content structures. If voids are present, the performance of the composite matrix will be significantly reduced. This is usually noticed by significant reductions in matrix-dominated properties, such as compression and shear strength. Voids in composite materials are areas that are absent of the composite components: matrix and fibers. The characteristics of the voids and their accurate estimation are critical to determine for high performance composite structures. One widely used method of performing void analysis on a composite structure sample is acquiring optical micrographs or Scanning Electron Microscope (SEM) images of lateral sides of the sample and retrieving the void areas within the micrographs/images using an image analysis technique. Segmentation for the retrieval and subsequent computation of void areas within the micrographs/images is challenging as the gray-scaled values of the void areas are close to the gray-scaled values of the matrix leading to the need of manually performing the segmentation based on the histogram of the micrographs/images to retrieve the void areas. The use of an algorithm developed by NASA and based on Fuzzy Reasoning (FR) proved to overcome the difficulty of suitably differentiate void and matrix image areas with similar gray-scaled values leading not only to a more accurate estimation of void areas on composite matrix micrographs but also to a faster void analysis process as the algorithm is fully autonomous.

  9. Protein quantitation using Ru-NHS ester tagging and isotope dilution high-pressure liquid chromatography-inductively coupled plasma mass spectrometry determination.

    Science.gov (United States)

    Liu, Rui; Lv, Yi; Hou, Xiandeng; Yang, Lu; Mester, Zoltan

    2012-03-20

    An accurate, simple, and sensitive method for the direct determination of proteins by nonspecies specific isotope dilution and external calibration high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) is described. The labeling of myoglobin (17 kDa), transferrin (77 kDa), and thyroglobulin (670 kDa) proteins was accomplished in a single-step reaction with a commercially available bis(2,2'-bipyridine)-4'-methyl-4-carboxybipyridine-ruthenium N-succinimidyl ester-bis(hexafluorophosphate) (Ru-NHS ester). Using excess amounts of Ru-NHS ester compared to the protein concentration at optimized labeling conditions, constant ratios for Ru to proteins were obtained. Bioconjugate solutions containing both labeled and unlabeled proteins as well as excess Ru-NHS ester reagent were injected onto a size exclusion HPLC column for separation and ICPMS detection without any further treatment. A (99)Ru enriched spike was used for nonspecies specific ID calibration. The accuracy of the method was confirmed at various concentration levels. An average recovery of 100% ± 3% (1 standard deviation (SD), n = 9) was obtained with a typical precision of better than 5% RSD at 100 μg mL(-1) for nonspecies specific ID. Detection limits (3SD) of 1.6, 3.2, and 7.0 fmol estimated from three procedure blanks were obtained for myoglobin, transferrin, and thyroglobulin, respectively. These detection limits are suitable for the direct determination of intact proteins at trace levels. For simplicity, external calibration was also tested. Good linear correlation coefficients, 0.9901, 0.9921, and 0.9980 for myoglobin, transferrin, and thyroglobulin, respectively, were obtained. The measured concentrations of proteins in a solution were in good agreement with their volumetrically prepared values. To the best of our knowledge, this is the first application of nonspecies specific ID for the accurate and direct determination of proteins using a Ru-NHS ester

  10. Texture one zero Dirac neutrino mass matrix with vanishing determinant or trace condition

    Science.gov (United States)

    Singh, Madan

    2018-06-01

    In the light of non-zero and relatively large value of rector mixing angle (θ13), we have performed a detailed analysis of texture one zero neutrino mass matrix Mν in the scenario of vanishing determinant/trace conditions, assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of Mν, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at 3σ confidence level. Numerical and some approximate analytical results are presented.

  11. CASD-NMR 2: robust and accurate unsupervised analysis of raw NOESY spectra and protein structure determination with UNIO

    International Nuclear Information System (INIS)

    Guerry, Paul; Duong, Viet Dung; Herrmann, Torsten

    2015-01-01

    UNIO is a comprehensive software suite for protein NMR structure determination that enables full automation of all NMR data analysis steps involved—including signal identification in NMR spectra, sequence-specific backbone and side-chain resonance assignment, NOE assignment and structure calculation. Within the framework of the second round of the community-wide stringent blind NMR structure determination challenge (CASD-NMR 2), we participated in two categories of CASD-NMR 2, namely using either raw NMR spectra or unrefined NOE peak lists as input. A total of 15 resulting NMR structure bundles were submitted for 9 out of 10 blind protein targets. All submitted UNIO structures accurately coincided with the corresponding blind targets as documented by an average backbone root mean-square deviation to the reference proteins of only 1.2 Å. Also, the precision of the UNIO structure bundles was virtually identical to the ensemble of reference structures. By assessing the quality of all UNIO structures submitted to the two categories, we find throughout that only the UNIO–ATNOS/CANDID approach using raw NMR spectra consistently yielded structure bundles of high quality for direct deposition in the Protein Data Bank. In conclusion, the results obtained in CASD-NMR 2 are another vital proof for robust, accurate and unsupervised NMR data analysis by UNIO for real-world applications

  12. Precise and accurate isotope ratio measurements by ICP-MS.

    Science.gov (United States)

    Becker, J S; Dietze, H J

    2000-09-01

    The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, quality assurance of fuel material, for reprocessing plants, nuclear material accounting and radioactive waste control, for tracer experiments using stable isotopes or long-lived radionuclides in biological or medical studies). Thermal ionization mass spectrometry (TIMS), which used to be the dominant analytical technique for precise isotope ratio measurements, is being increasingly replaced for isotope ratio measurements by ICP-MS due to its excellent sensitivity, precision and good accuracy. Instrumental progress in ICP-MS was achieved by the introduction of the collision cell interface in order to dissociate many disturbing argon-based molecular ions, thermalize the ions and neutralize the disturbing argon ions of plasma gas (Ar+). The application of the collision cell in ICP-QMS results in a higher ion transmission, improved sensitivity and better precision of isotope ratio measurements compared to quadrupole ICP-MS without the collision cell [e.g., for 235U/238U approximately 1 (10 microg x L(-1) uranium) 0.07% relative standard deviation (RSD) vs. 0.2% RSD in short-term measurements (n = 5)]. A significant instrumental improvement for ICP-MS is the multicollector device (MC-ICP-MS) in order to obtain a better precision of isotope ratio measurements (with a precision of up to 0.002%, RSD). CE- and HPLC-ICP-MS are used for the separation of isobaric interferences of long-lived radionuclides and stable isotopes by determination of spallation nuclide abundances in an irradiated tantalum target.

  13. Systematics of interaction and strong absorption radii determined from heavy-ion elastic scattering

    International Nuclear Information System (INIS)

    Birkelund, J.R.; Huizenga, J.R.

    1977-01-01

    Various methods for determining the strong absorption radius for light and intermediate mass nuclei are discussed. It is found that this determination in terms of the half-density radii of the target and projectile is more accurate over the whole range of available data than the other simple parametrizations. 62 references

  14. Determination of rivaroxaban in patient's plasma samples by anti-Xa chromogenic test associated to High Performance Liquid Chromatography tandem Mass Spectrometry (HPLC-MS/MS).

    Science.gov (United States)

    Derogis, Priscilla Bento Matos; Sanches, Livia Rentas; de Aranda, Valdir Fernandes; Colombini, Marjorie Paris; Mangueira, Cristóvão Luis Pitangueira; Katz, Marcelo; Faulhaber, Adriana Caschera Leme; Mendes, Claudio Ernesto Albers; Ferreira, Carlos Eduardo Dos Santos; França, Carolina Nunes; Guerra, João Carlos de Campos

    2017-01-01

    Rivaroxaban is an oral direct factor Xa inhibitor, therapeutically indicated in the treatment of thromboembolic diseases. As other new oral anticoagulants, routine monitoring of rivaroxaban is not necessary, but important in some clinical circumstances. In our study a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was validated to measure rivaroxaban plasmatic concentration. Our method used a simple sample preparation, protein precipitation, and a fast chromatographic run. It was developed a precise and accurate method, with a linear range from 2 to 500 ng/mL, and a lower limit of quantification of 4 pg on column. The new method was compared to a reference method (anti-factor Xa activity) and both presented a good correlation (r = 0.98, p plasma samples for rivaroxaban measurement by HPLC-MS/MS without interferences. The chromogenic and HPLC-MS/MS methods were highly correlated and should be used as clinical tools for drug monitoring. The method was applied successfully in a group of 49 real-life patients, which allowed an accurate determination of rivaroxaban in peak and trough levels.

  15. Pesticide residues determination in Polish organic crops in 2007-2010 applying gas chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Walorczyk, Stanisław; Drożdżyński, Dariusz; Kowalska, Jolanta; Remlein-Starosta, Dorota; Ziółkowski, Andrzej; Przewoźniak, Monika; Gnusowski, Bogusław

    2013-08-15

    A sensitive, accurate and reliable multiresidue method based on the application of gas chromatography-tandem quadrupole mass spectrometry (GC-QqQ-MS/MS) has been established for screening, identification and quantification of a large number of pesticide residues in produce. The method was accredited in compliance with PN-EN ISO/IEC 17025:2005 standard and it was operated under flexible scope as PB-11 method. The flexible scope of accreditation allowed for minor modifications and extension of the analytical scope while using the same analytical technique. During the years 2007-2010, the method was used for the purpose of verification of organic crop production by multiresidue analysis for the presence of pesticides. A total of 528 samples of differing matrices such as fruits, vegetables, cereals, plant leaves and other green parts were analysed, of which 4.4% samples contained pesticide residues above the threshold value of 0.01 mg/kg. A total of 20 different pesticide residues were determined in the samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Mass imbalances in EPANET water-quality simulations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Michael J.; Janke, Robert; Taxon, Thomas N.

    2018-04-06

    EPANET is widely employed to simulate water quality in water distribution systems. However, the time-driven simulation approach used to determine concentrations of water-quality constituents provides accurate results, in general, only for small water-quality time steps; use of an adequately short time step may not be feasible. Overly long time steps can yield errors in concentrations and result in situations in which constituent mass is not conserved. Mass may not be conserved even when EPANET gives no errors or warnings. This paper explains how such imbalances can occur and provides examples of such cases; it also presents a preliminary event-driven approach that conserves mass with a water-quality time step that is as long as the hydraulic time step. Results obtained using the current approach converge, or tend to converge, to those obtained using the new approach as the water-quality time step decreases. Improving the water-quality routing algorithm used in EPANET could eliminate mass imbalances and related errors in estimated concentrations.

  17. Accurate determination of high-risk coronary lesion type by multidetector cardiac computed tomography.

    Science.gov (United States)

    Alasnag, Mirvat; Umakanthan, Branavan; Foster, Gary P

    2008-07-01

    Coronary arteriography (CA) is the standard method to image coronary lesions. Multidetector cardiac computerized tomography (MDCT) provides high-resolution images of coronary arteries, allowing a noninvasive alternative to determine lesion type. To date, no studies have assessed the ability of MDCT to categorize coronary lesion types. The objective of this study was to determine the accuracy of lesion type categorization by MDCT using CA as a reference standard. Patients who underwent both MDCT and CA within 2 months of each other were enrolled. MDCT and CA images were reviewed in a blinded fashion. Lesions were categorized according to the SCAI classification system (Types I-IV). The origin, proximal and middle segments of the major arteries were analyzed. Each segment comprised a data point for comparison. Analysis was performed using the Spearman Correlation Test. Four hundred eleven segments were studied, of which 110 had lesions. The lesion distribution was as follows: 35 left anterior descending (LAD), 29 circumflex (Cx), 31 right coronary artery (RCA), 2 ramus intermedius, 8 diagonal, 4 obtuse marginal and 2 left internal mammary arteries. Correlations between MDCT and CA were significant in all major vessels (LAD, Cx, RCA) (p < 0.001). The overall correlation coefficient was 0.67. Concordance was strong for lesion Types II-IV (97%) and poor for Type I (30%). High-risk coronary lesion types can be accurately categorized by MDCT. This ability may allow MDCT to play an important noninvasive role in the planning of coronary interventions.

  18. Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

    2010-03-01

    Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

  19. Phenotyping polyclonal kappa and lambda light chain molecular mass distributions in patient serum using mass spectrometry.

    Science.gov (United States)

    Barnidge, David R; Dasari, Surendra; Ramirez-Alvarado, Marina; Fontan, Adrian; Willrich, Maria A V; Tschumper, Renee C; Jelinek, Diane F; Snyder, Melissa R; Dispenzieri, Angela; Katzmann, Jerry A; Murray, David L

    2014-11-07

    We previously described a microLC-ESI-Q-TOF MS method for identifying monoclonal immunoglobulins in serum and then tracking them over time using their accurate molecular mass. Here we demonstrate how the same methodology can be used to identify and characterize polyclonal immunoglobulins in serum. We establish that two molecular mass distributions observed by microLC-ESI-Q-TOF MS are from polyclonal kappa and lambda light chains using a combination of theoretical molecular masses from gene sequence data and the analysis of commercially available purified polyclonal IgG kappa and IgG lambda from normal human serum. A linear regression comparison of kappa/lambda ratios for 74 serum samples (25 hypergammaglobulinemia, 24 hypogammaglobulinemia, 25 normal) determined by microflowLC-ESI-Q-TOF MS and immunonephelometry had a slope of 1.37 and a correlation coefficient of 0.639. In addition to providing kappa/lambda ratios, the same microLC-ESI-Q-TOF MS analysis can determine the molecular mass for oligoclonal light chains observed above the polyclonal background in patient samples. In 2 patients with immune disorders and hypergammaglobulinemia, we observed a skewed polyclonal molecular mass distribution which translated into biased kappa/lambda ratios. Mass spectrometry provides a rapid and simple way to combine the polyclonal kappa/lambda light chain abundance ratios with the identification of dominant monoclonal as well as oligoclonal light chain immunoglobulins. We anticipate that this approach to evaluating immunoglobulin light chains will lead to improved understanding of immune deficiencies, autoimmune diseases, and antibody responses.

  20. 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.

  1. Nuclear equipment to determine soil and water mass attenuation coefficients

    International Nuclear Information System (INIS)

    Zucchi, O.L.A.D.; Nascimento Filho, V.F. do

    1984-01-01

    The feasibility of substituting the monochannel gamma spectrometer, traditionally used in the gamma ray attenuation technique, for a less sophisticated and less expensive system of integral counting is studied. The proposed system can be operated by a non-specialized person. Three detection systems were used in the determination of the mass attenuation coefficients for different types of soil and for water. (M.A.C.) [pt

  2. Radionuclide determination in environmental samples by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Lariviere, Dominic; Taylor, Vivien F.; Evans, R. Douglas; Cornett, R. Jack

    2006-01-01

    The determination of naturally occurring and anthropogenic radionuclides in the environment by inductively coupled plasma mass spectrometry has gained recognition over the last fifteen years, relative to radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment, and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels (fg range) of many radioisotopes, including those with half-lives between 1 and 1000 years, without requiring very complex sample pre-concentration schemes. However, the identification and quantification of radioisotopes in environmental matrices is still hampered by a variety of analytical issues such as spectral (both atomic and molecular ions) and non-spectral (matrix effect) interferences and instrumental limitations (e.g., abundance sensitivity). The scope of this review is to highlight recent analytical progress and issues associated with the determination of radionuclides by inductively coupled plasma mass spectrometry. The impact of interferences, instrumental limitations (e.g., degree of ionization, abundance sensitivity, detection limits) and low sample-to-plasma transfer efficiency on the measurement of radionuclides by inductively coupled plasma mass spectrometry will be described. Solutions that overcome these issues will be discussed, highlighting their pros and cons and assessing their impact on the measurement of environmental radioactivity. Among the solutions proposed, mass and chemical resolution through the use of sector-field instruments and chemical reactions/collisions in a pressurized cell, respectively, will be described. Other methods, such as unique sample introduction equipment (e.g., laser ablation, electrothermal vaporisation, high efficiency nebulization) and instrumental modifications/optimizations (e.g., instrumental vacuum, radiofrequency power, guard electrode) that improve sensitivity and performance

  3. Resin bead-thermal ionization mass spectrometry for determination of plutonium concentration in irradiated fuel dissolver solution

    International Nuclear Information System (INIS)

    Paul, Sumana; Shah, R.V.; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Determination of isotopic composition (IC) and concentration of plutonium (Pu) is necessary at various stages of nuclear fuel cycle which involves analysis of complex matrices like dissolver solution of irradiated fuel, nuclear waste stream etc. Mass spectrometry, e.g. thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS) are commonly used for determination of IC and concentration of plutonium. However, to circumvent matrix interferences, efficient separation as well as preconcentration of Pu is required prior to mass spectrometric analysis. Purification steps employing ion-exchange resins are widely used for the separation of Pu from dissolver solution or from mixture of other actinides e.g. U, Am. However, an alternative way is to selectively preconcentrate Pu on a resin bead, followed by direct loading of the bead on the filament of thermal ionization mass spectrometer

  4. Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

    Directory of Open Access Journals (Sweden)

    Yutaka Kitamura

    2018-02-01

    Full Text Available Platelet-rich fibrin (PRF clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

  5. Determination of void fraction from source range monitor and mass flow rate data

    International Nuclear Information System (INIS)

    McCormick, R.D.

    1986-09-01

    This is a report on the calculation of the TMI-2 primary coolant system local void fraction from source range neutron flux monitor data and from hot leg mass flowrate meter data during the first 100 minutes of the accident. The methods of calculation of void fraction from the two data sources is explained and the results are compared. It is indicated that the void fraction determined using the mass flowrate data contained an error of unknown magnitude due to the assumption of constant homogeneous volumetric flowrate used in the calculation and required further work. Void fraction determined from the source range monitor data is felt to be usable although an uncertainty analysis has not been performed

  6. Stable isotope dilution analysis by thermal ionization mass spectrometry. Pt. 2

    International Nuclear Information System (INIS)

    Broekman, A.; Raaphorst, J.G. van

    1984-01-01

    The combination of stable isotope dilution analysis (SIDA) and thermal ionization mass spectrometry (TIMS) is in use for lead and uranium determination at milligram per kilogram levels for over 20 years. However, several other elements can also be determined accurately by SIDA/TIMS. In this study the determinations of cadmium and copper are described. Details of the digestion, electrochemical and ion-exchange separations and the loading of the elements on a filament are given. The advantages of the SIDA/TIMS technique are shown and illustrated with results for several certified reference materials. (orig.) [de

  7. Accurate determination of sulfur in gasoline and related fuel samples using isotope dilution ICP-MS with direct sample injection and microwave-assisted digestion.

    Science.gov (United States)

    Heilmann, Jens; Boulyga, Sergei F; Heumann, Klaus G

    2004-09-01

    Inductively coupled plasma isotope-dilution mass spectrometry (ICP-IDMS) with direct injection of isotope-diluted samples into the plasma, using a direct injection high-efficiency nebulizer (DIHEN), was applied for accurate sulfur determinations in sulfur-free premium gasoline, gas oil, diesel fuel, and heating oil. For direct injection a micro-emulsion consisting of the corresponding organic sample and an aqueous 34S-enriched spike solution with additions of tetrahydronaphthalene and Triton X-100, was prepared. The ICP-MS parameters were optimized with respect to high sulfur ion intensities, low mass-bias values, and high precision of 32S/34S ratio measurements. For validation of the DIHEN-ICP-IDMS method two certified gas oil reference materials (BCR 107 and BCR 672) were analyzed. For comparison a wet-chemical ICP-IDMS method was applied with microwave-assisted digestion using decomposition of samples in a closed quartz vessel inserted into a normal microwave system. The results from both ICP-IDMS methods agree well with the certified values of the reference materials and also with each other for analyses of other samples. However, the standard deviation of DIHEN-ICP-IDMS was about a factor of two higher (5-6% RSD at concentration levels above 100 mircog g(-1)) compared with those of wet-chemical ICP-IDMS, mainly due to inhomogeneities of the micro-emulsion, which causes additional plasma instabilities. Detection limits of 4 and 18 microg g(-1) were obtained for ICP-IDMS in connection with microwave-assisted digestion and DIHEN-ICP-IDMS, respectively, with a sulfur background of the used Milli-Q water as the main limiting factor for both methods.

  8. Accurate determination of sulfur in gasoline and related fuel samples using isotope dilution ICP-MS with direct sample injection and microwave-assisted digestion

    Energy Technology Data Exchange (ETDEWEB)

    Heilmann, Jens; Boulyga, Sergei F.; Heumann, Klaus G. [Johannes Gutenberg-University, Institute of Inorganic Chemistry and Analytical Chemistry, Mainz (Germany)

    2004-09-01

    Inductively coupled plasma isotope-dilution mass spectrometry (ICP-IDMS) with direct injection of isotope-diluted samples into the plasma, using a direct injection high-efficiency nebulizer (DIHEN), was applied for accurate sulfur determinations in sulfur-free premium gasoline, gas oil, diesel fuel, and heating oil. For direct injection a micro-emulsion consisting of the corresponding organic sample and an aqueous {sup 34}S-enriched spike solution with additions of tetrahydronaphthalene and Triton X-100, was prepared. The ICP-MS parameters were optimized with respect to high sulfur ion intensities, low mass-bias values, and high precision of {sup 32}S/{sup 34}S ratio measurements. For validation of the DIHEN-ICP-IDMS method two certified gas oil reference materials (BCR 107 and BCR 672) were analyzed. For comparison a wet-chemical ICP-IDMS method was applied with microwave-assisted digestion using decomposition of samples in a closed quartz vessel inserted into a normal microwave system. The results from both ICP-IDMS methods agree well with the certified values of the reference materials and also with each other for analyses of other samples. However, the standard deviation of DIHEN-ICP-IDMS was about a factor of two higher (5-6% RSD at concentration levels above 100 {mu}g g{sup -1}) compared with those of wet-chemical ICP-IDMS, mainly due to inhomogeneities of the micro-emulsion, which causes additional plasma instabilities. Detection limits of 4 and 18 {mu}g g{sup -1} were obtained for ICP-IDMS in connection with microwave-assisted digestion and DIHEN-ICP-IDMS, respectively, with a sulfur background of the used Milli-Q water as the main limiting factor for both methods. (orig.)

  9. Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football

    Directory of Open Access Journals (Sweden)

    Nicolas H. Hart, Jodie L. Cochrane, Tania Spiteri, Sophia Nimphius, Robert U. Newton

    2016-06-01

    Full Text Available Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2 each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15 and inaccurate (n = 16 kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701. Relative lean mass was positively correlated with kicking accuracy (r = 0.631, while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083. Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy.

  10. Determining the minimum mass and cost of a magnetic refrigerator

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Smith, Anders; Bahl, Christian Robert Haffenden

    2011-01-01

    An expression is determined for the mass of the magnet and magnetocaloric material needed for a magnetic refrigerator and these are determined using numerical modeling for both parallel plate and packed sphere bed regenerators as function of temperature span and cooling power. As magnetocaloric......, respectively, the cheapest 100 W parallel plate refrigerator with a temperature span of 20 K using Gd and a Halbach magnet has 0.8 kg of magnet, 0.3 kg of Gd and a cost of $35. Using the constant material reduces this cost to $25. A packed sphere bed refrigerator with the constant material costs $7. It is also...

  11. Penning trap mass spectrometry Q-value determinations for highly forbidden β-decays

    Science.gov (United States)

    Sandler, Rachel; Bollen, Georg; Eibach, Martin; Gamage, Nadeesha; Gulyuz, Kerim; Hamaker, Alec; Izzo, Chris; Kandegedara, Rathnayake; Redshaw, Matt; Ringle, Ryan; Valverde, Adrian; Yandow, Isaac; Low Energy Beam Ion Trap Team

    2017-09-01

    Over the last several decades, extremely sensitive, ultra-low background beta and gamma detection techniques have been developed. These techniques have enabled the observation of very rare processes, such as highly forbidden beta decays e.g. of 113Cd, 50V and 138La. Half-life measurements of highly forbidden beta decays provide a testing ground for theoretical nuclear models, and the comparison of calculated and measured energy spectra could enable a determination of the values of the weak coupling constants. Precision Q-value measurements also allow for systematic tests of the beta-particle detection techniques. We will present the results and current status of Q value determinations for highly forbidden beta decays. The Q values, the mass difference between parent and daughter nuclides, are measured using the high precision Penning trap mass spectrometer LEBIT at the National Superconducting Cyclotron Laboratory.

  12. Current use of high-resolution mass spectrometry in drug screening relevant to clinical and forensic toxicology and doping control.

    Science.gov (United States)

    Ojanperä, Ilkka; Kolmonen, Marjo; Pelander, Anna

    2012-05-01

    Clinical and forensic toxicology and doping control deal with hundreds or thousands of drugs that may cause poisoning or are abused, are illicit, or are prohibited in sports. Rapid and reliable screening for all these compounds of different chemical and pharmaceutical nature, preferably in a single analytical method, is a substantial effort for analytical toxicologists. Combined chromatography-mass spectrometry techniques with standardised reference libraries have been most commonly used for the purpose. In the last ten years, the focus has shifted from gas chromatography-mass spectrometry to liquid chromatography-mass spectrometry, because of progress in instrument technology and partly because of the polarity and low volatility of many new relevant substances. High-resolution mass spectrometry (HRMS), which enables accurate mass measurement at high resolving power, has recently evolved to the stage that is rapidly causing a shift from unit-resolution, quadrupole-dominated instrumentation. The main HRMS techniques today are time-of-flight mass spectrometry and Orbitrap Fourier-transform mass spectrometry. Both techniques enable a range of different drug-screening strategies that essentially rely on measuring a compound's or a fragment's mass with sufficiently high accuracy that its elemental composition can be determined directly. Accurate mass and isotopic pattern acts as a filter for confirming the identity of a compound or even identification of an unknown. High mass resolution is essential for improving confidence in accurate mass results in the analysis of complex biological samples. This review discusses recent applications of HRMS in analytical toxicology.

  13. NEAR-INFRARED SPECTROSCOPY OF LOW-MASS X-RAY BINARIES: ACCRETION DISK CONTAMINATION AND COMPACT OBJECT MASS DETERMINATION IN V404 Cyg AND Cen X-4

    International Nuclear Information System (INIS)

    Khargharia, Juthika; Froning, Cynthia S.; Robinson, Edward L.

    2010-01-01

    We present near-infrared (NIR) broadband (0.80-2.42 μm) spectroscopy of two low-mass X-ray binaries: V404 Cyg and Cen X-4. One important parameter required in the determination of the mass of the compact objects in these systems is the binary inclination. We can determine the inclination by modeling the ellipsoidal modulations of the Roche-lobe filling donor star, but the contamination of the donor star light from other components of the binary, particularly the accretion disk, must be taken into account. To this end, we determined the donor star contribution to the infrared flux by comparing the spectra of V404 Cyg and Cen X-4 to those of various field K-stars of known spectral type. For V404 Cyg, we determined that the donor star has a spectral type of K3 III. We determined the fractional donor contribution to the NIR flux in the H and K bands as 0.98 ± 0.05 and 0.97 ± 0.09, respectively. We remodeled the H-band light curve from Sanwal et al. after correcting for the donor star contribution to obtain a new value for the binary inclination. From this, we determined the mass of the black hole in V404 Cyg to be M BH = 9.0 +0.2 -0.6 M sun . We performed the same spectral analysis for Cen X-4 and found the spectral type of the donor star to be in the range K5-M1 V. The donor star contribution in Cen X-4 is 0.94 ± 0.14 in the H band while in the K band, the accretion disk can contribute up to 10% of the infrared flux. We remodeled the H-band light curve from Shahbaz et al., again correcting for the fractional contribution of the donor star to obtain the inclination. From this, we determined the mass of the neutron star as M NS = 1.5 +0.1 -0.4 M sun . However, the masses obtained for both systems should be viewed with some caution since contemporaneous light curve and spectral data are required to obtain definitive masses.

  14. Discrete sensors distribution for accurate plantar pressure analyses.

    Science.gov (United States)

    Claverie, Laetitia; Ille, Anne; Moretto, Pierre

    2016-12-01

    The aim of this study was to determine the distribution of discrete sensors under the footprint for accurate plantar pressure analyses. For this purpose, two different sensor layouts have been tested and compared, to determine which was the most accurate to monitor plantar pressure with wireless devices in research and/or clinical practice. Ten healthy volunteers participated in the study (age range: 23-58 years). The barycenter of pressures (BoP) determined from the plantar pressure system (W-inshoe®) was compared to the center of pressures (CoP) determined from a force platform (AMTI) in the medial-lateral (ML) and anterior-posterior (AP) directions. Then, the vertical ground reaction force (vGRF) obtained from both W-inshoe® and force platform was compared for both layouts for each subject. The BoP and vGRF determined from the plantar pressure system data showed good correlation (SCC) with those determined from the force platform data, notably for the second sensor organization (ML SCC= 0.95; AP SCC=0.99; vGRF SCC=0.91). The study demonstrates that an adjusted placement of removable sensors is key to accurate plantar pressure analyses. These results are promising for a plantar pressure recording outside clinical or laboratory settings, for long time monitoring, real time feedback or for whatever activity requiring a low-cost system. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  15. Simultaneous determination of sulphoraphane and sulphoraphane nitrile in Brassica vegetables using ultra-performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Alvarez-Jubete, Laura; Smyth, Thomas J; Valverde, Juan; Rai, Dilip K; Barry-Ryan, Catherine

    2014-01-01

    Several analytical methods exist for the determination of sulphoraphane or sulphoraphane nitrile from biological matrices and plant extracts. However, no UPLC-MS/MS method exists for the simultaneous detection of both. To develop and validate an UPLC-MS/MS method for the simultaneous analysis of sulphoraphane and sulphoraphane nitrile from Brassica oleracea L. ssp. italica This method was developed utilising an Acquity BEH C8 column with gradient elution combined with tandem mass spectrometry, using positive electrospray ionisation in multiple reaction monitoring mode. The retention times for sulphoraphane and sulphoraphane nitrile were 0.4 and 0.6 min respectively, and total run time was 3 min. The method was validated for linearity, sensitivity, precision, accuracy, matrix effects and recovery. The method was employed to determine glucoraphanin hydrolysis products in broccoli and the predominant product was found to vary depending on the variety tested. It was also applied to the accurate determination of sulphoraphane and sulphoraphane nitrile in broccoli samples hydrolysed under different conditions. It was observed that the formation of sulphoraphane and sulphoraphane nitrile was influenced by the temperature of the reaction. The validated UPLC-MS/MS method for simultaneous detection of sulphoraphane and sulphoraphane nitrile was shown to be applicable to broccoli plants and is expected to be applicable to other cruciferous sources. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Precise determination of cosmogenic Ne in CREU-1 quartz standard, using the Helix-MC Plus mass spectrometer

    Science.gov (United States)

    Hamilton, D.; Honda, M.; Zhang, X.; Phillips, D.; Matchan, E.

    2017-12-01

    The Helix-MC Plus multi-collector noble gas mass spectrometer at the Australian National University is uniquely equipped with three high mass resolution collectors on H2, Axial and L2 positions. Their mass resolution and mass resolving power are as high as 1,800 and 8,000, respectively. The Helix-MC Plus can totally separate 20Ne+ from 40Ar++ isobaric interference and also partially separate 21Ne+ from 20NeH+ and 22Ne+ from 12C16O2++. By adjusting collector positions, we are able to measure interference-free Ne isotope intensities and have re-determined the 21Ne abundance in air [1]. Analyses by Honda et al. [1] demonstrated that 20Ne1H contributes approximately 2% to previously determined atmospheric 21Ne values [2], and a new atmospheric 21Ne/20Ne ratio of 0.002906 was calculated. Using the Helix-MC Plus mass spectrometer, we measured Ne abundances in the CREU-1 quartz standard [3] and determined cosmogenic concentrations by subtraction of atmospheric Ne with the new atmospheric 21Ne/20Ne value. The average concentration of cosmogenic 21Ne determined from four repeated analyses is 338 ± 12 × 106 atom/g (2σ). This compares with the average concentration of 348 ± 10 × 106 atom/g (2σ) from 45 analyses determined by several laboratories [3], where Ne isotope analyses were undertaken by conventional low resolution mass spectrometers and atmospheric Ne was subtracted using the conventional atmospheric 21Ne/20Ne [2]. On this basis, for a sample with abundant cosmogenic Ne, like CREU-1 quartz, previously measured by low mass resolution mass spectrometers are likely valid and their geological implications are unaffected. However, for low 21Ne concentration samples, combining new generation of mass spectrometers as well as the new atmospheric ratio may have significance for cosmogenic 21Ne surface exposure dating. References: [1] Honda M., et. al., International Journal of Mass Spectrometry, 387, 1 (2015). [2] Eberhardt P., et. al., Zeitschrift fur Naturforschung, 20

  17. [Determination of amitrole in agricultural products by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Li; Fu, Jian; Gao, Hongliang; Ren, Haitao; Lou, Xishan; Guan, Lihui

    2010-03-01

    A high performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) was developed for the analysis of amitrole residues in agricultural products. The samples were extracted by 25% acetone for wheat, fish, pork and liver samples, 1% acetic acid-25% acetone for maize and peanut samples, 1% acetic acid solution for honeysuckle, the powder of ginger, the powder of bunge prickly ash and tea leaves samples, 1% acetic acid solution-dichloromethane for apple, pineapple, spinach, carrot, perilla leaves samples, respectively, followed by liquid-liquid extraction with dichloromethane. The samples were then cleaned up by PCX or Envi-Carb solid-phase extraction cartridge. The amitrole was determined and confirmed by HPLC-MS/MS. The results showed a linear relationship in the range of 0.005 -0.1 mg/kg for amitrole. The correlation coefficient was 0.999 7. The average recoveries of amitrole in wheat, maize, peanut, pineapple, apple, carrot, spinach, pork, the powder of ginger, the powder of bunge prickly ash, perilla, liver, fish, honeysuckle and tea were 67.5% - 98.1%. The relative standard deviations (RSDs) were 1.0% - 9.8%. The limits of quantitation were 10 microg/kg for wheat, maize, peanut, pineapple, apple, carrot, spinach, pork, perilla, liver, fish, honeysuckle and 20 microg/kg for the powder of bunge prickly ash, the powder of ginger and tea, respectively. The method is simple, sensitive and accurate.

  18. Determining Mass and Persistence of a Reactive Brominated-Solvent DNAPL Source Using Mass Depletion-Mass Flux Reduction Relationships During Pumping

    Science.gov (United States)

    Johnston, C. D.; Davis, G. B.; Bastow, T.; Annable, M. D.; Trefry, M. G.; Furness, A.; Geste, Y.; Woodbury, R.; Rhodes, S.

    2011-12-01

    Measures of the source mass and depletion characteristics of recalcitrant dense non-aqueous phase liquid (DNAPL) contaminants are critical elements for assessing performance of remediation efforts. This is in addition to understanding the relationships between source mass depletion and changes to dissolved contaminant concentration and mass flux in groundwater. Here we present results of applying analytical source-depletion concepts to pumping from within the DNAPL source zone of a 10-m thick heterogeneous layered aquifer to estimate the original source mass and characterise the time trajectory of source depletion and mass flux in groundwater. The multi-component, reactive DNAPL source consisted of the brominated solvent tetrabromoethane (TBA) and its transformation products (mostly tribromoethene - TriBE). Coring and multi-level groundwater sampling indicated the DNAPL to be mainly in lower-permeability layers, suggesting the source had already undergone appreciable depletion. Four simplified source dissolution models (exponential, power function, error function and rational mass) were able to describe the concentration history of the total molar concentration of brominated organics in extracted groundwater during 285 days of pumping. Approximately 152 kg of brominated compounds were extracted. The lack of significant kinetic mass transfer limitations in pumped concentrations was notable. This was despite the heterogeneous layering in the aquifer and distribution of DNAPL. There was little to choose between the model fits to pumped concentration time series. The variance of groundwater velocities in the aquifer determined during a partitioning inter-well tracer test (PITT) were used to parameterise the models. However, the models were found to be relatively insensitive to this parameter. All models indicated an initial source mass around 250 kg which compared favourably to an estimate of 220 kg derived from the PITT. The extrapolated concentrations from the

  19. An accurate and nondestructive GC method for determination of cocaine on US paper currency.

    Science.gov (United States)

    Zuo, Yuegang; Zhang, Kai; Wu, Jingping; Rego, Christopher; Fritz, John

    2008-07-01

    The presence of cocaine on US paper currency has been known for a long time. Banknotes become contaminated during the exchange, storage, and abuse of cocaine. The analysis of cocaine on various denominations of US banknotes in the general circulation can provide law enforcement circles and forensic epidemiologists objective and timely information on epidemiology of illicit drug use and on how to differentiate money contaminated in the general circulation from banknotes used in drug transaction. A simple, nondestructive, and accurate capillary gas chromatographic method has been developed for the determination of cocaine on various denominations of US banknotes in this study. The method comprises a fast ultrasonic extraction using water as a solvent followed by a SPE cleanup process with a C(18) cartridge and capillary GC separation, identification, and quantification. This nondestructive analytical method has been successfully applied to determine the cocaine contamination in US paper currency of all denominations. Standard calibration curve was linear over the concentration range from the LOQ (2.00 ng/mL) to 100 microg/mL and the RSD less than 2.0%. Cocaine was detected in 67% of the circulated banknotes collected in Southeastern Massachusetts in amounts ranging from approximately 2 ng to 49.4 microg per note. On average, $5, 10, 20, and 50 denominations contain higher amounts of cocaine than $1 and 100 denominations of US banknotes.

  20. Characterization of the fracturation of rock masses for determining flow

    International Nuclear Information System (INIS)

    Derlich, S.

    1984-02-01

    Flow in a rock mass is the consequence of the permeability of the rock, which can be roughly separated into matrix permeability and fissure permeability. In crystalline rocks fissure permeability is dominant, especially where the rocks are extensively fractured. It is thus essential, by means of studies either at the surface or underground, to characterize the volume fracturation in the mass considered. The purpose of this paper is to illustrate the methodology for analysing fracturation at a site by the studies performed on the granite mass of Auriat in the French Massif Central. A number of geology laboratories have participated in this study and a broad spectrum of observations has been made which can be used for determining the various stages of a study with a view to selection of a site, the advantages and limitations of each method or study plan and additional methods which need to be used for gaining as complete a picture as possible of the fracturation. A brief examination of the results obtained at Auriat enables the relative advantages of using these various methods at a particular site to be compared

  1. Towards accurate T-3He Q-value

    Energy Technology Data Exchange (ETDEWEB)

    Eronen, Tommi; Hoecker, Martin; Ketter, Jochen; Streubel, Sebastian; Blaum, Klaus [Max-Planck Institut fuer Kernphysik, Heidelberg (Germany); Van Dyck, Robert S. Jr. [Department of Physics, University of Washington, Seattle, WA (United States)

    2013-07-01

    Great efforts have been put forward to determine the neutrino mass from tritium β decay. The most prominent experimental setup, KATRIN, is expected to deliver an upper limit to the neutrino mass that is one order of magnitude more stringent than the current value by measuring the endpoint and the shape of the β spectrum of the tritium decay. The endpoint energy (assuming zero neutrino mass) can also be deduced from the Q-value of the decay by measuring the mass difference of tritium and the daughter {sup 3}He using high-resolution mass spectrometry. Such a measurement would give an excellent, independent calibration point for the KATRIN experiment to deduce its systematics. Our mass-difference measurement utilizes the Tritium- Helium double Penning trap (THe-Trap) setup. Based on the anharmonic cyclotron frequency determination method pioneered at the University of Washington, Seattle, precision at the level of 1 part in 10{sup 11} in the T/{sup 3}He mass ratio is expected. In this contribution, I describe the motivation, the principle, current status, and expectations of the experiment.

  2. Use of Loran-C navigation system to accurately determine sampling site location in an above ground cooling reservoir

    International Nuclear Information System (INIS)

    Lockwood, R.E.; Blankinship, D.R.

    1994-01-01

    Environmental monitoring programs often require accurate determination of sampling site locations in aquatic environments. This is especially true when a open-quotes pictureclose quotes of high resolution is needed for observing a changing variable in a given area and location is assumed to be important to the distribution of that variable. Sample site location can be difficult if few visible land marks are available for reference on a large body of water. The use of navigational systems such as Global Positioning System (GPS) and its predecessor, Loran-C, provide an excellent method for sample site location. McFarland (1992) discusses the practicality of GPS for location determination. This article discusses the use of Loran-C in a sampling scheme implemented at the South Texas Project Electrical Generating Station (STPEGS), Wadsworth, Texas

  3. Determination of ribavirin in human serum using liquid chromatography tandem mass spectrometry

    NARCIS (Netherlands)

    van der Lijke, H.; Alffenaar, J.-W. C.; Kok, W.Th.; Greijdanus, B.; Uges, D.R.A.

    2012-01-01

    A method has been developed for the determination of ribavirin in human serum for therapeutic drug monitoring purposes, using liquid chromatography electrospray ionization mass spectrometry. Separation was obtained with a mobile phase gradient starting and ending in 100% aqueous conditions using a

  4. Mass Determination of Pluto and Charon from New Horizon REX Radio Science Observations

    Science.gov (United States)

    Paetzold, Martin; Andert, T. P.; Tyler, G.; Bird, M. K.; Hinson, D. P.; Linscott, I. R.

    2013-10-01

    The anticipated 14 July 2015 New Horizons fly-through of the Pluto system provides the first opportunity to determine both the total system mass and the individual masses of Pluto and Charon by direct observation. This will be accomplished by use of: i) two-way Doppler radio frequency tracking data during intervals along the fly-in and -out trajectory, and ii) one-way uplink Doppler frequency recorded by the on-board radio science instrument, REX, during the day of closest approaches to Pluto and Charon. Continuous tracking is not feasible as a result of pointing sharing with the instruments during the encounter phase. Needed radio tracking will be obtained during time slots shared with i) two-way Doppler tracking for navigation, ii) 'plasma rolls' with the spacecraft antenna pointing to Earth, and iii) during the ingress and egress phases of the occultations. Simulations of the NH encounter indicate the potential accuracies of the combined and individual mass determinations of Pluto and Charon in the order of 0.1%.

  5. Dynamic treatment of the fission mass asymmetry with the help of the two-centre-shell model

    International Nuclear Information System (INIS)

    Maruhn, J.A.

    1973-01-01

    In this work, a description of the distribution of the total mass of a fissioning nucleus on the fragments is proposed by means of a collective coordinate, and the applicability of the method is examined by various examples compared to the experiment. A quantitative agreement with the experiment cannot be expected in view of the necessary approximations and the relatively less accurate determination especially of the mass parameters. The experiments, however, exhibit good qualitative and semi-quantitative agreement with the experimental mass yields. (orig./LH) [de

  6. Rapid and Automated Determination of Plutonium and Neptunium in Environmental Samples

    DEFF Research Database (Denmark)

    Qiao, Jixin

    This thesis presents improved analytical methods for rapid and automated determination of plutonium and neptunium in environmental samples using sequential injection (SI) based chromatography and inductively coupled plasma mass spectrometry (ICP-MS). The progress of methodology development...... and optimization for rapid determination of plutonium in environmental samples using SIextraction chromatography prior to inductively coupled plasma mass spectrometry (Paper III); (3) Development of an SI-chromatographic method for simultaneous determination of plutonium and neptunium in environmental samples...... for rapid and simultaneous determination of plutonium and neptunium within an SI system (Paper VI). The results demonstrate that the developed methods in this study are reliable and efficient for accurate assays of trace levels of plutonium and neptunium as demanded in different situations including...

  7. [Determination of short chain chlorinated paraffins in polyvinyl chloride plastics by gas chromatography-negative chemical ion/mass spectrometry].

    Science.gov (United States)

    Xing, Yuanna; Lin, Zhihui; Feng, Anhong; Wang, Xin; Gong, Yemeng; Chen, Zeyong

    2015-02-01

    A novel method was established to determine short chain chlorinated paraffins (SC-CPs) in polyvinyl chloride (PVC) plastics by gas chromatography-negative chemical ion/mass spectrometry (GC-NCI/MS). Ultrasonic extraction was used to extract SCCPs from PVC plastics. The optimal extraction time was 1.5 h, and concentrated sulfuric acid was adopted to purify the extracted solution. Finally, SCCPs in a sample were detected by GC-NCI/MS at 160 C and with methane reagent gas at 1. 5 mL/min. This method was not influenced by medium chain chlorinated paraffins (MCCPs) in the sample, and accurate quantitation was made for SCCPs. Twelve batches of samples were analyzed and SCCPs were detected in each batch with the contents from 0. 3 x 10(2)mg/kg to 3. 5 x 10(4)mg/kg. With respect to European limitation of SC-CPs (1%), four batches of samples did not comply with the European regulation, and they accounted for 33. 3%. Obviously, high SCCPs risk was presented in PVC plastics.

  8. Mass determination of Hercules X-1

    International Nuclear Information System (INIS)

    Bahcall, J.N.; Chester, T.J.

    1977-01-01

    The allowed range of masses for Hercules X-1 is calculated using the optical pulsation data of Middleditch and Nelson, a simple geometrical model for the optical pulsations, and Uhuru X-ray observations of the mass function and eclipse duration. For a specific set of assumptions, we obtain 0.6M/sub sun/ 1 < or =2.0M/sub sun/

  9. Quantifying the resolution level where the GRACE satellites can separate Greenland's glacial mass balance from surface mass balance

    Science.gov (United States)

    Bonin, J. A.; Chambers, D. P.

    2015-09-01

    Mass change over Greenland can be caused by either changes in the glacial dynamic mass balance (DMB) or the surface mass balance (SMB). The GRACE satellite gravity mission cannot directly separate the two physical causes because it measures the sum of the entire mass column with limited spatial resolution. We demonstrate one theoretical way to indirectly separate cumulative SMB from DMB with GRACE, using a least squares inversion technique with knowledge of the location of the glaciers. However, we find that the limited 60 × 60 spherical harmonic representation of current GRACE data does not provide sufficient resolution to adequately accomplish the task. We determine that at a maximum degree/order of 90 × 90 or above, a noise-free gravity measurement could theoretically separate the SMB from DMB signals. However, current GRACE satellite errors are too large at present to separate the signals. A noise reduction of a factor of 10 at a resolution of 90 × 90 would provide the accuracy needed for the interannual cumulative SMB and DMB to be accurately separated.

  10. The determination of accurate dipole polarizabilities alpha and gamma for the noble gases

    Science.gov (United States)

    Rice, Julia E.; Taylor, Peter R.; Lee, Timothy J.; Almloef, Jan

    1989-01-01

    The static dipole polarizabilities alpha and gamma for the noble gases helium through xenon were determined using large flexible one-particle basis sets in conjunction with high-level treatments of electron correlation. The electron correlation methods include single and double excitation coupled-cluster theory (CCSD), an extension of CCSD that includes a perturbational estimate of connected triple excitations, CCSD(T), and second order perturbation theory (MP2). The computed alpha and gamma values are estimated to be accurate to within a few percent. Agreement with experimental data for the static hyperpolarizability gamma is good for neon and xenon, but for argon and krypton the differences are larger than the combined theoretical and experimental uncertainties. Based on our calculations, we suggest that the experimental value of gamma for argon is too low; adjusting this value would bring the experimental value of gamma for krypton into better agreement with our computed result. The MP2 values for the polarizabilities of neon, argon, krypton and zenon are in reasonabe agreement with the CCSD and CCSD(T) values, suggesting that this less expensive method may be useful in studies of polarizabilities for larger systems.

  11. An Illustration of Determining Quantitatively the Rock Mass Quality Parameters of the Hoek-Brown Failure Criterion

    Science.gov (United States)

    Wu, Li; Adoko, Amoussou Coffi; Li, Bo

    2018-04-01

    In tunneling, determining quantitatively the rock mass strength parameters of the Hoek-Brown (HB) failure criterion is useful since it can improve the reliability of the design of tunnel support systems. In this study, a quantitative method is proposed to determine the rock mass quality parameters of the HB failure criterion, namely the Geological Strength Index (GSI) and the disturbance factor ( D) based on the structure of drilling core and weathering condition of rock mass combined with acoustic wave test to calculate the strength of rock mass. The Rock Mass Structure Index and the Rock Mass Weathering Index are used to quantify the GSI while the longitudinal wave velocity ( V p) is employed to derive the value of D. The DK383+338 tunnel face of Yaojia tunnel of Shanghai-Kunming passenger dedicated line served as illustration of how the methodology is implemented. The values of the GSI and D are obtained using the HB criterion and then using the proposed method. The measured in situ stress is used to evaluate their accuracy. To this end, the major and minor principal stresses are calculated based on the GSI and D given by HB criterion and the proposed method. The results indicated that both methods were close to the field observation which suggests that the proposed method can be used for determining quantitatively the rock quality parameters, as well. However, these results remain valid only for rock mass quality and rock type similar to those of the DK383+338 tunnel face of Yaojia tunnel.

  12. Determination of trace quantities of uranium in rocks mass spectrometric isotope dilution technique

    International Nuclear Information System (INIS)

    Kakazu, Mauricio Hiromitu

    1980-01-01

    A detailed experimental investigation on the thermionic emission of uranium deposited on a single flat type rhenium filament has been carried out. The study was aimed at determining the influence of various forms of deposition on the emission sensitivity and thermal stability of U + , UO + and UO 2 + ions. Based on these investigations, a technique, involving an addition of a small quantity of colloidal suspension of graphite on top of the uranyl nitrate sample deposited, was chosen because of its higher, emission sensitivity for uranium metal ions. The experimental parameters of the technique were optimised and the technique was employed in the determination of trace quantities of uranium in rock samples using mass spectrometric isotope dilution method. For the mass spectrometric isotope dilution analysis National Bureau of Standards uranium isotopic standard NBS-U 970 was employed as a tracer, where as the mass discrimination effect in the uranium isotope analysis was corrected using the uranium isotopic standard NBS-U500. Uranium was determined in each of the seven granite samples from Wyoming, USA and two USGS standard rocks. The precision of the analysis was found to be ±1% . The uranium values obtained on the rock samples were compared with the analyses of other investigators. Influence of the sample splitting on the uranium analysis was discussed in the light of the analytical results obtained.(author)

  13. Accurate Determination of Glacier Surface Velocity Fields with a DEM-Assisted Pixel-Tracking Technique from SAR Imagery

    Directory of Open Access Journals (Sweden)

    Shiyong Yan

    2015-08-01

    Full Text Available We obtained accurate, detailed motion distribution of glaciers in Central Asia by applying digital elevation model (DEM assisted pixel-tracking method to L-band synthetic aperture radar imagery. The paper firstly introduces and analyzes each component of the offset field briefly, and then describes the method used to efficiently and precisely compensate the topography-related offset caused by the large spatial baseline and rugged terrain with the help of DEM. The results indicate that the rugged topography not only forms the complex shapes of glaciers, but also affects the glacier velocity estimation, especially with large spatial baseline. The maximum velocity, 0.85 m∙d−1, was observed in the middle part on the Fedchenko Glacier, which is the world’s longest mountain glacier. The motion fluctuation on its main trunk is apparently influenced by mass flowing in from tributaries, as well as angles between tributaries and the main stream. The approach presented in this paper was proved to be highly appropriate for monitoring glacier motion and will provide valuable sensitive indicators of current and future climate change for environmental analysis.

  14. Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review.

    Science.gov (United States)

    Cao, Liguo; Bu, Wenting; Zheng, Jian; Pan, Shaoming; Wang, Zhongtang; Uchida, Shigeo

    2016-05-01

    Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of (239+240)Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Rapid simultaneous determination of organophosphorus pesticides in human serum and urine by liquid chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Zlatković Milica

    2010-01-01

    Full Text Available Background/Aim. Analysis of organophosphosphorus compounds and their metabolites in a biological material includes the use of numerous methods, covering both preparation of samples for analysis and their identification that is considered to be very complex. Low concentrations monitoring requires implementation of highly sensitive analytical techniques. The aim of this study was to develop and validate an original and sensitive method for the detection and quantitation of organophosphorus pesticides (dimethoate, diazinon, malathion and malaoxon in human biological matrices (serum, urine. Methods. This method was based on a solid-phase extraction procedure, a chromatographic separation using an ACQUITY UPLC ® HSST3 column and mass spectrometric detection in the positve ion mode. Mobile phase: was consited of Solvent A (5 mM ammonium formate pH 3.0 and Solvent B (0.1% acetic formate in methanol, in a linear gradient (constant flow-rate 0.3 mL/min. Results. The standard curve was linear in the range of 0.05-5.00 mg/L for malathion and malaoxon, 0.10-5.00 mg/L for dimethoate and 0.05-2.50 mg/L for diazinon. The correlation coefficient was r ≥ 0.99. Extraction recoveries were satisfactory and ranged between 90-99%. The limits of detection (LOD was between 0.007- 0.07 mg/L and the limits of quantitation (LOQ ranged between 0.022-0.085 mg/L. Intra- and interassay precision and accuracy were satisfactory for all of the pesticides analyzed. Conclusion. The method of liquid chromatography - mass spectrometry is simple, accurate, and useful for the determination of organophosphorus pesticides in both clinical and forensic toxicology.

  16. Improved determination of the Higgs mass in the MSSM with heavy superpartners

    Energy Technology Data Exchange (ETDEWEB)

    Bagnaschi, Emanuele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pardo Vega, Javier [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); SISSA International School for Advanced Studies, Trieste (Italy); INFN, Trieste (Italy); Slavich, Pietro [UPMC Univ. Paris 06 Sorbonne Univs., Paris (France). LPTHE; CNRS, Paris (France). LPTHE

    2017-03-15

    We present several advances in the effective field theory calculation of the Higgs mass in MSSM scenarios with heavy superparticles. In particular, we compute the dominant two-loop threshold corrections to the quartic Higgs coupling for generic values of the relevant SUSY-breaking parameters, including all contributions controlled by the strong gauge coupling and by the third-family Yukawa couplings. We also study the effects of a representative subset of dimension-six operators in the effective theory valid below the SUSY scale. Our results will allow for an improved determination of the Higgs mass and of the associated theoretical uncertainty.

  17. Improved determination of the Higgs mass in the MSSM with heavy superpartners.

    Science.gov (United States)

    Bagnaschi, Emanuele; Vega, Javier Pardo; Slavich, Pietro

    2017-01-01

    We present several advances in the effective field theory calculation of the Higgs mass in MSSM scenarios with heavy superparticles. In particular, we compute the dominant two-loop threshold corrections to the quartic Higgs coupling for generic values of the relevant SUSY-breaking parameters, including all contributions controlled by the strong gauge coupling and by the third-family Yukawa couplings. We also study the effects of a representative subset of dimension-six operators in the effective theory valid below the SUSY scale. Our results will allow for an improved determination of the Higgs mass and of the associated theoretical uncertainty.

  18. Improved determination of the Higgs mass in the MSSM with heavy superpartners

    Energy Technology Data Exchange (ETDEWEB)

    Bagnaschi, Emanuele [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vega, Javier Pardo [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); SISSA International School for Advanced Studies, Trieste (Italy); INFN Trieste, Trieste (Italy); Slavich, Pietro [LPTHE, UPMC Univ. Paris 06, Sorbonne Universites, Paris (France); LPTHE, CNRS, Paris (France)

    2017-05-15

    We present several advances in the effective field theory calculation of the Higgs mass in MSSM scenarios with heavy superparticles. In particular, we compute the dominant two-loop threshold corrections to the quartic Higgs coupling for generic values of the relevant SUSY-breaking parameters, including all contributions controlled by the strong gauge coupling and by the third-family Yukawa couplings. We also study the effects of a representative subset of dimension-six operators in the effective theory valid below the SUSY scale. Our results will allow for an improved determination of the Higgs mass and of the associated theoretical uncertainty. (orig.)

  19. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  20. Structure elucidation of metabolite x17299 by interpretation of mass spectrometric data.

    Science.gov (United States)

    Zhang, Qibo; Ford, Lisa A; Evans, Anne M; Toal, Douglas R

    2017-01-01

    A major bottleneck in metabolomic studies is metabolite identification from accurate mass spectrometric data. Metabolite x17299 was identified in plasma as an unknown in a metabolomic study using a compound-centric approach where the associated ion features of the compound were used to determine the true molecular mass. The aim of this work is to elucidate the chemical structure of x17299, a new compound by de novo interpretation of mass spectrometric data. An Orbitrap Elite mass spectrometer was used for acquisition of mass spectra up to MS 4 at high resolution. Synthetic standards of N,N,N -trimethyl-l-alanyl-l-proline betaine (l,l-TMAP), a diastereomer, and an enantiomer were chemically prepared. The planar structure of x17299 was successfully proposed by de novo mechanistic interpretation of mass spectrometric data without any laborious purification and nuclear magnetic resonance spectroscopic analysis. The proposed structure was verified by deuterium exchanged mass spectrometric analysis and confirmed by comparison to a synthetic standard. Relative configuration of x17299 was determined by direct chromatographic comparison to a pair of synthetic diastereomers. Absolute configuration was assigned after derivatization of x17299 with a chiral auxiliary group followed by its chromatographic comparison to a pair of synthetic standards. The chemical structure of metabolite x17299 was determined to be l,l-TMAP.

  1. Fast mass spectrometry-based enantiomeric excess determination of proteinogenic amino acids.

    Science.gov (United States)

    Fleischer, Heidi; Thurow, Kerstin

    2013-03-01

    A rapid determination of the enantiomeric excess of proteinogenic amino acids is of great importance in various fields of chemical and biologic research and industries. Owing to their different biologic effects, enantiomers are interesting research subjects in drug development for the design of new and more efficient pharmaceuticals. Usually, the enantiomeric composition of amino acids is determined by conventional analytical methods such as liquid or gas chromatography or capillary electrophoresis. These analytical techniques do not fulfill the requirements of high-throughput screening due to their relative long analysis times. The method presented allows a fast analysis of chiral amino acids without previous time consuming chromatographic separation. The analytical measurements base on parallel kinetic resolution with pseudoenantiomeric mass tagged auxiliaries and were carried out by mass spectrometry with electrospray ionization. All 19 chiral proteinogenic amino acids were tested and Pro, Ser, Trp, His, and Glu were selected as model substrates for verification measurements. The enantiomeric excesses of amino acids with non-polar and aliphatic side chains as well as Trp and Phe (aromatic side chains) were determined with maximum deviations of the expected value less than or equal to 10ee%. Ser, Cys, His, Glu, and Asp were determined with deviations lower or equal to 14ee% and the enantiomeric excess of Tyr were calculated with 17ee% deviation. The total screening process is fully automated from the sample pretreatment to the data processing. The method presented enables fast measurement times about 1.38 min per sample and is applicable in the scope of high-throughput screenings.

  2. Native and mass labeled [13C14]-decabromodiphenylethane (DBDPE). Characterization and use in determination of DBDPE in sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    McCrindle, R. [Guelph Univ., ON (Canada). Chemistry Dept.; Chittim, B.; Konstantinov, A.; McAlees, A.; Potter, D.; Tashiro, C.; Yeo, B. [Wellington Laboratories, Guelph, ON (Canada); Kolic, T.; MacPherson, K.; Reiner, E. [Ontario Ministry of the Environment, Toronto, ON (Canada)

    2004-09-15

    Decabromodiphenylethane (DBDPE) is a relatively new brominated flame retardant for use in polystyrene and polyolefin-based thermoplastic formulations. DBDPE was introduced in the early 90's, and is marketed as a non-diphenyl oxide based alternative to brominated diphenyl ethers (BDE)i. One study has shown that DBDPE produces no dioxins and only minor quantities of 2,3,7,8-TBDF under pyrolysis conditions. Although currently DBDPE is not as widely used as decabromodiphenyl ether (BDE-209) because of the higher cost, it is predicted that DBDPE will soon become one of the major flame retardants used by the thermoplastics industry. The presence of DBDPE in sediments, sewage sludge and air samples was reported during Dioxin 2003. The levels of DBDPE found in sewage sludge ranged from 33 to approximately 100 ng/g dry weight, and its ratio to BDE-209 levels in quantified samples was 0.01 in the sediment and 0.3 to 0.6 in the sewage sludge samples examined. The lack of a surrogate standard for DBDPE definitely poses difficulties in determining levels accurately. This study has two goals: the characterization of mass-labeled DBDPE and an assessment of its utility in determining DBDPE levels in environmental samples.

  3. Calorimetric measurements of $^{163}$ holmium decay as tools to determine the electron neutrino mass

    CERN Document Server

    De Rújula, Alvaro

    1982-01-01

    Computes the spectrum of 'calorimetric' energy in the electron capture decay of /sup 163/Ho. A calorimetric experiment would yield an excellent determination of (/sup 163/Ho, /sup 163/Dy) mass difference. The proximity of the spectral endpoint to an atomic resonance makes the fraction of events that are sensitive to a non-zero neutrino mass superior in /sup 163/Ho decay than in tritium decay.

  4. Measurement of mass and isotopic fission yields for heavy fission products with the LOHENGRIN mass spectrometer

    International Nuclear Information System (INIS)

    Bail, A.

    2009-05-01

    In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupled to a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields of the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. To complete and improve the nuclear data libraries, these measurements have been extended in this work to the heavy mass region for the reactions 235 U(n th ,f), 239 Pu(n th ,f) and 241 Pu(n th ,f). For these higher masses an isotopic separation is no longer possible. So, a new method was undertaken with the reaction 239 Pu(n th ,f) to determine the isotopic yields by spectrometry. These experiments have allowed to reduce considerably the uncertainties. Moreover the ionic charge state and kinetic energy distributions were specifically studied and have shown, among others, nanosecond isomers for some masses. (author)

  5. Innovative application of the moisture analyzer for determination of dry mass content of processed cheese

    Science.gov (United States)

    Kowalska, Małgorzata; Janas, Sławomir; Woźniak, Magdalena

    2018-04-01

    The aim of this work was the presentation of an alternative method of determination of the total dry mass content in processed cheese. The authors claim that the presented method can be used in industry's quality control laboratories for routine testing and for quick in-process control. For the test purposes both reference method of determination of dry mass in processed cheese and moisture analyzer method were used. The tests were carried out for three different kinds of processed cheese. In accordance with the reference method, the sample was placed on a layer of silica sand and dried at the temperature of 102 °C for about 4 h. The moisture analyzer test required method validation, with regard to drying temperature range and mass of the analyzed sample. Optimum drying temperature of 110 °C was determined experimentally. For Hochland cream processed cheese sample, the total dry mass content, obtained using the reference method, was 38.92%, whereas using the moisture analyzer method, it was 38.74%. An average analysis time in case of the moisture analyzer method was 9 min. For the sample of processed cheese with tomatoes, the reference method result was 40.37%, and the alternative method result was 40.67%. For the sample of cream processed cheese with garlic the reference method gave value of 36.88%, and the alternative method, of 37.02%. An average time of those determinations was 16 min. Obtained results confirmed that use of moisture analyzer is effective. Compliant values of dry mass content were obtained for both of the used methods. According to the authors, the fact that the measurement took incomparably less time for moisture analyzer method, is a key criterion of in-process control and final quality control method selection.

  6. Differential extraction of endogenous and exogenous 25-OH-vitamin D from serum makes the accurate quantification in liquid chromatography-tandem mass spectrometry assays challenging.

    Science.gov (United States)

    Lankes, Ulrich; Elder, Peter A; Lewis, John G; George, Peter

    2015-01-01

    Extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis is the method of choice when it comes to the accurate quantification of 25-OH-vitamin D in blood samples. It is generally assumed that the addition of exogenous internal standard allows for the determination of the endogenous analyte concentration. In this study we investigated the extraction properties of endogenous and exogenous 25-OH-vitamin D. Eight samples were used for the evaluation of the extraction procedure and 59 patients' samples for a method comparison. The methanol-to-sample ratio (v/v) and the sample-to-hexane ratio (v/v) were varied and the LC-MS/MS signals of endogenous 25-OH-vitamin D3, spiked 25-OH-vitamin D2 and internal standard of the extracts recorded. The optimized 'in-house' LC-MS/MS assay was compared to two automated chemiluminescence immunoassays from DiaSorin and Abbott. Mathematical analysis of the data revealed a differential extraction of endogenous 25-OH-vitamin D3, spiked 25-OH-vitamin D2 and non-equilibrated internal standard. Exogenous 25-OH-vitamin D can be measured accurately if a definite methanol-to-sample ratio is used. Endogenous 25-OH-vitamin D is affected by critical quantification issues due to a differential slope in the extraction profile. The actual 25-OH-vitamin D concentration can be one-third above the measured extractable concentration. Results confirm that the 'in-house' LC-MS/MS assay provides reproducible 25-OH-vitamin D results. Discordant concentrations of 25-OH-vitamin D from LC-MS/MS assays can be caused by selection of suboptimal extraction conditions. Furthermore, a different sample pretreatment or solvent extraction system may result in a different dissociation and extraction yield of endogenous 25-OH-vitamin D and therefore contribute to variations of LC-MS/MS results. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  7. Measurement of the Mass of an Object Hanging from a Spring--Revisited

    Science.gov (United States)

    Serafin, Kamil; Oracz, Joanna; Grzybowski, Marcin; Koperski, Maciej; Sznajder, Pawel; Zinkiewicz, Lukasz; Wasylczyk, Piotr

    2012-01-01

    In an open competition, students were to determine the mass of a metal cylinder hanging on a spring inside a transparent enclosure. With the time for experiments limited to 24 h due to the unexpectedly large number of participants, a few surprisingly accurate results were submitted, the best of them differing by no more than 0.5% from the true…

  8. Mass Determination of Entire Amyloid Fibrils by Using Mass Spectrometry.

    Science.gov (United States)

    Doussineau, Tristan; Mathevon, Carole; Altamura, Lucie; Vendrely, Charlotte; Dugourd, Philippe; Forge, Vincent; Antoine, Rodolphe

    2016-02-12

    Amyloid fibrils are self-assembled protein structures with important roles in biology (either pathogenic or physiological), and are attracting increasing interest in nanotechnology. However, because of their high aspect ratio and the presence of some polymorphism, that is, the possibility to adopt various structures, their characterization is challenging and basic information such as their mass is unknown. Here we show that charge-detection mass spectrometry, recently developed for large self-assembled systems such as viruses, provides such information in a straightforward manner. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained...

  10. Reliability and validity of non-invasive determined haemoglobin mass and blood volumes

    DEFF Research Database (Denmark)

    Fagoni, Nazzareno; Andersen, Andreas Breenfeldt; Oberholzer, Laura

    2018-01-01

    INTRODUCTION: The carbon monoxide (CO) rebreathing method used for the determination of haemoglobin mass (Hbmass ) is associated with blood sample analysis (in this study: Radiometer ABL800). As an alternative hereto the aim of the present study was to evaluate the use of a portable and non-invas...

  11. Matrix effect on the determination of synthetic corticosteroids and diuretics by liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Dikunets, M. A.; Appolonova, S. A.; Rodchenkov, G. M.

    2009-04-01

    This work presents a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) procedure for selective and reliable screening of corticosteroids and diuretics in human urine. Sample preparation included the extraction, evaporation of the organic extract under nitrogen, and solution of the dry residue. The extract was analyzed by HPLC combined with tandem mass spectrometry using electro-spraying ionization at atmospheric pressure with negative ion recording. The mass spectra of all compounds were recorded, and the characteristic ions, retention times, and detection limits were determined. The procedure was validated by evaluating the degree of the matrix suppression of ionization, extraction of analytes from human biological liquid, and the selectivity and specificity of determination.

  12. Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

    Energy Technology Data Exchange (ETDEWEB)

    Herman, Christelle, E-mail: christelle.herman@ulb.ac.b [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium); Leyssens, Tom [Universite Catholique de Louvain, Institute of Condensed Matter and Nanosciences, 1 Place Louis Pasteur, 1348 Louvain-La-Neuve (Belgium); Vermylen, Valerie [UCB Pharma, 60 Allee de la Recherche, 1070 Braine l' Alleud (Belgium); Halloin, Veronique; Haut, Benoit [Universite Libre de Bruxelles, Transfers, Interfaces and Processes Department, Chemical Engineering Unit, 50 Avenue Franklin D-Roosevelt, CP 165/67, 1050 Bruxelles (Belgium)

    2011-05-15

    the second experimental method is a more accurate, precise, time- and effort-friendly method for the determination of T{sub tr}. The solid-solid transition temperature of the Etiracetam system, determined with the second method, using three different solvents, is found to be equal to 303.65 K {+-} 0.5 K.

  13. Towards an accurate and precise determination of the solid-solid transition temperature of enantiotropic systems

    International Nuclear Information System (INIS)

    Herman, Christelle; Leyssens, Tom; Vermylen, Valerie; Halloin, Veronique; Haut, Benoit

    2011-01-01

    while the second experimental method is a more accurate, precise, time- and effort-friendly method for the determination of T tr . The solid-solid transition temperature of the Etiracetam system, determined with the second method, using three different solvents, is found to be equal to 303.65 K ± 0.5 K.

  14. Determining the neutrino mass hierarchy with cosmology

    International Nuclear Information System (INIS)

    De Bernardis, Francesco; Kitching, Thomas D.; Heavens, Alan; Melchiorri, Alessandro

    2009-01-01

    The combination of current large-scale structure and cosmic microwave background anisotropies data can place strong constraints on the sum of the neutrino masses. Here we show that future cosmic shear experiments, in combination with cosmic microwave background constraints, can provide the statistical accuracy required to answer questions about differences in the mass of individual neutrino species. Allowing for the possibility that masses are nondegenerate we combine Fisher matrix forecasts for a weak lensing survey like Euclid with those for the forthcoming Planck experiment. Under the assumption that neutrino mass splitting is described by a normal hierarchy we find that the combination Planck and Euclid will possibly reach enough sensitivity to put a constraint on the mass of a single species. Using a Bayesian evidence calculation we find that such future experiments could provide strong evidence for either a normal or an inverted neutrino hierarchy. Finally we show that if a particular neutrino hierarchy is assumed then this could bias cosmological parameter constraints, for example, the dark energy equation of state parameter, by > or approx. 1σ, and the sum of masses by 2.3σ. We finally discuss the impact of uncertainties on the theoretical modeling of nonlinearities. The results presented in this analysis are obtained under an approximation to the nonlinear power spectrum. This significant source of uncertainty needs to be addressed in future work.

  15. Search for $\\beta$-transitions with the lowest decay energy for a determination of the neutrino mass

    CERN Multimedia

    From a variety of $\\beta$-transitions only those with decay energies of a few keV and smaller are considered suitable for a determination of the neutrino mass on a sub-eV level. The decay energy of a transition can be very small, if, e.g., in an allowed $\\beta$-decay or electron-capture transition, a nuclear excited state of the daughter nuclide is populated whose energy is very close to the mass difference of the transition nuclides. Investigation of these transitions can also be useful for the assessment of a validity of the current $\\beta$-decay theory in the region of vanishingly small decay energies. The authors of this proposal have found several such $\\beta$-transitions whose decay energies are expected to be extremely small. In order to assess the suitability of these $\\beta$-transitions for the determination of the neutrino mass, measurements of the mass differences of the transition nuclides must be carried out with a sub-keV uncertainty. Presently, only high-precision Penning-trap mass spectrometry...

  16. Recent results from the Penning trap mass spectrometer JYFLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Christine; Elomaa, Viki-Veikko; Eronen, Tommi; Hakala, Jani; Jokinen, Ari; Kankainen, Anu; Rahaman, Saidur; Rissanen, Juho; Aeystoe, Juha [Department of Physics, (YFL), University of Jyvaeskylae (Finland)

    2009-07-01

    Accurate mass determination employing Penning ion traps has gained increasing importance after the installation of several new on-line facilities at accelerator labs. These setups combine unique production possibilities for rare isotopes with elaborate ion-capture and manipulation techniques. Since the final commissioning of the JYFLTRAP setup at the IGISOL facility in Jyvaeskylae, the masses of more than 200 short-lived nuclides have been measured. Their knowledge applies to studies on nuclear structure, the modeling of nucleosynthesis processes, tests of the conserved vector current (CVC) hypothesis and the unitarity of the CKM matrix, and furthermore, can help to assist in ongoing searches of neutrinoless double-beta decays. This presentation focuses on recent highlights studied at JYFLTRAP.

  17. Indigenous instrumentation for mass spectrometry. PD-5-1

    International Nuclear Information System (INIS)

    Handu, V.K.

    2007-01-01

    Mass Spectrometry is a powerful analytical technique due to its high sensitivity, specificity, selectivity, and wide field of applications in elemental analysis, especially in the determination of trace and ultra trace elements, precise and accurate isotopic ratio measurements. Due to these excellent features, it is a crucial analytical tool for number of Department of Atomic Energy's (DAE) programs. BARC, over the years, has developed several mass spectrometers suitable for needs of a number of programs in DAE and, in this process, technologies have been developed in HV/UHV systems, precision mechanical engineering and fabrication, design and fabrication of electromagnets, ion optics, ultra stable analog and digital electronics, data systems etc. A large number of these mass spectrometers are being used regularly in various units of DAE. Since users are demanding TIMS mass spectrometer with better specifications, efforts are being made in house to develop TIMS with improved specifications. Efforts are also under way to develop a multi collector, plasma source mass spectrometer (MC-ICP-MS) with magnetic sector mass analyzer, since such instrument is increasingly being used to measure isotopic ratios with high precision

  18. Application of secondary ions mass spectrometry (SIMS) in studies of internal contamination

    International Nuclear Information System (INIS)

    Amaral, Ademir; Galle, Pierre; Colas-Linhart, Nicole

    2000-01-01

    Secondary Ion Mass Spectrometry (SIMS) permits the detection of stable and radioactive nuclides. Based on the ablation of specimens by ion bombardment this mass spectrometry method allows a rapid assessment of trace elements in biological samples. Its resolving mass power provides an efficient analytical method and, in particular, it makes possible accurate isotopic ratio determination. In this work, the application of SIMS has been investigated in studies of internal contamination. In vivo studies were carried out using duodenal tissue sections from rats contaminated with cerium. Tests were performed to localize this element as a result of the contamination. In this report, analytical procedures and the potential of SIMS in biological research are presented and discussed. (author)

  19. [Determination of glufosinate residue in tea by liquid chromatography-tandem mass spectrometry coupled with precolumn derivatization].

    Science.gov (United States)

    Lin, Yonghui; Liu, Zhengcai; Yang, Fang; Qiu, Yuanjin; Liu, Suzhen; Su, Zhijiao; Zhang, Qiong; Xue, Zhimin; Fang, Yu

    2012-12-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the determination of glufosinate (GLUF) residue in tea. The GLUF was extracted with water for 30 min under ultrasonication, and cleaned-up using a C18 solid phase extraction cartridge, then derived using fluorenylmethylchloroformate (FMOC-Cl) in borate buffer for 2 h. The separation was performed on a Kinetex C18 column with the mobile phases of acetonitrile and 5 mmol/L ammonium acetate aqueous solution (containing 0.2% (v/v) formic acid) in a gradient elution mode. The identification and quantification of the GLUF were carried out by MS/MS in negative electrospray ionization (ESI(-)) and multiple reaction monitoring (MRM) mode, the quantification analysis was performed by external standard method. The calibration curve showed good linearity in the range of 2.5 - 50.0 microg/L with the correlation coefficient r2 > 0.999. The limit of quantification (LOQ) was 0.10 mg/kg. The average recoveries of GLUF spiked at 0.10, 0.50 and 1.00 mg/kg levels in tea were between 61.6% and 81.4%, and the relative standard deviations (RSDs) were between 3.2% and 8.4%. The method is simple, rapid, sensitive, accurate and suitable for the confirmation and quantification of GLUF in tea.

  20. DETERMINATION OF CO2 MASSES IN THE EXHAUST GASES OF THE MARINE DIESEL ENGINES

    Directory of Open Access Journals (Sweden)

    Doru COSOFRET

    2016-05-01

    Full Text Available Currently, reducing CO2 emissions that contribute to the greenhouse effect is currently under attention of the relevant international bodies. In the field of maritime transport, in 2011 International Maritime Organization (IMO has taken steps to reduce emissions of CO2 from the exhaust gases of marine diesel engines on ships, by imposing their energy efficiency standards. In this regard, we conducted a laboratory study on a 4-stroke diesel engine naturally aspirated by using to power it diesel and different blends of biodiesel with diesel fuel. The purpose of the study was to determine the formulas for calculating the mass flow rates of CO2 from exhaust gases’ concentrations experimentally determined. Determining the mass flow of CO2 is necessary to calculate the energy efficiency coefficient of the ship to assess the energy efficiency of the board of the limits imposed by the IMO.

  1. Higgs-boson contributions to gauge-boson mass shifts in extended electroweak models

    International Nuclear Information System (INIS)

    Moore, S.R.

    1985-10-01

    In the minimal standard model, the difference between the tree-level and one-loop-corrected predictions for the gauge-boson masses, known as the mass shifts, are of the order of 4%. The dominant contribution is from light-fermion loops. The Higgs-dependent terms are small, even if the Higgs boson is heavy. We have analyzed the mass shifts for models with a more complicated Higgs sector. We use the on-shell renormalization scheme, in which the parameters of the theory are the physical masses and couplings. We have considered the 2-doublet, n-doublet, triplet and doublet-triplet models. We have found that the Z-boson mass prediction has a strong dependence on the charged-Higgs mass. In the limit that the charged Higgs is much heavier than the gauge bosons, the Higgs-dependent terms become significant, and may even cancel the light-fermion terms. In the models with a Higgs triplet, there is also a strong dependence on the neutral-Higgs masses, although this contribution tends to be suppressed in realistic models. The W-boson mass shift does not have a strong Higgs dependence. If we use the Z mass as input in determining the parameters of the theory, a scenario which will become attractive as the mass of the Z is accurately measured in the next few years, we find that the W-boson mass shift exhibits the same sort of behavior, differing from the minimal model for the case of the charged Higgs being heavy. We have found that when radiative corrections are taken into account, models with extended Higgs sectors may differ significantly from the minimal standard model in their predictions for the gauge-boson masses. Thus, an accurate measurement of the masses will help shed light on the structure of the Higgs sector. 68 refs

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

    Science.gov (United States)

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

    2005-05-01

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

  3. Engineering analysis of mass flow rate for turbine system control and design

    International Nuclear Information System (INIS)

    Yoo, Yong H.; Suh, Kune Y.

    2011-01-01

    Highlights: → A computer code is written to predict the steam mass flow rate through valves. → A test device is built to study the steam flow characteristics in the control valve. → Mass flow based methodology eases the programming and experimental procedures. → The methodology helps express the characteristics of each device of a turbine system. → The results can commercially be used for design and operation of the turbine system. - Abstract: The mass flow rate is determined in the steam turbine system by the area formed between the stem disk and the seat of the control valve. For precise control the steam mass flow rate should be known given the stem lift. However, since the thermal hydraulic characteristics of steam coming from the generator or boiler are changed going through each device, it is hard to accurately predict the steam mass flow rate. Thus, to precisely determine the steam mass flow rate, a methodology and theory are developed in designing the turbine system manufactured for the nuclear and fossil power plants. From the steam generator or boiler to the first bunch of turbine blades, the steam passes by a stop valve, a control valve and the first nozzle, each of which is connected with piping. The corresponding steam mass flow rate can ultimately be computed if the thermal and hydraulic conditions are defined at the stop valve, control valve and pipes. The steam properties at the inlet of each device are changed at its outlet due to geometry. The Compressed Adiabatic Massflow Analysis (CAMA) computer code is written to predict the steam mass flow rate through valves. The Valve Engineered Layout Operation (VELO) test device is built to experimentally study the flow characteristics of steam flowing inside the control valve with the CAMA input data. The Widows' Creek type control valve was selected as reference. CAMA is expected to be commercially utilized to accurately design and operate the turbine system for fossil as well as nuclear power

  4. Accurate LC peak boundary detection for ¹⁶O/¹⁸O labeled LC-MS data.

    Science.gov (United States)

    Cui, Jian; Petritis, Konstantinos; Tegeler, Tony; Petritis, Brianne; Ma, Xuepo; Jin, Yufang; Gao, Shou-Jiang S J; Zhang, Jianqiu Michelle

    2013-01-01

    In liquid chromatography-mass spectrometry (LC-MS), parts of LC peaks are often corrupted by their co-eluting peptides, which results in increased quantification variance. In this paper, we propose to apply accurate LC peak boundary detection to remove the corrupted part of LC peaks. Accurate LC peak boundary detection is achieved by checking the consistency of intensity patterns within peptide elution time ranges. In addition, we remove peptides with erroneous mass assignment through model fitness check, which compares observed intensity patterns to theoretically constructed ones. The proposed algorithm can significantly improve the accuracy and precision of peptide ratio measurements.

  5. Accurate measurement of the optical activity of alanine crystals and the determination of their absolute chirality

    Science.gov (United States)

    Ishikawa, Kazuhiko; Terasawa, Yukana; Tanaka, Masahito; Asahi, Toru

    2017-05-01

    Wavelength dependence measurements of the chiroptical properties in alanine crystals have so far been unsuccessful using conventional spectroscopic techniques. We describe our attempts to measure the wavelength dependence of the optical activity in L- and D-alanine crystals along each crystallographic axis, and to determine the absolute chirality of alanine crystals by correlating the absolute structure to the optical activity using an x-ray diffractometer and a generalized high accuracy universal polarimeter. We have succeeded in accurately measuring the optical rotatory dispersion in the direction, which shows that the optical rotation of the D-alanine crystal is dextrorotatory and that of the L-alanine crystal is laevorotatory, thereby determining the absolute chirality. Furthermore, comparison with the optical activity in solution shows that the optical activity in alanine crystals is different not only in value, but also in the sign. These results have led us to conclude that the optical rotatory power in the crystalline state should not be simply the summation of molecular optical rotatory power values. We propose the necessity of a theory, which contains the contribution of molecular interactions within the crystal, in order to calculate the optical rotatory power of the crystalline state.

  6. Rapid, accurate, and direct determination of total lycopene content in tomato paste

    Science.gov (United States)

    Bicanic, D.; Anese, M.; Luterotti, S.; Dadarlat, D.; Gibkes, J.; Lubbers, M.

    2003-01-01

    Lycopene that imparts red color to the tomato fruit is the most potent antioxidant among carotenes, an important nutrient and also used as a color ingredient in many food formulations. Since cooked and processed foods derived from tomatoes were shown to provide optimal lycopene boost, products such as paste, puree, juice, etc. are nowadays gaining popularity as dietary sources. The analysis of lycopene in tomato paste (partially dehydrated product prepared by vacuum concentrating tomato juice) is carried out using either high pressure liquid chromatography (HPLC), spectrophotometry, or by evaluating the color. The instability of lycopene during processes of extraction, etc., handling, and disposal of organic solvents makes the preparation of a sample for the analysis a delicate task. Despite a recognized need for accurate and rapid assessment of lycopene in tomato products no such method is available at present. The study described here focuses on a direct determination of a total lycopene content in different tomato pastes by means of the laser optothermal window (LOW) method at 502 nm. The concentration of lycopene in tomato paste ranged between 25 and 150 mg per 100 g product; the results are in excellent agreement with those obtained by spectrophotometry. The time needed to complete LOW analysis is very short, so that decomposition of pigment and the formation of artifacts are minimized. Preliminary results indicate a good degree of reproducibility making the LOW method suitable for routine assays of lycopene content in tomato paste.

  7. High throughput and accurate serum proteome profiling by integrated sample preparation technology and single-run data independent mass spectrometry analysis.

    Science.gov (United States)

    Lin, Lin; Zheng, Jiaxin; Yu, Quan; Chen, Wendong; Xing, Jinchun; Chen, Chenxi; Tian, Ruijun

    2018-03-01

    Mass spectrometry (MS)-based serum proteome analysis is extremely challenging due to its high complexity and dynamic range of protein abundances. Developing high throughput and accurate serum proteomic profiling approach capable of analyzing large cohorts is urgently needed for biomarker discovery. Herein, we report a streamlined workflow for fast and accurate proteomic profiling from 1μL of blood serum. The workflow combined an integrated technique for highly sensitive and reproducible sample preparation and a new data-independent acquisition (DIA)-based MS method. Comparing with standard data dependent acquisition (DDA) approach, the optimized DIA method doubled the number of detected peptides and proteins with better reproducibility. Without protein immunodepletion and prefractionation, the single-run DIA analysis enables quantitative profiling of over 300 proteins with 50min gradient time. The quantified proteins span more than five orders of magnitude of abundance range and contain over 50 FDA-approved disease markers. The workflow allowed us to analyze 20 serum samples per day, with about 358 protein groups per sample being identified. A proof-of-concept study on renal cell carcinoma (RCC) serum samples confirmed the feasibility of the workflow for large scale serum proteomic profiling and disease-related biomarker discovery. Blood serum or plasma is the predominant specimen for clinical proteomic studies while the analysis is extremely challenging for its high complexity. Many efforts had been made in the past for serum proteomics for maximizing protein identifications, whereas few have been concerned with throughput and reproducibility. Here, we establish a rapid, robust and high reproducible DIA-based workflow for streamlined serum proteomic profiling from 1μL serum. The workflow doesn't need protein depletion and pre-fractionation, while still being able to detect disease-relevant proteins accurately. The workflow is promising in clinical application

  8. Diagnostic peritoneal lavage: volume of lavage effluent needed for accurate determination of a negative lavage.

    Science.gov (United States)

    Sweeney, J F; Albrink, M H; Bischof, E; McAllister, E W; Rosemurgy, A S

    1994-12-01

    While the ability of diagnostic peritoneal lavage (DPL) to 'rule out' occult intra-abdominal injuries has been well established, the volume of lavage effluent necessary for accurate prediction of a negative lavage has not been determined. To address this, 60 injured adults with blunt (N = 45) or penetrating (N = 15) trauma undergoing DPL were evaluated prospectively through protocol. After infusion of 1l of Ringer's lactate solution, samples of lavage effluent were obtained at 100 cm3, 250 cm3, 500 cm3, and 759 cm3, and when no more effluent could be returned (final sample). DPL was considered negative if final sample RBC count was < or = 100,000/mm3 for blunt injury and < 50,000/mm3 for penetrating injury. The conclusion is that at 100 cm3 of lavage effluent returned, negative results are highly predictive of a negative DPL (98 per cent), though 250 cm3 of lavage effluent is required to predict a negative DPL uniformly (100 per cent).

  9. Rapid determination of anti-estrogens by gas chromatography/mass spectrometry in urine: Method validation and application to real samples

    Directory of Open Access Journals (Sweden)

    E. Gerace

    2012-02-01

    Full Text Available A fast screening protocol was developed for the simultaneous determination of nine anti-estrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid–liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/mass spectrometry (fast-GC/MS after derivatization. The use of a short column, high-flow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MS-sampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration. Keywords: Anti-estrogens, Fast-GC/MS, Urine screening, Validation, Breast cancer

  10. Determination of uranium in uranyl nitrate solutions of nuclear grade quality - Gravimetric method

    International Nuclear Information System (INIS)

    1990-01-01

    This international Standard specifies a precise and accurate gravimetric method for determining the uranium content in uranyl nitrate product solutions of nuclear grade quality at concentrations above 100 g/l of uranium. Non-volatile impurities influence the accuracy of the method. Uranyl nitrate is converted into uranium octoxide (U 3 O 8 ) by ignition in air to constant mass at 900 deg. C ± 10 deg. C. Calculation of the uranium content in the sample using a gravimetric conversion factor which depends on the isotopic composition of the uranium. The isotopic composition is determined by mass spectrometry

  11. Accurate Determination of the Volume of an Irregular Helium Balloon

    Science.gov (United States)

    Blumenthal, Jack; Bradvica, Rafaela; Karl, Katherine

    2013-01-01

    In a recent paper, Zable described an experiment with a near-spherical balloon filled with impure helium. Measuring the temperature and the pressure inside and outside the balloon, the lift of the balloon, and the mass of the balloon materials, he described how to use the ideal gas laws and Archimedes' principal to compute the average molecular…

  12. Improved Nuclear Reactor and Shield Mass Model for Space Applications

    Science.gov (United States)

    Robb, Kevin

    2004-01-01

    New technologies are being developed to explore the distant reaches of the solar system. Beyond Mars, solar energy is inadequate to power advanced scientific instruments. One technology that can meet the energy requirements is the space nuclear reactor. The nuclear reactor is used as a heat source for which a heat-to-electricity conversion system is needed. Examples of such conversion systems are the Brayton, Rankine, and Stirling cycles. Since launch cost is proportional to the amount of mass to lift, mass is always a concern in designing spacecraft. Estimations of system masses are an important part in determining the feasibility of a design. I worked under Michael Barrett in the Thermal Energy Conversion Branch of the Power & Electric Propulsion Division. An in-house Closed Cycle Engine Program (CCEP) is used for the design and performance analysis of closed-Brayton-cycle energy conversion systems for space applications. This program also calculates the system mass including the heat source. CCEP uses the subroutine RSMASS, which has been updated to RSMASS-D, to estimate the mass of the reactor. RSMASS was developed in 1986 at Sandia National Laboratories to quickly estimate the mass of multi-megawatt nuclear reactors for space applications. In response to an emphasis for lower power reactors, RSMASS-D was developed in 1997 and is based off of the SP-100 liquid metal cooled reactor. The subroutine calculates the mass of reactor components such as the safety systems, instrumentation and control, radiation shield, structure, reflector, and core. The major improvements in RSMASS-D are that it uses higher fidelity calculations, is easier to use, and automatically optimizes the systems mass. RSMASS-D is accurate within 15% of actual data while RSMASS is only accurate within 50%. My goal this summer was to learn FORTRAN 77 programming language and update the CCEP program with the RSMASS-D model.

  13. Determination of the total drug-related chlorine and bromine contents in human blood plasma using high performance liquid chromatography-tandem ICP-mass spectrometry (HPLC-ICP-MS/MS).

    Science.gov (United States)

    Klencsár, Balázs; Bolea-Fernandez, Eduardo; Flórez, María R; Balcaen, Lieve; Cuyckens, Filip; Lynen, Frederic; Vanhaecke, Frank

    2016-05-30

    A fast, accurate and precise method for the separation and determination of the total contents of drug-related Cl and Br in human blood plasma, based on high performance liquid chromatography - inductively coupled plasma - tandem mass spectrometry (HPLC-ICP-MS/MS), has been developed. The novel approach was proved to be a suitable alternative to the presently used standard methodology (i.e. based on a radiolabelled version of the drug molecule and radiodetection), while eliminating the disadvantages of the latter. Interference-free determination of (35)Cl has been accomplished via ICP-MS/MS using H2 as reaction gas and monitoring the (35)ClH2(+) reaction product at mass-to-charge ratio of 37. Br could be measured "on mass" at a mass-to-charge of 79. HPLC was relied on for the separation of the drug-related entities from the substantial amount of inorganic Cl. The method developed was found to be sufficiently precise (repeatability 0.990) from the limit of quantification (0.05 and 0.01 mg/L for Cl and Br in blood plasma, respectively) to at least 5 and 1mg/L for Cl and Br, respectively. Quantification via either external or internal standard calibration provides reliable results for both elements. As a proof-of-concept, human blood plasma samples from a clinical study involving a newly developed Cl- and Br-containing active pharmaceutical ingredient were analysed and the total drug exposure was successfully described. Cross-validation was achieved by comparing the results obtained on Cl- and on Br-basis. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The ATLAS(3D) project - XX. Mass-size and mass-Sigma distributions of early-type galaxies : bulge fraction drives kinematics, mass-to-light ratio, molecular gas fraction and stellar initial mass function

    NARCIS (Netherlands)

    Cappellari, Michele; McDermid, Richard M.; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Bureau, M.; Crocker, Alison F.; Davies, Roger L.; Davis, Timothy A.; de Zeeuw, P. T.; Duc, Pierre-Alain; Emsellem, Eric; Khochfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Serra, Paolo; Weijmans, Anne-Marie; Young, Lisa M.

    2013-01-01

    In the companion Paper XV of this series, we derive accurate total mass-to-light ratios (M/L)(JAM) approximate to (M/L)(r = R-e) within a sphere of radius r = R-e centred on the galaxy, as well as stellar (M/L)(stars) (with the dark matter removed) for the volume-limited and nearly mass-selected

  15. Planck Constant Determination from Power Equivalence

    Science.gov (United States)

    Newell, David B.

    2000-04-01

    Equating mechanical to electrical power links the kilogram, the meter, and the second to the practical realizations of the ohm and the volt derived from the quantum Hall and the Josephson effects, yielding an SI determination of the Planck constant. The NIST watt balance uses this power equivalence principle, and in 1998 measured the Planck constant with a combined relative standard uncertainty of 8.7 x 10-8, the most accurate determination to date. The next generation of the NIST watt balance is now being assembled. Modification to the experimental facilities have been made to reduce the uncertainty components from vibrations and electromagnetic interference. A vacuum chamber has been installed to reduce the uncertainty components associated with performing the experiment in air. Most of the apparatus is in place and diagnostic testing of the balance should begin this year. Once a combined relative standard uncertainty of one part in 10-8 has been reached, the power equivalence principle can be used to monitor the possible drift in the artifact mass standard, the kilogram, and provide an accurate alternative definition of mass in terms of fundamental constants. *Electricity Division, Electronics and Electrical Engineering Laboratory, Technology Administration, U.S. Department of Commerce. Contribution of the National Institute of Standards and Technology, not subject to copyright in the U.S.

  16. Determining picogram quantities of U in human urine by thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Kelly, W.R.; Fassett, J.D.; Hotes, S.A.

    1987-01-01

    The U concentration in Standard Reference Material 2670 (Toxic Metals in Freeze-Dried Urine) and the urine of two preschool-age children were determined by measuring the chemically separated U by isotope dilution thermal ionization mass spectrometry using ion counting detection. This procedure can detect about 1% of the U atoms loaded into the mass spectrometer and has a total chemical blank of about 5 pg U. The U concentration in SRM 2670 was found to be 113 +/- 2 pg 238 U/ml (1 s). At this concentration, a 1-ml sample is sufficient for a determination with a total uncertainty of less than 5%. The U concentrations in the two children were 3.1 +/- 0.9 and 3.6 +/- 0.9 pg 238 U/g. These values suggest that the U concentration in urine of unexposed persons may be at this low level or lower

  17. Image resolution influence on determination of resin injection rock mass

    Science.gov (United States)

    Wang, Weixing; Hakami, Eva

    2006-01-01

    In the context of nuclear waste repositories, an important approach to understanding brittle rock mass behavior to integrate new and powerful observational and numerical methods with multi-functional 3-D imaging and visualization techniques. Since 1994, Swedish Nuclear Fuel and Waste Management Company (SKB) have identified the need for a better understanding of radionuclide transport and retention processes in fractured rock. As a cooperation project between Sweden and China, we sampled a number of rock specimens for analyze rock fracture network by optical image technique. The samples are resin injected, in which way; opened fractures can be seen clearly by means of UV (Ultraviolet) light illumination. In the study period, we used different optical focuses to obtain the images from the same samples; we found that Image resolution influences on porosity determination of resin injected rock mass. This paper presents and discusses the six issues based on our research results: (1) Fracture porosity increases as camera focus distance decreases; (2) Porosity increases as illumination increases in resin injected fracture images; (3) To roughly estimate the porosity, the low resolution image can be used; (4) To collect more details of fracture information, the high resolution image is needed; (5) The resolution of image should be determined based on the aim of fracture analysis; (6) To acquire high resolution image, constructing a special illumination (standard) box maybe helpful to avoid light reflection and diffusion.

  18. Performance optimisation of a new-generation orthogonal-acceleration quadrupole-time-of-flight mass spectrometer.

    Science.gov (United States)

    Bristow, Tony; Constantine, Jill; Harrison, Mark; Cavoit, Fabien

    2008-04-01

    Orthogonal-acceleration quadrupole time-of-flight (oa-QTOF) mass spectrometers, employed for accurate mass measurement, have been commercially available for well over a decade. A limitation of the early instruments of this type was the narrow ion abundance range over which accurate mass measurements could be made with a high degree of certainty. Recently, a new generation of oa-QTOF mass spectrometers has been developed and these allow accurate mass measurements to be recorded over a much greater range of ion abundances. This development has resulted from new ion detection technology and improved electronic stability or by accurate control of the number of ions reaching the detector. In this report we describe the results from experiments performed to evaluate the mass measurement performance of the Bruker micrOTOF-Q, a member of the new-generation oa-QTOFs. The relationship between mass accuracy and ion abundance has been extensively evaluated and mass measurement accuracy remained stable (+/-1.5 m m/z units) over approximately 3-4 orders of magnitude of ion abundance. The second feature of the Bruker micrOTOF-Q that was evaluated was the SigmaFit function of the software. This isotope pattern-matching algorithm provides an exact numerical comparison of the theoretical and measured isotope patterns as an additional identification tool to accurate mass measurement. The smaller the value, the closer the match between theoretical and measured isotope patterns. This information is then employed to reduce the number of potential elemental formulae produced from the mass measurements. A relationship between the SigmaFit value and ion abundance has been established. The results from the study for both mass accuracy and SigmaFit were employed to define the performance criteria for the micrOTOF-Q. This provided increased confidence in the selection of elemental formulae resulting from accurate mass measurements.

  19. The determination of precious metals in geological samples by ICP - Mass Spectrometry

    International Nuclear Information System (INIS)

    Denoyer, E.; Ediger, R.; Hager, J.

    1989-01-01

    ICP - mass spectrometry with laser sampling has been used to determine gold directly in solid fire assay beads. A small portion of the lead bead is vaporized by Nd: YAG laser, and the resulting particulate material is passed by a flow of argon an ICP-mass spectrometer for quantitation of the gold content. Calibration with known geological materials gives linear calibration curves, and detection limits for gols are estimated to be 0.07 micrograms/gram in the original ore sample. The repeatability of the method is similar to that expected for traditional fire assay methods, and the analysis time for the solid lead bead is less than five minutes per sample. (author) [pt

  20. Determining total hemoglobin mass by means of {sup 13}CO breath analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Marcus; Hering, Peter [Institut fuer Lasermedizin, Universitaetsklinikum Duesseldorf (Germany)

    2010-07-01

    The aim of our investigations is the development of a non-invasive method for the determination of the total hemoglobin mass in the human body by means of Cavity Leak-Out Spectroscopy (CALOS). The mentioned CALOS system utilizes a CO gas laser in the mid infrared region around 5{mu}m. This system allows isotopologue selective online measurements of {sup 13}CO with a sensitivity of 7 ppb.Hz{sup -1/2}. {sup 13}CO is a non radioactive isotopologue occurring in a ratio of about 1.1 % of the natural CO composition. CO is commonly known as a highly toxic gas but it is also endogenously produced during heme degradation. About 80 % of this CO is exhaled yielding to CO concentrations between 1 ppm to 4 ppm in healthy humans. Transportation of CO through the body is established by hemoglobin which has a high affinity towards CO. Because of this fact inhaled CO is taken up by the blood until equilibrium between the alveolar air and the blood is reached. By determining the exhaled CO concentrations before and after the inhalation of a certain amount of CO a measure for the t-Hb mass can be calculated. The enormous advantage of the isotopologue measurement is the very small amount of {sup 13}CO which can be used for harmless CO inhalation. All data necessary for calculating the t-Hb mass are obtained from breath measurements making this method non invasive.

  1. Determination of trace amounts of impurities in molybdenum by spark source and glow discharge mass spectrometry

    International Nuclear Information System (INIS)

    Saito, Morimasa

    1994-01-01

    For the determination of trace and ultra-trace amounts of impurities in high-purity molybdenum, spark source mass spectrometry and glow discharge mass spectrometry were studied. In spark source mass spectrometry using the metal probe method, the liquid-helium cryogenic pump was used in order to protect the surface of the samples from oxidation. The theoretical relative sensitivity factors (Mo=1) calculated from physical properties were used. The analytical results obtained for molybdenum tablet and high-purity molybdenum were in good agreement with those obtained by other methods (atomic absorption spectrometry and others). In glow discharge mass spectrometry, the relative sensitivity factors were calculated by using the results obtained by spark source mass spectrometry and atomic absorption spectrometry, and this method was applied to the determination of ultra-trace amounts of impurities in ultra high-purity molybdenum and gave the satisfactory results. The detection limits (2σ, n=10) in the integration time of 600 s for U and Th were 0.6 ppb and 0.3 ppb, and the values for Al, Si, Cr, Mn and Cu were in the range of 10 ppb to 0.5 ppb. (author)

  2. Complete Hexose Isomer Identification with Mass Spectrometry

    Science.gov (United States)

    Nagy, Gabe; Pohl, Nicola L. B.

    2015-04-01

    The first analytical method is presented for the identification and absolute configuration determination of all 24 aldohexose and 2-ketohexose isomers, including the D and L enantiomers for allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, and tagatose. Two unique fixed ligand kinetic method combinations were discovered to create significant enough energetic differences to achieve chiral discrimination among all 24 hexoses. Each of these 24 hexoses yields unique ratios of a specific pair of fragment ions that allows for simultaneous determination of identification and absolute configuration. This mass spectrometric-based methodology can be readily employed for accurate identification of any isolated monosaccharide from an unknown biological source. This work provides a key step towards the goal of complete de novo carbohydrate analysis.

  3. 'Age' Determination of Irradiated Materials Utilizing Inductively Coupled Plasma Mass Spectrometric (ICP-MS) Detection

    International Nuclear Information System (INIS)

    Sommers, James; Giglio, Jeffrey J.; Cummings, Daniel; Carney, Kevin P.

    2009-01-01

    A gas pressurized extraction chromatography (GPEC) system has been developed to perform elemental separations on radioactive samples to determine total and isotopic compositions of Cs and Ba from an irradiated salt sample, fuel sample and two sealed radiation sources. The separation is necessary to remove isobaric interferences in the determination of 137Cs, 135Cs, 137Ba, 135Ba, which are used to determine the age of a sample from radioactive decay or purification. The micro-column extraction chromatography system employs compressed nitrogen to move liquid through the system, compared to gravity or pumped liquids that are typically used for separations. The use of compressed gas allows for accurate and precise recovery of all liquids put into the chromatography system, enabling very accurate dilutions. The use of a small analytical column permits the use of very small amounts of liquids to be used. As a benefit, the amount of radiological waste that is generated in the separation process is minimized. For this work, a commercially available Sr-Resin(trademark) was used to perform the separation for the above mentioned analytes. The column consists of a 7 inch piece of 1/16 in. O.D. x 0.030 in I.D. Teflon(trademark) tubing having an internal volume of 81 (micro)L. To this column, 49 mg of resin was added. The columns are re-usable after regeneration with 3 M HNO3. All samples were separated using batch collection, although real time analysis is possible with the current experimental design. A 1 % acetic acid solution was determined to be the best extractant for Ba. A flow rate of 0.1 mL/min was determined to be optimal for the separation of Ba. Complete recovery of the Cs and Ba was achieved, within the systematic error of the experiments.

  4. Mass Distribution in Rotating Thin-Disk Galaxies According to Newtonian Dynamics

    Directory of Open Access Journals (Sweden)

    James Q. Feng

    2014-04-01

    Full Text Available An accurate computational method is presented for determining the mass distribution in a mature spiral galaxy from a given rotation curve by applying Newtonian dynamics for an axisymmetrically rotating thin disk of finite size with or without a central spherical bulge. The governing integral equation for mass distribution is transformed via a boundary-element method into a linear algebra matrix equation that can be solved numerically for rotation curves with a wide range of shapes. To illustrate the effectiveness of this computational method, mass distributions in several mature spiral galaxies are determined from their measured rotation curves. All the surface mass density profiles predicted by our model exhibit approximately a common exponential law of decay, quantitatively consistent with the observed surface brightness distributions. When a central spherical bulge is present, the mass distribution in the galaxy is altered in such a way that the periphery mass density is reduced, while more mass appears toward the galactic center. By extending the computational domain beyond the galactic edge, we can determine the rotation velocity outside the cut-off radius, which appears to continuously decrease and to gradually approach the Keplerian rotation velocity out over twice the cut-off radius. An examination of circular orbit stability suggests that galaxies with flat or rising rotation velocities are more stable than those with declining rotation velocities especially in the region near the galactic edge. Our results demonstrate the fact that Newtonian dynamics can be adequate for describing the observed rotation behavior of mature spiral galaxies.

  5. Accurate modeling and maximum power point detection of ...

    African Journals Online (AJOL)

    Accurate modeling and maximum power point detection of photovoltaic ... Determination of MPP enables the PV system to deliver maximum available power. ..... adaptive artificial neural network: Proposition for a new sizing procedure.

  6. Determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Björn, Erik; Nygren, Yvonne; Nguyen, Tam T. T. N.

    2007-01-01

    A fast and robust method for the determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry was developed, characterized, and validated. Samples of isolated DNA and exosome fractions from human ovarian (2008) and melanoma (T289) cancer cell lines w...

  7. Fractal Structure of Nature's Preferred Masses: Application of the Model of Oscillations in a Chain System

    Directory of Open Access Journals (Sweden)

    Ries A.

    2010-10-01

    Full Text Available A numerical analysis of elementary particle masses on the logarithmic number line revealed systematic mass gaps of 2e, e, e/2, e/4, e/8 and e/16. Also in abundance data of the chemical elements, a repeated abundance gap of e/2 could be detected. This lead us to modify a fractal scaling model originally published by Müller in this journal, interpreting elementary particles as proton resonances. We express a set of 78 accurately determined particle masses on the logarithmic scale in a continued fraction form where all numerators are Euler’s number.

  8. Determination of ruthenium in photographic emulsions - Development and comparison of different sample treatments and mass spectrometric methods

    NARCIS (Netherlands)

    Krystek, Petra; Heumann, Klaus G.

    1999-01-01

    Different sample treatment procedures were combined with inductively coupled plasma mass spectrometry (ICP-MS) and negative thermal ionisation mass spectrometry (NTI-MS) for the determination of ruthenium traces in photographic emulsions. Dissolution of the samples in concentrated ammonia solution

  9. Rapid and accurate biofuel moisture content gauging using magnetic resonance measurement technology

    Energy Technology Data Exchange (ETDEWEB)

    Jaervinen, T.

    2013-04-15

    Biomass is extensively utilised in energy production and as a raw material, such as for the production of liquid biofuels. All those processes will benefit if the moisture content of bio material is known in advance as accurately as possible under transient circumstances. Biofuel trade is increasingly based on the calorific value of fuels. In the first step, this also increases the need for rapid and accurate moisture content determination. During the last few years, large biofuel standardisation has been implemented, emphasising biofuel quality control at all stages of the utilisation chain. In principle, the moisture instrumental measurement can be utilised by many technologies and procedures. Typical techniques are infrared, radiofrequency, microwave, radiometric, electrical conductivity, capacitance, and impedance. Nuclear magnetic resonance (MR) and thermal neutron absorption are also applied. The MR measurement principle has been known and utilised already since the early 1950s. It has become the basic instrumental analysis tool in chemistry. It is also well-known as a very accurate method for analysing most compounds, especially substances containing hydrogen. The utilisation of MR metering is expanded extensively to medical diagnostics as a form of magnetic resonance imaging (MRI). Because of the precision of the MR principle, there have for a long time been efforts to apply it in new and different areas, and to make more user-friendly, smaller, and even portable devices. Such a device was designed by Vaisala a few years ago. VTT has utilised Vaisala's MR prototype for approximately one year for moisture content measurement of different biofuels. The first step in the use of an MR device for moisture determination was the definition of its measurement accuracy compared to the standard method (EN 14774). Those tests proved that the absolute precision seems to be comparable to the standard moisture content measurement method. It was also found out that

  10. Fourier Transfrom Ion Cyclotron Resonance Mass Spectrometry at High Magnetic Field

    Science.gov (United States)

    Marshall, Alan G.

    1998-03-01

    At high magnetic field (9.4 tesla at NHMFL), Fourier transform ion cyclotron resonance mass spectrometry performance improves dramatically: mass resolving power, axialization efficiency, and scan speed (each proportional to B), maximum ion mass, dynamic range, ion trapping period, kinetic energy, and electron self-cooling rate for sympathetic cooling (each proportional to B^2), and ion coalescence tendency (proportional 1/B^2). These advantages may apply singly (e.g., unit mass resolution for proteins of >100,000 Da), or compound (e.g., 10-fold improvement in S/N ratio for 9.4 T vs. 6 T at the same resolving power). Examples range from direct determination of molecular formulas of diesel fuel components by accurate mass measurement (=B10.1 ppm) to protein structure and dynamics probed by H/D exchange. This work was supported by N.S.F. (CHE-93-22824; CHE-94-13008), N.I.H. (GM-31683), Florida State University, and the National High Magnetic Field Laboratory in Tallahassee, FL.

  11. MassTRIX: mass translator into pathways.

    Science.gov (United States)

    Suhre, Karsten; Schmitt-Kopplin, Philippe

    2008-07-01

    Recent technical advances in mass spectrometry (MS) have brought the field of metabolomics to a point where large numbers of metabolites from numerous prokaryotic and eukaryotic organisms can now be easily and precisely detected. The challenge today lies in the correct annotation of these metabolites on the basis of their accurate measured masses. Assignment of bulk chemical formula is generally possible, but without consideration of the biological and genomic context, concrete metabolite annotations remain difficult and uncertain. MassTRIX responds to this challenge by providing a hypothesis-driven approach to high precision MS data annotation. It presents the identified chemical compounds in their genomic context as differentially colored objects on KEGG pathway maps. Information on gene transcription or differences in the gene complement (e.g. samples from different bacterial strains) can be easily added. The user can thus interpret the metabolic state of the organism in the context of its potential and, in the case of submitted transcriptomics data, real enzymatic capacities. The MassTRIX web server is freely accessible at http://masstrix.org.

  12. Regional differences in brain glucose metabolism determined by imaging mass spectrometry

    OpenAIRE

    André Kleinridders; Heather A. Ferris; Michelle L. Reyzer; Michaela Rath; Marion Soto; M. Lisa Manier; Jeffrey Spraggins; Zhihong Yang; Robert C. Stanton; Richard M. Caprioli; C. Ronald Kahn

    2018-01-01

    Objective: Glucose is the major energy substrate of the brain and crucial for normal brain function. In diabetes, the brain is subject to episodes of hypo- and hyperglycemia resulting in acute outcomes ranging from confusion to seizures, while chronic metabolic dysregulation puts patients at increased risk for depression and Alzheimer's disease. In the present study, we aimed to determine how glucose is metabolized in different regions of the brain using imaging mass spectrometry (IMS). Metho...

  13. Radioimmunoassay and chemical ionization/mass spectrometry compared for plasma cortisol determination

    International Nuclear Information System (INIS)

    Lindberg, C.; Johnson, S.; Hedner, P.; Gustafsson, A.

    1982-01-01

    A method is described for determination of cortisol in plasma and urine, based on chemical ionization/mass spectrometry with deuterium-labeled cortisol as the internal standard. The within-run precision (CV) was 2.5-5.7%, the between-run precision 4.6%. Results by this method were compared with those by a radioimmunological method (RIANEN Cortisol, New England Nuclear) for 395 plasma samples. The latter method gave significantly higher (approx. 25%) cortisol values

  14. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bornø, Andreas; Foged, Lene; van Hall, Gerrit

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments...... of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14 days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination of glucose...

  15. An assessment of anti-neutrino mass determination via electrostatic measurements of tritium beta-decay

    International Nuclear Information System (INIS)

    Le Bas, P.A.

    1984-01-01

    Data on the mass of the anti-neutrino determined via electrostatic measurements of tritium beta-decay are assessed. Relativistic calculations concerning the finite mass of the electron anti-neutrino and the recoil of the nucleus, are given for the theoretical end-point spectrum of tritium beta-decay. The specifications are given for an electrostatic Spherical Retarding Beta-Spectrometer, and an electrostatic Cylindrical Mirror Analyser, both used in the tritium beta-decay experiment. The electrostatic measurements lead to a value of less than 50 ev (90% C.L.) for the electron anti-neutrino mass. These results are discussed in terms of the resolution of the electrostatic equipment and the Monte Carlo simulations of the data collection. (UK)

  16. Development of salt-tolerance interface for an high performance liquid chromatography/inductively coupled plasma mass spectrometry system and its application to accurate quantification of DNA samples.

    Science.gov (United States)

    Takasaki, Yuka; Sakagawa, Shinnosuke; Inagaki, Kazumi; Fujii, Shin-Ichiro; Sabarudin, Akhmad; Umemura, Tomonari; Haraguchi, Hiroki

    2012-02-03

    Accurate quantification of DNA is highly important in various fields. Determination of phosphorus by ICP-MS is one of the most effective methods for accurate quantification of DNA due to the fixed stoichiometry of phosphate to this molecule. In this paper, a smart and reliable method for accurate quantification of DNA fragments and oligodeoxythymidilic acids by hyphenated HPLC/ICP-MS equipped with a highly efficient interface device is presented. The interface was constructed of a home-made capillary-attached micronebulizer and temperature-controllable cyclonic spray chamber (IsoMist). As a separation column for DNA samples, home-made methacrylate-based weak anion-exchange monolith was employed. Some parameters, which include composition of mobile phase, gradient program, inner and outer diameters of capillary, temperature of spray chamber etc., were optimized to find the best performance for separation and accurate quantification of DNA samples. The proposed system could achieve many advantages, such as total consumption for small amount sample analysis, salt-tolerance for hyphenated analysis, high accuracy and precision for quantitative analysis. Using this proposed system, the samples of 20 bp DNA ladder (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 400, 500 base pairs) and oligodeoxythymidilic acids (dT(12-18)) were rapidly separated and accurately quantified. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Mobility-based correction for accurate determination of binding constants by capillary electrophoresis-frontal analysis.

    Science.gov (United States)

    Qian, Cheng; Kovalchik, Kevin A; MacLennan, Matthew S; Huang, Xiaohua; Chen, David D Y

    2017-06-01

    Capillary electrophoresis frontal analysis (CE-FA) can be used to determine binding affinity of molecular interactions. However, its current data processing method mandate specific requirement on the mobilities of the binding pair in order to obtain accurate binding constants. This work shows that significant errors are resulted when the mobilities of the interacting species do not meet these requirements. Therefore, the applicability of CE-FA in many real word applications becomes questionable. An electrophoretic mobility-based correction method is developed in this work based on the flux of each species. A simulation program and a pair of model compounds are used to verify the new equations and evaluate the effectiveness of this method. Ibuprofen and hydroxypropyl-β-cyclodextrinare used to demonstrate the differences in the obtained binding constant by CE-FA when different calculation methods are used, and the results are compared with those obtained by affinity capillary electrophoresis (ACE). The results suggest that CE-FA, with the mobility-based correction method, can be a generally applicable method for a much wider range of applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Planimetric volumetry of the prostate: how accurate is it?

    NARCIS (Netherlands)

    Aarnink, R. G.; Giesen, R. J.; de la Rosette, J. J.; Huynen, A. L.; Debruyne, F. M.; Wijkstra, H.

    1995-01-01

    Planimetric volumetry is used in clinical practice when accurate volume determination of the prostate is needed. The prostate volume is determined by discretization of the 3D prostate shape. The are of the prostate is calculated in consecutive ultrasonographic cross-sections. This area is multiplied

  19. [Determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhu, Feng

    2015-01-01

    A method has been developed for the determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds (DHTDMAC) in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry. (UPLC-MS/MS). The samples were extracted and diluted with acidified methanol by 5% (v/v) formic acid under ultrasonic assistance. The separation was performed on an Eclipse Plus C18 column (50 mm x 2.1 mm, 1.8 microm) using 0.1% (v/v) formic acid solution and methanol as the mobile phases. Identification and quantification were achieved by UPLC-MS/MS with electrospray ionization (ESI) source in positive ion mode and multiple reaction monitoring (MRM) mode. The results indicated that the calibration curve of DHTDMAC showed good linear relationship between peak area and mass concentration in the range of 10-280 microg/L with the correlation coefficient (r2) of 0.9991. The limit of detection (LOD, S/N=3) and the limit of quantification (LOQ, S/N= 10) of this method were 3 mg/kg and 10 mg/kg, respectively. The average recoveries from three typical textile auxiliary matrices including dispersant, antistatic agent and fabric softener, at three spiked levels were in the range of 97.2%-108.3% with the relative standard deviations (RSDs) of 1.5%-4.6%. The method is sensitive, accurate, simple and effective for the analysis of DHTDMAC in textile auxiliaries.

  20. Application of the two-film theory to the determination of mass transfer coefficients for bovine serum albumin on anion-exchange columns

    DEFF Research Database (Denmark)

    Hansen, Ernst; Mollerup, Jørgen

    1999-01-01

    The paper describes a method of simultaneous determination of the external and the solid phase mass-transfer coefficients from frontal analysis data. The protein flux to the solid particles is determined from the slope of the breakthrough curve and the mass-transfer coefficients are determined...

  1. Total cyanide mass measurement with micro-ion selective electrode for determination of specific activity of carbon-11 cyanide.

    Science.gov (United States)

    Shea, Colleen; Alexoff, David L; Kim, Dohyun; Hoque, Ruma; Schueller, Michael J; Fowler, Joanna S; Qu, Wenchao

    2015-08-01

    In this research, we aim to directly measure the specific activity (SA) of the carbon-11 cyanide ([(11)C]CN¯) produced by our in-house built automated [(11)C]HCN production system and to identify the major sources of (12)C-cyanide ((12)CN¯). The [(11)C]CN¯ is produced from [(11)C]CO2, which is generated by the (14)N(p,α)(11)C nuclear reaction using a cyclotron. Direct measurement of cyanide concentrations was accomplished using a relatively inexpensive, and easy to use ion selective electrode (ISE) which offered an appropriate range of sensitivity for detecting mass. Multiple components of the [(11)C]HCN production system were isolated in order to determine their relative contributions to (12)CN¯ mass. It was determined that the system gases were responsible for approximately 30% of the mass, and that the molecular sieve/nickel furnace unit contributed approximately 70% of the mass. Beam on target (33µA for 1 and 10min) did not contribute significantly to the mass. Additionally, we compared the SA of our [(11)C]HCN precursor determined using the ISE to the SA of our current [(11)C]CN¯ derived radiotracers determined by HPLC to assure there was no significant difference between the two methods. These results are the first reported use of an ion selective electrode to determine the SA of no-carrier-added cyanide ion, and clearly show that it is a valuable, inexpensive and readily available tool suitable for this purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Effect of atmospheric flux uncertainties on the determination of the neutrino mass hierarchy

    Directory of Open Access Journals (Sweden)

    Sandroos Joakim

    2016-01-01

    Full Text Available The next generation of large-volume neutrino telescopes will include low-energy subarrays which will be able to measure neutrinos with energies of a few GeV. In this energy range the primary signal below the horizon is neutrinos created by cosmic ray interactions in the atmosphere. The measured event rate will depend on the neutrino mass hierarchy, allowing determination of this quantity to a significance level of about 3.5 sigma within a 5-year period, mostly limited by systematic uncertainties. We present here the impact of the uncertainties on the atmospheric neutrino flux normalization on the determination of the neutrino mass hierarchy. We suggest constraining the systematic uncertainties by including the downgoing neutrino sample, which will increase the significance. This work was performed using simulation data from the low-energy extension to the IceCube detector located at the geographic south pole, PINGU, and is relevant to a wide range of other experiments.

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

    International Nuclear Information System (INIS)

    Drees, Manuel; Shan, Chung-Lin

    2008-01-01

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

  4. Recent advances in applying mass spectrometry and systems biology to determine brain dynamics.

    Science.gov (United States)

    Scifo, Enzo; Calza, Giulio; Fuhrmann, Martin; Soliymani, Rabah; Baumann, Marc; Lalowski, Maciej

    2017-06-01

    Neurological disorders encompass various pathologies which disrupt normal brain physiology and function. Poor understanding of their underlying molecular mechanisms and their societal burden argues for the necessity of novel prevention strategies, early diagnostic techniques and alternative treatment options to reduce the scale of their expected increase. Areas covered: This review scrutinizes mass spectrometry based approaches used to investigate brain dynamics in various conditions, including neurodegenerative and neuropsychiatric disorders. Different proteomics workflows for isolation/enrichment of specific cell populations or brain regions, sample processing; mass spectrometry technologies, for differential proteome quantitation, analysis of post-translational modifications and imaging approaches in the brain are critically deliberated. Future directions, including analysis of cellular sub-compartments, targeted MS platforms (selected/parallel reaction monitoring) and use of mass cytometry are also discussed. Expert commentary: Here, we summarize and evaluate current mass spectrometry based approaches for determining brain dynamics in health and diseases states, with a focus on neurological disorders. Furthermore, we provide insight on current trends and new MS technologies with potential to improve this analysis.

  5. Measurement of the mass of an object hanging from a spring—revisited

    International Nuclear Information System (INIS)

    Serafin, Kamil; Oracz, Joanna; Grzybowski, Marcin; Koperski, Maciej; Sznajder, Paweł; Zinkiewicz, Łukasz; Wasylczyk, Piotr

    2012-01-01

    In an open competition, students were to determine the mass of a metal cylinder hanging on a spring inside a transparent enclosure. With the time for experiments limited to 24 h due to the unexpectedly large number of participants, a few surprisingly accurate results were submitted, the best of them differing by no more than 0.5% from the true value with a relative uncertainty of less than 1%.

  6. Progress in determination of long-lived radionuclides by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Becker, J.S.; Dietze, H.J.

    2000-01-01

    Mass spectrometric methods (such as inductively coupled plasma mass spectrometry - ICP-MS and laser ablation (LA)-ICP-MS) with their ability to provide a very sensitive multielemental and precise isotopic analysis have become established for the determination of radionuclides in quite different sample materials. The determination of long-lived radionuclides is of increasing interest for the characterization of radioactive waste materials and for the detection of radionuclide contamination in environmental materials in which several radioactive nuclides are present from fallout due to nuclear weapons testing, nuclear power plants or nuclear accidents. Due to its multielement capability, excellent sensitivity, low detection limits (up to sub pg I 1 range), very good precision, easy sample preparation and measurement procedures ICP-MS of aqueous solutions has been increasingly applied for the ultrasensitive determination of long-lived radionuclides such as 99 Tc, 129 I, 230 Th, 232 Th, 234 U, 235 U, 236 U, 239 Pu, 240 Pu and 241 Am and precise isotope ratio measurements of U,Th and Pu. The application especially of microanalytical methods (analysis of some MU by flow injection and on-line coupling techniques as capillary electrophoresis (CE-ICP-MS) or HPLC-ICP-MS) for the precise determination nuclide abundances and concentration of long-lived radionuclides at ultra trace concentration levels in radioactive waste and also for controlling contamination from radioactive waste in the environment is a challenging task

  7. A precise determination of the top-quark pole mass

    International Nuclear Information System (INIS)

    Wang, Sheng-Quan; Wu, Xing-Gang; Si, Zong-Guo; Brodsky, Stanley J.

    2018-01-01

    The Principle of Maximum Conformality (PMC) provides a systematic way to eliminate the renormalization scheme and renormalization scale uncertainties for high-energy processes. We have observed that by applying PMC scale setting, one obtains comprehensive and self-consistent pQCD predictions for the top-quark pair total cross section and the top-quark pair forward-backward asymmetry in agreement with the measurements at the Tevatron and LHC. As a step forward, in the present paper, we determine the top-quark pole mass via a detailed comparison of the top-quark pair cross section with the measurements at the Tevatron and LHC. The results for the top-quark pole mass are m t = 174.6 +3.1 -3.2 GeV for the Tevatron with √(S) = 1.96 TeV, m t = 173.7 ± 1.5 and 174.2 ± 1.7 GeV for the LHC with √(S) = 7 and 8 TeV, respectively. Those predictions agree with the average, 173.34 ± 0.76 GeV, obtained from various collaborations via direct measurements. The consistency of the pQCD predictions using the PMC with all of the collider measurements at different energies provides an important verification of QCD. (orig.)

  8. A precise determination of the top-quark pole mass

    Science.gov (United States)

    Wang, Sheng-Quan; Wu, Xing-Gang; Si, Zong-Guo; Brodsky, Stanley J.

    2018-03-01

    The Principle of Maximum Conformality (PMC) provides a systematic way to eliminate the renormalization scheme and renormalization scale uncertainties for high-energy processes. We have observed that by applying PMC scale setting, one obtains comprehensive and self-consistent pQCD predictions for the top-quark pair total cross section and the top-quark pair forward-backward asymmetry in agreement with the measurements at the Tevatron and LHC. As a step forward, in the present paper, we determine the top-quark pole mass via a detailed comparison of the top-quark pair cross section with the measurements at the Tevatron and LHC. The results for the top-quark pole mass are m_t=174.6^{+3.1}_{-3.2} GeV for the Tevatron with √{S}=1.96 TeV, m_t=173.7± 1.5 and 174.2± 1.7 GeV for the LHC with √{S} = 7 and 8 TeV, respectively. Those predictions agree with the average, 173.34± 0.76 GeV, obtained from various collaborations via direct measurements. The consistency of the pQCD predictions using the PMC with all of the collider measurements at different energies provides an important verification of QCD.

  9. Absolute dimensions and masses of eclipsing binaries. V. IQ Persei

    International Nuclear Information System (INIS)

    Lacy, C.H.; Frueh, M.L.; McDonald Observatory, Austin)

    1985-01-01

    New photometric and spectroscopic observations of the 1.7 day eclipsing binary IQ Persei (B8 + A6) have been analyzed to yield very accurate fundamental properties of the system. Reticon spectroscopic observations obtained at McDonald Observatory were used to determine accurate radial velocities of both stars in this slightly eccentric large light-ratio binary. A new set of VR light curves obtained at McDonald Observatory were analyzed by synthesis techniques, and previously published UBV light curves were reanalyzed to yield accurate photometric orbits. Orbital parameters derived from both sets of photometric observations are in excellent agreement. The absolute dimensions, masses, luminosities, and apsidal motion period (140 yr) derived from these observations agree well with the predictions of theoretical stellar evolution models. The A6 secondary is still very close to the zero-age main sequence. The B8 primary is about one-third of the way through its main-sequence evolution. 27 references

  10. Application of »Mass Titration« to Determination of Surface Charge of Metal Oxides

    OpenAIRE

    1998-01-01

    The mass titration method, used for the point of zero charge determination, was extended to the measurement of the surface charge density. The results agree with the common method, which is the acid-base titration of the colloidal suspension. The advantage of mass titration is that one does not need to perform blank titration, instead one simply adds metal oxide powder to the electrolyte aqueous solution of known pH. To cover the pH range above and below the point of zero charge, two experime...

  11. Highly accurate determination of relative gamma-ray detection efficiency for Ge detector and its application

    International Nuclear Information System (INIS)

    Miyahara, H.; Mori, C.; Fleming, R.F.; Dewaraja, Y.K.

    1997-01-01

    When quantitative measurements of γ-rays using High-Purity Ge (HPGe) detectors are made for a variety of applications, accurate knowledge of oy-ray detection efficiency is required. The emission rates of γ-rays from sources can be determined quickly in the case that the absolute peak efficiency is calibrated. On the other hand, the relative peak efficiencies can be used for determination of intensity ratios for plural samples and for comparison to the standard source. Thus, both absolute and relative detection efficiencies are important in use of γ-ray detector. The objective of this work is to determine the relative gamma-ray peak detection efficiency for an HPGe detector with the uncertainty approaching 0.1% . We used some nuclides which emit at least two gamma-rays with energies from 700 to 2400 keV for which the relative emission probabilities are known with uncertainties much smaller than 0.1%. The relative peak detection efficiencies were calculated from the measurements of the nuclides, 46 Sc, 48 Sc, 60 Co and 94 Nb, emitting two γ- rays with the emission probabilities of almost unity. It is important that various corrections for the emission probabilities, the cascade summing effect, and the self-absorption are small. A third order polynomial function on both logarithmic scales of energy and efficiency was fitted to the data, and the peak efficiency predicted at certain energy from covariance matrix showed the uncertainty less than 0.5% except for near 700 keV. As an application, the emission probabilities of the 1037.5 and 1212.9 keV γ-rays for 48 Sc were determined using the function of the highly precise relative peak efficiency. Those were 0.9777+0,.00079 and 0.02345+0.00017 for the 1037.5 and 1212.9 keV γ-rays, respectively. The sum of these probabilities is close to unity within the uncertainty which means that the certainties of the results are high and the accuracy has been improved considerably

  12. Determination of gamma-aminobutyric acid in food matrices by isotope dilution hydrophilic interaction chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Zazzeroni, Raniero; Homan, Andrew; Thain, Emma

    2009-08-01

    The estimation of the dietary intake of gamma-aminobutyric acid (GABA) is dependent upon the knowledge of its concentration values in food matrices. To this end, an isotope dilution liquid chromatography-mass spectrometry method has been developed employing the hydrophilic interaction chromatography technique for analyte separation. This approach enabled accurate quantification of GABA in apple, potato, soybeans, and orange juice without the need of a pre- or post-column derivatization reaction. A selective and precise analytical measurement has been obtained with a triple quadrupole mass spectrometer operating in multiple reaction monitoring using the method of standard additions and GABA-d(6) as an internal standard. The concentrations of GABA found in the matrices tested are 7 microg/g of apple, 342 microg/g of potatoes, 211 microg/g of soybeans, and 344 microg/mL of orange juice.

  13. Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

    Energy Technology Data Exchange (ETDEWEB)

    Tazoe, Hirofumi, E-mail: tazoe@cc.hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Mediation, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan); Yamagata, Takeyasu [College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan); Obata, Hajime [Atmosphere and Ocean Research Institute, The Tokyo University, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8564 (Japan); Nagai, Hisao [College of Humanities and Sciences, Nihon University, 3-25-40, Sakurajosui, Setagaya-ku, Tokyo 156-8550 (Japan)

    2014-12-10

    Highlights: • We developesd the simplest and robust SPE method for ultra low picomolar level beryllium in seawater. • Just silica gel column can quantitatively adsorb beryllium in neutral pH condition containing natural seawater. • EDTA solution can eliminate seawater matrixes retaining Be in the column, which optimize to ICP-MS detemination. • Accurate and precise Be data have been obtained for natural seawater from North Pacific Ocean. - Abstract: A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg{sup −1} for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg{sup −1} at <200 m) to deep water (29.2 pmol kg{sup −1} from 3500 m to the bottom)

  14. Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

    International Nuclear Information System (INIS)

    Tazoe, Hirofumi; Yamagata, Takeyasu; Obata, Hajime; Nagai, Hisao

    2014-01-01

    Highlights: • We developesd the simplest and robust SPE method for ultra low picomolar level beryllium in seawater. • Just silica gel column can quantitatively adsorb beryllium in neutral pH condition containing natural seawater. • EDTA solution can eliminate seawater matrixes retaining Be in the column, which optimize to ICP-MS detemination. • Accurate and precise Be data have been obtained for natural seawater from North Pacific Ocean. - Abstract: A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg −1 for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg −1 at <200 m) to deep water (29.2 pmol kg −1 from 3500 m to the bottom)

  15. Nuclear fuel technology - Determination of uranium in uranyl nitrate solutions of nuclear grade quality - Gravimetric method

    International Nuclear Information System (INIS)

    2003-01-01

    This International Standard specifies a precise and accurate gravimetric method for determining the mass fraction of uranium in uranyl nitrate solutions of nuclear grade quality containing more than 100 g/kg of uranium. Non-volatile impurities influence the accuracy of the method

  16. Quantification of methionine and selenomethionine in biological samples using multiple reaction monitoring high performance liquid chromatography tandem mass spectrometry (MRM-HPLC-MS/MS).

    Science.gov (United States)

    Vu, Dai Long; Ranglová, Karolína; Hájek, Jan; Hrouzek, Pavel

    2018-05-01

    Quantification of selenated amino-acids currently relies on methods employing inductively coupled plasma mass spectrometry (ICP-MS). Although very accurate, these methods do not allow the simultaneous determination of standard amino-acids, hampering the comparison of the content of selenated versus non-selenated species such as methionine (Met) and selenomethionine (SeMet). This paper reports two approaches for the simultaneous quantification of Met and SeMet. In the first approach, standard enzymatic hydrolysis employing Protease XIV was applied for the preparation of samples. The second approach utilized methanesulfonic acid (MA) for the hydrolysis of samples, either in a reflux system or in a microwave oven, followed by derivatization with diethyl ethoxymethylenemalonate. The prepared samples were then analyzed by multiple reaction monitoring high performance liquid chromatography tandem mass spectrometry (MRM-HPLC-MS/MS). Both approaches provided platforms for the accurate determination of selenium/sulfur substitution rate in Met. Moreover the second approach also provided accurate simultaneous quantification of Met and SeMet with a low limit of detection, low limit of quantification and wide linearity range, comparable to the commonly used gas chromatography mass spectrometry (GC-MS) method or ICP-MS. The novel method was validated using certified reference material in conjunction with the GC-MS reference method. Copyright © 2018. Published by Elsevier B.V.

  17. Determination of Nerve Agent Metabolites by Ultraviolet Femtosecond Laser Ionization Mass Spectrometry.

    Science.gov (United States)

    Hamachi, Akifumi; Imasaka, Tomoko; Nakamura, Hiroshi; Li, Adan; Imasaka, Totaro

    2017-05-02

    Nerve agent metabolites, i.e., isopropyl methylphosphonic acid (IMPA) and pinacolyl methylphosphonic acid (PMPA), were derivatized by reacting them with 2,3,4,5,6-pentafluorobenzyl bromide (PFBBr) and were determined by mass spectrometry using an ultraviolet femtosecond laser emitting at 267 and 200 nm as the ionization source. The analytes of the derivatized compounds, i.e., IMPA-PFB and PMPA-PFB, contain a large side-chain, and molecular ions are very weak or absent in electron ionization mass spectrometry. The use of ultraviolet femtosecond laser ionization mass spectrometry, however, resulted in the formation of a molecular ion, even for compounds such as these that contain a highly bulky functional group. The signal intensity was larger at 200 nm due to resonance-enhanced two-photon ionization. In contrast, fragmentation was suppressed at 267 nm (nonresonant two-photon ionization) especially for PMPA-PFB, thus resulting in a lower background signal. This favorable result can be explained by the small excess energy in ionization at 267 nm and by the low-frequency vibrational mode of a bulky trimethylpropyl group in PMPA.

  18. Development of an on-line flow injection Sr/matrix separation method for accurate, high-throughput determination of Sr isotope ratios by multiple collector-inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Galler, Patrick; Limbeck, Andreas; Boulyga, Sergei F; Stingeder, Gerhard; Hirata, Takafumi; Prohaska, Thomas

    2007-07-01

    This work introduces a newly developed on-line flow injection (FI) Sr/Rb separation method as an alternative to the common, manual Sr/matrix batch separation procedure, since total analysis time is often limited by sample preparation despite the fast rate of data acquisition possible by inductively coupled plasma-mass spectrometers (ICPMS). Separation columns containing approximately 100 muL of Sr-specific resin were used for on-line FI Sr/matrix separation with subsequent determination of (87)Sr/(86)Sr isotope ratios by multiple collector ICPMS. The occurrence of memory effects exhibited by the Sr-specific resin, a major restriction to the repetitive use of this costly material, could successfully be overcome. The method was fully validated by means of certified reference materials. A set of two biological and six geological Sr- and Rb-bearing samples was successfully characterized for its (87)Sr/(86)Sr isotope ratios with precisions of 0.01-0.04% 2 RSD (n = 5-10). Based on our measurements we suggest (87)Sr/(86)Sr isotope ratios of 0.713 15 +/- 0.000 16 (2 SD) and 0.709 31 +/- 0.000 06 (2 SD) for the NIST SRM 1400 bone ash and the NIST SRM 1486 bone meal, respectively. Measured (87)Sr/(86)Sr isotope ratios for five basalt samples are in excellent agreement with published data with deviations from the published value ranging from 0 to 0.03%. A mica sample with a Rb/Sr ratio of approximately 1 was successfully characterized for its (87)Sr/(86)Sr isotope signature to be 0.718 24 +/- 0.000 29 (2 SD) by the proposed method. Synthetic samples with Rb/Sr ratios of up to 10/1 could successfully be measured without significant interferences on mass 87, which would otherwise bias the accuracy and uncertainty of the obtained data.

  19. Determination of aflatoxins in medicinal plants by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Siddique, Nadeem A; Mujeeb, Mohd; Ahmad, Sayeed; Panda, Bibhu P; Makhmoor, Mohd

    2013-01-01

    The intention of the proposed work is to study the presence of the aflatoxins B1, B2, G1 and G2 in medicinal plants, namely Mucuna pruriens, Delphinium denudatum and Portulaca oleraceae. The aflatoxins were extracted, purified by immunoaffinity column chromatography and analysed by high-performance liquid chromatography-tandem quadrupole mass spectrometry with electrospray ionisation (HPLC-MS/MS). Fungal count was carried out in PDA media. A good linear relationship was found for AFB1, AFB2, AFG1 and AFG2 at 1-10 ppb (r>0.9995). The analyte accuracy under three different spiking levels was 86.7-108.1 %, with low per cent relative standard deviations in each case. The aflatoxins can be separated within 5 to7 min using an Agilent XDB C18-column. We found that AFB1 and AFB2 were in trace amounts below the detection limit in M. pruriens whilst they were not detected in D. denudatum. P. oleraceae was found to be contaminated with AFB1 and AFB2. AFG1 and AFG2 were not detected in M. pruriens, P. oleraceae and were below the detection limit in D. denudatum. This was consistent with very low numbers of fungal colonies observed after 6 hr of incubation. The analytical method developed is simple, precise, accurate, economical and can be effectively used to determine the aflatoxins in medicinal plants and therefore to control the quality of products. The aflatoxin levels in the plant extracts examined were related to the minimal fungal load in the medicinal plants examined.

  20. Fast and accurate determination of modularity and its effect size

    International Nuclear Information System (INIS)

    Treviño, Santiago III; Nyberg, Amy; Bassler, Kevin E; Del Genio, Charo I

    2015-01-01

    We present a fast spectral algorithm for community detection in complex networks. Our method searches for the partition with the maximum value of the modularity via the interplay of several refinement steps that include both agglomeration and division. We validate the accuracy of the algorithm by applying it to several real-world benchmark networks. On all these, our algorithm performs as well or better than any other known polynomial scheme. This allows us to extensively study the modularity distribution in ensembles of Erdős–Rényi networks, producing theoretical predictions for means and variances inclusive of finite-size corrections. Our work provides a way to accurately estimate the effect size of modularity, providing a z-score measure of it and enabling a more informative comparison of networks with different numbers of nodes and links. (paper)