WorldWideScience

Sample records for tandem mass spectrometers

  1. Portable Tandem Mass Spectrometer Analyzer

    Science.gov (United States)

    1991-07-01

    FILE : MHCI TUNE TABLE 84 (SCANNING with PARENT) SCAN RANGE 10.9 TO 700.0 TUNE MASS 355.0 (AUTO) >LENS 1-3 -13. 88 0. 2: POFF - 1. 2 9: COFF - 4. 1 3...and 500 ng of caffeine in I uL of chloroform by GC/A?:,,MS using negative ions. Also analyzed were barbiturates, extracted from urine, in the 3-5 Mg

  2. Instruction manual for ORNL tandem high abundance sensitivity mass spectrometer

    International Nuclear Information System (INIS)

    Smith, D.H.; McKown, H.S.; Chrisite, W.H.; Walker, R.L.; Carter, J.A.

    1976-06-01

    This manual describes the physical characteristics of the tandem mass spectrometer built by Oak Ridge National Laboratory for the International Atomic Energy Agency. Specific requirements met include ability to run small samples, high abundance sensitivity, good precision and accuracy, and adequate sample throughput. The instrument is capable of running uranium samples as small as 10 -12 g and has an abundance sensitivity in excess of 10 6 . Precision and accuracy are enhanced by a special sweep control circuit. Sample throughput is 6 to 12 samples per day. Operating instructions are also given

  3. High Energy Collisions on Tandem Time-of-Flight Mass Spectrometers

    Science.gov (United States)

    Cotter, Robert J.

    2013-05-01

    Long before the introduction of matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), Orbitraps, and any of the other tools that are now used ubiquitously for proteomics and metabolomics, the highest performance mass spectrometers were sector instruments, providing high resolution mass measurements by combining an electrostatic energy analyzer (E) with a high field magnet (B). In its heyday, the four sector mass spectrometer (or EBEB) was the crown jewel, providing the highest performance tandem mass spectrometry using single, high energy collisions to induce fragmentation. During a time in which quadrupole and tandem triple quadrupole instruments were also enjoying increased usage and popularity, there were, nonetheless, some clear advantages for sectors over their low collision energy counterparts. Time-of-flight (TOF) mass spectrometers are high voltage, high vacuum instruments that have much in common with sectors and have inspired the development of tandem instruments exploiting single high energy collisions. In this retrospective, we recount our own journey to produce high performance TOFs and tandem TOFs, describing the basic theory, problems, and the advantages for such instruments. An experiment testing impulse collision theory (ICT) underscores the similarities with sector mass spectrometers where this concept was first developed. Applications provide examples of more extensive fragmentation, side chain cleavages, and charge-remote fragmentation, also characteristic of high energy sector mass spectrometers. Moreover, the so-called curved-field reflectron has enabled the design of instruments that are simpler, collect and focus all of the ions, and may provide the future technology for the clinic, for tissue imaging, and the characterization of microorganisms.

  4. Tandem Mass Spectrometry on a Miniaturized Laser Desorption Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Li, Xiang; Cornish, Timothy; Getty, Stephanie A.; Brinckerhoff, William B.

    2016-01-01

    Tandem mass spectrometry (MSMS) is a powerful and widely-used technique for identifying the molecular structure of organic constituents of a complex sample. Application of MSMS to the study of unknown planetary samples on a remote space mission would contribute to our understanding of the origin, evolution, and distribution of extraterrestrial organics in our solar system. Here we report on the realization of MSMS on a miniaturized laser desorption time-of-flight mass spectrometer (LD-TOF-MS), which is one of the most promising instrument types for future planetary missions. This achievement relies on two critical components: a curved-field reflectron and a pulsed-pin ion gate. These enable use of the complementary post-source decay (PSD) and laser-assisted collision induced dissociation (L-CID) MSMS methods on diverse measurement targets with only modest investment in instrument resources such as volume and weight. MSMS spectra of selected molecular targets in various organic standards exhibit excellent agreement when compared with results from a commercial, laboratory-scale TOF instrument, demonstrating the potential of this powerful technique in space and planetary environments.

  5. Improved tandem mass spectrometer coupled to a laser vaporization cluster ion source

    Science.gov (United States)

    Förstel, Marko; Jaeger, Bertram K. A.; Schewe, Wolfgang; Sporkhorst, Philipp H. A.; Dopfer, Otto

    2017-12-01

    We describe two improvements to an existing tandem mass spectrometer coupled to a laser vaporization cluster ion source suitable for photodissociation spectroscopy: (i) cooling of the cluster source nozzle and (ii) mass selection prior to the photodissociation region via replacing an octupole ion guide by a quadrupole mass spectrometer. The improved sensitivity and transmission enable the production of larger heteroatomic clusters as well as rare gas solvated clusters. We present two examples demonstrating the new capabilities of the improved setup. In the first application, cooling of the cluster source nozzle produces Si+Arn and Si2+Arn cluster cations with n = 1-25. Magic numbers are extracted from the mass spectrum by applying a transmission function obtained via simulations. In the second example, the vibronic photodissociation spectrum of cold Au4+ cluster ions is recorded with unprecedented detail, resolution, and sensitivity. Such high-resolution optical excitation spectra of metal cluster cations may serve as a benchmark for the performance of Franck-Condon simulations based on quantum chemical calculations for excited states.

  6. Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

    Science.gov (United States)

    Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

    2016-01-01

    Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

  7. Mass spectrometers

    International Nuclear Information System (INIS)

    Manojlov, V.E.; Nedelin, P.N.; Lukichev, A.N.; Sapozhkov, L.K.; Turubarov, V.I.

    1980-01-01

    Mass spectrometers of different types are suggested to use for qualitative and quantitative analyses of gas. The operation principles of static and dynamic mass spectrometer are studied. In static mass spectrometers mass separation of ions is performed by changing the value of accelerating voltage in the ion source when retaining the magnetic field intensity. Such devices are stationary. The device mass is conditioned by the magnet mass. Mass separation in dynamic mass spectrometers is dependent on the degree of energy increment of ions in HF-electric fields. Radio frequency mass spectrometers are used with advantage for studying upper layers of an atmosphere and are installed on radiosondes and satellites. The main technical characteristics of the MX-1330 mass spectrometer, the basis of which is the analyzer with 180 deg deviation of an ion beam in the field of permanent magnet, are presented. The device is intended for controlling the environment and permits to analyze gases with a molecular mass up to 450 using various systems of gas filling. The error of determination of molecular substance is not greater than +-3 %; the magnetic field intensity constitutes 4.8x10 5 A/m; the supply voltage is 380/220 V; the total power is 5.0 kVA [ru

  8. MASS SPECTROMETER

    Science.gov (United States)

    White, F.A.

    1960-08-23

    A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

  9. Assesment of endocrinal and biochemical entities through liquid chromatography?tandem mass spectrometry/mass spectrometer: Inter-relative investigation of the interaction based cardiovascular formulation

    OpenAIRE

    Das, Rakesh; Pal, Tapan Kumar

    2015-01-01

    Background: Combinatory oral dosage treatment of atorvastatin (ATVS) and olmesartan (OLM) drugs to cardiovascular patients reflects unpredicted results instead of its individual therapy, which was accessed on quantification of endocrinal and biochemicals of plasma through liquid chromatography-tandem mass spectrometry/mass spectrometer (LCMS/MS). Objective: Mission was to track the remarkable biochemical variation in the plasma after induction of the combined formulation, to evaluate the phar...

  10. GLYCEROPHOSPHOLIPID ANALYSIS OF EASTERN RED BAT (Lasiurus borealis) HAIR BY ELECTROSPRAY IONIZATION TANDEM MASS SPECTROMET

    Science.gov (United States)

    Pannkuk, Evan L.; McGuire, Liam P.; Gilmore, David F.; Savary, Brett J.; Risch, Thomas S.

    2014-01-01

    Pilosebaceous units found in the mammalian integument are composed of a hair follicle, the proximal portion of the hair shaft, a sebaceous gland, and the erector pili muscle. Pilosebaceous units release protective oils, or sebum, by holocrine secretion onto skin and hair through rupturing of sebocytes. Sebum is largely composed of polar and neutral lipids including glycerolipids, free fatty acids, sterols, wax esters, sterol esters, and squalene. In addition to these lipid classes, there is a small proportion of ionic/anionic glycerophospholipids (GPs). Composition of GPs on hair is rarely addressed despite their broad biological activities as signaling molecules and membrane stability. Furthermore, knowledge on GP composition in bats is lacking. Bat GP composition is important to document due to GP roles ranging from decreasing drag during migration to interaction with the integumentary microbiome. In this study, we analyzed GP molecular composition with liquid chromatography electrospray ionization tandem mass spectrometry and compared GP content to previous literature. A total of 152 GPs were detected. Broad GP classes identified include lysophosphatidylcholine, phosphatidylcholine (PC), lysophosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidic acid, and phosphatidylglycerol, with PC being the most abundant class. The acyl components were consistent with fatty acid methyl esters and triacylglyceride moieties found in Eastern red bat sebum. GP proportions of the hair surface were different from a previous study on bat lung surfactants. This study determined the broad class and molecular species of bat sebum GPs that may be used in future ecological studies in vespertilionid bats. PMID:24532214

  11. Determinations of airborne synthetic musks by polyurethane foam coupled with triple quadrupole gas chromatography tandem mass spectrometer.

    Science.gov (United States)

    Wang, I-Ting Ivy; Cheng, Shu-Fang; Tsai, Shih-Wei

    2014-02-21

    Synthetic musk is widely used in various scented consumer products. However, the exposure via inhalation is often ignored due to pleasant smells. In addition, the information regarding the distribution of synthetic musk in air is limited. Hence, this research is aimed to develop a highly sensitive and widely applicable method for the determination of airborne synthetic musk. In this study, polyurethane foam (PUF) and filter were employed for active air sampling. Microwave assisted extraction (MAE) and nitrogen evaporator were performed for sample preparation. A gas chromatography coupled with triple quadrupole tandem mass spectrometer (GC/MS-MS) with specific multiple reaction monitoring (MRM) transition pairs was applied for sample analysis. Compared with using selected ion monitoring (SIM) mode traditionally, the sensitivities were improved in this study about an order at least. In terms of air concentration, as low as 0.48ngm(-3) can be determined when sampling at 3.5Lmin(-1) for 8h. The method established was further applied to the analysis of synthetic musk compounds in air samples collected in a cosmetics plant. The results showed that the airborne concentrations of gaseous polycyclic musk, gaseous nitro-musk, and particle-phase polycyclic musk were 6.4×10(2), 4.0×10(1) and 3.1×10(2)ngm(-3), respectively. Meanwhile, Cashmeran, Celstolide, Galaxolide, and Tonalide were found as the dominant musk compounds in the factory investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. A high-resolution tandem mass spectrometer for the collision-induced dissociation of large molecule ions

    International Nuclear Information System (INIS)

    Ouwerkerk, C.E.D.

    1988-01-01

    Instrumental development in the field of tandem mass spectrometry is described in order to use the technique for the analysis of large organic molecules. Experiments are also described in which the process of collision-induced dissociation (CID) is investigated. The fragmentation pattern of CH 4 + has been measured for three different target gases He, Ar and Xe. From these measurements fragmentation cross sections are calculated. 192 refs.; 47 figs.; 6 tabs

  13. Assesment of endocrinal and biochemical entities through liquid chromatography-tandem mass spectrometry/mass spectrometer: Inter-relative investigation of the interaction based cardiovascular formulation

    Directory of Open Access Journals (Sweden)

    Rakesh Das

    2015-01-01

    Full Text Available Background: Combinatory oral dosage treatment of atorvastatin (ATVS and olmesartan (OLM drugs to cardiovascular patients reflects unpredicted results instead of its individual therapy, which was accessed on quantification of endocrinal and biochemicals of plasma through liquid chromatography-tandem mass spectrometry/mass spectrometer (LCMS/MS. Objective: Mission was to track the remarkable biochemical variation in the plasma after induction of the combined formulation, to evaluate the pharma-market rumor on its efficiency. Methods: To fulfil undergoing research objectives for digging-up of market insult, human patient volunteers were chosen according to the required criteria along with bioethical regulation. A sensitive, rapid and precise method was developed and validated to estimate aldosterone (ALD, angiotensin (ANG-II and the Mevalonate (MVA not Mevalonic acid through LCMS/MS over least samples of cardiovascular patients. Level of each endogenous biochemicals were determined in three stages - without drugs, with a single drug (OLM/ATVS and with their combination that was then correlate with blood pressure of respective volunteers. Result and Discussion: Comparative and correlative studies panaroma among these analytes was detected. The selectivity, specificity, linearity, precision, accuracy, extraction recovery, limit of detection and limit of quantification, stability were the essential points of validation of the developed methodology. And the significance of each endogenous analyte data were based on P ≥ 0.001. Thus, low value of ALD and reciprocally higher in ANG-II on administered single drug than its combination and equal concentration of mevalonate in both stages, was discovered. Conclusion: This concludes that the cardiovascular dosage formulation entrenched in the market are not synergistic and effective compared with a single drug as antihypertensive drug.

  14. Improved Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Improved Mass Spectrometer project will develop system requirements and analyze the path to space qualification.   The results of this project...

  15. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    Science.gov (United States)

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  16. Tandem mass spectrometry at low kinetic energy

    International Nuclear Information System (INIS)

    Cooks, R.G.; Hand, O.W.

    1987-01-01

    Recent progress in mass spectrometry, as applied to molecular analysis, is reviewed with emphasis on tandem mass spectrometry. Tandem instruments use multiple analyzers (sector magnets, quadrupole mass filters and time-of-flight devices) to select particular molecules in ionic form, react them in the gas-phase and then record the mass, momenta or kinetic energies of their products. The capabilities of tandem mass spectrometry for identification of individual molecules or particular classes of compounds in complex mixtures are illustrated. Several different types of experiments can be run using a tandem mass spectrometer; all share the feature of sifting the molecular mixture being analyzed on the basis of chemical properties expressed in terms of ionic mass, kinetic energy or charge state. Applications of mass spectrometry to biological problems often depend upon desorption methods of ionization in which samples are bombarded with particle beams. Evaporation of preformed charged species from the condensed phase into the vacuum is a particularly effective method of ionization. It is suggested that the use of accelerator mass spectrometers be extended to include problems of molecular analysis. In such experiments, low energy tandem mass spectrometry conducted in the eV or keV range of energies, would be followed by further characterization of the production ion beam using high selective MeV collision processes

  17. In Situ Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  18. MASS SPECTROMETER LEAK

    Science.gov (United States)

    Shields, W.R.

    1960-10-18

    An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

  19. The nanopore mass spectrometer

    Science.gov (United States)

    Bush, Joseph; Maulbetsch, William; Lepoitevin, Mathilde; Wiener, Benjamin; Mihovilovic Skanata, Mirna; Moon, Wooyoung; Pruitt, Cole; Stein, Derek

    2017-11-01

    We report the design of a mass spectrometer featuring an ion source that delivers ions directly into high vacuum from liquid inside a capillary with a sub-micrometer-diameter tip. The surface tension of water and formamide is sufficient to maintain a stable interface with high vacuum at the tip, and the gas load from the interface is negligible, even during electrospray. These conditions lifted the usual requirement of a differentially pumped system. The absence of a background gas also opened up the possibility of designing ion optics to collect and focus ions in order to achieve high overall transmission and detection efficiencies. We describe the operation and performance of the instrument and present mass spectra from solutions of salt ions and DNA bases in formamide and salt ions in water. The spectra show singly charged solute ions clustered with a small number of solvent molecules.

  20. LADEE Neutral Mass Spectrometer Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains the data collected by the Neutral Mass Spectrometer (NMS) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE)...

  1. Respiratory mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Mostert, J.W. (Pretoria Univ. (South Africa). Dept. of Anesthesiology)

    1983-06-01

    The high degree of technical perfection of the respiratory mass spectrometer has rendered the instrument feasible for routine monitoring of anesthetized patients. It is proposed that the difference between inspired and expired oxygen tension in mm Hg be equated with whole body oxygen consumption in ml/min/M/sup 2/ body-surface area at STPD, by the expedient of multiplying tension-differences by a factor of 2. Years of experience have confirmed the value of promptly recognizing sudden drops in this l/E tension difference below 50 mm Hg indicative of metabolic injury from hypovolemia or respiratory depression. Rises in l/E tension-differences were associated with shivering as well as voluntary muscle activity. Tension differences of less than 25 mm Hg (equated with a whole-body O/sub 2/ consumption of less than 50 ml O/sub 2//min/M/sup 2/) occurred in a patient in the sitting position for posterior fossa exploration without acidosis, hypoxia or hypotension for several hours prior to irreversible cardiac arrest. The value of clinical monitoring by mass spectrometry is especially impressive in open-heart surgery.

  2. Comparison of the quantitative performance of a Q-Exactive high-resolution mass spectrometer with that of a triple quadrupole tandem mass spectrometer for the analysis of illicit drugs in wastewater.

    Science.gov (United States)

    Fedorova, Ganna; Randak, Tomas; Lindberg, Richard H; Grabic, Roman

    2013-08-15

    Analysis of drugs in wastewater is gaining more interest, as new approaches to estimate drug consumption from the amount of drug residues in wastewater have been proposed. The aim of this study was to compare the quantitative performance of high-resolution mass spectrometry with that of triple quadrupole mass spectrometry. A Q-Exactive mass spectrometer was operated in full scan (HRFS) (70 000 FWHM) and product scan (HRPS) (17 500 FWHM) modes. The first and third quadrupoles of the QqQ MS/MS instrument were operated at 0.7 FWHM. A mass-extracted window of 5 ppm around the theoretical m/z of each analyte was used to construct chromatograms. An HESI-II ion source was used for the ionization of target compounds. In-line-SPE-LC configuration was used for the extraction and separation of target analytes. All three methods showed good linearity and repeatability. High-resolution detection of product ions exhibited better sensitivity and selectivity for some compounds. For most of the tested compounds, LOQs ranged from 0.46 to 20 ng L(-1) . Good agreement between measured and nominal concentrations was observed for most of the compounds at different levels of fortification. Both MS/MS methods showed good selectivity, while HRFS gave some false positive results. The Q-Exactive mass spectrometer proved to be suitable for trace detection and quantification of most of the tested drugs in wastewater, with performance comparable to that of the commonly used MS/MS triple quadrupole, but with better selectivity. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Quality evaluation of tandem mass spectral libraries.

    Science.gov (United States)

    Oberacher, Herbert; Weinmann, Wolfgang; Dresen, Sebastian

    2011-06-01

    Tandem mass spectral libraries are gaining more and more importance for the identification of unknowns in different fields of research, including metabolomics, forensics, toxicology, and environmental analysis. Particularly, the recent invention of reliable, robust, and transferable libraries has increased the general acceptance of these tools. Herein, we report on results obtained from thorough evaluation of the match reliabilities of two tandem mass spectral libraries: the MSforID library established by the Oberacher group in Innsbruck and the Weinmann library established by the Weinmann group in Freiburg. Three different experiments were performed: (1) Spectra of the libraries were searched against their corresponding library after excluding either this single compound-specific spectrum or all compound-specific spectra prior to searching; (2) the libraries were searched against each other using either library as reference set or sample set; (3) spectra acquired on different mass spectrometric instruments were matched to both libraries. Almost 13,000 tandem mass spectra were included in this study. The MSforID search algorithm was used for spectral matching. Statistical evaluation of the library search results revealed that principally both libraries enable the sensitive and specific identification of compounds. Due to higher mass accuracy of the QqTOF compared with the QTrap instrument, matches to the MSforID library were more reliable when comparing spectra with both libraries. Furthermore, only the MSforID library was shown to be efficiently transferable to different kinds of tandem mass spectrometers, including "tandem-in-time" instruments; this is due to the coverage of a large range of different collision energy settings-including the very low range-which is an outstanding characteristics of the MSforID library.

  4. Mechanism of Formation of the Major Estradiol Product Ions Following Collisional Activation of the Molecular Anion in a Tandem Quadrupole Mass Spectrometer

    Science.gov (United States)

    Wooding, Kerry M.; Barkley, Robert M.; Hankin, Joseph A.; Johnson, Christopher A.; Bradford, Andrew P.; Santoro, Nanette; Murphy, Robert C.

    2013-01-01

    The importance of the mass spectral product ion structure is highlighted in quantitative assays, which typically use MRM (multiple reaction monitoring), and in the discovery of novel metabolites. Estradiol is an important sex steroid whose quantitation and metabolite identification using tandem mass spectrometry has been widely employed in numerous clinical studies. Negative electrospray ionization tandem mass spectrometry of estradiol (E2) results in several product ions, including the abundant m/z 183 and m/z 169. While m/z 183 is one of the most abundant product ions used in many quantitative assays, the structure of m/z 183 has not been rigorously examined. We suggest a structure for m/z 183 and a mechanism of formation consistent with collision induced dissociation (CID) of E2 and several stable isotopes ([D4]-E2, [13C6]-E2, and [D1]-E2). An additional product ion from E2, namely m/z 169, has also been examined. MS3 experiments indicated that both m/z 183 and m/z 169 originate from only E2 [M-H]− m/z 271. These ions, m/z 183 and m/z 169, were also present in the collision induced decomposition mass spectra of other prominent estrogens, estrone (E1) and estriol (E3), indicating that these two product ions could be used to elucidate the estrogenic origin of novel metabolites. We propose two fragmentation schemes to explain the CID data and suggested a structure of m/z 183 and m/z 169 consistent with several isotopic variants and high resolution mass spectrometric measurements. PMID:23955001

  5. Ion mobility spectrometer / mass spectrometer (IMS-MS).

    Energy Technology Data Exchange (ETDEWEB)

    Hunka Deborah Elaine; Austin, Daniel E.

    2005-07-01

    The use of Ion Mobility Spectrometry (IMS) in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400). Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS) is described. The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.

  6. Development of Tandem, Double-Focusing, Electron Impact, Gas Source Mass Spectrometer for Measurement of Rare Double-Substituted Isotoplogues in Geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Young, Edward D. [University of California, Los Angeles, CA (United States)

    2015-07-30

    This project culminated in construction and delivery of the world’s first large-radius gas-source isotope ratio mass spectrometer that permits unparalleled analyses of the stable isotopic composition of methane gas. The instrument, referred to as the “Panorama” and installed at UCLA in March 2015, can now be used to determine the relative abundances of rare isotopic species of methane that serve as tracers of temperature of formation and/or subsequent processing of gas. With this technology we can begin to delineate different sources and sinks of methane isotopically in ways not possible until now.

  7. Inverse-magnetron mass spectrometer

    International Nuclear Information System (INIS)

    Pakulin, V.N.

    1979-01-01

    Considered is the operation of a typical magnetron mass spectrometer with an internal ion source and that of an inverse magnetron mass spectrometer with an external ion source. It is found that for discrimination of the same mass using the inverse design of mass spectrometers it is possible to employ either r 2 /r 1 times lesser magnetic fields at equal accelerating source-collector voltages, or r 2 /r 1 higher accelerating voltages at equal magnetic fields, as compared to the typical design (r 1 and r 2 being radii of the internal and external electrodes of the analyser, respectively). The design of an inverse-magnetron mass spectrometer is described. The mass analyzer is formed by a cylindrical electrode of 3 mm diameter and a coaxial tubular cylinder of 55 mm diameter. External to the analyzer is an ionizing chamber at the pressure of up to 5x10 -6 torr. The magnetic field along the chamber axis produced by a solenoid was 300 Oe. At the accelerating voltage of 100 V and mass 28, the spectrometer has a resolution of 30 at a half-peak height

  8. Mass spectrometer beam monitor

    International Nuclear Information System (INIS)

    McKinney, C.R.

    1980-01-01

    Improved apparatus and system were developed for determining the field desorption characteristics of a sample prior to field desorption mass spectrometry. A portion of the ion beam from the ion source is disabled so that it is undeflected in the beam analyzer. When sample ions are detected by a sensor in this portion of the beam it is then allowed to be deflected and the mass analysis occurs. Thus the source position, temperature and electric field strength can be varied until ions are produced from the sample and the field desorption characteristics can be determined. The source characteristics can be varied either automatically or manually. (DN)

  9. Imaging mass spectrometer with mass tags

    Science.gov (United States)

    Felton, James S.; Wu, Kuang Jen; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2010-06-01

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  10. Quadrupole Time-of-Flight Mass Spectrometer

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The system generates superior quality mass spectrometry (MS) and tandem mass spectrometry (MS/MS) data from both atmospheric pressure ionization (API) and...

  11. Optimized Fast and Sensitive Acquisition Methods for Shotgun Proteomics on a Quadrupole Orbitrap Mass Spectrometer

    DEFF Research Database (Denmark)

    Kelstrup, Christian D; Young, Clifford; Lavallee, Richard

    2012-01-01

    Advances in proteomics are continually driven by the introduction of new mass spectrometric instrumentation with improved performances. The recently introduced quadrupole Orbitrap (Q Exactive) tandem mass spectrometer allows fast acquisition of high-resolution higher-energy collisional dissociation...

  12. Tandem collimators for the JET tangential gamma-ray spectrometer

    International Nuclear Information System (INIS)

    Soare, Sorin; Balshaw, Nick; Blanchard, Patrick; Craciunescu, Teddy; Croft, David; Curuia, Marian; Edlington, Trevor; Kiptily, Vasily; Murari, Andrea; Prior, Phil; Sanders, Steven; Syme, Brian; Zoita, Vasile

    2011-01-01

    The tangential gamma-ray spectrometer (TGRS) of the JET tokamak fusion facility is an important diagnostics for investigating the fast particle evolution. A well defined field of view for the TGRS diagnostics is essential for its proper operation and this is to be determined by a rather complex system of collimators and shields both for the neutron and gamma radiations. A conceptual design for this system has been carried out with the main design target set to maximize the signal-to-background ratio at the spectrometer detector, the ratio being defined in terms of the plasma emitted gamma radiation and the gamma-ray background. As a first phase of the TGRS diagnostics upgrade a set of two tandem collimators has been designed with the aim of determining a quasi-tangential field of view through JET tokamak plasmas. A modular design of the tandem system has been developed in order to allow for the construction of different configurations for deuterium and deuterium-tritium discharges. The internal structure of the collimators consists of nuclear grade lead and high density polyethylene slabs arranged in an optimized pattern. The performance of a simplified geometry of the tandem collimator configuration has been evaluated by neutron and photon transport calculations and the numerical results show that the design parameters can be attained.

  13. A Compact Tandem Two-Step Laser Time-of-Flight Mass Spectrometer for In Situ Analysis of Non-Volatile Organics on Planetary Surfaces

    Science.gov (United States)

    Getty, Stephanie A.; Brinckerhoff, William B.; Li, Xiang; Elsila, Jamie; Cornish, Timothy; Ecelberger, Scott; Wu, Qinghao; Zare, Richard

    2014-01-01

    Two-step laser desorption mass spectrometry is a well suited technique to the analysis of high priority classes of organics, such as polycyclic aromatic hydrocarbons, present in complex samples. The use of decoupled desorption and ionization laser pulses allows for sensitive and selective detection of structurally intact organic species. We have recently demonstrated the implementation of this advancement in laser mass spectrometry in a compact, flight-compatible instrument that could feasibly be the centerpiece of an analytical science payload as part of a future spaceflight mission to a small body or icy moon.

  14. A Mass Spectrometer Simulator in Your Computer

    Science.gov (United States)

    Gagnon, Michel

    2012-01-01

    Introduced to study components of ionized gas, the mass spectrometer has evolved into a highly accurate device now used in many undergraduate and research laboratories. Unfortunately, despite their importance in the formation of future scientists, mass spectrometers remain beyond the financial reach of many high schools and colleges. As a result,…

  15. THOR Ion Mass Spectrometer (IMS)

    Science.gov (United States)

    Retinò, Alessandro

    2017-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The Ion Mass Spectrometer (IMS) onboard THOR will provide the first high-time resolution measurements of mass-resolved ions in near-Earth space, focusing on hot ions in the foreshock, shock and magnetosheath turbulent regions. These measurements are required to study how kinetic-scale turbulent fluctuations heat and accelerate different ion species. IMS will measure the full three-dimensional distribution functions of main ion species (H+, He++, O+) in the energy range 10 eV/q to 30 keV/q with energy resolution DE/E down to 10% and angular resolution down to 11.25˚ . The time resolution will be 150 ms for O+, 300 ms for He++ and ˜ 1s for O+, which correspond to ion scales in the the foreshock, shock and magnetosheath regions. Such high time resolution is achieved by mounting four identical IMS units phased by 90˚ in the spacecraft spin plane. Each IMS unit combines a top-hat electrostatic analyzer with deflectors at the entrance together with a time-of-flight section to perform mass selection. Adequate mass-per-charge resolution (M/q)/(ΔM/q) (≥ 8 for He++ and ≥ 3 for O+) is obtained through a 6 cm long Time-of-Flight (TOF) section. IMS electronics includes a fast sweeping high voltage board that is required to make measurements at high cadence. Ion detection includes Micro Channel Plates (MCPs) combined with Application-Specific Integrated Circuits (ASICs) for charge amplification and discrimination and a discrete Time-to-Amplitude Converter (TAC) to determine the ion time of flight. A processor board will be used to for ion events formatting and will interface with the Particle Processing Unit (PPU), which will perform data processing for THOR particle detectors. The IMS instrument is being designed and will be built and calibrated by an international consortium of scientific institutes from France, USA, Germany and Japan and Switzerland.

  16. Recent ion optics and mass spectrometers

    International Nuclear Information System (INIS)

    Matsuda, Hisashi

    1976-01-01

    The establishment of the third order approximation method for computing the orbit of the ion optical system for mass spectrometers and the completion of its computer program are reported. A feature of this orbit computation is in that the effect of the fringing field can be considered with the accuracy of third order approximation. Several new ion optical systems for mass spectrometers have been proposed by using such orbit computing programs. Brief explanation and the description on the future prospect and problems are made on the following items: the vertual image double focusing mass spectrometer, the second order double focusing mass spectrometer, the E x B superposed field mass spectrometer, and the apparatus with a cylindrical electric field and Q-lens. In the E x B superposed field with Matsuda plates, if the magnetic field is generated by an electromagnet instead of a permanent magnet, the dispersion of mass and energy can be changed at will. The Matsuda plates are known as the auxiliary electrodes positioned at the top and bottom of a cylindrical capacitor. Utilizing those characteristics, a zoom spectrometer can be made, with which only a necessary part of mass spectra can be investigated in detail, but the whole spectra are investigated roughly. In addition, the distribution of energy can be investigated simultaneously after the separation of ionic mass similarly to the parabola apparatus. (Iwakiri, K.)

  17. Mass spectrometry by means of tandem accelerators

    International Nuclear Information System (INIS)

    Tuniz, C.

    1985-01-01

    Mass spectrometry based on an accelerator allows to measure rare cosmogenic isotopes found in natural samples with isotopic abundances up to 10E-15. The XTU Tandem of Legnaro National Laboratories can measure mean heavy isotopes (36Cl, 41Ca, 129I) in applications interesting cosmochronology and Medicine. The TTT-3 Tandem of the Naples University has been modified in view of precision studies of C14 in Archeology, Paleantology and Geology. In this paper a review is made of principles and methodologies and of some applicationy in the framework of the National Program for mass spectrametry research with the aid of accelerators

  18. Low Power Mass Spectrometer employing TOF Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A low power Mass Spectrometer employing multiple time of flight circuits for parallel processing is possible with a new innovation in design of the Time of flight...

  19. Interpretation of tandem mass spectra of posttranslationally modified peptides

    DEFF Research Database (Denmark)

    Bunkenborg, J.; Matthiesen, R.

    2013-01-01

    Tandem mass spectrometry provides a sensitive means of analyzing the amino acid sequence of peptides and modified peptides by providing accurate mass measurements of precursor and fragment ions. Modern mass spectrometry instrumentation is capable of rapidly generating many thousands of tandem mas...... and validating tandem mass spectra and gives some useful tables to aid this process....

  20. Ion guide quadrupole mass spectrometer at Jyvaeskylae

    International Nuclear Information System (INIS)

    Iivonen, A.; Saintola, R.; Valli, K.; Morita, K.; Yoshida, A.

    1991-01-01

    A new mass analyzing device consisting of an ion guide connected to a commercial quadrupole mass spectrometer is being developed at the Department of Physics, University of Jyvaeskylae. The new spectrometer is expected to have the similar properties to the present ion guide isotope separator on-line (IGISOL): excellent stability, similar separation efficiency for all chemical elements and short separation time. This ion guide mass spectrometer (IGQMS) is schematically shown. The IGQMS differs from the IGISOL in four essential ways: a squeezer ion guide, a differential pumping section, a transport section in which an electrostatic lens system brings ions into high vacuum, and a commercial quadrupole spectrometer used in place of a magnetic separator. The entire spectrometer became operational in the summer of 1990. The tests have been done with the alpha-active Po-215 ions released from an Ac-227 source in the target chamber. The squeezer, differential pumping section, transport section and quadrupole mass spectrometer of the IGQMS are described. The results of the measured transmission yield and the total yield of Po-215 and some merits of the IGQMS are reported. (K.I.)

  1. Development of a time-resolved method for photodissociation mechanistic study of protonated peptides: use of a voltage-floated cell in a tandem time-of-flight mass spectrometer.

    Science.gov (United States)

    Yoon, So Hee; Kim, Myung Soo

    2007-10-01

    Photodissociation at 266 nm of some protonated peptides was investigated using a tandem-TOF spectrometer equipped with a cell near its first time focal point where the laser was irradiated. When a high voltage was applied to the cell, each product ion peak split into several components with different flight times. One of these was due to in-cell direct formation of the product ion and another due to post-cell formation. Those in between were due to consecutive dissociations, the first steps of which occurred inside the cell and the second steps outside the cell. A method based on flight time calculation was developed to analyze these components and to identify the intermediate ion for each consecutive component. The technique allows time-resolved photodissociation mechanistic studies on a 100-ns timescale.

  2. Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer

    International Nuclear Information System (INIS)

    Adamov, Alexey; Viidanoja, Jyrki; Kaerpaenoja, Esko; Paakkanen, Heikki; Ketola, Raimo A.; Kostiainen, Risto; Sysoev, Alexey; Kotiaho, Tapio

    2007-01-01

    This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate

  3. Estimating the Efficiency of Phosphopeptide Identification by Tandem Mass Spectrometry

    Science.gov (United States)

    Hsu, Chuan-Chih; Xue, Liang; Arrington, Justine V.; Wang, Pengcheng; Paez Paez, Juan Sebastian; Zhou, Yuan; Zhu, Jian-Kang; Tao, W. Andy

    2017-06-01

    Mass spectrometry has played a significant role in the identification of unknown phosphoproteins and sites of phosphorylation in biological samples. Analyses of protein phosphorylation, particularly large scale phosphoproteomic experiments, have recently been enhanced by efficient enrichment, fast and accurate instrumentation, and better software, but challenges remain because of the low stoichiometry of phosphorylation and poor phosphopeptide ionization efficiency and fragmentation due to neutral loss. Phosphoproteomics has become an important dimension in systems biology studies, and it is essential to have efficient analytical tools to cover a broad range of signaling events. To evaluate current mass spectrometric performance, we present here a novel method to estimate the efficiency of phosphopeptide identification by tandem mass spectrometry. Phosphopeptides were directly isolated from whole plant cell extracts, dephosphorylated, and then incubated with one of three purified kinases—casein kinase II, mitogen-activated protein kinase 6, and SNF-related protein kinase 2.6—along with 16O4- and 18O4-ATP separately for in vitro kinase reactions. Phosphopeptides were enriched and analyzed by LC-MS. The phosphopeptide identification rate was estimated by comparing phosphopeptides identified by tandem mass spectrometry with phosphopeptide pairs generated by stable isotope labeled kinase reactions. Overall, we found that current high speed and high accuracy mass spectrometers can only identify 20%-40% of total phosphopeptides primarily due to relatively poor fragmentation, additional modifications, and low abundance, highlighting the urgent need for continuous efforts to improve phosphopeptide identification efficiency. [Figure not available: see fulltext.

  4. L G Smith's RF mass spectrometer

    International Nuclear Information System (INIS)

    Koets, E.

    1981-01-01

    From 1948 on Lincoln G Smith developed mass spectrometers based on time and frequency measurements. With his last machine he obtained an accuracy of the order of 1 to 10 9 . After his untimely death in 1972 his unique instrument was moved to Delft, where its development is carried on. (author)

  5. Microscale ion trap mass spectrometer

    Science.gov (United States)

    Ramsey, J. Michael; Witten, William B.; Kornienko, Oleg

    2002-01-01

    An ion trap for mass spectrometric chemical analysis of ions is delineated. The ion trap includes a central electrode having an aperture; a pair of insulators, each having an aperture; a pair of end cap electrodes, each having an aperture; a first electronic signal source coupled to the central electrode; a second electronic signal source coupled to the end cap electrodes. The central electrode, insulators, and end cap electrodes are united in a sandwich construction where their respective apertures are coaxially aligned and symmetric about an axis to form a partially enclosed cavity having an effective radius r.sub.0 and an effective length 2z.sub.0, wherein r.sub.0 and/or z.sub.0 are less than 1.0 mm, and a ratio z.sub.0 /r.sub.0 is greater than 0.83.

  6. Portable gas chromatograph-mass spectrometer

    Science.gov (United States)

    Andresen, B.D.; Eckels, J.D.; Kimmons, J.F.; Myers, D.W.

    1996-06-11

    A gas chromatograph-mass spectrometer (GC-MS) is described for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units. 4 figs.

  7. Time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Managadze, G.G.

    1991-01-01

    A time-of-flight mass spectrometer comprises an ion source consisting of a grid assembly, a drift space with a focusing system, a reflector and a detector. The grid assembly has the shape of a ring with the internal diameter equal to that of the detector, whereas the focusing system consists of two cylinders coaxially mounted in the drift space whose diameters are equal, respectively, to the internal and the external diameter of the grid assembly of the ion source. The time-of-flight mass spectrometer is intended mainly for studying the mass composition of an inert gas, of a low-energy ion flux as well as of a plasma in a vacuum. (author)

  8. Interface for liquid chromatograph-mass spectrometer

    Science.gov (United States)

    Andresen, Brian D.; Fought, Eric R.

    1989-01-01

    A moving belt interface for real-time, high-performance liquid chromatograph (HPLC)/mass spectrometer (MS) analysis which strips away the HPLC solvent as it emerges from the end of the HPLC column and leaves a residue suitable for mass-spectral analysis. The interface includes a portable, stand-alone apparatus having a plural stage vacuum station, a continuous ribbon or belt, a drive train magnetically coupled to an external drive motor, a calibrated HPLC delivery system, a heated probe tip and means located adjacent the probe tip for direct ionization of the residue on the belt. The interface is also capable of being readily adapted to fit any mass spectrometer.

  9. Protein Sequencing with Tandem Mass Spectrometry

    Science.gov (United States)

    Ziady, Assem G.; Kinter, Michael

    The recent introduction of electrospray ionization techniques that are suitable for peptides and whole proteins has allowed for the design of mass spectrometric protocols that provide accurate sequence information for proteins. The advantages gained by these approaches over traditional Edman Degradation sequencing include faster analysis and femtomole, sometimes attomole, sensitivity. The ability to efficiently identify proteins has allowed investigators to conduct studies on their differential expression or modification in response to various treatments or disease states. In this chapter, we discuss the use of electrospray tandem mass spectrometry, a technique whereby protein-derived peptides are subjected to fragmentation in the gas phase, revealing sequence information for the protein. This powerful technique has been instrumental for the study of proteins and markers associated with various disorders, including heart disease, cancer, and cystic fibrosis. We use the study of protein expression in cystic fibrosis as an example.

  10. Capillary zone electrophoresis-mass spectrometer interface

    Science.gov (United States)

    D`Silva, A.

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.

  11. Hardware of automation systems of isotope mass spectrometers

    International Nuclear Information System (INIS)

    Manojlov, V.V.; Meleshkin, A.S.; Novikov, L.V.; Kornil'ev, S.O.; Voronin, B.M.

    1997-01-01

    The modernized hardware of isotope mass spectrometers is described. The modern control systems for the mass spectrometers are fulfilled on the basis of IBM/PC AT. Versions of subsystems mass spectrometer control through a standard bus and through a digital-to-analog converter are considered. The characteristics of an electrometric amplifier and interface cards developed for modernized automation systems of the isotope mass spectrometers are presented

  12. High-sensitivity mass spectrometry with a tandem accelerator

    International Nuclear Information System (INIS)

    Henning, W.

    1984-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems

  13. 21 CFR 862.2860 - Mass spectrometer for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mass spectrometer for clinical use. 862.2860 Section 862.2860 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Instruments § 862.2860 Mass spectrometer for clinical use. (a) Identification. A mass spectrometer for...

  14. Shotgun lipidomics on a LTQ Orbitrap mass spectrometer by successive switching between acquisition polarity modes

    DEFF Research Database (Denmark)

    Schuhmann, K.; Almeida, R.; Baumert, M.

    2012-01-01

    Topdown shotgun lipidomics relies on direct infusion of total lipid extracts into a high-resolution tandem mass spectrometer and implies that individual lipids are recognized by their accurately determined m/z. Lipid ionization efficiency and detection specificity strongly depend on the acquisition...... polarity, and therefore it is beneficial to analyze lipid mixtures in both positive and negative modes. Hybrid LTQ Orbitrap mass spectrometers are widely applied in topdown lipidomics; however, rapid polarity switching was previously unfeasible because of the severe and immediate degradation of mass...

  15. Silicon Microleaks for Inlets of Mass Spectrometers

    Science.gov (United States)

    Harpold, Dan; Hasso, Niemann; Jamieson, Brian G.; Lynch, Bernard A.

    2009-01-01

    Microleaks for inlets of mass spectrometers used to analyze atmospheric gases can be fabricated in silicon wafers by means of photolithography, etching, and other techniques that are commonly used in the manufacture of integrated circuits and microelectromechanical systems. The microleaks serve to limit the flows of the gases into the mass-spectrometer vacuums to specified very small flow rates consistent with the capacities of the spectrometer vacuum pumps. There is a need to be able to precisely tailor the dimensions of each microleak so as to tailor its conductance to a precise low value. (As used here, "conductance" signifies the ratio between the rate of flow in the leak and the pressure drop from the upstream to the downstream end of the leak.) To date, microleaks have been made, variously, of crimped metal tubes, pulled glass tubes, or frits. Crimped-metal and pulled-glass-tube microleaks cannot readily be fabricated repeatably to precise dimensions and are susceptible to clogging with droplets or particles. Frits tend to be differentially chemically reactive with various gas constituents and, hence, to distort the gas mixtures to be analyzed. The present approach involving microfabrication in silicon largely overcomes the disadvantages of the prior approaches.

  16. 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

  17. Analog and digital dividers for mass spectrometers

    International Nuclear Information System (INIS)

    Osipov, A.K.

    1980-01-01

    Errors of four different types of stress dividers used in statical mass-spectrometers for determination of mass number by accelerating stress are analyzed. The simplest flowsheet of the analog divider comprises operation amplifier, in the chain of the negative feedback of which a multiplication device on differential cascade is switched- in. This analog divider has high sensitivity to temperature and high error approximately 5%. Application of the multiplier on differential cascade with normalization permits to increase temperature stability and decrease the error up to 1%. Another type of the analog divider is a logarithmic divider the error of which is constant within the whole operation range and it constitutes 1-5%. The digital divider with a digital-analog transformer (DAT) has the error of +-0.015% which is determined by the error of detectors and resistance of keys in the locked state. Considered is the design of a divider based on transformation of the inlet stress into the time period. The error of the divider is determined in this case mainly by stress of the zero shift of the operation amplifier (it should be compensated) and relative threshold stability of the comparator triggering which equals (2-3)x10 -4 . It is noted that the divider with DAT application and the divider with the use of stress transformation within the time period are most perspective ones for statical mass-spectrometers [ru

  18. Computerized mass spectrometer data system at LLL

    International Nuclear Information System (INIS)

    Friesen, R.D.; Dupzyk, R.J.

    1976-01-01

    The data systems on the three mass spectrometers at LLL are computer-controlled, pulse-counting systems synchronized to a repeatedly swept magnetic field. The data are accumulated in the memory of the computer or in a Nuclear Data ND 180 in a multi-scaler mode of operation. This mode of data acquisition allows a continuous check of the background stability and makes tune-up easier. But the main benefit is a reduction in the required ion emission rate stability. By the use of standards to set the system dead time, we have been able to utilize the sensitivity of a pulse counting system without the expense of exotic equipment

  19. Mass spectrometer data system at LLL

    International Nuclear Information System (INIS)

    Friesen, R.D.

    1975-01-01

    The data systems on the three mass spectrometers at LLL are computer-controlled, pulse-counting systems synchronized to a repeatedly-swept magnetic field. The data are accumulated in the memory of the computer or in a Nuclear Data ND 180 in a multi-scaler mode of operation. This mode of sweeping allows a continuous check of the background stability and makes tune-up easier. But the main benefit is a reduction in the required ion emission rate stability. By the use of standards to set the system dead time, we have been able to utilize the sensitivity of a pulse counting system without the expense of exotic equipment

  20. Time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Ivanov, M.A.; Kozlov, B.N.; Mamyrin, B.A.; Shmikk, D.V.; Shebelin, V.G.

    1981-01-01

    A time-of-flight mass spectrometer containing a pulsed ion source with an electron gun and two electrodes limiting ionization range, drift space and ion acceptor, is described. To expand functional possibilities, a slot collimator of the gas stream, two quantum generators and two diaphragms for the inlet of quantum generator radiation located on both sides of the ion source, are introduced in the ion source. The above invention enables to study details of the complex interaction process of laser radiation with molecules of the gas stream, which is actual for laser isotope separation

  1. Plasma Desorption Mass Spectrometry using TANDEM accelerator in National Industrial Research Inst. of Nagoya

    Energy Technology Data Exchange (ETDEWEB)

    Mizota, Takeshi; Nakao, Setsuo; Niwa, Hiroaki; Saito, Kazuo [Particle Beam Sceince Laboratory, Multi-Function Material Science Department, National Industrial Research Inst. of Nagoya, Nagoya (Japan)

    2001-02-01

    Plasma Desorption Mass Spectrometry (PDMS) analysis was studied using TANDEM accelerator. The heavy ions of MeV range emit the secondary ions of atoms, molecules, polymers and clusters from the irradiated samples without destruction. The analysis system of PDMS designed and set-up using a mass spectrometer of Time of Flight and the TANDEM accelerator. The system performance was tested for C-60 fullerene on the surface of the samples using 11.2 MeV {sup 28}Si beams produced by the TANDEM accelerator of 1.7MV. The result shows that the hydrogen and hydrocarbons can be analyzed in the range of 1amu unit. The resolution (M/{delta}M) of the Mass Spectrometry system is confirmed to be about 1000 from the separation of the 720 and 721amu peaks, which is attributed to the C-60 fullerene including {sup 13}C atoms. (H. Katsuta)

  2. Fast atom bombardment tandem mass spectrometry of carotenoids

    Energy Technology Data Exchange (ETDEWEB)

    van Breeman, R.B. [Univ. of Illinois, Chicago, IL (United States); Schmitz, H.H.; Schwartz, S.J. [North Carolina State Univ., Raleigh, NC (United States)

    1995-02-01

    Positive ion fast atom bombardment (FAB) tandem mass spectrometry (MS-MS) using a double-focusing mass spectrometer with linked scanning at constant B/E and high-energy collisionally activated dissociation (CAD) was used to differentiate 17 different cartenoids, including {beta}-apo-8{prime}- carotenal, astaxanthin, {alpha}-carotene, {beta}-carotene, {gamma}-carotene, {zeta}-carotene, canthaxanthin, {beta}-cryptoxanthin, isozeaxanthin bis (pelargonate), neoxanthin, neurosporene, nonaprene, lutein, lycopene, phytoene, phytofluene, and zeaxanthin. The carotenoids were either synthetic or isolated from plant tissues. The use of FAB ionization minimized degradation or rearrangement of the carotenoid structures due to the inherent thermal instability generally ascribed to these compounds. Instead of protonated molecules, both polar xanthophylls and nonpolar carotenes formed molecular ions, M{sup {center_dot}+}, during FAB ionization. Following collisionally activated dissociation, fragment ions of selected molecular ion precursors showed structural features indicative of the presence of hydroxyl groups, ring systems, ester groups, and aldehyde groups and the extent of aliphatic polyene conjugation. The fragmentation patterns observed in the mass spectra herein may be used as a reference for the structural determination of carotenoids isolated from plant and animal tissues. 18 refs., 4 figs.

  3. An electrostatic autoresonant ion trap mass spectrometer

    International Nuclear Information System (INIS)

    Ermakov, A. V.; Hinch, B. J.

    2010-01-01

    A new method for ion extraction from an anharmonic electrostatic trap is introduced. Anharmonicity is a common feature of electrostatic traps which can be used for small scale spatial confinement of ions, and this feature is also necessary for autoresonant ion extraction. With the aid of ion trajectory simulations, novel autoresonant trap mass spectrometers (ART-MSs) have been designed based on these very simple principles. A mass resolution ∼60 is demonstrated for the prototypes discussed here. We report also on the pressure dependencies, and the (mV) rf field strength dependencies of the ART-MS sensitivity. Importantly the new MS designs do not require heavy magnets, tight manufacturing tolerances, introduction of buffer gases, high power rf sources, nor complicated electronics. The designs described here are very inexpensive to implement relative to other instruments, and can be easily miniaturized. Possible applications are discussed.

  4. Practical Limitations of Aerosol Separation by a Tandem Differential Mobility Analyzer-Aerosol Particle Mass Analyzer

    OpenAIRE

    Radney, James G.; Zangmeister, Christopher D.

    2016-01-01

    A cavity ring-down spectrometer and condensation particle counter were used to investigate the limitations in the separation of singly and multiply charged aerosol particles by a tandem differential mobility analyzer (DMA) and aerosol particle mass analyzer (APM). The impact of particle polydispersity and morphology was investigated using three materials: nearly-monodisperse polystyrene latex nanospheres (PSL); polydisperse, nearly-spherical ammonium sulfate (AS) and polydisperse lacey fracta...

  5. Screening of drugs and toxic compounds with liquid chromatography-linear ion trap tandem mass spectrometry.

    Science.gov (United States)

    Sauvage, François-Ludovic; Saint-Marcoux, Franck; Duretz, Bénédicte; Deporte, Didier; Lachatre, Gérard; Marquet, Pierre

    2006-09-01

    In clinical and forensic toxicology, general unknown screening is used to detect and identify exogenous compounds. In this study, we aimed to develop a comprehensive general unknown screening method based on liquid chromatography coupled with a hybrid triple-quadrupole linear ion trap mass spectrometer. After solid-phase extraction, separation was performed using gradient reversed-phase chromatography. The mass spectrometer was operated in the information-dependent acquisition mode, switching between a survey scan acquired in the Enhanced Mass Spectrometry mode with dynamic subtraction of background noise and a dependent scan obtained in the enhanced product ion scan mode. The complete cycle time was 1.36 s. A library of 1000 enhanced product ion-tandem mass spectrometry spectra in positive mode and 250 in negative mode, generated using 3 alternated collision tensions during each scan, was created by injecting pure solutions of drugs and toxic compounds. Comparison with HPLC-diode array detection and gas chromatography-mass spectrometry for the analysis of 36 clinical samples showed that linear ion trap tandem mass spectrometry could identify most of the compounds (94% of the total). Some compounds were detected only by 1 of the other 2 techniques. Specific clinical cases highlighted the advantages and limitations of the method. A unique combination of new operating modes provided by hybrid triple-quadrupole linear ion trap mass spectrometers and new software features allowed development of a comprehensive and efficient method for the general unknown screening of drugs and toxic compounds in blood or urine.

  6. Rapid comparison of diacetylmorphine on banknotes by tandem mass spectrometry.

    Science.gov (United States)

    Ebejer, Karl A; Brereton, Richard G; Carter, James F; Ollerton, Samantha L; Sleeman, Richard

    2005-01-01

    A procedure is described for the determination of the distribution of the contamination of banknotes with controlled drugs using tandem mass spectrometry. The method is illustrated using diacetylmorphine, which is the major active component of heroin. A series of banknotes is introduced into the mass spectrometer and the intensities of two product ions (m/z 328 and 268) derived from the precursor protonated molecule (m/z 370) are recorded. A banknote is considered contaminated if it shows a significant peak for both product ions, and if the ratio of intensities of these two peaks falls within accepted limits. The distribution of diacetylmorphine on sterling banknotes taken from general circulation within the UK can be modelled by an arcsin (square root) transformation of the data or by a log transformation of the data with a higher proportion of contamination. The two models were found to be in close agreement, predicting an upper limit (at 99.9% confidence) of contamination on banknotes from general circulation between 9 and 10%. The percentage contamination in a case study was calculated and compared to the background distribution using the two models proposed. This comparison revealed that the contamination present in the case study was inconsistent with that present on banknotes in general circulation. (c) 2005 John Wiley & Sons, Ltd.

  7. Recoil mass spectrometers in low-energy nuclear physics

    International Nuclear Information System (INIS)

    Cormier, T.M.

    1987-01-01

    By the ion-optical standards of modern spectrometers in nuclear physics the recoil mass spectrometer is a rather inelegant device. Satisfactory correction of the dominant second-order aberrations have expanded the useful mass range and solid angle of the new spectrometers but not without real loss of mass-resolving power. The new spectrometers will involve compromises between resolution and efficiency. Despite their ion-optical inelegance, existing recoil mass spectrometers have opened important new approaches in low-energy nuclear physics, and the new spectrometers promise similar developments. The authors considered a very limited sample of the potential applications of these instruments. Many new applications will follow the development of the new, higher efficiency spectrometers

  8. Analysis of posttranslational modifications of proteins by tandem mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Martin Røssel; Trelle, Morten B; Thingholm, Tine E

    2006-01-01

    -temporal distribution in cells and tissues. Most PTMs can be detected by protein and peptide analysis by mass spectrometry (MS), either as a mass increment or a mass deficit relative to the nascent unmodified protein. Tandem mass spectrometry (MS/MS) provides a series of analytical features that are highly useful...

  9. Phosphopeptide detection and sequencing by matrix-assisted laser desorption/ionization quadrupole time-of-flight tandem mass spectrometry

    DEFF Research Database (Denmark)

    Bennett, Keiryn L; Stensballe, Allan; Podtelejnikov, Alexandre V

    2002-01-01

    A prototype matrix-assisted laser desorption/ionization quadrupole time-of-flight (MALDI-TOF) tandem mass spectrometer was used to sequence a series of phosphotyrosine-, phosphothreonine- and phosphoserine-containing peptides. The high mass resolution and mass accuracy of the instrument allowed...... ion at m/z 216.04 was observed in these MALDI low-energy CID tandem mass spectra. Elimination of phosphate groups was evident from the triphosphorylated peptide but not from the monophosphorylated species. The main fragmentation pathway for the synthetic phosphothreonine-containing peptide...

  10. Ion Mobility Spectrometer / Mass Spectrometer (IMS-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Hunka, Deborah E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Austin, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2005-10-01

    The use of Ion Mobility Spectrometry (IMS)in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400).

  11. Small-sized time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Belov, A.S.

    1985-01-01

    A time-of-flight mass spectrometer with beam particle ionization by electron impact developed for the measurement of pulsed hydrogen beam parameters, is described. Duration of electron beam current pulses in the mass-spectrometer ionizer is varied within the 2-20 μs, interval electron pulse current is 0.6 mA, electron energy is 250 eV. Time resolution of the mass spectrometer is determined by the period of electron beam current pulse repetition and equals 40 μs. The ion drift range is 16 cm. Mass resolution ΔM/M=1/5 is sufficient for the determination of hydrogen beam composition. The mass spectrometer has 100% transparency in the direction of molecular beam particle movement. In this direction the mass spectrometer size is 7 cm

  12. Quantification of antidepressants and antipsychotics in human serum by precipitation and ultra high pressure liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo

    2011-01-01

    precipitated with zinc sulphate and methanol containing a stable isotope labelled analog for each analyte. Quantitative analysis was performed by ultra high pressure liquid chromatography combined with a tandem mass spectrometer using a Zorbax SB-C8 column (2.0×50mm; 1.8m) with a mobile phase consisting of 0...

  13. Quadrupole mass spectrometer driver with higher signal levels

    Science.gov (United States)

    Chutjian, Ara (Inventor); Aalami, Dean (Inventor); Darrach, Murray (Inventor); Orient, Otto (Inventor)

    2003-01-01

    Driving a quadrapole mass spectrometer includes obtaining an air core transformer with a primary and a secondary, matching the secondary to the mass spectrometer, and driving the primary based on first and second voltage levels. Driving of the primary is via an isolating stage that minimizes low level drive signal coupling.

  14. Calibration of a mass spectrometer in steady-state conditions

    International Nuclear Information System (INIS)

    Popov, E.V.; Kupryazhkin, A.Ya.

    1982-01-01

    The mass spectrometer calibration technique by 4 He in steady-state operation conditions by the method of gas expansion from the small volume into the large one using a capacitance micromanometer is described. For realizing steady-state operation of the mass-spectrometer one of the steam-mercury diffusion pumps has been replaced for an adsorption pump. Using adsorption pump permits to maintain working vacuum in the system for more than 3 h. The mass spectrometer calibration has been performed by comparing calibrated volume and mass spectrometer chamber volume. The mass spectrometer sensitivity value by 4 He in the steady-state operation ν=(4.1+-0.1)x10 - 7 Pa/mV is obtained

  15. THOR Ion Mass Spectrometer instrument - IMS

    Science.gov (United States)

    Retinò, Alessandro; Kucharek, Harald; Saito, Yoshifumi; Fraenz, Markus; Verdeil, Christophe; Leblanc, Frederic; Techer, Jean-Denis; Jeandet, Alexis; Macri, John; Gaidos, John; Granoff, Mark; Yokota, Shoichiro; Fontaine, Dominique; Berthomier, Matthieu; Delcourt, Dominique; Kistler, Lynn; Galvin, Antoniette; Kasahara, Satoshi; Kronberg, Elena

    2016-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. Specifically, THOR will study how turbulent fluctuations at kinetic scales heat and accelerate particles in different turbulent environments within the near-Earth space. To achieve this goal, THOR payload is being designed to measure electromagnetic fields and particle distribution functions with unprecedented resolution and accuracy. Here we present the Ion Mass Spectrometer (IMS) instrument that will measure the full three-dimensional distribution functions of near-Earth main ion species (H+, He+, He++ and O+) at high time resolution (~ 150 ms for H+ , ~ 300 ms for He++) with energy resolution down to ~ 10% in the range 10 eV/q to 30 keV/q and angular resolution ~ 10°. Such high time resolution is achieved by mounting multiple sensors around the spacecraft body, in similar fashion to the MMS/FPI instrument. Each sensor combines a top-hat electrostatic analyzer with deflectors at the entrance together with a time-of-flight section to perform mass selection. IMS electronics includes a fast sweeping high voltage board that is required to make measurements at high cadence. Ion detection includes Micro Channel Plates (MCP) combined with Application-Specific Integrated Circuits (ASICs) for charge amplification, discrimination and time-to-digital conversion (TDC). IMS is being designed to address many of THOR science requirements, in particular ion heating and acceleration by turbulent fluctuations in foreshock, shock and magnetosheath regions. The IMS instrument is being designed and will be built by an international consortium of scientific institutes with main hardware contributions from France, USA, Japan and Germany.

  16. Status of the naval research laboratory trace element accelerator mass spectrometer: Characterization of the Pretzel magnet

    Science.gov (United States)

    Knies, D. L.; Grabowski, K. S.; Hubler, G. K.; Treacy, D. J.; DeTurck, T. M.; Enge, H. A.

    1997-02-01

    A novel design for a trace element accelerator mass spectrometer has been developed at the Naval Research Laboratory and is now under construction. It will allow parallel analysis of a broad range of impurities in electronic, biological, and geological materials. The system includes a modified commercial secondary ion mass spectrometer (Physical Electronics, model 6300) as the source of secondary ions, a recombinator consisting of a Pretzel magnet that serves as a tunable notch mass filter, a 3MV Pelletron tandem accelerator, a large electrostatic analyzer, and a split-pole magnetic spectrograph with a 1.5-m-long focal plane. All other ion optical and steering elements are electrostatic, to maintain parallel transmission of different mass species. This paper summarizes the design concept, and describes in some detail the characteristics of the Pretzel magnet.

  17. Natural products in Glycyrrhiza glabra (licorice) rhizome imaged at the cellular level by atmospheric pressure matrix-assisted laser desorption/ionization tandem mass spectrometry imaging

    DEFF Research Database (Denmark)

    Li, Bin; Bhandari, Dhaka Ram; Janfelt, Christian

    2014-01-01

    The rhizome of Glycyrrhiza glabra (licorice) was analyzed by high-resolution mass spectrometry imaging and tandem mass spectrometry imaging. An atmospheric pressure matrix-assisted laser desorption/ionization imaging ion source was combined with an orbital trapping mass spectrometer in order...

  18. Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report

    Science.gov (United States)

    Santiago-Bond, Jo; Captain, Janine

    2015-01-01

    The purpose of this test report is to summarize results from the vibration testing of the INFICON Transpector MPH100M model Mass Spectrometer. It also identifies requirements satisfied, and procedures used in the test. As a payload of Resource Prospector, it is necessary to determine the survivability of the mass spectrometer to proto-qualification level random vibration. Changes in sensitivity of the mass spectrometer can be interpreted as a change in alignment of the instrument. The results of this test will be used to determine any necessary design changes as the team moves forward with flight design.

  19. Mass spectrometer for investigation of solar wind composition

    International Nuclear Information System (INIS)

    Kogan, V.T.; Kornienko, A.P.; Koshevenko, B.V.; Pavlov, A.K.; Chichagov, Yu.V.

    1989-01-01

    Mass-spectrometer designed for analysis of charged particles in solar wind is developed. Analysis of charged particle flux composition is realized in velocity space due to their selection. Properties of mass-spectrometer built using the scheme where analysis of ion composition after their passage through plane magnet with parallel boundaries is realized by means of electrostatic capacitor are considered. The suggested device differs from analog by fundamentally new possibility to carry out analysis of ion composition regardless of their energy within the selected range (solar wind). This property eliminates the necessity to carry out time successive energy analysis increases essentially mass-spectrometer sensitivity and enables to study fast processes

  20. Probe Heating Method for the Analysis of Solid Samples Using a Portable Mass Spectrometer.

    Science.gov (United States)

    Kumano, Shun; Sugiyama, Masuyuki; Yamada, Masuyoshi; Nishimura, Kazushige; Hasegawa, Hideki; Morokuma, Hidetoshi; Inoue, Hiroyuki; Hashimoto, Yuichiro

    2015-01-01

    We previously reported on the development of a portable mass spectrometer for the onsite screening of illicit drugs, but our previous sampling system could only be used for liquid samples. In this study, we report on an attempt to develop a probe heating method that also permits solid samples to be analyzed using a portable mass spectrometer. An aluminum rod is used as the sampling probe. The powdered sample is affixed to the sampling probe or a droplet of sample solution is placed on the tip of the probe and dried. The probe is then placed on a heater to vaporize the sample. The vapor is then introduced into the portable mass spectrometer and analyzed. With the heater temperature set to 130°C, the developed system detected 1 ng of methamphetamine, 1 ng of amphetamine, 3 ng of 3,4-methylenedioxymethamphetamine, 1 ng of 3,4-methylenedioxyamphetamine, and 0.3 ng of cocaine. Even from mixtures consisting of clove powder and methamphetamine powder, methamphetamine ions were detected by tandem mass spectrometry. The developed probe heating method provides a simple method for the analysis of solid samples. A portable mass spectrometer incorporating this method would thus be useful for the onsite screening of illicit drugs.

  1. Techniques of tandem accelerator mass spectrometry and their applications to 14C measurements

    International Nuclear Information System (INIS)

    Nakamura, Toshio; Nakai, Nobuyuki; Furukawa, Michiaki

    1990-01-01

    A tandem accelerator mass spectrometer, named Tandetron was installed at Nagoya University in 1982 for 14 C measurement. The Tandetron spectrometer consists of a Cs sputter ion source to produce negative carbon ions, a Schenkel-type 2.2 MV tandem accelerator, an ion-beam analyzing apparatus with a charge-energy selector and mass spectrometer, and a heavy ion detector to identify and count 14 C 3+ ions from various background ions. The 14 C concentrations in pine needles, sampled at the Higashiyama Campus of Nagoya University, have been measured since 1984. The present article describes some of the measurements of 14 C in pine needles, focusing on the annual changes in the Δ 14 C value of atmospheric CO 2 , and on the effect upon 14 C concentrations for pine needles of a local 14 CO 2 emission from incineration of radioactive organic solvent wastes containing 14 C, at the Radioisotope Center in the Higashiyama Campus. The pine needles at some locations seemed to be influenced by local artificial CO 2 emission. The Δ 14 C values increased noticeably from 1956 to 1964 as a result of artificial 14 C produced in nuclear weapon tests. (N.K.)

  2. Miniature Mass Spectrometer for Earth Science Research, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — By drastically reducing the physical footprint of a mass spectrometer to the size of a beverage can, Ceramitron could set a new performance/price standard in the...

  3. MAVEN Neutral Gas and Ion Mass Spectrometer Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains the data collected by the Neutral Gas and Ion Mass Spectrometer (NGIMS) instrument aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN)...

  4. Interpretation of Tandem Mass Spectrometry (MSMS) Spectra for Peptide Analysis

    DEFF Research Database (Denmark)

    Hjernø, Karin; Højrup, Peter

    2015-01-01

    The aim of this chapter is to give a short introduction to peptide analysis by mass spectrometry (MS) and interpretation of fragment mass spectra. Through examples and guidelines we demonstrate how to understand and validate search results and how to perform de novo sequencing based on the often...... very complex fragmentation pattern obtained by tandem mass spectrometry (also referred to as MSMS). The focus is on simple rules for interpretation of MSMS spectra of tryptic as well as non-tryptic peptides....

  5. TOFI: An isochronous time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Wollnik, H.

    1987-01-01

    A time-of-flight mass spectrometer was constructed to measure the masses of neutron-rich recoils produced in proton-induced fragmentation reactions. This system consists of four sector magnets designed such that the overall flight time is independent of the velocity of the recoil ions and thus depends only on their mass-to-charge ratios. (orig.)

  6. Ultra Performance Liquid Chromatography Tandem Mass ...

    African Journals Online (AJOL)

    NICOLAAS

    drugs alone.16. After a single oral dose of 120–800 mg of NTB in healthy sub- jects in a fasting state the peak plasma NTB concentration (tmax) was found to be 4–7 h, with a half-life of approximately 9–17 h.17 ... performance liquid chromatography mass spectrometry/mass .... to the likely biological plasma constituents.

  7. [Application of tandem mass spectrometry in diagnosis of organic acidemias].

    Science.gov (United States)

    Han, Lian-shu; Gao, Xiao-lan; Ye, Jun; Qiu, Wen-juan; Gu, Xue-fan

    2005-05-01

    The diagnosis of organic acidemia is very difficult and needs special test methods. Recently the tandem mass spectrometry has been used in screening for and diagnosis of this inborn error of metabolism. The aim of the present study was to utilize a dry blood filter paper method for acylcarnitines profiles test using tandem mass spectrometry in diagnosis of organic acidemias in high risk children. One thousand patients (642 were males and 358 females) with high risk of inborn error of metabolism were studied, the median of their age was 2 years. The blood specimens were collected on filter paper, punched and extracted into methanol solution with stable isotope labeled internal standards of acylcarnitine, then derivatized with butanolic-HCI. After preparation, the samples were analyzed by tandem mass spectrometry. The volume of the acylcarnitines was calculated with special software. Forty patients (4.0%) were diagnosed as organic acidemias among the 1000 patients, including 20 methylmalonic acidemia, 6 propionic acidemia, 3 isovaleric acidemia, 3 glutaric acidemia type I, 3 glutaric acidemia type II, 2 biotinidas deficiency, 1 3-methylcrotonyl-CoA carboxylase deficiency, 1 3-hydroxy-3-methylglutaryl-CoA lyase deficiency, and 1 beta-keto thiolase deficiency. The common clinical symptoms and signs of these patients were motor and mental developmental retardation, spasm, lethargy, coma, hypotonia, vomiting, and feeding difficulty. Routine laboratory tests suggested metabolic acidosis, hyperammonemia, hyperlactacidemia, hypoglycemia, anemia, and abnormal liver function. A part of organic acidemias can be rapidly diagnosed by tandem mass spectrometry through acylcarnitine profiles analysis in dry blood filter paper. Combination of tandem mass spectrometry with urine gas chromatography mass spectrometry would improve more accurate diagnosis of organic acidemias.

  8. A high-throughput method for liquid chromatography-tandem mass spectrometry determination of plasma alkylresorcinols, biomarkers of whole grain wheat and rye intake

    DEFF Research Database (Denmark)

    Ross, Alastair B; Svelander, Cecilia; Savolainen, Otto I

    2016-01-01

    supported extraction methods for extracting alkylresorcinols from plasma and improved a normal-phase liquid chromatography coupled to a tandem mass spectrometer method to reduce sample analysis time. The method was validated and compared with gas chromatography-mass spectrometry analysis. Sample preparation...

  9. Annotating and Interpreting Linear and Cyclic Peptide Tandem Mass Spectra.

    Science.gov (United States)

    Niedermeyer, Timo Horst Johannes

    2016-01-01

    Nonribosomal peptides often possess pronounced bioactivity, and thus, they are often interesting hit compounds in natural product-based drug discovery programs. Their mass spectrometric characterization is difficult due to the predominant occurrence of non-proteinogenic monomers and, especially in the case of cyclic peptides, the complex fragmentation patterns observed. This makes nonribosomal peptide tandem mass spectra annotation challenging and time-consuming. To meet this challenge, software tools for this task have been developed. In this chapter, the workflow for using the software mMass for the annotation of experimentally obtained peptide tandem mass spectra is described. mMass is freely available (http://www.mmass.org), open-source, and the most advanced and user-friendly software tool for this purpose. The software enables the analyst to concisely annotate and interpret tandem mass spectra of linear and cyclic peptides. Thus, it is highly useful for accelerating the structure confirmation and elucidation of cyclic as well as linear peptides and depsipeptides.

  10. Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping.

    Science.gov (United States)

    Dickel, Timo; Plaß, Wolfgang R; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I; Geissel, Hans; Scheidenberger, Christoph

    2017-06-01

    A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. Graphical Abstract ᅟ.

  11. Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping

    Science.gov (United States)

    Dickel, Timo; Plaß, Wolfgang R.; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I.; Geissel, Hans; Scheidenberger, Christoph

    2017-06-01

    A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. [Figure not available: see fulltext.

  12. Analysis of posttranslational modifications of proteins by tandem mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Martin Røssel; Trelle, Morten B; Thingholm, Tine E

    2006-01-01

    -temporal distribution in cells and tissues. Most PTMs can be detected by protein and peptide analysis by mass spectrometry (MS), either as a mass increment or a mass deficit relative to the nascent unmodified protein. Tandem mass spectrometry (MS/MS) provides a series of analytical features that are highly useful...... for the characterization of modified proteins via amino acid sequencing and specific detection of posttranslationally modified amino acid residues. Large-scale, quantitative analysis of proteins by MS/MS is beginning to reveal novel patterns and functions of PTMs in cellular signaling networks and biomolecular structures....

  13. Online hydrogen/deuterium exchange performed in the ion mobility cell of a hybrid mass spectrometer.

    Science.gov (United States)

    Nagy, Kornél; Redeuil, Karine; Rezzi, Serge

    2009-11-15

    The present paper describes the performance of online, gas-phase hydrogen/deuterium exchange implemented in the ion mobility cell of a quadrupole time-of-flight mass spectrometer. Deuterium oxide and deuterated methanol were utilized to create deuterated vapor that is introduced into the ion mobility region of the mass spectrometer. Hydrogen/deuterium exchange occurs spontaneously in the milliseconds time frame without the need of switching the instrument into ion mobility mode. The exchange was studied in case of low molecular weight molecules and proteins. The observed number of exchanged hydrogens was equal to the number of theoretically exchangeable hydrogens for all low molecular weight compounds. This method needs only minimal instrumental modifications, is simple, cheap, environment friendly, compatible with ultraperformance liquid chromatography, and can be implemented on commercially available instruments. It does not compromise choice of liquid chromatographic solvents and accurate mass or parallel-fragmentation (MS(E)) methods. The performance of this method was compared to that of conventional alternatives where the deuterated solvent is introduced into the cone gas of the instrument. Although the degree of exchange was similar between the two methods, the "cone gas method" requires 10 times higher deuterated solvent volumes (50 muL/min) and offers reduced sensitivity in the tandem mass spectrometry (MS/MS) mode. The presented method is suggested as a standard future element of mass spectrometers to aid online structural characterization of unknowns and to study conformational changes of proteins with hydrogen/deuterium exchange.

  14. Extending The Useful Life Of Older Mass Spectrometers

    International Nuclear Information System (INIS)

    Johnson, S.; Cordaro, J.; Holland, M.; Jones, V.

    2010-01-01

    Thermal ionization and gas mass spectrometers are widely used across the Department of Energy (DOE) Complex and contractor laboratories. These instruments support critical missions, where high reliability and low measurement uncertainty are essential. A growing number of these mass spectrometers are significantly older than their original design life. The reality is that manufacturers have declared many of the instrument models obsolete, with direct replacement parts and service no longer available. Some of these obsolete models do not have a next generation, commercially available replacement. Today's budget conscious economy demands for the use of creative funds management. Therefore, the ability to refurbish (or upgrade) these valuable analytical tools and extending their useful life is a cost effective option. The Savannah River Site (SRS) has the proven expertise to breathe new life into older mass spectrometers, at a significant cost savings compared to the purchase and installation of new instruments. A twenty-seven year old Finnigan MAT-261(trademark) Thermal Ionization Mass Spectrometer (TIMS), located at the SRS F/H Area Production Support Laboratory, has been successfully refurbished. Engineers from the Savannah River National Laboratory (SRNL) fabricated and installed the new electronics. These engineers also provide continued instrument maintenance services. With electronic component drawings being DOE Property, other DOE Complex laboratories have the option to extend the life of their aged Mass Spectrometers.

  15. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

    2013-01-15

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  16. Tandem Mass Spectrometry of Novel Ether-Linked Phospholipid Analogs of Anionic Pulmonary Surfactant Phospholipids

    Science.gov (United States)

    Fickes, Rachel; Voelker, Dennis R.; Berry, Karin Zemski; Murphy, Robert C.

    2016-01-01

    RATIONALE Structural analogs of the bioactive lipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol, were synthesized with a xylitol polar headgroup and both diacyl and diether radyl groups. Mass spectral characterization of xylitol phospholipids (PX) was carried out using collisional activation and high resolution mass measurements of positive molecular ion species and compared with the phosphatidylglycerol (PG) analogs. METHODS Xylitol phospholipids were synthesized using a transphosphatidylation reaction catalyzed by phospholipase D and purified by HPLC. Compounds were subjected to electrospray ionization and CID was performed using a tandem quadrupole mass spectrometer to generate positive and negative molecular ions. Diether phospholipids were additionally analyzed by high resolution mass spectrometry as protonated and sodiated molecular species in positive ion mode. RESULTS Ester linked xylitol phospholipid analogs behaved similar to PG after collisional activation of [M-H]−. The product ions formed by CID of the diether PG and PX negative ions only revealed information about the headgroup with no information about the aliphatic chains. In contrast, CID of protonated and sodiated diether phospholipid positive ions, revealed reactions corresponding to cleavage of the ether chain, likely occurring by charge driven reaction mechanisms. CONCLUSIONS Novel xylitol phospholipid analogs with diacyl and diether radyl substituents of the glycerol backbone were characterized by tandem mass spectrometry. These unique diether phospholipid analogs enabled exploration of ether cleavage reactions of the positive molecular ion species induced by collision induced decomposition. PMID:27689848

  17. An improved data acquisition system for isotopic ratio mass spectrometers

    International Nuclear Information System (INIS)

    Saha, T.K.; Reddy, B.; Nazare, C.K.; Handu, V.K.

    1999-01-01

    Isotopic ratio mass spectrometers designed and fabricated to measure the isotopic ratios with a precision of better than 0.05%. In order to achieve this precision, the measurement system consisting of ion signal to voltage converters, analog to digital converters, and data acquisition electronics should be at least one order better than the overall precision of measurement. Using state of the art components and techniques, a data acquisition system, which is an improved version of the earlier system, has been designed and developed for use with multi-collector isotopic ratio mass spectrometers

  18. [Tandem mass spectrometry as screening for inborn errors of metabolism].

    Science.gov (United States)

    Campos H, Derbis

    2011-10-01

    The use of tandem mass spectrometry for the diagnosis of inborn errors of metabolism has the potential to expand the newborn screening panel to include a vast number of diseases. This technology allows the detection, in the same spot of dried blood on filter paper and during one single analytical run, of different metabolic diseases. Tandem mass spectrometry is rapidly replacing the classical screening techniques approach of one-metabolite detected per analysis per disease by its ability of simultaneous quantification of several metabolites as markers of many diseases, such as acylcarnitines and amino acids. It is clear that a single metabolite can be a biomarker for several diseases, so the multiplex approach of using tandem mass spectrometry enhances, on average, the sensitivity and specificity of the screening. However, there are differences for particular metabolites and the diseases they detect within the same method. Disorders such as the tyrosinemias and among the organic acidemias, the methylmalonic acidemias, have a substantially higher false-positive rate than other more common metabolic diseases such as medium-chain acyl-CoA dehydrogenase deficiency and phenylketonuria. Before introducing this technology into routine newborn screening programs it is necessary to consider the frequency of each disease, as well as the response to early treatment or variables related to the collection of the sample.

  19. Accelerator mass spectrometry with a coupled tandem-linac system

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

    A coupled system provides higher energies, which allows one to extend AMS to hitherto untouched mass regions. Another important argument is that the complexity, although bothersome for the operation, increases the selectivity of detecting a particular isotope. The higher-energy argument holds for any heavy-ion accelerator which is capable of delivering higher energy than a tandem. The present use of tandem-linac combinations for AMS, rather than cyclotrons, linacs or combinations of these machines, has mainly to do with the fact that this technique was almost exclusively developed around tandem accelerators. Therefore the tandem-linac combination is a natural extension to higher energies. The use of negative ions has some particular advantages in suppressing background from unwanted elements that do not form stable negative ions (e.g., N, Mg, Ar). On the other hand, this limits the detection of isotopes to elements which do form negative ions. For particular problems it may therefore be advantageous to use a positive-ion machine. What really matters most for choosing one or the other machine is to what extent the entire accelerator system can be operated in a truly quantiative way from the ion source to the detection system. 20 references, 4 figures

  20. A cyclotron as a mass spectrometer

    International Nuclear Information System (INIS)

    Bricault, P.; Auger, G.; Bajard, M.; Baron, E.; Bibet, D.; Chabert, A.; Ferme, J.; Gaudart, L.; Joubert, J.; Audi, G.; Fifield, K.

    1992-01-01

    Taking advantage of the system of coupled cyclotrons at GANIL, a method has been developed for mass measurements with a cyclotron. The secondary nuclei are produced in a target located between the two separated sector cyclotrons by the interaction of a beam coming from the first cyclotron. They are subsequently accelerated in the second cyclotron. The prior tuning of this cyclotron for those very low intensity is accomplished using a beam having the same q/A ratio at the right velocity. For fine tuning, a probe inside one sector of the cyclotron has been developed. This new probe is described and first results are presented. (author) 7 refs., 4 figs

  1. The Varian MAT-250 mass spectrometer. Steady isotopes laboratory

    International Nuclear Information System (INIS)

    Hernandez M, V.; Tavera D, M.L.

    1997-01-01

    This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)

  2. Portable mass spectrometer for field and laboratory use

    International Nuclear Information System (INIS)

    Newton, J.C.; Crawford, R.W.; Stump, R.K.

    1975-01-01

    A rugged, portable mass spectrometer is described that can be used for gas analyses in remote areas, yet is suitable for laboratory use. Representative results from several studies, including preshot gas analyses of atmospheres from canisters used in the Cannikin Event, are given. Operational procedures and performance experience are included. (auth)

  3. Cherenkov detectors and a new effective-mass spectrometer method

    Czech Academy of Sciences Publication Activity Database

    Hladký, Jan

    2006-01-01

    Roč. 75, - (2006), s. 854-855 ISSN 0969-806X Institutional research plan: CEZ:AV0Z10100502 Keywords : Cherenkov radiation * spectrometer * effective mass method Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.868, year: 2006

  4. A mass spectrometer for pain-response monitoring in rats

    Science.gov (United States)

    Elizarov, A. Yu.

    2017-06-01

    A mass spectrometer with a membrane interface has been used for measuring the relative concentration of carbon dioxide (CO2) released from rat skin in response to thermal irritation and pain stimulus during intraperitoneal propofol-lidocaine anesthesia. It is established that the local anesthetic lidocaine directly influences the central nervous system and induces antinociceptive reaction to thermal irritation.

  5. Fabrication and testing of the recoil mass spectrometer at Bombay ...

    Indian Academy of Sciences (India)

    A recoil mass spectrometer (RMS) has been designed, fabricated and installed at the. 15. °. S beam-line of the Pelletron at TIFR. The RMS consists of a quadrupole doublet just after the target chamber followed by an 'electrostatic deflector', a magnetic dipole and a second electrostatic deflector. The recoils produced in the.

  6. A new time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Ching-Shen Su.

    1984-01-01

    A new time-of-flight mass spectrometer using a cylindrical mirror analyzer and a cylindrical sector analyzer to select ion energies was reported. The cylindrical sector acts as a flight path for ions also. An energy spread of +- 0.41% can be achieved. (orig.)

  7. The History of Planetary Exploration Using Mass Spectrometers

    Science.gov (United States)

    Mahaffy, Paul R.

    2012-01-01

    At the Planetary Probe Workshop Dr. Paul Mahaffy will give a tutorial on the history of planetary exploration using mass spectrometers. He will give an introduction to the problems and solutions that arise in making in situ measurements at planetary targets using this instrument class.

  8. Tandem analyzer crystals system doubles counting rate for Bonse Hart ultra-small-angle neutron-scattering spectrometer

    Science.gov (United States)

    Yamaguchi, Daisuke; Koizumi, Satoshi; Motokawa, Ryuhei; Kumada, Takayuki; Aizawa, Kazuya; Hashimoto, Takeji

    2006-11-01

    A new tandem analyzer crystals system was introduced on Bonse-Hart ultra-small-angle neutron-scattering spectrometer at research reactor JRR-3, Tokai, Japan. Conventional Bonse-Hart setup consumes a considerable time to measure a scattering profile of whole q range (2×10 -4 nm -1neutrons from the sample and having different q are measured step by step. To overcome this difficulty two analyzer channel-cut silicon perfect crystals were settled in tandem and each of them diffracted the scattering of different q. In consequence, a simultaneous detection at two different q positions was realized and the measurement time was reduced to half.

  9. Retarding potential and induction charge detectors in tandem for measuring the charge and mass of nanodroplets

    International Nuclear Information System (INIS)

    Gamero-Castano, Manuel

    2009-01-01

    The determination of the mass of a nanoparticle via time-of-flight typically requires a direct measurement of its charge. This can be done with a differential retarding potential analyzer and an induction charge detector operating in tandem. The spectrometer described in this article selects a particle with a specified retarding potential from a beam and directs it to an induction charge detector where both its velocity and charge are measured. The retarding potential, velocity, and charge also yield the particle's mass. The particle is analyzed without the need to collect it, and therefore can be employed in a subsequent experiment. The high charge sensitivity of the induction charge detector and the capability for working at low retarding potentials make the characterization of electrosprayed nanodroplets possible for the first time.

  10. Molecular beam detector on the MX7304 mass spectrometer base

    International Nuclear Information System (INIS)

    Akimov, V.M.; Rusin, L.Yu.; Tsyganov, F.A.

    1991-01-01

    A modified monitor for the MKh-7304 mass spectrometer installed in one of differentially evacuated chambers of the time-of-flight spectrometer. The limit vacuum under operational conditions is 10 -8 torr. The results of testing the molecular beams when recording time-of-flight spectra of Ar, Xe, N 2 are given. It is revealed that the vacuum system time conctant decrease as compared with the system with standard monitor gives an opportunity to register reliability the time-of-flight spectra of molecular beams

  11. Micro mass spectrometer on a chip.

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Dolores Y.; Blain, Matthew Glenn; Fleming, James Grant

    2005-11-01

    The design, simulation, fabrication, packaging, electrical characterization and testing analysis of a microfabricated a cylindrical ion trap ({mu}CIT) array is presented. Several versions of microfabricated cylindrical ion traps were designed and fabricated. The final design of the individual trap array element consisted of two end cap electrodes, one ring electrode, and a detector plate, fabricated in seven tungsten metal layers by molding tungsten around silicon dioxide (SiO{sub 2}) features. Each layer of tungsten is then polished back in damascene fashion. The SiO{sub 2} was removed using a standard release processes to realize a free-hung structure. Five different sized traps were fabricated with inner radii of 1, 1.5, 2, 5 and 10 {micro}m and heights ranging from 3-24 {micro}m. Simulations examined the effects of ion and neutral temperature, the pressure and nature of cooling gas, ion mass, trap voltage and frequency, space-charge, fabrication defects, and other parameters on the ability of micrometer-sized traps to store ions. The electrical characteristics of the ion trap arrays were determined. The capacitance was 2-500 pF for the various sized traps and arrays. The resistance was in the order of 1-2 {Omega}. The inductance of the arrays was calculated to be 10-1500 pH, depending on the trap and array sizes. The ion traps' field emission characteristics were assessed. It was determined that the traps could be operated up to 125 V while maintaining field emission currents below 1 x 10{sup -15} A. The testing focused on using the 5-{micro}m CITs to trap toluene (C{sub 7}H{sub 8}). Ion ejection from the traps was induced by termination of the RF voltage applied to the ring electrode and current measured on the collector electrode suggested trapping of ions in 1-10% of the traps. Improvements to the to the design of the traps were defined to minimize voltage drop to the substrate, thereby increasing trapping voltage applied to the ring electrode, and to

  12. Inhomogeneous oscillatory electric field time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Carrico, J.P.

    1977-01-01

    The mass-to-charge ratio of an ion can be determined from the measurement of its flight time in an inhomogeneous, oscillatory electric field produced by the potential distribution V(x, y, t) = Vsub(DC) + Vsub(AC) cos ωt) (αsub(x)X 2 + αsub(y)Y 2 + αsub(z)Z 2 ). The governing equation of motion is the Mathieu equation. The principle of operation of this novel mass spectrometer is described and results of computer calculations of the flight time and resolution are reported. An experimental apparatus and results and results demonstrating the feasibility of this mass spectrometer principle are described. (author)

  13. Mini Mass Spectrometer Integrated with a Miniature Ion Funnel.

    Science.gov (United States)

    Zhai, Yanbing; Zhang, Xiaohua; Xu, Hualei; Zheng, Yongchang; Yuan, Tao; Xu, Wei

    2017-04-04

    Previously, a continuous atmospheric pressure interfaced miniature mass spectrometer was developed in our lab. The continuous atmospheric pressure interface improves system robustness, stability, and scan speed, but it also results in limited ion transfer efficiency and reduced mass resolution. To solve these problems, a miniature ion funnel was designed and integrated into the miniature mass spectrometer for the first time. Besides ion transfer efficiency, dimension and power consumption of the ion funnel also need to be considered throughout the design process. After a systematic optimization, the designed miniature ion funnel could increase ion transfer efficiency by more than 10 times, while lowering the background pressure of ion trap by ∼2 times. As a result, sensitivity and mass resolution of the second generation miniature mass spectrometer were improved by 20 times and ∼2 times, respectively, while maintaining its high scan speed and stability. A sensitive and robust mini-MS, capable of coupling with ambient ionization sources would meet the needs of many on-site chemical analysis applications, such as in food, drug, and agricultural administrations, forensic science, homeland security, and etc.

  14. Illustrating the Basic Functioning of Mass Analyzers in Mass Spectrometers with Ball-Rolling Mechanisms

    Science.gov (United States)

    Horikoshi, Ryo; Takeiri, Fumitaka; Mikita, Riho; Kobayashi, Yoji; Kageyama, Hiroshi

    2017-01-01

    A unique demonstration with ball-rolling mechanisms has been developed to illustrate the basic principles of mass analyzers as components of mass spectrometers. Three ball-rolling mechanisms mimicking the currently used mass analyzers (i.e., a quadrupole mass filter, a magnetic sector, and a time-of- flight) have been constructed. Each mechanism…

  15. Tandem mass spectrometric studies of lanthanum-α-hydroxycarboxylate complexes

    International Nuclear Information System (INIS)

    Kumar, Pranaw; Telmore, V.M.; Jaison, P.G.; Sadhu, Biswajit; Sundararajan, Mahesh

    2017-01-01

    The complexation of lanthanides with hydroxycarboxylic acids is important to understand its separation behavior on liquid chromatography. Electrospray ionization mass spectrometry (ESI-MS) being the soft ionization technique is known for studying the speciation and stoichiometry of metal ligand species. The gentle ionization process of this technique is well suited for transferring the species from solution to gas phase with the retention of stoichiometry. The use of tandem mass spectrometric application has been utilized for studying the path of dissociation. The possible pathways of fragmentation and its geometry have been explained by using the density functional theory (OFT) in the gas phase. Present work describes integrated DFT and tandem mass spectrometric studies of La with α-hydroxyisobutyric acid (HIBA) along with their dissociation studies. In this study, unusual elimination of -CO with the loss of m/z 28 from the complex was observed. This fragmentation resulted the conversion of HIBA into acetone in the fragmented product. The possible fragmentation pathways with the energetic were identified

  16. AI mass spectrometers for space shuttle health monitoring

    Science.gov (United States)

    Adams, F. W.

    1991-01-01

    The facility Hazardous Gas Detection System (HGDS) at Kennedy Space Center (KSC) is a mass spectrometer based gas analyzer. Two instruments make up the HGDS, which is installed in a prime/backup arrangement, with the option of using both analyzers on the same sample line, or on two different lines simultaneously. It is used for monitoring the Shuttle during fuel loading, countdown, and drainback, if necessary. The use of complex instruments, operated over many shifts, has caused problems in tracking the status of the ground support equipment (GSE) and the vehicle. A requirement for overall system reliability has been a major force in the development of Shuttle GSE, and is the ultimate driver in the choice to pursue artificial intelligence (AI) techniques for Shuttle and Advanced Launch System (ALS) mass spectrometer systems. Shuttle applications of AI are detailed.

  17. The development of a completely automated oxygen isotope mass spectrometer

    International Nuclear Information System (INIS)

    Ahern, T.K.

    1980-01-01

    A completely automated mass spectrometer system has been developed to measure the oxygen isotope ratio of carbon dioxide samples. The system has an accuracy of 0.03 percent, and is capable of analyzing more than 100 samples a day. The system uses an Interdata minicomputer as the primary controller. The intelligence of the system is contained within hardware circuits, software within the minicomputer, and firmware written for a Motorola 6802 microprocessor. A microprocessor-based inlet system controller maximizes the throughput of carbon dioxide samples within the inlet system. The inlet system normally contains four different aliquots of carbon dioxide and introduces these samples to the mass spectrometer through a single admittance leak. The system has been used in the analysis of 111 samples of ice taken from the Steele glacier

  18. Commissioning of the AEI MS702 mass spectrometer

    International Nuclear Information System (INIS)

    Pearton, D.C.G.; Sobiecki, A.

    1978-01-01

    The setting-up and commissioning of the AEI MS702 mass spectrometer is described. Its individual components and their use are discussed, as well as the sample preparation, analysis, and reduction of data. A comprehensive list is given of instrumental breakdowns, and the application of the technique to several matrices is outlined. Improvements and modifications to the technique, including the use of a minicomputer, are suggested

  19. A high efficiency thermal ionization source adapted to mass spectrometers

    International Nuclear Information System (INIS)

    Chamberlin, E.P.; Olivares, J.A.

    1996-01-01

    A tungsten crucible thermal ionization source mounted on a quadrupole mass spectrometer is described. The crucible is a disposable rod with a fine hole bored in one end; it is heated by electron bombardment. The schematic design of the assembly, including water cooling, is described and depicted. Historically, the design is derived from that of ion sources used on ion separators at Los Alamos and Dubna, but the crucible is made smaller and simplified. 10 refs., 4 figs

  20. Digital Waveform Technology and the Next Generation of Mass Spectrometers

    Science.gov (United States)

    Hoffman, Nathan M.; Gotlib, Zachary P.; Opačić, Bojana; Huntley, Adam P.; Moon, Ashley M.; Donahoe, Katherine E. G.; Brabeck, Gregory F.; Reilly, Peter T. A.

    2018-02-01

    Ion traps and guides are integral parts of current commercial mass spectrometers. They are currently operated with sinusoidal waveform technology that has been developed over many years. Recently, digital waveform technology has begun to emerge and promises to supplant its older cousin because it presents new capabilities that result from the ability to instantaneously switch the frequency and duty cycle of the waveforms. This manuscript examines these capabilities and reveals their uses and effects on instrumentation.

  1. A quadrupole mass spectrometer system for nuclear safeguards applications

    International Nuclear Information System (INIS)

    Evans, P.J.

    1987-12-01

    An on-line enrichment monitor for nuclear safeguards-related surveillance of a pilot-scale gas centrifuge plant is described. This monitor utilises a quadrupole mass spectrometer to measure the isotopic composition of UF 6 in the feed and product gas streams. Details of the design and construction are given, and several difficulties are identified and discussed. Finally, the performance of this system is illustrated with typical results

  2. Application of the mass-spectrometer MASHA for mass-spectrometry and laser-spectroscopy

    Science.gov (United States)

    Rodin, A. M.; Belozerov, A. V.; Dmitriev, S. N.; Oganessian, Yu. Ts.; Sagaidak, R. N.; Salamatin, V. S.; Stepantsov, S. V.; Vanin, D. V.

    2010-02-01

    We report the present status of the mass-spectrometer MASHA (Mass-Analyzer of Supper Heavy Atoms) designed for determination of the masses of superheavy elements. The mass-spectrometer is connected to the U-400M cyclotron of the Flerov Laboratory for Nuclear Reactions (FLNR) JINR, Dubna. The first experiments on mass-measurements for 112 and 114 elements will be performed in the upcoming 2010. For this purpose a hot catcher, based on a graphite stopper, is constructed. The α-decay of the superheavy nuclides or spontaneous fission products will be detected with a silicon 192 strips detector. The experimental program of future investigations using the technique of a gas catcher is discussed. It should be regarded as an alternative of the classical ISOL technique. The possibilities are considered for using this mass-spectrometer for laser spectroscopy of nuclei far off-stability.

  3. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-01-01

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

  4. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization.

    Science.gov (United States)

    Jjunju, Fred P M; Li, Anyin; Badu-Tawiah, Abraham; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S; Cooks, R Graham

    2013-07-07

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL(-1)) and over a dynamic range of ∼5 pg μL(-1) to 500 pg μL(-1) (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL(-1).

  5. Tandem mass spectrometric analysis of novel peptide-modified gemini surfactants used as gene delivery vectors.

    Science.gov (United States)

    Al-Dulaymi, M; El-Aneed, A

    2017-06-01

    Diquaternary ammonium gemini surfactants have emerged as effective gene delivery vectors. A novel series of 11 peptide-modified compounds was synthesized, showing promising results in delivering genetic materials. The purpose of this work is to elucidate the tandem mass spectrometric (MS/MS) dissociation behavior of these novel molecules establishing a generalized MS/MS fingerprint. Exact mass measurements were achieved using a hybrid quadrupole orthogonal time-of-flight mass spectrometer, and a multi-stage MS/MS analysis was conducted using a triple quadrupole-linear ion trap mass spectrometer. Both instruments were operated in the positive ionization mode and are equipped with electrospray ionization. Abundant triply charged [M+H] 3+ species were observed in the single-stage analysis of all the evaluated compounds with mass accuracies of less than 8 ppm in mass error. MS/MS analysis showed that the evaluated gemini surfactants exhibited peptide-related dissociation characteristics because of the presence of amino acids within the compounds' spacer region. In particular, diagnostic product ions were originated from the neutral loss of ammonia from the amino acids' side chain resulting in the formation of pipecolic acid at the N-terminus part of the gemini surfactants. In addition, a charge-directed amide bond cleavage was initiated by the amino acids' side chain producing a protonated α-amino-ε-caprolactam ion and its complimentary C-terminus ion that contains quaternary amines. MS/MS and MS 3 analysis revealed common fragmentation behavior among all tested compounds, resulting in the production of a universal MS/MS fragmentation pathway. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Design, construction and commissioning of an ortho-TOF mass spectrometer for investigations of exotic nuclei

    International Nuclear Information System (INIS)

    Eliseev, S.

    2004-01-01

    Precise atomic mass measurements are very important in many disciplines of science, e.g. in physics, biochemistry, medicine, archaeology and environmental research. In nuclear physics, mass measurements of nuclides are essential for testing nuclear mass models. From the knowledge of the mass of a nuclide the nuclear binding energy can be derived. The mass measurements provide a better knowledge of the strong interaction between the constituents in the nucleus. In nuclear astrophysics, mass measurements of exotic nuclides are of great importance for our understanding of the synthesis of the elements. In biochemistry and medicine, mass measurement methods are helpful in a structural analysis of complex biomolecules. Mass measurement techniques are widely used in the trace analysis of poisonous substances in environmental research. Leak searchers and rest gas analysers are also based on the principles of mass measurements. The most precise methods of mass measurements, employed in nuclear physics, are based either on the determination of the time of flight (TOF), the revolution frequency (RF), or cyclotron frequency (CF) of the ion in mass spectrometers. Nowadays, there are several scientific centers such as GSI, CERN, GANIL and ANL employing these techniques. The RF-technique is realized at GSI in the Experimental Storage Ring (ESR) (Schottky Mass Spectrometry SMS and Isochronous Mass Spectrometry IMS) for ions produced in the in-flight FRagment Separator (FRS). At GANIL, the TOF-technique is employed at the Second Separated-Sector Cyclotron (CSS2) and at the Spectrometre a Perte d'Energie du Ganil (SPEG). The CF-technique is implemented in MISTRALand in Penning traps ISOLTRAP at ISOLDE (CERN). The CF- technique is also used at SHIPTRAP at GSI and at the Canadian Penning Trap (CPT), coupled to the Argonne Tandem Linac Accelerating System (ATLAS) at ANL. In the following the relative accuracy of mass determination achieved by the above mentioned techniques and typical

  7. Design, construction and commissioning of an ortho-TOF mass spectrometer for investigations of exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, S.

    2004-07-01

    Precise atomic mass measurements are very important in many disciplines of science, e.g. in physics, biochemistry, medicine, archaeology and environmental research. In nuclear physics, mass measurements of nuclides are essential for testing nuclear mass models. From the knowledge of the mass of a nuclide the nuclear binding energy can be derived. The mass measurements provide a better knowledge of the strong interaction between the constituents in the nucleus. In nuclear astrophysics, mass measurements of exotic nuclides are of great importance for our understanding of the synthesis of the elements. In biochemistry and medicine, mass measurement methods are helpful in a structural analysis of complex biomolecules. Mass measurement techniques are widely used in the trace analysis of poisonous substances in environmental research. Leak searchers and rest gas analysers are also based on the principles of mass measurements. The most precise methods of mass measurements, employed in nuclear physics, are based either on the determination of the time of flight (TOF), the revolution frequency (RF), or cyclotron frequency (CF) of the ion in mass spectrometers. Nowadays, there are several scientific centers such as GSI, CERN, GANIL and ANL employing these techniques. The RF-technique is realized at GSI in the Experimental Storage Ring (ESR) (Schottky Mass Spectrometry SMS and Isochronous Mass Spectrometry IMS) for ions produced in the in-flight FRagment Separator (FRS). At GANIL, the TOF-technique is employed at the Second Separated-Sector Cyclotron (CSS2) and at the Spectrometre a Perte d'Energie du Ganil (SPEG). The CF-technique is implemented in MISTRALand in Penning traps ISOLTRAP at ISOLDE (CERN). The CF- technique is also used at SHIPTRAP at GSI and at the Canadian Penning Trap (CPT), coupled to the Argonne Tandem Linac Accelerating System (ATLAS) at ANL. In the following the relative accuracy of mass determination achieved by the above mentioned techniques and

  8. Precise mass measurements of exotic nuclei--the SHIPTRAP Penning trap mass spectrometer

    International Nuclear Information System (INIS)

    Herfurth, F.; Ackermann, D.; Block, M.; Dworschak, M.; Eliseev, S.; Hessberger, F.; Hofmann, S.; Kluge, H.-J.; Maero, G.; Martin, A.; Mazzocco, M.; Rauth, C.; Vorobjev, G.; Blaum, K.; Ferrer, R.; Neidherr, D.; Chaudhuri, A.; Marx, G.; Schweikhard, L.; Neumayr, J.

    2007-01-01

    The SHIPTRAP Penning trap mass spectrometer has been designed and constructed to measure the mass of short-lived, radioactive nuclei. The radioactive nuclei are produced in fusion-evaporation reactions and separated in flight with the velocity filter SHIP at GSI in Darmstadt. They are captured in a gas cell and transfered to a double Penning trap mass spectrometer. There, the cyclotron frequencies of the radioactive ions are determined and yield mass values with uncertainties ≥4.5·10 -8 . More than 50 nuclei have been investigated so far with the present overall efficiency of about 0.5 to 2%

  9. Ion Source Multiplexing on a Single Mass Spectrometer.

    Science.gov (United States)

    Kostyukevich, Yury; Nikolaev, Eugene

    2018-03-06

    We present the simple approach for the combination of different ion sources on a single mass spectrometer without any interference between them. Each ion source can be positioned as far as 1 m from the mass spectrometer; ions are transported by the means of flexible copper tubes, which are connected, to the separate inlet capillaries. Special valves enable switching channels on and off. Using this approach, we successfully combined native electrospray ionization (ESI), regular ESI, β-electrons ionization, and atmospheric pressure photoionization (APPI) of thermally desorbed vapors of petroleum on a single mass spectrometer. In addition, separate channels allow infusing internal calibration mixture or performing ion molecular reactions in one channel and using the other as a reference. Using this idea, we have developed an original sequential window acquisition of all theoretical mass spectra (SWATH MS) approach in which peptide ions are transported in different channels, one of which is heated to high temperature so that ions are thermally fragmented, and the other channel ensures the presence of nonfragmented ions in the spectrum. Also, we demonstrated the possibility to perform gas phase H/D exchange reaction in one channel and using another as reference. Use of valves makes it possible to exclude any interference between them. Thus, we have demonstrated the possibility to create a multichannel system in which ions would be transported through several inlet tubes in which different ion molecular reactions such as Paternò-Büchi, ozonation, or H/D exchange will occur. Comparison of mass spectra recorded when different channels are open will provide structural and chemical information about unknown species.

  10. Improving the Sensitivity of Mass Spectrometer using a High-Pressure Electrodynamic Ion Funnel Interface

    Science.gov (United States)

    Ibrahim, Yehia; Tang, Keqi; Tolmachev, Aleksey V.; Shvartsburg, Alexandre A.

    2006-01-01

    We report on a new electrodynamic ion funnel that operates at a pressure of 30 Torr with no loss of ion transmission. The enhanced performance compared to previous ion funnel designs optimized for pressures of funnel capacitance and increasing the RF drive frequency (1.7 MHz) and amplitude (100-170 V peak-to-peak). No degradation of ion transmission was observed for pressures from 2 - 30 Torr. The ability to operate at higher pressure enabled a new tandem ion funnel mass spectrometer (MS) interface design that can accommodate a greater gas load. When combined with a multicapillary inlet, the interface provided more efficient introduction of ions, resulting in a significant enhancement in MS sensitivity and detection limits. PMID:16839773

  11. Proton Transfer Time-of-Flight Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-03-01

    The Proton Transfer Reaction Mass Spectrometer (PTRMS) measures gas-phase compounds in ambient air and headspace samples before using chemical ionization to produce positively charged molecules, which are detected with a time-of-flight (TOF) mass spectrometer. This ionization method uses a gentle proton transfer reaction method between the molecule of interest and protonated water, or hydronium ion (H3O+), to produce limited fragmentation of the parent molecule. The ions produced are primarily positively charged with the mass of the parent ion, plus an additional proton. Ion concentration is determined by adding the number of ions counted at the molecular ion’s mass-to-charge ratio to the number of air molecules in the reaction chamber, which can be identified according to the pressure levels in the reaction chamber. The PTRMS allows many volatile organic compounds in ambient air to be detected at levels from 10–100 parts per trillion by volume (pptv). The response time is 1 to 10 seconds.

  12. Calibration of a mass spectrometer by means of the nonstationary flow method

    International Nuclear Information System (INIS)

    Gulin, L.V.; Volobuev, P.V.; Suetin, P.E.

    1976-01-01

    A linear dependence between the gas flow and signal of a mass spectrometer existing in a wide range of flux variation permits to calibrate the mass spectrometer with respect to the flow. The non-stationary flow method consists in the simultaneous recording of a mass spectrometer signal and the gas flow coming into it. A system for mass spectrometer calibration has been elaborated. The system comprises a capacity-type micromanometer, a graduating volume, a potentiometer and a frequency meter. The method described makes it possible to calibrate the mass spectrometer rather easily and quickly

  13. Characterization of Disulfide-Linked Peptides Using Tandem Mass Spectrometry Coupled with Automated Data Analysis Software

    Science.gov (United States)

    Liang, Zhidan; McGuinness, Kenneth N.; Crespo, Alejandro; Zhong, Wendy

    2018-01-01

    Disulfide bond formation is critical for maintaining structure stability and function of many peptides and proteins. Mass spectrometry has become an important tool for the elucidation of molecular connectivity. However, the interpretation of the tandem mass spectral data of disulfide-linked peptides has been a major challenge due to the lack of appropriate tools. Developing proper data analysis software is essential to quickly characterize disulfide-linked peptides. A thorough and in-depth understanding of how disulfide-linked peptides fragment in mass spectrometer is a key in developing software to interpret the tandem mass spectra of these peptides. Two model peptides with inter- and intra-chain disulfide linkages were used to study fragmentation behavior in both collisional-activated dissociation (CAD) and electron-based dissociation (ExD) experiments. Fragments generated from CAD and ExD can be categorized into three major types, which result from different S-S and C-S bond cleavage patterns. DiSulFinder is a computer algorithm that was newly developed based on the fragmentation observed in these peptides. The software is vendor neutral and capable of quickly and accurately identifying a variety of fragments generated from disulfide-linked peptides. DiSulFinder identifies peptide backbone fragments with S-S and C-S bond cleavages and, more importantly, can also identify fragments with the S-S bond still intact to aid disulfide linkage determination. With the assistance of this software, more comprehensive disulfide connectivity characterization can be achieved. [Figure not available: see fulltext.

  14. TANDEM

    Data.gov (United States)

    Federal Laboratory Consortium — The Tandem Van de Graaff facility provides researchers with beams of more than 40 different types of ions - atoms that have been stripped of their electrons. One of...

  15. Mass spectrometer for quantification and characterization of DNA damage in mammalian and human systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The instrument grant was used to purchase a Finnigan TSQ 7000 tandem quadruple mass spectrometer with electrospray and atmospheric-pressure chemical-ionization ion sources for the amount of the grant, $371,857. MIT contributed $50,000 in refurbishing costs for the laboratory in which the instrument is used. This mass spectrometer has been in operation since July, 1995 in professor Steven Tannenbaum`s Laboratory in the MIT Division of Toxicology, under the direct supervision of Dr. John S. Wishnok. Its current location is in MIT Building 56, room 747. It is in good operating condition, and is being actively used. Since the original purchase, the instrument has been upgraded by the addition of a (1) dedicated high-performance liquid chromatograph with an autosampler and (2) a nanoelectrospray ion source. The instrument has been used in a number of research projects including the identification of proteins and oligonucleotides, identification of PAH-DNA and PAH-protein adducts, quantitation of food-related carcinogens, and characterization of nitric oxide- and peroxynitrite-related DNA damage.

  16. Structural Characterisation of Acetogenins from Annona muricata by Supercritical Fluid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Laboureur, Laurent; Bonneau, Natacha; Champy, Pierre; Brunelle, Alain; Touboul, David

    2017-11-01

    Acetogenins are plant polyketides known to be cytotoxic and proposed as antitumor candidates. They are also suspected to be alimentary neurotoxins. Their occurrence as complex mixtures renders their dereplication and structural identification difficult using liquid chromatography coupled to tandem mass spectrometry and efforts are required to improve the methodology. To develop a supercritical fluid chromatography (SFC) high-resolution tandem mass spectrometry method, involving lithium post-column cationisation, for the structural characterisation of Annonaceous acetogenins in crude extracts. The seeds of Annona muricata L. were extracted with methanol. Supercritical fluid chromatography of the extract, using a 2-ethylpyridine stationary phase column, was monitored using a high-resolution quadrupole time-of-flight mass spectrometer. Lithium iodide was added post-column in the make-up solvent. For comparison, the same extract was analysed using high-pressure liquid chromatography coupled to the same mass spectrometer, with a column based on solid core particles. Sensitivity was similar for both HPLC and SFC approaches. Retention behaviour and fragmentation pathways of three different isomer groups are described. A previously unknown group of acetogenins was also evidenced for the first time. The use of SFC-MS/MS allows the reduction of the time of analysis, of environmental impact and an increase in the chromatographic resolution, compared to liquid chromatography. This new methodology enlightened a new group of acetogenins, isomers of montanacin-D. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Tandem analyzer crystals system doubles counting rate for Bonse-Hart ultra-small-angle neutron-scattering spectrometer

    International Nuclear Information System (INIS)

    Yamaguchi, Daisuke; Koizumi, Satoshi; Motokawa, Ryuhei; Kumada, Takayuki; Aizawa, Kazuya; Hashimoto, Takeji

    2006-01-01

    A new tandem analyzer crystals system was introduced on Bonse-Hart ultra-small-angle neutron-scattering spectrometer at research reactor JRR-3, Tokai, Japan. Conventional Bonse-Hart setup consumes a considerable time to measure a scattering profile of whole q range (2x10 -4 nm -1 -2 nm -1 , where q denotes magnitude of scattering vector) due to the step scan system, in which the scattered neutrons from the sample and having different q are measured step by step. To overcome this difficulty two analyzer channel-cut silicon perfect crystals were settled in tandem and each of them diffracted the scattering of different q. In consequence, a simultaneous detection at two different q positions was realized and the measurement time was reduced to half

  18. Practical Limitations of Aerosol Separation by a Tandem Differential Mobility Analyzer-Aerosol Particle Mass Analyzer.

    Science.gov (United States)

    Radney, James G; Zangmeister, Christopher D

    2016-01-01

    A cavity ring-down spectrometer and condensation particle counter were used to investigate the limitations in the separation of singly and multiply charged aerosol particles by a tandem differential mobility analyzer (DMA) and aerosol particle mass analyzer (APM). The impact of particle polydispersity and morphology was investigated using three materials: nearly-monodisperse polystyrene latex nanospheres (PSL); polydisperse, nearly-spherical ammonium sulfate (AS) and polydisperse lacey fractal soot agglomerates. PSL and AS particles were easily resolved as a function of charge. For fresh soot, the presence of multiply charged particles severely affects the isolation of the singly charged particles. In cases where the DMA-APM was unable to fully resolve the singly charged particles of interest, the peak mass deviated by up to 13 % leading to errors in the mass specific extinction cross section of over 100 %. For measurements of non-spherical particles, non-symmetrical distributions of concentration as a function of mass were a sign of the presence of multiply charged particles. Under these conditions, the effects of multiply charged particles can be reduced by using a second charge neutralizer after the DMA and prior to the APM. Dilution of the aerosol stream serves to decrease the total number concentration of particles and does not remove the contributions of multiply charged particles.

  19. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    Science.gov (United States)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  20. Linear electric field time-of-flight ion mass spectrometer

    Science.gov (United States)

    Funsten, Herbert O [Los Alamos, NM; Feldman, William C [Los Alamos, NM

    2008-06-10

    A linear electric field ion mass spectrometer having an evacuated enclosure with means for generating a linear electric field located in the evacuated enclosure and means for injecting a sample material into the linear electric field. A source of pulsed ionizing radiation injects ionizing radiation into the linear electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between ionization of atoms or molecules and arrival of an ion out of the ionized atoms or molecules at a predetermined position.

  1. Simulation of Two Dimensional Electrophoresis and Tandem Mass Spectrometry for Teaching Proteomics

    Science.gov (United States)

    Fisher, Amanda; Sekera, Emily; Payne, Jill; Craig, Paul

    2012-01-01

    In proteomics, complex mixtures of proteins are separated (usually by chromatography or electrophoresis) and identified by mass spectrometry. We have created 2DE Tandem MS, a computer program designed for use in the biochemistry, proteomics, or bioinformatics classroom. It contains two simulations--2D electrophoresis and tandem mass spectrometry.…

  2. RELAX: An ultrasensitive, resonance ionization mass spectrometer for xenon

    Science.gov (United States)

    Gilmour, J. D.; Lyon, I. C.; Johnston, W. A.; Turner, G.

    1994-03-01

    RELAX is a resonance ionization, time-of-flight mass spectrometer to which a cryogenic sample concentrator has been added. This has resulted in an increase in sensitivity by a factor greater than 100. The sample concentrator consists of a localized cold spot in the ion source, onto which the sample condenses, and a heating laser to release the condensed sample into the ionization region. The lifetime against detection of a sample atom is close to 20 min, which corresponds to a count rate of 1 cps from a sample of 1000 atoms, while the mass resolution is 300 (10% peak height). Sensitivity depends on the return time of sample atoms to the cold spot (10 s) and the fraction of these atoms subsequently ionized (˜1%). The minimum sample size which can be measured is limited only by blank, which is currently 2×10-15 cc STP total xenon and isotopically atmospheric (this can be attributed to the large aliquots of xenon admitted to the instrument during development, and so may be expected to decrease with time). The precision of abundance measurements has been improved by the incorporation of pulse height discrimination and pulse counting detection for the less abundant isotopes. The design, construction, and operation of the spectrometer in its new configuration are described with particular attention to abundance extraction. The effects of the sample concentrator on ionization efficiency and discrimination are discussed in detail, as are interferences from nonresonantly ionized hydrocarbons and the means of accounting for them.

  3. Characterization of cationic glycoporphyrins by electrospray tandem mass spectrometry.

    Science.gov (United States)

    Silva, Eduarda M P; Serra, Vanda Vaz; Ribeiro, Anderson O; Tomé, João P C; Domingues, Pedro; Faustino, M Amparo F; Neves, M Graça P M S; Tomé, Augusto C; Cavaleiro, José A S; Ferrer-Correia, António J; Iamamoto, Yassuko; Domingues, M Rosário M

    2006-01-01

    Novel cationic porphyrin derivatives having a galactose or a bis(isopropylidene)galactose unit linked directly to a pyridine or to an aminophenyl group were characterized by electrospray tandem mass spectrometry (ESI-MS/MS). The electrospray mass spectra (ESI-MS) show the M(+) ions, since these porphyrins are already monocharged in solution. The fragmentation of these ions under ESI-MS/MS conditions was studied and it was found that elimination of the sugar residue as a radical (-163 or -243 Da) is a common fragmentation pathway. Loss of the sugar unit as a neutral fragment (-162 or -242 Da) and cross-ring fragmentations typical of glyco-derivatives are also observed for the pyridinium glycoporphyrins, but they are absent in the case of ammonium glycoporphyrins. The cationic beta-pyridiniumvinyl porphyrins show an atypical fragmentation due to the cleavage of the C(5)-C(6) bond of the sugar unit. Overall, the different patterns of fragmentation observed in the ESI-MS/MS spectra of the sugar pyridinium porphyrins and of the sugar ammonium phenyl porphyrins can give important information about the type of spacer between the porphyrin and the sugar unit. Copyright (c) 2006 John Wiley & Sons, Ltd.

  4. Screening of carnitine and biotin deficiencies on tandem mass spectrometry.

    Science.gov (United States)

    Hagiwara, Shin-Ichiro; Kubota, Mitsuru; Nambu, Ryusuke; Kagimoto, Seiichi

    2017-04-01

    It is important to assess pediatric patients for nutritional deficiency when they are receiving specific interventions, such as enteral feeding. We focused on measurement of C0 and 3-hydroxyisovalerylcarnitine (C5-OH) with tandem mass spectrometry (MS/MS), which is performed as part of the newborn mass screening. The purpose of this study was to investigate the usefulness of MS/MS for screening carnitine and biotin deficiencies. Forty-two children (24 boys, 18 girls) were enrolled between December 2013 and December 2015. Blood tests, including measurement of serum free carnitine via the enzyme cycling method, and acylcarnitine analysis on MS/MS of dried blood spot (DBS), were performed for the evaluation of nutrition status. Median patient age was 2 years (range, 2 months-14 years). Mean serum free carnitine was 41.8 ± 19.2 μmol/L. In six of the 42 patients, serum free carnitine was 1.00 nmol/L. Therapy-resistant eczema was improved by treatment with additional biotin and a non-hydrolyzed formula. C0 and C5-OH, measured on MS/MS of DBS, were useful for screening carnitine and biotin deficiencies. © 2016 Japan Pediatric Society.

  5. Rapid tryptic mapping using enzymatically active mass spectrometer probe tips

    Energy Technology Data Exchange (ETDEWEB)

    Dogruel, D.; Williams, P.; Nelson, R.W. [Arizona State Univ., Tempe, AZ (United States)

    1995-12-01

    A method has been developed for rapid, sensitive, and accurate tryptic mapping of polypeptides using matrix-assisted laser desorption/ionization time-of-flight mass analysis. The technique utilizes mass spectrometer probe tips which have been activated through the covalent immobilization of trypsin. The enzymatically active probe tips were used for the tryptic mapping of chicken egg lysozyme and the results compared with those obtained using either free trypsin or agarose-immobilized trypsin. A significant increase in the overall sensitivity of the process was observed using the active probe tips, as well as the production of more characteristic proteolytic fragments and the elimination of background signals due to the autolysis of the trypsin. Further, probe tip digestions were found to be rapid and convenient. 19 refs., 6 figs., 2 tabs.

  6. Sensitive liquid chromatography-tandem mass spectrometry method for quantification of hydrochlorothiazide in human plasma.

    Science.gov (United States)

    Ramakrishna, N V S; Vishwottam, K N; Manoj, S; Koteshwara, M; Wishu, S; Varma, D P

    2005-12-01

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of hydrochlorothiazide (I), a common diuretic and anti-hypertensive agent. The analyte and internal standard, tamsulosin (II) were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v) using a Glas-Col Multi-Pulse Vortexer. The chromatographic separation was performed on a reversed-phase column (Waters symmetry C18) with a mobile phase of 10 mm ammonium acetate-methanol (15:85, v/v). The protonated analyte was quantitated in negative ionization by multiple reaction monitoring with a mass spectrometer. The mass transitions m/z 296.1 solidus in circle 205.0 and m/z 407.2 solidus in circle 184.9 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.5-200 ng/mL for hydrochlorothiazide in human plasma. The lower limit of quantitation was 500 pg/mL, with a relative standard deviation of less than 9%. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.5 min for each sample made it possible to analyze a throughput of more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. (c) 2005 John Wiley & Sons, Ltd.

  7. Real-Time Food Authentication Using a Miniature Mass Spectrometer.

    Science.gov (United States)

    Gerbig, Stefanie; Neese, Stephan; Penner, Alexander; Spengler, Bernhard; Schulz, Sabine

    2017-10-17

    Food adulteration is a threat to public health and the economy. In order to determine food adulteration efficiently, rapid and easy-to-use on-site analytical methods are needed. In this study, a miniaturized mass spectrometer in combination with three ambient ionization methods was used for food authentication. The chemical fingerprints of three milk types, five fish species, and two coffee types were measured using electrospray ionization, desorption electrospray ionization, and low temperature plasma ionization. Minimum sample preparation was needed for the analysis of liquid and solid food samples. Mass spectrometric data was processed using the laboratory-built software MS food classifier, which allows for the definition of specific food profiles from reference data sets using multivariate statistical methods and the subsequent classification of unknown data. Applicability of the obtained mass spectrometric fingerprints for food authentication was evaluated using different data processing methods, leave-10%-out cross-validation, and real-time classification of new data. Classification accuracy of 100% was achieved for the differentiation of milk types and fish species, and a classification accuracy of 96.4% was achieved for coffee types in cross-validation experiments. Measurement of two milk mixtures yielded correct classification of >94%. For real-time classification, the accuracies were comparable. Functionality of the software program and its performance is described. Processing time for a reference data set and a newly acquired spectrum was found to be 12 s and 2 s, respectively. These proof-of-principle experiments show that the combination of a miniaturized mass spectrometer, ambient ionization, and statistical analysis is suitable for on-site real-time food authentication.

  8. The accelerator mass spectrometer facility at the Institute of Physics, Bhubaneswar (MUDRA, MUltiDisciplinary Research Accelerator)

    International Nuclear Information System (INIS)

    Mahapatra, D.P.; Gopalan, K.; Somayajulu, B.L.K.

    1998-01-01

    This article reports on the augmentation of the 3 MV tandem accelerator in the Institute of Physics, Bhubaneswar into a state-of-the-art accelerator mass spectrometer supported jointly by the Department of Atomic Energy, Department of Space, Department of Science and Technology and Council of Scientific and Industrial Research. This national facility, first of its kind and expected to be operational by the end of 1998, will be available part time for ultrasensitive detection of the radioisotopes 14 C and 10 Be for a variety of applications in earth and ocean sciences, environmental chemistry, archaeology and biomedicine. (author)

  9. Quantitative determination of carbonaceous particle mixing state in Paris using single-particle mass spectrometer and aerosol mass spectrometer measurements

    Directory of Open Access Journals (Sweden)

    R. M. Healy

    2013-09-01

    Full Text Available Single-particle mixing state information can be a powerful tool for assessing the relative impact of local and regional sources of ambient particulate matter in urban environments. However, quantitative mixing state data are challenging to obtain using single-particle mass spectrometers. In this study, the quantitative chemical composition of carbonaceous single particles has been determined using an aerosol time-of-flight mass spectrometer (ATOFMS as part of the MEGAPOLI 2010 winter campaign in Paris, France. Relative peak areas of marker ions for elemental carbon (EC, organic aerosol (OA, ammonium, nitrate, sulfate and potassium were compared with concurrent measurements from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS, a thermal–optical OCEC analyser and a particle into liquid sampler coupled with ion chromatography (PILS-IC. ATOFMS-derived estimated mass concentrations reproduced the variability of these species well (R2 = 0.67–0.78, and 10 discrete mixing states for carbonaceous particles were identified and quantified. The chemical mixing state of HR-ToF-AMS organic aerosol factors, resolved using positive matrix factorisation, was also investigated through comparison with the ATOFMS dataset. The results indicate that hydrocarbon-like OA (HOA detected in Paris is associated with two EC-rich mixing states which differ in their relative sulfate content, while fresh biomass burning OA (BBOA is associated with two mixing states which differ significantly in their OA / EC ratios. Aged biomass burning OA (OOA2-BBOA was found to be significantly internally mixed with nitrate, while secondary, oxidised OA (OOA was associated with five particle mixing states, each exhibiting different relative secondary inorganic ion content. Externally mixed secondary organic aerosol was not observed. These findings demonstrate the range of primary and secondary organic aerosol mixing states in Paris. Examination of the

  10. Atom-probe field-ion-microscope mass spectrometer

    International Nuclear Information System (INIS)

    Nishikawa, Osamu

    1983-01-01

    The titled analyzer, called simply atom-probe, has been developed by combining a field ion microscope (FIM) and a mass spectrometer, and is divided into the time-of-flight type, magnetic sector type, and quadrupole type depending on the types of mass spectrometers. In this paper, the author first describes on the principle and construction of a high resolution, time-of-flight atom-probe developed and fabricated in his laboratory. The feature of the atom-probe lies in the analysis of atoms and molecules in hyper-fine structure region one by one utilizing the high resolution of FIM. It also has the advantages of directly determining the composition by a ratio of the numbers of respective ions because of a constant detection sensitivity regardless of mass numbers, of the resolution as high as single atom layer in depth direction, and of detecting the positional relationship among detected ions by the order of detection in a sample. To determine the composition in a hyperfine structure region, the limited small number of atoms and molecules in the region must be identified distinctly one by one. In the analyzed result of Ni-silicide formed by heating Si evaporated on a Ni tip at 1000 K for 5 minutes, each isotope was not only clearly separated, but also their abundance ratio was very close to the natural abundance ratio. The second half of the paper reports on the analysis of TiC promising for a cold cathode material, adsorption of CO and alcohol, and the composition and structure of silicides, as a few application examples. (Wakatsuki, Y.)

  11. Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers

    Science.gov (United States)

    Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.

    2011-01-01

    This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system.When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.

  12. [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.

  13. Quantitative analysis of mitragynine in human urine by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lu, Shijun; Tran, Buu N; Nelsen, Jamie L; Aldous, Kenneth M

    2009-08-15

    Mitragynine is the primary active alkaloid extracted from the leaves of Mitragyna speciosa Korth, a plant that originates in South-East Asia and is commonly known as kratom in Thailand. Kratom has been used for many centuries for their medicinal and psychoactive qualities, which are comparable to that of opiate-based drugs. Kratom abuse can lead to a detectable content of mitragynine residue in urine. Ultra trace amount of mitragynine in human urine was determined by a high performance liquid chromatography coupled to an electrospray tandem mass spectrometry (HPLC-ESI/MS/MS). Mitragynine was extracted by methyl t-butyl ether (MTBE) and separated on a HILIC column. The ESI/MS/MS was accomplished using a triple quadrupole mass spectrometer in positive ion detection and multiple reactions monitoring (MRM) mode. Ajmalicine, a mitragynine's structure analog was selected as internal standard (IS) for method development. Quality control (QC) performed at three levels 0.1, 1 and 5 ng/ml of mitragynine in urine gave mean recoveries of 90, 109, and 98% with average relative standard deviation of 22, 12 and 16%, respectively. The regression linearity of mitragynine calibration ranged from 0.01 to 5.0 ng/ml was achieved with correlation coefficient greater than 0.995. A detection limit of 0.02 ng/ml and high precision data within-day and between days analysis were obtained.

  14. The role of vacuum in the quality of TOF mass spectrometer

    International Nuclear Information System (INIS)

    Bhowmick, A.; Gadkari, S.C.; Yakhmi, J.V.; Sahni, V.C.

    2005-01-01

    The art in the designing of time-of-flight mass spectrometers has come across a long course of development. The present day state-of-the-art machines are essentially the outcome of knowledge from the advances in different other areas of technology. This article discusses exclusively the role of UHV to enhance the quality of the TOF mass spectrometers and its application to the recently developed high resolution TOF mass spectrometer at TP and PED-BARC. (author)

  15. Pivotal Role of Computers and Software in Mass Spectrometry - SEQUEST and 20 Years of Tandem MS Database Searching

    Science.gov (United States)

    Yates, John R.

    2015-11-01

    Advances in computer technology and software have driven developments in mass spectrometry over the last 50 years. Computers and software have been impactful in three areas: the automation of difficult calculations to aid interpretation, the collection of data and control of instruments, and data interpretation. As the power of computers has grown, so too has the utility and impact on mass spectrometers and their capabilities. This has been particularly evident in the use of tandem mass spectrometry data to search protein and nucleotide sequence databases to identify peptide and protein sequences. This capability has driven the development of many new approaches to study biological systems, including the use of "bottom-up shotgun proteomics" to directly analyze protein mixtures.

  16. Pivotal role of computers and software in mass spectrometry - SEQUEST and 20 years of tandem MS database searching.

    Science.gov (United States)

    Yates, John R

    2015-11-01

    Advances in computer technology and software have driven developments in mass spectrometry over the last 50 years. Computers and software have been impactful in three areas: the automation of difficult calculations to aid interpretation, the collection of data and control of instruments, and data interpretation. As the power of computers has grown, so too has the utility and impact on mass spectrometers and their capabilities. This has been particularly evident in the use of tandem mass spectrometry data to search protein and nucleotide sequence databases to identify peptide and protein sequences. This capability has driven the development of many new approaches to study biological systems, including the use of "bottom-up shotgun proteomics" to directly analyze protein mixtures. Graphical Abstract ᅟ.

  17. A "Brick Mass Spectrometer" Driven by a Sinusoidal Frequency Scanning Technique.

    Science.gov (United States)

    Jiang, Ting; Zhang, Hongjia; Tang, Yang; Zhai, Yanbing; Xu, Wei; Xu, Hualei; Zhao, Xinying; Li, Dayu; Xu, Wei

    2017-05-16

    In this work, a "brick" size miniature mass spectrometer (28 cm × 21 cm × 16 cm) was developed and characterized, which was enabled by the development of a new frequency scanning technique. Different from the conventional voltage scanning method or the digital waveforms used on a digital ion trap, a sinusoidal frequency scanning technique was developed to drive the linear ion trap of the brick mass spectrometer (BMS). Both an in-vacuum plasma ionization source and an electrospray ionization source were coupled with this BMS for the analyses of volatile and nonvolatile samples. Stability diagram, sensitivity, mass resolution, and mass range of the BMS were explored. This new frequency scanning technique could not only reduce the size and power consumption of a miniature mass spectrometer but also improve its analytical performances, especially in terms of mass range and resolution. Analogous to the development of cell phones, this BMS would be an important step from "brick" mass spectrometer to "cell" mass spectrometer.

  18. Diagnostics aid for mass spectrometer trouble-shooting

    International Nuclear Information System (INIS)

    Filby, E.E.; Rankin, R.A.; Webb, G.W.

    1987-01-01

    The MS Expert system provides problem diagnostics for instruments used in the Mass Spectrometry Laboratory (MSL). The most critical results generated on these mass spectrometers are the uranium concentration and isotopic content data used for process control and materials accountability at the Idaho General Processing Plant. The two purposes of the system are: (1) to minimize instrument downtime and thereby provide the best possible support to the Plant, and (2) to improve long-term data quality. This system combines the knowledge of several experts on mass spectrometry to provide a diagnostic tool, and can make these skills available on a more timely basis. It integrates code written in the Pascal language with a knowledge base entered into a commercial expert system shell. The user performs some preliminary status checks, and then selects from among several broad diagnostic categories. These initial steps provide input to the rule base. The overall analysis provides the user with a set of possible solutions to the observed problems, graded as to their probabilities. Besides the trouble-shooting benefits expected from this system, it also provides structured diagnostic training for lab personnel. In addition, development of the system knowledge base has already produced a better understanding of instrument behavior. Two key findings are that a good user interface is necessary for full acceptance of the tool, and, a development system should include standard programming capabilities as well as the expert system shell

  19. Diagnostics aid for mass spectrometer trouble-shooting

    International Nuclear Information System (INIS)

    Filby, E.E.; Rankin, R.A.; Webb, G.W.

    1987-01-01

    The ''MS Expert'' system provides problem diagnostics for instruments used in the Mass Spectrometry Laboratory (MSL). The most critical results generated on these mass spectrometers are the uranium concentration and isotopic content data used for process control and materials accountability at the Idaho Chemical Processing Plant. The two purposes of the system are: (1) to minimize instrument downtime and thereby provide the best possible support to the Plant, and (2) to improve long-term data quality. This system combines the knowledge of several experts on mass spectrometry to provide a diagnostic tool, and can make these skills avilable on a more timely basis. It integrates code written in the Pascal language with a knowledge base entered into a commercial expert system ''shell.'' The user performs some preliminary status checks, and then selects from among several broad diagnostic categories. These initial steps provide input to the rule base. The overall analysis provides the user with a set of possible solutions to the observed problems, graded as to their probabilities. Besides the trouble-shooting benefits expected from this system, it will also provide structures diagnostic training for lab personnel. In addition, development of the system knowledge base has already produced a better understanding of instrument behavior. Two key findings are that a good user interface is necessary for full acceptance of the tool, and a development system should include standard programming capabilities as well as the expert system shell. 22 refs., 5 figs

  20. Multiple-ion-beam time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Rohrbacher, Andreas; Continetti, Robert E.

    2001-01-01

    An innovative approach to increase the throughput of mass spectrometric analyses using a multiple-ion-beam mass spectrometer is described. Two sample spots were applied onto a laser desorption/ionization target and each spot was simultaneously irradiated by a beam of quadrupled Nd:YLF laser radiation (261.75 nm) to produce ions by laser-desorption ionization. Acceleration of the ions in an electric field created parallel ion beams that were focused by two parallel einzel lens systems. After a flight path of 2.34 m, the ions were detected with a microchannel plate-phosphor screen assembly coupled with a charge coupled device camera that showed two resolved ion beams. Time-of-flight mass spectra were also obtained with this detector. Experiments were performed using both metal atom cations (Ti + and Cr + ) produced by laser desorption/ionization and the molecular ions of two different proteins (myoglobin and lysozyme), created by matrix assisted laser desorption/ionization using an excess of nicotinic acid as matrix

  1. Multiple-ion-beam time-of-flight mass spectrometer

    Science.gov (United States)

    Rohrbacher, Andreas; Continetti, Robert E.

    2001-08-01

    An innovative approach to increase the throughput of mass spectrometric analyses using a multiple-ion-beam mass spectrometer is described. Two sample spots were applied onto a laser desorption/ionization target and each spot was simultaneously irradiated by a beam of quadrupled Nd:YLF laser radiation (261.75 nm) to produce ions by laser-desorption ionization. Acceleration of the ions in an electric field created parallel ion beams that were focused by two parallel einzel lens systems. After a flight path of 2.34 m, the ions were detected with a microchannel plate-phosphor screen assembly coupled with a charge coupled device camera that showed two resolved ion beams. Time-of-flight mass spectra were also obtained with this detector. Experiments were performed using both metal atom cations (Ti+ and Cr+) produced by laser desorption/ionization and the molecular ions of two different proteins (myoglobin and lysozyme), created by matrix assisted laser desorption/ionization using an excess of nicotinic acid as matrix.

  2. Targeted Proteomic Quantification on Quadrupole-Orbitrap Mass Spectrometer*

    Science.gov (United States)

    Gallien, Sebastien; Duriez, Elodie; Crone, Catharina; Kellmann, Markus; Moehring, Thomas; Domon, Bruno

    2012-01-01

    There is an immediate need for improved methods to systematically and precisely quantify large sets of peptides in complex biological samples. To date protein quantification in biological samples has been routinely performed on triple quadrupole instruments operated in selected reaction monitoring mode (SRM), and two major challenges remain. Firstly, the number of peptides to be included in one survey experiment needs to be increased to routinely reach several hundreds, and secondly, the degree of selectivity should be improved so as to reliably discriminate the targeted analytes from background interferences. High resolution and accurate mass (HR/AM) analysis on the recently developed Q-Exactive mass spectrometer can potentially address these issues. This instrument presents a unique configuration: it is constituted of an orbitrap mass analyzer equipped with a quadrupole mass filter as the front-end for precursor ion mass selection. This configuration enables new quantitative methods based on HR/AM measurements, including targeted analysis in MS mode (single ion monitoring) and in MS/MS mode (parallel reaction monitoring). The ability of the quadrupole to select a restricted m/z range allows one to overcome the dynamic range limitations associated with trapping devices, and the MS/MS mode provides an additional stage of selectivity. When applied to targeted protein quantification in urine samples and benchmarked with the reference SRM technique, the quadrupole-orbitrap instrument exhibits similar or better performance in terms of selectivity, dynamic range, and sensitivity. This high performance is further enhanced by leveraging the multiplexing capability of the instrument to design novel acquisition methods and apply them to large targeted proteomic studies for the first time, as demonstrated on 770 tryptic yeast peptides analyzed in one 60-min experiment. The increased quality of quadrupole-orbitrap data has the potential to improve existing protein

  3. [Determination of congo red in beef by high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry].

    Science.gov (United States)

    Lin, Hui; Xu, Chunxiang; Yan, Chunrong; Zhang, Zheng; Wang, Suilou

    2013-09-01

    A method was developed for the determination of congo red in beef. The analyte was identified by high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry (LC-QTOF MS) and quantitatively determined by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry. After purified by liquid-liquid extraction, the congo red in the beef sample was separated on an Agilent ZORBAX Eclipse Plus C18 Rapid Resolution HD UPLC column (50 mm x 2.1 mm, 1.8 microm) HPLC , using 95% (volume percentage) methanol as the mobile phase at 0.2 mL/min. The detection was performed on an AB 4000 + triple quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operated in negative ion mode and multiple-reaction monitoring (MRM) mode. The results showed that the linear range of congo red mass concentration was 0.03 - 1 mg/L with the correlation coefficient of 0.999 8. The method had a good precision with the RSDs lower than 5% and the recoveries ranging from 88% to 91%. The limit of detection (LOD) of congo red was 0.01 mg/L. With good reproducibility, the method is simple, fast and effective for the determination of the illegally added congo red in beef and other meat products.

  4. Planetary In Situ Sample Analysis with Tandem Two-Step Laser Mass Spectrometry

    Science.gov (United States)

    Brinckerhoff, W. B.; Getty, S. A.; Cornish, T. J.; Ecelberger, S. A.; Li, X.; Merrill Floyd, M. A.; Arevalo, R.; Elsila, J.; Callahan, M. P.

    2012-12-01

    Future surface missions to comets and outer solar system satellites such as Europa, Enceladus, and Titan will benefit strongly from investigations that can detect a wide range of organics in complex sample mixtures and ices, as well as determine the structure of selected molecules, to provide insight into their origin and evolution. At the same time, such missions are likely to be among the most highly constrained in mass and power resources, particularly those flown within the tightly focused Discovery and New Frontiers programs. Techniques requiring minimal or no sample manipulation or preparation may be needed to reduce complexity. Pulsed laser-based mass spectrometry may satisfy such requirements, with total instrument masses potentially less than 5 kg, particularly where analysis of higher-molecular weight, nonvolatile species is a priority objective. Prototype flight-compatible mass spectrometers under active development in our lab are based on direct ultraviolet Nd:YAG laser desorption and ionization (LDI) of solid samples under high vacuum. Prompt ions from a single few ns-duration laser pulse are accelerated into a compact time-of-flight mass spectrometer (TOF-MS). Both inorganic species including elements and oxides such as M_xO_y (M = Mg, Al, Cl, Ca, Fe; x, y = 1-4) from the mineral matrix as well as organics with molecular weights up to several kDa are readily detected over a range of laser intensities. To improve our ability to distinguish among peaks and patterns in the often-complex LDI spectra obtained from natural samples, we have recently begun systematically testing several critical instrument enhancements. First, by moving the common voltage bias of the ion flight tube and detector to a common negative potential, we are able to switch between positive and negative ion detection modes with only electrostatic switching. Inter-comparison of cation and anion spectra can provide highly diagnostic information on both inorganic (e.g., Na+ and K+ vs. Cl

  5. Early synthetic dyes--a challenge for tandem mass spectrometry.

    Science.gov (United States)

    Lech, Katarzyna; Wilicka, Ewa; Witowska-Jarosz, Janina; Jarosz, Maciej

    2013-02-01

    The present study concerns identification of early yellow synthetic dyes from silk fibers taken from the 1930 spring color palette of the Lyon Dyers' Guild (La Chambre Syndicale des Teinturiers). The identification was based mainly on the electrospray ionization tandem mass spectrometry spectra obtained in the positive and negative ion modes. This technique was combined with high-performance liquid chromatography, which enabled separation of the analyzed compounds. Spectra registered for each of the examined synthetic dye allowed identification of their lost fragments. Moreover, isotopic profiles and exact measurements of m/z by using time of flight analyzer made possible to evaluate their elemental composition. In consequence, all obtained data, including UV-vis spectra, allowed to reconstruct molecular structures of examined colorants. Due to the lack of standards, the identification of the dyes was based only on the registration of fragment and quasi-molecular ions, what is rather uncommon in such analysis and means groping for the correct structure rather than proving signal identity by comparison with standards. Depending on substituents present in dye molecules, the lost fragments of the examined compounds involved SO(2), NO(•), NO(2)(•), CH(4), C(2)H(4), C(2)H(5)(•), C(2)H(6), CH(2)=N-CH(3), (CH(3))(2)NH, CH(2)= NH, CH(3)-NH(2), as well as CO and CO(2). The performed study led to identification of various colorants: rhodamine 6 G, rhodamine B, malachite green, quinoline yellow, picric acid and acetoquinone yellow 5JZ. Copyright © 2013 John Wiley & Sons, Ltd.

  6. Tandem Mass Spectrometry of Modified and Platinated Oligoribonucleotides

    Science.gov (United States)

    Nyakas, Adrien; Stucki, Silvan R.; Schürch, Stefan

    2011-05-01

    Therapeutic approaches for treatment of various diseases aim at the interruption of transcription or translation. Modified oligonucleotides, such as 2'- O-methyl- and methylphosphonate-derivatives, exhibit high resistance against cellular nucleases, thus rendering application for, e.g., antigene or antisense purposes possible. Other approaches are based on administration of cross-linking agents, such as cis-diamminedichloroplatinum(II) (cisplatin, DDP), which is still the most widely used anticancer drug worldwide. Due to the formation of 1,2-intrastrand cross links at adjacent guanines, replication of the double-strand is disturbed, thus resulting in significant cytotoxicity. Evidence for the gas-phase dissociation mechanism of platinated RNA is given, based on nano-electrospray ionization high-resolution multistage tandem mass spectrometry (MS n ). Confirmation was found by investigating the fragmentation pattern of platinated and unplatinated 2'-methoxy oligoribonucleotide hexamers and their corresponding methylphosphonate derivatives. Platinated 2'-methoxy oligoribonucleotides exhibit a similar gas-phase dissociation behavior as the corresponding DNA and RNA sequences, with the 3'-C-O bond adjacent to the vicinal guanines being cleaved preferentially, leading to wx-ion formation. By examination of the corresponding platinated methylphosphonate derivatives of the 2'-methoxy oligoribonucleotides, the key role of the negatively charged phosphate oxygen atoms in direct proximity to the guanines was proven. The significant alteration of fragmentation due to platination is demonstrated by comparison of the fragment ion patterns of unplatinated and platinated 2'- O-methyl- and 2'- O-methyl methylphosphonate oligoribonucleotides, and the results obtained by H/D exchange experiments.

  7. Product ion mass spectra of amphetamine-type substances, designer analogues, and ketamine using ultra-performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Apollonio, Luigino G; Whittall, Ian R; Pianca, Dennis J; Kyd, Jennelle M; Maher, William A

    2006-01-01

    This paper describes the application of ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) technology to separate and identify amphetamine-type substances (amphetamine, methamphetamine), common and novel designer analogues (MDA, MDMA, PMA, 4-MTA, MBDB), and ketamine using Acquity UPLC/Micromass Quattro Micro API mass spectrometer instrumentation (Waters Corporation, USA). From injection of drug reference standards, it was demonstrated that these compounds can be identified by product ion mass spectra in less than 4 min total analysis time, indicating that the technological advancements associated with UPLC/MS/MS allow it to serve as a powerful analytical tool for high-throughput testing. In addition to demonstrating the separation and response of these drug compounds under the stated UPLC/MS/MS conditions, we believe the acquired product ion spectra will be a beneficial reference to laboratories interested in incorporating the use of this technology in the routine analysis of drugs of abuse.

  8. Using a fully automatic mass spectrometer for fissile material control

    International Nuclear Information System (INIS)

    Wilhelmi, M.

    1978-08-01

    The demand for higher accuracy and a shorter delay in the analysis together with better objectifiability and data security needed in safeguards, lead to the automation of a mass spectrometer. Starting with a continuous feeding of samples via a high vacuum lock and including the subsequent heating, focussing and scanning of the samples as well as the final evaluation of the source data (taking alpha spectrometry and the weights required for the isotope dilution technique into account), the mass spectrometric procedure was completely automated. For this purpose, a serial CH-5 instrument of varian mat was modified to be operated by a varian 620/I computer. A newly developed three chamber high vacuum lock was attached to this system and the final evaluation is made with an IBM 370. The system has been used in operation for the isotope analysis of U, Pu and Nd for one year. Major breakdowns of the hardware did not occur, however, the computer programmes had to be steadily improved according to the changing characteristics of the samples. Compared to manual operation, the automat is superior in its throughput and speed of analysing series of similar samples. The automatic procedure objectifies the analysis and the complete evaluation ensures a better data security. (Orig./HP). (author)

  9. Measurement of tamsulosin in human serum by liquid chromatography–tandem mass spectrometry☆

    Science.gov (United States)

    Upreti, Rita; Homer, Natalie Z.M.; Naredo, Gregorio; Cobice, Diego F.; Hughes, Katherine A.; Stewart, Laurence H.; Walker, Brian R.; Andrew, Ruth

    2013-01-01

    A simple, sensitive and robust method to extract tamsulosin from human serum, and quantify by liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed and validated and is applicable as a measure of compliance in clinical research. Tamsulosin was extracted from human serum (100 μL) via liquid–liquid extraction with methyl tert-butyl ether (2 mL) following dilution with 0.1 M ammonium hydroxide (100 μL), achieving 99.9% analyte recovery. Internal standard, d9-finasteride, was synthesised in-house. Analyte and internal standard were separated on an Ascentis® Express C18 (100 mm × 3 mm, 2.7 μm) column using a gradient elution with mobile phases methanol and 2 mM aqueous ammonium acetate (5:95, v/v). Total run-time was 6 min. Tamsulosin was quantified using a triple quadrupole mass spectrometer operated in multi-reaction-monitoring (MRM) mode using positive electrospray ionisation. Mass transitions monitored for quantitation were: tamsulosin m/z 409 → 228 and d9-finasteride m/z 382 → 318, with the structural formulae of ions confirmed by Fourier transform ion cyclotron resonance mass spectrometry (within 10 ppm). The limit of quantitation was 0.2 ng/mL, and the method was validated in the linear range 0.2–50 ng/mL with acceptable inter- and intra-assay precision and accuracy and stability suitable for routine laboratory practice. The method was successfully applied to samples taken from research volunteers in a clinical study of benign prostatic hyperplasia. PMID:23743242

  10. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Science.gov (United States)

    Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

    2016-03-01

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  11. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, M., E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Håkansson, K.; Possnert, G. [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Wacker, L.; Synal, H.-A. [Ion Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 (Switzerland)

    2016-03-15

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV {sup 14,13,12}C{sup 3+} ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the {sup 14}C/{sup 12}C and the {sup 13}C/{sup 12}C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  12. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dron

    2010-08-01

    Full Text Available The functional group composition of various organic aerosols (OA is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCI-MS/MS. The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R´ respectively and precursor ion (nitro groups, R-NO2 scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular to 13.5% (o-xylene photooxidation of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France during a strong winter pollution event. The three functional groups under study account for a total functionalisation rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60

  13. Functional group composition of ambient and source organic aerosols determined by tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dron, J.; El Haddad, I.; Temime-Roussel, B.; Wortham, H.; Marchand, N. [Univ Aix Marseille, CNRS, Lab Chim Provence, Equipe Instrumentat and React Atmospher, UMR 6264, F-13331 Marseille 3 (France); Jaffrezo, J.L. [Univ Grenoble 1, CNRS, UMR 5183, Lab Glaciol and Geophys Environm, F-38402 St Martin Dheres (France)

    2010-07-01

    The functional group composition of various organic aerosols (OA) is investigated using a recently developed analytical approach based on atmospheric pressure chemical ionisation-tandem mass spectrometry (APCIMS/MS). The determinations of three functional groups contents are performed quantitatively by neutral loss (carboxylic and carbonyl groups, R-COOH and R-CO-R' respectively) and precursor ion (nitro groups, R-NO{sub 2}) scanning modes of a tandem mass spectrometer. Major organic aerosol sources are studied: vehicular emission and wood combustion for primary aerosol sources; and a secondary organic aerosol (SOA) produced through photooxidation of o-xylene. The results reveal significant differences in the functional group contents of these source aerosols. The laboratory generated SOA is dominated by carbonyls while carboxylics are preponderate in the wood combustion particles. On the other hand, vehicular emissions are characterised by a strong nitro content. The total amount of the three functional groups accounts for 1.7% (vehicular) to 13.5% (o-xylene photooxidation) of the organic carbon. Diagnostic functional group ratios are then used to tentatively discriminate sources of particles collected in an urban background environment located in an Alpine valley (Chamonix, France) during a strong winter pollution event. The three functional groups under study account for a total functionalization rate of 2.2 to 3.8% of the organic carbon in this ambient aerosol, which is also dominated by carboxylic moieties. In this particular case study of a deep alpine valley during winter, we show that the nitro- and carbonyl-to-carboxylic diagnostic ratios can be a useful tool to discriminate sources. In these conditions, the total OA concentrations are highly dominated by wood combustion OA. This result is confirmed by an organic markers source apportionment approach which assess a wood burning organic carbon contribution of about 60%. Finally, examples of functional

  14. 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Greatly Expands Mass Spectrometry Toolbox

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Jared B.; Lin, Tzu-Yung; Leach, Franklin E.; Tolmachev, Aleksey V.; Tolić, Nikola; Robinson, Errol W.; Koppenaal, David W.; Paša-Tolić, Ljiljana

    2016-10-12

    We provide the initial performance evaluation of a 21 Tesla Fourier transform ion cyclotron resonance mass spectrometer operating at the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory. The spectrometer constructed for the 21T system employs a commercial dual linear ion trap mass spectrometer coupled to a FTICR spectrometer designed and built in-house. Performance gains from moving to higher magnetic field strength are exemplified by the measurement of peptide isotopic fine structure, complex natural organic matter mixtures, and large proteins. Accurate determination of isotopic fine structure was demonstrated for doubly charged substance P with minimal spectral averaging, and 8,158 molecular formulas assigned to Suwannee River Fulvic Acid standard with RMS error of 10 ppb. We also demonstrated superior performance for intact proteins; namely, broadband isotopic resolution of the entire charge state distribution of apotransferrin (78 kDa) and facile isotopic resolution of monoclonal antibody under a variety of acquisition parameters (e.g. 6 s time-domains with absorption mode processing yielded resolution of approximately 1M at m/z =2,700).

  15. Capillary-HPLC with tandem mass spectrometry in analysis of alkaloid dyestuffs - a new approach.

    Science.gov (United States)

    Dąbrowski, Damian; Lech, Katarzyna; Jarosz, Maciej

    2017-11-10

    Development of the identification method of alkaloid compounds in Amur cork tree as well as not examined so far Oregon grape and European Barberry shrubs are presented. The novel approach to separation of alkaloids was applied and the capillary-high-performance liquid chromatography (capillary-HPLC) system was used, which has never previously been reported for alkaloid-based dyestuffs analysis. Its optimization was conducted with three different stationary phases (unmodified octadecylsilane-bonded silica, octadecylsilane modified with polar groups and silica-bonded pentaflourophenyls) as well as with different solvent buffers. Detection of the isolated compounds was carried out using diode-array detector (DAD) and tandem mass spectrometer with electrospray ionization (ESI MS/MS). The working parameters of ESI were optimized, whereas the multiple reactions monitoring (MRM) parameters of MS/MS detection were chosen based on the product ion spectra of the quasi-molecular ions. Calibration curve of berberine has been estimated (y = 1712091x + 4785.03 with the correlation coefficient 0.9999). Limit of detection and limit of quantification were calculated to be 3.2 and 9.7 ng/mL, respectively. Numerous alkaloids (i.e., berberine, jatrorrhizine and magnoflorine, as well as phellodendrine, menisperine and berbamine) were identified in the extracts from alkaloid plants and silk and wool fibers dyed with these dyestuffs, among them their markers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Liquid chromatography tandem mass spectrometry method for simultaneous determination of metoprolol tartrate and ramipril in human plasma.

    Science.gov (United States)

    Gowda, K Veeran; Mandal, Uttam; Senthamil Selvan, P; Sam Solomon, W D; Ghosh, Animesh; Sarkar, Amlan Kanti; Agarwal, Sangita; Nageswar Rao, T; Pal, Tapan Kumar

    2007-10-15

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of metoprolol tartrate (MT) and ramipril, in human plasma. Both the drugs were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v). The chromatographic separation was performed on a reversed-phase C8 column with a mobile phase of 10 mM ammonium formate-methanol (3:97, v/v). The protonated analyte was quantitated in positive ionization by multiple reaction monitoring with a mass spectrometer. The method was validated over the concentration range of 5-500 ng/ml for metoprolol and ramipril in human plasma. The precursor to product ion transitions of m/z 268.0-103.10 and m/z 417.20-117.20 were used to measure metoprolol and ramipril, respectively.

  17. Determination of olanzapine in whole blood using simple protein precipitation and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Marie Katrine Klose; Johansen, Sys Stybe

    2009-01-01

    A simple, sensitive, and reproducible liquid chromatography-tandem mass spectrometry method has been developed and validated for the quantification of the antipsychotic drug olanzapine in whole blood using dibenzepine as internal standard (IS). After acidic methanol-induced protein precipitation...... of the whole blood samples, olanzapine and IS were chromatographed on a reversed-phase Zorbax Extend-C(18)-column at pH 9.0. Quantification was performed on a triple-quadrupole mass spectrometer employing electrospray ionization technique operating in multiple reaction monitoring and positive ion mode. Total...... chromatographic run time was 15 min, and calibration curve was linear over the concentration range of 0.005 to 0.50 mg/kg olanzapine in whole blood. The method was validated for selectivity, matrix interference, recovery, linearity, limit of detection, limit of quantitation (LOQ), accuracy, precision...

  18. A laser desorption-electron impact ionization ion trap mass spectrometer for real-time analysis of single atmospheric particles

    Science.gov (United States)

    Simpson, E. A.; Campuzano-Jost, P.; Hanna, S. J.; Robb, D. B.; Hepburn, J. H.; Blades, M. W.; Bertram, A. K.

    2009-04-01

    A novel aerosol ion trap mass spectrometer combining pulsed IR laser desorption with electron impact (EI) ionization for single particle studies is described. The strengths of this instrument include a two-step desorption and ionization process to minimize matrix effects; electron impact ionization, a universal and well-characterized ionization technique; vaporization and ionization inside the ion trap to improve sensitivity; and an ion trap mass spectrometer for MSn experiments. The instrument has been used for mass spectral identification of laboratory generated pure aerosols in the 600 nm-1.1 [mu]m geometric diameter range of a variety of aromatic and aliphatic compounds, as well as for tandem mass spectrometry studies (up to MS3) of single caffeine particles. We investigate the effect of various operational parameters on the mass spectrum and fragmentation patterns. The single particle detection limit of the instrument was found to be a 325 nm geometric diameter particle (8.7 × 107 molecules or 22 fg) for 2,4-dihydroxybenzoic acid. Lower single particle detection limits are predicted to be attainable by modifying the EI pulse. The use of laser desorption-electron impact (LD-EI) in an ion trap is a promising technique for determining the size and chemical composition of single aerosol particles in real time.

  19. Similarity of High-Resolution Tandem Mass Spectrometry Spectra of Structurally Related Micropollutants and Transformation Products

    Science.gov (United States)

    Schollée, Jennifer E.; Schymanski, Emma L.; Stravs, Michael A.; Gulde, Rebekka; Thomaidis, Nikolaos S.; Hollender, Juliane

    2017-12-01

    High-resolution tandem mass spectrometry (HRMS2) with electrospray ionization is frequently applied to study polar organic molecules such as micropollutants. Fragmentation provides structural information to confirm structures of known compounds or propose structures of unknown compounds. Similarity of HRMS2 spectra between structurally related compounds has been suggested to facilitate identification of unknown compounds. To test this hypothesis, the similarity of reference standard HRMS2 spectra was calculated for 243 pairs of micropollutants and their structurally related transformation products (TPs); for comparison, spectral similarity was also calculated for 219 pairs of unrelated compounds. Spectra were measured on Orbitrap and QTOF mass spectrometers and similarity was calculated with the dot product. The influence of different factors on spectral similarity [e.g., normalized collision energy (NCE), merging fragments from all NCEs, and shifting fragments by the mass difference of the pair] was considered. Spectral similarity increased at higher NCEs and highest similarity scores for related pairs were obtained with merged spectra including measured fragments and shifted fragments. Removal of the monoisotopic peak was critical to reduce false positives. Using a spectral similarity score threshold of 0.52, 40% of related pairs and 0% of unrelated pairs were above this value. Structural similarity was estimated with the Tanimoto coefficient and pairs with higher structural similarity generally had higher spectral similarity. Pairs where one or both compounds contained heteroatoms such as sulfur often resulted in dissimilar spectra. This work demonstrates that HRMS2 spectral similarity may indicate structural similarity and that spectral similarity can be used in the future to screen complex samples for related compounds such as micropollutants and TPs, assisting in the prioritization of non-target compounds. [Figure not available: see fulltext.

  20. A new approach to mass spectrometer measurements of thermospheric density

    Science.gov (United States)

    Melfi, L. T., Jr.; Brock, F. J.; Brown, C. A., Jr.

    1974-01-01

    The gas sampling problem in satellite and high velocity probes was investigated by applying the theory of a drifting Maxwellian gas. A lens system using a free stream ion source was developed and experimentally evaluated over the pressure range of 0.00001 to 0.01 N/m sq (approx. 10 to the minus 7th power to 0.0001 torr). The source has high beam transparency, which minimizes gas-surface collisions within, or near, the ionization volume. It is shown that for high ion energy (60 eV), the extracted ion beam has an on-axis energy spread of less than 4 eV, and that 90 percent of the ions are within 2.5 deg of the beam axis. It is concluded that the molecular beam mass spectrometer concept, developed for gas density measurements in the upper atmosphere, substantially reduces gas-surface scattering and gas-surface reactions in the sample, and preserves the integrity of the gas sample during the analysis process. Studies show that both the Scout and Delta launch vehicles have adequate volume, control, velocity, and data acquisition capability necessary to obtain thermospheric number density in real time.

  1. MOMA and other next-generation ion trap mass spectrometers for planetary exploration

    Science.gov (United States)

    Arevalo, R. D., Jr.; Brinckerhoff, W. B.; Getty, S.; Mahaffy, P. R.; van Amerom, F. H. W.; Danell, R.; Pinnick, V. T.; Li, X.; Grubisic, A.; Southard, A. E.; Hovmand, L.; Cottin, H.; Makarov, A.

    2016-12-01

    Since the 1970's, quadrupole mass spectrometer (QMS) systems have served as low-risk, cost-efficient means to explore the inner and outer reaches of the solar system. These legacy instruments have interrogated the compositions of the lunar exosphere (LADEE), surface materials on Mars (MSL), and the atmospheres of Venus (Pioneer Venus), Mars (MAVEN) and outer planets (Galileo and Cassini-Huygens). However, the in situ detection of organic compounds on Mars and Titan, coupled with ground-based measurements of amino acids in meteorites and a variety of organics in comets, has underlined the importance of molecular disambiguation in the characterization of high-priority planetary environments. The Mars Organic Molecule Analyzer (MOMA) flight instrument, centered on a linear ion trap, enables the in situ detection of volatile and non-volatile organics, but also the characterization of molecular structures through SWIFT ion isolation/excitation and tandem mass spectrometry (MSn). Like the SAM instrument on MSL, the MOMA investigation also includes a gas chromatograph (GC), thereby enabling the chemical separation of potential isobaric interferences based on retention times. The Linear Ion Trap Mass Spectrometer (LITMS; PI: William Brinckerhoff), developed to TRL 6 via the ROSES MatISSE Program, augments the core MOMA design and adds: expanded mass range (from 20 - 2000 Da); high-temperature evolved gas analysis (up to 1300°C); and, dual polarity detector assemblies (supporting the measurement of negative ions). The LITMS instrument will be tested in the field in 2017 through the Atacama Rover Astrobiology Drilling Studies (ARADS; PI: Brian Glass) ROSES PSTAR award. Following on these advancements, the Advanced Resolution Organic Molecule Analyzer (AROMA; PI: Ricardo Arevalo Jr.), supported through the ROSES PICASSO Program, combines a highly capable MOMA/LITMS-like linear ion trap and the ultrahigh resolution CosmOrbitrap mass analyzer developed by a consortium of five

  2. Analysis of small carbohydrates in several bioactive botanicals by gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Moldoveanu, Serban; Scott, Wayne; Zhu, Jeff

    2015-11-01

    Bioactive botanicals contain natural compounds with specific biological activity, such as antibacterial, antioxidant, immune stimulating, and taste improving. A full characterization of the chemical composition of these botanicals is frequently necessary. A study of small carbohydrates from the plant materials of 18 bioactive botanicals is further described. The study presents the identification of the carbohydrate using a gas chromatographic-mass spectrometric analysis that allows detection of molecules as large as maltotetraose, after changing them into trimethylsilyl derivatives. A number of carbohydrates in the plant (fructose, glucose, mannose, sucrose, maltose, xylose, sorbitol, and myo-, chiro-, and scyllo-inositols) were quantitated using a novel liquid chromatography with tandem mass spectrometric technique. Both techniques involved new method developments. The gas chromatography with mass spectrometric analysis involved derivatization and separation on a Rxi(®)-5Sil MS column with H2 as a carrier gas. The liquid chromatographic separation was obtained using a hydrophilic interaction type column, YMC-PAC Polyamine II. The tandem mass spectrometer used an electrospray ionization source in multiple reaction monitoring positive ion mode with the detection of the adducts of the carbohydrates with Cs(+) ions. The validated quantitative procedure showed excellent precision and accuracy allowing the analysis in a wide range of concentrations of the analytes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Quantification of citalopram or escitalopram and their demethylated metabolites in neonatal hair samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Frison, Giampietro; Favretto, Donata; Vogliardi, Susanna; Terranova, Claudio; Ferrara, Santo Davide

    2008-08-01

    Citalopram and escitalopram are highly selective serotonin reuptake inhibitors widely used in the treatment of depression. They exhibit adverse drug reactions and side effects, however, and the development of specific methods for their determination is of great interest in clinical and forensic toxicology. A liquid chromatography-tandem mass spectrometry method has been developed and validated for the assay of citalopram, escitalopram, and their demethylated metabolites in 10-mg hair samples. The analytes were extracted by incubation in methanol and liquid/liquid extraction with diethyl ether/dichloromethane. Gradient elution on a narrow bore C18 column was realized using clomipramine-d3 as an internal standard. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method exhibited a linear range of 25 to 2000 pg/mg, a quantification limit of 25 pg/mg for all analytes, relative standard deviations in the range of 12.10 to 9.80 (intraassay), and 13.80 to 11.78 (interassay), and accuracies (as percent recovery of the spiked standards) in the range of 90% to 110%; it was applied to the determination of citalopram and escitalopram and their metabolites in hair samples of two newborns to document their in utero exposure to the drugs. The method proved suitable for neonatal hair analysis of citalopram or escitalopram and was applied to two real cases of gestational exposure.

  4. Direct Assay of δ-Aminolevulinic Acid Dehydratase in Heme Biosynthesis for the Detection of Porphyrias by Tandem Mass Spectrometry

    Science.gov (United States)

    Choiniere, John R.; Scott, C. Ronald; Gelb, Michael H.; Tureček, František

    2010-01-01

    We report a new assay of human δ-aminolevulinic acid dehydratase (ALAD), an enzyme converting δ-aminolevulinic acid (ALA) into porphobilinogen. The assay is developed for use in the clinical diagnosis of δ-aminolevulinic acid dehydratase-deficient porphyria, a rare enzymatic deficiency of the heme biosynthetic pathway. The assay involves the incubation of erythrocyte lysate with the natural substrate, ALA, followed by quantitative in situ conversion of porphobilinogen to its butyramide, and liquid-liquid extraction into a mass spectrometer-friendly solvent. Quantitation of the butyrylated porphobilinogen is done by electrospray ionization tandem mass spectrometry, using a deuterium labeled internal standard. The assay stays well within the range wherein ALAD activity is linear with time. The Km of ALAD for ALA was measured as 333 μM, and the Vmax was 19.3 μM/hr. Average enzyme activity among a random sample of 36 anonymous individuals was 277 μmol/L erythrocyte lysate/hour with a standard deviation of 90 μmol/L erythrocyte lysate/hour. The tandem mass spectrometric assay should easily detect the enzyme deficiency, which causes a reduction of activity by 95–99%. The assay shows good reproducibility, low background, requires a simple workup, and uses a commercially available substrate. PMID:20583792

  5. Direct assay of delta-aminolevulinic acid dehydratase in heme biosynthesis for the detection of porphyrias by tandem mass spectrometry.

    Science.gov (United States)

    Choiniere, John R; Scott, C Ronald; Gelb, Michael H; Turecek, Frantisek

    2010-08-01

    We report a new assay of human delta-aminolevulinic acid dehydratase (ALAD), an enzyme converting delta-aminolevulinic acid (ALA) into porphobilinogen. The assay is developed for use in the clinical diagnosis of delta-aminolevulinic acid dehydratase-deficient porphyria, a rare enzymatic deficiency of the heme biosynthetic pathway. The assay involves the incubation of erythrocyte lysate with the natural substrate, ALA, followed by quantitative in situ conversion of porphobilinogen to its butyramide, and liquid-liquid extraction into a mass spectrometer-friendly solvent. Quantitation of the butyrylated porphobilinogen is done by electrospray ionization tandem mass spectrometry, using a deuterium labeled internal standard. The assay stays well within the range wherein ALAD activity is linear with time. The K(m) of ALAD for ALA was measured as 333 microM, and the V(max) was 19.3 microM/h. Average enzyme activity among a random sample of 36 anonymous individuals was 277 micromol/L erythrocyte lysate/hour with a standard deviation of 90 micromol/L erythrocyte lysate/hour. The tandem mass spectrometric assay should easily detect the enzyme deficiency, which causes a reduction of activity by 95-99%. The assay shows good reproducibility and low background, requires a simple workup, and uses a commercially available substrate.

  6. Precise mass measurements of astrophysical interest made with the Canadian Penning trap mass spectrometer

    International Nuclear Information System (INIS)

    Clark, J.A.; Barber, R.C.; Blank, B.; Boudreau, C.; Buchinger, F.; Crawford, J.E.; Gulick, S.; Hardy, J.C.; Heinz, A.; Lee, J.K.P.; Levand, A.F.; Moore, R.B.; Savard, G.; Seweryniak, D.; Sharma, K.S.; Sprouse, G.D.; Trimble, W.; Vaz, J.; Wang, J.C.; Zhou, Z.

    2004-01-01

    The processes responsible for the creation of elements more massive than iron are not well understood. Possible production mechanisms involve the rapid capture of protons (rp-process) or the rapid capture of neutrons (r-process), which are thought to occur in explosive astrophysical events such as novae, x-ray bursts, and supernovae. Mass measurements of the nuclides involved with uncertainties on the order of 100 keV or better are critical to determine the process 'paths', the energy output of the events, and the resulting nuclide abundances. Particularly important are the masses of 'waiting-point' nuclides along the rp-process path where the process stalls until the subsequent β decay of the nuclides. This paper will discuss the precise mass measurements made of isotopes along the rp-process and r-process paths using the Canadian Penning Trap mass spectrometer, including the mass of the critical waiting-point nuclide 68 Se

  7. Negative Electron Transfer Dissociation Sequencing of Increasingly Sulfated Glycosaminoglycan Oligosaccharides on an Orbitrap Mass Spectrometer

    Science.gov (United States)

    Leach, Franklin E.; Riley, Nicholas M.; Westphall, Michael S.; Coon, Joshua J.; Amster, I. Jonathan

    2017-09-01

    The structural characterization of sulfated glycosaminoglycan (GAG) carbohydrates remains an important target for analytical chemists attributable to challenges introduced by the natural complexity of these mixtures and the defined need for molecular-level details to elucidate biological structure-function relationships. Tandem mass spectrometry has proven to be the most powerful technique for this purpose. Previously, electron detachment dissociation (EDD), in comparison to other methods of ion activation, has been shown to provide the largest number of useful cleavages for de novo sequencing of GAG oligosaccharides, but such experiments are restricted to Fourier transform ion cyclotron resonance mass spectrometers (FTICR-MS). Negative electron transfer dissociation (NETD) provides similar fragmentation results, and can be achieved on any mass spectrometry platform that is designed to accommodate ion-ion reactions. Here, we examine for the first time the effectiveness of NETD-Orbitrap mass spectrometry for the structural analysis of GAG oligosaccharides. Compounds ranging in size from tetrasaccharides to decasaccharides were dissociated by NETD, producing both glycosidic and cross-ring cleavages that enabled the location of sulfate modifications. The highly-sulfated, heparin-like synthetic GAG, ArixtraTM, was also successfully sequenced by NETD. In comparison to other efforts to sequence GAG chains without fully ionized sulfate constituents, the occurrence of sulfate loss peaks is minimized by judicious precursor ion selection. The results compare quite favorably to prior results with electron detachment dissociation (EDD). Significantly, the duty cycle of the NETD experiment is sufficiently short to make it an effective tool for on-line separations, presenting a straightforward path for selective, high-throughput analysis of GAG mixtures. [Figure not available: see fulltext.

  8. The time-of-flight isochronous (TOFI) spectrometer for direct mass measurements of exotic light nuclei

    International Nuclear Information System (INIS)

    Wouters, J.M.; Vieira, D.J.; Butler, G.W.; Wollnik, H.; Kraus, R.H. Jr.; Vaziri, K.

    1987-01-01

    A new type of time-of-flight recoil spectrometer designed to measure the masses of neutron-rich light nuclei has recently been completed at LAMPF. The spectrometer relies on an isochronous design that directly correlates an ion's time-of-flight through the spectrometer with its mass-to-charge ratio. Additional measurements of the ion's velocity and energy enable the charge state of the recoil to be uniquely defined and thus permit precision mass measurements given sufficient statistics. The performance of the spectrometer has been investigated in both-off line (using alpha sources) and on-line tests. The design resolution of ΔM/M=1/2000 (fwhm) has been achieved. Initial performance results of the spectrometer are described with emphasis placed on the techniques used to achieve the overall high mass resolution and large solid angle/momentum acceptance. (orig.)

  9. On the adge field effect of a quadrupole mass spectrometer on a charged particle beam

    International Nuclear Information System (INIS)

    Usacheva, T.V.; Kuz'min, A.F.

    1982-01-01

    Functional parameter dependences of charged particle beam transport in the edge field of a quadrupole mass spectrometer on the parameters of the spectrometer and the potential are presented, making an assumption of linear potential change in the direction parallel to the spectrometer electrodes. Obtained are: inequality, convenient for the passage through the edge field of ion beams with point source vertex and axis of symmetry, parallel to the spectrometer electrodes; inequality, giving the upper bound of maximal ion approach to the spectrometer electrodes in the edge field; inequality, estimating the maximum value of charged particle velocity on a plane, being perpendicular to the spectrometer electrodes at the particle passage through the edge field. The inequalities obtained have been determined the relationships among the ion beam, the spectrometer and the edge field parameters

  10. Structural elucidation of metolachlor photoproducts by liquid chromatography/high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Nicol, Édith; Genty, Christophe; Bouchonnet, Stéphane; Bourcier, Sophie

    2015-12-15

    Metolachlor is one of the most intensively used chloroacetanilide herbicides in agriculture. It has been detected in water; consequently, under UV-visible irradiation, it can be transformed in degradation products (TPs). The structures of TPs were elucidated by liquid chromatography/high-resolution tandem mass spectrometry (LC/HR-MS/MS). The potential toxicities of these TPs were estimated by in silico tests. Aqueous solutions of metolachlor were irradiated in a self-made reactor equipped with a mercury vapor lamp. Analyses were carried out using high-performance liquid chromatography coupled to quadrupole time-of-flight (QTOF) mass spectrometer. High-resolution m/z measurements, MS/MS and isotopic labeling experiments allowed structural elucidation of metolachlor TPs. Their toxicities were estimated in silico, using the T.E.S.T. Ten major metolachlor photoproducts were characterized by LC/MS/MS after irradiation of metolachlor in aqueous solution. Elucidation of their chemical structures was identified using high-resolution measurements and MS/MS experiments. They resulted from the combination of dehalogenation, hydroxylation and cyclisation processes. The potential oral rat lethal dose (LD50) was assessed with QSAR tests for metolachlor and each photoproduct. Results indicate that most of the TPs are much more toxic than metolachlor. UV-vis irradiation of metolachlor in aqueous solution leads to the formation of ten photoproducts. QSAR estimations show that the location of added hydroxyl group(s) is of key relevance as regards to biological activity and that routine water analysis should take into account the TPs are more toxic than the parent molecule. Copyright © 2015 John Wiley & Sons, Ltd.

  11. A new high resolution time-of-flight mass spectrometer with gridless reflector

    International Nuclear Information System (INIS)

    Bhowmick, A.; Korgaonkar, A.V.; Carvalho, W.C.J.; Yakhmi, J.V.; Sahni, V.C.

    2004-01-01

    High resolution in time-of-flight mass spectrometers essentially depends upon the capacity of the machine to control the initial spatial and energy distributions of the ions from the source or of any particular ionization process. In the present scenario, high resolution time-of-flight mass spectrometers are becoming more and more essential for rapid mass analysis of fairly large molecules or species e.g. large biomolecules, proteins, drugs, atomic clusters, etc. Simple mass measurements of atomic clusters have revealed major fundamental information about their electronic and geometric structures. Newer designs of time-of-flight mass spectrometers have high resolution, adaptability to multiple ionization techniques, high sensitivity, capability of addressing comparatively slower physical events etc. are, therefore, being reported regularly. A newly developed time-of-flight mass spectrometer is described

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

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, W; Laura Tovo, L

    2008-07-08

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

  13. Simultaneous determination of three pesticides and their metabolites in unprocessed foods using ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Rong, Lili; Wu, Xiaohu; Xu, Jun; Dong, Fengshou; Liu, Xingang; Pan, Xinglu; Du, Pengqiang; Wei, Dongmei; Zheng, Yongquan

    2018-02-01

    We have developed a rapid, multi-compound analytical method for measuring residues of the pesticides thiamethoxam and its metabolite, clothianidin; fipronil and its three metabolites, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl; and pyraclostrobin in unprocessed foods (rice, corn, cucumbers, tomatoes, apples, and bananas) by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Acetonitrile was used as the extraction solvent, and an octadecylsilane-dispersive SPE was used to clean up the analytes, which were then separated through a UPLC HSS T3 column connected to a tandem mass spectrometer via an electrospray ionisation source. The linearity of this method for the target analytes was excellent (R 2  ≥0.990) in the concentration range of 5-1000 μg kg -1 . The average recoveries of the seven compounds at concentrations of 10, 100, and 1000 μg kg -1 from six spiked matrix samples ranged from 73.6 to 110.6%, all with RSD values of ≤19.7%. The limit of quantification was 10 μg kg -1 . The method validated the effectiveness of the method for routine monitoring the residue of these pesticides and their metabolites in foods.

  14. Rapid Determination of Imatinib in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry: Application to a Pharmacokinetic Study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jeong Soo; Cho, Eun Gi; Huh, Wooseong; Ko, Jaewook; Jung, Jin Ah; Lee, Sooyoun [Samsung Medical Center, Seoul (Korea, Republic of)

    2013-08-15

    A simple, fast and robust analytical method was developed to determine imatinib in human plasma using liquid chromatography-tandem mass spectrometry with electrospray ionization in the positive ion mode. Imatinib and labeled internal standard were extracted from plasma with a simple protein precipitation. The chromatographic separation was performed using an isocratic elution of mobile phase involving 5.0 mM ammonium formate in water -5.0 mM ammonium formate in methanol (30:70, v/v) over 3.0 min on reversed-stationary phase. The detection was performed using a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring mode. The developed method was validated with lower limit of quantification of 10 ng/mL. The calibration curve was linear over 10-2000 ng/mL (R{sup 2} > 0.99). The method validation parameters met the acceptance criteria. The spiked samples and standard solutions were stable under conditions for storage and handling. The reliable method was successfully applied to real sample analyses and thus a pharmacokinetic study in 27 healthy Korean male volunteers.

  15. 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)

  16. spectrometer

    Directory of Open Access Journals (Sweden)

    J. K. Hedelius

    2016-08-01

    Full Text Available Bruker™ EM27/SUN instruments are commercial mobile solar-viewing near-IR spectrometers. They show promise for expanding the global density of atmospheric column measurements of greenhouse gases and are being marketed for such applications. They have been shown to measure the same variations of atmospheric gases within a day as the high-resolution spectrometers of the Total Carbon Column Observing Network (TCCON. However, there is little known about the long-term precision and uncertainty budgets of EM27/SUN measurements. In this study, which includes a comparison of 186 measurement days spanning 11 months, we note that atmospheric variations of Xgas within a single day are well captured by these low-resolution instruments, but over several months, the measurements drift noticeably. We present comparisons between EM27/SUN instruments and the TCCON using GGG as the retrieval algorithm. In addition, we perform several tests to evaluate the robustness of the performance and determine the largest sources of errors from these spectrometers. We include comparisons of XCO2, XCH4, XCO, and XN2O. Specifically we note EM27/SUN biases for January 2015 of 0.03, 0.75, –0.12, and 2.43 % for XCO2, XCH4, XCO, and XN2O respectively, with 1σ running precisions of 0.08 and 0.06 % for XCO2 and XCH4 from measurements in Pasadena. We also identify significant error caused by nonlinear sensitivity when using an extended spectral range detector used to measure CO and N2O.

  17. Laser ionization time of flight mass spectrometer for isotope mass detection and elemental analysis of materials

    Science.gov (United States)

    Ahmed, Nasar; Ahmed, Rizwan; Umar, Z. A.; Aslam Baig, M.

    2017-08-01

    In this paper we present the construction and modification of a linear time-of-flight mass spectrometer to improve its mass resolution. This system consists of a laser ablation/ionization section based on a Q-switched Nd:YAG laser (532 nm, 500 mJ, 5 ns pulse duration) integrated with a one meter linear time-of-flight mass spectrometer coupled with an electric sector and a magnetic lens and outfitted with a channeltron electron multiplier for ion detection. The resolution of the system has been improved by optimizing the accelerating potential and inserting a magnetic lens after the extraction region. The isotopes of lithium, lead and cadmium samples have been resolved and detected in accordance with their natural abundance. The capability of the system has been further exploited to determine the elemental composition of a brass alloy, having a certified composition of zinc and copper. Our results are in excellent agreement with its certified composition. This setup is found to be extremely efficient and convenient for fast analyses of any solid sample.

  18. Development of a miniature mass spectrometer with continuous atmospheric pressure interface.

    Science.gov (United States)

    Zhai, Yanbing; Feng, Yan; Wei, Yongzheng; Wang, Yuzhuo; Xu, Wei

    2015-05-21

    The demand for on-the-spot analysis is met by a miniature mass spectrometer which is preferred to be robust, stable, as small as possible and capable of analyzing different samples by coupling with various ionization methods. However, largely constrained by the atmospheric pressure interface (API), these aspects are difficult to be realized in one system. Herein, we describe the development of a new miniature mass spectrometer with balanced performance. The miniature mass spectrometer is small in size (30 × 30 × 18 cm) but has a continuous API, which was achieved by high-pressure ion trap operation and maximized ion transfer efficiency with the utilization of a differential pumping system. The miniature mass spectrometer was characterized and optimized in terms of stability, sensitivity, mass range, mass resolution and scan speed. Rapid analysis of mixtures was demonstrated by coupling the miniature mass spectrometer with the ambient ionization technique of paper spray. This is the smallest miniature mass spectrometer to date, which has a continuous API.

  19. Authentication of Fish Products by Large-Scale Comparison of Tandem Mass Spectra

    DEFF Research Database (Denmark)

    Wulff, Tune; Nielsen, Michael Engelbrecht; Deelder, André M.

    2013-01-01

    Authentication of food is a major concern worldwide to ensure that food products are correctly labeled in terms of which animals are actually processed for consumption. Normally authentication is based on species recognition by comparison of selected sequences of DNA or protein. We here present...... a new robust, proteome-wide tandem mass spectrometry method for species recognition and food product authentication. The method does not use or require any genome sequences or selection of tandem mass spectra but uses all acquired data. The experimental steps were performed in a simple, standardized...... workflow including protein extraction, digestion, and data analysis. First, a set of reference spectral libraries was generated using unprocessed muscle tissue from 22 different fish species. Query tandem mass spectrometry data sets from “unknown” fresh muscle tissue samples were then searched against...

  20. Miniature Time of Flight Mass Spectrometer for Space and Extraterrestrial Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The PI has developed a miniature time-of-flight mass spectrometer (TOF-MS), which can be op-timized for space and extraterrestrial applications, by using a...

  1. Physical design of time-of-flight mass spectrometer in energetic cluster impact deposition apparatus

    International Nuclear Information System (INIS)

    Yu Guoqing; Shi Ying; Chen Jingsheng; Zhu Dezhang; Pan Haochang; Xu Hongjie

    1999-01-01

    The principle and physical design of the time-of-flight mass spectrometer equipped in the energetic cluster impact deposition apparatus are introduced. Some problems existed in experiments and their solutions are also discussed

  2. An Atmospheric Sampling Ion Trap Mass Spectrometer for Global Health Assessment and Planetary Applications

    Data.gov (United States)

    National Aeronautics and Space Administration — We will develop a proof-of-principle prototype mass spectrometer that is capable of analyzing solid samples at elevated ambient pressures. Solid samples will be...

  3. Continuation of Mass determinations through a Double Focusing Mass Spectrometer on Line with ISOLDE

    CERN Multimedia

    2002-01-01

    In a previous experiment (1976-77) we have demonstrated the interest and feasibility of atomic mass determinations from the direct measurements of mass ratios on Rb, Cs and Fr isotopes. Masses of long series of isotopes on both side of stability were determined with an accuracy of a few tens to 300 keV (for th exotic). Interesting nuclear structure features could be observed as for example the indication for an onset of deformation, at N~=~60 for Z~=~37, which stimulated further experiments and theoretical calculations. The many mass values, until then unknown, we obtained in our experiments, gave in addition the possibility to make detailed tests of the nuclear mass predictions. Due to improvements on our mass spectrometer (better transmission and higher resolving power) and increased ISOLDE production yields, some new and valuable measurements can be performed. We plan: \\item a) to continue the measurements towards even heavier isotopes and explore the deformation regions which start at |9|7Rb and |1|4|6Cs;...

  4. An improved laser vaporization cluster source and time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Heer, W.A. de; Milani, P.

    1991-01-01

    We briefly describe an improved laser vaporization cluster source, which produces intense, stable and cold cluster beams, and a new time-of-flight mass spectrometer, which in several respects is more versatile and better suited for cluster studies than traditional designs. The mass spectrometer has a high resolution mode with a very large effective ionization region as well as position and velocity sensitive detection modes. (orig.)

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

    Science.gov (United States)

    Gallien, Sebastien; Domon, Bruno

    2014-08-01

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

  6. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer.

    Science.gov (United States)

    Blase, Ryan C; Miller, Greg; Westlake, Joseph; Brockwell, Tim; Ostrom, Nathaniel; Ostrom, Peggy H; Waite, J Hunter

    2015-10-01

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a "perfect focus" mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.(3)) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  7. Characterization of polyphenols in apricot and peach purees by UHPLC coupled to HRMS Q-Exactive(™) mass spectrometer: an approach in the identification of adulterations.

    Science.gov (United States)

    Cocconi, E; Stingone, C; Zanotti, A; Trifirò, A

    2016-09-01

    The genuineness of fruit juices and purees is regulated by guidelines of European Fruit Juice Association. Nevertheless, the addition of peach puree to apricot puree is considered the most common adulteration, very difficult to discover. In this study, the composition in free and conjugated polyphenols of apricot and peach purees was performed by target and untarget approaches with Q-Exactive(™) quadrupole-Orbitrap mass spectrometer. Apricot purees showed a higher polyphenol content than those of peaches. Between target coumpounds, chlorogenic acid, rutin, catechin and smaller quantities of hyperoside and kaempferol-3-rutinoside were found in both purees. Apricot puree was also found to contain epicatechin and procianidin B2, absent in peach puree. Peach puree was found to contain small amounts of kaempferol-3-glucoside, absent in apricot. In order to identify untarget polyphenols, data obtained by ultra-high pressure liquid chromatography tandem mass spectrometry analysis were processed with Thermo Scientific automated label-free differential expression software (sieve(™) 2.1 software). Three hydroxycinnamic acid conjugates and a procyanidin were identified and confirmed by tandem mass spectrometry spectra. Some compounds of interest found from differential analysis had a putative identification, while others remained unidentified. The high-resolution mass spectrometry approach using Q-Exactive(™) quadrupole-Orbitrap mass spectrometer could be an important and powerful tool for determination of new biomarkers in fruits and vegetables. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dworschak, Michael Gerhard

    2009-12-08

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

  9. Mass-spectrometer of knock-on nuclei for reactor 'Pik'

    International Nuclear Information System (INIS)

    Begzhanov, P.B.; Nazarov, A.G.; Petrov, G.A.; Pikul', V.P.

    1999-01-01

    For reactor 'Pik' (that is being built in St. Petersburg Institute of Nuclear Physics) there was designed a universal two shoulder mass-spectrometer for non-decelerated fission products (FP) of nuclei. The spectrometer helps to obtain different values of linear magnification, dispersion, aberration coefficients and transmission without making structural changes in the device. To separate FP for one shoulder of spectrometer we chose ion-optical scheme (IOS) consisting of three electrostatic analyzers and three-sectional magnet 'JOSEF' that had high dispersion by masses at small deflection radius. IOS calculations of mass-spectrometer were performed with the help of program TRANSVOL (transfer of phase volume) designed basing on TRIO program. The program allows calculating of complete IOS transmission with taking into account elements aperture and beam officering

  10. Arsenic speciation by liquid chromatography coupled with ionspray tandem mass spectrometry

    DEFF Research Database (Denmark)

    Corr, J. J.; Larsen, Erik Huusfeldt

    1996-01-01

    Ionspray mass spectrometry, a well established organic analysis technique, has been coupled to high-performance liquid chromatography for speciation of organic arsenic compounds, The ionspray source and differentially pumped interface of the mass spectrometer were operated in dual modes for eleme...

  11. An ion trap time-of-flight mass spectrometer with high mass resolution for cold trapped ion experiments

    Science.gov (United States)

    Schmid, P. C.; Greenberg, J.; Miller, M. I.; Loeffler, K.; Lewandowski, H. J.

    2017-12-01

    Trapping molecular ions that have been sympathetically cooled with laser-cooled atomic ions is a useful platform for exploring cold ion chemistry. We designed and characterized a new experimental apparatus for probing chemical reaction dynamics between molecular cations and neutral radicals at temperatures below 1 K. The ions are trapped in a linear quadrupole radio-frequency trap and sympathetically cooled by co-trapped, laser-cooled, atomic ions. The ion trap is coupled to a time-of-flight mass spectrometer to readily identify product ion species and to accurately determine trapped ion numbers. We discuss, and present in detail, the design of this ion trap time-of-flight mass spectrometer and the electronics required for driving the trap and mass spectrometer. Furthermore, we measure the performance of this system, which yields mass resolutions of m/Δm ≥ 1100 over a wide mass range, and discuss its relevance for future measurements in chemical reaction kinetics and dynamics.

  12. A multichannel ion mass spectrometer in laser-produced plasma studies

    International Nuclear Information System (INIS)

    Goforth, R.R.

    1976-01-01

    The theory and operation of a time-of-flight mass spectrometer employing a multichannel electrostatic analyzer are discussed with emphasis placed on laser-produced plasma studies. It is shown that the finite length of the analyzer leads to enhanced mass resolution. A method of in situ calibration of the analyzer channels is described, and measurements of the resolution and beam divergence are presented. Use of the mass spectrometer to calibrate ion-collecting probes for mass and kinetic energy measurements is also considered

  13. Mass spectrometer and method with improved ion transmission

    International Nuclear Information System (INIS)

    Douglas, D.J.; French, J.B.

    1992-01-01

    This invention relates to a mass analyzer, and to a method of operating a mass analyzer, of the kind in which ions are transmitted through a first rod set for focussing and separation from an accompanying gas, before passing through a mass filter rod set which which permits transmission only of ions of a selected mass to charge ratio. (author). 19 figs

  14. Comparison of mineral dust and droplet residuals measured with two single particle aerosol mass spectrometers

    Science.gov (United States)

    Wonaschütz, Anna; Ludwig, Wolfgang; Zawadowicz, Maria; Hiranuma, Naruki; Hitzenberger, Regina; Cziczo, Daniel; DeMott, Paul; Möhler, Ottmar

    2017-04-01

    Single Particle mass spectrometers are used to gain information on the chemical composition of individual aerosol particles, aerosol mixing state, and other valuable aerosol characteristics. During the Mass Spectrometry Intercomparison at the Fifth Ice Nucleation (FIN-01) Workshop, the new LAAPTOF single particle aerosol mass spectrometer (AeroMegt GmbH) was conducting simultaneous measurements together with the PALMS (Particle Analysis by Laser Mass Spectrometry) instrument. The aerosol particles were sampled from the AIDA chamber during ice cloud expansion experiments. Samples of mineral dust and ice droplet residuals were measured simultaneously. In this work, three expansion experiments are chosen for a comparison between the two mass spectrometers. A fuzzy clustering routine is used to group the spectra. Cluster centers describing the ensemble of particles are compared. First results show that while differences in the peak heights are likely due to the use of an amplifier in PALMS, cluster centers are comparable.

  15. A compact time-of-flight mass spectrometer for ion source characterization

    International Nuclear Information System (INIS)

    Chen, L.; Wan, X.; Jin, D. Z.; Tan, X. H.; Huang, Z. X.; Tan, G. B.

    2015-01-01

    A compact time-of-flight mass spectrometer with overall dimension of about 413 × 250 × 414 mm based on orthogonal injection and angle reflection has been developed for ion source characterization. Configuration and principle of the time-of-flight mass spectrometer are introduced in this paper. The mass resolution is optimized to be about 1690 (FWHM), and the ion energy detection range is tested to be between about 3 and 163 eV with the help of electron impact ion source. High mass resolution and compact configuration make this spectrometer useful to provide a valuable diagnostic for ion spectra fundamental research and study the mass to charge composition of plasma with wide range of parameters

  16. Ion optics of a time-of-flight mass spectrometer with electrostatic sector analyzers

    International Nuclear Information System (INIS)

    Sakurai, T.; Ito, H.; Matsuo, T.

    1995-01-01

    The ion optics for a high resolution time-of-flight mass spectrometer with electrostatic sector analyzers have been investigated. The multiple focusing (triple isochronous focusing and triple spacial focusing) conditions can be achieved by using a symmetrical arrangement of the sectors in a mass spectrometer. Both high mass resolution and high ion transmission can be accomplished simultaneously. The principles of MS/MS and MS/MS/MS analyses using a TOF mass spectrometer with electrostatic sector analyzers have been proposed. Product ion spectra can be obtained by measuring the total flight times and the kinetic energy of the products without any additional separation processes, any coincidence techniques or any special timing circuits. In an experiment, MS/MS and MS/MS/MS mass spectra have been obtained. The first generation product ions have been produced by a metastable decay, and the second generation products have been produced by a sequential decay. (orig.)

  17. Quantification and validation of ertapenem using a liquid chromatography-tandem mass spectrometry method

    NARCIS (Netherlands)

    van Rijn, S.P.; Wessels, A.M.A.; Greijdanus, B.; Touw, D.J.; Alffenaar, J.W.C.

    Ertapenem, a carbapenem, relies on time-dependent killing. Therapeutic drug monitoring (TDM) should be considered, when ertapenem is used in specific populations, to achieve optimal bactericidal activity and optimize drug-dosing regimens. No validated liquid chromatography-tandem mass spectrometry

  18. Determination of Bedaquiline in Human Serum Using Liquid Chromatography-Tandem Mass Spectrometry

    NARCIS (Netherlands)

    Alffenaar, Jan-Willem C.; Bolhuis, Mathieu; van Hateren, Kai; Sturkenboom, Marieke; Akkerman, Onno; de Lange, Wiel; Greijdanus, Ben; van der Werf, Tjip; Touw, Daan

    Bedaquiline, a diarylquinoline for the treatment of multidrug-resistant tuberculosis (TB), relies on exposure-dependent killing. As data on drug exposure in specific populations are scarce, pharmacokinetic studies may be of interest. No simple and robust validated liquid chromatography-tandem mass

  19. Liquid chromatographic-tandem mass spectrometric determination of selected sulphonamides in milk

    NARCIS (Netherlands)

    Rhijn, van J.A.; Lasaroms, J.J.P.; Berendsen, B.J.A.; Brinkman, U.A.Th.

    2002-01-01

    Liquid chromatography–tandem mass spectrometry is used for the quantitative analysis of selected sulphonamides in milk. Ultrafiltration is the only sample pre-treatment technique which is required. Consequently, sample throughput is much higher than with conventional procedures, and analyte

  20. Cytokinin profiling in plant tissues using ultra-performance liquid chromatography–electrospray tandem mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Novák, Ondřej; Hauserová, Eva; Amakorová, Petra; Doležal, Karel; Strnad, Miroslav

    2008-01-01

    Roč. 69, č. 11 (2008), s. 2214-2224 ISSN 0031-9422 R&D Projects: GA AV ČR KAN200380801 Institutional research plan: CEZ:AV0Z50380511 Keywords : Ultra-performance liquid chromatography (UPLC) * Tandem mass spectrometry (MS/MS) * Microextraction Subject RIV: EC - Immunology Impact factor: 2.946, year: 2008

  1. Rapid analysis of ß-agonists in urine by thermospray tandem mass spectrometry

    NARCIS (Netherlands)

    Rhijn, van J.A.; O'Keeffe, M.; Heskamp, H.H.; Collins, S.

    1995-01-01

    A method is described for the analysis of -agonists in urine of cattle. The method uses solid-phase extraction (SPE), followed by analysis of the resulting extract by flow injection thermospray tandem mass spectrometry (TSP-MS-MS). Sample preparation is performed using a mixed-bed SPE procedure

  2. Confirmatory analysis of acetylgestagens in plasma using liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Mortensen, Sarah Kelly; Pedersen, Mikael

    2007-01-01

    -assisted liquid-liquid extraction (LLE) on Extrelut NT columns followed by C18 solid-phase extraction (SPE). Analytes were analysed using liquid chromatography-tandem mass spectrometry (I-C-MS/MS), and quantification was performed using matrix-matched calibration standards in combination with deuterated internal...

  3. Tandem mass spectrometry newborn screening for inborn errors of intermediary metabolism: abnormal profile interpretation.

    Science.gov (United States)

    Fernández-Lainez, C; Aguilar-Lemus, J J; Vela-Amieva, M; Ibarra-González, I

    2012-01-01

    Expanded newborn screening for inherited metabolic disorders using tandem mass spectrometry was introduced in 1990's and is widely used around the world. In contrast to conventional screening methods, tandem mass spectrometry does not measure single analytes but identifies and quantifies metabolite profiles; one single blood spot analyzed provides information of about 60 metabolites including amino acids, acylcarnitines and related ratios that enable the diagnosis of approximately 50 different diseases. However, the interpretation of these profiles can become quite complex. The aim of this work is to present in an easy and practical manner a comprehensive compilation of information needed for tandem mass neonatal screening profile interpretation, and basic actions for immediate follow up of abnormal results, including the tests that are required for confirmatory purposes. Other conditions not attributable to metabolic disorders which can lead to an abnormal profile of these markers are also described as well as a series of general recommendations which would be useful for health professionals who are beginning newborn screening for inborn errors of intermediary metabolism using tandem mass spectrometry.

  4. Direct sampling tandem mass spectrometry (MS/MS) and multiway calibration for isomer quantitation

    NARCIS (Netherlands)

    Zampronio, Cleidiane G.; Gurden, Stephen P.; Moraes, Luis Alberto B.; Eberlin, Marcos N.; Smilde, Age K.; Poppi, Ronei J.

    2002-01-01

    Direct sampling tandem mass spectrometry (MS/MS) was used for the quantitation of mixtures of the isomers 2-, 3- and 4-ethyl pyridine. The similarity between the analytes and the second-order nature of MS/MS data require the use of multivariate calibration techniques capable of handling multiway

  5. Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

    Directory of Open Access Journals (Sweden)

    J Sreekumar

    2015-02-01

    Full Text Available Context: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. Objectives: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. Methods: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. Results: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. Conclusions: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions.

  6. Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer.

    Science.gov (United States)

    Sreekumar, J; France, N; Taylor, S; Matthews, T; Turner, P; Bliss, P; Brook, Alan H; Watson, Ajm

    2015-01-01

    In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions.

  7. Dereplication of Flavonoid Glycoconjugates from Adenocalymma imperatoris-maximilianii by Untargeted Tandem Mass Spectrometry-Based Molecular Networking.

    Science.gov (United States)

    de Oliveira, Gibson Gomes; Carnevale Neto, Fausto; Demarque, Daniel Pecoraro; de Sousa Pereira-Junior, José Antônio; Sampaio Peixoto Filho, Rômulo César; de Melo, Sebastião José; da Silva Almeida, Jackson Roberto Guedes; Lopes, João Luiz Callegari; Lopes, Norberto Peporine

    2017-05-01

    The interpretation of large datasets acquired using high performance liquid chromatography coupled with tandem mass spectrometry represents one of the major challenges in natural products research. Here we propose the use of molecular networking to rapid identify the known secondary metabolites from untargeted MS/MS analysis of Adenocalymma imperatoris-maximilianii plant extracts. The leaves, stems and roots of A. imperatoris-maximilianii were extracted using different solvents according to Snyder selectivity triangle. The samples were analyzed by HPLC coupled with ion trap mass spectrometer in a collision-induced dissociation MS/MS configuration in both positive and negative electrospray ionization modes. Molecular networking simultaneously organized the spectra by cosine similarity. The chemical identification was performed based on the systematic study of the main fragmentation pathways observed for the resulting network. The untargeted tandem mass spectrometry-based molecular networking allowed for the identification of 63 metabolites, mainly mono-, di- and tri-, C - and/or O -glycosyl flavones. Molecular networking was capable not only to dereplicate known flavonoids, but also to point out related prenyl derivatives, described for the first time in Adenocalymma species. The gas-phase reaction route to form the characteristic [M-H 2 O-(30/60/90)] + fragments in C -glycosyl flavones was suggested as sequential sugar ring opening followed by retro-aldol elimination involving aldose-ketose isomerization. The use of molecular networking with LC-CID-MS/MS assisted the identification of various isomeric and isobaric flavonoid glycoconjugates by establishing clusters according to the fragmentation similarities. Additionally, the proposed cross-ring sugar cleavages can contribute to the identification of C -glycosides by MS/MS analysis. Georg Thieme Verlag KG Stuttgart · New York.

  8. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...... response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m∕Δm > 2500. The system design...... is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0...

  9. Comparison of negative and positive ion electrospray tandem mass spectrometry for the liquid chromatography tandem mass spectrometry analysis of oxidized deoxynucleosides.

    Science.gov (United States)

    Hua, Y; Wainhaus, S B; Yang, Y; Shen, L; Xiong, Y; Xu, X; Zhang, F; Bolton, J L; van Breemen, R B

    2001-01-01

    Oxidized deoxynucleosides are widely used as biomarkers for DNA oxidation and oxidative stress assessment. Although gas chromatography mass spectrometry is widely used for the measurement of multiple DNA lesions, this approach requires complex sample preparation contributing to possible artifactual oxidation. To address these issues, a high performance liquid chromatography (HPLC)-tandem mass spectrometric (LC-MS/MS) method was developed to measure 8-hydroxy-2'-deoxyguanosine (8-OH-dG), 8-hydroxy-2'-deoxyadenosine (8-OH-dA), 2-hydroxy-2'-deoxyadenosine (2-OH-dA), thymidine glycol (TG), and 5-hydroxy-methyl-2'-deoxyuridine (HMDU) in DNA samples with fast sample preparation. In order to selectively monitor the product ions of these precursors with optimum sensitivity for use during quantitative LC-MS/MS analysis, unique and abundant fragment ions had to be identified during MS/MS with collision-induced dissociation (CID). Positive and negative ion electrospray tandem mass spectra with CID were compared for the analysis of these five oxidized deoxynucleosides. The most abundant fragment ions were usually formed by cleavage of the glycosidic bond in both positive and negative ion modes. However, in the negative ion electrospray tandem mass spectra of 8-OH-dG, 2-OH-dA, and 8-OH-dA, cleavage of two bonds within the sugar ring produced abundant S1 type ions with loss of a neutral molecule weighing 90 u, [M - H - 90]-. The signal-to-noise ratio was similar for negative and positive ion electrospray MS/MS except in the case of thymidine glycol where the signal-to-noise was 100 times greater in negative ionization mode. Therefore, negative ion electrospray tandem mass spectrometry with CID would be preferred to positive ion mode for the analysis of sets of oxidized deoxynucleosides that include thymidine glycol. Investigation of the fragmentation pathways indicated some new general rules for the fragmentation of negatively charged oxidized nucleosides. When purine

  10. Quantitative analysis of phytosterols in edible oils using APCI liquid chromatography-tandem mass spectrometry

    OpenAIRE

    Mo, Shunyan; Dong, Linlin; Hurst, W. Jeffrey; van Breemen, Richard B.

    2013-01-01

    Previous methods for the quantitative analysis of phytosterols have usually used GC-MS and require elaborate sample preparation including chemical derivatization. Other common methods such as HPLC with absorbance detection do not provide information regarding the identity of the analytes. To address the need for an assay that utilizes mass selectivity while avoiding derivatization, a quantitative method based on LC-tandem mass spectrometry (LC-MS-MS) was developed and validated for the measur...

  11. Replacing mass spectrometer with optical spectrometer for measuring 15N abundance in detecting the helicobacter pylori infection

    International Nuclear Information System (INIS)

    Zhu Yayi, Shen Yang; Wu Jicong

    1996-01-01

    Since the discovery of HP (Helicobacter pylori) and its close association with gastritis and peptic ulceration, it has been important to establish a practical method for conveniently testing HP infection. Because of the strong urease activity of HP, the urea administered orally is broken down into NH 3 and CO 2 by the HP urease in the patient's stomach. Then the NH 3 is absorbed by the blood and excreted in the urine. The HP infection can be detected with 15 N - tracing method, 15 NH 4 + excretion test, using 15 N urea as a tracer compound. Performing on the detection with a optical spectrometer made by us for measuring the 15 N - abundance in the urine is reported. A group of 24 patients was detected. The results are accurate and similar to microbiological tests. The optical spectrometer is cheaper, simpler and more convenient to operate than a mass spectrometer in measuring 15 N abundance. Using the optical instrument, the 15 NH 4 + excretion test could be widely used in hospitals. (author). 6 refs., 1 tab

  12. Indigenous instrumentation for mass spectrometry: Part II - development of plasma source mass spectrometers. PD-5-3

    International Nuclear Information System (INIS)

    Nataraju, V.

    2007-01-01

    The growing demands from analytical community, for a precise isotope ratio and ultra trace concentration measurements, has lead to significant improvement in mass spectrometer instrumentation development with respect to sensitivity, detection limits, precision and accuracy. Among the many analytical techniques available, plasma source mass spectrometers like Inductively Coupled Plasma Mass Spectrometry (ICPMS), multi collector (MC) ICPMS and Glow Discharge Mass Spectrometry (GDMS), have matured into reliable tools for the above applications. Where as ICPMS is by far the most successful method for aqueous solutions, GDMS is being applied for bulk and impurity analysis of conducting as well non-conducting solids. VPID, BARC has been developing mass spectrometers for different inorganic applications of DAE users. Over the years expertise has been developed in all the aspects of mass spectrometry instrumentation. Part 1 of this indigenous instrumentation on mass spectrometry gives details of magnetic sector instruments with either EI or TI source for isotopic ratio analysis. The present paper is a continuation of that on plasma source and quadrupole mass spectrometers. This paper covers i) ICP-QMS, ii) MC-ICPMS, iii) GDMS and iv) QMS

  13. Hard- and software complex for laser time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Sysoev, A.A.; Kas'yanov, V.B.; Poteshin, S.S.; Sil'nikov, E.E.; Sysoev, A.A.; Trofimov, A.S.

    2007-01-01

    The two-level principle serves as a basis to design the hardware and software system for the laser time-of-flight spectrometer. At the upper level the PC ensures the on-line control of the recording and the processing of the highest priority mass spectrometers. The controllers representing the control second level are responsible for monitoring and stabilization. The exchange between the controllers and the PC takes place in the periods free from recording and processing of the mass spectrometers. The use of the hardware and software system ensures as follows: to form up to 10 ns duration short mass peaks at the half-height; to reduce the scattering of the relative sensitivity coefficients from 2-3 orders up to 1 order; to improve the dynamic range of the recorded mass spectra up to 1-1x10 9 [ru

  14. A high resolution mass-energy spectrometer for the study of liquid metal ion sources

    International Nuclear Information System (INIS)

    Wilkens, B.

    1985-01-01

    A sector-magnet mass spectrometer has been modified to allow measurement of ion energy deficit and distributions as well as measurement of various mass species and their abundance to be made. The energy calibration and resolution measurement was achieved by using a simple, low cost, Cs surface ionization source which supplied monoenergetic Cs + and Cs + 2 ions of known energy. This energy analyzer has a resolution of < 2 eV and a mass energy product of 2 meV amu in the configuration in which it was used. Data are presented illustrating the versatility of the spectrometer in studying ion production mechanisms in liquid metal ion sources. (orig.)

  15. Application of double focusing mass spectrometer for sample analysis -prospects and problems

    International Nuclear Information System (INIS)

    Padma, N.; Nair, K.K.B.; Rama Rao, V.V.K.

    1996-01-01

    The indigenously built Double Focusing Mass Spectrometer (DFMS) was designed for high resolution mass analysis, especially, of organic samples. To ensure improved instrument performance required for analysis of samples, certain modifications have been made in the system. This paper discusses these and reports the performance evaluation of the instrument for solid and liquid samples

  16. Evaluation of species-dependent detection efficiencies in the aerosol mass spectrometer

    Science.gov (United States)

    Mass concentrations of chemical species calculated from the aerosol mass spectrometer (AMS) depend on two factors: particle collection efficiency (CE) and relative ionization efficiency (RIE, relative to the primary calibrant ammonium nitrate). While previous studies have characterized CE, RIE is re...

  17. Gas-phase ion-molecule reactions and high-pressure mass spectrometer, 1

    International Nuclear Information System (INIS)

    Hiraoka, Kenzo

    1977-01-01

    The reasons for the fact that the research in gas-phase ion-molecule reactions, to which wide interest is shown, have greatly contributed to the physical and chemical fields are that, first it is essential in understanding general phenomena concerning ions, second, it can furnish many unique informations in the dynamics of chemical reactions, and third, usefulness of '' chemical ionization'' methods has been established as its application to chemical analysis. In this review, the history and trend of studies and equipments in gas-phase ion-molecule reactions are surveyed. The survey includes the chemical ionization mass spectrometer for simultaneously measuring the positive and negative ions utilizing a quadrupole mass spectrometer presented by Hunt and others, flowing afterglow method derived from the flowing method which traces neutral chemical species mainly optically, ion cyclotron resonance mass spectrometer, trapped ion mass spectrometer and others. Number of reports referred to ion-molecule reactions issued during the last one year well exceeds the total number of reports concerning mass spectrometers presented before 1955. This truly shows how active the research and development are in this field. (Wakatsuki, Y.)

  18. Spectrometric electronic equipment for a 90-channel cherenkov mass spectrometer

    International Nuclear Information System (INIS)

    Astvatsaturov, R.G.; Basiladze, S.G.; Ivanov, V.I.

    1978-01-01

    Detecting spectrometric electronic equipment of a 90-channel cherenkov γ-spectrometer operating on-line with HP2116B type computer is described. The equipment contains linear amplifiers, analog memory blocks, a linear summator, discriminators, and a coincidence circuit. Three computer-controlled systems are used for checking the characteristics of the spectrometric electronic equipment, photomultipliers, and also for energy calibrations of the detectors. The long-term stability of the equipment has been measured with the aid of the checkup systems. It is established that the average instability of the pedestal magnitudes for all the channels is less than 10%, while the instability of the transmission coefficients is not worse than 0.5% for 5 days. The average nonlinearity over all the channels is 0.6%. The resolution time of the spectrometric equipment is 180 nsec

  19. A dynamic programming approach to de novo peptide sequencing via tandem mass spectrometry.

    Science.gov (United States)

    Chen, T; Kao, M Y; Tepel, M; Rush, J; Church, G M

    2001-01-01

    Tandem mass spectrometry fragments a large number of molecules of the same peptide sequence into charged molecules of prefix and suffix peptide subsequences and then measures mass/charge ratios of these ions. The de novo peptide sequencing problem is to reconstruct the peptide sequence from a given tandem mass spectral data of k ions. By implicitly transforming the spectral data into an NC-spectrum graph G (V, E) where /V/ = 2k + 2, we can solve this problem in O(/V//E/) time and O(/V/2) space using dynamic programming. For an ideal noise-free spectrum with only b- and y-ions, we improve the algorithm to O(/V/ + /E/) time and O(/V/) space. Our approach can be further used to discover a modified amino acid in O(/V//E/) time. The algorithms have been implemented and tested on experimental data.

  20. Capillary zone electrophoresis-mass spectromet of intact proteins

    NARCIS (Netherlands)

    Domínguez-Vega, Elena; Haselberg, Rob; Somsen, Govert W.

    2016-01-01

    Capillary electrophoresis (CE) coupled with mass spectrometry (MS) has proven to be a powerful analytical tool for the characterization of intact proteins. It combines the high separation efficiency, short analysis time, and versatility of CE with the mass selectivity and sensitivity offered by MS

  1. [Determination of propargite, tebuconazole and bromopropylate pesticide residues in Taiwan green jujubes by gas chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Qun; Liu, Chunhua; Wu, Nancun; Wu, Xiaofang; Li, Shuhuai

    2014-08-01

    An analytical method was established for the determination of propargite, tebuconazole and bromopropylate in Taiwan green jujubes (Zizyphus mauritiana Lam) by gas chromatography-tandem mass spectrometry (GC-MS/MS). The sample was extracted with acetonitrile from the Taiwan green jujubes after treated with a homogenizer. The organic phase was then separated from water phase by adding NaCl. The extract was further purified on a carbon/ NH2 cartridge with elution solvents of acetonitrile/toluene (3:1, v/v). Finally, the target analytes were separated by a capillary gas chromatographic column SLB-5MS (30 m x 0. 25 mm x 0. 25 μm). A tandem quadrupole mass spectrometer operated in either full scan mode or in MS/MS mode for multiple reaction monitoring (MRM) was used for the qualitative and quantitative analysis of the constituents, respectively. The results showed that the average recoveries of the three pesticides ranged from 75. 8% to 103. 6% with the RSDs of 1. 7%-9. 3% at the spiking levels from 0.01 mg/kg to 0. 50 mg/kg (n= 5). The calibration curves showed good linearity in the range of 0.01-0.50 mg/kg, with the determination coefficients over 0.99 (R2>0.99). The limits of quantification (LOQs) were 0.01 mg/kg for propargite, tebuconazole and bromopropylate in Taiwan green jujubes. The method is available for the determination of propargite, tebuconazole and bromopropylate pesticide residues in Taiwan green jujubes.

  2. Ultra-pressure liquid chromatography-electrospray tandem mass spectrometry for multiresidue determination of pesticides in water.

    Science.gov (United States)

    Gervais, G; Brosillon, S; Laplanche, A; Helen, C

    2008-08-22

    A multiresidue analysis method has been developed for the determination of pesticides in water by ultra-performance liquid chromatography (UPLC) combined with tandem mass spectrometry (MS/MS). The selected pesticides represent a broad range of polarity and volatility [benzoylcyclohexanedione (mesotrione and sulcotrione); chloroacetamide (acetochlor, alachlor, dimethenamide, and metolachlor); phenoxyacetic acid (2,4-D and MCPA); phenoxypropionic (dichloprop and mecoprop); phenylurea (chlortoluron, diuron, isoproturon, linuron, and metoxuron); sulfonylurea (foramsulfuron, iodosulfuron, and nicolsulfuron); triazine (atrazine, cyanazine, desethylatrazine (DEA), desisopropylatrazine (DIA), simazine, and terbutylazine)]. The analytes were extracted using solid-phase extraction (SPE). The separation was carried out on an acquity UPLC BEH C18 column (1.7 microm, 50 mm x 1 mm ID) using a gradient elution profile and mobile phase consisting of 0.1% formic acid in water and acetonitrile. The pesticides were detected with a tandem mass spectrometer after being ionised positively or negatively (depending on the molecule) using an electrospray ionisation (ESI) source. To achieve the suitable extraction conditions for sample preparation, several parameters affecting the efficiency of SPE such as the nature of the sorbent and the eluent, extractant volume and pH were studied. The best recovery was obtained by the extraction with an Oasis HLB cartridge and 3 mL of a solution of acetonitrile/dichloromethane (1:1, v/v) at pH 2. The average recoveries of the pesticides in different samples ranged from 82 to 109%. The weight least squares (WLS) linear regression was used to calculate the limits of detection and quantification (LOD and LOQ) because the dispersion was heteroskedastic. All the pesticides could be correctly quantified at a concentration level of 50 ng L(-1) and most of them could be detected at a concentration inferior or equal to 8 ng L(-1). Efficiency and robustness of

  3. A comparison of flavonoid glycosides by electrospray tandem mass spectrometry

    Science.gov (United States)

    March, Raymond E.; Lewars, Errol G.; Stadey, Christopher J.; Miao, Xiu-Sheng; Zhao, Xiaoming; Metcalfe, Chris D.

    2006-01-01

    A comparison is presented of product ion mass spectra of protonated and deprotonated molecules of kaempferol-3-O-glucoside, quercitin-3-O-glucoside (isoquercitrin), quercitin-3-O-galactoside (hyperoin), apigenin-7-O-glucoside, luteolin-7-O-glucoside, genistein-7-O-glucoside, naringenin-7-O-glucoside (prunin), luteolin-4'-O-glucoside, luteolin-6-C-glucoside (homoorientin, known also as isoorientin), apigenin-8-C-glucoside (vitexin), and luteolin-8-C-glucoside (orientin) together with the product ion mass spectrum of deprotonated kaempferol-7-O-glucoside. All isomeric ions were distinguishable on the basis of their product ion mass spectra. For protonated 3-O-, 7-O-, and 4'-O-glycosides at a collision energy of 46-47 eV, homolytic cleavage of the O-glycosidic bond yielded aglycon Y+ ions, whereas in deprotonated 3-O-, 7-O-, and 4'-O-glycosides, heterolytic and homolytic cleavage of the O-glycosidic bond yielded radical aglycon (Y-H)- and aglycon (Y-) ions. In each case, fragmentation of either the glycan or the aglycon or both was observed. For 6-C- and 8-C-glycosides at a collision energy of 46-47 eV, fragmentation was restricted almost exclusively to the glycan. For luteolin-6-C-glucoside, the integrity of the aglycon structure is preserved at the expense of the glycan for which some 30 fragmentations were observed. Breakdown curves were determined as a function of collision energy for protonated and deprotonated luteolin-6-C-glucoside. An attempt has been made to rationalize the product ion mass spectra derived from C-O- and C-C-luteolin glucosides in terms of computed structures that indicate significant intramolecular hydrogen bonding and rotation of the B-ring to form a coplanar luteolin structure. It is proposed that protonated and deprotonated luteolin-6-C-glucoside may afford examples of cooperative interactive bonding that plays a major role in directing fragmentation.

  4. Comparison of atmospheric density data from mass spectrometers and atmospheric drag on the Aeros satellites

    Science.gov (United States)

    Roemer, M.; Framke, W.; Krankowsky, D.; Spencer, N. W.

    1979-01-01

    The comparison of perigee density data near 230 km for satellite Aeros-A has been extended to the complete mission time. The average ratio between orbital drag derived density and mass spectrometer measurements is very near to 1 with a large scatter reflected by a standard deviation of the order of 20%. A method of comparison was developed and tested which uses the observed rate of change of orbital period in comparison with the orbital decay computed from the actual mass spectrometer data measured at discrete positions along the orbit. This method proves that deviations from the average ratio of 1 between perigee densities from drag and mass spectrometers are due to the smoothing and poor resolution of the orbital drag technique.

  5. Tandem Mass Spectrum Sequencing: An Alternative to Database Search Engines in Shotgun Proteomics.

    Science.gov (United States)

    Muth, Thilo; Rapp, Erdmann; Berven, Frode S; Barsnes, Harald; Vaudel, Marc

    2016-01-01

    Protein identification via database searches has become the gold standard in mass spectrometry based shotgun proteomics. However, as the quality of tandem mass spectra improves, direct mass spectrum sequencing gains interest as a database-independent alternative. In this chapter, the general principle of this so-called de novo sequencing is introduced along with pitfalls and challenges of the technique. The main tools available are presented with a focus on user friendly open source software which can be directly applied in everyday proteomic workflows.

  6. Proteome characterization of human pancreatic cyst fluid from intraductal papillary mucinous neoplasm by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Park, Joonho; Han, Dohyun; Do, Misol; Woo, Jongmin; Wang, Joseph I; Han, Youngmin; Kwon, Wooil; Kim, Sun-Whe; Jang, Jin-Young; Kim, Youngsoo

    2017-10-30

    In recent years, the molecular components of pancreatic cyst fluid have been used for diagnosis and prognosis. Because the protein markers that are currently used in clinical tests are unreliable, proteomic studies to find new protein markers are being conducted. However, such researches have been limited due to the complexity of pancreatic cyst fluid and the immaturity of proteomic techniques. To overcome these limitations and provide a pancreatic cyst proteome dataset, we examined cyst fluid proteome with tandem mass spectrometry. The proteomic analysis was performed using a Orbitrap-based mass spectrometer (Q-Exactive) coupled with a 50-cm-long nano-liquid chromatography column. Protein mutations were identified using mutation sequence database search. A total of 5850 protein groups were identified from microliters of cyst fluid. Among those, 3934 protein groups were reported for the first time in pancreatic cyst fluid. Although high-abundance proteins were not depleted in the experiment, our dataset detected almost all pancreatic tumor markers such as mucin family members, S100 proteins, and CEA-related proteins. In addition, 590 protein mutation marker candidates were discovered. We provide a comprehensive cyst proteome dataset that includes cystic cellular proteins and mutated proteins. Our findings would serve as a rich resource for further IPMN studies and clinical applications. The MS data have been deposited in the ProteomeXchange with identifier PXD005671 (http://proteomecentral.proteomexchange.org/dataset/PXD005671). Copyright © 2017 John Wiley & Sons, Ltd.

  7. Determination of Platycodin D and Platycodin D3 in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Tae-Hyun Kim

    2014-01-01

    Full Text Available Platycodon grandiflorum has long been used as a traditional oriental medicine for respiratory disorder. Platycodin D (PD is known as the main component isolated from the root of PG. A simple and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS method has been developed and validated for the quantitation of PD in rat plasma. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization and multiple reaction monitoring in positive ion mode. The total chromatographic run time was 4.0 min, and the calibration curves of PD were linear over the concentration range of 50–10,000 ng/mL in rat plasma. The coefficient of variation and relative error at five QC levels were 1.0 to 8.8% and 0.7 to 8.7%, respectively. After a single oral administration of 500 mg/kg and a single intravenous administration of 25 mg/kg of 3% PD extract (a PG extract including 3% of PD, platycodin D and platycodin D3 were detected and pharmacokinetic parameters were estimated. The oral bioavailability of platycodin D and platycodin D3 was 0.29% and 1.35% in rats at 500 mg/kg of 3% PD extract of PG, respectively. The present method can be applied to pharmacokinetic analysis of platycodins and platycosides of the PG.

  8. Simultaneous determination of piroxicam, meloxicam and tenoxicam in human plasma by liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Ji, Hye Young; Lee, Hye Won; Kim, Young Hoon; Jeong, Dong Won; Lee, Hye Suk

    2005-11-05

    A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of piroxicam, meloxicam and tenoxicam in human plasma was developed. Piroxicam, meloxicam, tenoxicam and isoxicam (internal standard) were extracted from human plasma with ethyl acetate at acidic pH and analyzed on a Sunfire column with the mobile phase of methanol:ammonium formate (15 mM, pH 3.0) (60:40, v/v). The analytes were detected using a mass spectrometer, equipped with electrospray ion source. The instrument was set in the multiple-reaction-monitoring (MRM) mode. The standard curve was linear (r=1.000) over the concentration range of 0.50-200 ng/ml. The coefficient of variation (CV) and relative error (RE) for intra- and inter-assay statistics at three QC levels were 1.0-5.4% and -5.9 to 2.8%, respectively. The recoveries of piroxicam, meloxicam and tenoxicam ranged from 78.3 to 87.1%, with that of isoxicam being 59.7%. The lower limit of quantification for piroxicam, meloxicam and tenoxicam was 0.50 ng/ml using a 100 microl plasma sample. This method was successfully applied to a pharmacokinetic study of piroxicam after application of transdermal piroxicam patches to humans.

  9. Liquid Chromatography with Tandem Mass Spectrometry: A Sensitive Method for the Determination of Dehydrodiisoeugenol in Rat Cerebral Nuclei

    Directory of Open Access Journals (Sweden)

    You-Bo Zhang

    2016-03-01

    Full Text Available A new liquid chromatography–tandem mass spectrometry (LC-MS/MS method is developed for the quantification of dehydrodiisoeugenol (DDIE in rat cerebral nuclei after single intravenous administration. DDIE and daidzein (internal standard were separated on a Diamonsil™ ODS C18 column with methanol–water containing 0.1% formic acid (81:19, v/v as a mobile phase. Detection of DDIE was performed on a positive electrospray ionization source using a triple quadrupole mass spectrometer. DDIE and daidzein were monitored at m/z 327.2→188.0 and m/z 255.0→199.2, respectively, in multiple reaction monitoring mode. This method enabled quantification of DDIE in various brain areas, including, cortex, hippocampus, striatum, hypothalamus, cerebellum and brainstem, with high specificity, precision, accuracy, and recovery. The data herein demonstrate that our new LC-MS/MS method is highly sensitive and suitable for monitoring cerebral nuclei distribution of DDIE.

  10. Threonine versus isothreonine in synthetic peptides analyzed by high-resolution liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Kuznetsova, Ksenia G; Trufanov, Pavel V; Moysa, Alexander A; Pyatnitskiy, Mikhail A; Zgoda, Viktor G; Gorshkov, Mikhail V; Moshkovskii, Sergei A

    2016-06-15

    One of the problems in proteogenomic research aimed at identification of variant peptides is the presence of peptides with amino acid isomers of different origin in the analyzed samples. Among the most challenging examples are peptides with threonine and isothreonine (homoserine) in their sequences. Indeed, the latter residue may appear in vitro as a methionine substitution during sample preparation for shotgun proteome analysis. Yet, this substitution of Met to isoThr is not encoded genetically and should be unambiguously distinguished from, e.g., point mutations in proteins that result in Met conversion to Thr. In this work we compared tandem mass (MS/MS) spectra produced by an Orbitrap mass spectrometer of Thr- and isoThr-containing tryptic peptides and found a distinctive feature in their collisionally activated fragmentation patterns. Up to 84% of MS/MS spectra for peptides containing isoThr residues have been positively specified. We also studied the differences in retention times for peptides containing Thr isoforms that can be further used for their distinction. Threonine can be distinguished from isothreonine by its retention time and HCD fragmentation pattern, specifically relative intensity of the bn - product ion, which can be further used in proteomic research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. [Determination of thyreostats in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Lech, Rodziewicz; Jolanta, MasŁOwiecka; Anna, Sadowska; Halina, Car

    2017-10-08

    Five thyreostats (TSs), namely tapazole, thiouracil, methylthiouracil, propylthiouracil, and phenylthiouracil, were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in positive electrospray ionization mode. Extraction and clean-up were achieved using a ChemElut cartridge with tert -butyl methyl ether, without a derivatization step. Separation was achieved on an Acquity UPLC SS T3 column. The mobile phase was acetonitrile and water containing 0.2% (v/v) formic acid. The mass spectrometer was operated in multiple reaction monitoring mode. Urine samples were spiked with TS solution at levels corresponding to 5, 10, 15, and 20 μg/L. The accuracy (internal standard corrected) ranged from 92% to 107%, with a repeatability precision (relative standard deviation, RSD) less than 15% for all five analytes. The RSDs within-laboratory reproducibility was less than 26%. The decision limits (CCα) and detection capabilities (CCβ) were obtained from a calibration curve and were in the ranges of 3.1-6.1 μg/L and 4.0-7.4 μg/L, respectively. The CCα and CCβ values were below the recommended concentration, which was set at 10 μg/L. The results show that the described method is suitable for the direct detection of TSs in bovine urine. This method can also be used to determine TSs in porcine urine.

  12. [Diagnosis of inborn errors of metabolism using tandem mass spectrometry and gas chromatography mass spectrometry].

    Science.gov (United States)

    Han, Lian-Shu; Ye, Jun; Qiu, Wen-Juan; Gao, Xiao-Lan; Wang, Yu; Jin, Jing; Gu, Xue-Fan

    2008-08-05

    To investigate the effects of tandem mass spectrometry (MS/MS) combined with gas chromatography mass spectrometry (GC-MS) in the diagnosis of inborn errors of metabolism in children. Amino acids and acylcarnitines in the dry blood filter papers were tested by MS/MS, and the organic acid profiles in urea were tested by GC-MS among 4981 children suspected to be with inborn errors of metabolism from more than 100 hospitals in China. A few pediatric patients underwent analysis of activity of enzyme and gene mutation analysis too. 319 of the 4981 children (6.4%) were diagnosed as with 24 kinds of diseases: 155 of the 319 cases (48.6%) with 8 kinds of amino acid diseases (97 with hyperphenylalaninemia, 14 with maple syrup urine disease 13 with ornithine transcarbamylase deficiency, 13 with citrullinemia type II, 10 with tyrosinemia type I, 5 with citrullinemia type I, 2 with homocystinuria, and 1 with arginasemia); 150 of the 319 cases (47.0%) were diagnosed as with 10 kinds of organic acidemias (81 with methylmalonic acidemia, 17 with propionic acidemia, 17 with multiple CoA carboxylase deficiency, 11 with glutaric acidemia type II, 8 with isovaleric acidemia, 6 with beta-keto thiolase deficiency, 5 with 3-methylcrotonyl-CoA carboxylase deficiency, and 3 with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency); 14 cases (4.4%) were diagnosed as with 6 kinds of fatty acid disorders (5 with medium chain acyl-CoA dehydrogenase deficiency, 3 with very long chain acyl CoA dehydrogenase deficiency, 2 with short chain acyl-CoA dehydrogenase deficiency, 2 with multiple acyl-CoA dehydrogenase deficiency, 1 with carnitine palmitoyl transferase type II, and 1 with carnitine palmitoyl transferase type I). MS/MS is specific for amino acid diseases and fatty acid disorders. GC-MS is specific for detect organic acidemias. And the diagnoses of part of amino acid diseases need the combination of both methods.

  13. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Science.gov (United States)

    Pierret, C.; Maunoury, L.; Pacquet, J. Y.; Saint-Laurent, M.-G.; Tuske, O.

    2008-10-01

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N+ charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [www.simion.com/] software.

  14. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, C. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France)], E-mail: Pierret@ganil.fr; Maunoury, L. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France); Pacquet, J.Y.; Saint-Laurent, M.-G. [GANIL, CEA/DSM CNRS/IN2P3, Boulevard Henri Becquerel, B.P. 55027, F-14076 Caen cedex 05 (France); Tuske, O. [CEA/Saclay, DSM/DAPNIA, 91191 Gif/Yvette (France)

    2008-10-15

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N{sup +} charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [ (http://www.simion.com/)] software.

  15. LESSONS IN DE NOVO PEPTIDE SEQUENCING BY TANDEM MASS SPECTROMETRY

    Science.gov (United States)

    Medzihradszky, Katalin F.; Chalkley, Robert J.

    2015-01-01

    Mass spectrometry has become the method of choice for the qualitative and quantitative characterization of protein mixtures isolated from all kinds of living organisms. The raw data in these studies are MS/MS spectra, usually of peptides produced by proteolytic digestion of a protein. These spectra are “translated” into peptide sequences, normally with the help of various search engines. Data acquisition and interpretation have both been automated, and most researchers look only at the summary of the identifications without ever viewing the underlying raw data used for assignments. Automated analysis of data is essential due to the volume produced. However, being familiar with the finer intricacies of peptide fragmentation processes, and experiencing the difficulties of manual data interpretation allow a researcher to be able to more critically evaluate key results, particularly because there are many known rules of peptide fragmentation that are not incorporated into search engine scoring. Since the most commonly used MS/MS activation method is collision-induced dissociation (CID), in this article we present a brief review of the history of peptide CID analysis. Next, we provide a detailed tutorial on how to determine peptide sequences from CID data. Although the focus of the tutorial is de novo sequencing, the lessons learned and resources supplied are useful for data interpretation in general. PMID:25667941

  16. Fast Multi-blind Modification Search through Tandem Mass Spectrometry*

    Science.gov (United States)

    Na, Seungjin; Bandeira, Nuno; Paek, Eunok

    2012-01-01

    With great biological interest in post-translational modifications (PTMs), various approaches have been introduced to identify PTMs using MS/MS. Recent developments for PTM identification have focused on an unrestrictive approach that searches MS/MS spectra for all known and possibly even unknown types of PTMs at once. However, the resulting expanded search space requires much longer search time and also increases the number of false positives (incorrect identifications) and false negatives (missed true identifications), thus creating a bottleneck in high throughput analysis. Here we introduce MODa, a novel “multi-blind” spectral alignment algorithm that allows for fast unrestrictive PTM searches with no limitation on the number of modifications per peptide while featuring over an order of magnitude speedup in relation to existing approaches. We demonstrate the sensitivity of MODa on human shotgun proteomics data where it reveals multiple mutations, a wide range of modifications (including glycosylation), and evidence for several putative novel modifications. Based on the reported findings, we argue that the efficiency and sensitivity of MODa make it the first unrestrictive search tool with the potential to fully replace conventional restrictive identification of proteomics mass spectrometry data. PMID:22186716

  17. 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.

  18. Proteomic characterization of wheat amyloplasts using identification of proteins by tandem mass spectrometry.

    Science.gov (United States)

    Andon, Nancy L; Hollingworth, Sarah; Koller, Antonius; Greenland, Andrew J; Yates, John R; Haynes, Paul A

    2002-09-01

    We describe the initial characterization of the wheat amyloplast proteome, consisting of the identification and classification of 171 proteins. Whole amyloplasts and purified amyloplast membranes were prepared from wheat (Triticum aestivum). Protein extracts were examined by one-dimensional and two-dimensional electrophoresis, followed by high performance liquid chromatography-tandem mass spectrometry of separated proteins. Tandem mass spectrometry data of individual peptides was then searched by SEQUEST, using a database containing known protein sequences from both wheat and other homologous cereal crops. Using this approach we identified 108 proteins from whole amyloplasts and 63 proteins from purified amyloplast membranes. The majority of protein identifications were derived from protein sequences from cereal crops other than wheat, for which relatively little gene sequence data is available. The highest percentage of protein identifications obtained from any individual species was 46% of the total number of proteins identified, using sequence data found in our proprietary rice (Oryza sativa) genome database.

  19. High-resolution mass spectrometer with correction of horizontal and vertical aberrations

    International Nuclear Information System (INIS)

    Sachenko, V.D.; Fridlyanskij, G.V.

    1980-01-01

    Principles of calculation of the ion-optical system of a high-precision two-cascade sector type mass-spectrometer with total correction of spherical aberrations as well as the group of second order vertical aberrations are considered. A mass-spectrometer construction is described and some test results of the spectrometer are given. Configuration of boundaries of a spectrometer magnetic field has been formed by means of convex magnetic screens adjoining concave edqes of pole pieces. An energy diaphragm has been installed in the intermediate focus of the system. Precision slits of a source and receiver were made according to a spring parallelogram resolution of spectrometer constituted 80-100 thousands at a level of 10% of peak height. At a residual pressure of 5x10 -7 torr and 3-5x10 -5 torr inlet pressure in the source for Ar ''tail'' intensity in a neighbouring line amounted to 0.6x10 -6 of a main line. A measurement error for relative mass difference using the method of peak matching didnot exceed 1-2x10 -6

  20. Cross contamination in dual inlet isotope ratio mass spectrometers

    NARCIS (Netherlands)

    Meijer, H.A.J.; Neubert, R.E.M.; Visser, G.H.

    2000-01-01

    Since the early days of geochemical isotope ratio mass spectrometry there has always been the problem of cross contamination, i.e. the contamination of the sample gas with traces of reference gas land vice versa) in a dual inlet system and the analyzer itself. This was attributable to valve leakages

  1. Screening newborns for metabolic disorders based on targeted metabolomics using tandem mass spectrometry

    OpenAIRE

    Yoon, Hye-Ran

    2015-01-01

    The main purpose of newborn screening is to diagnose genetic, metabolic, and other inherited disorders, at their earliest to start treatment before the clinical manifestations become evident. Understanding and tracing the biochemical data obtained from tandem mass spectrometry is vital for early diagnosis of metabolic diseases associated with such disorders. Accordingly, it is important to focus on the entire diagnostic process, including differential and confirmatory diagnostic options, and ...

  2. FAST DETECTION OF ACETYLSALICYLIC ACID BY LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY(LC-MSMS)

    OpenAIRE

    Abusoglu, Sedat; Unlu, Ali; Sivrikaya, Abdullah

    2018-01-01

    ObjectivesAcetylsalicylic acid (ASA) is themost widely used as an analgesic, anti-inflammatory and antipyretic drug, andalso used to inhibit cyclooxygenase dependent platelet aggregation.   The aimof this study was to develop a simple, fast and accurate tandem mass method fordetermination and quantification of ASA.  MethodsChromatographic seperation was performedusing an Shimadzu LC-20-AD (Kyoto, Japan) coupledwith a ABSCIEX API 3200 triple quadrupole massspectromete...

  3. Method for selective detection of explosives in mass spectrometer or ion mobility spectrometer at parts-per-quadrillion level

    Science.gov (United States)

    Ewing, Robert G.; Atkinson, David A.; Clowers, Brian H.

    2015-09-01

    A method for selective detection of volatile and non-volatile explosives in a mass spectrometer or ion mobility spectrometer at a parts-per-quadrillion level without preconcentration is disclosed. The method comprises the steps of ionizing a carrier gas with an ionization source to form reactant ions or reactant adduct ions comprising nitrate ions (NO.sub.3.sup.-); selectively reacting the reactant ions or reactant adduct ions with at least one volatile or non-volatile explosive analyte at a carrier gas pressure of at least about 100 Ton in a reaction region disposed between the ionization source and an ion detector, the reaction region having a length which provides a residence time (tr) for reactant ions therein of at least about 0.10 seconds, wherein the selective reaction yields product ions comprising reactant ions or reactant adduct ions that are selectively bound to the at least one explosive analyte when present therein; and detecting product ions with the ion detector to determine presence or absence of the at least one explosive analyte.

  4. Measurement of the transmission efficiency of He-jet laser time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Cheng Hongxing; Pang Wenning; Shang Rencheng; Zhang Wei; Ta La; Xiao Yuan; Xu Sida; Zhao Zhizheng; Luo Yixiao

    1999-01-01

    A He-jet laser time-of-flight (TOF) mass spectrometer system is built. The sample atoms evaporated in the atomization chamber are used to simulated the reaction products. The sample atoms are transferred by helium gas trough a thin capillary. After passing through a skimmer, the sample atoms are formed into a neutral atom stream. A two-or three-color laser beams perpendicular to the atom jet is used to excite and ionize the atoms by multi-step. Then a pulsed electrical field pulls the ionized atoms to the TOF mass spectrometer. By this processing, the (Z, A) values of the sample atoms can be determined precisely. The efficiency of the spectrometer is studied by measuring the radioactivity of 24 Na atoms. The transmission efficiency consists of two parts, the transportation efficiency and the efficiency of laser resonance ionization. The transportation efficiency is determined to be about 17%

  5. Recipe Estimation Using Mass Spectrometer and Large-Scale Data

    Science.gov (United States)

    Mamun, Al; Nakamoto, Takamichi

    An odor recorder is an instrument capable of determining the qualitative and quantitative composition of the target smell (e.g. apple), so called odor recipe. A variety of smells can be generated by blending multiple odor components; an odor recorder can reproduce smells as well as record them so that the sensor array output pattern of the blended odor can match that of the target odor. Although the range of smell to be recorded has been so far limited, this work enhances that range using mass spectrometry without GC. We previously proposed the algorithm to select appropriate odor components among huge number of candidates. Here we applied this proposed algorithm experimentally for reproducing different eight fruit flavors using odor components selected from our laboratory database, composed of recorded mass patterns of 190 components. The blended and target smells were compared using sensory test (triangle test). Sensory test revealed that the smell blended according to the estimated recipe using our proposed method was almost the same as the target one. Moreover, even if the less contributed components in mass spectra are eliminated from the estimated recipe, the flavor remains almost similar to that of the target one.

  6. The analysis of diagnostic markers of genetic disorders in human blood and urine using tandem mass spectrometry with liquid secondary ion mass spectrometry

    Science.gov (United States)

    Millington, David S.; Kodo, Naoki; Terada, Naoto; Roe, Diane; Chace, Donald H.

    1991-12-01

    A method has been developed for the rapid diagnosis of metabolic diseases based on the analysis of characteristic metabolites in body fluids by fast atom bombardment or liquid secondary ion tandem mass spectrometry (FAB-MS--MS or LSIMS--MS). Acylcarnitine profiles were obtained from 100 [mu]l urine. 200 [mu]l plasma or 25 [mu]l whole blood spotted onto filter paper by simple solvent extraction, esterification and analysis using a precursor ion scan function on a triple quadrupole mass spectrometer. Specificity and sensitivity were improved by adding a small percentage of sodium octyl sulfate to the liquid matrix, which forms ion pairs with acylcarnitine esters. Acylglycines in urine were specifically detected as a group using a different precursor ion scan function. By forming methyl esters, metabolic profiles of both acylcarnitines and acylglycines were achieved in the same sample loading by application of alternating scan functions. Quantitative analysis of selected metabolites was achieved by use of stable isotope-labeled internal standards. Amino acid profiles were obtained from 100 [mu]l plasma and 25 [mu]l whole blood spots using butyl esters and a neutral loss scan function. The quantitative analysis of phenylalanine and tyrosine was achieved in these samples using stable isotope dilution. This capability will facilitate the diagnosis of phenylketonuria and other amino acidemias. These new methods have the requirements of speed, accuracy and capability for automation necessary for large-scale neonatal screening of inborn errors of matabolism.

  7. Development and testing of a double-focusing, static, axisymmetric mass spectrometer

    International Nuclear Information System (INIS)

    Ritter, G.

    1979-04-01

    The developed mass spectrometer affords very high acceptance (cm 2 sr) compared with conventional mass spectrometers owing to its large solid angle of 0.178 sr. The ion optical properties of the instrument were tested by bombarding various targets (Al, Ni, Ti, Cu, Si) with potassium or caesium ions from a thermionic ion source with energies of 1, 2 and 3 keV and recording mass spectra of positive and negative sputtered ions. The ion optical beam path was calculated analytically (magnet system) in part and numerically in part (energy analyzer, einzel lenses and detector system) and represented in graph form. The results obtained from the mass spectra showed that the magnet system with its twelve permanent magnets is too irregular to produce mass linses with good resolution. Furthermore, it was found that the maximum primary energy of the alkali ions that was possible in this mass spectrometer owing to the breakdown strength was not sufficient to record surface-specific mass spectra since the target surface was covered within a very short time with an at least monatomic layer of alkali ions from the thermionic ion source. (orig./HP) [de

  8. Analysis of U and Pu resin bead samples with a single stage mass spectrometer

    International Nuclear Information System (INIS)

    Smith, D.H.; Walker, R.L.; Bertram, L.K.; Carter, J.A.

    1979-01-01

    Resin bead sampling enables the shipment of nanogram U and Pu quantities for analysis. Application of this sampling technique to safeguards was investigated with a single-stage mass spectrometer. Standards gave results in good agreement with NBS certified values. External precisions of +-0.5% were obtained on isotopic ratios of approx. 0.01; precisions on quantitative measurements are +-1.0%

  9. Use of the Isomass 54E thermal ionisation mass spectrometer at AEE Winfrith

    International Nuclear Information System (INIS)

    Knight, A.P.

    1982-03-01

    A Vacuum Generators Isomass 54E mass spectrometer is used to carry out isotopic analyses. The capabilities of the instrument and its method of operation are outlined, and the technique used for isotopic analysis of uranium is described in detail, with results of tests on NBS standard specimens and Zebra fuel element pellets. (U.K.)

  10. Up-gradation of hydrogen isotope ratio mass spectrometer for high precision water analysis

    International Nuclear Information System (INIS)

    Ingole, R.B.; Ochani, R.G.; Handu, V.K.

    2009-01-01

    BARC has built many mass spectrometers for the measurement of deuterium to hydrogen ratios in water samples in Heavy Water Plants and other laboratories in DAE. All these D/H mass spectrometers use manually operated sample inlet system which have limitations due to temperature variations, variable sample size, manual valve operation etc. and limit the precision of measurement especially in applications where small variation in D/H ratio (with a precision of 1 per mil) occur in nature. To overcome these limitations, a new automated sample inlet system (SIS) has been developed. Use of new SIS not only widens the applicability of in house built D/H mass spectrometers, it also meets the increasing demand for high precision (per mil) isotopic ratio measurements in water samples from oceanography, isotope hydrology and environmental sciences. With the auto sampler introduced in the D/H mass spectrometer, analysis of the known standard along with unknown sample is done to evaluate the δD (in units per mil) i.e. hydrogen isotopic values, for unknown sample

  11. FY16 Safeguards Technology Cart-Portable Mass Spectrometer Project Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Cyril V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitten, William B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    The Oak Ridge National Laboratory project for the Next Generation Safeguards Initiative Safeguards Technology Development Subprogram has been involved in the development of a cart portable mass spectrometer based on a Thermo ITQ ion trap mass spectrometer (referred to simply as the ITQ) for the field analysis of 235U/238U ratios in UF6. A recent discovery of the project was that combining CO2 with UF6 and introducing the mixture to the mass spectrometer (MS) appeared to increase the ionization efficiency and, thus, reduce the amount of UF6 needed for an analysis while also reducing the corrosive effects of the sample. However, initial experimentation indicated that mixing parameters should be closely controlled to ensure reproducible results. To this end, a sample manifold (SM) that would ensure the precise mixing of UF6 and CO2 was designed and constructed. A number of experiments were outlined and conducted to determine optimum MS and SM conditions which would provide the most stable isotope ratio analysis. The principal objective of the project was to provide a retrofit ITQ mass spectrometer operating with a SM capable of achieving a variation in precision of less than 1% over 1 hour of sampling. This goal was achieved by project end with a variation in precision of 0.5 to 0.8% over 1 hour of sampling.

  12. System for direct introduction of solid samples for the MI-1201 mass spectrometer

    International Nuclear Information System (INIS)

    Dzhaliashvili, V.L.; Vakhaniya, G.V.; Melitauri, I.K.; Ordzhonikidze, K.G.; Parulava, L.P.

    1989-01-01

    System for direct introduction of solid compound samples for the MI-1201 mass spectrometer, based on gas ion source is described. The system is designated for isotope analysis of solid compounds and enables to perform quick introduction of examined samples, control of sample input, use small substance quantities for analysis

  13. Quadrupole mass spectrometer for a mobile laboratory to measure isotope ratios

    Energy Technology Data Exchange (ETDEWEB)

    Walton, J.R.; Smith, D.H.; McKown, H.S.; Carter, J.A.

    1981-01-01

    A mobile laboratory has been assembled for on-site inspection of plant operations handlng special nuclear materials. The isotopic composition of U, Pu, and other elements can be analyzed using a quadrupole mass spectrometer. Some results of analysis of uranium and boron standards are given. (DLC)

  14. Microsystem with integrated capillary leak to mass spectrometer for high sensitivity temperature programmed desorption

    DEFF Research Database (Denmark)

    Quaade, Ulrich; Jensen, Søren; Hansen, Ole

    2004-01-01

    Temperature programmed desorption (TPD) is a method for obtaining information about quantities and binding properties of adsorbed species on a surface. A microfabricated flow system for TPD with an integrated capillary leak to a mass spectrometer is presented. The use of an integrated capillary...

  15. Ultrasensitive resonance ionization mass spectrometer for evaluating krypton contamination in xenon dark matter detectors

    International Nuclear Information System (INIS)

    Iwata, Y.; Sekiya, H.; Ito, C.

    2015-01-01

    An ultrasensitive resonance ionization mass spectrometer that can be applied to evaluate krypton (Kr) contamination in xenon (Xe) dark matter detectors has been developed for measuring Kr at the parts-per-trillion (ppt) or sub-ppt level in Xe. The gas sample is introduced without any condensation into a time-of-flight mass spectrometer through a pulsed supersonic valve. Using a nanosecond pulsed laser at 212.6 nm, 84 Kr atoms in the sample are resonantly ionized along with other Kr isotopes. 84 Kr ions are then mass separated and detected by the mass spectrometer in order to measure the Kr impurity concentration. With our current setup, approximately 0.4 ppt of Kr impurities contained in pure argon (Ar) gas are detectable with a measurement time of 1000 s. Although Kr detection sensitivity in Xe is expected to be approximately half of that in Ar, our spectrometer can evaluate Kr contamination in Xe to the sub-ppt level

  16. A compact sector-type multi-turn time-of-flight mass spectrometer 'MULTUM II'

    International Nuclear Information System (INIS)

    Okumura, Daisuke; Toyoda, Michisato; Ishihara, Morio; Katakuse, Itsuo

    2004-01-01

    A new compact sector-type multi-turn time-of-flight mass spectrometer 'MULTUM II' was constructed. The ion optical system was simplified compared with former sector-type multi-turn time-of-flight mass spectrometer 'MULTUM Linear plus'. The multi-turn part of the new instruments consisted of only four toroidal electric sector fields. The mean radius of cylindrical electric sectors was 50 mm and the deflection angle was 157.1 deg. . The total flight path length of one cycle was 1.308 m. All ion optical elements were hanged on the top plate (480 mmx380 mm) of the vacuum housing. Variations of the mass resolution and ion transmission according to the number of cycles were determined. The mass resolution of 33,000 was achieved after 150 cycles

  17. Surface profiling of lithium with a laser-desorption mass-spectrometer microprobe

    International Nuclear Information System (INIS)

    Bickel, G.A.; Adams, H.M.

    1999-01-01

    A laser-desorption mass-spectrometer microprobe has been developed to profile Li distributions on the crevice surfaces of Cr-plated rolled-joint hubs. A single laser pulse is used to desorb and ionize the surface species followed by detection of Li + in a time-of-flight mass spectrometer. Images of the surface Li distribution are obtained with are solution of <10 μm. These images are directly compared with Li images from the more conventional secondary ion mass spectrometry technique and evaluated with respect to surface topographical features measured by secondary electron microscopy and atomic force microscopy. The laser-desorption images are shown to provide the same qualitative information as that available from secondary ion mass spectrometry. (author)

  18. A qualitative study of amlodipine and its related compounds by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Gibbons, John; Pugh, Jonathan; Dimopoulos-Italiano, Gina; Pike, Richard

    2006-01-01

    A comprehensive structural analysis of amlodipine and certain related compounds was performed by electrospray ionization tandem mass spectrometry. Triple quadrupole and quadrupole time-of-flight instruments were used to provide collision-induced dissociation and accurate mass measurement for selected product and second-generation product ions. A unique ion rearrangement was observed, which was found to be characteristic of certain dihydropyridines. This study provides a fundamental understanding of the fragmentation of these compounds. The structural elucidation of an unknown impurity is presented as an example. Copyright (c) 2006 John Wiley & Sons, Ltd.

  19. Performance evaluation of a miniature magnetic sector mass spectrometer onboard a satellite in space.

    Science.gov (United States)

    Guo, Meiru; Li, Detian; Cheng, Yongjun; Wang, Yongjun; Sun, Wenjun; Pei, Xiaoqiang; Dong, Meng; Sheng, Xuemin; Zhao, Lan; Li, Yanwu

    2018-04-01

    With the rapid development of space technology in China, it is urgent to use mass spectrometer to detect the space environment. In this work, a space miniature magnetic sector mass spectrometer is evaluated, which consists of three subsystems: (1) physical unit, (2) electric control unit, (3) and high voltage power. It has 90° magnetic sector-field analyzer with double trajectory, in which a trajectory measurement range is from 1 to 12 amu, the other range is from 6 to 90 amu.The mass spectrometer has two work models, one is used to measure space neutral gas when the filament of mass spectrometer ion source turned on, the other is used to measure space charged ions when the filament turned off. The absolute resolution of this device is less than 1 amu, the minimum detectable ion current is about 10 -13  A, and the sensitivity is 10 -6  A/Pa (N 2 ). Its overall size is 170 mm × 165 mm × 170 mm, its weight is 4.5 kg, and its power consumption is 18 W. A series of environmental adaptability tests, including high and low temperature cycle, shock, vibration, thermal vacuum cycle, were carried out on the ground before launching, and sensitivity and peak position were also calibrated on the ground. In November 2012, the mass spectrometer was carried by an experimental satellite to 499 km sun synchronization and is still working right now. It successfully detected the atmosphere compositions both in the satellite orbit and gas-emitted from satellite, including O, He, 12 CO 2 , 13 CO 2 , H 2 , N 2 , O 2 , H 2 O, and so on.

  20. Quantitative Caffeine Analysis Using a Surface Sampling Probe Electrospray Ionization Tandem Mass Spectrometry System

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Michael J [ORNL; Deibel, Michael A. [Earlham College; Tomkins, Bruce A [ORNL; Van Berkel, Gary J [ORNL

    2005-01-01

    Quantitative determination of caffeine on reversed-phase C8 thin-layer chromatography plates using a surface sampling electrospray ionization system with tandem mass spectrometry detection is reported. The thin-layer chromatography/electrospray tandem mass spectrometry method employed a deuterium-labeled caffeine internal standard and selected reaction monitoring detection. Up to nine parallel caffeine bands on a single plate were sampled in a single surface scanning experiment requiring 35 min at a surface scan rate of 44 {mu}m/s. A reversed-phase HPLC/UV caffeine assay was developed in parallel to assess the mass spectrometry method performance. Limits of detection for the HPLC/UV and thin-layer chromatography/electrospray tandem mass spectrometry methods determined from the calibration curve statistics were 0.20 ng injected (0.50 {mu}L) and 1.0 ng spotted on the plate, respectively. Spike recoveries with standards and real samples ranged between 97 and 106% for both methods. The caffeine content of three diet soft drinks (Diet Coke, Diet Cherry Coke, Diet Pepsi) and three diet sport drinks (Diet Turbo Tea, Speed Stack Grape, Speed Stack Fruit Punch) was measured. The HPLC/UV and mass spectrometry determinations were in general agreement, and these values were consistent with the quoted values for two of the three diet colas. In the case of Diet Cherry Coke and the diet sports drinks, the determined caffeine amounts using both methods were consistently higher (by 8% or more) than the literature values.

  1. Tandem mass spectrometry multiplex analysis of methylated and non-methylated urinary Gb3 isoforms in Fabry disease patients.

    Science.gov (United States)

    Abaoui, Mona; Boutin, Michel; Lavoie, Pamela; Auray-Blais, Christiane

    2016-01-15

    Fabry disease is a lysosomal storage disorder leading to the accumulation of glycosphingolipids in biological fluids and tissues. Globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3) are currently used for Fabry screening and diagnosis. However, these biomarkers are not always increased in Fabry patients with residual enzyme activity. We recently identified 7 urinary methylated Gb3-related isoforms. The aims of this study were (1) to develop and validate a novel LC-MS/MS method for the relative quantification of methylated and non-methylated Gb3 isoforms normalized to creatinine, (2) to evaluate these biomarkers in Fabry patients and healthy controls, and (3) to assess correlations between biomarker urinary excretion with age, gender, treatment and genotype of patients. Urine samples from 150 Fabry patients and 95 healthy controls were analyzed. Samples were purified and injected in the tandem mass spectrometer working in positive electrospray ionization. Relative quantification was performed for 15 methylated and non-methylated Gb3 isoforms. Significant correlations (pFabry patients with late-onset cardiac variant mutations. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. On-line immunoaffinity column-liquid chromatography-tandem mass spectrometry method for trace analysis of diuron in wastewater treatment plant effluent sample.

    Science.gov (United States)

    Zhang, Xiuli; Martens, Dieter; Krämer, Petra M; Kettrup, Antonius A; Liang, Xinmiao

    2006-11-10

    An on-line immunoaffinity column with liquid chromatography/tandem mass spectrometry (IAC-LC-MS/MS) method for the determination of diuron in water matrices was described. This method used a sol-gel immunoaffinity column (20 mm x 4 mm I.D.) for on-line sample cleanup and enrichment, a monolithic analytical column (100 mm x 4.6 mm I.D.) for separation, and a triple quadrupole mass spectrometer for quantitation. The major challenges for the on-line set-up were discussed. The optimized on-line protocol was emphasized by the fact that low limit of quantitation (LOQ) of 1.0 ng/L was achieved with only 2.5-mL sample. In addition, a satisfactory accuracy ( approximately 90% of recovery) and precision (effect, the on-line IAC-LC-MS/MS analysis method can reliably determine diuron in wastewater treatment plant effluent sample.

  3. Inverted time-of-flight spectrometer for mass-to-charge analysis of plasma.

    Science.gov (United States)

    Gushenets, V I; Burachevsky, Yu A; Vizir, A V; Oks, E M; Savkin, K P; Tynkov, A V; Yushkov, G Yu

    2014-02-01

    The paper describes the principle of operation, design special features, and parameters of an inverted time-of-flight spectrometer. The spectrometer is designed in such way that its deflecting plates, drift tube, and primary measuring system are at high potential with respect to the ground potential, whereas plasma is formed near grounded electrodes. This type of configuration greatly extends the application range of the device, making it possible to measure the mass-to-charge composition of plasma with wide range of parameters.

  4. Accelerator Mass Spectrometry on SIRIUS: New 6 MV spectrometer at ANSTO

    Science.gov (United States)

    Wilcken, K. M.; Fink, D.; Hotchkis, M. A. C.; Garton, D.; Button, D.; Mann, M.; Kitchen, R.; Hauser, T.; O'Connor, A.

    2017-09-01

    The Centre for Accelerator Science at ANSTO operates four tandem accelerator systems for Accelerator Mass Spectrometry (AMS) and Ion Beam Analysis (IBA). The latest addition to the fleet is SIRIUS, a 6 MV combined IBA and AMS system. Following initial ion beam testing, conditioning and debugging software and hardware, SIRIUS is now commissioned. Details of the instrument design and performance data for 10Be, 26Al and 36Cl are presented.

  5. Doping control analysis of anabolic steroids in equine urine by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wong, April S Y; Leung, Gary N W; Leung, David K K; Wan, Terence S M

    2017-09-01

    Anabolic steroids are banned substances in equine sports. Gas chromatography-mass spectrometry (GC-MS) has been the traditional technique for doping control analysis of anabolic steroids in biological samples. Although liquid chromatography-mass spectrometry (LC/MS) has become an important technique in doping control, the detection of saturated hydroxysteroids by LC-MS remains a problem due to their low ionization efficiency under electrospray. The recent development in fast-scanning gas-chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) has provided a better alternative with a significant reduction in chemical noise by means of selective reaction monitoring. Herein, we present a sensitive and selective method for the screening of over 50 anabolic steroids in equine urine using gas chromatography-tandem mass spectrometry (GC-MS/MS). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Measuring the mass and width of the Z0: The status of the energy spectrometers

    International Nuclear Information System (INIS)

    Rouse, F.; Levi, M.; Kent, J.; King, M.; Von Zanthier, C.; Watson, S.; Bambade, P.; Erickson, R.; Jung, C.K.; Nash, J.; Wormser, G.

    1989-05-01

    The Stanford Linear Collider (SLC) located at the Stanford Linear Accelerator Center (SLAC) collides electrons and positrons produced in the linear accelerator pulse by pulse. The object is to produce collisions energetic enough to produce the heavy intermediate vector boson, the Z 0 . An essential component of the SLC physics program is the precise knowledge of the center-of-mass energy of each interaction. We measure the energy of each collision by using two energy spectrometers. The spectrometers are located in extraction lines of each beam. We will measure the energy of each beam to 20 MeV or 5 parts in 10 4 . We report here on the status of the energy spectrometer system. 13 refs., 7 figs., 3 tabs

  7. Validation and application of a high-performance liquid chromatography--tandem mass spectrometry assay for mosapride in human plasma.

    Science.gov (United States)

    Ramakrishna, N V S; Vishwottam, K N; Manoj, S; Koteshwara, M; Chidambara, J; Varma, D P

    2005-09-01

    A simple, rapid, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for quantification of mosapride (I), a novel and potent gastroprokinetic agent that enhances the upper gastrointestinal motility by stimulating 5-HT(4) receptor. The analyte and internal standard, tamsulosin (II), were extracted by liquid-liquid extraction with diethyl ether-dichloromethane (70:30, v/v) using a Glas-Col Multi-Pulse Vortexer. The chromatographic separation was performed on a reversed-phase Waters symmetry C(18) column with a mobile phase of 0.03% formic acid-acetonitrile (10:90, v/v). The protonated analyte was quantitated in positive ionization by multiple reaction monitoring with a mass spectrometer. The mass transitions m/z 422.3 -->198.3 and m/z 409.1 -->228.1 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.5-100.0 ng/mL for mosapride in human plasma. The lower limit of quantitation was 500 pg/mL with a relative standard deviation of less than 15%. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges. A run time of 2.0 min for each sample made it possible to analyze a throughput of more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. Copyright (c) 2005 John Wiley & Sons, Ltd.

  8. Accurate Identification of Deamidated Peptides in Global Proteomics using a Quadrupole Orbitrap Mass Spectrometer

    Science.gov (United States)

    Nepomuceno, Angelito I.; Gibson, Radiance J.; Randall, Shan M.; Muddiman, David C.

    2014-01-01

    Deamidation of asparagine and glutamine residues is a common post-translational modification. Researchers often rely on mass spectrometric based proteomic techniques for the identification of these post-translational sites. Mass spectral analysis of deamidated peptides is complicated and often misassigned due to overlapping 13C peak of the amidated form with the deamidated monoisotopic peak; these two peaks are only separated by 19.34 mDa. For proper assignment it is inherently important to use a mass spectrometer with high mass measurement accuracy and high resolving power. Herein, mouse brain tissue lysate was prepared using filter-aided sample preparation (FASP) method and Stage Tip fractionation followed by analysis on a nanoLC coupled to a quadrupole orbitrap (Q-Exactive) mass spectrometer to accurately identify more than 5400 proteins. Mass spectral data was processed using MASCOT and ProteoIQ for accurate identification of peptides and proteins. MASCOT search values for precursor and MS/MS mass tolerances were investigated, and it was determined data searched with greater than 5 ppm precursor mass tolerance resulted in the misassignment of deamidated peptides. Peptides that were identified with a mass measurement accuracy of ± 5 ppm were correctly assigned. PMID:24289162

  9. A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings

    Science.gov (United States)

    Blashenkov, N. M.; Sheshenya, E. S.; Solov'ev, S. M.; Sachenko, V. D.; Gall, L. N.; Zarutskii, I. V.; Gall, N. R.

    2013-05-01

    A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings based on the carbon-13 isotope breath test has been designed and constructed. Important stages of the work included (i) calculating a low-aberration mass analyzer, (ii) manufacturing and testing special gas inlet system, and (iii) creating a small-size collector of ions. The proposed instrument ensures 13C/12C isotopic ratio measurement to within 1.7‰ (pro mille) accuracy, which corresponds to requirements for a diagnostic tool. Preliminary medical testing showed that the mass spectrometer is applicable to practical diagnostics. The instrument is also capable of measuring isotopic ratios of other light elements, including N, O, B (for BF2+ ions), Ar, Cl, and S.

  10. Spray-inlet microwave plasma torch ionization tandem mass spectrometry for the direct detection of drug samples in liquid solutions.

    Science.gov (United States)

    Miao, Meng; Zhao, Gaosheng; Wang, Yaliang; Xu, Li; Dong, Junguo; Cheng, Ping

    2017-12-30

    Drug abuse or dependence results in a series of social problems, including crime and traffic accidents. Spray-inlet microwave plasma torch tandem mass spectrometry (MPT-MS/MS) was developed and used for the direct detection of such drugs in liquid solutions. Drug sample solutions were directly sprayed into the flame of an MPT by a sampling pump and the ions produced by Penning ionization and ion-molecule reactions were guided into a quadrupole time-of-flight (QTOF) tandem mass spectrometer for mass analysis. The MPT was operated at 40 W and 2.45 GHz in a 700 mL/min argon flow both for the inner and middle plasma. Intact quasi-molecular and molecular ions of various drugs were successfully characterized by spray-inlet MPT-MS/MS. The analysis of one sample was finished within 30 s. Furthermore, the method exhibited excellent efficiency, precision and sensitivity, and the limits of detection and limits of quantification of the samples in methanol were in the range of 5.25-60.0 and 17.5-200 ng g -1 , respectively. Excellent linearities with coefficients of determination (R 2 ) of 0.9627-0.9980 were verified in the range 0.05-50 μg g -1 . Four different beverages purchased locally were also analyzed with spray-inlet MPT-MS/MS, and caffeine was directly determined in two of the beverages. By adding six standard drug samples to sport drinks (each drug was 1 μg g -1 ) and Chinese spirit (each drug was 0.1 μg g -1 ), all the drugs except for caffeine were detected successfully. This study indicates that spay-inlet MPT-MS/MS is an effective method for direct and rapid identification of drug solutions, and it has substantial potential for fast and sensitive drug residue detection. Copyright © 2017 John Wiley & Sons, Ltd.

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  12. Planar differential mobility spectrometer as a pre-filter for atmospheric pressure ionization mass spectrometry

    Science.gov (United States)

    Schneider, Bradley B.; Covey, Thomas R.; Coy, Stephen L.; Krylov, Evgeny V.

    2010-01-01

    Ion filters based on planar DMS can be integrated with the inlet configuration of most mass spectrometers, and are able to enhance the quality of mass analysis and quantitative accuracy by reducing chemical noise, and by pre-separating ions of similar mass. This paper is the first in a series of three papers describing the optimization of DMS / MS instrumentation. In this paper the important physical parameters of a planar DMS-MS interface including analyzer geometry, analyzer coupling to a mass spectrometer, and transport gas flow control are considered. The goal is to optimize ion transmission and transport efficiency, provide optimal and adjustable resolution, and produce stable operation under conditions of high sample contamination. We discuss the principles of DMS separations and highlight the theoretical underpinnings. The main differences between planar and cylindrical geometries are presented, including a discussion of the advantages and disadvantages of RF ion focusing. In addition, we present a description of optimization of the frequency and amplitude of the DMS fields for resolution and ion transmission, and a discussion of the influence and importance of ion residence time in DMS. We have constructed a mass spectrometer interface for planar geometries that takes advantage of atmospheric pressure gas dynamic principles, rather than ion focusing, to minimize ion losses from diffusion in the analyzer and to maximize total ion transport into the mass spectrometer. A variety of experimental results has been obtained that illustrate the performance of this type of interface, including tests of resistance to high contamination levels, and the separation of stereoisomers. In a subsequent publication the control of the chemical interactions that drive the separation process of a DMS / MS system will be considered. In a third publication we describe novel electronics designed to provide the high voltages asymmetric waveform fields (SV) required for these

  13. Program able detector of the output signals of a mass spectrometer

    International Nuclear Information System (INIS)

    Naumov, V.V.

    2000-01-01

    The detector intended for separating according to the assigned program the signals from the output signals of the mass spectrometers required for registration and analysis of the mass-spectrum peaks, as well as for separation of the superimposed peaks is described. The detector makes it possible by analysis of complex compounds to select from the multitude of the mass-spectrum peaks the set of signals required for processing, whereby the time for analysis is essentially reduced and the microprocessor operational memory is used more efficiently [ru

  14. Small mass spectrometer with extended measurement capabilities at high pressures. [for planetary atmosphere analysis

    Science.gov (United States)

    Von Zahn, U.; Mauersberger, K.

    1978-01-01

    For the in situ investigation of planetary atmospheres a small Mattauch-Herzog mass spectrometer has been developed. Its high-pressure performance has been improved by incorporating differential pumping between the ion source and the analyzing fields, shortening the path-length as well as increasing the extraction field in the ion source. In addition doubly ionized and dissociated ions are used for mass analysis. These measures make possible operation up to 0.01 millibars. Results of laboratory tests related to linearity, dynamic range, and mass resolution are presented, in particular for CO2.

  15. A Dual Source Ion Trap Mass Spectrometer for the Mars Organic Molecule Analyzer of ExoMars 2018

    Science.gov (United States)

    Brickerhoff, William B.; vanAmerom, F. H. W.; Danell, R. M.; Arevalo, R.; Atanassova, M.; Hovmand, L.; Mahaffy, P. R.; Cotter, R. J.

    2011-01-01

    We present details on the objectives, requirements, design and operational approach of the core mass spectrometer of the Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars mission. The MOMA mass spectrometer enables the investigation to fulfill its objective of analyzing the chemical composition of organic compounds in solid samples obtained from the near surface of Mars. Two methods of ionization are realized, associated with different modes of MOMA operation, in a single compact ion trap mass spectrometer. The stringent mass and power constraints of the mission have led to features such as low voltage and low frequency RF operation [1] and pulse counting detection.

  16. Quantitative analysis of phytosterols in edible oils using APCI liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Mo, Shunyan; Dong, Linlin; Hurst, W. Jeffrey; van Breemen, Richard B.

    2014-01-01

    Previous methods for the quantitative analysis of phytosterols have usually used GC-MS and require elaborate sample preparation including chemical derivatization. Other common methods such as HPLC with absorbance detection do not provide information regarding the identity of the analytes. To address the need for an assay that utilizes mass selectivity while avoiding derivatization, a quantitative method based on LC-tandem mass spectrometry (LC-MS-MS) was developed and validated for the measurement of six abundant dietary phytosterols and structurally related triterpene alcohols including brassicasterol, campesterol, cycloartenol, β-sitosterol, stigmasterol, and lupeol in edible oils. Samples were saponified, extracted with hexane and then analyzed using reversed phase HPLC with positive ion atmospheric pressure chemical ionization tandem mass spectrometry and selected reaction monitoring. The utility of the LC-MS-MS method was demonstrated by analyzing 14 edible oils. All six compounds were present in at least some of the edible oils. The most abundant phytosterol in all samples was β-sitosterol, which was highest in corn oil at 4.35 ± 0.03 mg/g, followed by campesterol in canola oil at 1.84 ± 0.01 mg/g. The new LC-MS-MS method for the quantitative analysis of phytosterols provides a combination of speed, selectivity and sensitivity that exceed those of previous assays. PMID:23884629

  17. Analysis of xyloglucans by ambient chloride attachment ionization tandem mass spectrometry.

    Science.gov (United States)

    Vinueza, Nelson R; Gallardo, Vanessa A; Klimek, John F; Carpita, Nicholas C; Kenttämaa, Hilkka I

    2013-10-15

    Xyloglucan oligomers obtained upon enzyme digestion from Hymenaea courbaril, Arabidopsis Columbia-0 and mur3 were ionized and analyzed by using chloride anion attachment electrospray ionization (ESI) and tandem mass spectrometry. MW determination and structural elucidation of several xyloglucan oligomers was performed directly from the mixture solutions without sample pretreatment or derivatization. Sodium cation attachment was used to determine the number of xyloglucans present in the mixtures and their MWs. However, tandem mass spectrometry results showed that structure elucidation based on the sodium adducts is ambiguous. Chloride anion also forms stable adducts with these xyloglucans upon ESI. These adducts can be readily identified due to the chlorine isotope pattern. The mass spectral profile of xyloglucans obtained for the mixtures matches the HPAEC results, thus validating this methodology for the determination of the xyloglucan composition and the MW of each xyloglucan. Upon collisional activation in MS(2) experiments, the chloride anion adducts readily lose HCl, which helps verify the molecular weight of each xyloglucan. Isolating the resulting anion (deprotonated oligomer) and subjecting it to further collision-activated dissociation experiments (MS(n); n=3-4) yields useful structural information that allows the differentiation between isomeric anions and hence determination of the sequence of the xyloglucan oligomers. The deprotonated oligomers fragment by a stepwise loss of sugar units from the reducing end. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Applications of Tandem Mass Spectrometry in the Structure Determination of Permethylated Sialic Acid-containing Oligosaccharides

    International Nuclear Information System (INIS)

    Yoo, Eun Sun; Yoon, In Mo

    2005-01-01

    Sets of sialic acid-containing trisaccharides having different internal and terminal linkages have been synthesized to develop a sensitive method for analysis of the reducing terminal linkage positions. The trisaccharides, sialyl(α 2-3)Gal(β 1-3)GalNAc and sialyl(α 2-3)Gal(β 1-X)GlcNAc where X=3, 4 and 6, were synthesized and examined using electrospray ionization (ESI)-collision induced dissociation (CID) tandem mass spectrometry (MS/MS). The compounds chosen for this study are related to terminal groups likely to be found on polylactosamine-like glycoproteins and glycolipids which occur on the surface of mammalian cells. The purpose of this study is to develop tandem mass spectrometral methods to determine detailed carbohydrate structures on permethylated or partially methylated oligosaccharides for future applications on biologically active glycoconjugates and to exploit a faster method of synthesizing a series of structural isomeric oligosaccharides to be used for further mass spectrometry and instrumental analysis

  19. Mars Organic Molecule Analyzer (MOMA) Mass Spectrometer Status and Science Operations on the ExoMars Rover

    Science.gov (United States)

    Brinckerhoff, W. B.; van Amerom, F. H. W.; Danell, R.; Pinnick, V. T.; Arevalo, R. D., Jr.; Li, X.; Hovmand, L.; Mahaffy, P. R.; Goetz, W.; Goesmann, F.; Steininger, H.

    2014-12-01

    The Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars rover will examine the chemical composition of samples acquired from depths of up to two meters below the martian surface, where organics may be protected from radiative and oxidative degradation. MOMA combines analyses of acquired drill fines via (i) pyrolysis gas chromatography mass spectrometry (GCMS) and (ii) Mars ambient laser desorption mass spectrometry (LDMS), enabled by a fast-valve capillary ion inlet system. This "dual source" approach gives MOMA unprecedented breadth of detection over a wide range of molecular weights and volatilities. Analysis of nonvolatile, higher-molecular weight organics such as carboxylic acids and peptides even in the presence of significant perchlorate concentrations is enabled by the extremely short (~1 ns) pulses of the desorption laser. Use of the MOMA ion trap's tandem mass spectrometry (MS/MS) mode permits selective focus on key species for isolation and controlled fragmentation, providing structural analysis capabilities. The flight-like engineering test unit (ETU) of MOMA's ion trap mass spectrometer has been put through a battery of tests to assure robustness of operation in the martian environment, to assess science performance, and to prepare for the flight model build under extremely sterile conditions as required by ExoMars. These tests have included coupling campaigns with advanced prototypes of the MOMA GC (provided by the University of Paris) and the MOMA tapping station, ovens, and laser (provided by MPS and LZH). Planning for science operations has expanded with the development of scripts for MOMA's various parameterized modes, including MS/MS. Given the limited duration of the baseline mission (218 sols), MOMA will benefit from a thorough characterization of its performance with a variety of Mars analog samples and a careful comparison with current science results from the SAM experiment on MSL. Such preparation will enable efficient

  20. The fragmentation mechanism of five-membered lactones by electrospray ionisation tandem mass spectrometry

    Science.gov (United States)

    Crotti, Antônio E. M.; Fonseca, Tatiana; Hong, Hui; Staunton, James; Galembeck, Sérgio E.; Lopes, Norberto P.; Gates, Paul J.

    2004-04-01

    A series of five-membered lactones (both saturated and unsaturated) and a lactam were analysed by electrospray ionisation tandem (ESI-MS/MS) and sequential mass spectrometry (ESI-MSn). It was observed that the main fragment ions were derived from neutral losses of CO and/or H2O (NH3 for the lactam). The fragmentation pathways followed are rationalised in terms of the resulting carbocation stability and the energy of the possible fragment ions, calculated by the CBS-Q composite method.

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

    CERN Document Server

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

    1999-01-01

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

  2. Atmospheric pressure ionization-tandem mass spectrometry of the phenicol drug family.

    Science.gov (United States)

    Alechaga, Élida; Moyano, Encarnación; Galceran, M Teresa

    2013-11-01

    In this work, the mass spectrometry behaviour of the veterinary drug family of phenicols, including chloramphenicol (CAP) and its related compounds thiamphenicol (TAP), florfenicol (FF) and FF amine (FFA), was studied. Several atmospheric pressure ionization sources, electrospray (ESI), atmospheric pressure chemical ionization and atmospheric pressure photoionization were compared. In all atmospheric pressure ionization sources, CAP, TAP and FF were ionized in both positive and negative modes; while for the metabolite FFA, only positive ionization was possible. In general, in positive mode, [M + H](+) dominated the mass spectrum for FFA, while the other compounds, CAP, TAP and FF, with lower proton affinity showed intense adducts with species present in the mobile phase. In negative mode, ESI and atmospheric pressure photoionization showed the deprotonated molecule [M-H](-), while atmospheric pressure chemical ionization provided the radical molecular ion by electron capture. All these ions were characterized by tandem mass spectrometry using the combined information obtained by multistage mass spectrometry and high-resolution mass spectrometry in a quadrupole-Orbitrap instrument. In general, the fragmentation occurred via cyclization and losses or fragmentation of the N-(alkyl)acetamide group, and common fragmentation pathways were established for this family of compounds. A new chemical structure for the product ion at m/z 257 for CAP, on the basis of the MS(3) and MS(4) spectra is proposed. Thermally assisted ESI and selected reaction monitoring are proposed for the determination of these compounds by ultra high-performance liquid chromatography coupled to tandem mass spectrometry, achieving instrumental detection limits down to 0.1 pg. Copyright © 2013 John Wiley & Sons, Ltd.

  3. A new time of flight mass spectrometer for absolute dissociative electron attachment cross-section measurements in gas phase

    Science.gov (United States)

    Chakraborty, Dipayan; Nag, Pamir; Nandi, Dhananjay

    2018-02-01

    A new time of flight mass spectrometer (TOFMS) has been developed to study the absolute dissociative electron attachment (DEA) cross section using a relative flow technique of a wide variety of molecules in gas phase, ranging from simple diatomic to complex biomolecules. Unlike the Wiley-McLaren type TOFMS, here the total ion collection condition has been achieved without compromising the mass resolution by introducing a field free drift region after the lensing arrangement. The field free interaction region is provided for low energy electron molecule collision studies. The spectrometer can be used to study a wide range of masses (H- ion to few hundreds atomic mass unit). The mass resolution capability of the spectrometer has been checked experimentally by measuring the mass spectra of fragment anions arising from DEA to methanol. Overall performance of the spectrometer has been tested by measuring the absolute DEA cross section of the ground state SO2 molecule, and the results are satisfactory.

  4. A new time of flight mass spectrometer for absolute dissociative electron attachment cross-section measurements in gas phase.

    Science.gov (United States)

    Chakraborty, Dipayan; Nag, Pamir; Nandi, Dhananjay

    2018-02-01

    A new time of flight mass spectrometer (TOFMS) has been developed to study the absolute dissociative electron attachment (DEA) cross section using a relative flow technique of a wide variety of molecules in gas phase, ranging from simple diatomic to complex biomolecules. Unlike the Wiley-McLaren type TOFMS, here the total ion collection condition has been achieved without compromising the mass resolution by introducing a field free drift region after the lensing arrangement. The field free interaction region is provided for low energy electron molecule collision studies. The spectrometer can be used to study a wide range of masses (H - ion to few hundreds atomic mass unit). The mass resolution capability of the spectrometer has been checked experimentally by measuring the mass spectra of fragment anions arising from DEA to methanol. Overall performance of the spectrometer has been tested by measuring the absolute DEA cross section of the ground state SO 2 molecule, and the results are satisfactory.

  5. The Multiplexed Chemical Kinetic Photoionization Mass Spectrometer: A New Approach To Isomer-resolved Chemical Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, David L.; Zou, Peng; Johnsen, Howard; Hayden, Carl C.; Taatjes, Craig A.; Knyazev, Vadim D.; North, Simon W.; Peterka, Darcy S.; Ahmed, Musahid; Leone, Stephen R.

    2008-08-28

    We have developed a multiplexed time- and photon-energy?resolved photoionizationmass spectrometer for the study of the kinetics and isomeric product branching of gasphase, neutral chemical reactions. The instrument utilizes a side-sampled flow tubereactor, continuously tunable synchrotron radiation for photoionization, a multi-massdouble-focusing mass spectrometer with 100percent duty cycle, and a time- and positionsensitive detector for single ion counting. This approach enables multiplexed, universal detection of molecules with high sensitivity and selectivity. In addition to measurement of rate coefficients as a function of temperature and pressure, different structural isomers can be distinguished based on their photoionization efficiency curves, providing a more detailed probe of reaction mechanisms. The multiplexed 3-dimensional data structure (intensity as a function of molecular mass, reaction time, and photoionization energy) provides insights that might not be available in serial acquisition, as well as additional constraints on data interpretation.

  6. A low energy, high current, pulsed electron gun for Time-of-flight mass spectrometers

    International Nuclear Information System (INIS)

    Reddy, Pratap; Rao, K.C.; Sule, Uday; Rodrigues, S.M.; Bhushan, K.G.

    2015-01-01

    A compact, low energy, high current pulsed electron gun specifically intended for use in time-of-flight mass spectrometers has been developed. The electron gun consists of a thoriated tungsten hairpin type filament, a wehnelt electrode, series of extracting electrodes, an x-y deflector and a set of pulsing electrodes, all mounted on a CF35 conflat flange. The electron gun delivers ∼ 1 mA of current at 70 eV, in the dc mode. The gun can be pulsed in nanosecond pulses with a repetition rate of upto 50 KHz which can be externally synchronized with conventional time-of-flight electronics. The design and performance of the electron gun over the energy range 20eV to 500 eV is presented along with the pulsing mode operation demonstrated in a time-of-flight mass spectrometer. (author)

  7. Hydrogen-deuterium exchange studies utilizing a thermospray mass spectrometer interface

    International Nuclear Information System (INIS)

    Siegel, M.M.

    1988-01-01

    A routine and efficient technique was developed for exchanging acidic hydrogen for deuterium, utilizing a thermospray mass spectrometer interface, to produce deuterium-enriched deuteron-adduct molecular and fragment ions. Samples dissolved in solvents containing acidic deuterium atoms (D 2 O/trifluoroacetic acid-d 1 or ammonium acetate-d 4 ) were introduced via slug injection into the thermospray interface sandwiched between slugs of the deuteriated solvent. At all other times, the carrier solvent system introduced into the mass spectrometer consisted of a non-deuterium-enriched mixture. Deuterium enrichments achieved were greater than 95%. Deuterium-enriched deuteron-adduct molecular and fragment ions enabled the determination of the number of acidic hydrogens and aided in structural elucidation of model compounds of pharmaceutical interest

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  9. System Assessment and Calibrations of the Kundsen Effusion QuadrupoleMass Spectrometer

    OpenAIRE

    黄 錦涛; 古川 智弘

    2000-01-01

    A vapor pressure measurement instrument was set up by utilizing the "Microvision Plus(LM70)" quadrupole mass spectrometer combined with the Knudsen vapor effusion cell. The purpose of the vapor pressure measurement is to obtain reliable thermodynamic data of sodium-iron complex compounds. Then, the behaviors of these compounds in various environmental conditions can be investigated in detail for analysis of sodium-leak related accidents in fast breeder reactors(FBR). Therefore, the reliabilit...

  10. Elimination of ``memory`` from sample handling and inlet system of a mass spectrometer

    Science.gov (United States)

    Chastgner, P.

    1991-05-08

    This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.

  11. Effective mass trigger at the Brookhaven Multi-Particle Spectrometer (MPS)

    International Nuclear Information System (INIS)

    Willen, E.H.

    1980-01-01

    An effective mass trigger for use at the Brookhaven Multiparticle Spectrometer (MPS) is described. It is a microprocessor based device using extensive fast memory attached to proportional wire chambers in the MPS magnetic field. It will select kinematic quantities unique to the reaction being studied, thereby permitting higher sensitivities and a reduction in data-processing cost for MPS experiments. The principles of operation for this trigger, and the results of simulations to assess its performance, are presented

  12. Portable, remotely operated, computer-controlled, quadrupole mass spectrometer for field use

    International Nuclear Information System (INIS)

    Friesen, R.D.; Newton, J.C.; Smith, C.F.

    1982-04-01

    A portable, remote-controlled mass spectrometer was required at the Nevada Test Site to analyze prompt post-event gas from the nuclear cavity in support of the underground testing program. A Balzers QMG-511 quadrupole was chosen for its ability to be interfaced to a DEC LSI-11 computer and to withstand the ground movement caused by this field environment. The inlet system valves, the pumps, the pressure and temperature transducers, and the quadrupole mass spectrometer are controlled by a read-only-memory-based DEC LSI-11/2 with a high-speed microwave link to the control point which is typically 30 miles away. The computer at the control point is a DEC LSI-11/23 running the RSX-11 operating system. The instrument was automated as much as possible because the system is run by inexperienced operators at times. The mass spectrometer has been used on an initial field event with excellent performance. The gas analysis system is described, including automation by a novel computer control method which reduces operator errors and allows dynamic access to the system parameters

  13. Dust Impact Mass-Spectrometer for the Elemental Composition of Micrometeroroids Research

    Science.gov (United States)

    Rodin, D.; Semkin, N.; Piyakov, I.

    2013-08-01

    Time-of-flight mass spectrometers are widely used for the solution of a set of problems at implementing space experiments for studying the chemical composition of cosmic dust, debris, the own atmosphere of spacecrafts, space objects ground, gas-dust tails of comets, etc. So, for example, dust impact mass spectrometers are applied for the analysis of micrometeoroids flows. In such mass-spectrometers, because of the high energy scattering of ions, arising as a result of shock interaction of the impact- particle and the target, as a rule, sufficiently high resolution capability is obtained by means of application of the large accelerating voltages (about 1-1,5kV). In accordance with the well-known data on the distribution of micrometeoroid flows both in terrestrial and outer space, notably in view of the low probability of shock interaction of dust particles with the target device, the working area of the sensitive surface of the dust impact of mass-spectrometer should be as big as possible when maintaining the device characteristics. The authors have proposed the construction implementation, which should satisfy the following requirements: - minimization of dependence of the output characteristics from the point of collision; - high resolution capability; - high sensitivity; - minimization of the overall and mass characteristics of the spectrometer. To achieve this result the parabolic reflector is applied in the design of the device allowing significantly reduce the dependence of the mass-spectra from the point of collision of the particle and the target, diaphragm of the receiver that limits the number of possible trajectories of ions, reaching the receiver. However, it causes some decline of ions collection ratio, as well as non-linear electrostatic deflector allowing removal of the influence of the initial energy dispersion on the ions' flight time. The design verification was carried out with the help of the electrodynamics amplifier and Van de Graaff generator

  14. Determination of bromadiolone and brodifacoum in human hair by liquid chromatography/tandem mass spectrometry and its application to poisoning cases.

    Science.gov (United States)

    Zhu, Lin; Yan, Hui; Shen, Baohua; Shi, Yan; Shen, Min; Xiang, Ping

    2013-02-28

    Bromadiolone and brodifacoum, two common anticoagulant rodenticides, are involved in the majority of anticoagulant rodenticide poisoning cases in humans in China. Hair analysis can provide long-term information on drug exposure. A method using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) was developed and validated for the measurement of bromadiolone and brodifacoum in human hair. A 1 mL aliquot of a phosphate buffer solution (pH 6.8) was added to 20 mg of pulverized hair followed by ultrasonication and liquid-liquid extraction. Liquid chromatography was performed using a C(18) column with a mobile phase gradient of ammonium acetate (10 mM) and methanol. A tandem mass spectrometer in multiple reaction monitoring mode with a negative electrospray ionization source was employed for detection. Warfarin-d(5) was used as an internal standard for both analytes. The limits of detection (LODs) for bromadiolone and brodifacoum were 0.010 and 0.025 ng/mg, respectively. The calibration curves for both analytes were linear from 0.025 to 1 ng/mg. The accuracy ranged from 90.3 to 109.3%, and the intra-day and inter-day imprecisions were less than 15%. The established method was found effective when applied to the analyses of bromadiolone or brodifacoum in five cases, indicating that segmental hair analysis could be useful for clinical and forensic purposes by identifying the time of ingestion. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Determination of parabens in urine samples by microextraction using packed sorbent and ultra-performance liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Cristina Jardim, Valeria; de Paula Melo, Lidervan; Soares Domingues, Diego; Costa Queiroz, Maria Eugênia

    2015-01-01

    A simple, sensitive, and selective method using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was developed and validated for simultaneous determination of parabens [methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP), butyl paraben (BuP), and benzyl paraben (BzP)] in human urine samples. After microextraction by packed sorbent (MEPS) using a C18 phase, the parabens were separated on a Kinetex C18 column (100 mm × 2.1 mm × 1.7 μm) within 4.6 min using isocratic elution. These compounds were detected on a triple quadrupole tandem mass spectrometer using the multiple reactions monitoring (MRM) mode via an electrospray ionization source operating in the negative ionization mode. Important factors that influence MEPS performance were evaluated, such as the sample pH, draw-eject sample volume, clean-up step, and desorption conditions. The proposed MEPS/UPLC-MS/MS method presented a linear range from 0.5 ng mL(-1) (limit of quantification - LOQ) to 50 ng mL(-1), and interassay precision with coefficients of variation lower than 15%, and relative standard error values of the accuracy ranged from -8.8% to 15%. The MEPS/UPLC-MS/MS method was applied successfully to determine parabens in urine samples from 30 postpartum volunteers, enabling assessment of human exposure to these compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Development of a dedicated isotope mass spectrometer for the noninvasive diagnostics of humans infected with Helicobacter Pylori

    Science.gov (United States)

    Blashenkov, N. M.; Sheshenya, E. S.; Solov'ev, S. M.; Gall', L. N.; Sachenko, V. M.; Zarutskii, I. V.; Gall', N. R.

    2013-06-01

    A dedicated isotope mass spectrometer for the noninvasive diagnostics of humans infected with Helicobacter Pylori using the isotope respiratory test is developed. A low-aberration mass analyzer is calculated, an input system that makes it possible to eliminate the memory effects is developed, and a small-size ion detector is constructed. The mass spectrometer is created, and the tests are performed. The measurement accuracy of the 13C/12C and 16O/18O isotope ratios are 1.7 and 2.2‰, respectively. Preliminary medical tests show that the spectrometer can be employed for the desired diagnostics.

  17. Screening newborns for metabolic disorders based on targeted metabolomics using tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Hye-Ran Yoon

    2015-09-01

    Full Text Available The main purpose of newborn screening is to diagnose genetic, metabolic, and other inherited disorders, at their earliest to start treatment before the clinical manifestations become evident. Understanding and tracing the biochemical data obtained from tandem mass spectrometry is vital for early diagnosis of metabolic diseases associated with such disorders. Accordingly, it is important to focus on the entire diagnostic process, including differential and confirmatory diagnostic options, and the major factors that influence the results of biochemical analysis. Compared to regular biochemical testing, this is a complex process carried out by a medical physician specialist. It is comprised of an integrated program requiring multidisciplinary approach such as, pediatric specialist, expert scientist, clinical laboratory technician, and nutritionist. Tandem mass spectrometry is a powerful tool to improve screening of newborns for diverse metabolic diseases. It is likely to be used to analyze other treatable disorders or significantly improve existing newborn tests to allow broad scale and precise testing. This new era of various screening programs, new treatments, and the availability of detection technology will prove to be beneficial for the future generations.

  18. PepArML: A Meta-Search Peptide Identification Platform for Tandem Mass Spectra.

    Science.gov (United States)

    Edwards, Nathan J

    2013-12-01

    The PepArML meta-search peptide identification platform for tandem mass spectra provides a unified search interface to seven search engines; a robust cluster, grid, and cloud computing scheduler for large-scale searches; and an unsupervised, model-free, machine-learning-based result combiner, which selects the best peptide identification for each spectrum, estimates false-discovery rates, and outputs pepXML format identifications. The meta-search platform supports Mascot; Tandem with native, k-score and s-score scoring; OMSSA; MyriMatch; and InsPecT with MS-GF spectral probability scores—reformatting spectral data and constructing search configurations for each search engine on the fly. The combiner selects the best peptide identification for each spectrum based on search engine results and features that model enzymatic digestion, retention time, precursor isotope clusters, mass accuracy, and proteotypic peptide properties, requiring no prior knowledge of feature utility or weighting. The PepArML meta-search peptide identification platform often identifies two to three times more spectra than individual search engines at 10% FDR.

  19. Determination of parabens in serum by liquid chromatography-tandem mass spectrometry: Correlation with lipstick use.

    Science.gov (United States)

    Tahan, Gabriella Padovani; Santos, Nayara de Kássia Souza; Albuquerque, Ana Carolina; Martins, Isarita

    2016-08-01

    Parabens are the most widely used preservative and are considered to be relatively safe compounds. However, studies have demonstrated that they may have estrogenic activity, and there is ongoing debate regarding the safety and potential cancer risk of using products containing these compounds. In the present work, liquid chromatography-tandem mass spectrometry was applied to determine methylparaben and propylparaben concentrations in serum, and the results were correlated with lipstick application. Samples were analyzed using liquid-liquid extraction, followed by liquid chromatography-tandem mass spectrometry. The validation results demonstrated the linearity of the method over a range of 1-20 ng/mL, in addition to the method's precision and accuracy. A statistically significant difference was demonstrated between serum parabens in women who used lipstick containing these substances compared with those not using this cosmetic (p = 0.0005 and 0.0016, respectively), and a strong association was observed between serum parabens and lipstick use (Spearman correlation = 0.7202). Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Detection of various freshwater cyanobacterial toxins using ultra-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Oehrle, Stuart A; Southwell, Ben; Westrick, Judy

    2010-05-01

    Several freshwater cyanobacteria species have the capability to produce toxic compounds, frequently referred to as cyanotoxins. The most prevalent of these cyanotoxins is microcystin LR. Recognizing the potential health risk, France, Italy, Poland, Australia, Canada, and Brazil have set either standards or guidelines for the amount of microcystin LR permissible in drinking water based on the World Health Organization guideline of one microg/L of microcystin LR. Recently, the United States Environmental Protection Agency has begun to evaluate the occurrence and health effects of cyanotoxins and their susceptibility to water treatment under the Safe Drinking Water Act through the Contaminant Candidate List (CCL). A recent update of the Contaminant Candidate List focuses research and data collection on the cyanotoxins microcystin LR, anatoxin-a, and cylindrospermopsin. Liquid Chromatography/Tandem-Mass Spectrometry (LC/MS/MS) is a powerful tool for the analysis of various analytes in a wide variety of matrices because of its sensitivity and selectivity. The use of smaller column media (sub 2 microm particles) was investigated to both improve the speed, sensitivity and resolution, and to quantify the CCL cyanotoxins, in a single analysis, using Ultra-Performance Liquid Chromatography (UPLC) combined with tandem mass spectrometry. Natural waters and spiked samples were analyzed to show proof-of-performance. The presented method was able to clearly resolve each of the cyanotoxins in less than eight minutes with specificity and high spike recoveries. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. Confirmation of the structure of lipid A from Enterobacter agglomerans by electrospray ionization tandem mass spectrometry

    Science.gov (United States)

    Boue; Cole

    2000-03-01

    Electrospray ionization (ESI) combined with tandem mass spectrometry (MS/MS) was utilized for the structural confirmation of lipid A derived from Enterobacter agglomerans, a Gram-negative bacterium commonly found in field cotton. Previous ESI-MS studies conducted in our laboratory found that similarities exist between the fatty acid side-chains in the lipid A of E. agglomerans and that of Salmonella minnesota. It was noted that heterogeneity at the fatty acyl chain at position 3' of the diglucosamine backbone of E. agglomerans can take the form of either a myristyloxymyristyl group or, less commonly, a hydroxymyristyloxymyristyl moiety. In this work, tandem mass spectra obtained from heptaacyl and hexaacyl lipid A precursors derived from E. agglomerans and a known standard S. minnesota were compared to assist in structural elucidation. These ESI-MS/MS experiments confirmed the previously reported structure for lipid A derived from E. agglomerans. Moreover, MS/MS data indicated that the additional hydroxyl group of the 3'-position hydroxymyristyloxymyristyl moiety is present as the alpha-isomer.

  2. Determination of Sulfonamides in Chicken Muscle by Pulsed Direct Current Electrospray Ionization Tandem Mass Spectrometry.

    Science.gov (United States)

    Fu, Xian; Liang, Hengxing; Xia, Bing; Huang, Chunyan; Ji, Baocheng; Zhou, Yan

    2017-09-20

    A simple and rapid approach for the simultaneous detection of trace amounts of six sulfonamides in chicken muscle was developed using pulsed direct current electrospray ionization tandem mass spectrometry (pulsed-dc ESI-MS/MS). The pretreatment of chicken muscle samples consisted of two steps: acetonitrile extraction and n-hexane delipidation. Sulfonamides do not need to be derivatized or chromatographed prior to pulsed-dc ESI-MS/MS. The factors affecting the performance of pulsed-dc ESI-MS/MS were studied. Under optimum conditions, the quantitative performance of pulsed-dc ESI-MS/MS was validated according to European Union Decision 2002/657/EC, and the sensitivity of pulsed-dc ESI-MS/MS was 3 times higher than that of ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The limits of detection obtained by pulsed-dc ESI-MS/MS were in the range of 0.07-0.11 μg/kg. The proposed method was simple, rapid, and sensitive, and was successfully used for quantitation and rapid screening of sulfonamides in real chicken muscle samples.

  3. Detection of Inborn Errors of Metabolism using Tandem Mass Spectrometry among High-risk Omani Patients.

    Science.gov (United States)

    Al Riyami, Sulaiman; Al Maney, Matar; Joshi, Surendra Nath; Bayoumi, Riad

    2012-11-01

    This is a report on the types and patterns of inborn errors of metabolism (IEMs) of amino acids, organic acids and fatty acids oxidation detected by Tandem Mass Spectrometry for a period of 10 years (1998-2008) at Sultan Qaboos University Hospital (SQUH), the major centre for diagnosis and management of IEM in Oman. Tandem mass spectrometry (MS/MS) was used in the initial screening and diagnosis of IEMs in high risk neonatal and pediatric populations. Out of 1100 patients investigated, 119 were detected positive for IEM by MS/MS spectrometry. Twenty six different metabolic diseases were detected. Patients were categorized into three major groups: a) 54 with amino acids and urea cycle disorders, b) 35 with organic acid disorders, and c) 30 with fatty acid oxidation disorders. The commonest conditions encountered were maple syrup urine disease (MSUD), phenylketonuria (PKU), propionic and isovaleric acidurias, as well as HMG-CoA lyase deficiency and glutaric aciduria type II (GA-II). Most of these IEMs were over-represented in babies born to consanguineous parents, which is consistent with the recessive autosomal inheritance. This study shows that various types of IEMs, reported elsewhere, were also prevalent in Oman, but the pattern of prevalence and distribution is different. The situation, therefore, warrants the development of a nationwide screening and prevention program.

  4. Detection of Inborn Errors of Metabolism using Tandem Mass Spectrometry among High-risk Omani Patients

    Directory of Open Access Journals (Sweden)

    Sulaiman Al Riyami

    2012-11-01

    Full Text Available Objectives: This is a report on the types and patterns of inborn errors of metabolism (IEMs of amino acids, organic acids and fatty acids oxidation detected by Tandem Mass Spectrometry for a period of 10 years (1998-2008 at Sultan Qaboos University Hospital (SQUH, the major centre for diagnosis and management of IEM in Oman.Methods: Tandem mass spectrometry (MS/MS was used in the initial screening and diagnosis of IEMs in high risk neonatal and pediatric populations.Results: Out of 1100 patients investigated, 119 were detected positive for IEM by MS/MS spectrometry. Twenty six different metabolic diseases were detected. Patients were categorized into three major groups: a 54 with amino acids and urea cycle disorders, b 35 with organic acid disorders, and c 30 with fatty acid oxidation disorders. The commonest conditions encountered were maple syrup urine disease (MSUD, phenylketonuria (PKU, propionic and isovaleric acidurias, as well as HMG-CoA lyase deficiency and glutaric aciduria type II (GA-II. Most of these IEMs were over representedin babies born to consanguineous parents, which is consistent with the recessive autosomal inheritance.Conclusion: This study shows that various types of IEMs, reported elsewhere, were also prevalent in Oman, but the pattern of prevalence and distribution is different. The situation, therefore, warrants the development of a nationwide screening and prevention program.

  5. Time of flight spectrometer DEPIL and its use for high protein mass measurement greater than 5000 u

    International Nuclear Information System (INIS)

    Della-Negra, S.; Deprun, C.; Le Beyec, Y.

    1986-01-01

    A new time-of-flight mass spectrometer has been built at the Institut to measure high mass molecules. The mass range is between 1 and 20.000 u. We discuss briefly the apparatus and give results on high mass measurements [fr

  6. Simultaneous measurement of sulfur and lead isotopes in sulfides using nanosecond laser ablation coupled with two multi-collector inductively coupled plasma mass spectrometers

    Science.gov (United States)

    Yuan, Honglin; Liu, Xu; Chen, Lu; Bao, Zhian; Chen, Kaiyun; Zong, Chunlei; Li, Xiao-Chun; Qiu, Johnson Wenhong

    2018-04-01

    We herein report the coupling of a nanosecond laser ablation system with a large-scale multi-collector inductively coupled plasma mass spectrometer (Nu1700 MC-ICPMS, NP-1700) and a conventional Nu Plasma II MC-ICPMS (NP-II) for the simultaneous laser ablation and determination of in situ S and Pb isotopic compositions of sulfide minerals. We found that the required aerosol distribution between the two spectrometers depended on the Pb content of the sample. For example, for a sulfide containing 100-3000 ppm Pb, the aerosol was distributed between the NP-1700 and the NP-II spectrometers in a 1:1 ratio, while for lead contents >3000 and effect, so a matrix-matched external standard was used for standard-sample bracketing correction. The NIST NBS 977 (NBS, National Bureau of Standards; NIST, National Institute of Standards & Technology) Tl (thallium) dry aerosol internal standard and the NIST SRM 610 (SRM, standard reference material) external standard were employed to obtain accurate results for the analysis of Pb isotopes. In tandem experiments where airflow conditions were similar to those employed during stand-alone analyses, small changes in the aerosol carrier gas flow did not significantly influence the accurate determination of S and Pb isotope ratios. In addition, careful optimization of the flow ratio of the aerosol carrier (He) and makeup (Ar) gases to match stand-alone analytical conditions allowed comparable S and Pb isotope ratios to be obtained within an error of 2 s analytical uncertainties. Furthermore, the results of tandem analyses obtained using our method were consistent with those of previously reported stand-alone techniques for the S and Pb isotopes of chalcopyrite, pyrite, galena, and sphalerite, thus indicating that this method is suitable for the simultaneous analysis of S and Pb isotopes of natural sulfide minerals, and provides an effective tool to determine S and Pb isotope compositions of sulfides formed through multi-stage deposition

  7. Determination of phosphodiesterase type V inhibitors in wastewater by direct injection followed by liquid chromatography coupled to tandem mass spectrometry

    NARCIS (Netherlands)

    Causanilles, A.; Emke, E.; de Voogt, P.

    2016-01-01

    A simple, fast and reliable analytical method for the determination of phosphodiesterase type V inhibitors in wastewater was developed and validated. The method was based on direct injection followed by liquid chromatography coupled to tandem mass spectrometry with triple quadrupole as mass

  8. Solid Phase Microextraction and Miniature Time-of-Flight Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Hiller, j.m.

    1999-01-26

    A miniature mass spectrometer, based on the time-of-flight principle, has been developed for the detection of chemical warfare agent precursor molecules. The instrument, with minor modifications, could fulfill many of the needs for sensing organic molecules in various Defense Programs, including Enhanced Surveillance. The basic footprint of the instrument is about that of a lunch box. The instrument has a mass range to about 300, has parts-per-trillion detection limits, and can return spectra in less than a second. The instrument can also detect permanent gases and is especially sensitive to hydrogen. In volume, the device could be manufactured for under $5000.

  9. Electric and magnetic field optimization procedure for Penning trap mass spectrometers

    CERN Document Server

    Beck, D; Bollen, G; Delahaye, P; George, S; Guénaut, C; Herfurth, F; Herlert, A; Lunney, D; Schweikhard, L; Yazidjian, C

    2009-01-01

    Significant systematic errors in high-precision Penning trap mass spectrometry can result from electric and magnetic field imperfections. An experimental procedure to minimize these uncertainties is presented for the on-line Penning trap mass spectrometer ISOLTRAP, located at ISOLDE/CERN. The deviations from the ideal magnetic and electric fields are probed by measuring the cyclotron frequency and the reduced cyclotron frequency, respectively, of stored ions as a function of the time between the ejection of ions from the preparation trap and their capture in the precision trap, which influences the energy of their axial motion. The correction parameters are adjusted to minimize the frequency shifts.

  10. Determination of clarithromycin in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Jiang, Yao; Wang, Jiang; Li, Hao; Wang, Yingwu; Gu, Jingkai

    2007-03-12

    A rapid and sensitive method has been developed for the determination of clarithromycin in human plasma with liquid chromatography-tandem mass spectrometry. Clarithromycin and the internal standard, telmisartan were precipitated from the matrix (50 microl) with 200 microl acetonitrile and separated by HPLC using formic acid:10 mM ammonium acetate:methanol (1:99:400, v/v/v) as the mobile phase. The assay based on detection by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring mode was finished within 2.4 min. Linearity was over the concentration range 10-5000 ng/ml with a limit of detection of 0.50 ng/ml. Intra- and inter-day precision measured as relative standard deviation were bioequivalence study of two tablet formulations of clarithromycin.

  11. Liquid Chromatography-Tandem Mass Spectrometry: An Emerging Technology in the Toxicology Laboratory.

    Science.gov (United States)

    Zhang, Yan Victoria; Wei, Bin; Zhu, Yu; Zhang, Yanhua; Bluth, Martin H

    2016-12-01

    In the last decade, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has seen enormous growth in routine toxicology laboratories. LC-MS/MS offers significant advantages over other traditional testing, such as immunoassay and gas chromatography-mass spectrometry methodologies. Major strengths of LC-MS/MS include improvement in specificity, flexibility, and sample throughput when compared with other technologies. Here, the basic principles of LC-MS/MS technology are reviewed, followed by advantages and disadvantages of this technology compared with other traditional techniques. In addition, toxicology applications of LC-MS/MS for simultaneous detection of large panels of analytes are presented. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Enhancing Accuracy in Molecular Weight Determination of Highly Heterogeneously Glycosylated Proteins by Native Tandem Mass Spectrometry.

    Science.gov (United States)

    Wang, Guanbo; de Jong, Rob N; van den Bremer, Ewald T J; Parren, Paul W H I; Heck, Albert J R

    2017-05-02

    The determination of molecular weights (MWs) of heavily glycosylated proteins is seriously hampered by the physicochemical characteristics and heterogeneity of the attached carbohydrates. Glycosylation impacts protein migration during sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and size-exclusion chromatography (SEC) analysis. Standard electrospray ionization (ESI)-mass spectrometry does not provide a direct solution as this approach is hindered by extensive interference of ion signals caused by closely spaced charge states of broadly distributed glycoforms. Here, we introduce a native tandem MS-based approach, enabling charge-state resolution and charge assignment of protein ions including those that escape mass analysis under standard MS conditions. Using this method, we determined the MW of two model glycoproteins, the extra-cellular domains of the highly and heterogeneously glycosylated proteins CD38 and epidermal growth factor receptor (EGFR), as well as the overall MW and binding stoichiometries of these proteins in complex with a specific antibody.

  13. PECAN: library-free peptide detection for data-independent acquisition tandem mass spectrometry data

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Ying S.; Egertson, Jarrett D.; Bollinger, James G.; Searle, Brian C.; Payne, Samuel H.; Noble, William Stafford; MacCoss, Michael J.

    2017-08-07

    Data-independent acquisition (DIA) is an emerging mass spectrometry (MS)-based technique for unbiased and reproducible measurement of protein mixtures. DIA tandem mass spectrometry spectra are often highly multiplexed, containing product ions from multiple cofragmenting precursors. Detecting peptides directly from DIA data is therefore challenging; most DIA data analyses require spectral libraries. Here we present PECECAN (http://pecan.maccosslab.org), a library-free, peptide-centric tool that robustly and accurately detects peptides directly from DIA data. PECECAN reports evidence of detection based on product ion scoring, which enables detection of low-abundance analytes with poor precursor ion signal. We demonstrate the chromatographic peak picking accuracy and peptide detection capability of PECECAN, and we further validate its detection with data-dependent acquisition and targeted analyses. Lastly, we used PECECAN to build a plasma proteome library from DIA data and to query known sequence variants.

  14. Evaluation of the performance of a tandem mass spectral library with mass spectral data extracted from literature.

    Science.gov (United States)

    Würtinger, Philipp; Oberacher, Herbert

    2012-01-01

    MSforID represents a database of tandem mass spectral data obtained from (quasi-)molecular ions produced by atmospheric pressure ionization methods. At the current stage of development the library contains 12 122 spectra of 1208 small (bio-)organic molecules. The present work was aimed to evaluate the performance of the MSforID library in terms of accuracy and transferability with a collection of fragment ion mass spectra from various compounds acquired on multiple instruments. A literature survey was conducted to collect the set of sample spectra. A total number of 554 spectra covering 291 compounds were extracted from 109 publications. The majority of spectra originated from publications on applications of LC/MS/MS in drug monitoring, pharmacokinetics, environmental analysis, forensic analysis as well as food analysis. Almost all types of tandem mass spectrometric instruments distributed by the five most important instrument vendors were included in the study. The overall sensitivity of library search was found to be 96.4%, which clearly proves that the MSforID library can successfully handle data from a huge variety of mass spectrometric instruments to allow accurate compound identification. Only for spectra containing three or more fragment ions, however, the rate of classified matches (= matches with a relative average match probability (ramp) score > 40.0) was 95%. Ambiguous or unclassified results were mainly obtained for searches with single precursor-to-fragment ion transitions due to the insufficient specificity of such a low amount of structural information to unequivocally define a single compound. Copyright © 2011 John Wiley & Sons, Ltd.

  15. High-energy collision induced dissociation of biomolecules: MALDI-TOF/RTOF mass spectrometry in comparison to tandem sector mass spectrometry.

    Science.gov (United States)

    Pittenauer, Ernst; Allmaier, Günter

    2009-02-01

    MALDI in combination with high-energy collision-induced dissociation (CID) performed by tandem time-of-flight mass spectrometry (TOF/RTOF) is a relatively new technology for the structural analysis of various classes of biomolecules as e.g., peptides, carbohydrates, glycoconjugate drugs and lipids. Fragmentation mechanisms for these classes of compounds as well as corresponding fragment ion nomenclatures based mainly on data from tandem magnetic sector mass spectrometers are summarized in this article. The major instrumental differences between the present commercially available TOF/RTOFs are compiled (e.g., ion gate, gas-collision cell, type of reflectron, etc.). Whereas peptides have been investigated by MALDI-TOF/RTOF and their CID spectra are well understood, other classes of compounds (e.g., carbohydrates or lipids) are far less well investigated. By comparing data from two different MALDI-TOF/RTOF-instruments, it becomes evident that as they are operated at rather different collision energies for CID (1 versus 20 keV) strong differences in corresponding CID spectra for the same analyte are observed, causing problems with library searches in databases as e.g., abundant peptide side-chain fragmentations mainly occurring in the 8 to 20 keV collision regime are not considered. In contrast, differences in CID spectra of carbohydrates among different TOF/RTOF instruments are less clear-cut, because the required collision energy is spread across a wide range. Especially, carbohydrate cross-ring cleavages require less collision energy in the keV-range than the corresponding peptide side-chain fragmentations. Some of these carbohydrate cross-ring fragmentations are even observed by very low energy CID (tylosin A). The lipid class triacylglycerol needs rather high collision energies for dissociating carbon-carbon bonds based upon classical charge-remote fragmentation mechanisms. Comparison of high-energy CID-data of ESI generated triacylglycerol precursors with CID

  16. Enhancing MALDI time-of-flight mass spectrometer performance through spectrum averaging.

    Science.gov (United States)

    Mitchell, Morgan; Mali, Sujina; King, Charles C; Bark, Steven J

    2015-01-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometers are simple and robust mass spectrometers used for analysis of biologically relevant molecules in diverse fields including pathogen identification, imaging mass spectrometry, and natural products chemistry. Despite high nominal resolution and accuracy, we have observed significant variability where 30-50% of individual replicate measurements have errors in excess of 5 parts-per-million, even when using 5-point internal calibration. Increasing the number of laser shots for each spectrum did not resolve this observed variability. What is responsible for our observed variation? Using a modern MALDI-TOF/TOF instrument, we evaluated contributions to variability. Our data suggest a major component of variability is binning of the raw flight time data by the electronics and clock speed of the analog-to-digital (AD) detection system, which requires interpolation by automated peak fitting algorithms and impacts both calibration and the observed mass spectrum. Importantly, the variation observed is predominantly normal in distribution, which implies multiple components contribute to the observed variation and suggests a method to mitigate this variability through spectrum averaging. Restarting the acquisition impacts each spectrum within the electronic error of the AD detector system and defines a new calibration function. Therefore, averaging multiple independent spectra and not a larger number of laser shots leverages this inherent binning error to mitigate variability in accurate MALDI-TOF mass measurements.

  17. Enhancing MALDI time-of-flight mass spectrometer performance through spectrum averaging.

    Directory of Open Access Journals (Sweden)

    Morgan Mitchell

    Full Text Available Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrometers are simple and robust mass spectrometers used for analysis of biologically relevant molecules in diverse fields including pathogen identification, imaging mass spectrometry, and natural products chemistry. Despite high nominal resolution and accuracy, we have observed significant variability where 30-50% of individual replicate measurements have errors in excess of 5 parts-per-million, even when using 5-point internal calibration. Increasing the number of laser shots for each spectrum did not resolve this observed variability. What is responsible for our observed variation? Using a modern MALDI-TOF/TOF instrument, we evaluated contributions to variability. Our data suggest a major component of variability is binning of the raw flight time data by the electronics and clock speed of the analog-to-digital (AD detection system, which requires interpolation by automated peak fitting algorithms and impacts both calibration and the observed mass spectrum. Importantly, the variation observed is predominantly normal in distribution, which implies multiple components contribute to the observed variation and suggests a method to mitigate this variability through spectrum averaging. Restarting the acquisition impacts each spectrum within the electronic error of the AD detector system and defines a new calibration function. Therefore, averaging multiple independent spectra and not a larger number of laser shots leverages this inherent binning error to mitigate variability in accurate MALDI-TOF mass measurements.

  18. A Method for Estimating Mass-Transfer Coefficients in a Biofilter from Membrane Inlet Mass Spectrometer Data

    DEFF Research Database (Denmark)

    Nielsen, Anders Michael; Nielsen, Lars Peter; Feilberg, Anders

    2009-01-01

    of a filter bed with a consortium of effective sulfur oxidizers, the most likely mechanism for incomplete removal of sulfur compounds from the exhaust air was elucidated. This was found to be insufficient mass transfer and not inadequate bacterial activity as anticipated by the manager of the BF. Thus......A membrane inlet mass spectrometer (MIMS) was used in combination with a developed computer model to study and improve management of a biofilter (BF) treating malodorous ventilation air from a meat rendering facility. The MIMS was used to determine percentage removal efficiencies (REs) of selected......, knowing the relationship between mass-transfer coefficients and air velocity for a given type of BF allows for an improved dimensioning and managing of this and similar BFs. This research demonstrates that it is possible to estimate mass-transfer coefficients and air velocity in BFs using MIMS...

  19. Onsets of nuclear deformation from measurements with the Isoltrap mass spectrometer

    International Nuclear Information System (INIS)

    Naimi, S.

    2010-10-01

    Mass measurements provide important information concerning nuclear structure. This work presents results from the pioneering Penning trap spectrometer Isoltrap at CERN-Isolde. High-precision mass measurements of neutron-rich manganese ( 58 - 66 Mn) and krypton isotopes ( 96, 97 Kr) are presented, of which the 66 Mn and 96, 97 Kr masses are measured for the first time. In particular, the mass of 97 Kr was measured using the preparation trap and required the definition of a new fit function. In the case of the manganese isotopes, the N=40 shell closure is addressed. The two-neutron-separation energies calculated from the new masses show no shell closure at N=40 but give an estimation of the proton-neutron interaction (around 0.5 MeV) responsible for the increase of collectivity and nuclear deformation in this mass region. The new krypton masses show behavior in sharp contrast with heavier neighbors where sudden and intense deformation is present, interpreted as the establishment of a nuclear quantum shape/phase transition critical-point boundary. The new masses confirm findings from nuclear mean-square charge-radius measurements up to N=60 but are at variance with conclusions from recent gamma-ray spectroscopy. Another part of this work was the design of new decay spectroscopy system behind the Isoltrap mass spectrometer. The beam purity achievable with Isoltrap will allow decay studies with γ and β detection coupled to a tape-station. This system has been mounted and commissioned with the radioactive beam 80 Rb. (author)

  20. Urinary screening for methylphenidate (Ritalin) abuse: a comparison of liquid chromatography-tandem mass spectrometry, gas chromatography-mass spectrometry, and immunoassay methods.

    Science.gov (United States)

    Eichhorst, J; Etter, M; Lepage, J; Lehotay, D C

    2004-03-01

    To develop a routine method for detecting methylphenidate (Ritalin) use among drug abusers using liquid chromatography-tandem mass spectrometry (LC/MS/MS). The new methodology was designed to replace less reliable and/or more expensive and time-consuming techniques (GC/MS and ELISA) currently employed in our laboratory, and to provide a combined one-step screening and confirmation LC/MS/MS method. Because methylphenidate abuse is very prevalent in Saskatchewan, there is a demand to provide high volume urine screening both to detect abuse, and to monitor compliance. Random urine samples sent for drugs of abuse testing, standards, and controls were diluted 1:100 in methanol. Diluted specimens were injected directly into an Agilent 1100 liquid chromatograph coupled to a Sciex API 2000 mass spectrometer. The method utilized selected reaction monitoring (SRM) as well as an electrospray ionization source (EIS) to detect both urinary methylphenidate and the more prevalent metabolite, ritalinic acid (RA). There appeared to be little or no sacrifice in sensitivity because the higher dilutions exhibited much less matrix effect. Limit of quantitation (LOQ) for methylphenidate was 100 nM and 500 nM for RA. Linear calibration curves from 100 to 1000 nM for Ritalin and 500 to 5000 nM for RA were acquired. Imprecision of spiked and true specimens did not exceed 10% and at the LOQ, it was less than 20%. A rapid, sensitive, reliable, and highly specific method by LC/MS/MS for detecting methylphenidate and its metabolite, RA, were developed. Both the cost and performance of the LC/MS/MS method were superior to GC/MS or ELISA, and it allows use of a single rapid procedure for both screening and confirmation.

  1. In Situ Geochemical Analysis and Age Dating of Rocks Using Laser Ablation-Miniature Mass Spectrometer

    Science.gov (United States)

    Sinha, Mahadeva P.; Hecht, Michael H.; Hurowitz, Joel A.

    2012-01-01

    A miniaturized instrument for performing chemical and isotopic analysis of rocks has been developed. The rock sample is ablated by a laser and the neutral species produced are analyzed using the JPL-invented miniature mass spectrometer. The direct sampling of neutral ablated material and the simultaneous measurement of all the elemental and isotopic species are the novelties of this method. In this laser ablation-miniature mass spectrometer (LA-MMS) method, the ablated neutral atoms are led into the electron impact ionization source of the MMS, where they are ionized by a 70-eV electron beam. This results in a secondary ion pulse typically 10-100 microsecond wide, compared to the original 5-10-nanosecond laser pulse duration. Ions of different masses are then spatially dispersed along the focal plane of the magnetic sector of the miniature mass spectrometer and measured in parallel by a modified CCD (charge-coupled device) array detector capable of detecting ions directly. Compared to conventional scanning techniques, simultaneous measurement of the ion pulse along the focal plane effectively offers a 100% duty cycle over a wide mass range. LAMMS offers a more quantitative assessment of elemental composition than techniques that detect laser-ionized species produced directly in the ablation process because the latter can be strongly influenced by matrix effects that vary with the structure and geometry of the surface, the laser beam, and the ionization energies of the elements. The measurement of high-precision isotopic ratios and elemental composition of different rock minerals by LAMMS method has been demonstrated. The LA-MMS can be applied for the absolute age determination of rocks. There is no such instrument available presently in a miniaturized version that can be used for NASA space missions. Work is in progress in the laboratory for geochronology of rocks using LA-MMS that is based on K-Ar radiogenic dating technique.

  2. Mobile membrane introduction tandem mass spectrometry for on-the-fly measurements and adaptive sampling of VOCs around oil and gas projects in Alberta, Canada

    Science.gov (United States)

    Krogh, E.; Gill, C.; Bell, R.; Davey, N.; Martinsen, M.; Thompson, A.; Simpson, I. J.; Blake, D. R.

    2012-12-01

    The release of hydrocarbons into the environment can have significant environmental and economic consequences. The evolution of smaller, more portable mass spectrometers to the field can provide spatially and temporally resolved information for rapid detection, adaptive sampling and decision support. We have deployed a mobile platform membrane introduction mass spectrometer (MIMS) for the in-field simultaneous measurement of volatile and semi-volatile organic compounds. In this work, we report instrument and data handling advances that produce geographically referenced data in real-time and preliminary data where these improvements have been combined with high precision ultra-trace VOCs analysis to adaptively sample air plumes near oil and gas operations in Alberta, Canada. We have modified a commercially available ion-trap mass spectrometer (Griffin ICX 400) with an in-house temperature controlled capillary hollow fibre polydimethylsiloxane (PDMS) polymer membrane interface and in-line permeation tube flow cell for a continuously infused internal standard. The system is powered by 24 VDC for remote operations in a moving vehicle. Software modifications include the ability to run continuous, interlaced tandem mass spectrometry (MS/MS) experiments for multiple contaminants/internal standards. All data are time and location stamped with on-board GPS and meteorological data to facilitate spatial and temporal data mapping. Tandem MS/MS scans were employed to simultaneously monitor ten volatile and semi-volatile analytes, including benzene, toluene, ethylbenzene and xylene (BTEX), reduced sulfur compounds, halogenated organics and naphthalene. Quantification was achieved by calibrating against a continuously infused deuterated internal standard (toluene-d8). Time referenced MS/MS data were correlated with positional data and processed using Labview and Matlab to produce calibrated, geographical Google Earth data-visualizations that enable adaptive sampling protocols

  3. Analytical capabilities of an inductively coupled plasma Mattauch Herzog mass spectrometer

    Science.gov (United States)

    Solyom, David A.; Gron, Ole A.; Barnes, James H., IV; Hieftje, Gary M.

    2001-09-01

    An inductively coupled plasma (ICP) has been coupled to a custom-designed Mattauch-Herzog mass spectrometer, replacing a glow-discharge source used in earlier research. Adaptation to an ICP source required significant modifications to address concerns regarding shielding from RF radiation and coupling between the ICP and mass spectrometer. The detrimental impact of fringing magnetic fields on the earlier performance of the instrument's detector has also been addressed. Current figures of merit utilizing ultrasonic nebulization include sensitivities in the 10 8-10 9 cps ppm -1 isotope -1 regime and detection limits of 1-500 pg/l (ppq). Isotope-ratio accuracy and precision are 1% relative error and 1-2% relative standard deviation, respectively. Resolving power (5% valley) exceeds 400. Unfortunately, spectral peak shapes are somewhat disappointing and lead to abundance sensitivity values in the 10 3-10 4 range. Although the instrument is designed for use with a multichannel array detector, all results reported here were obtained in scanning mode to separate limitations of the spectrometer from those of the detector.

  4. A compact time-of-flight mass-spectrometer with electrostatic mirrors

    International Nuclear Information System (INIS)

    Wilken, B.; Stuedemann, W.

    1984-01-01

    A compact low-weight time-of-flight/solid state detector ion mass-spectrometer is described in detail. The two time-zero detectors for the TOF-measurement use secondary electron emission and microchannelplates. A symmetric dual electrostatic mirror is used to deflect both the 'START' and 'STOP' electrons by 90 0 . The crosstalk in the mirror system is measured as a function of the potential applied to the center grid. It is found that 'START' electrons dominate the 'STOP' rate for mirror voltages 0 0 . The primary source for this contamination are backscattered electrons. For Usub(CG) exceeding a critical limit the isolation between the 'START' and 'STOP' system is sufficient. Characteristic background signatures in the two-dimensional pulse height distribution of such a mass-spectrometer are discussed. With some limitations molecular particles can be identified even on an event by event basis. The described TOF spectrometer has particular advantages for ion composition measurements in space plasma research. (orig.)

  5. System for studying a sample of material using a heavy ion induced mass spectrometer source

    Science.gov (United States)

    Fries, D.P.; Browning, J.F.

    1998-07-21

    A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high (n,f) reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

  6. Method for studying a sample of material using a heavy ion induced mass spectrometer source

    Science.gov (United States)

    Fries, D.P.; Browning, J.F.

    1999-02-16

    A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu. 3 figs.

  7. Detection of single macromolecules using a cryogenic particle detector coupled to a biopolymer mass spectrometer

    Science.gov (United States)

    Twerenbold, Damian; Vuilleumier, Jean-Luc; Gerber, Daniel; Tadsen, Almut; van den Brandt, Ben; Gillevet, Patrick M.

    1996-06-01

    Macromolecules with masses up to 50 kDa have been detected with a cryogenic particle detector in a MALDI time-of-flight biopolymer mass spectrometer. The cryogenic particle detector was a Sn/Sn-ox/Sn tunnel junction operated at a temperature of 0.4 K. A calibration with 6 keV single photons inferred that the delayed detector pulses corresponded to the absorption of the kinetic energy of a single macromolecule. Time-of-flight spectra of lysozyme proteins are presented. The mass resolution is 100 Da at 14 300 Da. The energy sensitive detection mechanism suggests that cryogenic particle detectors have a high and mass independent detection efficiency for macromolecules.

  8. Diagnosing lysosomal storage diseases in a Brazilian non-newborn population by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Guilherme Dotto Brand

    2013-11-01

    Full Text Available OBJECTIVES: High-throughput mass spectrometry methods have been developed to screen newborns for lysosomal storage disorders, allowing the implementation of newborn screening pilot studies in North America and Europe. It is currently feasible to diagnose Pompe, Fabry, Gaucher, Krabbe, and Niemann-Pick A/B diseases, as well as mucopolysaccharidosis I, by tandem mass spectrometry in dried blood spots, which offers considerable technical advantages compared with standard methodologies. We aimed to investigate whether the mass spectrometry methodology for lysosomal storage disease screening, originally developed for newborns, can also discriminate between affected patients and controls of various ages. METHODS: A total of 205 control individuals were grouped according to age and subjected to mass spectrometry quantification of lysosomal α-glucosidase, β-glucocerebrosidase, α-galactosidase, acid sphingomyelinase, galactocerebrosidase, and α−L-iduronidase activities. Additionally, 13 affected patients were analyzed. RESULTS: The median activities for each enzyme and each age group were determined. Enzyme activities were significantly lower in individuals aged older than 18 years compared with those in newborns. Affected patients presented enzymatic activities corresponding to less than 20% of the age-matched controls. CONCLUSIONS: Our data indicate that the mass spectrometry methodology can be used for the screening of lysosomal storage diseases in non-newborn patients. However, for some diseases, such as Fabry and mucopolysaccharidosis I, a combination of biochemical and clinical data may be necessary to achieve accurate diagnoses.

  9. Gas-Phase Fragmentation Behavior of Oxidized Prenyl Peptides by CID and ETD Tandem Mass Spectrometry

    Science.gov (United States)

    Bhawal, Ruchika P.; Shahinuzzaman, A. D. A.; Chowdhury, Saiful M.

    2017-04-01

    Farnesylation and geranylgeranylation are the two types of prenyl modification of proteins. Prenylated peptides are highly hydrophobic and their abundances in biological samples are low. In this report, we studied the oxidized prenylated peptides by electrospray ionization mass spectrometry and identified them by collision-induced dissociation (CID) and electron-transfer dissociation (ETD) tandem mass spectrometry. Modified prenyl peptides were generated utilizing strong and low strength oxidizing agents to selectively oxidize and epoxidize cysteine sulfur and prenyl side chain. We selected three peptides with prenyl motifs and synthesized their prenylated versions. The detailed characteristic fragmentations of oxidized and epoxidized farnesylated and geranylgeranylated peptides were studied side by side with two popular fragmentation techniques. CID and ETD mass spectrometry clearly distinguished the modified version of these peptides. ETD mass spectrometry provided sequence information of the highly labile modified prenyl peptides and showed different characteristic fragmentations compared with CID. A detailed fragmentation of modified geranylgeranylated peptides was compared by CID and ETD mass spectrometry for the first time.

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

    Science.gov (United States)

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

    2017-04-30

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

  11. Fission product nuclear data obtained by use of an on-line mass spectrometer

    International Nuclear Information System (INIS)

    Reeder, P.L.; Wright, J.F.; Anderl, R.A.

    1975-01-01

    A Spectrometer for On-Line Analysis of Radionuclides (SOLAR) has been installed at a 1 MW TRIGA reactor at Washington State University. Fission product ions from a combination target/ion source located within the thermal column are brought out to a 60 0 magnetic sector mass spectrometer. Surface ionization provides copious beams of Rb + and Cs + ions and less intense beams of Br - and I - ions with negligible contamination by other elements. About 40 fission product nuclides can thus be chemically and physically separated in times of less than 1 second. Past results on independent and cumulative fission yields along with measurements of half-lives of some very neutron-rich nuclides are presented. Current work on delayed-neutron emission probabilities and energy spectra of delayed neutrons from individual nuclides is described. (7 tables, 2 figures) (U.S.)

  12. Dual cascade time-of-flight mass spectrometer basing on electrostatic mirrors with two dimensional fields

    International Nuclear Information System (INIS)

    Glikman, L. G.; Goloskokov, Yu. V.; Karetskaya, S.P.; Mit', A.G.

    1999-01-01

    In the report [1] we have suggested the scheme of time-of-flight spectrometer containing two electrostatic mirrors with two dimensional field that doesn't depend on one of the Cartesian coordinates). In the articles [2,3] there have been found conditions for obtaining high quality of time-of-flight and spatial focusing. One of basic advantages of this scheme - is availability of intermediate stigmatic image. In the plane where this image is it's possible to place controlled diaphragm that limits ion scatter along the energy if the scatter is too large. With the help of this diaphragm at the spectrometer you can register mass spectrum with the selected energy. Good focusing quality allows reducing of initial ion energy by this increasing the time of their flight and thus analyzers resolving ability. Ion source and receiver are spaced at rather a long distances. This can be useful to solve some practical tasks

  13. Micro-pulverized extraction pretreatment for highly sensitive analysis of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol in hair by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Kuwayama, Kenji; Miyaguchi, Hajime; Yamamuro, Tadashi; Tsujikawa, Kenji; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

    2015-11-30

    A primary metabolite of Δ(9) -tetrahydrocannabinol, 11-nor-9-carboxytetrahydrocannabinol (THC-COOH), serves as an effective indicator for cannabis intake. According to the recommendations of the Society of Hair Testing, at least 0.2 pg/mg of THC-COOH (cut-off level) must be present in a hair sample to constitute a positive result in a drug test. Typically, hair is digested with an alkaline solution and is subjected to gas chromatography/tandem mass spectrometry (GC/MS/MS) with negative ion chemical ionization (NICI). It is difficult to quantify THC-COOH at the cut-off level using liquid chromatography/tandem mass spectrometry (LC/MS/MS) without acquisition of second-generation product ions in triple quadrupole-ion trap mass spectrometers, because large amounts of matrix components in the low-mass range produced by digestion interfere with the THC-COOH peak. Using the typical pretreatment method (alkaline dissolution) and micro-pulverized extraction (MPE) with a stainless bullet, we compared the quantification of THC-COOH using GC/MS/MS and LC/MS/MS. MPE reduced the amount of matrix components in the low-mass range and enabled the quantification of THC-COOH at 0.2 pg/mg using a conventional triple quadrupole liquid chromatograph coupled to a mass spectrometer. On the other hand, the MPE pretreatment was unsuitable for GC/MS/MS, probably due to matrix components in the high-mass range. The proper combination of pretreatments and instrumental analyses was shown to be important for detecting trace amounts of THC-COOH in hair. In MPE, samples can be prepared rapidly, and LC/MS/MS is readily available, unlike GC/MS/MS with NICI. The combination of MPE and LC/MS/MS might therefore be used in the initial screening for THC-COOH in hair prior to confirmatory analysis using GC/MS/MS with NICI. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Development of a liquid chromatography tandem mass spectrometry method for the simultaneous measurement of voriconazole, posaconazole and itraconazole.

    Science.gov (United States)

    Wadsworth, John M; Milan, Anna M; Anson, James; Davison, Andrew S

    2017-11-01

    Background Azole-based antifungals are the first-line therapy for some of the most common mycoses and are now also being used prophylactically to protect immunocompromised patients. However, due to variability in both their metabolism and bioavailability, therapeutic drug monitoring is essential to avoid toxicity but still gain maximum efficacy. Methods Following protein precipitation of serum with acetonitrile, 20  µL of extract was injected onto a 2.1 × 50 mm Waters Atlantis dC18 3  µm column. Detection was via a Waters Quattro Premier XE tandem mass spectrometer operating in ESI-positive mode. Multiple reaction monitoring (MRM) detected two product ions for each compound and one for each isotopically labelled internal standard. Ion suppression, linearity, stability, matrix effects, recovery, imprecision, lower limits of measuring interval and detection were all assessed. Results Optimal chromatographic separation was achieved using gradient elution over 8 minutes. Voriconazole, posaconazole and itraconazole eluted at 1.71, 2.73 and 3.41 min, respectively. The lower limits of measuring interval for all three compounds was 0.1 mg/L. The assay was linear to 10 mg/L for voriconazole (R 2  = 0.995) and 5 mg/L for posaconazole (R 2  = 0.990) and itraconazole (R 2  = 0.991). The assay was both highly accurate and precise with % bias of voriconazole, posaconazole and itraconazole, respectively, when compared with previous NEQAS samples. The intra-assay precision (CV%) was 1.6%, 2.5% and 1.9% for voriconazole, posaconazole and itraconazole, respectively, across the linear range. Conclusion A simple and robust method has been validated for azole antifungal therapeutic drug monitoring. This new assay will result in a greatly improved sample turnaround time and will therefore vastly increase the clinical utility of azole antifungal drug monitoring.

  15. [Values of tandem mass spectrometry in etiologic diagnosis of cerebral developmental retardation].

    Science.gov (United States)

    Zhang, Jian-ming; Gu, Xue-fan; Shao, Xin-hua; Song, Xiao-qing; Han, Lian-shu; Ye, Jun; Qiu, Wen-juan; Gao, Xiao-lan; Wang, Yu; Wang, Mei-xian

    2007-12-01

    To investigate the values of tandem mass spectrometry (MS/MS) in etiologic diagnosis and understanding therapeutic effect in cerebral developmental retardation, and to help patients in early diagnosis, treatment and favorable prognosis. One hundred and fifty-eight childhood patients with brain heteroplasia were tested from July 2004 to October 2006. The blood was collected on filter paper, punched and extracted into methanol solution with stable isotope labeled internal standards, then derivatized with butanolic-HCl. After preparation, the samples were analysed by tandem mass spectrometry. Eleven MS/MS-positive patients were further analyzed based on gas chromatography/mass spectrometry (GC/MS) analysis of urine, clinical course, and treatment outcome. Eleven of 158 patients (7.0%) with inborn metabolic error were confirmed, including five with methylmalonic acidemia, two with propionic acidemia, one with ornithine transcarbamylase deficiency, one with maple syrup urine disease, one with phenylketonuria, and one with biotinidase deficiency. Among them, five were male, six were female, aged from 4 days to 21 months. The clinical manifestations were diverse, including mental developmental retardation or degradation (11 cases), convulsion (5 cases), coma (4 cases), vomiting (4 cases), malnutrition (4 cases), lethargy (3 cases), repeated infection (3 cases), hypotonia (2 cases), etc. Laboratory findings showed metabolic acidosis, hyperammonemia, hyperlactacidemia, anemia, etc. MRI findings of the brain showed cerebral atrophy, a pattern of bilateral T(2)W high signal intensity or/and T(1)W low signal intensity in cerebral white matter and multiple encephalomalacia or vesicular change, ect. In methylmalonic acidemia patients, the early onset with severe acidosis and coma have had a poor prognosis. Improvement was observed in 8 cases after treatment with vitamin B(12), L-carnitine, special milk, low-protein diet or biotin, etc. However 3 MMA patients died. MS/MS was

  16. [Present status of expanded newborn screening project for inborn errors of metabolism by tandem mass spectrometry].

    Science.gov (United States)

    Kuhara, Tomiko

    2014-01-01

    In Japan, screening for six diseases including four inborn errors of metabolism has been performed since 1977 for all neonates to prevent severe mental handicaps or death. A rapid screening procedure for analysis of several amino acids and acylcarnitines in blood spots by tandem mass spectrometry was developed by Millington DS et al. in the early 1990s. Although it is called expanded (or extended) newborn screening, the procedure is insufficiently sensitive to or specific for several diseases. Screening for all diseases that can be screened using this procedure is suggested to be cost-ineffective. Many European countries target only two diseases: medium-chain acyl-CoA dehydrogenase deficiency and phenylketonuria; their prevalence in Caucasian populations is very high, but some countries target more than twenty diseases and others an intermediate number. A pilot study targeting 22 diseases suggests that the combined incidence is one per 9,000 (0.01%) in Japan. This primary screening requires secondary screening to confirm the disease using urine, and either organic acids with solvent extraction or metabolome without fractionation are analyzed by gas chromatography-mass spectrometry. There is no need for primary or secondary screening tests to be performed at the same laboratory because the skills required are quite different. Understanding of the methodological problems of tandem mass screening and amelioration of variation and false positivity rate of this screening method among laboratories are critical to the success of the screening system in Japan. GC/MS-based urine metabolomics is expected to become one of the primary screening methodologies for neonates/infants who are already ill.

  17. USING AN ACCURATE MASS, TRIPLE QUADRUPOLE MASS SPECTROMETER AND AN ION CORRELATION PROGRAM TO IDENTIFY COMPOUNDS

    Science.gov (United States)

    Most compounds are not found in mass spectral libraries and must be identified by other means. Often, compound identities can be deduced from the compositions of the ions in their mass spectra and review of the chemical literature. Confirmation is provided by mass spectra and r...

  18. Elucidation of urinary metabolites of fluoxymesterone by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Pozo, Oscar J; Van Thuyne, Wim; Deventer, Koen; Van Eenoo, Peter; Delbeke, Frans T

    2008-03-01

    The suitability of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography mass spectrometry (GC-MS) for the elucidation of fluoxymesterone metabolism has been evaluated. Electrospray ionization (ESI) and collision induced dissociation (CID) fragmentation in LC-MS/MS and electron impact spectra (EI) in GC-MS have been studied for fluoxymesterone and two commercially available metabolites. MS(n) experiments and accurate mass measurements performed by an ion-trap analyser and a QTOF instrument respectively have been used for the elucidation of the fragmentation pathway. The neutral loss scan of 20 Da (loss of HF) in LC-MS/MS has been applied for the selective detection of fluoxymesterone metabolites. In a positive fluoxymesterone doping control sample, 9 different analytes have been detected including the parent compound. Seven of these metabolites were also confirmed by GC-MS including 5 previously unreported metabolites. On the basis of the ionization, the CID fragmentation, the accurate mass of the product ions and the EI spectra of these analytes, a tentative elucidation as well as a proposal for the metabolic pathway of fluoxymesterone has been suggested. The presence of these compounds has also been confirmed by the analysis of five other positive fluoxymesterone urine samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

  19. Laser Transmitter Development for Mass Spectrometry

    Data.gov (United States)

    National Aeronautics and Space Administration — In this project, we will focus on the development of two technologies that will be key for a future Spaceborne Two Step Laser Tandem Mass Spectrometer instrument by:...

  20. Identification of isomers and control of ionization and dissociation processes using dual-mass-spectrometer scheme and genetic algorithm optimization

    International Nuclear Information System (INIS)

    Chen Zhou; Qiu-Nan Tong; Zhang Cong-Cong; Hu Zhan

    2015-01-01

    Identification of acetone and its two isomers, and the control of their ionization and dissociation processes are performed using a dual-mass-spectrometer scheme. The scheme employs two sets of time of flight mass spectrometers to simultaneously acquire the mass spectra of two different molecules under the irradiation of identically shaped femtosecond laser pulses. The optimal laser pulses are found using closed-loop learning method based on a genetic algorithm. Compared with the mass spectra of the two isomers that are obtained with the transform limited pulse, those obtained under the irradiation of the optimal laser pulse show large differences and the various reaction pathways of the two molecules are selectively controlled. The experimental results demonstrate that the scheme is quite effective and useful in studies of two molecules having common mass peaks, which makes a traditional single mass spectrometer unfeasible. (paper)

  1. 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...... in connection to in vivo metabolic studies investigating glucose turnover and lipolytic rate. Moreover, in order to keep up with this new fast analysis, simple derivatization procedures have been developed. Prior to analysis, glucose and glycerol were derivatized using benzoyl chloride in order to form...... benzoylated derivatives via new simplified fast procedures. For glucose, two internal standards were evaluated, [U-(13) C(6)]glucose and [U-(13) C(6), D(7)]glucose, and for glycerol, [U-(13) C(3), D(8)]glycerol was used. The method was validated by means of calibration curves, quality control samples...

  2. Analysis of bromate in drinking water using liquid chromatography-tandem mass spectrometry without sample pretreatment.

    Science.gov (United States)

    Kosaka, Koji; Asami, Mari; Takei, Kanako; Akiba, Michihiro

    2011-01-01

    An analytical method for determining bromate in drinking water was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The (18)O-enriched bromate was used as an internal standard. The limit of quantification (LOQ) of bromate was 0.2 µg/L. The peak of bromate was separated from those of coexisting ions (i.e., chloride, nitrate and sulfate). The relative and absolute recoveries of bromate in two drinking water samples and in a synthesized ion solution (100 mg/L chloride, 10 mg N/L nitrate, and 100 mg/L sulfate) were 99-105 and 94-105%, respectively. Bromate concentrations in 11 drinking water samples determined by LC-MS/MS were water without sample pretreatment.

  3. Multiresidue determination of pesticides in fruit and vegetables by gas chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Gamón, M; Lleó, C; Ten, A; Mocholí, F

    2001-01-01

    Pesticide residues in fruit and vegetables were determined by gas chromatography/tandem mass spectrometry (GC/MS/MS). Electron impact (EI)/MS/MS and chemical ionization (CI)/MS/MS were developed for 80 compounds, including organochlorine, organophosphorus, organonitrogen, and pyrethroids, providing unambiguous spectral confirmation for these complex matrixes. Residues were extracted from samples with acetone followed by a mixture of dichloromethane-petroleum ether. Two injections per sample were required for analysis of the entire pesticide list by EI/MS/MS and CI/MS/MS. Initial steps involving cleanup and concentration of extracts were eliminated. The excellent selectivity and good linearity allowed quantification and identification of low levels of pesticides in the most difficult matrixes. The method has been used for routine analysis of many vegetables.

  4. Determination of dapsone in meat and milk by liquid chromatography tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hadjigeorgiou, M. [State General Laboratory of Cyprus, Veterinary Drug Residues Lab, Kimonos 44, 1451 Nicosia (Cyprus)], E-mail: mhadjigeorgiou@sgl.moh.gov.cy; Papachrysostomou, Ch.; Theodorou, Z.; Kanari, P.; Constantinou, S. [State General Laboratory of Cyprus, Veterinary Drug Residues Lab, Kimonos 44, 1451 Nicosia (Cyprus)

    2009-04-01

    Within the EU the use of dapsone (4,4-diaminodiphenylsulfone) is prohibited in food-producing animals and consequently it's included in the Annex IV of the Directive 90/2377/EC. A quantitative confirmatory method has been developed and validated according to the criteria defined in the Commission Decision 2002/657/EC, for the determination of dapsone in meat and milk. Samples, after homogenization in alkaline conditions and organic solvent extraction, were purified on silica gel solid phase extraction cartridges. The eluate was evaporated and redissolved in mobile phase and was analysed by liquid chromatography tandem mass spectrometry (LC-MS/MS) in positive electrospray ionisation (ESI) using deuterium labelled Sulphadimidine-d7 as internal standard. The calculated value for, decision limit, CC{alpha} is 0.12 {mu}g kg{sup -1}, and the detection capability; CC{beta} value is 0.16 {mu}g kg{sup -1}.

  5. [Neonatal onset of organic acidemia (propionic) diagnosed by tandem mass spectrometry].

    Science.gov (United States)

    Cifuentes, Yolanda; De la Hoz, Isabel; Bermúdez, Martha; Arteaga, Clara

    2008-03-01

    Propionic acidemia is an autosomal recessive disorder as a result of a deficient activity of propionyl-CoA carboxylase. Propionyl CoA is metabolized by propionyl-CoA carboxylase to methylmalonyl CoA. Propionic acidemia is a major cause of ketotic hyperglycinemia. This disorder is characterized by episodic vomiting, dehydratation, feeding intolerante, lethargy, hypotonia, metabolic acidosis, ketosis and hyperammonemia. The patient presented herein was a full-term female newborn with encephalopathy in the first days of life. She presented hypoglycemia, metabolic acidosis with increased anion gap, ketosis, hyperammonemia, anemia, leukopenia and thrombocytopenia. The brain ultrasonography was normal. The tandem mass expectrometry done by Pediatrix was abnormal, with the acylcarnitine results consistent with an organic acidemia. The parents are consanguineus and have a history of abortus, miscarriage and neonatal death, characteristics suggestive of the presence of genetic defects.

  6. Determination of dapsone in meat and milk by liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    Hadjigeorgiou, M.; Papachrysostomou, Ch.; Theodorou, Z.; Kanari, P.; Constantinou, S.

    2009-01-01

    Within the EU the use of dapsone (4,4-diaminodiphenylsulfone) is prohibited in food-producing animals and consequently it's included in the Annex IV of the Directive 90/2377/EC. A quantitative confirmatory method has been developed and validated according to the criteria defined in the Commission Decision 2002/657/EC, for the determination of dapsone in meat and milk. Samples, after homogenization in alkaline conditions and organic solvent extraction, were purified on silica gel solid phase extraction cartridges. The eluate was evaporated and redissolved in mobile phase and was analysed by liquid chromatography tandem mass spectrometry (LC-MS/MS) in positive electrospray ionisation (ESI) using deuterium labelled Sulphadimidine-d7 as internal standard. The calculated value for, decision limit, CCα is 0.12 μg kg -1 , and the detection capability; CCβ value is 0.16 μg kg -1

  7. Pressurized liquid extraction followed by liquid chromatography with tandem mass spectrometry to determine pharmaceuticals in mussels.

    Science.gov (United States)

    Núñez, Mireia; Borrull, Francesc; Pocurull, Eva; Fontanals, Núria

    2016-02-01

    An analytical method based on pressurized liquid extraction and solid-phase extraction with a mixed-mode Oasis(®) MAX sorbent as cleanup, followed by liquid chromatography with electrospray ionization and tandem mass spectrometry was developed and validated for the determination of seven widely used pharmaceuticals in mussel species. The optimization of the pressurized liquid extraction and the solid-phase extraction parameters is described. The method provided extraction recoveries ranging from 61 to 90%, and limits of detection ranging from 2 to 50 ng/g (dry weight). The repeatability and reproducibility of the method, expressed as relative standard deviation, were lower than 15 and 19%, respectively. The method was successfully applied to the analysis of mussel samples from different locations. The analyses showed that salicylic acid was present in mussels at concentrations up to 177 ng/g (dry weight). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tandem Mass Spectrometry Detection of Quorum Sensing Activity in Multidrug Resistant Clinical Isolate Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2014-01-01

    Full Text Available Many Proteobacteria communicate via production followed by response of quorum sensing molecules, namely, N-acyl homoserine lactones (AHLs. These molecules consist of a lactone moiety with N-acyl side chain with various chain lengths and degrees of saturation at C-3 position. AHL-dependent QS is often associated with regulation of diverse bacterial phenotypes including the expression of virulence factors. With the use of biosensor and high resolution liquid chromatography tandem mass spectrometry, the AHL production of clinical isolate A. baumannii 4KT was studied. Production of short chain AHL, namely, N-hexanoyl-homoserine lactone (C6-HSL and N-octanoyl-homoserine lactone (C8-HSL, was detected.

  9. A dedicated AMS setup for medium mass isotopes at the Cologne FN tandem accelerator

    Science.gov (United States)

    Schiffer, M.; Altenkirch, R.; Feuerstein, C.; Müller-Gatermann, C.; Hackenberg, G.; Herb, S.; Bhandari, P.; Heinze, S.; Stolz, A.; Dewald, A.

    2017-09-01

    AMS measurements of medium mass isotopes, e.g. of 53Mn and 60Fe, are gaining interest in various fields of operation, especially geoscience. Therefore a dedicated AMS setup has been built at the Cologne 10 MV FN tandem accelerator. This setup is designed to obtain a sufficient suppression of the stable isobars at energies around 100 MeV. In this contribution we report on the actual status of the new setup and the first in-beam tests of its individual components. The isobar suppression is done with (dE/dx) techniques using combinations of energy degrader foils with an electrostatic analyzer (ESA) and a time of flight (ToF) system, as well as a (dE/dx),E gas ionization detector. Furthermore, the upgraded ion source and its negative ion yield measurement for MnO- are presented.

  10. Advanced Ion Mass Spectrometer for Giant Planet Ionosphere, Magnetospheres and Moons

    Science.gov (United States)

    Sittler, Edward; Cooper, John; Paschalidis, Nick; Jones, Sarah; Brinkerhoff, William; Paterson, William; Ali, Ashraf; Coplan, Michael; Chornay, Dennis; Sturner, Steve; Benna, Mehdi; Bateman, Fred; Fontaine, Dominique; Verdeil, Christophe; Andre, Nicolas; Blanc, Michel; Wurz, Peter

    2017-01-01

    We present our Advanced Ion Mass Spectrometer (AIMS) for outer planet missions which has been under development from various NASA sources (NASA Living with a Star Instrument Development (LWSID), NASA Astrobiology Instrument Development (ASTID), NASA Goddard Internal Research and Development (IRAD)s) to measure elemental, isotopic, and simple molecular composition abundances of 1 V to 25 kV hot ions with wide field-of-view (FOV) in the 1 - 60 amu mass range at mass resolution M/ ΔM Jupiter and Saturn to the outer magnetospheric boundary regions and the upstream solar wind. This instrument will work for both spinning spacecraft and 3-axis stabilized spacecraft. AIMS will measure the ion velocity distribution functions (VDF) for the individual ion species from which velocity moments will give their ion density, flow velocity and temperature.

  11. Ion fragmentation in an electrospray ionization mass spectrometer interface with different gases.

    Science.gov (United States)

    Schneider, B B; Douglas, D J; Chen, D D

    2001-01-01

    Nitrogen, argon, and krypton are used as curtain gases in an electrospray ionization mass spectrometer in an attempt to study the effect of these gases on the extent of ion fragmentation between the orifice and the skimmer of the interface region. A previously published collision model predicts that the degree of ion fragmentation increases with increasing mass of the curtain gas. However, the fragmentation yields are found to be the opposite to that expected. It is believed that the reversed trend with argon and krypton is caused by condensation of the gases within the free jet expansion between the orifice and the skimmer. A condensation parameter can be used to predict the degree of clustering of gases within a free jet expansion. When the condensation parameter is minimized, the predicted trend of fragmentation with mass is observed. Copyright 2001 John Wiley & Sons, Ltd.

  12. Improvements in the injection system of the Canadian Penning trap mass spectrometer

    CERN Document Server

    Clark, J; Boudreau, C; Buchinger, F; Crawford, J E; Gulick, S; Hardy, J C; Heinz, A; Lee, J K P; Moore, R B; Savard, G; Seweryniak, D; Sharma, K S; Sprouse, G; Vaz, J; Wang, J C; Zhou, Z

    2003-01-01

    The Canadian Penning Trap (CPT) mass spectrometer is designed to make precise mass measurements on a variety of stable and short-lived isotopes. Modifications to the injection system of the CPT have been implemented in recent months, the purpose being to more efficiently collect and transfer weakly-produced reaction products from the target to the Penning trap. These include a magnetic triplet situated after the target chamber to increase the acceptance of the Enge spectrograph, a velocity filter to more effectively separate the beam from the reaction products and the replacement of the Paul trap with a linear trap resulting in more efficient capture and accumulation of ions from the ion cooler. This paper will discuss these recent modifications and how they have increased our ability in making mass measurements on isotopes of low abundance, including those from a sup 2 sup 5 sup 2 Cf fission source.

  13. Determination of ractopamine and salbutamol in pig hair by liquid chromatography tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Kai-Chun Chang

    2018-04-01

    Full Text Available A liquid chromatography tandem mass spectrometric method was developed for the determination of two β-agonists (ractopamine and salbutamol in pig hair samples. An isotope of ractopamine-d5 or salbutamol-d6 as an internal standard was used to carry out quantitative analysis. Concentrated sodium hydroxide was used to pretreat hair samples and then purified by the solid phase extraction (SPE procedure. The extracted solution was evaporated and reconstituted for injection in the instrument with electrospray ionization (ESI operating in a positive multiple-reaction-monitoring (MRM mode. Ractopamine and salbutamol separation were performed on C18 analytical column under gradient condition. The internal standard calibration curve was linear in the range of concentration from 0.5 to 100 ng mL−1 (R2 > 0.995. Recoveries of this method estimated at three spiked concentrations of 100, 250 and 500 ng mL−1 in pig hair samples, were 79–82% for ractopamine and 77–96% for salbutamol. The corresponding inter-day and intra-day precisions expressed as relative standard deviation (RSD % were 3.8–6.4% and 3.8–8.6%, respectively. The analytical time for one sample was 8 min. The detection limit of this method was 0.6 and 8.3 ng mL−1 for ractopamine and salbutamol, respectively. This developed method can be applied for monitoring the use of the β-agonists salbutamol and ractopamine in swine feed incurred pig hair. Keywords: Salbutamol, Ractopamine, Hair, Tandem mass

  14. Plasma free and total carnitine measured in children by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    J.H. Osorio

    2002-11-01

    Full Text Available Free and total carnitine quantification is important as a complementary test for the diagnosis of unusual metabolic diseases, including fatty acid degradation disorders. The present study reports a new method for the quantification of free and total carnitine in dried plasma specimens by isotope dilution electrospray tandem mass spectrometry with sample derivatization. Carnitine is determined by looking for the precursor of ions of m/z = 103 of N-butylester derivative, and the method is validated by comparison with radioenzymatic assay. We obtained an inter- and intra-day assay coefficient of variation of 4.3 and 2.3, respectively. Free and total carnitine was analyzed in 309 dried plasma spot samples from children ranging in age from newborn to 14 years using the new method, which was found to be suitable for calculating reference age-related values for free and total carnitine (less than one month: 19.3 ± 2.4 and 23.5 ± 2.9; one to twelve months: 28.8 ± 10.2 and 35.9 ± 11.4; one to seven years: 30.7 ± 10.3 and 38.1 ± 11.9; seven to 14 years: 33.7 ± 11.6, and 43.1 ± 13.8 µM, respectively. No difference was found between males and females. A significant difference was observed between neonates and the other age groups. We compare our data with reference values in the literature, most of them obtained by radioenzymatic assay. However, this method is laborious and time consuming. The electrospray tandem mass spectrometry method presented here is a reliable, rapid and automated procedure for carnitine quantitation.

  15. GoAmazon 2014/15 Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, JN [Univ. of California, Irvine, CA (United States)

    2016-04-01

    The Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) deployment to the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility T3 site in Manacapuru, Brazil, was motivated by two main scientific objectives of the Green Ocean Amazon (GoAmazon) 2014/15 field campaign. 1) Study the interactions between anthropogenic and biogenic emissions by determining important molecular species in ambient nanoparticles. To address this, TDCIMS data will be combined with coincident measurements such as gas-phase sulfuric acid to determine the contribution of sulfuric acid condensation to nucleation and growth. We can then compare that result to TDCIMS-derived nanoparticle composition to determine the fraction of growth that can be attributed to the uptake of organic compounds. The molecular composition of sampled particles will also be used to attribute specific chemical species and mechanisms to growth, such as the condensation of low-volatility species or the oligomerization of α-dicarbonyl compounds. 2) Determine the source of new ambient nanoparticles in the Amazon. The hypothesis prior to measurements was that potassium salts formed from the evaporation of primary particles emitted by fungal spores can provide a unique and important pathway for new particle production in the Amazon basin. To explore this hypothesis, the TDCIMS recorded the mass spectra of sampled ambient particles using a protonated water cluster Chemical Ionization Mass Spectrometer (CIMS). Laboratory tests performed using potassium salts show that the TDCIMS can detect potassium with high sensitivity with this technique.

  16. Feasibility of a Fieldable Mass Spectrometer FY 2015 Year-end Report

    Energy Technology Data Exchange (ETDEWEB)

    Barinaga, Charles J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hager, George J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hoegg, Edward D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carman, April J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hart, Garret L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched uranium hexafluoride (UF6) at declared facilities by collecting a few grams of product in sample tubes that are then sent to central laboratories for processing and isotope ratio analysis by thermal ionization mass spectrometry. Analysis of results may not be available for some time after collection. In addition, new shipping regulations will make it more difficult to transport this amount of UF6 to a laboratory. The IAEA is interested in an isotope ratio technique for uranium in UF6 that can be moved to and operated at the enrichment facility itself. This report covers the tasks and activities of the Feasibility of a Fieldable Mass Spectrometer Project for FY 2015, which investigates the feasibility of an in-field isotope ratio technique— the forward deployment of a technique to the non-laboratory situation of a protected room with power and heat at the facility of interest. A variety of nontraditional elemental ionization techniques were considered. It was determined that only two of these should be moved forward for testing with the candidate in-field mass spectrometer and with the adsorbed UF6 sample types.

  17. 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 $ \

  18. mMass as a Software Tool for the Annotation of Cyclic Peptide Tandem Mass Spectra

    Czech Academy of Sciences Publication Activity Database

    Niedermeyer, T. H. J.; Strohalm, Martin

    2012-01-01

    Roč. 7, č. 9 (2012), e44913 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) ME10013 Institutional research plan: CEZ:AV0Z50200510 Keywords : cyclic peptide s * nMass Subject RIV: CE - Biochemistry Impact factor: 3.730, year: 2012

  19. Monitoring salivary melatonin concentrations in children with sleep disorders using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Khan, Sohil A; George, Rani; Charles, Bruce G; Taylor, Paul J; Heussler, Helen S; Cooper, David M; McGuire, Treasure M; Pache, David; Norris, Ross L G

    2013-06-01

    Melatonin is synthesized in the pineal gland and is an important circadian phase marker, especially in the determination of sleep patterns. Both temporary and permanent abnormal sleep patterns occur in children; therefore, it is desirable to have methods for monitoring melatonin in biological fluids in the diagnosis and treatment of such disorders. The objective of the study is to develop a liquid chromatography-tandem mass spectrometry method for the determination of melatonin in saliva and to apply it to monitoring salivary concentrations in children with sleep disorders. A deuterated internal standard (d7-melatonin) was added to a diluted saliva sample (20 µL) in an autosampler vial insert, and 50 µL were injected. Plasticware was strictly avoided, and all glassware was scrupulously cleaned and then baked at 120°C for at least 48 hours to obtain satisfactory performance. Reverse-phase chromatography was performed on a C8 column using a linear gradient elution profile comprising mobile phases A (0.1% aqueous formic acid) and B (15% methanol in acetonitrile containing 0.1% formic acid), pumped at a total flow rate of 0.8 mL/min. The run time was 8 minutes. After atmospheric pressure chemical ionization, mass spectrometric detection was in positive ion mode. Mass detection was by selected reaction monitoring mode with the following mass transitions used for quantification: melatonin, m/z 233.0 → 173.8 and d7-melatonin, m/z 240.0 → 178.3. Linearity (r > 0.999) was established from 3.9 to 1000 pg/mL. Imprecision (coefficient of variation percent) was less than 11%, and accuracy was 100-105% (7.0-900 pg/mL). The method was selective, and the mean (range) ratio of the slopes of calibrations in water to those in daytime saliva samples collected from 10 healthy adult subjects was 0.989 (0.982-0.997), indicating negligible matrix effects. The application of the assay was demonstrated in healthy adults and in children being clinically investigated for sleep

  20. Measurement of high-mass dilepton production with the CMS-TOTEM Precision Proton Spectrometer

    CERN Document Server

    Shchelina, Ksenia

    2017-01-01

    The measurements of dilepton production in photon-photon fusion with the CMS-TOTEM Precision Proton Spectrometer (CT-PPS) are presented. For the first time, exclusive dilepton production at high masses have been observed in the CMS detector while one or two outgoing protons are measured in CT-PPS using around 10~${\\rm fb}^{-1}$ of data accumulated in 2016 during high-luminosity LHC operation. These first results show a good understanding, calibration and alignment of the new CT-PPS detectors installed in 2016.

  1. Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

    Science.gov (United States)

    Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

    2015-10-01

    The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

  2. Isotope ratio analysis by a combination of element analyzer and mass spectrometer

    International Nuclear Information System (INIS)

    Pichlmayer, F.

    1987-06-01

    The use of stable isotope ratios of carbon, nitrogen and sulfur as analytical tool in many fields of research is of growing interest. A method has therefore been developed, consisting in essential of coupling an Elemental Analyzer with an Isotope Mass Spectrometer, which enables the gas preparation of carbon dioxide, nitrogen and sulfur dioxide from any solid or liquid sample in a fast and easy way. Results of carbon isotope measurements in food analysis are presented, whereat it is possible to check origin and treatment of sugar, oils, fats, mineral waters, spirituous liquors etc. and to detect adulterations as well. Also applications in the field of environmental research are given. (Author)

  3. Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

    DEFF Research Database (Denmark)

    Kelstrup, Christian D; Jersie-Christensen, Rosa R; Batth, Tanveer Singh

    2014-01-01

    Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is evalu......Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage...

  4. Exploiting the multiplexing capabilities of tandem mass tags for high-throughput estimation of cellular protein abundances by mass spectrometry.

    Science.gov (United States)

    Ahrné, Erik; Martinez-Segura, Amalia; Syed, Afzal Pasha; Vina-Vilaseca, Arnau; Gruber, Andreas J; Marguerat, Samuel; Schmidt, Alexander

    2015-09-01

    The generation of dynamic models of biological processes critically depends on the determination of precise cellular concentrations of biomolecules. Measurements of system-wide absolute protein levels are particularly valuable information in systems biology. Recently, mass spectrometry based proteomics approaches have been developed to estimate protein concentrations on a proteome-wide scale. However, for very complex proteomes, fractionation steps are required, increasing samples number and instrument analysis time. As a result, the number of full proteomes that can be routinely analyzed is limited. Here we combined absolute quantification strategies with the multiplexing capabilities of isobaric tandem mass tags to determine cellular protein abundances in a high throughput and proteome-wide scale even for highly complex biological systems, such as a whole human cell line. We generated two independent data sets to demonstrate the power of the approach regarding sample throughput, dynamic range, quantitative precision and accuracy as well as proteome coverage in comparison to existing mass spectrometry based strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. De Novo Sequencing of Tryptic Phosphopeptides Using Matrix-Assisted Laser Desorption/Ionization Based Tandem Mass Spectrometry with Hydrogen Atom Attachment.

    Science.gov (United States)

    Asakawa, Daiki; Takahashi, Hidenori; Iwamoto, Shinichi; Tanaka, Koichi

    2018-02-20

    Phosphorylation is the most abundant protein modification, and tandem mass spectrometry (MS/MS) with radical-based fragmentation techniques has proven to be a promising method for phosphoproteomic applications, owing to its ability to determine phosphorylation sites on proteins. The radical-induced fragmentation technique involves the attachment or abstraction of hydrogen to peptides in an ion trap mass spectrometer, in a process called hydrogen attachment/abstraction dissociation (HAD), which has only been recently developed. In the present investigation, we have analyzed model phosphopeptides and phosphoprotein digests using HAD-MS/MS, combined with matrix-assisted laser desorption/ionization (MALDI), in order to demonstrate the usefulness of the HAD-MS/MS-based analytical method. The tryptic peptides were categorized as arginine- and lysine-terminated peptides, and MALDI HAD-MS/MS is found to facilitate the sequencing of arginine-terminated tryptic peptides, because of the selective observation of C-terminal side fragment ions. In contrast, MALDI HAD-MS/MS of lysine-terminated tryptic peptides produced both N- and C-terminal side fragments, such that the mass spectra were complex. The guanidination of peptide converted lysine into homoarginine, which facilitated the interpretation of MALDI HAD-MS/MS mass spectra. The present method was useful for de novo sequencing of tryptic phosphopeptides.

  6. Evaluation of flow-injection tandem mass spectrometry for rapid and high-throughput quantitative determination of B vitamins in nutritional supplements.

    Science.gov (United States)

    Bhandari, Deepak; Van Berkel, Gary J

    2012-08-29

    The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B vitamins, viz., B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed. Automated flow injection introduced 1 μL of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and SRM 3280. The quantity determined for each B vitamin in SRM 3280 was within the statistical range provided for the respective certified values. This approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B vitamins, as evidenced by an agreement with the label values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.

  7. Evaluation of Flow-Injection Tandem Mass Spectrometry for Rapid and High-Throughput Quantitative Determination of B-Vitamins in Nutritional Supplements

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Deepak [ORNL; Van Berkel, Gary J [ORNL

    2012-01-01

    The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B-vitamins, viz. B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed by adding extraction solvent to a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Automated flow injection introduced 1 L of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s representing significant improvement over conventional liquid chromatography approaches which typically require 25-45 min, and often require more significant sample preparation procedures. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and NIST standard reference material (SRM 3280) multivitamin/multielement tablets. The quantity determined for each B-vitamin in SRM 3280 was within the statistical range provided for the respective certified values. The same sample preparation and analysis approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B-vitamins as evidenced by an agreement with the labels values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.

  8. Simultaneous determination of ramipril, ramiprilat and telmisartan in human plasma using liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Gupta, V K; Jain, Rajeev; Lukram, Ojitkumar; Agarwal, Shilpi; Dwivedi, Ashish

    2011-01-15

    A rapid and sensitive liquid chromatography tandem mass spectrometry method has been developed and validated for the simultaneous determination of ramipril, ramiprilat and telmisartan in human plasma. The solid-phase extraction technique was used for the extraction of ramipril, ramiprilat and telmisartan from human plasma. Trandolaprilat and hydrochlorothiazide were used as the internal standards (ISs). Chromatography was performed on a Hypurity C18, 5 μm, 50 mm × 4.6mm column, with the mobile phase consisting of ammonium acetate and acetonitrile (in a 20:80 ratio), followed by detection using mass spectrometry. The method involves a simple reversed isocratic chromatography condition and mass spectrometry detection, which enables detection at sub-nanogram levels. The method was validated and the lower limit of quantification for ramipril, ramiprilat and telmisartan was found to be 0.1 ng mL(-1), 0.1 ng mL(-1) and 2 ng mL(-1), respectively. The mean recovery for ramipril, ramiprilat and telmisartan ranged from 90.1 to 104.1%. This method increased the sensitivity and selectivity; resulting in high-throughput analysis of ramipril, ramiprilat and telmisartan using two different ISs in a single experiment for bioequivalence studies, with a chromatographic run time of 1.5 min only. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Characterization of N,N-dimethyl amino acids by electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    Naresh Chary, V; Sudarshana Reddy, B; Kumar, Ch Dinesh; Srinivas, R; Prabhakar, S

    2015-05-01

    Methylation is an essential metabolic process for a number of critical reactions in the body. Methyl groups are involved in the healthy function of the body life processes, by conducting methylation process involving specific enzymes. In these processes, various amino acids are methylated, and the occurrence of methylated amino acids in nature is diverse. Nowadays, mass-spectrometric-based identification of small molecules as biomarkers for diseases is a growing research. Although all dimethyl amino acids are metabolically important molecules, mass spectral data are available only for a few of them in the literature. In this study, we report synthesis and characterization of all dimethyl amino acids, by electrospray ionization-tandem mass spectrometry (MS/MS) experiments on protonated molecules. The MS/MS spectra of all the studied dimethyl amino acids showed preliminary loss of H2O + CO to form corresponding immonium ions. The other product ions in the spectra are highly characteristic of the methyl groups on the nitrogen and side chain of the amino acids. The amino acids, which are isomeric and isobaric with the studied dimethyl amino acids, gave distinctive MS/MS spectra. The study also included MS/MS analysis of immonium ions of dimethyl amino acids that provide information on side chain structure, and it is further tested to determine the N-terminal amino acid of the peptides. Copyright © 2015 John Wiley & Sons, Ltd.

  10. On the isobaric space of 25-hydroxyvitamin D in human serum: potential for interferences in liquid chromatography/tandem mass spectrometry, systematic errors and accuracy issues.

    Science.gov (United States)

    Qi, Yulin; Geib, Timon; Schorr, Pascal; Meier, Florian; Volmer, Dietrich A

    2015-01-15

    Isobaric interferences in human serum can potentially influence the measured concentration levels of 25-hydroxyvitamin D [25(OH)D], when low resolving power liquid chromatography/tandem mass spectrometry (LC/MS/MS) instruments and non-specific MS/MS product ions are employed for analysis. In this study, we provide a detailed characterization of these interferences and a technical solution to reduce the associated systematic errors. Detailed electrospray ionization Fourier transform ion cyclotron resonance (FTICR) high-resolution mass spectrometry (HRMS) experiments were used to characterize co-extracted isobaric components of 25(OH)D from human serum. Differential ion mobility spectrometry (DMS), as a gas-phase ion filter, was implemented on a triple quadrupole mass spectrometer for separation of the isobars. HRMS revealed the presence of multiple isobaric compounds in extracts of human serum for different sample preparation methods. Several of these isobars had the potential to increase the peak areas measured for 25(OH)D on low-resolution MS instruments. A major isobaric component was identified as pentaerythritol oleate, a technical lubricant, which was probably an artifact from the analytical instrumentation. DMS was able to remove several of these isobars prior to MS/MS, when implemented on the low-resolution triple quadrupole mass spectrometer. It was shown in this proof-of-concept study that DMS-MS has the potential to significantly decrease systematic errors, and thus improve accuracy of vitamin D measurements using LC/MS/MS. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Effects of the source gap on transmission efficiency of a quadrupole mass spectrometer.

    Science.gov (United States)

    Antony Joseph, Mariya J; McIntosh, David; Gibson, Ray; Taylor, Stephen

    2018-02-28

    Recent trends towards miniature and portable quadrupole mass spectrometry (QMS) entail challenges in instrumental sensitivity, which is influenced by 3D fringe field effects on ion transmission in the Quadrupole Mass Filter (QMF). The relationship of these effects with the gap from the ion source to the QMF entrance (source gap) is significant and little explored. We examine transmission characteristics experimentally and use the results to test the predictive accuracy of a recently-developed 3D QMF simulation model. The model is then applied to directly investigate optimal transmission m/z ranges across multiple source gaps. Experimental: A portable single filter quadrupole mass spectrometer is used to analyse transmission characteristics across a range of common gases. We use an experimental approach originally proposed by Ehlert, enhanced with a novel method for absolute calibration of the transmission curve. Simulation: Custom QMF simulation software employs the boundary element method (BEM) to compute accurate 3D electric fields. This is used to study the effects of the source gap on transmission efficiency. Experimental findings confirm a centrally peaked transmission curve; simulations correctly predict the optimal transmission location (in m/z) and percentage, and extend the experimental trend. We compare several methods for determining fringe field length, demonstrating how the size of the physical source gap influences both the length and the intensity of the fringe field at the QMF entrance. A complex relationship with ion transmission is revealed in which different source gaps promote optimal transmission at differing m/z ranges. The presented results map the relationship between the source gap and transmission efficiency for the given instrument, using a simulation method transferrable to other setups. This is of importance to miniature and portable quadrupole mass spectrometers designed for specific applications, for the first time enabling the source

  12. Characterization of sulfur mustard induced structural modifications in human hemoglobin by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Noort, D.; Verheij, E.R.; Hulst, A.G.; Jong, L.P.A. de; Benschop, H.P.

    1996-01-01

    In this paper we describe the use of tandem mass spectrometry to identify modified sites in human hemoglobin after in vitro exposure to bis(2- chloroethyl) sulfide (sulfur mustard). Globin isolated from human whole blood which had been exposed to sulfur mustard was degraded with trypsin, and the

  13. Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry : A worldwide collaborative project

    NARCIS (Netherlands)

    McHugh, David M. S.; Cameron, Cynthia A.; Abdenur, Jose E.; Abdulrahman, Mahera; Adair, Ona; Al Nuaimi, Shahira Ahmed; Ahlman, Henrik; Allen, Jennifer J.; Antonozzi, Italo; Archer, Shaina; Au, Sylvia; Auray-Blais, Christiane; Baker, Mei; Bamforth, Fiona; Beckmann, Kinga; Pino, Gessi Bentz; Berberich, Stanton L.; Binard, Robert; Boemer, Francois; Bonham, Jim; Breen, Nancy N.; Bryant, Sandra C.; Caggana, Michele; Caldwell, S. Graham; Camilot, Marta; Campbell, Carlene; Carducci, Claudia; Cariappa, Rohit; Carlisle, Clover; Caruso, Ubaldo; Cassanello, Michela; Miren Castilla, Ane; Castineiras Ramos, Daisy E.; Chakraborty, Pranesh; Chandrasekar, Ram; Ramos, Alfredo Chardon; Cheillan, David; Chien, Yin-Hsiu; Childs, Thomas A.; Chrastina, Petr; Sica, Yuri Cleverthon; Cocho de Juan, Jose Angel; Elena Colandre, Maria; Cornejo Espinoza, Veronica; Corso, Gaetano; Currier, Robert; Cyr, Denis; Czuczy, Noemi; D'Apolito, Oceania; Davis, Tim; de Sain-Van der Velden, Monique G.; Delgado Pecellin, Carmen; Di Gangi, Iole Maria; Di Stefano, Cristina Maria; Dotsikas, Yannis; Downing, Melanie; Downs, Stephen M.; Dy, Bonifacio; Dymerski, Mark; Rueda, Inmaculada; Elvers, Bert; Eaton, Roger; Eckerd, Barbara M.; El Mougy, Fatma; Eroh, Sarah; Espada, Mercedes; Evans, Catherine; Fawbush, Sandy; Fijolek, Kristel F.; Fisher, Lawrence; Franzson, Leifur; Frazier, Dianne M.; Garcia, Luciana R. C.; Garcia-Valdecasas Bermejo, Maria Sierra; Gavrilov, Dimitar; Gerace, Rosemarie; Giordano, Giuseppe; Irazabal, Yolanda Gonzalez; Greed, Lawrence C.; Grier, Robert; Grycki, Elyse; Gu, Xuefan; Gulamali-Majid, Fizza; Hagar, Arthur F.; Han, Lianshu; Hannon, W. Harry; Haslip, Christa; Hassan, Fayza Abdelhamid; He, Miao; Hietala, Amy; Himstedt, Leslie; Hoffman, Gary L.; Hoffman, William; Hoggatt, Philis; Hopkins, Patrick V.; Hougaard, David M.; Hughes, Kerie; Hunt, Patricia R.; Hwu, Wuh-Liang; Hynes, June; Ibarra-Gonzalez, Isabel; Ingham, Cindy A.; Ivanova, Maria; Jacox, Ward B.; John, Catharine; Johnson, John P.; Jonsson, Jon J.; Karg, Eszter; Kasper, David; Klopper, Brenda; Katakouzinos, Dimitris; Khneisser, Issam; Knoll, Detlef; Kobayashi, Hirinori; Koneski, Ronald; Kozich, Viktor; Kouapei, Rasoul; Kohlmueller, Dirk; Kremensky, Ivo; la Marca, Giancarlo; Lavochkin, Marcia; Lee, Soo-Youn; Lehotay, Denis C.; Lemes, Aida; Lepage, Joyce; Lesko, Barbara; Lewis, Barry; Lim, Carol; Linard, Sharon; Lindner, Martin; Lloyd-Puryear, Michele A.; Lorey, Fred; Loukas, Yannis L.; Luedtke, Julie; Maffitt, Neil; Magee, J. Fergall; Manning, Adrienne; Manos, Shawn; Marie, Sandrine; Hadachi, Sonia Marchezi; Marquardt, Gregg; Martin, Stephen J.; Matern, Dietrich; Gibson, Stephanie K. Mayfield; Mayne, Philip; McCallister, Tonya D.; McCann, Mark; McClure, Julie; McGill, James J.; McKeever, Christine D.; McNeilly, Barbara; Morrissey, Mark A.; Moutsatsou, Paraskevi; Mulcahy, Eleanor A.; Nikoloudis, Dimitris; Norgaard-Pedersen, Bent; Oglesbee, Devin; Oltarzewski, Mariusz; Ombrone, Daniela; Ojodu, Jelili; Papakonstantinou, Vagelis; Reoyo, Sherly Pardo; Park, Hyung-Doo; Pasquali, Marzia; Pasquini, Elisabetta; Patel, Pallavi; Pass, Kenneth A.; Peterson, Colleen; Pettersen, Rolf D.; Pitt, James J.; Poh, Sherry; Pollak, Arnold; Porter, Cory; Poston, Philip A.; Price, Ricky W.; Queijo, Cecilia; Quesada, Jonessy; Randell, Edward; Ranieri, Enzo; Raymond, Kimiyo; Reddic, John E.; Reuben, Alejandra; Ricciardi, Charla; Rinaldo, Piero; Rivera, Jeff D.; Roberts, Alicia; Rocha, Hugo; Roche, Geraldine; Greenberg, Cheryl Rochman; Egea Mellado, Jose Maria; Jess Juan-Fita, Maria; Ruiz, Consuelo; Ruoppolo, Margherita; Rutledge, S. Lane; Ryu, Euijung; Saban, Christine; Sahai, Inderneel; Salazar Garcia-Blanco, Maria Isabel; Santiago-Borrero, Pedro; Schenone, Andrea; Schoos, Roland; Schweitzer, Barb; Scott, Patricia; Seashore, Margretta R.; Seeterlin, Mary A.; Sesser, David E.; Sevier, Darrin W.; Shone, Scott M.; Sinclair, Graham; Skrinska, Victor A.; Stanley, Eleanor L.; Strovel, Erin T.; Jones, April L. Studinski; Sunny, Sherlykutty; Takats, Zoltan; Tanyalcin, Tijen; Teofoli, Francesca; Thompson, J. Robert; Tomashitis, Kathy; Domingos, Mouseline Torquado; Torres, Jasmin; Torres, Rosario; Tortorelli, Silvia; Turi, Sandor; Turner, Kimberley; Tzanakos, Nick; Valiente, Alf G.; Vallance, Hillary; Vela-Amieva, Marcela; Vilarinho, Laura; von Doebeln, Ulrika; Vincent, Marie-Francoise; Vorster, B. Chris; Watson, Michael S.; Webster, Dianne; Weiss, Sheila; Wilcken, Bridget; Wiley, Veronica; Williams, Sharon K.; Willis, Sharon A.; Woontner, Michael; Wright, Katherine; Yahyaoui, Raquel; Yamaguchi, Seiji; Yssel, Melissa; Zakowicz, Wendy M.

    Purpose: To achieve clinical validation of cutoff values for newborn screening by tandem mass spectrometry through a worldwide collaborative effort. Methods: Cumulative percentiles of amino acids and acylcarnitines in dried blood spots of approximately 25-30 million normal newborns and 10,742

  14. Electrospray ionization quadrupole time-of-flight tandem mass spectrometric analysis of hexamethylenediamine-modified maltodextrin and dextran

    NARCIS (Netherlands)

    Sisu, E.; Bosker, W.T.E.; Norde, W.; Slaghek, T.M.; Timmermans, J.W.; Peter-Katalinić, J.; Cohen-Stuart, M.A.; Zamfir, A.D.

    2006-01-01

    A combined methodology for obtaining at the preparative scale and characterization by nanoelectrospray ionization (nanoESI) quadrupole time-of-flight (QTOF) mass spectrometry (MS) and tandem MS (MS/MS) of linear polysaccharides modified at the reducing end is presented. Two polydisperse

  15. Profiling ABA metabolites in Nicotiana tabacum L. leaves by ultra-performance liquid chromatography–electrospray tandem mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Turečková, Veronika; Novák, Ondřej; Strnad, Miroslav

    2009-01-01

    Roč. 80, č. 1 (2009), s. 390-399 ISSN 0039-9140 R&D Projects: GA AV ČR KAN200380801 Institutional research plan: CEZ:AV0Z50380511 Keywords : Abscisic acid * Ultra-performance liquid chromatography (UPLC) * Tandem mass spectrometry (MS/MS) Subject RIV: EC - Immunology Impact factor: 3.290, year: 2009

  16. Liquid chromatography coupled with tandem mass spectrometry for the quantitative analysis of anticancer drugs in biological matrices

    NARCIS (Netherlands)

    Stokvis, Ellen

    2004-01-01

    In this thesis, the development and validation of liquid chromatography tandem mass spectrometric (LC-MS/MS) methods for the quantitative bioanalysis of anticancer drugs are described. The monitoring of these drugs in biological fluids and tissues is important during both pre-clinical and clinical

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

    NARCIS (Netherlands)

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

    2003-01-01

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

  18. Determination of olanzapine in whole blood using simple protein precipitation and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Marie Katrine Klose; Johansen, Sys Stybe

    2009-01-01

    A simple, sensitive, and reproducible liquid chromatography-tandem mass spectrometry method has been developed and validated for the quantification of the antipsychotic drug olanzapine in whole blood using dibenzepine as internal standard (IS). After acidic methanol-induced protein precipitation...

  19. Structure of [M + H − H2O]+ from Protonated Tetraglycine Revealed by Tandem Mass Spectrometry and IRMPD Spectroscopy

    NARCIS (Netherlands)

    Bythell, B. J.; Dain, Ryan P.; Curtice, Stephanie S.; Oomens, Jos; Steill, Jeffrey D.; Groenewold, Gary S.; la Paizs, Bé; van Stipdonk, M. J.

    2010-01-01

    Multiple-stage tandem mass spectrometry and collision-induced dissociation were used to investigate loss of H2O or CH3OH from protonated versions of GGGX (where X = G, A, and V), GGGGG, and the methyl esters of these peptides. In addition, wavelength-selective infrared multiple photon dissociation

  20. Simultaneous determination of estrogens and progestogens in honey using high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    This work describes the development and validation of a method for the simultaneous determination of 13 estrogens and progestogens in honey by high performance liquid chromatography-tandem mass spectrometry. The target compounds were preconcentrated by solid phase extraction. Pretreatment variables ...

  1. Liquid chromatography-tandem mass spectrometric assay for the nucleoside reverse transcriptase inhibitor emtricitabine in human plasma

    NARCIS (Netherlands)

    Sparidans, Rolf W.; Prins, Jan M.; Schellens, Jan H. M.; Beijnen, Jos H.

    2007-01-01

    A liquid chromatography-tandem mass spectrometric assay for the determination of the antiretroviral nucleoside emtricitabine in human plasma was developed and validated using a simple sample pre-treatment procedure. After addition of 5'-deoxy-5-fluorocytidine as the internal standard and protein

  2. Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

    NARCIS (Netherlands)

    Bobeldijk, I.; Boonzaaijer, G.; Spies-Faber, E.J.; Vaes, W.H.J.

    2005-01-01

    Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual

  3. Inborn errors of metabolism detectable by tandem mass spectrometry in Egypt: The first newborn screening pilot study.

    Science.gov (United States)

    Hassan, Fayza A; El-Mougy, Fatma; Sharaf, Sahar A; Mandour, Iman; Morgan, Marian F; Selim, Laila A; Hassan, Sawsan A; Salem, Fadia; Oraby, Azza; Girgis, Marian Y; Mahmoud, Iman G; El-Badawy, Amira; El-Nekhely, Ibrahim; Moharam, Nadia; Mehaney, Dina A; Elmonem, Mohamed A

    2016-09-01

    To estimate the burden of metabolic disorders detectable by tandem mass spectrometry in Egypt, through a pilot expanded newborn screening programme at Cairo University Children's Hospital in 2008, and examining the results of 3,900 clinically at-risk children, investigated at Cairo University Children's Hospital for the same disorders over the past 7 years using the same technology. Dried blood spots of 25,276 healthy newborns from three governorates in Upper, Middle, and Lower Egypt were screened, to give a representative sample of the Egyptian newborn population. Based on the pilot study outcomes and the results of clinically suspected children, we estimated the total birth prevalence of tandem mass spectrometry detectable metabolic disorders, and the relative frequency of several individual disorders. Among the healthy newborns, 13 metabolic disorder cases (five phenylketonuria [1:5,000], two methylmalonic acidemia, and isovaleric acidemia [1:12,500], one each of maple syrup urine disease, propionic acidemia, β-ketothiolase deficiency, and primary carnitine deficiency [1:25,000]) were confirmed, giving a total birth prevalence of 1:1944 live births. Among the clinically suspected children, 235 cases were diagnosed, representing a much wider disease spectrum. Egypt has one of the highest reported birth prevalence rates for metabolic disorders detectable by tandem mass spectrometry. Early diagnosis and management are crucial for the survival and well-being of affected children. A nationwide NBS programme by tandem mass spectrometry is recommended. © The Author(s) 2016.

  4. Design of the multi-reflection time-of-flight mass spectrometer for the RAON facility

    International Nuclear Information System (INIS)

    Yoon, J.W.; Park, Y.H.; Park, S.J.; Kim, G.D.; Kim, Y.K.

    2014-01-01

    A multi-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been proposed for high precision mass measurements on the future Korean heavy ion accelerator called RAON. MR-TOF-MS will allow us to reach very high mass resolving power (> 10 5 ) with extremely short measurement times (several ms) in a compact device. The MR-TOF-MS is composed of two electrostatic ion mirrors in combination with einzel lenses. The principle is that the injected ions travel for hundreds of revolutions inside MR-TOF-MS and ions with different masses are temporally separated. When temporal separation becomes larger than the ion bunch width, ions are extracted from the MR-TOF-MS by switching off the mirror voltages, and then arrive at a detector plane located at time focus, where an MCP detector for the mass measurement or an ion gate for the isobar separation is deployed. In this paper, simulation results for the MR-TOF-MS design using SIMION code are presented. Temporal broadenings, caused by the kinetic energy spread and the transverse emittance, were minimized by optimization of the electrode potentials, and it was demonstrated that the mass resolving power of 10 5 is achievable for the condition of an energy spread of ±30 eV and an emittance of 0.75 π*mm*mrad

  5. A column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry method to determine anandamide and 2-arachidonoylglycerol in plasma samples.

    Science.gov (United States)

    Marchioni, Camila; de Souza, Israel Donizeti; Grecco, Caroline Fernandes; Crippa, José Alexandre; Tumas, Vitor; Queiroz, Maria Eugênia Costa

    2017-05-01

    This study reports a fast, sensitive, and selective column switching ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the endocannabinoids (eCBs), anandamide (AEA), and 2-arachidonoylglycerol (2-AG) in plasma samples. This bidimensional system used a restricted access media column (RP-8 ADS, 25 mm × 4 mm × 25 μM) in the first dimension and a core-shell Kinetex C18 (100 mm × 2, 1.7 mm × 1 μM) column in the second dimension, followed by detection in a mass spectrometer triple quadrupole (multiple reactions monitoring mode) operating in the positive mode. RP-8 ADS was used for trace enrichment of eCBs (reverse phase partitioning) and macromolecular matrix size exclusion; the core-shell column was used for the chromatographic separation. The column switching UHPLC-MS/MS method presented a linear range spanning from 0.1 ng mL -1 (LOQ) to 6 ng mL -1 for AEA and from 0.04 ng mL -1 (LOQ) to 10 ng mL -1 for 2-AG. Excluding the LLOQ values, the precision assays provided coefficients of variation lower than 8% and accuracy with relative standard error values lower than 14%. Neither carryover nor matrix effects were detected. This high-throughput column switching method compared to conventional methods is time saving as it involves fewer steps, consumes less solvent, and presents lower LLOQ. The column switching UHPLC-MS/MS method was successfully applied to determine AEA and 2-AG in plasma samples obtained from Alzheimer's disease patients. Graphical abstract A column switching ultra high-performance liquid chromatography-tandem mass spectrometry method using RP-8 ADS column and core shell column to determine endocannabinoids in plasma samples.

  6. Measurement of Atmospheric Isoprene Concentrations using an Automated Cylindrical Ion Trap Mass Spectrometer

    Science.gov (United States)

    Edwards, G. D.; Shepson, P. B.; Grossenbacher, J. W.; Wells, J. M.; Patterson, G.; Barkett, D. J.

    2005-12-01

    Volatile organic compounds (VOCs) released from the biosphere have been shown to substantially influence both ozone and aerosol chemistry. However, field instruments for the detection of these trace gases are often limited by instrument portability and the ability to distinguish compounds of interest from background or other interfering compounds. We have developed an automated sampling system that is coupled to a lightweight, low power cylindrical ion trap mass spectrometer. This instrument was used for high frequency isoprene measurements at a recent field campaign at the University of Michigan Biological Station PROPHET lab. The inlet uses a sample loop and 6-port valves to trap ambient air samples without the aid of cryogens. VOCs are preconcentrated by sampling directly into a pre-cooled capillary column that is then heated by moving the column to a pre-heated region to obtain rapid separation of isoprene from other species. Isoprene eluting from the end of the column is then introduced to the mass spectrometer. The commercially available cylindrical ion trap (Minotaur 400) interfaced with our preconcentrator yields limits of detection of <80 ppt. The data obtained during the PROPHET 2005 campaign suggest the new inlet system, when coupled with the Minotaur 400 detector provides a feasible field instrument for the fast and accurate evaluation of trace gases over a variety of atmospheric conditions.

  7. Super-Atmospheric Pressure Ion Sources: Application and Coupling to API Mass Spectrometer

    Science.gov (United States)

    Chen, Lee Chuin; Rahman, Md. Matiur; Hiraoka, Kenzo

    2014-01-01

    Pressurizing the ionization source to gas pressure greater than atmospheric pressure is a new tactic aimed at further improving the performance of atmospheric pressure ionization (API) sources. In principle, all API sources, such as ESI, APCI and AP-MALDI, can be operated at pressure higher than 1 atm if suitable vacuum interface is available. The gas pressure in the ion source can have different role for different ionization. For example, in the case of ESI, stable electrospray could be sustained for high surface tension liquid (e.g., pure water) under super-atmospheric pressure, owing to the absence of electric discharge. Even for nanoESI, which is known to work well with aqueous solution, its stability and sensitivity were found to be enhanced, particularly in the negative mode when the ion source was pressurized. For the gas phase ionization like APCI, measurement of gaseous compound also showed an increase in ion intensity with the ion source pressure until an optimum pressure at around 4–5 atm. The enhancement was due to the increased collision frequency among reactant ion and analyte that promoted the ion/molecule reaction and a higher intake rate of gas to the mass spectrometer. Because the design of vacuum interface for API instrument is based on the upstream pressure of 1 atm, some coupling aspects need to be considered when connecting the high pressure ion source to the mass spectrometer. Several coupling strategies are discussed in this paper. PMID:26819896

  8. Helium Mass Spectrometer Leak Detection: A Method to Quantify Total Measurement Uncertainty

    Science.gov (United States)

    Mather, Janice L.; Taylor, Shawn C.

    2015-01-01

    In applications where leak rates of components or systems are evaluated against a leak rate requirement, the uncertainty of the measured leak rate must be included in the reported result. However, in the helium mass spectrometer leak detection method, the sensitivity, or resolution, of the instrument is often the only component of the total measurement uncertainty noted when reporting results. To address this shortfall, a measurement uncertainty analysis method was developed that includes the leak detector unit's resolution, repeatability, hysteresis, and drift, along with the uncertainty associated with the calibration standard. In a step-wise process, the method identifies the bias and precision components of the calibration standard, the measurement correction factor (K-factor), and the leak detector unit. Together these individual contributions to error are combined and the total measurement uncertainty is determined using the root-sum-square method. It was found that the precision component contributes more to the total uncertainty than the bias component, but the bias component is not insignificant. For helium mass spectrometer leak rate tests where unit sensitivity alone is not enough, a thorough evaluation of the measurement uncertainty such as the one presented herein should be performed and reported along with the leak rate value.

  9. Super-Atmospheric Pressure Ion Sources: Application and Coupling to API Mass Spectrometer.

    Science.gov (United States)

    Chen, Lee Chuin; Rahman, Md Matiur; Hiraoka, Kenzo

    2014-01-01

    Pressurizing the ionization source to gas pressure greater than atmospheric pressure is a new tactic aimed at further improving the performance of atmospheric pressure ionization (API) sources. In principle, all API sources, such as ESI, APCI and AP-MALDI, can be operated at pressure higher than 1 atm if suitable vacuum interface is available. The gas pressure in the ion source can have different role for different ionization. For example, in the case of ESI, stable electrospray could be sustained for high surface tension liquid (e.g., pure water) under super-atmospheric pressure, owing to the absence of electric discharge. Even for nanoESI, which is known to work well with aqueous solution, its stability and sensitivity were found to be enhanced, particularly in the negative mode when the ion source was pressurized. For the gas phase ionization like APCI, measurement of gaseous compound also showed an increase in ion intensity with the ion source pressure until an optimum pressure at around 4-5 atm. The enhancement was due to the increased collision frequency among reactant ion and analyte that promoted the ion/molecule reaction and a higher intake rate of gas to the mass spectrometer. Because the design of vacuum interface for API instrument is based on the upstream pressure of 1 atm, some coupling aspects need to be considered when connecting the high pressure ion source to the mass spectrometer. Several coupling strategies are discussed in this paper.

  10. Determination of cyanuric acid residues in catfish, trout, tilapia, salmon and shrimp by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Karbiwnyk, Christine M. [Animal Drugs Research Center, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States)], E-mail: christine.karbiwnyk@fda.hhs.gov; Andersen, Wendy C.; Turnipseed, Sherri B. [Animal Drugs Research Center, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States); Storey, Joseph M.; Madson, Mark R. [Denver District Laboratory, U.S. Food and Drug Administration, P.O. Box 25087, Denver, CO 80225-0087 (United States); Miller, Keith E. [Center for Veterinary Medicine, U.S. Food and Drug Administration, 8401 Muirkirk Road, Laurel, MD 20708 (United States); Gieseker, Charles M.; Miller, Ron A.; Rummel, Nathan G.; Reimschuessel, Renate [University of Denver, Department of Chemistry and Biochemistry, Denver, CO 80208 (United States)

    2009-04-01

    In May 2007, investigators discovered that waste material from the pet food manufacturing process contaminated with melamine (MEL) and/or cyanuric acid (CYA) had been added to hog and chicken feeds. At this time, investigators also learned that adulterated wheat gluten had been used in the manufacture of aquaculture feeds. Concern that the contaminated feed had been used in aquaculture and could enter the human food supply prompted the development of a method for the determination of CYA residues in the edible tissues of fish and shrimp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed as a sensitive technique for the analysis of CYA in catfish, tilapia, salmon, trout and shrimp tissue. CYA was extracted from ground fish or shrimp with an acetic acid solution, defatted with hexane, and isolated with a graphitic carbon black solid-phase extraction column. Residues were separated from matrix components using a porous graphitic carbon LC column, and then analyzed with electrospray ionization in negative ion mode on a triple quadrupole mass spectrometer. Selective reaction monitoring was performed on the [M-H]{sup -}m/z 128 ion resulting in the product ions m/z 85 and 42. Recoveries from catfish, tilapia and trout fortified with 10-100 {mu}g kg{sup -1} of CYA averaged 67% with a relative standard deviation (R.S.D.) of 18% (n = 107). The average method detection limit (MDL) for catfish, tilapia and trout is 3.5 {mu}g kg{sup -1}. An internal standard, {sup 13}C{sub 3}-labeled CYA, was used in the salmon and shrimp extractions. Average recovery of CYA from salmon was 91% (R.S.D. = 15%, n = 18) with an MDL of 7.4 {mu}g kg{sup -1}. Average recovery of CYA from shrimp was 85% (R.S.D. = 10%, n = 13) with an MDL of 3.5 {mu}g kg{sup -1}.

  11. Laser Ablation Mass Spectrometer (LAMS) as a Standoff Analyzer in Space Missions for Airless Bodies

    Science.gov (United States)

    Li, X.; Brinckerhoff, W. B.; Managadze, G. G.; Pugel, D. E.; Corrigan, C. M.; Doty, J. H.

    2012-01-01

    A laser ablation mass spectrometer (LAMS) based on a time-of-flight (TOF) analyzer with adjustable drift length is proposed as a standoff elemental composition sensor for space missions to airless bodies. It is found that the use of a retarding potential analyzer in combination with a two-stage reflectron enables LAMS to be operated at variable drift length. For field-free drift lengths between 33 cm to 100 cm, at least unit mass resolution can be maintained solely by adjustment of internal voltages, and without resorting to drastic reductions in sensitivity. Therefore, LAMS should be able to be mounted on a robotic arm and analyze samples at standoff distances of up to several tens of cm, permitting high operational flexibility and wide area coverage of heterogeneous regolith on airless bodies.

  12. An Improvement on Space Focusing Resolution in Two-Field Time-of-Flight Mass Spectrometers

    International Nuclear Information System (INIS)

    Yildirim, M.; Aydin, R.; Akin, U.; Kilic, H. S.; Sise, O.; Ulu, M.; Dogan, M.

    2007-01-01

    Time-of-Flight Mass Spectrometer (TOFMS) is a sophisticated device for the mass selective analysis of a variety of samples. The main limitation on TOFMS technique is the obtainable resolution where the two main limiting factors are the initial space and energy spread of particles created in ionization region. Similar charged particles starting at different points will reach the detector at different times. So, this problem makes space focusing is very important subject. We have presented principles of two-fields TOFMS with second-order space focusing both using analytical methods and ray-tracing simulation. This work aims understanding of ion optical system clearly and gives hint of expectation for future developments

  13. Calibration procedure for secular frequency scanning in ion trap mass spectrometers.

    Science.gov (United States)

    Snyder, Dalton T; Pulliam, Christopher J; Cooks, R Graham

    2016-05-30

    Mass spectra can be recorded using ion traps by scanning the frequency of an alternating current (ac) signal that corresponds to the secular frequency of a trapped ion. There is a considerable simplification in the instrumentation needed to perform such a scan compared with conventional scans of the radiofrequency (rf) amplitude. However, mass calibration is difficult. An algorithm that can be used to achieve mass calibration is investigated and the factors that affect ion mass assignments are discussed. Time domain data, recorded using a commercial benchtop linear ion trap mass spectrometer, are converted to the m/z domain using ion Mathieu parameter q u values which are derived from the dimensionless frequency parameter β u expressed as a continuing fraction in terms of q u . The relationship between the operating parameters of an ideal ion trap and the ion m/z ratio is derived from the Mathieu equations and expressed as an algorithm which through successive approximations yields the Mathieu q u value and hence m/z values and peak widths. The predictions of the algorithm are tested against experiment by sweeping the frequency of a small supplementary ac signal so as to cause mass-selective ejection of trapped ions. Calibration accuracy is always better than 0.1%, often much better. Peak widths correspond to a mass resolution of 250 to 500 in the m/z 100-1800 range in secular frequency scans. A simple, effective method of calibration of mass spectra recorded using secular frequency scans is achieved. The effects of rf amplitude, scan rate, and ac amplitude on calibration parameters are shown using LTQ linear ion trap data. Corrections for differences in ion mass must be made for accurate calibration, and this is easily incorporated into the calibration procedure. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Ring positional differentiation of isomeric N-alkylated fluorocathinones by gas chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Westphal, Folker; Junge, Thomas

    2012-11-30

    In analogy to our previously published procedure for the differentiation of regioisomeric fluoroamphetamines a method was developed, to differentiate ring positional isomeric fluorocathinones by product ion spectrometry of ions generated by chemical ionization (CI) under GC-MS conditions using methane as reagent gas. N-alkylated ortho-, meta- and para-fluorocathinones could be unequivocally differentiated by product ion spectrometry of the hydrogen fluoride loss ions [M+H-HF](+) using a triple quadrupole mass spectrometer with argon as collision gas under normalized collision conditions. This method enables the differentiation of ring positional isomers of fluorocathinones even in complex mixtures and low concentrations. The applicability of the method was shown by the analysis of synthesized N-alkylated ortho-, meta- and para-fluorocathinones and seized designer drug mixtures. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  15. Sequencing Lys-N Proteolytic Peptides by ESI and MALDI Tandem Mass Spectrometry

    Science.gov (United States)

    Dupré, Mathieu; Cantel, Sonia; Verdié, Pascal; Martinez, Jean; Enjalbal, Christine

    2011-02-01

    In this study, we explored the MS/MS behavior of various synthetic peptides that possess a lysine residue at the N-terminal position. These peptides were designed to mimic peptides produced upon proteolysis by the Lys-N enzyme, a metalloendopeptidase issued from a Japanese fungus Grifola frondosa that was recently investigated in proteomic studies as an alternative to trypsin digestion, as a specific cleavage at the amide X-Lys chain is obtained that provides N-terminal lysine peptide fragments. In contrast to tryptic peptides exhibiting a lysine or arginine residue solely at the C-terminal position, and are thus devoid of such basic amino acids within the sequence, these Lys-N proteolytic peptides can contain the highly basic arginine residue anywhere within the peptide chain. The fragmentation patterns of such sequences with the ESI-QqTOF and MALDI-TOF/TOF mass spectrometers commonly used in proteomic bottom-up experiments were investigated.

  16. Development of analytically capable time-of-flight mass spectrometer with continuous ion introduction

    Science.gov (United States)

    Hárs, György; Dobos, Gábor

    2010-03-01

    The present article describes the results and findings explored in the course of the development of the analytically capable prototype of continuous time-of-flight (CTOF) mass spectrometer. Currently marketed pulsed TOF (PTOF) instruments use ion introduction with a 10 ns or so pulse width, followed by a waiting period roughly 100 μs. Accordingly, the sample is under excitation in 10-4 part of the total measuring time. This very low duty cycle severely limits the sensitivity of the PTOF method. A possible approach to deal with this problem is to use linear sinusoidal dual modulation technique (CTOF) as described in this article. This way the sensitivity of the method is increased, due to the 50% duty cycle of the excitation. All other types of TOF spectrometer use secondary electron multiplier (SEM) for detection, which unfortunately discriminates in amplification in favor of the lighter ions. This discrimination effect is especially undesirable in a mass spectrometric method, which targets high mass range. In CTOF method, SEM is replaced with Faraday cup detector, thus eliminating the mass discrimination effect. Omitting SEM is made possible by the high ion intensity and the very slow ion detection with some hundred hertz detection bandwidth. The electrometer electronics of the Faraday cup detector operates with amplification 1010 V/A. The primary ion beam is highly monoenergetic due to the construction of the ion gun, which made possible to omit any electrostatic mirror configuration for bunching the ions. The measurement is controlled by a personal computer and the intelligent signal generator Type Tabor WW 2571, which uses the direct digital synthesis technique for making arbitrary wave forms. The data are collected by a Labjack interface board, and the fast Fourier transformation is performed by the software. Noble gas mixture has been used to test the analytical capabilities of the prototype setup. Measurement presented proves the results of the mathematical

  17. Simultaneous Determination of 25 Common Pharmaceuticals in Whole Blood Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Marie Katrine Klose; Johansen, Sys Stybe

    2012-01-01

    An ultra-performance liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of 25 common pharmaceuticals in whole blood. The selected pharmaceuticals represent the most frequently detected drugs in our forensic laboratory with basic properties...... elution using a Waters ACQUITY Ultra-Performance Liquid Chromatography system. Quantification was performed on a Waters tandem quadrupole ACQUITY TQD using multiple reaction monitoring in positive mode. The analytes were eluted within 11 min. The limit of quantification (LOQ) ranged from 0.002 to 0.01 mg...

  18. Value of tandem mass spectrometry in etiological diagnosis of cholestasis in infants

    Directory of Open Access Journals (Sweden)

    XU Lingfen

    2015-08-01

    Full Text Available Objective To investigate the value of tandem mass spectrometry (MS/MS in the etiological diagnosis of cholestasis in infants. Methods A total of 153 infants with cholestasis who visited the Department of Pediatrics, Shengjing Hospital, China Medical University, from January 2013 to March 2015 were studied. All of them underwent blood and urine examinations by MS/MS. The patients′ medical history and physical examination characteristics were recorded. Clinical examination results in biochemistry, etiology, and imageology were analyzed. Blood test and urine test were carried out by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS and gas chromatography-mass spectrometry (GC-MS, respectively. For the patients with abnormal blood or urine MS/MS results, potential pathogenic genes were determined. Comparison of continuous data was made by non-parametric Mann-Whitney U test and comparison of categorical data was made by chi-square test. Results Among the 153 infants with cholestasis, 19 (12.4% had abnormal blood or urine MS/MS results. According to clinical data and gene analysis, 15 infants among them were diagnosed with neonatal intrahepatic cholestasis caused by citrin deficiency, 2 infants with tyrosinemia, 1 infant with methioninemia, and another 1 infant with propionic acidemia. Compared with the normal MS/MS group of infants, the abnormal MS/MS group had significantly longer jaundice duration (Z=-2.227, P<0.05 and significantly higher levels of alkaline phosphatase, gamma-glutamyl transferase, and total bile acids (830.0 vs 523.0 U/L, Z=-3.185, P<0.05; 215.0 vs 160.0 U/L, Z=-2.130, P<0.05; 174.8 vs 125.7 μmol/L, Z=-2.351, P<0.05 Significant differences were also found in prothrombin time and activated partial thromboplastin time (Z=-4.300, P<0.001; Z=-3.526, P<0.001Cytomegalovirus was detected in 58.8% (90/153 of all patients and in 78.9% (15/19 of patients with abnormal MS/MS results Conclusions Given the

  19. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    International Nuclear Information System (INIS)

    Breitenfeldt, Martin

    2009-01-01

    In the present work, mass determinations of the eleven neutron-deficient nuclides 99-109 Cd, of ten neutron-rich silver nuclides 112,114-121,123 Ag, and seven neutron-rich cadmium nuclides 114,120,122-124,126,128 Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of 99 Cd and 123 Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of 100 Cd. In the case of a potential isomeric mixture as for 115,117,119 Ag and 123 Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for 115,117,119 Ag and 123 Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH + ] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass 96 Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of 100 In were obtained. These mass measurements are an important step towards an understanding of the physics of the rp process that will enable a more reliable determination of

  20. Expert systems technology applied to instrument operation and data acquisition of a triple quadrupole mass spectrometer (TQMS)

    International Nuclear Information System (INIS)

    Wong, C.M.

    1984-01-01

    This presentation covers the work done at Lawrence Livermore National Laboratory by some computer programmers and analytical chemists specializing in mass spectrometry to develop an expert system for real-time tuning and optimization of operations of a triple quadrupole mass spectrometer (TQMS). This capability is important to increase the sensitivity possible for selected compounds throughout the entire mass range of the instrument, rather than settling for the traditional normalized calibration which lowers sensitivity at both ends of the mass scale

  1. Electrostatic mass spectrometer for concurrent mass-, energy- and angle-resolved measurements

    International Nuclear Information System (INIS)

    Golikov, Yu.K.; Krasnova, N.K.

    1999-01-01

    A new electron-optical scheme is considered. An energy- and mass-analyser with angular resolution are combined in one device, in which a time-of-flight principle of mass separation is used. The tool is created on the basis of electrostatic field of quasi-conical systems possessing the high-energy dispersion and high-angular resolution. A regime of simultaneous angular and energy resolution is found. If there is an ion-pulsed source then the ion groups of equal mass will be registered at the same time at a position-sensitive detector located at the edge of the field. Real parameters of the suggested scheme are calculated

  2. Absolute quantification method and validation of airborne snow crab allergen tropomyosin using tandem mass spectrometry.

    Science.gov (United States)

    Abdel Rahman, Anas M; Lopata, Andreas L; Randell, Edward W; Helleur, Robert J

    2010-11-29

    Measuring the levels of the major airborne allergens of snow crab in the workplace is very important in studying the prevalence of crab asthma in workers. Previously, snow crab tropomyosin (SCTM) was identified as the major aeroallergen in crab plants and a unique signature peptide was identified for this protein. The present study advances our knowledge on aeroallergens by developing a method of quantification of airborne SCTM by using isotope dilution mass spectrometry. Liquid chromatography tandem mass spectrometry was developed for separation and analysis of the signature peptides. The tryptic digestion conditions were optimized to accomplish complete digestion. The validity of the method was studied using international conference on harmonization protocol, Where 2-9% for CV (precision) and 101-110% for accuracy, at three different levels of quality control. Recovery of the spiked protein from PTFE and TopTip filters was measured to be 99% and 96%, respectively. To further demonstrate the applicability and the validity of the method for real samples, 45 kg of whole snow crab were processed in an enclosed (simulated) crab processing line and air samples were collected. The levels of SCTM ranged between 0.36-3.92 μg m(-3) and 1.70-2.31 μg m(-3) for butchering and cooking stations, respectively. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  3. Integrated gas and liquid chromatography tandem mass spectrometry for forensic engine lubricating oil identification

    International Nuclear Information System (INIS)

    Shang, D.; McPherson, B.

    2009-01-01

    This paper presented a method for rapid chemical characterization of engine lubricating oils. Motor oils typically contain up to 5 per cent additives, such as detergent, antifoamant, dispersant, emulsifier, antioxidant, friction modifier, colour stabilizer and corrosion inhibitors. Different lube oil products usually have either different additives in various concentrations. As such, the formulation of additives in lube oil products should provide fingerprint information for forensic oil identification. The characterization method used in this study was based on a newly developed fast solvent liquid-liquid sample extraction procedure that combined the use of both liquid chromatography tandem mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) simultaneously together with gas chromatography flame ionization detection (GC-FID). The method was used on a blind sample testing of commercially available engine lubricating products. The sample extraction procedure involved extraction of additives into acidified acetonitrile, two hexane washes of hydrophobic components of lube oil, filtration, and dilution with solvents for GC and LC analysis. The new method proved to be rapid and easy to use. It enabled the identification of unknown additives and hydrocarbons in many different types of fresh lube oils. Further tests will be needed to determine if this method can be used on real-world weathered samples. The method is part of an ongoing effort to deal with mysterious chemical spills, an important aspect of environmental protection and emergency preparedness. 8 refs., 7 figs

  4. Microfluidic platform for liquid chromatography-tandem mass spectrometry analyses of complex peptide mixtures.

    Science.gov (United States)

    Xie, Jun; Miao, Yunan; Shih, Jason; Tai, Yu-Chong; Lee, Terry D

    2005-11-01

    A microfluidic chip that integrates all the fluidic components of a gradient liquid chromatography (LC) system is described. These chips were batch-fabricated on a silicon wafer using photolithographic processes and with Parylene as the main structural material. The fabricated chip includes three electrolysis-based electrochemical pumps, one for loading the sample and the other two for delivering the solvent gradient; platinum electrodes for delivering current to the pumps and establishing the electrospray potential; a low-volume static mixer; a column packed with silica-based reversed-phase support; integrated frits for bead capture; and an electrospray nozzle. The fabricated structures were able to withstand pressures in excess of 250 psi. The device was used to perform a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of a mixture of peptides from the trypsin digestion of bovine serum albumen (BSA). Gradient elution through the 1.2-cm column was performed at a flow rate of 80 nL/min. Compared to the analysis of the same sample using a commercial nanoflow LC system, the chromatographic resolution was nearly as good, and the total cycle time was significantly reduced because of the minimal volume between the pumps and the column. Results demonstrate the potential of mass-produced, low-cost microfluidic systems capable of performing LC separations for proteomics applications.

  5. Redefining the Breast Cancer Exosome Proteome by Tandem Mass Tag Quantitative Proteomics and Multivariate Cluster Analysis.

    Science.gov (United States)

    Clark, David J; Fondrie, William E; Liao, Zhongping; Hanson, Phyllis I; Fulton, Amy; Mao, Li; Yang, Austin J

    2015-10-20

    Exosomes are microvesicles of endocytic origin constitutively released by multiple cell types into the extracellular environment. With evidence that exosomes can be detected in the blood of patients with various malignancies, the development of a platform that uses exosomes as a diagnostic tool has been proposed. However, it has been difficult to truly define the exosome proteome due to the challenge of discerning contaminant proteins that may be identified via mass spectrometry using various exosome enrichment strategies. To better define the exosome proteome in breast cancer, we incorporated a combination of Tandem-Mass-Tag (TMT) quantitative proteomics approach and Support Vector Machine (SVM) cluster analysis of three conditioned media derived fractions corresponding to a 10 000g cellular debris pellet, a 100 000g crude exosome pellet, and an Optiprep enriched exosome pellet. The quantitative analysis identified 2 179 proteins in all three fractions, with known exosomal cargo proteins displaying at least a 2-fold enrichment in the exosome fraction based on the TMT protein ratios. Employing SVM cluster analysis allowed for the classification 251 proteins as "true" exosomal cargo proteins. This study provides a robust and vigorous framework for the future development of using exosomes as a potential multiprotein marker phenotyping tool that could be useful in breast cancer diagnosis and monitoring disease progression.

  6. Analysis of 2-methylthio-derivatives of isoprenoid cytokinins by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tarkowski, Petr, E-mail: petr.tarkowski@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Vaclavikova, Katerina, E-mail: katka.vaclavik@seznam.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Novak, Ondrej, E-mail: ondrej.novak@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Pertry, Ine, E-mail: ine.pertry@ugent.BE [Department of Plant Biotechnology and Genetics, Ghent University, K.L.Ledeganckstraat 35, B-9000 Gent (Belgium); Hanus, Jan, E-mail: helehan@seznam.cz [Isotope Laboratory, Institute of Experimental Botany ASCR, Videnska 1083, 142 20 Prague (Czech Republic); Whenham, Robert [Apex Organics, Devon, England (United Kingdom); Vereecke, Danny, E-mail: danny.vereecke@hogent.BE [Department of Plant Production, University College Ghent, Ghent University, Schoonmeersstraat 52, B-9000 Gent (Belgium); Sebela, Marek, E-mail: marek.sebela@upol.cz [Department of Biochemistry, Faculty of Science, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Strnad, Miroslav, E-mail: miroslav.strnad@upol.cz [Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 783 71 Olomouc (Czech Republic)

    2010-11-08

    A sensitive and reliable high-performance liquid chromatographic method with tandem mass spectrometric detection has been developed and used for the determination of 2-methylthio-cytokinin derivatives produced by the phytopathogenic actinomycete Rhodococcus fascians. The cultivation medium containing secreted cytokinins was concentrated and subjected to a solid-phase extraction (C18 and ion-exchange). The purified samples were further separated and analyzed by HPLC-ESI-MS/MS. This allowed to achieve chromatographic resolution of six highly hydrophobic cytokinin species including 2-methylthio-isopentenyladenine, 2-methylthio-isopentenyladenosine, 2-methylthio-trans-zeatin and 2-methylthio-trans-zeatin riboside and their cis-isomers when a reversed-phase chromatographic column (C4) and a mobile phase consisting of acetonitrile and 20 mM ammonium formate, pH 5, were used. Quantification was performed by a standard isotope dilution method using a multiple-reaction monitoring (MRM) mode. In the MRM mode, limits of detection reached 20-30 fmol and linear ranges spanned four orders of magnitude. Recovery values were between 35% and 65% and the analytical accuracy between 95% and 149%. The proposed bioanalytical method, which takes advantage of effective chromatographic separation of six 2-methyltio-derivatives (including isomers of zeatin-type cytokinins) and sensitive mass spectrometric detection, may become useful for plant biologists studying the significance of these substances in plant-microbe interactions.

  7. Determination of synthetic dyes in bean and meat products by liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Li, Juan; Ding, Xiaoming; Zheng, Jiaxin; Liu, Dandan; Guo, Fei; Liu, Hongmin; Zhang, Yanbing

    2014-09-01

    A sensitive and efficient method was developed for the simultaneous determination of eight synthetic dyes (Chrysoidin, Auramine O, Sudan(I-IV), Para Red, and Rhodamine B) in bean and meat products using high-performance liquid chromatography with tandem mass spectrometry. A simple extraction procedure using acetonitrile has been applied for the extraction of these dyes from spiked bean and meat samples. Chromatographic separation was achieved on a Waters XTerra C18 column (2.1 × 150 mm, 5 μm) with a multistep gradient elution. Detection and quantification were performed using mass spectrometry in multiple reaction monitoring mode. Linear calibrations were obtained with correlation coefficients R(2) > 0.99. The limits of detection and quantification for the eight dyes were in the ranges of 0.03-0.75 and 0.1-2.0 μg/kg depending on matrices, respectively. The recoveries of these dyes in different food matrices were between 71.2 and 116.9% with relative standard deviations dyes at trace levels in bean and meat products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Characterization of the limonene oxidation products with liquid chromatography coupled to the tandem mass spectrometry

    Science.gov (United States)

    Witkowski, Bartłomiej; Gierczak, Tomasz

    2017-04-01

    Composition of the secondary organic aerosol (SOA) generated during ozonolysis of limonene was investigated with liquid chromatography coupled to the negative electrospray ionization (ESI), quadrupole tandem mass spectrometry (MS/MS) as well as high resolution Time-of-Flight mass spectrometry. Aerosol was generated in the flow-tube reactor. HR-MS/MS analysis allowed for proposing structures for the several up-to-date unknown limonene oxidation products. In addition to the low MW limonene oxidation products, significant quantities of oligomers characterized by elemental compositions: C19H30O5, C18H28O6, C19H28O7, C19H30O7 and C20H34O9 were detected in the SOA samples. It was concluded that these compounds are most likely esters, aldol reaction products and/or hemiacetals. In addition to detailed study of the limonene oxidation products, the reaction time as well as initial ozone concentration impact on the limonene SOA composition was investigated. The relative intensities of the two esters of the limonic acid and 7-hydroxy limononic acid increased as a result of lowering the initial ozone concentration and shortening the reaction time, indicating that esterification may be an important oligomerization pathway during limonene SOA formation.

  9. Accelerator mass spectrometry of the heaviest long-lived radionuclides with a 3-MV tandem accelerator

    Science.gov (United States)

    Vockenhuber, Christof; Golser, Robin; Kutschera, Walter; Priller, Alfred; Steier, Peter; Winkler, Stephan; Liechtenstein, Vitaly

    2002-12-01

    A 3-MV pelletron tandem accelerator is the heart of the Vienna environmental research accelerator (VERA). The original design of the beam transport components allows the transport of ions of all elements, from the lightest to the heaviest. For light ions the suppression of neighboring masses was sufficient to measure isotopic ratios of {(14}) C/{(12}) C and {(26}) Al/{(27}) Al as low as 10{(-15}) and {(10}) Be/{(9}) Be down to 10{(-13}) . To suppress neighboring masses for the heaviest radionuclides in the energy range of 10-20 MeV, the resolution of VERA was increased both by improving the ion optics of existing elements at the injection side and by installing a new high-resolution electrostatic separator at the high-energy side. Interfering ions which pass all beam filters are identified with a Bragg-type ionization detector and a high-resolution time-of-flight system. Two ultra-thin diamond-like carbon (DLC) foils are used in the start and stop detector, which substantially reduces losses due to beam straggling. This improved set up enables us to measure even the heaviest long-lived radionuclides, where stable isobaric interferences are absent (e.g. {(236}) U and {(244}) Pu), down to environmental levels. Moreover, the advantage of a `small' and well manageable machine like VERA lies in its higher stability and reliability which allows to measure these heavy radionuclides more accurately, and also a large number of samples.

  10. Liquid chromatography-tandem mass spectrometry for analysis of intestinal permeability of loperamide in physiological buffer.

    Directory of Open Access Journals (Sweden)

    Miriam S Rubelt

    Full Text Available Analysis of in vitro samples with high salt concentrations represents a major challenge for fast and specific quantification with liquid chromatography-tandem mass spectrometry (LC-MS/MS. To investigate the intestinal permeability of opioids in vitro employing the Ussing chamber technique, we developed and validated a fast, sensitive and selective method based on LC-MS/MS for the determination of loperamide in HEPES-buffered Ringer's solution. Chromatographic separation was achieved with an Atlantis dC18 column, 2.1 mm×20 mm, 3 µm particle size and a gradient consisting of methanol/0.1% formic acid and ammonium acetate. The flow rate was 0.7 ml/min, and the total run time was 3 min. For quantification, two mass transitions for loperamide and a deuterated internal standard (methadone-d(3 were used. The lower limit of loperamide quantification was 0.2 ng/ml. This new LC-MS/MS method can be used for the detection of loperamide in any experimental setup using HEPES-buffered Ringer's solution as a matrix compound.

  11. Dynamic Bayesian Network for Accurate Detection of Peptides from Tandem Mass Spectra.

    Science.gov (United States)

    Halloran, John T; Bilmes, Jeff A; Noble, William S

    2016-08-05

    A central problem in mass spectrometry analysis involves identifying, for each observed tandem mass spectrum, the corresponding generating peptide. We present a dynamic Bayesian network (DBN) toolkit that addresses this problem by using a machine learning approach. At the heart of this toolkit is a DBN for Rapid Identification (DRIP), which can be trained from collections of high-confidence peptide-spectrum matches (PSMs). DRIP's score function considers fragment ion matches using Gaussians rather than fixed fragment-ion tolerances and also finds the optimal alignment between the theoretical and observed spectrum by considering all possible alignments, up to a threshold that is controlled using a beam-pruning algorithm. This function not only yields state-of-the art database search accuracy but also can be used to generate features that significantly boost the performance of the Percolator postprocessor. The DRIP software is built upon a general purpose DBN toolkit (GMTK), thereby allowing a wide variety of options for user-specific inference tasks as well as facilitating easy modifications to the DRIP model in future work. DRIP is implemented in Python and C++ and is available under Apache license at http://melodi-lab.github.io/dripToolkit .

  12. Analysis of 2-methylthio-derivatives of isoprenoid cytokinins by liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Tarkowski, Petr; Vaclavikova, Katerina; Novak, Ondrej; Pertry, Ine; Hanus, Jan; Whenham, Robert; Vereecke, Danny; Sebela, Marek; Strnad, Miroslav

    2010-01-01

    A sensitive and reliable high-performance liquid chromatographic method with tandem mass spectrometric detection has been developed and used for the determination of 2-methylthio-cytokinin derivatives produced by the phytopathogenic actinomycete Rhodococcus fascians. The cultivation medium containing secreted cytokinins was concentrated and subjected to a solid-phase extraction (C18 and ion-exchange). The purified samples were further separated and analyzed by HPLC-ESI-MS/MS. This allowed to achieve chromatographic resolution of six highly hydrophobic cytokinin species including 2-methylthio-isopentenyladenine, 2-methylthio-isopentenyladenosine, 2-methylthio-trans-zeatin and 2-methylthio-trans-zeatin riboside and their cis-isomers when a reversed-phase chromatographic column (C4) and a mobile phase consisting of acetonitrile and 20 mM ammonium formate, pH 5, were used. Quantification was performed by a standard isotope dilution method using a multiple-reaction monitoring (MRM) mode. In the MRM mode, limits of detection reached 20-30 fmol and linear ranges spanned four orders of magnitude. Recovery values were between 35% and 65% and the analytical accuracy between 95% and 149%. The proposed bioanalytical method, which takes advantage of effective chromatographic separation of six 2-methyltio-derivatives (including isomers of zeatin-type cytokinins) and sensitive mass spectrometric detection, may become useful for plant biologists studying the significance of these substances in plant-microbe interactions.

  13. Continuous flow isotope ratio mass spectrometer (CF-IRMS) and its applications in hydrocarbon research and exploration

    International Nuclear Information System (INIS)

    Kalpana, G.; Patil, D.J.; Kumar, B.

    2004-01-01

    Stable isotope ratio mass spectrometers have been widely used to determine the isotopic ratios of light elements such as hydrogen, carbon, nitrogen, oxygen and sulphur. Continuous Flow Isotope Ratio Mass Spectrometry (CFIRMS) provides reliable data on nanomole amount of sample gas without the need for cryogenic trapping using cold fingers as in dual inlet isotope ratio mass spectrometer. High sample throughput is achieved as the system is configured with automated sample preparation devices and auto samplers. This paper presents a brief description of CFIRMS exploration

  14. Tandem mass spectrometric analysis of novel diquaternary ammonium gemini surfactants and their bromide adducts in electrospray-positive ion mode ionization.

    Science.gov (United States)

    Buse, Joshua; Badea, Ildiko; Verrall, Ronald E; El-Aneed, Anas

    2011-10-01

    Gemini surfactants are cationic lipids which are utilized for both in vitro and in vivo gene delivery. Structurally, they are comprised of two hydrophobic tail regions with polar head termini that are attached to one another through a spacer region. Structural elucidation and characterization of 29 novel diquaternary ammonium gemini surfactant molecules were achieved using a quadrupole time-of-flight mass spectrometer (QqToF-MS) and a quadrupole-hexapole-quadrupole mass spectrometer (QhQ-MS). The tested compounds were categorized into four distinct structural families based upon the composition of the spacer region. Single stage (MS), tandem stage (MS/MS) and quasimulti-stage (quasi MS(3)) mass spectrometric analysis allowed for confirmation of each gemini surfactant's molecular composition and structure through the identification of common and unique product ions. Identification of similarities in the gemini surfactants' fragmentation behaviour resulted in the production of a universal fragmentation pathway that can assist in the future MS/MS analysis of novel quaternary ammonium gemini surfactants, with unique product ions being indicative of specific structural elements. Furthermore, evidence for the association of agemini surfactant with bromine counter ion was confirmed during MS analysis of tested gemini surfactants regardless of their chemical composition; previously, evidence for bromine and gemini surfactant association was only observed with compounds bearing short alkyl spacer regions. MS/MS analysis of the bromine adducts was also confirmatory to the molecular structure.Understanding the ionization and fragmentation behaviour of gemini surfactants, including bromine adducts, will allow for future qualitative and quantitative identification of these novel drug delivery agents within biological samples. Copyright © 2011 John Wiley & Sons, Ltd.

  15. Simultaneous determination of tedizolid and linezolid in rat plasma by ultra performance liquid chromatography tandem mass spectrometry and its application to a pharmacokinetic study.

    Science.gov (United States)

    Yu, Hua-chen; Pan, Chen-wei; Xie, Qi-peng; Zheng, Yi; Hu, Yue-zheng; Lin, Yi-mu

    2016-02-01

    A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine tedizolid and linezolid in rat plasma simultaneously. Chromatographic separation was carried out on an Acquity UPLC BEH C18 column and mass spectrometric analysis was performed using a XEVO TQD triple quadruple mass spectrometer coupled with an electrospray ionization (ESI) source in the positive ion mode. Multiple reaction monitoring (MRM) mode was used for quantification using target fragment ions m/z 371.4→343.2 for tedizolid, and m/z 338.3→56.1 for linezolid. This assay method has been fully validated in terms of selectivity, linearity, recovery and matrix effect, accuracy, precision and stability. The linearity of this method was found to be within the concentration range of 5-5000ng/mL for tedizolid, and 10-10,000ng/mL for linezolid in rat plasma, respectively. Only 3.0min was needed for an analytical run. This assay was used to support a preclinical study where multiple oral doses were administered to rats to investigate the pharmacokinetics of tedizolid and linezolid. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Simultaneous determination of irbesartan and hydrochlorothiazide in human plasma by ultra high performance liquid chromatography tandem mass spectrometry and its application to a bioequivalence study.

    Science.gov (United States)

    Qiu, Xiangjun; Wang, Zhe; Wang, Bing; Zhan, Hui; Pan, Xiaofeng; Xu, Ren-ai

    2014-04-15

    An ultra high performance liquid chromatography tandem mass spectrometry (U-HPLC-MS/MS) method was developed and validated to determine irbesartan (IRB) and hydrochlorothiazide (HCTZ) in human plasma simultaneously. Plasma samples were prepared using protein precipitation with acetonitrile, the two analytes and the internal standard losartan were separated on an Acquity U-HPLC BEH C18 column and mass spectrometric analysis was performed using a QTrap5500 mass spectrometer coupled with an electro-spray ionization (ESI) source in the negative ion mode. The MRM transitions of m/z 427.2→206.9 and m/z 296.1→204.9 were used to quantify for IRB and HCTZ, respectively. The linearity of this method was found to be within the concentration range of 5-3000ng/mL for IRB, and 0.5-300ng/mL for HCTZ in human plasma, respectively. The lower limit of quantification (LLOQ) was 5ng/mL and 0.5ng/mL for IRB and HCTZ in human plasma, respectively. The relative standard deviations (RSD) of intra and inter precision were less than 12% for both IRB and HCTZ. The analysis time of per sample was 2.5min. The developed and validated method was successfully applied to a bioequivalence study of IRB (300mg) with HCTZ (12.5mg) tablet in Chinese healthy volunteers (N=20). Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Characterization of aromatic organosulfur model compounds relevant to fossil fuels by using atmospheric pressure chemical ionization with CS2 and high-resolution tandem mass spectrometry.

    Science.gov (United States)

    Tang, Weijuan; Sheng, Huaming; Jin, Chunfen; Riedeman, James S; Kenttämaa, Hilkka I

    2016-04-15

    The chemistry of desulfurization involved in processing crude oil is greatly dependent on the forms of sulfur in the oil. Sulfur exists in different chemical bonding environments in fossil fuels, including those in thiophenes and benzothiophenes, thiols, sulfides, and disulfides. In this study, the fragmentation behavior of the molecular ions of 17 aromatic organosulfur compounds with various functionalities was systematically investigated by using high-resolution tandem mass spectrometry. Multiple-stage tandem mass spectrometric experiments were carried out using a linear quadrupole ion trap (LQIT) equipped with an atmospheric pressure chemical ionization (APCI) source. (+)APCI/CS2 was used to generate stable dominant molecular ions for all the compounds studied except for three sulfides that also showed abundant fragment ions. The LQIT coupled with an orbitrap mass spectrometer was used for elemental composition analysis, which facilitated the identification of the neutral molecules lost during fragmentation. The characteristic fragment ions generated in MS(2) and MS(3) experiments provide clues for the chemical bonding environment of sulfur atoms in the examined compounds. Upon collision-induced dissociation (CID), the molecular ions can lose the sulfur atom in a variety of ways, including as S (32 Da), HS(•) (33 Da), H2 S (34 Da), CS (44 Da), (•) CHS (45 Da) and CH2 S (46 Da). These neutral fragments are not only indicative of the presence of sulfur, but also of the type of sulfur present in the compound. Generally, losses of HS(•) and H2 S were found to be associated with compounds containing saturated sulfur functionalities, while losses of S, CS and (•) CHS were more common for heteroaromatic sulfur compounds. High-resolution tandem mass spectrometry with APCI/CS2 ionization is a viable approach to determining the types of organosulfur compounds. It can potentially be applied to analysis of complex mixtures, which is beneficial to improving the

  18. A five-collector system for the simultaneous measurement of argon isotope ratios in a static mass spectrometer

    Science.gov (United States)

    Stacey, J.S.; Sherrill, N.D.; Dalrymple, G.B.; Lanphere, M.A.; Carpenter, N.V.

    1981-01-01

    A system is described that utilizes five separate Faraday-cup collector assemblies, aligned along the focal plane of a mass spectrometer, to collect simultaneous argon ion beams at masses 36-40. Each collector has its own electrometer amplifier and analog-to-digital measuring channel, the outputs of which are processed by a minicomputer that also controls the mass spectrometer. The mass spectrometer utilizes a 90?? sector magnetic analyzer with a radius of 23 cm, in which some degree of z-direction focussing is provided for all the ion beams by the fringe field of the magnet. Simultaneous measurement of the ion beams helps to eliminate mass-spectrometer memory as a significant source of measurement error during an analysis. Isotope ratios stabilize between 7 and 9 s after sample admission into the spectrometer, and thereafter changes in the measured ratios are linear, typically to within ??0.02%. Thus the multi-collector arrangement permits very short extrapolation times for computation of initial ratios, and also provides the advantages of simultaneous measurement of the ion currents in that errors due to variations in ion beam intensity are minimized. A complete analysis takes less than 10 min, so that sample throughput can be greatly enhanced. In this instrument, the factor limiting analytical precision now lies in short-term apparent variations in the interchannel calibration factors. ?? 1981.

  19. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Breitenfeldt, Martin

    2009-07-03

    In the present work, mass determinations of the eleven neutron-deficient nuclides {sup 99-109}Cd, of ten neutron-rich silver nuclides {sup 112,114-121,123}Ag, and seven neutron-rich cadmium nuclides {sup 114,120,122-124,126,128}Cd are reported. Due to the clean production of the neutron-deficient nuclides it was possible to reduce the experimental uncertainties down to 2 keV, whereas the measurements of neutron-rich nuclides were hampered by the presence of contaminations from more stable In and Cs nuclides. In the case of {sup 99}Cd and {sup 123}Ag the masses were determined for the first time and for the other nuclides the mass uncertainties could be reduced by up to a factor of 50 as in the case of {sup 100}Cd. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of a potential isomeric mixture as for {sup 115,117,119}Ag and {sup 123}Cd, where no assignment to either the ground state or the excited state was possible, the experimental results were adjusted accordingly. Afterwards all results were included in the framework of the atomic-mass evaluation and thus linked and compared with other experimental data. In the case of the neutron-deficient Cd nuclides a conflict between the mass values obtained in the present work and those published by the JYFLTRAP group [EEH{sup +}] could be solved by performing an atomic-mass evaluation. Thus, it was revealed that reason for the conflict was a different value of the JYFLTRAP reference mass {sup 96}Mo. Furthermore, a reduction of the mass uncertainty and a slight increase of the mass of {sup 100}In were obtained. These mass measurements are an important step towards an understanding of the physics of

  20. Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Llorca, Marta; Perez, Francisca [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Farre, Marinella, E-mail: mfuqam@cid.csic.es [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Agramunt, Silvia [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); Kogevinas, Manolis [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP), Barcelona (Spain); National School of Public Health, Athens (Greece); Barcelo, Damia [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Catalan Institute for Water Research (ICRA), Girona (Spain); King Saud University, Riyadh (Saudi Arabia)

    2012-09-01

    A fast on-line analytical method based on turbulent flow chromatography (TFC) in combination with tandem mass spectrometry has been applied for the first time for the analysis of eighteen perfluoroalkyl substances (PFASs), in cord blood. A simple and rapid sample pre-treatment was optimised consisting on protein precipitation of 100 {mu}L of sample with acetonitrile (1:1) followed by centrifugation during 10 min. The method was adapted to be sensitive enough and robust with minimum sample injection volume requirements (20 {mu}L). The optimised methodology presented method limits of detection (MLOD) between 0.031 and 0.76 {mu}g/L, detection capabilities (CC{alpha}) in the range between 0.005 and 0.99 {mu}g/L and decision limits (CC{beta}) ranging from 0.006 to 1.16 {mu}g/L. The recoveries in blank blood were calculated by spiking experiments with a mixture of 18 PFASs and established between 70 and 126% for most of compounds. Isotopic dilution was carried out for quantification of selected analytes. In-house validation of this new approach was carried out according to the requirements in the 2002/657/EC Decision. Finally the good applicability of this new approach was proved by the analysis of 60 cord blood samples from two different Mediterranean cities, Barcelona (Spain) and Heraklion (Greece). Ions perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were found at highest concentration and the more frequently compounds were PFHxS, PFOS and perfluorooctanoic acid (PFOA). The newly developed method proved to be suitable for large-scale epidemiologic studies, and to the data on PFASs exposure during pregnancy. -- Highlights: Black-Right-Pointing-Pointer An on-line method has been developed for the analysis of 18 perfluoroalkyl substances. Black-Right-Pointing-Pointer The method is based on turbulent flow chromatography tandem mass spectrometry. Black-Right-Pointing-Pointer The method was applied in 60 cord blood samples from 2 Mediterranean cities

  1. Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry

    International Nuclear Information System (INIS)

    Llorca, Marta; Pérez, Francisca; Farré, Marinella; Agramunt, Sílvia; Kogevinas, Manolis; Barceló, Damià

    2012-01-01

    A fast on-line analytical method based on turbulent flow chromatography (TFC) in combination with tandem mass spectrometry has been applied for the first time for the analysis of eighteen perfluoroalkyl substances (PFASs), in cord blood. A simple and rapid sample pre-treatment was optimised consisting on protein precipitation of 100 μL of sample with acetonitrile (1:1) followed by centrifugation during 10 min. The method was adapted to be sensitive enough and robust with minimum sample injection volume requirements (20 μL). The optimised methodology presented method limits of detection (MLOD) between 0.031 and 0.76 μg/L, detection capabilities (CCα) in the range between 0.005 and 0.99 μg/L and decision limits (CCβ) ranging from 0.006 to 1.16 μg/L. The recoveries in blank blood were calculated by spiking experiments with a mixture of 18 PFASs and established between 70 and 126% for most of compounds. Isotopic dilution was carried out for quantification of selected analytes. In-house validation of this new approach was carried out according to the requirements in the 2002/657/EC Decision. Finally the good applicability of this new approach was proved by the analysis of 60 cord blood samples from two different Mediterranean cities, Barcelona (Spain) and Heraklion (Greece). Ions perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were found at highest concentration and the more frequently compounds were PFHxS, PFOS and perfluorooctanoic acid (PFOA). The newly developed method proved to be suitable for large-scale epidemiologic studies, and to the data on PFASs exposure during pregnancy. -- Highlights: ► An on-line method has been developed for the analysis of 18 perfluoroalkyl substances. ► The method is based on turbulent flow chromatography tandem mass spectrometry. ► The method was applied in 60 cord blood samples from 2 Mediterranean cities. ► Acidic compounds were more frequently found and the method was proved to be suitable for

  2. 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.

  3. A liquid chromatography – tandem mass spectrometry method to measure a selected panel of uremic retention solutes derived from endogenous and colonic microbial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Loor, Henriette de; Poesen, Ruben [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); De Leger, Wout; Dehaen, Wim [KU Leuven – University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, B-3000 Leuven (Belgium); Augustijns, Patrick [KU Leuven – University of Leuven, Department of Pharmaceutical and Pharmacological Sciences, Drug Delivery and Disposition, B-3000 Leuven (Belgium); Evenepoel, Pieter [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium); Meijers, Björn, E-mail: bjorn.meijers@uzleuven.be [KU Leuven – University of Leuven, Department of Microbiology and Immunology, Laboratory of Nephrology, B-3000 Leuven (Belgium); University Hospitals Leuven, Department of Nephrology and Renal Transplantation, B-3000 Leuven (Belgium)

    2016-09-14

    Chronic kidney disease (CKD) is associated with an increased risk of mortality and cardiovascular disease, which is, at least partly, mediated by the accumulation of so-called uremic retention solutes. Although there has been an increasing interest in the behavior of these solutes, derived from both the endogenous and colonic microbial metabolism, methods to simultaneously and accurately measure a broad panel of relevant uremic retention solutes remain scarce. We developed a highly sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. A high throughput sample preparation was used with extraction of analytes from 50 μl serum using Ostro plate technology. For most solutes, stable isotopes labelled metabolites were used as internal standards. Chromatography was achieved using an Acquity UPLC CSH Fluoro Phenyl column. The total run time was 8 min, the mobile phase was a gradient of 0.1% formic acid in Milli-Q water and pure methanol at a flow rate of 0.5 ml min{sup −1}. Detection was performed using a tandem mass spectrometer with alternated positive and negative electrospray ionization. Calibration curves were linear for all solutes. Precision was assessed according to the NCCLS EP5-T guideline, being below 15% for all metabolites. Mean recoveries were between 83 and 104% for all metabolites. The validated method was successfully applied in a cohort of 488 patients with CKD. We developed and validated a sensitive and robust UPLC-MS/MS method for quantification of 15 uremic retention solutes derived from endogenous and colonic microbial metabolism. This method allows for studying the behavior and relevance of these solutes in patients with CKD. - Highlights: • Simultaneous quantification of fifteen relevant uremic retention solutes. • Comprehensive validation, highly sensitive and high through-put LC-MSMS method. • Comparison of different blood tubes. • Freeze-thaw stability. • Successful implementation in a

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

    Science.gov (United States)

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

    2017-02-01

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

  5. Mass spectra features of biomass burning boiler and coal burning boiler emitted particles by single particle aerosol mass spectrometer.

    Science.gov (United States)

    Xu, Jiao; Li, Mei; Shi, Guoliang; Wang, Haiting; Ma, Xian; Wu, Jianhui; Shi, Xurong; Feng, Yinchang

    2017-11-15

    In this study, single particle mass spectra signatures of both coal burning boiler and biomass burning boiler emitted particles were studied. Particle samples were suspended in clean Resuspension Chamber, and analyzed by ELPI and SPAMS simultaneously. The size distribution of BBB (biomass burning boiler sample) and CBB (coal burning boiler sample) are different, as BBB peaks at smaller size, and CBB peaks at larger size. Mass spectra signatures of two samples were studied by analyzing the average mass spectrum of each particle cluster extracted by ART-2a in different size ranges. In conclusion, BBB sample mostly consists of OC and EC containing particles, and a small fraction of K-rich particles in the size range of 0.2-0.5μm. In 0.5-1.0μm, BBB sample consists of EC, OC, K-rich and Al_Silicate containing particles; CBB sample consists of EC, ECOC containing particles, while Al_Silicate (including Al_Ca_Ti_Silicate, Al_Ti_Silicate, Al_Silicate) containing particles got higher fractions as size increase. The similarity of single particle mass spectrum signatures between two samples were studied by analyzing the dot product, results indicated that part of the single particle mass spectra of two samples in the same size range are similar, which bring challenge to the future source apportionment activity by using single particle aerosol mass spectrometer. Results of this study will provide physicochemical information of important sources which contribute to particle pollution, and will support source apportionment activities. Copyright © 2017. Published by Elsevier B.V.

  6. Quantitation of α-Lactalbumin by Liquid Chromatography Tandem Mass Spectrometry in Medicinal Adjuvant Lactose

    Directory of Open Access Journals (Sweden)

    Rui Yan

    2014-01-01

    Full Text Available Lactose is a widely used pharmaceutical excipient, sometimes irreplaceable. Traces of residual proteins left during production of lactose are potential allergen to body. The present paper describes a sensitive and specific LC-MS method for the determination of α-lactalbumin (α-La in lactose samples. Chromatographic separation was performed on an Acquity UPLC BEH300 C18 column (2.1×150 mm, 1.7 μm with an isocratic mobile phase consisting of water containing 0.1% TFA and acetonitrile containing 0.1% TFA (80 : 20, v/v. Mass spectrometric detection was achieved by a triple-quadrupole mass spectrometer equipped with an ESI interface operating in positive ionization mode. Quantitation was performed using selected ion monitoring of m/z 2364 for α-La. The calibration curve was linear from 0.2 to 10 µg/mL. The intra- and interday precisions were less than 7.6% and the accuracy ranged from 96.4 to 104.5%. The limit of quantification (LOQ was 0.15 µg/mL and the limit of detection (LOD was 0.05 µg/mL. This method was then successfully applied to investigate 6 different lactose samples. The application can provide technical preparation for the development of specification of lactose.

  7. Development of a Linear Ion Trap Mass Spectrometer (LITMS) Investigation for Future Planetary Surface Missions

    Science.gov (United States)

    Brinckerhoff, W.; Danell, R.; Van Ameron, F.; Pinnick, V.; Li, X.; Arevalo, R.; Glavin, D.; Getty, S.; Mahaffy, P.; Chu, P.; hide

    2014-01-01

    Future surface missions to Mars and other planetary bodies will benefit from continued advances in miniature sensor and sample handling technologies that enable high-performance chemical analyses of natural samples. Fine-scale (approx.1 mm and below) analyses of rock surfaces and interiors, such as exposed on a drill core, will permit (1) the detection of habitability markers including complex organics in association with their original depositional environment, and (2) the characterization of successive layers and gradients that can reveal the time-evolution of those environments. In particular, if broad-based and highly-sensitive mass spectrometry techniques could be brought to such scales, the resulting planetary science capability would be truly powerful. The Linear Ion Trap Mass Spectrometer (LITMS) investigation is designed to conduct fine-scale organic and inorganic analyses of short (approx.5-10 cm) rock cores such as could be acquired by a planetary lander or rover arm-based drill. LITMS combines both pyrolysis/gas chromatograph mass spectrometry (GCMS) of sub-sampled core fines, and laser desorption mass spectrometry (LDMS) of the intact core surface, using a common mass analyzer, enhanced from the design used in the Mars Organic Molecule Analyzer (MOMA) instrument on the 2018 ExoMars rover. LITMS additionally features developments based on the Sample Analysis at Mars (SAM) investigation on MSL and recent NASA-funded prototype efforts in laser mass spectrometry, pyrolysis, and precision subsampling. LITMS brings these combined capabilities to achieve its four measurement objectives: (1) Organics: Broad Survey Detect organic molecules over a wide range of molecular weight, volatility, electronegativity, concentration, and host mineralogy. (2) Organic: Molecular Structure Characterize internal molecular structure to identify individual compounds, and reveal functionalization and processing. (3) Inorganic Host Environment Assess the local chemical

  8. The successful implementation of a licensed data management interface between a Sunquest® laboratory information system and an AB SCIEX TM mass spectrometer

    Directory of Open Access Journals (Sweden)

    Deborah French

    2013-01-01

    Full Text Available Background: Interfacing complex laboratory equipment to laboratory information systems (LIS has become a more commonly encountered problem in clinical laboratories, especially for instruments that do not have an interface provided by the vendor. Liquid chromatography-tandem mass spectrometry is a great example of such complex equipment, and has become a frequent addition to clinical laboratories. As the testing volume on such instruments can be significant, manual data entry will also be considerable and the potential for concomitant transcription errors arises. Due to this potential issue, our aim was to interface an AB SCIEX TM mass spectrometer to our Sunquest® LIS. Materials and Methods: We licensed software for the data management interface from the University of Pittsburgh, but extended this work as follows: The interface was designed so that it would accept a text file exported from the AB SCIEX TM × 5500 QTrap® mass spectrometer, pre-process the file (using newly written code into the correct format and upload it into Sunquest® via file transfer protocol. Results: The licensed software handled the majority of the interface tasks with the exception of converting the output from the Analyst® software to the required Sunquest® import format. This required writing of a "pre-processor" by one of the authors which was easily integrated with the supplied software. Conclusions: We successfully implemented the data management interface licensed from the University of Pittsburgh. Given the coding that was required to write the pre-processor, and alterations to the source code that were performed when debugging the software, we would suggest that before a laboratory decides to implement such an interface, it would be necessary to have a competent computer programmer available.

  9. Evolving mass spectra of the oxidized component of organic aerosol: results from aerosol mass spectrometer analyses of aged diesel emissions

    Directory of Open Access Journals (Sweden)

    A. M. Sage

    2008-02-01

    Full Text Available The species and chemistry responsible for secondary organic aerosol (SOA formation remain highly uncertain. Laboratory studies of the oxidation of individual, high-flux SOA precursors do not lead to particles with mass spectra (MS matching those of ambient aged organic material. Additionally, the complexity of real organic particles challenges efforts to identify their chemical origins. We have previously hypothesized that SOA can form from the atmospheric oxidation of a large suite of precursors with varying vapor pressures. Here, we support this hypothesis by using an aerosol mass spectrometer to track the chemical evolution of diesel exhaust as it is photochemically oxidized in an environmental chamber. With explicit knowledge of the condensed-phase MS of the primary emissions from our engine, we are able to decompose each recorded MS into contributing primary and secondary spectra throughout the experiment. We find that the SOA becomes increasingly oxidized as a function of time, quickly approaching a final MS that closely resembles that of ambient aged organic particulate matter. This observation is consistent with our hypothesis of an evolving suite of SOA precursors. Low vapor pressure, semi-volatile organic emissions can form condensable products with even a single generation of oxidation, resulting in an early-arising, relatively less-oxidized SOA. Continued gas-phase oxidation can form highly oxidized SOA in surprisingly young air masses via reaction mechanisms that can add multiple oxygen atoms per generation and result in products with sustained or increased reactivity toward OH.

  10. Calibration of the Quadrupole Mass Spectrometer of the Sample Analysis at Mars Instrument Suite

    Science.gov (United States)

    Mahaffy, P. R.; Trainer, M. G.; Eigenbrode, J. L.; Franz, H. B.; Stern, J. C.; Harpold, D.; Conrad, P. G.; Raaen, E.; Lyness, E.

    2011-01-01

    The SAM suite of instruments on the "Curiosity" Rover of the Mars Science Laboratory (MSL) is designed to provide chemical and isotopic analysis of organic and inorganic volatiles for both atmospheric and solid samples. The mission of the MSL investigations is to advance beyond the successful search for aqueous transformation in surface environments at Mars toward a quantitative assessment of habitability and preservation through a series of chemical and geological measurements. The SAM suite was delivered in December 2010 (Figure 1) to the Jet Propulsion Laboratory for integration into the Curiosity Rover. We previously outlined the range of SAM solid and gas calibrations implemented or planned and here we discuss a specific set of calibration experiments to establish the response of the SAM Quadrupole Mass Spectrometer (QMS) to the four most abundant gases in the Martian atmosphere CO2, N2, Ar, and O2, A full SAM instrument description and calibration report is presently in preparation.

  11. Development and optimization of a high temperature coupling system thermoanalyzer/mass spectrometer

    International Nuclear Information System (INIS)

    Jagdfeld, H.J.

    1983-11-01

    The development of a high temperature coupling system was accomplished to carry out thermodynamic investigations during glass melting to solidify highly radioactive fission products into glass at a temperature up to 1200 0 C. The actual problem consisted of the fact that the gas species evaporating from the melter have to pass without condensation or without change of their composition a multistage pressure reducing system to enter the analysator unit of the mass spectrometer in the high vacuum. With the systems, offered at present, this is only possible up to approximately 450 0 C. The development of a new high temperature coupling included investigations of the gas dynamics, raw materials and thermic behaviour. (orig./EF) [de

  12. High-performance hybrid Orbitrap mass spectrometers for quantitative proteome analysis

    DEFF Research Database (Denmark)

    Williamson, James C; Edwards, Alistair V G; Verano-Braga, Thiago

    2016-01-01

    We present basic workups and quantitative comparisons for two current generation Orbitrap mass spectrometers, the Q Exactive Plus and Orbitrap Fusion Tribrid, which are widely considered two of the highest performing instruments on the market. We assessed the performance of two quantitative methods...... on both instruments, namely label-free quantitation and stable isotope labeling using isobaric tags, for studying the heat shock response in Escherichia coli. We investigated the recently reported MS3 method on the Fusion instrument and the potential of MS3-based reporter ion isolation Synchronous...... Precursor Selection (SPS) and its impact on quantitative accuracy. We confirm that the label-free approach offers a more linear response with a wider dynamic range than MS/MS-based isobaric tag quantitation and that the MS3/SPS approach alleviates but does not eliminate dynamic range compression. We...

  13. Gibbs free energy of formation of lanthanum rhodate by quadrupole mass spectrometer

    International Nuclear Information System (INIS)

    Prasad, R.; Banerjee, Aparna; Venugopal, V.

    2003-01-01

    The ternary oxide in the system La-Rh-O is of considerable importance because of its application in catalysis. Phase equilibria in the pseudo-binary system La 2 O 3 -Rh 2 O 3 has been investigated by Shevyakov et. al. Gibbs free energy of LaRhO 3 (s) was determined by Jacob et. al. using a solid state Galvanic cell in the temperature range 890 to 1310 K. No other thermodynamic data were available in the literature. Hence it was decided to determine Gibbs free energy of formation of LaRhO 3 (s) by an independent technique, viz. quadrupole mass spectrometer (QMS) coupled with a Knudsen effusion cell and the results are presented

  14. The Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution Mission

    Science.gov (United States)

    Mahaffy, Paul R.; Benna, Mehdi; King, Todd; Harpold, Daniel N.; Arvey, Robert; Barciniak, Michael; Bendt, Mirl; Carrigan, Daniel; Errigo, Therese; Holmes, Vincent; Johnson, Christopher S.; Kellogg, James; Kimvilakani, Patrick; Lefavor, Matthew; Hengemihle, Jerome; Jaeger, Ferzan; Lyness, Eric; Maurer, John; Melak, Anthony; Noreiga, Felix; Noriega, Marvin; Patel, Kiran; Prats, Benito; Raaen, Eric; Tan, Florence; Weidner, Edwin; Gundersen, Cynthia; Battel, Steven; Block, Bruce P.; Arnett, Ken; Miller, Ryan; Cooper, Curt; Edmonson, Charles; Nolan, J. Thomas

    2015-12-01

    The Neutral Gas and Ion Mass Spectrometer (NGIMS) of the Mars Atmosphere and Volatile Evolution Mission (MAVEN) is designed to measure the composition, structure, and variability of the upper atmosphere of Mars. The NGIMS complements two other instrument packages on the MAVEN spacecraft designed to characterize the neutral upper atmosphere and ionosphere of Mars and the solar wind input to this region of the atmosphere. The combined measurement set is designed to quantify atmosphere escape rates and provide input to models of the evolution of the martian atmosphere. The NGIMS is designed to measure both surface reactive and inert neutral species and ambient ions along the spacecraft track over the 125-500 km altitude region utilizing a dual ion source and a quadrupole analyzer.

  15. A low energy ion beam facility for mass spectrometer calibration: First results

    Science.gov (United States)

    Meyer, Stefan; Tulej, Marek; Wurz, Peter

    2018-01-01

    The exploration of habitable environments around the gas giants in the Solar System is of major interest in upcoming planetary missions. Exactly this theme is addressed by the Jupiter Icy Moons Explorer (JUICE) mission of the European Space Agency (ESA), which will characterise Ganymede, Europa, and Callisto as planetary objects and potential habitats. The NIM, Neutral gas and Ion Mass spectrometer, is part of the PEP experiment and will be used to measure the chemical composition of the exospheres of the icy Jovian moons. We designed and developed a calibration facility (SATANS, Supersonic cATion and ANion Source), especially for use with the NIM instrument. In a first step, we established a low energy ion beam for positive ions in the range of 0.01-30 eV. Then we conducted beam velocity calibrations with a velocity uncertainty mission conditions, i.e., for velocities from 1 up to 7 km/s and even more.

  16. Interfacing of thermal ionization mass spectrometer with PC/XT and related software development

    International Nuclear Information System (INIS)

    Moorthy, A.D.; Gurba, P.B.; Rajendrakumar; Singh, R.K.; Bajpai, D.D.; Coelho, G.J.M.; Das, K.V.; Indurkar, V.S.

    1992-01-01

    A completely automated Thermal Ionization Mass Spectrometer (TIMS), is used in Power Reactor Fuel Reprocessing Plant (PREFRE) Tarapur for precise and accurate measurement of isotopic composition and concentration determination of special nuclear materials (Uranium and Plutonium) for the purpose of input accounting of the plant. It is provided with one Hewlett-Packard, H-9845B desktop computer to control various instrument parameters and perform automatic analysis of 13 samples in sequence. The computer gave fairly good service for six years with intermittent minor maintenance before it developed major problems. In view of the fact that its repair and maintenance cost is several times the cost of locally available computer, it was decided to replace the imported Hewlett-Packard 9845B desktop computer with PC/XT. This report describes the interfacing of TIMS with PC/XT and the related Software development. (author). 3 refs., 8 figs., 2 annexures

  17. Determination of ractopamine in pig hair using liquid chromatography with tandem mass spectrometric detection.

    Science.gov (United States)

    Wu, Junlin; Liu, Xiaoyun; Peng, Yunping

    2014-01-01

    A quantitative analytical procedure for the determination of ractopamine in pig hair has been developed and validated. The hair samples were washed and incubated at 75°C with isoxuprine and hair extraction buffer. The drug present was quantified using mixed solid-phase extraction and liquid chromatography with tandem mass spectrometric detection. The limit of quantization (LOQ) was 10pg/mg and the intra-day precision at 25pg/mg and 750pg/mg was 0.49% and 2.8% respectively. Inter-day precision was 0.88% and 3.52% at the same concentrations. The hair extraction percentage recovery at 25pg/mg and 50ng/mL was 99.47% and 103.83% respectively. The extraction percentage recovery at 25pg/mg and 50ng/mg was 93.52% and 100.26% respectively. Our results showed that ractopamine residues persist in hair in 24days of withdrawal and also showed the possibility to test ractopamine from pig hair samples. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Determination of trinexapac in wheat by liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Hiemstra, Maurice; de Kok, André

    2003-09-24

    A quantitative and confirmatory method for the analysis of trinexapac (free acid metabolite of trinexapac-ethyl) in wheat is described. Residues were extracted from wheat with acetonitrile in aqueous phosphate buffer (pH 7) overnight. The extract was directly injected into the HPLC system. Chromatographic separation was achieved on an octadecylsilica column, and detection was performed by negative ion electrospray ionization tandem mass spectrometry. The precursor ion of trinexapac [M - H](-) at m/z 223 was subjected to collisional fragmentation with argon to yield two intense diagnostic product ions at m/z 135 and 179, respectively. Accuracy and specificity for routine analysis of trinexapac were demonstrated. The validated concentration range was 10-200 microg/kg based on a 0.10 g/mL wheat sample extract. Recoveries were within the range of 71-94%, with associated relative standard deviations better than 10%. The limit of detection for trinexapac in wheat was estimated at 5 microg/kg. The method has been applied to a survey of 100 samples of wheat. In 46% of the samples analyzed, a quantifiable amount of trinexapac was detected, ranging from 10 to 110 microg/kg. It has been demonstrated that analyses of trinexapac accurately reflect the total amount of residues of the plant growth regulator, trinexapac-ethyl, in the wheat samples following field application. No residues of the parent compound, trinexapac-ethyl, in wheat were detected.

  19. Liquid chromatography/electrospray ionisation tandem mass spectrometric study of sitagliptin and its stressed degradation products.

    Science.gov (United States)

    Vishnuvardhan, C; Radhakrishnanand, P; Navalgund, S G; Satheeshkumar, N

    2014-12-01

    A sensitive UPLC positive ion electrospray tandem mass spectrometry method was developed and validated for identification of degradation products of sitagliptin formed during stress study. Six of the major degradants were identi-fied with the proposed method. The separation of sitagliptin and its degradation products was achieved on a Acquity BEH C-18 column (50×2.1 mm, 1.7 µm) using a gradient programme. The mobile phase consists of solvent A (10 mM ammonium formate, pH 6.4 adjusted with formic acid) and solvent B (acetonitrile) and quantitative evaluation was performed at 267 nm with a flow rate of 0.15 mL min(-1). Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with International Conference on Harmonization (ICH) guidelines and can be used for routine analysis of sitagliptin formulations in quality control. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Identification of Protein Complexes from Tandem Affinity Purification/Mass Spectrometry Data via Biased Random Walk.

    Science.gov (United States)

    Cai, Bingjing; Wang, Haiying; Zheng, Huiru; Wang, Hui

    2015-01-01

    Systematic identification of protein complexes from protein-protein interaction networks (PPIs) is an important application of data mining in life science. Over the past decades, various new clustering techniques have been developed based on modelling PPIs as binary relations. Non-binary information of co-complex relations (prey/bait) in PPIs data derived from tandem affinity purification/mass spectrometry (TAP-MS) experiments has been unfairly disregarded. In this paper, we propose a Biased Random Walk based algorithm for detecting protein complexes from TAP-MS data, resulting in the random walk with restarting baits (RWRB). RWRB is developed based on Random walk with restart. The main contribution of RWRB is the incorporation of co-complex relations in TAP-MS PPI networks into the clustering process, by implementing a new restarting strategy during the process of random walk. Through experimentation on un-weighted and weighted TAP-MS data sets, we validated biological significance of our results by mapping them to manually curated complexes. Results showed that, by incorporating non-binary, co-membership information, significant improvement has been achieved in terms of both statistical measurements and biological relevance. Better accuracy demonstrates that the proposed method outperformed several state-of-the-art clustering algorithms for the detection of protein complexes in TAP-MS data.

  1. Optimized experimental workflow for tandem mass spectrometry molecular networking in metabolomics.

    Science.gov (United States)

    Olivon, Florent; Roussi, Fanny; Litaudon, Marc; Touboul, David

    2017-09-01

    New omics sciences generate massive amounts of data, requiring to be sorted, curated, and statistically analyzed by dedicated software. Data-dependent acquisition mode including inclusion and exclusion rules for tandem mass spectrometry is routinely used to perform such analyses. While acquisition parameters are well described for proteomics, no general rule is currently available to generate reliable metabolomic data for molecular networking analysis on the Global Natural Product Social Molecular Networking platform (GNPS). Following on from an exploration of key parameters influencing the quality of molecular networks, universal optimal acquisition conditions for metabolomic studies are suggested in the present paper. The benefit of data pre-clustering before initiating large datasets for GNPS analyses is also demonstrated. Moreover, an efficient workflow dedicated to Agilent Technologies instruments is described, making the dereplication process easier by unambiguously distinguishing isobaric isomers eluted at different retention times, annotating the molecular networks with chemical formulas, and giving access to semi-quantitative data. This specific workflow foreshadows future developments of the GNPS platform.

  2. Glycerophospholipid analysis of Eastern red bat (Lasiurus borealis) hair by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Pannkuk, Evan L; McGuire, Liam P; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-03-01

    Pilosebaceous units found in the mammalian integument are composed of a hair follicle, the proximal portion of the hair shaft, a sebaceous gland, and the erector pili muscle. Pilosebaceous units release protective oils, or sebum, by holocrine secretion onto skin and hair through rupturing of sebocytes. Sebum is composed largely of polar and neutral lipids including glycerolipids, free fatty acids, sterols, wax esters, sterol esters, and squalene. In addition to these lipid classes, there is a small proportion of ionic/anionic glycerophospholipids (GPs). Composition of GPs on hair is rarely addressed despite their broad biological activities as signaling molecules and membrane stability. Furthermore, knowledge on GP composition in bats is lacking. Bat GP composition is important to document due to GP roles ranging from decreasing drag during migration to interaction with the integumentary microbiome. In this study, we analyzed GP molecular composition with liquid chromatography electrospray ionization tandem mass spectrometry and compared GP content to previous literature. A total of 152 GPs were detected. Broad GP classes identified include lysophosphatidylcholine, phosphatidylcholine (PC), lysophosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidic acid, and phosphatidylglycerol, with PC being the most abundant class. The acyl components were consistent with fatty acid methyl esters and triacylglyceride moieties found in Eastern red bat sebum. Glycerophospholipid proportions of the hair surface were different from a previous study on bat lung surfactants. This study determined the broad class and molecular species of bat sebum GPs that may be used in future ecological studies in vespertilionid bats.

  3. Targeted liquid chromatography tandem mass spectrometry to quantitate wheat gluten using well-defined reference proteins.

    Directory of Open Access Journals (Sweden)

    Kathrin Schalk

    Full Text Available Celiac disease (CD is an inflammatory disorder of the upper small intestine caused by the ingestion of storage proteins (prolamins and glutelins from wheat, barley, rye, and, in rare cases, oats. CD patients need to follow a gluten-free diet by consuming gluten-free products with gluten contents of less than 20 mg/kg. Currently, the recommended method for the quantitative determination of gluten is an enzyme-linked immunosorbent assay (ELISA based on the R5 monoclonal antibody. Because the R5 ELISA mostly detects the prolamin fraction of gluten, a new independent method is required to detect prolamins as well as glutelins. This paper presents the development of a method to quantitate 16 wheat marker peptides derived from all wheat gluten protein types by liquid chromatography tandem mass spectrometry (LC-MS/MS in the multiple reaction monitoring mode. The quantitation of each marker peptide in the chymotryptic digest of a defined amount of the respective reference wheat protein type resulted in peptide-specific yields. This enabled the conversion of peptide into protein type concentrations. Gluten contents were expressed as sum of all determined protein type concentrations. This new method was applied to quantitate gluten in wheat starches and compared to R5 ELISA and gel-permeation high-performance liquid chromatography with fluorescence detection (GP-HPLC-FLD, which resulted in a strong correlation between LC-MS/MS and the other two methods.

  4. Analysis of nerve agent metabolites from nail clippings by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Appel, Amanda S; Logue, Brian A

    2016-09-15

    While several methods for the bioanalysis of nerve agents or their metabolites have been developed for the verification of nerve agent exposure, these methods are generally limited in the amount of time after an exposure that markers of exposure can be detected (due to rapid metabolism from biological matrices). In this study, a method for the analysis of nerve agent hydrolysis products from nail clippings was developed to allow evaluation of nails as a long-term repository of these markers. Pinacolyl methylphosphonic acid (PMPA) and isopropyl methylphosphonic acid (IMPA) were extracted from nail samples with N,N-dimethylformamide and subsequently analyzed by liquid chromatography-tandem mass spectrometry. Limits of detection for PMPA and IMPA were 0.3μg/kg and 7.5μg/kg and linear ranges were 0.75-300μg/kg and 30-1500μg/kg, respectively. Precision was within 10% and 8% for PMPA and IMPA, respectively, and accuracy was 100±12% for both analytes. The approach presented here is complementary to current methods for nerve agent exposure verification, and should allow for long-term determination of nerve agent poisoning. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Glycoalkaloid content in pet food by UPLC-tandem mass spectrometry.

    Science.gov (United States)

    Sheridan, Robert S; Kemnah, Jennifer L

    2010-11-01

    The glycoalkaloid content of pet food containing potatoes is investigated using a liquid-liquid solvent extraction followed by analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS-MS). Pet food samples are homogenized and extracted with a solution of 50:50 (v/v) acetonitrile-deionized water containing 5% acetic acid. Following vortexing and centrifugation, 3 mL of the supernatant is filtered and diluted in deionized water. The extract is injected onto a reverse phase C18 UPLC column with an initial mobile phase composed of 0.15% acetic acid in water (A) and 0.15% acetic acid in methanol (B) in a ratio of 70:30, respectively. The mobile phase reaches a final concentration of 15% A and 85% B over 10 min, at which point it is returned to the initial conditions. α-Solanine is measured by monitoring transitions m/z = 868.50 → 398.40 and 868.50 → 722.50, while α-chaconine is measure by monitoring transitions m/z = 852.60 → 97.80 and 852.60 → 706.50. Each analyte is measured and combined to determine total glycoalkaloid content (TGA). The results of the analysis of 52 pet food samples indicate both glycoalkaloids are present in all samples and two pet foods were found to contain > 100 μg/g total glycoalkaloid.

  6. Development of a dedicated peptide tandem mass spectral library for conservation science.

    Science.gov (United States)

    Fremout, Wim; Dhaenens, Maarten; Saverwyns, Steven; Sanyova, Jana; Vandenabeele, Peter; Deforce, Dieter; Moens, Luc

    2012-05-30

    In recent years, the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) on tryptic digests of cultural heritage objects has attracted much attention. It allows for unambiguous identification of peptides and proteins, and even in complex mixtures species-specific identification becomes feasible with minimal sample consumption. Determination of the peptides is commonly based on theoretical cleavage of known protein sequences and on comparison of the expected peptide fragments with those found in the MS/MS spectra. In this approach, complex computer programs, such as Mascot, perform well identifying known proteins, but fail when protein sequences are unknown or incomplete. Often, when trying to distinguish evolutionarily well preserved collagens of different species, Mascot lacks the required specificity. Complementary and often more accurate information on the proteins can be obtained using a reference library of MS/MS spectra of species-specific peptides. Therefore, a library dedicated to various sources of proteins in works of art was set up, with an initial focus on collagen rich materials. This paper discusses the construction and the advantages of this spectral library for conservation science, and its application on a number of samples from historical works of art. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. [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.

  8. Correction of errors in tandem mass spectrum extraction enhances phosphopeptide identification.

    Science.gov (United States)

    Hao, Piliang; Ren, Yan; Tam, James P; Sze, Siu Kwan

    2013-12-06

    The tandem mass spectrum extraction of phosphopeptides is more difficult and error-prone than that of unmodified peptides due to their lower abundance, lower ionization efficiency, the cofragmentation with other high-abundance peptides, and the use of MS(3) on MS(2) fragments with neutral losses. However, there are still no established methods to evaluate its correctness. Here we propose to identify and correct these errors via the combinatorial use of multiple spectrum extraction tools. We evaluated five free and two commercial extraction tools using Mascot and phosphoproteomics raw data from LTQ FT Ultra, in which RawXtract 1.9.9.2 identified the highest number of unique phosphopeptides (peptide expectation value exporting MS/MS fragments. We then corrected the errors by selecting the best extracted MGF file for each spectrum among the three tools for another database search. With the errors corrected, it results in the 22.4 and 12.2% increase in spectrum matches and unique peptide identification, respectively, compared with the best single method. Correction of errors in spectrum extraction improves both the sensitivity and confidence of phosphopeptide identification. Data analysis on nonphosphopeptide spectra indicates that this strategy applies to unmodified peptides as well. The identification of errors in spectrum extraction will promote the improvement of spectrum extraction tools in future.

  9. Liquid chromatography coupled to tandem mass spectrometry for detecting ten allergens in complex and incurred foodstuffs.

    Science.gov (United States)

    Planque, M; Arnould, T; Dieu, M; Delahaut, P; Renard, P; Gillard, N

    2017-12-29

    Food allergy is a considerable heath problem, as undesirable contaminations by allergens during food production are still widespread and may be dangerous for human health. To protect the population, laboratories need to develop reliable analytical methods in order to detect allergens in various food products. Currently, a large majority of allergen-related food recalls concern bakery products. It is therefore essential to detect allergens in unprocessed and processed foodstuffs. In this study, we developed a method for detecting ten allergens in complex (chocolate, ice cream) and processed (cookie, sauce) foodstuffs, based on ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Using a single protocol and considering a signal-to-noise ratio higher than 10 for the most abundant multiple reaction monitoring (MRM) transition, we were able to detect target allergens at 0.5mg/kg for milk proteins, 2.5mg/kg for peanut, hazelnut, pistachio, and cashew proteins, 3mg/kg for egg proteins, and 5mg/kg for soy, almond, walnut, and pecan proteins. The ability of the method to detect 10 allergens with a single protocol in complex and incurred food products makes it an attractive alternative to the ELISA method for routine laboratories. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. [Determination of 25 quinolones in cosmetics by liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Lin, Li; Zhang, Yi; Tu, Xiaoke; Xie, Liqi; Yue, Zhenfeng; Kang, Haining; Wu, Weidong; Luo, Yao

    2015-03-01

    An analytical method was developed for the simultaneous determination of 25 quinolones, including danofloxacin mesylate, enrofloxacin, flumequine, oxloinic acid, ciprofloxacin, sarafloxacin, nalidixic acid, norfloxacin, and ofloxacin etc in cosmetics using direct extraction and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Cosmetic sample was extracted by acidified acetonitrile, defatted by n-hexane and separated on Poroshell EC-C18 column with gradient elution program using acetonitrile and water (both containing 0. 1% formic acid) as the mobile phases and analyzed by LC-ESI-MS/MS under the positive mode using multiple reaction monitoring (MRM). The interference of matrix was reduced by the matrix-matched calibration standard curve. The method showed good linearities over the range of 1-200 mg/kg for the 25 quinolones with good linear correlation coefficients (r ≥ 0.999). The method detection limit of the 25 quinolones was 1.0 mg/kg, and the recoveries of all analytes in lotion, milky and cream cosmetics matrices ranged from 87.4% to 105% at the spiked levels of 1, 5 and 10 mg/kg with the relative standard deviations (RSD) of 4.54%-19.7% (n = 6). The results indicated that this method is simple, fast and credible, and suitable for the simultaneous determination of the quinolones in the above three types of cosmetics.

  11. Sensitive quantification of diphemanil methyl sulphate in human plasma by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Do, B; Goulay-Dufaÿ, S; Le Hoang, M D; Adoui, N; Graffard, H; Guyon, F; Pradeau, D

    2007-01-01

    A simple detection system with a high-performance liquid chromatography (HPLC) with positive ionisation-tandem mass spectrometry (ESI-MS/MS) for determining diphemanil methylsulphate (DMS) levels in human plasma using 4-diphemanylmethylene,1-methylpiperidine as an internal standard (I.S.), is proposed. The acquisition was performed with the multiple reactional monitoring (MRM) mode, by monitoring the transitions: m/z 278>262 for DMS and m/z 263>247 for the I.S. The method involved a simple single-step deproteinisation with acetonitrile. The analyte was chromatographed on a Zorbax C18 reversed-phase chromatographic column by isocratic elution with 10(-3)M ammonium acetate and 10(-3)M hexafluorobutyric acid, adjusted to pH 7.0 with ammoniac/acetonitrile (40/60, v/v). The results were linear over the studied range (0.5-50.0 ng mL(-1)) and the total analysis time for each run was 10 min. The mean extraction apparent recoveries expressed at the 95% intervals of confidence were 94-104% for DMS and 92-106% for the I.S. The intra- and inter-assay precisions were 4.6-8.4% and 2.9-10.6%, respectively. The limit of quantification was 0.15 ng mL(-1). The devised assay was successfully applied to the residual concentrations monitoring in infant.

  12. Real-time hydrogen/deuterium exchange kinetics via supercharged electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Sterling, Harry J; Williams, Evan R

    2010-11-01

    Amide hydrogen/deuterium exchange (HDX) rate constants of bovine ubiquitin in an ammonium acetate solution containing 1% of the electrospray ionization (ESI) "supercharging" reagent m-nitrobenzyl alcohol (m-NBA) were obtained using top-down, electron transfer dissociation (ETD) tandem mass spectrometry (MS). The supercharging reagent replaces the acid and temperature "quench" step in the conventional MS approach to HDX experiments by causing rapid protein denaturation to occur in the ESI droplet. The higher charge state ions that are produced with m-NBA are more unfolded, as measured by ion mobility, and result in higher fragmentation efficiency and higher sequence coverage with ETD. Single amino acid resolution was obtained for 44 of 72 exchangeable amide sites, and summed kinetic data were obtained for regions of the protein where adjacent fragment ions were not observed, resulting in an overall spatial resolution of 1.3 residues. Comparison of these results with previous values from NMR indicates that the supercharging reagent does not cause significant structural changes to the protein in the initial ESI solution and that scrambling or back-exchange is minimal. This new method for top-down HDX-MS enables real-time kinetic data measurements under physiological conditions, similar to those obtained using NMR, with comparable spatial resolution and significantly better sensitivity.

  13. Technological Journey From Colorimetric to Tandem Mass Spectrometric Measurements in the Diagnostic Investigation for Phenylketonuria

    Directory of Open Access Journals (Sweden)

    Donald H. Chace PhD

    2016-10-01

    Full Text Available Phenylalanine analysis for phenylketonuria (PKU detection in newborn screening (NBS was chosen as the model system to describe how advancements in laboratory technology improved laboratory performance. These advancements have made NBS programs better and have improved the health outcomes of the affected newborn through improvements in accurate early detection over the past 50 years. The most current state-of-the-art technology, tandem mass spectrometry (MS/MS, has proven that it is now the choice in almost all modern NBS facilities because it is a versatile instrument that continues to grow in its application not just for amino acid and acylcarnitine detection but for other metabolites and disorders such as lysosomal storage diseases and second-tier detection of some screen-positive results. The use of MS/MS will continue to expand, even with the anticipated introduction and expansion of molecular screening methods into NBS programs. Regarding technological advancements, the future of NBS will include even newer technologies and approaches that will enhance the detection and treatment of newborns affected by PKU and other inborn errors of metabolism.

  14. Cassini Ion Mass Spectrometer Peak Calibrations from Statistical Analysis of Flight Data

    Science.gov (United States)

    Woodson, A. K.; Johnson, R. E.

    2017-12-01

    The Cassini Ion Mass Spectrometer (IMS) is an actuating time-of-flight (TOF) instrument capable of resolving ion mass, energy, and trajectory over a field of view that captures nearly the entire sky. One of three instruments composing the Cassini Plasma Spectrometer, IMS sampled plasma throughout the Kronian magnetosphere from 2004 through 2012 when it was permanently disabled due to an electrical malfunction. Initial calibration of the flight instrument at Southwest Research Institute (SwRI) was limited to a handful of ions and energies due to time constraints, with only about 30% of planned measurements carried out prior to launch. Further calibration measurements were subsequently carried out after launch at SwRI and Goddard Space Flight Center using the instrument prototype and engineering model, respectively. However, logistical differences among the three calibration efforts raise doubts as to how accurately the post-launch calibrations describe the behavior of the flight instrument. Indeed, derived peak parameters for some ion species differ significantly from one calibration to the next. In this study we instead perform a statistical analysis on 8 years of flight data in order to extract ion peak parameters that depend only on the response of the flight instrument itself. This is accomplished by first sorting the TOF spectra based on their apparent compositional similarities (e.g. primarily water group ions, primarily hydrocarbon ions, etc.) and normalizing each spectrum. The sorted, normalized data are then binned according to TOF, energy, and counts in order to generate energy-dependent probability density maps of each ion peak contour. Finally, by using these density maps to constrain a stochastic peak fitting algorithm we extract confidence intervals for the model parameters associated with various measured ion peaks, establishing a logistics-independent calibration of the body of IMS data gathered over the course of the Cassini mission.

  15. Unmanned aerial mass spectrometer systems for in-situ volcanic plume analysis.

    Science.gov (United States)

    Diaz, Jorge Andres; Pieri, David; Wright, Kenneth; Sorensen, Paul; Kline-Shoder, Robert; Arkin, C Richard; Fladeland, Matthew; Bland, Geoff; Buongiorno, Maria Fabrizia; Ramirez, Carlos; Corrales, Ernesto; Alan, Alfredo; Alegria, Oscar; Diaz, David; Linick, Justin

    2015-02-01

    Technology advances in the field of small, unmanned aerial vehicles and their integration with a variety of sensor packages and instruments, such as miniature mass spectrometers, have enhanced the possibilities and applications of what are now called unmanned aerial systems (UAS). With such technology, in situ and proximal remote sensing measurements of volcanic plumes are now possible without risking the lives of scientists and personnel in charge of close monitoring of volcanic activity. These methods provide unprecedented, and otherwise unobtainable, data very close in space and time to eruptions, to better understand the role of gas volatiles in magma and subsequent eruption products. Small mass spectrometers, together with the world's smallest turbo molecular pump, have being integrated into NASA and University of Costa Rica UAS platforms to be field-tested for in situ volcanic plume analysis, and in support of the calibration and validation of satellite-based remote sensing data. These new UAS-MS systems are combined with existing UAS flight-tested payloads and assets, such as temperature, pressure, relative humidity, SO2, H2S, CO2, GPS sensors, on-board data storage, and telemetry. Such payloads are capable of generating real time 3D concentration maps of the Turrialba volcano active plume in Costa Rica, while remote sensing data are simultaneously collected from the ASTER and OMI space-borne instruments for comparison. The primary goal is to improve the understanding of the chemical and physical properties of emissions for mitigation of local volcanic hazards, for the validation of species detection and abundance of retrievals based on remote sensing, and to validate transport models.

  16. Development of a totally computer-controlled triple quadrupole mass spectrometer system

    International Nuclear Information System (INIS)

    Wong, C.M.; Crawford, R.W.; Barton, V.C.; Brand, H.R.; Neufeld, K.W.; Bowman, J.E.

    1983-01-01

    A totally computer-controlled triple quadrupole mass spectrometer (TQMS) is described. It has a number of unique features not available on current commercial instruments, including: complete computer control of source and all ion axial potentials; use of dual computers for data acquisition and data processing; and capability for self-adaptive control of experiments. Furthermore, it has been possible to produce this instrument at a cost significantly below that of commercial instruments. This triple quadrupole mass spectrometer has been constructed using components commercially available from several different manufacturers. The source is a standard Hewlett-Packard 5985B GC/MS source. The two quadrupole analyzers and the quadrupole CAD region contain Balzers QMA 150 rods with Balzers QMG 511 rf controllers for the analyzers and a Balzers QHS-511 controller for the CAD region. The pulsed-positive-ion-negative-ion-chemical ionization (PPINICI) detector is made by Finnigan Corporation. The mechanical and electronics design were developed at LLNL for linking these diverse elements into a functional TQMS as described. The computer design for total control of the system is unique in that two separate LSI-11/23 minicomputers and assorted I/O peripherals and interfaces from several manufacturers are used. The evolution of this design concept from totally computer-controlled instrumentation into future self-adaptive or ''expert'' systems for instrumental analysis is described. Operational characteristics of the instrument and initial results from experiments involving the analysis of the high explosive HMX (1,3,5,7-Tetranitro-1,3,5,7-Tetrazacyclooctane) are presented

  17. Response of an aerosol mass spectrometer to organonitrates and organosulfates and implications for atmospheric chemistry

    Science.gov (United States)

    Farmer, D. K.; Matsunaga, A.; Docherty, K. S.; Surratt, J. D.; Seinfeld, J. H.; Ziemann, P. J.; Jimenez, J. L.

    2010-01-01

    Organonitrates (ON) are important products of gas-phase oxidation of volatile organic compounds in the troposphere; some models predict, and laboratory studies show, the formation of large, multifunctional ON with vapor pressures low enough to partition to the particle phase. Organosulfates (OS) have also been recently detected in secondary organic aerosol. Despite their potential importance, ON and OS remain a nearly unexplored aspect of atmospheric chemistry because few studies have quantified particulate ON or OS in ambient air. We report the response of a high-resolution time-of-flight aerosol mass spectrometer (AMS) to aerosol ON and OS standards and mixtures. We quantify the potentially substantial underestimation of organic aerosol O/C, commonly used as a metric for aging, and N/C. Most of the ON-nitrogen appears as ions in the AMS, which are typically dominated by inorganic nitrate. Minor organonitrogen ions are observed although their identity and intensity vary between standards. We evaluate the potential for using fragment ratios, organonitrogen ions, ions, the ammonium balance of the nominally inorganic ions, and comparison to ion-chromatography instruments to constrain the concentrations of ON for ambient datasets, and apply these techniques to a field study in Riverside, CA. OS manifests as separate organic and sulfate components in the AMS with minimal organosulfur fragments and little difference in fragmentation from inorganic sulfate. The low thermal stability of ON and OS likely causes similar detection difficulties for other aerosol mass spectrometers using vaporization and/or ionization techniques with similar or larger energy, which has likely led to an underappreciation of these species. PMID:20194777

  18. Identification and Quantification of Glucosinolates in Kimchi by Liquid Chromatography-Electrospray Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ho Jin Kim

    2017-01-01

    Full Text Available A novel and simple method for detecting five glucosinolates (glucoalyssin, gluconapin, glucobrassicanapin, glucobrassicin, and 4-methoxyglucobrassicin in kimchi was developed using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS. The chromatographic peaks of the five glucosinolates were successfully identified by comparing their retention times, mass spectra. The mobile phase was composed of A (acetonitrile and B (water. As for glucosinolate, the relative quantities were found through sinigrin, and five different compounds that have not been previously discovered in kimchi were observed. Monitoring was carried out on the glucosinolate in 20 kimchis distributed in markets, and this study examined the various quality and quantity compositions of the five components. The glucoalyssin content ranged from 0.00 to 7.07 μmol/g of day weight (DW, with an average content of 0.86 μmol/g of DW, whereas the gluconapin content ranged from 0.00 to 5.85 μmol/g of DW, with an average of 1.17 μmol/g of DW. The content of glucobrassicanapin varied between 0.00 and 11.87 μmol/g of DW (average = 3.03 μmol/g of DW, whereas that of glucobrassicin varied between 0.00 and 0.42 μmol/g of DW (average = 0.06 μmol/g of DW. The 4-methoxyglucobrassicin content ranged from 0.12 to 9.36 μmol/g of DW (average = 3.52 μmol/g of DW. A comparison of the contents revealed that, in most cases, the content of 4-methoxyglucobrassicin was the highest.

  19. Computational refinement of post-translational modifications predicted from tandem mass spectrometry.

    Science.gov (United States)

    Chung, Clement; Liu, Jian; Emili, Andrew; Frey, Brendan J

    2011-03-15

    A post-translational modification (PTM) is a chemical modification of a protein that occurs naturally. Many of these modifications, such as phosphorylation, are known to play pivotal roles in the regulation of protein function. Henceforth, PTM perturbations have been linked to diverse diseases like Parkinson's, Alzheimer's, diabetes and cancer. To discover PTMs on a genome-wide scale, there is a recent surge of interest in analyzing tandem mass spectrometry data, and several unrestrictive (so-called 'blind') PTM search methods have been reported. However, these approaches are subject to noise in mass measurements and in the predicted modification site (amino acid position) within peptides, which can result in false PTM assignments. To address these issues, we devised a machine learning algorithm, PTMClust, that can be applied to the output of blind PTM search methods to improve prediction quality, by suppressing noise in the data and clustering peptides with the same underlying modification to form PTM groups. We show that our technique outperforms two standard clustering algorithms on a simulated dataset. Additionally, we show that our algorithm significantly improves sensitivity and specificity when applied to the output of three different blind PTM search engines, SIMS, InsPecT and MODmap. Additionally, PTMClust markedly outperforms another PTM refinement algorithm, PTMFinder. We demonstrate that our technique is able to reduce false PTM assignments, improve overall detection coverage and facilitate novel PTM discovery, including terminus modifications. We applied our technique to a large-scale yeast MS/MS proteome profiling dataset and found numerous known and novel PTMs. Accurately identifying modifications in protein sequences is a critical first step for PTM profiling, and thus our approach may benefit routine proteomic analysis. Our algorithm is implemented in Matlab and is freely available for academic use. The software is available online from http://genes.toronto.edu.

  20. Characterisation of polyacetylenes isolated from carrot (Daucus carota) extracts by negative ion tandem mass spectrometry.

    Science.gov (United States)

    Rai, Dilip K; Brunton, Nigel P; Koidis, Anastasios; Rawson, Ashish; McLoughlin, Padraig; Griffiths, William J

    2011-08-15

    The potential use of negative electrospray ionisation mass spectrometry (ESI-MS) in the characterisation of the three polyacetylenes common in carrots (Daucus carota) has been assessed. The MS scans have demonstrated that the polyacetylenes undergo a modest degree of in-source decomposition in the negative ionisation mode while the positive ionisation mode has shown predominantly sodiated ions and no [M+H](+) ions. Tandem mass spectrometric (MS/MS) studies have shown that the polyacetylenes follow two distinct fragmentation pathways: one that involves cleavage of the C3-C4 bond and the other with cleavage of the C7-C8 bond. The cleavage of the C7-C8 bond generated product ions m/z 105.0 for falcarinol, m/z 105/107.0 for falcarindiol, m/z 147.0/149.1 for falcarindiol-3-acetate. In addition to these product ions, the transitions m/z 243.2 → 187.1 (falcarinol), m/z 259.2 → 203.1 (falcarindiol), m/z 301.2 → 255.2/203.1 (falcarindiol-3-acetate), mostly from the C3-C4 bond cleavage, can form the basis of multiple reaction monitoring (MRM)-quantitative methods which are poorly represented in the literature. The 'MS(3) ' experimental data confirmed a less pronounced homolytic cleavage site between the C11-C12 bond in the falcarinol-type polacetylenes. The optimised liquid chromatography (LC)/MS conditions have achieved a baseline chromatographic separation of the three polyacetylenes investigated within 40 min total run-time. Copyright © 2011 John Wiley & Sons, Ltd.

  1. System assessment and calibrations of the Knudsen effusion quadrupole mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jintao; Furukawa, Tomohiro [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2000-08-01

    A vapor pressure measurement instrument was set up by utilizing the Microvision Plus (LM70)' quadrupole mass spectrometer combined with the Knudsen vapor effusion cell. The purpose of the vapor pressure measurement is to obtain reliable thermodynamic data of sodium-iron complex compounds. Then, the behaviors of these compounds in various environmental conditions can be investigated in detail for analysis of sodium-leak related accidents in fast breeder reactors (FBR). Therefore, the reliability of the measurement system is of great importance. The following major procedures were made step by step. (1) Vertical alignment arrangements (2) Alignment of the ion mass in Q-mass analyzer (3) 'True' signal identification (4) Noise reducing (5) Determination of electron impact conditions (6) Sensitivity improvement by adjusting parameters (7) Temperature calibration (8) Vapor pressure calibration. First, special attention was paid to the mechanical settlements, exploration of the parameters' effects, calibrations of temperature and pressure. Second, the vapor pressure measurement system was optimized for the specific requirements based on the extensive investigation in this study. Furthermore, it is confirmed that the measured pressures of the standard vapor species (silver and lead) are accurate. Finally, identical result can be reproduced in the same conditions so that the measurement system is believed to be reliable for the future researches. (author)

  2. Miniaturized Ion and Neutral Mass Spectrometer for CubeSat Atmospheric Measurements

    Science.gov (United States)

    Rodriguez, M.; Paschalidis, N.; Jones, S.; Sittler, E.; Chornay, D.; Uribe, P.; Cameron, T.

    2016-01-01

    To increase the number of single point in-situ measurements of thermosphere and exosphere ion and neutral composition and density, miniaturized instrumentation is in high demand to take advantage of the increasing platform opportunities available in the smallsat/cubesat industry. The INMS (Ion-Neutral Mass Spectrometer) addresses this need by providing simultaneous measurements of both the neutral and ion environment, essentially providing two instruments in one compact model. The 1.3U volume, 570 gram, 1.8W nominal power INMS instrument makes implementation into cubesat designs (3U and above) practical and feasible. With high dynamic range (0.1-500eV), mass dynamic range of 1-40amu, sharp time resolution (0.1s), and mass resolution of MdM16, the INMS instrument addresses the atmospheric science needs that otherwise would have required larger more expensive instrumentation. INMS-v1 (version 1) launched on Exocube (CalPoly 3U cubesat) in 2015 and INMS-v2 (version 2) is scheduled to launch on Dellingr (GSFC 6U cubesat) in 2017. New versions of INMS are currently being developed to increase and add measurement capabilities, while maintaining its smallsat/cubesat form.

  3. Identification and determination of coumateralyl and coumafuryl in animal tissues by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Jin, Mi-cong; Xu, Guo-zhang; Ren, Yi-ping; Chen, Xiao-hong; Xu, Xiao-ming

    2008-07-01

    A high-performance liquid chromatographic-tandem mass spectrometric (HPLC-MS-MS) method was developed and validated to determine simultaneously coumafuryl and coumateralyl in animal tissues using warfarin as an internal standard (IS). Animal tissue samples were extracted with ethyl acetate and cleaned by Oasis HLB solid-phase extraction (SPE) cartridges. After pretreatment, the separation was performed on a XDB C18 column with an isocratic mobile phase of acetic acid-ammonium acetate (5 mmol l(-1), pH = 4.5)/methanol (30:70, v/v). Detection was carried out on a mass spectrometer by negative electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curves were linear (r(2) > 0.998) in the concentration range 0.75-100.0 ng g(-1) with a lower limit of quantification of 0.75 ng g(-1) for coumafuryl, and 0.5 ng g(-1) for coumateralyl in liver and kidney samples. Intra-day and inter-day relative standard deviations (RSDs) were less than 8.6% and 10.9%, respectively. Recoveries of coumafuryl and coumateralyl were in the range 81.5-89.5%. The developed assay has been applied to the determination of trace residues of coumafuryl and coumateralyl in animal tissues to investigate suspected poisoning of human and animals. 2008 John Wiley & Sons, Ltd

  4. Ultra-high performance liquid chromatography-tandem mass spectrometry in high-throughput confirmation and quantification of 34 anabolic steroids in bovine muscle.

    Science.gov (United States)

    Vanhaecke, Lynn; Vanden Bussche, Julie; Wille, Klaas; Bekaert, Karen; De Brabander, Hubert F

    2011-08-26

    An ultra-high performance liquid chromatography tandem mass spectrometry multi-residue method for the determination of 34 anabolic steroids (10 estrogens including stilbenes, 14 androgens and 10 gestagens) in meat of bovine origin is reported. The extraction and clean-up procedure involved homogenization with methanol, defatting with hexane, liquid/liquid extraction with diethylether and finally SPE clean-up with coupled Si and NH(2) cartridges. The analytes were separated on a 1.9 μm Hypersil Gold column (100×2.1 mm) and quantified on a triple quadrupole mass spectrometer (TSQ Vantage) operating simultaneously in both positive and negative atmospheric pressure chemical ionisation (APCI) modes. This analytical procedure was subsequently validated according to EU criteria (CD 2002/657/EC), resulting in decision limits and detection capabilities ranging between 0.04 and 0.88 μg kg(-1) and 0.12 and 1.9 μg kg(-1), respectively. The method obtained for all, natural and synthetic steroids, adequate precisions and intra-laboratory reproducibilities (relative standard deviation below 20%), and the linearity ranged between 0.991 and 0.999. The performance characteristics fulfill the recommended concentrations fixed by the Community Reference Laboratories. The developed analysis is sensitive, and robust and therefore useful for confirmation and quantification of anabolic steroids for research purposes and residue control programs. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Investigation of the effect of plasma albumin levels on regorafenib-induced hepatotoxicity using a validated liquid chromatography-tandem mass spectrometry method.

    Science.gov (United States)

    Pang, Yi Yun; Tan, Yeong Lan; Ho, Han Kiat

    2017-09-01

    Regorafenib is an oral multikinase inhibitor indicated for metastatic colorectal cancer and gastrointestinal stromal tumour. Due to its extensive plasma protein binding and low calculated hepatic extraction ratio, the hepatotoxicity observed with usage of the drug may be related to its plasma exposure. To investigate the highly dynamic free:bound drug concentration for regorafenib in the plasma, a bioanalytical liquid chromatography-tandem mass spectrometric assay was developed and validated in human plasma. The concentration range of the assay was 2-1000ng/mL. Sample preparation was via protein precipitation using acetonitrile with sorafenib as the internal standard. The supernatant was injected into an ultra-performance liquid chromatographic system coupled to a triple quadrupole mass spectrometer. The analytes were separated on an AQUITY UPLC BEH C 18 column (120Å, 1.7μm, 2.1mm×50mm) and eluted with a gradient elution system. The ions were detected in multiple reaction monitoring mode. The linearity, lower limit of quantification, intra-day and inter-day precision and accuracy conformed to FDA guidelines. The validated method was successfully applied to determine the effect of albumin levels in plasma on the extent of protein binding of regorafenib. The results indicated that physiologically-relevant levels of albumin were found to have no significant effect on the extent of protein binding of regorafenib, hence imposing minimal effect on drug disposition. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Performance evaluation of Siemens ADVIA Centaur enhanced estradiol assay and a split sample comparison with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chen, Yu; Kinney, Lois; Soldin, Steven J

    2012-07-01

    The objective of this study was to evaluate the newly developed Siemens ADVIA Centaur enhanced Estradiol (eE2) assay and compare it with a well-established estradiol liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The Siemens eE2 assay was evaluated using the Clinical and Laboratory Standards Institute evaluation protocols. Split patient samples were compared with the eE2 assay, the current ADVIA Centaur E2-6 Ill assay; and LC-MS/MS method by API5000 mass spectrometer. Within-run and total imprecision of the eE2 assay demonstrated coefficient of variations of 5.7%, 3.2%, 1.5%, and 10.4%, 7.3%, and 6.8%, at levels of 380, 752, and 2051 pmol/L, respectively. The method comparisons showed: eE2=0.903(E2-6 III) -16.2, R(2)=0.938, average bias=-12.3%; and eE2=0.946(LC-MS/MS)+19.5, R(2)=0.925, average bias: 0%. The Siemens eE2 assay correlates well with LC-MS/MS. This method is reliable, and appropriate for routine clinical laboratory use. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  7. Setting up of a liquid chromatography-high resolution tandem mass spectrometry method for the detection of caseins in food. A comparison with ELISA method

    Directory of Open Access Journals (Sweden)

    Daniela Gastaldi

    2013-06-01

    Full Text Available Determination of caseins in food matrices is usually performed by using the competitiveenzyme- linked immunosorbent assay (ELISA technique. However such a technique suffers from a number of limitations. Among these, the applicability to a narrow concentration range, a non linear (logarithmic response, a non-negligible cross-reactivity and a high cost per kit. At the time of the completion of this study, in case of ELISA positive feedback, there was poor availability in the literature of finding reliable instrumental methods able to determine both qualitatively and quantitatively this class of substances. In the present study, a liquid chromatography-high resolution tandem mass spectrometry (HPLC-HRMS/MS instrumental method was developed with a high resolution mass spectrometer (Orbitrap. Real samples of sausages in which caseins were detected by ELISA technique were analysed. A casein-free sample of ham was used as a blank. The analytical characteristics of the instrumental method were compared with those of a commercial ELISA test, declared specific for α- and β-casein.

  8. A validated liquid chromatography tandem mass spectrometry method for quantification of erlotinib, OSI-420 and didesmethyl erlotinib and semi-quantification of erlotinib metabolites in human plasma.

    Science.gov (United States)

    Svedberg, Anna; Gréen, Henrik; Vikström, Anders; Lundeberg, Joakim; Vikingsson, Svante

    2015-03-25

    A liquid chromatography tandem mass spectrometry method was developed and validated for quantification of erlotinib and its metabolites in human plasma. The method is suitable for therapeutic drug monitoring and pharmacokinetic studies. The substances were extracted using protein precipitation, separated on a BEH XBridge C18 column (100 ×2.1 mm, 1.7 μm) by gradient elution at 0.7 mL/min of acetonitrile and 5 mM ammonium acetate. The concentration was determined using a Waters Xevo triple quadrupole mass spectrometer in a multi reaction monitoring mode. The total run time was 7 min. Deuterated erlotinib and OSI-597 were used as internal standard for erlotinib and its metabolites, respectively. Erlotinib, OSI-420 and didesmethyl erlotinib were quantified in the concentration range 25-5000 ng/mL, 0.5-500 ng/mL and 0.15-10 ng/mL, respectively. Precision and accuracy was OSI-420 at LLOQ (17%). Extraction recovery was above 89%, 99% and 89% for erlotinib, OSI-420 and didesmethyl erlotinib, respectively. The human liver microsomes generated 14 metabolites, three of them not previously reported. Twelve metabolites were measured semi-quantitatively and validated with respect to selectivity, precision and stability. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Dual Source Time-of-flight Mass Spectrometer and Sample Handling System

    Science.gov (United States)

    Brinckerhoff, W.; Mahaffy, P.; Cornish, T.; Cheng, A.; Gorevan, S.; Niemann, H.; Harpold, D.; Rafeek, S.; Yucht, D.

    We present details of an instrument under development for potential NASA missions to planets and small bodies. The instrument comprises a dual ionization source (laser and electron impact) time-of-flight mass spectrometer (TOF-MS) and a carousel sam- ple handling system for in situ analysis of solid materials acquired by, e.g., a coring drill. This DSTOF instrument could be deployed on a fixed lander or a rover, and has an open design that would accommodate measurements by additional instruments. The sample handling system (SHS) is based on a multi-well carousel, originally de- signed for Champollion/DS4. Solid samples, in the form of drill cores or as loose chips or fines, are inserted through an access port, sealed in vacuum, and transported around the carousel to a pyrolysis cell and/or directly to the TOF-MS inlet. Samples at the TOF-MS inlet are xy-addressable for laser or optical microprobe. Cups may be ejected from their holders for analyzing multiple samples or caching them for return. Samples are analyzed with laser desorption and evolved-gas/electron-impact sources. The dual ion source permits studies of elemental, isotopic, and molecular composition of unprepared samples with a single mass spectrometer. Pulsed laser desorption per- mits the measurement of abundance and isotope ratios of refractory elements, as well as the detection of high-mass organic molecules in solid samples. Evolved gas analysis permits similar measurements of the more volatile species in solids and aerosols. The TOF-MS is based on previous miniature prototypes at JHU/APL that feature high sensitivity and a wide mass range. The laser mode, in which the sample cup is directly below the TOF-MS inlet, permits both ablation and desorption measurements, to cover elemental and molecular species, respectively. In the evolved gas mode, sample cups are raised into a small pyrolysis cell and heated, producing a neutral gas that is elec- tron ionized and pulsed into the TOF-MS. (Any imaging

  10. Direct determination of trace phthalate esters in alcoholic spirits by spray-inlet microwave plasma torch ionization tandem mass spectrometry.

    Science.gov (United States)

    Miao, Meng; Zhao, Gaosheng; Xu, Li; Dong, Junguo; Cheng, Ping

    2018-03-01

    A direct analytical method based on spray-inlet microwave plasma torch tandem mass spectrometry was applied to simultaneously determine 4 phthalate esters (PAEs), namely, benzyl butyl phthalate, diethyl phthalate, dipentyl phthalate, and dodecyl phthalate with extremely high sensitivity in spirits without sample treatment. Among the 4 brands of spirit products, 3 kinds of PAE compounds were directly determined at very low concentrations from 1.30 to 114 ng·g -1 . Compared with other online and off-line methods, the spray-inlet microwave plasma torch tandem mass spectrometry technique is extremely simple, rapid, sensitive, and high efficient, providing an ideal screening tool for PAEs in spirits. Copyright © 2017 John Wiley & Sons, Ltd.

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

    Science.gov (United States)

    Prokai, Laszlo; Stevens, Stanley M

    2016-01-16

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

  12. Characterization of bisphenol A metabolites produced by Portulaca oleracea cv. by liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Watanabe, Ippei; Harada, Kazuo; Matsui, Takeshi; Miyasaka, Hitoshi; Okuhata, Hiroshi; Tanaka, Satoshi; Nakayama, Hideki; Kato, Ko; Bamba, Takeshi; Hirata, Kazumasa

    2012-01-01

    The garden plant portulaca (Portulaca oleracea cv.) efficiently removes bisphenol A (BPA), an endocrine-disrupting chemical, from a hydroponic solution, but the molecular mechanisms underlying BPA metabolism by portulaca remain unclear. In this study, BPA metabolites converted by portulaca were analyzed by liquid chromatography coupled with tandem mass spectrometry. We observed the hydroxylation of BPA and the oxidization of it to quinone. Polyphenol oxidases are likely to contribute to BPA degradation by portulaca.

  13. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sigaud, L., E-mail: lsigaud@if.uff.br [Instituto de Física, Universidade Federal Fluminense (UFF), 24210-346 Niterói, RJ (Brazil); Jesus, V. L. B. de [Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ), Campus Nilópolis, 26530-060 Nilópolis, RJ (Brazil); Ferreira, Natalia [CEFET/RJ, Unidade Maracanã, 20271-110 Rio de Janeiro, RJ (Brazil); Montenegro, E. C. [Instituto de Física, Universidade Federal do Rio de Janeiro (UFRJ), P.O. Box 68528, 21941-972 Rio de Janeiro, RJ (Brazil)

    2016-08-15

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell—to study ionization of atoms and molecules by electron impact—is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed.

  14. A novel scoring schema for peptide identification by searching protein sequence databases using tandem mass spectrometry data

    Directory of Open Access Journals (Sweden)

    Yu Chungong

    2006-04-01

    Full Text Available Abstract Background Tandem mass spectrometry (MS/MS is a powerful tool for protein identification. Although great efforts have been made in scoring the correlation between tandem mass spectra and an amino acid sequence database, improvements could be made in three aspects, including characterization ofpeaks in spectra, adoption of effective scoring functions and access to thereliability of matching between peptides and spectra. Results A novel scoring function is presented, along with criteria to estimate the performance confidence of the function. Through learning the typesof product ions and the probability of generating them, a hypothetic spectrum was generated for each candidate peptide. Then relative entropy was introduced to measure the similarity between the hypothetic and the observed spectra. Based on the extreme value distribution (EVD theory, a threshold was chosen to distinguish a true peptide assignment from a random one. Tests on a public MS/MS dataset demonstrated that this method performs better than the well-known SEQUEST. Conclusion A reliable identification of proteins from the spectra promises a more efficient application of tandem mass spectrometry to proteomes with high complexity.

  15. Determination of 4-Methylimidazole in Ammonia Caramel Using Gas Chromatography–Tandem Mass Spectrometry (GC-MS/MS

    Directory of Open Access Journals (Sweden)

    Martyna N. Wieczorek

    2018-01-01

    Full Text Available One of Maillard reaction products formed in the production of ammonia caramel is 4(5-methylimidazole (4-MeI classified as carcinogen. A method of 4-MeI determination based on ion-pair extraction and derivatisation with isobutyl chloroformate with subsequent gas chromatography-tandem mass spectrometry analysis was proposed. Tandem mass spectrometry was applied to reduce the influence of matrix and increase the selectivity and sensitivity of the method. Triple quadrupole GC-MS system was used for this study. The collision energies were optimized for MRM mode. The detection (LOD and quantification limits (LOQ of the elaborated method were 17 and 37.8 μg kg−1, respectively, repeatability was <15% RSD for analyzed caramel samples, and the recovery for 4-MeI was 101%. Comparison of MS/MS with SIM detection on the same instrument proved almost 30 times lower LODs achieved by tandem mass spectrometry compared to SIM. Described method can be routinely used for monitoring 4-MeI as a quality and safety marker in the production of ammonia caramel.

  16. Modifications to a commercially available linear mass spectrometer for mass-resolved microscopy with the pixel imaging mass spectrometry (PImMS) camera.

    Science.gov (United States)

    Halford, E; Winter, B; Mills, M D; Thompson, S P; Parr, V; John, J J; Nomerotski, A; Vallance, C; Turchetta, R; Brouard, M

    2014-08-15

    Imaging mass spectrometry is a powerful analytical technique capable of accessing a large volume of spatially resolved, chemical data from two-dimensional samples. Probing the entire surface of a sample simultaneously requires a detector with high spatial and temporal resolutions, and the ability to observe events relating to different mass-to-charge ratios. A commercially available time-of-flight mass spectrometer, designed for matrix-assisted laser desorption/ionization (MALDI) analysis, was combined with the novel pixel imaging mass spectrometry (PImMS) camera in order to perform multi-mass, microscope-mode imaging experiments. A number of minor modifications were made to the spectrometer hardware and ion optics so that spatial imaging was achieved for a number of small molecules. It was shown that a peak width of Δm50 %  <  1  m/z unit across the range 200 ≤ m/z  ≤  800 can be obtained while also achieving an optimum spatial resolution of 25 µm. It was further shown that these data were obtained simultaneously for all analytes present without the need to scan the experimental parameters. This work demonstrates the capability of multi-mass, microscope-mode imaging to reduce the acquisition time of spatially distributed analytes such as multi-arrays or biological tissue sections. It also shows that such an instrument can be commissioned by effecting relatively minor modifications to a conventional commercial machine. Copyright © 2014 John Wiley & Sons, Ltd.

  17. MSM, an Efficient Workflow for Metabolite Identification Using Hybrid Linear Ion Trap Orbitrap Mass Spectrometer

    Science.gov (United States)

    Cho, Robert; Huang, Yingying; Schwartz, Jae C.; Chen, Yan; Carlson, Timothy J.; Ma, Ji

    2012-05-01

    Identification of drug metabolites can often yield important information regarding clearance mechanism, pharmacologic activity, or toxicity for drug candidate molecules. Additionally, the identification of metabolites can provide beneficial structure-activity insight to help guide lead optimization efforts towards molecules with optimal metabolic profiles. There are challenges associated with detecting and identifying metabolites in the presence of complex biological matrices, and new LC-MS technologies have been developed to meet these challenges. In this report, we describe the development of an experimental approach that applies unique features of the hybrid linear ion trap Orbitrap mass spectrometer to streamline in vitro and in vivo metabolite identification experiments. The approach, referred to as MSM, utilizes multiple collision cells, dissociation methods, mass analyzers, and detectors. With multiple scan types and different dissociation modes built into one experimental method, along with flexible post-acquisition analysis options, the MSM workflow offers an attractive option to fast and reliable identification of metabolites in different kinds of in vitro and in vivo samples. The MSM workflow was successfully applied to metabolite identification analysis of verapamil in both in vitro rat hepatocyte incubations and in vivo rat bile samples.

  18. Sensitive helium leak detection in a deuterium atmosphere using a high-resolution quadrupole mass spectrometer

    International Nuclear Information System (INIS)

    Hiroki, S.; Abe, T.; Murakami, Y.

    1996-01-01

    In fusion machines, realizing a high-purity plasma is a key to improving the plasma parameters. Thus, leak detection is a necessary part of reducing the leak rate to a tolerable level. However, a conventional helium ( 4 He) leak detector is useless in fusion machines with a deuterium (D 2 ) plasma, because retained D particles on the first walls release D 2 for a long period and the released D 2 interferes with the signals from the leaked 4 He due to the near identical masses of 4.0026 u ( 4 He) and 4.0282 u (D 2 ). A high-resolution quadrupole mass spectrometer (HR-QMS) that we have recently developed, can detect a 4 He + population as small as 10 -4 peak in a D 2 atmosphere. Thus, the HR-QMS has been applied to detect 4 He leaks. To improve the minimum detectable limit of 4 He leak, a differentially pumped HR-QMS analyzer was attached to a chamber of the 4 He leak detector. In conclusion, the improved 4 He leak detector could detect 4 He leaks of the order of 10 -10 Pa · m 3 /s in a D 2 atmosphere. (Author)

  19. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    Yunguang Huang

    2015-01-01

    Full Text Available A vacuum ultraviolet lamp based single photon ionization- (SPI- photoelectron ionization (PEI portable reflecting time-of-flight mass spectrometer (TOFMS was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX, SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1 with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

  20. Development of a Portable Single Photon Ionization-Photoelectron Ionization Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Huang, Yunguang; Li, Jinxu; Tang, Bin; Zhu, Liping; Hou, Keyong; Li, Haiyang

    2015-01-01

    A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear. PMID:26587023