WorldWideScience

Sample records for accelerator mass spectrometry

  1. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  2. Biomedical accelerator mass spectrometry

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  3. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  4. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  5. Neuroscience and Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Palmblad, M N; Buchholz, B A; Hillegonds, D J; Vogel, J S

    2004-08-02

    Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.

  6. Accelerator Mass Spectrometry (AMS) 1977-1987

    Science.gov (United States)

    Gove, H. E.; Purser, K. H.; Litherland, A. E.

    2010-04-01

    The eleventh Accelerator Mass Spectrometry (AMS 11) Conference took place in September 2008, the Thirtieth Anniversary of the first Conference. That occurred in 1978 after discoveries with nuclear physics accelerators in 1977. Since the first Conference there have now been ten further conferences on the development and applications of what has become known as AMS. This is the accepted acronym for the use of accelerators, together with nuclear and atomic physics techniques, to enhance the performance of mass spectrometers for the detection and measurement of rare long-lived radioactive elements such as radiocarbon. This paper gives an outline of the events that led to the first conference together with a brief account of the first four conferences before the introduction of the second generation of accelerator mass spectrometers at AMS 5.

  7. Accelerator mass spectrometry: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.

  8. Biological accelerator mass spectrometry at Uppsala University.

    Science.gov (United States)

    Salehpour, Mehran; Possnert, Göran; Bryhni, Helge; Palminger-Hallén, Ira; Ståhle, Lars

    2009-03-01

    A new research programme for the biological applications of accelerator mass spectrometry has been initiated at Uppsala University and the first results are presented. A (14)C-labelled pharmaceutical substance has been dissolved in human blood, plasma and urine and diluted over 3 orders of magnitude. The measured drug concentrations were found to be in good agreement with the predicted values. Furthermore, the effect of the sample preparation background contribution has been studied as the sample amount was varied down to sub-microl sizes.

  9. Subattomole sensitivity in biological accelerator mass spectrometry.

    Science.gov (United States)

    Salehpour, Mehran; Possnert, Göran; Bryhni, Helge

    2008-05-15

    The Uppsala University 5 MV Pelletron tandem accelerator has been used to study (14)C-labeled biological samples utilizing accelerator mass spectrometry (AMS) technology. We have adapted a sample preparation method for small biological samples down to a few tens of micrograms of carbon, involving among others, miniaturizing of the graphitization reactor. Standard AMS requires about 1 mg of carbon with a limit of quantitation of about 10 amol. Results are presented for a range of small sample sizes with concentrations down to below 1 pM of a pharmaceutical substance in human blood. It is shown that (14)C-labeled molecular markers can be routinely measured from the femtomole range down to a few hundred zeptomole (10 (-21) mol), without the use of any additional separation methods.

  10. Accelerator mass spectrometry (AMS) in plutonium analysis.

    Science.gov (United States)

    Strumińska-Parulska, Dagmara I

    The paper summarizes the results of the (240)Pu/(239)Pu atomic ratio studies in atmospheric fallout samples collected in 1986 over Gdynia (Poland) as well as three Baltic fish species collected in 1997 using the accelerator mass spectrometry. A new generation of AMS has been developed during last years and this method is an efficient and good technique to measure long-lived radioisotopes in the environment and provides the most accurate determination of the atomic ratios between (240)Pu and (239)Pu. The nuclide compositions of plutonium in filter samples correspond to their means of production. AMS measurements of atmospheric fallout collected in April showed sufficient increase of the (240)Pu/(239)Pu atomic ratio from 0.28 from March to 0.47. Also such high increase of (240)Pu/(239)Pu atomic ratio, close to reactor core (240)Pu/(239)Pu atomic ratio, was observed in September and equaled 0.47.

  11. Accelerator Mass Spectrometry in Laboratory Nuclear Astrophysics

    Science.gov (United States)

    Nusair, O.; Bauder, W.; Gyürky, G.; Paul, M.; Collon, P.; Fülöp, Zs; Greene, J.; Kinoshita, N.; Palchan, T.; Pardo, R.; Rehm, K. E.; Scott, R.; Vondrasek, R.

    2016-01-01

    The extreme sensitivity and discrimination power of accelerator mass spectrometry (AMS) allows for the search and the detection of rare nuclides either in natural samples or produced in the laboratory. At Argonne National Laboratory, we are developing an AMS setup aimed in particular at the detection of medium and heavy nuclides, relying on the high ion energy achievable with the ATLAS superconducting linear accelerator and on gas-filled magnet isobaric separation. The setup was recently used for the detection of the 146Sm p-process nuclide and for a new determination of the 146Sm half-life (68.7 My). AMS plays an important role in the measurement of stellar nuclear reaction cross sections by the activation method, extending thus the technique to the study of production of long-lived radionuclides. Preliminary measurements of the 147Sm(γ,n)146Sm are described. A measurement of the 142Nd(α,γ)146Sm and 142Nd(α,n)145Sm reactions is in preparation. A new laser-ablation method for the feeding of the Electron Cyclotron Resonance (ECR) ion source is described.

  12. Accelerator mass spectrometry of small biological samples.

    Science.gov (United States)

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2008-12-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive technique for isotopic ratio measurements. In the biomedical field, AMS can be used to measure femtomolar concentrations of labeled drugs in body fluids, with direct applications in early drug development such as Microdosing. Likewise, the regenerative properties of cells which are of fundamental significance in stem-cell research can be determined with an accuracy of a few years by AMS analysis of human DNA. However, AMS nominally requires about 1 mg of carbon per sample which is not always available when dealing with specific body substances such as localized, organ-specific DNA samples. Consequently, it is of analytical interest to develop methods for the routine analysis of small samples in the range of a few tens of microg. We have used a 5 MV Pelletron tandem accelerator to study small biological samples using AMS. Different methods are presented and compared. A (12)C-carrier sample preparation method is described which is potentially more sensitive and less susceptible to contamination than the standard procedures.

  13. Applications of accelerator mass spectrometry to nuclear physics and astrophysics

    CERN Document Server

    Guo, Z Y

    2002-01-01

    As an ultra high sensitive analyzing method, accelerator mass spectrometry is playing an important role in the studies of nuclear physics and astrophysics. The accelerator mass spectrometry (AMS) applications in searching for violation of Pauli exclusion principle and study on supernovae are discussed as examples

  14. A New Accelerator-Based Mass Spectrometry.

    Science.gov (United States)

    Gove, H. E.

    1983-01-01

    Tandem electrostatic accelerators produce beams of positive ions which are used to penetrate atomic nuclei in a target, inducing nuclear reactions whose study elucidates varied properties of the nucleus. Uses of the system, which acts like a mass spectrometer, are discussed. These include radiocarbon dating measurements. (JN)

  15. Issues and opportunities in accelerator mass spectrometry for stable isotopes.

    Science.gov (United States)

    Matteson, Sam

    2008-01-01

    Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development.

  16. Accelerator mass spectrometry as a bioanalytical tool for nutritional research

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J.S.; Turteltaub, K.W.

    1997-09-01

    Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but recently has been developed for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram- sized samples. Its advantages over non-isotopeic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided.

  17. Accelerator mass spectrometry in biomedical research

    Science.gov (United States)

    Vogel, J. S.; Turteltaub, K. W.

    1994-06-01

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10 9) or less. Affected biomolecules may be separable in only milligram or microgram quantities. Quantification at attomole sensitivity is needed to study these interactions. AMS measures isotope concentrations to parts per 10 13-15 on milligram-sized samples and is ideal for quantifying long-lived radioisotopic labels for tracing biochemical pathways in natural systems. 14C-AMS has now been coupled to a variety of organic separation and definition technologies. Our primary research investigates pharmacokinetics and genotoxicities of toxins and drugs at very low doses. Human subjects research using AMS includes nutrition, toxicity and elemental balance studies. 3H, 41Ca and 26Al are also traced by AMS for fundamental biochemical kinetic research. Expansion of biomedical AMS awaits further development of biochemical and accelerator technologies designed specifically for these applications.

  18. Accelerator mass spectrometry in biomedical research

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J.S.; Turteltaub, K.W.

    1993-10-20

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10{sup 9}) or less. Affected biomolecules may be separable in only milligram or microgram quantities. Quantification at attomole sensitivity is needed to study these interactions. AMS measures isotope concentrations to parts per 10{sup 13--15} on milligram-sized samples and is ideal for quantifying long-lived radioisotopic labels that are commonly used to trace biochemical pathways in natural systems. {sup 14}C-AMS has now been coupled to a variety of organic separation and definition technologies. The primary research investigates pharmacokinetics and genotoxicities of toxins and drugs at very low doses. Human subject research using AMS includes nutrition, toxicity and elemental balance studies. {sup 3} H, {sup 41}Ca and {sup 26}Al are also traced by AMS for fundamental biochemical kinetic research. Expansion of biomedical AMS awaits further development of biochemical and accelerator technologies designed specifically for these applications.

  19. Determination of {sup 135}Cs by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, C.M.; Charles, C.R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L.; Kieser, W.E. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Cornett, R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [IsoTrace Laboratory, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada)

    2015-10-15

    The ratio of anthropogenic {sup 135}Cs and {sup 137}Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying {sup 135}Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn{sub 2}, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10{sup −3} and 1.7 × 10{sup −7} respectively. This quantification of {sup 135}Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

  20. Analytical validation of accelerator mass spectrometry for pharmaceutical development.

    Science.gov (United States)

    Keck, Bradly D; Ognibene, Ted; Vogel, John S

    2010-03-01

    The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of (14)C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the (14)C label), stable across samples storage conditions for at least 1 year, linear over four orders of magnitude with an analytical range from 0.1 Modern to at least 2000 Modern (instrument specific). Furthermore, accuracy was excellent (between 1 and 3%), while precision expressed as coefficient of variation was between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of (14)C, respectively (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with (14)C corresponds to 30 fg equivalents. Accelerator mass spectrometry provides a sensitive, accurate and precise method of measuring drug compounds in biological matrices.

  1. Accelerator mass spectrometry – from DNA to astrophysics

    Directory of Open Access Journals (Sweden)

    Kutschera Walter

    2013-12-01

    Full Text Available A brief review of accelerator mass spectrometry (AMS is presented. The present work touches on a few technical aspects and recent developments of AMS, and describes two specific applications of AMS, the dating of human DNA with the 14C bomb peak and the search for superheavy elements in nature. Since two extended general reviews on technical developments in AMS [1] and applications of AMS [2] will appear in 2013, frequent reference to these reviews is made.

  2. Accelerator mass spectrometry for quantitative in vivo tracing

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J S

    2005-04-19

    Accelerator mass spectrometry (AMS) counts individual rare, usually radio-, isotopes such as radiocarbon at high efficiency and specificity in milligram-sized samples. AMS traces very low chemical doses ({micro}g) and radiative doses (100 Bq) of isotope labeled compounds in animal models and directly in humans for pharmaceutical, nutritional, or toxicological research. Absorption, metabolism, distribution, binding, and elimination are all quantifiable with high precision after appropriate sample definition.

  3. Accelerator mass spectrometry at the Australian National University's 14UD accelerator: experience and developments

    Science.gov (United States)

    Fifield, L. K.; Ophel, T. R.; Allan, G. L.; Bird, J. R.; Davie, R. F.

    1990-12-01

    Although the major emphasis of the joint ANU/ANSTO accelerator mass spectrometry program has been the measurement of 36Cl samples, both 14C and 10Be capabilities have been implemented recently on the 14UD accelerator. The new developments and operating experience are reviewed.

  4. Small sample Accelerator Mass Spectrometry for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, M., E-mail: mehran.salehpour@physics.uu.se; Håkansson, K.; Possnert, G.

    2015-10-15

    The Accelerator Mass Spectrometry activities at Uppsala University include a group dedicated to the biomedical applications, involving natural level samples, as well as {sup 14}C-labeled substances requiring separate handling and preparation. For most applications sufficient sample amounts are available but many applications are limited to samples sizes in the μg-range. We have developed a preparation procedure for small samples biomedical applications, where a few μg C can be analyzed, albeit with compromised precision. The latest results for the small sample AMS method are shown and some of the biomedical activities at our laboratory are presented.

  5. Application of accelerator mass spectrometry in aluminum metabolism studies

    Science.gov (United States)

    Meirav, O.; Sutton, R. A. L.; Fink, D.; Middleton, R.; Klein, J.; Walker, V. R.; Halabe, A.; Vetterli, D.; Johnson, R. R.

    1990-12-01

    The recent recognition that aluminum causes toxicity in uremie patients and may be associated with Alzheimer's disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope 26Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as in humans.

  6. Biomedical applications of accelerator mass spectrometry at ANU

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Tada, M.L. di; Liu, K.; Cresswell, R.G. [Australian National University, Canberra, ACT (Australia). Department of Nuclear Physics; Day, J.P.; Oldham, C.L.; Popplewell, J.; Carson, R. [University of Manchester, (United Kingdom). Department of Chemistry

    1997-10-01

    Radioactive isotopic tracers are widely used in biomedical research, but for some elements of much current interest such as aluminium, silicon and plutonium, suitable isotopes for radioactive decay counting are not available. Each of these elements, however, possesses a long-lived isotope which could in principle be used if a suitable atom-counting detection technique were available. Accelerator Mass Spectrometry (AMS) is such a technique. AMS can provide ultra-sensitive detection of fewer than 10{sup 6} atoms of isotope, thereby enabling tracer experiments with human subjects without adding significantly to radiation body burdens. At the ANU, the AMS system based on the 14UD accelerator is being applied to a number of biomedical projects using {sup 26}AI, {sup 32}Si and the isotopes of plutonium as tracers

  7. Attomole quantitation of protein separations with accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J S; Grant, P G; Buccholz, B A; Dingley, K; Turteltaub, K W

    2000-12-15

    Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as 14C to sub-attomole sensitivity. We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5% . Micro-proton-induced-xray-emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phosphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome.

  8. Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

    Science.gov (United States)

    LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

    2010-01-01

    Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

  9. Plutonium measurements by accelerator mass spectrometry at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    McAninch, J E; Hamilton, T F; Broan, T A; Jokela, T A; Knezovich, T J; Ognibene, T J; Proctor, I D; Roberts, M L; Southon, J R; Vogel, J S; Sideras-Haddad, E

    1999-10-26

    Mass spectrometric methods provide sensitive, routine, and cost-effective analyses of long-lived radionuclides. Here the authors report on the status of work at Lawrence Livermore National Laboratory (LLNL) to develop a capability for actinide measurements by accelerator mass spectrometry (AMS) to take advantage of the high potential of AMS for rejection of interferences. This work demonstrates that the LLNL AMS spectrometer is well-suited for providing high sensitivity, robust, high throughput measurements of plutonium concentrations and isotope ratios. Present backgrounds are {approximately}2 x 10{sup 7}atoms per sample for environmental samples prepared using standard alpha spectrometry protocols. Recent measurements of {sup 239+240}Pu and {sup 241}Pu activities and {sup 240}Pu/{sup 239}Pu isotope ratios in IAEA reference materials agree well with IAEA reference values and with alpha spectrometry and recently published ICP-MS results. Ongoing upgrades of the AMS spectrometer are expected to reduce backgrounds below 1 x 10{sup 6} atoms per sample while allowing simplifications of the sample preparation chemistry. These simplifications will lead to lower per-sample costs, higher throughput, faster turn around and, ultimately, to larger and more robust data sets.

  10. {sup 1}4C Accelerator mass spectrometry in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Carvalho, C.R.A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica

    2011-07-01

    Radiocarbon Accelerator Mass Spectrometry is an ultra-sensitive technique that enables the direct measurement of carbon isotopes in samples as small as a few milligrams. The possibility of dating or tracing rare or even compound specific carbon samples has application in many fields of science such as Archaeology, Geosciences and Biomedicine. Several kinds of material such as wood, charcoal, carbonate and bone can be chemically treated and converted to graphite to be measured in the accelerator system. The Physics Institute of Universidade Federal Fluminense (UFF), in Brazil will soon be able to perform the complete {sup 14}C-AMS measurement of samples. At the Nuclear Chronology Laboratory (LACRON) samples are prepared and converted to carbon dioxide. A stainless steel vacuum system was constructed for carbon dioxide purification and graphitization is performed in sealed tubes in a muffle oven. Graphite samples will be analyzed in a 250 kV Single Stage Accelerator produced by National Electrostatic Corporation which will be installed in the beginning of 2012. With the sample preparation laboratory at LACRON and the SSAMS system, the Physics Institute of UFF will be the first {sup 14}C-AMS facility in Latin America. (author)

  11. Radiocarbon accelerator mass spectrometry (AMS) sample preparation laboratory in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Kita D.; Gomes, Paulo R. S.; Anjos, Roberto M. dos; Linares, Roberto; Queiroz, Eduardo; Oliveira, Fabiana M. de; Cardozo, Laio [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, Carla R.A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2011-07-01

    Full text: For decades Accelerator Mass Spectrometry has been widely used for radiocarbon measurements all over the world with application in several fields of science from archaeology to geosciences. This technique provides ultrasensitive analysis of reduced size samples or even specific compounds since sample atoms are accelerated to high energies and measured using nuclear particle detectors. Sample preparation is extremely important for accurate radiocarbon measurement and includes chemical pre-treatment to remove all possible contaminants. For beam extraction in the accelerator ion source, samples are usually converted to graphite. In this work we report a new radiocarbon sample preparation facility installed at the Physics Institute of Universidade Federal Fluminense (UFF), in Brazil. At the Nuclear Chronology Laboratory (LACRON) samples are chemically treated and converted to carbon dioxide by hydrolysis or combustion. A stainless steel based vacuum line was constructed for carbon dioxide separation and graphitization is performed in sealed quartz tubes in a muffle oven. Successful graphite production is important to provide stable beam currents and to minimize isotopic fractionation. Performance tests for graphite production are currently under way and isotopic analysis will soon be possible with the acquisition of a Single Stage AMS System by our group. The Single Stage Accelerator produced by National Electrostatic Corporation is a 250 kV air insulated accelerator especially constructed to measure the amount of {sup 14}C in small modern graphite samples to a precision of 0.3 % or better. With the installation of such equipment in the first half of 2012, UFF will be ready to perform the 14C -AMS technique. (author)

  12. Dating Studies of Elephant Tusks Using Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sideras-Haddad, E; Brown, T A

    2002-10-03

    A new method for determining the year of birth, the year of death, and hence, the age at death, of post-bomb and recently deceased elephants has been developed. The technique is based on Accelerator Mass Spectrometry radiocarbon analyses of small-sized samples extracted from along the length of a ge-line of an elephant tusk. The measured radiocarbon concentrations in the samples from a tusk can be compared to the {sup 14}C atmospheric bomb-pulse curve to derive the growth years of the initial and final samples from the tusk. Initial data from the application of this method to two tusks will be presented. Potentially, the method may play a significant role in wildlife management practices of African national parks. Additionally, the method may contribute to the underpinnings of efforts to define new international trade regulations, which could, in effect, decrease poaching and the killing of very young animals.

  13. Studies of Al metabolism in animal by accelerator mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    WangNa-Xiu; ZhuHan-Min; 等

    1997-01-01

    The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with 26Al,killed after 5,10,15,25,and 35d and 26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of 26Al,and the existed Al content and dementia was studied.

  14. Radionuclide measurements by accelerator mass spectrometry at Arizona

    Science.gov (United States)

    Jull, A. J. T.; Donahue, D. J.; Zabel, T. H.

    1986-01-01

    Over the past years, Tandem Accelerator Mass Spectrometry (TAMS) has become established as an important method for radionuclide analysis. In the Arizona system the accelerator is operated at a thermal voltage of 1.8MV for C-14 analysis, and 1.6 to 2MV for Be-10. Samples are inserted into a cesium sputter ion source in solid form. Negative ions sputtered from the target are accelerated to about 25kV, and the injection magnet selects ions of a particular mass. Ions of the 3+ charge state, having an energy of about 9MeV are selected by an electrostatic deflector, surviving ions pass through two magnets, where only ions of the desired mass-energy product are selected. The final detector is a combination ionization chamber to measure energy loss (and hence, Z), and a silicon surface-barrier detector which measures residual energy. After counting the trace iosotope for a fixed time, the injected ions are switched to the major isotope used for normalization. These ions are deflected into a Faraday cup after the first high-energy magnet. Repeated measurements of the isotope ratio of both sample and standards results in a measurement of the concentration of the radionuclide. Recent improvements in sample preparation for C-14 make preparation of high-beam current graphite targets directly from CO2 feasible. Except for some measurements of standards and backgrounds for Be-10 measurements to date have been on C-14. Although most results have been in archaeology and quaternary geology, studies have been expanded to include cosmogenic C-14 in meteorites. The data obtained so far tend to confirm the antiquity of Antarctic meteorites from the Allan Hills site. Data on three samples of Yamato meteorites gave terrestrial ages of between about 3 and 22 thousand years.

  15. Human folate metabolism using 14C-accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Arjomand, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Duecker, S. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, P. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zulim, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bucholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vogel, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-03-25

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkin's disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer.

  16. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, Matthew George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adamic, Mary Louise [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, John Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baeck, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fox, R. V. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hahn, P. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jenson, D. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lister, T. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world’s best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

  17. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    Science.gov (United States)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  18. FemtoMolar measurements using accelerator mass spectrometry.

    Science.gov (United States)

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2009-03-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive analytical method suitable for the detection of sub-nM concentrations of labeled biological substances such as pharmaceutical drugs in body fluids. A limiting factor in extending the concentration measurements to the sub-pM range is the natural (14)C content in living tissues. This was circumvented by separating the labeled drug from the tissue matrix, using standard high-performance liquid chromatography (HPLC) procedures. As the separated total drug amount is in the few fg range, it is not possible to use a standard AMS sample preparation method, where mg sizes are required. We have utilized a sensitive carbon carrier method where a (14)C-deficient compound is added to the HPLC fractions and the composite sample is prepared and analyzed by AMS. Using 50 microL human blood plasma aliquots, we have demonstrated concentration measurements below 20 fM, containing sub-amol amounts of the labeled drug. The method has the immediate potential of operating in the sub-fM region.

  19. Recent advances in biomedical applications of accelerator mass spectrometry.

    Science.gov (United States)

    Hah, Sang Soo; Henderson, Paul T; Turteltaub, Kenneth W

    2009-06-17

    The use of radioisotopes has a long history in biomedical science, and the technique of accelerator mass spectrometry (AMS), an extremely sensitive nuclear physics technique for detection of very low-abundant, stable and long-lived isotopes, has now revolutionized high-sensitivity isotope detection in biomedical research, because it allows the direct determination of the amount of isotope in a sample rather than measuring its decay, and thus the quantitative analysis of the fate of the radiolabeled probes under the given conditions. Since AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research, the biomedical applications of AMS to date range from in vitro to in vivo studies, including the studies of 1) toxicant and drug metabolism, 2) neuroscience, 3) pharmacokinetics, and 4) nutrition and metabolism of endogenous molecules such as vitamins. In addition, a new drug development concept that relies on the ultrasensitivity of AMS, known as human microdosing, is being used to obtain early human metabolism information of candidate drugs. These various aspects of AMS are reviewed and a perspective on future applications of AMS to biomedical research is provided.

  20. Recent advances in biomedical applications of accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Hah Sang

    2009-06-01

    Full Text Available Abstract The use of radioisotopes has a long history in biomedical science, and the technique of accelerator mass spectrometry (AMS, an extremely sensitive nuclear physics technique for detection of very low-abundant, stable and long-lived isotopes, has now revolutionized high-sensitivity isotope detection in biomedical research, because it allows the direct determination of the amount of isotope in a sample rather than measuring its decay, and thus the quantitative analysis of the fate of the radiolabeled probes under the given conditions. Since AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research, the biomedical applications of AMS to date range from in vitro to in vivo studies, including the studies of 1 toxicant and drug metabolism, 2 neuroscience, 3 pharmacokinetics, and 4 nutrition and metabolism of endogenous molecules such as vitamins. In addition, a new drug development concept that relies on the ultrasensitivity of AMS, known as human microdosing, is being used to obtain early human metabolism information of candidate drugs. These various aspects of AMS are reviewed and a perspective on future applications of AMS to biomedical research is provided.

  1. Detection of adriamycin-DNA adducts by accelerator mass spectrometry.

    Science.gov (United States)

    Coldwell, Kate; Cutts, Suzanne M; Ognibene, Ted J; Henderson, Paul T; Phillips, Don R

    2010-01-01

    There have been many attempts in the past to determine whether significant levels of Adriamycin-DNA adducts form in cells and contribute to the anticancer activity of this agent. Supraclincal drug levels have been required to study drug-DNA adducts because of the lack of sensitivity associated with many of the techniques employed, including liquid scintillation counting of radiolabeled drug. The use of accelerator mass spectrometry (AMS) has provided the first direct evidence of Adriamycin-DNA adduct formation in cells at clinically relevant Adriamycin concentrations. The exceedingly sensitive nature of AMS has enabled over three orders of magnitude increased sensitivity of Adriamycin-DNA adduct detection (compared to liquid scintillation counting) and has revealed adduct formation within an hour of drug treatment. The rigorous protocol required for this approach, together with many notes on the precautions and procedures required in order to ensure that absolute levels of Adriamycin-DNA adducts can be determined with good reproducibility, is outlined in this chapter.

  2. Improving tritium exposure reconstructions using accelerator mass spectrometry

    Science.gov (United States)

    Hunt, J. R.; Vogel, J. S.; Knezovich, J. P.

    2010-01-01

    Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. PMID:14735274

  3. Ion source memory in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany); Arnold, Maurice; Aumaitre, Georges; Bourles, Didier; Martschini, Martin [ASTER, Aix-en-Provence (France); Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Steier, Peter [VERA, Vienna (Austria)

    2013-07-01

    Since the DREAMS (Dresden Accelerator Mass Spectrometry) facility went operational in 2011, constant effort was put into enabling routine measurements of long-lived radionuclides as {sup 10}Be, {sup 26}Al and {sup 41}Ca. For precise AMS-measurements of the volatile element Cl the key issue is the minimization of the long term memory effect. For this purpose one of the two original HVE sources was mechanically modified, allowing the usage of bigger cathodes with individual target apertures. Additionally a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, a small inter-laboratory comparison had been initiated. The long-term memory effect in the Cs sputter ion sources of the AMS facilities VERA, ASTER and DREAMS had been investigated by running samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples containing highly enriched {sup 35}Cl({sup 35}Cl/{sup 37}Cl > 500). Primary goals of the research are the time constants of the recovery from the contaminated sample ratio to the initial ratio of the sample and the level of the long-term memory effect in the sources.

  4. Sample preparation for quantitation of tritium by accelerator mass spectrometry.

    Science.gov (United States)

    Chiarappa-Zucca, Marina L; Dingley, Karen H; Roberts, Mark L; Velsko, Carol A; Love, Adam H

    2002-12-15

    The capability to prepare samples accurately and reproducibly for analysis of tritium (3H) content by accelerator mass spectrometry (AMS) greatly facilitates isotopic tracer studies in which attomole levels of 3H can be measured in milligram-sized samples. A method has been developed to convert the hydrogen of organic samples to a solid, titanium hydride, which can be analyzed by AMS. Using a two-step process, the sample is first oxidized to carbon dioxide and water. In the second step, the water is transferred within a heated manifold into a quartz tube, reduced to hydrogen gas using zinc, and reacted with titanium powder. The 3H/1H ratio of the titanium hydride is measured by AMS and normalized to standards whose ratios were determined by decay counting to calculate the amount of 3H in the original sample. Water, organic compounds, and biological samples with 3H activities measured by liquid scintillation counting were utilized to develop and validate the method. The 3H/1H ratios were quantified in samples that spanned 5 orders of magnitude, from 10(-10) to 10(-15), with a detection limit of 3.0 x 10(-15), which is equivalent to 0.02 dpm tritium/mg of material. Samples smaller than 2 mg were analyzed following addition of 2 mg of a tritium-free-hydrogen carrier. Preparation of organic standards containing both 14C and 3H in 2-mg organic samples demonstrated that this sample preparation methodology can also be applied to quantify both of these isotopes from a single sample.

  5. Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Turteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-08

    The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

  6. Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Tuerteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-21

    The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

  7. Accelerating clinical insights: how to use accelerator mass spectrometry to make better early development decisions.

    Science.gov (United States)

    Seymour, Mark

    2010-12-01

    This paper is an overview of the applications of the technique of Accelerator Mass Spectrometry (AMS) in the biomedical drug development field. The work described here has been carried out at Xceleron (York, UK and Germantown, MD, USA), and it aims to apply AMS to provide better information about the human pharmacokinetic/metabolic behaviour of drugs or drug candidates as early as possible. It is hoped that the use of this technique will contribute to the delivery of better, more effective drugs onto the market sooner, which will be good news for all concerned.

  8. Investigations of paleoclimate variations using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Southon, J R; Kashgarian, M; Brown, T A

    2000-08-24

    This project has used Accelerator Mass Spectrometry (AMS) {sup 14}C measurements to study climate and carbon cycle variations on time scales from decades to millennia over the past 30,000 years, primarily in the western US and the North Pacific. {sup 14}C dates provide a temporal framework for records of climate change, and natural radiocarbon acts as a carbon cycle tracer in independently dated records. The overall basis for the study is the observation that attempts to model future climate and carbon cycle changes cannot be taken seriously if the models have not been adequately tested. Paleoclimate studies are unique because they provide realistic test data under climate conditions significantly different from those of the present, whereas instrumental results can only sample the system as it is today. The aim of this project has been to better establish the extent, timing, and causes of past climate perturbations, and the carbon cycle changes with which they are linked. This provides real-world data for model testing, both for the development of individual models and also for inter-model diagnosis and comparison activities such as those of LLNL's PCMDI program; it helps us achieve a better basic understanding of how the climate system works so that models can be improved; and it gives an indication of the natural variability in the climate system underlying any anthropogenically-driven changes. The research has involved four projects which test hypotheses concerning the overall behavior of the North Pacific climate system. All are aspects of an overall theme that climate linkages are strong and direct, so that regional climate records are correlated, details of fine structure are important, and accurate and precise dating is critical for establishing correlations and even causality. An important requirement for such studies is the requirement for an accurate and precise radiocarbon calibration, to allow better correlation of radiocarbon-dated records with

  9. Ultra-sensitive detection of plutonium by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Cresswell, R.G.; Ophel, T.R.; Ditada, M. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Day, J.P.; Clacher, A. [Manchester Univ. (United Kingdom). Dept. of Chemistry; Priest, N.D. [AEA Technology, Harwell (United Kingdom)

    1996-12-31

    On the bases of the measurements performed to date, a sensitivity of 10{sup 6} atoms is achievable with accelerator mass spectroscopy (AMS) for each of the plutonium isotopes. Not only does this open the way to the sort of study outlined, but it also makes possible other novel applications, of which two examples are given: (i)the ration of {sup 240}Pu to {sup 239}Pu as a sensitive indicator of the source of the plutonium; (ii) the biochemistry of plutonium in humans. The ultra-sensitive atom counting capability of AMS will make it possible to use the very long-lived {sup 244}Pu (8x10{sup 7}a) in human volunteer studies without any significant increase in radiation body burden. This paper will describe the AMS technique as applied to plutonium using the ANU`s 14UD accelerator, will present the results obtained to date, and will discuss the prospects for the future.

  10. Measurement of the 135Cs half-life with accelerator mass spectrometry and inductively coupled plasma mass spectrometry

    Science.gov (United States)

    MacDonald, C. M.; Cornett, R. J.; Charles, C. R. J.; Zhao, X. L.; Kieser, W. E.

    2016-01-01

    The isotope 135Cs is quoted as having a half-life of 2.3 Myr. However, there are three published values ranging from 1.8 to 3 Myr. This research reviews previous measurements and reports a new measurement of the half-life using newly developed accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICPMS) techniques along with β and γ radiometric analysis. The half-life was determined to be (1.6 ±0.6 ) ×106 yr by AMS and (1.3 ±0.2 ) ×106 yr by ICPMS with 95% confidence. The two values agree with each other but differ from the accepted value by ˜40 % .

  11. {sup 26}Al interferences in accelerator mass spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Sheng, E-mail: s.xu@suerc.gla.ac.uk; Freeman, Stewart P.H.T.; Rood, Dylan H.; Shanks, Richard P.

    2014-08-15

    Highlights: •We identified multi-interferences to {sup 26}Al{sup 3+}, {sup 26}Al{sup 5+} and {sup 26}Al{sup 7+} with SUERC 5 MV accelerator mass spectrometer. •{sup 37}Cl{sup 4+} as continuum events is the most significant interference to {sup 26}Al{sup 3+}. •The problem of interferences is generic in different charge states. -- Abstract: The identification of interferences to {sup 26}Al was conducted with a 5 MV tandem accelerator mass spectrometer. In addition to {sup 9}Be{sup 1+}, {sup 17}O{sup 2+} and {sup 35}Cl{sup 4+} ions observed previously, this study confirmed existence of the most significant interference {sup 37}Cl{sup 4+} continuum ion to 16 MeV {sup 26}Al{sup 3+} by measuring primary standard mixed with Cl with various {sup 37}Cl/{sup 35}Cl ratios. The {sup 37}Cl{sup −} ions were formed by {sup 37}Cl{sup 16}O{sup −} molecular-dissociation before the injection magnet, resulting in −0.7% of {sup 26}Al{sup −} magnetic rigidity. Subsequently, the {sup 37}Cl{sup 4+} ions have ME/q{sup 2} value that differ from {sup 26}Al{sup 3+} by −0.1%. These allow the {sup 37}Cl{sup −} and {sup 37}Cl{sup 4+} to simultaneously pass through injection magnet, analytical magnet and high-energy analyser, and finally reach the detector with {sup 26}Al{sup 3+}. Further investigations on high charge states ({sup 26}Al{sup 5+} and {sup 26}Al{sup 7+}) indicate that the problem of interferences is generic. That is, interferences closest to 24 MeV {sup 26}Al{sup 5+} ions include {sup 10}B{sup 2+}, {sup 16}O{sup 3+}, {sup 35}Cl{sup 7+} and {sup 37}Cl{sup 7+} ions, while 32 MeV {sup 26}Al{sup 7+} ions may be interfered by {sup 7}Li{sup 2+}, {sup 16}O{sup 4+}, {sup 18}O{sup 5+}, {sup 35}Cl{sup 9+} and {sup 37}Cl{sup 9+}. However, it remains unclear that {sup 37}Cl continuum events observed in {sup 26}Al{sup 3+}-AMS do not exist in {sup 26}Al{sup 5+} and {sup 26}Al{sup 7+}-AMS operations.

  12. Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

    Energy Technology Data Exchange (ETDEWEB)

    Povinec, Pavel P., E-mail: povinec@fmph.uniba.sk; Masarik, Jozef; Ješkovský, Miroslav; Kaizer, Jakub; Šivo, Alexander; Breier, Robert; Pánik, Ján; Staníček, Jaroslav; Richtáriková, Marta; Zahoran, Miroslav; Zeman, Jakub

    2015-10-15

    An Accelerator Mass Spectrometry (AMS) laboratory has been established at the Centre for Nuclear and Accelerator Technologies (CENTA) at the Comenius University in Bratislava comprising of a MC-SNICS ion source, 3 MV Pelletron tandem accelerator, and an analyzer of accelerated ions. The preparation of targets for {sup 14}C and {sup 129}I AMS measurements is described in detail. The development of AMS techniques for potassium, uranium and thorium analysis in radiopure materials required for ultra-low background underground experiments is briefly mentioned.

  13. Pushing the accelerator - speeding up drug research with accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Garner, R.C. E-mail: colin.garner@cbams.co.uk; Leong, D

    2000-10-01

    Accelerator mass spectrometry (AMS) is the most sensitive analytical method yet developed for elemental isotope analysis and has a broad range of applications. The measurement of {sup 14}C is of most interest to biomedical researchers but few studies have been reported using AMS in drug discovery and development. For biomedical use, {sup 14}C is incorporated into organic molecules by either radiosynthesis or biosynthetically and the isotope is used as a surrogate for the distribution of the radiolabelled molecule either in animal or human studies. The majority of users of {sup 14}C quantitate the radioactivity using decay counting usually with a liquid scintillation counter (LSC). Our Centre over the past 12 months has been evaluating and validating the use of AMS as an alternative detection method. In vitro spiking studies of human plasma with {sup 14}C-Fluconazole, a prescription antifungal drug has demonstrated an excellent correlation between AMS and LSC (correlation coefficient 0.999). Human Phase I clinical studies have been conducted with radioactive doses ranging from 120 Bq (7000 dpm) to 11 kBq (300 nCi) to provide mass balance, plasma concentration and radioactive metabolite profiling data. Limits of detection of 0.00022 Bq {sup 14}C-labelled drug/ml plasma have been accurately quantitated in a plasma background of 0.0078 Bq/ml (0.013 dpm/ml in a plasma background of 0.47 dpm/ml or 2.72 pMC in a background of 90.19 pMC)

  14. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range

    NARCIS (Netherlands)

    Duijn, E. van; Sandman, H.; Grossouw, D.; Mocking, J.A.J.; Coulier, L.; Vaes, W.H.J.

    2014-01-01

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput.

  15. Accelerator mass spectrometry with 14C and 10Be in utrecht

    NARCIS (Netherlands)

    Borg, K. van der; Alderliesten, C.; Houston, C.M.; Jong, A.F.M. de; Zwol, N.A. van

    1987-01-01

    The Utrecht facility for accelerator mass spectrometry is now in operation for routine measurements of 14C and 10Be in natural samples. Sample preparation techniques have been introduced. A 1% precision for 14C/12C ratios is routinely achieved. In the last year, more than 500 samples have been prepa

  16. Accelerator mass spectrometry in the study of vitamin and mineral metabolism in humans

    Science.gov (United States)

    Accelerator mass spectrometry is an isotopic ratio method that can estimate the concentrations of long-lived radioisotopes such as carbon-14 and calcium-41, making it useful in biochemical and physiological research. It is capable of measuring radio-labeled nutrients and their metabolites in attomol...

  17. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range

    NARCIS (Netherlands)

    Duijn, E. van; Sandman, H.; Grossouw, D.; Mocking, J.A.J.; Coulier, L.; Vaes, W.H.J.

    2014-01-01

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. H

  18. Integration of continuous-flow accelerator mass spectrometry with chromatography and mass-selective detection.

    Science.gov (United States)

    Flarakos, Jimmy; Liberman, Rosa G; Tannenbaum, Steven R; Skipper, Paul L

    2008-07-01

    Physical combination of an accelerator mass spectrometry (AMS) instrument with a conventional gas chromatograph-mass spectrometer (GC/MS) is described. The resulting hybrid instrument (GC/MS/AMS) was used to monitor mass chromatograms and radiochromatograms simultaneously when (14)C-labeled compounds were injected into the gas chromatograph. Combination of the two instruments was achieved by splitting the column effluent and directing half to the mass spectrometer and half to a flow-through CuO reactor in line with the gas-accepting AMS ion source. The reactor converts compounds in the GC effluent to CO2 as required for function of the ion source. With cholesterol as test compound, the limits of quantitation were 175 pg and 0.00175 dpm injected. The accuracy achieved in analysis of five nonzero calibration standards and three quality control standards, using cholesterol-2,2,3,4,4,6-d6 as injection standard, was 100 +/- 11.8% with selected ion monitoring and 100 +/- 16% for radiochromatography. Respective values for interday precision were 1.0-3.2 and 22-32%. Application of GC/MS/AMS to a current topic of interest was demonstrated in a model metabolomic study in which cultured primary hepatocytes were given [(14)C]glucose and organic acids excreted into the culture medium were analyzed.

  19. Accelerator mass spectrometry best practices for accuracy and precision in bioanalytical (14)C measurements.

    Science.gov (United States)

    Vogel, John S; Giacomo, Jason A; Schulze-König, Tim; Keck, Bradly D; Lohstroh, Peter; Dueker, Stephen

    2010-03-01

    Accelerator mass spectrometers have an energy acceleration and charge exchange between mass definition stages to destroy molecular isobars and allow single ion counting of long-lived isotopes such as (14)C (t½=5370 years.). 'Low' voltage accelerations to 200 kV allow laboratory-sized accelerator mass spectrometers instruments for bioanalytical quantitation of (14)C to 2-3% precision and accuracy in isolated biochemical fractions. After demonstrating this accuracy and precision for our new accelerator mass spectrometer, we discuss the critical aspects of maintaining quantitative accuracy from the defined biological fraction to the accelerator mass spectrometry quantitation. These aspects include sufficient sample mass for routine rapid sample preparation, isotope dilution to assure this mass, isolation of the carbon from other sample combustion gasses and use of high-efficiency biochemical separations. This review seeks to address a bioanalytical audience, who should know that high accuracy data of physiochemical processes within living human subjects are available, as long as a (14)C quantitation can be made indicative of the physiochemistry of interest.

  20. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    The authors describe the development of a new instrument for the detection of trace amounts of rare isotopes, a Cyclotron Mass Spectrometer (CMS). A compact low energy cyclotron optimized for high mass resolution has been designed and has been fabricated. The instrument has high sensitivity and is designed to measure carbon-14 at abundances of < 10{sup {minus}12}. A novel feature of the instrument is the use of permanent magnets to energize the iron poles of the cyclotron. The instrument uses axial injection, employing a spiral inflector. The instrument has been assembled and preliminary measurements of the magnetic field show that it has a uniformity on the order of 2 parts in 10{sup 4}.

  1. Accelerator mass spectrometry-enabled studies: current status and future prospects.

    Science.gov (United States)

    Arjomand, Ali

    2010-03-01

    Accelerator mass spectrometry is a detection platform with exceptional sensitivity compared with other bioanalytical platforms. Accelerator mass spectrometry (AMS) is widely used in archeology for radiocarbon dating applications. Early exploration of the biological and pharmaceutical applications of AMS began in the early 1990s. AMS has since demonstrated unique problem-solving ability in nutrition science, toxicology and pharmacology. AMS has also enabled the development of new applications, such as Phase 0 microdosing. Recent development of AMS-enabled applications has transformed this novelty research instrument to a valuable tool within the pharmaceutical industry. Although there is now greater awareness of AMS technology, recognition and appreciation of the range of AMS-enabled applications is still lacking, including study-design strategies. This review aims to provide further insight into the wide range of AMS-enabled applications. Examples of studies conducted over the past two decades will be presented, as well as prospects for the future of AMS.

  2. Analysis of a Fossil Bone from the Archaeological Settlement Malu Rosu, Romania by Accelerator Mass Spectrometry

    CERN Document Server

    Olariu, A; Hellborg, R; Stenström, K; Faarinen, M P; Persson, P; Erlandsson, B; Skog, G; Alexandrescu, E; Olariu, Agata; Popescu, Ion V.; Hellborg, Ragnar; Stenstr\\"om, Kristina; Faarinen, Mikko; Persson, Per; Erlandsson, Bengt; Alexandrescu, Emilian

    2001-01-01

    A fossil bone from the archaeological site Malu Rosu Giurgiu, in Romania has been analyzed by accelerator mass spectrometry to estimate its age by determining its $^{14}$C content. The radiocarbon age of the bone is in agreement with the date obtained by the method for age determination, based on fluorine content. This is the first radiocarbon dating for the final Neolithic period, for this archaeological settlement in the Romanian region.

  3. Half-life of Si-32 from tandem-accelerator mass spectrometry

    Science.gov (United States)

    Elmore, D.; Anantaraman, N.; Fulbright, H. W.; Gove, H. E.; Nishiizumi, K.; Murrell, M. T.; Honda, M.; Hans, H. S.

    1980-01-01

    A newly developed mass-spectrometry technique employing a tandem Van de Graaff accelerator together with a special beam-transport system and heavy-ion detector has been used to determine the half-life of Si-32. The result obtained, 108 plus or minus 18 yr, disagrees with the accepted value of 330 plus or minus 40 yr. The implications of the new half-life of Si-32, which is used for dating studies, are discussed.

  4. Constant-momentum acceleration time-of-flight mass spectrometry with energy focusing.

    Science.gov (United States)

    Dennis, Elise A; Ray, Steven J; Gundlach-Graham, Alexander W; Enke, Christie G; Barinaga, Charles J; Koppenaal, David W; Hieftje, Gary M

    2013-12-01

    Fundamental aspects of constant-momentum acceleration time-of-flight mass spectrometry (CMA-TOFMS) are explored as a means to improve mass resolution. By accelerating all ions to the same momentum rather than to the same energy, the effects of the initial ion spatial and energy distributions upon the total ion flight time are decoupled. This decoupling permits the initial spatial distribution of ions in the acceleration region to be optimized independently, and energy focus, including ion turn-around-time error, to be accomplished with a linear-field reflectron. Constant-momentum acceleration also linearly disperses ions across time according to mass-to-charge (m/z) ratio, instead of the quadratic relationship between flight time and m/z found in conventional TOFMS. Here, CMA-TOFMS is shown to achieve simultaneous spatial and energy focusing over a selected portion of the mass spectrum. An orthogonal-acceleration time-of-flight system outfitted with a reduced-pressure DC glow discharge (GD) ionization source is used to demonstrate CMA-TOFMS with atomic ions. The influence of experimental parameters such as the amplitude and width of the time-dependent CMA pulse on mass resolution is investigated, and a useful CMA-TOFMS focusing window of 2 to 18 Da is found for GD-CMA-TOFMS.

  5. Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

    Science.gov (United States)

    Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

    2014-01-01

    Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions.

  6. Morphine brain pharmacokinetics at very low concentrations studied with accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Sadiq, Muhammad Waqas; Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran; Hammarlund-Udenaes, Margareta

    2011-02-01

    Morphine has been predicted to show nonlinear blood-brain barrier transport at lower concentrations. In this study, we investigated the possibility of separating active influx of morphine from its efflux by using very low morphine concentrations and compared accelerator mass spectrometry (AMS) with liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a method for analyzing microdialysis samples. A 10-min bolus infusion of morphine, followed by a constant-rate infusion, was given to male rats (n = 6) to achieve high (250 ng/ml), medium (50 ng/ml), and low (10 ng/ml) steady-state plasma concentrations. An additional rat received infusions to achieve low (10 ng/ml), very low (2 ng/ml), and ultralow (0.4 ng/ml) concentrations. Unbound morphine concentrations from brain extracellular fluid and blood were sampled by microdialysis and analyzed by LC-MS/MS and AMS. The average partition coefficient for unbound drug (K(p,uu)) values for the low and medium steady-state levels were 0.22 ± 0.08 and 0.21 ± 0.05, respectively, when measured by AMS [not significant (NS); p = 0.5]. For the medium and high steady-state levels, K(p,uu) values were 0.24 ± 0.05 and 0.26 ± 0.05, respectively, when measured by LC-MS/MS (NS; p = 0.2). For the low, very low, and ultralow steady-state levels, K(p,uu) values were 0.16 ± 0.01, 0.16 ± 0.02, and 0.18 ± 0.03, respectively, when measured by AMS. The medium-concentration K(p,uu) values were, on average, 16% lower when measured by AMS than by LC-MS/MS. There were no significant changes in K(p,uu) over a 625-fold concentration range (0.4-250 ng/ml). It was not possible to separate active uptake transport from active efflux using these low concentrations. The two analytical methods provided indistinguishable results for plasma concentrations but differed by up to 38% for microdialysis samples; however, this difference did not affect our conclusions.

  7. HUMAN MASS BALANCE STUDY OF TAS-102 USING 14C ANALYZED BY ACCELERATOR MASS SPECTROMETRY

    Science.gov (United States)

    Lee, James J.; Seraj, Jabed; Yoshida, Kenichiro; Mizuguchi, Hirokazu; Strychor, Sandra; Fiejdasz, Jillian; Faulkner, Tyeler; Parise, Robert A.; Fawcett, Patrick; Pollice, Laura; Mason, Scott; Hague, Jeremy; Croft, Marie; Nugteren, James; Tedder, Charles; Sun, Weijing; Chu, Edward; Beumer, Jan Hendrik

    2016-01-01

    Background TAS-102 is an oral fluoropyrimidine prodrug composed of trifluridine (FTD) and tipiracil hydrochloride (TPI) in a 1:0.5 ratio. FTD is a thymidine analog, and it is degraded by thymidine phosphorylase (TP) to the inactive trifluoromethyluracil (FTY) metabolite. TPI inhibits degradation of FTD by TP, increasing systemic exposure to FTD. Methods Patients with advanced solid tumors (6 M/2 F; median age 58 years; PS 0–1) were enrolled on this study. Patients in group A (N = 4) received 60 mg TAS-102 with 200 nCi [14C]-FTD, while patients in group B (N = 4) received 60 mg TAS-102 with 1000 nCi [14C]-TPI orally. Plasma, blood, urine, feces, and expired air (group A only) were collected up to 168 h, and were analyzed for 14C by accelerator mass spectrometry and analytes by LC-MS/MS. Results FTD: 59.8% of the 14C dose was recovered; 54.8% in urine mostly as FTY and FTD glucuronide isomers. The extractable radioactivity in the pooled plasma consisted of 52.7% FTD and 33.2% FTY. TPI: 76.8% of the 14C dose was recovered; 27.0% in urine mostly as TPI, and 49.7% in feces. The extractable radioactivity in the pooled plasma consisted of 53.1% TPI and 30.9% 6-HMU, the major metabolite of TPI. Conclusion Absorbed 14C-FTD was metabolized and mostly excreted in urine. The majority of 14C-TPI was recovered in feces, and the majority of absorbed TPI was excreted in urine. The current data with the ongoing hepatic and renal dysfunction studies will provide an enhanced understanding of the TAS-102 elimination profile. PMID:26787503

  8. Human mass balance study of TAS-102 using (14)C analyzed by accelerator mass spectrometry.

    Science.gov (United States)

    Lee, James J; Seraj, Jabed; Yoshida, Kenichiro; Mizuguchi, Hirokazu; Strychor, Sandra; Fiejdasz, Jillian; Faulkner, Tyeler; Parise, Robert A; Fawcett, Patrick; Pollice, Laura; Mason, Scott; Hague, Jeremy; Croft, Marie; Nugteren, James; Tedder, Charles; Sun, Weijing; Chu, Edward; Beumer, Jan Hendrik

    2016-03-01

    TAS-102 is an oral fluoropyrimidine prodrug composed of trifluridine (FTD) and tipiracil hydrochloride (TPI) in a 1:0.5 ratio. FTD is a thymidine analog, and it is degraded by thymidine phosphorylase (TP) to the inactive trifluoromethyluracil (FTY) metabolite. TPI inhibits degradation of FTD by TP, increasing systemic exposure to FTD. Patients with advanced solid tumors (6 M/2 F; median age 58 years; PS 0-1) were enrolled on this study. Patients in group A (N = 4) received 60 mg TAS-102 with 200 nCi [(14)C]-FTD, while patients in group B (N = 4) received 60 mg TAS-102 with 1000 nCi [(14)C]-TPI orally. Plasma, blood, urine, feces, and expired air (group A only) were collected up to 168 h and were analyzed for (14)C by accelerator mass spectrometry and analytes by LC-MS/MS. FTD: 59.8% of the (14)C dose was recovered: 54.8% in urine mostly as FTY and FTD glucuronide isomers. The extractable radioactivity in the pooled plasma consisted of 52.7% FTD and 33.2% FTY. TPI: 76.8% of the (14)C dose was recovered: 27.0% in urine mostly as TPI and 49.7% in feces. The extractable radioactivity in the pooled plasma consisted of 53.1% TPI and 30.9% 6-HMU, the major metabolite of TPI. Absorbed (14)C-FTD was metabolized and mostly excreted in urine. The majority of (14)C-TPI was recovered in feces, and the majority of absorbed TPI was excreted in urine. The current data with the ongoing hepatic and renal dysfunction studies will provide an enhanced understanding of the TAS-102 elimination profile.

  9. Accelerator mass spectrometry of the heaviest long-lived radionuclides with a 3-MV tandem accelerator

    Indian Academy of Sciences (India)

    Christof Vockenhuber; Robin Golser; Walter Kutschera; Alfred Priller; Peter Steier; Stephan Winkler; Vitaly Liechtenstein

    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 14C/12C and 26Al/27Al as low as 10-15 and 10Be/9Be 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. 236U and 244Pu), 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. Determination of protein-ligand interactions using accelerator mass spectrometry: modified crosslinking assay.

    Science.gov (United States)

    Hah, Sang Soo

    2009-05-01

    A highly sensitive detection method for the determination of protein-ligand interactions has been developed. Radiocarbon-labeled 17beta-estradiol was incubated with estrogen receptor-alpha; as a selective binding partner, and covalently attached using crosslinking agents, to form covalently linked protein-ligand complexes. After separation using a denaturing gel, the (14)C content in the sliced gels was identified by accelerator mass spectrometry. The obtained data demonstrated specific binding of the small molecule to its binding partner. In theory, this method can be applied to most protein-ligand interaction studies.

  11. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    Energy Technology Data Exchange (ETDEWEB)

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

  12. Optimizing a microwave gas ion source for continuous-flow accelerator mass spectrometry.

    Science.gov (United States)

    von Reden, K F; Roberts, M L; Burton, J R; Beaupré, S R

    2012-02-01

    A 2.45 GHz microwave ion source coupled with a magnesium charge exchange canal (C × C) has been successfully adapted to a large acceptance radiocarbon accelerator mass spectrometry system at the National Ocean Sciences Accelerator Mass Spectrometry (AMS) Facility, Woods Hole Oceanographic Institution. CO(2) samples from various preparation sources are injected into the source through a glass capillary at 370 μl∕min. Routine system parameters are about 120-140 μA of negative (12)C current after the C × C, leading to about 400 (14)C counts per second for a modern sample and implying a system efficiency of 0.2%. While these parameters already allow us to perform high-quality AMS analyses on large samples, we are working on ways to improve the output of the ion source regarding emittance and efficiency. Modeling calculations suggest modifications in the extraction triode geometry, shape, and size of the plasma chamber could improve emittance and, hence, ion transport efficiency. Results of experimental tests of these modifications are presented.

  13. Determination of the stellar (n,gamma) cross section of 40Ca with accelerator mass spectrometry

    CERN Document Server

    Dillmann, I; Heil, M; Käppeler, F; Wallner, A; Forstner, O; Golser, R; Kutschera, W; Priller, A; Steier, P; Mengoni, A; Gallino, R; Paul, M; Vockenhuber, C; 10.1103/PhysRevC.79.065805

    2009-01-01

    The stellar (n,gamma) cross section of 40Ca at kT=25 keV has been measured with a combination of the activation technique and accelerator mass spectrometry (AMS). This combination is required when direct off-line counting of the produced activity is compromised by the long half-life and/or missing gamma-ray transitions. The neutron activations were performed at the Karlsruhe Van de Graaff accelerator using the quasistellar neutron spectrum of kT=25 keV produced by the 7Li(p,n)7Be reaction. The subsequent AMS measurements were carried out at the Vienna Environmental Research Accelerator (VERA) with a 3 MV tandem accelerator. The doubly magic 40Ca is a bottle-neck isotope in incomplete silicon burning, and its neutron capture cross section determines the amount of leakage, thus impacting on the eventual production of iron group elements. Because of its high abundance, 40Ca can also play a secondary role as "neutron poison" for the s-process. Previous determinations of this value at stellar energies were based o...

  14. Use of an intravenous microdose of 14C-labeled drug and accelerator mass spectrometry to measure absolute oral bioavailability in dogs; cross-comparison of assay methods by accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Miyaji, Yoshihiro; Ishizuka, Tomoko; Kawai, Kenji; Hamabe, Yoshimi; Miyaoka, Teiji; Oh-hara, Toshinari; Ikeda, Toshihiko; Kurihara, Atsushi

    2009-01-01

    A technique utilizing simultaneous intravenous microdosing of (14)C-labeled drug with oral dosing of non-labeled drug for measurement of absolute bioavailability was evaluated using R-142086 in male dogs. Plasma concentrations of R-142086 were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and those of (14)C-R-142086 were measured by accelerator mass spectrometry (AMS). The absence of metabolites in the plasma and urine was confirmed by a single radioactive peak of the parent compound in the chromatogram after intravenous microdosing of (14)C-R-142086 (1.5 microg/kg). Although plasma concentrations of R-142086 determined by LC-MS/MS were approximately 20% higher than those of (14)C-R-142086 as determined by AMS, there was excellent correlation (r=0.994) between both concentrations after intravenous dosing of (14)C-R-142086 (0.3 mg/kg). The oral bioavailability of R-142086 at 1 mg/kg obtained by simultaneous intravenous microdosing of (14)C-R-142086 was 16.1%, this being slightly higher than the value (12.5%) obtained by separate intravenous dosing of R-142086 (0.3 mg/kg). In conclusion, on utilizing simultaneous intravenous microdosing of (14)C-labeled drug in conjunction with AMS analysis, absolute bioavailability could be approximately measured in dogs, but without total accuracy. Bioavailability in humans may possibly be approximately measured at an earlier stage and at a lower cost.

  15. Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom.

    Science.gov (United States)

    Barker, J; Garner, R C

    1999-01-01

    Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology

  16. Interlaboratory study of the ion source memory effect in 36Cl accelerator mass spectrometry

    Science.gov (United States)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Martschini, Martin; Merchel, Silke; Rugel, Georg; Steier, Peter

    2014-06-01

    Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural 35Cl/37Cl-ratio and samples highly-enriched in 35Cl (35Cl/37Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion sources were widely spread between 61 and 1390 s, where the modified DREAMS ion source with values between 156 and 262 s showed the fastest recovery in 80% of the measurements.

  17. Accelerator mass spectrometry of ultra-small samples with applications in the biosciences

    Science.gov (United States)

    Salehpour, Mehran; Håkansson, Karl; Possnert, Göran

    2013-01-01

    An overview is presented covering the biological accelerator mass spectrometry activities at Uppsala University. The research utilizes the Uppsala University Tandem laboratory facilities, including a 5 MV Pelletron tandem accelerator and two stable isotope ratio mass spectrometers. In addition, a dedicated sample preparation laboratory for biological samples with natural activity is in use, as well as another laboratory specifically for 14C-labeled samples. A variety of ongoing projects are described and presented. Examples are: (1) Ultra-small sample AMS. We routinely analyze samples with masses in the 5-10 μg C range. Data is presented regarding the sample preparation method, (2) bomb peak biological dating of ultra-small samples. A long term project is presented where purified and cell-specific DNA from various part of the human body including the heart and the brain are analyzed with the aim of extracting regeneration rate of the various human cells, (3) biological dating of various human biopsies, including atherosclerosis related plaques is presented. The average built up time of the surgically removed human carotid plaques have been measured and correlated to various data including the level of insulin in the human blood, and (4) In addition to standard microdosing type measurements using small pharmaceutical drugs, pre-clinical pharmacokinetic data from a macromolecular drug candidate are discussed.

  18. Method for (236)U Determination in Seawater Using Flow Injection Extraction Chromatography and Accelerator Mass Spectrometry.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Nielsen, Sven; Golser, Robin

    2015-07-21

    An automated analytical method implemented in a flow injection (FI) system was developed for rapid determination of (236)U in 10 L seawater samples. (238)U was used as a chemical yield tracer for the whole procedure, in which extraction chromatography (UTEVA) was exploited to purify uranium, after an effective iron hydroxide coprecipitation. Accelerator mass spectrometry (AMS) was applied for quantifying the (236)U/(238)U ratio, and inductively coupled plasma mass spectrometry (ICPMS) was used to determine the absolute concentration of (238)U; thus, the concentration of (236)U can be calculated. The key experimental parameters affecting the analytical effectiveness were investigated and optimized in order to achieve high chemical yields and simple and rapid analysis as well as low procedure background. Besides, the operational conditions for the target preparation prior to the AMS measurement were optimized, on the basis of studying the coprecipitation behavior of uranium with iron hydroxide. The analytical results indicate that the developed method is simple and robust, providing satisfactory chemical yields (80-100%) and high analysis speed (4 h/sample), which could be an appealing alternative to conventional manual methods for (236)U determination in its tracer application.

  19. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained r...

  20. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-15

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  1. Ultra-trace analysis of 36Cl by accelerator mass spectrometry: an interlaboratory study.

    Science.gov (United States)

    Merchel, S; Bremser, W; Alfimov, V; Arnold, M; Aumaître, G; Benedetti, L; Bourlès, D L; Caffee, M; Fifield, L K; Finkel, R C; Freeman, S P H T; Martschini, M; Matsushi, Y; Rood, D H; Sasa, K; Steier, P; Takahashi, T; Tamari, M; Tims, S G; Tosaki, Y; Wilcken, K M; Xu, S

    2011-07-01

    A first international (36)Cl interlaboratory comparison has been initiated. Evaluation of the final results of the eight participating accelerator mass spectrometry (AMS) laboratories on three synthetic AgCl samples with (36)Cl/Cl ratios at the 10(-11), 10(-12), and 10(-13) level shows no difference in the sense of simple statistical significance. However, more detailed statistical analyses demonstrate certain interlaboratory bias and underestimation of uncertainties by some laboratories. Following subsequent remeasurement and reanalysis of the data from some AMS facilities, the round-robin data indicate that (36)Cl/Cl data from two individual AMS laboratories can differ by up to 17%. Thus, the demand for further work on harmonising the (36)Cl-system on a worldwide scale and enlarging the improvement of measurements is obvious.

  2. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Science.gov (United States)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  3. Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

    Directory of Open Access Journals (Sweden)

    J.T. Jull

    2002-01-01

    Full Text Available There are many diverse uses of accelerator mass spectrometry (AMS. 14C studies at our laboratory include much research related to paleoclimate, with 14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation, or on the millennial time scale. In tracer applications, we have developed the use of 129I as well as 14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

  4. Accelerator mass spectrometry at Arizona: geochronology of the climate record and connections with the ocean.

    Science.gov (United States)

    Jull, A J T; Burr, G S; Beck, J W; Donahue, D J; Biddulph, D; Hatheway, A L; Lange, T E; McHargue, L R

    2003-01-01

    There are many diverse uses of accelerator mass spectrometry (AMS). Carbon-14 studies at our laboratory include much research related to paleoclimate, both with 14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments and many terrestrial records. Terrestrial records such as forest fires can also show the influence of oceanic oscillations, whether they are short-term such as ENSO, or on the millennial time scale. In tracer applications, we have developed the use of 129I as well as 14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson for several of these fields and hope to give some idea of the breadth of these studies.

  5. Accelerator mass spectrometry for human biochemistry: The practice and the potential

    Science.gov (United States)

    Vogel, John S.

    2000-10-01

    Isotopic labels are a primary tool for tracing chemicals in natural systems. Accelerator mass spectrometry (AMS) quantifies long-lived isotopes that can be used in safe, sensitive and precise biochemical research with human participants. AMS could reduce the use of animals in biochemical research and remove the uncertain extrapolations from animal models to humans. Animal data seldom represent the sort of variability expected in a human population. People, knowingly or not, routinely expose themselves to radiation risks much greater than AMS-based biochemical research that traces μg/kg doses of chemicals containing tens of nCi of 14C for as long as 7 months. AMS is applied to research in toxicology, pharmacology and nutrition.

  6. High-performance liquid chromatography accelerator mass spectrometry: correcting for losses during analysis by internal standardization.

    Science.gov (United States)

    Lappin, G; Simpson, M; Shishikura, Y; Garner, C

    2008-07-01

    A method was developed to account for analytical losses of (14)C-analyte when determining the concentration in biological samples using chromatographic separation and analysis by accelerator mass spectrometry. From the equations of J. Vogel and A.H. Love (in: A.L. Burlingame (Ed.), Methods in Enzymology, Academic Press, New York, 2005), new equations were derived to describe the isotopic dilution of a chromatographically isolated (14)C-analyte. The analytical recovery for each sample was determined by the use of the UV response for nonlabeled analyte, as an internal standard against a standard curve. The slope of the curve was substituted into the equations to provide a method of accurately determining the analyte concentration.

  7. Isobaric Identification Using Gas-Filled Time-of-Flight Measurements in an Accelerator Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    GUAN Yong-Jing; RUAN Xiang-Dong; HE Ming; WANG Hui-Juan; LI Guo-Qiang; WU Shao-Yong; DONG Ke-Jun; LIN Min; JIANG Shan

    2005-01-01

    @@ A gas-filled time-of-flight (GF-TOF) detector has been built and developed to improve the ability of isobaric identification in accelerator mass spectrometry (AMS) measurements, and a time resolution (without gas filled)of better than 350ps is achieved. The GF-TOF detector is tested by means of measuring a standard AgCl(36Cl/Cl = 7.6 × 10-9g/g) sample with the 36Cl ion energy of 64, 49 and 33MeV, respectively. 36Cl and 36S particles were successfully separated in the TOF spectra output from the GF-TOF detector. The comparison between the gas-filled time-of-flight method and the △E - E method is described. Some results relative to the GF-TOF method are given as well.

  8. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Zakir H. [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Cornett, Jack R., E-mail: jack.cornett@uottawa.ca [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Zhao, Xaiolei; Kieser, Liam [Department of Physics, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada)

    2014-06-01

    Highlights: • Am and Pu were adsorbed and separated using a single extraction chromatography DGA column. • Pu was eluted from the column completely using on-column reduction of Pu(IV) to Pu(III). • ²⁴¹Am and 239,240Pu measurements by accelerator mass spectrometry (AMS) agree with the certified values in two SRMs. Abstract: A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8 M HNO₃ with 0.05 M NaNO₂ before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO₃, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl₃ facilitated the complete desorption of Pu. Interferences (e.g. Ca²⁺, Fe³⁺) were washed off from the resin bed with excess HNO₃. Using NdF₃, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7 ± 5.3% and 95.5 ± 4.6% for ²⁴¹Am and ²⁴²Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1 ± 6.0 and 96.8 ± 5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1–100 Bq kg⁻¹. The single column separation of Pu and Am saves reagents, separation time, and cost.

  9. Isolation of Pu-isotopes from environmental samples using ion chromatography for accelerator mass spectrometry and alpha spectrometry.

    Science.gov (United States)

    Chamizo, E; Jiménez-Ramos, M C; Wacker, L; Vioque, I; Calleja, A; García-León, M; García-Tenorio, R

    2008-01-14

    A radiochemical method for the isolation of plutonium-isotopes from environmental samples, based on the use of specific extraction chromatography resins for actinides (TEVA), Eichrom Industries, Inc.), has been set up in our laboratory and optimised for their posterior determination by alpha spectrometry (AS) or accelerator mass spectrometry (AMS). The proposed radiochemical method has replaced in our lab a well-established one based on the use of a relatively un-specific anion-exchange resin (AG) 1X8, Bio-rad Laboratories, Inc.), because it is clearly less time consuming, reduces the amounts and molarities of acid wastes produced, and reproducibly gives high radiochemical yields. In order to check the reliability of the proposed radiochemical method for the determination of plutonium-isotopes in different environmental matrixes, twin aliquots of a set of samples were prepared with TEVA and with AG 1X8 resins and measured by AS. Some samples prepared with TEVA resins were measured as well by AMS. As it is shown in the text, there is a comfortable agreement between AS and AMS, which adequately validates the method.

  10. Corona discharge ion mobility spectrometry with orthogonal acceleration time of flight mass spectrometry for monitoring of volatile organic compounds.

    Science.gov (United States)

    Sabo, Martin; Matejčík, Štefan

    2012-06-19

    We demonstrate the application of corona discharge ion mobility spectrometry with orthogonal acceleration time of flight mass spectrometry (CD IMS-oaTOF) for volatile organic compounds (VOCs) monitoring. Two-dimensional (2D) IMS-oaTOF spectra of VOCs were recorded in nearly real time. The corona discharge atmospheric pressure chemical ionization (APCI) source was operated in positive mode in nitrogen and air. The CD ion source generates in air H(3)O(+)(H(2)O)(n) and NO(+). The NO(+) offers additional possibility for selective ionization and for an increase of the sensitivity of monoaromatic compounds. In addition to H(3)O(+)(H(2)O)(n) and NO(+), we have carried out ionization of VOCs using acetone as dopant gas ((CH(3))(2)COH(+)). Sixteen model VOCs (tetrahydrofuran, butanol, n-propanol, iso-propano, acetone, methanol, ethanol, toluene, benzene, amomnia, dioxan, triethylamine, acetonitrile, formaldehyde, m-xylene, 2,2,2-trifluoroethylamine) were tested using these ionization techniques.

  11. Isolation of Pu-isotopes from environmental samples using ion chromatography for accelerator mass spectrometry and alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo, E. [Centro Nacional de Aceleradores (CNA), Avda. Thomas A. Edison, 41092 Sevilla (Spain)], E-mail: elechacal@alum.us.es; Jimenez-Ramos, M.C. [Applied Nuclear Physics Group, University of Sevilla, P.O. Box 1065, 41080 Sevilla (Spain); Wacker, L. [Institute of Particle Physics, ETH Hoenggerberg, CH-8093 Zuerich (Switzerland); Vioque, I.; Calleja, A. [Applied Nuclear Physics Group, University of Sevilla, P.O. Box 1065, 41080 Sevilla (Spain); Garcia-Leon, M. [Centro Nacional de Aceleradores (CNA), Avda. Thomas A. Edison, 41092 Sevilla (Spain); Applied Nuclear Physics Group, University of Sevilla, P.O. Box 1065, 41080 Sevilla (Spain); Garcia-Tenorio, R. [Applied Nuclear Physics Group, University of Sevilla, P.O. Box 1065, 41080 Sevilla (Spain)

    2008-01-14

    A radiochemical method for the isolation of plutonium-isotopes from environmental samples, based on the use of specific extraction chromatography resins for actinides (TEVA, Eichrom Industries, Inc.), has been set up in our laboratory and optimised for their posterior determination by alpha spectrometry (AS) or accelerator mass spectrometry (AMS). The proposed radiochemical method has replaced in our lab a well-established one based on the use of a relatively un-specific anion-exchange resin (AG 1X8, Bio-rad Laboratories, Inc.), because it is clearly less time consuming, reduces the amounts and molarities of acid wastes produced, and reproducibly gives high radiochemical yields. In order to check the reliability of the proposed radiochemical method for the determination of plutonium-isotopes in different environmental matrixes, twin aliquots of a set of samples were prepared with TEVA and with AG 1X8 resins and measured by AS. Some samples prepared with TEVA resins were measured as well by AMS. As it is shown in the text, there is a comfortable agreement between AS and AMS, which adequately validates the method.

  12. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Eliades J.

    2012-04-01

    Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  13. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry.

    Science.gov (United States)

    Kazi, Zakir H; Cornett, Jack R; Zhao, Xaiolei; Kieser, Liam

    2014-06-04

    A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8M HNO3 with 0.05 M NaNO2 before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO3, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl3 facilitated the complete desorption of Pu. Interferences (e.g. Ca(2+), Fe(3+)) were washed off from the resin bed with excess HNO3. Using NdF3, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7±5.3% and 95.5±4.6% for (241)Am and (242)Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1±6.0 and 96.8±5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1-100 Bq kg(-1). The single column separation of Pu and Am saves reagents, separation time, and cost.

  14. Determination of cosmogenic Ca-41 in a meteorite with tandem accelerator mass spectrometry

    Science.gov (United States)

    Kubik, P. W.; Elmore, D.; Conard, N. J.; Nishiizumi, K.; Arnold, J. R.

    1986-01-01

    The first use of tandem accelerator mass spectrometry (TAMS) to measure the content of Ca-41 in a natural sample, the iron Bogou meteorite, is reported. Ca in the samples was extracted by hydroxide precipitation and purified by means of a caution exchange resin (AG 50W-X8). After adding 4 percent ammonium oxide, the precipitate was ignited to CaO in a quartz vial at about 1100 C. The Ca-41/Ca ratios were determined following acceleration by alternate measurements of the Ca-40 beam current in an image Faraday cup. Ca-41 particles were also measured using a gas counter. The measured Ca-41/Ca ratio was 3.8 + or -0.6 x 10 to the 12th, which corresponds to a Ca-41 activity of 6.9 + or -1.1 d.p.m. per kg. Calculation of the half-life of Ca-41 in the Bogou meteorite yielded an age of 103,000 years.

  15. Current perspectives of {sup 14}C-isotope measurement in biomedical accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lappin, Graham; Garner, R.Colin [Xceleron Ltd, York Biocentre, Innovation Way, YO10 5NY, York (United Kingdom)

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched {sup 14}C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided. (orig.)

  16. Proof-of-concept development of PXAMS (projectile x-ray accelerator mass spectrometry)

    Energy Technology Data Exchange (ETDEWEB)

    Proctor, I.D.; Roberts, M.L.; McAninch, J.E.; Bench, G.S.

    1996-03-01

    Prior to the current work, accelerator mass spectrometry (AMS) was limited to a set of {approximately}8--10 isotopes. This limitation is caused primarily by the inability to discriminate against stable atomic isobars. An analysis scheme that combines the isotopic sensitivity of AMS with similar isobar selectivity would open a large new class of isotope applications. This project was undertaken to explore the use of characteristic x rays as a method for the detection and identification of ions,and to allow the post-spectrometer rejection of isobaric interferences for isotopes previously inaccessible to AMS. During the second half of FY94 (with Advanced Concepts funding from the Office of Non-Proliferation and National Security), we examined the feasability of this technique, which we are referring to as PXAMS (Projectile X ray AMS), to the detection of several isotopes at Lawrence Livermore National Laboratory (LLNL). In our first exploratory work, we measured the x ray yield vs energy for {sup 80}Se ions stopped in a thick Y target. These results, demonstrated that useful detection efficiencies could be obtained for Se ions at energies accessible with our accelerator, and that the count rate from target x rays is small compared to the Se K{alpha} rate. We followed these measurements with a survey of x ray yields for Z = 14-46.

  17. Interlaboratory study of the ion source memory effect in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan, E-mail: s.pavetich@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Akhmadaliev, Shavkat [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Arnold, Maurice; Aumaître, Georges; Bourlès, Didier [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Buchriegler, Josef [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Golser, Robin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Keddadouche, Karim [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Martschini, Martin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Merchel, Silke; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Steier, Peter [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria)

    2014-06-01

    Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of {sup 36}Cl/Cl and {sup 129}I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples highly-enriched in {sup 35}Cl ({sup 35}Cl/{sup 37}Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion

  18. Challenging developments in three decades of accelerator mass spectrometry at ETH: from large particle accelerators to table size instruments.

    Science.gov (United States)

    Suter, Martin

    2010-01-01

    Accelerator mass spectrometry (AMS) was invented for the detection of radiocarbon at natural isotopic concentrations (10(-12) to 10(-15)) more than 30 years ago. Meanwhile this method has also been applied for the analysis of many other long-lived radioisotopes, which are found at very low concentrations. The first investigations were made at large tandem accelerators originally built for nuclear physics research and operating at voltages of 6-12 MV. Today dedicated instruments are mostly used for AMS, which are optimized for associated applications. In the past 15 years, a new generation of much smaller instruments has been developed. For many years it was believed that accelerators with voltages of 2 MV or higher are needed to eliminate the molecular interferences. At these energies the ions are predominantly stripped to charge state 3+, thereby removing the binding electrons of the molecules. In contrast, the new compact facilities use 1+ or 2+ ions. In this case the molecular destruction process is based on molecule-atom collisions in the gas cell. The cross sections for this destruction are sufficiently large that the intensity of molecular components such as (12)CH(2) and (13)CH can be reduced by 10 orders of magnitude. These new facilities can be built much smaller due to the lower energies. Universal instruments providing analysis for many isotopes over the whole range of periodic table have a space requirement of about 4 x 6 m(2); dedicated radiocarbon facilities based on a 200 kV accelerator have a footprint of about 2.5 x 3 m(2). This smallest category of instruments use special technologies: The high voltage terminal with the gas stripper canal is vacuum insulated and the gas is pumped to ground potential through a ceramic pipe. A conventional 200 kV power supply provides the terminal voltage from outside. A review of this new generation of compact AMS facilities is given. Design considerations and performance of these new instruments will be presented

  19. Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

    NARCIS (Netherlands)

    Garner, C.R.; Park, K.B.; French, N.S.; Earnshaw, C.; Schipani, A.; Selby, A.M.; Byrne, L.; Siner, S.; Crawley, F.P.; Vaes, W.H.J.; Duijn, E. van; ligt, R. de; Varendi, H.; Lass, J.; Grynkiewicz, G.; Maruszak, W.; Turner, M.A.

    2015-01-01

    Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group. Meth

  20. Accelerator mass spectrometry analyses of environmental radionuclides: sensitivity, precision and standardisation

    Science.gov (United States)

    Hotchkis; Fink; Tuniz; Vogt

    2000-07-01

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. AMS allows an isotopic sensitivity as low as one part in 10(15) for 14C (5.73 ka), 10Be (1.6 Ma), 26Al (720 ka), 36Cl (301 ka), 41Ca (104 ka), 129I (16 Ma) and other long-lived radionuclides occurring in nature at ultra-trace levels. These radionuclides can be used as tracers and chronometers in many disciplines: geology, archaeology, astrophysics, biomedicine and materials science. Low-level decay counting techniques have been developed in the last 40-50 years to detect the concentration of cosmogenic, radiogenic and anthropogenic radionuclides in a variety of specimens. Radioactivity measurements for long-lived radionuclides are made difficult by low counting rates and in some cases the need for complicated radiochemistry procedures and efficient detectors of soft beta-particles and low energy x-rays. The sensitivity of AMS is unaffected by the half-life of the isotope being measured, since the atoms not the radiations that result from their decay, are counted directly. Hence, the efficiency of AMS in the detection of long-lived radionuclides is 10(6)-10(9) times higher than decay counting and the size of the sample required for analysis is reduced accordingly. For example, 14C is being analysed in samples containing as little as 20 microg carbon. There is also a world-wide effort to use AMS for the analysis of rare nuclides of heavy mass, such as actinides, with important applications in safeguards and nuclear waste disposal. Finally, AMS microprobes are being developed for the in-situ analysis of stable isotopes in geological samples, semiconductors and other materials. Unfortunately, the use of AMS is limited by the expensive accelerator technology required, but there are several attempts to develop compact AMS spectrometers at low (< or = 0.5 MV

  1. Highly Sensitive 14C and 3H Quantification of Biochemical Samples Using Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, T J; Vogel, J S

    2003-10-23

    Accelerator Mass Spectrometry (AMS) is an isotope ratio mass spectrometer that quantifies low levels of rare isotopes with half-lives between 10 and 10{sup 8} years. Typical sensitivities are 10{sup 6} atoms in a milligram-sized sample. AMS was originally developed for use in the geosciences as a tool to carbon date archaeological artifacts, but has applications in many fields. In the biosciences, the extreme sensitivity of AMS is used to trace nutrients, toxins and therapeutics in humans and animals using less than {micro}g/kg doses containing between 1-100 nCi of {sup 14}C. This sensitivity is used to reduce sample size, reduce chemical exposures to environmental or physiological levels, reduce radiation exposures to subjects, and/or reduce radioactive (and ''mixed'') waste. Compared to decay counting, AMS provides for a much higher measurement throughput for low activity samples. For example, a milligram-sized sample containing 1 dpm of {sup 14}C can be measured to 3% precision in several seconds. That same sample would require approximately 1 week of decay counting to obtain similar precision.

  2. Adding value through accelerator mass spectrometry-enabled first in human studies.

    Science.gov (United States)

    Seymour, Mark A

    2016-12-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive technique for the analysis of radiocarbon. It is applicable to bioanalysis of any (14) C-labelled analyte and any sample type. The increasing body of data generated using LC+AMS indicates that the methodology is robust and reliable, and capable of meeting the same validation criteria as conventional bioanalytical techniques. Because it is a tracer technique, AMS is capable of discriminating between an administered radiolabelled dose and endogenous compound or non-radiolabelled compound administered separately. This paper discusses how it can be used to enhance the design of first in human (FIH) clinical studies and generate significant additional data, including: fundamental pharmacokinetics (CL and V), absolute bioavailability, mass balance, routes and rates of excretion, metabolic fate (including first-pass metabolism, identification of biliary metabolites and quantitative data to address metabolite safety testing issues), and tissue disposition of parent compound and metabolites. Because the (14) C-labelled microtracer dose is administered at the same time as a pharmacologically relevant non-radiolabelled dose, there is no concern about dose-linearity. However the mass of the microtracer dose itself is negligible and therefore does not affect the outcome of the FIH study. The addition of microtracer doses to a FIH study typically requires little additional expense, apart from the AMS analytics, making the approach cost-effective. It can also save significant time, compared to conventional approaches, and, by providing reliable human in vivo data as early as possible, prevent unnecessary expenditure later in drug development.

  3. Use of Accelerator Mass Spectrometry in Human Health and Molecular Toxicology.

    Science.gov (United States)

    Enright, Heather A; Malfatti, Michael A; Zimmermann, Maike; Ognibene, Ted; Henderson, Paul; Turteltaub, Kenneth W

    2016-12-19

    Accelerator mass spectrometry (AMS) has been adopted as a powerful bioanalytical method for human studies in the areas of pharmacology and toxicology. The exquisite sensitivity (10(-18) mol) of AMS has facilitated studies of toxins and drugs at environmentally and physiologically relevant concentrations in humans. Such studies include risk assessment of environmental toxicants, drug candidate selection, absolute bioavailability determination, and more recently, assessment of drug-target binding as a biomarker of response to chemotherapy. Combining AMS with complementary capabilities such as high performance liquid chromatography (HPLC) can maximize data within a single experiment and provide additional insight when assessing drugs and toxins, such as metabolic profiling. Recent advances in the AMS technology at Lawrence Livermore National Laboratory have allowed for direct coupling of AMS with complementary capabilities such as HPLC via a liquid sample moving wire interface, offering greater sensitivity compared to that of graphite-based analysis, therefore enabling the use of lower (14)C and chemical doses, which are imperative for clinical testing. The aim of this review is to highlight the recent efforts in human studies using AMS, including technological advancements and discussion of the continued promise of AMS for innovative clinical based research.

  4. European Bioanalysis Forum recommendation: scientific validation of quantification by accelerator mass spectrometry.

    Science.gov (United States)

    Higton, David; Young, Graeme; Timmerman, Philip; Abbott, Richard; Knutsson, Magnus; Svensson, Leif D

    2012-11-01

    Accelerator mass spectrometry (AMS) is being used more widely to provide PK data for early decision making or to generate absolute bioavailability data in later phases of development. Presently, there is no clear consensus on the level of the scientific validation required for these assays. The European Bioanalysis Forum (EBF) has conducted two surveys with its members and presented the results at its 4th Open Symposium. With AMS being used for discrete scientific assessment, method establishment of AMS assays should focus on science rather than trying to fit the assay parameters into validation criteria used for Regulated Bioanalysis guidance, and an amount of freedom of execution and interpretation is needed. Hence, the EBF focuses their recommendation on introducing terminology around scientific qualification or validation to be used in relation to AMS. Guidance is given on which parameters should be investigated when a qualified method is required. The recommendations of the EBF for scientific validation are described herein. The scientific validation of AMS assays will be different to that applied for LC-MS/MS assays, and an example is that accuracy and precision limits, as used for ligand-binding assays, would be more appropriate.

  5. Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry

    CERN Document Server

    Dong, K J

    2007-01-01

    Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Among the radio-isotopes, $\\k40$ is one of the most abundant and yet whose signatures are difficult to reject. Procedures were devised to measure trace potassium concentrations in the inorganic salt CsI as well as in organic liquid scintillator (LS) with Accelerator Mass Spectrometry (AMS), giving, respectively, the $\\k40$-contamination levels of $\\sim 10^{-10}$ and $\\sim 10^{-13}$ g/g. Measurement flexibilities and sensitivities are improved over conventional methods. The projected limiting sensitivities if no excess of potassium signals had been observed over background are $8 \\times 10^{-13}$ g/g and $3 \\times 10^{-17}$ g/g for the CsI and LS, respectively. Studies of the LS samples indicate that the radioactive contaminations come mainly in the dye solutes, while the base solvents are orders of magnitude cleaner. The work demonstrate the possibilities of measuring naturally-occurring isoto...

  6. Preparation of Plant 41Ca Tracer Samples for Accelerator Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    ZHAO Qing-zhang1;JANG Ping-ping3;LIN De-yu4;YANG Xian-lin1;DOU Liang1;PANG Yi-jun1;WANG Xiao-ming1;ZHANG Hui1,5;YANG Xu-ran1;WU Shao-yong1;GAO Dong-sheng2;LI Ling2;WANG Lei2;SUN Ke-peng2;ZHOU Jun2;DONG Ke-jun1;HE Ming1

    2016-11-01

    Full Text Available Calcium plays an important role in the metabolism of plants and animals. In this paper, the preparation method of plant 41Ca for accelerator mass spectrometry (AMS measurement was developed for the first time in China. AMS, with its advantages of high sensitivity, small dose of radioactivity, high accuracy, large measuring range, and long tracer cycle, can be used to measure cosmogenic nuclide 41Ca , which has long half-life. The intensity of the beam in ion source is an important parameter for the sensitivity of AMS measurement. The high beam current can improve the sensitivity of AMS. The preparation methods of plant samples of 41Ca tracer were systematically studied to obtain high beam current using wet, dry and a combining method with wet and dry re-fluoride. A reliable preparation procedure of plant samples for 41Ca tracer and its optimization parameters were determined by testing beam currents of various samples and lay a foundation for the 41Ca-AMS technology at plant tracer applications.

  7. Yeast dynamic metabolic flux measurement in nutrient-rich media by HPLC and accelerator mass spectrometry.

    Science.gov (United States)

    Stewart, Benjamin J; Navid, Ali; Turteltaub, Kenneth W; Bench, Graham

    2010-12-01

    Metabolic flux, the flow of metabolites through networks of enzymes, represents the dynamic productive output of cells. Improved understanding of intracellular metabolic fluxes will enable targeted manipulation of metabolic pathways of medical and industrial importance to a greater degree than is currently possible. Flux balance analysis (FBA) is a constraint-based approach to modeling metabolic fluxes, but its utility is limited by a lack of experimental measurements. Incorporation of experimentally measured fluxes as system constraints will significantly improve the overall accuracy of FBA. We applied a novel, two-tiered approach in the yeast Saccharomyces cerevisiae to measure nutrient consumption rates (extracellular fluxes) and a targeted intracellular flux using a (14)C-labeled precursor with HPLC separation and flux quantitation by accelerator mass spectrometry (AMS). The use of AMS to trace the intracellular fate of (14)C-glutamine allowed the calculation of intracellular metabolic flux through this pathway, with glutathione as the metabolic end point. Measured flux values provided global constraints for the yeast FBA model which reduced model uncertainty by more than 20%, proving the importance of additional constraints in improving the accuracy of model predictions and demonstrating the use of AMS to measure intracellular metabolic fluxes. Our results highlight the need to use intracellular fluxes to constrain the models. We show that inclusion of just one such measurement alone can reduce the average variability of model predicted fluxes by 10%.

  8. Ultrasensitive detection of inhaled organic aerosol particles by accelerator mass spectrometry.

    Science.gov (United States)

    Parkhomchuk, E V; Gulevich, D G; Taratayko, A I; Baklanov, A M; Selivanova, A V; Trubitsyna, T A; Voronova, I V; Kalinkin, P N; Okunev, A G; Rastigeev, S A; Reznikov, V A; Semeykina, V S; Sashkina, K A; Parkhomchuk, V V

    2016-09-01

    Accelerator mass spectrometry (AMS) was shown to be applicable for studying the penetration of organic aerosols, inhaled by laboratory mice at ultra-low concentration ca. 10(3) cm(-3). We synthesized polystyrene (PS) beads, composed of radiocarbon-labeled styrene, for testing them as model organic aerosols. As a source of radiocarbon we used methyl alcohol with radioactivity. Radiolabeled polystyrene beads were obtained by emulsifier-free emulsion polymerization of synthesized (14)C-styrene initiated by K2S2O8 in aqueous media. Aerosol particles were produced by pneumatic spraying of diluted (14)C-PS latex. Mice inhaled (14)C-PS aerosol consisting of the mix of 10(3) 225-nm particles per 1 cm(3) and 5·10(3) 25-nm particles per 1 cm(3) for 30 min every day during five days. Several millions of 225-nm particles deposited in the lungs and slowly excreted from them during two weeks of postexposure. Penetration of particles matter was also observed for liver, kidneys and brain, but not for a heart.

  9. Gas chromatograph-combustion system for 14C-accelerator mass spectrometry.

    Science.gov (United States)

    McIntyre, Cameron P; Sylva, Sean P; Roberts, Mark L

    2009-08-01

    A gas chromatograph-combustion (GC-C) system is described for the introduction of samples as CO(2) gas into a (14)C accelerator mass spectrometry (AMS) system with a microwave-plasma gas ion source. Samples are injected into a gas chromatograph fitted with a megabore capillary column that uses H(2) as the carrier gas. The gas stream from the outlet of the column is mixed with O(2) and Ar gas and passed through a combustion furnace where the H(2) carrier gas and separated components are quantitatively oxidized to CO(2) and H(2)O. Water vapor is removed using a heated nafion dryer. The Ar carries the CO(2) to the ion source. The system is able to separate and oxidize up to 10 microg of compound and transfer the products from 7.6 mL/min of H(2) carrier gas into 0.2-1.0 mL/min of Ar carrier gas. Chromatographic performance and isotopic fidelity satisfy the requirements of the (14)C-AMS system for natural abundance measurements. The system is a significant technical advance for GC-AMS and may be capable of providing an increase in sensitivity for other analytical systems such as an isotope-ratio-monitoring GC/MS.

  10. Applying accelerator mass spectrometry for low-level detection of complex engineered nanoparticles in biological media.

    Science.gov (United States)

    Wang, Binghui; Jackson, George S; Yokel, Robert A; Grulke, Eric A

    2014-08-01

    Complex engineered nanoparticles (CENPs), which have different core and surface components, are being developed for medicinal, pharmaceutical and industrial applications. One of the key challenges for environmental health and safety assessments of CENPs is to identify and quantity their transformations in biological environments. This study reports the effects of in vivo exposure of citrate-coated nanoalumina with different rare isotope labels on each component. This CENP was dosed to the rat and accelerator mass spectrometry (AMS) was used to quantify (26)Al, (14)C, and their ratio in the dosing material and tissue samples. For CENPs detected in the liver, the rare isotope ratio, (14)C/(26)Al, was 87% of the dosing material's ratio. The citrate coating on the nanoalumina in the liver was stable or, if it degraded, its metabolites were incorporated with nearby tissues. However, in brain and bone where little alumina was detected, the rare isotope ratio greatly exceeded that of the dosing material. Therefore, in the animal, citrate dissociated from CENPs and redistributed to brain and bone. Tracking both the core and surface components by AMS presents a new approach for characterizing transformations of CENPs components in biological milieu or environments.

  11. Accelerator mass spectrometry offers new opportunities for microdosing of peptide and protein pharmaceuticals.

    Science.gov (United States)

    Salehpour, Mehran; Ekblom, Jonas; Sabetsky, Vladimir; Håkansson, Karl; Possnert, Göran

    2010-05-30

    Accelerator Mass Spectrometry (AMS) is an ultra-sensitive analytical method which has been instrumental in developing microdosing as a strategic tool in early drug development. Considerable data is available for AMS microdosing using typical pharmaceutical drugs with a molecular weight of a few hundred Daltons. The so-called biopharmaceuticals such as proteins offer interesting possibilities as drug candidates; however, experimental data for protein microdosing and AMS is scarce. The analysis of proteins in conjunction with early drug development and microdosing is overviewed and three case studies are presented on the topic. In the first case study AMS experimental data is presented, for the measured concentration of orally administered recombinant insulin in the blood stream of laboratory rabbits. Case study 2 concerns minimum sample size requirements. AMS samples normally require about 1 mg of carbon (10 microL of blood) which makes AMS analysis unsuitable in some applications due to the limited availability of samples such as human biopsies or DNA from specific cells. Experimental results are presented where the sample size requirements have been reduced by about two orders of magnitude. The third case study concerns low concentration studies. It is generally accepted that protein pharmaceuticals may be potentially more hazardous than smaller molecules because of immunological reactions. Therefore, future first-in-man microdosing studies might require even lower exposure concentrations than is feasible today, in order to increase the safety margin. This issue is discussed based on the current available analytical capabilities.

  12. DNA isolation and sample preparation for quantification of adduct levels by accelerator mass spectrometry.

    Science.gov (United States)

    Dingley, Karen H; Ubick, Esther A; Vogel, John S; Ognibene, Ted J; Malfatti, Michael A; Kulp, Kristen; Haack, Kurt W

    2014-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels.

  13. Biological and biomedical (14)C-accelerator mass spectrometry and graphitization of carbonaceous samples.

    Science.gov (United States)

    Chung, Ill-Min; Kim, Seung-Hyun

    2013-06-21

    Accelerator mass spectrometry (AMS) is the ultimate technique for measuring rare isotopes in small samples. Biological and biomedical applications of (14)C-AMS (bio-(14)C-AMS) commenced in the early 1990s and are now widely used in many research fields including pharmacology, toxicology, food, and nutrition. For accurate, precise, and reproducible bio-(14)C-AMS analysis, the graphitization step in sample preparation is the most critical step. So, various sample preparation methods for a process called graphitization have been reported for specific applications. Catalytic graphitization using either a flame-sealed borosilicate tube or a septa-sealed vial is a popular sample preparation method for bio-(14)C-AMS. In this review, we introduce the AMS system, especially for bio-(14)C-AMS. In addition, we also review the graphitization method for bio-(14)C-AMS to promote further understanding and improvement of sample preparation for this technique. Examples of catalytic graphitization methods over the past two decades are described.

  14. Detection of Adriamycin-DNA adducts by accelerator mass spectrometry at clinically relevant Adriamycin concentrations.

    Science.gov (United States)

    Coldwell, Kate E; Cutts, Suzanne M; Ognibene, Ted J; Henderson, Paul T; Phillips, Don R

    2008-09-01

    Limited sensitivity of existing assays has prevented investigation of whether Adriamycin-DNA adducts are involved in the anti-tumour potential of Adriamycin. Previous detection has achieved a sensitivity of a few Adriamycin-DNA adducts/10(4) bp DNA, but has required the use of supra-clinical drug concentrations. This work sought to measure Adriamycin-DNA adducts at sub-micromolar doses using accelerator mass spectrometry (AMS), a technique with origins in geochemistry for radiocarbon dating. We have used conditions previously validated (by less sensitive decay counting) to extract [(14)C]Adriamycin-DNA adducts from cells and adapted the methodology to AMS detection. Here we show the first direct evidence of Adriamycin-DNA adducts at clinically-relevant Adriamycin concentrations. [(14)C]Adriamycin treatment (25 nM) resulted in 4.4 +/- 1.0 adducts/10(7) bp ( approximately 1300 adducts/cell) in MCF-7 breast cancer cells, representing the best sensitivity and precision reported to date for the covalent binding of Adriamycin to DNA. The exceedingly sensitive nature of AMS has enabled over three orders of magnitude increased sensitivity of Adriamycin-DNA adduct detection and revealed adduct formation within an hour of drug treatment. This method has been shown to be highly reproducible for the measurement of Adriamycin-DNA adducts in tumour cells in culture and can now be applied to the detection of these adducts in human tissues.

  15. Pharmacokinetic analysis of 14C-ursodiol in newborn infants using accelerator mass spectrometry.

    Science.gov (United States)

    Gordi, Toufigh; Baillie, Rebecca; Vuong, Le T; Abidi, Saira; Dueker, Stephen; Vasquez, Herbert; Pegis, Priscilla; Hopper, Andrew O; Power, Gordon G; Blood, Arlin B

    2014-09-01

    Pharmacokinetic studies in the neonatal population are often limited by the small volume of blood that can be collected. The high sensitivity of (14) C-accelerator mass spectrometry (AMS) enables pharmacokinetic studies to be conducted with greatly reduced sample volumes. We demonstrated the utility of AMS in infants by studying the plasma pharmacokinetic behavior of nanogram doses of (14) C-ursodiol administered as a non-perturbing microdose or as a microtracer with therapeutic doses of non-labeled ursodiol in infants. Five non-cholestatic infants were administered 3 consecutive oral microdoses of (14) C-ursodiol: 8 ng (1.0 nCi), 26 ng (3.3 nCi), and 80 ng (10 nCi) 48 hours apart. Three additional infants with cholestasis were administered a single 80 ng (10.0 nCi) oral dose of (14) C-ursodiol together with a therapeutic dose of 40 mg/kg of non-labeled ursodiol. A pharmacokinetic model describing ursodiol concentrations was developed using nonlinear mixed-effects modeling. The pharmacokinetics of ursodiol in this pilot study were best described by a two-compartment model with first-order elimination. This study demonstrates the feasibility and utility of microdose and microtrace methodology in pediatric research.

  16. Detection of long-lived plutonium isotopes in environmental samples by Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Gomez Guzman, Jose Manuel; Korschinek, Gunther; Ludwig, Peter [Technische Universitaet Muenchen (Germany); Shinonaga, Taeko [Helmholtz Zentrum Muenchen (Germany)

    2013-07-01

    The Plutonium isotopes {sup 239}Pu (T{sub 1/2}=2.4.10{sup 4}a), {sup 240}Pu (T{sub 1/2}=6.5.10{sup 3}a) and {sup 242}Pu (T{sub 1/2}=3.7.10{sup 5}a) are anthropogenic radionuclides emitted into the environment by nuclear activities. Pu is accumulated in the human body and hence, poses a considerable hazard to human health. Due to the long half-lives, these isotopes are present in the biosphere on large time scales and a build-up can be expected. Therefore it is important to study the contamination pathway of Pu into the drinking water. At the Maier-Leibnitz-Laboratory in Munich a method to detect long-lived Pu isotopes by Accelerator Mass Spectrometry (AMS) is being developed. AMS requires only few milligrams of sample material, which is a substantial advantage over decay counting techniques. Consequently, more samples from different locations can be taken which is essential when searching for locally increased Pu concentrations as in the Pacific Ocean after the Fukushima accident in March 2011. Samples from different locations in the Pacific Ocean and from the snow-hydrosphere are planned to be investigated by AMS. The principle detection method using AMS and an overview of the status of the project is presented.

  17. Kinetics of Beta-14[14C] Carotene in a Human Subject Using Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dueker, S.R.; Lin, Y.; Follett, J.R.; Clifford, A.J.; Buchholz, B.A.

    2000-01-31

    {beta}-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of {beta}-[{sup 14}C]carotene (200 nanoCuries; 0.57 {micro}mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed {beta}-carotene was lost slowly via urine in accord with the slow body turnover of {beta}-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between {beta}-carotene and retinyl esters (vitamin A) derived from intestinal metabolism.

  18. Accelerator mass spectrometry targets of submilligram carbonaceous samples using the high-throughput Zn reduction method.

    Science.gov (United States)

    Kim, Seung-Hyun; Kelly, Peter B; Clifford, Andrew J

    2009-07-15

    The high-throughput Zn reduction method was developed and optimized for various biological/biomedical accelerator mass spectrometry (AMS) applications of mg of C size samples. However, high levels of background carbon from the high-throughput Zn reduction method were not suitable for sub-mg of C size samples in environmental, geochronology, and biological/biomedical AMS applications. This study investigated the effect of background carbon mass (mc) and background 14C level (Fc) from the high-throughput Zn reduction method. Background mc was 0.011 mg of C and background Fc was 1.5445. Background subtraction, two-component mixing, and expanded formulas were used for background correction. All three formulas accurately corrected for backgrounds to 0.025 mg of C in the aerosol standard (NIST SRM 1648a). Only the background subtraction and the two-component mixing formulas accurately corrected for backgrounds to 0.1 mg of C in the IAEA-C6 and -C7 standards. After the background corrections, our high-throughput Zn reduction method was suitable for biological (diet)/biomedical (drug) and environmental (fine particulate matter) applications of sub-mg of C samples (> or = 0.1 mg of C) in keeping with a balance between throughput (270 samples/day/analyst) and sensitivity/accuracy/precision of AMS measurement. The development of a high-throughput method for examination of > or = 0.1 mg of C size samples opens up a range of applications for 14C AMS studies. While other methods do exist for > or = 0.1 mg of C size samples, the low throughput has made them cost prohibitive for many applications.

  19. A single dose mass balance study of the Hedgehog pathway inhibitor vismodegib (GDC-0449) in humans using accelerator mass spectrometry.

    Science.gov (United States)

    Graham, Richard A; Lum, Bert L; Morrison, Glenn; Chang, Ilsung; Jorga, Karin; Dean, Brian; Shin, Young G; Yue, Qin; Mulder, Teresa; Malhi, Vikram; Xie, Minli; Low, Jennifer A; Hop, Cornelis E C A

    2011-08-01

    Vismodegib (GDC-0449), a small-molecule Hedgehog pathway inhibitor, was well tolerated in patients with solid tumors and showed promising efficacy in advanced basal cell carcinoma in a Phase I trial. The purpose of the study presented here was to determine routes of elimination and the extent of vismodegib metabolism, including assessment and identification of metabolites in plasma, urine, and feces. Six healthy female subjects of nonchildbearing potential were enrolled; each received a single 30-ml oral suspension containing 150 mg of vismodegib with 6.5 μg of [(14)C]vismodegib to yield a radioactivity dose of approximately 37 kBq (1000 nCi). Plasma, urine, and feces samples were collected over 56 days to permit sample collection for up to 5 elimination half-lives. Nonradioactive vismodegib was measured in plasma using liquid chromatographic-tandem mass spectrometry, and total radioactivity in plasma, urine, and feces was measured using accelerator mass spectrometry. Vismodegib was slowly eliminated by a combination of metabolism and excretion of parent drug, most of which was recovered in feces. The estimated excretion of the administered dose was 86.6% on average, with 82.2 and 4.43% recovered in feces and urine, respectively. Vismodegib was predominant in plasma, with concentrations representing >98% of the total circulating drug-related components. Metabolic pathways of vismodegib in humans included oxidation, glucuronidation, and uncommon pyridine ring cleavage. We conclude that vismodegib and any associated metabolic products are mainly eliminated through feces after oral administration in healthy volunteers.

  20. Verification of the sputter-generated 32SFn- (n = 1-6) anions by accelerator mass spectrometry

    Science.gov (United States)

    Mane, R. G.; Surendran, P.; Kumar, Sanjay; Nair, J. P.; Yadav, M. L.; Hemalatha, M.; Thomas, R. G.; Mahata, K.; Kailas, S.; Gupta, A. K.

    2016-01-01

    Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase 32SFn- (n = 1-6) anions for all size 'n' can be readily generated from a variety of surfaces undergoing Cs+ ion sputtering in the presence of high purity SF6 gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio 34SFn-/32SFn- (n = 1-6) was found to be close to its natural abundance but not for all size 'n'. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant 32SFn- (n = 1-6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

  1. Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Leisvik, Mathias [Lund Univ. (Sweden)

    2001-08-01

    During the summer 2000, I was given the opportunity to work for about three months as a technical trainee at Lawrence Livermore National Laboratory, or LLNL as I will refer to it hereafter. University of California runs this Department of Energy laboratory, which is located 70 km east of San Francisco, in the small city of Livermore. This master thesis in Radioecology is based on the work I did here. LLNL, as a second U.S.-facility for development of nuclear weapons, was built in Livermore in the beginning of the 1950's (Los Alamos in New Mexico was the other one). It has since then also become a 'science center' for a number of areas like magnetic and laser fusion energy, non-nuclear energy, biomedicine, and environmental science. The Laboratory's mission has changed over the years to meet new national needs. The following two statements were found on the homepage of LLNL (http://www.llnl.gov), at 2001-03-05, where also information about the laboratory and the scientific projects that takes place there, can be found. 'Our primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable and to prevent the spread and use of nuclear weapons worldwide'. 'Our goal is to apply the best science and technology to enhance the security and well-being of the nation and to make the world a safer place.' The Marshall Islands Dose Assessment and Radioecology group at the Health and Ecological Assessments division employed me, and I also worked to some extent with the Centre for Accelerator Mass Spectrometry (CAMS) group. The work I did at LLNL can be divided into two parts. In the first part Plutonium (Pu) measurements in sediments from the Rongelap atoll in Marshall Islands, using Accelerator Mass Spectrometry (AMS) were done. The method for measuring these kinds of samples is well understood at LLNL since soil samples have been measured with AMS for Pu in the past. Therefore it was the results that

  2. Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry.

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-08-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

  3. The earliest archaeological maize (Zea mays L.) from highland Mexico: New accelerator mass spectrometry dates and their implications

    OpenAIRE

    Piperno, D.R.; Flannery, K. V.

    2001-01-01

    Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, to...

  4. Biobased carbon content of resin extracted from polyethylene composite by carbon-14 concentration measurements using accelerator mass spectrometry

    OpenAIRE

    Taguchi, Kazuhiro; Kunioka, Masao; Funabashi, Masahiro; Ninomiya, Fumi

    2014-01-01

    An estimation procedure for biobased carbon content of polyethylene composite was studied using carbon-14 (14C) concentration ratios as measured by accelerated mass spectrometry (AMS). Prior to the measurement, additives and fillers in composites should be removed because they often contain a large amount of biobased carbon and may shift the estimation. Samples of resin with purity suitable for measurement were isolated from composites with a Soxhlet extractor using heated cyclohexanone. Afte...

  5. Calcium Isolation from Large-Volume Human Urine Samples for 41Ca Analysis by Accelerator Mass Spectrometry

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-01-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for 41Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after 41Ca administration during which human samples, collected over a lifetime, provide 41Ca:Ca ratios that are significantly above background. PMID:23672965

  6. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range.

    Science.gov (United States)

    van Duijn, Esther; Sandman, Hugo; Grossouw, Dimitri; Mocking, Johannes A J; Coulier, Leon; Vaes, Wouter H J

    2014-08-05

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. Here, we describe the combination of automated sample combustion with an elemental analyzer (EA) online coupled to an AMS via a dedicated interface. This setup allows direct radiocarbon measurements for over 70 samples daily by AMS. No sample processing is required apart from the pipetting of the sample into a tin foil cup, which is placed in the carousel of the EA. In our system, up to 200 AMS analyses are performed automatically without the need for manual interventions. We present results on the direct total (14)C count measurements in <2 μL human plasma samples. The method shows linearity over a range of 0.65-821 mBq/mL, with a lower limit of quantification of 0.65 mBq/mL (corresponding to 0.67 amol for acetaminophen). At these extremely low levels of activity, it becomes important to quantify plasma specific carbon percentages. This carbon percentage is automatically generated upon combustion of a sample on the EA. Apparent advantages of the present approach include complete omission of sample preparation (reduced hands-on time) and fully automated sample analysis. These improvements clearly stimulate the standard incorporation of microtracer research in the drug development process. In combination with the particularly low sample volumes required and extreme sensitivity, AMS strongly improves its position as a bioanalysis method.

  7. Disposition and metabolic profiling of [(14)C]cerlapirdine using accelerator mass spectrometry.

    Science.gov (United States)

    Tse, Susanna; Leung, Louis; Raje, Sangeeta; Seymour, Mark; Shishikura, Yoko; Obach, R Scott

    2014-12-01

    Cerlapirdine (SAM-531, PF-05212365) is a selective, potent, full antagonist of the 5-hydroxytryptamine 6 (5-HT6) receptor. Cerlapirdine and other 5-HT6 receptor antagonists have been in clinical development for the symptomatic treatment of Alzheimer's disease. A human absorption, distribution, metabolism, and excretion study was conducted to gain further understanding of the metabolism and disposition of cerlapirdine. Because of the low amount of radioactivity administered, total (14)C content and metabolic profiles in plasma, urine, and feces were determined using accelerator mass spectrometry (AMS). After a single, oral 5-mg dose of [(14)C]cerlapirdine (177 nCi), recovery of total (14)C was almost complete, with feces being the major route of elimination of the administered dose, whereas urinary excretion played a lesser role. The extent of absorption was estimated to be at least 70%. Metabolite profiling in pooled plasma samples showed that unchanged cerlapirdine was the major drug-related component in circulation, representing 51% of total (14)C exposure in plasma. One metabolite (M1, desmethylcerlapirdine) was detected in plasma, and represented 9% of the total (14)C exposure. In vitro cytochrome P450 reaction phenotyping studies showed that M1 was formed primarily by CYP2C8 and CYP3A4. In pooled urine samples, three major drug-related peaks were detected, corresponding to cerlapirdine-N-oxide (M3), cerlapirdine, and desmethylcerlapirdine. In feces, cerlapirdine was the major (14)C component excreted, followed by desmethylcerlapirdine. The results of this study demonstrate that the use of the AMS technique enables comprehensive quantitative elucidation of the disposition and metabolic profiles of compounds administered at a low radioactive dose.

  8. Application of accelerator mass spectrometry to macromolecules: preclinical pharmacokinetic studies on a polybisphosphonate.

    Science.gov (United States)

    Salehpour, Mehran; Håkansson, Karl; Höglund, Urban; Grahn-Westin, Annika; Nilsson, Sten; Márquez, Marcela; Possnert, Göran; Holmberg, Anders R

    2011-09-15

    Data on the use of accelerator mass spectrometry (AMS) in conjunction with in vivo studies of macromolecular drugs are scarce. The present study shows the versatility of this technique when investigating the pharmacokinetics (PK) of a macromolecular drug candidate, a polybisphosphonate conjugate (ODX). The aforementioned is a polymer (molecular weight ~30 kDa) constituting a carbohydrate backbone with covalently linked ligands (aldendronate and aminoguanidine) and is intended for treatment of osteoporosis and the therapy of bone metastasis from prostate cancer. The conjugate is prepared through partial oxidation of the carbohydrate and sequential coupling of the ligands by reductive amination. (14)C was incorporated in the conjugate by means of coupling a commercially available (14)C-lysine in the conjugation sequence. Fifteen rats were injected intravenously with (14)C-labelled ODX (150 µg, 14 Bq/rat) and blood samples were collected at 1, 2, 4, 6, and 24 h post-injection (3 rats/time point). Liver, spleen and kidney samples were collected at 4 and 24 h post-injection. Blood from each time point (triplicate) were collected for AMS measurement determining the isotopic ratio ((14)C/(12)C) and consequently the drug concentration in blood. ODX showed a transient presence in blood circulation; 93% of the total dose was cleared from the circulation within 1 h. The half-life after 1 h was estimated to be about 3 h; 0.7% of the administered (14)C dose of ODX remained in circulation after 24 h. The major (14)C accumulation was in the liver, the spleen and the kidneys indicating the probable route of metabolism and excretion. This study demonstrates the versatility of AMS for pharmacological in vivo studies of macromolecules. Labelling with (14)C is relatively simple, inexpensive and the method requires minimal radioactivity, eliminating the need for radioprotection precautions in contrast to methods using scintillation counting.

  9. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    Energy Technology Data Exchange (ETDEWEB)

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  10. Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    DeGregorio, M W; Dingley, K H; Wurz, G T; Ubick, E; Turteltaub, K W

    2005-04-12

    Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as {sup 14}C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining cellular [{sup 14}C]doxorubicin (DOX) concentrations and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of DOX at the tumor level. In order to validate the superior sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular DOX content up to 4 hours following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 {micro}g/ml (3.45 {micro}M) [{sup 14}C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, DOX was administered intravenously at two dose levels. Additionally, we tested the AMS method in a nude mouse xenograft model of multidrug resistance (MDR) in which each mouse was implanted with both wild type and MDR+ cells on opposite flanks. The results of the second and third studies showed that DOX concentrations were significantly higher in the wild type tumors compared to the MDR+ tumors, consistent with the MDR model. The extreme sensitivity of AMS should facilitate similar studies in humans to establish target site drug delivery and to potentially determine the optimal treatment dose and regimen.

  11. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Science.gov (United States)

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  12. Zoom-TOFMS: addition of a constant-momentum-acceleration "zoom" mode to time-of-flight mass spectrometry.

    Science.gov (United States)

    Dennis, Elise A; Gundlach-Graham, Alexander W; Ray, Steven J; Enke, Christie G; Barinaga, Charles J; Koppenaal, David W; Hieftje, Gary M

    2014-11-01

    In this study, we demonstrate the performance of a new mass spectrometry concept called zoom time-of-flight mass spectrometry (zoom-TOFMS). In our zoom-TOFMS instrument, we combine two complementary types of TOFMS: conventional, constant-energy acceleration (CEA) TOFMS and constant-momentum acceleration (CMA) TOFMS to provide complete mass-spectral coverage as well as enhanced resolution and duty factor for a narrow, targeted mass region, respectively. Alternation between CEA- and CMA-TOFMS requires only that electrostatic instrument settings (i.e., reflectron and ion optics) and ion acceleration conditions be changed. The prototype zoom-TOFMS instrument has orthogonal-acceleration geometry, a total field-free distance of 43 cm, and a direct-current glow-discharge ionization source. Experimental results demonstrate that the CMA-TOFMS "zoom" mode offers resolution enhancement of 1.6 times over single-stage acceleration CEA-TOFMS. For the atomic mass range studied here, the maximum resolving power at full-width half-maximum observed for CEA-TOFMS was 1,610 and for CMA-TOFMS the maximum was 2,550. No difference in signal-to-noise (S/N) ratio was observed between the operating modes of zoom-TOFMS when both were operated at equivalent repetition rates. For a 10-kHz repetition rate, S/N values for CEA-TOFMS varied from 45 to 990 and from 67 to 10,000 for CMA-TOFMS. This resolution improvement is the result of a linear TOF-to-mass scale and the energy-focusing capability of CMA-TOFMS. Use of CMA also allows ions outside a given m/z range to be rejected by simple ion-energy barriers to provide a substantial improvement in duty factor.

  13. Rapid revelation of radiocarbon records with laser ablation Accelerator Mass Spectrometry.

    Science.gov (United States)

    Münsterer, Caroline; Wacker, Lukas; Hattendorf, Bodo; Christl, Marcus; Koch, Joachim; Dietiker, Rolf; Synal, Hans-Arno; Günther, Detlef

    2014-01-01

    By focusing high-intensity laser pulses on carbonate samples carbon dioxide is generated and can be directly introduced into the gas ion source (GIS) of an Accelerator Mass Spectrometer (AMS). This new technique allows rapid radiocarbon analyses at high spatial resolution. The design of the deignated laser ablation cell as well as first results on a stalagmite sample are presented.

  14. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway.

    Science.gov (United States)

    Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L; Turteltaub, Kenneth W; Newman, Lee S

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) than HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  15. A safer method for studying hormone metabolism in an Asian elephant (Elephas maximus): accelerator mass spectrometry.

    Science.gov (United States)

    Yon, Lisa; Faulkner, Brian; Kanchanapangka, Sumolya; Chaiyabutr, Narongsak; Meepan, Sompast; Lasley, Bill

    2010-01-01

    Noninvasive hormone assays provide a way to determine an animal's health or reproductive status without the need for physical or chemical restraint, both of which create unnecessary stress for the animal, and can potentially alter the hormones being measured. Because hormone metabolism is highly species-specific, each assay must be validated for use in the species of interest. Validation of noninvasive steroid hormone assays has traditionally required the administration of relatively high doses of radiolabelled compounds (100 µCi or more of (14)C labeled hormone) to permit subsequent detection of the excreted metabolites in the urine and feces. Accelerator mass spectrometry (AMS) is sensitive to extremely low levels of rare isotopes such as (14)C, and provides a way to validate hormone assays using much lower levels of radioactivity than those traditionally employed. A captive Asian bull elephant was given 1 µCi of (14)C-testosterone intravenously, and an opportunistic urine sample was collected 2 hr after the injection. The sample was separated by HPLC and the (14)C in the fractions was detected by AMS to characterize the metabolites present in the urine. A previously established HPLC protocol was used, which permitted the identification of fractions into which testosterone sulfate, testosterone glucuronide, and the parent compound testosterone elute. Results from this study indicate that the majority of testosterone excreted in the urine of the Asian bull elephant is in the form of testosterone sulfate. A small amount of testosterone glucuronide is also excreted, but there is no parent compound present in the urine at all. These results underscore the need for enzymatic hydrolysis to prepare urine samples for hormone assay measurement. Furthermore, they highlight the importance of proper hormone assay validation in order to ensure accurate measurement of the desired hormone. Although this study demonstrated the utility of AMS for safer validation of

  16. Accelerator mass spectrometry measurement of intracellular concentrations of active drug metabolites in human target cells in vivo.

    Science.gov (United States)

    Chen, J; Garner, R C; Lee, L S; Seymour, M; Fuchs, E J; Hubbard, W C; Parsons, T L; Pakes, G E; Fletcher, C V; Flexner, C

    2010-12-01

    Accelerator mass spectrometry (AMS) is an ultrasensitive technique to detect radiolabeled compounds. We administered a microdose (100 µg) of (14)C-labeled zidovudine (ZDV) with or without a standard unlabeled dose (300 mg) to healthy volunteers. Intracellular ZDV-triphosphate (ZDV-TP) concentration was measured using AMS and liquid chromatography-tandem mass spectrometry (LC/MS/MS). AMS analysis yielded excellent concordance with LC/MS/MS and was 30,000-fold more sensitive. The kinetics of intracellular ZDV-TP formation changed several-fold over the dose range studied (100 µg-300 mg). AMS holds promise as a tool for quantifying intracellular drug metabolites and other biomediators in vivo.

  17. A multi-sample changer coupled to an electron cyclotron resonance source for accelerator mass spectrometry experiments.

    Science.gov (United States)

    Vondrasek, R; Palchan, T; Pardo, R; Peters, C; Power, M; Scott, R

    2014-02-01

    A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving between samples in 1 min. The sample changer is part of a project using Accelerator Mass Spectrometry (AMS) at the Argonne Tandem Linac Accelerator System (ATLAS) facility to measure neutron capture rates on a wide range of actinides in a reactor environment. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly charged positive ions in an electron cyclotron resonance ion source followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation chosen to limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples.

  18. Ultra-trace analysis of (41)Ca in urine by accelerator mass spectrometry: an inter-laboratory comparison.

    Science.gov (United States)

    Jackson, George S; Hillegonds, Darren J; Muzikar, Paul; Goehring, Brent

    2013-10-15

    A (41)Ca interlaboratory comparison between Lawrence Livermore National Laboratory (LLNL) and the Purdue Rare Isotope Laboratory (PRIME Lab) has been completed. Analysis of the ratios assayed by accelerator mass spectrometry (AMS) shows that there is no statistically significant difference in the ratios. Further, Bayesian analysis shows that the uncertainties reported by both facilities are correct with the possibility of a slight under-estimation by one laboratory. Finally, the chemistry procedures used by the two facilities to produce CaF2 for the cesium sputter ion source are robust and don't yield any significant differences in the final result.

  19. Determining the pharmacokinetics and long-term biodistribution of SiO2 nanoparticles in vivo using accelerator mass spectrometry.

    Science.gov (United States)

    Malfatti, Michael A; Palko, Heather A; Kuhn, Edward A; Turteltaub, Kenneth W

    2012-11-14

    Biodistribution is an important factor in better understanding silica dioxide nanoparticle (SiNP) safety. Currently, comprehensive studies on biodistribution are lacking, most likely due to the lack of suitable analytical methods. Accelerator mass spectrometry was used to investigate the relationship between administered dose, pharmacokinetics (PK), and long-term biodistribution of (14)C-SiNPs in vivo. PK analysis showed that SiNPs were rapidly cleared from the central compartment, were distributed to tissues of the reticuloendothelial system, and persisted in the tissue over the 8 week time course, raising questions about the potential for bioaccumulation and associated long-term effects.

  20. Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

    OpenAIRE

    Kim, Seung-Hyun; Kelly, Peter B.; Ortalan, Volkan; Browning, Nigel D.; Clifford, Andrew J.

    2010-01-01

    Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target ...

  1. C-14 content of ten meteorites measured by tandem accelerator mass spectrometry

    Science.gov (United States)

    Brown, R. M.; Andrews, H. R.; Ball, G. C.; Burn, N.; Imahori, Y.; Milton, J. C. D.; Fireman, E. L.

    1984-01-01

    Measurements of C-14 in three North American and seven Antarctic meteorites show in most cases that this cosmogenic isotope, which is tightly bound, was separated from absorbed atmospheric radiocarbon by stepwise heating extractions. The present upper limit to age determination by the accelerator method varies from 50,000 to 70,000 years, depending on the mass and carbon content of the sample. The natural limit caused by cosmic ray production of C-14 in silicate rocks at 2000 m elevation is estimated to be 55,000 + or - 5000 years. An estimation is also made of the 'weathering ages' of the Antarctic meteorites from the specific activity of loosely bound CO2 which is thought to be absorbed from the terrestrial atmosphere. Accelerator measurements are found to agree with previous low level counting measurements, but are more sensitive and precise.

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

    Science.gov (United States)

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

    2013-04-02

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

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per;

    2013-01-01

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement...... show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging...... time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu...

  5. Measurement of Trace $^{129}I$ Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry

    CERN Document Server

    Dong, K J

    2007-01-01

    Levels of trace radiopurity in active detector materials is a subject of major concern in low-background experiments. Procedures were devised to measure trace concentrations of I-129 in the inorganic salt CsI as well as in organic liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to improvement in sensitivities by several orders of magnitude over other methods. No evidence of their existence in these materials were observed. Limits of < 6 X 10^{-13} g/g and < 2.6 X 10^{-17} g/g on the contaminations of I-129 in CsI and liquid scintillator, respectively, were derived.These are the first results in a research program whose goals are to develop techniques to measure trace radioactivity in detector materials by AMS.

  6. Accurate determination of ⁴¹Ca concentrations in spent resins from the nuclear industry by accelerator mass spectrometry.

    Science.gov (United States)

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

    2013-12-01

    The radiological characterisation of nuclear waste is essential for managing storage sites. Determining the concentration of Long-Lived RadioNuclides (LLRN) is fundamental for their long-term management. This paper focuses on the measurement of low (41)Ca concentrations in ions exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). (41)Ca concentrations were successfully measured by Accelerator Mass Spectrometry (AMS) after the acid digestion of resin samples, followed by radioactive decontamination and isobaric suppression through successive hydroxide, carbonate, nitrate and final CaF2 precipitations. Measured (41)Ca concentrations ranged from 0.02 to 0.03 ng/g, i.e. from 0.06 to 0.09 Bq/g. The (41)Ca/(60)Co activity ratios obtained were remarkably reproducible and in good agreement with the current ratio used for resins management.

  7. The earliest archaeological maize (Zea mays L.) from highland Mexico: new accelerator mass spectrometry dates and their implications.

    Science.gov (United States)

    Piperno, D R; Flannery, K V

    2001-02-13

    Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize.

  8. Precise measurement of the thermal and stellar 54Fe(n ,γ )55Fe cross sections via accelerator mass spectrometry

    Science.gov (United States)

    Wallner, A.; Buczak, K.; Belgya, T.; Bichler, M.; Coquard, L.; Dillmann, I.; Golser, R.; Käppeler, F.; Karakas, A.; Kutschera, W.; Lederer, C.; Mengoni, A.; Pignatari, M.; Priller, A.; Reifarth, R.; Steier, P.; Szentmiklosi, L.

    2017-08-01

    Accelerator mass spectrometry (AMS) represents a complementary approach for precise measurements of neutron capture cross sections, e.g., for nuclear astrophysics. This technique, completely independent of previous experimental methods, was applied for the measurement of the 54Fe(n ,γ )55Fe reaction. Following a series of irradiations with neutrons from cold and thermal to keV energies, the produced long-lived 55Fe nuclei (t1 /2=2.744 +-0.009 ) yr) were analyzed at the Vienna Environmental Research Accelerator. A reproducibility of about 1% could be achieved for the detection of 55Fe, yielding cross-section uncertainties of less than 3%. Thus, this method produces new and precise data that can serve as anchor points for time-of-flight experiments. We report significantly improved neutron capture cross sections at thermal energy (σth=2.30 ±0.07 b) as well as for a quasi-Maxwellian spectrum of k T =25 keV (σ =30.3 ±1.2 mb) and for En=481 ±53 keV (σ =6.01 ±0.23 mb). The new experimental cross sections have been used to deduce improved Maxwellian-averaged cross sections in the temperature regime of the common s -process scenarios. The astrophysical impact is discussed by using stellar models for low-mass asymptotic giant branch stars.

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

    Science.gov (United States)

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

    1984-01-01

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

  10. Thermally Accelerated Oxidative Degradation of Quercetin Using Continuous Flow Kinetic Electrospray-Ion Trap-Time of Flight Mass Spectrometry

    Science.gov (United States)

    Barnes, Jeremy S.; Foss, Frank W.; Schug, Kevin A.

    2013-10-01

    Thermally accelerated oxidative degradation of aqueous quercetin at pH 5.9 and 7.4 was kinetically measured using an in-house built online continuous flow device made of concentric capillary tubes, modified to fit to the inlet of an electrospray ionization-ion trap-time-of-flight-mass spectrometer (ESI-IT-TOF-MS). Time-resolved mass spectral measurements ranging from 2 to 21 min were performed in the negative mode to track intermediate degradation products and to evaluate the degradation rate of the deprotonated quercetin ion, [Q-H]-. Upon heating solutions in the presence of dissolved oxygen, degradation of [Q-H]- was observed and was accelerated by an increase in pH and temperature. Regardless of the condition, the same degradation pathways were observed. Degradation mechanisms and structures were determined using higher order tandem mass spectrometry (up to MS3) and high mass accuracy. The observed degradation mechanisms included oxidation, hydroxylation, and ring-cleavage by nucleophilic attack. A chalcan-trione structure formed by C-ring opening after hydroxylation at C2 was believed to be a precursor for other degradation products, formed by hydroxylation at the C2, C3, and C4 carbons from attack by nucleophilic species. This resulted in A-type and B-type ions after cross-ring cleavage of the C-ring. Based on time of appearance and signal intensity, nucleophilic attack at C3 was the preferred degradation pathway, which generated 2,4,6-trihydroxymandelate and 2,4,6-trihydroxyphenylglyoxylate ions. Overall, 23 quercetin-related ions were observed.

  11. Use of accelerator mass spectrometry to measure the pharmacokinetics and peripheral blood mononuclear cell concentrations of zidovudine.

    Science.gov (United States)

    Vuong, Le T; Ruckle, Jon L; Blood, Arlin B; Reid, Michael J; Wasnich, Richard D; Synal, Hans-Arno; Dueker, Stephen R

    2008-07-01

    The remarkable sensitivity of accelerator mass spectrometry (AMS) is finding many new applications in pharmacology. In this study AMS was used to measure [(14)C]-Zidovudine (ZDV) concentrations at the drug's site of action (peripheral blood mononuclear cells, PBMCs) following a dose of 520 ng (less than one-millionth of the standard daily dose) to a healthy volunteer. In addition, the pharmacokinetics of this microdose were determined and compared to previously published parameters for therapeutic doses. Microdose ZDV pharmacokinetic parameters fell within reported 95% confidence intervals or standard deviations of most previously published values for therapeutic doses. Blood, urine, stool, saliva, and isolated PBMCs were collected periodically through 96 h postdose and analyzed for ZDV and metabolite concentrations. The results showed that ZDV is rapidly absorbed and eliminated, has one major metabolite, and is sequestered in PBMCs. (14)C mass balance assessments indicated a significant portion of ZDV remained after 96 h with a much prolonged elimination half-life. Results of this study demonstrate the usefulness of microdosing and AMS as a tool for studying the pharmacokinetic characteristics, including PBMC concentrations, of ZDV and underscore the value of AMS as a tool with which to perform pharmacokinetic and mass balance studies using trace amounts of radiolabeled compound.

  12. Ultra-High Sensitivity Techniques for the Determination of 3 He /4 He Abundances in Helium by Accelerator Mass Spectrometry

    Science.gov (United States)

    Mumm, H. P.; Huber, M.; Bauder, W.; Abrams, N.; Deibel, C.; Huffer, C.; Huffman, P.; Schelhammer, K.; Janssens, R.; Jiang, C.; Scott, R.; Pardo, R.; Rehm, K.; Vondrasek, R.; Swank, C.; O'Shaughnessy, C.; Paul, M.; Yang, L.

    2017-01-01

    We report the development of an Accelerator Mass Spectrometry technique to measure the 3He/4He isotopic ratio using a radio frequency (RF) discharge source and the ATLAS facility at Argonne National Laboratory. Control over 3He/4He ratio in helium several orders of magnitude lower than natural abundance is critical for neutron lifetime and source experiments using liquid helium. Due to low ultimate beam currents, the ATLAS accelerator and beam line were tuned using a succession of species of the same M/q. A unique RF source was developed for the experiment due to large natural 3He backgrounds. Analog H_3 + and DH + molecular ions are eliminated by dissociation via a gold stripper foil near the detector. The stripped ions were dispersed in a magnetic spectrograph and 3He2 + ions counted in the focal plane detector. This technique is sensitive to 3 He /4 He ratios in the regime of 10-12 with backgrounds that appear to be below 10-14. The techniques used to reduce the backgrounds and remaining outstanding problems will be presented along with results from measurements on high purity 4He samples.

  13. Calorimetric low temperature detectors for low-energetic heavy ions and their application in accelerator mass spectrometry.

    Science.gov (United States)

    Kraft-Bermuth, S; Andrianov, V A; Bleile, A; Echler, A; Egelhof, P; Kiseleva, A; Kiselev, O; Meier, H J; Meier, J P; Shrivastava, A; Weber, M; Golser, R; Kutschera, W; Priller, A; Steier, P; Vockenhuber, C

    2009-10-01

    The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E=0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T approximately 1.5 K. They were irradiated with various ion beams (13C, 197Au, 238U) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was DeltaE/E=(5-9) x 10(-3), even for the heaviest ions such as 238U. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of 236U/238U for several samples of natural uranium, 236U being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of 236U/238U=6.1 x 10(-12) could be obtained, representing the smallest 236U/238U ratio measured at the time. In addition, we contributed to establishing an improved material standard of 236U/238U, which can be used as a reference for future AMS measurements.

  14. Calorimetric low temperature detectors for low-energetic heavy ions and their application in accelerator mass spectrometry

    Science.gov (United States)

    Kraft-Bermuth, S.; Andrianov, V. A.; Bleile, A.; Echler, A.; Egelhof, P.; Kiseleva, A.; Kiselev, O.; Meier, H. J.; Meier, J. P.; Shrivastava, A.; Weber, M.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.; Vockenhuber, C.

    2009-10-01

    The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E =0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T ˜1.5 K. They were irradiated with various ion beams (C13,A197u,U238) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was ΔE /E=(5-9)×10-3, even for the heaviest ions such as U238. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of U236/U238 for several samples of natural uranium, U236 being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of U236/U238=6.1×10-12 could be obtained, representing the smallest U236/U238 ratio measured at the time. In addition, we contributed to establishing an improved material standard of U236/U238, which can be used as a reference for future AMS measurements.

  15. Accelerator mass spectrometry in pharmaceutical research and development--a new ultrasensitive analytical method for isotope measurement.

    Science.gov (United States)

    Garner, R C

    2000-09-01

    Accelerator mass spectrometry (AMS) permits the measurement of elemental isotopes at the individual atom level. The main application of AMS in drug discovery and development will be in the analysis of 14-carbon (14C). The principle behind AMS is the separation of individual positively charged atoms through mass, charge and momentum differences. In order to obtain the high-energy charge state required for separation, negative atoms are accelerated through a high voltage field (up to 10 million volts) generated by a tandem Van de Graaff accelerator. In the middle of the accelerator, the outer valency electrons are stripped from the atom and the resulting charged species are separated and counted. For 14C, AMS counts the number of individual atoms rather than measuring radioactive decays. The result is that AMS is up to one million times more sensitive than decay counting. Radioactivity levels as low 0.0001 dpm can be detected using AMS. The exquisite sensitivity of AMS analysis means that much lower amounts of 14C can be used than for conventional counting methods. This makes it easier to use 14C for in vitro, preclinical and clinical research programmes. As 14C poses both a biological and environmental hazard, AMS permits much lower doses to be used. Human drug mass balance studies have been conducted with doses of 50 nanoCuries and below. Radioactive HPLC metabolite profiles of plasma extracts from subjects given nanoCurie doses of 14C-labelled drug have been obtained by injecting as little as 0.25 dpm onto an HPLC column. In studies of biologics, biosynthetically 14C-labelled recombinant protein has been produced with a specific radioactivity sufficient to conduct human clinical studies with AMS analysis. For one human recombinant protein an increase in sensitivity of 2,000-fold over ELISA was obtained with AMS measurement. AMS is an enabling technology that should prove of value in increasing human and environmental safety as well as allowing new research

  16. {sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

    1999-03-01

    The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  17. State and Perspectives of the Center for Collective Use «Accelerated Mass Spectrometry» of the Institute of Applied Physics

    Directory of Open Access Journals (Sweden)

    Moskalenko, V.B.

    2014-03-01

    Full Text Available The paper discusses the development of the Center for collective use device «Accelerated Mass Spectrometry» IAP NASU. The results of the first experiments on the dating of some archaeological samples is presented. The main tasks aimed at further development of the Center are given.

  18. The André E. Lalonde AMS Laboratory – The new accelerator mass spectrometry facility at the University of Ottawa

    Energy Technology Data Exchange (ETDEWEB)

    Kieser, W.E., E-mail: liam.kieser@uottawa.ca [University of Ottawa, Dept. of Physics and A. E. Lalonde Lab, 25 Templeton St., Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L. [University of Ottawa, Dept. of Physics and A. E. Lalonde Lab, 25 Templeton St., Ottawa, ON K1N 6N5 (Canada); Clark, I.D.; Cornett, R.J. [University of Ottawa, Dept. of Earth Sciences and A. E. Lalonde Lab, 25 Templeton St., Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [University of Toronto, Dept. of Physics, 60 St. George St., Toronto, ON M5S 1A7 (Canada); Klein, M.; Mous, D.J.W. [High Voltage Engineering Europa B.V., 3800 AB Amersfoort (Netherlands); Alary, J.-F. [Isobarex Corp., 32 Nixon Road, Unit 1, Bolton, ON L7E 1W2 (Canada)

    2015-10-15

    The University of Ottawa, Canada, has installed a multi-element, 3 MV tandem AMS system as the cornerstone of their new Advanced Research Complex and the principal analytical instrument of the André E. Lalonde Accelerator Mass Spectrometry Laboratory. Manufactured by High Voltage Engineering Europa B.V., the Netherlands, it is equipped with a 200 sample ion source, a high resolution, 120° injection magnet, a 90° high energy analysis magnet (mass-energy product 350 MeV-AMU), a 65°, 1.7 m radius electric analyzer and a 2 channel gas ionization detector. It is designed to analyze isotopes ranging from tritium to the actinides and to accommodate the use of fluoride target materials. This system is being extended with a second injection line, consisting of selected components from the IsoTrace Laboratory, University of Toronto. This line will contain a pre-commercial version of the Isobar Separator for Anions, manufactured by Isobarex Corp., Bolton, Ontario, Canada. This instrument uses selective ion–gas reactions in a radio-frequency quadrupole cell to attenuate both atomic and molecular isobars. This paper discusses the specifications of the new AMS equipment, reports on the acceptance test results for {sup 10}Be, {sup 14}C, {sup 26}Al and {sup 127}I and presents typical spectra for {sup 10}Be and actinide analyses.

  19. Biobased carbon content of resin extracted from polyethylene composite by carbon-14 concentration measurements using accelerator mass spectrometry.

    Science.gov (United States)

    Taguchi, Kazuhiro; Kunioka, Masao; Funabashi, Masahiro; Ninomiya, Fumi

    2014-01-01

    An estimation procedure for biobased carbon content of polyethylene composite was studied using carbon-14 ((14)C) concentration ratios as measured by accelerated mass spectrometry (AMS). Prior to the measurement, additives and fillers in composites should be removed because they often contain a large amount of biobased carbon and may shift the estimation. Samples of resin with purity suitable for measurement were isolated from composites with a Soxhlet extractor using heated cyclohexanone. After cooling of extraction solutions, the resin was recovered as a fine semi-crystalline precipitate, which was easily filtered. Recovery rates were almost identical (99%), even for low-density polyethylene and linear low-density polyethylene, which may have lower crystallinity. This procedure could provide a suitable approach for estimation of biobased carbon content by AMS on the basis of the standard ASTM D 6866. The biobased carbon content for resin extracted from polyethylene composites allow for the calculation of biosynthetic polymer content, which is an indicator of mass percentage of the biobased plastic resin in the composite.

  20. Measurement of {sup 59}Ni and {sup 63}Ni by accelerator mass spectrometry at CIAE

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoming [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); He, Ming, E-mail: minghe@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Ruan, Xiangdong [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Xu, Yongning [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Shen, Hongtao [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Lan, Xiaoxi [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Wu, Shaoyong; Zhao, Qingzhang [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Cai, Li [College of Physics and Technology, Guangxi University, Nanning 530004 (China); Pang, Fangfang [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China)

    2015-10-15

    The long lived isotopes {sup 59}Ni and {sup 63}Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for {sup 59}Ni and {sup 63}Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of {sup 59}Ni and {sup 63}Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of {sup 59}Ni and {sup 63}Ni measurements are determined as {sup 59}Ni/Ni = 1 × 10{sup −13} and {sup 63}Ni/Ni = 2 × 10{sup −12}, respectively.

  1. New frontiers-accelerator mass spectrometry (AMS): Recommendation for best practices and harmonization from Global Bioanalysis Consortium Harmonization Team.

    Science.gov (United States)

    Young, Graeme C; Seymour, Mark; Dueker, Stephen R; Timmerman, Philip; Arjomand, Ali; Nozawa, Kohei

    2014-03-01

    The technique of accelerator mass spectrometry (AMS) is applicable to the analysis of a wide range of trace elemental isotopes. However, in the context of the pharmaceutical industry, it is invariably used to measure radiocarbon ((14)C). There are two broad modes of application: analysis of total (14)C sometimes termed "direct AMS" and analysis of specific (14)C-labelled analytes in a variety of matrices following some method of isolation. It is the latter application which is within the remit of the GBC team, and the team has made efforts to propose harmonized recommendations for the validation of AMS when used in a regulatory bioanalytical mode, i.e. the quantification of specific analyte(s) using liquid chromatography with off-line detection by AMS now known as "LC + AMS". The GBC team has reached a position where they have agreed to many aspects, but also differ on some aspects of what constitutes a bioanalytical assay validation in support of clinical studies using this technology. The detail of most of this will be covered under separate publication(s), but for the purposes of this paper, we have outlined the points of consensus. The purpose of this article is not to provide a roadmap for validation of LC + AMS assays, but to highlight agreements amongst the industry representative experts and the practitioners, as well as identifying specific areas essential for establishing assay quality but where additional discussion is required to reach agreement.

  2. Estimating the impact from Fukushima in Southern Spain by (131)I and Accelerator Mass Spectrometry detection of (129)I.

    Science.gov (United States)

    Gómez-Guzmán, J M; López-Gutiérrez, J M; García-Tenorio, R; Agulló, L; Peruchena, J I; Manjón, G; García-León, M

    2017-01-01

    After the Fukushima accident, large amounts of radionuclides were discharged to the atmosphere. Some of them travelled long distances and were detected in places as far from Japan as Spain a few days after the accident. One of these radionuclides was (131)I. Its isotope (129)I (T1/2 = 15.7 × 106 years) was also expected to follow the same pathway. In this work, we present the results for the (129)I concentration in the same atmospheric samples from Seville (Spain) where (131)I activity was measured in 2011 by Baeza et al. (2012). (129)I concentrations in aerosol and gaseous samples showed concentrations in the order of 104 and 105 atoms/m(3), typically higher in the gaseous form with respect to the aerosol form. Also (129)I in rainwater was measured, showing concentrations in the order of 10(8) atoms/L. The results show a very good agreement with the (131)I profile, showing that, if background from other sources is not relevant, it is possible to estimate the impact of similar events years after them thanks to the sensitivity of techniques like Accelerator Mass Spectrometry.

  3. Laser Ablation - Accelerator Mass Spectrometry: An Approach for Rapid Radiocarbon Analyses of Carbonate Archives at High Spatial Resolution.

    Science.gov (United States)

    Welte, Caroline; Wacker, Lukas; Hattendorf, Bodo; Christl, Marcus; Fohlmeister, Jens; Breitenbach, Sebastian F M; Robinson, Laura F; Andrews, Allen H; Freiwald, André; Farmer, Jesse R; Yeman, Christiane; Synal, Hans-Arno; Günther, Detlef

    2016-09-06

    A new instrumental setup, combining laser ablation (LA) with accelerator mass spectrometry (AMS), has been investigated for the online radiocarbon ((14)C) analysis of carbonate records. Samples were placed in an in-house designed LA-cell, and CO2 gas was produced by ablation using a 193 nm ArF excimer laser. The (14)C/(12)C abundance ratio of the gas was then analyzed by gas ion source AMS. This configuration allows flexible and time-resolved acquisition of (14)C profiles in contrast to conventional measurements, where only the bulk composition of discrete samples can be obtained. Three different measurement modes, i.e. discrete layer analysis, survey scans, and precision scans, were investigated and compared using a stalagmite sample and, subsequently, applied to terrestrial and marine carbonates. Depending on the measurement mode, a precision of typically 1-5% combined with a spatial resolution of 100 μm can be obtained. Prominent (14)C features, such as the atomic bomb (14)C peak, can be resolved by scanning several cm of a sample within 1 h. Stalagmite, deep-sea coral, and mollusk shell samples yielded comparable signal intensities, which again were comparable to those of conventional gas measurements. The novel LA-AMS setup allowed rapid scans on a variety of sample materials with high spatial resolution.

  4. Preliminary study of 10Be/7Be in rainwater from Xi’an by Accelerator Mass Spectrometry

    Science.gov (United States)

    Zhang, Li; Fu, Yun-Chong

    2017-01-01

    The 10Be/7Be ratio is a sensitive tracer for the study of atmospheric transport, particularly with regard to stratosphere-troposphere exchange. Measurements with high accuracy and efficiency are crucial to 7Be and 10Be tracer studies. This article describes sample preparation procedures and analytical benchmarks for 7Be and 10Be measurements at the Xi’an Accelerator Mass Spectrometry (Xi’an-AMS) laboratory for the study of rainwater samples. We describe a sample preparation procedure to fabricate beryllium oxide (BeO) AMS targets that includes co-precipitation, anion exchange column separation and purification. We then provide details for the AMS measurement of 7Be and 10Be following the sequence BeO-→Be2+→Be4+ in the Xi’an- AMS. The 10Be/7Be ratio of rainwater collected in Xi’an is shown to be about 1.3 at the time of rainfall. The virtue of the method described here is that both 7Be and 10Be are measured in the same sample, and it is suitable for routine analysis of large numbers of rainwater samples by AMS. Supported by National Natural Science Foundation of China (11205161) and CAS Key Technology Talent Program

  5. Quality of graphite target for biological/biomedical/environmental applications of 14C-accelerator mass spectrometry.

    Science.gov (United States)

    Kim, Seung-Hyun; Kelly, Peter B; Ortalan, Volkan; Browning, Nigel D; Clifford, Andrew J

    2010-03-15

    Catalytic graphitization for (14)C-accelerator mass spectrometry ((14)C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 degrees C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe(3)C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 degrees C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise (14)C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental (14)C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals.

  6. Preliminary study of 10Be/7Be in rainwater from Xi'an by Accelerator Mass Spectrometry

    CERN Document Server

    Zhang, Li

    2016-01-01

    The 10Be/7Be ratio is a sensitive tracer for the study of atmospheric transport, particularly with regard to stratosphere-troposphere exchange. Measurements with high accuracy and efficiency are crucial to 7Be and 10Be tracer studies. This article describes sample preparation procedures and analytical benchmarks for 7Be and 10Be measurements at the Xian Accelerator Mass Spectrometry (Xian-AMS) laboratory for the study of rainwater samples. We describe a sample preparation procedure to fabricate beryllium oxide (BeO) AMS targets that includes co-precipitation, anion exchange column separation and purification. We then provide details for the AMS measurement of 7Be and 10Be following the sequence BeO- -> Be2+ -> Be4+ in the Xian- AMS. The 10Be/7Be ratio of rainwater collected in Xian is shown to be about 1.3 at the time of rainfall. The virtue of the method described here is that both 7Be and 10Be are measured in the same sample, and is suitable for routine analysis of large numbers of rainwater samples by AMS.

  7. Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

    Science.gov (United States)

    2010-01-01

    Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise 14C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental14C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals. PMID:20163100

  8. A Novel 14C-Postlabeling Assay Using Accelerator Mass Spectrometry For the Detection of O6-Methyldeoxyguanosine Adducts

    Energy Technology Data Exchange (ETDEWEB)

    Thompkins, E M; Farmer, P B; Lamb, J H; Jukes, R; Dingley, K; Ubick, E A; Turteltaub, K W; Martin, E A; Brown, K

    2005-11-17

    Accelerator mass spectrometry (AMS) is currently one of the most sensitive methods available for the trace detection of DNA adducts and is particularly valuable for measuring adducts in humans or animal models. However, the standard approach requires administration of a radiolabeled compound. As an alternative, we have developed a preliminary {sup 14}C-postlabeling assay for detection of the highly mutagenic O{sup 6}-MedG, by AMS. Procedures were developed for derivatizing O{sup 6}-MedG using unlabeled acetic anhydride. Using conventional LC-MS analysis, the limit of detection for the major product, triacetylated O{sup 6}-MedG, was 10 fmoles. On reaction with {sup 14}C-acetic anhydride, using a specially designed enclosed system, the predominant product was {sup 14}C-di-acetyl O{sup 6}-MedG. This change in reaction profile was due to a modification of the reaction procedure, introduced as a necessary safety precaution. The limit of detection for {sup 14}C-diacetyl O{sup 6}-MedG by AMS was determined as 79 attomoles, {approx}18,000 fold lower than that achievable by LSC. Although the assay has so far only been carried out with labeled standards, the degree of sensitivity obtained illustrates the potential of this assay for measuring O{sup 6}-MedG levels in humans.

  9. Biological/biomedical accelerator mass spectrometry targets. 1. optimizing the CO2 reduction step using zinc dust.

    Science.gov (United States)

    Kim, Seung-Hyun; Kelly, Peter B; Clifford, Andrew J

    2008-10-15

    Biological and biomedical applications of accelerator mass spectrometry (AMS) use isotope ratio mass spectrometry to quantify minute amounts of long-lived radioisotopes such as (14)C. AMS target preparation involves first the oxidation of carbon (in sample of interest) to CO 2 and second the reduction of CO 2 to filamentous, fluffy, fuzzy, or firm graphite-like substances that coat a -400-mesh spherical iron powder (-400MSIP) catalyst. Until now, the quality of AMS targets has been variable; consequently, they often failed to produce robust ion currents that are required for reliable, accurate, precise, and high-throughput AMS for biological/biomedical applications. Therefore, we described our optimized method for reduction of CO 2 to high-quality uniform AMS targets whose morphology we visualized using scanning electron microscope pictures. Key features of our optimized method were to reduce CO 2 (from a sample of interest that provided 1 mg of C) using 100 +/- 1.3 mg of Zn dust, 5 +/- 0.4 mg of -400MSIP, and a reduction temperature of 500 degrees C for 3 h. The thermodynamics of our optimized method were more favorable for production of graphite-coated iron powders (GCIP) than those of previous methods. All AMS targets from our optimized method were of 100% GCIP, the graphitization yield exceeded 90%, and delta (13)C was -17.9 +/- 0.3 per thousand. The GCIP reliably produced strong (12)C (-) currents and accurate and precise F m values. The observed F m value for oxalic acid II NIST SRM deviated from its accepted F m value of 1.3407 by only 0.0003 +/- 0.0027 (mean +/- SE, n = 32), limit of detection of (14)C was 0.04 amol, and limit of quantification was 0.07 amol, and a skilled analyst can prepare as many as 270 AMS targets per day. More information on the physical (hardness/color), morphological (SEMs), and structural (FT-IR, Raman, XRD spectra) characteristics of our AMS targets that determine accurate, precise, and high-hroughput AMS measurement are in the

  10. Measurement of Uranium Isotopes in Particles of U3O8 by Secondary Ion Mass Spectrometry-Single-Stage Accelerator Mass Spectrometry (SIMS-SSAMS).

    Science.gov (United States)

    Fahey, Albert J; Groopman, Evan E; Grabowski, Kenneth S; Fazel, Kamron C

    2016-07-19

    A commercial secondary ion mass spectrometer (SIMS) was coupled to a ± 300 kV single-stage accelerator mass spectrometer (SSAMS). Positive secondary ions generated with the SIMS were injected into the SSAMS for analysis. This combined instrument was used to measure the uranium isotopic ratios in particles of three certified reference materials (CRM) of uranium, CRM U030a, CRM U500, and CRM U850. The ability to inject positive ions into the SSAMS is unique for AMS systems and allows for simple analysis of nearly the entire periodic table because most elements will readily produce positive ions. Isotopic ratios were measured on samples of a few picograms to nanograms of total U. Destruction of UH(+) ions in the stripper tube of the SSAMS reduced hydride levels by a factor of ∼3 × 10(4) giving the UH(+)/U(+) ratio at the SSAMS detector of ∼1.4 × 10(-8). These hydride ion levels would allow the measurement of (239)Pu at the 10 ppb level in the presence of U and the equivalent of ∼10(-10 236)U concentration in natural uranium. SIMS-SSAMS analysis of solid nuclear materials, such as these, with signals nearly free of molecular interferences, could have a significant future impact on the way some measurements are made for nuclear nonproliferation.

  11. Determination of Atto- to Femtogram Levels of Americium and Curium Isotopes in Large-Volume Urine Samples by Compact Accelerator Mass Spectrometry.

    Science.gov (United States)

    Dai, Xiongxin; Christl, Marcus; Kramer-Tremblay, Sheila; Synal, Hans-Arno

    2016-03-01

    Ultralow level analysis of actinides in urine samples may be required for dose assessment in the event of internal exposures to these radionuclides at nuclear facilities and nuclear power plants. A new bioassay method for analysis of sub-femtogram levels of Am and Cm in large-volume urine samples was developed. Americium and curium were co-precipitated with hydrous titanium oxide from the urine matrix and purified by column chromatography separation. After target preparation using mixed titanium/iron oxides, the final sample was measured by compact accelerator mass spectrometry. Urine samples spiked with known quantities of Am and Cm isotopes in the range of attogram to femtogram levels were measured for method evaluation. The results are in good agreement with the expected values, demonstrating the feasibility of compact accelerator mass spectrometry (AMS) for the determination of minor actinides at the levels of attogram/liter in urine samples to meet stringent sensitivity requirements for internal dosimetry assessment.

  12. Fourier transform mass spectrometry.

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-07-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook.

  13. A comparative study of 129I content in environmental standard materials IAEA-375, NIST SRM 4354 and NIST SRM 4357 by Thermal Ionization Mass Spectrometry and Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Olson, John; Adamic, Mary; Snyder, Darin; Brookhart, Jacob; Hahn, Paula; Watrous, Matthew

    2016-11-01

    Iodine environmental measurements have consistently been backed up in the literature by standard materials like IAEA-375, Chernobyl Soil. There are not many other sources of a certified reference material for 129I content for mass spectrometry measurements. Some that have been found in the literature include NIST-4354 and NIST-4357. They are still available at the time of this writing. They don’t have certified content or isotopic values. There has been some work in the literature to show that iodine is present, but there hasn’t been enough to establish a consensus value. These materials have been analyzed at INL through two separate mass spectrometry techniques. They involve a combustion method of the starting material in oxygen, followed by TIMS analysis and a leaching preparation analyzed by accelerator mass spectrometry. Combustion/TIMS preparation of NIST SRM-4354 resulted in a 129I/127I ratio of 1.92 x 10-6 which agrees with AMS measurements which measured the 129I/127I ratio to be 1.93 x 10-6.

  14. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method.

  15. Human vitamin B12 absorption measurement by accelerator mass spectrometry using specifically labeled (14)C-cobalamin.

    Science.gov (United States)

    Carkeet, Colleen; Dueker, Stephen R; Lango, Jozsef; Buchholz, Bruce A; Miller, Joshua W; Green, Ralph; Hammock, Bruce D; Roth, John R; Anderson, Peter J

    2006-04-11

    There is a need for an improved test of human ability to assimilate dietary vitamin B(12). Assaying and understanding absorption and uptake of B(12) is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry is uniquely suited for assessing absorption and kinetics of carbon-14 ((14)C)-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of (14)C in microliter volumes of biological samples with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B(12) in the range of normal dietary intake. The B(12) used was quantitatively labeled with (14)C at one particular atom of the dimethylbenzimidazole (DMB) moiety by exploiting idiosyncrasies of Salmonella metabolism. To grow aerobically on ethanolamine, Salmonella enterica must be provided with either preformed B(12) or two of its precursors, cobinamide and DMB. When provided with (14)C-DMB specifically labeled in the C2 position, cells produced (14)C-B(12) of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) (1 Ci = 37 GBq) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 microg, 2.2 kBq/59 nCi) of purified (14)C-B(12) was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B(12) assimilation.

  16. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    Energy Technology Data Exchange (ETDEWEB)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-26

    There is need for an improved test of human ability to assimilate dietary vitamin B{sub 12}. Assaying and understanding absorption and uptake of B{sub 12} is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of {sup 14}C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ({sup 14}C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B{sub 12} in the range of normal dietary intake. The B{sub 12} used was quantitatively labeled with {sup 14}C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B{sub 12} or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with {sup 14}C-DMB specifically labeled in the C2 position, cells produced {sup 14}C-B{sub 12} of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified {sup 14}C-B{sub 12} was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B{sub 12} assimilation.

  17. preparation of microgram samples on iron wool for radiocarbon analysis via accelerator mass spectrometry: A closed-system approach

    Science.gov (United States)

    Verkouteren, R. Michael; Klouda, George A.; Currie, Lloyd A.; Donahue, Douglas J.; Jull, A. J. Timothy; Linick, T. W.

    1987-11-01

    A technique has been developed at NBS for the production of high quality targets for radiocarbon analysis by accelerator mass spectrometry (AMS). Our process optimizes chemical yields, ion currents and characterizes the chemical blank. The approach encompasses sample combustion to CO 2, catalytic reduction of CO 2 by Zn to CO, reduction to graphitic carbon on high-purity iron wool and in situ formation of a homogeneous iron-carbon bead; all steps are performed in a closed system. The total measurement system blank and variability are considered in the light of contributions from combustion, iron wool, reduction, bead formation and instrument blank. Additionally, use of this approach provides an increase in throughput, i.e. the effective management of large numbers of samples. Chemical yields for 50-800 μg C samples deposited on 15 mg iron wool were greater than 90%. Integrated 12C - ion currents observed were significant, being 4-64% of those observed in pure graphite. These currents are about an order of magnitude greater than those expected from dilution of graphite with an inert substrate. Isotopic accuracy, precision and blank were assessed by measuring the {14C }/{13C } ratios of a series of targets prepared from dead carbon and oxalic acid (SRM 4990C). Each target was typically measured for one hour; bead consumption was estimated at 5% to 10%. System blank subsequent to combustion was equivalent to (2.2 ± 0.5) μg modern carbon (chemistry + instrument); combustion blank currently stands at (0.4 ± 0.1) (SE, n = 6) μg C.

  18. Accelerated solvent extraction method for the quantification of polycyclic aromatic hydrocarbons in cocoa beans by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Belo, Renata França Cassimiro; Figueiredo, Júlia Pereira; Nunes, Carolina Mariana; Pissinatti, Rafael; Souza, Scheilla Vitorino Carvalho de; Junqueira, Roberto Gonçalves

    2017-05-15

    An accelerated solvent extraction (ASE) procedure for use with gas chromatography-mass spectrometry (GC-MS) was optimized for the determination of eight polycyclic aromatic hydrocarbons (PAHs) in cocoa beans. Plackett-Burman and rotatable central composite design (RCCD) indicated that three variables affected the recoveries of PAHs during the extraction and purification steps: agitation time in the second liquid-liquid partition, weight of silica gel in the column, and volume of hexane for PAH elution from the column. After obtaining the optimal conditions, a single laboratory method validation was performed. Linearity was demonstrated for benzo[a]pyrene in the concentration range from 0.5 to 8.0mgkg(-1) of sample, corresponding to 1.25-20.0μgkg(-1) of cocoa on a fat basis. For the other analytes, linearity was observed from 0.75 to 8.0μgkg(-1) of sample (1.88-20.0μgkg(-1) of cocoa on a fat basis). Significant matrix effects were found for chrysene and benzo[b]fluoranthene. The precision of the method was verified with relative standard deviations (RSDs) ranging from 2.57 to 14.13% and from 4.36 to 19.77% under repeatability and intermediate precision conditions, respectively. The average recoveries of the eight PAHs ranged from 74.99 to 109.73%. These parameters, limits and measurement uncertainties met the performance criteria established by European Union regulations, except for the theoretical limit of detection for chrysene. The method was applied to the analysis of samples of Brazilian cocoa beans, and only one sample was found to have a PAH content above the maximum limit defined by the European Union legislation. This optimized and validated method is intended to be used as part of the official Brazilian monitoring programs investigating contaminants and residues in food. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Kinetics of carboplatin-DNA binding in genomic DNA and bladder cancer cells as determined by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hah, S S; Stivers, K M; Vere White, R; Henderson, P T

    2005-12-29

    Cisplatin and carboplatin are platinum-based drugs that are widely used in cancer chemotherapy. The cytotoxicity of these drugs is mediated by platinum-DNA monoadducts and intra- and interstrand diadducts, which are formed following uptake of the drug into the nucleus of cells. The pharmacodynamics of carboplatin display fewer side effects than for cisplatin, albeit with less potency, which may be due to differences in rates of DNA adduct formation. We report the use of accelerator mass spectrometry (AMS), a sensitive detection method often used for radiocarbon quantitation, to measure both the kinetics of [{sup 14}C]carboplatin-DNA adduct formation with genomic DNA and drug uptake and DNA binding in T24 human bladder cancer cells. Only carboplatin-DNA monoadducts contain radiocarbon in the platinated DNA, which allowed for calculation of kinetic rates and concentrations within the system. The percent of radiocarbon bound to salmon sperm DNA in the form of monoadducts was measured by AMS over 24 h. Knowledge of both the starting concentration of the parent carboplatin and the concentration of radiocarbon in the DNA at a variety of time points allowed calculation of the rates of Pt-DNA monoadduct formation and conversion to toxic cross-links. Importantly, the rate of carboplatin-DNA monoadduct formation was approximately 100-fold slower than that reported for the more potent cisplatin analogue, which may explain the lower toxicity of carboplatin. T24 human bladder cancer cells were incubated with a subpharmacological dose of [{sup 14}C]carboplatin, and the rate of accumulation of radiocarbon in the cells and nuclear DNA was measured by AMS. The lowest concentration of radiocarbon measured was approximately 1 amol/10 {micro}g of DNA. This sensitivity may allow the method to be used for clinical applications.

  20. Biomedical Accelerator Mass Spectrometry

    Data.gov (United States)

    Federal Laboratory Consortium — Industrial partner projects focus on big, complex challenges and opportunities like smart grid, weather forecasting for renewable energy sources, alternative energy...

  1. The French accelerator mass spectrometry facility ASTER after 4 years: Status and recent developments on 36Cl and 129I

    Science.gov (United States)

    Arnold, Maurice; Aumaître, Georges; Bourlès, Didier L.; Keddadouche, Karim; Braucher, Régis; Finkel, Robert C.; Nottoli, Emmanuelle; Benedetti, Lucilla; Merchel, Silke

    2013-01-01

    Since the acceptance tests of the French 5 MV accelerator mass spectrometry facility ASTER in 2007, routine measurement conditions for the long-lived radionuclides 10Be and 26Al have been established. Yearly sample throughput as high as over 3300 unknowns has been reached for 10Be in 2010. Cross-contamination for volatile elements has been largely solved by an ion source upgrade allowing 36Cl measurements at ASTER. However, recent long-term tests using 35Cl/37Cl samples with strongly varying ratios have shown that identical targets lead to different 35Cl/37Cl results at the 2-4% level when being measured after a time gap of 24 h while the source is running other samples. Besides time dependent mass fractionation, another likely reason for this effect might be source memory, thus, asking for sophisticated measurement strategies and improved data evaluation and eventually further ion source improvement. Finally, after establishing quality assurance by cross-calibration of secondary in-house 26Al and 41Ca standards and taking part in round-robin exercises of 10Be and 36Cl, a two-step cross-calibration of secondary in-house 129I standards has been performed. The NIST 3231 standard containing 129I/127I at (0.981 ± 0.012) × 10-6 has been used for step-wise dilution with NaI to produce gram-quantities of lower-level standards for every-day use. The resulting material SM-I-9 (129I/127I: ∼1 × 10-9) has been measured vs. AgI produced using minimum chemistry from the two NIST ampoules containing a solution with a nominal ratio 129I/127I of (0.982 ± 0.012) × 10-8. In a second stage, SM-I-10 and SM-I-11 with ratios of ∼1 × 10-10 and ∼1 × 10-11, respectively, have been cross-calibrated against SM-I-9. Individual uncertainties of the traceable secondary standards are 1.3-1.4% (2σ), mainly originating from the given uncertainty of the primary NIST 3231 at the 10-8 level. The cross-contamination for iodine is in the range of 0.4-0.6% within the first 20 h of running

  2. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  3. Human in Vivo Pharmacokinetics of [(14)C]Dibenzo[def,p]chrysene by Accelerator Mass Spectrometry Following Oral Microdosing.

    Science.gov (United States)

    Madeen, Erin; Corley, Richard A; Crowell, Susan; Turteltaub, Kenneth; Ognibene, Ted; Malfatti, Mike; McQuistan, Tammie J; Garrard, Mary; Sudakin, Dan; Williams, David E

    2015-01-20

    Dibenzo(def,p)chrysene (DBC), (also known as dibenzo[a,l]pyrene), is a high molecular weight polycyclic aromatic hydrocarbon (PAH) found in the environment, including food, produced by the incomplete combustion of hydrocarbons. DBC, classified by IARC as a 2A probable human carcinogen, has a relative potency factor (RPF) in animal cancer models 30-fold higher than benzo[a]pyrene. No data are available describing the disposition of high molecular weight (>4 rings) PAHs in humans to compare to animal studies. Pharmacokinetics of DBC was determined in 3 female and 6 male human volunteers following oral microdosing (29 ng, 5 nCi) of [(14)C]-DBC. This study was made possible with highly sensitive accelerator mass spectrometry (AMS), capable of detecting [(14)C]-DBC equivalents in plasma and urine following a dose considered of de minimus risk to human health. Plasma and urine were collected over 72 h. The plasma Cmax was 68.8 ± 44.3 fg·mL(-1) with a Tmax of 2.25 ± 1.04 h. Elimination occurred in two distinct phases: a rapid (α)-phase, with a T1/2 of 5.8 ± 3.4 h and an apparent elimination rate constant (Kel) of 0.17 ± 0.12 fg·h(-1), followed by a slower (β)-phase, with a T1/2 of 41.3 ± 29.8 h and an apparent Kel of 0.03 ± 0.02 fg·h(-1). In spite of the high degree of hydrophobicity (log Kow of 7.4), DBC was eliminated rapidly in humans, as are most PAHs in animals, compared to other hydrophobic persistent organic pollutants such as, DDT, PCBs and TCDD. Preliminary examination utilizing a new UHPLC-AMS interface, suggests the presence of polar metabolites in plasma as early as 45 min following dosing. This is the first in vivo data set describing pharmacokinetics in humans of a high molecular weight PAH and should be a valuable addition to risk assessment paradigms.

  4. Precision and accuracy in the quantitative analysis of biological samples by accelerator mass spectrometry: application in microdose absolute bioavailability studies.

    Science.gov (United States)

    Gao, Lan; Li, Jing; Kasserra, Claudia; Song, Qi; Arjomand, Ali; Hesk, David; Chowdhury, Swapan K

    2011-07-15

    Determination of the pharmacokinetics and absolute bioavailability of an experimental compound, SCH 900518, following a 89.7 nCi (100 μg) intravenous (iv) dose of (14)C-SCH 900518 2 h post 200 mg oral administration of nonradiolabeled SCH 900518 to six healthy male subjects has been described. The plasma concentration of SCH 900518 was measured using a validated LC-MS/MS system, and accelerator mass spectrometry (AMS) was used for quantitative plasma (14)C-SCH 900518 concentration determination. Calibration standards and quality controls were included for every batch of sample analysis by AMS to ensure acceptable quality of the assay. Plasma (14)C-SCH 900518 concentrations were derived from the regression function established from the calibration standards, rather than directly from isotopic ratios from AMS measurement. The precision and accuracy of quality controls and calibration standards met the requirements of bioanalytical guidance (U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research, Center for Veterinary Medicine. Guidance for Industry: Bioanalytical Method Validation (ucm070107), May 2001. http://www.fda.gov/downloads/Drugs/GuidanceCompilanceRegulatoryInformation/Guidances/ucm070107.pdf ). The AMS measurement had a linear response range from 0.0159 to 9.07 dpm/mL for plasma (14)C-SCH 900158 concentrations. The CV and accuracy were 3.4-8.5% and 94-108% (82-119% for the lower limit of quantitation (LLOQ)), respectively, with a correlation coefficient of 0.9998. The absolute bioavailability was calculated from the dose-normalized area under the curve of iv and oral doses after the plasma concentrations were plotted vs the sampling time post oral dose. The mean absolute bioavailability of SCH 900518 was 40.8% (range 16.8-60.6%). The typical accuracy and standard deviation in AMS quantitative analysis of drugs from human plasma samples have been reported for the first time, and the impact of these

  5. Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    le Gac, S.; le Gac, Severine; van den Berg, Albert; van den Berg, A.; Unknown, [Unknown

    2009-01-01

    With this book we want to illustrate how two quickly growing fields of instrumentation and technology, both applied to life sciences, mass spectrometry and microfluidics (or microfabrication) naturally came to meet at the end of the last century and how this marriage impacts on several types of appl

  6. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  7. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  8. Radioecological studies at the National Center of Accelerators based on the use of the accelerator mass spectrometry; Estudios radioecologicos en el Centro Nacional de Aceleradores basados en el uso de la Espectrometria de Masas con Acelerador (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Chamizo, E.; Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-03-01

    Since mid-2006 a compact Accelerator Mass Spectrometry (AMS) of 1 MV, Tandetron type, named SARA (Spanish Accelerator for Radionuclide Analysis) is installed at the National Accelerator Centre in Seville. After an initial period, to set-up the equipment and to study its capability to detect the long-lived radionuclides {sup 1}4C, {sup 1}0B, {sup 2}6Al, {sup 1}29I and plutonium isotopes ({sup 2}39Pu and {sup 2}40Pu) compared to other techniques of mass spectrometry (MS), numerous research lines in fields as diverse as archaeology, geology, palaeontology, oceanography, internal dosimetry, astrophysics and characterization of radioactive waste, among others, have been opened. In particular, since 2008 numerous contributions in the field of Radioecology have been done, based in the measurements of {sup 1}29I and Pu isotopes ({sup 2}39Pu and {sup 2}40Pu). In this article, some of these radioecological researches are summarized and presented, with special emphasis on showing that its accomplishment requires the application of the AMS technique, to be able to achieve sensitivities and detection limits which are impossible to reach when radiometric and mass spectrometry conventional techniques are applied. (Author) 13 refs.

  9. Possible incorporation of petroleum-based carbons in biochemicals produced by bioprocess--biomass carbon ratio measured by accelerator mass spectrometry.

    Science.gov (United States)

    Kunioka, Masao

    2010-06-01

    The biomass carbon ratios of biochemicals related to biomass have been reviewed. Commercial products from biomass were explained. The biomass carbon ratios of biochemical compounds were measured by accelerator mass spectrometry (AMS) based on the (14)C concentration of carbons in the compounds. This measuring method uses the mechanism that biomass carbons include a very low level of (14)C and petroleum carbons do not include (14)C similar to the carbon dating measuring method. It was confirmed that there were some biochemicals synthesized from petroleum-based carbons. This AMS method has a high accuracy with a small standard deviation and can be applied to plastic products.

  10. Tritium retention measurements by accelerator mass spectrometry and full combustion of W-coated and uncoated CFC tiles from the JET divertor

    Science.gov (United States)

    Stan-Sion, C.; Bekris, N.; Kizane, G.; Enachescu, M.; Likonen, J.; Halitovs, M.; Petre, A.; contributors, JET

    2016-04-01

    Accelerator mass spectrometry (AMS) and the full combustion method (FCM) followed by liquid scintillation counting were applied to quantitatively determine the tritium retention in the tungsten-coated carbon fibre composites (CFC), in comparison to uncoated CFC tiles from the JET divertor. The tiles were adjacent and exposed to plasma operations between 2007 and 2009. The tritium depth profiles are showing that the tritium retention on the W-coated tile was reduced by a factor of 13.5 in comparison to the uncoated tile whereas the bulk tritium concentration is approximately the same for both tiles.

  11. sup 26 Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi

    1990-12-01

    Accelerator mass spectrometry (AMS) was applied for {sup 26}Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using {sup 26}Al as a tracer. When {sup 26}Al was intraperitoneally injected into rats, a considerable amount of {sup 26}Al was incorporated into the cerebrum after 5-35 days of the injection. (author).

  12. Fast ion mass spectrometry and charged particle spectrography investigations of transverse ion acceleration and beam-plasma interactions

    Science.gov (United States)

    Gibson, W. C.; Tomlinson, W. M.; Marshall, J. A.

    1987-01-01

    Ion acceleration transverse to the magnetic field in the topside ionosphere was investigated. Transverse acceleration is believed to be responsible for the upward-moving conical ion distributions commonly observed along auroral field lines at altitudes from several hundred to several thousand kilometers. Of primary concern in this investigation is the extent of these conic events in space and time. Theoretical predictions indicate very rapid initial heating rates, depending on the ion species. These same theories predict that the events will occur within a narrow vertical region of only a few hundred kilometers. Thus an instrument with very high spatial and temporal resolution was required; further, since different heating rates were predicted for different ions, it was necessary to obtain composition as well as velocity space distributions. The fast ion mass spectrometer (FIMS) was designed to meet these criteria. This instrument and its operation is discussed.

  13. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  14. Hydrogen Exchange Mass Spectrometry.

    Science.gov (United States)

    Mayne, Leland

    2016-01-01

    Hydrogen exchange (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.

  15. Verification of the sputter-generated {sup 32}SF{sub n}{sup −} (n = 1–6) anions by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mane, R.G.; Surendran, P. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Sanjay [Physics Department, Agra College Agra, Agra 282002 (India); Nair, J.P.; Yadav, M.L. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Hemalatha, M. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Thomas, R.G.; Mahata, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kailas, S. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Gupta, A.K., E-mail: anit@tifr.res.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-01-01

    Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase {sup 32}SF{sub n}{sup −} (n = 1–6) anions for all size ‘n’ can be readily generated from a variety of surfaces undergoing Cs{sup +} ion sputtering in the presence of high purity SF{sub 6} gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio {sup 34}SF{sub n}{sup −}/{sup 32}SF{sub n}{sup −} (n = 1–6) was found to be close to its natural abundance but not for all size ‘n’. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant {sup 32}SF{sub n}{sup −} (n = 1–6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

  16. Evaluation of laser desorption mass spectrometry and UV accelerated aging of dyes on paper as tools for the evaluation of a questioned document.

    Science.gov (United States)

    Grim, Donzna M; Siegel, Jay; Allison, John

    2002-11-01

    Laser desorption mass spectrometry (LDMS) may be used for the detection and identification of dyes found in inks. Naturally-aged and artificially-aged blue and black ballpoint pen inks containing the cationic dye methyl violet were analyzed on paper. The average molecular weight of the dye sample was calculated from LD mass spectral data and plotted versus time. The resulting aging curves demonstrate that, as dye degradation increases, the average molecular weight of the dye decreases. Typical variables involved in ink aging, such as the type of paper and ink formulation, were investigated. Results show that these variables influence the rate of dye degradation. Furthermore, UV accelerated aging has been developed and tested as an alternative to thermal approaches.

  17. "Magic" Ionization Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  18. Microwave accelerated selective Soxhlet extraction for the determination of organophosphorus and carbamate pesticides in ginseng with gas chromatography/mass spectrometry.

    Science.gov (United States)

    Zhou, Ting; Xiao, Xiaohua; Li, Gongke

    2012-07-03

    Microwave accelerated selective Soxhlet extraction (MA-SSE), a novel selective extraction technique, was investigated in this study. A Soxhlet extraction system containing a glass filter was designed as an extractor. During the procedure of MA-SSE, both the target analytes and the interfering components were extracted from the sample into the extraction solvent enhanced by microwave irradiation. After the solvent flowed though the sorbent, the interfering components were adsorbed by the sorbent, and the target analytes remaining in the solvent were collected in the extraction bottle. No cleanup or filtration was required after extraction. The efficiency of the MA-SSE approach was demonstrated in the determination of organophosphorus and carbamate pesticide residues in ginseng by gas chromatography/mass spectrometry (GC/MS). Under the optimized conditions, low limits of detection (0.050-0.50 μg/kg) were obtained. The recoveries were in the range of 72.0-110.1% with relative standard deviations less than 7.1%. Because of the effect of microwave irradiation, MA-SSE showed significant advantage compared with other extraction techniques. The sorbent used in this study showed good cleanup ability. The mechanism of MA-SSE was demonstrated to be based on the rupture of the cell walls according to the structural changes of ginseng samples. On the basis of the results, MA-SSE as a simple and effective sample preparation technique for the analysis of pesticide residues in complex matrixes shows great promise.

  19. Accelerator mass spectrometry measurements of the 13C (n ,γ )14C and 14N(n ,p )14C cross sections

    Science.gov (United States)

    Wallner, A.; Bichler, M.; Buczak, K.; Dillmann, I.; Käppeler, F.; Karakas, A.; Lederer, C.; Lugaro, M.; Mair, K.; Mengoni, A.; Schätzel, G.; Steier, P.; Trautvetter, H. P.

    2016-04-01

    The technique of accelerator mass spectrometry (AMS), offering a complementary tool for sensitive studies of key reactions in nuclear astrophysics, was applied for measurements of the 13C (n ,γ )14C and the 14N(n ,p )14C cross sections, which act as a neutron poison in s -process nucleosynthesis. Solid samples were irradiated at Karlsruhe Institute of Technology with neutrons closely resembling a Maxwell-Boltzmann distribution for k T =25 keV, and also at higher energies between En=123 and 182 keV. After neutron irradiation the produced amount of 14C in the samples was measured by AMS at the Vienna Environmental Research Accelerator (VERA) facility. For both reactions the present results provide important improvements compared to previous experimental data, which were strongly discordant in the astrophysically relevant energy range and missing for the comparably strong resonances above 100 keV. For 13C (n ,γ ) we find a four times smaller cross section around k T =25 keV than a previous measurement. For 14N(n ,p ), the present data suggest two times lower cross sections between 100 and 200 keV than had been obtained in previous experiments and data evaluations. The effect of the new stellar cross sections on the s process in low-mass asymptotic giant branch stars was studied for stellar models of 2 M⊙ initial mass, and solar and 1 /10th solar metallicity.

  20. Matrix-Free UV-Laser Desorption Ionization Mass Spectrometry as a Versatile Approach for Accelerating Dereplication Studies on Lichens.

    Science.gov (United States)

    Le Pogam, Pierre; Schinkovitz, Andreas; Legouin, Béatrice; Le Lamer, Anne-Cécile; Boustie, Joël; Richomme, Pascal

    2015-10-20

    The present study examined the suitability of laser desorption/ionization time-of-flight mass spectrometry (LDI-MS) for the rapid chemical fingerprinting of lichen extracts. Lichens are known to produce a wide array of secondary metabolites. Most of these compounds are unique to the symbiotic condition but some can be found in many species. Therefore, dereplication, that is, the rapid identification of known compounds within a complex mixture is crucial in the search for novel natural products. Over the past decade, significant advances were made in analytical techniques and profiling methods specifically adapted to crude lichen extracts, but LDI-MS has never been applied in this context. However, most classes of lichen metabolites have UV chromophores, which are quite similar to commercial matrix molecules used in matrix-assisted laser desorption ionization (MALDI). It is consequently postulated that these molecules could be directly detectable by matrix-free LDI-MS. The present study evaluated the versatility of this technique by investigating the LDI properties of a vast array of single lichen metabolites as well as lichen extracts of known chemical composition. Results from the LDI experiments were compared with those obtained by direct ESI-MS detection as well as LC-ESI-MS. It was shown that LDI ionization leads to strong molecular ion formation with little fragmentation, thus, facilitating straightforward spectra interpretation and representing a valuable alternative to time-consuming LC-MS analysis.

  1. Accelerated solvent extraction combined with dispersive liquid-liquid microextraction before gas chromatography with mass spectrometry for the sensitive determination of phenols in soil samples.

    Science.gov (United States)

    Xing, Han-Zhu; Wang, Xia; Chen, Xiang-Feng; Wang, Ming-Lin; Zhao, Ru-Song

    2015-05-01

    A method combining accelerated solvent extraction with dispersive liquid-liquid microextraction was developed for the first time as a sample pretreatment for the rapid analysis of phenols (including phenol, m-cresol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol) in soil samples. In the accelerated solvent extraction procedure, water was used as an extraction solvent, and phenols were extracted from soil samples into water. The dispersive liquid-liquid microextraction technique was then performed on the obtained aqueous solution. Important accelerated solvent extraction and dispersive liquid-liquid microextraction parameters were investigated and optimized. Under optimized conditions, the new method provided wide linearity (6.1-3080 ng/g), low limits of detection (0.06-1.83 ng/g), and excellent reproducibility (extraction with dispersive liquid-liquid microextraction as a sample pretreatment procedure coupled with gas chromatography and mass spectrometry is an excellent method for the rapid analysis of trace levels of phenols in environmental soil samples.

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

    Science.gov (United States)

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

    2014-04-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low (129)I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO3/HClO4, (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured (129)I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of (129)I/(137)Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples.

  3. Aluminum and phosphorus separation: application to preparation of target from brain tissue for {sup 26}Al determination by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, Russell D.; Robertson, J. David; Sharma, Pankaj; Yokel, Robert A. E-mail: ryokel1@pop.uky.edu

    1999-04-01

    Acid digested brain containing 4 mg added {sup 27}Al was ashed at 1000 deg. C to prepare an Al{sub 2}O{sub 3} target for accelerator mass spectrometry (AMS) analysis of {sup 26}Al. A glass-like material usually resulted which was thought to be aluminum (Al) oxyphosphate. The separation of Al and phosphate was investigated. Al, but not phosphate, was bound by a cation exchange resin (AG 50-X8). Hydrofluoric acid eluted the Al from the resin. Removal of phosphate from acid digested brain by this method produced an amorphous material after ashing that was easier to recover from the porcelain crucible and had a higher AMS beam current. This procedure to separate Al from phosphate may have utility in other applications.

  4. Pharmacokinetics, absorption, and excretion of radiolabeled revexepride: a Phase I clinical trial using a microtracer and accelerator mass spectrometry-based approach

    Directory of Open Access Journals (Sweden)

    Flach S

    2016-09-01

    Full Text Available Stephen Flach,1 Marie Croft,2 Jie Ding,1 Ron Budhram,3 Todd Pankratz,2 Mike Pennick,3 Graeme Scarfe,3 Steven Troy,4 Jay Getsy4 1Covance Laboratories Inc., Madison, WI, USA; 2Xceleron Inc., Germantown, MD, USA; 3Shire, Basingstoke, UK; 4Shire, Lexington, MA, USA Purpose: Gastroesophageal reflux disease involves the reflux of gastric and/or duodenal content into the esophagus. Prokinetic therapies, such as the selective 5-hydroxytryptamine receptor 4 agonist revexepride, may aid gastric emptying. This Phase I study evaluated the pharmacokinetics and excretion pathways of [14C]revexepride in healthy individuals using a microtracer approach with accelerator mass spectrometry. Participants and methods: Six healthy men received a single oral dose of 2 mg [14C]revexepride containing ~200 nCi of radioactivity; blood, urine, and fecal samples were collected over a 10-day period. Results: Almost 100% of 14C was recovered: 38.2%±10.3% (mean ± standard deviation was recovered in urine, and 57.3%±0.4% was recovered in feces. Blood cell uptake was low, based on the blood plasma total radioactivity ratio of 0.8. The mean revexepride renal clearance was 8.6 L/h, which was slightly higher than the typical glomerular filtration rate in healthy individuals. Time to reach maximal concentration was 1.75±1.17 hours (mean ± standard deviation. No safety signals were identified. Conclusion: This study demonstrated that revexepride had rapid and moderate-to-good oral absorption. Excretion of radioactivity was completed with significant amounts in feces and urine. Renal clearance slightly exceeded the typical glomerular filtration rate, suggesting the involvement of active transportation in the renal tubules. Keywords: accelerator mass spectrometry, gastroesophageal reflux disease, pharmacokinetics, revexepride, 5-hydroxytryptamine receptor 4 agonist

  5. Accelerator Mass Spectrometry of Actinides in Ground- and Seawater: An Innovative Method Allowing for the Simultaneous Analysis of U, Np, Pu, Am, and Cm Isotopes below ppq Levels.

    Science.gov (United States)

    Quinto, Francesca; Golser, Robin; Lagos, Markus; Plaschke, Markus; Schäfer, Thorsten; Steier, Peter; Geckeis, Horst

    2015-06-02

    (236)U, (237)Np, and Pu isotopes and (243)Am were determined in ground- and seawater samples at levels below ppq (fg/g) with a maximum sample size of 250 g. Such high sensitivity was possible by using accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) with extreme selectivity and recently improved efficiency and a significantly simplified separation chemistry. The use of nonisotopic tracers was investigated in order to allow for the determination of (237)Np and (243)Am, for which isotopic tracers either are rarely available or suffer from various isobaric mass interferences. In the present study, actinides were concentrated from the sample matrix via iron hydroxide coprecipitation and measured sequentially without previous chemical separation from each other. The analytical method was validated by the analysis of the Reference Material IAEA 443 and was applied to groundwater samples from the Colloid Formation and Migration (CFM) project at the deep underground rock laboratory of the Grimsel Test Site (GTS) and to natural water samples affected solely by global fallout. While the precision of the presented analytical method is somewhat limited by the use of nonisotopic spikes, the sensitivity allows for the determination of ∼10(5) atoms in a sample. This provides, e.g., the capability to study the long-term release and retention of actinide tracers in field experiments as well as the transport of actinides in a variety of environmental systems by tracing contamination from global fallout.

  6. Accelerated Analyte Uptake on Single Beads in Microliter-scale Batch Separations using Acoustic Streaming: Plutonium Uptake by Anion Exchange for Analysis by Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, Walter F.; O' Hara, Matthew J.; Peper, Shane M.; Petersen, Steven L.; Grate, Jay W.

    2008-06-01

    The use of acoustic streaming as a non-contact mixing platform to accelerate mass transport-limited diffusion processes in small volume heterogeneous reactions has been investigated. Single bead anion exchange of plutonium at nanomolar and sub-picomolar concentrations in 20 microliter liquid volumes was used to demonstrate the effect of acoustic mixing. Pu uptake rates on individual ~760 micrometer diameter AG 1x4 anion exchange resin beads were determined using acoustic mixing and compared with Pu uptake rates achieved by static diffusion alone. An 82 MHz surface acoustic wave (SAW) device was placed in contact with the underside of a 384-well microplate containing flat-bottomed semiconical wells. Acoustic energy was coupled into the solution in the well, inducing acoustic streaming. Pu uptake rates were determined by the plutonium remaining in solution after specific elapsed time intervals, using liquid scintillation counting (LSC) for nanomolar concentrations and thermal ionization mass spectrometry (TIMS) analysis for the sub-picomolar concentration experiments. It was found that this small batch uptake reaction could be accelerated by a factor of about five-fold or more, depending on the acoustic power applied.

  7. Applications of accelerator mass spectrometry in nuclear science%加速器质谱在核科学中的应用

    Institute of Scientific and Technical Information of China (English)

    姜山; 杨旭冉; 何明; 董克君; 窦亮

    2015-01-01

    Belonging to the category of isotope mass spectrometry ( MS) , accelerator mass spectrometry ( AMS) is a high-energy mass spectrometry based on accelerators and ion detectors. AMS overcomes the molecular and isobaric background interferences extant in conventional MS, and therefore has an extremely high isotopic abundance sensitivity, which reaches 10 -15 ( isotopic abundance sensitivity of conventional MS is 10 -8 at highest) for measure-ment of nuclides such as 14 C( T1/2 =5 730 a) , 10 Be( T1/2 =1. 5 × 106 a) and 36 Cl( T1/2 =3. 0 × 105 a) . Accordingly, AMS has extremely broad application prospects. This paper introduces the principle, technique and development sta-tus of AMS and focuses on the introduction of CIAE’s AMS technique and research advances in its application in nu-clear science and technology, such as studies on measurements of the half-life of long-lived nuclides(79Se), small nuclear reaction cross sections(238U(n,3n)236U) and long-lived fission product nucleus in valley areas, as well as AMS measurements of 129I as the new approach for nuclear facility monitoring, nuclear environment and emergency detection.%加速器质谱( accelerator mass spectrometry, AMS)是基于加速器和离子探测器的一种高能质谱,属于一种同位素质谱( mass spectroscopy, MS),它克服了传统MS存在的分子本底和同量异位素本底干扰,因此同位素丰度灵敏度很高,对14 C( T1/2=5730 a)、10 Be( T1/2=1.5×106 a)和36 Cl( T1/2=3.0×105 a)等核素测量的丰度灵敏度均达10-15(传统MS的同位素丰度灵敏度最高为10-8).因此, AMS具有极其广泛的应用前景.简述AMS原理、技术和发展现状,介绍中国原子能科学研究院的AMS技术,及该技术在核科学与技术中的应用研究进展,包括长寿命核素半衰期的测量(如79 Se ),核反应微小截面的测量(如238U(n,3n)236U),长寿命谷区裂变产物核测量以及129I的AMS测量作为核设施监测、核环境与核应急检测的新方法等.

  8. Cluster SIMS Microscope Mode Mass Spectrometry Imaging

    CERN Document Server

    Kiss, András; Jungmann, Julia H; Heeren, Ron M A

    2013-01-01

    Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with polyatomic primary ion sources, are required to exploit the full potential of microscope mode mass spectrometry imaging, i.e. to efficiently push the limits of ultra-high spatial resolution, sample throughput and sensitivity. In this work, a C60 primary source is combined with a commercial mass microscope for microscope mode secondary ion mass spectrometry imaging. The detector setup is a pixelated detector from the Medipix/Timepix family with high-voltage post-acceleration capabilities. The mass spectral and imaging performance of the system is tested with various benchmark samples and thin tissue sections. We show that the high secondary ion yield (with respect to traditional monatomic primary ion sources) of the C60 primary ion ...

  9. Screening and identification of unknown contaminants in water with liquid chromatography and quadrupole-orthogonal acceleration-time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Bobeldijk, I; Vissers, J P; Kearney, G; Major, H; Van Leerdam, J A

    2001-09-21

    In order to assess and maintain the quality of surface waters, target compound monitoring is often not sufficient. Many unknown micro-contaminants are present in water, originating in municipal, industrial or agricultural effluents. Some of these might pose a risk to drinking water production and consequently to human health. The possibilities of screening surface water and identification of these non-target water pollutants with modern data acquisition possibilities of hybrid quadrupole-orthogonal acceleration time of flight mass spectrometers (Q-TOF), such as data-dependent MS to MS/MS switching were investigated. Using model compounds, a procedure for the liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening of water extracts was developed, enabling the detection and identification of compounds at levels < or = 0.25 microg/l in surface water. Based on the accurate mass the elemental compositions for the precursor and product ions are calculated. The calculated chemical formulae are searched against the Merck index, the NIST library, an own database containing about 2,500 water pollutants (pesticides and other contaminants) as well as a CI-CID library containing tandem MS spectra of about 100 water contaminants. The developed approach was applied for the identification of unknown compounds, present in native surface water extract. For three of these compounds, structures were proposed. Confirmation of the proposed structures with standards was beyond the scope of this study.

  10. International Mass Spectrometry Society (IMSS).

    Science.gov (United States)

    Cooks, R G; Gelpi, E; Nibbering, N M

    2001-02-01

    This paper gives a brief description of the recently formalized International Mass Spectrometry Society (IMSS). It is presented here in order to increase awareness of the opportunities for collaboration in mass spectrometry in an international context. It also describes the recent 15th International Mass Spectrometry Conference, held August/September 2000, in Barcelona. Each of the authors is associated with the IMSS. The 15th Conference, which covers all of mass spectrometry on a triennial basis, was chaired by Professor Emilio Gelpi of the Instituto de Investigaciones Biomedicas, Barcelona. The outgoing and founding President of the IMSS is Professor Graham Cooks, Purdue University, and the incoming President is Professor Nico Nibbering, University of Amsterdam. Similar material has been provided to the Editors of other journals that cover mass spectrometry.

  11. Effective determination of the long-lived nuclide 41Ca in nuclear reactor bioshield concretes: comparison of liquid scintillation counting and accelerator mass spectrometry.

    Science.gov (United States)

    Warwick, P E; Croudace, I W; Hillegonds, D J

    2009-03-01

    The routine application of liquid scintillation counting to (41)Ca determination has been hindered by the absence of traceable calibration standards of known (41)Ca activity concentrations. The introduction of the new IRMM (41)Ca mass-spectrometric standards with sufficiently high (41)Ca activities for radiometric detection has partly overcome this although accurate measurement of stable Ca concentrations coupled with precise half-life data are still required to correct the certified (41)Ca:(40)Ca ratios to (41)Ca activity concentrations. In this study, (41)Ca efficiency versus quench curves have been produced using the IRMM standard, and their accuracy validated by comparison with theoretical calculations of (41)Ca efficiencies. Further verification of the technique was achieved through the analysis of (41)Ca in a reactor bioshield core that had been previously investigated for other radionuclide variations. Calcium-41 activity concentrations of up to 25 Bq/g were detected. Accelerator mass spectrometry (AMS) measurements of the same suite of samples showed a very good agreement, providing validation of the procedure. Calcium-41 activity concentrations declined exponentially with distance from the core of the nuclear reactor and correlated well with the predicted neutron flux.

  12. Accelerator mass spectrometry analysis of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets.

    Science.gov (United States)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian; Fu, Yunchong

    2015-05-01

    Separation of carrier-free iodine from low-level iodine samples and accurate measurement of ultra-low-level (129)I in microgram iodine target are essential but a bottleneck in geology and environment research using naturally produced (129)I. This article presents a detection technique of accelerator mass spectrometry (AMS) for accurate determination of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally and electrically conductive matrix to be mixed with AgI-AgCl powder, in order to obtain and maintain a stable and high iodine ion current intensity, as well as less memory effect and low background level of (129)I. The most optimal ratio of the Nb matrix to the AgI-AgCl powder was found to be 5:1 by mass. The typical current of (127)I(5+) using AgI-AgCl targets with iodine content from 5 to 80 μg was measured to be 5 to 100 nA. Four-year AMS measurements of the (129)I/(127)I ratios in standards of low iodine content and the machine blanks showed a good repeatability and stability.

  13. Comparison of accelerator mass spectrometry with gas chromatography for the determination of pesticide residues in individual items in the diets of wild birds and mammals.

    Science.gov (United States)

    Brown, Peter; Garner, Colin; Glass, Richard; Ridgway, Chris; Hart, Andy

    2004-06-16

    Methods to refine the assessment of exposure of wild birds and mammals to pesticides required measurement of pesticide residues in very small samples of their diets. Sample sizes were in the 1-100 mg range, and the target residue for measurement was 0.01 mg/kg. Gas chromatography-mass spectrometry (GC-MS) with large volume injection was compared with the use of an accelerator mass spectrometer (AMS) to measure residues of pesticide labeled at near-background levels with carbon-14. The GC-MS method was able to detect residues down to 0.1 ng per item of diet, and the AMS detected the radiolabel down to 1 mBq (0.06 disintegration per minute, 1 ng of pesticide at the specific activity used) per sample. The target residue level was achieved by the GC-MS method for samples down to 10 mg. The GC method appeared to be best suited to monitoring residues in field studies, and the AMS shows great potential for use in laboratory experiments concerning pesticide degradation.

  14. Addressing metabolite safety during first-in-man studies using ¹⁴C-labeled drug and accelerator mass spectrometry.

    Science.gov (United States)

    Lappin, Graham; Seymour, Mark

    2010-07-01

    Active drug metabolites formed in humans but present in relatively low abundance in preclinical species can lead to unpredicted adverse effects during clinical use. The regulatory guidelines in recent years have therefore required that the metabolism of a drug be quantitatively compared between preclinical species and human at the earliest practicable stage of drug development. Amongst the variety of methods available, inclusion of low radioactive doses of ¹⁴C drug in first-in-man studies coupled to the sensitive analytical technology of accelerator MS (AMS) has found utility. Measurement of ¹⁴C by AMS allows for quantification of metabolites, even if their structures are unknown, and, when used in conjunction with LC-MS, can provide both quantitative and structural data. This review examines a typical approach to using AMS and associated analytical methods in addressing the regulatory guidelines and discusses a number of possible scenarios including the question of steady state.

  15. Speciation analysis of 129I in seawater using coprecipitation and accelerator mass spectrometry and its applications

    DEFF Research Database (Denmark)

    Xing, Shan; Hou, Xiaolin; Aldahan, Ala

    2017-01-01

    Speciation analysis of long-lived 129I in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of 129I based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of 127I carrier, the sep...

  16. Mass Spectrometry of Halopyrazolium Salts

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Pande, U. C.;

    1983-01-01

    Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry. Dealkylation was found to be the predominant thermal decomposition. An exchange between covalent and ionic halogen prior...

  17. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    Science.gov (United States)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  18. Accelerator mass spectrometry analysis of {sup 14}C-oxaliplatin concentrations in biological samples and {sup 14}C contents in biological samples and antineoplastic agents

    Energy Technology Data Exchange (ETDEWEB)

    Toyoguchi, Teiko, E-mail: tteiko@med.id.yamagata-u.ac.jp [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kato, Kazuhiro; Tokanai, Fuyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the {sup 14}C concentration in {sup 14}C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of {sup 14}C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a {sup 14}C content of water in three vacuum blood collection tubes and a syringe were measured. {sup 14}C was not detected from water in these devices. The mean {sup 14}C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of {sup 14}C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, {sup 14}C contents of the antineoplastic agents were quantitated. {sup 14}C contents were different among 10 antineoplastic agents; {sup 14}C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  19. Microdose study of 14C-acetaminophen with accelerator mass spectrometry to examine pharmacokinetics of parent drug and metabolites in healthy subjects.

    Science.gov (United States)

    Tozuka, Z; Kusuhara, H; Nozawa, K; Hamabe, Y; Ikushima, I; Ikeda, T; Sugiyama, Y

    2010-12-01

    A study of the pharmacokinetics of (14)C-labeled acetaminophen (AAP) was performed in healthy Japanese subjects receiving an oral microdose of the drug. After separation by high-performance liquid chromatography (HPLC), the levels of AAP and its metabolites in the pooled plasma specimens were quantified using accelerator mass spectrometry (AMS). The total body clearance (CL(tot))/bioavailability (F) of AAP was within the variation in the reported values at therapeutic doses, indicating the linearity of AAP pharmacokinetics. AAP-glucuronide (Glu) and AAP-4-O-sulfate satisfied the criteria of safety testing of drug metabolites. AMS could detect AAP-Cys, the active metabolite of AAP conjugated with cysteine, in the urine. Probenecid prolonged the systemic elimination of total radioactivity and caused a marked decrease in AAP-Glu levels in plasma. Probenecid likely inhibited the glucuronidation of AAP and the renal elimination of AAP-4-O-sulfate. Microdosing of (14)C-labeled drug followed by AMS is a powerful tool that can be used in the early phase of drug development for pharmacokinetic analysis of drugs and their metabolites and for detecting the formation of active metabolites in humans.

  20. Early Upper Paleolithic chronology in the Levant: new ABOx-SC accelerator mass spectrometry results from the Mughr el-Hamamah Site, Jordan.

    Science.gov (United States)

    Stutz, Aaron Jonas; Shea, John J; Rech, Jason A; Pigati, Jeffrey S; Wilson, Jim; Belmaker, Miriam; Albert, Rosa Maria; Arpin, Trina; Cabanes, Dan; Clark, Jamie L; Hartman, Gideon; Hourani, Fuad; White, Chantel E; Nilsson Stutz, Liv

    2015-08-01

    Methodological developments and new paleoanthropological data remain jointly central to clarifying the timing and systemic interrelationships between the Middle-Upper Paleolithic (MP-UP) archaeological transition and the broadly contemporaneous anatomically modern human-archaic biological turnover. In the recently discovered cave site of Mughr el-Hamamah, Jordan, in situ flint artifacts comprise a diagnostic early Upper Paleolithic (EUP) assemblage. Unusually well-preserved charcoal from hearths and other anthropogenic features associated with the lithic material were subjected to acid-base-wet oxidation-stepped combustion (ABOx-SC) pretreatment. This article presents the ABOx-SC accelerator mass spectrometry (AMS) radiocarbon dates on nine charcoal specimens from a single palimpsest occupation layer. Date calibration was carried out using the INTCAL13 radiocarbon calibration dataset. With the bulk of the material dating to 45-39 ka cal BP (thousands of years calibrated before present), the Mughr el-Hamamah lithic artifacts reveal important differences from penecontemporaneous sites in the region, documenting greater technological variability than previously known for this time frame in the Levant. The radiocarbon data from this EUP archaeological context highlight remaining challenges for increasing chronological precision in documenting the MP-UP transition.

  1. Towards biomarker-dependent individualized chemotherapy: exploring cell-specific differences in oxaliplatin-DNA adduct distribution using accelerator mass spectrometry.

    Science.gov (United States)

    Hah, Sang Soo; Henderson, Paul T; Turteltaub, Kenneth W

    2010-04-15

    Oxaliplatin is a third-generation platinum-based anticancer drug that is currently used in the treatment of metastatic colorectal cancer. Oxaliplatin, like other platinum-based anticancer drugs such as cisplatin and carboplatin, is known to induce apoptosis in tumor cells by binding to nuclear DNA, forming monoadducts, and intra- and interstrand diadducts. Previously, we reported an accelerator mass spectrometry (AMS) assay to measure the kinetics of oxaliplatin-induced DNA damage and repair [Hah, S. S.; Sumbad, R. A.; de Vere White, R. W.; Turteltaub, K. W.; Henderson, P. T. Chem. Res. Toxicol.2007, 20, 1745]. Here, we describe another application of AMS to the measurement of oxaliplatin-DNA adduct distribution in cultured platinum-sensitive testicular (833K) and platinum-resistant breast (MDA-MB-231) cancer cells, which resulted in elucidation of cell-dependent differentiation of oxaliplatin-DNA adduct formation, implying that differential adduction and/or accumulation of the drug in cellular DNA may be responsible for the sensitivity of cancer cells to platinum treatment. Ultimately, we hope to use this method to measure the intrinsic platinated DNA adduct repair capacity in cancer patients for use as a biomarker for diagnostics or a predictor of patient outcome.

  2. An effective method of UV-oxidation of dissolved organic carbon in natural waters for radiocarbon analysis by accelerator mass spectrometry

    Science.gov (United States)

    Xue, Yuejun; Ge, Tiantian; Wang, Xuchen

    2015-12-01

    Radiocarbon (14C) measurement of dissolved organic carbon (DOC) is a very powerful tool to study the sources, transformation and cycling of carbon in the ocean. The technique, however, remains great challenges for complete and successful oxidation of sufficient DOC with low blanks for high precision carbon isotopic ratio analysis, largely due to the overwhelming proportion of salts and low DOC concentrations in the ocean. In this paper, we report an effective UV-Oxidation method for oxidizing DOC in natural waters for radiocarbon analysis by accelerator mass spectrometry (AMS). The UV-oxidation system and method show 95%±4% oxidation efficiency and high reproducibility for DOC in both river and seawater samples. The blanks associated with the method was also low (about 3 µg C) that is critical for 14C analysis. As a great advantage of the method, multiple water samples can be oxidized at the same time so it reduces the sample processing time substantially compared with other UV-oxidation method currently being used in other laboratories. We have used the system and method for 14C studies of DOC in rivers, estuaries, and oceanic environments and have received promise results.

  3. Accelerator mass spectrometry can be used to assess vitamin A metabolism quantitatively in boys in a community setting.

    Science.gov (United States)

    Aklamati, Emmanuel K; Mulenga, Modest; Dueker, Stephen R; Buchholz, Bruce A; Peerson, Janet M; Kafwembe, Emmanuel; Brown, Kenneth H; Haskell, Marjorie J

    2010-09-01

    A survey indicated that high-dose vitamin A (HD-VA) supplements had no apparent effect on vitamin A (VA) status, assessed by serum retinol concentrations, of Zambian children lt 5 y of age. To explore possible reasons for the lack of response, we quantified absorption, retention, and urinary elimination of either a single HD-VA supplement (209.8 micromol; 60 mg) or a smaller dose of stable isotope (SI)-labeled VA (17.5 micromol; 5 mg), which was used to estimate VA pool size, in 3- to 4-y-old Zambian boys (n = 4 for each VA dose). A tracer dose of [(14)C(2)]-labeled VA (0.925 kBq; 25 nCi) was coadministered with the HD-VA supplement or SI-labeled VA, and 24-h stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-h urine samples at 4 later time points. Accelerator MS was used to quantify (14)C in stool and urine. Estimates of absorption, retention, and the urinary elimination rate (UER) were 83.8 +/- 7.1%, 76.3 +/- 6.7%, and 1.9 +/- 0.6%/d, respectively, for the HD-VA supplement and 76.5 +/- 9.5%, 71.1 +/- 9.4%, and 1.8 +/- 1.2%/d, respectively, for the SI-labeled VA. Mean estimates of absorption, retention, and the UER did not differ by size of the VA dose administered. Estimated absorption and retention were negatively associated with reported fever (r = minus 0.83; P = 0.011). The HD-VA supplement and SI-labeled VA were adequately absorbed, retained, and utilized in apparently healthy Zambian preschool-age boys; absorption and retention may be affected by recent fever.

  4. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  5. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  6. Mass Spectrometry Instrumentation in Proteomics

    DEFF Research Database (Denmark)

    Sprenger, Richard Remko; Roepstorff, Peter

    2012-01-01

    Mass spectrometry has evolved into a crucial technology for the field of proteomics, enabling the comprehensive study of proteins in biological systems. Innovative developments have yielded flexible and versatile mass spectrometric tools, including quadrupole time-of-flight, linear ion trap...

  7. Functional genomics by mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Mann, M

    2000-01-01

    Systematic analysis of the function of genes can take place at the oligonucleotide or protein level. The latter has the advantage of being closest to function, since it is proteins that perform most of the reactions necessary for the cell. For most protein based ('proteomic') approaches to gene...... function, mass spectrometry is the method of choice. Mass spectrometry can now identify proteins with very high sensitivity and medium to high throughput. New instrumentation for the analysis of the proteome has been developed including a MALDI hybrid quadrupole time of flight instrument which combines...... numbers of intact proteins by mass spectrometry directly. Examples from this laboratory illustrate biological problem solving by modern mass spectrometric techniques. These include the analysis of the structure and function of the nucleolus and the analysis of signaling complexes....

  8. Digital Imaging Mass Spectrometry

    CERN Document Server

    Bamberger, Casimir; Bamberger, Andreas

    2011-01-01

    Methods to visualize the two-dimensional distribution of molecules by mass spectrometric imaging evolve rapidly and yield novel applications in biology, medicine, and material surface sciences. Most mass spectrometric imagers acquire high mass resolution spectra spot-by-spot and thereby scan the object's surface. Thus, imaging is slow and image reconstruction remains cumbersome. Here we describe an imaging mass spectrometer that exploits the true imaging capabilities by ion optical means for the time of flight mass separation. The mass spectrometer is equipped with the ASIC Timepix chip as an array detector to acquire the position, mass, and intensity of ions that are imaged by MALDI directly from the target sample onto the detector. This imaging mass spectrometer has a spatial resolving power at the specimen of (84\\pm35) \\mu m with a mass resolution of 45 and locates atoms or organic compounds on a surface area up to ~2 cm2. Extended laser spots of ~5 mm2 on structured specimens allowed parallel imaging of s...

  9. Plutonium Isotopes ((239-241)Pu) Dissolved in Pacific Ocean Waters Detected by Accelerator Mass Spectrometry: No Effects of the Fukushima Accident Observed.

    Science.gov (United States)

    Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Golser, Robin; Gómez-Guzmán, José Manuel; Korschinek, Gunther; Kortmann, Florian; Lierse von Gostomski, Christoph; Ludwig, Peter; Steier, Peter; Tazoe, Hirofumi; Yamada, Masatoshi

    2017-02-21

    The concentration of plutonium (Pu) and the isotopic ratios of (240)Pu to (239)Pu and (241)Pu to (239)Pu were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples (20 L each) collected in late 2012. The isotopic Pu ratios are important indicators of different contamination sources and were used to identify a possible release of Pu into the ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. In particular, (241)Pu is a well-suited indicator for a recent entry of Pu because (241)Pu from fallout of nuclear weapon testings has already significantly decayed. A total of 10 ocean water samples were prepared at the Radiochemie München of the TUM and analyzed at the Vienna Environmental Research Laboratory (VERA). Several samples showed a slightly elevated (240)Pu/(239)Pu ratio of up to 0.22 ± 0.02 compared to global fallout ((240)Pu/(239)Pu = 0.180 ± 0.007), whereas all measured (241)Pu-to-(239)Pu ratios were consistent with nuclear weapon fallout ((241)Pu/(239)Pu < 2.4 × 10(-3)), which means that no impact from the Fukushima accident was detected. From the average (241)Pu-to-(239)Pu ratio of 8-2(+3) ×10(-4) at a sampling station located at a distance of 39.6 km to FDNPP, the 1-σ upper limit for the FDNPP contribution to the (239)Pu inventory in the water column was estimated to be 0.2%. Pu, with the signature of weapon-grade Pu was found in a single sample collected around 770 km off the west coast of the United States.

  10. Determination of ultralow level 129I/127I in natural samples by separation of microgram carrier free iodine and accelerator mass spectrometry detection.

    Science.gov (United States)

    Hou, Xiaolin; Zhou, Weijian; Chen, Ning; Zhang, Luyuan; Liu, Qi; Luo, Maoyi; Fan, Yukun; Liang, Wangguo; Fu, Yunchong

    2010-09-15

    Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level (129)I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced (129)I. In this work, we present a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass spectrometry was used to measure ultralow level (129)I in micrograms of iodine target. The recovery of iodine in the entire separation procedure is higher than 80% and 65% for solid and water samples, respectively. One microgram iodine in the target (AgI-AgCl) can produce a stable (127)I signal for AMS measurement of (129)I/(127)I, and a detection limit of this method for (129)I is calculated to be 10(5) atoms. This will allow us to accurately determine (129)I in prenuclear geological samples of low iodine concentration with (129)I/(127)I of 10(-12), such as loess, soil, coral, rock, sediment, and groundwater. Some samples with low iodine content have been successfully analyzed, and the lowest value of the (129)I/(127)I ratio of 2 × 10(-11) was observed in 23.5 and 63.5 m loess samples collected in the Loess Plateau, China. The developed method sheds light on a wide application in earth science.

  11. First-order ion-optics calculations for an Accelerator Mass Spectrometry system using SRIM and S{sup 3}M

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Guzman, J.M., E-mail: jm_gomez@us.es [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Dpto. de Fisica Atomica, Molecular y Nuclear, University of Seville (Spain); Gomez-Morilla, I. [Technische Universitaet Dresden, Fakultaet Maschinenwesen, Professur fuer Magnetofluiddynamik (Germany); Enamorado-Baez, S.M.; Moreno Suarez, A.I.; Pinto-Gomez, A.R. [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain)

    2012-06-15

    In this paper, we describe the transport of a simulated beam, created with the S{sup 3}M beam generation module, along the real beam line of the Accelerator Mass Spectrometry (AMS) facility located at Centro Nacional de Aceleradores (CNA, Seville, Spain). The beam transport through the optical system was determined using the transfer-matrix method, which can easily calculate the beam envelopes without having to track all individual particles, evaluating the ability of such systems and saving computation time. The beam size results given by S{sup 3}M were compared to the real beam size in three of the four image points that the system has (P1, P2 and P3), corresponding with the position of Faradays Cups where the {sup 127}I current was measured, obtaining a good agreement between them. This suggests that the first order approximation model is enough to simulate the optical behavior of the system. It is shown that the beam line has a focusing behavior, minimizing the beam size from {+-}3 mm at the exit of the ion source to {+-}1.09 mm at the detector's entrance window. Using the beam emittance diagram simulations, it is shown that when ions pass through the stripper, the angles of their trajectories are altered by scattering with the gas molecules and the geometrical emittance enlarges, according to Liouville's Theorem. The study presented in this work gives confidence and open new perspectives in simulations with S{sup 3}M in AMS facilities contributing to the understanding of their optical behavior.

  12. Accelerator Mass Spectrometry Analysis of Ultra-Low-Level 129I in Carrier-Free AgI-AgCl Sputter Targets

    DEFF Research Database (Denmark)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian;

    2015-01-01

    mass spectrometry (AMS) for accurate determination of ultra-low-level 129I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally...

  13. Mass spectrometry for biomarker development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chaochao; Liu, Tao; Baker, Erin Shammel; Rodland, Karin D.; Smith, Richard D.

    2015-06-19

    Biomarkers potentially play a crucial role in early disease diagnosis, prognosis and targeted therapy. In the past decade, mass spectrometry based proteomics has become increasingly important in biomarker development due to large advances in technology and associated methods. This chapter mainly focuses on the application of broad (e.g. shotgun) proteomics in biomarker discovery and the utility of targeted proteomics in biomarker verification and validation. A range of mass spectrometry methodologies are discussed emphasizing their efficacy in the different stages in biomarker development, with a particular emphasis on blood biomarker development.

  14. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging

    NARCIS (Netherlands)

    Kiss, A.; Smith, D.F.; Jungmann, JH; Heeren, R.M.A.

    2013-01-01

    RATIONALE: Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with

  15. A history of mass spectrometry in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Downard, K.M.; de Laeter, J.R. [University of Sydney, Sydney, NSW (Australia)

    2005-09-01

    An interest in mass spectrometry in Australia can be traced back to the 1920s with an early correspondence with Francis Aston who first visited these shores a decade earlier. The region has a rich tradition in both the development of the field and its application, from early measurements of ionization and appearance potentials by Jim Morrison at the Council for Scientific and Industrial Research (CSIR) around 1950 to the design and construction of instrumentation including the first use of a triple quadrupole mass spectrometer for tandem mass spectrometry, the first suite of programs to simulate ion optics (SIMION), the development of early TOF/TOF instruments and orthogonal acceleration and the local design and construction of several generations of a sensitive high-resolution ion microprobe (SHRIMP) instrument. Mass spectrometry has been exploited in the study and characterization of the constituents of this nation's unique flora and fauna from Australian apples, honey, tea plant and eucalyptus oil, snake, spider, fish and frog venoms, coal, oil, sediments and shale, environmental studies of groundwater to geochronological dating of limestone and granite, other terrestrial and meteoritic rocks and coral from the Great Barrier Reef. This article traces the history of mass spectrometry in its many guises and applications in the island continent of Australia. It focuses on contributions of scientists who played a major role in the early establishment of mass spectrometry in Australia. In general, those who are presently active in the field, and whose histories are incomplete, have been mentioned at best only briefly despite their important contributions to the field.

  16. A mass spectrometry primer for mass spectrometry imaging.

    Science.gov (United States)

    Rubakhin, Stanislav S; Sweedler, Jonathan V

    2010-01-01

    Mass spectrometry imaging (MSI), a rapidly growing subfield of chemical imaging, employs mass spectrometry (MS) technologies to create single- and multi-dimensional localization maps for a variety of atoms and molecules. Complimentary to other imaging approaches, MSI provides high chemical specificity and broad analyte coverage. This powerful analytical toolset is capable of measuring the distribution of many classes of inorganics, metabolites, proteins, and pharmaceuticals in chemically and structurally complex biological specimens in vivo, in vitro, and in situ. The MSI approaches highlighted in this Methods in Molecular Biology volume provide flexibility of detection, characterization, and identification of multiple known and unknown analytes. The goal of this chapter is to introduce investigators who may be unfamiliar with MS to the basic principles of the mass spectrometric approaches as used in MSI. In addition to guidelines for choosing the most suitable MSI method for specific investigations, cross-references are provided to the chapters in this volume that describe the appropriate experimental protocols.

  17. Chemical Ionization Mass Spectrometry.

    Science.gov (United States)

    1980-01-30

    mass spectrometer. Also discussed were Corporation, St. Louis , Mo. unique analytical applications of several negative ion chemical Synthesis of the...were purchsed from obtained at a probe temperature of 180-200 °C and displays Sigma Chemical Co.. St. Louis , Mo. Arginine hydrochloride (4) a M4...13) Rosenstock. H, M.: Drax . K.: Stener. B. W: Hernon J. T. J. Phys. Chem, Ref. Data 1977, 6, Supl. 1. 774-783,167 occur in the ratio of 10/ 1

  18. Human Microdosing with Carcinogenic Polycyclic Aromatic Hydrocarbons: In Vivo Pharmacokinetics of Dibenzo[def,p]chrysene and Metabolites by UPLC Accelerator Mass Spectrometry.

    Science.gov (United States)

    Madeen, Erin P; Ognibene, Ted J; Corley, Richard A; McQuistan, Tammie J; Henderson, Marilyn C; Baird, William M; Bench, Graham; Turteltaub, Ken W; Williams, David E

    2016-10-17

    Metabolism is a key health risk factor following exposures to pro-carcinogenic polycyclic aromatic hydrocarbons (PAHs) such as dibenzo[def,p]chrysene (DBC), an IARC classified 2A probable human carcinogen. Human exposure to PAHs occurs primarily from the diet in nonsmokers. However, little data is available on the metabolism and pharmacokinetics in humans of high molecular weight PAHs (≥4 aromatic rings), including DBC. We previously determined the pharmacokinetics of DBC in human volunteers orally administered a microdose (29 ng; 5 nCi) of [(14)C]-DBC by accelerator mass spectrometry (AMS) analysis of total [(14)C] in plasma and urine. In the current study, we utilized a novel "moving wire" interface between ultraperformance liquid chromatography (UPLC) and AMS to detect and quantify parent DBC and its major metabolites. The major [(14)C] product identified in plasma was unmetabolized [(14)C]-DBC itself (Cmax = 18.5 ±15.9 fg/mL, Tmax= 2.1 ± 1.0 h), whereas the major metabolite was identified as [(14)C]-(+/-)-DBC-11,12-diol (Cmax= 2.5 ±1.3 fg/mL, Tmax= 1.8 h). Several minor species of [(14)C]-DBC metabolites were also detected for which no reference standards were available. Free and conjugated metabolites were detected in urine with [(14)C]-(+/-)-DBC-11,12,13,14-tetraol isomers identified as the major metabolites, 56.3% of which were conjugated (Cmax= 35.8 ± 23.0 pg/pool, Tmax = 6-12 h pool). [(14)C]-DBC-11,12-diol, of which 97.5% was conjugated, was also identified in urine (Cmax = 29.4 ± 11.6 pg/pool, Tmax = 6-12 h pool). Parent [(14)C]-DBC was not detected in urine. This is the first data set to assess metabolite profiles and associated pharmacokinetics of a carcinogenic PAH in human volunteers at an environmentally relevant dose, providing the data necessary for translation of high dose animal models to humans for translation of environmental health risk assessment.

  19. The effect of different acid-treatments on the age spectrum of organic matter in sediments determined by Ramped PyrOx/accelerator mass spectrometry

    Science.gov (United States)

    McNichol, A. P.; Bao, R.

    2016-02-01

    Studies of the radiocarbon and stable carbon isotopes of organic matter (OM) in sediments have become common and are an effective way to understand the fate of sedimentary OM burial in the aquatic environment. In practice, obtaining the radiocarbon and stable carbon isotopic composition in sediments requires first removing inorganic carbon by acid treatment. Two common treatments are acid rinsing and fumigation. The radiocarbon ages and stable carbon isotopic values obtained using the different acid-treatments can differ significantly, but the details of the change of organic components have received much less attention. A new approach was recently developed for radiocarbon dating of carbonate -poor and/or rich sediments using a so-called ramped pyrolysis/oxidation ("Ramped PyrOx") method in combination with accelerator mass spectrometry. Radiocarbon and stable carbon isotopic analysis of the CO2 that evolves under a linear temperature program allows separation of OC components in sediments based on their thermochemical stability (Rosenheim et al., 2008). In this preliminary study, we explore the utility of the Ramped PyrOx method for determining the effect of different acid-treatments on radiocarbon ages and carbon isotopic compositions of OM in sediments. The observations indicate that the HCl rinsing method alters OM more than fumigation in lower carbonate samples while the opposite occurs in the high carbonate samples. This result has implications for studies of the transfer of carbon from the terrestrial to the marine environment because these are samples that contain low amounts of carbonate material. Recommendations for the most appropriate way to treat these samples will be made. The loss of organic matter during the HCl rinsing in the marine carbonate poor sediments could be one of the reasons that radiocarbon ages in the labile thermal fractions were older than that processed by fumigation, whereas younger in the resistant thermal fractions. The distinct

  20. Application of Accelerator Mass Spectrometry in Nuclear Science%加速器质谱在核科学研究中的应用进展

    Institute of Scientific and Technical Information of China (English)

    王晓波; 王伟; 胡金君; 王慧娟; 管永精

    2013-01-01

      Accelerator mass spectrometry (AMS) is a promising method to provide extreme sensitivity measurements of the production yields of long-lived radioisotopes, which cannot be detected by other methods. AMS technique plays an important role in the research of nuclear physics, as well as the application field of AMS covered nuclear science and technology, life science, earth science, environmental science, archaeology etc. The newest AMS field is that of actinide, particularly U and Pu, isotopic assay with expanding applications in nuclear safeguards and monitoring, and as a modern bomb-fallout tracer for atmospheric transport and surface sediment movement. This paper reviews the applications of AMS in the research of nuclear energy and nuclear security including the research of half life of radionuclides, cross section of nuclear reaction.%  加速器质谱(AMS)由于其极高的测量灵敏度而广泛应用于核科学、生命科学、地球科学、环境科学和考古学等研究领域,同时,AMS还可以用来分析样品中的微量核素,是核科学领域的重要研究工具。目前,AMS研究的最新领域是U和Pu等锕系元素的测量,在核保障、核监测及核试验沉降物示踪大气输运和表面沉积物的迁移等研究中也显示出了较大潜力。综述了AMS在核科学研究中的应用及研究现状,主要包括AMS在放射性核素半衰期的测定、核反应截面的测量等方面的研究进展。

  1. Determination of the Tissue Distribution and Excretion by Accelerator Mass Spectrometry of the Nonadecapeptide 14C-Moli1901 in Beagle dogs after Intratracheal Instillation

    Energy Technology Data Exchange (ETDEWEB)

    Rickert, D E; Dingley, K H; Ubick, E; Dix, K J; Molina, L

    2004-07-02

    Administration of {sup 14}C-Moli1901 (duramycin, 2622U90), a 19 amino acid polycyclic peptide by intratracheal instillation (approximately 100 {micro}g) into the left cranial lobe of the lung of beagle dogs resulted in retention of 64% of the dose in the left cranial lobe for up to 28 days. In this study, we used accelerator mass spectrometry (AMS) to quantify Moli901 following administration of only 0.045 {micro}Ci of {sup 14}C-Moli901 per dog. Limits of quantitation of AMS were 0.03 (urine) to 0.3 (feces) ng equiv. Moli1901/g. Whole blood and plasma concentrations of {sup 14}C were <5ng/ml at all times after the dose. Concentrations of {sup 14}C in whole blood and plasma declined over the first day after the dose and rose thereafter, with the rise in plasma concentrations lagging behind those in whole blood. During the first 3 days after the dose, plasma accounted for the majority of {sup 14}C in whole blood, but after that time, plasma accounted for only 25-30% of the {sup 14}C in whole blood. Tissue (left and right caudal lung lobe, liver, kidney, spleen, brain) and bile concentrations were low, always less than 0.25% the concentrations found in the left cranial lung lobe. Approximately 13% of the dose was eliminated in urine and feces in 28 days, with fecal elimination accounting for about 10% of the dose. The data presented here are consistent with that obtained in other species. Moli1901 is slowly absorbed and excreted from the lung, and it does not accumulate in other tissues. Moli1901 is currently in the clinic and has proven to be safe in single dose studies in human volunteers and cystic fibrosis patients by the inhalation route. No information on the disposition of the compound in humans is available. This study in dogs demonstrates the feasibility of obtaining that information using {sup 14}C-Moli1901 and AMS.

  2. Quantification of DNA strand breaks and abasic sites by oxime derivatization and accelerator mass spectrometry: application to gamma-radiation and peroxynitrite.

    Science.gov (United States)

    Zhou, Xinfeng; Liberman, Rosa G; Skipper, Paul L; Margolin, Yelena; Tannenbaum, Steven R; Dedon, Peter C

    2005-08-01

    We report a highly sensitive method to quantify abasic sites and deoxyribose oxidation products arising in damaged DNA. The method exploits the reaction of aldehyde- and ketone-containing deoxyribose oxidation products and abasic sites with [(14)C]methoxyamine to form stable oxime derivatives, as originally described by Talpaert-Borle and Liuzzi [Reaction of apurinic/apyrimidinic sites with [(14)C]methoxyamine. A method for the quantitative assay of AP sites in DNA, Biochim. Biophys. Acta 740 (1983) 410-416]. The sensitivity of the method was dramatically improved by the application of accelerator mass spectrometry to quantify the (14)C, with a limit of detection of 1 lesion in 10(6) nucleotides in 1 microg of DNA. The method was validated using DNA containing a defined quantity of abasic sites, with a >0.95 correlation between the quantities of abasic sites and those of methoxyamine labels. The original applications of this and similar oxyamine derivatization methods have assumed that abasic sites are the only aldehyde-containing DNA damage products. However, deoxyribose oxidation produces strand breaks and abasic sites containing a variety of degradation products with aldehyde and ketone moieties. To assess the utility of methoxyamine labeling for quantifying strand breaks and abasic sites, the method was applied to plasmid DNA treated with gamma-radiation and peroxynitrite. For gamma-radiation, there was a 0.99 correlation between the quantity of methoxyamine labels and the quantity of strand breaks and abasic sites determined by a plasmid nicking assay; the abasic sites comprised less than 10% of the radiation-induced DNA damage. Studies with peroxynitrite demonstrate that the method, in conjunction with DNA repair enzymes that remove damaged bases to produce aldehydic sugar residues or abasic sites, is also applicable to quantifying nucleobase lesions in addition to strand break products. Compared to other abasic site quantification techniques, the modified

  3. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zastepa, Arthur; Pick, Frances R; Blais, Jules M; Saleem, Ammar

    2015-05-04

    The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic-lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g(-1) dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g(-1) dw on sediment particles and 132 ng mL(-1) in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (K(d)), MC-RR had the highest affinity for sediment particles (log K(d)=1.3) while MC-LA had the lowest affinity (log K(d)=-0.4), partitioning mainly into pore waters. Our findings confirm that sediments serve as a reservoir for microcystins but suggest that some variants may diffuse into overlying water thereby constituting a new route of exposure following the dissipation of toxic blooms. The method is well suited to determine the fate and persistence of different

  4. Quantification of absorption, retention and elimination of two different oral doses of vitamin A in Zambian boys using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aklamati, E K; Mulenga, M; Dueker, S R; Buchholz, B A; Peerson, J M; Kafwembe, E; Brown, K H; Haskell, M J

    2009-10-12

    A recent survey indicated that high-dose vitamin A supplements (HD-VAS) had no apparent effect on vitamin A (VA) status of Zambian children <5 y of age. To explore possible reasons for the lack of response to HD-VAS among Zambian children, we quantified the absorption, retention, and urinary elimination of either a single HDVAS (60 mg) or a smaller dose of stable isotope (SI)-labeled VA (5 mg), which was used to estimate VA pool size, in 3-4 y old Zambian boys (n = 4 for each VA dose). A 25 nCi tracer dose of [{sup 14}C{sub 2}]-labeled VA was co-administered with the HD-VAS or SI-labeled VA, and 24-hr stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-hr urine samples at 4 later time points. Accelerator Mass Spectrometry (AMS) was used to measure the cumulative excretion of {sup 14}C in stool and urine 3d after dosing to estimate, respectively, absorption and retention of the VAS and SI-labeled VA. The urinary elimination rate (UER) was estimated by plotting {sup 14}C in urine vs. time, and fitting an exponential equation to the data. Estimates of mean absorption, retention and the UER were 83.8 {+-} 7.1%, 76.3 {+-} 6.7%, and 1.9 {+-} 0.6%/d, respectively, for the HD-VAS and 76.5 {+-} 9.5%, 71.1 {+-} 9.4%, and 1.8 {+-} 1.2%/d, respectively for the smaller dose of SI-labeled VA. Estimates of absorption, retention and the UER did not differ by size of the VA dose administered (P=0.26, 0.40, 0.88, respectively). Estimated absorption and retention were negatively associated with reported fever (P=0.011) and malaria (P =0.010). HD-VAS and SI-labeled VA were adequately absorbed, retained and utilized in apparently healthy Zambian preschool-age boys, although absorption and retention may be affected by recent infections.

  5. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zastepa, Arthur, E-mail: arthur.zastepa@gmail.com; Pick, Frances R.; Blais, Jules M.; Saleem, Ammar

    2015-05-04

    Highlights: • First analytical method for intracellular microcystins (MCs) in sediment. • Includes a suite of variants (LR, {sup 7dm}LR, RR, YR, WR, LA, LF, LY, LW) and nodularin. • Reports the first measurements of MCs in sediment pore waters. • MCs detected in >100 year old lake sediments suggesting long-term preservation. • Sediment-pore water distribution (K{sub d}) differed between variants suggesting differences in environmental fate. - Abstract: The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic–lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g{sup −1} dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g{sup −1} dw on sediment particles and 132 ng mL{sup −1} in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water

  6. Mass Spectrometry in Polymer Chemistry

    CERN Document Server

    Barner-Kowollik, Christopher; Falkenhagen, Jana; Weidner, Steffen

    2011-01-01

    Combining an up-to-date insight into mass-spectrometric polymer analysis beyond MALDI with application details of the instrumentation, this is a balanced and thorough presentation of the most important and widely used mass-spectrometric methods.Written by the world's most proficient experts in the field, the book focuses on the latest developments, covering such technologies and applications as ionization protocols, tandem and liquid chromatography mass spectrometry, gas-phase ion-separation techniques and automated data processing. Chapters on sample preparation, polymer degradation and the u

  7. Optimization of an accelerated solvent extraction dispersive liquid-liquid microextraction method for the separation and determination of essential oil from Ligusticum chuanxiong Hort by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Yang, Guang; Sun, Qiushi; Hu, Zhiyan; Liu, Hua; Zhou, Tingting; Fan, Guorong

    2015-10-01

    In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually extraction and analysis of essential oil.

  8. A high-throughput method for the conversion of CO2 obtained from biochemical samples to graphite in septa-sealed vials for quantification of 14C via accelerator mass spectrometry.

    Science.gov (United States)

    Ognibene, Ted J; Bench, Graham; Vogel, John S; Peaslee, Graham F; Murov, Steve

    2003-05-01

    The growth of accelerator mass spectrometry as a tool for quantitative isotope ratio analysis in the biosciences necessitates high-throughput sample preparation. A method has been developed to convert CO(2) obtained from carbonaceous samples to solid graphite for highly sensitive and precise (14)C quantification. Septa-sealed vials are used along with commercially available disposable materials, eliminating sample cross contamination, minimizing complex handling, and keeping per sample costs low. Samples containing between 0.25 and 10 mg of total carbon can be reduced to graphite in approximately 4 h in routine operation. Approximately 150 samples per 8-h day can be prepared by a single technician.

  9. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    Urban, Pawel L.

    2016-10-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry-especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue 'Quantitative mass spectrometry'.

  10. Electrophoresis-mass spectrometry probe

    Science.gov (United States)

    Andresen, Brian D.; Fought, Eric R.

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

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

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Zhou, Weijian; Chen, Ning;

    2010-01-01

    a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass...... of 129I/127I, and a detection limit of this method for 129I is calculated to be 105 atoms. This will allow us to accurately determine 129I in prenuclear geological samples of low iodine concentration with 129I/127I of 10−12, such as loess, soil, coral, rock, sediment, and groundwater. Some samples...

  12. Radiocarbon positive-ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Stewart P.H.T.; Shanks, Richard P. [Scottish Universities Environmental Research Centre (SUERC), Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Donzel, Xavier; Gaubert, Gabriel [Pantechnik S.A., 13 Rue de la Résistance, 14400 Bayeux (France)

    2015-10-15

    Proof-of-principle of a new mass spectrometric technique for radiocarbon measurement is demonstrated. Interfering nitrogen and hydrocarbon molecules are largely eliminated in a charge-exchange cell operating on non-metallic gas. The positive-to-negative ion conversion is the reverse of that conventionally used in accelerator mass spectrometry (AMS) and is compatible with plasma ion sources that may be significantly more efficient and capable of greater output than are AMS sputter ion sources. The Nanogan electron cyclotron resonance (ECR) ion source employed exhibited no sample memory and the >50 kyrs age range of AMS was reproduced. A bespoke prototype new instrument is now required to optimise the plasma and cell physics and to realise hypothetical performance gains over AMS.

  13. Protein Analysis by Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Cindic, M.

    2008-04-01

    Full Text Available Soft ionization techniques, electrospray (ESI and matrix-assisted laser desorption/ionization (MALDI make the analysis of biomolecules by mass spectrometry (MS possible. MS is used for determination of the molecular weight of peptides and protein, sequence analysis, characterization of protein-ligand interactions etc. The detection limit, resolution and mass accuracy depend on instrument used (Table 1. Impurities (buffers, salts, detergents can reduce the ion intensities or even totally suppress them, so a separation method (chromatography, 2D-gel electrophoresis must be used for purification of the sample.Molecular mass of intact protein can be determined by ESI or MALDI MS. Multiply charged ions are produced by ESI MS, while singly charged ions are predominant in MALDI spectra (Fig. 2.Sequence analysis of proteins by MS can be performed using peptide mass fingerprint. In this method, proteins are separated by 2-D gel electrophoresis and digested with specific protease (Table 2 or digested and then separated by two-dimensional chromatography (Fig. 1. The obtained peptide mixtures are analyzed by MS or MALDI-TOF technique. The masses determined by MS are compared with calculated masses from database entries. Different algorithms have been developed for protein identification. Example of posttranslational modifications (N- and O-glycosylation and protein sequence complex analysis after dual digestion (endoproteinase digestion followed by endoglycosidase digestion is shown in Fig. 3.It is known that detection of peptides by MS is influenced by intrinsic properties like amino acid composition, the basicity of the C-terminal amino acid, hydrophobicity, etc. Arginine-containing peptides dominate in MS spectra of tryptic digest, so the chemical derivatization of lysine terminal residue by O-methilisourea or 2-methoxy-4,5-1H-imidazole was suggested (Fig. 4.The peptide mass fingerprint method can be improved further by peptide fragmentation using tandem

  14. Mass Spectrometry Applications for Toxicology

    Science.gov (United States)

    Mbughuni, Michael M.; Jannetto, Paul J.

    2016-01-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MSn) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  15. Mass Spectrometry Applications for Toxicology.

    Science.gov (United States)

    Mbughuni, Michael M; Jannetto, Paul J; Langman, Loralie J

    2016-12-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MS(n)) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  16. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    2016-01-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry—especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644965

  17. Radioecological studies at the National Accelerator Centre based on the determination of {sup 1}29I by accelerator mass spectrometry (AMS); Estudios radioecologicos en el Centro Nacional de Aceleradores basados en la determinacion de {sup 1}29I mediante espectrometria de masas con acelerador (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Chamizo, E.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-07-01

    Since 2006 a compact system of mass spectrometry with Accelerator (AMS) is installed at the National Center of Accelerators, Seville. After an initial set-up and study have been opening many lines of research in fields such as archeology, geology, paleontology, oceanography, oceanography, internal dosimetry and characterization of radioactive waste, among others. In particular, based on the measurement of {sup 1}29I have made contributions to the field of radioecology and radiation protection. In this work they are summarized and presented some of these investigations. (Author)

  18. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Nimz, G; Caffee, M W; McAninch, J

    2000-04-01

    This project developed techniques for measuring globally distributed radionuclides that occur today in extremely low abundances (''fallout'' from the era of atmospheric nuclear testing), and then applied these techniques to better understand the mechanisms by which radionuclides migrate. The techniques employ accelerator mass spectrometry (AMS), a relatively new analytical tool that permits this work to be conducted for the first time. The goal in this project was to develop AMS analytical techniques for {sup 129}I (fallout concentration: {approx} 10{sup 6} atoms/g) {sup 99}Tc ({approx} 10{sup 9} atoms/g), {sup 90}Sr ({approx}10{sup 7} atoms/gram soil), and {sup 93}Zr ({approx} 10{sup 9} atoms/g), and improved methods for {sup 36}Cl ({approx} 10{sup 9} atoms/g). As a demonstration of the analytical techniques, and as an investigation of identified problems associated with characterizing moisture and radionuclide movement in unsaturated desert soils, we developed a vadose zone research site at the Nevada Test Site. Our findings can be summarized as follows: (1) The distribution of chloride and {sup 36}Cl at the research site indicates that the widely-used ''chloride accumulation'' method for estimating moisture flux is erroneous; some mechanism for attenuation of chloride exists, violating an assumption of the accumulation method; (2) {sup 129}I is fractionated into several soil compartments that have varying migration abilities; the two most mobile can be tentatively identified as Fe/Mn oxyhydroxides and organic acids based on our sequential leaching techniques; (3) These most mobile constituents are capable of migrating at a rate greater than that of {sup 36}Cl, usually considered the most mobile solute in hydrologic systems; these constituents may be colloidal in character, of neutral surface charge, and therefore conservative in aqueous migration; (4) {sup 99}Tc is readily measurable by AMS, as we demonstrate by the first

  19. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  20. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  1. NICHD Biomedical Mass Spectrometry Core Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The NICHD Biomedical Mass Spectrometry Core Facility was created under the auspices of the Office of the Scientific Director to provide high-end mass-spectrometric...

  2. Single photon ionization and chemical ionization combined ion source based on a vacuum ultraviolet lamp for orthogonal acceleration time-of-flight mass spectrometry.

    Science.gov (United States)

    Hua, Lei; Wu, Qinghao; Hou, Keyong; Cui, Huapeng; Chen, Ping; Wang, Weiguo; Li, Jinghua; Li, Haiyang

    2011-07-01

    A novel combined ion source based on a vacuum ultraviolet (VUV) lamp with both single photon ionization (SPI) and chemical ionization (CI) capabilities has been developed for an orthogonal acceleration time-of-flight mass spectrometer (oaTOFMS). The SPI was accomplished using a commercial 10.6 eV krypton discharge lamp with a photon flux of about 10(11) photons s(-1), while the CI was achieved through ion-molecule reactions with O(2)(+) reactant ions generated by photoelectron ionization at medium vacuum pressure (MVP). To achieve high ionization efficiency, the ion source pressure was elevated to 0.3 mbar and the photoionization length was extended to 36 mm. As a result, limits of detection (LODs) down to 3, 4, and 6 ppbv were obtained for benzene, toluene, and p-xylene in MVP-SPI mode, and values of 8 and 10 ppbv were obtained for toluene and chloroform, respectively, in SPI-CI mode. As it is feasible to switch between MVP-SPI mode and SPI-CI mode rapidly, this system is capable of monitoring complex organic mixtures with a wide range of ionization energies (IEs). The analytical capacity of this system was demonstrated by measuring dehydrogenation products of long-chain paraffins to olefins through direct capillary sampling and drinking water disinfection byproducts from chlorine through a membrane interface.

  3. Assessment of Protein Binding of 5-Hydroxythalidomide Bioactivated in Humanized Mice with Human P450 3A-Chromosome or Hepatocytes by Two-Dimensional Electrophoresis/Accelerator Mass Spectrometry.

    Science.gov (United States)

    Yamazaki, Hiroshi; Suemizu, Hiroshi; Kazuki, Yasuhiro; Oofusa, Ken; Kuribayashi, Shunji; Shimizu, Makiko; Ninomiya, Shinichi; Horie, Toru; Shibata, Norio; Guengerich, F Peter

    2016-08-15

    Bioactivation of 5-hydroxy-[carbonyl-(14)C]thalidomide, a known metabolite of thalidomide, by human artificial or native cytochrome P450 3A enzymes, and nonspecific binding in livers of mice was assessed using two-dimensional electrophoresis combined with accelerator mass spectrometry. The apparent major target proteins were liver microsomal cytochrome c oxidase subunit 6B1 and ATP synthase subunit α in mice containing humanized P450 3A genes or transplanted humanized liver. Liver cytosolic retinal dehydrogenase 1 and glutathione transferase A1 were targets in humanized mice with P450 3A and hepatocytes, respectively. 5-Hydroxythalidomide is bioactivated by human P450 3A enzymes and trapped with proteins nonspecifically in humanized mice.

  4. Aerosol MALDI mass spectrometry for bioaerosol analysis

    NARCIS (Netherlands)

    Kleefsman, W.A.

    2008-01-01

    In the thesis Aerosol MALDI mass spectrometry for bioaerosol analysis is described how the aerosol mass spectrometer of the TU Delft has been further developed for the on-line analysis of bioaerosols. Due to the implemented improvements mass spectra with high resolution and a high mass range can be

  5. Absorption Mode FTICR Mass Spectrometry Imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kilgour, D.P.A.; Konijnenburg, M.; O'Connor, P.B.; Heeren, R.M.A.

    2013-01-01

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields

  6. Proteomics and Mass Spectrometry for Cancer Biomarker Discovery

    Directory of Open Access Journals (Sweden)

    Ming Lu

    2007-01-01

    Full Text Available Proteomics is a rapidly advancing field not only in the field of biology but also in translational cancer research. In recent years, mass spectrometry and associated technologies have been explored to identify proteins or a set of proteins specific to a given disease, for the purpose of disease detection and diagnosis. Such biomarkers are being investigated in samples including cells, tissues, serum/plasma, and other types of body fluids. When sufficiently refined, proteomic technologies may pave the way for early detection of cancer or individualized therapy for cancer. Mass spectrometry approaches coupled with bioinformatic tools are being developed for biomarker discovery and validation. Understanding basic concepts and application of such technology by investigators in the field may accelerate the clinical application of protein biomarkers in disease management.Abbreviations: 2DE: two-dimensional gel electrophoresis; ABPP: activity-based protein profiling; CEA: carcinoembryonic antigen; CI: confidence interval; ESI: electrospray ionization; FP: fluorophosphonate; HPLC: high performance liquid chromatography; ICAT: isotope coded affi nitytags; IEF: isoelectric focusing; iTRAQ: isobaric tags for relative and absolute quantification; LCMS: combined liquid chromatography-mass spectrometry; LCMSMS: liquid chromatography tandem mass spectrometry; LOD: limit of detection; m/z: mass to charge ratio; MALDI: matrix-assisted laser desorption ionization; MS: mass spectrometry; MUDPIT: multidimensional protein identification technology; NAF: nipple aspirate fluid; PMF: peptide mass fingerprinting; PSA: prostate specifi c antigen; PTMs: post-translational modifications; RPMA: reverse phase protein microarray; SELDI: surface enhanced laser desorption ionization; TOF: time-of-flight.

  7. Zero voltage mass spectrometry probes and systems

    Energy Technology Data Exchange (ETDEWEB)

    Cooks, Robert Graham; Wleklinski, Michael Stanley; Bag, Soumabha; Li, Yafeng

    2017-10-10

    The invention generally relates to zero volt mass spectrometry probes and systems. In certain embodiments, the invention provides a system including a mass spectrometry probe including a porous material, and a mass spectrometer (bench-top or miniature mass spectrometer). The system operates without an application of voltage to the probe. In certain embodiments, the probe is oriented such that a distal end faces an inlet of the mass spectrometer. In other embodiments, the distal end of the probe is 5 mm or less from an inlet of the mass spectrometer.

  8. Analysis of vitamin K-1 in fruits and vegetables using accelerated solvent extraction and liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Jakobsen, Jette

    2016-01-01

    spectrometry with atmospheric pressure chemical ionization in selected reaction monitoring mode with deuterium-labeled vitamin K1 as an internal standard. The precision was estimated as the pooled estimate of three replicates performed on three different days for spinach, peas, apples, banana, and beetroot...

  9. Methods for recalibration of mass spectrometry data

    Science.gov (United States)

    Tolmachev, Aleksey V.; Smith, Richard D.

    2009-03-03

    Disclosed are methods for recalibrating mass spectrometry data that provide improvement in both mass accuracy and precision by adjusting for experimental variance in parameters that have a substantial impact on mass measurement accuracy. Optimal coefficients are determined using correlated pairs of mass values compiled by matching sets of measured and putative mass values that minimize overall effective mass error and mass error spread. Coefficients are subsequently used to correct mass values for peaks detected in the measured dataset, providing recalibration thereof. Sub-ppm mass measurement accuracy has been demonstrated on a complex fungal proteome after recalibration, providing improved confidence for peptide identifications.

  10. Introduction to mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Matthiesen, Rune; Bunkenborg, Jakob

    2013-01-01

    Mass spectrometry has been widely applied to study biomolecules and one rapidly developing field is the global analysis of proteins, proteomics. Understanding and handling mass spectrometry data is a multifaceted task that requires many decisions to be made to get the most comprehensive information...... from an experiment. Later chapters in this book deal in-depth with various aspects of the process and how different tools can be applied to the many analytical challenges. This introductory chapter is intended as a basic introduction to mass spectrometry (MS)-based proteomics to set the scene...... for newcomers and give pointers to reference material. There are many applications of mass spectrometry in proteomics and each application is associated with some analytical choices, instrumental limitations and data processing steps that depend on the aim of the study and means of conducting it. Different...

  11. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Saiz-Jimenez, C.; Gonzalez-Vila, F.J.

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  12. Mass spectrometry of fluorocarbon-labeled glycosphingolipids

    DEFF Research Database (Denmark)

    Li, Yunsen; Arigi, Emma; Eichert, Heather;

    2010-01-01

    A method for generation of novel fluorocarbon derivatives of glycosphingolipids (GSLs) with high affinity for fluorocarbon phases has been developed, and their potential applications to mass spectrometry (MS)-based methodologies for glycosphingolipidomics have been investigated. Sphingolipid...

  13. Imaging mass spectrometry of polymeric materials

    NARCIS (Netherlands)

    Klerk, L.A.

    2009-01-01

    Imaging mass spectrometry (MS) is a technique that makes images of molecular distributions at surfaces based on mass spectral information. At a range (typically a raster) of positions, mass spectra are measured from the surface giving a characteristic fingerprint for the material that is present at

  14. Accurate mass measurements for the confirmation of Sudan azo-dyes in hot chilli products by capillary liquid chromatography-electrospray tandem quadrupole orthogonal-acceleration time of flight mass spectrometry.

    Science.gov (United States)

    Calbiani, F; Careri, M; Elviri, L; Mangia, A; Zagnoni, I

    2004-11-26

    The potential of capillary liquid chromatography (microLC)-quadrupole/time-of-flight mass spectrometry (Q-TOF MS) for the confirmation of Sudan I, II, III and IV azo-dyes as contaminants in hot-chilli food products was demonstrated. Using the microLC-electrospray ionization (ESI)-Q-TOF MS technique, accurate mass measurements of Sudan dyes were performed both on standard solutions and on matrices. Precision of exact mass measurements was calculated taking into account the ion statistics according to the number of ion sampled in the measurement. Accurate mass measurements by MS/MS experiments were performed to elucidate azo-dye fragmentation patterns. Selectivity of the microLC-Q-TOF MS method was assessed by evaluating matrix suppression effects by pre-column injection of blank hot chilli tomato sauce matrices. The results were compared with those obtained on a LC-triple quadrupole-MS system. Confirmation of Sudan I present in hot chill tomato sauce samples was obtained by accurate mass measurements. In real samples trueness of exact mass measurements was estimated to be 1.6 and 4.4 ppm when calculated for hot chilli tomato sauce and hot chilli tomato with cheese sauce samples, respectively; precision was calculated around 9.5 ppm.

  15. Microdose pharmacogenetic study of ¹⁴C-tolbutamide in healthy subjects with accelerator mass spectrometry to examine the effects of CYP2C9∗3 on its pharmacokinetics and metabolism.

    Science.gov (United States)

    Ikeda, Toshihiko; Aoyama, Shinsuke; Tozuka, Zenzaburo; Nozawa, Kohei; Hamabe, Yoshimi; Matsui, Takao; Kainuma, Michiko; Hasegawa, Setsuo; Maeda, Kazuya; Sugiyama, Yuichi

    2013-07-16

    Microdose study enables us to understand the pharmacokinetic profiles of drugs in humans prior to the conventional clinical trials. The advantage of microdose study is that the unexpected pharmacological/toxicological effects of drugs caused by drug interactions or genetic polymorphisms of metabolic enzymes/transporters can be avoided due to the limited dose. With a combination use of accelerator mass spectrometry (AMS) and (14)C-labaled compounds, the pharmacokinetics of both parent drug and its metabolites can be sensitively monitored. Thus, to demonstrate the usability of microdose study with AMS for the prediction of the impact of genetic polymorphisms of CYP enzyme on the pharmacokinetics of unchanged drugs and metabolites, we performed microdose pharmacogenetic study using tolbutamide as a CYP2C9 probe drug. A microdose of (14)C-tolbutamide (100 μg) was administered orally to healthy volunteers with the CYP2C9(∗)1/(∗)1 or CYP2C9(∗)1/(∗)3 diplotype. Area under the plasma concentration-time curve for the (14)C-radioactivity, determined by AMS, or that for the parent drug, determined by liquid chromatography/mass spectrometry, was about 1.6 times or 1.7 times greater in the CYP2C9(∗)1/(∗)3 than in the CYP2C9(∗)1/(∗)1 group, which was comparable to the previous reports at therapeutic dose. In the plasma and urine, tolbutamide, carboxytolbutamide, and 4-hydroxytolbutamide were detected and practically no other metabolites could be found in both diplotype groups. The fraction of metabolites in plasma radioactivity was slightly lower in the CYP2C9(∗)1/(∗)3 group. Microdose study can be used for the prediction of the effects of genetic polymorphisms of enzymes on the pharmacokinetics and metabolic profiles of drugs with minimal care of their pharmacological/toxicological effects.

  16. [Determination of 19 antibiotic and 2 sulfonamide metabolite residues in wild fish muscle in mariculture areas of Laizhou Bay using accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Liu, Sisi; Du, Juan; Chen, Jingwen; Zhao, Hongxia

    2014-12-01

    A sample preparation and analytical method with accelerated solvent extraction (ASE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) was developed to detect 19 antibiotic (9 sulfonamides, 4 quinolones, 3 macrolides and 3 others) and 2 sulfonamide metabolite residues in fish muscle. The target compounds were extracted using ASE and purified simultaneously by a C18 resin in the extraction cell. The extracts were evaporated to dryness, and redissolved with the initial mobile phase for HPLC-MS/MS analysis after freezing centrifugation (10,000 r/min, -4 °C) to remove the fat and other matrix compounds further. The separation of the analytes was carried out on an Xterra MS C18 column with methanol-acetonitrile (1:1, v/v) as mobile phase A and 0. 1% formic acid (containing 0. 1% ammonium formate) as mobile phase B. The spiked recoveries of the method were 55. 2%-113. 3%, with the relative standard deviations of 0. 1% - 17. 6% (n = 6). The limits of detection ranged from 0. 003 to 0. 6 ng/g. The method was applied to two fish (Synechogobius hasta and Liza haematocheilus) collected in mariculture areas of Laizhou Bay and six antibiotics were detected, in which the mass concentrations of norfloxacin were highest with mean values of 67. 01 and 27. 58 ng/g, respectively. The method is simple, rapid, highly sensitive, and useful in the study on exposure levels and environmental behavior of the antibiotics.

  17. Analysis of mass spectrometry data in proteomics

    DEFF Research Database (Denmark)

    Matthiesen, Rune; Jensen, Ole N

    2008-01-01

    that in turn allow protein identification, annotation of secondary modifications, and determination of the absolute or relative abundance of individual proteins. Advances in mass spectrometry-driven proteomics rely on robust bioinformatics tools that enable large-scale data analysis. This chapter describes......The systematic study of proteins and protein networks, that is, proteomics, calls for qualitative and quantitative analysis of proteins and peptides. Mass spectrometry (MS) is a key analytical technology in current proteomics and modern mass spectrometers generate large amounts of high-quality data...... some of the basic concepts and current approaches to the analysis of MS and MS/MS data in proteomics....

  18. A REVIEW ON MASS SPECTROMETRY DETECTORS

    Directory of Open Access Journals (Sweden)

    Khatri Neetu

    2012-10-01

    Full Text Available Mass spectrometry is an analytical technique for "weighing" molecules. Obviously, this is not done with a conventional scale or balance. Instead, mass spectrometry is based upon the principle of the motion of a charged particle that is called an ion, in an electric or magnetic field. The mass to charge ratio (m/z of the ion affects particles motion. Since the charge of an electron is known, the mass to charge ratio (m/z is a measurement of mass of an ion. Mass spectrometry research focuses on the formation of gas phase ions, and detection of ions. Detectors in mass spectrometer detect the separated ions according to m/z ratio. The main disadvantages of conventional detectors are very low sensitivity and poor detection efficiency. Detectors are of a great interest to a wide range of industrial, military, environmental and even biological applications. In recent developments, molecules of higher mass can also be detected and enhanced lifetime under the less than ideal environments typically encountered in mass spectrometers. This review deals in detail about the design, working and principle of mass spectrometric detectors and their recent developments.

  19. Linear electric field mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McComas, D.J.; Nordholt, J.E.

    1991-03-29

    A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

  20. Recent developments in Penning-trap mass spectrometry

    Science.gov (United States)

    Block, M.

    2016-06-01

    Penning-trap mass spectrometry provides atomic masses with the highest precision. At accelerator-based on-line facilities it is applied to investigate exotic radionuclides in the context of tests of fundamental symmetries, nuclear structure studies, and nuclear astrophysics research. Recent progress in slowing down radioactive ion-beams in buffer-gas cells in combination with advanced ion-manipulation techniques has paved the way to reach nuclides ever-more far from stability. In this endeavor many efforts are underway to increase the sensitivity, the efficiency, and the precision of Penning-trap mass spectrometry. In this article some recent experimental developments are addressed with the focus on the phase-imaging ion-cyclotron-resonance technique and the Fourier transform ion-cyclotron-resonance technique.

  1. Combination of accelerated solvent extraction and vortex-assisted liquid-liquid microextraction for the determination of dimethyl fumarate in textiles and leathers by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Lu, Yang; Zhu, Yan

    2014-02-01

    A simple and environmentally friendly sample preparation procedure coupled with gas chromatography-mass spectrometry was developed to assay dimethyl fumarate in textiles and leathers. The sample preparation procedure involved an accelerated solvent extraction (ASE) using water as the extract solvent, followed by the extraction and concentration of dimethyl fumarate from the aqueous solution using vortex-assisted liquid-liquid microextraction (VALLME). The parameters affecting the ASE and VALLME were optimized to achieve the maximum extraction efficiency, and the performance of the developed method was evaluated. Good linearity was observed over the range assayed (0.01-1mg/kg) with a regression coefficient of 0.998. The limit of detection and enrichment factor for the VALLME step were 0.001 mg/kg and 53, respectively. The intra- and inter-day precision were below 8.9%, and the recovery was approximately 84-103%. The as-developed method was successfully applied to textiles and leather samples.

  2. Determination of polychlorinated biphenyls in fish: optimisation and validation of a method based on accelerated solvent extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ottonello, Giuliana; Ferrari, Angelo; Magi, Emanuele

    2014-01-01

    A simple and robust method for the determination of 18 polychlorinated biphenyls (PCBs) in fish was developed and validated. A mixture of acetone/n-hexane (1:1, v/v) was selected for accelerated solvent extraction (ASE). After the digestion of fat, the clean-up was carried out using solid phase extraction silica cartridges. Samples were analysed by GC-MS in selected ion monitoring (SIM) using three fragment ions for each congener (one quantifier and two qualifiers). PCB 155 and PCB 198 were employed as internal standards. The lowest limit of detection was observed for PCB 28 (0.4ng/g lipid weight). The accuracy of the method was verified by means of the Certified Reference Material EDF-2525 and good results in terms of linearity (R(2)>0.994) and recoveries (80-110%) were also achieved. Precision was evaluated by spiking blank samples at 4, 8 and 12ng/g. Relative standard deviation values for repeatability and reproducibility were lower than 8% and 16%, respectively. The method was applied to the determination of PCBs in 80 samples belonging to four Mediterranean fish species. The proposed procedure is particularly effective because it provides good recoveries with lowered extraction time and solvent consumption; in fact, the total time of extraction is about 12min per sample and, for the clean-up step, a total solvent volume of 13ml is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. High-accuracy mass spectrometry for fundamental studies.

    Science.gov (United States)

    Kluge, H-Jürgen

    2010-01-01

    Mass spectrometry for fundamental studies in metrology and atomic, nuclear and particle physics requires extreme sensitivity and efficiency as well as ultimate resolving power and accuracy. An overview will be given on the global status of high-accuracy mass spectrometry for fundamental physics and metrology. Three quite different examples of modern mass spectrometric experiments in physics are presented: (i) the retardation spectrometer KATRIN at the Forschungszentrum Karlsruhe, employing electrostatic filtering in combination with magnetic-adiabatic collimation-the biggest mass spectrometer for determining the smallest mass, i.e. the mass of the electron anti-neutrino, (ii) the Experimental Cooler-Storage Ring at GSI-a mass spectrometer of medium size, relative to other accelerators, for determining medium-heavy masses and (iii) the Penning trap facility, SHIPTRAP, at GSI-the smallest mass spectrometer for determining the heaviest masses, those of super-heavy elements. Finally, a short view into the future will address the GSI project HITRAP at GSI for fundamental studies with highly-charged ions.

  4. Characterization of Synthetic Peptides by Mass Spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala K; Mirza, Osman; Højrup, Peter;

    2015-01-01

    Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI-TOF-MS an......Mass spectrometry (MS) is well suited for analysis of the identity and purity of synthetic peptides. The sequence of a synthetic peptide is most often known, so the analysis is mainly used to confirm the identity and purity of the peptide. Here, simple procedures are described for MALDI...

  5. Human sports drug testing by mass spectrometry.

    Science.gov (United States)

    Schänzer, Wilhelm; Thevis, Mario

    2017-01-01

    Since the installation of anti-doping rules and regulations and their international enforcement in the mid-1960s, mass spectrometry has been an integral part of doping control procedures. Although its utility was limited in the first decade, instrumental improvements and method optimizations have made mass spectrometry, in all its facets, an indispensable tool in modern sports drug testing. In this review, milestones in doping control analysis accomplished in Germany and reaching from the early developments to the current use of hyphenated mass spectrometric techniques concerning low- and high molecular mass analytes are presented. The considered drug classes include anabolic agents, peptidic drugs, nucleotide-derived therapeutics, approved and non-approved organic as well as inorganic analytes, and particular focus is put on drug class- and instrument-driven strategies. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:16-46, 2017.

  6. Accelerator Mass Spectrometry Analysis of Ultra-Low-Level 129I in Carrier-Free AgI-AgCl Sputter Targets

    DEFF Research Database (Denmark)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian;

    2015-01-01

    and electrically conductive matrix to be mixed with AgI-AgCl powder, in order to obtain and maintain a stable and high iodine ion current intensity, as well as less memory effect and low background level of 129I. The most optimal ratio of the Nb matrix to the AgI-AgCl powder was found to be 5:1 by mass....... The typical current of 127I5+ using AgI-AgCl targets with iodine content from 5 to 80 μg was measured to be 5 to 100 nA. Four-year AMS measurements of the 129I/127I ratios in standards of low iodine content and the machine blanks showed a good repeatability and stability....

  7. Absorption mode FTICR mass spectrometry imaging.

    Science.gov (United States)

    Smith, Donald F; Kilgour, David P A; Konijnenburg, Marco; O'Connor, Peter B; Heeren, Ron M A

    2013-12-03

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here, we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image, and then, these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode "Datacubes" for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

  8. Introduction to mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Matthiesen, R.; Bunkenborg, J.

    2013-01-01

    for newcomers and give pointers to reference material. There are many applications of mass spectrometry in proteomics and each application is associated with some analytical choices, instrumental limitations and data processing steps that depend on the aim of the study and means of conducting it. Different...

  9. Atmospheric pressure femtosecond laser imaging mass spectrometry

    Science.gov (United States)

    Coello, Yves; Gunaratne, Tissa C.; Dantus, Marcos

    2009-02-01

    We present a novel imaging mass spectrometry technique that uses femtosecond laser pulses to directly ionize the sample. The method offers significant advantages over current techniques by eliminating the need of a laser-absorbing sample matrix, being suitable for atmospheric pressure sampling, and by providing 10μm resolution, as demonstrated here with a chemical image of vegetable cell walls.

  10. Nanostructure-initiator mass spectrometry biometrics

    Science.gov (United States)

    Leclerc, Marion; Bowen, Benjamin; Northen, Trent

    2015-09-08

    Several embodiments described herein are drawn to methods of identifying an analyte on a subject's skin, methods of generating a fingerprint, methods of determining a physiological change in a subject, methods of diagnosing health status of a subject, and assay systems for detecting an analyte and generating a fingerprint, by nanostructure-initiator mass spectrometry (NIMS).

  11. Nanostructure-initiator mass spectrometry biometrics

    Energy Technology Data Exchange (ETDEWEB)

    Leclerc, Marion; Bowen, Benjamin; Northen, Trent

    2015-09-08

    Several embodiments described herein are drawn to methods of identifying an analyte on a subject's skin, methods of generating a fingerprint, methods of determining a physiological change in a subject, methods of diagnosing health status of a subject, and assay systems for detecting an analyte and generating a fingerprint, by nanostructure-initiator mass spectrometry (NIMS).

  12. Mass spectrometry and bioinformatics analysis data

    Directory of Open Access Journals (Sweden)

    Mainak Dutta

    2015-03-01

    Full Text Available 2DE and 2D-DIGE based proteomics analysis of serum from women with endometriosis revealed several proteins to be dysregulated. A complete list of these proteins along with their mass spectrometry data and subsequent bioinformatics analysis are presented here. The data is related to “Investigation of serum proteome alterations in human endometriosis” by Dutta et al. [1].

  13. Introduction to mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Matthiesen, R.; Bunkenborg, J.

    2013-01-01

    for newcomers and give pointers to reference material. There are many applications of mass spectrometry in proteomics and each application is associated with some analytical choices, instrumental limitations and data processing steps that depend on the aim of the study and means of conducting it. Different...

  14. Four decades of joy in mass spectrometry

    NARCIS (Netherlands)

    Nibbering, Nico M.M.

    2006-01-01

    Tremendous developments in mass spectrometry have taken place in the last 40 years. This holds for both the science and the instrumental revolutions in this field. In chemistry the research was heavily focused on organic molecules that upon electron ionization fragmented via complex mechanistic path

  15. Mass spectrometry in a multicusp ion source

    Energy Technology Data Exchange (ETDEWEB)

    Mullan, A.A. (Applied Physical Science, University of Ulster, Coleraine (Northern Ireland)); Graham, W.G. (Physics Department, Queen' s University, Belfast, (Northern Ireland))

    1990-08-05

    Mass spectrometry has been used for the detection of positive and negative ions in a multicusp ion source operating with both hydrogen and deuterium gas. The mass spectrometer operation has been optimized and it is shown that applying ion extraction voltages can disturb the discharge. Using this technique combined with a Langmuir probe technique we are able to study the positive ionic fractions present when operating with both gases (and the negative ion densities.)

  16. Polymer and Additive Mass Spectrometry Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-06

    The use of mass spectrometry in fields related to polymers has increased significantly over the past three decades and will be explored in this literature review. The importance of this technique is highlighted when exploring how polymers degrade, verifying purchased materials, and as internal requirements change. The primary focus will be on four ionization techniques and the triple quadrupole and quadrupole / time-of-flight mass spectrometers. The advantages and limitations of each will also be explored.

  17. Proteomics and Mass Spectrometry for Cancer Biomarker Discovery

    Science.gov (United States)

    Lu, Ming; Faull, Kym F.; Whitelegge, Julian P.; He, Jianbo; Shen, Dejun; Saxton, Romaine E.; Chang, Helena R.

    2007-01-01

    Proteomics is a rapidly advancing field not only in the field of biology but also in translational cancer research. In recent years, mass spectrometry and associated technologies have been explored to identify proteins or a set of proteins specific to a given disease, for the purpose of disease detection and diagnosis. Such biomarkers are being investigated in samples including cells, tissues, serum/plasma, and other types of body fluids. When sufficiently refined, proteomic technologies may pave the way for early detection of cancer or individualized therapy for cancer. Mass spectrometry approaches coupled with bioinformatic tools are being developed for biomarker discovery and validation. Understanding basic concepts and application of such technology by investigators in the field may accelerate the clinical application of protein biomarkers in disease management. PMID:19662217

  18. Guideline on Isotope Dilution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, Amy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-19

    Isotope dilution mass spectrometry is used to determine the concentration of an element of interest in a bulk sample. It is a destructive analysis technique that is applicable to a wide range of analytes and bulk sample types. With this method, a known amount of a rare isotope, or ‘spike’, of the element of interest is added to a known amount of sample. The element of interest is chemically purified from the bulk sample, the isotope ratio of the spiked sample is measured by mass spectrometry, and the concentration of the element of interest is calculated from this result. This method is widely used, although a mass spectrometer required for this analysis may be fairly expensive.

  19. Analysis of DNA adducts formed in vivo in rats and mice from 1,2-dibromoethane, 1,2-dichloroethane, dibromomethane, and dichloromethane using HPLC/accelerator mass spectrometry and relevance to risk estimates.

    Science.gov (United States)

    Watanabe, Kengo; Liberman, Rosa G; Skipper, Paul L; Tannenbaum, Steven R; Guengerich, F Peter

    2007-11-01

    Dihaloalkanes are of toxicological interest because of their high-volume use in industry and their abilities to cause tumors in rodents, particularly dichloromethane and 1,2-dichloroethane. The brominated analogues are not used as extensively but are known to produce more toxicity in some systems. Rats and mice were treated i.p. with (14)C-dichloromethane, -dibromomethane, -1,2-dichloroethane, or -1,2-dibromoethane [5 mg (kg body weight)(-1)], and livers and kidneys were collected to rapidly isolate DNA. The DNA was digested using a procedure designed to minimize processing time, because some of the potential dihalomethane-derived DNA-glutathione (GSH) adducts are known to be unstable, and the HPLC fractions corresponding to major adduct standards were separated and analyzed for (14)C using accelerator mass spectrometry. The level of liver or kidney S-[2-(N(7)-guanyl)ethyl]GSH in rats treated with 1,2-dibromoethane was approximately 1 adduct/10(5) DNA bases; in male or female mice, the level was approximately one-half of this. The levels of 1,2-dichloroethane adducts were 10-50-fold lower. None of four known (in vitro) GSH-DNA adducts was detected at a level of >2/10(8) DNA bases from dibromomethane or dichloromethane. These results provide parameters for risk assessment of these compounds: DNA binding occurs with 1,2-dichloroethane but is considerably less than from 1,2-dibromoethane in vivo, and low exposure to dihalomethanes does not produce appreciable DNA adduct levels in rat or mouse liver and kidney of the doses used. The results may be used to address issues in human risk assessment.

  20. Approach for in vivo protein binding of 5-n-butyl-pyrazolo[1,5-a]pyrimidine bioactivated in chimeric mice with humanized liver by two-dimensional electrophoresis with accelerator mass spectrometry.

    Science.gov (United States)

    Yamazaki, Hiroshi; Kuribayashi, Shunji; Inoue, Tae; Tateno, Chise; Nishikura, Yasufumi; Oofusa, Ken; Harada, Daisuke; Naito, Shinsaku; Horie, Toru; Ohta, Shigeru

    2010-01-01

    Drug development of a potential analgesic agent 5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a]pyrimidine was withdrawn because of its limited hepatotoxic effects in humans that could not be predicted from regulatory animal or in vitro studies. In vivo formation of glutathione conjugates and covalent binding of a model compound 5-n-butyl-pyrazolo[1,5-a]pyrimidine were investigated in the present study after intravenous administration to chimeric mice with a human or rat liver because of an interesting capability of human cytochrome P450 1A2 in forming a covalently bound metabolite in vitro. Rapid distribution and elimination of radiolabeled 5-n-butyl-pyrazolo[1,5-a]pyrimidine in plasma or liver fractions were seen in chimeric mice after intravenous administration. However, similar covalent binding in liver was detected over 0.17-24 h after intravenous administration. Radio-LC analyses revealed that the chimeric mice with humanized liver preferentially gave the 3-hydroxylated metabolite and its glutathione conjugate in the plasma and liver. On the contrary, chimeric mice with a rat liver had some rat-specific metabolites in vivo. Analyses by electrophoresis with accelerator mass spectrometry of in vivo radiolabeled liver proteins in chimeric mice revealed that bioactivated 5-n-butyl-pyrazolo[1,5-a]pyrimidine bound nonspecifically to a variety of microsomal proteins including human P450 1A2 as well as cytosolic proteins in the livers from chimeric mice with humanized liver. These results suggest that the hepatotoxic model compound 5-n-butyl-pyrazolo[1,5-a]pyrimidine was activated by human liver microsomal P450 1A2 to reactive intermediate(s) in vivo in humanized chimeric mice and could relatively nonspecifically bind to biomolecules such as P450 1A2 and other proteins.

  1. Biokinetics and radiation dosimetry of {sup 14}C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, Mikael

    2002-08-01

    {sup 14}C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used {sup 14}C-breath tests: {sup 14}C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low {sup 14}C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform {sup 14}C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of {sup 14}C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: {sup 14}C-glycocholic acid - 0.4 mSv/MBq, {sup 14}C-triolein - 0.3 mSv/MBq, {sup 14}C-xylose - 0.1 mSv/MBq and {sup 14}C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the {sup 14}C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  2. Microbial proteomics using mass spectrometry.

    Science.gov (United States)

    Hines, Harry B

    2012-01-01

    Proteomic analyses involve a series of intricate, interdependent steps involving approaches and technical issues that must be fully coordinated to obtain the optimal amount of required information about the test subject. Fortunately, many of these steps are common to most test subjects, requiring only modifications to or, in some cases, substitution of some of the steps to ensure they are relevant to the desired objective of a study. This fortunate occurrence creates an essential core of proteomic approaches and techniques that are consistently available for most studies, regardless of test subject. In this chapter, an overview of some of these core approaches, techniques, and mass spectrometric instrumentation is given, while indicating how such steps are useful for and applied to bacterial investigations. To exemplify how such proteomic concepts and techniques are applicable to bacterial investigations, a practical, quantitative method useful for bacterial proteomic analysis is presented with a discussion of possibilities, pitfalls, and some emerging technology to provide a compilation of information from the diverse literature that is intermingled with experimental experience.

  3. Space Applications of Mass Spectrometry. Chapter 31

    Science.gov (United States)

    Hoffman, John H.; Griffin, Timothy P.; Limero, Thomas; Arkin, C. Richard

    2010-01-01

    Mass spectrometers have been involved in essentially all aspects of space exploration. This chapter outlines some of these many uses. Mass spectrometers have not only helped to expand our knowledge and understanding of the world and solar system around us, they have helped to put man safely in space and expand our frontier. Mass spectrometry continues to prove to be a very reliable, robust, and flexible analytical instrument, ensuring that its use will continue to help aid our investigation of the universe and this small planet that we call home.

  4. Accelerator mass spectrometry dating at Catalhoeyuek

    Energy Technology Data Exchange (ETDEWEB)

    Goektuerk, E.H. [Dept. of Chemistry, Middle East Technical Univ., Ankara (Turkey); Hillegonds, D.J.; Lipschutz, M.E. [Dept. of Chemistry, Purdue Univ., West Lafayette, IN (United States); Hodder, I. [Dept. of Cultural and Social Anthropology, Standford Univ., Standford, CA (United States)

    2002-07-01

    Several charred plant and charcoal samples from various stratigraphic levels of the Neolithic Site, Catalhoeyuek - Turkey, were dated in the AMS facility of Purdue University (PRIME Lab). Radiocarbon dates reveal a complicated chronology, as was foreseen from archeological investigations. Our measurements suggest that this unique Neolithic town may have been initiated at the East mound around 8390 BP. (orig.)

  5. Use of mass spectrometry to study signaling pathways

    DEFF Research Database (Denmark)

    Pandey, A; Andersen, Jens S.; Mann, M

    2000-01-01

    biochemical assays have been used to identify molecules involved in signaling pathways. Lately, mass spectrometry, combined with elegant biochemical approaches, has become a powerful tool for identifying proteins and posttranslational modifications. With this protocol, we hope to bridge the gap between...... identification by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry and nanoelectrospray tandem mass spectrometry. We discuss the special requirements for the identification of phosphorylation sites in proteins by mass spectrometry. We describe enrichment of phosphopeptides from unseparated...

  6. Boundaries of mass resolution in native mass spectrometry

    NARCIS (Netherlands)

    Lössl, Philip; Snijder, Joost; Heck, Albert J R

    2014-01-01

    Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)-protein interactions, to nanomachineries such as the proteasome and ribosome, to even viru

  7. Laser-cooling-assisted mass spectrometry

    CERN Document Server

    Schneider, Christian; Chen, Kuang; Sullivan, Scott T; Hudson, Eric R

    2014-01-01

    Mass spectrometry is used in a wide range of scientific disciplines including proteomics, pharmaceutics, forensics, and fundamental physics and chemistry. Given this ubiquity, there is a worldwide effort to improve the efficiency and resolution of mass spectrometers. However, the performance of all techniques is ultimately limited by the initial phase-space distribution of the molecules being analyzed. Here, we dramatically reduce the width of this initial phase-space distribution by sympathetically cooling the input molecules with laser-cooled, co-trapped atomic ions, improving both the mass resolution and detection efficiency of a time-of-flight mass spectrometer by over an order of magnitude. Detailed molecular dynamics simulations verify the technique and aid with evaluating its effectiveness. Our technique appears to be applicable to other types of mass spectrometers.

  8. Laser-Cooling-Assisted Mass Spectrometry

    Science.gov (United States)

    Schneider, Christian; Schowalter, Steven J.; Chen, Kuang; Sullivan, Scott T.; Hudson, Eric R.

    2014-09-01

    Mass spectrometry is used in a wide range of scientific disciplines including proteomics, pharmaceutics, forensics, and fundamental physics and chemistry. Given this ubiquity, there is a worldwide effort to improve the efficiency and resolution of mass spectrometers. However, the performance of all techniques is ultimately limited by the initial phase-space distribution of the molecules being analyzed. Here, we dramatically reduce the width of this initial phase-space distribution by sympathetically cooling the input molecules with laser-cooled, cotrapped atomic ions, improving both the mass resolution and detection efficiency of a time-of-flight mass spectrometer by over an order of magnitude. Detailed molecular-dynamics simulations verify the technique and aid with evaluating its effectiveness. This technique appears to be applicable to other types of mass spectrometers.

  9. Crux: rapid open source protein tandem mass spectrometry analysis.

    Science.gov (United States)

    McIlwain, Sean; Tamura, Kaipo; Kertesz-Farkas, Attila; Grant, Charles E; Diament, Benjamin; Frewen, Barbara; Howbert, J Jeffry; Hoopmann, Michael R; Käll, Lukas; Eng, Jimmy K; MacCoss, Michael J; Noble, William Stafford

    2014-10-03

    Efficiently and accurately analyzing big protein tandem mass spectrometry data sets requires robust software that incorporates state-of-the-art computational, machine learning, and statistical methods. The Crux mass spectrometry analysis software toolkit ( http://cruxtoolkit.sourceforge.net ) is an open source project that aims to provide users with a cross-platform suite of analysis tools for interpreting protein mass spectrometry data.

  10. Preliminary Investigation into Pyrotechnic Chemical Products via Mass Spectrometry Techniques

    Science.gov (United States)

    2015-03-11

    via Mass Spectrometry Techniques 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jonathan Dilger, Eric...undesirable side reactions within the combustion. Mass spectrometry (MS) enables the rapid analysis of these products with instrumentation that offers...predicted by theory. 15. SUBJECT TERMS mass spectrometry , gas chromatography, pyrolysis, combustion products, pyrotechnics 16. SECURITY CLASSIFICATION OF

  11. Application of Nanodiamonds in Biomolecular Mass Spectrometry

    OpenAIRE

    Ping Cheng; Xianglei Kong

    2010-01-01

    The combination of nanodiamond (ND) with biomolecular mass spectrometry (MS) makes rapid, sensitive detection of biopolymers from complex biosamples feasible. Due to its chemical inertness, optical transparency and biocompatibility, the advantage of NDs in MS study is unique. Furthermore, functionalization on the surfaces of NDs expands their application in the fields of proteomics and genomics for specific requirements greatly. This review presents methods of MS analysis based on solid phase...

  12. Laser mass spectrometry for selective ultratrace determination

    CERN Document Server

    Wendt, K; Müller, P; Nörtershäuser, W; Schmitt, A; Trautmann, N; Bushaw, B A

    1999-01-01

    Resonance ionization mass spectrometry has been explored in respect to its capabilities for isobaric suppression, isotopic selectivity, and overall efficiency. Theoretical calculations within the density matrix formalism on coherent multi-step excitation processes predict high specifications, which have been confirmed by spectroscopic measurements in Ca and which make the technique attractive for ultratrace detection. Analytical applications are found in the determination of the ultratrace isotope sup 4 sup 1 Ca for cosmochemical, radiodating, and medical applications.

  13. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  14. Trends in mass spectrometry instrumentation for proteomics.

    Science.gov (United States)

    Smith, Richard D

    2002-12-01

    Mass spectrometry has become a primary tool for proteomics because of its capabilities for rapid and sensitive protein identification and quantitation. It is now possible to identify thousands of proteins from microgram sample quantities in a single day and to quantify relative protein abundances. However, the need for increased capabilities for proteome measurements is immense and is now driving both new strategies and instrument advances. These developments include those based on integration with multi-dimensional liquid separations and high accuracy mass measurements and promise more than order of magnitude improvements in sensitivity, dynamic range and throughput for proteomic analyses in the near future.

  15. Human Microdosing with Carcinogenic Polycyclic Aromatic Hydrocarbons: In Vivo Pharmacokinetics of Dibenzo[ def,p ]chrysene and Metabolites by UPLC Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Madeen, Erin P.; Ognibene, Ted J.; Corley, Richard A.; McQuistan, Tammie J.; Henderson, Marilyn C.; Baird, William M.; Bench, Graham; Turteltaub, Ken W.; Williams, David E.

    2016-10-17

    Metabolism is a key health risk factor following exposures to pro-carcinogenic polycyclic aromatic hydrocarbons (PAHs) such as dibenzo[def,p]chrysene (DBC), an IARC classified 2A probable human carcinogen. Human exposure to PAHs occurs primarily from the diet in non-smokers. However, little data is available on the metabolism and pharmacokinetics in humans of high molecular weight PAHs (≥4 aromatic rings), including DBC. We previously determined the pharmacokinetics of DBC in human volunteers orally administered a micro-dose (29 ng; 5 nCi) of [14C]-DBC by accelerator mass spectrometry (AMS) analysis of total [14C] in plasma and urine. In the current study, we utilized a novel “moving wire” interface between ultra-performance liquid chromatography (UPLC) and AMS to detect and quantify parent DBC and its major metabolites. The major [14C] product identified in plasma was unmetabolized [14C]-DBC itself, (Cmax= 18.5 ± 15.9 fg/mL, Tmax= 2.1 ± 1.0 h), whereas the major metabolite was identified as [14C]-(+/-)-DBC-11,12-diol (Cmax= 2.5 ± 1.3 fg/mL, Tmax= 1.8 h). Several minor species of [14C]-DBC metabolites were also detected for which no reference standards were available. Free and conjugated metabolites were detected in urine with [14C]-(+/-)-DBC-11,12,13,14-tetraol isomers identified as the major metabolites, 56.3% of which were conjugated (Cmax= 35.8 ± 23.0 pg/pool, Tmax= 6-12 h pool). [14C]-DBC-11,12-diol, of which 97.5% was conjugated, was also identified in urine (Cmax= 29.4 ± 11.6 pg/pool, Tmax= 6-12 h pool). Parent [14C]-DBC was not detected in urine. This is the first dataset to assess metabolite profiles and associated pharmacokinetics of a carcinogenic PAH in human volunteers at an environmentally relevant dose, providing the data necessary for translation of high dose animal models to humans for translation of environmental health risk assessment.

  16. Distance-of-Flight Mass Spectrometry: What, Why, and How?

    Science.gov (United States)

    Dennis, Elise A.; Gundlach-Graham, Alexander W.; Ray, Steven J.; Enke, Christie G.; Hieftje, Gary M.

    2016-11-01

    Distance-of-flight mass spectrometry (DOFMS) separates ions of different mass-to-charge ( m/ z) by the distance they travel in a given time after acceleration. Like time-of-flight mass spectrometry (TOFMS), separation and mass assignment are based on ion velocity. However, DOFMS is not a variant of TOFMS; different methods of ion focusing and detection are used. In DOFMS, ions are driven orthogonally, at the detection time, onto an array of detectors parallel to the flight path. Through the independent detection of each m/ z, DOFMS can provide both wider dynamic range and increased throughput for m/ z of interest compared with conventional TOFMS. The iso-mass focusing and detection of ions is achieved by constant-momentum acceleration (CMA) and a linear-field ion mirror. Improved energy focus (including turn-around) is achieved in DOFMS, but the initial spatial dispersion of ions remains unchanged upon detection. Therefore, the point-source nature of surface ionization techniques could put them at an advantage for DOFMS. To date, three types of position-sensitive detectors have been used for DOFMS: a microchannel plate with a phosphorescent screen, a focal plane camera, and an IonCCD array; advances in detector technology will likely improve DOFMS figures-of-merit. In addition, the combination of CMA with TOF detection has provided improved resolution and duty factor over a narrow m/ z range (compared with conventional, single-pass TOFMS). The unique characteristics of DOFMS can enable the intact collection of large biomolecules, clusters, and organisms. DOFMS might also play a key role in achieving the long-sought goal of simultaneous MS/MS.

  17. Distance-of-Flight Mass Spectrometry: What, Why, and How?

    Science.gov (United States)

    Dennis, Elise A.; Gundlach-Graham, Alexander W.; Ray, Steven J.; Enke, Christie G.; Hieftje, Gary M.

    2016-08-01

    Distance-of-flight mass spectrometry (DOFMS) separates ions of different mass-to-charge (m/z) by the distance they travel in a given time after acceleration. Like time-of-flight mass spectrometry (TOFMS), separation and mass assignment are based on ion velocity. However, DOFMS is not a variant of TOFMS; different methods of ion focusing and detection are used. In DOFMS, ions are driven orthogonally, at the detection time, onto an array of detectors parallel to the flight path. Through the independent detection of each m/z, DOFMS can provide both wider dynamic range and increased throughput for m/z of interest compared with conventional TOFMS. The iso-mass focusing and detection of ions is achieved by constant-momentum acceleration (CMA) and a linear-field ion mirror. Improved energy focus (including turn-around) is achieved in DOFMS, but the initial spatial dispersion of ions remains unchanged upon detection. Therefore, the point-source nature of surface ionization techniques could put them at an advantage for DOFMS. To date, three types of position-sensitive detectors have been used for DOFMS: a microchannel plate with a phosphorescent screen, a focal plane camera, and an IonCCD array; advances in detector technology will likely improve DOFMS figures-of-merit. In addition, the combination of CMA with TOF detection has provided improved resolution and duty factor over a narrow m/z range (compared with conventional, single-pass TOFMS). The unique characteristics of DOFMS can enable the intact collection of large biomolecules, clusters, and organisms. DOFMS might also play a key role in achieving the long-sought goal of simultaneous MS/MS.

  18. Distance-of-Flight Mass Spectrometry: What, Why, and How?

    Science.gov (United States)

    Dennis, Elise A; Gundlach-Graham, Alexander W; Ray, Steven J; Enke, Christie G; Hieftje, Gary M

    2016-11-01

    Distance-of-flight mass spectrometry (DOFMS) separates ions of different mass-to-charge (m/z) by the distance they travel in a given time after acceleration. Like time-of-flight mass spectrometry (TOFMS), separation and mass assignment are based on ion velocity. However, DOFMS is not a variant of TOFMS; different methods of ion focusing and detection are used. In DOFMS, ions are driven orthogonally, at the detection time, onto an array of detectors parallel to the flight path. Through the independent detection of each m/z, DOFMS can provide both wider dynamic range and increased throughput for m/z of interest compared with conventional TOFMS. The iso-mass focusing and detection of ions is achieved by constant-momentum acceleration (CMA) and a linear-field ion mirror. Improved energy focus (including turn-around) is achieved in DOFMS, but the initial spatial dispersion of ions remains unchanged upon detection. Therefore, the point-source nature of surface ionization techniques could put them at an advantage for DOFMS. To date, three types of position-sensitive detectors have been used for DOFMS: a microchannel plate with a phosphorescent screen, a focal plane camera, and an IonCCD array; advances in detector technology will likely improve DOFMS figures-of-merit. In addition, the combination of CMA with TOF detection has provided improved resolution and duty factor over a narrow m/z range (compared with conventional, single-pass TOFMS). The unique characteristics of DOFMS can enable the intact collection of large biomolecules, clusters, and organisms. DOFMS might also play a key role in achieving the long-sought goal of simultaneous MS/MS. Graphical Abstract ᅟ.

  19. Neutral particle Mass Spectrometry with Nanomechanical Systems

    CERN Document Server

    Sage, Eric; Alava, Thomas; Morel, Robert; Dupré, Cécilia; Hanay, Mehmet Selim; Duraffourg, Laurent; Masselon, Christophe; Hentz, Sébastien

    2014-01-01

    Current approaches to Mass Spectrometry (MS) necessarily rely on the ionization of the analytes of interest and subsequent spectrum interpretation is based on the mass-to-charge ratios of the ions. The resulting charge state distribution can be very complex for high-mass species which may hinder correct interpretation. A new form of MS analysis based on Nano-Electro-Mechanical Systems (NEMS) was recently demonstrated with high-mass ions. Thanks to a dedicated setup comprising both conventional time-of-flight MS (TOF-MS) and NEMS-MS in-situ, we show here for the first time that NEMS-MS analysis is insensitive to charge state: it provides one single peak regardless of the species charge state, highlighting effective clarification over existing MS analysis. All charged particles were thereafter removed from the beam electrostatically, and unlike TOF-MS, NEMS-MS retained its ability to perform mass measurements. This constitutes the first unequivocal measurement of mass spectra of neutral particles. This ability ...

  20. Simultaneous mass detection for direct inlet mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, R.L.

    1979-05-01

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

  1. Mass spectrometry imaging: applications to food science.

    Science.gov (United States)

    Taira, Shu; Uematsu, Kohei; Kaneko, Daisaku; Katano, Hajime

    2014-01-01

    Two-dimensional mass spectrometry (MS) analysis of biological samples by means of what is called MS imaging (MSI) is now being used to analyze analyte distribution because it facilitates determination of the existence (what is it?) and localization (where is it?) of biomolecules. Reconstruction of mass image by target signal is given after two-dimensional MS measurements on a sample section. From only one section, we can understand the existence and localization of many molecules without the need of an antibody or fluorescent reagent. In this review, we introduce the analysis of localization of functional constituents and nutrients in herbal medicine products via MSI. The ginsenosides were mainly distributed in the periderm and the tip region of the root of Panax ginseng. The capsaicin was found to be more dominantly localized in the placenta than the pericarp and seed in Capsicum fruits. We expect MSI will be a useful technique for optical quality assurance.

  2. Damping effects in Penning trap mass spectrometry

    CERN Document Server

    George, S; Kowalska, M; Dworschak, M; Neidherr, D; Blaum, K; Schweikhard, L; Ramirez, E M; Breitenfeldt, M; Kretzschmar, M; Herfurth, F; Schwarz, S; Herlert, A

    2011-01-01

    Collisions of ions with residual gas atoms in a Penning trap can have a strong influence on the trajectories of the ions, depending on the atom species and the gas pressure. We report on investigations of damping effects in time-of-flight ion-cyclotron resonance mass spectrometry with the Penning trap mass spectrometers ISOLTRAP at ISOLDE/CERN (Geneva, Switzerland) and SHIPTRAP at GSI (Darmstadt, Germany). The work focuses on the interconversion of the magnetron and cyclotron motional modes, in particular the modification of the resonance profiles for quadrupolar excitation due to the damping effect of the residual gas. Extensive experiments have been performed with standard and Ramsey excitation schemes. The results are in good agreement with predictions obtained by analytical continuation of the formulae for the undamped case.

  3. Proteome analysis of adenovirus using mass spectrometry.

    Science.gov (United States)

    Lind, Sara Bergström; Artemenko, Konstantin A; Pettersson, Ulf

    2014-01-01

    Analysis of proteins and their posttranslational modifications is important for understanding different biological events. For analysis of viral proteomes, an optimal protocol includes production of a highly purified virus that can be investigated with a high-resolving analytical method. In this Methods in Molecular Biology paper we describe a working strategy for how structural proteins in the Adenovirus particle can be studied using liquid chromatography-high-resolving mass spectrometry. This method provides information on the chemical composition of the virus particle. Further, knowledge about amino acids carrying modifications that could be essential for any part of the virus life cycle is collected. We describe in detail alternatives available for preparation of virus for proteome analysis as well as choice of mass spectrometric instrumentation suitable for this kind of analysis.

  4. Mass Spectrometry for Rapid Characterization of Microorganisms

    Science.gov (United States)

    Demirev, Plamen A.; Fenselau, Catherine

    2008-07-01

    Advances in instrumentation, proteomics, and bioinformatics have contributed to the successful applications of mass spectrometry (MS) for detection, identification, and classification of microorganisms. These MS applications are based on the detection of organism-specific biomarker molecules, which allow differentiation between organisms to be made. Intact proteins, their proteolytic peptides, and nonribosomal peptides have been successfully utilized as biomarkers. Sequence-specific fragments for biomarkers are generated by tandem MS of intact proteins or proteolytic peptides, obtained after, for instance, microwave-assisted acid hydrolysis. In combination with proteome database searching, individual biomarker proteins are unambiguously identified from their tandem mass spectra, and from there the source microorganism is also identified. Such top-down or bottom-up proteomics approaches permit rapid, sensitive, and confident characterization of individual microorganisms in mixtures and are reviewed here. Examples of MS-based functional assays for detection of targeted microorganisms, e.g., Bacillus anthracis, in environmental or clinically relevant backgrounds are also reviewed.

  5. Imaging mass spectrometry at cellular length scales.

    Science.gov (United States)

    Altelaar, A F Maarten; Luxembourg, Stefan L; McDonnell, Liam A; Piersma, Sander R; Heeren, Ron M A

    2007-01-01

    Imaging mass spectrometry (IMS) allows the direct investigation of both the identity and the spatial distribution of the molecular content directly in tissue sections, single cells and many other biological surfaces. In this protocol, we present the steps required to retrieve the molecular information from tissue sections using matrix-enhanced (ME) and metal-assisted (MetA) secondary ion mass spectrometry (SIMS) as well as matrix-assisted laser desorption/ionization (MALDI) IMS. These techniques require specific sample preparation steps directed at optimal signal intensity with minimal redistribution or modification of the sample analytes. After careful sample preparation, different IMS methods offer a unique discovery tool in, for example, the investigation of (i) drug transport and uptake, (ii) biological processing steps and (iii) biomarker distributions. To extract the relevant information from the huge datasets produced by IMS, new bioinformatics approaches have been developed. The duration of the protocol is highly dependent on sample size and technique used, but on average takes approximately 5 h.

  6. Mass Spectrometry on Future Mars Landers

    Science.gov (United States)

    Brinckerhoff, W. B.; Mahaffy, P. R.

    2011-01-01

    Mass spectrometry investigations on the 2011 Mars Science Laboratory (MSL) and the 2018 ExoMars missions will address core science objectives related to the potential habitability of their landing site environments and more generally the near-surface organic inventory of Mars. The analysis of complex solid samples by mass spectrometry is a well-known approach that can provide a broad and sensitive survey of organic and inorganic compounds as well as supportive data for mineralogical analysis. The science value of such compositional information is maximized when one appreciates the particular opportunities and limitations of in situ analysis with resource-constrained instrumentation in the context of a complete science payload and applied to materials found in a particular environment. The Sample Analysis at Mars (SAM) investigation on MSL and the Mars Organic Molecule Analyzer (MOMA) investigation on ExoMars will thus benefit from and inform broad-based analog field site work linked to the Mars environments where such analysis will occur.

  7. Isotope ratio analysis by Orbitrap mass spectrometry

    Science.gov (United States)

    Eiler, J. M.; Chimiak, L. M.; Dallas, B.; Griep-Raming, J.; Juchelka, D.; Makarov, A.; Schwieters, J. B.

    2016-12-01

    Several technologies are being developed to examine the intramolecular isotopic structures of molecules (i.e., site-specific and multiple substitution), but various limitations in sample size and type or (for IRMS) resolution have so far prevented the creation of a truly general technique. We will discuss the initial findings of a technique based on Fourier transform mass spectrometry, using the Thermo Scientific Q Exactive GC — an instrument that contains an Orbitrap mass analyzer. Fourier transform mass spectrometry is marked by exceptionally high mass resolutions (the Orbitrap reaches M/∆M in the range 250,000-1M in the mass range of greatest interest, 50-200 amu). This allows for resolution of a large range of nearly isobaric interferences for isotopologues of volatile and semi-volatile compounds (i.e., involving isotopes of H, C, N, O and S). It also provides potential to solve very challenging mass resolution problems for isotopic analysis of other, heavier elements. Both internal and external experimental reproducibilities of isotope ratio analyses using the Orbitrap typically conform to shot-noise limits down to levels of 0.2 ‰ (1SE), and routinely in the range 0.5-1.0 ‰, with similar accuracy when standardized to concurrently run reference materials. Such measurements can be made without modifications to the ion optics of the Q Exactive GC, but do require specially designed sample introduction devices to permit sample/standard comparison and long integration times. The sensitivity of the Q Exactive GC permits analysis of sub-nanomolar samples and quantification of multiply-substituted species. The site-specific capability of this instrument arises from the fact that mass spectra of molecular analytes commonly contain diverse fragment ion species, each of which samples a specific sub-set of molecular sites. We will present applications of this technique to the biological and abiological chemistry of amino acids, forensic identification of

  8. Comparison of a 250 kV single-stage accelerator mass spectrometer with a 5 MV tandem accelerator mass spectrometer--fitness for purpose in bioanalysis.

    Science.gov (United States)

    Young, G C; Corless, S; Felgate, C C; Colthup, P V

    2008-12-01

    The introduction of 'compact' accelerator mass spectrometers into biomedical science, including use in drug metabolism and bioanalytical applications, is an exciting recent development. Comparisons are presented here between a more established and relatively large tandem accelerator which operates at up to 5 MV and a conventional laboratory-sized 250 kV single-stage accelerator mass spectrometer. Biological samples were enriched with low levels of radiocarbon, then converted into graphite prior to analysis on each of the two instruments. The data obtained showed the single-stage instrument to be capable of delivering comparable results, and thus able to provide similar study support, with that provided by the 5 MV instrument, without the significant overheads and complexities which are inherent to the operation of the larger instrument. We believe that the advent of these laboratory-sized accelerator mass spectrometry (AMS) instruments represents a real turning point in the potential for application of AMS by a wider user group.

  9. Ambient ionization mass spectrometry: A tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Shiea, Jentaie, E-mail: jetea@fac.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

    2011-09-19

    Highlights: {yields} Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. {yields} We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. {yields} The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.

  10. Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Pan; Wang, Hung-Ta; Yang, Peidong; Wang, Daojing

    2011-06-16

    Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA), and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3-inch silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel, can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nanoelectrospray for the high-density emitter array. We showed that electrospray current of the multinozzle emitter at a given total flow rate was approximately proportional to the square root of the number of its spraying-nozzles, suggesting the capability of high MS sensitivity for multinozzle emitters. Using a conventional Z-spray mass spectrometer, we demonstrated reproducible MS detection of peptides and proteins for serial MEA emitters, achieving sensitivity and stability comparable to the commercial capillary emitters. Our robust silicon-based MEA chip opens up the possibility of a fully-integrated microfluidic system for ultrahigh-sensitivity and ultrahigh-throughput proteomics and metabolomics.

  11. Mass spectrometry for high-throughput metabolomics analysis of urine

    OpenAIRE

    Abdelrazig, Salah M.A.

    2015-01-01

    Direct electrospray ionisation-mass spectrometry (direct ESI-MS), by omitting the chromatographic step, has great potential for application as a high-throughput approach for untargeted urine metabolomics analysis compared to liquid chromatography-mass spectrometry (LC-MS). The rapid development and technical innovations revealed in the field of ambient ionisation MS such as nanoelectrospray ionisation (nanoESI) chip-based infusion and liquid extraction surface analysis mass spectrometry (LESA...

  12. Characterisation of DEFB107 by mass spectrometry

    Science.gov (United States)

    McCullough, Bryan J.; Eastwood, Hayden; Clark, Dave J.; Polfer, Nick C.; Campopiano, Dominic J.; Dorin, Julia A.; Maxwell, Alison; Langley, Ross J.; Govan, John R. W.; Bernstein, Summer L.; Bowers, Michael T.; Barran, Perdita E.

    2006-05-01

    Mammalian defensins are small endogenous cationic proteins which form a class of antimicrobial peptides that is part of the innate immune response of all mammalian species [R. Lehrer, Nat. Rev. Microbiol. 2 (9) (2004) 727; T. Ganz, R.I. Lehrer, Curr. Opin. Immunol. 6 (4) (1994) 584] [1] and [2]. We have developed mass spectrometry based strategies for characterising the structure-activity relationship of defensins [D.J. Campopiano, D.J. Clarke, N.C. Polfer, P.E. Barran, R.J. Langley, J.R.W. Govan, A. Maxwell, J.R. Dorin, J. Biol. Chem. 279 (47) (2004) 48671; P.E. Barran, N.C. Polfer, D.J. Campopiano, D.J. Clarke, P.R.R. Langridge-Smith, R.J. Langley, J.R.W. Govan, A. Maxwell, J.R. Dorin, R.P. Millar, M.T. Bowers, Int. J. Mass Spectrom. 240 (2005) 273] [3] and [4], and here we present data obtained from a five cysteine containing [beta]-defensin, DEFB107. The synthetic product of this human defensin exists with a glutathione capping group, its oxidation state and disulphide connectivity have been determined via accurate mass measurements and peptide mass mapping respectively, and despite possessing three disulphide bridges, it does not fit the [beta]-defensin canonical motif. With the use of molecular modelling, we have generated candidate geometries to discern the influence of disulphide bridging on the overall tertiary structure of DEFB107. These are compared with experimental results from ion mobility measurements. Defensins display activity against a wide variety of pathogens including both gram-negative and gram-positive bacteria. Their mechanism of mode of action is unknown, but is believed to involve defensin aggregation at cell surfaces, followed by cell permeabilisation and hence deathE To probe this mechanism, the localisation of DEFB107 in synthetic vesicles was studied using H/D exchange and mass spectrometry. The results obtained are used to analyse the antimicrobial activity of DEFB107.

  13. Mass spectrometry of hyper-velocity impacts of organic micrograins.

    Science.gov (United States)

    Srama, Ralf; Woiwode, Wolfgang; Postberg, Frank; Armes, Steven P; Fujii, Syuji; Dupin, Damien; Ormond-Prout, Jonathan; Sternovsky, Zoltan; Kempf, Sascha; Moragas-Klostermeyer, Georg; Mocker, Anna; Grün, Eberhard

    2009-12-01

    The study of hyper-velocity impacts of micrometeoroids is important for the calibration of dust sensors in space applications. For this purpose, submicron-sized synthetic dust grains comprising either polystyrene or poly[bis(4-vinylthiophenyl)sulfide] were coated with an ultrathin overlayer of an electrically conductive organic polymer (either polypyrrole or polyaniline) and were accelerated to speeds between 3 and 35 km s(-1) using the Heidelberg Dust Accelerator facility. Time-of-flight mass spectrometry was applied to analyse the resulting ionic impact plasma using a newly developed Large Area Mass Analyser (LAMA). Depending on the projectile type and the impact speed, both aliphatic and aromatic molecular ions and cluster species were identified in the mass spectra with masses up to 400 u. Clusters resulting from the target material (silver) and mixed clusters of target and projectile species were also observed. Impact velocities of between 10 and 35 km s(-1) are suitable for a principal identification of organic materials in micrometeoroids, whereas impact speeds below approximately 10 km s(-1) allow for an even more detailed analysis. Molecular ions and fragments reflect components of the parent molecule, providing determination of even complex organic molecules embedded in a dust grain. In contrast to previous measurements with the Cosmic Dust Analyser instrument, the employed LAMA instrument has a seven times higher mass resolution--approximately 200--which allowed for a detailed analysis of the complex mass spectra. These fundamental studies are expected to enhance our understanding of cometary, interplanetary and interstellar dust grains, which travel at similar hyper-velocities and are known to contain both aliphatic and aromatic organic compounds. Copyright 2009 John Wiley & Sons, Ltd.

  14. Mass spectrometry and Web 2.0.

    Science.gov (United States)

    Murray, Kermit K

    2007-10-01

    The term Web 2.0 is a convenient shorthand for a new era in the Internet in which users themselves are both generating and modifying existing web content. Several types of tools can be used. With social bookmarking, users assign a keyword to a web resource and the collection of the keyword 'tags' from multiple users form the classification of these resources. Blogs are a form of diary or news report published on the web in reverse chronological order and are a popular form of information sharing. A wiki is a website that can be edited using a web browser and can be used for collaborative creation of information on the site. This article is a tutorial that describes how these new ways of creating, modifying, and sharing information on the Web are being used for on-line mass spectrometry resources.

  15. Recent trends in inorganic mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.H.; Barshick, C.M.; Duckworth, D.C.; Riciputi, L.R.

    1996-10-01

    The field of inorganic mass spectrometry has seen substantial change in the author`s professional lifetime (over 30 years). Techniques in their infancy 30 years ago have matured; some have almost disappeared. New and previously unthought of techniques have come into being; some of these, such as ICP-MS, are reasonably mature now, while others have some distance to go before they can be so considered. Most of these new areas provide fertile fields for researchers, both in the development of new analytical techniques and by allowing fundamental studies to be undertaken that were previously difficult, impossible, or completely unforeseen. As full coverage of the field is manifestly impossible within the framework of this paper, only those areas with which the author has personal contact will be discussed. Most of the work originated in his own laboratory, but that of other laboratories is covered where it seemed appropriate.

  16. Application of Nanodiamonds in Biomolecular Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ping Cheng

    2010-03-01

    Full Text Available The combination of nanodiamond (ND with biomolecular mass spectrometry (MS makes rapid, sensitive detection of biopolymers from complex biosamples feasible. Due to its chemical inertness, optical transparency and biocompatibility, the advantage of NDs in MS study is unique. Furthermore, functionalization on the surfaces of NDs expands their application in the fields of proteomics and genomics for specific requirements greatly. This review presents methods of MS analysis based on solid phase extraction and elution on NDs and different application examples including peptide, protein, DNA, glycan and others. Owing to the quick development of nanotechnology, surface chemistry, new MS methods and the intense interest in proteomics and genomics, a huge increase of their applications in biomolecular MS analysis in the near future can be predicted.

  17. [Application of mass spectrometry in mycology].

    Science.gov (United States)

    Quiles Melero, Inmaculada; Peláez, Teresa; Rezusta López, Antonio; Garcia-Rodríguez, Julio

    2016-06-01

    MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry (MS) is becoming an essential tool in most microbiology laboratories. At present, by using a characteristic fungal profile obtained from whole cells or through simple extraction protocols, MALDI-TOF MS allows the identification of pathogenic fungi with a high performance potential. This methodology decreases the laboratory turnaround time, optimizing the detection of mycoses. This article describes the state-of-the-art of the use of MALDI-TOF MS for the detection of human clinical fungal pathogens in the laboratory and discusses the future applications of this technology, which will further improve routine mycological diagnosis. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  18. Mass Spectrometry Methodology in Lipid Analysis

    Directory of Open Access Journals (Sweden)

    Lin Li

    2014-06-01

    Full Text Available Lipidomics is an emerging field, where the structures, functions and dynamic changes of lipids in cells, tissues or body fluids are investigated. Due to the vital roles of lipids in human physiological and pathological processes, lipidomics is attracting more and more attentions. However, because of the diversity and complexity of lipids, lipid analysis is still full of challenges. The recent development of methods for lipid extraction and analysis and the combination with bioinformatics technology greatly push forward the study of lipidomics. Among them, mass spectrometry (MS is the most important technology for lipid analysis. In this review, the methodology based on MS for lipid analysis was introduced. It is believed that along with the rapid development of MS and its further applications to lipid analysis, more functional lipids will be identified as biomarkers and therapeutic targets and for the study of the mechanisms of disease.

  19. Glass microfabricated nebulizer chip for mass spectrometry.

    Science.gov (United States)

    Saarela, Ville; Haapala, Markus; Kostiainen, Risto; Kotiaho, Tapio; Franssila, Sami

    2007-05-01

    A microfluidic nebulizer chip for mass spectrometry is presented. It is an all-glass device which consists of fusion bonded Pyrex wafers with embedded flow channels and a nozzle at the chip edge. A platinum heater is located on the wafer backside. Fabrication of the chip is detailed, especially glass deep etching, wafer bonding, and metal patterning. Various process combinations of bonding and metallization have been considered (anodic bonding vs. fusion bonding; heater inside/outside channel; metallization before/after bonding; platinum lift-off vs. etching). The chip vaporizes the liquid sample (0.1-10 microL min(-1)) and mixes it with a nebulizer gas (ca. 100 sccm N2). Operating temperatures can go up to 500 degrees C ensuring efficient vaporization. Thermal insulation of the glass ensures low temperatures at the far end of the chip, enabling easy interconnections.

  20. Enantioselectivity of mass spectrometry: challenges and promises.

    Science.gov (United States)

    Awad, Hanan; El-Aneed, Anas

    2013-01-01

    With the fast growing market of pure enantiomer drugs and bioactive molecules, new chiral-selective analytical tools have been instigated including the use of mass spectrometry (MS). Even though MS is one of the best analytical tools that has efficiently been used in several pharmaceutical and biological applications, traditionally MS is considered as a "chiral-blind" technique. This limitation is due to the MS inability to differentiate between two enantiomers of a chiral molecule based merely on their masses. Several approaches have been explored to assess the potential role of MS in chiral analysis. The first approach depends on the use of MS-hyphenated techniques utilizing fast and sensitive chiral separation tools such as liquid chromatography (LC), gas chromatography (GC), and capillary electrophoresis (CE) coupled to MS detector. More recently, several alternative separation techniques have been evaluated such as supercritical fluid chromatography (SFC) and capillary electrochromatography (CEC); the latter being a hybrid technique that combines the efficiency of CE with the selectivity of LC. The second approach is based on using the MS instrument solely for the chiral recognition. This method depends on the behavioral differences between enantiomers towards a foreign molecule and the ability of MS to monitor such differences. These behavioral differences can be divided into three types: (i) differences in the enantiomeric affinity for association with the chiral selector, (ii) differences of the enantiomeric exchange rate with a foreign reagent, and (iii) differences in the complex MS dissociation behaviors of the enantiomers. Most recently, ion mobility spectrometry was introduced to qualitatively and quantitatively evaluate chiral compounds. This article provides an overview of MS role in chiral analysis by discussing MS based methodologies and presenting the challenges and promises associated with each approach.

  1. Advantageous Uses of Mass Spectrometry for the Quantification of Proteins

    Directory of Open Access Journals (Sweden)

    John E. Hale

    2013-01-01

    Full Text Available Quantitative protein measurements by mass spectrometry have gained wide acceptance in research settings. However, clinical uptake of mass spectrometric protein assays has not followed suit. In part, this is due to the long-standing acceptance by regulatory agencies of immunological assays such as ELISA assays. In most cases, ELISAs provide highly accurate, sensitive, relatively inexpensive, and simple assays for many analytes. The barrier to acceptance of mass spectrometry in these situations will remain high. However, mass spectrometry provides solutions to certain protein measurements that are difficult, if not impossible, to accomplish by immunological methods. Cases where mass spectrometry can provide solutions to difficult assay development include distinguishing between very closely related protein species and monitoring biological and analytical variability due to sample handling and very high multiplexing capacity. This paper will highlight several examples where mass spectrometry has made certain protein measurements possible where immunological techniques have had a great difficulty.

  2. Fluxomics: mass spectrometry versus quantitative imaging.

    Science.gov (United States)

    Wiechert, Wolfgang; Schweissgut, Oliver; Takanaga, Hitomi; Frommer, Wolf B

    2007-06-01

    The recent development of analytic high-throughput technologies enables us to take a bird's view of how metabolism is regulated in real time. We have known for a long time that metabolism is highly regulated at all levels, including transcriptional, posttranslational and allosteric controls. Flux through a metabolic or signaling pathway is determined by the activity of its individual components. Fluxomics aims to define the genes involved in regulation by following the flux. Two technologies are used to monitor fluxes. Pulse labeling of the organism or cell with a tracer, such as 13C, followed by mass spectrometric analysis of the partitioning of label into different compounds provides an efficient tool to study flux and to compare the effect of mutations on flux. The second approach is based on the use of flux sensors, proteins that respond with a conformational change to ligand binding. Fluorescence resonance energy transfer (FRET) detects the conformational change and serves as a proxy for ligand concentration. In contrast to the mass spectrometry assays, FRET nanosensors monitor only a single compound. Both methods provide high time resolution. The major advantages of FRET nanosensors are that they yield data with cellular and subcellular resolution and the method is minimally invasive.

  3. From structure to function : Protein assemblies dissected by mass spectrometry

    NARCIS (Netherlands)

    Lorenzen, K.

    2008-01-01

    This thesis demonstrates some of the possibilities mass spectrometry can provide to gain new insight into structure and function of protein complexes. While technologies in native mass spectrometry are still under development, it already allows research on complete proteins and protein complexes up

  4. Clinical Mass Spectrometry: Achieving Prominence in Laboratory Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Annesley, Thomas M.; Cooks, Robert G.; Herold, David A.; Hoofnagle, Andrew N.

    2016-01-04

    Each year the journal Clinical Chemistry publishes a January special issue on a topic that is relevant to the laboratory medicine community. In January 2016 the topic is mass spectrometry, and the issue is entitled “Clinical Mass Spectrometry: Achieving Prominence in Laboratory Medicine”. One popular feature in our issues is a Q&A on a topic, clearly in this case mass spectrometry. The journal is assembling a panel of 5-6 experts from various areas of mass spectrometry ranging from instrument manufacturing to practicing clinical chemists. Dick Smith is one of the scientist requested to participate in this special issue Q&A on Mass Spectrometry. The Q&A Transcript is attached

  5. Identification of Unknown Contaminants in Water Samples from ISS Employing Liquid Chromatography/Mass Spectrometry/Mass Spectrometry

    Science.gov (United States)

    Rutz, Jeffrey A.; Schultz, John R.

    2008-01-01

    Mass Spectrometry/Mass Spectrometry (MS/MS) is a powerful technique for identifying unknown organic compounds. For non-volatile or thermally unstable unknowns dissolved in liquids, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) is often the variety of MS/MS used for the identification. One type of LC/MS/MS that is rapidly becoming popular is time-of-flight (TOF) mass spectrometry. This technique is now in use at the Johnson Space Center for identification of unknown nonvolatile organics in water samples from the space program. An example of the successful identification of one unknown is reviewed in detail in this paper. The advantages of time-of-flight instrumentation are demonstrated through this example as well as the strategy employed in using time-of-flight data to identify unknowns.

  6. Detection of Gunshot Residues Using Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Regina Verena Taudte

    2014-01-01

    Full Text Available In recent years, forensic scientists have become increasingly interested in the detection and interpretation of organic gunshot residues (OGSR due to the increasing use of lead- and heavy metal-free ammunition. This has also been prompted by the identification of gunshot residue- (GSR- like particles in environmental and occupational samples. Various techniques have been investigated for their ability to detect OGSR. Mass spectrometry (MS coupled to a chromatographic system is a powerful tool due to its high selectivity and sensitivity. Further, modern MS instruments can detect and identify a number of explosives and additives which may require different ionization techniques. Finally, MS has been applied to the analysis of both OGSR and inorganic gunshot residue (IGSR, although the “gold standard” for analysis is scanning electron microscopy with energy dispersive X-ray microscopy (SEM-EDX. This review presents an overview of the technical attributes of currently available MS and ionization techniques and their reported applications to GSR analysis.

  7. Secondary Ion Mass Spectrometry SIMS XI

    Science.gov (United States)

    Gillen, G.; Lareau, R.; Bennett, J.; Stevie, F.

    2003-05-01

    This volume contains 252 contributions presented as plenary, invited and contributed poster and oral presentations at the 11th International Conference on Secondary Ion Mass Spectrometry (SIMS XI) held at the Hilton Hotel, Walt Disney World Village, Orlando, Florida, 7 12 September, 1997. The book covers a diverse range of research, reflecting the rapid growth in advanced semiconductor characterization, ultra shallow depth profiling, TOF-SIMS and the new areas in which SIMS techniques are being used, for example in biological sciences and organic surface characterization. Papers are presented under the following categories: Isotopic SIMS Biological SIMS Semiconductor Characterization Techniques and Applications Ultra Shallow Depth Profiling Depth Profiling Fundamental/Modelling and Diffusion Sputter-Induced Topography Fundamentals of Molecular Desorption Organic Materials Practical TOF-SIMS Polyatomic Primary Ions Materials/Surface Analysis Postionization Instrumentation Geological SIMS Imaging Fundamentals of Sputtering Ion Formation and Cluster Formation Quantitative Analysis Environmental/Particle Characterization Related Techniques These proceedings provide an invaluable source of reference for both newcomers to the field and experienced SIMS users.

  8. Tandem mass spectrometry: analysis of complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, K.E.

    1985-01-01

    Applications of tandem mass spectrometry (MS/MS) for the analysis of complex mixtures results in increased specificity and selectivity by using a variety of reagent gases in both negative and positive ion modes. Natural isotopic abundance ratios were examined in both simple and complex mixtures using parent, daughter and neutral loss scans. MS/MS was also used to discover new compounds. Daughter scans were used to identify seven new alkaloids in a cactus species. Three of these alkaloids were novel compounds, and included the first simple, fully aromatic isoquinoline alkaloids reported in Cactaceae. MS/MS was used to characterize the chemical reaction products of coal in studies designed to probe its macromolecular structure. Negative ion chemical ionization was utilized to study reaction products resulting from the oxidation of coal. Possible structural units in the precursor coal were predicted based on the reaction products identified, aliphatic and aromatic acids and their anhydrides. The MS/MS method was also used to characterize reaction products resulting from coal liquefaction and/or extraction. These studies illustrate the types of problems for which MS/MS is useful. Emphasis has been placed on characterization of complex mixtures by selecting experimental parameters which enhance the information obtained. The value of using MS/MS in conjunction with other analytical techniques as well as the chemical pretreatment is demonstrated.

  9. Proton Dynamics in Protein Mass Spectrometry.

    Science.gov (United States)

    Li, Jinyu; Lyu, Wenping; Rossetti, Giulia; Konijnenberg, Albert; Natalello, Antonino; Ippoliti, Emiliano; Orozco, Modesto; Sobott, Frank; Grandori, Rita; Carloni, Paolo

    2017-02-22

    Native electrospray ionization/ion mobility-mass spectrometry (ESI/IM-MS) allows an accurate determination of low-resolution structural features of proteins. Yet, the presence of proton dynamics, observed already by us for DNA in the gas phase, and its impact on protein structural determinants, have not been investigated so far. Here, we address this issue by a multistep simulation strategy on a pharmacologically relevant peptide, the N-terminal residues of amyloid-β peptide (Aβ(1-16)). Our calculations reproduce the experimental maximum charge state from ESI-MS and are also in fair agreement with collision cross section (CCS) data measured here by ESI/IM-MS. Although the main structural features are preserved, subtle conformational changes do take place in the first ∼0.1 ms of dynamics. In addition, intramolecular proton dynamics processes occur on the picosecond-time scale in the gas phase as emerging from quantum mechanics/molecular mechanics (QM/MM) simulations at the B3LYP level of theory. We conclude that proton transfer phenomena do occur frequently during fly time in ESI-MS experiments (typically on the millisecond time scale). However, the structural changes associated with the process do not significantly affect the structural determinants.

  10. MSSimulator: Simulation of mass spectrometry data.

    Science.gov (United States)

    Bielow, Chris; Aiche, Stephan; Andreotti, Sandro; Reinert, Knut

    2011-07-01

    Mass spectrometry coupled to liquid chromatography (LC-MS and LC-MS/MS) is commonly used to analyze the protein content of biological samples in large scale studies, enabling quantitation and identification of proteins and peptides using a wide range of experimental protocols, algorithms, and statistical models to analyze the data. Currently it is difficult to compare the plethora of algorithms for these tasks. So far, curated benchmark data exists for peptide identification algorithms but data that represents a ground truth for the evaluation of LC-MS data is limited. Hence there have been attempts to simulate such data in a controlled fashion to evaluate and compare algorithms. We present MSSimulator, a simulation software for LC-MS and LC-MS/MS experiments. Starting from a list of proteins from a FASTA file, the simulation will perform in-silico digestion, retention time prediction, ionization filtering, and raw signal simulation (including MS/MS), while providing many options to change the properties of the resulting data like elution profile shape, resolution and sampling rate. Several protocols for SILAC, iTRAQ or MS(E) are available, in addition to the usual label-free approach, making MSSimulator the most comprehensive simulator for LC-MS and LC-MS/MS data.

  11. Charging of Proteins in Native Mass Spectrometry

    Science.gov (United States)

    Susa, Anna C.; Xia, Zijie; Tang, Henry Y. H.; Tainer, John A.; Williams, Evan R.

    2017-02-01

    Factors that influence the charging of protein ions formed by electrospray ionization from aqueous solutions in which proteins have native structures and function were investigated. Protein ions ranging in molecular weight from 12.3 to 79.7 kDa and pI values from 5.4 to 9.6 were formed from different solutions and reacted with volatile bases of gas-phase basicities higher than that of ammonia in the cell of a Fourier-transform ion cyclotron resonance mass spectrometer. The charge-state distribution of cytochrome c ions formed from aqueous ammonium or potassium acetate is the same. Moreover, ions formed from these two solutions do not undergo proton transfer to 2-fluoropyridine, which is 8 kcal/mol more basic than ammonia. These results provide compelling evidence that proton transfer between ammonia and protein ions does not limit protein ion charge in native electrospray ionization. Both circular dichroism and ion mobility measurements indicate that there are differences in conformations of proteins in pure water and aqueous ammonium acetate, and these differences can account for the difference in the extent of charging and proton-transfer reactivities of protein ions formed from these solutions. The extent of proton transfer of the protein ions with higher gas-phase basicity bases trends with how closely the protein ions are charged to the value predicted by the Rayleigh limit for spherical water droplets approximately the same size as the proteins. These results indicate that droplet charge limits protein ion charge in native mass spectrometry and are consistent with these ions being formed by the charged residue mechanism.

  12. Experimental simulation of negative ion chemistry in Martian atmosphere using ion mobility spectrometry-mass spectrometry

    Science.gov (United States)

    Sabo, Martin; Lichvanová, Zuzana; Orszagh, Juraj; Mason, Nigel; Matejčík, Štefan

    2014-08-01

    We have studied the formation of negative ions in a negative Corona Discharge (CD) fed by CO2/N2 mixtures (with 0, 2, 4, 6, 8, 10% N2) using the technique of ion mobility spectrometry-orthogonal acceleration time of flight mass spectrometry (IMS-oaTOF). The composition of the negative ions was found to be dependent on the initial gas composition, the gas flow regime, the concentrations of neutral reactive species formed in the discharge and the trace amounts on water in the gases were found to play an important role in the negative ions formation. In a pure CO2 discharge operating under standard gas flow conditions of IMS (associated with strong interaction of ions with neutral reactive species formed in discharge) the ions CO3 - (H2O) and CO4 -(H2O) dominated the measured negative ion spectrum while in CO2/N2 mixtures NO3 -(H2O) n , NO3 -(HNO3) ( n = 0, 1) ions prevailed. In the case of reverse gas flow regime (low interaction of ions with neutral reactive species formed in discharge), the negative ions detected were O2 -(H2O) n , and O2 -.CO2(H2O) n both in pure CO2 and N2/CO2 mixtures. The spectra of negative ions recorded for a gas mixture containing 4% N2 in CO2 were compared with theoretical predictions of negative ion composition in the lower atmosphere of Mars.

  13. 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....

  14. Characterization of Membrane Protein-Lipid Interactions by Mass Spectrometry Ion Mobility Mass Spectrometry

    Science.gov (United States)

    Liu, Yang; Cong, Xiao; Liu, Wen; Laganowsky, Arthur

    2016-12-01

    Lipids in the biological membrane can modulate the structure and function of integral and peripheral membrane proteins. Distinguishing individual lipids that bind selectively to membrane protein complexes from an ensemble of lipid-bound species remains a daunting task. Recently, ion mobility mass spectrometry (IM-MS) has proven to be invaluable for interrogating the interactions between protein and individual lipids, where the complex undergoes collision induced unfolding followed by quantification of the unfolding pathway to assess the effect of these interactions. However, gas-phase unfolding experiments for membrane proteins are typically performed on the entire ensemble (apo and lipid bound species), raising uncertainty to the contribution of individual lipids and the species that are ejected in the unfolding process. Here, we describe the application of mass spectrometry ion mobility mass spectrometry (MS-IM-MS) for isolating ions corresponding to lipid-bound states of a model integral membrane protein, ammonia channel (AmtB) from Escherichia coli. Free of ensemble effects, MS-IM-MS reveals that bound lipids are ejected as neutral species; however, no correlation was found between the lipid-induced stabilization of complex and their equilibrium binding constants. In comparison to data obtained by IM-MS, there are surprisingly limited differences in stability measurements from IM-MS and MS-IM-MS. The approach described here to isolate ions of membrane protein complexes will be useful for other MS methods, such as surface induced dissociation or collision induced dissociation to determine the stoichiometry of hetero-oligomeric membrane protein complexes.

  15. Mass spectrometry for characterizing plant cell wall polysaccharides

    Directory of Open Access Journals (Sweden)

    Stefan eBauer

    2012-03-01

    Full Text Available Mass spectrometry is a selective and powerful technique to obtain identification and structural information on compounds present in complex mixtures. Since it requires only small sample amount it is an excellent tool for researchers interested in detecting changes in composition of complex carbohydrates of plants. This mini-review gives an overview of common mass spectrometry techniques applied to the analysis of plant cell wall carbohydrates. It presents examples in which mass spectrometry has been used to elucidate the structure of oligosaccharides derived from hemicelluloses and pectins and illustrates how information on sequence, linkages, branching and modifications are obtained from characteristic fragmentation patterns.

  16. The Vanderbilt Mass Spectrometry Shared Facilities

    Science.gov (United States)

    Friedman, D.B.; Reyzer, M.L.; Seeley, E.H.; Calcutt, M. Wade; Hachey, D.L.; Caprioli, R.M.; McDonald, W.H.

    2010-01-01

    CF-33 The Vanderbilt Mass Spectrometry Research Center (MSRC) provides an integrated bioanalytical service facility to Vanderbilt researchers coupled with a strong MS research component.The synergies achieved by merging research and service provide investigators with state-of-the-art proteomics, tissue profiling/imaging, and bioanalytical MS technologies. These cores are managed by a professional staff of six faculty members and five research assistants, bioinformatics specialists, and an instrument engineer. The Proteomics Laboratory supports multiple technology platforms, including HPLC peptide separations and 2D gel separations of intact proteins. Analysis can be performed by ESI-linear ion trap/orbitrap and MALDI-TOF/TOF MS with all of the necessary downstream bioinformatics for protein identification and characterization. We routinely utilize single- and multi-dimensional LC/MS/MS for protein cataloguing and differential-expression studies (using spectral counting), and Difference Gel Electrophoresis (DIGE) for large-scale expression studies on complex proteomes. The Tissue Imaging core provides tissue sectioning, staining, and MS directly from tissue sections via either high resolution imaging across an entire tissue section, or higher-throughput histology-directed profiling using specific tissue areas.As with the proteomics analysis, the necessary tools and infrastructure are available for downstream biostatistical analysis of the MS data. Both of these cores work closely with users at all stages of experiments including detailed informatics consultations and training. They generally operate as limited-access facilities where users prepare samples and core technical staff performs the analyses. The Bioanalytical MS Core provides instrumentation to perform a wide variety of analyses (e.g. identification and structural analysis of biological molecules, and qualitative and quantitative assays of drugs and metabolites). The MS Core operates in an open access

  17. A Review on Mass Spectrometry: Technique and Tools

    Directory of Open Access Journals (Sweden)

    Ms. Ashwini Yerlekar

    2014-04-01

    Full Text Available Protein structure prediction has gain important in area of life sciences, because of its complex structure. The protein-protein interaction is necessary to study the behavior of protein in a specific environment, and study molecular relationship in living systems. Therefore, large scale proteomics technologies are required to measure physical connection of proteins in living organisms. Mass Spectrometry uses the technique to measure mass-to-charge ratio of ion. It's an evolving technique for characterization of proteins. A Mass Spectrometer can be more sensitive and specific, also complement with other LC detectors. Liquid Chromatography, unlike gas chromatography is a separation technique which helps to separate wide range of organic compounds from small molecular metabolites to peptides and proteins. This paper addresses the study of data analysis using mass Spectrometry. It also includes the study of various methods of Mass Spectrometry data analysis, the tools and various applications of Mass Spectrometry.This review briefs on Mass Spectrometry technique, its application, usage, and tools used by Mass Spectrometry

  18. Application of Lithium Attachment Mass Spectrometry for Knudsen Evaporation and Chemical Ionisation Mass Spectrometry (KEMS, CIMS)

    Science.gov (United States)

    Bannan, Thomas; Booth, A. Murray; Alfarra, Rami; Bacak, Asan; Pericval, Carl

    2016-04-01

    Lithium ion attachment mass spectrometry provides a non-specific, non-fragmenting and sensitive method for detection of volatile species in the gas phase. The design, manufacture, and results from lithium ion attachment ionisation sources for two mass spectrometry systems are presented. Trace gas analysis is investigated using a modified Chemical Ionization Mass Spectrometer (CIMS) and vapour pressure (VP) measurements using a modified Knudsen Effusion Mass Spectrometer (KEMS) are presented. The Li+ modified CIMS provided limits of detection of 4 ppt for acetone, 0.2 ppt for formic acid, 15 ppt for nitric acid and 120 ppt from ammonia. Despite improvements, the problem of burnout remained persistent. The Li+ CIMS would unlikely be suitable for field or aircraft work, but could be appropriate for certain lab applications. The KEMS currently utilizes an electron impact (EI) ionisation source which provides a highly sensitive source, with the drawback of fragmentation of ionized molecules (Booth et al., 2009). Using Li+ KEMS the VP of samples can be measured without fragmentation and can therefore be used to identify VPs of individual components in mixtures. The validity of using Li+ for determining the VP of mixtures was tested by making single component VP measurements, which showed good agreement with EI measurements of Poly ethylene glycol (PEG) 3 and PEG 4, both when individually measured and when mixed. The Li+ KEMS was then used to investigate a system of atmospheric relevance, α-pinene secondary organic aerosol, generated in a reaction chamber (Alfarra et al., 2012). The VPs of the individual components from this generated sample are within the range we expect for compounds capable of partitioning between the particle and gas phase of an aerosol (0.1-10-5 Pa). Li+ source has a calculated sensitivity approximately 75 times less than that of EI, but the lack of fragmentation using the Li+ source is a significant advantage.

  19. imzML: Imaging Mass Spectrometry Markup Language: A common data format for mass spectrometry imaging.

    Science.gov (United States)

    Römpp, Andreas; Schramm, Thorsten; Hester, Alfons; Klinkert, Ivo; Both, Jean-Pierre; Heeren, Ron M A; Stöckli, Markus; Spengler, Bernhard

    2011-01-01

    Imaging mass spectrometry is the method of scanning a sample of interest and generating an "image" of the intensity distribution of a specific analyte. The data sets consist of a large number of mass spectra which are usually acquired with identical settings. Existing data formats are not sufficient to describe an MS imaging experiment completely. The data format imzML was developed to allow the flexible and efficient exchange of MS imaging data between different instruments and data analysis software.For this purpose, the MS imaging data is divided in two separate files. The mass spectral data is stored in a binary file to ensure efficient storage. All metadata (e.g., instrumental parameters, sample details) are stored in an XML file which is based on the standard data format mzML developed by HUPO-PSI. The original mzML controlled vocabulary was extended to include specific parameters of imaging mass spectrometry (such as x/y position and spatial resolution). The two files (XML and binary) are connected by offset values in the XML file and are unambiguously linked by a universally unique identifier. The resulting datasets are comparable in size to the raw data and the separate metadata file allows flexible handling of large datasets.Several imaging MS software tools already support imzML. This allows choosing from a (growing) number of processing tools. One is no longer limited to proprietary software, but is able to use the processing software which is best suited for a specific question or application. On the other hand, measurements from different instruments can be compared within one software application using identical settings for data processing. All necessary information for evaluating and implementing imzML can be found at http://www.imzML.org .

  20. Gas Chromatography Mass Spectrometry of Quassia undulata Seed ...

    African Journals Online (AJOL)

    Prof. Ogunji

    ... fatty acid methyl ester analysis. Gas chromatography (GC) and mass spectrometry (MS) has proved an effective ... extensive qualitative and quantitative research on the fatty ... chemical properties of biodiesel and other derivatives of fatty ...

  1. Laser mass spectrometry for DNA sequencing, disease diagnosis, and fingerprinting

    Energy Technology Data Exchange (ETDEWEB)

    Winston Chen, C.H.; Taranenko, N.I.; Zhu, Y.F.; Chung, C.N.; Allman, S.L.

    1997-03-01

    Since laser mass spectrometry has the potential for achieving very fast DNA analysis, the authors recently applied it to DNA sequencing, DNA typing for fingerprinting, and DNA screening for disease diagnosis. Two different approaches for sequencing DNA have been successfully demonstrated. One is to sequence DNA with DNA ladders produced from Snager`s enzymatic method. The other is to do direct sequencing without DNA ladders. The need for quick DNA typing for identification purposes is critical for forensic application. The preliminary results indicate laser mass spectrometry can possibly be used for rapid DNA fingerprinting applications at a much lower cost than gel electrophoresis. Population screening for certain genetic disease can be a very efficient step to reducing medical costs through prevention. Since laser mass spectrometry can provide very fast DNA analysis, the authors applied laser mass spectrometry to disease diagnosis. Clinical samples with both base deletion and point mutation have been tested with complete success.

  2. Determination of Organophosphorus Pesticides in Soil Using Accelerated Solvent Extraction and Gas Chromatography and Negative Chemical Ionization Mass Spectrometry%加速溶剂萃取-气相色谱-负化学离子化质谱法测定土壤中有机磷农药

    Institute of Scientific and Technical Information of China (English)

    林长青; 张纯淳; 李钟瑜; 高鹏

    2014-01-01

    An effective method for trace analysis of organophosphorus pesticides in soil was developed using accelerated solvent extraction ( ASE) followed by gas chromatography-electron ionization-mass spectrometry ( GC-EI-MS) and gas chromatography-negative chemical ionization- mass spectrometry ( GC-NCI-MS ) . The results show that both GC-EI-MS and GC-NCI-MS are sufficient for the daily analysis. GC-EI-MS method has an extensive application scope and is easy to operate. Also the GC-NCI-MS method has advantages in selectivity and sensitivity.%用加速溶剂萃取法( ASE)萃取土壤中的有机磷农药,用气相色谱-负化学离子化质谱法( GC-NCI-MS)进行测定,并与气相色谱-电子轰击电离质谱法( GC-EI-MS)进行了对比。结果表明,EI法和NCI法均能满足目前的有机磷农药的分析需要。 GC-EI-MS的适用范围比较广,操作比较简单;GC-NCI-MS在选择性和灵敏度等方面均具有较强优势。

  3. Analysis of chirality by femtosecond laser ionization mass spectrometry.

    Science.gov (United States)

    Horsch, Philipp; Urbasch, Gunter; Weitzel, Karl-Michael

    2012-09-01

    Recent progress in the field of chirality analysis employing laser ionization mass spectrometry is reviewed. Emphasis is given to femtosecond (fs) laser ionization work from the author's group. We begin by reviewing fundamental aspects of determining circular dichroism (CD) in fs-laser ionization mass spectrometry (fs-LIMS) discussing an example from the literature (resonant fs-LIMS of 3-methylcyclopentanone). Second, we present new data indicating CD in non-resonant fs-LIMS of propylene oxide.

  4. Yeast expression proteomics by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  5. Subcellular analysis by laser ablation electrospray ionization mass spectrometry

    Science.gov (United States)

    Vertes, Akos; Stolee, Jessica A; Shrestha, Bindesh

    2014-12-02

    In various embodiments, a method of laser ablation electrospray ionization mass spectrometry (LAESI-MS) may generally comprise micro-dissecting a cell comprising at least one of a cell wall and a cell membrane to expose at least one subcellular component therein, ablating the at least one subcellular component by an infrared laser pulse to form an ablation plume, intercepting the ablation plume by an electrospray plume to form ions, and detecting the ions by mass spectrometry.

  6. Chiral recognition detected by fast atom bombardment mass spectrometry.

    Science.gov (United States)

    Sawada, M

    1997-01-01

    Detection of chiral recognition in various intermolecular interaction systems using mass spectrometry has become important for the modern fields of analytical chemistry, organic chemistry, and biochemistry due to the characteristic nature of the rapid method and the trace amount needed. This review presents the various methods for detecting and evaluating chiral recognition used primarily in fast atom bombardment mass spectrometry. Emphasis is put on fundamentals and applications of these methods for variously existing enantioselective intermolecular interaction systems.

  7. Secondary Ion Mass Spectrometry Imaging of Dictyostelium discoideum Aggregation Streams

    Energy Technology Data Exchange (ETDEWEB)

    Debord, J. Daniel; Smith, Donald F.; Anderton, Christopher R.; Heeren, Ronald M.; Pasa-Tolic, Ljiljana; Gomer, Richard H.; Fernandez-Lima, Francisco A.

    2014-06-09

    High resolution imaging mass spectrometry could become a valuable tool for cell and developmental biology, but both, high spatial and mass spectral resolution are needed to enable this. In this report, we employed Bi3 bombardment time-of-flight (Bi3 ToF-SIMS) and C60 bombardment Fourier transform ion cyclotron resonance secondary ion mass spectrometry (C60 FTICR-SIMS) to image Dictyostelium discoideum aggregation streams. Nearly 300 lipid species were identified from the aggregation streams. High resolution mass spectrometry imaging (FTICR-SIMS) enabled the generation of multiple molecular ion maps at the nominal mass level and provided good coverage for fatty acyls, prenol lipids, and sterol lipids. The comparison of Bi3 ToF-SIMS and C60 FTICR-SIMS suggested that while the first provides fast, high spatial resolution molecular ion images, the chemical complexity of biological samples warrants the use of high resolution analyzers for accurate ion identification.

  8. NCBI Peptidome: a new repository for mass spectrometry proteomics data.

    Science.gov (United States)

    Ji, Li; Barrett, Tanya; Ayanbule, Oluwabukunmi; Troup, Dennis B; Rudnev, Dmitry; Muertter, Rolf N; Tomashevsky, Maxim; Soboleva, Alexandra; Slotta, Douglas J

    2010-01-01

    Peptidome is a public repository that archives and freely distributes tandem mass spectrometry peptide and protein identification data generated by the scientific community. Data from all stages of a mass spectrometry experiment are captured, including original mass spectra files, experimental metadata and conclusion-level results. The submission process is facilitated through acceptance of data in commonly used open formats, and all submissions undergo syntactic validation and curation in an effort to uphold data integrity and quality. Peptidome is not restricted to specific organisms, instruments or experiment types; data from any tandem mass spectrometry experiment from any species are accepted. In addition to data storage, web-based interfaces are available to help users query, browse and explore individual peptides, proteins or entire Samples and Studies. Results are integrated and linked with other NCBI resources to ensure dissemination of the information beyond the mass spectroscopy proteomics community. Peptidome is freely accessible at http://www.ncbi.nlm.nih.gov/peptidome.

  9. 'Extreme mass spectrometry': the role of mass spectrometry in the study of the Antarctic environment.

    Science.gov (United States)

    Magi, Emanuele; Tanwar, Shivani

    2014-11-01

    A focus on the studies of the Antarctic environment that have been performed by mass spectrometry is presented herein; our aim is to give evidence of the essential role of this instrumental technique in the framework of the scientific research in Antarctica, with a comprehensive review on the main literature of the last two decades. Due to the wideness of the topic, the present review is limited to the determination of organic pollutants, natural molecules and biomarkers in Antarctica, thus excluding elemental analysis and studies on inorganic species. The work has been divided into five sections, on the basis of the considered environmental compartment: air; ice and snow; seawater, pack ice and lakes; soil and sediments; and organisms and biomarkers.

  10. Noncovalent Shiga-like toxin assemblies: characterization by means of mass spectrometry and tandem mass spectrometry.

    Science.gov (United States)

    Williams, Jonathan P; Green, Brian N; Smith, Daniel C; Jennings, Keith R; Moore, Katherine A H; Slade, Susan E; Roberts, Lynne M; Scrivens, James H

    2005-06-14

    Shiga-like toxin 1 (SLTx), produced by enterohemorrhagic strains of Escherichia coli (EHEC), belongs to a family of structurally and functionally related AB(5) protein toxins that are associated with human disease. EHEC infection often gives rise to hemolytic colitis, while toxin-induced kidney damage is one of the major causes of hemolytic uremic syndrome (HUS) and acute renal failure in children. As such, an understanding and analysis of the noncovalent interactions that maintain the quaternary structure of this toxin are fundamentally important since such interactions have significant biochemical and medical implications. This paper reports on the analysis of the noncovalent homopentameric complex of Shiga-like toxin B chain (SLTx-B(5)) using electrospray ionization (ESI) triple-quadrupole (QqQ) mass spectrometry (MS) and tandem mass spectrometry (MS/MS) and the analysis of the noncovalent hexameric holotoxin (SLTx-AB(5)) using ESI time-of-flight (TOF) MS. The triple-quadrupole analysis revealed highly charged monomer ions dissociate from the multiprotein complex to form dimer, trimer, and tetramer product ions, which were also seen to further dissociate. The ESI-TOFMS analysis of SLTx-AB(5) revealed the complex remained intact and was observed in the gas phase over a range of pHs. Theses findings demonstrate that the gas-phase structure observed for both the holotoxin and the isoloated B chains correlates well with the structures reported to exist in the solution phase for these proteins. Such analysis provides a rapid screening technique for assessing the noncovalent structure of this family of proteins and other structurally related toxins.

  11. EP3 Fundamentals of Protein Sequence Characterization by Mass Spectrometry

    OpenAIRE

    Annan, R. S.; Johnson, R. S.; Papayannopoulos, I. A.

    2007-01-01

    The first section of the tutorial will describe the instrumentation typically used in biological mass spectrometry applications related to protein identification. We focus on the relevant ionization techniques, common mass analyzers, and sample introduction systems. Attention will be given to properties, such as mass accuracy and mass resolution, which are important to protein characterization and database search strategies for protein identification. Practical considerations regarding the se...

  12. Incorporating Biological Mass Spectrometry into Undergraduate Teaching Labs, Part 2: Peptide Identification via Molecular Mass Determination

    Science.gov (United States)

    Arnquist, Isaac J.; Beussman, Douglas J.

    2009-01-01

    Mass spectrometry has become a routine analytical tool in the undergraduate curriculum in the form of GC-MS. While relatively few undergraduate programs have incorporated biological mass spectrometry into their programs, the importance of these techniques, as demonstrated by their recognition with the 2002 Nobel Prize, will hopefully lead to…

  13. Incorporating Biological Mass Spectrometry into Undergraduate Teaching Labs, Part 2: Peptide Identification via Molecular Mass Determination

    Science.gov (United States)

    Arnquist, Isaac J.; Beussman, Douglas J.

    2009-01-01

    Mass spectrometry has become a routine analytical tool in the undergraduate curriculum in the form of GC-MS. While relatively few undergraduate programs have incorporated biological mass spectrometry into their programs, the importance of these techniques, as demonstrated by their recognition with the 2002 Nobel Prize, will hopefully lead to…

  14. Top-Down Mass Spectrometry: Proteomics to Proteoforms.

    Science.gov (United States)

    Patrie, Steven M

    2016-01-01

    This chapter highlights many of the fundamental concepts and technologies in the field of top-down mass spectrometry (TDMS), and provides numerous examples of contributions that TD is making in biology, biophysics, and clinical investigations. TD workflows include variegated steps that may include non-specific or targeted preparative strategies, orthogonal liquid chromatography techniques, analyte ionization, mass analysis, tandem mass spectrometry (MS/MS) and informatics procedures. This diversity of experimental designs has evolved to manage the large dynamic range of protein expression and diverse physiochemical properties of proteins in proteome investigations, tackle proteoform microheterogeneity, as well as determine structure and composition of gas-phase proteins and protein assemblies.

  15. NEGATIVE-ION MASS SPECTROMETRY OF SULFONYLUREA HERBICIDES

    Science.gov (United States)

    Sulfonylurea herbicides have been studied using neg-ion desorption chem.-ionization (DCI) mass spectrometry (MS) and DCI-MS/MS techniques. Both {M-H]- and M.- ions were obsd. in the DCI mass spectra. The collisonally activated dissocn. (CAD) spectra were characteristic of the str...

  16. A Review of the Emerging Field of Underwater Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Emily Chua

    2016-11-01

    Full Text Available Mass spectrometers are versatile sensor systems, owing to their high sensitivity and ability to simultaneously measure multiple chemical species. Over the last two decades, traditional laboratory-based membrane inlet mass spectrometers have been adapted for underwater use. Underwater mass spectrometry has drastically improved our capability to monitor a broad suite of gaseous compounds (e.g., dissolved atmospheric gases, light hydrocarbons, and volatile organic compounds in the aquatic environment. Here we provide an overview of the progress made in the field of underwater mass spectrometry since its inception in the 1990s to the present. In particular, we discuss the approaches undertaken by various research groups in developing in situ mass spectrometers. We also provide examples to illustrate how underwater mass spectrometers have been used in the field. Finally, we present future trends in the field of in situ mass spectrometry. Most of these efforts are aimed at improving the quality and spatial and temporal scales of chemical measurements in the ocean. By providing up-to-date information on underwater mass spectrometry, this review offers guidance for researchers interested in adapting this technology as well as goals for future progress in the field.

  17. Surface-MALDI mass spectrometry in biomaterials research

    DEFF Research Database (Denmark)

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

    2004-01-01

    Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for over a decade for the determination of purity and accurate molecular masses of macromolecular analytes, such as proteins, in solution. In the last few years the technique has been adapted to become a new...

  18. Applications of Mass Spectrometry to Structural Analysis of Marine Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Yinzhi Lang

    2014-06-01

    Full Text Available Marine oligosaccharides have attracted increasing attention recently in developing potential drugs and biomaterials for their particular physical and chemical properties. However, the composition and sequence analysis of marine oligosaccharides are very challenging for their structural complexity and heterogeneity. Mass spectrometry (MS has become an important technique for carbohydrate analysis by providing more detailed structural information, including molecular mass, sugar constituent, sequence, inter-residue linkage position and substitution pattern. This paper provides an overview of the structural analysis based on MS approaches in marine oligosaccharides, which are derived from some biologically important marine polysaccharides, including agaran, carrageenan, alginate, sulfated fucan, chitosan, glycosaminoglycan (GAG and GAG-like polysaccharides. Applications of electrospray ionization mass spectrometry (ESI-MS are mainly presented and the general applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS are also outlined. Some technical challenges in the structural analysis of marine oligosaccharides by MS have also been pointed out.

  19. Applications of mass spectrometry to structural analysis of marine oligosaccharides.

    Science.gov (United States)

    Lang, Yinzhi; Zhao, Xia; Liu, Lili; Yu, Guangli

    2014-06-30

    Marine oligosaccharides have attracted increasing attention recently in developing potential drugs and biomaterials for their particular physical and chemical properties. However, the composition and sequence analysis of marine oligosaccharides are very challenging for their structural complexity and heterogeneity. Mass spectrometry (MS) has become an important technique for carbohydrate analysis by providing more detailed structural information, including molecular mass, sugar constituent, sequence, inter-residue linkage position and substitution pattern. This paper provides an overview of the structural analysis based on MS approaches in marine oligosaccharides, which are derived from some biologically important marine polysaccharides, including agaran, carrageenan, alginate, sulfated fucan, chitosan, glycosaminoglycan (GAG) and GAG-like polysaccharides. Applications of electrospray ionization mass spectrometry (ESI-MS) are mainly presented and the general applications of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) are also outlined. Some technical challenges in the structural analysis of marine oligosaccharides by MS have also been pointed out.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  1. Development of stereotactic mass spectrometry for brain tumor surgery.

    Science.gov (United States)

    Agar, Nathalie Y R; Golby, Alexandra J; Ligon, Keith L; Norton, Isaiah; Mohan, Vandana; Wiseman, Justin M; Tannenbaum, Allen; Jolesz, Ferenc A

    2011-02-01

    Surgery remains the first and most important treatment modality for the majority of solid tumors. Across a range of brain tumor types and grades, postoperative residual tumor has a great impact on prognosis. The principal challenge and objective of neurosurgical intervention is therefore to maximize tumor resection while minimizing the potential for neurological deficit by preserving critical tissue. To introduce the integration of desorption electrospray ionization mass spectrometry into surgery for in vivo molecular tissue characterization and intraoperative definition of tumor boundaries without systemic injection of contrast agents. Using a frameless stereotactic sampling approach and by integrating a 3-dimensional navigation system with an ultrasonic surgical probe, we obtained image-registered surgical specimens. The samples were analyzed with ambient desorption/ionization mass spectrometry and validated against standard histopathology. This new approach will enable neurosurgeons to detect tumor infiltration of the normal brain intraoperatively with mass spectrometry and to obtain spatially resolved molecular tissue characterization without any exogenous agent and with high sensitivity and specificity. Proof of concept is presented in using mass spectrometry intraoperatively for real-time measurement of molecular structure and using that tissue characterization method to detect tumor boundaries. Multiple sampling sites within the tumor mass were defined for a patient with a recurrent left frontal oligodendroglioma, World Health Organization grade II with chromosome 1p/19q codeletion, and mass spectrometry data indicated a correlation between lipid constitution and tumor cell prevalence. The mass spectrometry measurements reflect a complex molecular structure and are integrated with frameless stereotaxy and imaging, providing 3-dimensional molecular imaging without systemic injection of any agents, which can be implemented for surgical margins delineation of

  2. Laser electrospray mass spectrometry of adsorbed molecules at atmospheric pressure

    Science.gov (United States)

    Brady, John J.; Judge, Elizabeth J.; Simon, Kuriakose; Levis, Robert J.

    2010-02-01

    Atmospheric pressure mass analysis of solid phase biomolecules is performed using laser electrospray mass spectrometry (LEMS). A non-resonant femtosecond duration laser pulse vaporizes native samples at atmospheric pressure for subsequent electrospray ionization and transfer into a mass spectrometer. LEMS was used to detect a complex molecule (irinotecan HCl), a complex mixture (cold medicine formulation with active ingredients: acetaminophen, dextromethorphan HBr and doxylamine succinate), and a biological building block (deoxyguanosine) deposited on steel surfaces without a matrix molecule.

  3. Advanced Mass Calibration and Visualization for FT-ICR Mass Spectrometry Imaging

    CERN Document Server

    Smith, Donald F; Konijnenburg, Marco; Klinkert, Ivo; Pasa-Tolic, Ljiljana; Heeren, Ron M A

    2013-01-01

    Mass spectrometry imaging by Fourier transform ion cyclotron resonance yields hundreds of unique peaks, many of which cannot be resolved by lower performance mass spectrometers. The high mass accuracy and high mass resolving power allow confident identification of small molecules and lipids directly from biological tissue sections. Here, calibration strategies for Fourier transform ion cyclotron resonance mass spectrometry imaging were investigated. Sub parts-per-million mass accuracy is demonstrated over an entire tissue section. Ion abundance fluctuations are corrected for by addition of total and relative ion abundances for a root-mean-square error of 0.158 ppm on 16,764 peaks. A new approach for visualization of Fourier transform ion cyclotron resonance mass spectrometry imaging data at high resolution is presented. The Mosaic Data-cube provides a flexible means to visualize the entire mass range at a mass spectral bin width of 0.001 Dalton. The high resolution Mosaic Data-cube resolves spectral features ...

  4. Pharmaceutical metabolite profiling using quadrupole/ion mobility spectrometry/time-of-flight mass spectrometry.

    Science.gov (United States)

    Chan, Eric C Y; New, Lee Sun; Yap, Chun Wei; Goh, Lin Tang

    2009-02-01

    The use of hybrid quadrupole ion mobility spectrometry time-of-flight mass spectrometry (Q/IMS/TOFMS) in the metabolite profiling of leflunomide (LEF) and acetaminophen (APAP) is presented. The IMS drift times (T(d)) of the drugs and their metabolites were determined in the IMS/TOFMS experiments and correlated with their exact monoisotopic masses and other in silico generated structural properties, such as connolly molecular area (CMA), connolly solvent-excluded volume (CSEV), principal moments of inertia along the X, Y and Z Cartesian coordinates (MI-X, MI-Y and MI-Z), inverse mobility and collision cross-section (CCS). The correlation of T(d) with these parameters is presented and discussed. IMS/TOF tandem mass spectrometry experiments (MS(2) and MS(3)) were successfully performed on the N-acetyl-p-benzoquinoneimine glutathione (NAPQI-GSH) adduct derived from the in vitro microsomal metabolism of APAP. As comparison, similar experiments were also performed using hybrid triple quadrupole linear ion trap mass spectrometry (QTRAPMS) and quadrupole time-of-flight mass spectrometry (QTOFMS). The abilities to resolve the product ions of the metabolite within the drift tube and fragment the ion mobility resolved product ions in the transfer travelling wave-enabled stacked ring ion guide (TWIG) demonstrated the potential applicability of the Q/IMS/TOFMS technique in pharmaceutical metabolite profiling.

  5. A GPU Accelerated Spring Mass System for Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... to accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  6. Sample preparation in biological mass spectrometry

    CERN Document Server

    Ivanov, Alexander R

    2011-01-01

    The aim of this book is to provide the researcher with important sample preparation strategies in a wide variety of analyte molecules, specimens, methods, and biological applications requiring mass spectrometric analysis as a detection end-point.

  7. Xenon purity analysis for EXO-200 via mass spectrometry

    CERN Document Server

    Dobi, A; Slutsky, S; Yen, Y -R; Aharmin, B; Auger, M; Barbeau, P S; Benitez-Medina, C; Breidenbach, M; Cleveland, B; Conley, R; Cook, J; Cook, S; Counts, I; Craddock, W; Daniels, T; Davis, C G; Davis, J; deVoe, R; Dixit, M; Dolinski, M J; Donato, K; Fairbank, W; Farine, J; Fierlinger, P; Franco, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Green, C; Hagemann, C; Hall, K; Hallman, D; Hargrove, C; Herrin, S; Hughes, M; Hodgson, J; Juget, F; Karelin, A; Kaufman, L J; Kuchenkov, A; Kumar, K; Leonard, D S; Lutter, G; Mackay, D; MacLellan, R; Marino, M; Mong, B; Díez, M Montero; Morgan, P; Müller, A R; Neilson, R; Odian, A; O'Sullivan, K; Piepke, A; Pocar, A; Prescott, C Y; Pushkin, K; Rivas, A; Rollin, E; Rowson, P C; Sabourov, A; Sinclair, D; Skarpaas, K; Stekhanov, V; Strickland, V; Swift, M; Twelker, K; Vuilleumier, J -L; Vuilleumier, J -M; Weber, M; Wichoski, U; Wodin, J; Wright, J D; Yang, L

    2011-01-01

    We describe purity measurements of the natural and enriched xenon stockpiles used by the EXO-200 double beta decay experiment based on a mass spectrometry technique. The sensitivity of the spectrometer is enhanced by several orders of magnitude by the presence of a liquid nitrogen cold trap, and many impurity species of interest can be detected at the level of one part-per-billion or better. We have used the technique to screen the EXO-200 xenon before, during, and after its use in our detector, and these measurements have proven useful. This is the first application of the cold trap mass spectrometry technique to an operating physics experiment.

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

    Science.gov (United States)

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

    2015-07-07

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

  9. Identifying modifications in RNA by MALDI mass spectrometry

    DEFF Research Database (Denmark)

    Douthwaite, Stephen; Kirpekar, Finn

    2007-01-01

    Posttranscriptional modifications on the base or sugar of ribonucleosides generally result in mass increases that can be measured by mass spectrometry. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a direct and accurate means of determining the masses of RNAs. Mass...... spectra produced by MALDI are relatively straightforward to interpret, because they are dominated by singly charged ions, making it possible to analyze complex mixtures of RNA oligonucleotides ranging from trinucleotides up to 20-mers. Analysis of modifications within much longer RNAs, such as ribosomal...... RNAs, can be achieved by digesting the RNA with nucleotide-specific enzymes. In some cases, it may be desirable to isolate specific sequence regions before MALDI-MS analysis, and this requires a few additional steps. The method is applicable to the study of modified RNAs from cell extracts as well...

  10. Mass varying neutrinos, symmetry breaking, and cosmic acceleration

    Science.gov (United States)

    Sadjadi, H. Mohseni; Anari, V.

    2017-06-01

    We introduce a new proposal for the onset of cosmic acceleration based on mass varying neutrinos. When massive neutrinos become nonrelativistic, the Z2 symmetry breaks, and the quintessence potential becomes positive from its initially zero value. This positive potential behaves like a cosmological constant at the present era and drives the Universe's acceleration during the slow roll evolution of the quintessence. In contrast to Λ CDM model, the dark energy in our model is dynamical, and the acceleration is not persistent. Contrary to some of the previous models of dark energy with mass varying neutrinos, we do not use the adiabaticity condition, which leads to instability.

  11. Hybrid ion mobility and mass spectrometry as a separation tool.

    Science.gov (United States)

    Ewing, Michael A; Glover, Matthew S; Clemmer, David E

    2016-03-25

    Ion mobility spectrometry (IMS) coupled to mass spectrometry (MS) has seen spectacular growth over the last two decades. Increasing IMS sensitivity and capacity with improvements in MS instrumentation have driven this growth. As a result, a diverse new set of techniques for separating ions by their mobility have arisen, each with characteristics that make them favorable for some experiments and some mass spectrometers. Ion mobility techniques can be broken down into dispersive and selective techniques based upon whether they pass through all mobilities for later analysis by mass spectrometry or select ions by mobility or a related characteristic. How ion mobility techniques fit within a more complicated separation including mass spectrometry and other techniques such as liquid chromatography is of fundamental interest to separations scientists. In this review we explore the multitude of ion mobility techniques hybridized to different mass spectrometers, detailing current challenges and opportunities for each ion mobility technique and for what experiments one technique might be chosen over another. The underlying principles of ion mobility separations, including: considerations regarding separation capabilities, ion transmission, signal intensity and sensitivity, and the impact that the separation has upon the ion structure (i.e., the possibility of configurational changes due to ion heating) are discussed.

  12. Mass Spectrometry Imaging, an Emerging Technology in Neuropsychopharmacology

    Science.gov (United States)

    Shariatgorji, Mohammadreza; Svenningsson, Per; Andrén, Per E

    2014-01-01

    Mass spectrometry imaging is a powerful tool for directly determining the distribution of proteins, peptides, lipids, neurotransmitters, metabolites and drugs in neural tissue sections in situ. Molecule-specific imaging can be achieved using various ionization techniques that are suited to different applications but which all yield data with high mass accuracies and spatial resolutions. The ability to simultaneously obtain images showing the distributions of chemical species ranging from metal ions to macromolecules makes it possible to explore the chemical organization of a sample and to correlate the results obtained with specific anatomical features. The imaging of biomolecules has provided new insights into multiple neurological diseases, including Parkinson's and Alzheimer's disease. Mass spectrometry imaging can also be used in conjunction with other imaging techniques in order to identify correlations between changes in the distribution of important chemical species and other changes in the properties of the tissue. Here we review the applications of mass spectrometry imaging in neuroscience research and discuss its potential. The results presented demonstrate that mass spectrometry imaging is a useful experimental method with diverse applications in neuroscience. PMID:23966069

  13. Aerosol mass spectrometry systems and methods

    Science.gov (United States)

    Fergenson, David P.; Gard, Eric E.

    2013-08-20

    A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

  14. Mass spectrometry on the surface of Mercury

    Science.gov (United States)

    Whitby, J.; Rohner, U.; Benz, W.; Wurz, P.

    2003-04-01

    The proposed Mercury Surface Element of the BepiColombo mission will place a lander on Mercury equipped with a geochemistry instrumentation package. We will discuss the utility of elemental and isotopic analyses of individual mineral grains in the hermean regolith, and present relevant results from a prototype laser-ablation time-of-flight mass spectrometer.

  15. Leptoquarks: Neutrino masses and accelerator phenomenology

    CERN Document Server

    Sierra, D Aristizabal; Kovalenko, S G

    2007-01-01

    Leptoquark-Higgs interactions induce mixing between leptoquark states with different chiralities once the electro-weak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the neutrino mass matrix and explore the constraints on the parameter space enforced by the assumption that LQ-loops explain current neutrino oscillation data. LQs will be produced at the LHC, if their masses are at or below the TeV scale. Since the fermionic decays of LQs are governed by the same Yukawa couplings, which are responsible for the non-trivial neutrino mass matrix, several decay branching ratios of LQ states can be predicted from measured neutrino data. Especially interesting is that large lepton flavour violating rates in muon and tau final states are expected. In addition, the model predicts that, if kinematically possible, heavier LQs decay into lighter ones plus either a standard model Higgs boson or a $Z^0/W^{\\pm}$ gauge boson. Thus, experiments at the LHC might be...

  16. Laser Mass Spectrometry in Planetary Science

    Science.gov (United States)

    Wurz, P.; Whitby, J. A.; Managadze, G. G.

    2009-06-01

    Knowing the chemical, elemental, and isotopic composition of planetary objects allows the study of their origin and evolution within the context of our solar system. Exploration plans in planetary research of several space agencies consider landing spacecraft for future missions. Although there have been successful landers in the past, more landers are foreseen for Mars and its moons, Venus, the jovian moons, and asteroids. Furthermore, a mass spectrometer on a landed spacecraft can assist in the sample selection in a sample-return mission and provide mineralogical context, or identify possible toxic soils on Mars for manned Mars exploration. Given the resources available on landed spacecraft mass spectrometers, as well as any other instrument, have to be highly miniaturised.

  17. Plasma source mass spectrometry in experimental nutrition.

    Science.gov (United States)

    Barnes, R M

    1998-01-01

    The development and commercial availability of plasma ion source, specifically inductively coupled plasma, mass spectrometers (ICP-MS) have significantly extended the potential application of stable isotopes for nutritional modeling. The status of research and commercial ICP-MS instruments, and their applications and limitations for stable isotopic studies are reviewed. The consequences of mass spectroscopic resolution and measurement sensitivity obtainable with quadrupole, sector, time-of-flight, and trap instruments on stable isotope analysis are examined. Requirements for reliable isotope measurements with practical biological samples including tissues and fluids are considered. The possibility for stable isotope analysis in chemically separated compounds (speciation) also is explored. On-line compound separations by chromatography or electrophoresis, for example, have been combined instrumentally with ICP-MS. Som possibilities and requirements are described for stable isotope speciation analysis.

  18. Calcium isotope analysis by mass spectrometry.

    Science.gov (United States)

    Boulyga, Sergei F

    2010-01-01

    The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. The present article discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. In Sections 2 and 3, mass spectrometric methods applied to precise stable isotope analysis and to the determination of (41)Ca are described. Section 4 contains a short summary of selected applications, and includes tracer experiments and the potential use

  19. Calcium Isotope Analysis by Mass Spectrometry

    Science.gov (United States)

    Boulyga, S.; Richter, S.

    2010-12-01

    The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. This presentation discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. Additionally, the availability of Ca isotope reference materials will be discussed.

  20. High-Performance Liquid Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Vestal, Marvin L.

    1984-01-01

    Reviews techniques for online coupling of high-performance liquid chromatography with mass spectrometry, emphasizing those suitable for application to nonvolatile samples. Also summarizes the present status, strengths, and weaknesses of various techniques and discusses potential applications of recently developed techniques for combined liquid…

  1. Decoding signalling networks by mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Choudhary, Chuna Ram; Mann, Matthias

    2010-01-01

    Signalling networks regulate essentially all of the biology of cells and organisms in normal and disease states. Signalling is often studied using antibody-based techniques such as western blots. Large-scale 'precision proteomics' based on mass spectrometry now enables the system...

  2. Mass Spectrometry Imaging for the Classification of Tumor Tissue

    NARCIS (Netherlands)

    Mascini, N.E.

    2016-01-01

    Mass spectrometry imaging (MSI) can detect and identify many different molecules without the need for labeling. In addition, it can provide their spatial distributions as ‘molecular maps’. These features make MSI well suited for studying the molecular makeup of tumor tissue. Currently, there is an i

  3. Exploring signal transduction networks using mass spectrometry-based proteomics

    NARCIS (Netherlands)

    Meijer, L.A.T.

    2012-01-01

    Mass spectrometry (MS)-based proteomics can be used to answer a diversity of biological questions. In this thesis, we describe the application of several MS-based proteomics approaches to get insight into several aspects of signal transduction. In Chapter 2, quantitative global phosphoproteomics are

  4. Electrochemistry-mass spectrometry in drug metabolism and protein research

    NARCIS (Netherlands)

    Permentier, Hjalmar P.; Bruins, Andries P.; Bischoff, Rainer

    2008-01-01

    The combination of electrochemistry coupled on-line to mass spectrometry (EC-MS) forms a powerful analytical technique with unique applications in the fields of drug metabolism and proteomics. In this review the latest developments are surveyed from both instrumental and application perspectives. Th

  5. Characterisation of cholera toxin by liquid chromatography - Electrospray mass spectrometry

    NARCIS (Netherlands)

    Baar, B.L.M. van; Hulst, A.G.; Wils, E.R.J.

    1999-01-01

    Cholera toxin, one of the toxins that may be generated by various strains of the bacterium Vibrio cholerae, can be considered as a substance possibly used in biological warfare. The possibilities of characterising the toxin by liquid chromatography electrospray mass spectrometry (LC-ES-MS) were inve

  6. Diagnosing Prion Diseases: Mass Spectrometry-Based Approaches

    Science.gov (United States)

    Mass spectrometry is an established means of quantitating the prions present in infected hamsters. Calibration curves relating the area ratios of the selected analyte peptides and their oxidized analogs to stable isotope labeled internal standards were prepared. The limit of detection (LOD) and limi...

  7. MICELLAR ELECTROKINETIC CHROMATOGRAPHY-MASS SPECTROMETRY (R823292)

    Science.gov (United States)

    The combination of micellar electrokinetic chromatography (MEKC) with mass spectrometry (MS) is very attractive for the direct identification of analyte molecules, for the possibility of selectivity enhancement, and for the structure confirmation and analysis in a MS-MS mode. The...

  8. Traveling-wave ion mobility mass spectrometry of protein complexes

    DEFF Research Database (Denmark)

    Salbo, Rune; Bush, Matthew F; Naver, Helle

    2012-01-01

    The collision cross-section (Ω) of a protein or protein complex ion can be measured using traveling-wave (T-wave) ion mobility (IM) mass spectrometry (MS) via calibration with compounds of known Ω. The T-wave Ω-values depend strongly on instrument parameters and calibrant selection. Optimization...

  9. Characterisation of cholera toxin by liquid chromatography - Electrospray mass spectrometry

    NARCIS (Netherlands)

    Baar, B.L.M. van; Hulst, A.G.; Wils, E.R.J.

    1999-01-01

    Cholera toxin, one of the toxins that may be generated by various strains of the bacterium Vibrio cholerae, can be considered as a substance possibly used in biological warfare. The possibilities of characterising the toxin by liquid chromatography electrospray mass spectrometry (LC-ES-MS) were

  10. Mass Spectrometry Imaging for the Classification of Tumor Tissue

    NARCIS (Netherlands)

    Mascini, N.E.

    2016-01-01

    Mass spectrometry imaging (MSI) can detect and identify many different molecules without the need for labeling. In addition, it can provide their spatial distributions as ‘molecular maps’. These features make MSI well suited for studying the molecular makeup of tumor tissue. Currently, there is an i

  11. Advancing liquid chromatography- mass spectrometry based technologies for proteome research

    NARCIS (Netherlands)

    Boersema, P.J.

    2010-01-01

    In proteomics, high-tech nano-liquid chromatography (LC) and mass spectrometry (MS) instrumentation is used to routinely sequence proteins at a large scale. In this thesis, several technological developments are described to advance proteomics and their applicability is demonstrated in several diffe

  12. Gas chromatography mass spectrometry : key technology in metabolomics

    NARCIS (Netherlands)

    Koek, Maud Marijtje

    2009-01-01

    Metabolomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues. Gas chromatography coupled to mass spectrometry (GC-MS) is very suitable for metabolomics analysis, as it combines high separation power with sensiti

  13. Fusion of mass spectrometry-based metabolomics data

    NARCIS (Netherlands)

    Smilde, A.K.; Werf, M.J. van der; Bijlsma, S.; Werff-van der Vat, B.J.C. van der; Jellema, R.H.

    2005-01-01

    A general method is presented for combining mass spectrometry-based metabolomics data. Such data are becoming more and more abundant, and proper tools for fusing these types of data sets are needed. Fusion of metabolomics data leads to a comprehensive view on the metabolome of an organism or biologi

  14. Analysis of essential oils by gas chromatography and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Masada, Y.

    1976-01-01

    The book is in two parts: first part Essential Oil includes compositae; labiatae; verbenaceae; oleaceae; umbelliferae; myrtaceae; euphorbiaceae; rutaceae; geraniaceae; rosaceae; lauraceae; myristicaceae; anonaceae; santalaceae; moraceae; piperaceae; zingiberaceae; araceae; gramineae; and cupressaceae written in English and Japanese. Part two includes essential oil; gas chromatography, and mass spectrometry written in Japanese. (DP)

  15. Triple Bioaffinity Mass Spectrometry Concept for Thyroid Transporter Ligands

    NARCIS (Netherlands)

    Aqai, P.; Fryganas, C.; Mizuguchi, M.; Haasnoot, W.; Nielen, M.W.F.

    2012-01-01

    For the analysis of thyroid transporter ligands, a triple bioaffinity mass spectrometry (BioMS) concept was developed, with the aim at three different analytical objectives: rapid screening of any ligand, confirmation of known ligands in accordance with legislative requirements, and identification o

  16. Gas chromatography mass spectrometry : key technology in metabolomics

    NARCIS (Netherlands)

    Koek, Maud Marijtje

    2009-01-01

    Metabolomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues. Gas chromatography coupled to mass spectrometry (GC-MS) is very suitable for metabolomics analysis, as it combines high separation power with

  17. May the Best Molecule Win: Competition ESI Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Sarah Laughlin

    2015-10-01

    Full Text Available Electrospray ionization mass spectrometry has become invaluable in the characterization of macromolecular biological systems such as nucleic acids and proteins. Recent advances in the field of mass spectrometry and the soft conditions characteristic of electrospray ionization allow for the investigation of non-covalent interactions among large biomolecules and ligands. Modulation of genetic processes through the use of small molecule inhibitors with the DNA minor groove is gaining attention as a potential therapeutic approach. In this review, we discuss the development of a competition method using electrospray ionization mass spectrometry to probe the interactions of multiple DNA sequences with libraries of minor groove binding molecules. Such an approach acts as a high-throughput screening method to determine important information including the stoichiometry, binding mode, cooperativity, and relative binding affinity. In addition to small molecule-DNA complexes, we highlight other applications in which competition mass spectrometry has been used. A competitive approach to simultaneously investigate complex interactions promises to be a powerful tool in the discovery of small molecule inhibitors with high specificity and for specific, important DNA sequences.

  18. Mass Spectrometry Imaging for the Classification of Tumor Tissue

    NARCIS (Netherlands)

    Mascini, N.E.

    2016-01-01

    Mass spectrometry imaging (MSI) can detect and identify many different molecules without the need for labeling. In addition, it can provide their spatial distributions as ‘molecular maps’. These features make MSI well suited for studying the molecular makeup of tumor tissue. Currently, there is an

  19. Advances in mass spectrometry driven O-glycoproteomics

    DEFF Research Database (Denmark)

    Levery, Steven B; Steentoft, Catharina; Halim, Adnan;

    2015-01-01

    BACKGROUND: Global analyses of proteins and their modifications by mass spectrometry are essential tools in cell biology and biomedical research. Analyses of glycoproteins represent particular challenges and we are only at the beginnings of the glycoproteomic era. Some of the challenges have been...

  20. Data analysis for mass spectrometry imaging : methods and applications

    NARCIS (Netherlands)

    Abdelmoula, Walid Mohamed

    2017-01-01

    In this dissertation we developed a number of automatic methods for multi-modal data registration, mainly between mass spectrometry imaging, imaging microscopy, and the Allen Brain Atlas. We have shown the importance of these methods for performing large scale preclinical biomarker discovery

  1. Analysis of proteins using DIGE and MALDI mass spectrometry

    Science.gov (United States)

    In this work the sensitivity of the quantitative proteomics approach 2D-DIGE/MS (twoDimensional Difference Gel Electrophoresis / Mass Spectrometry) was tested by detecting decreasing amounts of a specific protein at the low picomole and sub-picomole range. Sensitivity of the 2D-D...

  2. Resolving brain regions using nanostructure initiator mass spectrometry imaging

    OpenAIRE

    Lee, Do Yup; Platt, Virginia; Bowen, Ben; Louie, Katherine; Canaria, Christie; McMurray, Cynthia T.; Northen, Trent

    2012-01-01

    Specific cell types are critically implicated in a variety of neuropathologies that exhibit region-specific susceptibility. Neuronal and glial function is impaired in a host of neurodegenerative diseases. Previous reports suggest that mass spectrometry imaging has the potential to resolve cell-specific enrichment in brain regions; however, individual ions cannot resolve glial and neuronal cells within the complex structure of brain tissue. Here, we utilized a matrix-free surface mass spectrom...

  3. Measurement of boron isotopes by negative thermal ionization mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The isobaric interference for boron isotopic measurement by negative thermal ionization mass spectrometry (NTIMS) has been studied. The result shows that the CNO- is not only from the organic material, but also from nitrate in loading reagent in NTIMS. Monitoring the mass 43 ion intensity and 43/42 ratio of blank are also necessary for the boron isotopic measurement by NTIMS, other than is only boron content.

  4. Critical comparison of mass analyzers for forensic hair analysis by ambient ionizations mass spectrometry

    NARCIS (Netherlands)

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

    2016-01-01

    Rationale
    Recently, several direct and/or ambient mass spectrometry (MS) approaches have been suggested for drugs of abuse imaging in hair. The use of mass spectrometers with insufficient selectivity could result in false-positive measurements due to isobaric interferences. Different mass analyz

  5. Application of Laser Mass Spectrometry to Art and Archaeology

    Science.gov (United States)

    Gulian, Lase Lisa E.; Callahan, Michael P.; Muliadi, Sarah; Owens, Shawn; McGovern, Patrick E.; Schmidt, Catherine M.; Trentelman, Karen A.; deVries, Mattanjah S.

    2011-01-01

    REMPI laser mass spectrometry is a combination of resonance enhanced multiphoton ionization spectroscopy and time of flight mass spectrometry, This technique enables the collection of mass specific optical spectra as well as of optically selected mass spectra. Analytes are jet-cooled by entrainment in a molecular beam, and this low temperature gas phase analysis has the benefit of excellent vibronic resolution. Utilizing this method, mass spectrometric analysis of historically relevant samples can be simplified and improved; Optical selection of targets eliminates the need for chromatography while knowledge of a target's gas phase spectroscopy allows for facile differentiation of molecules that are in the aqueous phase considered spectroscopically indistinguishable. These two factors allow smaller sample sizes than commercial MS instruments, which in turn will require less damage to objects of antiquity. We have explored methods to optimize REMPI laser mass spectrometry as an analytical tool to archaeology using theobromine and caffeine as molecular markers in Mesoamerican pottery, and are expanding this approach to the field of art to examine laccaic acid in shellacs.

  6. Ion mobility tandem mass spectrometry enhances performance of bottom-up proteomics.

    Science.gov (United States)

    Helm, Dominic; Vissers, Johannes P C; Hughes, Christopher J; Hahne, Hannes; Ruprecht, Benjamin; Pachl, Fiona; Grzyb, Arkadiusz; Richardson, Keith; Wildgoose, Jason; Maier, Stefan K; Marx, Harald; Wilhelm, Mathias; Becher, Isabelle; Lemeer, Simone; Bantscheff, Marcus; Langridge, James I; Kuster, Bernhard

    2014-12-01

    One of the limiting factors in determining the sensitivity of tandem mass spectrometry using hybrid quadrupole orthogonal acceleration time-of-flight instruments is the duty cycle of the orthogonal ion injection system. As a consequence, only a fraction of the generated fragment ion beam is collected by the time-of-flight analyzer. Here we describe a method utilizing postfragmentation ion mobility spectrometry of peptide fragment ions in conjunction with mobility time synchronized orthogonal ion injection leading to a substantially improved duty cycle and a concomitant improvement in sensitivity of up to 10-fold for bottom-up proteomic experiments. This enabled the identification of 7500 human proteins within 1 day and 8600 phosphorylation sites within 5 h of LC-MS/MS time. The method also proved powerful for multiplexed quantification experiments using tandem mass tags exemplified by the chemoproteomic interaction analysis of histone deacetylases with Trichostatin A.

  7. 160 keV {sup 26}Al-AMS with a single-stage accelerator mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Richard P.; Freeman, Stewart P.H.T.

    2015-10-15

    Proof-of-principle {sup 26}Al-AMS analysis is achieved with a single-stage accelerator mass spectrometer (SSAMS) utilising very low ion energy. The SSAMS operates by discriminating against atomic isobar interference in a negative ion source and suppressing molecules with thick gas stripper. Resulting 1+ ions counting is with a surface barrier detector. The NEC designed SSAMS for {sup 14}C analysis is a popular model accelerator mass spectrometer and the developed further capability might be a significant addition to established {sup 26}Al-AMS capacity. Measurements at these energies should also be sufficient for alternative {sup 26}Al positive-ion mass spectrometry (PIMS).

  8. Capillary electrophoresis-mass spectrometry of carbohydrates.

    Science.gov (United States)

    Zaia, Joseph

    2013-01-01

    The development of methods for capillary electrophoresis (CE) with on-line mass spectrometric detection (CE/MS) is driven by the need for accurate, robust, and sensitive glycomics analysis for basic biomedicine, biomarker discovery, and analysis of recombinant protein therapeutics. One important capability is to profile glycan mixtures with respect to the patterns of substituents including sialic acids, acetate, sulfate, phosphate, and other groups. There is additional need for an MS-compatible separation system capable of resolving carbohydrate isomers. This chapter summarizes applications of CS/MS to analysis of carbohydrates, glycoproteins, and glycopeptides that have appeared since 2008. Readers are referred to recent comprehensive reviews covering earlier publications.

  9. Analysis of Milk Oligosaccharides by Mass Spectrometry.

    Science.gov (United States)

    Wu, Lauren D; Ruhaak, L Renee; Lebrilla, Carlito B

    2017-01-01

    Human milk oligosaccharides (HMOs) are a highly abundant constituent in human milk, and its protective and prebiotic properties have attracted considerable attention. HMOs have been shown to directly and indirectly benefit the overall health of the infant due to a number of functions including serving as a beneficial food for gut bacteria, block to pathogens, and aiding in brain development. Researchers are currently exploring whether these structures may act as possible disease and nutrition biomarkers. Because of this, rapid-throughput methods are desired to investigate biological activity in large patient sets. We have optimized a rapid-throughput protocol to analyze human milk oligosaccharides using micro-volumes of human breast milk for nutritional biomarkers. This method may additionally be applied to other biological fluid substrates such as plasma, urine, and feces. The protocol involves lipid separation via centrifugation, protein precipitation using ethanol, alditol reduction with sodium borohydride, and a final solid-phase extraction purification step using graphitized carbon cartridges. Samples are analyzed using HPLC-Chip/TOF-MS and data filtered on Agilent MassHunter using an in-house library. Individual structural identification is matched against a previously developed HMO library using accurate mass and retention time. Using this method will allow in-depth characterization and profiling of HMOs in large patient sets, and will ease the process of discovering significant nutritional biomarkers in human milk.

  10. Early discovery drug screening using mass spectrometry.

    Science.gov (United States)

    Siegel, Marshall M

    2002-01-01

    Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometric methods useful for early discovery drug screening are reviewed. All methods described involve studies of non-covalent complexes between biopolymer receptors and small molecule ligands formed in the condensed phase. The complexes can be sprayed intact directly into the gas phase by ESI-MS using gentle experimental conditions. Gas phase screening applications are illustrated for drug ligand candidates non-covalently interacting with peptides, proteins, RNA, and DNA. In the condensed phase, the complexes can be also isolated, denatured and analyzed by ESI-MS to identify the small molecule ligands. Condensed phase drug screening examples are illustrated for the ESI-MS ancillary techniques of affinity chromatography, ultrafiltration, ultracentrifugation, gel permeation chromatography (GPC), reverse phase-high performance liquid chromatography (RP-HPLC) and capillary electrophoretic methods. Solid phase drug screening using MALDI-MS is illustrated for small molecule ligands bound to MALDI affinity probe tips and to beads. Since ESI and MALDI principally produce molecular ions, high throughput screening is achieved by analyzing mass indexed mixtures.

  11. Hands-on Electrospray Ionization-Mass Spectrometry for Upper-Level Undergraduate and Graduate Students

    Science.gov (United States)

    Stock, Naomi L.; March, Raymond E.

    2014-01-01

    Electrospray ionization-mass spectrometry (ESI-MS) is a powerful technique for the detection, identification, and quantification of organic compounds. As mass spectrometers have become more user-friendly and affordable, many students--often with little experience in mass spectrometry--find themselves needing to incorporate mass spectrometry into…

  12. Hands-on Electrospray Ionization-Mass Spectrometry for Upper-Level Undergraduate and Graduate Students

    Science.gov (United States)

    Stock, Naomi L.; March, Raymond E.

    2014-01-01

    Electrospray ionization-mass spectrometry (ESI-MS) is a powerful technique for the detection, identification, and quantification of organic compounds. As mass spectrometers have become more user-friendly and affordable, many students--often with little experience in mass spectrometry--find themselves needing to incorporate mass spectrometry into…

  13. Accelerator mass spectrometer with ion selection in high-voltage terminal

    Science.gov (United States)

    Rastigeev, S. A.; Goncharov, A. D.; Klyuev, V. F.; Konstantinov, E. S.; Kutnyakova, L. A.; Parkhomchuk, V. V.; Petrozhitskii, A. V.; Frolov, A. R.

    2016-12-01

    The folded electrostatic tandem accelerator with ion selection in a high-voltage terminal is the basis of accelerator mass spectrometry (AMS) at the BINP. Additional features of the BINP AMS are the target based on magnesium vapors as a stripper without vacuum deterioration and a time-of-flight telescope with thin films for reliable ion identification. The acceleration complex demonstrates reliable operation in a mode of 1 MV with 50 Hz counting rate of 14C+3 radiocarbon for modern samples (14C/12C 1.2 × 10-12). The current state of the AMS has been considered and the experimental results of the radiocarbon concentration measurements in test samples have been presented.

  14. Advances in structure elucidation of small molecules using mass spectrometry

    Science.gov (United States)

    Fiehn, Oliver

    2010-01-01

    The structural elucidation of small molecules using mass spectrometry plays an important role in modern life sciences and bioanalytical approaches. This review covers different soft and hard ionization techniques and figures of merit for modern mass spectrometers, such as mass resolving power, mass accuracy, isotopic abundance accuracy, accurate mass multiple-stage MS(n) capability, as well as hybrid mass spectrometric and orthogonal chromatographic approaches. The latter part discusses mass spectral data handling strategies, which includes background and noise subtraction, adduct formation and detection, charge state determination, accurate mass measurements, elemental composition determinations, and complex data-dependent setups with ion maps and ion trees. The importance of mass spectral library search algorithms for tandem mass spectra and multiple-stage MS(n) mass spectra as well as mass spectral tree libraries that combine multiple-stage mass spectra are outlined. The successive chapter discusses mass spectral fragmentation pathways, biotransformation reactions and drug metabolism studies, the mass spectral simulation and generation of in silico mass spectra, expert systems for mass spectral interpretation, and the use of computational chemistry to explain gas-phase phenomena. A single chapter discusses data handling for hyphenated approaches including mass spectral deconvolution for clean mass spectra, cheminformatics approaches and structure retention relationships, and retention index predictions for gas and liquid chromatography. The last section reviews the current state of electronic data sharing of mass spectra and discusses the importance of software development for the advancement of structure elucidation of small molecules. Electronic supplementary material The online version of this article (doi:10.1007/s12566-010-0015-9) contains supplementary material, which is available to authorized users. PMID:21289855

  15. Electrochemistry-mass spectrometry in drug metabolism and protein research.

    Science.gov (United States)

    Permentier, Hjalmar P; Bruins, Andries P; Bischoff, Rainer

    2008-01-01

    The combination of electrochemistry coupled on-line to mass spectrometry (EC-MS) forms a powerful analytical technique with unique applications in the fields of drug metabolism and proteomics. In this review the latest developments are surveyed from both instrumental and application perspectives. The limitations and solutions for coupling an electrochemical system to a mass spectrometer are discussed. The electrochemical mimicking of drug metabolism, specifically by Cytochrome P450, is high-lighted as an application with high biomedical relevance. The EC-MS analysis of proteins also has promising new applications for both proteomics research and biomarker discovery. EC-MS has furthermore advantages for improved analyte detection with mass spectrometry, both for small molecules and large biomolecules. Finally, potential future directions of development of the technique are briefly discussed.

  16. T cells recognizing a peptide contaminant undetectable by mass spectrometry

    DEFF Research Database (Denmark)

    Brezar, Vedran; Culina, Slobodan; Østerbye, Thomas

    2011-01-01

    Synthetic peptides are widely used in immunological research as epitopes to stimulate their cognate T cells. These preparations are never completely pure, but trace contaminants are commonly revealed by mass spectrometry quality controls. In an effort to characterize novel major histocompatibility...... complex (MHC) Class I-restricted ß-cell epitopes in non-obese diabetic (NOD) mice, we identified islet-infiltrating CD8+ T cells recognizing a contaminating peptide. The amount of this contaminant was so small to be undetectable by direct mass spectrometry. Only after concentration by liquid...... chromatography, we observed a mass peak corresponding to an immunodominant islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(206-214) epitope described in the literature. Generation of CD8+ T-cell clones recognizing IGRP(206-214) using a novel method confirmed the identity...

  17. LILBID-mass spectrometry of the mitochondrial preprotein translocase TOM.

    Science.gov (United States)

    Mager, Frauke; Sokolova, Lucie; Lintzel, Julia; Brutschy, Bernhard; Nussberger, Stephan

    2010-11-17

    In the present work we applied a novel mass spectrometry method termed laser-induced liquid bead ion desorption mass spectrometry (LILBID-MS) to the outer mitochondrial membrane protein translocon TOM to analyze its subunit composition and stoichiometry. With TOM core complex, purified at high pH, we demonstrate that a TOM core complex of Neurospora crassa is composed of at least two Tom40 and Tom22 molecules, respectively, and more than five small Tom subunits between 5.5 and 6.4 kDa. We show that the multiprotein complex has a total molecular mass higher than 170 depending on the number of Tom5, Tom6 and Tom7 molecules bound.

  18. Trends in biochemical and biomedical applications of mass spectrometry

    Science.gov (United States)

    Gelpi, Emilio

    1992-09-01

    This review attempts an in-depth evaluation of progress and achievements made since the last 11th International Mass Spectrometry Conference in the application of mass spectrometric techniques to biochemistry and biomedicine. For this purpose, scientific contributions in this field at major international meetings have been monitored, together with an extensive appraisal of literature data covering the period from 1988 to 1991. A bibliometric evaluation of the MEDLINE database for this period provides a total of almost 4000 entries for mass spectrometry. This allows a detailed study of literature and geographical sources of the most frequent applications, of disciplines where mass spectrometry is most active and of types of sample and instrumentation most commonly used. In this regard major efforts according to number of publications (over 100 literature reports) are concentrated in countries like Canada, France, Germany, Italy, Japan, Sweden, UK and the USA. Also, most of the work using mass spectrometry in biochemistry and biomedicine is centred on studies on biotransformation, metabolism, pharmacology, pharmacokinetics and toxicology, which have been carried out on samples of blood, urine, plasma and tissue, by order of frequency of use. Human and animal studies appear to be evenly distributed in terms of the number of reports published in the literature in which the authors make use of experimental animals or describe work on human samples. Along these lines, special attention is given to the real usefulness of mass spectrometry (MS) technology in routine medical practice. Thus the review concentrates on evaluating the progress made in disease diagnosis and overall patient care. As regards prevailing techniques, GCMS continues to be the mainstay of the state of the art methods for multicomponent analysis, stable isotope tracer studies and metabolic profiling, while HPLC--MS and tandem MS are becoming increasingly important in biomedical research. However

  19. Microscale mass spectrometry systems, devices and related methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, John Michael

    2017-04-11

    Mass spectrometry systems or assemblies therefore include an ionizer that includes at least one planar conductor, a mass analyzer with a planar electrode assembly, and a detector comprising at least one planar conductor. The ionizer, the mass analyzer and the detector are attached together in a compact stack assembly. The stack assembly has a perimeter that bounds an area that is between about 0.01 mm.sup.2 to about 25 cm.sup.2 and the stack assembly has a thickness that is between about 0.1 mm to about 25 mm.

  20. Microscale mass spectrometry systems, devices and related methods

    Science.gov (United States)

    Ramsey, John Michael

    2016-06-21

    Mass spectrometry systems or assemblies therefore include an ionizer that includes at least one planar conductor, a mass analyzer with a planar electrode assembly, and a detector comprising at least one planar conductor. The ionizer, the mass analyzer and the detector are attached together in a compact stack assembly. The stack assembly has a perimeter that bounds an area that is between about 0.01 mm.sup.2 to about 25 cm.sup.2 and the stack assembly has a thickness that is between about 0.1 mm to about 25 mm.

  1. A statistical investigation of the mass discrepancy-acceleration relation

    Science.gov (United States)

    Desmond, Harry

    2017-02-01

    We use the mass discrepancy-acceleration relation (the correlation between the ratio of total-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 16 statistics that quantify its four most important features: shape, scatter, the presence of a `characteristic acceleration scale', and the correlation of its residuals with other galaxy properties. We construct an empirical framework for the galaxy-halo connection in LCDM to generate predictions for these statistics, starting with conventional correlations (halo abundance matching; AM) and introducing more where required. Comparing to the SPARC data, we find that: (1) the approximate shape of the MDAR is readily reproduced by AM, and there is no evidence that the acceleration at which dark matter becomes negligible has less spread in the data than in AM mocks; (2) even under conservative assumptions, AM significantly overpredicts the scatter in the relation and its normalization at low acceleration, and furthermore positions dark matter too close to galaxies' centres on average; (3) the MDAR affords 2σ evidence for an anticorrelation of galaxy size and Hubble type with halo mass or concentration at fixed stellar mass. Our analysis lays the groundwork for a bottom-up determination of the galaxy-halo connection from relations such as the MDAR, provides concrete statistical tests for specific galaxy formation models, and brings into sharper focus the relative evidence accorded by galaxy kinematics to LCDM and modified gravity alternatives.

  2. Negative ion-gas reaction studies using ion guides and accelerator mass spectrometry I: SrF{sub 3}{sup −}, YF{sub 3}{sup −}, ZrF{sub 3}{sup −}, YF{sub 4}{sup −} and ZrF{sub 5}{sup −} in NO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Eliades, J.A., E-mail: j.eliades@alum.utoronto.ca [Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Zhao, X.-L. [University of Ottawa, Department of Physics and Lalonde AMS Laboratory, 25 Templeton St., Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [University of Toronto, Department of Physics, 60 St. George St., Toronto, ON M5S 1A7 (Canada); Kieser, W.E. [University of Ottawa, Department of Physics and Lalonde AMS Laboratory, 25 Templeton St., Ottawa, ON K1N 6N5 (Canada)

    2015-10-15

    Typical accelerator mass spectrometry (AMS) ion sources readily produce useable currents of a wide variety of negative ions, including exotic species, and the sensitivity and dynamic range of AMS can be used for relatively unambiguous ion identification at low count rates. Difficulty producing negative ion currents with high fluxes (ex. when electron binding energies are small) and unambiguous identification of reaction products can be obstacles to negative ion-gas reaction studies. Thus, an AMS setup can be considered to be suitable for certain ion-gas reaction studies. Presented here are preliminary studies on interactions of SrF{sub 3}{sup −}, YF{sub 3}{sup −}, ZrF{sub 3}{sup −}, YF{sub 4}{sup −} and ZrF{sub 5}{sup −} with NO{sub 2} gas at <50 eV kinetic energies using a prototype radio-frequency quadrupole (RFQ) instrument installed before the accelerator on the low-energy side of an AMS system. The superhalogen anions SrF{sub 3}{sup −}, YF{sub 4}{sup −} and ZrF{sub 5}{sup −} were found to be highly unreactive with NO{sub 2}, consistent with expected electron binding energies greater than 3.6 eV. YF{sub 3}{sup −} and ZrF{sub 3}{sup −} were found to have large overall attenuation cross sections in NO{sub 2} of 7.6 × 10{sup −15} ± 4.4% cm{sup 2} and 1.5 × 10{sup −14} ± 21% cm{sup 2} respectively at the ion energies created under the experimental conditions. The major reaction channels were shown to be electron transfer and oxygen capture. A cluster NO{sub 2}·(YF{sub 3}{sup −}) was also observed.

  3. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    CERN Document Server

    Smith, Donald F; Leach, Franklin E; Robinson, Errol W; Paša-Tolić, Ljiljana; Heeren, Ron M A

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for elemental formula assignment based on exact mass measurement. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissu...

  4. Plutonium determination in urine by techniques of mass spectrometry; Determinacion de plutonio en orina por tecnicas de espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of {sup 239}Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of {sup 239}Pu). (author)

  5. Comprehensive multiresidue method for the simultaneous determination of 74 pesticides and metabolites in traditional Chinese herbal medicines by accelerated solvent extraction with high-performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Jia, Zhengwei; Mao, Xiuhong; Chen, Ke; Wang, Ke; Ji, Shen

    2010-01-01

    In this paper, a multiresidue method for the simultaneous target analysis of 74 pesticides and metabolites in traditional Chinese herbal medicines (TCHMs) was developed using accelerated solvent extraction (ASE) coupled with HPLC/MS/MS. Pesticide residues were extracted from the different samples using ASE, then purified by gel permeation chromatography and graphitized carbon black/primary, secondary amine SPE. Gradient elution was used in conjunction with positive mode electrospray ionization MS/MS to detect 74 pesticides and metabolites from Cortex Cinnamomi, Flos Carthami, Folium Ginkgo, Herba Pogostemonis, Radix Ginseng, and Semen Ginkgo using a single chromatographic run. The analytical performance was demonstrated by the analysis of extracts spiked at three concentration levels ranging from 0.005 to 0.125 mg/kg for each pesticide and metabolite. In general, recoveries ranging from 70 to 110%, with RSDs better than 15%, were obtained. The recovery and repeatability data were in good accordance with European Union guidelines for pesticide residue analysis. The LOD for most of the targeted pesticides and metabolites tested was below 0.01 mg/kg.

  6. Optimization of Whole-Body Zebrafish Sectioning Methods for Mass Spectrometry Imaging

    Science.gov (United States)

    Mass spectrometry imaging methods and protocols have become widely adapted to a variety of tissues and species. However, the mass spectrometry imaging literature contains minimal information on whole-body cryosection preparation for the zebrafish (Danio rerio), a model organism ...

  7. High-throughput shotgun lipidomics by quadrupole time-of-flight mass spectrometry

    DEFF Research Database (Denmark)

    Ståhlman, Marcus; Ejsing, Christer S.; Tarasov, Kirill;

    2009-01-01

    Technological advances in mass spectrometry and meticulous method development have produced several shotgun lipidomic approaches capable of characterizing lipid species by direct analysis of total lipid extracts. Shotgun lipidomics by hybrid quadrupole time-of-flight mass spectrometry allows...

  8. Native Mass Spectrometry: What is in the Name?

    Science.gov (United States)

    Leney, Aneika C.; Heck, Albert J. R.

    2016-12-01

    Electrospray ionization mass spectrometry (ESI-MS) is nowadays one of the cornerstones of biomolecular mass spectrometry and proteomics. Advances in sample preparation and mass analyzers have enabled researchers to extract much more information from biological samples than just the molecular weight. In particular, relevant for structural biology, noncovalent protein-protein and protein-ligand complexes can now also be analyzed by MS. For these types of analyses, assemblies need to be retained in their native quaternary state in the gas phase. This initial small niche of biomolecular mass spectrometry, nowadays often referred to as "native MS," has come to maturation over the last two decades, with dozens of laboratories using it to study mostly protein assemblies, but also DNA and RNA-protein assemblies, with the goal to define structure-function relationships. In this perspective, we describe the origins of and (re)define the term native MS, portraying in detail what we meant by "native MS," when the term was coined and also describing what it does (according to us) not entail. Additionally, we describe a few examples highlighting what native MS is, showing its successes to date while illustrating the wide scope this technology has in solving complex biological questions.

  9. Native Mass Spectrometry: What is in the Name?

    Science.gov (United States)

    Leney, Aneika C.; Heck, Albert J. R.

    2017-01-01

    Electrospray ionization mass spectrometry (ESI-MS) is nowadays one of the cornerstones of biomolecular mass spectrometry and proteomics. Advances in sample preparation and mass analyzers have enabled researchers to extract much more information from biological samples than just the molecular weight. In particular, relevant for structural biology, noncovalent protein-protein and protein-ligand complexes can now also be analyzed by MS. For these types of analyses, assemblies need to be retained in their native quaternary state in the gas phase. This initial small niche of biomolecular mass spectrometry, nowadays often referred to as "native MS," has come to maturation over the last two decades, with dozens of laboratories using it to study mostly protein assemblies, but also DNA and RNA-protein assemblies, with the goal to define structure-function relationships. In this perspective, we describe the origins of and (re)define the term native MS, portraying in detail what we meant by "native MS," when the term was coined and also describing what it does (according to us) not entail. Additionally, we describe a few examples highlighting what native MS is, showing its successes to date while illustrating the wide scope this technology has in solving complex biological questions.

  10. Advances in 193 nm excimer lasers for mass spectrometry applications

    Science.gov (United States)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  11. New Types of Ionization Sources for Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-12-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between UT-Battelle (Contractor) and MDS Sciex (Participant) and ESA, Inc. (Participant) is to research, develop and apply new types of ionization sources and sampling/inlet systems for analytical mass spectrometry making use of the Participants state-of-the-art atmospheric sampling mass spectrometry electrochemical cell technology instrumentation and ancillary equipment. The two overriding goals of this research project are: to understand the relationship among the various instrumental components and operational parameters of the various ion sources and inlet systems under study, the chemical nature of the gases, solvents, and analytes in use, and the nature and abundances of the ions ultimately observed in the mass spectrometer; and to develop new and better analytical and fundamental applications of these ion sources and inlet systems or alternative sources and inlets coupled with mass spectrometry on the basis of the fundamental understanding obtained in Goal 1. The end results of this work are expected to be: (1) an expanded utility for the ion sources and inlet systems under study (such as the analysis of new types of analytes) and the control or alteration of the ionic species observed in the gas-phase; (2) enhanced instrument performance as judged by operational figures-of-merit such as dynamic range, detection limits, susceptibility to matrix signal suppression and sensitivity; and (3) novel applications (such as surface sampling with electrospray) in both applied and fundamental studies. The research projects outlined herein build upon work initiated under the previous CRADA between the Contractor and MDS Sciex on ion sources and inlet systems for mass spectrometry. Specific ion source and inlet systems for exploration of the fundamental properties and practical implementation of these principles are given.

  12. Fourier Transform Mass Spectrometry: The Transformation of Modern Environmental Analyses

    Directory of Open Access Journals (Sweden)

    Lucy Lim

    2016-01-01

    Full Text Available Unknown compounds in environmental samples are difficult to identify using standard mass spectrometric methods. Fourier transform mass spectrometry (FTMS has revolutionized how environmental analyses are performed. With its unsurpassed mass accuracy, high resolution and sensitivity, researchers now have a tool for difficult and complex environmental analyses. Two features of FTMS are responsible for changing the face of how complex analyses are accomplished. First is the ability to quickly and with high mass accuracy determine the presence of unknown chemical residues in samples. For years, the field has been limited by mass spectrometric methods that were based on knowing what compounds of interest were. Secondly, by utilizing the high resolution capabilities coupled with the low detection limits of FTMS, analysts also could dilute the sample sufficiently to minimize the ionization changes from varied matrices.

  13. The Use of Gas Chromatography and Mass Spectrometry to Introduce General Chemistry Students to Percent Mass and Atomic Mass Calculations

    Science.gov (United States)

    Pfennig, Brian W.; Schaefer, Amy K.

    2011-01-01

    A general chemistry laboratory experiment is described that introduces students to instrumental analysis using gas chromatography-mass spectrometry (GC-MS), while simultaneously reinforcing the concepts of mass percent and the calculation of atomic mass. Working in small groups, students use the GC to separate and quantify the percent composition…

  14. The Use of Gas Chromatography and Mass Spectrometry to Introduce General Chemistry Students to Percent Mass and Atomic Mass Calculations

    Science.gov (United States)

    Pfennig, Brian W.; Schaefer, Amy K.

    2011-01-01

    A general chemistry laboratory experiment is described that introduces students to instrumental analysis using gas chromatography-mass spectrometry (GC-MS), while simultaneously reinforcing the concepts of mass percent and the calculation of atomic mass. Working in small groups, students use the GC to separate and quantify the percent composition…

  15. Quantitative aspects of inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Bulska, Ewa; Wagner, Barbara

    2016-10-01

    Accurate determination of elements in various kinds of samples is essential for many areas, including environmental science, medicine, as well as industry. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool enabling multi-elemental analysis of numerous matrices with high sensitivity and good precision. Various calibration approaches can be used to perform accurate quantitative measurements by ICP-MS. They include the use of pure standards, matrix-matched standards, or relevant certified reference materials, assuring traceability of the reported results. This review critically evaluates the advantages and limitations of different calibration approaches, which are used in quantitative analyses by ICP-MS. Examples of such analyses are provided. This article is part of the themed issue 'Quantitative mass spectrometry'.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-15

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

  17. Protein identification using nano liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Negroni, Luc

    2007-01-01

    Tandem mass spectrometry is an efficient technique for the identification of peptides on the basis of their fragmentation pattern (MS/MS scan). It can generate individual spectra for each peptide, thereby creating a powerful tool for protein identification on the basis of peptide characterization. This important advance in automatic data acquisition has allowed an efficient association between liquid chromatography and tandem mass spectrometry, and the use of nanocolumns and nanoelectrospray ionization has dramatically increased the efficiency of this method. Now large sets of peptides can be identified at a femtomole level. At the end of the process, batch processing of the MS/MS spectra produces peptide lists that identify purified proteins or protein mixtures with high confidence.

  18. Analysis of Protein O-GlcNAcylation by Mass Spectrometry.

    Science.gov (United States)

    Ma, Junfeng; Hart, Gerald W

    2017-02-02

    O-linked β-D-N-acetyl glucosamine (O-GlcNAc) addition (O-GlcNAcylation), a post-translational modification of serine/threonine residues of proteins, is involved in diverse cellular metabolic and signaling pathways. Aberrant O-GlcNAcylation underlies the initiation and progression of multiple chronic diseases including diabetes, cancer, and neurodegenerative diseases. Numerous methods have been developed for the analysis of protein O-GlcNAcylation, but instead of discussing the classical biochemical techniques, this unit covers O-GlcNAc characterization by combining several enrichment methods and mass spectrometry detection techniques [including collision-induced dissociation (CID), higher energy collision dissociation (HCD), and electron transfer dissociation (ETD) mass spectrometry]. © 2017 by John Wiley & Sons, Inc.

  19. Metabolome analysis - mass spectrometry and microbial primary metabolites

    DEFF Research Database (Denmark)

    Højer-Pedersen, Jesper Juul

    2008-01-01

    that are highly sensitive and specific, and to undertake this challenge mass spectrometry (MS) is among the best candidates. Along with analysis of the metabolome the research area of metabolomics has evolved. Metabolomics combines metabolite profiles, data mining and biochemistry and aims at understanding...... the interplay between metabolites. In this thesis, different topics have been addressed and discussed with the aim of advancing metabolomics to explore the concept in a physiological context. The metabolome comprises a wide variety of chemical compounds that act differently upon sample preparation...... glucose, galactose or ethanol, and metabolic footprinting by mass spectrometry was used to study the influence of carbon source on the extracellular metabolites. The results showed that footprints clustered according to the carbon source. Advances in technologies for analytical chemistry have mediated...

  20. Sharing and community curation of mass spectrometry data with GNPS

    Science.gov (United States)

    Nguyen, Don Duy; Watrous, Jeramie; Kapono, Clifford A; Luzzatto-Knaan, Tal; Porto, Carla; Bouslimani, Amina; Melnik, Alexey V; Meehan, Michael J; Liu, Wei-Ting; Crüsemann, Max; Boudreau, Paul D; Esquenazi, Eduardo; Sandoval-Calderón, Mario; Kersten, Roland D; Pace, Laura A; Quinn, Robert A; Duncan, Katherine R; Hsu, Cheng-Chih; Floros, Dimitrios J; Gavilan, Ronnie G; Kleigrewe, Karin; Northen, Trent; Dutton, Rachel J; Parrot, Delphine; Carlson, Erin E; Aigle, Bertrand; Michelsen, Charlotte F; Jelsbak, Lars; Sohlenkamp, Christian; Pevzner, Pavel; Edlund, Anna; McLean, Jeffrey; Piel, Jörn; Murphy, Brian T; Gerwick, Lena; Liaw, Chih-Chuang; Yang, Yu-Liang; Humpf, Hans-Ulrich; Maansson, Maria; Keyzers, Robert A; Sims, Amy C; Johnson, Andrew R.; Sidebottom, Ashley M; Sedio, Brian E; Klitgaard, Andreas; Larson, Charles B; P., Cristopher A Boya; Torres-Mendoza, Daniel; Gonzalez, David J; Silva, Denise B; Marques, Lucas M; Demarque, Daniel P; Pociute, Egle; O'Neill, Ellis C; Briand, Enora; Helfrich, Eric J. N.; Granatosky, Eve A; Glukhov, Evgenia; Ryffel, Florian; Houson, Hailey; Mohimani, Hosein; Kharbush, Jenan J; Zeng, Yi; Vorholt, Julia A; Kurita, Kenji L; Charusanti, Pep; McPhail, Kerry L; Nielsen, Kristian Fog; Vuong, Lisa; Elfeki, Maryam; Traxler, Matthew F; Engene, Niclas; Koyama, Nobuhiro; Vining, Oliver B; Baric, Ralph; Silva, Ricardo R; Mascuch, Samantha J; Tomasi, Sophie; Jenkins, Stefan; Macherla, Venkat; Hoffman, Thomas; Agarwal, Vinayak; Williams, Philip G; Dai, Jingqui; Neupane, Ram; Gurr, Joshua; Rodríguez, Andrés M. C.; Lamsa, Anne; Zhang, Chen; Dorrestein, Kathleen; Duggan, Brendan M; Almaliti, Jehad; Allard, Pierre-Marie; Phapale, Prasad; Nothias, Louis-Felix; Alexandrov, Theodore; Litaudon, Marc; Wolfender, Jean-Luc; Kyle, Jennifer E; Metz, Thomas O; Peryea, Tyler; Nguyen, Dac-Trung; VanLeer, Danielle; Shinn, Paul; Jadhav, Ajit; Müller, Rolf; Waters, Katrina M; Shi, Wenyuan; Liu, Xueting; Zhang, Lixin; Knight, Rob; Jensen, Paul R; Palsson, Bernhard O; Pogliano, Kit; Linington, Roger G; Gutiérrez, Marcelino; Lopes, Norberto P; Gerwick, William H; Moore, Bradley S; Dorrestein, Pieter C; Bandeira, Nuno

    2017-01-01

    The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry techniques are well-suited to high-throughput characterization of natural products, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social molecular networking (GNPS, http://gnps.ucsd.edu), an open-access knowledge base for community wide organization and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations. We also introduce the concept of ‘living data’ through continuous reanalysis of deposited data. PMID:27504778

  1. Challenges ahead for mass spectrometry and proteomics applications in epigenetics.

    Science.gov (United States)

    Kessler, Benedikt M

    2010-02-01

    Inheritance of biological information to future generations depends on the replication of DNA and the Mendelian principle of distribution of genes. In addition, external and environmental factors can influence traits that can be propagated to offspring, but the molecular details of this are only beginning to be understood. The discoveries of DNA methylation and post-translational modifications on chromatin and histones provided entry points for regulating gene expression, an area now defined as epigenetics and epigenomics. Mass spectrometry turned out to be instrumental in uncovering molecular details involved in these processes. The central role of histone post-translational modifications in epigenetics related biological processes has revitalized mass spectrometry based investigations. In this special report, current approaches and future challenges that lay ahead due to the enormous complexity are discussed.

  2. Native Mass Spectrometry in Fragment-Based Drug Discovery

    Directory of Open Access Journals (Sweden)

    Liliana Pedro

    2016-07-01

    Full Text Available The advent of native mass spectrometry (MS in 1990 led to the development of new mass spectrometry instrumentation and methodologies for the analysis of noncovalent protein–ligand complexes. Native MS has matured to become a fast, simple, highly sensitive and automatable technique with well-established utility for fragment-based drug discovery (FBDD. Native MS has the capability to directly detect weak ligand binding to proteins, to determine stoichiometry, relative or absolute binding affinities and specificities. Native MS can be used to delineate ligand-binding sites, to elucidate mechanisms of cooperativity and to study the thermodynamics of binding. This review highlights key attributes of native MS for FBDD campaigns.

  3. Practical aspects of trapped ion mass spectrometry, 5 applications of ion trapping devices

    CERN Document Server

    March, Raymond E

    2009-01-01

    Examines ion/neutral and ion/ion reactions, ion spectroscopy, and the structural characterization of proteins and peptides using quadropole ion trap mass spectrometry, Fourier transform - ion cyclotron resonance (FT-ICR) mass spectrometry, and traveling wave ion mobility mass spectrometry.

  4. Determining the topology of virus assembly intermediates using ion mobility spectrometry-mass spectrometry.

    Science.gov (United States)

    Knapman, Tom W; Morton, Victoria L; Stonehouse, Nicola J; Stockley, Peter G; Ashcroft, Alison E

    2010-10-30

    We have combined ion mobility spectrometry-mass spectrometry with tandem mass spectrometry to characterise large, non-covalently bound macromolecular complexes in terms of mass, shape (cross-sectional area) and stability (dissociation) in a single experiment. The results indicate that the quaternary architecture of a complex influences its residual shape following removal of a single subunit by collision-induced dissociation tandem mass spectrometry. Complexes whose subunits are bound to several neighbouring subunits to create a ring-like three-dimensional (3D) architecture undergo significant collapse upon dissociation. In contrast, subunits which have only a single neighbouring subunit within a complex retain much of their original shape upon complex dissociation. Specifically, we have determined the architecture of two transient, on-pathway intermediates observed during in vitro viral capsid assembly. Knowledge of the mass, stoichiometry and cross-sectional area of each viral assembly intermediate allowed us to model a range of potential structures based on the known X-ray structure of the coat protein building blocks. Comparing the cross-sectional areas of these potential architectures before and after dissociation provided tangible evidence for the assignment of the topologies of the complexes, which have been found to encompass both the 3-fold and the 5-fold symmetry axes of the final icosahedral viral shell. Such insights provide unique information about virus assembly pathways that could allow the design of anti-viral therapeutics directed at the assembly step. This methodology can be readily applied to the structural characterisation of many other non-covalently bound macromolecular complexes and their assembly pathways.

  5. Nanostructure-initiator mass spectrometry metabolite analysis and imaging.

    Science.gov (United States)

    Greving, Matthew P; Patti, Gary J; Siuzdak, Gary

    2011-01-01

    Nanostructure-Initiator Mass Spectrometry (NIMS) is a matrix-free desorption/ionization approach that is particularly well-suited for unbiased (untargeted) metabolomics. An overview of the NIMS technology and its application in the detection of biofluid and tissue metabolites are presented. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html .).

  6. Fluorescence preselection of bioaerosol for single-particle mass spectrometry

    Science.gov (United States)

    Stowers, M. A.; van Wuijckhuijse, A. L.; Marijnissen, J. C. M.; Kientz, Ch. E.; Ciach, T.

    2006-11-01

    We have designed, constructed, and tested a system that preselects the biological fraction of airborne particles from the overall aerosol. The preselection is based on fluorescence emission excited by a continuous 266 nm laser beam. This beam is one of two cw beams used to measure the aerodynamic particle size of sampled particles. The intention in our system is that single particles, based on size and fluorescence emission, can be selected and further examined for chemical composition by mass spectrometry.

  7. Mass spectrometry based protein identification with accurate statistical significance assignment

    OpenAIRE

    Alves, Gelio; Yu, Yi-Kuo

    2014-01-01

    Motivation: Assigning statistical significance accurately has become increasingly important as meta data of many types, often assembled in hierarchies, are constructed and combined for further biological analyses. Statistical inaccuracy of meta data at any level may propagate to downstream analyses, undermining the validity of scientific conclusions thus drawn. From the perspective of mass spectrometry based proteomics, even though accurate statistics for peptide identification can now be ach...

  8. Kinetic Studies of Reactions in Solution Using Fast Mass Spectrometry

    Science.gov (United States)

    2013-08-13

    REPORT Directorate of Chemistry and Materials Research NUMBER(S) AFOSR/RSA, 875 Randolph St., Suite 325, Rm 3112, Arlington, VA 222C 3 12...Mass Spectrometry to detect transient intermediates and decomposition products of catalyzed organometallic reactions Identifying intermediates is...in organometallic catalysis. HV N2 45o 5 mm 2 mm Reagent A Reagent B MS Secondary microdroplets Surface ~2-5 ms reaction time

  9. New Applications of Mass Spectrometry in Lipid Analysis*

    OpenAIRE

    Robert C. Murphy; Gaskell, Simon J

    2011-01-01

    Mass spectrometry has emerged as a powerful tool for the analysis of all lipids. Lipidomic analysis of biological systems using various approaches is now possible with a quantitative measurement of hundreds of lipid molecular species. Although availability of reference and internal standards lags behind the field, approaches using stable isotope-labeled derivative tagging permit precise determination of specific phospholipids in an experimental series. The use of reactivity of ozone has enabl...

  10. Quality management in clinical application of mass spectrometry measurement systems.

    Science.gov (United States)

    Vogeser, Michael; Seger, Christoph

    2016-09-01

    Thanks to highly specific analyte detection and potentially complete compensation for matrix variables based on the principle of stable isotope derivative internal standardisation, mass spectrometry methods allow the development of diagnostic tests of outstanding analytical quality. However, these features per se do not guarantee reliability of tests. A wide range of factors can introduce analytical errors and inaccuracy due to the extreme complexity of the methods involved. Furthermore, it can be expected that the application patterns of MS methods in diagnostic laboratories will change substantially during the coming years - with presumably less specialised laboratories implementing mass spectrometry. Introduction of highly automated test solutions by manufacturers will require some trade-off between operation convenience, sample throughput and analytical performance. Structured and careful quality and risk management is therefore crucial to translate the analytical power of mass spectrometry into actionable and reliable results for individual patients' care and to maintain the degree of reliability that is expected from MS methods in clinical pathology. This reflection review discusses whether particular quality assurance tools have to be applied for MS-based diagnostic tests and whether these tools are different from those applied for optical- and affinity-based standard tests. Both pre-implementation strategies and surveillance of assays with assessment of metadata in routine testing are addressed. The release of the CLSI guideline C62-A in 2014 was a substantial achievement in this context because it addresses a wide spectrum of relevant issues in quality assurance of mass spectrometry-based clinical tests. However, the translation of this best practice document into individual laboratory settings is likely to be heterogeneous.

  11. ESI and MALDI Mass Spectrometry of Large POSS Oligomers (Preprint)

    Science.gov (United States)

    2010-03-10

    Materials Science, 8 (2004) 21-29. [10] J. Wu and P. T. Mather, POSS Polymers: Physical Properties and Biomaterials Applications. Polym. Rev.. 49 (2009...10 (1999) 224-230. [16] M. Farahani, J. M. Antonucci and C. M. Guttman, Analysis of the interactions of a trialkoxysilane with dental monomers...Antonucci and C. M. Guttman, Analysis by mass spectrometry of the hydrolysis/condensation reaction of a trialkoxysilane in various dental monomer

  12. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  13. Injection system of the minicyclotron accelerator mass spectrometer

    Institute of Scientific and Technical Information of China (English)

    LIUYonghao; LIDeming; 等

    1999-01-01

    The existing injection system of the SMCAMS(super-sensitive minicyclotron accelerator mass spectrometer)is described together with the discussion of its disadvantages exposed after having been operating for five years.which provides a basis for consideration of improvements to the injection system.An optimized injection system with an analytical magent added prior to the minicryclotron has been proposed and calculated.

  14. History of mass spectrometry at the Olympic Games.

    Science.gov (United States)

    Hemmersbach, Peter

    2008-07-01

    Mass spectrometry has played a decisive role in doping analysis and doping control in human sport for almost 40 years. The standard of qualitative and quantitative determinations in body fluids has always attracted maximum attention from scientists. With its unique sensitivity and selectivity properties, mass spectrometry provides state-of-the-art technology in analytical chemistry. Both anti-doping organizations and the athletes concerned expect the utmost endeavours to prevent false-positive and false-negative results of the analytical evidence. The Olympic Games play an important role in international sport today and are milestones for technical development in doping analysis. This review of the part played by mass spectrometry in doping control from Munich 1972 to Beijing 2008 Olympics gives an overview of how doping analysis has developed and where we are today. In recognizing the achievements made towards effective doping control, it is of the utmost importance to applaud the joint endeavours of the World Anti-Doping Agency, the International Olympic Committee, the international federations and national anti-doping agencies to combat doping. Advances against the misuse of prohibited substances and methods, which are performance-enhancing, dangerous to health and violate the spirit of sport, can be achieved only if all the stakeholders work together.

  15. Multidimensional Mass Spectrometry of Synthetic Polymers and Advanced Materials.

    Science.gov (United States)

    Wesdemiotis, Chrys

    2017-02-01

    Multidimensional mass spectrometry interfaces a suitable ionization technique and mass analysis (MS) with fragmentation by tandem mass spectrometry (MS(2) ) and an orthogonal online separation method. Separation choices include liquid chromatography (LC) and ion-mobility spectrometry (IMS), in which separation takes place pre-ionization in the solution state or post-ionization in the gas phase, respectively. The MS step provides elemental composition information, while MS(2) exploits differences in the bond stabilities of a polymer, yielding connectivity and sequence information. LC conditions can be tuned to separate by polarity, end-group functionality, or hydrodynamic volume, whereas IMS adds selectivity by macromolecular shape and architecture. This Minireview discusses how selected combinations of the MS, MS(2) , LC, and IMS dimensions can be applied, together with the appropriate ionization method, to determine the constituents, structures, end groups, sequences, and architectures of a wide variety of homo- and copolymeric materials, including multicomponent blends, supramolecular assemblies, novel hybrid materials, and large cross-linked or nonionizable polymers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Significant advancement of mass spectrometry imaging for food chemistry.

    Science.gov (United States)

    Yoshimura, Yukihiro; Goto-Inoue, Naoko; Moriyama, Tatsuya; Zaima, Nobuhiro

    2016-11-01

    Food contains various compounds that have an impact on our daily lives. Many technologies have been established to analyze these molecules of interest in foods. However, the analysis of the spatial distribution of these compounds in foods using conventional technology, such as high-performance liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry is difficult. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is considered an ideal complementary approach. MALDI-MSI is a two-dimensional MALDI-MS technology that can detect compounds in a tissue section without extraction, purification, separation, or labeling. MALDI-MSI can be used to visualize the spatial distribution of chemical compounds or biomolecules in foods. Although the methodology of MALDI-MSI in food science is not yet fully established, the versatility of MALDI-MSI is expected to open a new frontier in food science. Herein, we describe the principles and applications of MALDI-MSI in food science and related fields.

  17. Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    National Research Council Canada - National Science Library

    van Agthoven, Maria A; Barrow, Mark P; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O’Connor, Peter B

    2015-01-01

    ...) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated...

  18. Characterization of individual particles in gaseous media by mass spectrometry

    Science.gov (United States)

    Sinha, M. P.

    1990-01-01

    An introduction is given to a system for particle analysis by mass spectrometry (PAMS) which employs particle-beam techniques to measure mass spectra on a continuous real-time basis. The system is applied to particles of both organic and inorganic compounds, and the measurements give the chemical characteristics of particles in mixtures and indicate source apportionment. The PAMS system can be used for process control and studying heterogeneous/catalytic reactions in particles, and can be fitted to study the real-time attributes of PAMS.

  19. SVSCf plasma desorption mass spectrometry: recent advances and applications

    Energy Technology Data Exchange (ETDEWEB)

    Kamensky, I.; Craig, A.G.

    1987-01-01

    SVSCf plasma desorption mass spectrometry (PDMS) as utilized in the BIO-ION instruments is described. The sensitivity of the technique is investigated for varying amounts of bovine insulin. The results show accurate mass assignment for pmole amounts of sample. Several methods, currently used for sample preparation in PDMS, are described. Spectra of the antibiotic nisin using two different sample preparation techniques show significant variation. The fragmentation pattern of reduced acetylated maltoheptaose is also presented. The initial results obtained using a new PDMS instrument equipped with variable flight path are shown. The increased resolution is illustrated using the extended flight path to measure the molecular ion region of the maltoheptaose.

  20. Tissue MALDI Mass Spectrometry Imaging (MALDI MSI) of Peptides.

    Science.gov (United States)

    Beine, Birte; Diehl, Hanna C; Meyer, Helmut E; Henkel, Corinna

    2016-01-01

    Matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a technique to visualize molecular features of tissues based on mass detection. This chapter focuses on MALDI MSI of peptides and provides detailed operational instructions for sample preparation of cryoconserved and formalin-fixed paraffin-embedded (FFPE) tissue. Besides sample preparation we provide protocols for the MALDI measurement, tissue staining, and data analysis. On-tissue digestion and matrix application are described for two different commercially available and commonly used spraying devices: the SunCollect (SunChrom) and the ImagePrep (Bruker Daltonik GmbH).

  1. Structural analyses of sucrose laurate regioisomers by mass spectrometry techniques

    DEFF Research Database (Denmark)

    Lie, Aleksander; Stensballe, Allan; Pedersen, Lars Haastrup

    2015-01-01

    6- And 6′-O-lauroyl sucrose were isolated and analyzed by matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) mass spectrometry (MS), Orbitrap high-resolution (HR) MS, and electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). The analyses aimed to explore.......8, respectively, and Orbitrap HRMS confirmed the mass of [M+Na]+ (m/z 547.2712). ESI-MS/MS on the precursor ion [M+Na]+ resulted in product ion mass spectra showing two high-intensity signals for each sample. 6-O-Lauroyl sucrose produced signals located at m/z 547.27 and m/z 385.21, corresponding to the 6-O......-lauroyl glucose sodium adduct ions, while the signals for 6′-O-lauroyl sucrose were located at m/z 385.22 and 367.20, respectively corresponding to the sodium adduct ions with 6-O-lauroyl fructose and 6-O-lauroyl fructosyl. The mass spectra of the two regioisomers were clearly different, and the investigation...

  2. Neuropeptide Signaling in Crustaceans Probed by Mass Spectrometry

    Science.gov (United States)

    Liang, Zhidan

    Neuropeptides are one of the most diverse classes of signaling molecules whose identities and functions are not yet fully understood. They have been implicated in the regulation of a wide range of physiological processes, including feeding-related and motivated behaviors, and also environmental adaptations. In this work, improved mass spectrometry-based analytical platforms were developed and applied to the crustacean systems to characterize signaling molecules. This dissertation begins with a review of mass spectrometry-based neuropeptide studies from both temporal- and spatial-domains. This review is then followed by several chapters detailing a few research projects related to the crustacean neuropeptidomic characterization and comparative analysis. The neuropeptidome of crayfish, Orconectes rusticus is characterized for the first time using mass spectrometry-based tools. In vivo microdialysis sampling technique offers the capability of direct sampling from extracellular space in a time-resolved manner. It is used to investigate the secreted neuropeptide and neurotransmitter content in Jonah crab, Cancer borealis, in this work. A new quantitation strategy using alternative mass spectrometry data acquisition approach is developed and applied for the first time to quantify neuropeptides. Coupling of this method with microdialysis enables the study of neuropeptide dynamics concurrent with different behaviors. Proof-of-principle experiments validating this approach have been carried out in Jonah crab, Cancer borealis to study feeding- and circadian rhythm-related neuropeptide changes using micoridialysis in a time-resolved manner. This permits a close correlation between behavioral and neurochemical changes, providing potential candidates for future validation of regulatory roles. In addition to providing spatial information, mass spectrometry imaging (MSI) technique enables the characterization of signaling molecules while preserving the temporal resolution. A

  3. Ion sampling and transport in Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Farnsworth, Paul B.; Spencer, Ross L.

    2017-08-01

    Quantitative accuracy and high sensitivity in inductively coupled plasma mass spectrometry (ICP-MS) depend on consistent and efficient extraction and transport of analyte ions from an inductively coupled plasma to a mass analyzer, where they are sorted and detected. In this review we examine the fundamental physical processes that control ion sampling and transport in ICP-MS and compare the results of theory and computerized models with experimental efforts to characterize the flow of ions through plasma mass spectrometers' vacuum interfaces. We trace the flow of ions from their generation in the plasma, into the sampling cone, through the supersonic expansion in the first vacuum stage, through the skimmer, and into the ion optics that deliver the ions to the mass analyzer. At each stage we consider idealized behavior and departures from ideal behavior that affect the performance of ICP-MS as an analytical tool.

  4. Fast characterization of cheeses by dynamic headspace-mass spectrometry.

    Science.gov (United States)

    Pérès, Christophe; Denoyer, Christian; Tournayre, Pascal; Berdagué, Jean-Louis

    2002-03-15

    This study describes a rapid method to characterize cheeses by analysis of their volatile fraction using dynamic headspace-mass spectrometry. Major factors governing the extraction and concentration of the volatile components were first studied. These components were extracted from the headspace of the cheeses in a stream of helium and concentrated on a Tenax TA trap. They were then desorbed by heating and injected directly into the source of a mass spectrometer via a short deactivated silica transfer line. The mass spectra of the mixture of volatile components were considered as fingerprints of the analyzed substances. Forward stepwise factorial discriminant analysis afforded a limited number of characteristic mass fragments that allowed a good classification of the batches of cheeses studied.

  5. Analysis of aromatic hydrocarbons in petroleum fractions using gas chromatography, mass spectrometry and mass fragmentrography

    Energy Technology Data Exchange (ETDEWEB)

    Kubelka, V.

    1980-01-01

    Mass spectrometry in combination with gas chrom. used to analyze hydrocarbon mixtures results in qualit. and semi-quant. data regarding composition of the analyzed mixture. Use of mass fragmentrography during chromatographic separation will allow simultaneous recording of changes in intensity of characteristic ions and thus determine the retention index, for this substance. Combining mass spectre and retention index, it is possible to identify the given subst. or limit the number of possible combinations.

  6. Accurate Mass Determination of Amino Alcohols by Turboionspray/Time-of-Flight Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    GENG,Yu(耿昱); GUO,Yin-Long(郭寅龙); ZHAO,Shi-Min(赵士民); MA,Sheng-Ming(麻生明)

    2002-01-01

    Amino alcohols were studied by turboionspray/time-of-flight mass spectrometry (TIS/TOF-MS) with the aim of determining the accurate mass of their protonated molecule ions.Polyethylene glycol (PEG) was used as the internal reference.Compared with the theoretical values, all relative errors were less than 5×10-6. The effects of nozzle potential, nozzle temperature, acquisition rate etc. on accurate mass determination were also studied.

  7. Elucidating rhizosphere processes by mass spectrometry - A review.

    Science.gov (United States)

    Rugova, Ariana; Puschenreiter, Markus; Koellensperger, Gunda; Hann, Stephan

    2017-03-01

    The presented review discusses state-of-the-art mass spectrometric methods, which have been developed and applied for investigation of chemical processes in the soil-root interface, the so-called rhizosphere. Rhizosphere soil's physical and chemical characteristics are to a great extent influenced by a complex mixture of compounds released from plant roots, i.e. root exudates, which have a high impact on nutrient and trace element dynamics in the soil-root interface as well as on microbial activities or soil physico-chemical characteristics. Chemical characterization as well as accurate quantification of the compounds present in the rhizosphere is a major prerequisite for a better understanding of rhizosphere processes and requires the development and application of advanced sampling procedures in combination with highly selective and sensitive analytical techniques. During the last years, targeted and non-targeted mass spectrometry-based methods have emerged and their combination with specific separation methods for various elements and compounds of a wide polarity range have been successfully applied in several studies. With this review we critically discuss the work that has been conducted within the last decade in the context of rhizosphere research and elemental or molecular mass spectrometry emphasizing different separation techniques as GC, LC and CE. Moreover, selected applications such as metal detoxification or nutrient acquisition will be discussed regarding the mass spectrometric techniques applied in studies of root exudates in plant-bacteria interactions. Additionally, a more recent isotope probing technique as novel mass spectrometry based application is highlighted. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Study of coal structure using secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tingey, G.L.; Lytle, J.M.; Baer, D.R.; Thomas, M.T.

    1980-12-01

    Secondary-ion Mass Spectrometry (SIMS) is examined as a tool for studying the chemical structure of coal. SIMS has potential for analysis of coal because of the following characteristics: sensitivity to chemical structure; high sensitivity to all masses; application to solids; excellent depth resolution; and reasonable spatial resolution. SIMS spectra of solid coals show differences with respect to coal rank, the spectra of high rank coal being similar to that of graphite, and the spectra of low rank coal being similar to that of wood. Some functional group analysis is also possible using SIMS. Low rank coals show a larger peak at 15 amu indicating more methyl groups than found in the higher rank coals. Fragments with two and three carbon atoms have also been examined; much larger fragments are undoubtedly present but were not evaluated in this study. Examination of these groups, which are expected to contain valuable information on coal structure, is planned for future work. It has been observed that mineral atoms present in the coal have large secondary ion yields which complicate the interpretation of the spectra. Studies on mineral-free coals and model compounds are therefore recommended to facilitate determination of organic coal structure. In addition, mass spectrometry with much greater mass resolution will aid in distinguishing between various ion species.

  9. Mass spectrometry improvement on an high current ion implanter

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.G., E-mail: jgabriel@deea.isel.ipl.pt [Instituto Superior de Engenharia de Lisboa and Centro de Fisica Nuclear of the University of Lisbon, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Alegria, F.C., E-mail: falegria@lx.it.pt [Instituto Superior Tecnico/Technical University of Lisbon and Instituto de Telecomunicacoes, Av. Rovisco Pais, 1, 1049-001 Lisbon (Portugal); Redondo, L.M., E-mail: lmredondo@deea.isel.ipl.pt [Instituto Superior de Engenharia de Lisboa and Centro de Fisica Nuclear of the University of Lisbon, Rua Conselheiro Emidio Navarro, 1, 1959-007 Lisbon (Portugal); Rocha, J., E-mail: jrocha@itn.pt [Instituto Tecnologico Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Alves, E., E-mail: ealves@itn.pt [Instituto Tecnologico Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal)

    2011-12-15

    The development of accurate mass spectrometry, enabling the identification of all the ions extracted from the ion source in a high current implanter is described. The spectrometry system uses two signals (x-y graphic), one proportional to the magnetic field (x-axes), taken from the high-voltage potential with an optic fiber system, and the other proportional to the beam current intensity (y-axes), taken from a beam-stop. The ion beam mass register in a mass spectrum of all the elements magnetically analyzed with the same radius and defined by a pair of analyzing slits as a function of their beam intensity is presented. The developed system uses a PC to control the displaying of the extracted beam mass spectrum, and also recording of all data acquired for posterior analysis. The operator uses a LabVIEW code that enables the interfacing between an I/O board and the ion implanter. The experimental results from an ion implantation experiment are shown.

  10. Capillary supercritical fluid chromatography-mass spectrometry (SFC-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Kalinoski, H.T.; Udseth, H.R.; Chess, E.K.; Smith, R.D.

    1986-10-01

    The physical and chemical characteristics of supercritical fluids have prompted the development of supercritical fluid chromatography (SFC) for the analysis of labile and less volatile compounds. High resolution chromatographic separations with efficiencies approaching those of gas chromatography and high speed analyses are possible in capillary SFC using pressure programming methods and narrow bore columns. Further refinement of the SFC-mass spectrometry interface (SFC-MS) provides the basis for extension to more polar fluid systems with greater solvating power and the selectivity and sensitivity of mass spectrometric detection. The use of polar modified fluids has been facilitated by advances in understanding of supercritical fluid phase behavior. Fluid mixtures have been prepared for analysis of more polar, higher molecular weight analytes, that allow mild chromatographic temperatures and allow full exploitation of selectivity offered through control of fluid pressure (i.e., density). Continuing development of the SFC-MS interface has led to designs which can be near routinely applied with fluids such as CO/sub 2/, and providing enhanced transport of truly nonvolatile compounds to the mass spectrometer ionization regions. These advances also include an SFC interface to a high resolution, dual electric magnetic sector instrument, allowing supercritical fluid solvents to be explited for on-line extraction-mass spectrometry for characterization of complex, often otherwise intractable, materials. 26 refs., 5 figs., 1 tab.

  11. Study of coal structure using secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tingey, G.L.; Lytle, J.M.; Baer, D.R.; Thomas, M.T.

    1980-12-01

    Secondary-ion Mass Spectrometry (SIMS) is examined as a tool for studying the chemical structure of coal. SIMS has potential for analysis of coal because of the following characteristics: sensitivity to chemical structure; high sensitivity to all masses; application to solids; excellent depth resolution; and reasonable spatial resolution. SIMS spectra of solid coals show differences with respect to coal rank, the spectra of high rank coal being similar to that of graphite, and the spectra of low rank coal being similar to that of wood. Some functional group analysis is also possible using SIMS. Low rank coals show a larger peak at 15 amu indicating more methyl groups than found in the higher rank coals. Fragments with two and three carbon atoms have also been examined; much larger fragments are undoubtedly present but were not evaluated in this study. Examination of these groups, which are expected to contain valuable information on coal structure, is planned for future work. It has been observed that mineral atoms present in the coal have large secondary ion yields which complicate the interpretation of the spectra. Studies on mineral-free coals and model compounds are therefore recommended to facilitate determination of organic coal structure. In addition, mass spectrometry with much greater mass resolution will aid in distinguishing between various ion species.

  12. Quantitative mass spectrometry of unconventional human biological matrices

    Science.gov (United States)

    Dutkiewicz, Ewelina P.; Urban, Pawel L.

    2016-10-01

    The development of sensitive and versatile mass spectrometric methodology has fuelled interest in the analysis of metabolites and drugs in unconventional biological specimens. Here, we discuss the analysis of eight human matrices-hair, nail, breath, saliva, tears, meibum, nasal mucus and skin excretions (including sweat)-by mass spectrometry (MS). The use of such specimens brings a number of advantages, the most important being non-invasive sampling, the limited risk of adulteration and the ability to obtain information that complements blood and urine tests. The most often studied matrices are hair, breath and saliva. This review primarily focuses on endogenous (e.g. potential biomarkers, hormones) and exogenous (e.g. drugs, environmental contaminants) small molecules. The majority of analytical methods used chromatographic separation prior to MS; however, such a hyphenated methodology greatly limits analytical throughput. On the other hand, the mass spectrometric methods that exclude chromatographic separation are fast but suffer from matrix interferences. To enable development of quantitative assays for unconventional matrices, it is desirable to standardize the protocols for the analysis of each specimen and create appropriate certified reference materials. Overcoming these challenges will make analysis of unconventional human biological matrices more common in a clinical setting. This article is part of the themed issue 'Quantitative mass spectrometry'.

  13. Constraining Anthropogenic and Biogenic Emissions Using Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Spencer, Kathleen M.

    Numerous gas-phase anthropogenic and biogenic compounds are emitted into the atmosphere. These gases undergo oxidation to form other gas-phase species and particulate matter. Whether directly or indirectly, primary pollutants, secondary gas-phase products, and particulate matter all pose health and environmental risks. In this work, ambient measurements conducted using chemical ionization mass spectrometry are used as a tool for investigating regional air quality. Ambient measurements of peroxynitric acid (HO2NO2) were conducted in Mexico City. A method of inferring the rate of ozone production, PO3, is developed based on observations of HO2NO 2, NO, and NO2. Comparison of this observationally based PO3 to a highly constrained photochemical box model indicates that regulations aimed at reducing ozone levels in Mexico City by reducing NOx concentrations may be effective at higher NO x levels than predicted using accepted photochemistry. Measurements of SO2 and particulate sulfate were conducted over the Los Angeles basin in 2008 and are compared to measurements made in 2002. A large decrease in SO2 concentration and a change in spatial distribution are observed. Nevertheless, only a modest reduction in sulfate concentration is observed at ground sites within the basin. Possible explanations for these trends are investigated. Two techniques, single and triple quadrupole chemical ionization mass spectrometry, were used to quantify ambient concentrations of biogenic oxidation products, hydroxyacetone and glycolaldehyde. The use of these techniques demonstrates the advantage of triple quadrupole mass spectrometry for separation of mass analogues, provided the collision-induced daughter ions are sufficiently distinct. Enhancement ratios of hydroxyacetone and glycolaldehyde in Californian biomass burning plumes are presented as are concentrations of these compounds at a rural ground site downwind of Sacramento.

  14. Analysis of fluticasone propionate in induced sputum by mass spectrometry.

    Science.gov (United States)

    Hagan, John B; Taylor, Robert L; Kita, Hirohito; Singh, Ravinder J

    2011-01-01

    Although evaluation of induced sputum has shown promise as a marker of eosinophilic airway inflammation in asthmatic subjects, most studies, to date, do not adequately address the potential effect that inhaled corticosteroids may have on sputum eosinophilia. This study was designed to prospectively evaluate analysis of fluticasone propionate (FP) in whole sputum by mass spectrometry as a tool to determine recent administration of inhaled FP. Induced sputum of nonsmoking asthmatic subjects was prospectively analyzed 16-24 hours after witnessed administration of orally inhaled FP. FP was extracted from whole sputum via an acetonitrile protein precipitation followed by methylene chloride liquid extraction of the supernatant (AB 4000; AB Sciex). A portion of the reconstituted sample was analyzed by liquid chromatography tandem mass spectrometry using a triple quad tandem mass spectrometer. Results were compared with those from nonsmoking asthmatic subjects not receiving inhaled FP. Twenty-two asthmatic subjects on FP and 9 asthmatic subjects without FP underwent sputum induction 16-24 hours following witnessed administration of FP. Sufficient sputum for analysis was obtained from 30 of 31 subjects. FP was detected in 22 of 22 asthmatic subjects receiving FP (range, 29-133,000 pg/mL) and was undetectable in 8 of 8 subjects not receiving FP. The sensitivity and specificity of tandem mass spectrometry's ability to detect FP in sputum was 100% and 100%, respectively. Analysis of FP in induced sputum is a reliable method to verify recent administration of inhaled FP. Induced asthmatic sputum from one induction may be used to concomitantly assess sputum eosinophilia as well as recent administration of FP.

  15. Intact MicroRNA Analysis Using High Resolution Mass Spectrometry

    Science.gov (United States)

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

    2014-01-01

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

  16. Invited review article: Recent developments in isotope-ratio mass spectrometry for geochemistry and cosmochemistry.

    Science.gov (United States)

    Ireland, Trevor R

    2013-01-01

    Mass spectrometry is fundamental to measurements of isotope ratios for applications in isotope geochemistry, geochronology, and cosmochemistry. Magnetic-sector mass spectrometers are most common because these provide the best precision in isotope ratio measurements. Where the highest precision is desired, chemical separation followed by mass spectrometric analysis is carried out with gas (noble gas and stable isotope mass spectrometry), liquid (inductively coupled plasma mass spectrometry), or solid (thermal ionization mass spectrometry) samples. Developments in in situ analysis, including ion microprobes and laser ablation inductively coupled plasma mass spectrometry, have opened up issues concerning homogeneity according to domain size, and allow ever smaller amounts of material to be analyzed. While mass spectrometry is built solidly on developments in the 20th century, there are new technologies that will push the limits in terms of precision, accuracy, and sample efficiency. Developments of new instruments based on time-of-flight mass spectrometers could open up the ultimate levels of sensitivity per sample atom.

  17. Development of Secondary Ion Mass Spectrometry%二次离子质谱进展

    Institute of Scientific and Technical Information of China (English)

    祝兆文; 侯杰; 郑涛; 马宏骥; 聂锐; 丁富荣

    2011-01-01

    Secondary ion mass spectrometry technique has been widely used in the material surface analysis.With the renovation of the detection method,this technique is developing rapidly.In the lab of 2×1.7MV tandem accelerator in Peking University,a facility of accelerator-based time-of-flight secondary ion mass spectrometry was built and upgraded.After analyzing the carbon-based material such as carbon nano tube and graphite,we found that carbon nano tube material could absorb hydrogen strongly.This result proved the capability of carbon nano tube material in hydrogen storage.%指出了二次离子质谱技术在材料表面分析方面有着广泛的应用,随着探测方法的改进,此技术也得到了迅速发展.在北京大学2×1.7MV串列静电加速器实验室,利用加速器飞行时间二次离子质谱装置对碳基材料进行了分析,通过实验观察到碳纳米管材料对氢具有很强的吸附能力,证实了理论上对此材料储氢能力的预言.

  18. 加速溶剂萃取-气相色谱质谱法测定海洋沉积物中多氯联苯残留%Determination of polychlorinated biphenyls residues in marine sediments using accelerated solvent extraction with gas chromatog raphy-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    贺玉林; 刘泽伟; 邹潍力; 卢伟华; 胡浩光

    2012-01-01

    A rapid and accurate method was developed for the determination of polychlorinated biphenyls ( PCBs) residues in marine sediments by accelerated solvent extraction( ASE) and gas chromatography-mass spectrometry( GC-MS) . The target analytes were extracted with hexane/acetone(1: 1 ,v/v) by ASE and cleaned up by composite silica gel column and graphitization carbon column. The results demonstrated that the method detection limits was (0. 005 -0. 038) × 10-9 for PCBs( wet weight). The recovery percentages and RSD of two-level spiked samples were 68. 5% - 108. 4% and 2.1% -11.8% for PCBs, respectively. The method was precise, sensitive, and highly efficient in extraction, and has been applied in the actual POPs monitoring in sediments of marine environment.%样品采用加速溶剂萃取,萃取液依次经复合硅胶和石墨化炭黑柱净化后,采用GC-MS法测定样品中的多氯联苯残留.结果表明,方法检出限为(0.005 ~0.038)×10-9(湿重),样品加标回收率为68.5%~ 108.4%,RSD为2.1%~11.8%.本方法具有提取效率高,净化效果好,回收率高,准确灵敏等优点,可应用于海洋沉积物中多氯联苯等持久性有机污染物残留的监测.

  19. 快速溶剂萃取–气相色谱质谱法测定土壤中戊唑醇残留量%Determination of Residue Tebuconazole in Soil by Accelerated Solvent Extraction and Gas Chromatography Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴小春; 姚科伟; 魏双利; 翁际渊; 章巧林; 王鼎

    2015-01-01

    A method was established to determine residue tebuconazole in soil by accelerated solvent extraction and gas chromatography mass spectrometry. Soil sample was prepared byASE–350 fast solvent extraction,purified and concentrated by magnesium silicate (florisil) column. The extract was injected into GC for separation and followed by MS detection under EI ionization and synchronous SIM/SCAN data acquisition mode. The detection limit found for tebuconazole in soil was 0.008 mg/kg,the recovery was 84.0%–97.5%,RSD was 2.2%–11.6%(n=6). The method could be used to detect the residue tebuconazole in soil,which showed good separating result,high sensitivity,good reproducibility, pretreatment with simple operation.%建立快速溶剂萃取–气相色谱质谱法测定土壤中戊唑醇残留量的分析方法.土壤样品经ASE–350快速溶剂萃取仪萃取,萃取液用硅酸镁(弗罗里硅土)柱净化浓缩,然后用选择离子监测/全扫描(SIM/SCAN)模式,气相色谱–质谱法测定土壤中的戊唑醇含量.该方法检出限为0.008 mg/kg,加标回收率为84.0%~97.5%,测定结果的相对标准偏差为2.2%~11.6%(n=6).该方法具有分离效果好,灵敏度高,重现性好,前处理操作简便等优点,可用于测定土壤中戊唑醇的残留量.

  20. Analyzing the posttranslational modification status of Notch using mass spectrometry.

    Science.gov (United States)

    Kakuda, Shinako; Haltiwanger, Robert S

    2014-01-01

    Notch is modified by multiple types of posttranslational modifications, most of which are known to affect Notch function. The extracellular domain (ECD) is modified with N-glycosylation and at least three types of O-glycosylation (O-fucose, O-glucose, and O-GlcNAc), while the intracellular domain is hydroxylated, phosphorylated, and ubiquitinated. In order to analyze the structure and function of the O-glycans decorating the ECD, we have developed semiquantitative mass spectral methods for identifying modifications at individual sites on Notch that are generally applicable to most posttranslational modifications. Here we describe the expression and purification of Notch ECD fragments, digestion of the fragments with proteases to prepare for mass spectral analysis, and identification of peptides modified with O-glycans using mass spectrometry.