WorldWideScience

Sample records for exchange mass spectrometry

  1. Hydrogen Exchange Mass Spectrometry

    Science.gov (United States)

    Mayne, Leland

    2018-01-01

    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. PMID:26791986

  2. Hydrogen/deuterium exchange in mass spectrometry.

    Science.gov (United States)

    Kostyukevich, Yury; Acter, Thamina; Zherebker, Alexander; Ahmed, Arif; Kim, Sunghwan; Nikolaev, Eugene

    2018-03-30

    The isotopic exchange approach is in use since the first observation of such reactions in 1933 by Lewis. This approach allows the investigation of the pathways of chemical and biochemical reactions, determination of structure, composition, and conformation of molecules. Mass spectrometry has now become one of the most important analytical tools for the monitoring of the isotopic exchange reactions. Investigation of conformational dynamics of proteins, quantitative measurements, obtaining chemical, and structural information about individual compounds of the complex natural mixtures are mainly based on the use of isotope exchange in combination with high resolution mass spectrometry. The most important reaction is the Hydrogen/Deuterium exchange, which is mainly performed in the solution. Recently we have developed the approach allowing performing of the Hydrogen/Deuterium reaction on-line directly in the ionization source under atmospheric pressure. Such approach simplifies the sample preparation and can accelerate the exchange reaction so that certain hydrogens that are considered as non-labile will also participate in the exchange. The use of in-ionization source H/D exchange in modern mass spectrometry for structural elucidation of molecules serves as the basic theme in this review. We will focus on the mechanisms of the isotopic exchange reactions and on the application of in-ESI, in-APCI, and in-APPI source Hydrogen/Deuterium exchange for the investigation of petroleum, natural organic matter, oligosaccharides, and proteins including protein-protein complexes. The simple scenario for adaptation of H/D exchange reactions into mass spectrometric method is also highlighted along with a couple of examples collected from previous studies. © 2018 Wiley Periodicals, Inc.

  3. Radiocarbon detection by ion charge exchange mass spectrometry

    International Nuclear Information System (INIS)

    Hotchkis, Michael; Wei, Tao

    2007-01-01

    A method for detection of radiocarbon at low levels is described and the results of tests are presented. We refer to this method as ion charge exchange mass spectrometry (ICE-MS). The ICE-MS instrument is a two stage mass spectrometer. In the first stage, molecular interferences which would otherwise affect radiocarbon detection at mass 14 are eliminated by producing high charge state ions directly in the ion source (charge state ≥2). 14 N interference is eliminated in the second stage by converting the beam to negative ions in a charge exchange cell. The beam is mass-analysed at each stage. We have built a test apparatus consisting of an electron cyclotron resonance ion source and a pair of analysing magnets with a charge exchange cell in between, followed by an electrostatic analyser to improve the signal to background ratio. With this apparatus we have measured charge exchange probabilities for (C n+ → C - ) from 4.5 to 40.5 keV (n = 1-3). We have studied the sources of background including assessment of limits for nitrogen interference by searching for negative ions from charge exchange of 14 N ions. Our system has been used to detect 14 C in enriched samples of CO 2 gas with 14 C/ 12 C isotopic ratio down to the 10 -9 level. Combined with a measured sample consumption rate of 4 ng/s, this corresponds to a capability to detect transient signals containing only a few μBq of 14 C activity, such as may be obtained from chromatographic separation. The method will require further development to match the sensitivity of AMS with a gas ion source; however, even in its present state its sensitivity is well suited to tracer studies in biomedical research and drug development

  4. Atmospheric pressure photo ionization hydrogen/deuterium exchange mass spectrometry--a method to differentiate isomers by mass spectrometry.

    Science.gov (United States)

    Ahmed, Arif; Kim, Sunghwan

    2013-12-01

    In this report, a method for in-source hydrogen/deuterium (H/D) exchange at atmospheric pressure is reported. The method was named atmospheric pressure photo ionization hydrogen/deuterium exchange mass spectrometry (APPI HDX MS). H/D exchange was performed by mixing samples dissolved in toluene with CH3OD solvent and analyzing the mixture using atmospheric pressure photo ionization mass spectrometry (APPI-MS). The APPI HDX spectra obtained with contact times between the analyte solution and methanol-OD (CH3OD) of atmospheric pressure. H/D exchange can be performed in any laboratory with a mass spectrometer and a commercial APPI source. Using this method, multiple H/D exchanges of aromatic hydrogen and/or H/D exchange of active hydrogen were observed. These results demonstrated that H/D exchange can be used to distinguish between isomers containing primary, secondary, and tertiary amines, as well as pyridine and pyrrole functional groups.

  5. Ion mobility spectrometry-hydrogen deuterium exchange mass spectrometry of anions: part 1. Peptides to proteins.

    Science.gov (United States)

    Donohoe, Gregory C; Khakinejad, Mahdiar; Valentine, Stephen J

    2015-04-01

    Ion mobility spectrometry (IMS) coupled with hydrogen deuterium exchange (HDX)-mass spectrometry (MS) has been used to study the conformations of negatively-charged peptide and protein ions. Results are presented for ion conformers of angiotensin 1, a synthetic peptide (SP), bovine insulin, ubiquitin, and equine cytochrome c. In general, the SP ion conformers demonstrate a greater level of HDX efficiency as a greater proportion of the sites undergo HDX. Additionally, these ions exhibit the fastest rates of exchange. Comparatively, the angiotensin 1 ions exhibit a lower rate of exchange and HDX level presumably because of decreased accessibility of exchange sites by charge sites. The latter are likely confined to the peptide termini. Insulin ions show dramatically reduced HDX levels and exchange rates, which can be attributed to decreased conformational flexibility resulting from the disulfide bonds. For the larger ubiquitin and protein ions, increased HDX is observed for larger ions of higher charge state. For ubiquitin, a conformational transition from compact to more elongated species (from lower to higher charge states) is reflected by an increase in HDX levels. These results can be explained by a combination of interior site protection by compact conformers as well as decreased access by charge sites. The elongated cytochrome c ions provide the largest HDX levels where higher values correlate with charge state. These results are consistent with increased exchange site accessibility by additional charge sites. The data from these enhanced IMS-HDX experiments are described in terms of charge site location, conformer rigidity, and interior site protection.

  6. Empirical Correction for Differences in Chemical Exchange Rates in Hydrogen Exchange-Mass Spectrometry Measurements.

    Science.gov (United States)

    Toth, Ronald T; Mills, Brittney J; Joshi, Sangeeta B; Esfandiary, Reza; Bishop, Steven M; Middaugh, C Russell; Volkin, David B; Weis, David D

    2017-09-05

    A barrier to the use of hydrogen exchange-mass spectrometry (HX-MS) in many contexts, especially analytical characterization of various protein therapeutic candidates, is that differences in temperature, pH, ionic strength, buffering agent, or other additives can alter chemical exchange rates, making HX data gathered under differing solution conditions difficult to compare. Here, we present data demonstrating that HX chemical exchange rates can be substantially altered not only by the well-established variables of temperature and pH but also by additives including arginine, guanidine, methionine, and thiocyanate. To compensate for these additive effects, we have developed an empirical method to correct the hydrogen-exchange data for these differences. First, differences in chemical exchange rates are measured by use of an unstructured reporter peptide, YPI. An empirical chemical exchange correction factor, determined by use of the HX data from the reporter peptide, is then applied to the HX measurements obtained from a protein of interest under different solution conditions. We demonstrate that the correction is experimentally sound through simulation and in a proof-of-concept experiment using unstructured peptides under slow-exchange conditions (pD 4.5 at ambient temperature). To illustrate its utility, we applied the correction to HX-MS excipient screening data collected for a pharmaceutically relevant IgG4 mAb being characterized to determine the effects of different formulations on backbone dynamics.

  7. Minimizing Back Exchange in the Hydrogen Exchange-Mass Spectrometry Experiment

    Science.gov (United States)

    Walters, Benjamin T.; Ricciuti, Alec; Mayne, Leland; Englander, S. Walter

    2012-12-01

    The addition of mass spectrometry (MS) analysis to the hydrogen exchange (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back exchange of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back exchange (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back exchange due to intrinsic amino acid HX rate differences. Accordingly, large back exchange leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back exchange by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back exchange by ~2 %, while sacrificing S/N and peptide count. An unexpected dependence of back exchange on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90 % ± 5 %.

  8. Minimizing back exchange in the hydrogen exchange-mass spectrometry experiment.

    Science.gov (United States)

    Walters, Benjamin T; Ricciuti, Alec; Mayne, Leland; Englander, S Walter

    2012-12-01

    The addition of mass spectrometry (MS) analysis to the hydrogen exchange (HX) proteolytic fragmentation experiment extends powerful HX methodology to the study of large biologically important proteins. A persistent problem is the degradation of HX information due to back exchange of deuterium label during the fragmentation-separation process needed to prepare samples for MS measurement. This paper reports a systematic analysis of the factors that influence back exchange (solution pH, ionic strength, desolvation temperature, LC column interaction, flow rates, system volume). The many peptides exhibit a range of back exchange due to intrinsic amino acid HX rate differences. Accordingly, large back exchange leads to large variability in D-recovery from one residue to another as well as one peptide to another that cannot be corrected for by reference to any single peptide-level measurement. The usual effort to limit back exchange by limiting LC time provides little gain. Shortening the LC elution gradient by 3-fold only reduced back exchange by ~2%, while sacrificing S/N and peptide count. An unexpected dependence of back exchange on ionic strength as well as pH suggests a strategy in which solution conditions are changed during sample preparation. Higher salt should be used in the first stage of sample preparation (proteolysis and trapping) and lower salt (<20 mM) and pH in the second stage before electrospray injection. Adjustment of these and other factors together with recent advances in peptide fragment detection yields hundreds of peptide fragments with D-label recovery of 90% ± 5%.

  9. On line determination of deuterium in hydrogen water exchange reaction by mass spectrometry. IRP-10

    International Nuclear Information System (INIS)

    Sharma, J.D.; Alphonse, K.P.; Mishra, Sushama; Prabhu, S.A.; Mohan, Sadhana; Tangri, V.K.

    2007-01-01

    The Deuterium (D)/Hydrogen (H) analysis at low Concentration is generally carried out by Mass Spectrometry. Mass Spectrometer is specially designed for the measurement of Mass 2 and 3 ratio. The Deuterium analysis of water and hydrogen in concentration range of a few ppm to about 1% plays an important role in the Heavy Water Production Plants. For the enrichment of the Deuterium concentration in H 2 O by H 2 - H 2 O exchange a catalyst is essential as reaction is relatively slow. Heavy Water Division has developed in house Platinum based catalyst for the isotopic exchange of Hydrogen and Water

  10. Time-resolved pulsed hydrogen/deuterium exchange mass spectrometry probes gaseous proteins structural kinetics.

    Science.gov (United States)

    Rajabi, Khadijeh

    2015-01-01

    A pulsed hydrogen/deuterium exchange (HDX) method has been developed for rapid monitoring of the exchange kinetics of protein ions with D2O a few milliseconds after electrospray ionization (ESI). The stepwise gradual evolution of HDX of multiply charged protein ions was monitored using the pulsed HDX mass spectrometry technique. Upon introducing a very short pulse of D2O (in the μs to ms time scale) into the linear ion trap (LIT) of a time-of-flight (TOF) mass spectrometer, bimodal distributions were detected for the ions of cytochrome c and ubiquitin. Mechanistic details of HDX reactions for ubiquitin and cytochrome c in the gas phase were uncovered and the structural transitions were followed by analyzing the kinetics of HDX.

  11. Hydrogen deuterium exchange mass spectrometry in biopharmaceutical discovery and development – A review

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Bin, E-mail: dengbin@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada); Lento, Cristina, E-mail: clento@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada); Wilson, Derek J., E-mail: dkwilson@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada)

    2016-10-12

    Protein therapeutics have emerged as a major class of biopharmaceuticals over the past several decades, a trend that has motivated the advancement of bioanalytical technologies for protein therapeutic characterization. Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful and sensitive technique that can probe the higher order structure of proteins and has been used in the assessment and development of monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs) and biosimilar antibodies. It has also been used to quantify protein-ligand, protein-receptor and other protein-protein interactions involved in signaling pathways. In manufacturing and development, HDX-MS can validate storage formulations and manufacturing processes for various biotherapeutics. Currently, HDX-MS is being refined to provide additional coverage, sensitivity and structural specificity and implemented on the millisecond timescale to reveal residual structure and dynamics in disordered domains and intrinsically disordered proteins. - Highlights: • The pharmaceuticals industry is increasingly shifting to protein therapeutics. • Hydrogen deuterium exchange mass spectrometry is uniquely well suited to support biopharmaceutical development. • Applications for hydrogen deuterium exchange span drug discovery, development and manufacturing. • Future developments will allow improved sensitivity, structural resolution and a broader range of dynamics to be monitored.

  12. Hydrogen deuterium exchange mass spectrometry in biopharmaceutical discovery and development – A review

    International Nuclear Information System (INIS)

    Deng, Bin; Lento, Cristina; Wilson, Derek J.

    2016-01-01

    Protein therapeutics have emerged as a major class of biopharmaceuticals over the past several decades, a trend that has motivated the advancement of bioanalytical technologies for protein therapeutic characterization. Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful and sensitive technique that can probe the higher order structure of proteins and has been used in the assessment and development of monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs) and biosimilar antibodies. It has also been used to quantify protein-ligand, protein-receptor and other protein-protein interactions involved in signaling pathways. In manufacturing and development, HDX-MS can validate storage formulations and manufacturing processes for various biotherapeutics. Currently, HDX-MS is being refined to provide additional coverage, sensitivity and structural specificity and implemented on the millisecond timescale to reveal residual structure and dynamics in disordered domains and intrinsically disordered proteins. - Highlights: • The pharmaceuticals industry is increasingly shifting to protein therapeutics. • Hydrogen deuterium exchange mass spectrometry is uniquely well suited to support biopharmaceutical development. • Applications for hydrogen deuterium exchange span drug discovery, development and manufacturing. • Future developments will allow improved sensitivity, structural resolution and a broader range of dynamics to be monitored.

  13. SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium Exchange Mass Spectrometry.

    Science.gov (United States)

    Villar, Maria T; Miller, Danny E; Fenton, Aron W; Artigues, Antonio

    2010-01-01

    Deuterium/hydrogen exchange in combination with mass spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium exchange that interfaces the HPLC pumps with a mass spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and mass analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back exchange during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have exchanged hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide.

  14. 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...

  15. Protein hydrogen exchange measured at single-residue resolution by electron transfer dissociation mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper D; Zehl, Martin; Jensen, Ole Nørregaard

    2009-01-01

    Because of unparalleled sensitivity and tolerance to protein size, mass spectrometry (MS) has become a popular method for measuring the solution hydrogen (1H/2H) exchange (HX) of biologically relevant protein states. While incorporated deuterium can be localized to different regions by pepsin....... The deuterium labeling pattern of beta2-microglobulin is retained in the gaseous fragment ions by employing mild declustering conditions for electrospray ionization. A recently developed model peptide is used to arrive at such ion source declustering conditions that prevent the occurrence of intramolecular gas...

  16. Electrochemical reduction of disulfide-containing proteins for hydrogen/deuterium exchange monitored by mass spectrometry

    DEFF Research Database (Denmark)

    Mysling, Simon; Salbo, Rune; Ploug, Michael

    2014-01-01

    Characterization of disulfide bond-containing proteins by hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS) requires reduction of the disulfide bonds under acidic and cold conditions, where the amide hydrogen exchange reaction is quenched (pH 2.5, 0 °C). The reduction typically...... of TCEP. In the present study, we explore the feasibility of using electrochemical reduction as a substitute for TCEP in HDX-MS analyses. Our results demonstrate that efficient disulfide bond reduction is readily achieved by implementing an electrochemical cell into the HDX-MS workflow. We also identify...... some challenges in using electrochemical reduction in HDX-MS analyses and provide possible conditions to attenuate these limitations. For example, high salt concentrations hamper disulfide bond reduction, necessitating additional dilution of the sample with aqueous acidic solution at quench conditions....

  17. Spatially resolved protein hydrogen exchange measured by subzero-cooled chip-based nanoelectrospray ionization tandem mass spectrometry

    DEFF Research Database (Denmark)

    Amon, Sabine; Trelle, Morten B; Jensen, Ole N

    2012-01-01

    . After a given period of deuteration, the exchange reaction is quenched by acidification (pH 2.5) and cooling (0 °C) and the deuterated protein (or a digest thereof) is analyzed by mass spectrometry. The unavoidable loss of deuterium (back-exchange) that occurs under quench conditions is undesired...... as it leads to loss of information. Here we describe the successful application of a chip-based nanoelectrospray ionization mass spectrometry top-down fragmentation approach based on cooling to subzero temperature (-15 °C) which reduces the back-exchange at quench conditions to very low levels. For example...

  18. Hydrogen Exchange Mass Spectrometry of Functional Membrane-bound Chemotaxis Receptor Complexes

    Science.gov (United States)

    Koshy, Seena S.; Eyles, Stephen J.; Weis, Robert M.; Thompson, Lynmarie K.

    2014-01-01

    The transmembrane signaling mechanism of bacterial chemotaxis receptors is thought to involve changes in receptor conformation and dynamics. The receptors function in ternary complexes with two other proteins, CheA and CheW, that form extended membrane-bound arrays. Previous studies have shown that attractant binding induces a small (~2 Å) piston displacement of one helix of the periplasmic and transmembrane domains towards the cytoplasm, but it is not clear how this signal propagates through the cytoplasmic domain to control the kinase activity of the CheA bound at the membrane-distal tip, nearly 200 Å away. The cytoplasmic domain has been shown to be highly dynamic, which raises the question of how a small piston motion could propagate through a dynamic domain to control CheA kinase activity. To address this, we have developed a method for measuring dynamics of the receptor cytoplasmic fragment (CF) in functional complexes with CheA and CheW. Hydrogen exchange mass spectrometry (HDX-MS) measurements of global exchange of CF demonstrate that CF exhibits significantly slower exchange in functional complexes than in solution. Since the exchange rates in functional complexes are comparable to that of other proteins of similar structure, the CF appears to be a well-structured protein within these complexes, which is compatible with its role in propagating a signal that appears to be a tiny conformational change in the periplasmic and transmembrane domains of the receptor. We also demonstrate the feasibility of this protocol for local exchange measurements, by incorporating a pepsin digest step to produce peptides with 87% sequence coverage and only 20% back exchange. This method extends HDX-MS to membrane-bound functional complexes without detergents that may perturb the stability or structure of the system. PMID:24274333

  19. Ion Mobility Spectrometry-Mass Spectrometry Coupled with Gas-Phase Hydrogen/Deuterium Exchange for Metabolomics Analyses

    Science.gov (United States)

    Maleki, Hossein; Karanji, Ahmad K.; Majuta, Sandra; Maurer, Megan M.; Valentine, Stephen J.

    2018-02-01

    Ion mobility spectrometry-mass spectrometry (IMS-MS) in combination with gas-phase hydrogen/deuterium exchange (HDX) and collision-induced dissociation (CID) is evaluated as an analytical method for small-molecule standard and mixture characterization. Experiments show that compound ions exhibit unique HDX reactivities that can be used to distinguish different species. Additionally, it is shown that gas-phase HDX kinetics can be exploited to provide even further distinguishing capabilities by using different partial pressures of reagent gas. The relative HDX reactivity of a wide variety of molecules is discussed in light of the various molecular structures. Additionally, hydrogen accessibility scoring (HAS) and HDX kinetics modeling of candidate ( in silico) ion structures is utilized to estimate the relative ion conformer populations giving rise to specific HDX behavior. These data interpretation methods are discussed with a focus on developing predictive tools for HDX behavior. Finally, an example is provided in which ion mobility information is supplemented with HDX reactivity data to aid identification efforts of compounds in a metabolite extract.

  20. Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling

    Science.gov (United States)

    Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.

    2016-03-01

    Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M - 2H]2- ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites, whereas for the more diffuse [M - 3H]3- ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M - 2H]2- ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M - 3H]3- ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.

  1. Real-time hydrogen/deuterium exchange kinetics via supercharged electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Sterling, Harry J; Williams, Evan R

    2010-11-01

    Amide hydrogen/deuterium exchange (HDX) rate constants of bovine ubiquitin in an ammonium acetate solution containing 1% of the electrospray ionization (ESI) "supercharging" reagent m-nitrobenzyl alcohol (m-NBA) were obtained using top-down, electron transfer dissociation (ETD) tandem mass spectrometry (MS). The supercharging reagent replaces the acid and temperature "quench" step in the conventional MS approach to HDX experiments by causing rapid protein denaturation to occur in the ESI droplet. The higher charge state ions that are produced with m-NBA are more unfolded, as measured by ion mobility, and result in higher fragmentation efficiency and higher sequence coverage with ETD. Single amino acid resolution was obtained for 44 of 72 exchangeable amide sites, and summed kinetic data were obtained for regions of the protein where adjacent fragment ions were not observed, resulting in an overall spatial resolution of 1.3 residues. Comparison of these results with previous values from NMR indicates that the supercharging reagent does not cause significant structural changes to the protein in the initial ESI solution and that scrambling or back-exchange is minimal. This new method for top-down HDX-MS enables real-time kinetic data measurements under physiological conditions, similar to those obtained using NMR, with comparable spatial resolution and significantly better sensitivity.

  2. Conformational Assessment of Adnectin and Adnectin-Drug Conjugate by Hydrogen/Deuterium Exchange Mass Spectrometry

    Science.gov (United States)

    Huang, Richard Y.-C.; O'Neil, Steven R.; Lipovšek, Daša; Chen, Guodong

    2018-05-01

    Higher-order structure (HOS) characterization of therapeutic protein-drug conjugates for comprehensive assessment of conjugation-induced protein conformational changes is an important consideration in the biopharmaceutical industry to ensure proper behavior of protein therapeutics. In this study, conformational dynamics of a small therapeutic protein, adnectin 1, together with its drug conjugate were characterized by hydrogen/deuterium exchange mass spectrometry (HDX-MS) with different spatial resolutions. Top-down HDX allows detailed assessment of the residue-level deuterium content in the payload conjugation region. HDX-MS dataset revealed the ability of peptide-based payload/linker to retain deuterium in HDX experiments. Combined results from intact, top-down, and bottom-up HDX indicated no significant conformational changes of adnectin 1 upon payload conjugation. [Figure not available: see fulltext.

  3. Dynamics of urokinase receptor interaction with Peptide antagonists studied by amide hydrogen exchange and mass spectrometry

    DEFF Research Database (Denmark)

    Jørgensen, Thomas J D; Gårdsvoll, Henrik; Danø, Keld

    2004-01-01

    Using amide hydrogen exchange combined with electrospray ionization mass spectrometry, we have in this study determined the number of amide hydrogens on several peptides that become solvent-inaccessible as a result of their high-affinity interaction with the urokinase-type plasminogen activator...... receptor (uPAR). These experiments reveal that at least six out of eight amide hydrogens in a synthetic nine-mer peptide antagonist (AE105) become sequestered upon engagement in uPAR binding. Various uPAR mutants with decreased affinity for this peptide antagonist gave similar results, thereby indicating...... that deletion of the favorable interactions involving the side chains of these residues in uPAR does not affect the number of hydrogen bonds established by the main chain of the peptide ligand. The isolated growth factor-like domain (GFD) of the cognate serine protease ligand for uPAR showed 11 protected amide...

  4. Conformational analysis of g protein-coupled receptor signaling by hydrogen/deuterium exchange mass spectrometry.

    Science.gov (United States)

    Li, Sheng; Lee, Su Youn; Chung, Ka Young

    2015-01-01

    Conformational change and protein-protein interactions are two major mechanisms of membrane protein signal transduction, including G protein-coupled receptors (GPCRs). Upon agonist binding, GPCRs change conformation, resulting in interaction with downstream signaling molecules such as G proteins. To understand the precise signaling mechanism, studies have investigated the structural mechanism of GPCR signaling using X-ray crystallography, nuclear magnetic resonance (NMR), or electron paramagnetic resonance. In addition to these techniques, hydrogen/deuterium exchange mass spectrometry (HDX-MS) has recently been used in GPCR studies. HDX-MS measures the rate at which peptide amide hydrogens exchange with deuterium in the solvent. Exposed or flexible regions have higher exchange rates and excluded or ordered regions have lower exchange rates. Therefore, HDX-MS is a useful tool for studying protein-protein interfaces and conformational changes after protein activation or protein-protein interactions. Although HDX-MS does not give high-resolution structures, it analyzes protein conformations that are difficult to study with X-ray crystallography or NMR. Furthermore, conformational information from HDX-MS can help in the crystallization of X-ray crystallography by suggesting highly flexible regions. Interactions between GPCRs and downstream signaling molecules are not easily analyzed by X-ray crystallography or NMR because of the large size of the GPCR-signaling molecule complexes, hydrophobicity, and flexibility of GPCRs. HDX-MS could be useful for analyzing the conformational mechanism of GPCR signaling. In this chapter, we discuss details of HDX-MS for analyzing GPCRs using the β2AR-G protein complex as a model system. © 2015 Elsevier Inc. All rights reserved.

  5. Platform dependencies in bottom-up hydrogen/deuterium exchange mass spectrometry.

    Science.gov (United States)

    Burns, Kyle M; Rey, Martial; Baker, Charles A H; Schriemer, David C

    2013-02-01

    Hydrogen-deuterium exchange mass spectrometry is an important method for protein structure-function analysis. The bottom-up approach uses protein digestion to localize deuteration to higher resolution, and the essential measurement involves centroid mass determinations on a very large set of peptides. In the course of evaluating systems for various projects, we established two (HDX-MS) platforms that consisted of a FT-MS and a high-resolution QTOF mass spectrometer, each with matched front-end fluidic systems. Digests of proteins spanning a 20-110 kDa range were deuterated to equilibrium, and figures-of-merit for a typical bottom-up (HDX-MS) experiment were compared for each platform. The Orbitrap Velos identified 64% more peptides than the 5600 QTOF, with a 42% overlap between the two systems, independent of protein size. Precision in deuterium measurements using the Orbitrap marginally exceeded that of the QTOF, depending on the Orbitrap resolution setting. However, the unique nature of FT-MS data generates situations where deuteration measurements can be inaccurate, because of destructive interference arising from mismatches in elemental mass defects. This is shown through the analysis of the peptides common to both platforms, where deuteration values can be as low as 35% of the expected values, depending on FT-MS resolution, peptide length and charge state. These findings are supported by simulations of Orbitrap transients, and highlight that caution should be exercised in deriving centroid mass values from FT transients that do not support baseline separation of the full isotopic composition.

  6. qcML: an exchange format for quality control metrics from mass spectrometry experiments.

    Science.gov (United States)

    Walzer, Mathias; Pernas, Lucia Espona; Nasso, Sara; Bittremieux, Wout; Nahnsen, Sven; Kelchtermans, Pieter; Pichler, Peter; van den Toorn, Henk W P; Staes, An; Vandenbussche, Jonathan; Mazanek, Michael; Taus, Thomas; Scheltema, Richard A; Kelstrup, Christian D; Gatto, Laurent; van Breukelen, Bas; Aiche, Stephan; Valkenborg, Dirk; Laukens, Kris; Lilley, Kathryn S; Olsen, Jesper V; Heck, Albert J R; Mechtler, Karl; Aebersold, Ruedi; Gevaert, Kris; Vizcaíno, Juan Antonio; Hermjakob, Henning; Kohlbacher, Oliver; Martens, Lennart

    2014-08-01

    Quality control is increasingly recognized as a crucial aspect of mass spectrometry based proteomics. Several recent papers discuss relevant parameters for quality control and present applications to extract these from the instrumental raw data. What has been missing, however, is a standard data exchange format for reporting these performance metrics. We therefore developed the qcML format, an XML-based standard that follows the design principles of the related mzML, mzIdentML, mzQuantML, and TraML standards from the HUPO-PSI (Proteomics Standards Initiative). In addition to the XML format, we also provide tools for the calculation of a wide range of quality metrics as well as a database format and interconversion tools, so that existing LIMS systems can easily add relational storage of the quality control data to their existing schema. We here describe the qcML specification, along with possible use cases and an illustrative example of the subsequent analysis possibilities. All information about qcML is available at http://code.google.com/p/qcml. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. qcML: An Exchange Format for Quality Control Metrics from Mass Spectrometry Experiments*

    Science.gov (United States)

    Walzer, Mathias; Pernas, Lucia Espona; Nasso, Sara; Bittremieux, Wout; Nahnsen, Sven; Kelchtermans, Pieter; Pichler, Peter; van den Toorn, Henk W. P.; Staes, An; Vandenbussche, Jonathan; Mazanek, Michael; Taus, Thomas; Scheltema, Richard A.; Kelstrup, Christian D.; Gatto, Laurent; van Breukelen, Bas; Aiche, Stephan; Valkenborg, Dirk; Laukens, Kris; Lilley, Kathryn S.; Olsen, Jesper V.; Heck, Albert J. R.; Mechtler, Karl; Aebersold, Ruedi; Gevaert, Kris; Vizcaíno, Juan Antonio; Hermjakob, Henning; Kohlbacher, Oliver; Martens, Lennart

    2014-01-01

    Quality control is increasingly recognized as a crucial aspect of mass spectrometry based proteomics. Several recent papers discuss relevant parameters for quality control and present applications to extract these from the instrumental raw data. What has been missing, however, is a standard data exchange format for reporting these performance metrics. We therefore developed the qcML format, an XML-based standard that follows the design principles of the related mzML, mzIdentML, mzQuantML, and TraML standards from the HUPO-PSI (Proteomics Standards Initiative). In addition to the XML format, we also provide tools for the calculation of a wide range of quality metrics as well as a database format and interconversion tools, so that existing LIMS systems can easily add relational storage of the quality control data to their existing schema. We here describe the qcML specification, along with possible use cases and an illustrative example of the subsequent analysis possibilities. All information about qcML is available at http://code.google.com/p/qcml. PMID:24760958

  8. Probing Conformational Dynamics of Tau Protein by Hydrogen/Deuterium Exchange Mass Spectrometry

    Science.gov (United States)

    Huang, Richard Y.-C.; Iacob, Roxana E.; Sankaranarayanan, Sethu; Yang, Ling; Ahlijanian, Michael; Tao, Li; Tymiak, Adrienne A.; Chen, Guodong

    2018-01-01

    Fibrillization of the microtubule-associated protein tau has been recognized as one of the signature pathologies of the nervous system in Alzheimer's disease, progressive supranuclear palsy, and other tauopathies. The conformational transition of tau in the fibrillization process, tau monomer to soluble aggregates to fibrils in particular, remains unclear. Here we report on the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) in combination with other biochemical approaches, including Thioflavin S fluorescence measurements, enzyme-linked immunosorbent assay (ELISA), and Western blotting to understand the heparin-induced tau's fibrillization. HDX-MS studies including anti-tau antibody epitope mapping experiments provided molecular level details of the full-length tau's conformational dynamics and its regional solvent accessibility upon soluble aggregates formation. The results demonstrate that R3 region in the full-length tau's microtubule binding repeat region (MTBR) is stabilized in the aggregation process, leaving both N and C terminal regions to be solvent exposed in the soluble aggregates and fibrils. The findings also illustrate the practical utility of orthogonal analytical methodologies for the characterization of protein higher order structure. [Figure not available: see fulltext.

  9. Probing the Binding Interfaces of Protein Complexes Using Gas-Phase H/D Exchange Mass Spectrometry

    DEFF Research Database (Denmark)

    Mistarz, Ulrik H; Brown, Jeffery M; Haselmann, Kim F

    2016-01-01

    Fast gas-phase hydrogen/deuterium exchange mediated by ND3 gas and measured by mass spectrometry (gas-phase HDX-MS) is a largely unharnessed, fast, and sensitive method for probing primary- and higher-order polypeptide structure. Labeling of heteroatom-bound non-amide hydrogens in a sub-milliseco......Fast gas-phase hydrogen/deuterium exchange mediated by ND3 gas and measured by mass spectrometry (gas-phase HDX-MS) is a largely unharnessed, fast, and sensitive method for probing primary- and higher-order polypeptide structure. Labeling of heteroatom-bound non-amide hydrogens in a sub......-millisecond time span after electrospray ionization by ND3 gas can provide structural insights into protein conformers present in solution. Here, we have explored the use of gas-phase HDX-MS for probing the higher-order structure and binding interfaces of protein complexes originating from native solution...

  10. Calcium isotope effects in ion exchange electromigration and calcium isotope analysis by thermo-ionization mass spectrometry

    International Nuclear Information System (INIS)

    Fujii, Y.; Hoshi, J.; Iwamoto, H.; Okamoto, M.; Kakihana, H.

    1985-01-01

    Calcium ions were made to electromigrate along a cation exchange membrane. The abundance ratios of the calcium isotopes (Ca-40, 42, 43, 44, 48) in the migrated bands were measured by thermo-ionization mass spectrometry. The lighter isotopes were enriched in the front part of the migrated band. The increments in the isotope abundance ratios were found to be proportional to the mass difference of the isotopes. The observed epsilon-values per unit mass difference (epsilon/ΔM) were 1.26 x 10 -4 (at 20 0 C), 1.85 x 10 -4 (at 25 0 C) and 2.4 x 10 -4 (at 40 0 C). The mass spectrometry was improved by using a low temperature for the evaporation of CaI 2 . (orig.)

  11. Gas-phase fragmentation of peptides to increase the spatial resolution of the Hydrogen Exchange Mass Spectrometry experiment

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    are produced after precursor ion selection and thus do not add complexity to the LC-MS analysis. The key to obtaining optimal spatial resolution in a hydrogen exchange mass spectrometry (HX-MS) experiment is the fragmentation efficiency. This chapter discusses common fragmentation techniques like collision....../D scrambling, thus making them suitable for HX applications. By combining the classic bottom-up HX-MS workflow with gas-phase fragmentation by ETD, detailed information on protein HX can be obtained....

  12. Effective Removal of Nonionic Detergents in Protein Mass Spectrometry, Hydrogen/Deuterium Exchange, and Proteomics

    Czech Academy of Sciences Publication Activity Database

    Rey, M.; Mrázek, H.; Pompach, Petr; Novák, P.; Pelosi, L.; Brandolin, G.; Forest, E.; Havlíček, Vladimír; Man, P.

    2010-01-01

    Roč. 82, č. 12 (2010), s. 5107-5116 ISSN 0003-2700 R&D Projects: GA AV ČR KJB500200612; GA MŠk LC545 Institutional research plan: CEZ:AV0Z50200510 Keywords : mass spectrometry * proteomics * peptides Subject RIV: CE - Biochemistry Impact factor: 5.874, year: 2010

  13. qcML : an exchange format for quality control metrics from mass spectrometry experiments

    NARCIS (Netherlands)

    Walzer, Mathias; Pernas, Lucia Espona; Nasso, Sara; Bittremieux, Wout; Nahnsen, Sven; Kelchtermans, Pieter; Pichler, Peter; van den Toorn, Henk W P|info:eu-repo/dai/nl/31093205X; Staes, An; Vandenbussche, Jonathan; Mazanek, Michael; Taus, Thomas; Scheltema, Richard A; Kelstrup, Christian D; Gatto, Laurent; van Breukelen, Bas|info:eu-repo/dai/nl/244219087; Aiche, Stephan; Valkenborg, Dirk; Laukens, Kris; Lilley, Kathryn S; Olsen, Jesper V; Heck, Albert J R|info:eu-repo/dai/nl/105189332; Mechtler, Karl; Aebersold, Ruedi; Gevaert, Kris; Vizcaíno, Juan Antonio; Hermjakob, Henning; Kohlbacher, Oliver; Martens, Lennart

    Quality control is increasingly recognized as a crucial aspect of mass spectrometry based proteomics. Several recent papers discuss relevant parameters for quality control and present applications to extract these from the instrumental raw data. What has been missing, however, is a standard data

  14. Protein structural dynamics at the gas/water interface examined by hydrogen exchange mass spectrometry.

    Science.gov (United States)

    Xiao, Yiming; Konermann, Lars

    2015-08-01

    Gas/water interfaces (such as air bubbles or foam) are detrimental to the stability of proteins, often causing aggregation. This represents a potential problem for industrial processes, for example, the production and handling of protein drugs. Proteins possess surfactant-like properties, resulting in a high affinity for gas/water interfaces. The tendency of previously buried nonpolar residues to maximize contact with the gas phase can cause significant structural distortion. Most earlier studies in this area employed spectroscopic tools that could only provide limited information. Here we use hydrogen/deuterium exchange (HDX) mass spectrometry (MS) for probing the conformational dynamics of the model protein myoglobin (Mb) in the presence of N(2) bubbles. HDX/MS relies on the principle that unfolded and/or highly dynamic regions undergo faster deuteration than tightly folded segments. In bubble-free solution Mb displays EX2 behavior, reflecting the occurrence of short-lived excursions to partially unfolded conformers. A dramatically different behavior is seen in the presence of N(2) bubbles; EX2 dynamics still take place, but in addition the protein shows EX1 behavior. The latter results from interconversion of the native state with conformers that are globally unfolded and long-lived. These unfolded species likely correspond to Mb that is adsorbed to the surface of gas bubbles. N(2) sparging also induces aggregation. To explain the observed behavior we propose a simple model, that is, "semi-unfolded" ↔ "native" ↔ "globally unfolded" → "aggregated". This model quantitatively reproduces the experimentally observed kinetics. To the best of our knowledge, the current study marks the first exploration of surface denaturation phenomena by HDX/MS. © 2015 The Protein Society.

  15. 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...

  16. Slow Histidine H/D Exchange Protocol for Thermodynamic Analysis of Protein Folding and Stability using Mass Spectrometry

    OpenAIRE

    Tran, Duc T.; Banerjee, Sambuddha; Alayash, Abdu I.; Crumbliss, Alvin L.; Fitzgerald, Michael C.

    2012-01-01

    Described here is a mass spectrometry based protocol to study the thermodynamic stability of proteins and protein-ligand complexes using the slow H/D exchange reaction of the imidazole C2 proton in histidine side chains. The protocol, which involves evaluating the denaturant dependence of this slow H/D exchange reaction in proteins, allows the global and/or subglobal unfolding/refolding properties of proteins and protein-ligand complexes to be probed. The protocol is developed using several m...

  17. U/Th dating by SHRIMP RG ion-microprobe mass spectrometry using single ion-exchange beads

    Science.gov (United States)

    Bischoff, J.L.; Wooden, J.; Murphy, F.; Williams, Ross W.

    2005-01-01

    We present a new analytical method for U-series isotopes using the SHRIMP RG (Sensitive High mass Resolution Ion MicroProbe) mass spectrometer that utilizes the preconcentration of the U-series isotopes from a sample onto a single ion-exchange bead. Ion-microprobe mass spectrometry is capable of producing Th ionization efficiencies in excess of 2%. Analytical precision is typically better than alpha spectroscopy, but not as good as thermal ionization mass spectroscopy (TIMS) and inductively coupled plasma multicollector mass spectrometry (ICP-MS). Like TIMS and ICP-MS the method allows analysis of small samples sizes, but also adds the advantage of rapidity of analysis. A major advantage of ion-microprobe analysis is that U and Th isotopes are analyzed in the same bead, simplifying the process of chemical separation. Analytical time on the instrument is ???60 min per sample, and a single instrument-loading can accommodate 15-20 samples to be analyzed in a 24-h day. An additional advantage is that the method allows multiple reanalyses of the same bead and that samples can be archived for reanalysis at a later time. Because the ion beam excavates a pit only a few ??m deep, the mount can later be repolished and reanalyzed numerous times. The method described of preconcentrating a low concentration sample onto a small conductive substrate to allow ion-microprobe mass spectrometry is potentially applicable to many other systems. Copyright ?? 2005 Elsevier Ltd.

  18. Application of Atmospheric Pressure Photoionization H/D-exchange Mass Spectrometry for Speciation of Sulfur-containing Compounds.

    Science.gov (United States)

    Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Ha, Ji-Hyoung; Kim, Sunghwan

    2017-08-01

    Herein we report the observation of atmospheric pressure in-source hydrogen-deuterium exchange (HDX) of thiol group for the first time. The HDX for thiol group was optimized for positive atmospheric pressure photoionization (APPI) mass spectrometry (MS). The optimized HDX-MS was applied for 31 model compounds (thiols, thiophenes, and sulfides) to demonstrate that exchanged peaks were observed only for thiols. The optimized method has been successfully applied to the isolated fractions of sulfur-rich oil samples. The exchange of one and two thiol hydrogens with deuterium was observed in the thiol fraction; no HDX was observed in the other fractions. Thus, the results presented in this study demonstrate that the HDX-MS method using APPI ionization source can be effective for speciation of sulfur compounds. This method has the potential to be used to access corrosion problems caused by thiol-containing compounds. Graphical Abstract ᅟ.

  19. Improved protein hydrogen/deuterium exchange mass spectrometry platform with fully automated data processing.

    Science.gov (United States)

    Zhang, Zhongqi; Zhang, Aming; Xiao, Gang

    2012-06-05

    Protein hydrogen/deuterium exchange (HDX) followed by protease digestion and mass spectrometric (MS) analysis is accepted as a standard method for studying protein conformation and conformational dynamics. In this article, an improved HDX MS platform with fully automated data processing is described. The platform significantly reduces systematic and random errors in the measurement by introducing two types of corrections in HDX data analysis. First, a mixture of short peptides with fast HDX rates is introduced as internal standards to adjust the variations in the extent of back exchange from run to run. Second, a designed unique peptide (PPPI) with slow intrinsic HDX rate is employed as another internal standard to reflect the possible differences in protein intrinsic HDX rates when protein conformations at different solution conditions are compared. HDX data processing is achieved with a comprehensive HDX model to simulate the deuterium labeling and back exchange process. The HDX model is implemented into the in-house developed software MassAnalyzer and enables fully unattended analysis of the entire protein HDX MS data set starting from ion detection and peptide identification to final processed HDX output, typically within 1 day. The final output of the automated data processing is a set (or the average) of the most possible protection factors for each backbone amide hydrogen. The utility of the HDX MS platform is demonstrated by exploring the conformational transition of a monoclonal antibody by increasing concentrations of guanidine.

  20. Rapid Conformational Analysis of Protein Drugs in Formulation by Hydrogen/Deuterium Exchange Mass Spectrometry (HDX-MS)

    DEFF Research Database (Denmark)

    Esmail Nazari, Zeinab; van de Weert, Marco; Bou-Assaf, George

    2016-01-01

    Hydrogen Deuterium Exchange coupled to Mass Spectrometry (HDX-MS) has become an established method for analysis of protein higher-order structure. Here, we use HDX-MS methodology based on manual Solid-Phase Extraction (SPE) to allow fast and simplified conformational analysis of proteins under...... pharmaceutically relevant formulation conditions. Of significant practical utility, the methodology allows global HDX-MS analyses to be performed without refrigeration or external cooling of the setup. In Mode 1, we used DMSO-containing solvents for SPE, allowing the HDX-MS analysis to be performed at acceptable...... in formulation, using an internal HDX reference peptide (P7I) to control for any sample-to-sample variations in back exchange. Advantages of the methodology include low sample use, optimized excipient removal using multiple solvents, and fast data acquisition. Our results indicate that the SPE-HDX-MS system can...

  1. Investigating the Interaction between the Neonatal Fc Receptor and Monoclonal Antibody Variants by Hydrogen/Deuterium Exchange Mass Spectrometry

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Larraillet, Vincent; Schlothauer, Tilman

    2015-01-01

    The recycling of immunoglobulins by the neonatal Fc receptor (FcRn) is of crucial importance in the maintenance of antibody levels in plasma and is responsible for the long half-lives of endogenous and recombinant monoclonal antibodies. From a therapeutic point of view there is great interest...... in understanding and modulating the IgG-FcRn interaction to optimize antibody pharmacokinetics and ultimately improve efficacy and safety. Here we studied the interaction between a full-length human IgG1 and human FcRn via hydrogen/deuterium exchange mass spectrometry and targeted electron transfer dissociation...... to map sites perturbed by binding on both partners of the IgG-FcRn complex. Several regions in the antibody Fc region and the FcRn were protected from exchange upon complex formation, in good agreement with previous crystallographic studies of FcRn in complex with the Fc fragment. Interestingly, we found...

  2. KRAS G12C Drug Development: Discrimination between Switch II Pocket Configurations Using Hydrogen/Deuterium-Exchange Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jia; Harrison, Rane A.; Li, Lianbo; Zeng, Mei; Gondi, Sudershan; Scott, David; Gray, Nathanael S.; Engen, John R.; Westover, Kenneth D. (NEU); (DFCI); (UTSMC); (Harvard-Med)

    2017-09-01

    KRAS G12C, the most common RAS mutation found in non-small-cell lung cancer, has been the subject of multiple recent covalent small-molecule inhibitor campaigns including efforts directed at the guanine nucleotide pocket and separate work focused on an inducible pocket adjacent to the switch motifs. Multiple conformations of switch II have been observed, suggesting that switch II pocket (SIIP) binders may be capable of engaging a range of KRAS conformations. Here we report the use of hydrogen/deuterium-exchange mass spectrometry (HDX MS) to discriminate between conformations of switch II induced by two chemical classes of SIIP binders. We investigated the structural basis for differences in HDX MS using X-ray crystallography and discovered a new SIIP configuration in response to binding of a quinazoline chemotype. These results have implications for structure-guided drug design targeting the RAS SIIP.

  3. Time resolved investigations on biogenic trace gases exchanges using proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Karl, T.

    2000-02-01

    Volatile organic compounds (VOCs) released from vegetation, including wound-induced VOCs, can have important effects on atmospheric chemistry. The analytical methods for measuring wound-induced VOCs, especially the hexenal family of VOCs (hexenals, hexenols and hexenyl esters) but also compounds like acetaldehyde, are complicated by their chemical instability and the transient nature of their formation after leaf and stem wounding. The goal of this thesis was to assess, quantify and complement our understanding on the origin of tropospheric VOCs. This thesis demonstrates that formation and emission of hexenal family compounds can be monitored on-line using proton-transfer-reaction mass spectrometry (PTR-MS), avoiding the need for preconcentration or chromatography. These measurements revealed the rapid emission of the parent compound, (Z)-3-hexenal, within 1-2 seconds of wounding of leaves from various woody and nonwoody plants, and its metabolites including (E)-2-hexenal, hexenols and hexenyl acetates. Emission of (Z)-3-hexenal from detached, drying leaves averaged 500 μg (gram dry weight)-1. PTR-MS showed to be a useful tool for the analysis of VOC emissions resulting from grazing, herbivory, harvesting and senescing leaves. The release of reactive VOCs during lawn mowing was observed in on-line ambient air measurements in July and August 1998 in the outskirts of Innsbruck. Also obtained were data on emission rates of reactive aldehydes (hexenyl compounds) and other abundant VOCs such as methanol, acetaldehyde and acetone from drying grass in various chamber experiments. Fluxes were measured after cutting of grass using eddy covariance measurements and the micrometeorological gradient method (Obhukov-Similarity-Method). Comparison of data obtained by these different methods showed satisfactory agreement. The highest fluxes for methanol during drying were 5 mg/m2h, for (Z)-3-hexenal 1.5 mg/m2h. Experiments conducted on the Sonnblick Observatory in Fall and Winter

  4. Glycomics using mass spectrometry

    OpenAIRE

    Wuhrer, Manfred

    2013-01-01

    Mass spectrometry plays an increasingly important role in structural glycomics. This review provides an overview on currently used mass spectrometric approaches such as the characterization of glycans, the analysis of glycopeptides obtained by proteolytic cleavage of proteins and the analysis of glycosphingolipids. The given examples are demonstrating the application of mass spectrometry to study glycosylation changes associated with congenital disorders of glycosylation, lysosomal storage di...

  5. Supercritical fluid chromatography coupled with in-source atmospheric pressure ionization hydrogen/deuterium exchange mass spectrometry for compound speciation.

    Science.gov (United States)

    Cho, Yunju; Choi, Man-Ho; Kim, Byungjoo; Kim, Sunghwan

    2016-04-29

    An experimental setup for the speciation of compounds by hydrogen/deuterium exchange (HDX) with atmospheric pressure ionization while performing chromatographic separation is presented. The proposed experimental setup combines the high performance supercritical fluid chromatography (SFC) system that can be readily used as an inlet for mass spectrometry (MS) and atmospheric pressure photo ionization (APPI) or atmospheric pressure chemical ionization (APCI) HDX. This combination overcomes the limitation of an approach using conventional liquid chromatography (LC) by minimizing the amount of deuterium solvents used for separation. In the SFC separation, supercritical CO2 was used as a major component of the mobile phase, and methanol was used as a minor co-solvent. By using deuterated methanol (CH3OD), AP HDX was achieved during SFC separation. To prove the concept, thirty one nitrogen- and/or oxygen-containing standard compounds were analyzed by SFC-AP HDX MS. The compounds were successfully speciated from the obtained SFC-MS spectra. The exchange ions were observed with as low as 1% of CH3OD in the mobile phase, and separation could be performed within approximately 20min using approximately 0.24 mL of CH3OD. The results showed that SFC separation and APPI/APCI HDX could be successfully performed using the suggested method. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Fourier Transform Mass Spectrometry

    Science.gov (United States)

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

    2011-01-01

    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. PMID:21742802

  7. Fourier Transform Mass Spectrometry.

    Science.gov (United States)

    Gross, Michael L.; Rempel, Don L.

    1984-01-01

    Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

  8. Atomic mass spectrometry

    International Nuclear Information System (INIS)

    Sanz-Medel, A.

    1997-01-01

    The elemental inorganic analysis seems to be dominated today by techniques based on atomic spectrometry. After an evaluation of advantages and limitations of using mass analysers (ion detectors) versus conventional photomultipliers (photon detector) a brief review of the more popular techniques of the emerging Atomic Mass spectrometry is carried out. Their huge potential for inorganic trace analysis is such that in the future we could well witness how this end of the century and millennium marked the fall of the photons empire in Analytical Atomic Spectrometry. (Author)

  9. The origins of enhanced activity in factor VIIa analogs and the interplay between key allosteric sites revealed by hydrogen exchange mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper D; Andersen, Mette D; Olsen, Ole H

    2008-01-01

    Factor VIIa (FVIIa) circulates in the blood in a zymogen-like state. Only upon association with membrane-bound tissue factor (TF) at the site of vascular injury does FVIIa become active and able to initiate blood coagulation. Here we used hydrogen exchange monitored by mass spectrometry to invest......Factor VIIa (FVIIa) circulates in the blood in a zymogen-like state. Only upon association with membrane-bound tissue factor (TF) at the site of vascular injury does FVIIa become active and able to initiate blood coagulation. Here we used hydrogen exchange monitored by mass spectrometry...... to investigate the conformational effects of site-directed mutagenesis at key positions in FVIIa and the origins of enhanced intrinsic activity of FVIIa analogs. The differences in hydrogen exchange of two highly active variants, FVIIa(DVQ) and FVIIa(VEAY), imply that enhanced catalytic efficiency was attained...

  10. Probing conserved helical modules of portal complexes by mass spectrometry-based hydrogen/deuterium exchange.

    Science.gov (United States)

    Kang, Sebyung; Poliakov, Anton; Sexton, Jennifer; Renfrow, Matthew B; Prevelige, Peter E

    2008-09-05

    The Double-stranded DNA bacteriophage P22 has a ring-shaped dodecameric complex composed of the 84 kDa portal protein subunit that forms the central channel of the phage DNA packaging motor. The overall morphology of the P22 portal complex is similar to that of the portal complexes of Phi29, SPP1, T3, T7 phages and herpes simplex virus. Secondary structure prediction of P22 portal protein and its threading onto the crystal structure of the Phi29 portal complexes suggested that the P22 portal protein complex shares conserved helical modules that were found in the dodecameric interfaces of the Phi29 portal complex. To identify the amino acids involved in intersubunit contacts in the P22 portal ring complexes and validate the threading model, we performed comparative hydrogen/deuterium exchange analysis of monomeric and in vitro assembled portal proteins of P22 and the dodecameric Phi29 portal. Hydrogen/deuterium exchange experiments provided evidence of intersubunit interactions in the P22 portal complex similar to those in the Phi29 portal that map to the regions predicted to be conserved helical modules.

  11. Quantification of genetically modified soya using strong anion exchange chromatography and time-of-flight mass spectrometry.

    Science.gov (United States)

    Chang, Po-Chih; Reddy, P Muralidhar; Ho, Yen-Peng

    2014-09-01

    Stable-isotope dimethyl labeling was applied to the quantification of genetically modified (GM) soya. The herbicide-resistant gene-related protein 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) was labeled using a dimethyl labeling reagent, formaldehyde-H2 or -D2. The identification and quantification of CP4 EPSPS was performed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The CP4 EPSPS protein was separated from high abundance proteins using strong anion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, the tryptic peptides from the samples and reference were labeled with formaldehyde-H2 and formaldehyde-D2, respectively. The two labeled pools were mixed and analyzed using MALDI-MS. The data showed a good correlation between the peak ratio of the H- and D-labeled peptides and the GM soya percentages at 0.5, 1, 3, and 5 %, with R (2) of 0.99. The labeling reagents are readily available. The labeling experiments and the detection procedures are simple. The approach is useful for the quantification of GM soya at a level as low as 0.5 %.

  12. Hexicon 2: automated processing of hydrogen-deuterium exchange mass spectrometry data with improved deuteration distribution estimation.

    Science.gov (United States)

    Lindner, Robert; Lou, Xinghua; Reinstein, Jochen; Shoeman, Robert L; Hamprecht, Fred A; Winkler, Andreas

    2014-06-01

    Hydrogen-deuterium exchange (HDX) experiments analyzed by mass spectrometry (MS) provide information about the dynamics and the solvent accessibility of protein backbone amide hydrogen atoms. Continuous improvement of MS instrumentation has contributed to the increasing popularity of this method; however, comprehensive automated data analysis is only beginning to mature. We present Hexicon 2, an automated pipeline for data analysis and visualization based on the previously published program Hexicon (Lou et al. 2010). Hexicon 2 employs the sensitive NITPICK peak detection algorithm of its predecessor in a divide-and-conquer strategy and adds new features, such as chromatogram alignment and improved peptide sequence assignment. The unique feature of deuteration distribution estimation was retained in Hexicon 2 and improved using an iterative deconvolution algorithm that is robust even to noisy data. In addition, Hexicon 2 provides a data browser that facilitates quality control and provides convenient access to common data visualization tasks. Analysis of a benchmark dataset demonstrates superior performance of Hexicon 2 compared with its predecessor in terms of deuteration centroid recovery and deuteration distribution estimation. Hexicon 2 greatly reduces data analysis time compared with manual analysis, whereas the increased number of peptides provides redundant coverage of the entire protein sequence. Hexicon 2 is a standalone application available free of charge under http://hx2.mpimf-heidelberg.mpg.de.

  13. Hexicon 2: Automated Processing of Hydrogen-Deuterium Exchange Mass Spectrometry Data with Improved Deuteration Distribution Estimation

    Science.gov (United States)

    Lindner, Robert; Lou, Xinghua; Reinstein, Jochen; Shoeman, Robert L.; Hamprecht, Fred A.; Winkler, Andreas

    2014-06-01

    Hydrogen-deuterium exchange (HDX) experiments analyzed by mass spectrometry (MS) provide information about the dynamics and the solvent accessibility of protein backbone amide hydrogen atoms. Continuous improvement of MS instrumentation has contributed to the increasing popularity of this method; however, comprehensive automated data analysis is only beginning to mature. We present Hexicon 2, an automated pipeline for data analysis and visualization based on the previously published program Hexicon (Lou et al. 2010). Hexicon 2 employs the sensitive NITPICK peak detection algorithm of its predecessor in a divide-and-conquer strategy and adds new features, such as chromatogram alignment and improved peptide sequence assignment. The unique feature of deuteration distribution estimation was retained in Hexicon 2 and improved using an iterative deconvolution algorithm that is robust even to noisy data. In addition, Hexicon 2 provides a data browser that facilitates quality control and provides convenient access to common data visualization tasks. Analysis of a benchmark dataset demonstrates superior performance of Hexicon 2 compared with its predecessor in terms of deuteration centroid recovery and deuteration distribution estimation. Hexicon 2 greatly reduces data analysis time compared with manual analysis, whereas the increased number of peptides provides redundant coverage of the entire protein sequence. Hexicon 2 is a standalone application available free of charge under http://hx2.mpimf-heidelberg.mpg.de.

  14. Hydrogen-deuterium exchange and mass spectrometry reveal the pH-dependent conformational changes of diphtheria toxin T domain.

    Science.gov (United States)

    Li, Jing; Rodnin, Mykola V; Ladokhin, Alexey S; Gross, Michael L

    2014-11-04

    The translocation (T) domain of diphtheria toxin plays a critical role in moving the catalytic domain across the endosomal membrane. Translocation/insertion is triggered by a decrease in pH in the endosome where conformational changes of T domain occur through several kinetic intermediates to yield a final trans-membrane form. High-resolution structural studies are only applicable to the static T-domain structure at physiological pH, and studies of the T-domain translocation pathway are hindered by the simultaneous presence of multiple conformations. Here, we report the application of hydrogen-deuterium exchange mass spectrometry (HDX-MS) for the study of the pH-dependent conformational changes of the T domain in solution. Effects of pH on intrinsic HDX rates were deconvolved by converting the on-exchange times at low pH into times under our "standard condition" (pH 7.5). pH-Dependent HDX kinetic analysis of T domain clearly reveals the conformational transition from the native state (W-state) to a membrane-competent state (W(+)-state). The initial transition occurs at pH 6 and includes the destabilization of N-terminal helices accompanied by the separation between N- and C-terminal segments. The structural rearrangements accompanying the formation of the membrane-competent state expose a hydrophobic hairpin (TH8-9) to solvent, prepare it to insert into the membrane. At pH 5.5, the transition is complete, and the protein further unfolds, resulting in the exposure of its C-terminal hydrophobic TH8-9, leading to subsequent aggregation in the absence of membranes. This solution-based study complements high resolution crystal structures and provides a detailed understanding of the pH-dependent structural rearrangement and acid-induced oligomerization of T domain.

  15. Hydrogen–Deuterium Exchange and Mass Spectrometry Reveal the pH-Dependent Conformational Changes of Diphtheria Toxin T Domain

    Science.gov (United States)

    2015-01-01

    The translocation (T) domain of diphtheria toxin plays a critical role in moving the catalytic domain across the endosomal membrane. Translocation/insertion is triggered by a decrease in pH in the endosome where conformational changes of T domain occur through several kinetic intermediates to yield a final trans-membrane form. High-resolution structural studies are only applicable to the static T-domain structure at physiological pH, and studies of the T-domain translocation pathway are hindered by the simultaneous presence of multiple conformations. Here, we report the application of hydrogen–deuterium exchange mass spectrometry (HDX-MS) for the study of the pH-dependent conformational changes of the T domain in solution. Effects of pH on intrinsic HDX rates were deconvolved by converting the on-exchange times at low pH into times under our “standard condition” (pH 7.5). pH-Dependent HDX kinetic analysis of T domain clearly reveals the conformational transition from the native state (W-state) to a membrane-competent state (W+-state). The initial transition occurs at pH 6 and includes the destabilization of N-terminal helices accompanied by the separation between N- and C-terminal segments. The structural rearrangements accompanying the formation of the membrane-competent state expose a hydrophobic hairpin (TH8–9) to solvent, prepare it to insert into the membrane. At pH 5.5, the transition is complete, and the protein further unfolds, resulting in the exposure of its C-terminal hydrophobic TH8–9, leading to subsequent aggregation in the absence of membranes. This solution-based study complements high resolution crystal structures and provides a detailed understanding of the pH-dependent structural rearrangement and acid-induced oligomerization of T domain. PMID:25290210

  16. 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.

  17. Mass spectrometry in oceanography

    International Nuclear Information System (INIS)

    Aggarwal, Suresh K.

    2000-01-01

    Mass spectrometry plays an important role in oceanography for various applications. Different types of inorganic as well as organic mass spectrometric techniques are being exploited world-wide to understand the different aspects of marine science, for palaeogeography, palaeoclimatology and palaeoecology, for isotopic composition and concentrations of different elements as well as for speciation studies. The present paper reviews some of the applications of atomic mass spectrometric techniques in the area of oceanography

  18. Ambient ionization mass spectrometry

    International Nuclear Information System (INIS)

    Lebedev, A T

    2015-01-01

    Ambient ionization mass spectrometry emerged as a new scientific discipline only about ten years ago. A considerable body of information has been reported since that time. Keeping the sensitivity, performance and informativity of classical mass spectrometry methods, the new approach made it possible to eliminate laborious sample preparation procedures and triggered the development of miniaturized instruments to work directly in the field. The review concerns the theoretical foundations and design of ambient ionization methods. Their advantages and drawbacks, as well as prospects for application in chemistry, biology, medicine, environmetal analysis, etc., are discussed. The bibliography includes 194 references

  19. Recombinant immobilized rhizopuspepsin as a new tool for protein digestion in hydrogen/deuterium exchange mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Rey, M.; Man, Petr; Brandolin, G.; Forest, E.; Pelosi, L.

    2009-01-01

    Roč. 23, č. 21 (2009), s. 3431-3438 ISSN 0951-4198 Institutional research plan: CEZ:AV0Z50200510 Keywords : mass spectrometry * recombinant immobilized rhizopuspepsin * protease Subject RIV: CE - Biochemistry Impact factor: 2.695, year: 2009

  20. Hydrogen-Deuterium Exchange Mass Spectrometry Reveals Calcium Binding Properties and Allosteric Regulation of Downstream Regulatory Element Antagonist Modulator (DREAM).

    Science.gov (United States)

    Zhang, Jun; Li, Jing; Craig, Theodore A; Kumar, Rajiv; Gross, Michael L

    2017-07-18

    Downstream regulatory element antagonist modulator (DREAM) is an EF-hand Ca 2+ -binding protein that also binds to a specific DNA sequence, downstream regulatory elements (DRE), and thereby regulates transcription in a calcium-dependent fashion. DREAM binds to DRE in the absence of Ca 2+ but detaches from DRE under Ca 2+ stimulation, allowing gene expression. The Ca 2+ binding properties of DREAM and the consequences of the binding on protein structure are key to understanding the function of DREAM. Here we describe the application of hydrogen-deuterium exchange mass spectrometry (HDX-MS) and site-directed mutagenesis to investigate the Ca 2+ binding properties and the subsequent conformational changes of full-length DREAM. We demonstrate that all EF-hands undergo large conformation changes upon calcium binding even though the EF-1 hand is not capable of binding to Ca 2+ . Moreover, EF-2 is a lower-affinity site compared to EF-3 and -4 hands. Comparison of HDX profiles between wild-type DREAM and two EF-1 mutated constructs illustrates that the conformational changes in the EF-1 hand are induced by long-range structural interactions. HDX analyses also reveal a conformational change in an N-terminal leucine-charged residue-rich domain (LCD) remote from Ca 2+ -binding EF-hands. This LCD domain is responsible for the direct interaction between DREAM and cAMP response element-binding protein (CREB) and regulates the recruitment of the co-activator, CREB-binding protein. These long-range interactions strongly suggest how conformational changes transmit the Ca 2+ signal to CREB-mediated gene transcription.

  1. Effective Application of Bicelles for Conformational Analysis of G Protein-Coupled Receptors by Hydrogen/Deuterium Exchange Mass Spectrometry

    Science.gov (United States)

    Duc, Nguyen Minh; Du, Yang; Thorsen, Thor S.; Lee, Su Youn; Zhang, Cheng; Kato, Hideaki; Kobilka, Brian K.; Chung, Ka Young

    2015-05-01

    G protein-coupled receptors (GPCRs) have important roles in physiology and pathology, and 40% of drugs currently on the market target GPCRs for the treatment of various diseases. Because of their therapeutic importance, the structural mechanism of GPCR signaling is of great interest in the field of drug discovery. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is a useful tool for analyzing ligand binding sites, the protein-protein interaction interface, and conformational changes of proteins. However, its application to GPCRs has been limited for various reasons, including the hydrophobic nature of GPCRs and the use of detergents in their preparation. In the present study, we tested the application of bicelles as a means of solubilizing GPCRs for HDX-MS studies. GPCRs (e.g., β2-adrenergic receptor [β2AR], μ-opioid receptor, and protease-activated receptor 1) solubilized in bicelles produced better sequence coverage (greater than 90%) than GPCRs solubilized in n-dodecyl-β-D-maltopyranoside (DDM), suggesting that bicelles are a more effective method of solubilization for HDX-MS studies. The HDX-MS profile of β2AR in bicelles showed that transmembrane domains (TMs) undergo lower deuterium uptake than intracellular or extracellular regions, which is consistent with the fact that the TMs are highly ordered and embedded in bicelles. The overall HDX-MS profiles of β2AR solubilized in bicelles and in DDM were similar except for intracellular loop 3. Interestingly, we detected EX1 kinetics, an important phenomenon in protein dynamics, at the C-terminus of TM6 in β2AR. In conclusion, we suggest the application of bicelles as a useful method for solubilizing GPCRs for conformational analysis by HDX-MS.

  2. 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

  3. 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)

  4. 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)

  5. Hydrogen exchange mass spectrometry of bacteriorhodopsin reveals light-induced changes in the structural dynamics of a biomolecular machine.

    Science.gov (United States)

    Pan, Yan; Brown, Leonid; Konermann, Lars

    2011-12-21

    Many proteins act as molecular machines that are fuelled by a nonthermal energy source. Examples include transmembrane pumps and stator-rotor complexes. These systems undergo cyclic motions (CMs) that are being driven along a well-defined conformational trajectory. Superimposed on these CMs are thermal fluctuations (TFs) that are coupled to stochastic motions of the solvent. Here we explore whether the TFs of a molecular machine are affected by the occurrence of CMs. Bacteriorhodopsin (BR) is a light-driven proton pump that serves as a model system in this study. The function of BR is based on a photocycle that involves trans/cis isomerization of a retinal chromophore, as well as motions of transmembrane helices. Hydrogen/deuterium exchange (HDX) mass spectrometry was used to monitor the TFs of BR, focusing on the monomeric form of the protein. Comparative HDX studies were conducted under illumination and in the dark. The HDX kinetics of BR are dramatically accelerated in the presence of light. The isotope exchange rates and the number of backbone amides involved in EX2 opening transitions increase roughly 2-fold upon illumination. In contrast, light/dark control experiments on retinal-free protein produced no discernible differences. It can be concluded that the extent of TFs in BR strongly depends on photon-driven CMs. The light-induced differences in HDX behavior are ascribed to protein destabilization. Specifically, the thermodynamic stability of the dark-adapted protein is estimated to be 5.5 kJ mol(-1) under the conditions of our work. This value represents the free energy difference between the folded state F and a significantly unfolded conformer U. Illumination reduces the stability of F by 2.2 kJ mol(-1). Mechanical agitation caused by isomerization of the chromophore is transferred to the surrounding protein scaffold, and subsequently, the energy dissipates into the solvent. Light-induced retinal motions therefore act analogously to an internal heat

  6. Online Simultaneous Hydrogen/Deuterium Exchange of Multitarget Gas-Phase Molecules by Electrospray Ionization Mass Spectrometry Coupled with Gas Chromatography.

    Science.gov (United States)

    Jeong, Eun Sook; Cha, Eunju; Cha, Sangwon; Kim, Sunghwan; Oh, Han Bin; Kwon, Oh-Seung; Lee, Jaeick

    2017-11-21

    In this study, a hydrogen/deuterium (H/D) exchange method using gas chromatography-electrospray ionization/mass spectrometry (GC-ESI/MS) was first investigated as a novel tool for online H/D exchange of multitarget analytes. The GC and ESI source were combined with a homemade heated column transfer line. GC-ESI/MS-based H/D exchange occurs in an atmospheric pressure ion source as a result of reacting the gas-phase analyte eluted from GC with charged droplets of deuterium oxide infused as the ESI spray solvent. The consumption of the deuterated solvent at a flow rate of 2 μL min -1 was more economical than that in online H/D exchange methods reported to date. In-ESI-source H/D exchange by GC-ESI/MS was applied to 11 stimulants with secondary amino or hydroxyl groups. After H/D exchange, the spectra of the stimulants showed unexchanged, partially exchanged, and fully exchanged ions showing various degrees of exchange. The relative abundances corrected for naturally occurring isotopes of the fully exchanged ions of stimulants, except for etamivan, were in the range 24.3-85.5%. Methylephedrine and cyclazodone showed low H/D exchange efficiency under acidic, neutral, and basic spray solvent conditions and nonexchange for etamivan with an acidic phenolic OH group. The in-ESI-source H/D exchange efficiency by GC-ESI/MS was sufficient to determine the number of hydrogen by elucidation of fragmentation from the spectrum. Therefore, this online H/D exchange technique using GC-ESI/MS has potential as an alternative method for simultaneous H/D exchange of multitarget analytes.

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

    Science.gov (United States)

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

    2017-04-01

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

  8. 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

  9. Electron spray ionization mass spectrometry and 2D 31P NMR for monitoring 18O/16O isotope exchange and turnover rates of metabolic oligophosphates

    International Nuclear Information System (INIS)

    Nemutlu, Emirhan; Juranic, Nenad; Macura, Slobodan; Zhang, Song; Terzic, Andre; Dzeja, Petras P.; Ward, Lawrence E.; Dutta, Tumpa; Nair, K.S.

    2012-01-01

    A new method was here developed for the determination of 18 O-labeling ratios in metabolic oligophosphates, such as ATP, at different phosphoryl moieties (α-, β-, and γ-ATP) using sensitive and rapid electrospray ionization mass spectrometry (ESI-MS). The ESI-MS-based method for monitoring of 18 O/ 16 O exchange was validated with gas chromatography-mass spectrometry and 2D 31 P NMR correlation spectroscopy, the current standard methods in labeling studies. Significant correlation was found between isotopomer selective 2D 31 P NMR spectroscopy and isotopomer less selective ESI-MS method. Results demonstrate that ESI-MS provides a robust analytical platform for simultaneous determination of levels, 18 O-labeling kinetics and turnover rates of α-, β-, and γ-phosphoryls in ATP molecule. Such method is advantageous for large scale dynamic phosphometabolomic profiling of metabolic networks and acquiring information on the status of probed cellular energetic system. (orig.)

  10. Mass spectrometry in clinical chemistry

    International Nuclear Information System (INIS)

    Pettersen, J.E.

    1977-01-01

    A brief description is given of the functional elements of a mass spectrometer and of some currently employed mass spectrometric techniques, such as combined gas chromatography-mass spectrometry, mass chromatography, and selected ion monitoring. Various areas of application of mass spectrometry in clinical chemistry are discussed, such as inborn errors of metabolism and other metabolic disorders, intoxications, quantitative determinations of drugs, hormones, gases, and trace elements, and the use of isotope dilution mass spectrometry as a definitive method for the establishment of true values for concentrations of various compounds in reference sera. It is concluded that mass spectrometry is of great value in clinical chemistry. (Auth.)

  11. Affinity capture of biotinylated proteins at acidic conditions to facilitate hydrogen/deuterium exchange mass spectrometry analysis of multimeric protein complexes

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Jørgensen, Thomas J. D.; Koefoed, Klaus

    2013-01-01

    Characterization of conformational and dynamic changes associated with protein interactions can be done by hydrogen/deuterium exchange mass spectrometry (HDX-MS) by comparing the deuterium uptake in the bound and unbound state of the proteins. Investigation of local hydrogen/deuterium exchange...... in heteromultimeric protein complexes poses a challenge for the method due to the increased complexity of the mixture of peptides originating from all interaction partners in the complex. Previously, interference of peptides from one interaction partner has been removed by immobilizing the intact protein on beads...... complexes without interference of peptides originating from other interaction partners in the complex. The biotin-streptavidin strategy has been successfully implemented in a model system with two recombinant monoclonal antibodies that target nonoverlapping epitopes on the human epidermal growth factor...

  12. Qualitative and quantitative analysis of branches in dextran using high-performance anion exchange chromatography coupled to quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Yi, Lin; Ouyang, Yilan; Sun, Xue; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2015-12-04

    Dextran, a family of natural polysaccharides, consists of an α (1→6) linked-glucose main (backbone) chain having a number of branches. The determination of the types and the quantities of branches in dextran is important in understanding its various biological roles. In this study, a hyphenated method using high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to qualitative and quantitative analysis of dextran branches. A rotary cation-exchange cartridge array desalter was used for removal of salt from the HPAEC eluent making it MS compatible. MS and MS/MS were used to provide structural information on the enzymatically prepared dextran oligosaccharides. PAD provides quantitative data on the ratio of enzyme-resistant, branched dextran oligosaccharides. Both the types and degree of branching found in a variety of dextrans could be simultaneously determined online using this method. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Rapid Screening for Potential Epitopes Reactive with a Polycolonal Antibody by Solution-Phase H/D Exchange Monitored by FT-ICR Mass Spectrometry

    Science.gov (United States)

    Zhang, Qian; Noble, Kyle A.; Mao, Yuan; Young, Nicolas L.; Sathe, Shridhar K.; Roux, Kenneth H.; Marshall, Alan G.

    2013-07-01

    The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.

  14. Impurity profiling of liothyronine sodium by means of reversed phase HPLC, high resolution mass spectrometry, on-line H/D exchange and UV/Vis absorption.

    Science.gov (United States)

    Ruggenthaler, M; Grass, J; Schuh, W; Huber, C G; Reischl, R J

    2017-09-05

    For the first time, a comprehensive investigation of the impurity profile of the synthetic thyroid API (active pharmaceutical ingredient) liothyronine sodium (LT 3 Na) was performed by using reversed phase HPLC and advanced structural elucidation techniques including high resolution tandem mass spectrometry (HRMS/MS) and on-line hydrogen-deuterium (H/D) exchange. Overall, 39 compounds were characterized and 25 of these related substances were previously unknown to literature. The impurity classification system recently developed for the closely related API levothyroxine sodium (LT 4 Na) could be applied to the newly characterized liothyronine sodium impurities resulting in a wholistic thyroid API impurity classification system. Furthermore, the mass-spectrometric CID-fragmentation of specific related substances was discussed and rationalized by detailed fragmentation pathways. Moreover, the UV/Vis absorption characteristics of the API and selected impurities were investigated to corroborate chemical structure assignments derived from MS data. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A

    International Nuclear Information System (INIS)

    Fang, Mei-Juan; Zhang, He; Liao, Chao; Qiu, Ying-Kun; Fang, Hua; Zheng, Zhen-Yu; Gao, Xiang; Zhao, Yu-Fen; Wu, Zhen

    2015-01-01

    Highlights: • ESI-MS n , HRMS and H/D exchange were used. • The fragmentation pathways of NPAAE-BFA in ESI-MS n were described. • Fragment ions involved in phosphorus group’s rearrangement reactions were observed. • Two rearrangement mechanisms about phosphorylation–dephosphorylation were proposed. - Abstract: As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a–2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments’s structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a–2d have been summarized and the plausible schemes for the fragmentation pathways were proposed. In this study, one dephosphorylated ion and two phosphorylated ions were observed in ESI-MS 2 spectra of [M + Na] + ions for compounds 2a–2d. The possible mechanisms about phosphorylation and dephosphorylation were proposed and confirmed by H/D exchange. For the “dephosphorylation” rearrangement, a nitrogen atom was migrated from the phosphoryl group to the carbon atom of Brefeldin A’s backbone with losing a molecule of C 3 H 7 PO 3 (122 Da). For the “phosphorylation” rearrangement, an oxygen atom of one phosphoryl group attacked the sideward phosphorus atom to form a nine-member ring intermediate, then two steps of C-H covalent bond cleavage with consecutive migration of hydrogen atom to lose a molecule of C 16 H 20 O 2 (244 Da). The two proposed rearrangement mechanisms about phosphoryl group transfer might be valuable for the structure analysis of other analogs and provide insights into elucidating the dynamic process of the phosphorylation–dephosphorylation of proteins

  16. Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Mei-Juan; Zhang, He; Liao, Chao; Qiu, Ying-Kun [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); Fang, Hua [The Third Institute of Oceanography of the State Oceanic Administration, Xiamen 361005 (China); Zheng, Zhen-Yu [College of Chemistry and Chemical Engineering, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Gao, Xiang [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); Zhao, Yu-Fen [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China); College of Chemistry and Chemical Engineering, Department of Chemistry, Xiamen University, Xiamen 361005 (China); Wu, Zhen, E-mail: wuzhen@xmu.edu.cn [School of Pharmaceutical Sciences and the Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiang-An South Road, Xiamen 361102 (China)

    2015-01-01

    Highlights: • ESI-MS{sup n}, HRMS and H/D exchange were used. • The fragmentation pathways of NPAAE-BFA in ESI-MS{sup n} were described. • Fragment ions involved in phosphorus group’s rearrangement reactions were observed. • Two rearrangement mechanisms about phosphorylation–dephosphorylation were proposed. - Abstract: As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a–2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments’s structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a–2d have been summarized and the plausible schemes for the fragmentation pathways were proposed. In this study, one dephosphorylated ion and two phosphorylated ions were observed in ESI-MS{sup 2} spectra of [M + Na]{sup +} ions for compounds 2a–2d. The possible mechanisms about phosphorylation and dephosphorylation were proposed and confirmed by H/D exchange. For the “dephosphorylation” rearrangement, a nitrogen atom was migrated from the phosphoryl group to the carbon atom of Brefeldin A’s backbone with losing a molecule of C{sub 3}H{sub 7}PO{sub 3} (122 Da). For the “phosphorylation” rearrangement, an oxygen atom of one phosphoryl group attacked the sideward phosphorus atom to form a nine-member ring intermediate, then two steps of C-H covalent bond cleavage with consecutive migration of hydrogen atom to lose a molecule of C{sub 16}H{sub 20}O{sub 2} (244 Da). The two proposed rearrangement mechanisms about phosphoryl group transfer might be valuable for the structure analysis of other analogs and provide insights into elucidating the dynamic process of the phosphorylation–dephosphorylation of proteins.

  17. Preface Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

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

    2009-01-01

    Miniaturization and Mass Spectrometry illustrates this trend and focuses on one particular analysis technique, mass spectrometry whose popularity has "dramatically" increased in the last two decades with the explosion of the field of biological analysis and the development of two "soft" ionization

  18. Negative chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Smit, A.L.C.

    1979-01-01

    This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)

  19. Laboratory of acceleration mass spectrometry

    International Nuclear Information System (INIS)

    Hybler, P.; Chrapan, J.

    2002-01-01

    In this paper authors describe the principle of the method of acceleration mass spectrometry and the construction plans of this instrument at the Faculty of ecology and environmental sciences in Banska Stiavnica. Using of this instrument for radiocarbon dating is discussed. A review of laboratories with acceleration mass spectrometry is presented

  20. Determination of Equine Cytochrome c Backbone Amide Hydrogen/Deuterium Exchange Rates by Mass Spectrometry Using a Wider Time Window and Isotope Envelope.

    Science.gov (United States)

    Hamuro, Yoshitomo

    2017-03-01

    A new strategy to analyze amide hydrogen/deuterium exchange mass spectrometry (HDX-MS) data is proposed, utilizing a wider time window and isotope envelope analysis of each peptide. While most current scientific reports present HDX-MS data as a set of time-dependent deuteration levels of peptides, the ideal HDX-MS data presentation is a complete set of backbone amide hydrogen exchange rates. The ideal data set can provide single amide resolution, coverage of all exchange events, and the open/close ratio of each amide hydrogen in EX2 mechanism. Toward this goal, a typical HDX-MS protocol was modified in two aspects: measurement of a wider time window in HDX-MS experiments and deconvolution of isotope envelope of each peptide. Measurement of a wider time window enabled the observation of deuterium incorporation of most backbone amide hydrogens. Analysis of the isotope envelope instead of centroid value provides the deuterium distribution instead of the sum of deuteration levels in each peptide. A one-step, global-fitting algorithm optimized exchange rate and deuterium retention during the analysis of each amide hydrogen by fitting the deuterated isotope envelopes at all time points of all peptides in a region. Application of this strategy to cytochrome c yielded 97 out of 100 amide hydrogen exchange rates. A set of exchange rates determined by this approach is more appropriate for a patent or regulatory filing of a biopharmaceutical than a set of peptide deuteration levels obtained by a typical protocol. A wider time window of this method also eliminates false negatives in protein-ligand binding site identification. Graphical Abstract ᅟ.

  1. 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. Copyright 2008 Wiley Periodicals, Inc.

  2. Imaging mass spectrometry statistical analysis.

    Science.gov (United States)

    Jones, Emrys A; Deininger, Sören-Oliver; Hogendoorn, Pancras C W; Deelder, André M; McDonnell, Liam A

    2012-08-30

    Imaging mass spectrometry is increasingly used to identify new candidate biomarkers. This clinical application of imaging mass spectrometry is highly multidisciplinary: expertise in mass spectrometry is necessary to acquire high quality data, histology is required to accurately label the origin of each pixel's mass spectrum, disease biology is necessary to understand the potential meaning of the imaging mass spectrometry results, and statistics to assess the confidence of any findings. Imaging mass spectrometry data analysis is further complicated because of the unique nature of the data (within the mass spectrometry field); several of the assumptions implicit in the analysis of LC-MS/profiling datasets are not applicable to imaging. The very large size of imaging datasets and the reporting of many data analysis routines, combined with inadequate training and accessible reviews, have exacerbated this problem. In this paper we provide an accessible review of the nature of imaging data and the different strategies by which the data may be analyzed. Particular attention is paid to the assumptions of the data analysis routines to ensure that the reader is apprised of their correct usage in imaging mass spectrometry research. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Simultaneous determination of platinum group elements and rhenium in rock samples using isotope dilution inductively coupled plasma mass spectrometry after cation exchange separation followed by solvent extraction

    International Nuclear Information System (INIS)

    Shinotsuka, Kazunori; Suzuki, Katsuhiko

    2007-01-01

    A simple and precise determination method for platinum group elements (PGEs) and Re in rock samples was developed using isotope dilution coupled with inductively coupled plasma mass spectrometry (ID-ICP-MS). Cation exchange separation was employed for simplicity, because it is applicable to group separation and simultaneous isotopic measurement in contrast with the widely used anion exchange separation which entails separate elution. However, its application to ID-ICP-MS has been limited due to spectral interferences from impurities retained in the PGE fraction even after ion chromatography. To overcome this limitation, solvent extraction using N-benzoyl-N-phenylhydroxylamine (BPHA) in chloroform was successfully applied for further purification. After the examination of optimum experimental parameters in cation exchange separation and solvent extraction using synthetic PGE solution, the established procedure was applied to the determination of PGEs and Re in some geochemical reference materials. The obtained results agreed well with the literature data determined using the different digestion methods (NiS fire assay and the use of a high-pressure asher) within the analytical uncertainties of each other. Significant difference in reproducibility between Ru, Ir, Pt and Os group, and Pd and Re group was observed in the results for BHVO-2 and JA-2. By considering the error factors affecting analytical reproducibility, we concluded that the difference is ascribed to the sample heterogeneity of minor minerals enriched in Ru, Ir, Pt and Os

  4. Structure-dependent degradation of polar compounds in weathered oils observed by atmospheric pressure photo-ionization hydrogen/deuterium exchange ultrahigh resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Ananna; Kim, Donghwi [Kyungpook National University, Department of Chemistry, Daegu 702-701 (Korea, Republic of); Yim, Un Hyuk; Shim, Won Joon [Oil and POPs Research Group, Korea Institute of Ocean Science and Technology, KIOST, Geoje 656-834 (Korea, Republic of); Kim, Sunghwan, E-mail: sunghwank@knu.ac.kr [Kyungpook National University, Department of Chemistry, Daegu 702-701 (Korea, Republic of); Green Nano Center, Department of Chemistry, Daegu 702-701 (Korea, Republic of)

    2015-10-15

    Highlights: • We examined source crude oil and weathered oils from M/V Hebei accident. • APPI hydrogen/deuterium exchange ultrahigh mass spectrometry was applied. • N{sub 1} class compounds with 2° and/or 3° amine decrease in larger scale than pyridines. • Preferential degradation of nitrogen-containing compounds was confirmed. • Significant increase in S{sub 1}O{sub 1} compounds was observed as the weathering proceeds. - Abstract: The resin fractions of fresh mixtures of three oils spilled during the M/V Hebei Spirit oil spill, as well as weathered oils collected at weathering stages II and IV from the oil spill site were analyzed and compared by atmospheric pressure photo-ionization hydrogen/deuterium exchange mass spectrometry (HDX MS). The significantly decreased abundance of N{sup +}· and [N − H + D]{sup +} ions suggested that secondary and tertiary amine-containing compounds were preferentially degraded during the early stage of weathering. [N + H]{sup +} and [N + D]{sup +} ions previously attributed to pyridine-type compounds degraded more slowly than secondary and tertiary amine-containing compounds. The preferential degradation of nitrogen-containing compounds was confirmed by photo-degradation experiments using 15 standard compounds. In addition, significant increases of [S{sub 1}O{sub 1} + H]{sup +} and [S{sub 1}O{sub 1} + D]{sup +} ions with higher DBE values were observed from fresh oil mixtures as compared to stages II and IV samples, and that could be linked with the decrease of higher DBE compounds of the S{sub 1} class. This study presented convincing arguments and evidence demonstrating that secondary and tertiary amines were more vulnerable to photo-degradation than compounds containing pyridine, and hence, preferential degradation depending on chemical structures must be considered in the production of hazardous or toxic components.

  5. Structure-dependent degradation of polar compounds in weathered oils observed by atmospheric pressure photo-ionization hydrogen/deuterium exchange ultrahigh resolution mass spectrometry

    International Nuclear Information System (INIS)

    Islam, Ananna; Kim, Donghwi; Yim, Un Hyuk; Shim, Won Joon; Kim, Sunghwan

    2015-01-01

    Highlights: • We examined source crude oil and weathered oils from M/V Hebei accident. • APPI hydrogen/deuterium exchange ultrahigh mass spectrometry was applied. • N 1 class compounds with 2° and/or 3° amine decrease in larger scale than pyridines. • Preferential degradation of nitrogen-containing compounds was confirmed. • Significant increase in S 1 O 1 compounds was observed as the weathering proceeds. - Abstract: The resin fractions of fresh mixtures of three oils spilled during the M/V Hebei Spirit oil spill, as well as weathered oils collected at weathering stages II and IV from the oil spill site were analyzed and compared by atmospheric pressure photo-ionization hydrogen/deuterium exchange mass spectrometry (HDX MS). The significantly decreased abundance of N + · and [N − H + D] + ions suggested that secondary and tertiary amine-containing compounds were preferentially degraded during the early stage of weathering. [N + H] + and [N + D] + ions previously attributed to pyridine-type compounds degraded more slowly than secondary and tertiary amine-containing compounds. The preferential degradation of nitrogen-containing compounds was confirmed by photo-degradation experiments using 15 standard compounds. In addition, significant increases of [S 1 O 1 + H] + and [S 1 O 1 + D] + ions with higher DBE values were observed from fresh oil mixtures as compared to stages II and IV samples, and that could be linked with the decrease of higher DBE compounds of the S 1 class. This study presented convincing arguments and evidence demonstrating that secondary and tertiary amines were more vulnerable to photo-degradation than compounds containing pyridine, and hence, preferential degradation depending on chemical structures must be considered in the production of hazardous or toxic components

  6. Optimization and application of atmospheric pressure chemical and photoionization hydrogen-deuterium exchange mass spectrometry for speciation of oxygen-containing compounds.

    Science.gov (United States)

    Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Jin, Jang Mi; Yim, Un Hyuk; Shim, Won Joon; Kim, Young Hwan; Kim, Sunghwan

    2016-05-01

    This paper presents a detailed investigation of the feasibility of optimized positive and negative atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and atmospheric pressure photoionization (APPI) MS coupled to hydrogen-deuterium exchange (HDX) for structural assignment of diverse oxygen-containing compounds. The important parameters for optimization of HDX MS were characterized. The optimized techniques employed in the positive and negative modes showed satisfactory HDX product ions for the model compounds when dichloromethane and toluene were employed as a co-solvent in APCI- and APPI-HDX, respectively. The evaluation of the mass spectra obtained from 38 oxygen-containing compounds demonstrated that the extent of the HDX of the ions was structure-dependent. The combination of information provided by different ionization techniques could be used for better speciation of oxygen-containing compounds. For example, (+) APPI-HDX is sensitive to compounds with alcohol, ketone, or aldehyde substituents, while (-) APPI-HDX is sensitive to compounds with carboxylic functional groups. In addition, the compounds with alcohol can be distinguished from other compounds by the presence of exchanged peaks. The combined information was applied to study chemical compositions of degraded oils. The HDX pattern, double bond equivalent (DBE) distribution, and previously reported oxidation products were combined to predict structures of the compounds produced from oxidation of oil. Overall, this study shows that APCI- and APPI-HDX MS are useful experimental techniques that can be applied for the structural analysis of oxygen-containing compounds.

  7. Accelerator-based ultrasensitive mass spectrometry

    International Nuclear Information System (INIS)

    Gove, H.E.

    1985-01-01

    This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

  8. Hyphenation of capillary high-performance ion-exchange chromatography with mass spectrometry using sheath-flow electrospray ionization.

    Science.gov (United States)

    Kochmann, Sven; Matysik, Frank-Michael

    2014-12-15

    Mass spectrometry (MS) is an attractive method for extending capillary-size ion chromatography (cHPIC) to create a valuable technique for speciation analysis. For hyphenation, the aqueous effluent of cHPIC has to be transformed into a volatile mixture for MS while preserving analytical concentrations as well as peak shapes during transfer from cHPIC to MS. Finally, the approach should technically be flexible and easy-to-use. A combination of cHPIC and sheath-flow electrospray ionization (ESI)-MS offers to solve all these challenges. cHPIC/sheath-flow-ESI-TOFMS was used in this study for the speciation analysis of various arsenic model compounds. These model compounds were analyzed with different hyphenation setups and configurations of cHPIC/MS and their respective assets and drawbacks were examined and discussed. The parameters (flow rate and composition of sheath liquid) of sheath-flow ESI and their influence on the performance of the spray and the sensitivity of the detector were investigated and compared with those of sheathless ESI. Using an injection valve to couple cHPIC and MS was found to be the best method for hyphenation, since it constitutes a flexible and dead-volume-free approach. The investigation of sheath-flow ESI revealed that the flow rate of the sheath liquid has to resemble the flow rate of the IC effluent to ensure a stable spray and that a composition of 2-propanol/water/ammonia at 50:50:0.2 (v/v/v) suits most applications without unilaterally promoting the sensitivity for either organic or inorganic compounds. The optimized setup and conditions were successfully applied to the analysis of a mixture of important arsenic species and used to determine limits of detection of organic and inorganic arsenic species (3.7 µg L(-1) elemental arsenic). A method for cHPIC/sheath-flow-ESI-MS was developed. The method was shown to be a valuable tool for speciation and trace analysis. It features no dead volume, fast transfer from IC to MS, only minimal

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

    Science.gov (United States)

    Kiss, András; Smith, Donald F; Jungmann, Julia H; Heeren, Ron M A

    2013-12-30

    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 was 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 system's mass spectral and imaging performance is tested with various benchmark samples and thin tissue sections. The high secondary ion yield (with respect to 'traditional' monatomic primary ion sources) of the C60 primary ion source and the increased sensitivity of the high voltage detector setup improve microscope mode secondary ion mass spectrometry imaging. The analysis time and the signal-to-noise ratio are improved compared with other microscope mode imaging systems, all at high spatial resolution. We have demonstrated the unique capabilities of a C60 ion microscope with a Timepix detector for high spatial resolution microscope mode secondary ion mass spectrometry imaging. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Measuring the hydrogen/deuterium exchange of proteins at high spatial resolution by mass spectrometry: overcoming gas-phase hydrogen/deuterium scrambling.

    Science.gov (United States)

    Rand, Kasper D; Zehl, Martin; Jørgensen, Thomas J D

    2014-10-21

    Proteins are dynamic molecules that exhibit conformational flexibility to function properly. Well-known examples of this are allosteric regulation of protein activity and ligand-induced conformational changes in protein receptors. Detailed knowledge of the conformational properties of proteins is therefore pertinent to both basic and applied research, including drug development, since the majority of drugs target protein receptors and a growing number of drugs introduced to the market are therapeutic peptides or proteins. X-ray crystallography provides a static picture at atomic resolution of the lowest-energy structure of the native ensemble. There is a growing need for sensitive analytical tools to explore all of the significant molecular structures in the conformational landscape of proteins. Hydrogen/deuterium exchange monitored by mass spectrometry (HDX-MS) has recently emerged as a powerful method for characterizing protein conformational dynamics. The basis of this method is the fact that backbone amides in stable hydrogen-bonded structures (e.g., α-helices and β-sheets) are protected against exchange with the aqueous solvent. All protein structures are dynamic, however, and eventually all of the protecting hydrogen bonds will transiently break as the protein--according to thermodynamic principles--cycles through partially unfolded states that correspond to excited free energy levels. As a result, all of the backbone amides will eventually become temporarily solvent-exposed and exchange-competent over time. Consequently, a folded protein in D2O will gradually incorporate deuterium into its backbone amides, and the kinetics of the process can be readily monitored by mass spectrometry. The deuterium uptake kinetics for the intact protein (global exchange kinetics) represents the sum of the exchange kinetics for the individual backbone amides. Local exchange kinetics is typically achieved by using pepsin digestion under quench conditions (i.e., under cold

  11. Structure and Dynamics of NBD1 from CFTR Characterized Using Crystallography and Hydrogen/Deuterium Exchange Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, H.A.; Wang, C.; Zhao, X.; Hamuro, Y.; Conners, K.; Kearins, M.C.; Lu, F.; Sauder, J.M.; Molnar, K.S.; Coales, S.J.; Maloney, P.C.; Guggino, W.B.; Wetmore, D.R.; Weber, P.C.; Hunt, J.F. (SGX); (ExSAR); (Cystic); (JHU-MED); (Columbia)

    2012-04-30

    The {Delta}F508 mutation in nucleotide-binding domain 1 (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) is the predominant cause of cystic fibrosis. Previous biophysical studies on human F508 and {Delta}F508 domains showed only local structural changes restricted to residues 509-511 and only minor differences in folding rate and stability. These results were remarkable because {Delta}F508 was widely assumed to perturb domain folding based on the fact that it prevents trafficking of CFTR out of the endoplasmic reticulum. However, the previously reported crystal structures did not come from matched F508 and {Delta}F508 constructs, and the {Delta}F508 structure contained additional mutations that were required to obtain sufficient protein solubility. In this article, we present additional biophysical studies of NBD1 designed to address these ambiguities. Mass spectral measurements of backbone amide {sup 1}H/{sup 2}H exchange rates in matched F508 and {Delta}F508 constructs reveal that {Delta}F508 increases backbone dynamics at residues 509-511 and the adjacent protein segments but not elsewhere in NBD1. These measurements also confirm a high level of flexibility in the protein segments exhibiting variable conformations in the crystal structures. We additionally present crystal structures of a broader set of human NBD1 constructs, including one harboring the native F508 residue and others harboring the {Delta}F508 mutation in the presence of fewer and different solubilizing mutations. The only consistent conformational difference is observed at residues 509-511. The side chain of residue V510 in this loop is mostly buried in all non-{Delta}F508 structures but completely solvent exposed in all {Delta}F508 structures. These results reinforce the importance of the perturbation {Delta}F508 causes in the surface topography of NBD1 in a region likely to mediate contact with the transmembrane domains of CFTR. However, they also suggest that increased

  12. Determination of Histidine pKa Values in the Propeptides of Furin and Proprotein Convertase 1/3 Using Histidine Hydrogen-Deuterium Exchange Mass Spectrometry.

    Science.gov (United States)

    Elferich, Johannes; Williamson, Danielle M; David, Larry L; Shinde, Ujwal

    2015-08-04

    Propeptides of proprotein convertases regulate activation of their protease domains by sensing the organellar pH within the secretory pathway. Earlier experimental work highlighted the importance of a conserved histidine residue within the propeptide of a widely studied member, furin. A subsequent evolutionary analysis found an increase in histidine content within propeptides of secreted eukaryotic proteases compared with their prokaryotic orthologs. However, furin activates in the trans-golgi network at a pH of 6.5 while a paralog, proprotein convertase 1/3, activates in secretory vesicles at a pH of 5.5. It is unclear how a conserved histidine can mediate activation at two different pH values. In this manuscript, we measured the pKa values of histidines within the propeptides of furin and proprotein convertase 1/3 using a histidine hydrogen-deuterium exchange mass spectrometry approach. The high density of histidine residues combined with an abundance of basic residues provided challenges for generation of peptide ions with unique histidine residues, which were overcome by employing ETD fragmentation. During this analysis, we found slow hydrogen-deuterium exchange in residues other than histidine at basic pH. Finally, we demonstrate that the pKa of the conserved histidine in proprotein convertase 1/3 is acid-shifted compared with furin and is consistent with its lower pH of activation.

  13. 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.

  14. 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......, Orbitrap and ion mobility instruments. Together they offer various and complementary capabilities in terms of ionization, sensitivity, speed, resolution, mass accuracy, dynamic range and methods of fragmentation. Mass spectrometers can acquire qualitative and quantitative information on a large scale...

  15. 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.

  16. Simultaneous measurement of proline and related compounds in oak leaves by high-performance ligand-exchange chromatography and electrospray ionization mass spectrometry for environmental stress studies.

    Science.gov (United States)

    Oufir, Mouhssin; Schulz, Nadine; Sha Vallikhan, Patan Shaik; Wilhelm, Eva; Burg, Kornel; Hausman, Jean-Francois; Hoffmann, Lucien; Guignard, Cedric

    2009-02-13

    A mass spectrometer was coupled to high-performance ligand-exchange liquid chromatography (HPLEC) for simultaneous analysis of stress associated solutes such as proline, hydroxyproline, methylproline, glycine betaine and trigonelline extracted from leaves of drought stressed oaks and an internal standard namely N-acetylproline. Methanol/chloroform/water extracts were analyzed using an Aminex HPX-87C column and specifically quantified by the positive ion mode of an electrospray ionisation-mass spectrometry (ESI-MS) in single ion monitoring (SIM) mode. The recovery of N-acetyl proline added to oak leaf extracts ranged from 85.2 to 122.1% for an intra-day study. Standard calibration curves showed good linearity in the measured range from 0.3125 to 10micromolL(-1) with the lowest correlation coefficient of 0.99961 for trigonelline. The advantages of this alternative procedure, compared to previously published methods using fluorescence or amperometric detections, are the simultaneous and direct detection of osmoprotectants in a single chromatographic run, a minimal sample preparation, a good specificity and reduced limits of quantification, ranging from 0.1 to 0.6micromolL(-1). Fifty-six days of water deficit exposure resulted in increased foliar free proline levels (2.4-fold, P<0.001, 155micromolg(-1) FW) and glycine betaine contents (2.5-fold, P<0.05, 175micromolg(-1) FW) of drought stressed oak compared to control.

  17. Symposium on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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.

  20. Design and Validation of In-Source Atmospheric Pressure Photoionization Hydrogen/Deuterium Exchange Mass Spectrometry with Continuous Feeding of D2O.

    Science.gov (United States)

    Acter, Thamina; Lee, Seulgidaun; Cho, Eunji; Jung, Maeng-Joon; Kim, Sunghwan

    2018-01-01

    In this study, continuous in-source hydrogen/deuterium exchange (HDX) atmospheric pressure photoionization (APPI) mass spectrometry (MS) with continuous feeding of D 2 O was developed and validated. D 2 O was continuously fed using a capillary line placed on the center of a metal plate positioned between the UV lamp and nebulizer. The proposed system overcomes the limitations of previously reported APPI HDX-MS approaches where deuterated solvents were premixed with sample solutions before ionization. This is particularly important for APPI because solvent composition can greatly influence ionization efficiency as well as the solubility of analytes. The experimental parameters for APPI HDX-MS with continuous feeding of D 2 O were optimized, and the optimized conditions were applied for the analysis of nitrogen-, oxygen-, and sulfur-containing compounds. The developed method was also applied for the analysis of the polar fraction of a petroleum sample. Thus, the data presented in this study clearly show that the proposed HDX approach can serve as an effective analytical tool for the structural analysis of complex mixtures. Graphical abstract ᅟ.

  1. Sites involved in intra- and interdomain allostery associated with the activation of factor VIIa pinpointed by hydrogen-deuterium exchange and electron transfer dissociation mass spectrometry.

    Science.gov (United States)

    Song, Hongjian; Olsen, Ole H; Persson, Egon; Rand, Kasper D

    2014-12-19

    Factor VIIa (FVIIa) is a trypsin-like protease that plays an important role in initiating blood coagulation. Very limited structural information is available for the free, inactive form of FVIIa that circulates in the blood prior to vascular injury and the molecular details of its activity enhancement remain elusive. Here we have applied hydrogen/deuterium exchange mass spectrometry coupled to electron transfer dissociation to pinpoint individual residues in the heavy chain of FVIIa whose conformation and/or local interaction pattern changes when the enzyme transitions to the active form, as induced either by its cofactor tissue factor or a covalent active site inhibitor. Identified regulatory residues are situated at key sites across one continuous surface of the protease domain spanning the TF-binding helix across the activation pocket to the calcium binding site and are embedded in elements of secondary structure and at the base of flexible loops. Thus these residues are optimally positioned to mediate crosstalk between functional sites in FVIIa, particularly the cofactor binding site and the active site. Our results unambiguously show that the conformational allosteric activation signal extends to the EGF1 domain in the light chain of FVIIa, underscoring a remarkable intra- and interdomain allosteric regulation of this trypsin-like protease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Hydrogen/deuterium exchange mass spectrometry and computational modeling reveal a discontinuous epitope of an antibody/TL1A Interaction.

    Science.gov (United States)

    Huang, Richard Y-C; Krystek, Stanley R; Felix, Nathan; Graziano, Robert F; Srinivasan, Mohan; Pashine, Achal; Chen, Guodong

    2018-01-01

    TL1A, a tumor necrosis factor-like cytokine, is a ligand for the death domain receptor DR3. TL1A, upon binding to DR3, can stimulate lymphocytes and trigger secretion of proinflammatory cytokines. Therefore, blockade of TL1A/DR3 interaction may be a potential therapeutic strategy for autoimmune and inflammatory diseases. Recently, the anti-TL1A monoclonal antibody 1 (mAb1) with a strong potency in blocking the TL1A/DR3 interaction was identified. Here, we report on the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to obtain molecular-level details of mAb1's binding epitope on TL1A. HDX coupled with electron-transfer dissociation MS provided residue-level epitope information. The HDX dataset, in combination with solvent accessible surface area (SASA) analysis and computational modeling, revealed a discontinuous epitope within the predicted interaction interface of TL1A and DR3. The epitope regions span a distance within the approximate size of the variable domains of mAb1's heavy and light chains, indicating it uses a unique mechanism of action to block the TL1A/DR3 interaction.

  3. Fast analysis of quaternary ammonium pesticides in food and beverages using cation-exchange chromatography coupled with isotope-dilution high-resolution mass spectrometry.

    Science.gov (United States)

    Nardin, Tiziana; Barnaba, Chiara; Abballe, Franco; Trenti, Gianmaria; Malacarne, Mario; Larcher, Roberto

    2017-10-01

    A fast separation based on cation-exchange liquid chromatography coupled with high-resolution mass spectrometry is proposed for simultaneous determination of chlormequat, difenzoquat, diquat, mepiquat and paraquat in several food and beverage commodities. Solid samples were extracted using a mixture of water/methanol/formic acid (69.6:30:0.4, v/v/v), while liquid samples were ten times diluted with the same solution. Separation was carried out on an experimental length-modified IonPac CS17 column (2 × 15 mm 2 ) that allowed the use of formic acid and acetonitrile as mobile phase. Detection limits for food and beverage matrices were established at 1.5 μg/L for chlormequat, difenzoquat and mepiquat, and 3 μg/L for diquat and paraquat, while for drinking water a pre-analytical sample concentration allowed detection limits of 9 and 20 ng/L, respectively. Precision, as repeatability (RSD%), ranged from 0.2 to 24%, with a median value of 6%, and trueness, as recovery, ranged from 64 to 118%, with a median value of 96%. The method developed was successfully applied to investigate the presence of herbicide residues in commercial commodities (mineral water, orange juice, beer, tea, green coffee bean, toasted coffee powder, cocoa bean, white corn flour, rice and sugar samples). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Eleventh ISMAS workshop on mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.

    2004-10-01

    This volume deals with the latest developments in this field, exposing the innumerable applications of mass spectrometry. The topics covered include basic fundamentals of mass spectrometry, qualitative and quantitative aspects and data interpretation, maintenance of mass spectrometers, selection of a mass spectrometer, its applications in various branches of science as well as recent advances in mass spectrometry. Emphasis is also laid on the practical aspects of mass spectrometry. Papers relevant to INIS are indexed separately

  5. Mass spectrometry in epigenetic research

    DEFF Research Database (Denmark)

    Beck, Hans Christian

    2010-01-01

    cancers has gained tremendous interest in recent years, and many of these inhibitors are currently undergoing clinical trials. Despite intense research, however, the exact molecular mechanisms of action of these molecules remain, to a wide extent, unclear. The recent application of mass spectrometry...

  6. Mass spectrometry of large molecules

    International Nuclear Information System (INIS)

    Facchetti, S.

    1985-01-01

    The lectures in this volume were given at a course on mass spectrometry of large molecules, organized within the framework of the Training and Education programme of the Joint Research Centre of the European Communities. Although first presented in 1983, most of the lectures have since been updated by their authors. (orig.)

  7. Mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

  8. Weak cation exchange magnetic beads coupled with matrix-assisted laser desorption ionization-time of flight-mass spectrometry in screening serum protein markers in osteopenia.

    Science.gov (United States)

    He, Wei-Tao; Liang, Bo-Cheng; Shi, Zhen-Yu; Li, Xu-Yun; Li, Chun-Wen; Shi, Xiao-Lin

    2016-01-01

    The present study aimed at investigating the weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of osteopenia from ten postmenopausal women and ten postmenopausal women without osteopenia as control group, to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were collected from postmenopausal women with osteopenia and postmenopausal women with normal bone mass. Proteins were extracted from serum samples by weak cation exchange magnetic beads technology, and mass spectra acquisition was done by MALDI-TOF-MS. The visualization and comparison of data sets, statistical peak evaluation, model recognition, and discovery of biomarker candidates were handled by the proteinchip data analysis system software(ZJU-PDAS). The diagnostic models were established using genetic arithmetic based support vector machine (SVM). The SVM result with the highest Youden Index was selected as the model. Combinatorial Peaks having the highest accuracy in distinguishing different samples were selected as potential biomarker. From the two group serum samples, a total of 133 differential features were selected. Ten features with significant intensity differences were screened. In the pair-wise comparisons, processing of MALDI-TOF spectra resulted in the identification of ten differential features between postmenopausal women with osteopenia and postmenopausal women with normal bone mass. The difference of features by Youden index showed that the highest features had a mass to charge ratio of 1699 and 3038 Da. A diagnosis model was established with these two peaks as the candidate marker, and the specificity of the model is 100 %, the sensitivity was 90 % by leave-one-out cross validation test. The two groups of specimens in SVM results on the scatter plot could be clearly distinguished. The peak

  9. Direct analysis of ultra-trace semiconductor gas by inductively coupled plasma mass spectrometry coupled with gas to particle conversion-gas exchange technique.

    Science.gov (United States)

    Ohata, Masaki; Sakurai, Hiromu; Nishiguchi, Kohei; Utani, Keisuke; Günther, Detlef

    2015-09-03

    An inductively coupled plasma mass spectrometry (ICPMS) coupled with gas to particle conversion-gas exchange technique was applied to the direct analysis of ultra-trace semiconductor gas in ambient air. The ultra-trace semiconductor gases such as arsine (AsH3) and phosphine (PH3) were converted to particles by reaction with ozone (O3) and ammonia (NH3) gases within a gas to particle conversion device (GPD). The converted particles were directly introduced and measured by ICPMS through a gas exchange device (GED), which could penetrate the particles as well as exchange to Ar from either non-reacted gases such as an air or remaining gases of O3 and NH3. The particle size distribution of converted particles was measured by scanning mobility particle sizer (SMPS) and the results supported the elucidation of particle agglomeration between the particle converted from semiconductor gas and the particle of ammonium nitrate (NH4NO3) which was produced as major particle in GPD. Stable time-resolved signals from AsH3 and PH3 in air were obtained by GPD-GED-ICPMS with continuous gas introduction; however, the slightly larger fluctuation, which could be due to the ionization fluctuation of particles in ICP, was observed compared to that of metal carbonyl gas in Ar introduced directly into ICPMS. The linear regression lines were obtained and the limits of detection (LODs) of 1.5 pL L(-1) and 2.4 nL L(-1) for AsH3 and PH3, respectively, were estimated. Since these LODs revealed sufficiently lower values than the measurement concentrations required from semiconductor industry such as 0.5 nL L(-1) and 30 nL L(-1) for AsH3 and PH3, respectively, the GPD-GED-ICPMS could be useful for direct and high sensitive analysis of ultra-trace semiconductor gas in air. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Hydrogen/deuterium exchange mass spectrometry with top-down electron capture dissociation for characterizing structural transitions of a 17 kDa protein.

    Science.gov (United States)

    Pan, Jingxi; Han, Jun; Borchers, Christoph H; Konermann, Lars

    2009-09-09

    Amide H/D exchange (HDX) mass spectrometry (MS) is widely used for protein structural studies. Traditionally, this technique involves protein labeling in D(2)O, followed by acid quenching, proteolytic digestion, and analysis of peptide deuteration levels by HPLC/MS. There is great interest in the development of alternative HDX approaches involving the top-down fragmentation of electrosprayed protein ions, instead of relying on enzymatic cleavage and solution-phase separations. A number of recent studies have demonstrated that electron capture dissociation (ECD) results in fragmentation of gaseous protein ions with little or no H/D scrambling. However, the successful application of this approach for in-depth protein conformational studies has not yet been demonstrated. The current work uses horse myoglobin as a model system for assessing the suitability of HDX-MS with top-down ECD for experiments of this kind. It is found that ECD can pinpoint the locations of protected amides with an average resolution of less than two residues for this 17 kDa protein. Native holo-myoglobin (hMb) shows considerable protection from exchange in all of its helices, whereas loops are extensively deuterated. Fraying is observable at some helix termini. Removal of the prosthetic heme group from hMb produces apo-myoglobin (aMb). Both hMb and aMb share virtually the same HDX protection pattern in helices A-E, whereas helix F is unfolded in aMb. In addition, destabilization is evident for some residues close to the beginning of helix G, the end of helix H, and the C-terminus of the protein. The structural changes reported herein are largely consistent with earlier NMR data for sperm whale myoglobin, although small differences between the two systems are evident. Our findings demonstrate that the level of structural information obtainable with top-down ECD for small to medium-sized proteins considerably surpasses that of traditional HDX-MS experiments, while at the same time greatly reducing

  11. Mass spectrometry and tandem mass spectrometry of citrus limonoids.

    Science.gov (United States)

    Tian, Qingguo; Schwartz, Steven J

    2003-10-15

    Methods for atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) of citrus limonoid aglycones and electrospray ionization tandem mass spectrometry (ESI-MS/MS) of limonoid glucosides are reported. The fragmentation patterns of four citrus limonoid aglycones (limonin, nomilin, obacunone, and deacetylnomilin) and six limonoid glucosides, that is, limonin 17-beta-D-glucopyranoside (LG), nomilin 17-beta-D-glucopyranoside (NG), nomilinic acid 17-beta-D-glucopyranoside (NAG), deacetyl nomilinic acid 17-beta-D-glucopyranoside (DNAG), obacunone 17-beta-D-glucopyranoside (OG), and obacunoic acid 17-beta-D-glucopyranoside (OAG) were investigated using a quadruple mass spectrometer in low-energy collisionally activated dissociation (CAD). The four limonoid aglycones and four limonoid glucosides (LG, OG, NAG, and DNAG) were purified from citrus seeds; the other two limonoid glucosides (NG and OAG) were tentatively identified in the crude extract of grapefruit seeds by ESI mass spectrometry in both positive and negative ion analysis. Ammonium hydroxide or acetic acid was added to the mobile phase to facilitate ionization. During positive ion APCI analysis of limonoid aglycones, protonated molecular ion, [M + H]+, or adduct ion, [M + NH3 + H]-, was formed as base peaks when ammonium hydroxide was added to the mobile phase. Molecular anions or adduct ions with acetic acid ([M + HOAc - H] and [M + HOAc]-) or a deprotonated molecular ion were produced during negative ion APCI analysis of limonoid aglycones, depending on the mobile-phase modifier used. Positive ion ESI-MS of limonoid glucosides produced adduct ions of [M + H + NH3]+, [M + Na]+, and [M + K]+ when ammonium hydroxide was added to the mobile phase. After collisionally activated dissociation (CAD) of the limonoid aglycone molecular ions in negative ion APCI analysis, fragment ions indicated structural information of the precursor ions, showing the presence of methyl, carboxyl, and oxygenated ring

  12. Characterization of oligosaccharides with capillary high performance anion exchange chromatography hyphenated to pulsed amperometric detection and ion trap mass spectrometry : application to the analysis of human lysosomal disorders

    NARCIS (Netherlands)

    Bruggink, Cornelis

    The development of a capillary ion chromatograph is described together with a matching desalter. This desalter made it possible to use on-line a mass spectrometer. The mass spectrometer enables partly to characterize carbohydrates eluting from the anion exchange column. This separation technology is

  13. Simultaneous separation and determination of six arsenic species in rice by anion-exchange chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Ma, Li; Yang, Zhaoguang; Tang, Jie; Wang, Lin

    2016-06-01

    The simultaneous separation and determination of arsenite As(III), arsenate As(V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) in rice samples have been carried out in one single anion-exchange column run by high-performance liquid chromatography with inductively coupled plasma mass spectrometry. To estimate the effect of variables on arsenic (As) speciation, the chromatographic conditions including type of competing anion, ionic strength, pH of elution buffer, and flow rate of mobile phase have been investigated by a univariate approach. Under the optimum chromatographic conditions, baseline separation of six As species has been achieved within 10 min by gradient elution program using 4 mM NH4 HCO3 at pH 8.6 as mobile phase A and 4 mM NH4 HCO3 , 40 mM NH4 NO3 at pH 8.6 as mobile phase B. The method detection limits for As(III), As(V), MMA, DMA, AsB, and AsC were 0.4, 0.9, 0.2, 0.4, 0.5, and 0.3 μg/kg, respectively. The proposed method has been applied to separation and quantification of As species in real rice samples collected from Hunan Province, China. The main As species detected in all samples were As(III), As(V) and DMA, with inorganic As accounting for over 80% of total As in these samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Detection of lipid-induced structural changes of the Marburg virus matrix protein VP40 using hydrogen/deuterium exchange-mass spectrometry.

    Science.gov (United States)

    Wijesinghe, Kaveesha J; Urata, Sarah; Bhattarai, Nisha; Kooijman, Edgar E; Gerstman, Bernard S; Chapagain, Prem P; Li, Sheng; Stahelin, Robert V

    2017-04-14

    Marburg virus (MARV) is a lipid-enveloped virus from the Filoviridae family containing a negative sense RNA genome. One of the seven MARV genes encodes the matrix protein VP40, which forms a matrix layer beneath the plasma membrane inner leaflet to facilitate budding from the host cell. MARV VP40 (mVP40) has been shown to be a dimeric peripheral protein with a broad and flat basic surface that can associate with anionic phospholipids such as phosphatidylserine. Although a number of mVP40 cationic residues have been shown to facilitate binding to membranes containing anionic lipids, much less is known on how mVP40 assembles to form the matrix layer following membrane binding. Here we have used hydrogen/deuterium exchange (HDX) mass spectrometry to determine the solvent accessibility of mVP40 residues in the absence and presence of phosphatidylserine and phosphatidylinositol 4,5-bisphosphate. HDX analysis demonstrates that two basic loops in the mVP40 C-terminal domain make important contributions to anionic membrane binding and also reveals a potential oligomerization interface in the C-terminal domain as well as a conserved oligomerization interface in the mVP40 N-terminal domain. Lipid binding assays confirm the role of the two basic patches elucidated with HD/X measurements, whereas molecular dynamics simulations and membrane insertion measurements complement these studies to demonstrate that mVP40 does not appreciably insert into the hydrocarbon region of anionic membranes in contrast to the matrix protein from Ebola virus. Taken together, we propose a model by which association of the mVP40 dimer with the anionic plasma membrane facilitates assembly of mVP40 oligomers. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

    International Nuclear Information System (INIS)

    Beinhauer, Jana; Bian, Liangqiao; Fan, Hui; Šebela, Marek; Kukula, Maciej; Barrera, Jose A.

    2015-01-01

    Highlights: • Analysis of estrogens in small volume samples at low parts-per-trillion concentration. • Charged bulk derivatization facilitates on-line ion exchange sample preparation. • On-line WCX restricted access media traps analytes, but not proteins and lipids. • Complete preparation and LC–MS/MS analysis completed in 30 min/sample. - Abstract: Estrone (E1), estradiols (α/β-E2), and estriol (E3) are four major metabolically active estrogens exerting strong biological activities at very low circulating concentrations. This paper reports a sensitive and efficient method with automated, on-line clean-up and detection to determine trace estrogens in a small volume of serum samples using liquid chromatography–electrospray ionization–tandem mass spectrometry directly, without off-line liquid–liquid or solid-phase extraction pretreatments. Serum aliquots (charcoal stripped fetal bovine serum, 100 μL) were spiked with four estrogen standards and their corresponding isotope-labeled internal standards, then bulk derivatized with 2-fluoro-1-methyl-pyridium p-toluenesulfonate (2-FMP) to establish the calibration curves and perform method validation. Calibration was established in the concentration ranges of 5–1000 pg mL −1 , and demonstrated good linearity of R 2 from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL −1 . Good accuracy and precision in the range of 86–112% and 2.3–11.9%, respectively, were observed for the quality control (QC) samples at low, medium, and high concentration levels. The stability tests showed that the derivatized serum samples were stable 8 h after derivatization at room temperature and at least to 48 h if stored at −20 °C. The method was applied to measure trace estrogens in real human and bovine serum samples, and three of four estrogen compounds studied were observed and quantified

  16. Ion-exchange solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for the determination of veterinary drugs in organic fertilizers.

    Science.gov (United States)

    Zhao, Zhiyong; Zhang, Yanmei; Xuan, Yanfang; Song, Wei; Si, Wenshuai; Zhao, Zhihui; Rao, Qinxiong

    2016-06-01

    The analysis of veterinary drugs in organic fertilizers is crucial for an assessment of potential risks to soil microbial communities and human health. We develop a robust and sensitive method to quantitatively determine 19 veterinary drugs (amantadine, sulfonamides and fluoroquinolones) in organic fertilizers. The method involved a simple solid-liquid extraction step using the combination of acetonitrile and McIlvaine buffer as extraction solvent, followed by cleanup with a solid-phase extraction cartridge containing polymeric mixed-mode anion-exchange sorbents. Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was used to separate and detect target analytes. We particularly focused on the optimization of sample clean-up step: different diluents and dilution factors were tested. The developed method was validated in terms of linearity, recovery, precision, sensitivity and specificity. The recoveries of all the drugs ranged from 70.9% to 112.7% at three concentration levels, with the intra-day and inter-day relative standard deviation lower than 15.7%. The limits of quantification were between 1.0 and 10.0μg/kg for all the drugs. Matrix effect was minimized by matrix-matched calibration curves. The analytical method was successfully applied for the survey of veterinary drugs contamination in 20 compost samples. The results indicated that fluoroquinolones had higher incidence rate and mean concentration levels ranging from 31.9 to 308.7μg/kg compared with other drugs. We expect the method will provide the basis for risk assessment of veterinary drugs in organic fertilizers. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. H/D exchange mass spectrometry and statistical coupling analysis reveal a role for allostery in a ferredoxin-dependent bifurcating transhydrogenase catalytic cycle.

    Science.gov (United States)

    Berry, Luke; Poudel, Saroj; Tokmina-Lukaszewska, Monika; Colman, Daniel R; Nguyen, Diep M N; Schut, Gerrit J; Adams, Michael W W; Peters, John W; Boyd, Eric S; Bothner, Brian

    2018-01-01

    Recent investigations into ferredoxin-dependent transhydrogenases, a class of enzymes responsible for electron transport, have highlighted the biological importance of flavin-based electron bifurcation (FBEB). FBEB generates biomolecules with very low reduction potential by coupling the oxidation of an electron donor with intermediate potential to the reduction of high and low potential molecules. Bifurcating systems can generate biomolecules with very low reduction potentials, such as reduced ferredoxin (Fd), from species such as NADPH. Metabolic systems that use bifurcation are more efficient and confer a competitive advantage for the organisms that harbor them. Structural models are now available for two NADH-dependent ferredoxin-NADP + oxidoreductase (Nfn) complexes. These models, together with spectroscopic studies, have provided considerable insight into the catalytic process of FBEB. However, much about the mechanism and regulation of these multi-subunit proteins remains unclear. Using hydrogen/deuterium exchange mass spectrometry (HDX-MS) and statistical coupling analysis (SCA), we identified specific pathways of communication within the model FBEB system, Nfn from Pyrococus furiosus, under conditions at each step of the catalytic cycle. HDX-MS revealed evidence for allosteric coupling across protein subunits upon nucleotide and ferredoxin binding. SCA uncovered a network of co-evolving residues that can provide connectivity across the complex. Together, the HDX-MS and SCA data show that protein allostery occurs across the ensemble of iron‑sulfur cofactors and ligand binding sites using specific pathways that connect domains allowing them to function as dynamically coordinated units. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Structural Dynamics of the GW182 Silencing Domain Including its RNA Recognition motif (RRM) Revealed by Hydrogen-Deuterium Exchange Mass Spectrometry

    Science.gov (United States)

    Cieplak-Rotowska, Maja K.; Tarnowski, Krzysztof; Rubin, Marcin; Fabian, Marc R.; Sonenberg, Nahum; Dadlez, Michal; Niedzwiecka, Anna

    2018-01-01

    The human GW182 protein plays an essential role in micro(mi)RNA-dependent gene silencing. miRNA silencing is mediated, in part, by a GW182 C-terminal region called the silencing domain, which interacts with the poly(A) binding protein and the CCR4-NOT deadenylase complex to repress protein synthesis. Structural studies of this GW182 fragment are challenging due to its predicted intrinsically disordered character, except for its RRM domain. However, detailed insights into the properties of proteins containing disordered regions can be provided by hydrogen-deuterium exchange mass spectrometry (HDX/MS). In this work, we applied HDX/MS to define the structural state of the GW182 silencing domain. HDX/MS analysis revealed that this domain is clearly divided into a natively unstructured part, including the CCR4-NOT interacting motif 1, and a distinct RRM domain. The GW182 RRM has a very dynamic structure, since water molecules can penetrate the whole domain in 2 h. The finding of this high structural dynamics sheds new light on the RRM structure. Though this domain is one of the most frequently occurring canonical protein domains in eukaryotes, these results are - to our knowledge - the first HDX/MS characteristics of an RRM. The HDX/MS studies show also that the α2 helix of the RRM can display EX1 behavior after a freezing-thawing cycle. This means that the RRM structure is sensitive to environmental conditions and can change its conformation, which suggests that the state of the RRM containing proteins should be checked by HDX/MS in regard of the conformational uniformity. [Figure not available: see fulltext.

  19. Imaging Mass Spectrometry in Neuroscience

    Science.gov (United States)

    2013-01-01

    Imaging mass spectrometry is an emerging technique of great potential for investigating the chemical architecture in biological matrices. Although the potential for studying neurobiological systems is evident, the relevance of the technique for application in neuroscience is still in its infancy. In the present Review, a principal overview of the different approaches, including matrix assisted laser desorption ionization and secondary ion mass spectrometry, is provided with particular focus on their strengths and limitations for studying different neurochemical species in situ and in vitro. The potential of the various approaches is discussed based on both fundamental and biomedical neuroscience research. This Review aims to serve as a general guide to familiarize the neuroscience community and other biomedical researchers with the technique, highlighting its great potential and suitability for comprehensive and specific chemical imaging. PMID:23530951

  20. Mass Spectrometry Applications for Toxicology

    OpenAIRE

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

  1. Mass spectrometry. [review of techniques

    Science.gov (United States)

    Burlingame, A. L.; Kimble, B. J.; Derrick, P. J.

    1976-01-01

    Advances in mass spectrometry (MS) and its applications over the past decade are reviewed in depth, with annotated literature references. New instrumentation and techniques surveyed include: modulated-beam MS, chromatographic MS on-line computer techniques, digital computer-compatible quadrupole MS, selected ion monitoring (mass fragmentography), and computer-aided management of MS data and interpretation. Areas of application surveyed include: organic MS and electron impact MS, field ionization kinetics, appearance potentials, translational energy release, studies of metastable species, photoionization, calculations of molecular orbitals, chemical kinetics, field desorption MS, high pressure MS, ion cyclotron resonance, biochemistry, medical/clinical chemistry, pharmacology, and environmental chemistry and pollution studies.

  2. 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 f...... 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....

  3. 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

    1994-12-31

    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.

  4. 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.

  5. Ninth ISMAS workshop on mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2000-12-01

    Mass spectrometry has wide-ranging applications in such diverse areas as nuclear industry, agriculture, drugs, environment, petroleum and lentils. There is an urgent need to absorb and assimilate state-of-the-art technological developments in the field. Emerging trends in atomic mass spectrometry, advances in organic mass spectrometry, qualitative and quantitative analyses by mass spectrometry and mass spectrometry in oceanography are some of the areas that need to be expeditiously examined and are covered in this volume. Papers relevant to INIS are indexed separately

  6. 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'.

  7. Bulk derivatization and cation exchange restricted access media-based trap-and-elute liquid chromatography–mass spectrometry method for determination of trace estrogens in serum

    Energy Technology Data Exchange (ETDEWEB)

    Beinhauer, Jana [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Bian, Liangqiao [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Fan, Hui [Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX (United States); Šebela, Marek [Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Centre of the Region Haná for Biotechnological and Agricultural Research - Department of Protein Biochemistry and Proteomics, Faculty of Science, Palacký University, Šlechtitelů 11, CZ-783 71 Olomouc (Czech Republic); Kukula, Maciej [Shimadzu Center for Advanced Analytical Chemistry, The University of Texas at Arlington, Arlington, TX (United States); Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); Barrera, Jose A. [Shimadzu Institute for Research Technologies, The University of Texas at Arlington, Arlington, TX (United States); and others

    2015-02-09

    Highlights: • Analysis of estrogens in small volume samples at low parts-per-trillion concentration. • Charged bulk derivatization facilitates on-line ion exchange sample preparation. • On-line WCX restricted access media traps analytes, but not proteins and lipids. • Complete preparation and LC–MS/MS analysis completed in 30 min/sample. - Abstract: Estrone (E1), estradiols (α/β-E2), and estriol (E3) are four major metabolically active estrogens exerting strong biological activities at very low circulating concentrations. This paper reports a sensitive and efficient method with automated, on-line clean-up and detection to determine trace estrogens in a small volume of serum samples using liquid chromatography–electrospray ionization–tandem mass spectrometry directly, without off-line liquid–liquid or solid-phase extraction pretreatments. Serum aliquots (charcoal stripped fetal bovine serum, 100 μL) were spiked with four estrogen standards and their corresponding isotope-labeled internal standards, then bulk derivatized with 2-fluoro-1-methyl-pyridium p-toluenesulfonate (2-FMP) to establish the calibration curves and perform method validation. Calibration was established in the concentration ranges of 5–1000 pg mL{sup −1}, and demonstrated good linearity of R{sup 2} from 0.9944 to 0.9997 for the four derivatized estrogens. The lower detection limits obtained were 3–7 pg mL{sup −1}. Good accuracy and precision in the range of 86–112% and 2.3–11.9%, respectively, were observed for the quality control (QC) samples at low, medium, and high concentration levels. The stability tests showed that the derivatized serum samples were stable 8 h after derivatization at room temperature and at least to 48 h if stored at −20 °C. The method was applied to measure trace estrogens in real human and bovine serum samples, and three of four estrogen compounds studied were observed and quantified.

  8. Different conformational dynamics of β-arrestin1 and β-arrestin2 analyzed by hydrogen/deuterium exchange mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Youngjoo; Kim, Dong Kyun [School of Pharmacy, Sungkyunkwan University, Suwon (Korea, Republic of); Seo, Min-Duk [College of Pharmacy & Department of Molecular Science and Technology, Ajou University, Suwon (Korea, Republic of); Kim, Kyeong-Man [College of Pharmacy, Chonnam National University, Gwang-Ju (Korea, Republic of); Chung, Ka Young, E-mail: kychung2@skku.edu [School of Pharmacy, Sungkyunkwan University, Suwon (Korea, Republic of)

    2015-01-30

    Highlights: • The conformational dynamics of β-arrestin1 or β-arrestin2 were analyzed by HDX-MS. • β-Strands II through IV were more dynamic in β-arrestin2 than in β-arrestin1. • The middle loop was less dynamic in β-arrestin2 than in β-arrestin1. • Upon pre-activation by the R169E mutation, β-arrestins became more dynamic. • Pre-activation affected a wider region of β-arrestin1 compared to β-arrestin2. - Abstract: Arrestins have important roles in G protein-coupled receptor (GPCR) signaling including desensitization of GPCRs and G protein-independent signaling. There have been four arrestins identified: arrestin1, arrestin2 (e.g. β-arrestin1), arrestin3 (e.g. β-arrestin2), and arrestin4. β-Arrestin1 and β-arrestin2 are ubiquitously expressed and regulate a broad range of GPCRs, while arrestin1 and arrestin4 are expressed in the visual system. Although the functions of β-arrestin1 and β-arrestin2 widely overlap, β-arrestin2 has broader receptor selectivity, and a few studies have suggested that β-arrestin1 and β-arrestin2 have distinct cellular functions. Here, we compared the conformational dynamics of β-arrestin1 and β-arrestin2 by hydrogen/deuterium exchange mass spectrometry (HDX-MS). We also used the R169E mutant as a pre-activation model system. HDX-MS data revealed that β-strands II through IV were more dynamic in β-arrestin2 in the basal state, while the middle loop was more dynamic in β-arrestin1. With pre-activation, both β-arrestin1 and β-arrestin2 became more flexible, but broader regions of β-arrestin1 became flexible compared to β-arrestin2. The conformational differences between β-arrestin1 and β-arrestin2 in both the basal and pre-activated states might determine their different receptor selectivities and different cellular functions.

  9. Time resolved native ion-mobility mass spectrometry to monitor dynamics of IgG4 Fab arm exchange and "bispecific" monoclonal antibody formation.

    Science.gov (United States)

    Debaene, François; Wagner-Rousset, Elsa; Colas, Olivier; Ayoub, Daniel; Corvaïa, Nathalie; Van Dorsselaer, Alain; Beck, Alain; Cianférani, Sarah

    2013-10-15

    Monoclonal antibodies (mAbs) and derivatives such as antibody-drug conjugates (ADC) and bispecific antibodies (bsAb), are the fastest growing class of human therapeutics. Most of the therapeutic antibodies currently on the market and in clinical trials are chimeric, humanized, and human immunoglobulin G1 (IgG1). An increasing number of IgG2s and IgG4s that have distinct structural and functional properties are also investigated to develop products that lack or have diminished antibody effector functions compared to IgG1. Importantly, wild type IgG4 has been shown to form half molecules (one heavy chain and one light chain) that lack interheavy chain disulfide bonds and form intrachain disulfide bonds. Moreover, IgG4 undergoes a process of Fab-arm exchange (FAE) in which the heavy chains of antibodies of different specificities can dissociate and recombine in bispecific antibodies both in vitro and in vivo. Here, native mass spectrometry (MS) and time-resolved traveling wave ion mobility MS (TWIM-MS) were used for the first time for online monitoring of FAE and bsAb formation using Hz6F4-2v3 and natalizumab, two humanized IgG4s which bind to human Junctional Adhesion Molecule-A (JAM-A) and alpha4 integrin, respectively. In addition, native MS analysis of bsAb/JAM-A immune complexes revealed that bsAb can bind up to two antigen molecules, confirming that the Hz6F4 family preferentially binds dimeric JAM-A. Our results illustrate how IM-MS can rapidly assess bsAb structural heterogeneity and be easily implemented into MS workflows for bsAb production follow up and bsAb/antigen complex characterization. Altogether, these results provide new MS-based methodologies for in-depth FAE and bsAb formation monitoring. Native MS and IM-MS will play an increasing role in next generation biopharmaceutical product characterization like bsAbs, antibody mixtures, and antibody-drug conjugates (ADC) as well as for biosimilar and biobetter antibodies.

  10. Principle of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Matsuzaki, Hiroyuki

    2007-01-01

    The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

  11. 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

  12. Ion detection in mass spectrometry

    International Nuclear Information System (INIS)

    Bolbach, Gerard

    2016-03-01

    This course aims at providing some elements for a better understanding of ion detectors used in mass spectrometers, of their operations, and of their limitations. A first part addresses the functions and properties of an ideal detector, how to detect ions in gas phase, and particle detectors and ion detectors used in mass spectrometry. The second part proposes an overview of currently used detectors with respect to their operation principle: detection from the ion charge (Faraday cylinder), detection by inductive effects (FTICR, Fourier Transform Ion Cyclotron Resonance), and detection by secondary electron emission. The third part discusses the specificities of secondary electron emission. The fourth one addresses operating modes and parameters related to detectors. The sixth part proposes a prospective view on future detectors by addressing the following issues: cryo-detector, inductive effect and charge detectors, ion detection and nano materials

  13. 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.

  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. PMID:28149262

  15. Radiocarbon positive-ion mass spectrometry

    International Nuclear Information System (INIS)

    Freeman, Stewart P.H.T.; Shanks, Richard P.; Donzel, Xavier; Gaubert, Gabriel

    2015-01-01

    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.

  16. 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.

  17. Probing the Conformational and Functional Consequences of Disulfide Bond Engineering in Growth Hormone by Hydrogen-Deuterium Exchange Mass Spectrometry Coupled to Electron Transfer Dissociation

    DEFF Research Database (Denmark)

    Seger, Signe T; Breinholt, Jens; Faber, Johan H

    2015-01-01

    Human growth hormone (hGH), and its receptor interaction, is essential for cell growth. To stabilize a flexible loop between helices 3 and 4, while retaining affinity for the hGH receptor, we have engineered a new hGH variant (Q84C/Y143C). Here, we employ hydrogen-deuterium exchange mass spectrom......Human growth hormone (hGH), and its receptor interaction, is essential for cell growth. To stabilize a flexible loop between helices 3 and 4, while retaining affinity for the hGH receptor, we have engineered a new hGH variant (Q84C/Y143C). Here, we employ hydrogen-deuterium exchange mass...

  18. OBT measurement of vegetation by mass spectrometry and radiometry

    International Nuclear Information System (INIS)

    Tamari, T.; Kakiuchi, H.; Momoshima, N.; Sugihara, S.; Baglan, N.; Uda, T.

    2011-01-01

    We carried out OBT (organically bound tritium) measurement by two different methods those are radiometry and mass spectrometry and compared the applicability of these methods for environmental tritium analysis. The dried grass sample was used for the experiments. To eliminate the exchangeable OBT, the sample was washed with tritium free water before analysis. Three times washing reduced the tritium activity in the labile sites below the detectable level. In radiometry the sample was combusted to convert the OBT as well as other hydrogen isotopes to. water and tritium activity in the water was measured by liquid scintillation counting (LSC). In mass spectrometry, the sample was kept in a glass container and 3 He produced by tritium decay was measured by mass spectrometry. The results were in good agreement suggesting applicability of these methods for environmental tritium analysis. The mass spectrometry is more suitable for environmental tritium research because of a lower detection limit than that of the LSC. (authors)

  19. Role of Mass Spectrometry in Clinical Endocrinology.

    Science.gov (United States)

    Ketha, Siva S; Singh, Ravinder J; Ketha, Hemamalini

    2017-09-01

    The advent of mass spectrometry into the clinical laboratory has led to an improvement in clinical management of several endocrine diseases. Liquid chromatography tandem mass spectrometry found some of its first clinical applications in the diagnosis of inborn errors of metabolism, in quantitative steroid analysis, and in drug analysis laboratories. Mass spectrometry assays offer analytical sensitivity and specificity that is superior to immunoassays for many analytes. This article highlights several areas of clinical endocrinology that have witnessed the use of liquid chromatography tandem mass spectrometry to improve clinical outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Accelerator mass spectrometry in NIPNE

    International Nuclear Information System (INIS)

    Ivascu, M; Marinescu, L.; Dima, R.; Cata-Danil, D.; Petrascu, M.; Popescu, I.; Stan-Sion, C.; Radulescu, M.; Plostinaru, D.

    1997-01-01

    The Accelerator Mass Spectrometry (AMS) is today the method capable to measure the lowest concentration of a particular nuclide in sample materials. The method has applications in environmental physics, medicine, measurements of cosmic-ray or nuclear power plant produced radionuclides in the earth's atmosphere. All over the world, more than 40 charged particles and heavy ion accelerators are performing such analyses concerning the research interest of a huge number of laboratories. The Romanian Institute of Nuclear Physics and Engineering in Bucharest has initiated a construction project for the AMS facility at the FN - Van de Graaff Tandem accelerator. This program benefits of technical and financial assistance provided by IAEA in the frame of the IAEA-TC Project ROM 8014-265C. A general lay-out of the AMS project is presented. The construction work has begun and first tests of the AMS injector will take place between July - September this year. (authors)

  1. A REVIEW ON MASS SPECTROMETRY DETECTORS

    OpenAIRE

    Khatri Neetu; Gupta Ankit; Taneja Ruchi; Bilandi Ajay; Beniwal Prashant

    2012-01-01

    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 ...

  2. Alpha spectrometry and secondary ion mass spectrometry of thorium

    International Nuclear Information System (INIS)

    Strisovska, Jana; Kuruc, Jozef; Galanda, Dusan; Matel, Lubomir; Velic, Dusan; Aranyosiova, Monika

    2009-01-01

    A sample of thorium content on steel discs was prepared by electrodeposition with a view to determining the natural thorium isotope. Thorium was determined by alpha spectrometry and by secondary ion mass spectrometry and the results of the two methods were compared

  3. 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...

  4. Atom counting with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kutschera, Walter

    1995-01-01

    A brief review of the current status and some recent applications of accelerator mass spectrometry (AMS) are presented. Some connections to resonance ionization mass spectroscopy (RIS) as the alternate atom counting method are discussed

  5. Mass spectrometry-assisted protease substrate screening

    DEFF Research Database (Denmark)

    Schlüter, Hartmut; Rykl, Jana; Thiemann, Joachim

    2007-01-01

    -phase chromatography they are analyzed by tandem mass spectrometry and the substrates identified by database searching. The proof of principle in this study is demonstrated by incubating immobilized human plasma proteins with thrombin and by identifying by tandem mass spectrometry the fibrinopeptides, released...

  6. Inorganic mass spectrometry of solid samples

    International Nuclear Information System (INIS)

    Adams, F.; Vertes, A.

    1990-01-01

    In this review some recent developments in the field of inorganic mass spectrometry of solids are described with special emphasis on the actual state of understanding of the ionization processes. It concentrates on the common characteristics of methods such as spark source-, laser-, secondary ion-, inductively coupled plasma- and glow discharge mass spectrometry. (orig.)

  7. Surface analysis by imaging mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Vidová, Veronika; Volný, Michael; Lemr, Karel; Havlíček, Vladimír

    2009-01-01

    Roč. 74, 7-8 (2009), s. 1101-1116 ISSN 0010-0765 Institutional research plan: CEZ:AV0Z50200510 Keywords : secondary ion mass spectrometry * matrix assisted laser desorption ionization * mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.856, year: 2009

  8. Introduction to mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Matthiesen, R.; Bunkenborg, J.

    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 informati...

  9. Development of anion-exchange/reversed-phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry methods for the speciation of bio-available iodine and bromine from edible seaweed.

    Science.gov (United States)

    Romarís-Hortas, Vanessa; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2012-05-04

    Anion exchange high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry has been novelly applied to assess inorganic (iodide and iodate) and organic (3-iodotyrosine - MIT, and 3,5-diiodotyrosine - DIT) iodine species in a single chromatographic run. The optimized operating conditions (Dionex IonPac AS7, gradient elution with 175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase and flow rates within the 0.5-1.5 mL min(-1) range) have also been used to perform inorganic bromine speciation analysis (bromide and bromate). The developed method has been applied for determining the bio-available contents of iodine and bromine species in dialyzates from edible seaweed. Reverse phase high performance liquid chromatography (Zorbax Eclipse XDB-C8, gradient elution with 0.2% (m/m) acetic acid, and 0.2% (m/m) acetic acid in methanol, as mobile phases, and a constant flow rate of 0.75 mL min(-1)) also hyphenated with inductively coupled plasma-mass spectrometry was used to confirm the presence of organic iodine species (MIT and DIT) in the dialyzates. The verification of the presence of iodinated amino acids (MIT and DIT) in the extracts was also performed by reverse phase high performance liquid chromatography-electrospray ionization-mass spectrometry (LTQ Orbitrap). The developed methods have provided good repeatability (RSD values lower than 10% for both anion exchange and reverse phase separations) and analytical recoveries within the 90-105% range for all cases. The in vitro bio-availability method consisted of a simulated gastric and an intestinal digestion/dialysis (10 kDa molecular weight cut-off - MWCO) two-stage procedure. Iodide and MIT were the main bio-available species quantified, whereas bromide was the major bromine species found in the extracts. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Zero voltage mass spectrometry probes and systems

    Science.gov (United States)

    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.

  11. Mass spectrometry at the Pittsburgh conference

    International Nuclear Information System (INIS)

    Borman, S.

    1987-01-01

    Each year analytical chemists flock to the Pittsburgh Conference to learn about the latest trends in analytical instrumentation. In this Focus, a number of prominent mass spectroscopists who attended this year's meeting in Atlantic City, NJ, discuss their perceptions of current developments in the field of mass spectrometry (MS). In the June 1 issue of Analytical Chemistry, the authors coverage of the Pittsburgh Conferences continues with a follow-up article on specific developments in hyphenated mass spectrometry - primarily liquid chromatography - MS (LC/MS) and gas chromatography - infrared spectrometry MS (GC/IR/MS)

  12. Chromatography–mass spectrometry in aerospace industry

    International Nuclear Information System (INIS)

    Buryak, Alexey K; Serduk, T M

    2013-01-01

    The applications of chromatography–mass spectrometry in aerospace industry are considered. The primary attention is devoted to the development of physicochemical grounds of the use of various chromatography–mass spectrometry procedures to solve topical problems of this industry. Various methods for investigation of the composition of rocket fuels, surfaces of structural materials and environmental media affected by aerospace activities are compared. The application of chromatography–mass spectrometry for the development and evaluation of processes for decontaminations of equipment, industrial wastes and soils from rocket fuel components is substantiated. The bibliography includes 135 references.

  13. Determination of ethephon residues in water by gas chromatography with cubic mass spectrometry after ion-exchange purification and derivatisation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide.

    Science.gov (United States)

    Royer, A; Laporte, F; Bouchonnet, S; Communal, P-Y

    2006-03-03

    An analytical method has been developed for the determination of residues of ethephon (2-chloroethyl phosphonic acid) in drinking and surface water. The procedure is based on de-ionisation with an anion/cation-exchange resin, solid phase extraction by means of anion-exchange polystyrene-divinylbenzene extraction disks, elution with a mixture of methanol and 10 M hydrochloric acid (98/2, v/v), redisolution into acetonitrile after evaporation and silylation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA). Quantification is performed by gas chromatography with ion-trap cubic mass spectrometric detection in the electron impact mode (GC-EI-MS3). Method validation was conducted using samples of mineral, tap, and river water that were fortified with ethephon at concentration levels ranging from 0.1 to 1.0 microg/L. The mean recovery from all the fortified samples (n = 36) amounted to 88% with a relative standard deviation of 17%. The method, therefore, was shown to allow accurate determination of ethephon residues in drinking and surface water with a limit of quantification of 0.1 microg/L.

  14. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

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

  15. Ultra-sensitive radionuclide spectrometry. Radiometrics and mass spectrometry synergy

    International Nuclear Information System (INIS)

    Povinec, P.P.

    2005-01-01

    Recent developments in radiometrics and mass spectrometry techniques for ultra-sensitive analysis of radionuclides in the marine environment are reviewed. In the radiometrics sector the dominant development has been the utilization of large HPGe detectors in underground laboratories with anti-cosmic or anti-Compton shielding for the analysis of short and medium-lived radionuclides in the environment. In the mass spectrometry sector, applications of inductively coupled plasma mass spectrometry (ICP-MS) and accelerator mass spectrometry (AMS) for the analysis of long-lived radionuclides in the environment are the most important recent achievements. The recent developments do not only considerably decrease the detection limits for several radionuclides (up to several orders of magnitude), but they also enable to decrease sample volumes so that sampling, e.g., of the water column can be much easier and more effective. A comparison of radiometrics and mass spectrometry results for the analysis of radionuclides in the marine environment shows a reasonable agreement - within quoted uncertainties, for wide range of activities and different sample matrices analyzed. (author)

  16. Tandem mass spectrometry at low kinetic energy

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  17. 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. © 2013 Wiley Periodicals, Inc.

  18. Methods for recalibration of mass spectrometry data

    Science.gov (United States)

    Tolmachev, Aleksey V [Richland, WA; Smith, Richard D [Richland, WA

    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.

  19. 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.

  20. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  1. Mass Spectrometry-Based Biomarker Discovery.

    Science.gov (United States)

    Zhou, Weidong; Petricoin, Emanuel F; Longo, Caterina

    2017-01-01

    The discovery of candidate biomarkers within the entire proteome is one of the most important and challenging goals in proteomic research. Mass spectrometry-based proteomics is a modern and promising technology for semiquantitative and qualitative assessment of proteins, enabling protein sequencing and identification with exquisite accuracy and sensitivity. For mass spectrometry analysis, protein extractions from tissues or body fluids and subsequent protein fractionation represent an important and unavoidable step in the workflow for biomarker discovery. Following extraction of proteins, the protein mixture must be digested, reduced, alkylated, and cleaned up prior to mass spectrometry. The aim of our chapter is to provide comprehensible and practical lab procedures for sample digestion, protein fractionation, and subsequent mass spectrometry analysis.

  2. Radiation Biomarker Research Using Mass Spectrometry

    National Research Council Canada - National Science Library

    Bach, Stephan B; Hubert, Walter

    2007-01-01

    .... This review is intended to give an overview of mass spectrometry and its application to biological systems and biomarker discovery and how that might relate to relevant radiation dosimetry studies...

  3. Mass Spectrometry Analyses of Multicellular Tumor Spheroids.

    Science.gov (United States)

    Acland, Mitchell; Mittal, Parul; Lokman, Noor A; Klingler-Hoffmann, Manuela; Oehler, Martin K; Hoffmann, Peter

    2018-05-01

    Multicellular tumor spheroids (MCTS) are a powerful biological in vitro model, which closely mimics the 3D structure of primary avascularized tumors. Mass spectrometry (MS) has established itself as a powerful analytical tool, not only to better understand and describe the complex structure of MCTS, but also to monitor their response to cancer therapeutics. The first part of this review focuses on traditional mass spectrometry approaches with an emphasis on elucidating the molecular characteristics of these structures. Then the mass spectrometry imaging (MSI) approaches used to obtain spatially defined information from MCTS is described. Finally the analysis of primary spheroids, such as those present in ovarian cancer, and the great potential that mass spectrometry analysis of these structures has for improved understanding of cancer progression and for personalized in vitro therapeutic testing is discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Mass spectrometry in life science research.

    Science.gov (United States)

    Lehr, Stefan; Markgraf, Daniel

    2016-12-01

    Investigating complex signatures of biomolecules by mass spectrometry approaches has become indispensable in molecular life science research. Nowadays, various mass spectrometry-based omics technologies are available to monitor qualitative and quantitative changes within hundreds or thousands of biological active components, including proteins/peptides, lipids and metabolites. These comprehensive investigations have the potential to decipher the pathophysiology of disease development at a molecular level and to monitor the individual response of pharmacological treatment or lifestyle intervention.

  5. Mass Spectrometry in the Home and Garden

    Science.gov (United States)

    Pulliam, Christopher J.; Bain, Ryan M.; Wiley, Joshua S.; Ouyang, Zheng; Cooks, R. Graham

    2015-02-01

    Identification of active components in a variety of chemical products used directly by consumers is described at both trace and bulk levels using mass spectrometry. The combination of external ambient ionization with a portable mass spectrometer capable of tandem mass spectrometry provides high chemical specificity and sensitivity as well as allowing on-site monitoring. These experiments were done using a custom-built portable ion trap mass spectrometer in combination with the ambient ionization methods of paper spray, leaf spray, and low temperature plasma ionization. Bactericides, garden chemicals, air fresheners, and other products were examined. Herbicide applied to suburban lawns was detected in situ on single leaves 5 d after application.

  6. The mzTab data exchange format: communicating mass-spectrometry-based proteomics and metabolomics experimental results to a wider audience.

    Science.gov (United States)

    Griss, Johannes; Jones, Andrew R; Sachsenberg, Timo; Walzer, Mathias; Gatto, Laurent; Hartler, Jürgen; Thallinger, Gerhard G; Salek, Reza M; Steinbeck, Christoph; Neuhauser, Nadin; Cox, Jürgen; Neumann, Steffen; Fan, Jun; Reisinger, Florian; Xu, Qing-Wei; Del Toro, Noemi; Pérez-Riverol, Yasset; Ghali, Fawaz; Bandeira, Nuno; Xenarios, Ioannis; Kohlbacher, Oliver; Vizcaíno, Juan Antonio; Hermjakob, Henning

    2014-10-01

    The HUPO Proteomics Standards Initiative has developed several standardized data formats to facilitate data sharing in mass spectrometry (MS)-based proteomics. These allow researchers to report their complete results in a unified way. However, at present, there is no format to describe the final qualitative and quantitative results for proteomics and metabolomics experiments in a simple tabular format. Many downstream analysis use cases are only concerned with the final results of an experiment and require an easily accessible format, compatible with tools such as Microsoft Excel or R. We developed the mzTab file format for MS-based proteomics and metabolomics results to meet this need. mzTab is intended as a lightweight supplement to the existing standard XML-based file formats (mzML, mzIdentML, mzQuantML), providing a comprehensive summary, similar in concept to the supplemental material of a scientific publication. mzTab files can contain protein, peptide, and small molecule identifications together with experimental metadata and basic quantitative information. The format is not intended to store the complete experimental evidence but provides mechanisms to report results at different levels of detail. These range from a simple summary of the final results to a representation of the results including the experimental design. This format is ideally suited to make MS-based proteomics and metabolomics results available to a wider biological community outside the field of MS. Several software tools for proteomics and metabolomics have already adapted the format as an output format. The comprehensive mzTab specification document and extensive additional documentation can be found online. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. The mzTab Data Exchange Format: Communicating Mass-spectrometry-based Proteomics and Metabolomics Experimental Results to a Wider Audience*

    Science.gov (United States)

    Griss, Johannes; Jones, Andrew R.; Sachsenberg, Timo; Walzer, Mathias; Gatto, Laurent; Hartler, Jürgen; Thallinger, Gerhard G.; Salek, Reza M.; Steinbeck, Christoph; Neuhauser, Nadin; Cox, Jürgen; Neumann, Steffen; Fan, Jun; Reisinger, Florian; Xu, Qing-Wei; del Toro, Noemi; Pérez-Riverol, Yasset; Ghali, Fawaz; Bandeira, Nuno; Xenarios, Ioannis; Kohlbacher, Oliver; Vizcaíno, Juan Antonio; Hermjakob, Henning

    2014-01-01

    The HUPO Proteomics Standards Initiative has developed several standardized data formats to facilitate data sharing in mass spectrometry (MS)-based proteomics. These allow researchers to report their complete results in a unified way. However, at present, there is no format to describe the final qualitative and quantitative results for proteomics and metabolomics experiments in a simple tabular format. Many downstream analysis use cases are only concerned with the final results of an experiment and require an easily accessible format, compatible with tools such as Microsoft Excel or R. We developed the mzTab file format for MS-based proteomics and metabolomics results to meet this need. mzTab is intended as a lightweight supplement to the existing standard XML-based file formats (mzML, mzIdentML, mzQuantML), providing a comprehensive summary, similar in concept to the supplemental material of a scientific publication. mzTab files can contain protein, peptide, and small molecule identifications together with experimental metadata and basic quantitative information. The format is not intended to store the complete experimental evidence but provides mechanisms to report results at different levels of detail. These range from a simple summary of the final results to a representation of the results including the experimental design. This format is ideally suited to make MS-based proteomics and metabolomics results available to a wider biological community outside the field of MS. Several software tools for proteomics and metabolomics have already adapted the format as an output format. The comprehensive mzTab specification document and extensive additional documentation can be found online. PMID:24980485

  8. Sm isotope composition and Sm/Eu ratio determination in an irradiated 153Eu sample by ion exchange chromatography-quadrupole inductively coupled plasma mass spectrometry combined with double spike isotope dilution technique

    International Nuclear Information System (INIS)

    Bourgeois, M.; Isnard, H.; Gourgiotis, A.; Stadelmann, G.; Gautier, C.; Mialle, S.; Nonell, A.; Chartier, F.

    2011-01-01

    Within the framework of the research undertaken by the French Atomic Energy Commission on transmutation of long-lived radionuclides, targets of highly enriched actinides and fission products were irradiated in the fast neutron reactor Phenix. Precise and accurate measurements of the isotopic and elemental composition of the enriched elements are therefore required. In order to obtain the uncertainties of several per mil and to reduce handling time and exposure to analyst on radioactive material, the on-line coupling of ion exchange chromatography with quadrupole inductively coupled plasma mass spectrometry has been associated with the technique of the double spike isotope dilution. We present in this paper the results obtained on an irradiated sample of Europium oxide powder (enriched at 99.13% in 153 Eu). After irradiation of around 5 mg of Eu 2 O 3 powder the theoretical calculations predict the formation of several micrograms of gadolinium and samarium isotopes. In relation to the very high activity of the sample after irradiation and the very low quantity of Sm formed, the on-line ion exchange chromatography separation of Gd, Sm and Eu before Sm isotope ratio measurements has been developed for the quantification of the 152 Sm/ 153 Eu ratio. These on-line measurements were associated with the double spike isotope dilution technique after calibration of a 147 Sm/ 151 Eu spike solution. The external reproducibility of Sm isotopic ratios was determined to be around 0.5% (2 σ) resulting in a final uncertainty on the 152 Sm/ 153 Eu ratio of around 1% (2 σ). These on-line measurements present therefore a robust and high-throughput alternative to the thermal-ionisation mass spectrometry technique used so far in combination with off-line chromatographic separation, particularly in nuclear applications where characterisation of high activity sample solutions is required. (authors)

  9. Gas-phase ion/molecule isotope-exchange reactions: methodology for counting hydrogen atoms in specific organic structural environments by chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Hunt, D.F.; Sethi, S.K.

    1980-01-01

    Ion/molecule reactions are described which facilitate exchange of hydrogens for deuteriums in a variety of different chemical environments. Aromatic hydrogens in alkylbenzenes, oxygenated benzenes, m-toluidine, m-phenylenediamine, thiophene, and several polycyclic aromatic hydrocarbons and metallocenes are exchanged under positive ion CI conditions by using either D 2 O, EtOD, or ND 3 as the reagent gas. Aromatic hydrogens, benzylic hydrogens, and hydrogens on carbon adjacent to carbonyl groups suffer exchange under negative ion CI conditions in ND 3 , D 2 O, and EtOD, respectively. A possible mechanism for the exchange process is discussed. 1 figure, 2 tables

  10. Analysis of mass spectrometry data in proteomics

    DEFF Research Database (Denmark)

    Matthiesen, Rune; Jensen, Ole N

    2008-01-01

    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...... 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...... some of the basic concepts and current approaches to the analysis of MS and MS/MS data in proteomics....

  11. Mass spectrometry: a revolution in clinical microbiology?

    Science.gov (United States)

    Lavigne, Jean-Philippe; Espinal, Paula; Dunyach-Remy, Catherine; Messad, Nourredine; Pantel, Alix; Sotto, Albert

    2013-02-01

    Recently, different bacteriological laboratory interventions that decrease reporting time have been developed. These promising new broad-based techniques have merit, based on their ability to identify rapidly many bacteria, organisms difficult to grow or newly emerging strains, as well as their capacity to track disease transmission. The benefit of rapid reporting of identification and/or resistance of bacteria can greatly impact patient outcomes, with an improvement in the use of antibiotics, in the reduction of the emergence of multidrug resistant bacteria and in mortality rates. Different techniques revolve around mass spectrometry (MS) technology: matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), PCR combined with electrospray ionization-mass spectrometry (PCR/ESIMS), iPLEX MassArray system and other new evolutions combining different techniques. This report emphasizes the (r)evolution of these technologies in clinical microbiology.

  12. Approach to characterization of the higher order structure of disulfide-containing proteins using hydrogen/deuterium exchange and top-down mass spectrometry.

    Science.gov (United States)

    Wang, Guanbo; Kaltashov, Igor A

    2014-08-05

    Top-down hydrogen/deuterium exchange (HDX) with mass spectrometric (MS) detection has recently matured to become a potent biophysical tool capable of providing valuable information on higher order structure and conformational dynamics of proteins at an unprecedented level of structural detail. However, the scope of the proteins amenable to the analysis by top-down HDX MS still remains limited, with the protein size and the presence of disulfide bonds being the two most important limiting factors. While the limitations imposed by the physical size of the proteins gradually become more relaxed as the sensitivity, resolution and dynamic range of modern MS instrumentation continue to improve at an ever accelerating pace, the presence of the disulfide linkages remains a much less forgiving limitation even for the proteins of relatively modest size. To circumvent this problem, we introduce an online chemical reduction step following completion and quenching of the HDX reactions and prior to the top-down MS measurements of deuterium occupancy of individual backbone amides. Application of the new methodology to the top-down HDX MS characterization of a small (99 residue long) disulfide-containing protein β2-microglobulin allowed the backbone amide protection to be probed with nearly a single-residue resolution across the entire sequence. The high-resolution backbone protection pattern deduced from the top-down HDX MS measurements carried out under native conditions is in excellent agreement with the crystal structure of the protein and high-resolution NMR data, suggesting that introduction of the chemical reduction step to the top-down routine does not trigger hydrogen scrambling either during the electrospray ionization process or in the gas phase prior to the protein ion dissociation.

  13. Mass spectrometry in nuclear science and technology

    International Nuclear Information System (INIS)

    Komori, Takuji

    1985-01-01

    Mass spectrometry has been widely used and playing a very important role in the field of nuclear science and technology. A major reason for this is that not only the types of element but also its isotopes have to be identified and measured in this field. Thus, some applications of this analytical method are reviewed and discussed in this article. Its application to analytical chemistry is described in the second section following an introductory section, which includes subsections for isotropic dilution mass spectrometry, resonance ionization mass spectrometry and isotopic correlation technique. The isotopic ratio measurement for hydrogen, uranium and plutonium as well as nuclear material control and safeguards are also reviewed in this section. In the third section, mass spectrometry is discussed in relation to nuclear reactors, with subsections on natural uranium reactor and neutron flux observation. Some techniques for measuring the burnup fraction, including the heavy isotopic ratio method and fission product monitoring, are also described. In the fourth section, application of mass spectrometry to measurement of nuclear constants, such as ratio of effective cross-sectional area for 235 U, half-life and fission yield is reviewed. (Nogami, K.)

  14. 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 .

  15. Co-existence of two different α-synuclein oligomers with different core structures determined by hydrogen/deuterium exchange mass spectrometry

    DEFF Research Database (Denmark)

    Paslawski, Wojciech; Mysling, Simon; Thomsen, Karen

    2014-01-01

    Neurodegenerative disorders are characterized by the formation of protein oligomers and amyloid fibrils, which in the case of Parkinson's disease involves the protein α-synuclein (αSN). Cytotoxicity is mainly associated with the oligomeric species, but we still know little about their assembly...... are protected from exchange with D2 O until they dissociate into monomeric αSN by EX1 exchange kinetics. Fewer residues are protected against exchange in oligomer type II, but this type does not revert to αSN monomers. Both oligomers are protected in the core sequence Y39-A89. Based on incubation studies...

  16. [Imaging Mass Spectrometry in Histopathologic Analysis].

    Science.gov (United States)

    Yamazaki, Fumiyoshi; Seto, Mitsutoshi

    2015-04-01

    Matrix-assisted laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS) enables visualization of the distribution of a range of biomolecules by integrating biochemical information from mass spectrometry with positional information from microscopy. IMS identifies a target molecule. In addition, IMS enables global analysis of biomolecules containing unknown molecules by detecting the ratio of the molecular weight to electric charge without any target, which makes it possible to identify novel molecules. IMS generates data on the distribution of lipids and small molecules in tissues, which is difficult to visualize with either conventional counter-staining or immunohistochemistry. In this review, we firstly introduce the principle of imaging mass spectrometry and recent advances in the sample preparation method. Secondly, we present findings regarding biological samples, especially pathological ones. Finally, we discuss the limitations and problems of the IMS technique and clinical application, such as in drug development.

  17. Sequencing Cyclic Peptides by Multistage Mass Spectrometry

    Science.gov (United States)

    Mohimani, Hosein; Yang, Yu-Liang; Liu, Wei-Ting; Hsieh, Pei-Wen; Dorrestein, Pieter C.; Pevzner, Pavel A.

    2012-01-01

    Some of the most effective antibiotics (e.g., Vancomycin and Daptomycin) are cyclic peptides produced by non-ribosomal biosynthetic pathways. While hundreds of biomedically important cyclic peptides have been sequenced, the computational techniques for sequencing cyclic peptides are still in their infancy. Previous methods for sequencing peptide antibiotics and other cyclic peptides are based on Nuclear Magnetic Resonance spectroscopy, and require large amount (miligrams) of purified materials that, for most compounds, are not possible to obtain. Recently, development of mass spectrometry based methods has provided some hope for accurate sequencing of cyclic peptides using picograms of materials. In this paper we develop a method for sequencing of cyclic peptides by multistage mass spectrometry, and show its advantages over single stage mass spectrometry. The method is tested on known and new cyclic peptides from Bacillus brevis, Dianthus superbus and Streptomyces griseus, as well as a new family of cyclic peptides produced by marine bacteria. PMID:21751357

  18. Effects of air exchange, temperature and slurry management on odorant emissions from pig production units and slurry tanks studied by proton-transfer-reaction mass spectrometry (PTR-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Feilberg, A.; Adamsen, A.P.S.; Liu, D.; Hansen, M.J.; Bildsoe, P. [Aarhus Univ., Tjele (Denmark). Dept. of Biosystems Engineering

    2010-07-01

    The factors affecting the variability of odorant emissions from intensive pig production facilities were examined using proton-transfer-reaction mass spectrometry (PTR-MS) to monitor emissions of odorants. Quantitative and time-resolved results for protonated ions representing hydrogen sulphide (H{sub 2}S), volatile organic sulphur compounds, organic amines, volatile carboxylic acids, carbonyls, phenols and indoles can be obtained. This study presented the results from PTRMS measurements of odorant emissions from finisher pig houses and finisher manure storage tanks. The measurements were performed at an experimental full-scale pig section with mechanical ventilation and at an experimental manure storage facility with controlled air exchange. Field measurements were taken during variable air exchange rates and temperatures, during finisher growth, and during emptying of the slurry pit. The results revealed a pronounced diurnal variation in emissions of odorants from the pig section with peaks in daytime coinciding with the highest ventilation rates and highest room temperatures. The highest emission rates were observed for H{sub 2}S and carboxylic acids. Based on odour threshold values, methanethiol and 4-methylphenol were estimated to contribute considerably to the odour nuisance. Discharging of the slurry pit led to reduced H{sub 2}S emissions, but peaks of H{sub 2}S were observed during manure handling.

  19. Parsimonious Charge Deconvolution for Native Mass Spectrometry

    Science.gov (United States)

    2018-01-01

    Charge deconvolution infers the mass from mass over charge (m/z) measurements in electrospray ionization mass spectra. When applied over a wide input m/z or broad target mass range, charge-deconvolution algorithms can produce artifacts, such as false masses at one-half or one-third of the correct mass. Indeed, a maximum entropy term in the objective function of MaxEnt, the most commonly used charge deconvolution algorithm, favors a deconvolved spectrum with many peaks over one with fewer peaks. Here we describe a new “parsimonious” charge deconvolution algorithm that produces fewer artifacts. The algorithm is especially well-suited to high-resolution native mass spectrometry of intact glycoproteins and protein complexes. Deconvolution of native mass spectra poses special challenges due to salt and small molecule adducts, multimers, wide mass ranges, and fewer and lower charge states. We demonstrate the performance of the new deconvolution algorithm on a range of samples. On the heavily glycosylated plasma properdin glycoprotein, the new algorithm could deconvolve monomer and dimer simultaneously and, when focused on the m/z range of the monomer, gave accurate and interpretable masses for glycoforms that had previously been analyzed manually using m/z peaks rather than deconvolved masses. On therapeutic antibodies, the new algorithm facilitated the analysis of extensions, truncations, and Fab glycosylation. The algorithm facilitates the use of native mass spectrometry for the qualitative and quantitative analysis of protein and protein assemblies. PMID:29376659

  20. Fourier transform ion cyclotron resonance mass spectrometry

    Science.gov (United States)

    Marshall, Alan G.

    1998-06-01

    As for Fourier transform infrared (FT-IR) interferometry and nuclear magnetic resonance (NMR) spectroscopy, the introduction of pulsed Fourier transform techniques revolutionized ion cyclotron resonance mass spectrometry: increased speed (factor of 10,000), increased sensitivity (factor of 100), increased mass resolution (factor of 10,000-an improvement not shared by the introduction of FT techniques to IR or NMR spectroscopy), increased mass range (factor of 500), and automated operation. FT-ICR mass spectrometry is the most versatile technique for unscrambling and quantifying ion-molecule reaction kinetics and equilibria in the absence of solvent (i.e., the gas phase). In addition, FT-ICR MS has the following analytically important features: speed (~1 second per spectrum); ultrahigh mass resolution and ultrahigh mass accuracy for analysis of mixtures and polymers; attomole sensitivity; MSn with one spectrometer, including two-dimensional FT/FT-ICR/MS; positive and/or negative ions; multiple ion sources (especially MALDI and electrospray); biomolecular molecular weight and sequencing; LC/MS; and single-molecule detection up to 108 Dalton. Here, some basic features and recent developments of FT-ICR mass spectrometry are reviewed, with applications ranging from crude oil to molecular biology.

  1. Determination of mycophenolic acid in mest products using mixed mode reversed phase-anion exchange clean-up and liquid chromatography-high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Sørensen, Louise Marie; Nielsen, Kristian Fog; Jacobsen, Thomas

    2008-01-01

    A method for determination of mycophenolic acid (MPA) in dry-cured ham, fermented sausage and liver pate is described. MPA was extracted from meat with bicarbonate-acetonitrile, further cleaned-up by mixed mode reversed phase-anion exchange and detected using a LC-MS system with electrospray...

  2. Rapid isolation of plutonium in environmental solid samples using sequential injection anion exchange chromatography followed by detection with inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Qiao Jixin, E-mail: jixin.qiao@risoe.d [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark); Hou Xiaolin; Roos, Per [Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, DK-4000 Roskilde (Denmark); Miro, Manuel [Department of Chemistry, Faculty of Sciences, University of the Balearic Islands, Carretera de Valldemossa km. 7.5, E-07122 Palma de Mallorca, Illes Balears (Spain)

    2011-01-31

    This paper reports an automated analytical method for rapid determination of plutonium isotopes ({sup 239}Pu and {sup 240}Pu) in environmental solid extracts. Anion exchange chromatographic columns were incorporated in a sequential injection (SI) system to undertake the automated separation of plutonium from matrix and interfering elements. The analytical results most distinctly demonstrated that the crosslinkage of the anion exchanger is a key parameter controlling the separation efficiency. AG 1-x4 type resin was selected as the most suitable sorbent material for analyte separation. Investigation of column size effect upon the separation efficiency revealed that small-sized (2 mL) columns sufficed to handle up to 50 g of environmental soil samples. Under the optimum conditions, chemical yields of plutonium exceeded 90% and the decontamination factors for uranium, thorium and lead ranged from 10{sup 3} to 10{sup 4}. The determination of plutonium isotopes in three standard/certified reference materials (IAEA-375 soil, IAEA-135 sediment and NIST-4359 seaweed) and two reference samples (Irish Sea sediment and Danish soil) revealed a good agreement with reference/certified values. The SI column-separation method is straightforward and less labor intensive as compared with batch-wise anion exchange chromatographic procedures. Besides, the automated method features low consumption of ion-exchanger and reagents for column washing and elution, with the consequent decrease in the generation of acidic waste, thus bearing green chemical credentials.

  3. Mass spectrometry applied to high temperature chemistry, (2)

    International Nuclear Information System (INIS)

    Asano, Mitsuru; Kato, Eiichi; Sata, Toshiyuki.

    1980-01-01

    The application of mass spectrometry to high temperature chemistry is reviewed. As a blanket material for fusion reactors, the behavior of lithium has been investigated by using mass analysers. The enthalpies of the chemical reactions of metallic lithium were obtained. The enthalpies of isomolecular exchange reactions and the derived atomization energies of LiD, Li 2 D and Li 2 D 2 were also obtained by mass spectrometry. The thermomechanical character of lithium oxide was studied. The vaporization behaviors of LiCrO 2 and Li 5 FeO 4 were studied with a quadrupole mass analyser. The vaporization of cobalt from nickel alloy was studied. The evaporated ions were analysed with a mass analyser. The measurement of the vaporized molecules of metals and fused silicate was made by mass spectrometry. The activities of Fe-V system were determined by measuring the ion current ratio. The activities of Fe-V-Cr system were also obtained. The vapor pressure of phosphor from Fe-P alloys can be measured. The activity coefficients and interaction parameters for the dilute solutions of elements, such as Mn, Al, Cu, Cr, Co, Ni, Si, Ti, V, B, Zr, Mo, C, S, and P, dissolved in liquid iron are shown in a table. The activities of NaCl-KCl system were derived by measuring the ion current ratio and by monomer-dimer method. (Kato, T.)

  4. 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.

  5. Laser-induced mass spectrometry

    International Nuclear Information System (INIS)

    Polanyi, J.C.

    1981-01-01

    This invention provides a method for the spectroscopic analysis of gas. The gas molecules are internally excited by irradiation with laser light having a wavelength which is absorbed by the sample. The gas is then ionized and passed through a mass spectrometer and the amount of the ionized species in the irradiated and ionized sample is compared with that in a similar ionized but not irradiated sample

  6. Phylogenetic Analysis Using Protein Mass Spectrometry.

    Science.gov (United States)

    Ma, Shiyong; Downard, Kevin M; Wong, Jason W H

    2017-01-01

    Through advances in molecular biology, comparative analysis of DNA sequences is currently the cornerstone in the study of molecular evolution and phylogenetics. Nevertheless, protein mass spectrometry offers some unique opportunities to enable phylogenetic analyses in organisms where DNA may be difficult or costly to obtain. To date, the methods of phylogenetic analysis using protein mass spectrometry can be classified into three categories: (1) de novo protein sequencing followed by classical phylogenetic reconstruction, (2) direct phylogenetic reconstruction using proteolytic peptide mass maps, and (3) mapping of mass spectral data onto classical phylogenetic trees. In this chapter, we provide a brief description of the three methods and the protocol for each method along with relevant tools and algorithms.

  7. Identification of bacteria using mass spectrometry techniques

    Czech Academy of Sciences Publication Activity Database

    Krásný, Lukáš; Hynek, R.; Hochel, I.

    2013-01-01

    Roč. 353, NOV 2013 (2013), s. 67-79 ISSN 1387-3806 R&D Projects: GA ČR GAP503/10/0664 Institutional support: RVO:61388971 Keywords : Mass spectrometry * Bacteria * Identification Subject RIV: EE - Microbiology, Virology Impact factor: 2.227, year: 2013

  8. Four decades of joy in mass spectrometry

    NARCIS (Netherlands)

    Nibbering, N.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

  9. Inductively coupled plasma- mass spectrometry. Chapter 13

    International Nuclear Information System (INIS)

    Mahalingam, T.R.

    1997-01-01

    Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) is a new technique for elemental and isotopic analysis which is currently attracting a great deal of interest. This relatively new technique has found wide applications in different fields of research viz., nuclear, geological, biological and environmental sciences

  10. Characterization of synthetic peptides by mass spectrometry

    DEFF Research Database (Denmark)

    Prabhala, Bala Krishna; Mirza, Osman Asghar; 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 and LC-MS of synthetic peptides....

  11. 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).

  12. Characterization of microbial siderophores by mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Pluháček, Tomáš; Lemr, Karel; Ghosh, D.; Milde, D.; Novák, Jiří; Havlíček, Vladimír

    2016-01-01

    Roč. 35, č. 1 (2016), s. 35-47 ISSN 0277-7037 R&D Projects: GA MŠk(CZ) LD13038; GA ČR(CZ) GAP206/12/1150; GA MŠk(CZ) LO1509 Institutional support: RVO:61388971 Keywords : iron * siderophores * mass spectrometry Subject RIV: CE - Biochemistry Impact factor: 9.373, year: 2016

  13. 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.

  14. Radiocarbon accelerator mass spectrometry: background and contamination

    International Nuclear Information System (INIS)

    Beukens, R.P.

    1993-01-01

    Since the advent of radiocarbon accelerator mass spectrometry (AMS) many studies have been conducted to understand the background from mass spectrometric processes and the origins of contamination associated with the ion source and sample preparation. By studying the individual contributions a better understanding of these processes has been obtained and it has been demonstrated that it is possible to date samples reliably up to 60 000 BP. (orig.)

  15. Optimization Of A Mass Spectrometry Process

    International Nuclear Information System (INIS)

    Lopes, Jose; Alegria, F. Correa; Redondo, Luis; Barradas, N. P.; Alves, E.; Rocha, Jorge

    2011-01-01

    In this paper we present and discuss a system developed in order to optimize the mass spectrometry process of an ion implanter. The system uses a PC to control and display the mass spectrum. The operator interacts with the I/O board, that interfaces with the computer and the ion implanter by a LabVIEW code. Experimental results are shown and the capabilities of the system are discussed.

  16. Ligand induced structural isomerism in phosphine coordinated gold clusters revealed by ion mobility mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ligare, Marshall R.; Baker, Erin M.; Laskin, Julia; Johnson, Grant E.

    2017-01-01

    Structural isomerism in ligated gold clusters is revealed using electrospray ionization ion mobility spectrometry mass spectrometry. Phosphine ligated Au8 clusters are shown to adopt more “extended” type structures with increasing exchange of methyldiphenylphosphine (MePPh2) for triphenylphosphine (PPh3). These ligand-dependant structure-property relationships are critical to applications of clusters in catalysis.

  17. 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.

  18. Accelerator mass spectrometry: state of the art

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

  19. 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.

  20. A Multidimensional System for Phosphopeptide Analysis Using TiO{sub 2} Enrichment and Ion-exchange Chromatography with Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Kun; Yoo, Jisun; Kim, Eunmin; Kim, Jin Young; Kim, Young Hwan; Yoo, Jong Shin [Korea Basic Science Institute, Ochang (Korea, Republic of); Oh, Han Bin [Sogang Univ., Seoul (Korea, Republic of)

    2012-10-15

    Although offline enrichment of phosphorylated peptides is widely used, enrichment for phosphopeptides using TiO{sub 2} is often performed manually, which is labor-intensive and can lead to irreproducible results. To address the problems associated with offline enrichment and to improve the effectiveness of phosphopeptide detection, we developed an automated online enrichment system for phosphopeptide analysis. A standard protein mixture comprising BSA, fetuin, crystalline, α-casein and β-casein, and ovalbumin was assessed using our new system. Our multidimensional system has four main parts: a sample pump, a 20-mm TiO{sub 2}-based column, a weak anion-exchange, and a strong cation-exchange (2:1 WAX:SCX) separation column with LC/MS. Phosphorylated peptides were successfully detected using the TiO{sub 2}-based online system with little interference from nonphosphorylated peptides. Our results confirmed that our online enrichment system is a simple and efficient method for detecting phosphorylated peptides.

  1. 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.

  2. Thermal ionisation mass spectrometry (TIMS): what, how and why?

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2002-01-01

    Thermal ionisation mass spectrometry (TIMS) is one of the oldest mass spectrometric techniques, which has been used for determining the isotopic composition and concentration of different elements using isotope dilution. In spite of the introduction of many other inorganic mass spectrometric techniques like spark source mass spectrometry (SSMS), glow discharge mass spectrometry (GDMS), inductively coupled plasma-mass spectrometry (ICP-MS), secondary ion mass spectrometry (SIMS), the TIMS technique plays the role of a definitive analytical methodology and still occupies a unique position in terms of its capabilities with respect to precision and accuracy as well as sensitivity

  3. Conformational preludes to the latency transition in PAI-1 as determined by atomistic computer simulations and hydrogen/deuterium-exchange mass spectrometry

    DEFF Research Database (Denmark)

    Petersen, Michael; Madsen, Jeppe B; Jørgensen, Thomas J D

    2017-01-01

    activator inhibitor 1 (PAI-1). We report the first multi-microsecond atomistic molecular dynamics simulations of PAI-1 and compare the data with experimental hydrogen/deuterium-exchange data (HDXMS). The simulations reveal notable conformational flexibility of helices D, E and F and major fluctuations...... are observed in the W86-loop which occasionally leads to progressive detachment of β-strand 2 A from β-strand 3 A. An interesting correlation between Cα-RMSD values from simulations and experimental HDXMS data is observed. Helices D, E and F are known to be important for the overall stability of active PAI-1......Both function and dysfunction of serine protease inhibitors (serpins) involve massive conformational change in their tertiary structure but the dynamics facilitating these events remain poorly understood. We have studied the dynamic preludes to conformational change in the serpin plasminogen...

  4. A simple method using on-line continuous leaching and ion exchange chromatography coupled to inductively coupled plasma mass spectrometry for the speciation analysis of bio-accessible arsenic in rice.

    Science.gov (United States)

    Horner, Nolan S; Beauchemin, Diane

    2012-03-02

    A simple method for the speciation analysis of bio-accessible arsenic (As) in rice was developed using a continuous on-line leaching method to release the bio-accessible fraction. The continuous on-line leaching method has several advantages over commonly used batch methods including quicker and easier sample preparation, reduced risk of contamination and access to real time leaching data. The bio-accessibility of As in the samples was monitored using inductively coupled plasma mass spectrometry (ICP-MS). Results from a certified reference material as well as cooked and uncooked white rice showed that the majority of As was leached by saliva. Results obtained using the continuous on-line leaching method were comparable to those obtained using a batch method. Speciation analysis of the saliva leachate was performed using ion exchange chromatography coupled to ICP-MS. The four most toxic forms of As (As(III), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and As(V)) were clearly separated within 5 min in a single chromatographic run. Over 92% of bio-accessible As in the certified reference material and uncooked white rice sample was in the form of DMA and As(V), whereas it was present as DMA and As(III) in the cooked white rice. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Alpha spectrometry and the secondary ion mass spectrometry of thorium

    International Nuclear Information System (INIS)

    Strisovska, J.; Kuruc, J.; Galanda, D.; Matel, L.; Aranyosiova, M.; Velic, D.

    2009-01-01

    The main objective of this master thesis was preparation of samples with thorium content on the steel discs by electrodeposition for determination of natural thorium isotope by alpha spectrometry and the secondary ion mass spectrometry and finding out their possible linear correlation between these methods. The samples with electrolytically excluded isotope of 232 Th were prepared by electrodeposition from solution Th(NO 3 ) 4 ·12 H2 O on steel discs in electrodeposition cell with use of solutions Na 2 SO 4 , NaHSO 4 , KOH and (NH 4 ) 2 (C 2 O 4 ) by electric current 0.75 A. Discs were measured by alpha spectrometer. Activity was calculated from the registered impulses for 232 Th and surface's weight. After alpha spectrometry measurements discs were analyzed by TOF-SIMS IV which is installed in the International Laser Centre in Bratislava. Intensities of isotope of 232 Th and ions of ThO + , ThOH + , ThO 2 H + , Th 2 O 4 H + , ThO 2 - , ThO 3 H - , ThH 3 O 3 - and ThN 2 O 5 H - were identified. The linear correlation is between surface's weights of Th and intensities of ions of Th + from SIMS, however the correlation coefficient has relatively low value. We found out with SIMS method that oxidized and hydride forms of thorium are significantly represented in samples with electroplated thorium. (authors)

  6. Mass Spectrometry Imaging under Ambient Conditions

    Science.gov (United States)

    Wu, Chunping; Dill, Allison L.; Eberlin, Livia S.; Cooks, R. Graham; Ifa, Demian R.

    2012-01-01

    Mass spectrometry imaging (MSI) has emerged as an important tool in the last decade and it is beginning to show potential to provide new information in many fields owing to its unique ability to acquire molecularly specific images and to provide multiplexed information, without the need for labeling or staining. In MSI, the chemical identity of molecules present on a surface is investigated as a function of spatial distribution. In addition to now standard methods involving MSI in vacuum, recently developed ambient ionization techniques allow MSI to be performed under atmospheric pressure on untreated samples outside the mass spectrometer. Here we review recent developments and applications of MSI emphasizing the ambient ionization techniques of desorption electrospray ionization (DESI), laser ablation electrospray ionization (LAESI), probe electrospray ionization (PESI), desorption atmospheric pressure photoionization (DAPPI), femtosecond laser desorption ionization (fs-LDI), laser electrospray mass spectrometry (LEMS), infrared laser ablation metastable-induced chemical ionization (IR-LAMICI), liquid microjunction surface sampling probe mass spectrometry (LMJ-SSP MS), nanospray desorption electrospray ionization (nano-DESI), and plasma sources such as the low temperature plasma (LTP) probe and laser ablation coupled to flowing atmospheric-pressure afterglow (LA-FAPA). Included are discussions of some of the features of ambient MSI including the ability to implement chemical reactions with the goal of providing high abundance ions characteristic of specific compounds of interest and the use of tandem mass spectrometry to either map the distribution of targeted molecules with high specificity or to provide additional MS information in the structural identification of compounds. We also describe the role of bioinformatics in acquiring and interpreting the chemical and spatial information obtained through MSI, especially in biological applications for tissue

  7. Boundaries of mass resolution in native mass spectrometry

    NARCIS (Netherlands)

    Lössl, Philip|info:eu-repo/dai/nl/371559693; Snijder, Joost|info:eu-repo/dai/nl/338018328; Heck, Albert J R|info:eu-repo/dai/nl/105189332

    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

  8. Burnup determination of mass spectrometry for nuclear fuels

    International Nuclear Information System (INIS)

    Zhang Chunhua.

    1987-01-01

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

  9. [Sample preparation and bioanalysis in mass spectrometry].

    Science.gov (United States)

    Bourgogne, Emmanuel; Wagner, Michel

    2015-01-01

    The quantitative analysis of compounds of clinical interest of low molecular weight (sample preparation. Sample preparation is a crucial part of chemical/biological analysis and in a sense is considered the bottleneck of the whole analytical process. The main objectives of sample preparation are the removal of potential interferences, analyte preconcentration, and converting (if needed) the analyte into a more suitable form for detection or separation. Without chromatographic separation, endogenous compounds, co-eluted products may affect a quantitative method in mass spectrometry performance. This work focuses on three distinct parts. First, quantitative bioanalysis will be defined, different matrices and sample preparation techniques currently used in bioanalysis by mass spectrometry of/for small molecules of clinical interest in biological fluids. In a second step the goals of sample preparation will be described. Finally, in a third step, sample preparation strategies will be made either directly ("dilute and shoot") or after precipitation.

  10. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing [Daly City, CA; Yang, Peidong [Kensington, CA; Kim, Woong [Seoul, KR; Fan, Rong [Pasadena, CA

    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.

  11. Accelerator mass spectrometry - From DNA to astrophysics

    International Nuclear Information System (INIS)

    Kutschera, W.

    2013-01-01

    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 14 C 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. (authors)

  12. A mass spectrometry proteomics data management platform.

    Science.gov (United States)

    Sharma, Vagisha; Eng, Jimmy K; Maccoss, Michael J; Riffle, Michael

    2012-09-01

    Mass spectrometry-based proteomics is increasingly being used in biomedical research. These experiments typically generate a large volume of highly complex data, and the volume and complexity are only increasing with time. There exist many software pipelines for analyzing these data (each typically with its own file formats), and as technology improves, these file formats change and new formats are developed. Files produced from these myriad software programs may accumulate on hard disks or tape drives over time, with older files being rendered progressively more obsolete and unusable with each successive technical advancement and data format change. Although initiatives exist to standardize the file formats used in proteomics, they do not address the core failings of a file-based data management system: (1) files are typically poorly annotated experimentally, (2) files are "organically" distributed across laboratory file systems in an ad hoc manner, (3) files formats become obsolete, and (4) searching the data and comparing and contrasting results across separate experiments is very inefficient (if possible at all). Here we present a relational database architecture and accompanying web application dubbed Mass Spectrometry Data Platform that is designed to address the failings of the file-based mass spectrometry data management approach. The database is designed such that the output of disparate software pipelines may be imported into a core set of unified tables, with these core tables being extended to support data generated by specific pipelines. Because the data are unified, they may be queried, viewed, and compared across multiple experiments using a common web interface. Mass Spectrometry Data Platform is open source and freely available at http://code.google.com/p/msdapl/.

  13. High-sensitivity mass spectrometry with a tandem accelerator

    International Nuclear Information System (INIS)

    Henning, W.

    1984-01-01

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

  14. Mass spectrometry by means of tandem accelerators

    International Nuclear Information System (INIS)

    Tuniz, C.

    1985-01-01

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

  15. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  16. Mass spectrometry imaging: Towards a lipid microscope?

    Science.gov (United States)

    Touboul, David; Brunelle, Alain; Laprévote, Olivier

    2011-01-01

    Biological imaging techniques are the most efficient way to locally measure the variation of different parameters on tissue sections. These analyses are gaining increasing interest since 20 years and allow observing extremely complex biological phenomena at lower and lower time and resolution scale. Nevertheless, most of them only target very few compounds of interest, which are chosen a priori, due to their low resolution power and sensitivity. New chemical imaging technique has to be introduced in order to overcome these limitations, leading to more informative and sensitive analyses for biologists and physicians. Two major mass spectrometry methods can be efficiently used to generate the distribution of biological compounds over a tissue section. Matrix-Assisted Laser Desorption/Ionisation-Mass Spectrometry (MALDI-MS) needs the co-crystallization of the sample with a matrix before to be irradiated by a laser, whereas the analyte is directly desorbed by a primary ion bombardment for Secondary Ion Mass Spectrometry (SIMS) experiments. In both cases, energy used for desorption/ionization is locally deposited -some tens of microns for the laser and some hundreds of nanometers for the ion beam- meaning that small areas over the surface sample can be separately analyzed. Step by step analysis allows spectrum acquisitions over the tissue sections and the data are treated by modern informatics software in order to create ion density maps, i.e., the intensity plot of one specific ion versus the (x,y) position. Main advantages of SIMS and MALDI compared to other chemical imaging techniques lie in the simultaneous acquisition of a large number of biological compounds in mixture with an excellent sensitivity obtained by Time-of-Flight (ToF) mass analyzer. Moreover, data treatment is done a posteriori, due to the fact that no compound is selectively marked, and let us access to the localization of different lipid classes in only one complete acquisition. Copyright © 2010

  17. Computational mass spectrometry for small molecules

    Science.gov (United States)

    2013-01-01

    The identification of small molecules from mass spectrometry (MS) data remains a major challenge in the interpretation of MS data. This review covers the computational aspects of identifying small molecules, from the identification of a compound searching a reference spectral library, to the structural elucidation of unknowns. In detail, we describe the basic principles and pitfalls of searching mass spectral reference libraries. Determining the molecular formula of the compound can serve as a basis for subsequent structural elucidation; consequently, we cover different methods for molecular formula identification, focussing on isotope pattern analysis. We then discuss automated methods to deal with mass spectra of compounds that are not present in spectral libraries, and provide an insight into de novo analysis of fragmentation spectra using fragmentation trees. In addition, this review shortly covers the reconstruction of metabolic networks using MS data. Finally, we list available software for different steps of the analysis pipeline. PMID:23453222

  18. Optimization of collision/reaction gases for determination of 90Sr in atmospheric particulate matter by inductively coupled plasma tandem mass spectrometry after direct introduction of air via a gas-exchange device

    Science.gov (United States)

    Suzuki, Yoshinari; Ohara, Ryota; Matsunaga, Kirara

    2017-09-01

    Nuclear power plant accidents release radioactive strontium 90 (90Sr) into the environment. Monitoring of 90Sr, although important, is difficult and time consuming because it emits only beta radiation. We have developed a new analytical system that enables real-time analysis of 90Sr in atmospheric particulate matter with an analytical run time of only 10 min. Briefly, after passage of an air sample through an impactor, a small fraction of the sample is introduced into a gas-exchange device, where the air is replaced by Ar. Then the sample is directly introduced into an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) system equipped with a collision/reaction cell to eliminate isobaric interferences on 90Sr from 90Zr+, 89Y1H+, and 90Y+. Experiments with various reaction gas conditions revealed that these interferences could be minimized under the following optimized conditions: 1.0 mL min- 1 O2, 10.0 mL min- 1 H2, and 1.0 mL min- 1 NH3. The estimated background equivalent concentration and estimated detection limit of the system were 9.7 × 10- 4 and 3.6 × 10- 4 ng m- 3, respectively, which are equivalent to 4.9 × 10- 6 and 1.8 × 10- 6 Bq cm- 3. Recoveries of Sr in PM2.5 measured by real-time analysis compared to those obtained by simultaneously collection on filter was 53 ± 23%, and using this recovery, the detection limit as PM2.5 was estimated to be 3.4 ± 1.5 × 10- 6 Bq cm- 3. That is, this system enabled detection of 90Sr at concentrations < 5 × 10- 6 Bq cm- 3 even considering the insufficient fusion/vaporization/ionization efficiency of Sr in PM2.5.

  19. Silver nanostructures in laser desorption/ionization mass spectrometry and mass spectrometry imaging.

    Science.gov (United States)

    Sekuła, Justyna; Nizioł, Joanna; Rode, Wojciech; Ruman, Tomasz

    2015-09-21

    Silver nanoparticles have been successfully applied as a matrix replacement for the laser desorption/ionization time-of-flight mass spectrometry (LDI-ToF-MS). Nanoparticles, producing spectra with highly reduced chemical background in the low m/z region, are perfectly suited for low-molecular weight compound analysis and imaging. Silver nanoparticles (AgNPs) can efficiently absorb ultraviolet laser radiation, transfer energy to the analyte and promote analyte desorption, but also constitute a source of silver ions suitable for analyte cationisation. This review provides an overview of the literature on silver nanomaterials as non-conventional desorption and ionization promoters in LDI-MS and mass spectrometry imaging.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  1. Depth resolution of secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Pustovit, A.N.

    2004-01-01

    The effect of the solid body discreteness in the direction of the normal to the sample surface on the depth resolution of the secondary ion mass spectrometry method is analyzed. It is shown that for this case the dependence of the width at the semi-height of the delta profiles of the studied elements depth distribution on the energy and angle of incidence of the initial ions should have the form of the stepwise function. This is experimentally proved by the silicon-germanium delta-layers in the silicon samples [ru

  2. Mass spectrometry investigation of magnetron sputtering discharges

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Petr; Musil, Jindřich; Lančok, Ján; Fitl, Přemysl; Novotný, Michal; Bulíř, Jiří; Vlček, Jan

    2017-01-01

    Roč. 143, č. 6 (2017), s. 438-443 ISSN 0042-207X R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA TA ČR(CZ) TA03010490; GA ČR GA17-13427S Institutional support: RVO:68378271 Keywords : mass spectrometry * atoms * radicals and ions * RF discharge * contamination * metallic films Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.530, year: 2016

  3. Mass Determination of Entire Amyloid Fibrils by Using Mass Spectrometry.

    Science.gov (United States)

    Doussineau, Tristan; Mathevon, Carole; Altamura, Lucie; Vendrely, Charlotte; Dugourd, Philippe; Forge, Vincent; Antoine, Rodolphe

    2016-02-12

    Amyloid fibrils are self-assembled protein structures with important roles in biology (either pathogenic or physiological), and are attracting increasing interest in nanotechnology. However, because of their high aspect ratio and the presence of some polymorphism, that is, the possibility to adopt various structures, their characterization is challenging and basic information such as their mass is unknown. Here we show that charge-detection mass spectrometry, recently developed for large self-assembled systems such as viruses, provides such information in a straightforward manner. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Simultaneous mass detection for direct inlet mass spectrometry

    International Nuclear Information System (INIS)

    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

  5. Theory of the Protein Equilibrium Population Snapshot by H/D Exchange Electrospray Ionization Mass Spectrometry (PEPS-HDX-ESI-MS) Method used to obtain Protein Folding Energies/Rates and Selected Supporting Experimental Evidence.

    Science.gov (United States)

    Liyanage, Rohana; Devarapalli, Nagarjuna; Pyland, Derek B; Puckett, Latisha M; Phan, N H; Starch, Joel A; Okimoto, Mark R; Gidden, Jennifer; Stites, Wesley E; Lay, Jackson O

    2012-12-15

    Protein equilibrium snapshot by hydrogen/deuterium exchange electrospray ionization mass spectrometry (PEPS-HDX-ESI-MS or PEPS) is a method recently introduced for estimating protein folding energies and rates. Herein we describe the basis for this method using both theory and new experiments. Benchmark experiments were conducted using ubiquitin because of the availability of reference data for folding and unfolding rates from NMR studies. A second set of experiments was also conducted to illustrate the surprising resilience of the PEPS to changes in HDX time, using staphylococcal nuclease and time frames ranging from a few seconds to several minutes. Theory suggests that PEPS experiments should be conducted at relatively high denaturant concentrations, where the protein folding/unfolding rates are slow with respect to HDX and the life times of both the closed and open states are long enough to be sampled experimentally. Upon deliberate denaturation, changes in folding/unfolding are correlated with associated changes in the ESI-MS signal upon fast HDX. When experiments are done quickly, typically within a few seconds, ESI-MS signals, corresponding to the equilibrium population of the native (closed) and denatured (open) states can both be detected. The interior of folded proteins remains largely un-exchanged. Amongst MS methods, the simultaneous detection of both states in the spectrum is unique to PEPS and provides a "snapshot" of these populations. The associated ion intensities are used to estimate the protein folding equilibrium constant (or the free energy change, ΔG). Linear extrapolation method (LEM) plots of derived ΔG values for each denaturant concentration can then be used to calculate ΔG in the absence of denaturant, ΔG(H(2)O). In accordance with the requirement for detection of signals for both the folded and unfolded states, this theoretical framework predicts that PEPS experiments work best at the middle of the denaturation curve where natured

  6. Surface ionization mass spectrometry of opiates

    International Nuclear Information System (INIS)

    Usmanov, D.T.

    2009-07-01

    Key words: surface ionization, adsorption, heterogeneous reactions, surface ionization mass spectrometry, thermodesorption surface ionization spectroscopy, thermoemitter, opiates, extracts of biosamples. Subjects of study. The mass - spectrometric study of thermal - ion emission: surface ionization of opiates by on the surface of oxidized refractory metals. Purpose of work is to establish the regularities of surface ionization (SI) of multi-atomic molecule opiates and their mixtures develop the scientific base of SI methods for high sensitive and selective detection and analysis of these substances in the different objects, including biosamples. Methods of study: surface ionization mass spectrometry, thermodesorption surface ionization spectroscopy. The results obtained and their novelty. For the first time, SI of molecule opiates on the oxidized tungsten surface has been studied and their SI mass-spectra and temperature dependences of ion currents have been obtained, the characteristic heterogeneous reactions of an adsorbed molecules and the channels of monomolecular decays vibrationally-excited ions on their way in mass-spectrometry have been revealed, sublimation energy has been defined, the activation energy of E act , of these decays has been estimated for given period of time. Additivity of the SI mass-spectra of opiate mixtures of has been established under conditions of joint opiate adsorption. High selectivity of SI allows the extracts of biosamples to be analyzed without their preliminary chromatographic separation. The opiates are ionized by SI with high efficiency (from 34 C/mol to 112 C/mol), which provides high sensitivity of opiate detection by SI/MS and APTDSIS methods from - 10 -11 g in the samples under analysis. Practical value. The results of these studies create the scientific base for novel SI methods of high sensitive detection and analysis of the trace amounts of opiates in complicated mixtures, including biosamples without their preliminary

  7. Boundaries of mass resolution in native mass spectrometry.

    Science.gov (United States)

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

    2014-06-01

    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 virus assembly. In native MS, ions attain high m/z values, requiring special mass analyzers for their detection. Depending on the particular mass analyzer used, instrumental mass resolution does often decrease at higher m/z but can still be above a couple of thousand at m/z 5000. However, the mass resolving power obtained on charge states of protein complexes in this m/z region is experimentally found to remain well below the inherent instrument resolution of the mass analyzers employed. Here, we inquire into reasons for this discrepancy and ask how native MS would benefit from higher instrumental mass resolution. To answer this question, we discuss advantages and shortcomings of mass analyzers used to study intact biomolecules and biomolecular complexes in their native state, and we review which other factors determine mass resolving power in native MS analyses. Recent examples from the literature are given to illustrate the current status and limitations.

  8. Recent development in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Platzner, I.

    1992-01-01

    Within the limited of this review the following topics will be briefly discussed: a) Accuracy, precision, internal relative standard deviation (RISD) and external relative standard deviation (RESD) of isotope ratio measurements. With advanced instrumentation and use of standard reference materials, high accuracy and RESD = 0.002% (or better) may be achieved; b) The advantages of modern automatic isotope ratio mass spectrometer are briefly described. Computer controlled operation and data acquisition, and multiple ion collection are the recent important improvement; c) The isotopic fractionation during the course of isotope ratio measurement is considered as a major source of errors in thermal ionization of metallic elements. The phenomenon in strontium, neodymium, uranium, lead and calcium and methods to correct the measured data are discussed; d) Applications of isotope ratio mass spectrometry in atomic weight determinations, the isotope dilution technique, isotope geology, and isotope effects in biological systems are described together with specific applications in various research and technology area. (author)

  9. 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.

  10. Lipid imaging by mass spectrometry - a review.

    Science.gov (United States)

    Gode, David; Volmer, Dietrich A

    2013-03-07

    Mass spectrometry imaging (MSI) has proven to be extremely useful for applications such as the spatial analysis of peptides and proteins in biological tissue, the performance assessment of drugs in vivo or the measurement of protein or metabolite expression as tissue classifiers or biomarkers from disease versus control tissue comparisons. The most popular MSI technique is MALDI mass spectrometry. First invented by Richard Caprioli in the mid-1990s, it is the highest performing MSI technique in terms of spatial resolution, sensitivity for intact biomolecules and application range today. The unique ability to identify and spatially resolve numerous compounds simultaneously, based on m/z values has inter alia been applied to untargeted and targeted chemical mapping of biological compartments, revealing changes of physiological states, disease pathologies and metabolic faith and distribution of xenobiotics. Many MSI applications focus on lipid species because of the lipids' diverse roles as structural components of cell membranes, their function in the surfactant cycle, and their involvement as second messengers in signalling cascades of tissues and cells. This article gives a comprehensive overview of lipid imaging techniques and applications using established MALDI and SIMS methods but also other promising MSI techniques such as DESI.

  11. Impact of automation on mass spectrometry.

    Science.gov (United States)

    Zhang, Yan Victoria; Rockwood, Alan

    2015-10-23

    Mass spectrometry coupled to liquid chromatography (LC-MS and LC-MS/MS) is an analytical technique that has rapidly grown in popularity in clinical practice. In contrast to traditional technology, mass spectrometry is superior in many respects including resolution, specificity, multiplex capability and has the ability to measure analytes in various matrices. Despite these advantages, LC-MS/MS remains high cost, labor intensive and has limited throughput. This specialized technology requires highly trained personnel and therefore has largely been limited to large institutions, academic organizations and reference laboratories. Advances in automation will be paramount to break through this bottleneck and increase its appeal for routine use. This article reviews these challenges, shares perspectives on essential features for LC-MS/MS total automation and proposes a step-wise and incremental approach to achieve total automation through reducing human intervention, increasing throughput and eventually integrating the LC-MS/MS system into the automated clinical laboratory operations. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. [Mass spectrometry in the clinical microbiology laboratory].

    Science.gov (United States)

    Jordana-Lluch, Elena; Martró Català, Elisa; Ausina Ruiz, Vicente

    2012-12-01

    Infectious diseases are still a cause of high mortality and morbidity rates. Current microbiological diagnostic methods are based on culture and phenotypic identification of isolated microorganisms, which can be obtained in about 24-48 h. Given that the microbiological identification is of major importance for patient management, new diagnostic methods are needed in order to detect and identify microorganisms in a timely and accurate manner. Over the last few years, several molecular techniques based on the amplification of microbial nucleic acids have been developed with the aim of reducing the time needed for the identification of the microorganisms involved in different infectious processes. On the other hand, mass spectrometry has emerged as a rapid and consistent alternative to conventional methods for microorganism identification. This review describes the most widely used mass spectrometry technologies -matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization time-of-flight (ESI-TOF)-, both for protein and nucleic acid analysis, as well as the commercial platforms available. Related publications of most interest in clinical microbiology are also reviewed. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  13. 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.

  14. Ambient ionization mass spectrometry: A tutorial

    International Nuclear Information System (INIS)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu; Shiea, Jentaie

    2011-01-01

    Highlights: → Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. → We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. → 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.

  15. Mass Spectrometry for Large Undergraduate Laboratory Sections

    Science.gov (United States)

    Illies, A.; Shevlin, P. B.; Childers, G.; Peschke, M.; Tsai, J.

    1995-08-01

    Mass spectrometry is routinely covered in undergraduate organic chemistry courses and a number of valuable laboratory experiments featuring its use have been discussed (1-7). Although such experiments work well at institutions with limited laboratory enrollments, we typically teach laboratories with enrollments of 160 or more in which it is difficult to allow each student to carry out a meaningful "hands on" mass spectrometry experiment. Since we feel that some practical experience with this technique is important, we have designed a simple gas chromatography-mass spectrometry (gc/ms) exercise that allows each student to analyze the products of a simple synthesis that they have performed. The exercise starts with the microscale SN2 synthesis of 1-bromobutane from 1-butanol as described by Williamson (8). The students complete the synthesis and place one drop of the distilled product in a screw capped vial. The vials are then sealed, labeled with the students name and taken to the mass spectrometry laboratory by a teaching assistant. Students are instructed to sign up for a 20-min block of time over the next few days in order to analyze their sample. When the student arrives at the laboratory, he or she adds 1 ml CH2Cl2 to the sample and injects 0.3 microliters of the solution into the gas chromatograph. The samples typically contain the 1-butanol starting material and the 1-bromobutane product along with traces of dibutyl ether. The figure shows a mass chromatogram along with the mass spectra of the starting material and product from an actual student run. For this analysis to be applicable to large numbers of students, the gc separation must be as rapid as possible. We have been able to analyze each sample in 6 minutes on a 30 m DB-5 capillary column with the following temperature program: 70 oC for 1 min, 70-80 oC at 10 oC/min, 86-140 oC at 67.5 oC/min, 140-210 oC at 70 oC/min, and 210 oC for 1 min. A mass range of 20-200 amu is scanned with a solvent delay of 2

  16. High-efficiency thermal ionization sources for mass spectrometry

    International Nuclear Information System (INIS)

    Olivares, Jose A.

    1996-01-01

    A version of the thermal ionization cavity (TIC) source developed specifically for use in mass spectrometry is presented. The performance of this ion source has been characterized extensively both with the use of an isotope separator and a quadrupole mass spectrometer. A detailed description of the TIC source for mass spectrometry is given along with the performance characteristics observed

  17. Cs+ ion source for secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Bentz, B.L.; Weiss, H.; Liebl, H.

    1981-12-01

    Various types of cesium ionization sources currently used in secondary ion mass spectrometry are briefly reviewed, followed by a description of the design and performance of a novel, thermal surface ionization Cs + source developed in this laboratory. The source was evaluated for secondary ion mass spectrometry applications using the COALA ion microprobe mass analyzer. (orig.)

  18. The emergence of mass spectrometry in biochemical research

    OpenAIRE

    1995-01-01

    The initial steps toward routinely applying mass spectrometry in the biochemical laboratory have been achieved. In the past, mass spectrometry was confined to the realm of small, relatively stable molecules; large or thermally labile molecules did not survive the desorption and ionization processes intact. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry allow for the analysis of both small and large biomolecules through "mild" desorption...

  19. Mass spectrometry a versatile aid to inorganic analysis

    International Nuclear Information System (INIS)

    Stefani, Rene

    1976-01-01

    Several hundred publications have appeared in the last three years that deal with applications of Mass Spectrometry to inorganic analysis. Bulk and localized trace analysis, surface and thin film characterization and microstructure examination are currently performed by Secondary Ion Mass Spectrometry, Spark Source Mass Spectrometry and the newly developed Laser Probe Mass Spectrometry. Suitable experimental procedures allow insulators, biologic materials and microsamples to be analysed. In spite of the classification by techniques this review is essentially devoted to the most significant papers in analytical applications but instrumental and basic features are sometimes introduced to support the discussions

  20. Inductively coupled plasma source mass spectrometry

    International Nuclear Information System (INIS)

    Price Russ, G. III

    1993-01-01

    Inductively coupled plasma source mass spectrometry (ICP-MS) is a relatively new (5 y commercial availability) technique for simultaneously determining the concentration and isotopic composition of a large number of elements at trace levels. The principle advantages of ICP-MS are the ability to measure essentially all the metallic elements at concentrations as low as 1 part in 10 12 by weight, to analyse aqueous samples directly, to determine the isotopic composition of essentially all the metallic elements, and to analyse samples rapidly (minutes). The history of the development of ICP-MS and discussions of a variety of applications have been discussed in detail in Date and Gray (1988). Koppenaal (1988, 1990) has reviewed the ICP-MS literature. In that ICP-MS is a relatively new and still evolving technique, this chapter will discuss potential capability more than proven performance. (author). 24 refs

  1. 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.

  2. [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.

  3. Calibration samples for accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hershberger, R.L.; Flynn, D.S.; Gabbard, F.

    1981-01-01

    Radioactive samples with precisely known numbers of atoms are useful as calibration sources for lifetime measurements using accelerator mass spectrometry. Such samples can be obtained in two ways: either by measuring the production rate as the sample is created or by measuring the decay rate after the sample has been obtained. The latter method requires that a large sample be produced and that the decay constant be accurately known. The former method is a useful and independent alternative, especially when the decay constant is not well known. The facilities at the University of Kentucky for precision measurements of total neutron production cross sections offer a source of such calibration samples. The possibilities, while quite extensive, would be limited to the proton rich side of the line of stability because of the use of (p,n) and (α,n) reactions for sample production

  4. 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.

  5. Radiocarbon dating with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Blake, W. Jr.

    1985-01-01

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  6. Analysis of barium by isotope mass spectrometry

    International Nuclear Information System (INIS)

    Long Kaiming; Jia Baoting; Liu Xuemei

    2004-01-01

    The isotopic abundance ratios for barium at sub-microgram level are analyzed by thermal surface ionization mass spectrometry (TIMS). Rhenium trips used for sample preparation are firstly treated to eliminate possible barium background interference. During the preparation of barium samples phosphoric acid is added as an emitting and stabilizing reagent. The addition of phosphoric acid increases the collection efficiency and ion current strength and stability for barium. A relative standard deviation of 0.02% for the isotopic abundance ratio of 137 Ba to 138 Ba is achieved when the 138 Ba ion current is (1-3) x 10 -12 A. The experimental results also demonstrate that the isotope fractionation effect is negligibly small in the isotopic analysis of barium

  7. Guidelines for reporting quantitative mass spectrometry based experiments in proteomics.

    Science.gov (United States)

    Martínez-Bartolomé, Salvador; Deutsch, Eric W; Binz, Pierre-Alain; Jones, Andrew R; Eisenacher, Martin; Mayer, Gerhard; Campos, Alex; Canals, Francesc; Bech-Serra, Joan-Josep; Carrascal, Montserrat; Gay, Marina; Paradela, Alberto; Navajas, Rosana; Marcilla, Miguel; Hernáez, María Luisa; Gutiérrez-Blázquez, María Dolores; Velarde, Luis Felipe Clemente; Aloria, Kerman; Beaskoetxea, Jabier; Medina-Aunon, J Alberto; Albar, Juan P

    2013-12-16

    Mass spectrometry is already a well-established protein identification tool and recent methodological and technological developments have also made possible the extraction of quantitative data of protein abundance in large-scale studies. Several strategies for absolute and relative quantitative proteomics and the statistical assessment of quantifications are possible, each having specific measurements and therefore, different data analysis workflows. The guidelines for Mass Spectrometry Quantification allow the description of a wide range of quantitative approaches, including labeled and label-free techniques and also targeted approaches such as Selected Reaction Monitoring (SRM). The HUPO Proteomics Standards Initiative (HUPO-PSI) has invested considerable efforts to improve the standardization of proteomics data handling, representation and sharing through the development of data standards, reporting guidelines, controlled vocabularies and tooling. In this manuscript, we describe a key output from the HUPO-PSI-namely the MIAPE Quant guidelines, which have developed in parallel with the corresponding data exchange format mzQuantML [1]. The MIAPE Quant guidelines describe the HUPO-PSI proposal concerning the minimum information to be reported when a quantitative data set, derived from mass spectrometry (MS), is submitted to a database or as supplementary information to a journal. The guidelines have been developed with input from a broad spectrum of stakeholders in the proteomics field to represent a true consensus view of the most important data types and metadata, required for a quantitative experiment to be analyzed critically or a data analysis pipeline to be reproduced. It is anticipated that they will influence or be directly adopted as part of journal guidelines for publication and by public proteomics databases and thus may have an impact on proteomics laboratories across the world. This article is part of a Special Issue entitled: Standardization and

  8. Mass spectrometry of acoustically levitated droplets.

    Science.gov (United States)

    Westphall, Michael S; Jorabchi, Kaveh; Smith, Lloyd M

    2008-08-01

    Containerless sample handling techniques such as acoustic levitation offer potential advantages for mass spectrometry, by eliminating surfaces where undesired adsorption/desorption processes can occur. In addition, they provide a unique opportunity to study fundamental aspects of the ionization process as well as phenomena occurring at the air-droplet interface. Realizing these advantages is contingent, however, upon being able to effectively interface levitated droplets with a mass spectrometer, a challenging task that is addressed in this report. We have employed a newly developed charge and matrix-assisted laser desorption/ionization (CALDI) technique to obtain mass spectra from a 5-microL acoustically levitated droplet containing peptides and an ionic matrix. A four-ring electrostatic lens is used in conjunction with a corona needle to produce bursts of corona ions and to direct those ions toward the droplet, resulting in droplet charging. Analyte ions are produced from the droplet by a 337-nm laser pulse and detected by an atmospheric sampling mass spectrometer. The ion generation and extraction cycle is repeated at 20 Hz, the maximum operating frequency of the laser employed. It is shown in delayed ion extraction experiments that both positive and negative ions are produced, behavior similar to that observed for atmospheric pressure matrix-assisted laser absorption/ionization. No ion signal is observed in the absence of droplet charging. It is likely, although not yet proven, that the role of the droplet charging is to increase the strength of the electric field at the surface of the droplet, reducing charge recombination after ion desorption.

  9. Liquid chromatography - mass spectrometry analysis of pharmaceuticals

    International Nuclear Information System (INIS)

    Macasek, F.

    2003-01-01

    The drugs represent mostly non-volatile and thermally labile solutes, often available only in small amounts like it is in case of radiopharmaceuticals. Therefor, the favourable separation techniques for such compounds are HPLC, capillary electrophoresis and also TLC 1. Liquid chromatography with mass spectrometric detector (LC/MS) is especially powerful for their microanalysis. Mass spectrometry separating the ions in high vacuum was presumably used as detector for gas chromatography effluent but the on-line coupling with liquid eluant flow 0.1-1 mL/min is far more challenging. New types of ion sources were constructed for simultaneous removal of solvent and ionisation of solutes at atmospheric pressure (API). At present, a relatively wide choice of successfully designed commercial equipment is available either for small organic molecules and larger biomolecules (Perkin-Elmer, Agilent, Jeol, Bruker Daltonics, ThermoQuest, Shimadzu). The features of the LC/MS systems are presented. LC/MS as a new quality control tool for [F-18]fluorodeoxyglucose (FDG) radiopharmaceutical, which has became the most spread radiopharmaceutical for positron emission tomography (PET), was proposed. Other applications of the LC/MS are reviewed. (author)

  10. Radiocarbon mass spectrometry for drug development

    International Nuclear Information System (INIS)

    Ulrich, Schulze-Konig Tim

    2011-01-01

    Full text: Radiocarbon has a huge potential as a tracer for metabolism studies in humans. By using Accelerator Mass Spectrometry (AMS) for its detection, a unique sensitivity is reached reducing required radiation doses to a negligible level. Until recently, a widespread use of AMS in biomedical research was impeded by the high complexity of the instrument, time-consuming sample preparation, and a limited availability of measurement capacity. Over the last few years, tremendous progress has been achieved in the reduction of size and complexity of AMS instruments. It allowed designing a compact AMS system, dubbed BioMICADAS to address the needs of biomedical users. For more than two years, this system is in successful operation at a commercial service provider for the pharmaceutical industry. A further drastic simplification of radiocarbon mass spectrometers seems possible and could establish a regular usage of this technology in drug development. However, to reach this goal a better integration of AMS into the workflow of bioanalytical laboratories will be necessary. For this purpose, CO 2 accepting ion sources may be a key, since they enable an almost automated sample preparation. The status of radiocarbon AMS in biomedical research and its perspective will be discussed

  11. Compressed sensing in imaging mass spectrometry

    International Nuclear Information System (INIS)

    Bartels, Andreas; Dülk, Patrick; Trede, Dennis; Alexandrov, Theodore; Maaß, Peter

    2013-01-01

    Imaging mass spectrometry (IMS) is a technique of analytical chemistry for spatially resolved, label-free and multipurpose analysis of biological samples that is able to detect the spatial distribution of hundreds of molecules in one experiment. The hyperspectral IMS data is typically generated by a mass spectrometer analyzing the surface of the sample. In this paper, we propose a compressed sensing approach to IMS which potentially allows for faster data acquisition by collecting only a part of the pixels in the hyperspectral image and reconstructing the full image from this data. We present an integrative approach to perform both peak-picking spectra and denoising m/z-images simultaneously, whereas the state of the art data analysis methods solve these problems separately. We provide a proof of the robustness of the recovery of both the spectra and individual channels of the hyperspectral image and propose an algorithm to solve our optimization problem which is based on proximal mappings. The paper concludes with the numerical reconstruction results for an IMS dataset of a rat brain coronal section. (paper)

  12. Probing the Composition, Assembly and Activity of Protein Molecular Machines using Native Mass Spectrometry

    NARCIS (Netherlands)

    van de Waterbeemd, M.J.

    2017-01-01

    Native mass spectrometry and mass spectrometry in general, are powerful analytical tools for studying proteins and protein complexes. Native mass spectrometry may provide accurate mass measurements of large macromolecular assemblies enabling the investigation of their composition and stoichiometry.

  13. Statistical methods for mass spectrometry-based clinical proteomics

    NARCIS (Netherlands)

    Kakourou, A.

    2018-01-01

    The work presented in this thesis focuses on methods for the construction of diagnostic rules based on clinical mass spectrometry proteomic data. Mass spectrometry has become one of the key technologies for jointly measuring the expression of thousands of proteins in biological samples.

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

    International Nuclear Information System (INIS)

    Guo Zhiyu; Zhang Chuan

    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

  15. Mass spectrometry for real-time quantitative breath analysis

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Španěl, Patrik; Herbig, J.; Beauchamp, J.

    2014-01-01

    Roč. 8, č. 2 (2014), 027101 ISSN 1752-7155 Institutional support: RVO:61388955 Keywords : breath analysis * proton transfer reaction mass spectrometry * selected ion flow tube mass spectrometry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.631, year: 2014

  16. 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

  17. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Watrous, Matthew George; Adamic, Mary Louise; Olson, John Eric; Baeck, D. L.; Fox, R. V.; Hahn, P. A.; Jenson, D. D.; Lister, T. E.

    2015-01-01

    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

  18. 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

  19. 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.

  20. New applications of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Davis, J.C.

    1991-01-01

    Since its invention in the late 70's, and reduction to near-routine practice by the mid-80's, accelerator mass spectrometry (AMS) has become a powerful tool for archaeological and geochemical measurements in which cosmogenic isotopes such as 10 Be, 14 C, 26 Al, 36 Cl and 129 I are used as either tracers or chronometers. The utility of such measurements is demonstrated by the fact that most accelerators having AMS capabilities have significant backlogs of samples awaiting measurement. In designing and justifying a new accelerator facility in which AMS was to be a major feature, we sought to advance the field and increase the resources available for it by two steps: (1) development of new research applications in which intentionally added isotopic labels were used rather than just naturally present ones; and (2) enhancement of spectrometer throughout, making new classes of experiments possible by greatly increasing the number of samples that could be measured in individual experiments. Results of the effort to date suggest that development of a family of very small spectrometers optimized for just tritium and/or radiocarbon will be attractive in the near future

  1. Accelerator mass spectrometry for radiocarbon dating

    International Nuclear Information System (INIS)

    Bronk, C.R.

    1987-01-01

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. This thesis describes theoretical work to understand the reasons for low accuracy and range and offers practical solutions. The production and transport of the ions used in the measurements are found to be the most crucial stages in the process. The theories behind ion production by sputtering are discussed and applied to the specific case of carbon sputtered by caesium. Experimental evidence is also examined in relation to the theories. The phenomena of space charge and lens aberrations are discussed along with the interaction between ion beams and gas molecules in the vacuum. Computer programs for calculating phase space transformations are then described; these are designed to help investigations of the effects of space charge and aberrations on AMS measurements. Calculations using these programs are discussed in relation both to measured ion beam profiles in phase space and to the current dependent transmission of ions through the Oxford radiocarbon accelerator. Improvements have been made to this accelerator and these are discussed in the context of the calculations. C - ions are produced directly from carbon dioxide at the Middleton High Intensity Sputter Source. Experiments to evaluate the performance of such a source are described and detailed design criteria established. An ion source designed and built specifically for radiocarbon measurements using carbon dioxide is described. Experiments to evaluate its performance and investigate the underlying physical processes are discussed. (author)

  2. 14C Accelerator mass spectrometry in Brazil

    International Nuclear Information System (INIS)

    Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L.; Carvalho, C.R.A.

    2011-01-01

    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 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 14 C-AMS facility in Latin America. (author)

  3. 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.

  4. Tandem mass spectrometry: analysis of complex mixtures

    International Nuclear Information System (INIS)

    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

  5. Imaging mass spectrometry in drug development and toxicology.

    Science.gov (United States)

    Karlsson, Oskar; Hanrieder, Jörg

    2017-06-01

    During the last decades, imaging mass spectrometry has gained significant relevance in biomedical research. Recent advances in imaging mass spectrometry have paved the way for in situ studies on drug development, metabolism and toxicology. In contrast to whole-body autoradiography that images the localization of radiolabeled compounds, imaging mass spectrometry provides the possibility to simultaneously determine the discrete tissue distribution of the parent compound and its metabolites. In addition, imaging mass spectrometry features high molecular specificity and allows comprehensive, multiplexed detection and localization of hundreds of proteins, peptides and lipids directly in tissues. Toxicologists traditionally screen for adverse findings by histopathological examination. However, studies of the molecular and cellular processes underpinning toxicological and pathologic findings induced by candidate drugs or toxins are important to reach a mechanistic understanding and an effective risk assessment strategy. One of IMS strengths is the ability to directly overlay the molecular information from the mass spectrometric analysis with the tissue section and allow correlative comparisons of molecular and histologic information. Imaging mass spectrometry could therefore be a powerful tool for omics profiling of pharmacological/toxicological effects of drug candidates and toxicants in discrete tissue regions. The aim of the present review is to provide an overview of imaging mass spectrometry, with particular focus on MALDI imaging mass spectrometry, and its use in drug development and toxicology in general.

  6. Correcting mass shifts: A lock mass-free recalibration procedure for mass spectrometry imaging data

    Czech Academy of Sciences Publication Activity Database

    Kulkarni, P.; Kaftan, F.; Kynast, P.; Svatoš, Aleš; Böcker, S.

    2015-01-01

    Roč. 407, č. 25 (2015), s. 7603-7613 ISSN 1618-2642 Institutional support: RVO:61388963 Keywords : mass spectrometry imaging * recalibration * mass shift correction * data processing Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 3.125, year: 2015

  7. 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....

  8. Analysis of organic compounds by secondary neutral mass spectrometry (SNMS) and secondary ion mass spectrometry (SIMS)

    International Nuclear Information System (INIS)

    Ewinger, H.P.

    1993-05-01

    This study is about the use of secondary neutral mass spectrometry (SNMS) and secondary ion mass spectrometry (SIMS) as analytical techniques with depth resolution in determining organic components in environmental solid microparticles. The first application of plasma SNMS to organic compounds revealed the spectra to be composed mainly of signals from the atoms of all participating elements, such as C, H, O, N, S, P, and Cl. In addition, signals produced by multi-atomic clusters can be detected, such as CH, C 2 , CH 2 , C 2 H, and C 3 , as well as signals indicating the presence of organic compounds with hetero elements, such as OH, NH, and CN. Their intensity decreases very markedly with increasing numbers of atoms. Among the signals from bi-atomic clusters, those coming from elements with large mass differences are most intense. The use of plasma SNMS with organic compounds has shown that, except for spurious chemical reactions induced by ion bombardment and photodesorption by the photons of the plasma, it is possible to analyze with resolution in depth, elements of organic solids. A more detailed molecular characterization of organic compounds is possible by means of SIMS on the basis of multi-atomic fragments and by comparison with suitable signal patterns. (orig./BBR) [de

  9. Optical spectroscopy versus mass spectrometry: The race for fieldable isotopic analysis

    International Nuclear Information System (INIS)

    Barshick, C.M.; Young, J.P.; Shaw, R.W.

    1995-01-01

    Several techniques have been developed to provide on-site isotopic analyses, including decay-counting and mass spectrometry, as well as methods that rely on the accessibility of optical transitions for isotopic selectivity (e.g., laser-induced fluorescence and optogalvanic spectroscopy). The authors have been investigating both mass spectrometry and optogalvanic spectroscopy for several years. Although others have considered these techniques for isotopic analysis, the authors have focussed on the use of a dc glow discharge for atomization and ionization, and a demountable discharge cell for rapid sample exchange. The authors' goal is a fieldable instrument that provides useful uranium isotope ratio information

  10. [Advances in mass spectrometry-based approaches for neuropeptide analysis].

    Science.gov (United States)

    Ji, Qianyue; Ma, Min; Peng, Xin; Jia, Chenxi; Ji, Qianyue

    2017-07-25

    Neuropeptides are an important class of endogenous bioactive substances involved in the function of the nervous system, and connect the brain and other neural and peripheral organs. Mass spectrometry-based neuropeptidomics are designed to study neuropeptides in a large-scale manner and obtain important molecular information to further understand the mechanism of nervous system regulation and the pathogenesis of neurological diseases. This review summarizes the basic strategies for the study of neuropeptides using mass spectrometry, including sample preparation and processing, qualitative and quantitative methods, and mass spectrometry imagining.

  11. 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.

  12. [Latest development in mass spectrometry for clinical application].

    Science.gov (United States)

    Takino, Masahiko

    2013-09-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has seen enormous growth in special clinical chemistry laboratories. It significantly increases the analytic potential in clinical chemistry, especially in the field of low molecular weight biomarker analysis. This review summarizes the state of the art in mass spectrometry and related techniques for clinical application with a main focus on recent developments in LC-MS. Current trends in ionization techniques, automated online sample preparation techniques coupled with LC-MS, and ion mobility spectrometry are discussed. Emerging mass spectrometric approaches complementary to LC-MS are discussed as well.

  13. Proteomic Mass Spectrometry Imaging for Skin Cancer Diagnosis.

    Science.gov (United States)

    Lazova, Rossitza; Seeley, Erin H

    2017-10-01

    Mass spectrometry imaging can be successfully used for skin cancer diagnosis, particularly for the diagnosis of challenging melanocytic lesions. This method analyzes proteins within benign and malignant melanocytic tumor cells and, based on their differences, which constitute a unique molecular signature of 5 to 20 proteins, can render a diagnosis of benign nevus versus malignant melanoma. Mass spectrometry imaging may assist in the differentiation between metastases and nevi as well as between proliferative nodules in nevi and melanoma arising in a nevus. In the difficult area of atypical Spitzoid neoplasms, mass spectrometry diagnosis can predict clinical outcome better than histopathology. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. New developments in glow discharge optical emission and mass spectrometry

    International Nuclear Information System (INIS)

    Hoffmann, Volker; Dorka, Roland; Wilken, Ludger; Wetzig, Klaus

    2000-01-01

    This paper describes new developments in flow discharge optical emission (GD-OES) and mass spectrometry (GD-MS) at IFW and presents corresponding new applications (analysis of microelectronic multi-layer system by radio frequency glow discharge optical emission spectrometry (RF-GD-OES) and analysis of pure iron by a new Grimm-type GD-MS source)

  15. Use of mass spectrometry for study of coordination compounds

    International Nuclear Information System (INIS)

    Gehrbehlehu, N.V.; Indrichan, K.M.

    1981-01-01

    A review on mass-spectrometry of coordination compounds including the works published up to 1979 inclusive is provided. Mainly the products of metals with bi- and tetradentate ligands are considered using the method. Mo and Be carboxylates for which molecular ions lines are found in mass-spectra are studied. The study of mass-spectra for VO chelates with thiosemicarbazone of salicyl aldehyde is carried out. Application of the mass-spectrometry method permits to establish the mass of coordination compounds, the structure of complexes, dentate structure and the way of ligand coordination, the bond strength [ru

  16. Negative ion electrospray ionization mass spectrometry of nucleoside phosphoramidate monoesters: elucidation of novel rearrangement mechanisms by multistage mass spectrometry incorporating in-source deuterium labelling.

    Science.gov (United States)

    Xu, Peng-Xiang; Hu, An-Fu; Hu, Dan; Gao, Xiang; Zhao, Yu-Fen

    2008-10-01

    Several O-2',3'-isopropylideneuridine-O-5'-phosphoramidate monoesters were synthesized and analyzed by negative ion electrospray ionization tandem mass spectrometry (ESI-MS(n)). Two kinds of novel rearrangement reactions were observed due to the difference in the amino acid in the nucleoside phosphoramidate monoesters, and possible mechanisms were proposed. One involves a five-membered cyclic transition state. The other is formation of a stable five-membered ring intermediate by Michael addition. Results were confirmed by tandem mass spectrometry and isotopically labeled hydrogen atoms. Furthermore, the internal hydrogen exchange between active hydrogen and methyl acrylate in the heated capillary of the mass spectrometer was found. The characteristic fragmentation behavior in ESI-MS may be used to monitor this kind of compounds in the biological metabolism.

  17. The allure of mass spectrometry: From an earlyday chemist's perspective.

    Science.gov (United States)

    Tőkés, László

    2017-07-01

    This reminiscing review article is an account of the author's fascination and involvements with mass spectrometry from the perspective of an organic chemist with an interest in natural product chemistry. It covers a period from 1961 through the mid 1990s as mass spectrometry evolved form a novelty technique to become a most widely used analytical technique. Following a brief synopsis of my pathway to mass spectrometry, my research efforts in this field are presented with a focus mainly on evolving principles and technologies which I had personal involvements with. To provide historical perspectives, discussions of these developments are accompanied by brief outlines of the relevant state-of-the-art, shedding light on the technical and conceptual challenges encountered during those early days in mass spectrometry. Examples are presented of my involvements with basic and applied research in mass spectrometry during graduate studies at Stanford University and close to three decade tenure in pharmaceutical research at Syntex Research. My basic research interests focused mainly on principles of electron ionization induced fragmentation mechanisms, with an emphasis on steroids and other model compounds. Extensive deuterium labeling evidence was used to determine the fragmentation mechanisms of the diagnostically significant ions in the spectra of numerous model compounds, uncovering examples of wide-ranging hydrogen transfers, skeletal rearrangements, methyl and phenyl migrations, stereoselective fragmentations and low and high energy fragmentation processes. Depiction of the industrial research phase of my career includes comments on the pivotal role mass spectrometry played on advancing modern pharmaceutical research. Examples are presented of involvements with instrumental developments and a few select cases of applied research, including studies of bile mechanisms in vertebrates, identification of bisphenol-A leaching from sterilized polycarbonate containers, high

  18. The diverse and expanding role of mass spectrometry in structural and molecular biology.

    Science.gov (United States)

    Lössl, Philip; van de Waterbeemd, Michiel; Heck, Albert Jr

    2016-12-15

    The emergence of proteomics has led to major technological advances in mass spectrometry (MS). These advancements not only benefitted MS-based high-throughput proteomics but also increased the impact of mass spectrometry on the field of structural and molecular biology. Here, we review how state-of-the-art MS methods, including native MS, top-down protein sequencing, cross-linking-MS, and hydrogen-deuterium exchange-MS, nowadays enable the characterization of biomolecular structures, functions, and interactions. In particular, we focus on the role of mass spectrometry in integrated structural and molecular biology investigations of biological macromolecular complexes and cellular machineries, highlighting work on CRISPR-Cas systems and eukaryotic transcription complexes. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  19. Microbial metabolomics with gas chromatography/mass spectrometry

    NARCIS (Netherlands)

    Koek, M.M.; Muilwijk, B.; Werf, M.J. van der; Hankemeier, T.

    2006-01-01

    An analytical method was set up suitable for the analysis of microbial metabolomes, consisting of an oximation and silylation derivatization reaction and subsequent analysis by gas chromatography coupled to mass spectrometry. Microbial matrixes contain many compounds that potentially interfere with

  20. Sampling and analyte enrichment strategies for ambient mass spectrometry.

    Science.gov (United States)

    Li, Xianjiang; Ma, Wen; Li, Hongmei; Ai, Wanpeng; Bai, Yu; Liu, Huwei

    2018-01-01

    Ambient mass spectrometry provides great convenience for fast screening, and has showed promising potential in analytical chemistry. However, its relatively low sensitivity seriously restricts its practical utility in trace compound analysis. In this review, we summarize the sampling and analyte enrichment strategies coupled with nine modes of representative ambient mass spectrometry (desorption electrospray ionization, paper vhspray ionization, wooden-tip spray ionization, probe electrospray ionization, coated blade spray ionization, direct analysis in real time, desorption corona beam ionization, dielectric barrier discharge ionization, and atmospheric-pressure solids analysis probe) that have dramatically increased the detection sensitivity. We believe that these advances will promote routine use of ambient mass spectrometry. Graphical abstract Scheme of sampling stretagies for ambient mass spectrometry.

  1. Analytical strategies in mass spectrometry-based phosphoproteomics

    DEFF Research Database (Denmark)

    Rosenqvist, Heidi; Ye, Juanying; Jensen, Ole N

    2011-01-01

    then discuss various tandem mass spectrometry approaches for phosphopeptide sequencing and quantification, and we consider aspects of phosphoproteome data analysis and interpretation. Efficient integration of these stages of phosphoproteome analysis is highly important to ensure a successful outcome of large...

  2. Biomarker discovery in high grade sarcomas by mass spectrometry imaging

    OpenAIRE

    Lou, S.

    2017-01-01

    This thesis demonstrates a detailed biomarker discovery Mass Spectrometry Imaging workflow for histologically heterogeneous high grade sarcomas. Panels of protein and metabolite signatures were discovered either distinguishing different histological subtypes or stratifying high risk patients with poor survival.

  3. A theory of stable-isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Pickup, J.F.; McPherson, C.K.

    1977-01-01

    In order to perform quantitative analysis using stable isotope dilution with mass spectrometry, an equation is derived which describes the relationship between the relative proportions of natural and labelled material and measured isotope ratios

  4. Chemical ionisation mass spectrometry: a survey of instrument technology

    International Nuclear Information System (INIS)

    Mather, R.E.; Todd, J.F.J.

    1979-01-01

    The purpose of this review is to survey the innovations and improvements which have been made in both instrumentation and methodology in chemical ionization mass spectrometry in the past ten years. (Auth.)

  5. 13th International Mass Spectrometry Conference. Book of Abstracts

    International Nuclear Information System (INIS)

    1994-01-01

    The collection contains abstracts of several hundred papers presented at the international conference on new research and development results and applications of mass spectrometry. Abstracts falling into the INIS scope were indexed separately in the INIS database. (Roboz, P.)

  6. 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.

  7. Recent applications of mass spectrometry in forensic toxicology

    Science.gov (United States)

    Foltz, Rodger L.

    1992-09-01

    This review encompasses applications of mass spectrometry reported during the years 1989, 1990 and 1991 for the analysis of cannabinoids, cocaine, opiates, amphetamines, lysergic acid diethylamide (LSD), and their metabolites in physiological specimens.

  8. Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry

    KAUST Repository

    Raji, Misjudeen; Amad, Maan H.; Emwas, Abdul-Hamid M.

    2013-01-01

    RATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed

  9. 13th International Mass Spectrometry Conference. Book of Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The collection contains abstracts of several hundred papers presented at the international conference on new research and development results and applications of mass spectrometry. Abstracts falling into the INIS scope were indexed separately in the INIS database. (Roboz, P.).

  10. Gas Chromatography Mass Spectrometry of Quassia undulata Seed ...

    African Journals Online (AJOL)

    Prof. Ogunji

    The use of gas chromatography mass spectrometry (GC MS) as a sensitive and specific technique ... cold flow properties and stability of the fuel to oxidation, peroxidation and polymerization .... determinants of both the physical and chemical ...

  11. Practical aspects and trends in analytical organic mass spectrometry

    International Nuclear Information System (INIS)

    Schlunegger, U.P.

    1981-01-01

    Proceeding from the fundamentals of mass spectrometry (MS), some more recent developments of analytical organic MS are shown in comparison with conventional MS. Sections are headed: the vacuum, production of ions in the mass spectrometer, ions in the analyzer of a mass spectrometer, general considerations, practice of modern MS: selected examples

  12. 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.

  13. Automated, parallel mass spectrometry imaging and structural identification of lipids

    DEFF Research Database (Denmark)

    Ellis, Shane R.; Paine, Martin R.L.; Eijkel, Gert B.

    2018-01-01

    We report a method that enables automated data-dependent acquisition of lipid tandem mass spectrometry data in parallel with a high-resolution mass spectrometry imaging experiment. The method does not increase the total image acquisition time and is combined with automatic structural assignments....... This lipidome-per-pixel approach automatically identified and validated 104 unique molecular lipids and their spatial locations from rat cerebellar tissue....

  14. Quantification of steroid conjugates using fast atom bombardment mass spectrometry

    International Nuclear Information System (INIS)

    Gaskell, S.J.

    1990-01-01

    Fast atom bombardment/mass spectrometry or liquid secondary ion mass spectrometry provides the capability for direct analysis of steroid conjugates (sulfates, glucuronides) without prior hydrolysis or derivatization. During the analysis of biologic extracts, limitations on the sensitivity of detection arise from the presence of co-extracted material which may suppress or obscure the analyte signal. A procedure is described for the quantitative determination of dehydroepiandrosterone sulfate in serum which achieved selective isolation of the analyte using immunoadsorption extraction and highly specific detection using tandem mass spectrometry. A stable isotope-labeled analog [( 2H2]dehydroepiandrosterone sulfate) was used as internal standard. Fast atom bombardment of dehydroepiandrosterone sulfate yielded abundant [M-H]- ions that fragmented following collisional activation to give HSO4-; m/z 97. During fast atom bombardment/tandem mass spectrometry of serum extracts, a scan of precursor ions fragmenting to give m/z 97 detected dehydroepiandrosterone sulfate and the [2H2]-labeled analog with a selectivity markedly superior to that observed using conventional mass spectrometry detection. Satisfactory agreement was observed between quantitative data obtained in this way and data obtained by gas chromatography/mass spectrometry of the heptafluorobutyrates of dehydroepiandrosterone sulfate and [2H2]dehydroepiandrosterone sulfate obtained by direct derivatization. 21 refs

  15. New approaches for metabolomics by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vertes, Akos [George Washington Univ., Washington, DC (United States)

    2017-07-10

    Small molecules constitute a large part of the world around us, including fossil and some renewable energy sources. Solar energy harvested by plants and bacteria is converted into energy rich small molecules on a massive scale. Some of the worst contaminants of the environment and compounds of interest for national security also fall in the category of small molecules. The development of large scale metabolomic analysis methods lags behind the state of the art established for genomics and proteomics. This is commonly attributed to the diversity of molecular classes included in a metabolome. Unlike nucleic acids and proteins, metabolites do not have standard building blocks, and, as a result, their molecular properties exhibit a wide spectrum. This impedes the development of dedicated separation and spectroscopic methods. Mass spectrometry (MS) is a strong contender in the quest for a quantitative analytical tool with extensive metabolite coverage. Although various MS-based techniques are emerging for metabolomics, many of these approaches include extensive sample preparation that make large scale studies resource intensive and slow. New ionization methods are redefining the range of analytical problems that can be solved using MS. This project developed new approaches for the direct analysis of small molecules in unprocessed samples, as well as pushed the limits of ultratrace analysis in volume limited complex samples. The projects resulted in techniques that enabled metabolomics investigations with enhanced molecular coverage, as well as the study of cellular response to stimuli on a single cell level. Effectively individual cells became reaction vessels, where we followed the response of a complex biological system to external perturbation. We established two new analytical platforms for the direct study of metabolic changes in cells and tissues following external perturbation. For this purpose we developed a novel technique, laser ablation electrospray

  16. MPAI (mass probes aided ionization) method for total analysis of biomolecules by mass spectrometry.

    Science.gov (United States)

    Honda, Aki; Hayashi, Shinichiro; Hifumi, Hiroki; Honma, Yuya; Tanji, Noriyuki; Iwasawa, Naoko; Suzuki, Yoshio; Suzuki, Koji

    2007-01-01

    We have designed and synthesized various mass probes, which enable us to effectively ionize various molecules to be detected with mass spectrometry. We call the ionization method using mass probes the "MPAI (mass probes aided ionization)" method. We aim at the sensitive detection of various biological molecules, and also the detection of bio-molecules by a single mass spectrometry serially without changing the mechanical settings. Here, we review mass probes for small molecules with various functional groups and mass probes for proteins. Further, we introduce newly developed mass probes for proteins for highly sensitive detection.

  17. 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…

  18. Data recording and processing in mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McKown, H. [International Atomic Energy Agency, Vienna (Austria)

    1978-12-15

    When a mass spectrometer is going to be obtained, it must be specified to do a particular task. It follows that the data recording system must be designed to work satisfactorily with hardware that produces the ion current or currents. The author describes two systems: the AVCO mass spectrometer and the tandem mass spectrometer.

  19. Towards airborne nanoparticle mass spectrometry with nanomechanical string resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Kurek, Maksymilian; Boisen, Anja

    2013-01-01

    airborne nanoparticle sensors. Recently, nanomechanical mass spectrometry was established. One of the biggest challenges of nanomechanical sensors is the low efficiency of diffusion-based sampling. We developed an inertial-based sampling method that enables the efficient sampling of airborne nanoparticles...... mode. Mass spectrometry of airborne nanoparticles requires the simultaneous operation in the first and second mode, which can be implemented in the transduction scheme of the resonator. The presented results lay the cornerstone for the realization of a portable airborne nanoparticle mass spectrometer....

  20. AM1 and electron impact mass spectrometry study of the ...

    African Journals Online (AJOL)

    Recently, in electron impact mass spectrometry (EIMS), it has been found a good correlation between the fragmentation processes of coumarins and the electronic charges of the atoms of their skeleton. In this paper, the same analytical method has been applied to 4-acyl isochroman-1,3-diones, whose mass spectra had ...

  1. 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.

  2. Plutonium determination in urine by techniques of mass spectrometry

    International Nuclear Information System (INIS)

    Hernandez M, H.; Yllera de Ll, A.

    2013-10-01

    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 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 239 Pu). (author)

  3. Knudsen effusion mass spectrometry. Chapter 20

    International Nuclear Information System (INIS)

    Sai Baba, M.

    1997-01-01

    The Knudsen effusion mass spectrometric method for the determination of vapour pressures and thermodynamic properties is described. The aim of the article is to give a general introduction to the method rather than to give a critical review of the technique. The latest developments in this area of research are reviewed by the peers in the field during the triennial international mass spectrometric conferences. The Knudsen effusion mass spectrometric method is being applied for thermodynamic measurements. In recent times, laser vaporisation mass spectrometric methods have emerged as a source of determination of vapour pressures at very high temperatures and beyond the pressure regime far exceeding Knudsen effusion range

  4. 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.

  5. 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

  6. Emerging mass spectrometry techniques for the direct analysis of microbial colonies

    OpenAIRE

    Fang, Jinshu; Dorrestein, Pieter C.

    2014-01-01

    One of the emerging areas in microbiology is detecting specialized metabolites produced by microbial colonies and communities with mass spectrometry. In this review/perspective, we illustrate the emerging mass spectrometry methodologies that enable the interrogation of specialized metabolites directly from microbial colonies. Mass spectrometry techniques such as imaging mass spectrometry and real-time mass spectrometry allow two and three dimensional visualization of the distri...

  7. Mass Spectrometry Imaging of Drugs of Abuse in Hair.

    Science.gov (United States)

    Flinders, Bryn; Cuypers, Eva; Porta, Tiffany; Varesio, Emmanuel; Hopfgartner, Gérard; Heeren, Ron M A

    2017-01-01

    Hair testing is a powerful tool routinely used for the detection of drugs of abuse. The analysis of hair is highly advantageous as it can provide prolonged drug detectability versus that in biological fluids and chronological information about drug intake based on the average growth of hair. However, current methodology requires large amounts of hair samples and involves complex time-consuming sample preparation followed by gas or liquid chromatography coupled with mass spectrometry. Mass spectrometry imaging is increasingly being used for the analysis of single hair samples, as it provides more accurate and visual chronological information in single hair samples.Here, two methods for the preparation of single hair samples for mass spectrometry imaging are presented.The first uses an in-house built cutting apparatus to prepare longitudinal sections, the second is a method for embedding and cryo-sectioning hair samples in order to prepare cross-sections all along the hair sample.

  8. Proceedings of twelfth ISMAS symposium cum workshop on mass spectrometry

    International Nuclear Information System (INIS)

    Alamelu, D.; Jaison, P.G.; Aggarwal, S.K.

    2007-03-01

    Mass Spectrometry is an important analytical tool and has encompassed almost all branches of science and technology including Agricultural, biology, Chemistry, Earth sciences, environment, Forensic Science, Medical Sciences, Hydrology, Nuclear Technology, Oceanography, Physics etc. Recent advancements in the instrumentation of Mass Spectrometry have further strengthened its role for various applications. It is indeed a matter of great pleasure to present this special Issue of ISMAS Bulletin which is brought out on the occasion of the 12th ISMAS Symposium cum Workshop on Mass spectrometry (12th ISMAS-WS 2007) being held at Cidade-de-Goa, Dona Paula, Goa from March 25 to 30, 2007 in association with National Institute of Oceanography, Goa. This Symposium cum Workshop is co-sponsored by Scientific Departments of Government of India. Papers relevant to INIS are indexed separately

  9. Paradigms in isotope dilution mass spectrometry for elemental speciation analysis

    International Nuclear Information System (INIS)

    Meija, Juris; Mester, Zoltan

    2008-01-01

    Isotope dilution mass spectrometry currently stands out as the method providing results with unchallenged precision and accuracy in elemental speciation. However, recent history of isotope dilution mass spectrometry has shown that the extent to which this primary ratio measurement method can deliver accurate results is still subject of active research. In this review, we will summarize the fundamental prerequisites behind isotope dilution mass spectrometry and discuss their practical limits of validity and effects on the accuracy of the obtained results. This review is not to be viewed as a critique of isotope dilution; rather its purpose is to highlight the lesser studied aspects that will ensure and elevate current supremacy of the results obtained from this method

  10. High efficiency nebulization for helium inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

    2006-01-01

    A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

  11. Laser desorption mass spectrometry for biomolecule detection and its applications

    Science.gov (United States)

    Winston Chen, C. H.; Sammartano, L. J.; Isola, N. R.; Allman, S. L.

    2001-08-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications.

  12. Laser desorption mass spectrometry for biomolecule detection and its applications

    International Nuclear Information System (INIS)

    Winston Chen, C.H.; Allman, S.L.; Sammartano, L.J.; Isola, N.R.

    2001-01-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications

  13. Accelerator mass spectrometry-current status in techniques and applications

    International Nuclear Information System (INIS)

    Imamura, Mineo; Nagai, Hisao; Kobayashi, Koichi.

    1991-01-01

    Accelerator mass spectrometry (AMS) is the mass spectrometry by incorporating an accelerator. After samples are ionized, they are accelerated to a certain energy, and mass, energy, nuclear charge (atomic number) are distinguished, and ion counting is made one by one with a heavy ion detector. For the measurement of long half-life radioisotopes, mass spectrometry has been used because of the high sensitivity, but in low energy mass spectrometry, there are the difficulties due to the mixing of the molecular ions having nearly same mass and the existence of isobars. One of the methods solving these difficulties is an accelerator which enables background-free measurement. The progress of AMS is briefly described, and at present, it is carried out in about 30 facilities in the world. In AMS, the analysis is carried out in the order of the ionization of samples, the acceleration of beam, the electron stripping with a thin film, the sorting of the momentum and energy of beam and the identification of particles. The efficiency, sensitivity and accuracy of detection and the application are reported. (K.I.)

  14. 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 the physic......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...

  15. Radiogas chromatography mass spectrometry in the selected ion monitoring mode

    International Nuclear Information System (INIS)

    Doerfler, D.L.; Rosenblum, E.R.; Malloy, J.M.; Naworal, J.D.; McManus, I.R.; Campbell, I.M.

    1980-01-01

    The value of selected ion monitoring in analyzing biological radio isotope incorporation experiments by radiogas chromatography mass spectrometry is illustrated with reference to the biosynthesis of the mycotoxin mycophenolic acid in Penicillium brevicompactum and the mode of action of the anticholesterolemic drug 20,25-diazacholesterol. Both examples used 1-[ 14 C]acetate precursors. It is shown that the increased sensitivity and specificity of the selected ion monitoring mode detector permits straightforward detection and identification of the relatively small cellular pools associated with metabolic intermediates. The computer program RADSIM is described. Problems that still exist in using radiogas gas chromatography mass spectrometry technology to analyse isotope incorporation experiments are discussed. (author)

  16. 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. Copyright © 2012 Wiley Periodicals, Inc., A Wiley Company.

  17. 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. Copyright 2008 Wiley Periodicals, Inc.

  18. Native Mass Spectrometry in Fragment-Based Drug Discovery.

    Science.gov (United States)

    Pedro, Liliana; Quinn, Ronald J

    2016-07-28

    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.

  19. Quantitating subcellular metabolism with multi-isotope imaging mass spectrometry

    OpenAIRE

    Steinhauser, Matthew L.; Bailey, Andrew; Senyo, Samuel E.; Guillermier, Christelle; Perlstein, Todd S.; Gould, Alex P.; Lee, Richard T.; Lechene, Claude P.

    2012-01-01

    Mass spectrometry with stable isotope labels has been seminal in discovering the dynamic state of living matter 1,2 but is limited to bulk tissues or cells. We developed multi-isotope imaging mass spectrometry (MIMS) that allowed us to view and measure stable isotope incorporation with sub-micron resolution 3,4 . Here we apply MIMS to diverse organisms, including Drosophila, mice, and humans. We test the “immortal strand hypothesis,” which predicts that during asymmetric stem cell division ch...

  20. Major roles for minor bacterial lipids identified by mass spectrometry.

    Science.gov (United States)

    Garrett, Teresa A

    2017-11-01

    Mass spectrometry of lipids, especially those isolated from bacteria, has ballooned over the past two decades, affirming in the process the complexity of the lipidome. With this has come the identification of new and interesting lipid structures. Here is an overview of several novel lipids, from both Gram-negative and Gram-positive bacteria with roles in health and disease, whose structural identification was facilitated using mass spectrometry. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Determination of glufosinate ammonium and its metabolite (AE F064619 and AE F061517) residues in water by gas chromatography with tandem mass spectrometry after ion exchange cleanup and derivatization.

    Science.gov (United States)

    Royer, A; Beguin, S; Sochor, H; Communal, P Y

    2000-11-01

    An analytical method for the determination of glufosinate ammonium and its principal metabolites, AE F064619 and AE F061517, in water of two different hardnesses (5 and 30 DH, French hardness) has been developed and validated. Samples were spiked at different levels (0. 05 and 0.5 microgram/L) and were purified by column chromatography on ion-exchange resins. After derivatization with glacial acetic acid and trimethylarthoacetate mixture, the derivatives were quantified by using capillary gas chromatography with an ion-trap tandem mass spectrometric detector. Analytical conditions for MS/MS detection were optimized, and the quantification was carried out on the areas of the most representative ions. The limit of quantification was validated at 0.05 microgram/L for each compound. The mean recovery value and the relative standard deviation (n = 20) were 92.0% and 17. 8% for glufosinate ammonium, 90.2% and 15.8% for AE F064619, and 89. 7% and 12.7% for AE F061517.

  2. Identifying modifications in RNA by MALDI mass spectrometry

    DEFF Research Database (Denmark)

    Douthwaite, Stephen; Kirpekar, Finn

    2007-01-01

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

  3. Simple setup for gas-phase H/D exchange mass spectrometry coupled to electron transfer dissociation and ion mobility for analysis of polypeptide structure on a liquid chromatographic time scale.

    Science.gov (United States)

    Mistarz, Ulrik H; Brown, Jeffery M; Haselmann, Kim F; Rand, Kasper D

    2014-12-02

    Gas-phase hydrogen/deuterium exchange (HDX) is a fast and sensitive, yet unharnessed analytical approach for providing information on the structural properties of biomolecules, in a complementary manner to mass analysis. Here, we describe a simple setup for ND3-mediated millisecond gas-phase HDX inside a mass spectrometer immediately after ESI (gas-phase HDX-MS) and show utility for studying the primary and higher-order structure of peptides and proteins. HDX was achieved by passing N2-gas through a container filled with aqueous deuterated ammonia reagent (ND3/D2O) and admitting the saturated gas immediately upstream or downstream of the primary skimmer cone. The approach was implemented on three commercially available mass spectrometers and required no or minor fully reversible reconfiguration of gas-inlets of the ion source. Results from gas-phase HDX-MS of peptides using the aqueous ND3/D2O as HDX reagent indicate that labeling is facilitated exclusively through gaseous ND3, yielding similar results to the infusion of purified ND3-gas, while circumventing the complications associated with the use of hazardous purified gases. Comparison of the solution-phase- and gas-phase deuterium uptake of Leu-Enkephalin and Glu-Fibrinopeptide B, confirmed that this gas-phase HDX-MS approach allows for labeling of sites (heteroatom-bound non-amide hydrogens located on side-chains, N-terminus and C-terminus) not accessed by classical solution-phase HDX-MS. The simple setup is compatible with liquid chromatography and a chip-based automated nanoESI interface, allowing for online gas-phase HDX-MS analysis of peptides and proteins separated on a liquid chromatographic time scale at increased throughput. Furthermore, online gas-phase HDX-MS could be performed in tandem with ion mobility separation or electron transfer dissociation, thus enabling multiple orthogonal analyses of the structural properties of peptides and proteins in a single automated LC-MS workflow.

  4. 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

  5. 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.

  6. Elucidating rhizosphere processes by mass spectrometry – A review

    Energy Technology Data Exchange (ETDEWEB)

    Rugova, Ariana [Division of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences-BOKU, Vienna (Austria); Puschenreiter, Markus [Department of Forest and Soil Sciences, Rhizosphere Ecology and Biogeochemistry Group, University of Natural Resources and Life Sciences-BOKU, Vienna (Austria); Koellensperger, Gunda [Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna (Austria); Hann, Stephan, E-mail: stephan.hann@boku.ac.at [Division of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences-BOKU, Vienna (Austria)

    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. - Highlights: • State-of-the-art mass spectrometry methods developed and applied in rhizosphere research are reviewed. • Elemental and molecular mass spectrometry emphasizing different separation techniques (GC, LC or CE) are discussed. • Case studies on metal detoxification

  7. Elucidating rhizosphere processes by mass spectrometry – A review

    International Nuclear Information System (INIS)

    Rugova, Ariana; Puschenreiter, Markus; Koellensperger, Gunda; Hann, Stephan

    2017-01-01

    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. - Highlights: • State-of-the-art mass spectrometry methods developed and applied in rhizosphere research are reviewed. • Elemental and molecular mass spectrometry emphasizing different separation techniques (GC, LC or CE) are discussed. • Case studies on metal detoxification and

  8. The analysis of aqueous mixtures using liquid chromatography-electrospray mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Steven [Iowa State Univ., Ames, IA (United States)

    1999-02-12

    The focus of this dissertation is the use of chromatographic methods coupled with electrospray mass spectrometry (ES-MS) for the determination of both organic and inorganic compounds in aqueous solutions. The combination of liquid chromatography (LC) methods and ES-MS offers one of the foremost methods for determining compounds in complex aqueous solutions. In this work, LC-ES-MS methods are devised using ion exclusion chromatography, reversed phase chromatography, and ion exchange chromatography, as well as capillary electrophoresis (CE). For an aqueous sample, these LC-ES-MS and CE-ES-MS techniques require no sample preparation or analyte derivatization, which makes it possible to observe a wide variety of analytes as they exist in solution. The majority of this work focuses on the use of LC-ES-MS for the determination of unknown products and intermediates formed during electrochemical incineration (ECI), an experimental waste remediation process. This report contains a general introduction to the project and the general conclusions. Four chapters have been removed for separate processing. Titles are: Chapter 2: Determination of small carboxylic acids by ion exclusion chromatography with electrospray mass spectrometry; Chapter 3: Electrochemical incineration of benzoquinone in aqueous media using a quaternary metal oxide electrode in the absence of a soluble supporting electrolyte; Chapter 4: The determination of electrochemical incineration products of 4-chlorophenol by liquid chromatography-electrospray mass spectrometry; and Chapter 5: Determination of small carboxylic acids by capillary electrophoresis with electrospray mass spectrometry.

  9. Principles of isotopic analysis by mass spectrometry

    International Nuclear Information System (INIS)

    Herrmann, M.

    1980-01-01

    The use of magnetic sector field mass spectrometers in isotopic analysis, especially for nitrogen gas, is outlined. Two measuring methods are pointed out: the scanning mode for significantly enriched samples and the double collector method for samples near the natural abundance of 15 N. The calculation formulas are derived and advice is given for corrections. (author)

  10. 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)

  11. Characterizing the lipid and metabolite changes associated with placental function and pregnancy complications using ion mobility spectrometry-mass spectrometry and mass spectrometry imaging

    Energy Technology Data Exchange (ETDEWEB)

    Burnum-Johnson, Kristin E.; Baker, Erin S.; Metz, Thomas O.

    2017-12-01

    Successful pregnancy is dependent upon discrete biological events, which include embryo implantation, decidualization, and placentation. Problems associated with each of these events can cause infertility or conditions such as preeclampsia. A greater understanding of the molecular changes associated with these complex processes is necessary to aid in identifying treatments for each condition. Previous nuclear magnetic resonance spectroscopy and mass spectrometry studies have been used to identify metabolites and lipids associated with pregnancy-related complications. However, due to limitations associated with conventional implementations of both techniques, novel technology developments are needed to more fully understand the initiation and development of pregnancy related problems at the molecular level. In this perspective, we describe current analytical techniques for metabolomic and lipidomic characterization of pregnancy complications and discuss the potential for new technologies such as ion mobility spectrometry-mass spectrometry and mass spectrometry imaging to contribute to a better understanding of the molecular changes that affect the placenta and pregnancy outcomes.

  12. Laser Mass Spectrometry in Planetary Science

    International Nuclear Information System (INIS)

    Wurz, P.; Whitby, J. A.; Managadze, G. G.

    2009-01-01

    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.

  13. Trace amount analysis using spark mass spectrometry

    International Nuclear Information System (INIS)

    Stefani, Rene

    1975-01-01

    Characteristics of spark mass spectrometers (ion source, properties of the ion beam, ion optics, and performance) and their use in qualitative and quantitative analysis are described. This technique is very interesting for the semi-quantitative analysis of trace amounts, down to 10 -8 atoms. Examples of applications such as the analysis of high purity materials and non-conducting mineral samples, and determination of carbon and gas trace amounts are presented. (50 references) [fr

  14. Hydrogen isotope analysis by quadrupole mass spectrometry

    International Nuclear Information System (INIS)

    Ellefson, R.E.; Moddeman, W.E.; Dylla, H.F.

    1981-03-01

    The analysis of isotopes of hydrogen (H, D, T) and helium ( 3 He, 4 He) and selected impurities using a quadrupole mass spectrometer (QMS) has been investigated as a method of measuring the purity of tritium gas for injection into the Tokamak Fusion Test Reactor (TFTR). A QMS was used at low resolution, m/Δm 3 He, and 4 He in HT/D 2

  15. Total evaporation in thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Callis, E.L.; Cappis, J.H.

    1996-01-01

    Experiments were conducted to assess the effects of impurities on the total evaporation method for mass spectrometric measurement of the isotope ratio of uranium. Standard samples were spiked with Na, Ca, Fe, Zr and Ba. The results indicated that only Fe, and possible Na, displayed any interference, and then only at high concentrations. One problem limiting the accuracy of the method is the determination of the relative efficiency of the collectors in the multicollector system. 3 refs., 1 tab

  16. Inorganic trace analysis by laser ionization mass spectrometry

    International Nuclear Information System (INIS)

    Becker, S.; Dietze, H.J.

    1991-01-01

    Among the different spectrometric techniques for trace analysis Laser Ionization Mass Spectrometry (LIMS) is well established as a trace analytic method with a wide coverage. In the LIMS the sample material is evaporated and ionized by means of a focused pulsed laser beam in a laser microplasma, which is formed in the spot area of the irradiated sample. All chemical elements in the sample materials are evaporated and ionized in the laser plasma. The formed ions are separated according to mass and energy by a time-of-flight, quadrupole or double focusing mass spectrometer. In this review the characteristics and analytical features, some recent developments, and applications of laser ionization mass spectrometry in inorganic trace analysis are described. (orig.)

  17. Laser ionization mass spectrometry in inorganic trace analysis

    International Nuclear Information System (INIS)

    Becker, J.S.; Dietze, H.J.

    1992-01-01

    Among the different spectrometric techniques for trace analysis Laser Ionization Mass Spectrometry (LIMS) is well established as a trace analytical method. With the LIMS technique the sample material is evaporated and ionized by means of a focused pulsed laser in a laser microplasma, which is formed in the spot area of the irradiated sample. All chemical elements in the sample materials are evaporated and ionized in the laser plasma. The ions formed are separated according to their mass and energy by a time-of-flight, quadrupole or double focusing mass spectrometer. In this review the characteristics and analytical features, some recent developments and applications of laser ionization mass spectrometry in inorganic trace analysis are described. (orig.)

  18. 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.

  19. Statistical design of mass spectrometry calibration procedures

    International Nuclear Information System (INIS)

    Bayne, C.K.

    1996-11-01

    The main objective of this task was to agree on calibration procedures to estimate the system parameters (i.e., dead-time correction, ion-counting conversion efficiency, and detector efficiency factors) for SAL's new Finnigan MAT-262 mass spectrometer. SAL will use this mass spectrometer in a clean-laboratory which was opened in December 1995 to measure uranium and plutonium isotopes on environmental samples. The Finnigan MAT-262 mass spectrometer has a multi-detector system with seven Faraday cup detectors and one ion- counter for the measurement of very small signals (e.g. 10 -17 Ampere range). ORNL has made preliminary estimates of the system parameters based on SAL's experimental data measured in late 1994 when the Finnigan instrument was relatively new. SAL generated additional data in 1995 to verify the calibration procedures for estimating the dead-time correction factor, the ion-counting conversion factor and the Faraday cup detector efficiency factors. The system parameters estimated on the present data will have to be reestablished when the Finnigan MAT-262 is moved-to the new clean- laboratory. Different methods will be used to analyzed environmental samples than the current measurement methods being used. For example, the environmental samples will be electroplated on a single filament rather than using the current two filament system. An outline of the calibration standard operating procedure (SOP) is included

  20. 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.

  1. Absorption Mode FT-ICR Mass Spectrometry Imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  2. The combined measurement of uranium by alpha spectrometry and secondary ion mass spectrometry (SIMS)

    International Nuclear Information System (INIS)

    Harvan, D.

    2009-01-01

    The aim of thesis was to found the dependence between radiometric method - alpha spectrometry and surface sensitive method - Secondary Ion Mass Spectrometry (SIMS). Uranium or naturally occurring uranium isotopes were studied. Samples (high polished stainless steel discs) with uranium isotopes were prepared by electrodeposition. Samples were measured by alpha spectrometry after electrodeposition and treatment. It gives surface activities. Weights, as well as surface's weights of uranium isotopes were calculated from their activities, After alpha spectrometry samples were analyzed by TOF-SIMS IV instrument in International Laser Centre in Bratislava. By the SIMS analysis intensities of uranium-238 were obtained. The interpretation of SIMS intensities vs. surface activity, or surface's weights of uranium isotopes indicates the possibility to use SIMS in quantitative analysis of surface contamination by uranium isotopes, especially 238 U. (author)

  3. Specialized Gas Chromatography--Mass Spectrometry Systems for Clinical Chemistry.

    Science.gov (United States)

    Gochman, Nathan; And Others

    1979-01-01

    A discussion of the basic design and characteristics of gas chromatography-mass spectrometry systems used in clinical chemistry. A comparison of three specific systems: the Vitek Olfax IIA, Hewlett-Packard HP5992, and Du Pont DP-102 are included. (BB)

  4. Role of mass spectrometry in nuclear forensic science

    International Nuclear Information System (INIS)

    Joseph, M.; Sivaraman, N.

    2016-01-01

    The present talk will focus on the role of mass spectrometry in NFS in general; besides that, the various chromatographic methods developed towards separation of actinides and lanthanide fission products and characterization of dissolver solutions of nuclear reactor fuels using TIMS and some applications of using ICP-MS as well

  5. Identification of Secreted Candida Proteins Using Mass Spectrometry

    NARCIS (Netherlands)

    Gómez-Molero, E.; Dekker, H.L.; de Boer, A.D.; de Groot, P.W.; Calderone, R.; Cihlar, R.

    2016-01-01

    Analysis of fungal secretomes using mass spectrometry is a useful technique in cell biology. Knowledge of the secretome of a human fungal pathogen may yield important information of host-pathogen interactions and may be useful for identifying vaccines candidates or diagnostic markers for antifungal

  6. 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…

  7. Biomedical applications of mass spectrometry. Clinical uses of stable isotopes

    International Nuclear Information System (INIS)

    Krahmer, U.I.; McCloskey, J.A.

    1978-01-01

    The review covers typical or important examples of stable isotope usage in clinical fields during the period since the last triennial mass spectrometry conference in 1973. Items are included which involve uses of stable isotopes in human or clinically oriented studies, including measurements carried out on materials of human origin. 163 references. (U.K.)

  8. Recent research and progress of laser mass spectrometry

    International Nuclear Information System (INIS)

    Li Jinying; Wang Fan; Zhao Yonggang; Xiao Guoping; Guo Dongfa; Cui Haiping

    2012-01-01

    The progress of laser mass spectrometry (LMS) was introduced. Its history and principle characteristics were reviewed. The research and applications of LMS in geology, mining, organics, biochemistry, environment and nuclear industry were given. The trend of LMS in the future was outlined, and the main issue and the available solutions were discussed. (authors)

  9. Advances in characterizing ubiquitylation sites by mass spectrometry

    DEFF Research Database (Denmark)

    Sylvestersen, K.B.; Young, C.; Nielsen, M.L.

    2013-01-01

    of ubiquitylation is a two-fold challenge that involves the mapping of ubiquitylation sites and the determination of ubiquitin chain topology. This review focuses on the technical advances in the mass spectrometry-based characterization of ubiquitylation sites, which have recently involved the large...

  10. The use of mass spectrometry in peptide chemistry

    NARCIS (Netherlands)

    Leclercq, P.A.; White, P.A.; Hägele, K.; Desiderio, D.M.; Meienhofer, J.

    1972-01-01

    A review with 16 refs. Methods are detailed for derivatizing peptides (mg quantities) in order to provide sufficient volatility for mass spectrometry (at least 10-5 mm vapor pressure at 300 Deg is required). Three steps are used in producing the desired derivs.: (a) arginine side chains are

  11. 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

  12. Fusion of mass spectrometry-based metabolomics data

    NARCIS (Netherlands)

    Smilde, Age K.; van der Werf, Mariët J.; Bijlsma, Sabina; van der Werff-van der Vat, Bianca J. C.; Jellema, Renger 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

  13. Discovery based and targeted Mass Spectrometry in farm animal proteomics

    DEFF Research Database (Denmark)

    Bendixen, Emøke

    2013-01-01

    for investigating farm animal biology. SRM is particularly important for validation biomarker candidates This talk will introduce the use of different mass spectrometry approaches through examples related to food quality and animal welfare, including studies of gut health in pigs, host pathogen interactions...

  14. Thermal ionisation mass spectrometry: recent developments and future prospects

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    1996-01-01

    This paper presents the current state of art of thermal ionization mass spectrometry (TIMS) instrumentation and highlights some of the recent applications of TIMS in geological, biological and nuclear sciences with special emphasis on some of the recent work undertaken in the area of nuclear science and technology. A few examples from the published literature are also discussed here

  15. 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...

  16. 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…

  17. 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

  18. Applications of accelerator mass spectrometry: advances and innovation

    International Nuclear Information System (INIS)

    Fifield, L.K.

    2004-01-01

    Emerging trends in the applications of accelerator mass spectrometry (AMS) are identified and illustrated with specific examples. Areas of application covered include rapid landscape evolution, calibration of the radiocarbon time scale, compound-specific radiocarbon studies, tracing of nuclear discharges, and searches for extraterrestrial isotopes

  19. Biomedical mass spectrometry in today's and tomorrow's clinical microbiology laboratories

    NARCIS (Netherlands)

    A.F. van Belkum (Alex); M. Welker (Martin); M. Erhard (Marcel); S. Chatellier (Sonia)

    2012-01-01

    textabstractClinical microbiology is a conservative laboratory exercise where base technologies introduced in the 19th century remained essentially unaltered. High-tech mass spectrometry (MS) has changed that. Within a few years following its adaptation to microbiological diagnostics, MS has been

  20. Capillary filling of miniaturized sources for electrospray mass spectrometry

    International Nuclear Information System (INIS)

    Arscott, Steve; Gaudet, Matthieu; Brinkmann, Martin; Ashcroft, Alison E; Blossey, Ralf

    2006-01-01

    Capillary slot-based emitter tips are a novel tool for use in electrospray ionization-mass spectrometry of large biomolecules. We have performed a combined theoretical and experimental study of capillary filling in micron-sized slots with the aim of developing a rational design procedure for miniaturized electrospray sources, ultimately enabling the integration of ESI into laboratory-on-a-chip devices

  1. Mass spectrometry. Environment, biology, oenology, medicine, geology, chemistry, archaeology, mechanisms

    International Nuclear Information System (INIS)

    1999-01-01

    This document provides the papers (communications and posters) presented at the 16. French days of mass spectrometry, held September 6-9, 1999 in Nancy, France. 5 papers are interesting for the INIS database and are analyzed separately. (O.M.)

  2. Automatic Compound Annotation from Mass Spectrometry Data Using MAGMa.

    NARCIS (Netherlands)

    Ridder, L.O.; Hooft, van der J.J.J.; Verhoeven, S.

    2014-01-01

    The MAGMa software for automatic annotation of mass spectrometry based fragmentation data was applied to 16 MS/MS datasets of the CASMI 2013 contest. Eight solutions were submitted in category 1 (molecular formula assignments) and twelve in category 2 (molecular structure assignment). The MS/MS

  3. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Science.gov (United States)

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  4. Molecular mass spectrometry imaging in biomedical and life science research

    Czech Academy of Sciences Publication Activity Database

    Pól, Jaroslav; Strohalm, Martin; Havlíček, Vladimír; Volný, Michael

    2010-01-01

    Roč. 134, č. 5 (2010), s. 423-443 ISSN 0948-6143 R&D Projects: GA MŠk LC545; GA ČR GPP206/10/P018 Institutional research plan: CEZ:AV0Z50200510 Keywords : Mass spectrometry * Chemical imaging * Molecular imaging Subject RIV: EE - Microbiology, Virology Impact factor: 4.727, year: 2010

  5. 14 C dating by using mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P.R.S.; Yokoyama, Y.; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K.

    1999-01-01

    The different aspects concerning the 14 C dating are described, including the cosmogenic origin of 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)

  6. Dynamic Secondary Ion Mass Spectrometry | Materials Science | NREL

    Science.gov (United States)

    Ion Mass Spectrometry (SIMS) uses a continuous, focused beam of primary ions to remove material from the surface of a sample by sputtering. The fraction of sputtered material that is ionized is extracted Identifies all elements or isotopes present in a material, from hydrogen to uranium. Different primary-ion

  7. 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 ...

  8. The matrix effect in secondary ion mass spectrometry

    Science.gov (United States)

    Seah, M. P.; Shard, A. G.

    2018-05-01

    Matrix effects in the secondary ion mass spectrometry (SIMS) of selected elemental systems have been analyzed to investigate the applicability of a mathematical description of the matrix effect, called here the charge transfer (CT) model. This model was originally derived for proton exchange and organic positive secondary ions, to characterise the enhancement or suppression of intensities in organic binary systems. In the systems considered in this paper protons are specifically excluded, which enables an assessment of whether the model applies for electrons as well. The present importance is in organic systems but, here we analyse simpler inorganic systems. Matrix effects in elemental systems cannot involve proton transfer if there are no protons present but may be caused by electron transfer and so electron transfer may also be involved in the matrix effects for organic systems. There are general similarities in both the magnitudes of the ion intensities as well as the matrix effects for both positive and negative secondary ions in both systems and so the CT model may be more widely applicable. Published SIMS analyses of binary elemental mixtures are analyzed. The data of Kim et al., for the Pt/Co system, provide, with good precision, data for such a system. This gives evidence for the applicability of the CT model, where electron, rather than proton, transfer is the matrix enhancing and suppressing mechanism. The published data of Prudon et al., for the important Si/Ge system, provides further evidence for the effects for both positive and negative secondary ions and allows rudimentary rules to be developed for the enhancing and suppressing species.

  9. Tandem Mass Spectrometry of Modified and Platinated Oligoribonucleotides

    Science.gov (United States)

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

    2011-05-01

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

  10. Mass spectrometry with ionization induced by 252Cf fission fragments

    International Nuclear Information System (INIS)

    Sysoev, A.A.; Artaev, V.B.

    1991-01-01

    The review deals with mass-spectrometry with ionization induced by 252 Cf fission fragments. Equipment and technique of the analysis, analytic possibilities of the method are considered. The method permits to determine molecular masses of large nonvolatile biological molecules. The method is practically nondestructive, it possesses a high resolution over the depth and surface, which permits to use it for the analysis of surface of semiconductors, dielectrics, catalysts, for the study of formation kinetics of complex unstable molecules on the surface

  11. Mass spectrometry of submicrogram quantities of lead and cadmium

    International Nuclear Information System (INIS)

    Moraes, Noemia M.P. de; Kakazu, M.H.; Iyer, S.S.

    1980-01-01

    Isotope analyses of submicrogram quantities of lead and cadmium are carried out by single filament solid source mass spectrometry. Thermionic emission of Pb and Cd is enhanced using silica gel as an emitter. Details of the chemical and mass spectrometric techniques are described. The low blank levels are maintained by extra purification of the reagents. The applications of isotope ratios of Pb and Cd in environmental sciences and geochemistry are discussed. (Author) [pt

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

    DEFF Research Database (Denmark)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

    2016-01-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

  13. Focusing procedures in time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Ioanoviciu, D.

    2002-01-01

    Time-of-flight mass spectrometry is a fast growing field due to its ability to handle very fast processes and due to its theoretically unlimited mass range. The performances of the time-of-flight mass analysers are heavily dependent on the progress in ion optics, a periodically reviewed field. In this presentation the various focusing procedures in time-of-flight mass spectrometry are reviewed. For ions of the same charge and mass flight time differences result from different potentials at the location of formation and from the initial velocity spread. There is no simultaneous space and velocity focusing in time-of-flight mass spectrometry. Space focusing of first and second order can be reached in time-of-flight mass analysers having two homogeneous electric field ion sources followed by a field free space in front of the detector. Single and double stage homogeneous electric field mirrors can focus in time ions of different energies. These different energies result when ions leaving different initial sites and arriving simultaneously to an intermediate space focus. Convenient mass dispersion can be obtained by including a mirror. Initial velocity focusing is obtained by the delayed extraction procedure in drift space and mirror time-of-flight mass analysers. Post source pulse focusing aims at the same purpose. Ion source electrodes of hyperbolic shape, operated by high voltage pulses can bring major improvements of the resolution, especially at high masses. For each focusing procedure the geometric and/or electric conditions are given as well as the aberrations allowing the mass resolution determination. The various focusing procedures are compared and a prediction of their future performances was tempted. (author)

  14. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, M.; Mulder, P.P.J.; Bire, R.; Hess, P.; Boer, de J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC¿MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  15. Solid phase extraction for removal of matrix effects in lipophilic marine toxin analysis by liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Gerssen, A.; McElhinney, A. M.; Mulder, P.P.J.; Bire, L.; Hess, P.; de Boer, J.

    2009-01-01

    The potential of solid phase extraction (SPE) clean-up has been assessed to reduce matrix effects (signal suppression or enhancement) in the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of lipophilic marine toxins. A large array of ion-exchange, silica-based, and mixed-function

  16. Mass spectrometry of fluorocarbon-labeled glycosphingolipids

    DEFF Research Database (Denmark)

    Li, Yunsen; Arigi, Emma; Eichert, Heather

    2010-01-01

    ceramide N-deacylase (SCDase) is used to remove the fatty acid from the ceramide moiety, after which a fluorocarbon-rich substituent (F-Tag) is incorporated at the free amine of the sphingoid. In initial trials, a neutral GSL, globotriaosylceramide (Gb(3)Cer), three purified bovine brain gangliosides...... with subsequent per-N,O-methylation was established for the F-tagged Gb(3) Cer and purified gangliosides, and extensive mass spectra (MS(1) and MS(2)) consistent with all of the expected products were acquired. The potential use of F-tagged derivatives for a comprehensive MS based profiling application...

  17. Automated Intelligent Assistant for mass spectrometry operation

    International Nuclear Information System (INIS)

    Filby, E.E.; Rankin, R.A.; Yoshida, D.E.

    1991-01-01

    The Automated Intelligent Assistant is designed to insure that our mass spectrometers produce timely, high-quality measurement data. The design combines instrument interfacing and expert system technology to automate an adaptable set-point damage prevention strategy. When shutdowns occur, the Assistant can help guide troubleshooting efforts. Stored real-time data will help our development program upgrade and improve the system, and also make it possible to re-run previously-observed instrument problems as ''live'' training exercises for the instrument operators. Initial work has focused on implementing the Assistant for the instrument ultra-high vacuum components. 14 refs., 5 figs

  18. 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.

  19. Resin bead-thermal ionization mass spectrometry for determination of plutonium concentration in irradiated fuel dissolver solution

    International Nuclear Information System (INIS)

    Paul, Sumana; Shah, R.V.; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Determination of isotopic composition (IC) and concentration of plutonium (Pu) is necessary at various stages of nuclear fuel cycle which involves analysis of complex matrices like dissolver solution of irradiated fuel, nuclear waste stream etc. Mass spectrometry, e.g. thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS) are commonly used for determination of IC and concentration of plutonium. However, to circumvent matrix interferences, efficient separation as well as preconcentration of Pu is required prior to mass spectrometric analysis. Purification steps employing ion-exchange resins are widely used for the separation of Pu from dissolver solution or from mixture of other actinides e.g. U, Am. However, an alternative way is to selectively preconcentrate Pu on a resin bead, followed by direct loading of the bead on the filament of thermal ionization mass spectrometer

  20. Liquid chromatography-mass spectrometry in forensic toxicology.

    Science.gov (United States)

    Van Bocxlaer, J F; Clauwaert, K M; Lambert, W E; Deforce, D L; Van den Eeckhout, E G; De Leenheer, A P

    2000-01-01

    Liquid chromatography-mass spectrometry has evolved from a topic of mainly research interest into a routinely usable tool in various application fields. With the advent of new ionization approaches, especially atmospheric pressure, the technique has established itself firmly in many areas of research. Although many applications prove that LC-MS is a valuable complementary analytical tool to GC-MS and has the potential to largely extend the application field of mass spectrometry to hitherto "MS-phobic" molecules, we must recognize that the use of LC-MS in forensic toxicology remains relatively rare. This rarity is all the more surprising because forensic toxicologists find themselves often confronted with the daunting task of actually searching for evidence materials on a scientific basis without any indication of the direction in which to search. Through the years, mass spectrometry, mainly in the GC-MS form, has gained a leading role in the way such quandaries are tackled. The advent of robust, bioanalytically compatible combinations of liquid chromatographic separation with mass spectrometric detection really opens new perspectives in terms of mass spectrometric identification of difficult molecules (e.g., polar metabolites) or biopolymers with toxicological relevance, high throughput, and versatility. Of course, analytical toxicologists are generally mass spectrometry users rather than mass spectrometrists, and this difference certainly explains the slow start of LC-MS in this field. Nevertheless, some valuable applications have been published, and it seems that the introduction of the more universal atmospheric pressure ionization interfaces really has boosted interests. This review presents an overview of what has been realized in forensic toxicological LC-MS. After a short introduction into LC-MS interfacing operational characteristics (or limitations), it covers applications that range from illicit drugs to often abused prescription medicines and some

  1. Photoionization mass spectrometry of UF6

    International Nuclear Information System (INIS)

    Berkowitz, J.

    1979-01-01

    The photoionization mass spectrum of 238 UF 6 was obtained. At 600 A = 20.66 eV, the relative ionic abundances were as follows: UF 6 + , 1.4; UF 5 + , 100; UF + , 17; UF 3 + , approx. 0.7; UF 2 + , very weak; UF + , very weak; U + , essentially zero. The adiabatic ionization potential for UF 6 was 13.897 +- 0.005 eV. The production of UF 5 + begins at approx. 887 A = 13.98 eV, at which energy the UF 6 + partial cross section abruptly declines and then levels off. This behavior suggests the vague possibility of an isotope effect. The UF 4 + signal begins at approx. 725 A = 17.10 eV, at which energy the UF 5 + signal reaches a plateau value. The UF 5 + photoionization yield curve displays some autoionization structure from its threshold to approx. 750 A

  2. Complete Hexose Isomer Identification with Mass Spectrometry

    Science.gov (United States)

    Nagy, Gabe; Pohl, Nicola L. B.

    2015-04-01

    The first analytical method is presented for the identification and absolute configuration determination of all 24 aldohexose and 2-ketohexose isomers, including the D and L enantiomers for allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, and tagatose. Two unique fixed ligand kinetic method combinations were discovered to create significant enough energetic differences to achieve chiral discrimination among all 24 hexoses. Each of these 24 hexoses yields unique ratios of a specific pair of fragment ions that allows for simultaneous determination of identification and absolute configuration. This mass spectrometric-based methodology can be readily employed for accurate identification of any isolated monosaccharide from an unknown biological source. This work provides a key step towards the goal of complete de novo carbohydrate analysis.

  3. Intact glycopeptide characterization using mass spectrometry.

    Science.gov (United States)

    Cao, Li; Qu, Yi; Zhang, Zhaorui; Wang, Zhe; Prytkova, Iya; Wu, Si

    2016-05-01

    Glycosylation is one of the most prominent and extensively studied protein post-translational modifications. However, traditional proteomic studies at the peptide level (bottom-up) rarely characterize intact glycopeptides (glycosylated peptides without removing glycans), so no glycoprotein heterogeneity information is retained. Intact glycopeptide characterization, on the other hand, provides opportunities to simultaneously elucidate the glycan structure and the glycosylation site needed to reveal the actual biological function of protein glycosylation. Recently, significant improvements have been made in the characterization of intact glycopeptides, ranging from enrichment and separation, mass spectroscopy (MS) detection, to bioinformatics analysis. In this review, we recapitulated currently available intact glycopeptide characterization methods with respect to their advantages and limitations as well as their potential applications.

  4. Precise atomic mass measurements by deflection mass spectrometry

    CERN Document Server

    Barber, R C

    2003-01-01

    Since its inception nearly 90 years ago by J.J. Thomson, the precise determination of atomic masses by the classical technique of deflecting charged particles in electric and magnetic fields has provided a large body of data on naturally occurring nuclides. Currently, such measurements on stable nuclides have frequently achieved a precision of better than two parts in 10 sup 9 of the mass. A review of the technique, together with a brief summary of the important historical developments in the field of precise atomic mass measurements, will be given. The more recent contributions to this field by the deflection mass spectrometer at the University of Manitoba will be provided as illustrations of the culmination of the techniques used and the applications that have been studied. A brief comparison between this and newer techniques using Penning traps will be presented.

  5. 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…

  6. Meet interesting abbreviations in clinical mass spectrometry: from compound classification by REIMS to multimodal and mass spectrometry imaging (MSI)

    Czech Academy of Sciences Publication Activity Database

    Luptáková, Dominika; Pluháček, Tomáš; Palyzová, Andrea; Přichystal, Jakub; Balogh, J.; Lemr, Karel; Juránek, I.; Havlíček, Vladimír

    2017-01-01

    Roč. 61, č. 3 (2017), s. 353-360 ISSN 0001-723X R&D Projects: GA MŠk(CZ) LO1509; GA ČR(CZ) GA16-20229S Institutional support: RVO:61388971 Keywords : REIMS * multimodal * mass spectrometry imaging Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 0.673, year: 2016

  7. Mass-Spectrometric Investigations of Isotopic Exchange Reactions of Gaseous Hydrocarbon Ions; Recherches, par Spectrometrie de Masse, sur les Echanges Isotopiques des Ions d'Hydrocarbures Gazeux; Mass-spektrometricheskie issledovaniya reaktsij izotopnogo obmena ionov gazoobraznogo uglevodoroda; Estudio del Intercambio Isotopico de Iones Hidrocarburo Gaseosos por Espectrometria de Masas

    Energy Technology Data Exchange (ETDEWEB)

    Wexler, S. [Argonne National Laboratory, Argonne, IL (United States)

    1965-10-15

    Techniques of ''high pressure'' mass spectrometry have been employed to study the exchange of hydrogen isotopes in carbon-containing products of ion-molecule reactions. Comparison of the positively charged mass spectra of H{sub 2} + CH{sub 4}, D{sub 2} + CH{sub 4} and T{sub 2} + CH{sub 4} mixtures with those of the individual components, observed for source pressures of approximately 0.1 torr, demonstrated that the CH{sup +}{sub 3} and molecular hydrogen primary ions react rapidly with the other component of the gas mixture to create, by consecutive reactions, secondary and tertiary ionic species in which the hydrogen isotopes are extensively exchanged. When methane is added to D{sub 2}, the principal species of deuterium, D{sub 2}{sup +} and D{sub 3}{sup +}, are almost completely quenched; and C{sub 2}H{sub 4}D{sup +}, C{sub 2}H{sub 3}D{sub 2}{sup +} and C{sub 2}H{sub 2}D{sub 3}{sup +} are formed in high yield. The CH{sub 3}{sup +} ion is also shown to react readily with D{sub 2} molecules to produce the same deuterated ethyl species. Analogous findings came from study of T{sub 2}-CH{sub 4} systems. Observations on H{sub 2} + CH{sub 4} mixtures confirmed that the deuterated and tritiated products were C{sub 2}H{sub 5}{sup +} -type ions with one, two or three hydrogen atoms replaced by the heavier isotope. Correspondence of appearance potentials and ionization efficiency curves gave further evidence that D{sub 2}{sup +} and CH{sub 3}{sup +} are the primary precursors of the deuterated ethyl ions. The enhancements of the C{sub 2}H{sub 4}D{sup +}/C{sub 2}H{sub 5}{sup +}, C{sub 2}H{sub 3}D{sub 2}{sup +}/C{sub 2}H{sub 5}{sup +} intensity ratios observed with increasing deuterium concentration (at constant CH{sub 4} pressure) suggest that the isotopically-exchanged species are produced by mechanisms involving consecutive ion-molecule reactions that are at least one kinetic order higher in D{sub 2} concentration than those for formation of C{sub 2}H{sub 5}{sup +}. This

  8. 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...

  9. Analytical applications of resonance ionization mass spectrometry (RIMS)

    International Nuclear Information System (INIS)

    Fassett, J.D.; Travis, J.C.

    1988-01-01

    A perspective on the role of resonance ionization mass spectrometry (RIMS) in the field of analytical chemistry is presented. RIMS provides new, powerful, and complementary capabilities relative to traditional methods of inorganic mass spectrometry. Much of the initial work in RIMS has been to illustrate these capabilities and define the potential of RIMS in the generalized field of chemical analysis. Three areas of application are reviewed here: (1) noble gas measurements; (2) materials analysis using isotope dilution (IDMS); and, (3) solids analysis using direct sampling. The role of RIMS is discussed relative to the more traditional mass spectrometric methods of analysis in these areas. The applications are meant to illustrate the present state-of-the-art as well as point to the future state-of-the-art of RIMS in chemical analysis. (author)

  10. 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.

  11. LILBID-mass spectrometry of the mitochondrial preprotein translocase TOM

    International Nuclear Information System (INIS)

    Mager, Frauke; Lintzel, Julia; Nussberger, Stephan; Sokolova, Lucie; Brutschy, Bernhard

    2010-01-01

    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.

  12. LILBID-mass spectrometry of the mitochondrial preprotein translocase TOM

    Science.gov (United States)

    Mager, Frauke; Sokolova, Lucie; Lintzel, Julia; Brutschy, Bernhard; Nussberger, Stephan

    2010-11-01

    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.

  13. Resonance ionization mass spectrometry system for measurement of environmental samples

    International Nuclear Information System (INIS)

    Pibida, L.; McMahon, C.A.; Noertershaeuser, W.; Bushaw, B.A.

    2002-01-01

    A resonance ionization mass spectrometry (RIMS) system has been developed at the National Institute of Standards and Technology (NIST) for sensitive and selective determination of radio-cesium in the environment. The overall efficiency was determined to be 4x10-7 with a combined (laser and mass spectrometer) selectivity of 108 for both 135Cs and 137Cs with respect to 133Cs. RIMS isotopic ratio measurements of 135Cs/ 137Cs were performed on a nuclear fuel burn-up sample and compared to measurements on a similar system at Pacific Northwest National Laboratory (PNNL) and to conventional thermal ionization mass spectrometry (TIMS). Results of preliminary RIMS investigations on a freshwater lake sediment sample are also discussed

  14. Mass spectrometry of selective androgen receptor modulators.

    Science.gov (United States)

    Thevis, Mario; Schänzer, Wilhelm

    2008-07-01

    Nonsteroidal selective androgen receptor modulators (SARMs) are an emerging class of drugs for treatment of various diseases including osteoporosis and muscle wasting as well as the correction of age-related functional decline such as muscle strength and power. Several SARMs, which have advanced to preclinical and clinical trials, are composed of diverse chemical structures including arylpropionamide-, bicyclic hydantoin-, quinoline-, and tetrahydroquinoline-derived nuclei. Since January 2008, SARMs have been categorized as anabolic agents and prohibited by the World Anti-Doping Agency (WADA). Suitable detection methods for these low-molecular weight drugs were based on mass spectrometric approaches, which necessitated the elucidation of dissociation pathways in order to characterize and identify the target analytes in doping control samples as well as potential metabolic products and synthetic analogs. Fragmentation patterns of representatives of each category of SARMs after electrospray ionization (ESI) and collision-induced dissociation (CID) as well as electron ionization (EI) are summarized. The complexity and structural heterogeneity of these drugs is a daunting challenge for detection methods. Copyright 2008 John Wiley & Sons, Ltd.

  15. Analytical capabilities of laser-probe mass spectrometry

    International Nuclear Information System (INIS)

    Kovalev, I.D.; Madsimov, G.A.; Suchkov, A.I.; Larin, N.V.

    1978-01-01

    The physical bases and quantitative analytical procedures of laser-probe mass spectrometry are considered in this review. A comparison is made of the capabilities of static and dynamic mass spectrometers. Techniques are studied for improving the analytical characteristics of laser-probe mass spectrometers. The advantages, for quantitative analysis, of the Q-switched mode over the normal pulse mode for lasers are: (a) the possibility of analysing metals, semiconductors and insulators without the use of standards; and (b) the possibility of layer-by-layer and local analysis. (Auth.)

  16. Computer automation of an accelerator mass spectrometry system

    International Nuclear Information System (INIS)

    Gressett, J.D.; Maxson, D.L.; Matteson, S.; McDaniel, F.D.; Duggan, J.L.; Mackey, H.J.; North Texas State Univ., Denton, TX; Anthony, J.M.

    1989-01-01

    The determination of trace impurities in electronic materials using accelerator mass spectrometry (AMS) requires efficient automation of the beam transport and mass discrimination hardware. The ability to choose between a variety of charge states, isotopes and injected molecules is necessary to provide survey capabilities similar to that available on conventional mass spectrometers. This paper will discuss automation hardware and software for flexible, high-sensitivity trace analysis of electronic materials, e.g. Si, GaAs and HgCdTe. Details regarding settling times will be presented, along with proof-of-principle experimental data. Potential and present applications will also be discussed. (orig.)

  17. Chemically assisted laser ablation ICP mass spectrometry.

    Science.gov (United States)

    Hirata, Takafumi

    2003-01-15

    A new laser ablation technique combined with a chemical evaporation reaction has been developed for elemental ratio analysis of solid samples using an inductively coupled plasma mass spectrometer (ICPMS). Using a chemically assisted laser ablation (CIA) technique developed in this study, analytical repeatability of the elemental ratio measurement was successively improved. To evaluate the reliability of the CLA-ICPMS technique, Pb/U isotopic ratios were determined for zircon samples that have previously been analyzed by other techniques. Conventional laser ablation for Pb/U shows a serious elemental fractionation during ablation mainly due to the large difference in elemental volatility between Pb and U. In the case of Pb/U ratio measurement, a Freon R-134a gas (1,1,1,2-tetrafluoroethane) was introduced into the laser cell as a fluorination reactant. The Freon gas introduced into the laser cell reacts with the ablated sample U, and refractory U compounds are converted to a volatile U fluoride compound (UF6) under the high-temperature condition at the ablation site. This avoids the redeposition of U around the ablation pits. Although not all the U is reacted with Freon, formation of volatile UF compounds improves the transmission efficiency of U. Typical precision of the 206Pb/238U ratio measurement is 3-5% (2sigma) for NIST SRM 610 and Nancy 91500 zircon standard, and the U-Pb age data obtained here show good agreement within analytical uncertainties with the previously reported values. Since the observed Pb/U ratio for solid samples is relatively insensitive to laser power and ablation time, optimization of ablation conditions or acquisition parameters no longer needs to be performed on a sample-to-sample basis.

  18. Cortisol production rates measured by liquid chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Esteban, N.V.; Yergey, A.L.

    1990-01-01

    Cortisol production rates (FPRs) in physiologic and pathologic states in humans have been investigated over the past 30 years. However, there has been conflicting evidence concerning the validity of the currently accepted value of FPRs in humans (12 to 15 mg/m2/d) as determined by radiotracer methodology. The present study reviews previous methods proposed for the measurement of FPRs in humans and discusses the applications of the first method for the direct determination of 24-hour plasma FPRs during continuous administration of a stable isotope, using a thermospray high-pressure liquid chromatography-mass spectrometry technique. The technique is fast, sensitive, and, unlike gas chromatography-mass spectrometry methods, does not require derivatization, allowing on-line detection and quantification of plasma cortisol after a simple extraction procedure. The results of determination of plasma FPRs by stable tracer/mass spectrometry are directly in units of mass/time and, unlike radiotracer methods, are independent of any determination of volume of distribution or cortisol concentration. Our methodology offers distinct advantages over radiotracer techniques in simplicity and reliability since only single measurements of isotope ratios are required. The technique was validated in adrenalectomized patients. Circadian variations in daily FRPs were observed in normal volunteers, and, to date, results suggest a lower FRP in normal children and adults than previously believed. 88 references

  19. 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.

  20. Microchannel laminated mass exchanger and method of making

    Science.gov (United States)

    Martin, Peter M.; Bennett, Wendy D.; Matson, Dean W.; Stewart, Donald C.; Drost, Monte K.; Wegeng, Robert S.; Perez, Joseph M.; Feng, Xiangdong; Liu, Jun

    2000-01-01

    The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

  1. CYLINDER OF THE DISPOSABLE MASS EXCHANGE DEVICE FOR HEMOSORPTION

    Directory of Open Access Journals (Sweden)

    F. I. Kazakov

    2015-01-01

    Full Text Available BACKGROUND. Hemocarboperfusion, previously widely used in our country, can universally pass out of use due to the lack of industrial production of disposable mass exchange devices.MATERIAl AND METHODS. Physicochemical properties of materials and design features of the body samples elements of various sizes have been studied.RESULTS. The elements and materials properties of the hemosorption mass exchanger cylinder have been studied. Hydrodynamic parameters of manipulation using the developed cylinders at different perfusion rates have been studied in bench experiments.CONCLUSION. The original cylinder of the disposable mass exchange device for hemosorption, which meets the current clinical needs, has been developed. 

  2. Mass Spectrometry Imaging of Biological Tissue: An Approach for Multicenter Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rompp, Andreas; Both, Jean-Pierre; Brunelle, Alain; Heeren, Ronald M.; Laprevote, Olivier; Prideaux, Brendan; Seyer, Alexandre; Spengler, Bernhard; Stoeckli, Markus; Smith, Donald F.

    2015-03-01

    Mass spectrometry imaging has become a popular tool for probing the chemical complexity of biological surfaces. This led to the development of a wide range of instrumentation and preparation protocols. It is thus desirable to evaluate and compare the data output from different methodologies and mass spectrometers. Here, we present an approach for the comparison of mass spectrometry imaging data from different laboratories (often referred to as multicenter studies). This is exemplified by the analysis of mouse brain sections in five laboratories in Europe and the USA. The instrumentation includes matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF), MALDI-QTOF, MALDIFourier transform ion cyclotron resonance (FTICR), atmospheric-pressure (AP)-MALDI-Orbitrap, and cluster TOF-secondary ion mass spectrometry (SIMS). Experimental parameters such as measurement speed, imaging bin width, and mass spectrometric parameters are discussed. All datasets were converted to the standard data format imzML and displayed in a common open-source software with identical parameters for visualization, which facilitates direct comparison of MS images. The imzML conversion also allowed exchange of fully functional MS imaging datasets between the different laboratories. The experiments ranged from overview measurements of the full mouse brain to detailed analysis of smaller features (depending on spatial resolution settings), but common histological features such as the corpus callosum were visible in all measurements. High spatial resolution measurements of AP-MALDI-Orbitrap and TOF-SIMS showed comparable structures in the low-micrometer range. We discuss general considerations for planning and performing multicenter studies in mass spectrometry imaging. This includes details on the selection, distribution, and preparation of tissue samples as well as on data handling. Such multicenter studies in combination with ongoing activities for reporting guidelines, a common

  3. Study by Auger spectrometry and mass spectrometry of the chemisorption of carbon monoxide on polycrystalline molybdenum

    International Nuclear Information System (INIS)

    Gillet, E.; Chiarena, J.C.; Gillet, M.

    1976-01-01

    A combination of Auger spectrometry and mass spectrometry was employed to study CO chemisorption on polycrystalline Mo surfaces at room temperature. Five adsorption states were observed and the binding parameters (E,n 0 ,tau 0 ) were calculated for the three important states. The results obtained by the two methods are in accord but the occurence of electronic desorption in Auger experiments was pointed out. Contamination effects by C atoms in such studies were investigated by repeated cycles of adsorption-desorption and a characteristic evolution of flash desorption was observed. The results are discussed in this point of view enhancing the importance of a control of the adsorption surface cleanness by a method of great sensibility like Auger spectrometry. (Auth.)

  4. 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…

  5. Establishing Drug Resistance in Microorganisms by Mass Spectrometry

    Science.gov (United States)

    Demirev, Plamen A.; Hagan, Nathan S.; Antoine, Miquel D.; Lin, Jeffrey S.; Feldman, Andrew B.

    2013-08-01

    A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and 13C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

  6. Fourier Transform Mass Spectrometry: The Transformation of Modern Environmental Analyses

    Science.gov (United States)

    Lim, Lucy; Yan, Fangzhi; Bach, Stephen; Pihakari, Katianna; Klein, David

    2016-01-01

    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. PMID:26784175

  7. 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.

  8. 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.

  9. Mass Spectrometry-Based N-Glycomics of Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Manveen K. Sethi

    2015-12-01

    Full Text Available Colorectal cancer (CRC is one of the most prevalent cancers worldwide. An increased molecular understanding of the CRC pathology is warranted to gain insights into the underlying molecular and cellular mechanisms of the disease. Altered protein glycosylation patterns are associated with most diseases including malignant transformation. Recent advances in mass spectrometry and bioinformatics have accelerated glycomics research and present a new paradigm for cancer biomarker discovery. Mass spectrometry (MS-based glycoproteomics and glycomics, therefore, hold considerable promise to improve the discovery of novel biomarkers with utility in disease diagnosis and therapy. This review focuses on the emerging field of glycomics to present a comprehensive review of advances in technologies and their application in studies aimed at discovering novel glycan-based biomarkers. We will also discuss some of the challenges associated with using glycans as biomarkers.

  10. Statistical methods for quantitative mass spectrometry proteomic experiments with labeling

    Directory of Open Access Journals (Sweden)

    Oberg Ann L

    2012-11-01

    Full Text Available Abstract Mass Spectrometry utilizing labeling allows multiple specimens to be subjected to mass spectrometry simultaneously. As a result, between-experiment variability is reduced. Here we describe use of fundamental concepts of statistical experimental design in the labeling framework in order to minimize variability and avoid biases. We demonstrate how to export data in the format that is most efficient for statistical analysis. We demonstrate how to assess the need for normalization, perform normalization, and check whether it worked. We describe how to build a model explaining the observed values and test for differential protein abundance along with descriptive statistics and measures of reliability of the findings. Concepts are illustrated through the use of three case studies utilizing the iTRAQ 4-plex labeling protocol.

  11. Statistical methods for quantitative mass spectrometry proteomic experiments with labeling.

    Science.gov (United States)

    Oberg, Ann L; Mahoney, Douglas W

    2012-01-01

    Mass Spectrometry utilizing labeling allows multiple specimens to be subjected to mass spectrometry simultaneously. As a result, between-experiment variability is reduced. Here we describe use of fundamental concepts of statistical experimental design in the labeling framework in order to minimize variability and avoid biases. We demonstrate how to export data in the format that is most efficient for statistical analysis. We demonstrate how to assess the need for normalization, perform normalization, and check whether it worked. We describe how to build a model explaining the observed values and test for differential protein abundance along with descriptive statistics and measures of reliability of the findings. Concepts are illustrated through the use of three case studies utilizing the iTRAQ 4-plex labeling protocol.

  12. Centrosome isolation and analysis by mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Jakobsen, Lis; Schrøder, Jacob Morville; Larsen, Katja M

    2013-01-01

    Centrioles are microtubule-based scaffolds that are essential for the formation of centrosomes, cilia, and flagella with important functions throughout the cell cycle, in physiology and during development. The ability to purify centriole-containing organelles on a large scale, combined with advan...... to isolate centrosomes from human cells and strategies to selectively identify and study the properties of the associated proteins using quantitative mass spectrometry-based proteomics.......Centrioles are microtubule-based scaffolds that are essential for the formation of centrosomes, cilia, and flagella with important functions throughout the cell cycle, in physiology and during development. The ability to purify centriole-containing organelles on a large scale, combined...... with advances in protein identification using mass spectrometry-based proteomics, have revealed multiple centriole-associated proteins that are conserved during evolution in eukaryotes. Despite these advances, the molecular basis for the plethora of processes coordinated by cilia and centrosomes is not fully...

  13. 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.

  14. Desorption and ionization processes in laser mass spectrometry

    International Nuclear Information System (INIS)

    Peyl, G.J.Q. van der.

    1984-01-01

    In this thesis results are reported from a study on the desorption- and ionization process initiated by infra-red laser irradiation (LDMS) or ion bombardment (SIMS) of thin organic sample layers. The study is especially focused on the formation of quasimolecular ions under these conditions. Results of these investigations can be used for a better optimization of the LDMS and SIMS techniques in organic mass spectrometry. First, an overview is given of laser desorption mass spectrometry. Next, the coupling of the laser energy into the organic sample layer is investigated. It is concluded that the laser energy is primarily absorbed by the substrate material and not by the organic overlayer. The formation of quasi-molecular ions, either in the gas phase or in the substrate surface is investigated. The final section reports kinetic energy distributions for ions sputtered from organic solids and liquids. (Auth.)

  15. 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

  16. Investigating quantitation of phosphorylation using MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Parker, Laurie; Engel-Hall, Aaron; Drew, Kevin; Steinhardt, George; Helseth, Donald L; Jabon, David; McMurry, Timothy; Angulo, David S; Kron, Stephen J

    2008-04-01

    Despite advances in methods and instrumentation for analysis of phosphopeptides using mass spectrometry, it is still difficult to quantify the extent of phosphorylation of a substrate because of physiochemical differences between unphosphorylated and phosphorylated peptides. Here we report experiments to investigate those differences using MALDI-TOF mass spectrometry for a set of synthetic peptides by creating calibration curves of known input ratios of peptides/phosphopeptides and analyzing their resulting signal intensity ratios. These calibration curves reveal subtleties in sequence-dependent differences for relative desorption/ionization efficiencies that cannot be seen from single-point calibrations. We found that the behaviors were reproducible with a variability of 5-10% for observed phosphopeptide signal. Although these data allow us to begin addressing the issues related to modeling these properties and predicting relative signal strengths for other peptide sequences, it is clear that this behavior is highly complex and needs to be further explored. John Wiley & Sons, Ltd

  17. Membrane introduction proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Alexander, M.; Boscaini, E.; Maerk, T.; Lindinger, W.

    2002-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) is a rapidly expanding field with multiple applications in ion physics, atmospheric chemistry, food chemistry, volatile organic compounds monitoring and biology. Initial studies that combine PTR-MS and membrane introduction mass spectrometry (MIMS) were researched and outlined. First using PTR-MS, certain fundamental physical properties of a poly-dimethylsiloxane (PDMS) membrane including solubilities and diffusion coefficients were measured. Second, it was shown how the chemical selectivity of the (PDMS) can be used to extend the capabilities of the PTR-MS instrument by eliminating certain isobaric interferences and excluding water from volatile organic compounds (VOCs). Experiments with mixtures of several VOCs (toluene, benzene, acetone, propanal, methanol) are presented. (nevyjel)

  18. Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

    Science.gov (United States)

    Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers. © American Society for Mass Spectrometry, 2011

  19. Secondary neutral mass spectrometry depth profile analysis of silicides

    International Nuclear Information System (INIS)

    Beckmann, P.; Kopnarski, M.; Oechsner, H.

    1985-01-01

    The Direct Bombardment Mode (DBM) of Secondary Neutral Mass Spectrometry (SNMS) has been applied for depth profile analysis of two different multilayer systems containing metal silicides. Due to the extremely high depth resolution obtained with low energy SNMS structural details down to only a few atomic distances are detected. Stoichiometric information on internal oxides and implanted material is supplied by the high quantificability of SNMS. (Author)

  20. 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.

  1. Report of the consultants' meeting on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. Its use within the IAEA is recommended by the consultants in this meeting. The IAEA programs in which the technology would be useful and beneficial are: safeguards, physical and chemical sciences, human health, food and agriculture, radioactive waste management, radiation safety, industry and earth sciences.

  2. Global Surveillance of Emerging Influenza Virus Genotypes by Mass Spectrometry

    Science.gov (United States)

    2007-05-30

    Intercontinental circulation of human influenza A( H1N2 ) reassortant viruses during the 2001–2002 influenza season. J Infect Dis 186: 1490–1493. 6. Taubenberger...Global Surveillance of Emerging Influenza Virus Genotypes by Mass Spectrometry Rangarajan Sampath1*, Kevin L. Russell2, Christian Massire1, Mark W...Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America Background. Effective influenza surveillance requires

  3. Report of the consultants' meeting on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    1995-01-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. Its use within the IAEA is recommended by the consultants in this meeting. The IAEA programs in which the technology would be useful and beneficial are: safeguards, physical and chemical sciences, human health, food and agriculture, radioactive waste management, radiation safety, industry and earth sciences

  4. Accelerator mass spectrometry at the Rossendorf 5 MV tandem accelerator

    International Nuclear Information System (INIS)

    Friedrich, M.; Buerger, W.; Curian, H.; Hartmann, B.; Hentschel, E.; Matthes, H.; Probst, W.; Seidel, M.; Turuc, S.; Hebert, D.; Rothe, T.; Stolz, W.

    1992-01-01

    The Rossendorf electrostatic accelerators (5 MV tandem accelerator and single ended 2 MV van de Graaff accelerator) are already used for ion beam analysis. The existing methods (RBS, PIXE, ERDA, NRA, nuclear microprobe and external beam) will be completed by introduction of Accelerator Mass Spectrometry (AMS). A short description of the Rossendorf AMS system is given and first experimental results are presented. (R.P.) 4 refs.; 6 figs

  5. Optimizing the identification of citrullinated peptides by mass spectrometry

    DEFF Research Database (Denmark)

    Bennike, Tue; Lauridsen, Kasper B.; Olesen, Michael Kruse

    2013-01-01

    Citrullinated proteins have been associated with several diseases and citrullination can most likely function as a target for novel diagnostic agents and unravel disease etiologies. The correct identification of citrullinated proteins is therefore of most importance. Mass spectrometry (MS) driven...... of trypsin, digestion was performed on synthetic peptide sets containing either arginine or citrulline. The peptide sequences originated from disease-associated in vivo citrullinated proteins; some reported as being C-terminal tryptic citrullinated peptides. Furthermore, the proteolytic activity was verified...

  6. Myofiber metabolic type determination by mass spectrometry imaging

    OpenAIRE

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

    2017-01-01

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

  7. High temperature mass spectrometry for thermodynamic study of radioactive materials

    International Nuclear Information System (INIS)

    Pattoret, Andre; Philippot, Joseph; Pesme, Olivier.

    1983-01-01

    Thermodynamic properties and evaporation kinetics are essential data to evaluate the nuclear fuel behaviour under accidental conditions. High temperature mass spectrometry appears as a valuable method to set up a such assessment. However, because of size, complexity and radioactivity of the irradiated samples, important improvements of the classical method are required. The device built in CEN/FAR to overcome these problems is described; performances and possible applications out of the nuclear safety field are presented [fr

  8. Diagrams of ion stability in radio-frequency mass spectrometry

    International Nuclear Information System (INIS)

    Sudakov, M.Yu.

    1994-01-01

    For solving radio-frequency mass spectrometry problems and dynamic ion containment are studied and systematized different ways for constructing the ion stability diagrams. A new universal set of parameters is proposed for diagram construction-angular variables, which are the phase raid of ion oscillational motion during positive and negative values of the supplying voltage. An effective analytical method is proposed for optimization of the parameters of the pulsed supplying voltage, in particular its repetition rate

  9. Analysis of Ketones by Selected Ion Flow Tube Mass Spectrometry

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Wang, T.; Španěl, Patrik

    2003-01-01

    Roč. 17, - (2003), s. 2655-2660 ISSN 0951-4198 R&D Projects: GA ČR GA202/03/0827; GA ČR GA203/02/0737 Institutional research plan: CEZ:AV0Z4040901 Keywords : mass spectrometry * selected ion flow tube * ketones Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.789, year: 2003

  10. 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.

  11. Isotopic analysis of plutonium by computer controlled mass spectrometry

    International Nuclear Information System (INIS)

    1974-01-01

    Isotopic analysis of plutonium chemically purified by ion exchange is achieved using a thermal ionization mass spectrometer. Data acquisition from and control of the instrument is done automatically with a dedicated system computer in real time with subsequent automatic data reduction and reporting. Separation of isotopes is achieved by varying the ion accelerating high voltage with accurate computer control

  12. Mass spectrometry-based analysis of whole-grain phytochemicals.

    Science.gov (United States)

    Koistinen, Ville Mikael; Hanhineva, Kati

    2017-05-24

    Whole grains are a rich source of several classes of phytochemicals, such as alkylresorcinols, benzoxazinoids, flavonoids, lignans, and phytosterols. A high intake of whole grains has been linked to a reduced risk of some major noncommunicable diseases, and it has been postulated that a complex mixture of phytochemicals works in synergy to generate beneficial health effects. Mass spectrometry, especially when coupled with liquid chromatography, is a widely used method for the analysis of phytochemicals owing to its high sensitivity and dynamic range. In this review, the current knowledge of the mass spectral properties of the most important classes of phytochemicals found in cereals of common wheat, barley, oats, and rye is discussed.

  13. Temperature-programmed desorption for membrane inlet mass spectrometry

    DEFF Research Database (Denmark)

    Ketola, R.A.; Grøn, C.; Lauritsen, F.R.

    1998-01-01

    We present a novel technique for analyzing volatile organic compounds in air samples using a solid adsorbent together with temperature-programmed desorption and subsequent detection by membrane inlet mass spectrometry (TPD-MIMS). The new system has the advantage of a fast separation of compounds...... to diffuse through the membrane into the mass spectrometer in a few seconds. In this fashion we could completely separate many similar volatile compounds, for example toluene from xylene and trichloroethene from tetrachloroethene. Typical detection limits were at low or sub-nanogram levels, the dynamic range...

  14. 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.

  15. Stable isotope dilution analysis by thermal ionization mass spectrometry. Pt. 2

    International Nuclear Information System (INIS)

    Broekman, A.; Raaphorst, J.G. van

    1984-01-01

    The combination of stable isotope dilution analysis (SIDA) and thermal ionization mass spectrometry (TIMS) is in use for lead and uranium determination at milligram per kilogram levels for over 20 years. However, several other elements can also be determined accurately by SIDA/TIMS. In this study the determinations of cadmium and copper are described. Details of the digestion, electrochemical and ion-exchange separations and the loading of the elements on a filament are given. The advantages of the SIDA/TIMS technique are shown and illustrated with results for several certified reference materials. (orig.) [de

  16. Surface-MALDI mass spectrometry in biomaterials research

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  17. 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.

  18. Classical electron ionization mass spectra in gas chromatography/mass spectrometry with supersonic molecular beams.

    Science.gov (United States)

    Gordin, Alexander; Fialkov, Alexander B; Amirav, Aviv

    2008-09-01

    A major benefit of gas chromatography/mass spectrometry (GC/MS) with a supersonic molecular beam (SMB) interface and its fly-through ion source is the ability to obtain electron ionization of vibrationally cold molecules (cold EI), which show enhanced molecular ions. However, GC/MS with an SMB also has the flexibility to perform 'classical EI' mode of operation which provides mass spectra to mimic those in commercial 70 eV electron ionization MS libraries. Classical EI in SMB is obtained through simple reduction of the helium make-up gas flow rate, which reduces the SMB cooling efficiency; hence the vibrational temperatures of the molecules are similar to those in traditional EI ion sources. In classical EI-SMB mode, the relative abundance of the molecular ion can be tuned and, as a result, excellent identification probabilities and very good matching factors to the NIST MS library are obtained. Classical EI-SMB with the fly-through dual cage ion source has analyte sensitivity similar to that of the standard EI ion source of a basic GC/MS system. The fly-through EI ion source in combination with the SMB interface can serve for cold EI, classical EI-SMB, and cluster chemical ionization (CCI) modes of operation, all easily exchangeable through a simple and quick change (not involving hardware). Furthermore, the fly-through ion source eliminates sample scattering from the walls of the ion source, and thus it offers full sample inertness, tailing-free operation, and no ion-molecule reaction interferences. It is also robust and enables increased column flow rate capability without affecting the sensitivity.

  19. 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.

  20. Review on investigations of antisense oligonucleotides with the use of mass spectrometry.

    Science.gov (United States)

    Studzińska, Sylwia

    2018-01-01

    Antisense oligonucleotides have been investigated as potential drugs for years. They inhibit target gene or protein expression. The present review summarizes their modifications, modes of action, and applications of liquid chromatography coupled with mass spectrometry for qualitative and quantitative analysis of these compounds. The most recent reports on a given topic were given prominence, while some early studies were reviewed in order to provide a theoretical background. The present review covers the issues of using ion-exchange chromatography, ion-pair reversed-phase high performance liquid chromatography and hydrophilic interaction chromatography for the separation of antisense oligonucleotides. The application of mass spectrometry was described with regard to the ionization type used for the determination of these potential therapeutics. Moreover, the current approaches and applications of mass spectrometry for quantitative analysis of antisense oligonucleotides and their metabolites as well as their impurities during in vitro and in vivo studies were discussed. Finally, certain conclusions and perspectives on the determination of therapeutic oligonucleotides in various samples were briefly described. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 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'.

  2. Identification of inorganic anions by gas chromatography/mass spectrometry.

    Science.gov (United States)

    Sakayanagi, Masataka; Yamada, Yaeko; Sakabe, Chikako; Watanabe, Kunio; Harigaya, Yoshihiro

    2006-03-10

    Inorganic anions were identified by using gas chromatography/mass spectrometry (GC/MS). Derivatization of the anions was achieved with pentafluorobenzyl p-toluenesulphonate (PFB-Tos) as the reaction reagent and a crown ether as a phase transfer catalyst. When PFB-Br was used as the reaction reagent, the retention time of it was close to those of the derivatized inorganic anions and interfered with the analysis. In contrast, the retention time of PFB-Tos differed greatly from the PFB derivatives of the inorganic anions and the compounds of interest could be detected without interference. Although the PFB derivatives of SO4, S2O3, CO3, ClO4, and ClO3 could not be detected, the derivatives of F, Cl, Br, I, CN, OCN, SCN, N3, NO3, and NO2 were detected using PFB-Tos as the derivatizing reagent. The inorganic anions were detectable within 30 ng approximately, which is of sufficient sensitivity for use in forensic chemistry. Accurate mass number was measured for each PFB derivative by high-resolution mass spectrometry (HRMS) within a measurement error of 2 millimass units (mmu), which allowed determination of the compositional formula from the mass number. In addition, actual analysis was performed successively by our method using trial samples of matrix.

  3. Surface Ionization and Soft Landing Techniques in Mass Spectrometry

    International Nuclear Information System (INIS)

    Futrell, Jean H.; Laskin, Julia

    2010-01-01

    The advent of soft ionization techniques, notably electrospray and laser desorption ionization methods, has extended mass spectrometric methods to large molecules and molecular complexes. This both greatly expands applications of mass spectrometry and makes the activation and dissociation of complex ions an integral part of large molecule mass spectrometry. A corollary of the much greater number of internal degrees of freedom and high density of states associated with molecular complexity is that internal energies much higher than the dissociation energies for competing fragmentation processes are required for observable fragmentation in time scales sampled by mass spectrometers. This article describes the kinetics of surface-induced dissociation (SID), a particularly efficient activation method for complex ions. Two very important characteristics of SID are very rapid, sub-picosecond activation and precise control of ion internal energy by varying ion collision energy. The nature of the surface plays an important role in SID, determining both efficiency and mechanism of ion activation. Surface composition and morphology strongly influence the relative importance of competing reactions of SID, ion capture (soft-landing), surface reaction and neutralization. The important features of SID and ion soft-landing are described briefly in this review and more fully in the recommended reading list.

  4. Linking high resolution mass spectrometry data with exposure ...

    Science.gov (United States)

    There is a growing need in the field of exposure science for monitoring methods that rapidly screen environmental media for suspect contaminants. Measurement and analysis platforms, based on high resolution mass spectrometry (HRMS), now exist to meet this need. Here we describe results of a study that links HRMS data with exposure predictions from the U.S. EPA's ExpoCast™ program and in vitro bioassay data from the U.S. interagency Tox21 consortium. Vacuum dust samples were collected from 56 households across the U.S. as part of the American Healthy Homes Survey (AHHS). Sample extracts were analyzed using liquid chromatography time-of-flight mass spectrometry (LC–TOF/MS) with electrospray ionization. On average, approximately 2000 molecular features were identified per sample (based on accurate mass) in negative ion mode, and 3000 in positive ion mode. Exact mass, isotope distribution, and isotope spacing were used to match molecular features with a unique listing of chemical formulas extracted from EPA's Distributed Structure-Searchable Toxicity (DSSTox) database. A total of 978 DSSTox formulas were consistent with the dust LC–TOF/molecular feature data (match score ≥ 90); these formulas mapped to 3228 possible chemicals in the database. Correct assignment of a unique chemical to a given formula required additional validation steps. Each suspect chemical was prioritized for follow-up confirmation using abundance and detection frequency results, along wi

  5. Lipidomic mass spectrometry and its application in neuroscience

    Institute of Scientific and Technical Information of China (English)

    Mabel; Enriquez-Algeciras; Sanjoy; K; Bhattacharya

    2013-01-01

    Central and peripheral nervous systems are lipid rich tissues. Lipids, in the context of lipid-protein complexes, surround neurons and provide electrical insulation for transmission of signals allowing neurons to remain embedded within a conducting environment. Lipids play a key role in vesicle formation and fusion in synapses. They provide means of rapid signaling, cell motility and migration for astrocytes and other cell types that surround and play supporting roles neurons. Unlike many other signaling molecules, lipids are capable of multiple signaling events based on the different fragments generated from a single precursor during each event. Lipidomics, until recently suffered from two major disadvantages:(1) level of expertise required an overwhelming amount of chemical detail to correctly identify a vast number of different lipids which could be close in their chemical reactivity; and(2) high amount of purified compounds needed by analytical techniques to determine their structures. Advances in mass spectrometry have enabled overcoming these two limitations. Mass spectrometry offers a great degree of simplicity in identification and quantification of lipids directly extracted from complex biological mixtures. Mass spectrometers can be regarded to as mass analyzers. There are those that separate and analyze the product ion fragments in space(spatial) and those which separate product ions in time in the same space(temporal). Databases and standardized instrument parameters have further aided the capabilities of the spatial instruments while recent advances in bioinformatics have made the identification and quantification possible using temporal instruments.

  6. Speciation of arsenic in marine food (Anemonia sulcata) by liquid chromatography coupled to inductively coupled plasma mass spectrometry and organic mass spectrometry.

    Science.gov (United States)

    Contreras-Acuña, M; García-Barrera, T; García-Sevillano, M A; Gómez-Ariza, J L

    2013-03-22

    Arsenic species have been investigated in Anemonia sulcata, which is frequently consumed food staple in Spain battered in wheat flour and fried with olive oil. Speciation in tissue extracts was carried out by anion/cation exchange chromatography with inductively coupled plasma mass spectrometry (HPLC-(AEC/CEC)-ICP-MS). Three methods for the extraction of arsenic species were investigated (ultrasonic bath, ultrasonic probe and focused microwave) and the optimal one was applied. Arsenic speciation was carried out in raw and cooked anemone and the dominant species are dimethylarsinic acid (DMA(V)) followed by arsenobetaine (AB), As(V), monomethylarsonic acid (MA(V)), tetramethylarsonium ion (TETRA) and trimethylarsine oxide (TMAO). In addition, arsenocholine (AsC), glyceryl phosphorylarsenocholine (GPAsC) and dimethylarsinothioic acid (DMAS) were identified by liquid chromatography coupled to triple quadrupole mass spectrometry (HPLC-MS). These results are interesting since GPAsC has been previously reported in marine organisms after experimental exposure to AsC, but not in natural samples. In addition, this paper reports for the first time the identification of DMAS in marine food. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Validation of a confirmatory method for the determination of melamine in egg by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Xia Xi; Ding Shuangyang; Li Xiaowei; Gong Xiao; Zhang Suxia; Jiang Haiyang; Li Jiancheng; Shen Jianzhong

    2009-01-01

    A sensitive and reliable method was developed and validated for detection and confirmation of melamine in egg based on gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Trichloroacetic acid solution was used for sample extraction and precipitation of proteins. The aqueous extracts were subjected to solid-phase extraction by mixed-mode reversed-phase/strong cation-exchange cartridges. Using ultra-performance liquid chromatography and electrospray ionization in the positive ion mode, melamine was determined by LC-MS/MS, which was completed in 5 min for each injection. For the GC-MS analysis, extracted melamine was derivatized with N,O-bis(trimethylsilyl)trifluoracetamide prior to selected ion monitoring detection in electron impact mode. The average recovery of melamine from fortified samples ranged from 85.2% to 103.2%, with coefficients of variation lower than 12%. The limit of detection obtained by GC-MS and UPLC-MS/MS was 10 and 5 μg kg -1 , respectively. This validated method was successfully applied to the determination of melamine in real samples from market.

  8. Electronic sputtering of biomolecules and its application in mass spectrometry

    International Nuclear Information System (INIS)

    Haakansson, P.; Sundqvist, B.U.R.

    1989-01-01

    In 1974 Macfarlane discovered that fast heavy ions from a 252-Cf source can desorb and ionize molecules from a solid surface. The mass of the molecules was determined by time-of-flight technique. It has been shown that the desorption mechanism is associated with the electron part of the stopping power of the primary ion and the name 'electron sputtering' has been adopted for the phenomenon to distinguish it from the well-known sputtering process with ions of KeV energy. A review of electronic sputtering of biomolecules will be given as well as recent measurements on Langmuir-Blodgett films. One important application of electronic sputtering is in the field of mass spectrometry. With this technique large and nonvolatile molecules can be studied. Particularly adsorption of biomolecules to a nitrocellulose backing has proven to be very useful. Examples will be given of mass spectra from peptides with a molecular weight above 20,000 u. (author)

  9. Multifactorial Understanding of Ion Abundance in Tandem Mass Spectrometry Experiments.

    Science.gov (United States)

    Fazal, Zeeshan; Southey, Bruce R; Sweedler, Jonathan V; Rodriguez-Zas, Sandra L

    2013-01-29

    In a bottom-up shotgun approach, the proteins of a mixture are enzymatically digested, separated, and analyzed via tandem mass spectrometry. The mass spectra relating fragment ion intensities (abundance) to the mass-to-charge are used to deduce the amino acid sequence and identify the peptides and proteins. The variables that influence intensity were characterized using a multi-factorial mixed-effects model, a ten-fold cross-validation, and stepwise feature selection on 6,352,528 fragment ions from 61,543 peptide ions. Intensity was higher in fragment ions that did not have neutral mass loss relative to any mass loss or that had a +1 charge state. Peptide ions classified for proton mobility as non-mobile had lowest intensity of all mobility levels. Higher basic residue (arginine, lysine or histidine) counts in the peptide ion and low counts in the fragment ion were associated with lower fragment ion intensities. Higher counts of proline in peptide and fragment ions were associated with lower intensities. These results are consistent with the mobile proton theory. Opposite trends between peptide and fragment ion counts and intensity may be due to the different impact of factor under consideration at different stages of the MS/MS experiment or to the different distribution of observations across peptide and fragment ion levels. Presence of basic residues at all three positions next to the fragmentation site was associated with lower fragment ion intensity. The presence of proline proximal to the fragmentation site enhanced fragmentation and had the opposite trend when located distant from the site. A positive association between fragment ion intensity and presence of sulfur residues (cysteine and methionine) on the vicinity of the fragmentation site was identified. These results highlight the multi-factorial nature of fragment ion intensity and could improve the algorithms for peptide identification and the simulation in tandem mass spectrometry experiments.

  10. Comparison of gas chromatography/isotope ratio mass spectrometry and liquid chromatography/isotope ratio mass spectrometry for carbon stable-isotope analysis of carbohydrates

    NARCIS (Netherlands)

    Moerdijk-Poortvliet, Tanja C. W.; Schierbeek, Henk; Houtekamer, Marco; van Engeland, Tom; Derrien, Delphine; Stal, Lucas J.; Boschker, Henricus T. S.

    2015-01-01

    We compared gas chromatography/isotope ratio mass spectrometry (GC/IRMS) and liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) for the measurement of δ(13)C values in carbohydrates. Contrary to GC/IRMS, no derivatisation is needed for LC/IRMS analysis of carbohydrates. Hence, although

  11. Identification of Fatty Acids, Phospholipids, and Their Oxidation Products Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry and Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Harmon, Christopher W.; Mang, Stephen A.; Greaves, John; Finlayson-Pitts, Barbara J.

    2010-01-01

    Electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) have found increasing application in the analysis of biological samples. Using these techniques to solve problems in analytical chemistry should be an essential component of the training of undergraduate chemists. We…

  12. Characterisation of the volatile profiles of infant formulas by proton transfer reaction-mass spectrometry and gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    Ruth, van S.M.; Floris, V.; Fayoux, S.

    2006-01-01

    The volatile profiles of 13 infant formulas were evaluated by proton transfer reaction-mass spectrometry (PTR-MS) and gas chromatography¿mass spectrometry (GC¿MS). The infant formulas varied in brand (Aptamil, Cow & Gate, SMA), type (for different infant target groups) and physical form

  13. Comparison of gas chromatography/isotope ratio mass spectrometry and liquid chromatography/isotope ratio mass spectrometry for carbon stable-isotope analysis of carbohydrates

    NARCIS (Netherlands)

    Moerdijk-Poortvliet, T.C.W.; Schierbeek, H.; Houtekamer, M.; van Engeland, T.; Derrien, D.; Stal, L.J.; Boschker, H.T.S.

    2015-01-01

    We compared gas chromatography/isotope ratio mass spectrometry (GC/IRMS) and liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) for the measurement of d13C values in carbohydrates. Contrary to GC/IRMS, no derivatisation is needed for LC/IRMS analysis of carbohydrates. Hence, although

  14. Comparison of gas chromatography/isotope ratio mass spectrometry and liquid chromatography/isotope ratio mass spectrometry for carbon stable-isotope analysis of carbohydrates

    NARCIS (Netherlands)

    Moerdijk-Poortvliet, T.C.W.; Schierbeek, H.; Houtekamer, M.; van Engeland, T.; Derrien, D.; Stal, L.J.; Boschker, H.T.S.

    2015-01-01

    Rationale: We compared gas chromatography/isotope ratio mass spectrometry (GC/IRMS) and liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) for the measurement of δ13C values in carbohydrates. Contrary to GC/IRMS, no derivatisation is needed for LC/IRMS analysis of carbohydrates. Hence,

  15. Analysis of [U-13C6]glucose in human plasma using liquid chromatography/isotope ratio mass spectrometry compared with two other mass spectrometry techniques

    NARCIS (Netherlands)

    Schierbeek, H.; Moerdijk-Poortvliet, T.C.W.; van den Akker, C.H.P.; te Braake, F.W.J.; Boschker, H.T.S.; van Goudoever, J.B.

    2009-01-01

    The use of stable isotope labelled glucose provides insight into glucose metabolism. The 13C-isotopic enrichment of glucose is usually measured by gas chromatography/mass spectrometry (GC/MS) or gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). However, in both techniques

  16. Accelerator mass spectrometry for measurement of long-lived radioisotopes.

    Science.gov (United States)

    Elmore, D; Phillips, F M

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

  17. Mass Spectrometry Based Lipidomics: An Overview of Technological Platforms

    Science.gov (United States)

    Köfeler, Harald C.; Fauland, Alexander; Rechberger, Gerald N.; Trötzmüller, Martin

    2012-01-01

    One decade after the genomic and the proteomic life science revolution, new ‘omics’ fields are emerging. The metabolome encompasses the entity of small molecules—Most often end products of a catalytic process regulated by genes and proteins—with the lipidome being its fat soluble subdivision. Within recent years, lipids are more and more regarded not only as energy storage compounds but also as interactive players in various cellular regulation cycles and thus attain rising interest in the bio-medical community. The field of lipidomics is, on one hand, fuelled by analytical technology advances, particularly mass spectrometry and chromatography, but on the other hand new biological questions also drive analytical technology developments. Compared to fairly standardized genomic or proteomic high-throughput protocols, the high degree of molecular heterogeneity adds a special analytical challenge to lipidomic analysis. In this review, we will take a closer look at various mass spectrometric platforms for lipidomic analysis. We will focus on the advantages and limitations of various experimental setups like ‘shotgun lipidomics’, liquid chromatography—Mass spectrometry (LC-MS) and matrix assisted laser desorption ionization-time of flight (MALDI-TOF) based approaches. We will also examine available software packages for data analysis, which nowadays is in fact the rate limiting step for most ‘omics’ workflows. PMID:24957366

  18. Deep learning for tumor classification in imaging mass spectrometry.

    Science.gov (United States)

    Behrmann, Jens; Etmann, Christian; Boskamp, Tobias; Casadonte, Rita; Kriegsmann, Jörg; Maaß, Peter

    2018-04-01

    Tumor classification using imaging mass spectrometry (IMS) data has a high potential for future applications in pathology. Due to the complexity and size of the data, automated feature extraction and classification steps are required to fully process the data. Since mass spectra exhibit certain structural similarities to image data, deep learning may offer a promising strategy for classification of IMS data as it has been successfully applied to image classification. Methodologically, we propose an adapted architecture based on deep convolutional networks to handle the characteristics of mass spectrometry data, as well as a strategy to interpret the learned model in the spectral domain based on a sensitivity analysis. The proposed methods are evaluated on two algorithmically challenging tumor classification tasks and compared to a baseline approach. Competitiveness of the proposed methods is shown on both tasks by studying the performance via cross-validation. Moreover, the learned models are analyzed by the proposed sensitivity analysis revealing biologically plausible effects as well as confounding factors of the considered tasks. Thus, this study may serve as a starting point for further development of deep learning approaches in IMS classification tasks. https://gitlab.informatik.uni-bremen.de/digipath/Deep_Learning_for_Tumor_Classification_in_IMS. jbehrmann@uni-bremen.de or christianetmann@uni-bremen.de. Supplementary data are available at Bioinformatics online.

  19. Mass Spectrometry Based Lipidomics: An Overview of Technological Platforms

    Directory of Open Access Journals (Sweden)

    Harald C. Köfeler

    2012-01-01

    Full Text Available One decade after the genomic and the proteomic life science revolution, new ‘omics’ fields are emerging. The metabolome encompasses the entity of small molecules—Most often end products of a catalytic process regulated by genes and proteins—with the lipidome being its fat soluble subdivision. Within recent years, lipids are more and more regarded not only as energy storage compounds but also as interactive players in various cellular regulation cycles and thus attain rising interest in the bio-medical community. The field of lipidomics is, on one hand, fuelled by analytical technology advances, particularly mass spectrometry and chromatography, but on the other hand new biological questions also drive analytical technology developments. Compared to fairly standardized genomic or proteomic high-throughput protocols, the high degree of molecular heterogeneity adds a special analytical challenge to lipidomic analysis. In this review, we will take a closer look at various mass spectrometric platforms for lipidomic analysis. We will focus on the advantages and limitations of various experimental setups like ‘shotgun lipidomics’, liquid chromatography—Mass spectrometry (LC-MS and matrix assisted laser desorption ionization-time of flight (MALDI-TOF based approaches. We will also examine available software packages for data analysis, which nowadays is in fact the rate limiting step for most ‘omics’ workflows.

  20. Laser desorption mass spectrometry for point mutation detection

    Energy Technology Data Exchange (ETDEWEB)

    Taranenko, N.I.; Chung, C.N.; Zhu, Y.F. [Oak Ridge National Lab., TN (United States)] [and others

    1996-10-01

    A point mutation can be associated with the pathogenesis of inherited or acquired diseases. Laser desorption mass spectrometry coupled with allele specific polymerase chain reaction (PCR) was first used for point mutation detection. G551D is one of several mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene present in 1-3% of the mutant CFTR alleles in most European populations. In this work, two different approaches were pursued to detect G551D point mutation in the cystic fibrosis gene. The strategy is to amplify the desired region of DNA template by PCR using two primers that overlap one base at the site of the point mutation and which vary in size. If the two primers based on the normal sequence match the target DNA sequence, a normal PCR product will be produced. However, if the alternately sized primers that match the mutant sequence recognize the target DNA, an abnormal PCR product will be produced. Thus, the mass spectrometer can be used to identify patients that are homozygous normal, heterozygous for a mutation or homozygous abnormal at a mutation site. Another approach to identify similar mutations is the use of sequence specific restriction enzymes which respond to changes in the DNA sequence. Mass spectrometry is used to detect the length of the restriction fragments generated by digestion of a PCR generated target fragment. 21 refs., 10 figs., 2 tabs.

  1. Laser desorption mass spectrometry for point mutation detection

    Energy Technology Data Exchange (ETDEWEB)

    Taranenko, N.I.; Chung, C.N.; Zhu, Y.F. [Oak Ridge National Lab., TN (United States)] [and others

    1996-12-31

    A point mutation can be associated with the pathogenesis of inherited or acquired diseases. Laser desorption mass spectrometry coupled with allele specific polymerase chain reaction (PCR) was first used for point mutation detection. G551D is one of several mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene present in 1-3% of the mutant CFTR alleles in most European populations. In this work, two different approaches were pursued to detect G551D point mutation in the cystic fibrosis gene. The strategy is to amplify the desired region of DNA template by PCR using two primers that overlap one base at the site of the point mutation and which vary in size. If the two primers based on the normal sequence match the target DNA sequence, a normal PCR product will be produced. However, if the alternately sized primers that match the mutant sequence recognize the target DNA, an abnormal PCR product will be produced. Thus, the mass spectrometer can be used to identify patients that are homozygous normal, heterozygous for a mutation or homozygous abnormal at a mutation site. Another approach to identify similar mutations is the use of sequence specific restriction enzymes which respond to changes in the DNA sequence. Mass spectrometry is used to detect the length of the restriction fragments by digestion of a PCR generated target fragment. 21 refs., 10 figs., 2 tabs.

  2. Uncovering biologically significant lipid isomers with liquid chromatography, ion mobility spectrometry and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kyle, Jennifer E.; Zhang, Xing; Weitz, Karl K.; Monroe, Matthew E.; Ibrahim, Yehia M.; Moore, Ronald J.; Cha, Jeeyeon; Sun, Xiaofei; Lovelace, Erica S.; Wagoner, Jessica; Polyak, Steve; Metz, Thomas O.; Dey, Sudhansu K.; Smith, Richard D.; Burnum-Johnson, Kristin E.; Baker, Erin Shammel

    2016-01-01

    Understanding how biological molecules are generated, metabolized and eliminated in living systems is important for interpreting processes such as immune response and disease pathology. While genomic and proteomic studies have provided vast amounts of information over the last several decades, interest in lipidomics has also grown due to improved analytical technologies revealing altered lipid metabolism in type 2 diabetes, cancer, and lipid storage disease. Liquid chromatography and mass spectrometry (LC-MS) measurements are currently the dominant approach for characterizing the lipidome by providing detailed information on the spatial and temporal composition of lipids. However, interpreting lipids’ biological roles is challenging due to the existence of numerous structural and stereoisomers (i.e. distinct acyl chain and double-bond positions), which are unresolvable using present LC-MS approaches. Here we show that combining structurally-based ion mobility spectrometry (IMS) with LC-MS measurements distinguishes lipid isomers and allows insight into biological and disease processes.

  3. High-field asymmetric waveform ion mobility spectrometry for mass spectrometry-based proteomics.

    Science.gov (United States)

    Swearingen, Kristian E; Moritz, Robert L

    2012-10-01

    High-field asymmetric waveform ion mobility spectrometry (FAIMS) is an atmospheric pressure ion mobility technique that separates gas-phase ions by their behavior in strong and weak electric fields. FAIMS is easily interfaced with electrospray ionization and has been implemented as an additional separation mode between liquid chromatography (LC) and mass spectrometry (MS) in proteomic studies. FAIMS separation is orthogonal to both LC and MS and is used as a means of on-line fractionation to improve the detection of peptides in complex samples. FAIMS improves dynamic range and concomitantly the detection limits of ions by filtering out chemical noise. FAIMS can also be used to remove interfering ion species and to select peptide charge states optimal for identification by tandem MS. Here, the authors review recent developments in LC-FAIMS-MS and its application to MS-based proteomics.

  4. High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) for Mass Spectrometry-Based Proteomics

    Science.gov (United States)

    Swearingen, Kristian E.; Moritz, Robert L.

    2013-01-01

    SUMMARY High field asymmetric waveform ion mobility spectrometry (FAIMS) is an atmospheric pressure ion mobility technique that separates gas-phase ions by their behavior in strong and weak electric fields. FAIMS is easily interfaced with electrospray ionization and has been implemented as an additional separation mode between liquid chromatography (LC) and mass spectrometry (MS) in proteomic studies. FAIMS separation is orthogonal to both LC and MS and is used as a means of on-line fractionation to improve detection of peptides in complex samples. FAIMS improves dynamic range and concomitantly the detection limits of ions by filtering out chemical noise. FAIMS can also be used to remove interfering ion species and to select peptide charge states optimal for identification by tandem MS. Here, we review recent developments in LC-FAIMS-MS and its application to MS-based proteomics. PMID:23194268

  5. Dehydrodimerization of pterostilbene during electrospray ionization mass spectrometry

    KAUST Repository

    Raji, Misjudeen

    2013-04-30

    RATIONALE Pterostilbene is a member of the hydroxystilbene family of compounds commonly found in plants such as blueberry and grapes. During the analysis of this compound by electrospray ionization mass spectrometry (ESI-MS), an ion was observed that corresponds to the dehydrodimer of pterostilbene in mass-to-charge ratio. Since such unexpected dimerization may lead to decreased monomer signal during quantitative analysis, it was of interest to identify the origin and structure of the observed pterostilbene dimer and examine the experimental conditions that influence its formation. METHODS Liquid Chromatography/Mass Spectrometry (LC/MS), Nuclear Magnetic Resonance (NMR), and High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) were used to examine the origin of the dimerization products. The structure of the formed pterostilbene dimer was examined by performing MSn analysis on the dimer ion. Effects of solvent composition, analyte concentration, radical scavenger, and other experimental conditions on the dimerization were also studied. RESULTS LC/MS and NMR analyses clearly showed that the starting solution did not contain the pterostilbene dimer. Solvent type and radical scavenger concentration were found to have pronounced effects on the dimer formation. Particularly, presence of acetonitrile or ammonium acetate had favorable effects on the extent of dimerization during ESI-MS analysis whereas hydroquinone and butylated hydroquinone had negative effects. Dimer formation decreased at high flow rates and when fused-silica capillary was used as the spray needle. CONCLUSIONS The data indicate that this dimerization occurs as a result of solution-phase electrochemical reactions taking place during the electrospray process. A possible structure for this dimer was proposed based on the MSn analysis and was similar to that of the enzymatically derived pterostilbene dehydrodimer already reported in the literature. Copyright © 2013 John Wiley & Sons, Ltd

  6. Simple setup for gas-phase h/d exchange mass spectrometry coupled to electron transfer dissociation and ion mobility for analysis of polypeptide structure on a liquid chromatographic time scale

    DEFF Research Database (Denmark)

    Mistarz, Ulrik Hvid; Brown, Jeffery M; Haselmann, Kim F

    2014-01-01

    gas immediately upstream or downstream of the primary skimmer cone. The approach was implemented on three commercially available mass spectrometers and required no or minor fully reversible reconfiguration of gas-inlets of the ion source. Results from gas-phase HDX-MS of peptides using the aqueous ND3....../D2O as HDX reagent indicate that labeling is facilitated exclusively through gaseous ND3, yielding similar results to the infusion of purified ND3-gas, while circumventing the complications associated with the use of hazardous purified gases. Comparison of the solution-phase- and gas-phase deuterium...

  7. Methodology for nuclear magnetic resonance and ion cyclotron resonance mass spectrometry

    International Nuclear Information System (INIS)

    Sehgal, Akansha

    2014-01-01

    This thesis encompasses methodological developments in both nuclear magnetic resonance and Fourier transform ion cyclotron resonance mass spectrometry. The NMR section explores the effects of scalar relaxation on a coupled nucleus to measure fast exchange rates. In order to quantify these rates accurately, a precise knowledge of the chemical shifts of the labile protons and of the scalar couplings is normally required. We applied the method to histidine where no such information was available a priori, neither about the proton chemical shifts nor about the one-bond scalar coupling constants J( 1 H 15 N), since the protons were invisible due to fast exchange. We have measured the exchange rates of the protons of the imidazole ring and of amino protons in histidine by indirect detection via 15 N. Not only the exchange rate constants, but also the elusive chemical shifts of the protons and the coupling constants could be determined. For the mass spectrometry section, the ion isolation project was initiated to study the effect of phase change of radiofrequency pulses. Excitation of ions in the ICR cell is a linear process, so that the pulse voltage required for ejecting ions must be inversely proportional to the pulse duration. A continuous sweep pulse propels the ion to a higher radius, whereas a phase reversal causes the ion to come to the centre. This represents the principle of 'notch ejection', wherein the ion for which the phase is reversed is retained in the ICR cell, while the remaining ions are ejected. The manuscript also contains a theoretical chapter, wherein the ion trajectories are plotted by solving the Lorentzian equation for the three-pulse scheme used for two-dimensional ICR. Through our simulations we mapped the ion trajectories for different pulse durations and for different phase relations. (author)

  8. Applications of ambient mass spectrometry in high-throughput screening.

    Science.gov (United States)

    Li, Li-Ping; Feng, Bao-Sheng; Yang, Jian-Wang; Chang, Cui-Lan; Bai, Yu; Liu, Hu-Wei

    2013-06-07

    The development of rapid screening and identification techniques is of great importance for drug discovery, doping control, forensic identification, food safety and quality control. Ambient mass spectrometry (AMS) allows rapid and direct analysis of various samples in open air with little sample preparation. Recently, its applications in high-throughput screening have been in rapid progress. During the past decade, various ambient ionization techniques have been developed and applied in high-throughput screening. This review discusses typical applications of AMS, including DESI (desorption electrospray ionization), DART (direct analysis in real time), EESI (extractive electrospray ionization), etc., in high-throughput screening (HTS).

  9. Multielement ultratrace analysis in tungsten using secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Wilhartitz, P.; Virag, A.; Friedbacher, G.; Grasserbauer, M.

    1987-01-01

    The ever increasing demands on properties of materials create a trend also towards ultrapure products. Characterization of these materials is only possible with modern, highly sophisticated analytical techniques such as activation analysis and mass spectrometry, particularly SSMS, SIMS and GDMS. Analytical strategies were developed for the determination of about 40 elements in a tungsten matrix with high-performance SIMS. Difficulties like the elimination of interferences had to be overcome. Extrapolated detection limits were established in the range of pg/g (alkali metals, halides) to ng/g (e.g. Ta, Th). Depth profiling and ion imaging gave additional information about the lateral and the depth distribution of the elements. (orig.)

  10. Electrospray mass spectrometry for actinides and lanthanide speciation

    International Nuclear Information System (INIS)

    Moulin, C.; Amekraz, B.; Colette, S.; Doizi, D.; Jacopin, C.; Lamouroux, C.; Plancque, G.

    2006-01-01

    Electrospray mass spectrometry (ES-MS) is a new speciation technique that has the great interest to be able to probe the element, the ligand and the complex in order to reach the speciation. This paper will focus on the use of ES-MS for the speciation of actinides/lanthanides on several systems of interest in various fields such as the interaction between DTPA (decorporant) and europium, HEBP and uranium, BTP (new extracting agent) and lanthanides with comparison with known chemistry as well as whenever possible with other speciation techniques

  11. Multinozzle emitter arrays for ultrahigh-throughput nanoelectrospray mass spectrometry

    Science.gov (United States)

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

    2017-10-17

    The present invention provides for a structure comprising a plurality of emitters, wherein a first nozzle of a first emitter and a second nozzle of a second emitter emit in two directions that are not or essentially not in the same direction; wherein the walls of the nozzles and the emitters form a monolithic whole. The present invention also provides for a structure comprising an emitter with a sharpened end from which the emitter emits; wherein the emitters forms a monolithic whole. The present invention also provides for a fully integrated separation of proteins and small molecules on a silicon chip before the electrospray mass spectrometry analysis.

  12. Vaporization Studies of Olivine via Knudsen Effusion Mass Spectrometry

    Science.gov (United States)

    Costa, G. C. C.; Jacobson, N. S.

    2014-01-01

    Olivine is the major mineral in the Earth's upper mantle occurring predominantly in igneous rocks and has been identified in meteorites, asteroids, the Moon and Mars. Among many other important applications in planetary and materials sciences, the thermodynamic properties of vapor species from olivine are crucial as input parameters in computational modelling of the atmospheres of hot, rocky exoplanets (lava planets). There are several weight loss studies of olivine vaporization in the literature and one Knudsen Effusion Mass Spectrometry (KEMS) study. In this study, we examine a forsterite-rich olivine (93% forsterite and 7% fayalite, Fo93Fa7) with KEMS to further understand its vaporization and thermodynamic properties.

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

    International Nuclear Information System (INIS)

    Bievre, P. de

    1978-01-01

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

  14. Application of accelerator mass spectrometry in aluminum metabolism studies

    International Nuclear Information System (INIS)

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

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic 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 26 Al. 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 humans. (Author) (24 refs., 3 figs.)

  15. Diesel characterization by high-resolution mass spectrometry - gas chromatography

    International Nuclear Information System (INIS)

    Baldrich, C.A

    1998-01-01

    High-resolution mass spectrometry-gas chromatography is combined with the HC22 method in order to obtain detailed information about the chemical composition of diesel and the distribution of different compound types in terms of its final boiling temperature from a single analysis. The total time elapsed from sample injection and signal processing to obtain final results is 90 minutes. This fact makes this methodology a new and very important tool for the decision making process concerning the most suitable final boiling temperature and the type of treatment of the product in order to obtain diesel that fulfills the international standards. The consistency and repeatability of the experimental results are demonstrated

  16. Application of accelerator mass spectrometry in aluminum metabolism studies

    Energy Technology Data Exchange (ETDEWEB)

    Meirav, O; Vetterli, D; Johnson, R R [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Sutton, R A.L.; Walker, V R; Halabe, A [British Columbia U.iv., Vancouver, BC (Canada). Dept. of Medicine; Fink, D; Middleton, R; Klein, J [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Physics

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic 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 {sup 26}Al. 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 humans. (Author) (24 refs., 3 figs.).

  17. A novel ion imager for secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Matsumoto, Kazuya; Miyata, Kenji; Nakamura, Tsutomu

    1993-01-01

    This paper describes a new area detector for secondary ion mass spectrometry (SIMS) ion microscope, and its performance. The operational principle is based on detecting the change in potential of a floating photodiode caused by the ion-induced secondary-electron emission and the incoming ion itself. The experiments demonstrated that 10 1 -10 5 aluminum ions per pixel can be detected with good linear response. Moreover, relative ion sensitivities from hydrogen to lead were constant within a factor of 2. The performance of this area detector provides the potential for detection of kiloelectronvolt ion images with current ion microscopy

  18. Imaging mass spectrometry tackles interfacial challenges in electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying

    2017-12-01

    Electrochemistry has played a significant role in many research fields. Owing to its sensitivity and selectivity, in situ electroanalysis has been widely used as a fast and economical means for achieving outstanding results. Although many spectroscopic techniques have been used in electrochemistry, the challenges to capture short-lived intermediate species as a result of electron transfer in the buried solid electrode and electrolyte solution interface remains a grand challenge. In situ imaging mass spectrometry (IMS) recently has been extended to capture transient species in electrochemistry. This review intends to summarize newest development of IMS and its applications in advancing fundamental electrochemistry.

  19. Two possible improvements for mass spectrometry analysis of intact biomolecules.

    Science.gov (United States)

    Raznikov, Valeriy V; Zelenov, Vladislav V; Aparina, Elena V; Pikhtelev, Alexander R; Sulimenkov, Ilia V; Raznikova, Marina O

    2017-08-01

    The goals of our study were to investigate abilities of two approaches to eliminate possible errors in electrospray mass spectrometry measurements of biomolecules. Passing of a relatively dense supersonic gas jet through ionization region followed by its hitting the spray of the analyzed solution in low vacuum may be effective to keep an initial biomolecule structure in solution. Provided that retention of charge carriers for some sites in the biomolecule cannot be changed noticeably in electrospray ion source, decomposition and separation of charge-state distributions of electrosprayed ions may give additional information about native structure of biomolecules in solution.

  20. Uncertainty of relative sensitivity factors in glow discharge mass spectrometry

    Science.gov (United States)

    Meija, Juris; Methven, Brad; Sturgeon, Ralph E.

    2017-10-01

    The concept of the relative sensitivity factors required for the correction of the measured ion beam ratios in pin-cell glow discharge mass spectrometry is examined in detail. We propose a data-driven model for predicting the relative response factors, which relies on a non-linear least squares adjustment and analyte/matrix interchangeability phenomena. The model provides a self-consistent set of response factors for any analyte/matrix combination of any element that appears as either an analyte or matrix in at least one known response factor.

  1. Monitoring of wine aging process by electrospray ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    Alexandra Christine Helena Frankland Sawaya

    2011-09-01

    Full Text Available The characterization of wine samples by direct insertion electrospray ionization mass spectrometry (ESI-MS, without pre-treatment or chromatographic separation, in a process denominated fingerprinting, has been applied to several samples of wine produced with grapes of the Pinot noir, Merlot and Cabernet Sauvignon varieties from the state o Rio Grande do Sul, in Brazil. The ESI-MS fingerprints of the samples detected changes which occurred during the aging process in the three grape varieties. Principal Component Analysis (PCA of the negative ion mode fingerprints was used to group the samples, pinpoint the main changes in their composition, and indicate marker ions for each group of samples.

  2. Indigenous instrumentation for mass spectrometry. PD-5-1

    International Nuclear Information System (INIS)

    Handu, V.K.

    2007-01-01

    Mass Spectrometry is a powerful analytical technique due to its high sensitivity, specificity, selectivity, and wide field of applications in elemental analysis, especially in the determination of trace and ultra trace elements, precise and accurate isotopic ratio measurements. Due to these excellent features, it is a crucial analytical tool for number of Department of Atomic Energy's (DAE) programs. BARC, over the years, has developed several mass spectrometers suitable for needs of a number of programs in DAE and, in this process, technologies have been developed in HV/UHV systems, precision mechanical engineering and fabrication, design and fabrication of electromagnets, ion optics, ultra stable analog and digital electronics, data systems etc. A large number of these mass spectrometers are being used regularly in various units of DAE. Since users are demanding TIMS mass spectrometer with better specifications, efforts are being made in house to develop TIMS with improved specifications. Efforts are also under way to develop a multi collector, plasma source mass spectrometer (MC-ICP-MS) with magnetic sector mass analyzer, since such instrument is increasingly being used to measure isotopic ratios with high precision

  3. Determination of aminopolycarboxylic acids at ultra-trace levels by means of online coupling ion exchange chromatography and inductively coupled plasma-mass spectrometry with indirect detection via their Pd2+-complexes

    International Nuclear Information System (INIS)

    Nette, David; Seubert, Andreas

    2015-01-01

    Highlights: • 8 important APCA’s analyzed in one run instead of 3 in the previous method. • Pd 2+ extents the methods applicability to 3 and more dentate amino carboxylic acids. • Separation system optimized for the isocratic determination of important APCA’s. • Thermodynamic stability of APCA–Pd 2+ complexes is higher than for Fe 3+ and In 3+ . • Pd 2+ is kinetically much slower than Fe 3+ and In 3+ and makes the method more rugged. - Abstract: A new indirect IC-ICP-MS method for the determination of aminopolycarboxylic acids in water samples is described. It is based on the addition of an excess of Pd(II) to water samples. The analytes are forced into very strong and negatively charged palladium complexes, separated by ion exchange chromatography and detected by their palladium content, utilizing an on-line coupled ICP-MS. This method is suitable to determine the concentration of 8 aminopolycarboxylic acids (nitrilotriacetic acid (NTA), (2-carboxyethyl) iminodiacetic acid (β-ADA), methylglycinediacetic acid (MGDA), 2-hydroxyethyl) ethylenediamine triacetic acid (HEDTA), diethylene triamine pentaacetic acid (DTPA), ethylendiamine tetraacetic acid (EDTA), 1,3-diaminopropane tetraacetic acid (1,3-PDTA) and 1,2-diaminopropane tetraacetic acid (1,2-PDTA) at the ng kg −1 level. The method is faster and easier than the established gas chromatography (GC)-method ISO 16588:2002 [1] and up to two orders of magnitude more sensitive than the ion pair chromatography based method of DIN 38413-8. Analytic performance is superior to ISO 16588:2002 and the comparability is good

  4. Determination of aminopolycarboxylic acids at ultra-trace levels by means of online coupling ion exchange chromatography and inductively coupled plasma-mass spectrometry with indirect detection via their Pd{sup 2+}-complexes

    Energy Technology Data Exchange (ETDEWEB)

    Nette, David; Seubert, Andreas, E-mail: seubert@staff.uni-marburg.de

    2015-07-16

    Highlights: • 8 important APCA’s analyzed in one run instead of 3 in the previous method. • Pd{sup 2+} extents the methods applicability to 3 and more dentate amino carboxylic acids. • Separation system optimized for the isocratic determination of important APCA’s. • Thermodynamic stability of APCA–Pd{sup 2+} complexes is higher than for Fe{sup 3+} and In{sup 3+}. • Pd{sup 2+} is kinetically much slower than Fe{sup 3+} and In{sup 3+} and makes the method more rugged. - Abstract: A new indirect IC-ICP-MS method for the determination of aminopolycarboxylic acids in water samples is described. It is based on the addition of an excess of Pd(II) to water samples. The analytes are forced into very strong and negatively charged palladium complexes, separated by ion exchange chromatography and detected by their palladium content, utilizing an on-line coupled ICP-MS. This method is suitable to determine the concentration of 8 aminopolycarboxylic acids (nitrilotriacetic acid (NTA), (2-carboxyethyl) iminodiacetic acid (β-ADA), methylglycinediacetic acid (MGDA), 2-hydroxyethyl) ethylenediamine triacetic acid (HEDTA), diethylene triamine pentaacetic acid (DTPA), ethylendiamine tetraacetic acid (EDTA), 1,3-diaminopropane tetraacetic acid (1,3-PDTA) and 1,2-diaminopropane tetraacetic acid (1,2-PDTA) at the ng kg{sup −1} level. The method is faster and easier than the established gas chromatography (GC)-method ISO 16588:2002 [1] and up to two orders of magnitude more sensitive than the ion pair chromatography based method of DIN 38413-8. Analytic performance is superior to ISO 16588:2002 and the comparability is good.

  5. Tandem mass spectrometry data quality assessment by self-convolution

    Directory of Open Access Journals (Sweden)

    Tham Wai

    2007-09-01

    Full Text Available Abstract Background Many algorithms have been developed for deciphering the tandem mass spectrometry (MS data sets. They can be essentially clustered into two classes. The first performs searches on theoretical mass spectrum database, while the second based itself on de novo sequencing from raw mass spectrometry data. It was noted that the quality of mass spectra affects significantly the protein identification processes in both instances. This prompted the authors to explore ways to measure the quality of MS data sets before subjecting them to the protein identification algorithms, thus allowing for more meaningful searches and increased confidence level of proteins identified. Results The proposed method measures the qualities of MS data sets based on the symmetric property of b- and y-ion peaks present in a MS spectrum. Self-convolution on MS data and its time-reversal copy was employed. Due to the symmetric nature of b-ions and y-ions peaks, the self-convolution result of a good spectrum would produce a highest mid point intensity peak. To reduce processing time, self-convolution was achieved using Fast Fourier Transform and its inverse transform, followed by the removal of the "DC" (Direct Current component and the normalisation of the data set. The quality score was defined as the ratio of the intensity at the mid point to the remaining peaks of the convolution result. The method was validated using both theoretical mass spectra, with various permutations, and several real MS data sets. The results were encouraging, revealing a high percentage of positive prediction rates for spectra with good quality scores. Conclusion We have demonstrated in this work a method for determining the quality of tandem MS data set. By pre-determining the quality of tandem MS data before subjecting them to protein identification algorithms, spurious protein predictions due to poor tandem MS data are avoided, giving scientists greater confidence in the

  6. Tandem mass spectrometry data quality assessment by self-convolution.

    Science.gov (United States)

    Choo, Keng Wah; Tham, Wai Mun

    2007-09-20

    Many algorithms have been developed for deciphering the tandem mass spectrometry (MS) data sets. They can be essentially clustered into two classes. The first performs searches on theoretical mass spectrum database, while the second based itself on de novo sequencing from raw mass spectrometry data. It was noted that the quality of mass spectra affects significantly the protein identification processes in both instances. This prompted the authors to explore ways to measure the quality of MS data sets before subjecting them to the protein identification algorithms, thus allowing for more meaningful searches and increased confidence level of proteins identified. The proposed method measures the qualities of MS data sets based on the symmetric property of b- and y-ion peaks present in a MS spectrum. Self-convolution on MS data and its time-reversal copy was employed. Due to the symmetric nature of b-ions and y-ions peaks, the self-convolution result of a good spectrum would produce a highest mid point intensity peak. To reduce processing time, self-convolution was achieved using Fast Fourier Transform and its inverse transform, followed by the removal of the "DC" (Direct Current) component and the normalisation of the data set. The quality score was defined as the ratio of the intensity at the mid point to the remaining peaks of the convolution result. The method was validated using both theoretical mass spectra, with various permutations, and several real MS data sets. The results were encouraging, revealing a high percentage of positive prediction rates for spectra with good quality scores. We have demonstrated in this work a method for determining the quality of tandem MS data set. By pre-determining the quality of tandem MS data before subjecting them to protein identification algorithms, spurious protein predictions due to poor tandem MS data are avoided, giving scientists greater confidence in the predicted results. We conclude that the algorithm performs well

  7. Continuous high-frequency dissolved O2/Ar measurements by equilibrator inlet mass spectrometry.

    Science.gov (United States)

    Cassar, Nicolas; Barnett, Bruce A; Bender, Michael L; Kaiser, Jan; Hamme, Roberta C; Tilbrook, Bronte

    2009-03-01

    The oxygen (O(2)) concentration in the surface ocean is influenced by biological and physical processes. With concurrent measurements of argon (Ar), which has similar solubility properties as oxygen, we can remove the physical contribution to O(2) supersaturation and determine the biological oxygen supersaturation. Biological O(2) supersaturation in the surface ocean reflects the net metabolic balance between photosynthesis and respiration, i.e., the net community productivity (NCP). We present a new method for continuous shipboard measurements of O(2)/Ar by equilibrator inlet mass spectrometry (EIMS). From these measurements and an appropriate gas exchange parametrization, NCP can be estimated at high spatial and temporal resolution. In the EIMS configuration, seawater from the ship's continuous intake flows through a cartridge enclosing a gas-permeable microporous membrane contactor. Gases in the headspace of the cartridge equilibrate with dissolved gases in the flowing seawater. A fused-silica capillary continuously samples headspace gases, and the O(2)/Ar ratio is measured by mass spectrometry. The ion current measurements on the mass spectrometer reflect the partial pressures of dissolved gases in the water flowing through the equilibrator. Calibration of the O(2)/Ar ion current ratio (32/40) is performed automatically every 2 h by sampling ambient air through a second capillary. A conceptual model demonstrates that the ratio of gases reaching the mass spectrometer is dependent on several parameters, such as the differences in molecular diffusivities and solubilities of the gases. Laboratory experiments and field observations performed by EIMS are discussed. We also present preliminary evidence that other gas measurements, such as N(2)/Ar and pCO(2) measurements, may potentially be performed with EIMS. Finally, we compare the characteristics of the EIMS with the previously described membrane inlet mass spectrometry (MIMS) approach.

  8. Characterization of a Distributed Plasma Ionization Source (DPIS) for Ion Mobility Spectrometry and Mass Spectrometry

    International Nuclear Information System (INIS)

    Waltman, Melanie J.; Dwivedi, Prabha; Hill, Herbert; Blanchard, William C.; Ewing, Robert G.

    2008-01-01

    A recently developed atmospheric pressure ionization source, a distributed plasma ionization source (DPIS), was characterized and compared to commonly used atmospheric pressure ionization sources with both mass spectrometry and ion mobility spectrometry. The source consisted of two electrodes of different sizes separated by a thin dielectric. Application of a high RF voltage across the electrodes generated plasma in air yielding both positive and negative ions depending on the polarity of the applied potential. These reactant ions subsequently ionized the analyte vapors. The reactant ions generated were similar to those created in a conventional point-to-plane corona discharge ion source. The positive reactant ions generated by the source were mass identified as being solvated protons of general formula (H2O)nH+ with (H2O)2H+ as the most abundant reactant ion. The negative reactant ions produced were mass identified primarily as CO3-, NO3-, NO2-, O3- and O2- of various relative intensities. The predominant ion and relative ion ratios varied depending upon source construction and supporting gas flow rates. A few compounds including drugs, explosives and environmental pollutants were selected to evaluate the new ionization source. The source was operated continuously for several months and although deterioration was observed visually, the source continued to produce ions at a rate similar that of the initial conditions. The results indicated that the DPIS may have a longer operating life than a conventional corona discharge.

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

    Science.gov (United States)

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

    2009-05-02

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

  10. Theory and technique of spark source mass spectrometry; Theorie et technique de la spectrometrie de masse a etincelles

    Energy Technology Data Exchange (ETDEWEB)

    Stefani, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    Trace analysis in solids by spark source mass spectrometry involves complicated phenomena: element ionization in spark and blacking of sensitive emulsion by focused ion beam. However the principal risk of selectivity lies in analyser system, which realizes double focusing only for a part of the ions. Therefore, each analyst has to known ionic optics of his apparatus, for ensuring the transmission of mean energetic ions, which are representative of sample composition. By a careful photometry of mass spectrum, good reproducibility can be obtained. Thereafter accuracy depends on the knowledge of sensitivity coefficients proper to this apparatus. (author) [French] L'analyse de traces dans les solides par spectrometrie de masse a etincelles met en jeu des phenomenes complexes qui sont l'ionisation des elements dans l'etincelle, et le noircissement de l'emulsion sensible par les faisceaux ioniques focalises. Cependant, le risque majeur de selectivite provient de l'ensemble analyseur, qui realise la double focalisation sur une fraction seulement du faisceau d'ions. L'analyste doit donc connaitre en detail l'optique ionique de son appareil, pour assurer le passage de la bande d'energie moyenne des ions, qui seule caracterise quantitativement la composition chimique de l'echantillon. Une exploitation photometrique soignee du spectrogramme donne alors des resultats reproductibles, dont la justesse ne depend plus que des coefficients de sensibilite propres a ce type d'instrument. (auteur)

  11. Steroid Profiling by Gas Chromatography–Mass Spectrometry and High Performance Liquid Chromatography–Mass Spectrometry for Adrenal Diseases

    Science.gov (United States)

    McDonald, Jeffrey G.; Matthew, Susan

    2012-01-01

    The ability to measure steroid hormone concentrations in blood and urine specimens is central to the diagnosis and proper treatment of adrenal diseases. The traditional approach has been to assay each steroid hormone, precursor, or metabolite using individual aliquots of serum, each with a separate immunoassay. For complex diseases, such as congenital adrenal hyperplasia and adrenocortical cancer, in which the assay of several steroids is essential for management, this approach is time consuming and costly, in addition to using large amounts of serum. Gas chromatography/mass spectrometry profiling of steroid metabolites in urine has been employed for many years but only in a small number of specialized laboratories and suffers from slow throughput. The advent of commercial high-performance liquid chromatography instruments coupled to tandem mass spectrometers offers the potential for medium- to high-throughput profiling of serum steroids using small quantities of sample. Here, we review the physical principles of mass spectrometry, the instrumentation used for these techniques, the terminology used in this field and applications to steroid analysis. PMID:22170384

  12. Ultratrace analysis of uranium and plutonium by mass spectrometry

    International Nuclear Information System (INIS)

    Wogman, N.A.; Wacker, J.F.; Olsen, K.B.; Petersen, S.L.; Farmer, O.T.; Kelley, J.M.; Eiden, G.C.; Maiti, T.C.

    2002-01-01

    Full text: Uranium and plutonium have traditionally been analyzed using alpha energy spectrometry. Both isotopic compositions and elemental abundances can be characterized on samples containing microgram to milligram quantities of uranium and nanogram to microgram quantities of plutonium. In the past ten years or so, considerable interest has developed in measuring nanograms quantities of uranium and sub-picogram quantities of plutonium in environmental samples. Such measurements require high sensitivity and as a consequence, sensitive mass spectrometric-based methods have been developed. Thus, the analysis of uranium and plutonium have gone from counting decays to counting atoms, with considerable increases in both sensitivity and precision for isotopic measurements. At the Pacific Northwest National Laboratory (PNNL), we have developed highly sensitive methods to analyze uranium and plutonium in environmental samples. The development of an ultratrace analysis capability for measuring uranium and plutonium has arisen from a need to detect and characterize environmental samples for signatures associated with nuclear industry processes. Our most sensitive well-developed methodologies employ thermal ionization mass spectrometry (TIMS), however, recent advances in inductively coupled plasma mass spectrometry (ICP-MS) have shown considerable promise for use in detecting uranium and plutonium at ultratrace levels. The work at PNNL has included the development of both chemical separation and purification techniques, as well as the development of mass spectrometric instrumentation and techniques. At the heart of our methodology for TIMS analysis is a procedure that utilizes 100-microliter-volumes of analyte for chemical processing to purify, separate, and load actinide elements into resin beads for subsequent mass spectrometric analysis. The resin bead technique has been combined with a thorough knowledge of the physicochemistry of thermal ion emission to achieve

  13. Isolation and mass spectrometry of transcription factor complexes.

    Science.gov (United States)

    Sebastiaan Winkler, G; Lacomis, Lynne; Philip, John; Erdjument-Bromage, Hediye; Svejstrup, Jesper Q; Tempst, Paul

    2002-03-01

    Protocols are described that enable the isolation of novel proteins associated with a known protein and the subsequent identification of these proteins by mass spectrometry. We review the basics of nanosample handling and of two complementary approaches to mass analysis, and provide protocols for the entire process. The protein isolation procedure is rapid and based on two high-affinity chromatography steps. The method does not require previous knowledge of complex composition or activity and permits subsequent biochemical characterization of the isolated factor. As an example, we provide the procedures used to isolate and analyze yeast Elongator, a histone acetyltransferase complex important for transcript elongation, which led to the identification of three novel subunits.

  14. Tritium depth profiling in carbon by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Friedrich, M.; Pilz, W.; Sun, G.; Behrisch, R.; Garcia-Rosales, C.; Bekris, N.; Penzhorn, R.-D.

    2000-01-01

    Tritium depth profiling measurements by accelerator mass spectrometry have been performed at the facility installed at the Rossendorf 3 MV Tandetron. In order to achieve a uniform erosion at the target surface inside a commercial Cs ion sputtering source and to avoid edge effects, the samples were mechanically scanned and the signals were recorded only during sputtering at the centre of the sputtered area. The sputtered negative ions were mass analysed by the injection magnet of the Tandetron. Hydrogen and deuterium profiles were measured with the Faraday cup between the injection magnet and the accelerator, while the tritium was counted after the accelerator with semiconductor detectors. Depth profiles have been measured for carbon samples which had been exposed to the plasma at the first wall of the Garching fusion experiment ASDEX-Upgrade and from the European fusion experiment JET, Culham, UK

  15. Mass spectrometry for protein quantification in biomarker discovery.

    Science.gov (United States)

    Wang, Mu; You, Jinsam

    2012-01-01

    Major technological advances have made proteomics an extremely active field for biomarker discovery in recent years due primarily to the development of newer mass spectrometric technologies and the explosion in genomic and protein bioinformatics. This leads to an increased emphasis on larger scale, faster, and more efficient methods for detecting protein biomarkers in human tissues, cells, and biofluids. Most current proteomic methodologies for biomarker discovery, however, are not highly automated and are generally labor-intensive and expensive. More automation and improved software programs capable of handling a large amount of data are essential to reduce the cost of discovery and to increase throughput. In this chapter, we discuss and describe mass spectrometry-based proteomic methods for quantitative protein analysis.

  16. Differential Rapid Screening of Phytochemicals by Leaf Spray Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Thomas; Graham Cooks, R. [Univ. of Innsbruck, Innsbruck (Austria)

    2014-03-15

    Ambient ionization can be achieved by generating an electrospray directly from plant tissue ('leaf spray'). The resulting mass spectra are characteristic of ionizable phytochemicals in the plant material. By subtracting the leaf spray spectra recorded from the petals of two hibiscus species H. moscheutos and H. syriacus one gains rapid access to the metabolites that differ most in the two petals. One such compound was identified as the sambubioside of quercitin (or delphinidin) while others are known flavones. Major interest centered on a C{sub 19}H{sub 29}NO{sub 5} compound that occurs only in the large H. moscheutos bloom. Attempts were made to characterize this compound by mass spectrometry alone as a test of such an approach. This showed that the compound is an alkaloid, assigned to the polyhydroxylated pyrrolidine class, and bound via a C{sub 3} hydrocarbon unit to a monoterpene.

  17. Differential Rapid Screening of Phytochemicals by Leaf Spray Mass Spectrometry

    International Nuclear Information System (INIS)

    Mueller, Thomas; Graham Cooks, R.

    2014-01-01

    Ambient ionization can be achieved by generating an electrospray directly from plant tissue ('leaf spray'). The resulting mass spectra are characteristic of ionizable phytochemicals in the plant material. By subtracting the leaf spray spectra recorded from the petals of two hibiscus species H. moscheutos and H. syriacus one gains rapid access to the metabolites that differ most in the two petals. One such compound was identified as the sambubioside of quercitin (or delphinidin) while others are known flavones. Major interest centered on a C 19 H 29 NO 5 compound that occurs only in the large H. moscheutos bloom. Attempts were made to characterize this compound by mass spectrometry alone as a test of such an approach. This showed that the compound is an alkaloid, assigned to the polyhydroxylated pyrrolidine class, and bound via a C 3 hydrocarbon unit to a monoterpene

  18. Good quantification practices of flavours and fragrances by mass spectrometry.

    Science.gov (United States)

    Begnaud, Frédéric; Chaintreau, Alain

    2016-10-28

    Over the past 15 years, chromatographic techniques with mass spectrometric detection have been increasingly used to monitor the rapidly expanded list of regulated flavour and fragrance ingredients. This trend entails a need for good quantification practices suitable for complex media, especially for multi-analytes. In this article, we present experimental precautions needed to perform the analyses and ways to process the data according to the most recent approaches. This notably includes the identification of analytes during their quantification and method validation, when applied to real matrices, based on accuracy profiles. A brief survey of application studies based on such practices is given.This article is part of the themed issue 'Quantitative mass spectrometry'. © 2016 The Authors.

  19. Mass spectrometry as a quantitative tool in plant metabolomics

    Science.gov (United States)

    Jorge, Tiago F.; Mata, Ana T.

    2016-01-01

    Metabolomics is a research field used to acquire comprehensive information on the composition of a metabolite pool to provide a functional screen of the cellular state. Studies of the plant metabolome include the analysis of a wide range of chemical species with very diverse physico-chemical properties, and therefore powerful analytical tools are required for the separation, characterization and quantification of this vast compound diversity present in plant matrices. In this review, challenges in the use of mass spectrometry (MS) as a quantitative tool in plant metabolomics experiments are discussed, and important criteria for the development and validation of MS-based analytical methods provided. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644967

  20. Testing and Validation of Computational Methods for Mass Spectrometry.

    Science.gov (United States)

    Gatto, Laurent; Hansen, Kasper D; Hoopmann, Michael R; Hermjakob, Henning; Kohlbacher, Oliver; Beyer, Andreas

    2016-03-04

    High-throughput methods based on mass spectrometry (proteomics, metabolomics, lipidomics, etc.) produce a wealth of data that cannot be analyzed without computational methods. The impact of the choice of method on the overall result of a biological study is often underappreciated, but different methods can result in very different biological findings. It is thus essential to evaluate and compare the correctness and relative performance of computational methods. The volume of the data as well as the complexity of the algorithms render unbiased comparisons challenging. This paper discusses some problems and challenges in testing and validation of computational methods. We discuss the different types of data (simulated and experimental validation data) as well as different metrics to compare methods. We also introduce a new public repository for mass spectrometric reference data sets ( http://compms.org/RefData ) that contains a collection of publicly available data sets for performance evaluation for a wide range of different methods.