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Sample records for differential mass spectrometry

  1. 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.

  2. 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

  3. Differentiating Fragmentation Pathways of Cholesterol by Two-Dimensional Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    Science.gov (United States)

    van Agthoven, Maria A; Barrow, Mark P; Chiron, Lionel; Coutouly, Marie-Aude; Kilgour, David; Wootton, Christopher A; Wei, Juan; Soulby, Andrew; Delsuc, Marc-André; Rolando, Christian; O'Connor, Peter B

    2015-12-01

    Two-dimensional Fourier transform ion cyclotron resonance mass spectrometry is a data-independent analytical method that records the fragmentation patterns of all the compounds in a sample. This study shows the implementation of atmospheric pressure photoionization with two-dimensional (2D) Fourier transform ion cyclotron resonance mass spectrometry. In the resulting 2D mass spectrum, the fragmentation patterns of the radical and protonated species from cholesterol are differentiated. This study shows the use of fragment ion lines, precursor ion lines, and neutral loss lines in the 2D mass spectrum to determine fragmentation mechanisms of known compounds and to gain information on unknown ion species in the spectrum. In concert with high resolution mass spectrometry, 2D Fourier transform ion cyclotron resonance mass spectrometry can be a useful tool for the structural analysis of small molecules. Graphical Abstract ᅟ.

  4. Differentiation of 2- and 6-isomers of (2-dimethylaminopropylbenzofuran by tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    V. A. Shevyrin

    2016-07-01

    Full Text Available Reliable identification of new psychoactive substances of 2-(2-methylaminopropylbenzofuran and 6-(2-methylaminopropylbenzofuran is problematic when analyzing by gas chromatography–mass spectrometry method. It found that these two isomers can be reliably differentiated by MS/MS spectra obtained by collision-induced dissociation of their protonated molecules.

  5. 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...

  6. 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.

  7. Differentiation of endogenous and exogenous steroids by gas chromatography-combustion-mass spectrometry isotope ratio

    International Nuclear Information System (INIS)

    Montes de Oca Porto, Rodny; Rosado Perez, Aristides; Correa Vidal, Margarita Teresa

    2007-01-01

    Urinary steroids profiles are used to control the misuse of endogenous steroids such as testosterone and dihydrotestosterone. The testosterone/epistestosterone ratio, measured by Gas Chromatography-Mass Spectrometry, is used to control testosterone administration. When T/E ratio is higher than 4, consumption of testosterone or its precursors is suspected. Recent researches have demonstrated the effectiveness of Carbon Isotope Ratio Mass Spectrometry to detect and confirm endogenous steroids administration. The ratio of the two stable carbon isotopes 1 3 C and 1 2 C allows the differentiation of natural and synthetic steroids because synthetic steroids have lower 1 3 C abundance. In fact, the carbon isotope ratios can be used to determine endogenous steroids administration even when testosterone/epistestosterone ratio is at its normal value. In the current work, some of the most important aspects related to differentiation of endogenous and exogenous steroids by means of Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry are discussed. Also, this article provides a review about the purification and sample preparation previous to the analysis, and diet effects on carbon isotope ratio of endogenous anabolics steroids is presented too

  8. Silver complexation and tandem mass spectrometry for differentiation of isomeric flavonoid diglycosides.

    Science.gov (United States)

    Zhang, Junmei; Brodbelt, Jennifer S

    2005-03-15

    For detection and differentiation of isomeric flavonoids, electrospray ionization mass spectrometry is used to generate silver complexes of the type (Ag + flavonoid)+. Collisionally activated dissociation (CAD) of the resulting 1:1 silver/flavonoid complexes allows isomer differentiation of flavonoids. Eighteen flavonoid diglycosides constituting seven isomeric series are distinguishable from each other based on the CAD patterns of their silver complexes. Characteristic dissociation pathways allow identification of the site of glycosylation, the type of disaccharide (rutinose versus neohesperidose), and the type of aglycon (flavonol versus flavone versus flavanone). This silver complexation method is more universal than previous metal complexation methods, as intense silver complexes are observed even for flavonoids that lack the typical metal chelation sites. To demonstrate the feasibility of using silver complexation and tandem mass spectrometry to characterize flavonoids in complex mixtures, flavonoids extracted from grapefruit juice are separated by high-performance liquid chromatography and analyzed via a postcolumn complexation ESI-MS/MS strategy. Diagnostic fragmentation pathways of the silver complexes of the individual eluting flavonoids allow successful identification of the six flavonoids in the extract.

  9. Detection of Radiation-Exposure Biomarkers by Differential Mobility Prefiltered Mass Spectrometry (DMS-MS).

    Science.gov (United States)

    Coy, Stephen L; Krylov, Evgeny V; Schneider, Bradley B; Covey, Thomas R; Brenner, David J; Tyburski, John B; Patterson, Andrew D; Krausz, Kris W; Fornace, Albert J; Nazarov, Erkinjon G

    2010-04-15

    Technology to enable rapid screening for radiation exposure has been identified as an important need, and, as a part of a NIH / NIAD effort in this direction, metabolomic biomarkers for radiation exposure have been identified in a recent series of papers. To reduce the time necessary to detect and measure these biomarkers, differential mobility spectrometry - mass spectrometry (DMS-MS) systems have been developed and tested. Differential mobility ion filters preselect specific ions and also suppress chemical noise created in typical atmospheric-pressure ionization sources (ESI, MALDI, and others). Differential-mobility-based ion selection is based on the field dependence of ion mobility, which, in turn, depends on ion characteristics that include conformation, charge distribution, molecular polarizability, and other properties, and on the transport gas composition which can be modified to enhance resolution. DMS-MS is able to resolve small-molecule biomarkers from nearly-isobaric interferences, and suppresses chemical noise generated in the ion source and in the mass spectrometer, improving selectivity and quantitative accuracy. Our planar DMS design is rapid, operating in a few milliseconds, and analyzes ions before fragmentation. Depending on MS inlet conditions, DMS-selected ions can be dissociated in the MS inlet expansion, before mass analysis, providing a capability similar to MS/MS with simpler instrumentation. This report presents selected DMS-MS experimental results, including resolution of complex test mixtures of isobaric compounds, separation of charge states, separation of isobaric biomarkers (citrate and isocitrate), and separation of nearly-isobaric biomarker anions in direct analysis of a bio-fluid sample from the radiation-treated group of a mouse-model study. These uses of DMS combined with moderate resolution MS instrumentation indicate the feasibility of field-deployable instrumentation for biomarker evaluation.

  10. Analysis and differentiation of mineral dust by single particle laser mass spectrometry

    International Nuclear Information System (INIS)

    Gallavardin, S. J.; Lohmann, U.; Cziczo, Daniel J.

    2008-01-01

    This study evaluates the potential of single particle laser desorption/ionization mass spectrometry for the analysis of atmospherically relevant mineral dusts. Samples of hematite, goethite, calcium carbonate, calcium sulfate, silica, quartz, montmorrillonite, kaolinite, illite, hectorite, wollastonite and nephelinsyenit were investigated in positive and negative ion mode with a monopolar time-of-flight mass spectrometer where the desorption/ionization step was performed with a 193 nm excimer laser (∼10 9 W/cm 2 ). Particle size ranged from 500 nm to 3 (micro)m. Positive mass spectra mainly provide elemental composition whereas negative ion spectra provide information on element speciation and of a structural nature. The iron oxide, calcium-rich and aluminosilicate nature of particles is established in positive ion mode. The differentiation of calcium materials strongly relies on the calcium counter-ions in negative mass spectra. Aluminosilicates can be differentiated in both positive and negative ion mode using the relative abundance of various aluminum and silicon ions

  11. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

    Science.gov (United States)

    van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

    2016-05-01

    We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. High-throughput differentiation of heparin from other glycosaminoglycans by pyrolysis mass spectrometry.

    Science.gov (United States)

    Nemes, Peter; Hoover, William J; Keire, David A

    2013-08-06

    Sensors with high chemical specificity and enhanced sample throughput are vital to screening food products and medical devices for chemical or biochemical contaminants that may pose a threat to public health. For example, the rapid detection of oversulfated chondroitin sulfate (OSCS) in heparin could prevent reoccurrence of heparin adulteration that caused hundreds of severe adverse events including deaths worldwide in 2007-2008. Here, rapid pyrolysis is integrated with direct analysis in real time (DART) mass spectrometry to rapidly screen major glycosaminoglycans, including heparin, chondroitin sulfate A, dermatan sulfate, and OSCS. The results demonstrate that, compared to traditional liquid chromatography-based analyses, pyrolysis mass spectrometry achieved at least 250-fold higher sample throughput and was compatible with samples volume-limited to about 300 nL. Pyrolysis yielded an abundance of fragment ions (e.g., 150 different m/z species), many of which were specific to the parent compound. Using multivariate and statistical data analysis models, these data enabled facile differentiation of the glycosaminoglycans with high throughput. After method development was completed, authentically contaminated samples obtained during the heparin crisis by the FDA were analyzed in a blinded manner for OSCS contamination. The lower limit of differentiation and detection were 0.1% (w/w) OSCS in heparin and 100 ng/μL (20 ng) OSCS in water, respectively. For quantitative purposes the linear dynamic range spanned approximately 3 orders of magnitude. Moreover, this chemical readout was successfully employed to find clues in the manufacturing history of the heparin samples that can be used for surveillance purposes. The presented technology and data analysis protocols are anticipated to be readily adaptable to other chemical and biochemical agents and volume-limited samples.

  13. Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods.

    Science.gov (United States)

    Wunschel, David S; Melville, Angela M; Ehrhardt, Christopher J; Colburn, Heather A; Victry, Kristin D; Antolick, Kathryn C; Wahl, Jon H; Wahl, Karen L

    2012-05-07

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of Ricinus communis, commonly known as the castor plant. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatography-mass spectrometry (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid, as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods, starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid, or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method, independent of the seed source. In particular, the abundance of mannose, arabinose, fucose, ricinoleic acid, and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation than would be possible using a single analytical method.

  14. A hybrid approach to protein differential expression in mass spectrometry-based proteomics

    KAUST Repository

    Wang, X.; Anderson, G. A.; Smith, R. D.; Dabney, A. R.

    2012-01-01

    MOTIVATION: Quantitative mass spectrometry-based proteomics involves statistical inference on protein abundance, based on the intensities of each protein's associated spectral peaks. However, typical MS-based proteomics datasets have substantial

  15. A hybrid approach to protein differential expression in mass spectrometry-based proteomics

    KAUST Repository

    Wang, X.

    2012-04-19

    MOTIVATION: Quantitative mass spectrometry-based proteomics involves statistical inference on protein abundance, based on the intensities of each protein\\'s associated spectral peaks. However, typical MS-based proteomics datasets have substantial proportions of missing observations, due at least in part to censoring of low intensities. This complicates intensity-based differential expression analysis. RESULTS: We outline a statistical method for protein differential expression, based on a simple Binomial likelihood. By modeling peak intensities as binary, in terms of \\'presence/absence,\\' we enable the selection of proteins not typically amenable to quantitative analysis; e.g. \\'one-state\\' proteins that are present in one condition but absent in another. In addition, we present an analysis protocol that combines quantitative and presence/absence analysis of a given dataset in a principled way, resulting in a single list of selected proteins with a single-associated false discovery rate. AVAILABILITY: All R code available here: http://www.stat.tamu.edu/~adabney/share/xuan_code.zip.

  16. Self-assembly of triangular metallomacrocycles using unsymmetrical bisterpyridine ligands: isomer differentiation via TWIM mass spectrometry.

    Science.gov (United States)

    Liang, Yen-Peng; He, Yun-Jui; Lee, Yin-Hsuan; Chan, Yi-Tsu

    2015-03-21

    Three unsymmetrical, 60°-bended bisterpyridine ligands with varying phenylene spacer lengths have been synthesized via the Suzuki-Miyaura coupling reactions. Their self-assembly processes were found to be strongly dependent on the ligand geometry. Upon complexation with Zn(II) ions, only 2,4''-di(4'-terpyridinyl)-1,1':4',1''-terphenyl underwent self-selection to give a trinuclear metallomacrocycle with perfect heteroleptic connectivity and the other two afforded a mixture of constitutional isomers. The metallosupramolecular assemblies were characterized by NMR spectroscopy, electrospray mass spectrometry (ESI MS), and single-crystal X-ray diffraction. In particular, the identification of isomeric architecture was accomplished using tandem mass spectrometry (MS(2)) coupled with traveling wave ion mobility mass spectrometry (TWIM MS).

  17. Capabilities of laser ablation mass spectrometry in the differentiation of natural and artificial opal gemstones.

    Science.gov (United States)

    Erel, Eric; Aubriet, Frédéric; Finqueneisel, Gisèle; Muller, Jean-François

    2003-12-01

    The potentialities of laser ablation coupled to ion cyclotron resonance Fourier transform mass spectrometry are evaluated to distinguish natural and artificial opals. The detection of specific species in both ion detection modes leads us to obtain relevant criteria of differentiation. In positive ions, species including hafnium and large amounts of zirconium atoms are found to be specific for artificial opal. In contrast, aluminum, titanium, iron, and rubidium are systematically detected in the study of natural opals. Moreover, some ions allow us to distinguish between natural opal from Australia and from Mexico. Australian gemstone includes specifically strontium, cesium, and barium. Moreover, it is also found that the yield of (H2O)0-1(SiO2)nX- (X- = O-, OH-, KO-, NaO-, SiO2-, AlO1-2-, FeO2-, ZrO2-, and ZrO3-) and (Al2O3)(SiO2)nAlO2- ions depends on the composition of the sample when opals are laser ablated. Ions, which include zirconium oxide species, are characteristics of artificial gem. In contrast, natural opals lead us, after laser ablation, to the production of ions including H2O, Al2O3 motifs and AlO-, KO-, NaO-, and FeO2- species.

  18. UV-induced bond modifications in thymine and thymine dideoxynucleotide: structural elucidation of isomers by differential mobility mass spectrometry.

    Science.gov (United States)

    St-Jacques, Antony; Anichina, Janna; Schneider, Bradley B; Covey, Thomas R; Bohme, Diethard K

    2010-07-15

    Differential mobility spectrometry has been applied to reveal the occurrence of isomerization of thymine nucleobase and of thymine dideoxynucleotide d(5'-TT-3') due to bond redisposition induced by UV irradiation at 254 nm of frozen aqueous solutions of these molecules. Collision-induced dissociation (CID) spectra of electrosprayed photoproducts of the thymine solution suggest the presence of two isomers (the so-called cyclobutane and 6,4-photoproducts) in addition to the proton-bound thymine dimer, and these were separated using differential mobility spectrometry/mass spectrometry (DMS/MS) techniques with water as the modifier. Similar experiments with d(5'-TT-3') revealed the formation of a new isomer of deprotonated thymine dideoxynucleotide upon UV irradiation that was easily distinguished using DMS/MS with isopropanol as the modifier. The results reinforce the usefulness of DMS/MS in isomer separation.

  19. [Screening differentially expressed plasma proteins in cold stress rats based on iTRAQ combined with mass spectrometry technology].

    Science.gov (United States)

    Liu, Yan-zhi; Guo, Jing-ru; Peng, Meng-ling; Ma, Li; Zhen, Li; Ji, Hong; Yang, Huan-min

    2015-09-01

    Isobaric tags for relative and absolute quantitation (iTRAQ) combined with mass spectrometry were used to screen differentially expressed plasma proteins in cold stress rats. Thirty health SPF Wistar rats were randomly divided into cold stress group A and control group B, then A and B were randomly divided into 3 groups (n = 5): A1, A2, A3 and B1, B2, B3. The temperature of room raising was (24.0 +/- 0.1) degrees C, and the cold stress temperature was (4.0 +/- 0.1) degrees C. The rats were treated with different temperatures until 12 h. The abdominal aortic blood was collected with heparin anticoagulation suction tube. Then, the plasma was separated for protein extraction, quantitative, enzymolysis, iTHAQ labeling, scx fractionation and mass spectrometry analysis. Totally, 1085 proteins were identified in the test, 39 differentially expressed proteins were screened, including 29 up-regulated proteins and 10 down-regulated proteins. Three important differentially expressed proteins related to cold stress were screened by bioinfonnatics analysis (Minor histocompatihility protein HA-1, Has-related protein Rap-1b, Integrin beta-1). In the experiment, the differentially expressed plasma proteins were successfully screened in cold stress rats. iTRAQ technology provided a good platform to screen protein diaguostic markers on cold stress rats, and laid a good foundation for further. study on animal cold stress mechanism.

  20. 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...

  1. 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

  2. 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)

  3. Separation and simultaneous quantitation of PGF2α and its epimer 8-iso-PGF2α using modifier-assisted differential mobility spectrometry tandem mass spectrometry

    Directory of Open Access Journals (Sweden)

    Chunsu Liang

    2018-03-01

    Full Text Available Because many therapeutic agents are contaminated by epimeric impurities or form epimers as a result of metabolism, analytical tools capable of determining epimers are increasingly in demand. This article is a proof-of-principle report of a novel DMS–MS/MS method to separate and simultaneously quantify epimers, taking PGF2α and its 8-epimer, 8-iso-PGF2α, as an example. Good accuracy and precision were achieved in the range of 10–500 ng/mL with a run time of only 1.5 min. Isopropanol as organic modifier facilitated a good combination of sensitivity and separation. The method is the first example of the quantitation of epimers without chromatographic separation. KEY WORDS: Differential mobility spectrometry, Mass spectrometry, Epimer, PGF2α, 8-iso-PGF2α

  4. Differential Mobility Spectrometry for Improved Selectivity in Hydrophilic Interaction Liquid Chromatography-Tandem Mass Spectrometry Analysis of Paralytic Shellfish Toxins

    Science.gov (United States)

    Beach, Daniel G.

    2017-08-01

    Paralytic shellfish toxins (PSTs) are neurotoxins produced by dinoflagellates and cyanobacteria that cause paralytic shellfish poisoning in humans. PST quantitation by LC-MS is challenging because of their high polarity, lability as gas-phase ions, and large number of potentially interfering analogues. Differential mobility spectrometry (DMS) has the potential to improve the performance of LC-MS methods for PSTs in terms of selectivity and limits of detection. This work describes a comprehensive investigation of the separation of 16 regulated PSTs by DMS and the development of highly selective LC-DMS-MS methods for PST quantitation. The effects of all DMS parameters on the separation of PSTs from one another were first investigated in detail. The labile nature of 11α-gonyautoxin epimers gave unique insight into fragmentation of labile analytes before, during, and after the DMS analyzer. Two sets of DMS parameters were identified that either optimized the resolution of PSTs from one another or transmitted them at a limited number of compensation voltage (CV) values corresponding to structural subclasses. These were used to develop multidimensional LC-DMS-MS/MS methods using existing HILIC-MS/MS parameters. In both cases, improved selectivity was observed when using DMS, and the quantitative capabilities of a rapid UPLC-DMS-MS/MS method were evaluated. Limits of detection of the developed method were similar to those without DMS, and differences were highly analyte-dependant. Analysis of shellfish matrix reference materials showed good agreement with established methods. The developed methods will be useful in cases where specific matrix interferences are encountered in the LC-MS/MS analysis of PSTs in complex biological samples.

  5. 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)

  6. Chemometric brand differentiation of commercial spices using direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Pavlovich, Matthew J; Dunn, Emily E; Hall, Adam B

    2016-05-15

    Commercial spices represent an emerging class of fuels for improvised explosives. Being able to classify such spices not only by type but also by brand would represent an important step in developing methods to analytically investigate these explosive compositions. Therefore, a combined ambient mass spectrometric/chemometric approach was developed to quickly and accurately classify commercial spices by brand. Direct analysis in real time mass spectrometry (DART-MS) was used to generate mass spectra for samples of black pepper, cayenne pepper, and turmeric, along with four different brands of cinnamon, all dissolved in methanol. Unsupervised learning techniques showed that the cinnamon samples clustered according to brand. Then, we used supervised machine learning algorithms to build chemometric models with a known training set and classified the brands of an unknown testing set of cinnamon samples. Ten independent runs of five-fold cross-validation showed that the training set error for the best-performing models (i.e., the linear discriminant and neural network models) was lower than 2%. The false-positive percentages for these models were 3% or lower, and the false-negative percentages were lower than 10%. In particular, the linear discriminant model perfectly classified the testing set with 0% error. Repeated iterations of training and testing gave similar results, demonstrating the reproducibility of these models. Chemometric models were able to classify the DART mass spectra of commercial cinnamon samples according to brand, with high specificity and low classification error. This method could easily be generalized to other classes of spices, and it could be applied to authenticating questioned commercial samples of spices or to examining evidence from improvised explosives. Copyright © 2016 John Wiley & Sons, Ltd.

  7. A differential mobility spectrometry/mass spectrometry platform for the rapid detection and quantitation of DNA adduct dG-ABP.

    Science.gov (United States)

    Kafle, Amol; Klaene, Joshua; Hall, Adam B; Glick, James; Coy, Stephen L; Vouros, Paul

    2013-07-15

    There is continued interest in exploring new analytical technologies for the detection and quantitation of DNA adducts, biomarkers which provide direct evidence of exposure and genetic damage in cells. With the goal of reducing clean-up steps and improving sample throughput, a Differential Mobility Spectrometry/Mass Spectrometry (DMS/MS) platform has been introduced for adduct analysis. A DMS/MS platform has been utilized for the analysis of dG-ABP, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl (4-ABP). After optimization of the DMS parameters, each sample was analyzed in just 30 s following a simple protein precipitation step of the digested DNA. A detection limit of one modification in 10^6 nucleosides has been achieved using only 2 µg of DNA. A brief comparison (quantitative and qualitative) with liquid chromatography/mass spectrometry is also presented highlighting the advantages of using the DMS/MS method as a high-throughput platform. The data presented demonstrate the successful application of a DMS/MS/MS platform for the rapid quantitation of DNA adducts using, as a model analyte, the deoxyguanosine adduct of the bladder carcinogen 4-aminobiphenyl. Copyright © 2013 John Wiley & Sons, Ltd.

  8. 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.

  9. Identification and differentiation of methcathinone analogs by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Tsujikawa, Kenji; Mikuma, Toshiyasu; Kuwayama, Kenji; Miyaguchi, Hajime; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

    2013-08-01

    To overcome a number of challenges involved in analyzing methcathinone (MC) analogues, we performed gas chromatography-mass spectrometry (GC-MS) analysis, including sample preparation, of nine MC analogues - 4-methylmethcathinone, three positional isomers of fluoromethcathinones, 4-methoxymethcathinone, N-ethylcathinone, N,N-dimethylcathinone, buphedrone, and pentedrone. The MC analogues underwent dehydrogenation when the free bases were analyzed using splitless injection. Most of this thermal degradation was prevented using split injection. This indicated that a shorter residence time in the hot injector prevented decomposition. Uniquely, 2-fluoromethcathinone degraded to another product in a process that could not be prevented by the split injection. Replacing the liner with a new, clean one was also effective in preventing thermal degradation. Most of the analytes showed a substantial loss (>30%) when the free base solution in ethyl acetate was evaporated under a nitrogen stream. Adding a small amount of dimethylformamide as a solvent keeper had a noticeable effect, but it did not completely prevent the loss. Three positional isomers of fluoromethcathinones were separated with baseline resolution by heptafluorobutyrylation with a slow column heating rate (8 °C/min) using a non-polar DB-5 ms capillary column. These results will be useful for the forensic analysis of MC analogues in confiscated materials. Copyright © 2012 John Wiley & Sons, Ltd.

  10. Differentiation of essential oils in Atractylodes lancea and Atractylodes koreana by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Liu, Qiutao; Zhang, Shanshan; Yang, Xihui; Wang, Ruilin; Guo, Weiying; Kong, Weijun; Yang, Meihua

    2016-12-01

    Atractylodes rhizome is a valuable traditional Chinese medicinal herb that comprises complex several species whose essential oils are the primary pharmacologically active component. Essential oils of Atractylodes lancea and Atractylodes koreana were extracted by hydrodistillation, and the yield was determined. The average yield of essential oil obtained from A. lancea (2.91%) was higher than that from A. koreana (2.42%). The volatile components of the essential oils were then identified by a gas chromatography with mass spectrometry method that demonstrated good precision. The method showed clear differences in the numbers and contents of volatile components between the two species. 41 and 45 volatile components were identified in A. lancea and A. koreana, respectively. Atractylon (48.68%) was the primary volatile component in A. lancea, while eudesma-4(14)-en-11-ol (11.81%) was major in A. koreana. However, the most significant difference between A. lancea and A. koreana was the major component of atractylon and atractydin. Principal component analysis was utilized to reveal the correlation between volatile components and species, and the analysis was used to successfully discriminate between A. lancea and A. koreana samples. These results suggest that different species of Atractylodes rhizome may yield essential oils that differ significantly in content and composition. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 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

  12. 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

  13. Optimization of a Differential Ion Mobility Spectrometry-Tandem Mass Spectrometry Method for High-Throughput Analysis of Nicotine and Related Compounds: Application to Electronic Cigarette Refill Liquids.

    Science.gov (United States)

    Regueiro, Jorge; Giri, Anupam; Wenzl, Thomas

    2016-06-21

    Fast market penetration of electronic cigarettes is leading to an exponentially growing number of electronic refill liquids with different nicotine contents and an endless list of flavors. Therefore, rapid and simple methods allowing a fast screening of these products are necessary to detect harmful substances which can negatively impact the health of consumers. In this regard, the present work explores the capabilities of differential ion mobility spectrometry coupled to tandem mass spectrometry for high-throughput analysis of nicotine and 11 related compounds in commercial refill liquids for electronic cigarettes. The influence of main factors affecting the ion mobility separation, such as modifier types and concentration, separation voltage, and temperature, was systematically investigated. Despite small molecular weight differences among the studied compounds, a good separation was achieved in the ion mobility cell under the optimized conditions, which involved the use of ethanol as a polar gas-phase chemical modifier. Indeed, differential ion mobility was able to resolve (resolution >4) nicotine from its structural isomer anabasine without the use of any chromatographic separation. The quantitative performance of the proposed method was then evaluated, showing satisfactory precision (RSD ≤ 16%) and recoveries ranging from 85 to 100% for nicotine, and from 84 to 126% for the rest of the target analytes. Several commercial electronic cigarette refill liquids were analyzed to demonstrate the applicability of the method. In some cases, significant differences were found between labeled and measured levels of nicotine. Anatabine, cotinine, myosmine, and nornicotine were also found in some of the analyzed samples.

  14. Selective quantitation of the neurotoxin BMAA by use of hydrophilic-interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS).

    Science.gov (United States)

    Beach, Daniel G; Kerrin, Elliott S; Quilliam, Michael A

    2015-11-01

    The neurotoxin β-N-methylamino-L-alanine (BMAA) has been reported in cyanobacteria and shellfish, raising concerns about widespread human exposure. However, inconsistent results for BMAA analysis have led to controversy. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most appropriate method for analysis of BMAA, but the risk of interference from isomers, other sample components, and the electrospray background is still present. We have investigated differential mobility spectrometry (DMS) as an ion filter to improve selectivity in the hydrophilic interaction liquid chromatographic (HILIC)-MS/MS determination of BMAA. We obtained standards for two BMAA isomers not previously analyzed by HILIC-MS, β-amino-N-methylalanine and 3,4-diaminobutanoic acid, and the typically used 2,4-diaminobutanoic acid and N-(2-aminoethyl)glycine. DMS separation of BMAA from these isomers was achieved and optimized conditions were used to develop a sensitive and highly selective multidimensional HILIC-DMS-MS/MS method. This work revealed current technical limitations of DMS for trace quantitation, and practical solutions were implemented. Accurate control of low levels of DMS carrier gas modifier was essential, but required external metering. The linearity of our optimized method was excellent from 0.01 to 6 μmol L(-1). The instrumental LOD was 0.4 pg BMAA injected on-column and the estimated method LOD was 20 ng g(-1) dry weight for BMAA in sample matrix. The method was used to analyze cycad plant tissue, a cyanobacterial reference material, and mussel tissues, by use of isotope-dilution quantitation with deuterated BMAA. This confirmed the presence of BMAA and several of its isomers in cycad and mussel tissues, including commercially available mussel tissue reference materials certified for other biotoxins. Graphical Abstract Differential Mobility Spectrometry is used to increases the selectivity of BMAA analysis by HILIC-MS/MS.

  15. Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry

    Science.gov (United States)

    Chen, Zhidan; Coy, Stephen L.; Pannkuk, Evan L.; Laiakis, Evagelia C.; Hall, Adam B.; Fornace, Albert J.; Vouros, Paul

    2016-10-01

    Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre- and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure.

  16. 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

  17. 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)

  18. 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)

  19. Building biomarker libraries with novel chemical sensors: correlating differential mobility spectrometer signal outputs with mass spectrometry data

    International Nuclear Information System (INIS)

    Schivo, Michael; Kenyon, Nicholas J; Aksenov, Alexander A; Bardaweel, Hamzeh; Zhao Weixiang; Davis, Cristina E

    2011-01-01

    Gas chromatography/mass spectrometry (GC/MS) is a widely used analytic tool for qualitative and quantitative analysis of volatile and semi-volatile compounds. However, GC/MS use is limited by its large size, lack of portability, high cost and inherent complexity. Smaller instruments capable of high-throughput analysis of volatile compounds have the potential of combining MS-like sensitivity with portability. The micromachined differential mobility spectrometer (DMS) is a miniature sensor capable of registering volatile compounds in sub-parts-per-million (ppm) concentrations. It is small, portable, and can be coupled with multiple other compound separation methods. Here we describe paired volatile sample analyses using both GC/MS and GC/DMS which show that the DMS is capable of registering known compounds as verified by MS. Furthermore, we show that MS can be used to help build a library for our unique DMS sensor outputs and detect compounds in chemically complex backgrounds.

  20. Building biomarker libraries with novel chemical sensors: correlating differential mobility spectrometer signal outputs with mass spectrometry data

    Energy Technology Data Exchange (ETDEWEB)

    Schivo, Michael; Kenyon, Nicholas J [Division of Pulmonary and Critical Care Medicine, Genome and Biomedical Sciences Facility, University of California, Davis, CA 95616 (United States); Aksenov, Alexander A; Bardaweel, Hamzeh; Zhao Weixiang; Davis, Cristina E, E-mail: cedavis@ucdavis.edu [Department of Mechanical and Aerospace Engineering, One Shields Avenue, University of California, Davis, CA 95616 (United States)

    2011-10-29

    Gas chromatography/mass spectrometry (GC/MS) is a widely used analytic tool for qualitative and quantitative analysis of volatile and semi-volatile compounds. However, GC/MS use is limited by its large size, lack of portability, high cost and inherent complexity. Smaller instruments capable of high-throughput analysis of volatile compounds have the potential of combining MS-like sensitivity with portability. The micromachined differential mobility spectrometer (DMS) is a miniature sensor capable of registering volatile compounds in sub-parts-per-million (ppm) concentrations. It is small, portable, and can be coupled with multiple other compound separation methods. Here we describe paired volatile sample analyses using both GC/MS and GC/DMS which show that the DMS is capable of registering known compounds as verified by MS. Furthermore, we show that MS can be used to help build a library for our unique DMS sensor outputs and detect compounds in chemically complex backgrounds.

  1. A SELDI mass spectrometry study of experimental autoimmune encephalomyelitis: sample preparation, reproducibility, and differential protein expression patterns.

    Science.gov (United States)

    Azzam, Sausan; Broadwater, Laurie; Li, Shuo; Freeman, Ernest J; McDonough, Jennifer; Gregory, Roger B

    2013-05-01

    Experimental autoimmune encephalomyelitis (EAE) is an autoimmune, inflammatory disease of the central nervous system that is widely used as a model of multiple sclerosis (MS). Mitochondrial dysfunction appears to play a role in the development of neuropathology in MS and may also play a role in disease pathology in EAE. Here, surface enhanced laser desorption ionization mass spectrometry (SELDI-MS) has been employed to obtain protein expression profiles from mitochondrially enriched fractions derived from EAE and control mouse brain. To gain insight into experimental variation, the reproducibility of sub-cellular fractionation, anion exchange fractionation as well as spot-to-spot and chip-to-chip variation using pooled samples from brain tissue was examined. Variability of SELDI mass spectral peak intensities indicates a coefficient of variation (CV) of 15.6% and 17.6% between spots on a given chip and between different chips, respectively. Thinly slicing tissue prior to homogenization with a rotor homogenizer showed better reproducibility (CV = 17.0%) than homogenization of blocks of brain tissue with a Teflon® pestle (CV = 27.0%). Fractionation of proteins with anion exchange beads prior to SELDI-MS analysis gave overall CV values from 16.1% to 18.6%. SELDI mass spectra of mitochondrial fractions obtained from brain tissue from EAE mice and controls displayed 39 differentially expressed proteins (p≤ 0.05) out of a total of 241 protein peaks observed in anion exchange fractions. Hierarchical clustering analysis showed that protein fractions from EAE animals with severe disability clearly segregated from controls. Several components of electron transport chain complexes (cytochrome c oxidase subunit 6b1, subunit 6C, and subunit 4; NADH dehydrogenase flavoprotein 3, alpha subcomplex subunit 2, Fe-S protein 4, and Fe-S protein 6; and ATP synthase subunit e) were identified as possible differentially expressed proteins. Myelin Basic Protein isoform 8 (MBP8) (14.2 k

  2. Fast quantitation of opioid isomers in human plasma by differential mobility spectrometry/mass spectrometry via SPME/open-port probe sampling interface.

    Science.gov (United States)

    Liu, Chang; Gómez-Ríos, Germán Augusto; Schneider, Bradley B; Le Blanc, J C Yves; Reyes-Garcés, Nathaly; Arnold, Don W; Covey, Thomas R; Pawliszyn, Janusz

    2017-10-23

    Mass spectrometry (MS) based quantitative approaches typically require a thorough sample clean-up and a decent chromatographic step in order to achieve needed figures of merit. However, in most cases, such processes are not optimal for urgent assessments and high-throughput determinations. The direct coupling of solid phase microextraction (SPME) to MS has shown great potential to shorten the total sample analysis time of complex matrices, as well as to diminish potential matrix effects and instrument contamination. In this study, we demonstrate the use of the open-port probe (OPP) as a direct and robust sampling interface to couple biocompatible-SPME (Bio-SPME) fibres to MS for the rapid quantitation of opioid isomers (i.e. codeine and hydrocodone) in human plasma. In place of chromatography, a differential mobility spectrometry (DMS) device was implemented to provide the essential selectivity required to quantify these constitutional isomers. Taking advantage of the simplified sample preparation process based on Bio-SPME and the fast separation with DMS-MS coupling via OPP, a high-throughput assay (10-15 s per sample) with limits of detection in the sub-ng/mL range was developed. Succinctly, we demonstrated that by tuning adequate ion mobility separation conditions, SPME-OPP-MS can be employed to quantify non-resolved compounds or those otherwise hindered by co-extracted isobaric interferences without further need of coupling to other separation platforms. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 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

  4. 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

  5. Detection of cervical cancer biomarker patterns in blood plasma and urine by differential scanning calorimetry and mass spectrometry.

    Science.gov (United States)

    Garbett, Nichola C; Merchant, Michael L; Helm, C William; Jenson, Alfred B; Klein, Jon B; Chaires, Jonathan B

    2014-01-01

    Improved methods for the accurate identification of both the presence and severity of cervical intraepithelial neoplasia (CIN) and extent of spread of invasive carcinomas of the cervix (IC) are needed. Differential scanning calorimetry (DSC) has recently been shown to detect specific changes in the thermal behavior of blood plasma proteins in several diseases. This methodology is being explored to provide a complementary approach for screening of cervical disease. The present study evaluated the utility of DSC in differentiating between healthy controls, increasing severity of CIN and early and advanced IC. Significant discrimination was apparent relative to the extent of disease with no clear effect of demographic factors such as age, ethnicity, smoking status and parity. Of most clinical relevance, there was strong differentiation of CIN from healthy controls and IC, and amongst patients with IC between FIGO Stage I and advanced cancer. The observed disease-specific changes in DSC profiles (thermograms) were hypothesized to reflect differential expression of disease biomarkers that subsequently bound to and affected the thermal behavior of the most abundant plasma proteins. The effect of interacting biomarkers can be inferred from the modulation of thermograms but cannot be directly identified by DSC. To investigate the nature of the proposed interactions, mass spectrometry (MS) analyses were employed. Quantitative assessment of the low molecular weight protein fragments of plasma and urine samples revealed a small list of peptides whose abundance was correlated with the extent of cervical disease, with the most striking plasma peptidome data supporting the interactome theory of peptide portioning to abundant plasma proteins. The combined DSC and MS approach in this study was successful in identifying unique biomarker signatures for cervical cancer and demonstrated the utility of DSC plasma profiles as a complementary diagnostic tool to evaluate cervical cancer

  6. Detection of cervical cancer biomarker patterns in blood plasma and urine by differential scanning calorimetry and mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Nichola C Garbett

    Full Text Available Improved methods for the accurate identification of both the presence and severity of cervical intraepithelial neoplasia (CIN and extent of spread of invasive carcinomas of the cervix (IC are needed. Differential scanning calorimetry (DSC has recently been shown to detect specific changes in the thermal behavior of blood plasma proteins in several diseases. This methodology is being explored to provide a complementary approach for screening of cervical disease. The present study evaluated the utility of DSC in differentiating between healthy controls, increasing severity of CIN and early and advanced IC. Significant discrimination was apparent relative to the extent of disease with no clear effect of demographic factors such as age, ethnicity, smoking status and parity. Of most clinical relevance, there was strong differentiation of CIN from healthy controls and IC, and amongst patients with IC between FIGO Stage I and advanced cancer. The observed disease-specific changes in DSC profiles (thermograms were hypothesized to reflect differential expression of disease biomarkers that subsequently bound to and affected the thermal behavior of the most abundant plasma proteins. The effect of interacting biomarkers can be inferred from the modulation of thermograms but cannot be directly identified by DSC. To investigate the nature of the proposed interactions, mass spectrometry (MS analyses were employed. Quantitative assessment of the low molecular weight protein fragments of plasma and urine samples revealed a small list of peptides whose abundance was correlated with the extent of cervical disease, with the most striking plasma peptidome data supporting the interactome theory of peptide portioning to abundant plasma proteins. The combined DSC and MS approach in this study was successful in identifying unique biomarker signatures for cervical cancer and demonstrated the utility of DSC plasma profiles as a complementary diagnostic tool to evaluate

  7. Identification of differential metabolites in liquid diet fermented with Bacillus subtilis using gas chromatography time of flight mass spectrometry

    Directory of Open Access Journals (Sweden)

    Yuyong He

    2016-12-01

    Full Text Available Growth and health responses of pigs fed fermented liquid diet are not always consistent and causes for this issue are still not very clear. Metabolites produced at different fermentation time points should be one of the most important contributors. However, currently no literatures about differential metabolites of fermented liquid diet are reported. The aim of this experiment was to explore the difference of metabolites in a fermented liquid diet between different fermentation time intervals. A total of eighteen samples that collected from Bacillus subtilis fermented liquid diet on days 7, 21 and 35 respectively were used for the identification of metabolites by gas chromatography time of flight mass spectrometry (GC-TOF-MS. Fifteen differential metabolites including melibiose, sortitol, ribose, cellobiose, maltotriose, sorbose, isomaltose, maltose, fructose, d-glycerol-1-phosphate, 4-aminobutyric acid, beta-alanine, tyrosine, pyruvic acid and pantothenic acid were identified between 7-d samples and 21-d samples. The relative level of melibiose, ribose, maltotriose, d-glycerol-1-phosphate, tyrosine and pyruvic acid in samples collected on day 21 was significantly higher than that in samples collected on day 7 (P < 0.01, respectively. Eight differential metabolites including ribose, sorbose, galactinol, cellobiose, pyruvic acid, galactonic acid, pantothenic acid and guanosine were found between 21-d samples and 35-d samples. Samples collected on day 35 had a higher relative level of ribose than that in samples collected on day 21 (P < 0.01. In conclusion, many differential metabolites which have important effects on the growth and health of pigs are identified and findings contribute to explain the difference in feeding response of fermented liquid diet.

  8. Evaluation of MALDI-TOF mass spectrometry for differentiation of Pichia kluyveri strains isolated from traditional fermentation processes.

    Science.gov (United States)

    De la Torre González, Francisco Javier; Gutiérrez Avendaño, Daniel Oswaldo; Gschaedler Mathis, Anne Christine; Kirchmayr, Manuel Reinhart

    2018-06-06

    Non- Saccharomyces yeasts are widespread microorganisms and some time ago were considered contaminants in the beverage industry. However, nowadays they have gained importance for their ability to produce aromatic compounds, which in alcoholic beverages improves aromatic complexity and therefore the overall quality. Thus, identification and differentiation of the species involved in fermentation processes is vital and can be classified in traditional methods and techniques based on molecular biology. Traditional methods, however, can be expensive, laborious and/or unable to accurately discriminate on strain level. In the present study, a total of 19 strains of Pichia kluyveri isolated from mezcal, tejuino and cacao fermentations were analyzed with rep-PCR fingerprinting and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The comparative analysis between MS spectra and rep-PCR patterns obtained from these strains showed a high similarity between both methods. However, minimal differences between the obtained rep-PCR and MALDI-TOF MS clusters could be observed. The data shown suggests that MALDI-TOF MS is a promising alternative technique for rapid, reliable and cost-effective differentiation of natives yeast strains isolated from different traditional fermented foods and beverages. This article is protected by copyright. All rights reserved.

  9. Use of isotope ratio mass spectrometry to differentiate between endogenous steroids and synthetic homologues in cattle: a review.

    Science.gov (United States)

    Janssens, Geert; Courtheyn, Dirk; Mangelinckx, Sven; Prévost, Stéphanie; Bichon, Emmanuelle; Monteau, Fabrice; De Poorter, Geert; De Kimpe, Norbert; Le Bizec, Bruno

    2013-04-15

    Although substantial technical advances have been achieved during the past decades to extend and facilitate the analysis of growth promoters in cattle, the detection of abuse of synthetic analogs of naturally occurring hormones has remained a challenging issue. When it became clear that the exogenous origin of steroid hormones could be traced based on the (13)C/(12)C isotope ratio of the substances, GC/C/IRMS has been successfully implemented to this aim since the end of the past century. However, due to the costly character of the instrumental setup, the susceptibility of the equipment to errors and the complex and time consuming sample preparation, this method is up until now only applied by a limited number of laboratories. In this review, the general principles as well as the practical application of GC/C/IRMS to differentiate between endogenous steroids and exogenously synthesized homologous compounds in cattle will be discussed in detail, and will be placed next to other existing and to be developed methods based on isotope ratio mass spectrometry. Finally, the link will be made with the field of sports doping, where GC/C/IRMS has been established within the World Anti-Doping Agency (WADA) approved methods as the official technique to differentiate between exogenous and endogenous steroids over the past few years. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. A Comparison of Tissue Spray and Lipid Extract Direct Injection Electrospray Ionization Mass Spectrometry for the Differentiation of Eutopic and Ectopic Endometrial Tissues

    Science.gov (United States)

    Chagovets, Vitaliy; Wang, Zhihao; Kononikhin, Alexey; Starodubtseva, Natalia; Borisova, Anna; Salimova, Dinara; Popov, Igor; Kozachenko, Andrey; Chingin, Konstantin; Chen, Huanwen; Frankevich, Vladimir; Adamyan, Leila; Sukhikh, Gennady

    2018-02-01

    Recent research revealed that tissue spray mass spectrometry enables rapid molecular profiling of biological tissues, which is of great importance for the search of disease biomarkers as well as for online surgery control. However, the payback for the high speed of analysis in tissue spray analysis is the generally lower chemical sensitivity compared with the traditional approach based on the offline chemical extraction and electrospray ionization mass spectrometry detection. In this study, high resolution mass spectrometry analysis of endometrium tissues of different localizations obtained using direct tissue spray mass spectrometry in positive ion mode is compared with the results of electrospray ionization analysis of lipid extracts. Identified features in both cases belong to three lipid classes: phosphatidylcholines, phosphoethanolamines, and sphingomyelins. Lipids coverage is validated by hydrophilic interaction liquid chromatography with mass spectrometry of lipid extracts. Multivariate analysis of data from both methods reveals satisfactory differentiation of eutopic and ectopic endometrium tissues. Overall, our results indicate that the chemical information provided by tissue spray ionization is sufficient to allow differentiation of endometrial tissues by localization with similar reliability but higher speed than in the traditional approach relying on offline extraction.

  11. 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.)

  12. Differential Mobility Spectrometry-Mass Spectrometry (DMS-MS) in Radiation Biodosimetry: Rapid and High-Throughput Quantitation of Multiple Radiation Biomarkers in Nonhuman Primate Urine

    Science.gov (United States)

    Chen, Zhidan; Coy, Stephen L.; Pannkuk, Evan L.; Laiakis, Evagelia C.; Fornace, Albert J.; Vouros, Paul

    2018-05-01

    High-throughput methods to assess radiation exposure are a priority due to concerns that include nuclear power accidents, the spread of nuclear weapon capability, and the risk of terrorist attacks. Metabolomics, the assessment of small molecules in an easily accessible sample, is the most recent method to be applied for the identification of biomarkers of the biological radiation response with a useful dose-response profile. Profiling for biomarker identification is frequently done using an LC-MS platform which has limited throughput due to the time-consuming nature of chromatography. We present here a chromatography-free simplified method for quantitative analysis of seven metabolites in urine with radiation dose-response using urine samples provided from the Pannkuk et al. (2015) study of long-term (7-day) radiation response in nonhuman primates (NHP). The stable isotope dilution (SID) analytical method consists of sample preparation by strong cation exchange-solid phase extraction (SCX-SPE) to remove interferences and concentrate the metabolites of interest, followed by differential mobility spectrometry (DMS) ion filtration to select the ion of interest and reduce chemical background, followed by mass spectrometry (overall SID-SPE-DMS-MS). Since no chromatography is used, calibration curves were prepared rapidly, in under 2 h (including SPE) for six simultaneously analyzed radiation biomarkers. The seventh, creatinine, was measured separately after 2500× dilution. Creatinine plays a dual role, measuring kidney glomerular filtration rate (GFR), and indicating kidney damage at high doses. The current quantitative method using SID-SPE-DMS-MS provides throughput which is 7.5 to 30 times higher than that of LC-MS and provides a path to pre-clinical radiation dose estimation. [Figure not available: see fulltext.

  13. Differential Mobility Spectrometry-Mass Spectrometry (DMS-MS) in Radiation Biodosimetry: Rapid and High-Throughput Quantitation of Multiple Radiation Biomarkers in Nonhuman Primate Urine.

    Science.gov (United States)

    Chen, Zhidan; Coy, Stephen L; Pannkuk, Evan L; Laiakis, Evagelia C; Fornace, Albert J; Vouros, Paul

    2018-05-07

    High-throughput methods to assess radiation exposure are a priority due to concerns that include nuclear power accidents, the spread of nuclear weapon capability, and the risk of terrorist attacks. Metabolomics, the assessment of small molecules in an easily accessible sample, is the most recent method to be applied for the identification of biomarkers of the biological radiation response with a useful dose-response profile. Profiling for biomarker identification is frequently done using an LC-MS platform which has limited throughput due to the time-consuming nature of chromatography. We present here a chromatography-free simplified method for quantitative analysis of seven metabolites in urine with radiation dose-response using urine samples provided from the Pannkuk et al. (2015) study of long-term (7-day) radiation response in nonhuman primates (NHP). The stable isotope dilution (SID) analytical method consists of sample preparation by strong cation exchange-solid phase extraction (SCX-SPE) to remove interferences and concentrate the metabolites of interest, followed by differential mobility spectrometry (DMS) ion filtration to select the ion of interest and reduce chemical background, followed by mass spectrometry (overall SID-SPE-DMS-MS). Since no chromatography is used, calibration curves were prepared rapidly, in under 2 h (including SPE) for six simultaneously analyzed radiation biomarkers. The seventh, creatinine, was measured separately after 2500× dilution. Creatinine plays a dual role, measuring kidney glomerular filtration rate (GFR), and indicating kidney damage at high doses. The current quantitative method using SID-SPE-DMS-MS provides throughput which is 7.5 to 30 times higher than that of LC-MS and provides a path to pre-clinical radiation dose estimation. Graphical Abstract.

  14. Mass spectrometry-based methods for detection and differentiation of botulinum neurotoxins

    Science.gov (United States)

    Schmidt, Jurgen G [Los Alamos, NM; Boyer, Anne E [Atlanta, GA; Kalb, Suzanne R [Atlanta, GA; Moura, Hercules [Tucker, GA; Barr, John R [Suwannee, GA; Woolfitt, Adrian R [Atlanta, GA

    2009-11-03

    The present invention is directed to a method for detecting the presence of clostridial neurotoxins in a sample by mixing a sample with a peptide that can serve as a substrate for proteolytic activity of a clostridial neurotoxin; and measuring for proteolytic activity of a clostridial neurotoxin by a mass spectroscopy technique. In one embodiment, the peptide can have an affinity tag attached at two or more sites.

  15. Characterization of lipidic markers of chondrogenic differentiation using mass spectrometry imaging.

    Science.gov (United States)

    Rocha, Beatriz; Cillero-Pastor, Berta; Eijkel, Gert; Bruinen, Anne L; Ruiz-Romero, Cristina; Heeren, Ron M A; Blanco, Francisco J

    2015-02-01

    Mesenchymal stem cells (MSC) are an interesting alternative for cell-based therapy of cartilage defects attributable to their capacity to differentiate toward chondrocytes in the process termed chondrogenesis. The metabolism of lipids has recently been associated with the modulation of chondrogenesis and also with the development of pathologies related to cartilage degeneration. Information about the distribution and modulation of lipids during chondrogenesis could provide a panel of putative chondrogenic markers. Thus, the discovery of new lipid chondrogenic markers could be highly valuable for improving MSC-based cartilage therapies. In this work, MS imaging was used to characterize the spatial distribution of lipids in human bone marrow MSCs during the first steps of chondrogenic differentiation. The analysis of MSC micromasses at days 2 and 14 of chondrogenesis by MALDI-MSI led to the identification of 20 different lipid species, including fatty acids, sphingolipids, and phospholipids. Phosphocholine, several sphingomyelins, and phosphatidylcholines were found to increase during the undifferentiated chondrogenic stage. A particularly detected lipid profile was verified by TOF secondary ion MS. Using this technology, a higher intensity of phosphocholine-related ions was observed in the peripheral region of the micromasses collected at day 14. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Characterization of Two Different Clay Materials by Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Dilatometry (DIL) and Mass Spectrometry (MS) - 12215

    Energy Technology Data Exchange (ETDEWEB)

    Post, Ekkehard [NETZSCH Geraetebau GmbH, Wittelsbacherstrasse 42, 95100 Selb (Germany); Henderson, Jack B. [NETZSCH Instruments North America, LLC, 129 Middlesex Turnpike, Burlington, MA 01803 (United States)

    2012-07-01

    An illitic clay containing higher amounts of organic materials was investigated by dilatometry, thermogravimetry and differential scanning calorimetric. The evolved gases were studied during simultaneous TG-DSC (STA) and dilatometer measurements with simultaneous mass spectrometry in inert gas and oxidizing atmosphere. The dilatometer results were compared with the STA-MS results which confirmed and explained the reactions found during heating of the clay, like dehydration, dehydroxylation, shrinkage, sintering, quartz phase transition, combustion or pyrolysis of organics and the solid state reactions forming meta-kaolinite and mullite. The high amount of organic material effects in inert gas atmosphere most probably a reduction of the oxides which leads to a higher mass loss than in oxidizing atmosphere. Due to this reduction an additional CO{sub 2} emission at around 1000 deg. C was detected which did not occur in oxidizing atmosphere. Furthermore TG-MS results of a clay containing alkali nitrates show that during heating, in addition to water and CO{sub 2}, NO and NO{sub 2} are also evolved, leading to additional mass loss steps. These types of clays showed water loss starting around 100 deg. C or even earlier. This relative small mass loss affects only less shrinkage during the expansion of the sample. The dehydroxylation and the high crystalline quartz content result in considerable shrinkage and expansion of the clay. During the usual solid state reaction where the clay structure collapses, the remaining material finally shrinks down to a so-called clinker. With the help of MS the TG steps can be better interpreted as the evolved gases are identified. With the help of the MS it is possible to distinguish between CO{sub 2} and water (carbonate decomposition, oxidation of organics or dehydration/dehydroxylation). The MS also clearly shows that mass number 44 is found during the TG step of the illitic clay at about 900 deg. C in inert gas, which was interpreted

  17. Use of isotope ratio mass spectrometry to differentiate between endogenous steroids and synthetic homologues in cattle: A review

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, Geert, E-mail: Geert.janssens@favv.be [Federal Agency for the Safety of the Food Chain, Directorate General Laboratories, Kruidtuinlaan 55, 1000 Brussels (Belgium); Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Courtheyn, Dirk [Federal Agency for the Safety of the Food Chain, Directorate General Laboratories, Kruidtuinlaan 55, 1000 Brussels (Belgium); Mangelinckx, Sven [Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Prévost, Stéphanie; Bichon, Emmanuelle; Monteau, Fabrice [LUNAM Université, Oniris, Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), F-44307 Nantes (France); De Poorter, Geert [Federal Agency for the Safety of the Food Chain, Directorate General Laboratories, Kruidtuinlaan 55, 1000 Brussels (Belgium); De Kimpe, Norbert [Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Le Bizec, Bruno [LUNAM Université, Oniris, Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), F-44307 Nantes (France)

    2013-04-15

    Graphical abstract: Scheme: Representation of the observed isotope ratios and the relation to exogenous and endogenous natural steroids. AS stands for “amount of steroid”. Highlights: ► The difference between endogenous and exogenous steroids is thoroughly laid out. ► Factors influencing the carbon ratio and the use of Δ{sup 13}C-values are explained. ► Implementation of GC/C/IRMS to detect steroid abuse in cattle is reviewed. ► Alternative methods and upcoming techniques are discussed. ► The differences and similarities with sports doping control are highlighted. -- Abstract: Although substantial technical advances have been achieved during the past decades to extend and facilitate the analysis of growth promoters in cattle, the detection of abuse of synthetic analogs of naturally occurring hormones has remained a challenging issue. When it became clear that the exogenous origin of steroid hormones could be traced based on the {sup 13}C/{sup 12}C isotope ratio of the substances, GC/C/IRMS has been successfully implemented to this aim since the end of the past century. However, due to the costly character of the instrumental setup, the susceptibility of the equipment to errors and the complex and time consuming sample preparation, this method is up until now only applied by a limited number of laboratories. In this review, the general principles as well as the practical application of GC/C/IRMS to differentiate between endogenous steroids and exogenously synthesized homologous compounds in cattle will be discussed in detail, and will be placed next to other existing and to be developed methods based on isotope ratio mass spectrometry. Finally, the link will be made with the field of sports doping, where GC/C/IRMS has been established within the World Anti-Doping Agency (WADA) approved methods as the official technique to differentiate between exogenous and endogenous steroids over the past few years.

  18. Use of isotope ratio mass spectrometry to differentiate between endogenous steroids and synthetic homologues in cattle: A review

    International Nuclear Information System (INIS)

    Janssens, Geert; Courtheyn, Dirk; Mangelinckx, Sven; Prévost, Stéphanie; Bichon, Emmanuelle; Monteau, Fabrice; De Poorter, Geert; De Kimpe, Norbert; Le Bizec, Bruno

    2013-01-01

    Graphical abstract: Scheme: Representation of the observed isotope ratios and the relation to exogenous and endogenous natural steroids. AS stands for “amount of steroid”. Highlights: ► The difference between endogenous and exogenous steroids is thoroughly laid out. ► Factors influencing the carbon ratio and the use of Δ 13 C-values are explained. ► Implementation of GC/C/IRMS to detect steroid abuse in cattle is reviewed. ► Alternative methods and upcoming techniques are discussed. ► The differences and similarities with sports doping control are highlighted. -- Abstract: Although substantial technical advances have been achieved during the past decades to extend and facilitate the analysis of growth promoters in cattle, the detection of abuse of synthetic analogs of naturally occurring hormones has remained a challenging issue. When it became clear that the exogenous origin of steroid hormones could be traced based on the 13 C/ 12 C isotope ratio of the substances, GC/C/IRMS has been successfully implemented to this aim since the end of the past century. However, due to the costly character of the instrumental setup, the susceptibility of the equipment to errors and the complex and time consuming sample preparation, this method is up until now only applied by a limited number of laboratories. In this review, the general principles as well as the practical application of GC/C/IRMS to differentiate between endogenous steroids and exogenously synthesized homologous compounds in cattle will be discussed in detail, and will be placed next to other existing and to be developed methods based on isotope ratio mass spectrometry. Finally, the link will be made with the field of sports doping, where GC/C/IRMS has been established within the World Anti-Doping Agency (WADA) approved methods as the official technique to differentiate between exogenous and endogenous steroids over the past few years

  19. Single Particle Laser Mass Spectrometry Applied to Differential Ice Nucleation Experiments at the AIDA Chamber

    International Nuclear Information System (INIS)

    Gallavardin, S. J.; Froyd, Karl D.; Lohmann, U.; Moehler, Ottmar; Murphy, Daniel M.; Cziczo, Dan

    2008-01-01

    Experiments conducted at the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber located in Karlsruhe, Germany permit investigation of particle properties that affect the nucleation of ice at temperature and water vapor conditions relevant to cloud microphysics and climate issues. Ice clouds were generated by heterogeneous nucleation of Arizona test dust (ATD), illite, and hematite and homogeneous nucleation of sulfuric acid. Ice crystals formed in the chamber were inertially separated from unactivated, or 'interstitial' aerosol particles with a pumped counterflow virtual impactor (PCVI), then evaporated. The ice residue (i.e., the aerosol which initiated ice nucleation plus any material which was scavenged from the gas- and/or particle-phase), was chemically characterized at the single particle level using a laser ionization mass spectrometer. In this manner the species that first nucleated ice could be identified out of a mixed aerosol population in the chamber. Bare mineral dust particles were more effective ice nuclei (IN) than similar particles with a coating. Metallic particles from contamination in the chamber initiated ice nucleation before other species but there were few enough that they did not compromise the experiments. Nitrate, sulfate, and organics were often detected on particles and ice residue, evidently from scavenging of trace gas-phase species in the chamber. Hematite was a more effective ice nucleus than illite. Ice residue was frequently larger than unactivated test aerosol due to the formation of aggregates due to scavenging, condensation of contaminant gases, and the predominance of larger aerosol in nucleation

  20. Differentiation of isomeric 2-aryldimethyltetrahydro-5-quinolinones by electron ionization and electrospray ionization mass spectrometry.

    Science.gov (United States)

    Kumar, Ch Dinesh; Chary, V Naresh; Dinesh, A; Reddy, P S; Srinivas, K; Gayatri, G; Sastry, G N; Prabhakar, S

    2011-10-15

    A series of isomeric 2-aryl-6,6-dimethyltetrahydro-5-quinolinones (set I) and 2-aryl-7,7-dimethyltetrahydro-5-quinolinones (set II) were studied under positive ion electron ionization (EI) and electrospray ionization (ESI) techniques. Under EI conditions, the molecular ions were found to be less stable in set I isomers, and they resulted in abundant fragment ions, i.e., [M-CH(3)](+), [M-CO](+.), [M-HCO](+), [M-(CH(3),CO)](+), and [M-(CH(3),CH(2)O)](+), when compared with set II isomers. In addition, the set I isomers showed specific fragment ions corresponding to [M-OH](+) and [M-OCH(3)](+). The retro-Diels-Alder (RDA) product ion was always higher in set II isomers. The ESI mass spectra produced [M + H](+) ions, and their decomposition showed favorable loss of CH(3) radical, CH(4) and C(2)H(6) molecules in set I isomers. The set II isomers, however, showed predominant RDA product ions, and specific loss of H(2)O. The selectivity in EI and ESI was attributed to the instability of set I isomers by the presence of a gem-dimethyl group at the α-position, and it was supported by the data from model compounds without a gem-dimethyl group. Density functional theory (DFT) calculations successfully corroborated the fragmentation pathways for diagnostic ions. This study revealed the effect of a gem-dimethyl group located at the α-position to the carbonyl having aromatic/unsaturated carbon on the other side of the carbonyl group. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Differential fragmentation patterns of pectin oligogalacturonides observed by nanoelectrospray quadrupole ion-trap mass spectrometry using automated spectra interpretation

    DEFF Research Database (Denmark)

    Mutenda, Kudzai E; Matthiesen, Rune; Roepstorff, Peter

    2007-01-01

    Oligogalacturonides of different degrees of polymerization (DP) and methyl esterification (DE) were structurally analyzed by nanoESI quadrupole ion-trap mass spectrometry. The fragmentation patterns of the oligogalacturonides were compared using the program 'Virtual Expert Mass Spectrometrist...... with free carboxylic acid groups underwent higher water loss compared to fully methyl-esterified oligogalacturonides under the same fragmentation conditions. Cross-ring cleavage, in which fragmentation occurs across the ring system of the galacturonate residue and signified by unique mass losses...... water loss than methyl-esterified ones will be postulated. In addition, the VEMS program was extended to automatically interpret and assign the fragment ions peaks generated in this study....

  2. Connecting imaging mass spectrometry and magnetic resonance imaging-based anatomical atlases for automated anatomical interpretation and differential analysis.

    Science.gov (United States)

    Verbeeck, Nico; Spraggins, Jeffrey M; Murphy, Monika J M; Wang, Hui-Dong; Deutch, Ariel Y; Caprioli, Richard M; Van de Plas, Raf

    2017-07-01

    Imaging mass spectrometry (IMS) is a molecular imaging technology that can measure thousands of biomolecules concurrently without prior tagging, making it particularly suitable for exploratory research. However, the data size and dimensionality often makes thorough extraction of relevant information impractical. To help guide and accelerate IMS data analysis, we recently developed a framework that integrates IMS measurements with anatomical atlases, opening up opportunities for anatomy-driven exploration of IMS data. One example is the automated anatomical interpretation of ion images, where empirically measured ion distributions are automatically decomposed into their underlying anatomical structures. While offering significant potential, IMS-atlas integration has thus far been restricted to the Allen Mouse Brain Atlas (AMBA) and mouse brain samples. Here, we expand the applicability of this framework by extending towards new animal species and a new set of anatomical atlases retrieved from the Scalable Brain Atlas (SBA). Furthermore, as many SBA atlases are based on magnetic resonance imaging (MRI) data, a new registration pipeline was developed that enables direct non-rigid IMS-to-MRI registration. These developments are demonstrated on protein-focused FTICR IMS measurements from coronal brain sections of a Parkinson's disease (PD) rat model. The measurements are integrated with an MRI-based rat brain atlas from the SBA. The new rat-focused IMS-atlas integration is used to perform automated anatomical interpretation and to find differential ions between healthy and diseased tissue. IMS-atlas integration can serve as an important accelerator in IMS data exploration, and with these new developments it can now be applied to a wider variety of animal species and modalities. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann. Copyright © 2017. Published by Elsevier B.V.

  3. 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

  4. 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.)

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. 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.

  11. Differential Auger spectrometry

    International Nuclear Information System (INIS)

    Strongin, M.; Varma, M.N.; Anne, J.

    1976-01-01

    A differential Auger spectroscopy method is given for increasing the sensitivity of micro-Auger spectroanalysis of the surfaces of dilute alloys, by alternately periodically switching an electron beam back and forth between an impurity free reference sample and a test sample containing a trace impurity. The Auger electrons from the samples produce representative Auger spectrum signals which cancel to produce an Auger test sample signal corresponding to the amount of the impurity in the test samples

  12. 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.

  13. 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...

  14. 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.

  15. Differentiation of isomeric N-glycan structures by normal-phase liquid chromatography-MALDI-TOF/TOF tandem mass spectrometry.

    Science.gov (United States)

    Maslen, Sarah; Sadowski, Pawel; Adam, Alex; Lilley, Kathryn; Stephens, Elaine

    2006-12-15

    The detailed characterization of protein N-glycosylation is very demanding given the many different glycoforms and structural isomers that can exist on glycoproteins. Here we report a fast and sensitive method for the extensive structure elucidation of reducing-end labeled N-glycan mixtures using a combination of capillary normal-phase HPLC coupled off-line to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and TOF/TOF-MS/MS. Using this method, isobaric N-glycans released from honey bee phospholipase A2 and Arabidopsis thaliana glycoproteins were separated by normal-phase chromatography and subsequently identified by key fragment ions in the MALDI-TOF/TOF tandem mass spectra. In addition, linkage and branching information were provided by abundant cross-ring and "elimination" fragment ions in the MALDI-CID spectra that gave extensive structural information. Furthermore, the fragmentation characteristics of N-glycans reductively aminated with 2-aminobenzoic acid and 2-aminobenzamide were compared. The identification of N-glycans containing 3-linked core fucose was facilitated by distinctive ions present only in the MALDI-CID spectra of 2-aminobenzoic acid-labeled oligosaccharides. To our knowledge, this is the first MS/MS-based technique that allows confident identification of N-glycans containing 3-linked core fucose, which is a major allergenic determinant on insect and plant glycoproteins.

  16. Identification of differentially expressed proteins between human esophageal immortalized and carcinomatous cell lines by two-dimensional electrophoresis and MALDI-TOF-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Xing-Dong Xiong; Li-Yan Xu; Zhong-Ying Shen; Wei-Jia Cai; Jian-Min Luo; Ya-Li Han; En-Min Li

    2002-01-01

    AIM: To identify the differentially expressed proteins between the human immortalized esophageal epithelial cell line (SHEE) and the malignant transformed esophageal carcinoma cell line (SHEEC), and to explore new ways for studying esophageal carcinoma associated genes. METHODS: SHEE and SHEEC cell lines were used to separate differentially expressed proteins by two-dimensional electrophoresis/The silver-stained 2-D gels was scanned with EDAS290 digital camera system and analyzed with the PDQuest 6.2 Software. Six spots in which the differentially expressed protein was more obvious were selected and analyzed with matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS).RESULTS: There were 107±4.58 and 115±9.91 protein spots observed in SHEE and SHEEC respectively, and the majority of these spots between the two cell lines matched each other (r=-0.772), only a few were expressed differentially. After analyzed by MALDI-TOF-MS and database search for the six differentially expressed proteins, One new protein as well as other five sequence-known proteins including RNPEP-like protein, human rRNA gene upstream sequence binding transcription factor, uracil DNA glycosylase,Annexin A2 and p300/CBP-associated factor were preliminarily identified.CONCLUSION: These differentially expressed proteins might play an importance role during malignant transformation of SHEEC from SHEE. The identification of these proteins may serve as a new way for studying esophageal carcinoma associated genes.

  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. 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

  1. 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...

  2. 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.)

  3. 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

  4. Differential isotope dansylation labeling combined with liquid chromatography mass spectrometry for quantification of intact and N-terminal truncated proteins

    International Nuclear Information System (INIS)

    Tang, Yanan; Li, Liang

    2013-01-01

    Graphical abstract: -- Highlights: •LC–MS was developed for quantifying protein mixtures containing both intact and N-terminal truncated proteins. • 12 C 2 -Dansylation of the N-terminal amino acid of proteins was done first, followed by microwave-assisted acid hydrolysis. •The released 12 C 2 -dansyl labeled N-terminal amino acid was quantified using 13 C 2 -dansyl labeled amino acid standards. •The method provided accurate and precise results for quantifying intact and N-terminal truncated proteins within 8 h. -- Abstract: The N-terminal amino acids of proteins are important structure units for maintaining the biological function, localization, and interaction networks of proteins. Under different biological conditions, one or several N-terminal amino acids could be cleaved from an intact protein due to processes, such as proteolysis, resulting in the change of protein properties. Thus, the ability to quantify the N-terminal truncated forms of proteins is of great importance, particularly in the area of development and production of protein-based drugs where the relative quantity of the intact protein and its truncated form needs to be monitored. In this work, we describe a rapid method for absolute quantification of protein mixtures containing intact and N-terminal truncated proteins. This method is based on dansylation labeling of the N-terminal amino acids of proteins, followed by microwave-assisted acid hydrolysis of the proteins into amino acids. It is shown that dansyl labeled amino acids are stable in acidic conditions and can be quantified by liquid chromatography mass spectrometry (LC–MS) with the use of isotope analog standards

  5. Differential isotope dansylation labeling combined with liquid chromatography mass spectrometry for quantification of intact and N-terminal truncated proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanan; Li, Liang, E-mail: Liang.Li@ualberta.ca

    2013-08-20

    Graphical abstract: -- Highlights: •LC–MS was developed for quantifying protein mixtures containing both intact and N-terminal truncated proteins. •{sup 12}C{sub 2}-Dansylation of the N-terminal amino acid of proteins was done first, followed by microwave-assisted acid hydrolysis. •The released {sup 12}C{sub 2}-dansyl labeled N-terminal amino acid was quantified using {sup 13}C{sub 2}-dansyl labeled amino acid standards. •The method provided accurate and precise results for quantifying intact and N-terminal truncated proteins within 8 h. -- Abstract: The N-terminal amino acids of proteins are important structure units for maintaining the biological function, localization, and interaction networks of proteins. Under different biological conditions, one or several N-terminal amino acids could be cleaved from an intact protein due to processes, such as proteolysis, resulting in the change of protein properties. Thus, the ability to quantify the N-terminal truncated forms of proteins is of great importance, particularly in the area of development and production of protein-based drugs where the relative quantity of the intact protein and its truncated form needs to be monitored. In this work, we describe a rapid method for absolute quantification of protein mixtures containing intact and N-terminal truncated proteins. This method is based on dansylation labeling of the N-terminal amino acids of proteins, followed by microwave-assisted acid hydrolysis of the proteins into amino acids. It is shown that dansyl labeled amino acids are stable in acidic conditions and can be quantified by liquid chromatography mass spectrometry (LC–MS) with the use of isotope analog standards.

  6. Differentiation of Herba Cistanches by fingerprint with high-performance liquid chromatography-diode array detection-mass spectrometry.

    Science.gov (United States)

    Jiang, Y; Li, S P; Wang, Y T; Chen, X J; Tu, P F

    2009-03-13

    Herba Cistanche (Rou Cong Rong in Chinese), dried succulent stems of Cistanche deserticola or C. tubulosa, is a famous Chinese herbal medicine and has been recorded in the Chinese Pharmacopoeia. In recent years, another two non-official species, C. salsa and C. sinensis have also been used as Herba Cistanche in some regions of China. To investigate the possibility of using these two non-official species as alternatives to the official species, a high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS) fingerprint method was developed to comparatively analyze the crude herbs of these four species. The fingerprint of C. deserticola, a historically certified species of Herba Cistanche, serves as 'standard pattern' for comparing the similarities with the other species by means of similarity and Principle Component Analysis. Additionally, 18 characteristic peaks in the fingerprints were identified by comparing their retention times, UV spectra and ESI-MS data with those of the reference substances and/or the data in the literatures. The comparative results demonstrate that the fingerprints of C. tubulosa and C. salsa possess high similarity to the standard pattern, suggesting that these two species may be used as alternative species; while that of C. sinensis has low similarity (0.053 correlation coefficient) to the standard pattern, indicating that it cannot be used as the substitute of the official herb. However, the varying fingerprint patterns among the samples of C. deserticola collected from various habitats illustrate that the quality consistency of crude herbs is still a problem worthy of serious concern.

  7. Characterization of thermal reaction of aluminum/copper (II) oxide/poly(tetrafluoroethene) nanocomposite by thermogravimetric analysis, differential scanning calorimetry, mass spectrometry and X-ray diffraction

    International Nuclear Information System (INIS)

    Li, Xiangyu; Yang, Hongtao; Li, Yan-chun

    2015-01-01

    Highlights: • The thermal reaction properties of the Al/CuO/PTFE nanocomposite were investigated. • The Al/PTFE and CuO/PTFE nanocomposites were prepared and tested for comparison. • TG/DSC–MS and XRD analysis were performed. • PTFE is oxidizing Al and reducing CuO during the thermal decomposition. - Abstract: The application of fluoropolymers as reactive agent in energetic materials have attracted significant interest recently. In this study, the thermal reaction properties of the aluminum nanoparticles/copper (II) oxide nanoparticles/poly(tetrafluoroethene) (Al-NPs/CuO-NPs/PTFE) nanocomposite (mass ratio of Al-NPs/CuO-NPs/PTFE = 20/60/20) were investigated by means of thermogravimetry/differential scanning calorimetry–mass spectrometry (TG/DSC–MS) and X-ray diffraction (XRD) analyses. The Al-NPs/PTFE (mass ratio of Al-NPs/PTFE = 50/50) and CuO-NPs/PTFE (mass ratio of CuO-NPs/PTFE = 75/25) nanocomposites were also prepared and tested for comparison. It is observed that PTFE is acting as both oxidizer and reducer during the thermal decomposition process of Al-NPs/CuO-NPs/PTFE nanocomposites. Before 615 °C, PTFE is oxidized by CuO-NPs and oxidizing Al-NPs, resulting mass reduction. After 615 °C, the excessive aluminum and copper (I)/copper (II) oxide will proceed the exothermic condensed phase reaction.

  8. Tandem differential mobility analysis-mass spectrometry reveals partial gas-phase collapse of the GroEL complex.

    Science.gov (United States)

    Hogan, Christopher J; Ruotolo, Brandon T; Robinson, Carol V; Fernandez de la Mora, Juan

    2011-04-07

    A parallel-plate differential mobility analyzer and a time-of-flight mass spectrometer (DMA-MS) are used in series to measure true mobility in dry atmospheric pressure air for mass-resolved electrosprayed GroEL tetradecamers (14-mers; ~800 kDa). Narrow mobility peaks are found (2.6-2.9% fwhm); hence, precise mobilities can be obtained for these ions without collisional activation, just following their generation by electrospray ionization. In contrast to previous studies, two conformers are found with mobilities (Z) differing by ~5% at charge state z ~ 79. By extrapolating to small z, a common mobility/charge ratio Z(0)/z = 0.0117 cm(2) V(-1) s(-1) is found for both conformers. When interpreted as if the GroEL ion surface were smooth and the gas molecule-protein collisions were perfectly elastic and specular, this mobility yields an experimental collision cross section, Ω, 11% smaller than in an earlier measurement, and close to the cross section, A(C,crystal), expected for the crystal structure (determined by a geometric approximation). However, the similarity between Ω and A(C,crystal) does not imply a coincidence between the native and gas-phase structures. The nonideal nature of protein-gas molecule collisions introduces a drag enhancement factor, ξ = 1.36, with which the true cross section A(C) is related to Ω via A(C) = Ω/ξ. Therefore, A(C) for GroEL 14-mer ions determined by DMA measurements is 0.69A(C,crystal). The factor 1.36 used here is based on the experimental Stokes-Millikan equation, as well as on prior and new numerical modeling accounting for multiple scattering events via exact hard-sphere scattering calculations. Therefore, we conclude that the gas-phase structure of the GroEL complex as electrosprayed is substantially more compact than the corresponding X-ray crystal structure.

  9. 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

  10. Differential Proteomics Identification of HSP90 as Potential Serum Biomarker in Hepatocellular Carcinoma by Two-dimensional Electrophoresis and Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yiyi Sun

    2010-03-01

    Full Text Available The aim of the current study is to identify the potential biomarkers involved in Hepatocellular carcinoma (HCC carcinogenesis. A comparative proteomics approach was utilized to identify the differentially expressed proteins in the serum of 10 HCC patients and 10 controls. A total of 12 significantly altered proteins were identified by mass spectrometry. Of the 12 proteins identified, HSP90 was one of the most significantly altered proteins and its over-expression in the serum of 20 HCC patients was confirmed using ELISA analysis. The observations suggest that HSP90 might be a potential biomarker for early diagnosis, prognosis, and monitoring in the therapy of HCC. This work demonstrates that a comprehensive strategy of proteomic identification combined with further validation should be adopted in the field of cancer biomarker discovery.

  11. 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

  12. Differentiation of Lactobacillus brevis strains using Matrix-Assisted-Laser-Desorption-Ionization-Time-of-Flight Mass Spectrometry with respect to their beer spoilage potential.

    Science.gov (United States)

    Kern, Carola C; Vogel, Rudi F; Behr, Jürgen

    2014-06-01

    Lactobacillus (L.) brevis is one of the most frequently encountered bacteria in beer-spoilage incidents. As the species Lactobacillus brevis comprises strains showing varying ability to grow in beer, ranging from growth in low hopped wheat to highly hopped pilsner beer, differentiation and classification of L. brevis with regard to their beer-spoiling ability is of vital interest for the brewing industry. Matrix-Assisted-Laser-Desorption-Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown as a powerful tool for species and sub-species differentiation of bacterial isolates and is increasingly used for strain-level differentiation. Seventeen L. brevis strains, representative of different spoilage types, were characterized according to their tolerance to iso-alpha-acids and their growth in wheat-, lager- and pilsner beer. MALDI-TOF MS spectra were acquired to perform strain-level identification, cluster analysis and biomarker detection. Strain-level identification was achieved in 90% out of 204 spectra. Misidentification occurred nearly exclusively among strains belonging to the same spoilage type. Though spectra of strongly beer-spoiling strains showed remarkable similarity, no decisive single markers were detected to be present in all strains of one group. However, MALDI-TOF MS spectra can be reliably assigned to the corresponding strain and thus allow to track single strains and connect them to their physiological properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. 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...

  14. Differential Mobility-Mass Spectrometry Double Spike Isotope Dilution Study of Release of β-Methylaminoalanine and Proteinogenic Amino Acids during Biological Sample Hydrolysis.

    Science.gov (United States)

    Beach, Daniel G; Kerrin, Elliott S; Giddings, Sabrina D; Quilliam, Michael A; McCarron, Pearse

    2018-01-08

    The non-protein amino acid β-methylamino-L-alanine (BMAA) has been linked to neurodegenerative disease and reported throughout the environment. Proposed mechanisms of bioaccumulation, trophic transfer and chronic toxicity of BMAA rely on the hypothesis of protein misincorporation. Poorly selective methods for BMAA analysis have led to controversy. Here, a recently reported highly selective method for BMAA quantitation using hydrophilic interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS) is expanded to include proteinogenic amino acids from hydrolyzed biological samples. For BMAA quantitation, we present a double spiking isotope dilution approach using D 3 -BMAA and 13 C 15 N 2 -BMAA. These methods were applied to study release of BMAA during acid hydrolysis under a variety of conditions, revealing that the majority of BMAA can be extracted along with only a small proportion of protein. A time course hydrolysis of BMAA from mussel tissue was carried out to assess the recovery of BMAA during sample preparation. The majority of BMAA measured by typical methods was released before a significant proportion of protein was hydrolyzed. Little change was observed in protein hydrolysis beyond typical hydrolysis times but the concentration of BMAA increased linearly. These findings demonstrate protein misincorporation is not the predominant form of BMAA in cycad and shellfish.

  15. 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.

  16. 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....

  17. 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.

  18. 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.

  19. 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

  20. 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'.

  1. Functional characterization and phenotypic monitoring of human hematopoietic stem cell expansion and differentiation of monocytes and macrophages by whole-cell mass spectrometry

    Directory of Open Access Journals (Sweden)

    Guido Vogel

    2018-01-01

    Full Text Available The different facets of macrophages allow them to play distinct roles in tissue homeostasis, tissue repair and in response to infections. Individuals displaying dysregulated macrophage functions are proposed to be prone to inflammatory disorders or infections. However, this being a cause or a consequence of the pathology remains often unclear. In this context, we isolated and expanded CD34+ HSCs from healthy blood donors and derived them into CD14+ myeloid progenitors which were further enriched and differentiated into macrophages. Aiming for a comprehensive phenotypic profiling, we generated whole-cell mass spectrometry (WCMS fingerprints of cell samples collected along the different stages of the differentiation process to build a predictive model using a linear discriminant analysis based on principal components. Through the capacity of the model to accurately predict sample's identity of a validation set, we demonstrate that WCMS profiles obtained from bona fide blood monocytes and respectively derived macrophages mirror profiles obtained from equivalent HSC derivatives. Finally, HSC-derived macrophage functionalities were assessed by quantifying cytokine and chemokine responses to a TLR agonist in a 34-plex luminex assay and by measuring their capacity to phagocytise mycobacteria. These functional read-outs could not discriminate blood monocytes-derived from HSC-derived macrophages. To conclude, we propose that this method opens new avenues to distinguish the impact of human genetics on the dysregulated biological properties of macrophages in pathological conditions.

  2. A novel differential electrochemical mass spectrometry method to determine the product distribution from parasitic Methanol oxidation reaction on oxygen reduction reaction catalysts

    Science.gov (United States)

    Jurzinsky, Tilman; Kurzhals, Philipp; Cremers, Carsten

    2018-06-01

    The oxygen reduction reaction is in research focus since several decades due to its importance for the overall fuel cell performance. In direct methanol fuel cells, the crossover of methanol and its subsequent parasitic oxidation are main issues when it comes to preventing fuel cell performance losses. In this work, we present a novel differential electrochemical mass spectrometry method to evaluate oxygen reduction reaction catalysts on their tolerance to methanol being present at the cathode. Besides this, the setup allows to measure under more realistic fuel cell conditions than typical rotating disc electrode measurements, because the oxygen reduction reaction is evaluated in gaseous phase and a gas diffusion electrode is used as working electrode. Due to the new method, it was possible to investigate the oxygen reduction reaction on two commonly used catalysts (Pt/C and Pt3Co/C) in absence and presence of methanol. It was found, that Pt3Co/C is less prone to parasitic current losses due to methanol oxidation reaction. By connecting a mass spectrometer to the electrochemical cell, the new method allows to determine the products formed on the catalysts due to parasitic methanol electrooxidation.

  3. 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.)

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. Differentiation of oral bacteria in in vitro cultures and human saliva by secondary electrospray ionization - mass spectrometry

    Science.gov (United States)

    Bregy, Lukas; Müggler, Annick R.; Martinez-Lozano Sinues, Pablo; García-Gómez, Diego; Suter, Yannick; Belibasakis, Georgios N.; Kohler, Malcolm; Schmidlin, Patrick R.; Zenobi, Renato

    2015-10-01

    The detection of bacterial-specific volatile metabolites may be a valuable tool to predict infection. Here we applied a real-time mass spectrometric technique to investigate differences in volatile metabolic profiles of oral bacteria that cause periodontitis. We coupled a secondary electrospray ionization (SESI) source to a commercial high-resolution mass spectrometer to interrogate the headspace from bacterial cultures and human saliva. We identified 120 potential markers characteristic for periodontal pathogens Aggregatibacter actinomycetemcomitans (n = 13), Porphyromonas gingivalis (n = 70), Tanerella forsythia (n = 30) and Treponema denticola (n = 7) in in vitro cultures. In a second proof-of-principle phase, we found 18 (P. gingivalis, T. forsythia and T. denticola) of the 120 in vitro compounds in the saliva from a periodontitis patient with confirmed infection with P. gingivalis, T. forsythia and T. denticola with enhanced ion intensity compared to two healthy controls. In conclusion, this method has the ability to identify individual metabolites of microbial pathogens in a complex medium such as saliva.

  10. A differential centrifugation protocol and validation criterion for enhancing mass spectrometry (MALDI-TOF) results in microbial identification using blood culture growth bottles.

    Science.gov (United States)

    March-Rosselló, G A; Muñoz-Moreno, M F; García-Loygorri-Jordán de Urriés, M C; Bratos-Pérez, M A

    2013-05-01

    Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF) is a widely used tool in clinical microbiology for rapidly identifying microorganisms. This technique can be applied directly on positive blood cultures without the need for its culturing, thereby, reducing the time required for microbiological diagnosis. The present study proposes an innovative identification protocol applied to positive blood culture bottles using MALDI-TOF. We have processed 100 positive blood culture bottles, of which 36 of 37 Gram-negative bacteria (97.3 %) were correctly identified directly with 100 % of Enterobacteriaceae and other Gram-negative rods and 87.5 % of non-fermenting Gram-negative rods. We also correctly identified directly 62 of 63 of Gram-positive bacteria (98.4 %) with 100 % of Streptococcus, Enterococcus, and Gram-positive bacilli and 98 % of Staphylococcus. Applying the differential centrifugation protocol at the moment the automatic blood culture incubation system gives a positive reading together with the proposed validation criterion offers 98 % sensitivity (95 % confidence interval: 95.2-100 %). The MALDI-TOF system, thus, provides a rapid and reliable system for identifying microorganisms from blood culture growth bottles.

  11. Differential quantitative proteomics of Porphyromonas gingivalis by linear ion trap mass spectrometry: Non-label methods comparison, q-values and LOWESS curve fitting

    Science.gov (United States)

    Xia, Qiangwei; Wang, Tiansong; Park, Yoonsuk; Lamont, Richard J.; Hackett, Murray

    2007-01-01

    Differential analysis of whole cell proteomes by mass spectrometry has largely been applied using various forms of stable isotope labeling. While metabolic stable isotope labeling has been the method of choice, it is often not possible to apply such an approach. Four different label free ways of calculating expression ratios in a classic "two-state" experiment are compared: signal intensity at the peptide level, signal intensity at the protein level, spectral counting at the peptide level, and spectral counting at the protein level. The quantitative data were mined from a dataset of 1245 qualitatively identified proteins, about 56% of the protein encoding open reading frames from Porphyromonas gingivalis, a Gram-negative intracellular pathogen being studied under extracellular and intracellular conditions. Two different control populations were compared against P. gingivalis internalized within a model human target cell line. The q-value statistic, a measure of false discovery rate previously applied to transcription microarrays, was applied to proteomics data. For spectral counting, the most logically consistent estimate of random error came from applying the locally weighted scatter plot smoothing procedure (LOWESS) to the most extreme ratios generated from a control technical replicate, thus setting upper and lower bounds for the region of experimentally observed random error.

  12. Targeted Quantitation of Site-Specific Cysteine Oxidation in Endogenous Proteins Using a Differential Alkylation and Multiple Reaction Monitoring Mass Spectrometry Approach

    Science.gov (United States)

    Held, Jason M.; Danielson, Steven R.; Behring, Jessica B.; Atsriku, Christian; Britton, David J.; Puckett, Rachel L.; Schilling, Birgit; Campisi, Judith; Benz, Christopher C.; Gibson, Bradford W.

    2010-01-01

    Reactive oxygen species (ROS) are both physiological intermediates in cellular signaling and mediators of oxidative stress. The cysteine-specific redox-sensitivity of proteins can shed light on how ROS are regulated and function, but low sensitivity has limited quantification of the redox state of many fundamental cellular regulators in a cellular context. Here we describe a highly sensitive and reproducible oxidation analysis approach (OxMRM) that combines protein purification, differential alkylation with stable isotopes, and multiple reaction monitoring mass spectrometry that can be applied in a targeted manner to virtually any cysteine or protein. Using this approach, we quantified the site-specific cysteine oxidation status of endogenous p53 for the first time and found that Cys182 at the dimerization interface of the DNA binding domain is particularly susceptible to diamide oxidation intracellularly. OxMRM enables analysis of sulfinic and sulfonic acid oxidation levels, which we validate by assessing the oxidation of the catalytic Cys215 of protein tyrosine phosphatase-1B under numerous oxidant conditions. OxMRM also complements unbiased redox proteomics discovery studies as a verification tool through its high sensitivity, accuracy, precision, and throughput. PMID:20233844

  13. In situ Fourier transform infrared spectroscopy and on-line differential electrochemical mass spectrometry study of the NH3BH3 oxidation reaction on gold electrodes

    International Nuclear Information System (INIS)

    Belén Molina Concha, M.; Chatenet, Marian; Lima, Fabio H.B.; Ticianelli, Edson A.

    2013-01-01

    The ammonia borane (NH 3 BH 3 ) oxidation reaction (ABOR) was studied on gold electrodes using the rotating disk electrode (RDE) setup and coupled physical techniques: on-line differential electrochemical mass spectrometry (DEMS) and in situ Fourier transform infrared spectroscopy (FTIR). Non-negligible heterogeneous hydrolysis in the low-potential region was asserted via molecular H 2 detection. As a consequence, the number of electron exchanged per BH 3 OH − species is ca. 3 at low potential, and only reaches ca. 6 above 0.6 V vs. RHE. These figures were confirmed by Levich and Koutecki–Levich calculations using the RDE experiments data. The nature of the ABOR intermediates and products was determined using in situ FTIR. While BH 2 species were detected during the ABOR, it seems that its adsorption onto the Au electrode proceeds via the O atom, in opposition to what happens during the borohydride oxidation reaction (BOR). Therefore, it is likely that the mechanism of the ABOR differs from that of the BOR. From the whole set of data (RDE, DEMS, FTIR), a relevant reaction pathway was proposed, including competition between the BH 3 OH − heterogeneous hydrolysis and oxidation at low potential, and preponderant oxidation at higher potential. Finally, a simplified kinetic modeling accounting with this reaction pathway was proposed, which nicely fits the stationary (i vs. E) ABOR plot

  14. Rapid Differentiation of Haemophilus influenzae and Haemophilus haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry with ClinProTools Mass Spectrum Analysis.

    Science.gov (United States)

    Chen, Jonathan H K; Cheng, Vincent C C; Wong, Chun-Pong; Wong, Sally C Y; Yam, Wing-Cheong; Yuen, Kwok-Yung

    2017-09-01

    Haemophilus influenzae is associated with severe invasive disease, while Haemophilus haemolyticus is considered part of the commensal flora in the human respiratory tract. Although the addition of a custom mass spectrum library into the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system could improve identification of these two species, the establishment of such a custom database is technically complicated and requires a large amount of resources, which most clinical laboratories cannot afford. In this study, we developed a mass spectrum analysis model with 7 mass peak biomarkers for the identification of H. influenzae and H. haemolyticus using the ClinProTools software. We evaluated the diagnostic performance of this model using 408 H. influenzae and H. haemolyticus isolates from clinical respiratory specimens from 363 hospitalized patients and compared the identification results with those obtained with the Bruker IVD MALDI Biotyper. The IVD MALDI Biotyper identified only 86.9% of H. influenzae (311/358) and 98.0% of H. haemolyticus (49/50) clinical isolates to the species level. In comparison, the ClinProTools mass spectrum model could identify 100% of H. influenzae (358/358) and H. haemolyticus (50/50) clinical strains to the species level and significantly improved the species identification rate (McNemar's test, P mass spectrometry to handle closely related bacterial species when the proprietary spectrum library failed. This approach should be useful for the differentiation of other closely related bacterial species. Copyright © 2017 American Society for Microbiology.

  15. 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.

  16. 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)

  17. The differentiation of fibre- and drug type Cannabis seedlings by gas chromatography/mass spectrometry and chemometric tools.

    Science.gov (United States)

    Broséus, Julian; Anglada, Frédéric; Esseiva, Pierre

    2010-07-15

    Cannabis cultivation in order to produce drugs is forbidden in Switzerland. Thus, law enforcement authorities regularly ask forensic laboratories to determinate cannabis plant's chemotype from seized material in order to ascertain that the plantation is legal or not. As required by the EU official analysis protocol the THC rate of cannabis is measured from the flowers at maturity. When laboratories are confronted to seedlings, they have to lead the plant to maturity, meaning a time consuming and costly procedure. This study investigated the discrimination of fibre type from drug type Cannabis seedlings by analysing the compounds found in their leaves and using chemometrics tools. 11 legal varieties allowed by the Swiss Federal Office for Agriculture and 13 illegal ones were greenhouse grown and analysed using a gas chromatograph interfaced with a mass spectrometer. Compounds that show high discrimination capabilities in the seedlings have been identified and a support vector machines (SVMs) analysis was used to classify the cannabis samples. The overall set of samples shows a classification rate above 99% with false positive rates less than 2%. This model allows then discrimination between fibre and drug type Cannabis at an early stage of growth. Therefore it is not necessary to wait plants' maturity to quantify their amount of THC in order to determine their chemotype. This procedure could be used for the control of legal (fibre type) and illegal (drug type) Cannabis production. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  18. 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 ...

  19. Structural analysis and differentiation of reducing and nonreducing neutral model starch oligosaccharides by negative-ion electrospray ionization ion-trap mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Čmelík, Richard; Chmelík, Josef

    2010-01-01

    Roč. 291, 1-2 (2010), s. 33-40 ISSN 1387-3806 R&D Projects: GA MŠk 2B06037 Institutional research plan: CEZ:AV0Z40310501 Keywords : structural analysis * oligosaccharides * electrospray mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.009, year: 2010

  20. Differentiation of Clinically Relevant mucorales Rhizopus microsporus and R. arrhizus by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)

    NARCIS (Netherlands)

    Dolatabadi, S.; Kolecka, A.; Versteeg, Matthijs; de Hoog, Sybren G; Boekhout, Teun

    This study addresses the usefulness of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) for reliable identification of the two most frequently occuring clinical species of Rhizopus, namely R. arrhizus with its two varieties arrhizus and delemar and R.

  1. DIFFERENTIATION OF AEROMONAS ISOLATES OBTAINED FROM DRINKING WATER DISTRIBUTION SYSTEM USING MATRIX-ASSISTED LASER DESCRIPTION/IONIZATION-MASS SPECTROMETRY (MALDI-MS)

    Science.gov (United States)

    The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the...

  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. Differentiation of wood-derived vanillin from synthetic vanillin in distillates using gas chromatography/combustion/isotope ratio mass spectrometry for δ13 C analysis.

    Science.gov (United States)

    van Leeuwen, Katryna A; Prenzler, Paul D; Ryan, Danielle; Paolini, Mauro; Camin, Federica

    2018-02-28

    Typical storage in oak barrels releases in distillates different degradation products such as vanillin, which play an important role in flavour and aroma. The addition of vanillin, as well as other aroma compounds, of different origin is prohibited by European laws. As vanillin samples from different sources have different δ 13 C values, the δ 13 C value could be used to determine whether the vanillin is authentic (lignin-derived), or if it has been added from another source (e.g. synthetic). The δ 13 C values for vanillin derived from different sources, including natural, synthetic and tannins, were measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), after diethyl ether addition and/or ethanol dilution. A method for analysing vanillin in distillates after dichloromethane extraction was developed. Tests were undertaken to prove the reliability, reproducibility and accuracy of the method with standards and samples. Distillate samples were run to measure the δ 13 C values of vanillin and to compare them with values for other sources of vanillin. δ 13 C values were determined for: natural vanillin extracts (-21.0 to -19.3‰, 16 samples); vanillin ex-lignin (-28.2‰, 1 sample); and synthetic vanillin (-32.6 to -29.3‰, 7 samples). Seventeen tannin samples were found to have δ 13 C values of -29.5 to -26.7‰, which were significantly different (p distillates (-28.9 to -25.7‰) were mainly in the tannin range, although one spirit (-32.5‰) was found to contain synthetic vanillin. The results show that synthetic vanillin added to a distillate could be differentiated from vanillin derived from oak barrels by their respective δ 13 C values. The GC/C/IRMS method could be a useful tool in the determination of adulteration of distillates. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Differential extraction of endogenous and exogenous 25-OH-vitamin D from serum makes the accurate quantification in liquid chromatography-tandem mass spectrometry assays challenging.

    Science.gov (United States)

    Lankes, Ulrich; Elder, Peter A; Lewis, John G; George, Peter

    2015-01-01

    Extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis is the method of choice when it comes to the accurate quantification of 25-OH-vitamin D in blood samples. It is generally assumed that the addition of exogenous internal standard allows for the determination of the endogenous analyte concentration. In this study we investigated the extraction properties of endogenous and exogenous 25-OH-vitamin D. Eight samples were used for the evaluation of the extraction procedure and 59 patients' samples for a method comparison. The methanol-to-sample ratio (v/v) and the sample-to-hexane ratio (v/v) were varied and the LC-MS/MS signals of endogenous 25-OH-vitamin D3, spiked 25-OH-vitamin D2 and internal standard of the extracts recorded. The optimized 'in-house' LC-MS/MS assay was compared to two automated chemiluminescence immunoassays from DiaSorin and Abbott. Mathematical analysis of the data revealed a differential extraction of endogenous 25-OH-vitamin D3, spiked 25-OH-vitamin D2 and non-equilibrated internal standard. Exogenous 25-OH-vitamin D can be measured accurately if a definite methanol-to-sample ratio is used. Endogenous 25-OH-vitamin D is affected by critical quantification issues due to a differential slope in the extraction profile. The actual 25-OH-vitamin D concentration can be one-third above the measured extractable concentration. Results confirm that the 'in-house' LC-MS/MS assay provides reproducible 25-OH-vitamin D results. Discordant concentrations of 25-OH-vitamin D from LC-MS/MS assays can be caused by selection of suboptimal extraction conditions. Furthermore, a different sample pretreatment or solvent extraction system may result in a different dissociation and extraction yield of endogenous 25-OH-vitamin D and therefore contribute to variations of LC-MS/MS results. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  11. 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.

  12. 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)

  13. 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.

  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. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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....

  7. 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.

  8. Mass spectrometry detection of G3m and IGHG3 alleles and follow-up of differential mother and neonate IgG3.

    Directory of Open Access Journals (Sweden)

    Célia Dechavanne

    Full Text Available Mass spectrometry (MS analysis for detection of immunoglobulins (IG of the human IgG3 subclass is described that relies on polymorphic amino acids of the heavy gamma3 chains. IgG3 is the most polymorphic human IgG subclass with thirteen G3m allotypes located on the constant CH2 and CH3 domains of the gamma3 chain, the combination of which leads to six major G3m alleles. Amino acid changes resulting of extensive sequencing previously led to the definition of 19 IGHG3 alleles that have been correlated to the G3m alleles. As a proof of concept, MS proteotypic peptides were defined which encompass discriminatory amino acids for the identification of the G3m and IGHG3 alleles. Plasma samples originating from ten individuals either homozygous or heterozygous for different G3m alleles, and including one mother and her baby (drawn sequentially from birth to 9 months of age, were analyzed. Total IgG3 were purified using affinity chromatography and then digested by a combination of AspN and trypsin proteases, and peptides of interest were detected by mass spectrometry. The sensitivity of the method was assessed by mixing variable amounts of two plasma samples bearing distinct G3m allotypes. A label-free approach using the high-performance liquid chromatography (HPLC retention time of peptides and their MS mass analyzer peak intensity gave semi-quantitative information. Quantification was realized by selected reaction monitoring (SRM using synthetic peptides as internal standards. The possibility offered by this new methodology to detect and quantify neo-synthesized IgG in newborns will improve knowledge on the first acquisition of antibodies in infants and constitutes a promising diagnostic tool for vertically-transmitted diseases.

  9. 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.)

  10. [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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Gas chromatography-mass spectrometry analysis of di-n-octyl disulfide in a straight oil metalworking fluid: application of differential permeation and Box-Cox transformation.

    Science.gov (United States)

    Xu, Wenhai; Que Hee, Shane S

    2006-01-06

    The aim of this study was to identify and quantify an unknown peak in the chromatogram of a very complex mixture, a straight oil metalworking fluid (MWF). The fraction that permeated through a thin nitrile polymer membrane had less mineral oil background than the original MWF did at the retention time of the unknown peak, thus facilitating identification by total ion current (TIC) gas chromatography-mass spectrometry (GC-MS). The peak proved to be di-n-octyl disulfide (DOD) through retention time and mass spectral comparisons. Quantitation of DOD was by extracted ion chromatogram analysis of the DOD molecular ion (mass-to-charge ratio (m/z) 290), and of the m/z 71 ion for the internal standard, n-triacontane. Linear models of the area ratio (y) of these two ions versus DOD concentration showed a systematic negative bias at low concentrations, a common occurrence in analysis. The linear model of y(0.8) (from Box-Cox power transformation) versus DOD concentration showed negligible bias from the lowest measured standard of 1.51 mg/L to the highest concentration tested at 75.5 mg/L. The intercept did not differ statistically from zero. The concentration of DOD in the MWF was then calculated to be 0.398+/-0.034% (w/w) by the internal standard method, and 0.387+/-0.036% (w/w) by the method of standard additions. These two results were not significantly different at p Box-Cox transformation is therefore recommended when the data for standards are non-linear.

  18. 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

  19. 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

  20. 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

  1. 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....

  2. 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).

  3. 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

  4. 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.

  5. 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.)

  6. 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.

  7. Mass spectrometry for fragment screening.

    Science.gov (United States)

    Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

    2017-11-08

    Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  8. [Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of Pangxidong Composite Granitoid Pluton and Its Implications for Magmatic Differentiation].

    Science.gov (United States)

    Zeng, Chang-yu; Ding, Ru-xin; Li, Hong-zhong; Zhou, Yong-zhang; Niu, Jia; Zhang, Jie-tang

    2015-11-01

    Pangxidong composite granitoid pluton located in the southwestern margin of Yunkai massif. The metamorphic grade of this pluton increases from outside to inside, that is, banded-augen granitic gneisses, gneissoid granites and granites distribute in order from edge to core. X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry are conducted to study the geochemical characteristics of the three types of rocks. The result shows that all the three types of rocks are peraluminous rocks and their contents of main elements and rare earth elements change gradually. From granitic gneisses to granites, the contents of Al₂O₃, CaO, MgO, TiO₂, total rare earth elements and light rare earth elements increase, but the contents of SiO₂ and heavy rare earth elements decrease. It is suggested that the phylogenetic relationship exists between granitic gneisses, gneissoid granites and granites during the multi-stage tectonic evolution process. Furthermore, the remelting of metamorphosed supracrustal rocks in Yunkai massif is probably an important cause of granitoid rocks forming. The evolutionary mechanism is probably that SiO₂ and heavy rare earth elements were melt out from the protolith and gradually enriched upward, but Al₂O₃, CaO, MgO, TiO₂ and light rare earth elements enriched downward.

  9. Differentiating chondroitin sulfate glycosaminoglycans using collision-induced dissociation; uronic acid cross-ring diagnostic fragments in a single stage of tandem mass spectrometry.

    Science.gov (United States)

    Kailemia, Muchena J; Patel, Anish B; Johnson, Dane T; Li, Lingyun; Linhardt, Robert J; Amster, I Jonathan

    2015-01-01

    The stereochemistry of the hexuronic acid residues of the structure of glycosaminoglycans (GAGs) is a key feature that affects their interactions with proteins and other biological functions. Electron based tandem mass spectrometry methods, in particular electron detachment dissociation (EDD), have been able to distinguish glucuronic acid (GlcA) from iduronic acid (IdoA) residues in some heparan sulfate tetrasaccharides by producing epimer-specific fragments. Similarly, the relative abundance of glycosidic fragment ions produced by collision-induced dissociation (CID) or EDD has been shown to correlate with the type of hexuronic acid present in chondroitin sulfate GAGs. The present work examines the effect of charge state and degree of sodium cationization on the CID fragmentation products that can be used to distinguish GlcA and IdoA containing chondroitin sulfate A and dermatan sulfate chains. The cross-ring fragments (2,4)A(n) and (0,2)X(n) formed within the hexuronic acid residues are highly preferential for chains containing GlcA, distinguishing it from IdoA. The diagnostic capability of the fragments requires the selection of a molecular ion and fragment ions with specific ionization characteristics, namely charge state and number of ionizable protons. The ions with the appropriate characteristics display diagnostic properties for all the chondroitin sulfate and dermatan sulfate chains (degree of polymerization of 4-10) studied.

  10. Differentiation between lutein monoester regioisomers and detection of lutein diesters from marigold flowers (Tagetes erecta L.) and several fruits by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Breithaupt, Dietmar E; Wirt, Ursula; Bamedi, Ameneh

    2002-01-02

    Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCIMS) was employed for the identification of eight lutein monoesters, formed by incomplete enzymatic saponification of lutein diesters of marigold (Tagetes erecta L.) by Candida rugosa lipase. Additionally, the main lutein diesters naturally occurring in marigold oleoresin were chromatographically separated and identified. The LC-MS method allows for characterization of lutein diesters occurring as minor components in several fruits; this was demonstrated by analysis of extracts of cape gooseberry (Physalis peruviana L.), kiwano (Cucumis metuliferus E. Mey. ex Naud.), and pumpkin (Cucurbita pepo L.). The assignment of the regioisomers of lutein monoesters is based on the characteristic fragmentation pattern: the most intense daughter ion generally results from the loss of the substituent (fatty acid or hydroxyl group) bound to the epsilon-ionone ring, yielding an allylic cation. The limit of detection was estimated at 0.5 microg/mL with lutein dimyristate as reference compound. This method provides a useful tool to obtain further insight into the biochemical reactions leading to lutein ester formation in plants.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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)

  18. 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

  19. Meconium Nicotine and Metabolites by Liquid Chromatography–Tandem Mass Spectrometry: Differentiation of Passive and Nonexposure and Correlation with Neonatal Outcome Measures

    Science.gov (United States)

    Gray, Teresa R.; Magri, Raquel; Shakleya, Diaa M.; Huestis, Marilyn A.

    2011-01-01

    BACKGROUND Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes’ concentrations with neonatal outcomes is unexplored. Our objectives were to quantify nicotine, cotinine, trans-3′-hydroxycotinine (OH-cotinine), nornicotine, norcotinine, and glucuronide concentrations in meconium, identify the best biomarkers of in utero tobacco exposure, compare meconium concentrations of tobacco-exposed and nonexposed neonates, and investigate concentration–outcome relationships. METHODS We quantified concentrations of nicotine and 4 metabolites with and without hydrolysis simultaneously in meconium from tobacco-exposed and nonexposed neonates by liquid chromatography–tandem mass spectrometry. We compared meconium concentrations to birth weight, length, head circumference, gestational age, and 1- and 5-min Apgar scores. RESULTS Nicotine, cotinine, and OH-cotinine were the most prevalent and abundant meconium tobacco biomarkers and were found in higher concentrations in tobacco-exposed neonates. Whereas cotinine and OH-cotinine are glucuronide bound, performing the lengthy and costly enzymatic hydrolysis identified only 1 additional positive specimen. Unconjugated nicotine, cotinine, or OH-cotinine meconium concentration >10 ng/g most accurately discriminated active from passive and nonexposed neonates. There was no significant correlation between quantitative nicotine and metabolite meconium results and neonatal outcomes, although presence of a nicotine biomarker predicted decreased head circumference. CONCLUSIONS Unconjugated nicotine, cotinine, and OH-cotinine should be analyzed in meconium to detect in utero tobacco exposure, as approximately 25% of positive specimens did not contain cotinine. Immunoassay testing monitoring cotinine only would underestimate the prevalence of prenatal

  20. 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

  1. 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

  2. [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.

  3. 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.

  4. 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)

  5. 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/.

  6. 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

  7. 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

  8. Specificity enhancement by electrospray ionization multistage mass spectrometry--a valuable tool for differentiation and identification of 'V'-type chemical warfare agents.

    Science.gov (United States)

    Weissberg, Avi; Tzanani, Nitzan; Dagan, Shai

    2013-12-01

    The use of chemical warfare agents has become an issue of emerging concern. One of the challenges in analytical monitoring of the extremely toxic 'V'-type chemical weapons [O-alkyl S-(2-dialkylamino)ethyl alkylphosphonothiolates] is to distinguish and identify compounds of similar structure. MS analysis of these compounds reveals mostly fragment/product ions representing the amine-containing residue. Hence, isomers or derivatives with the same amine residue exhibit similar mass spectral patterns in both classical EI/MS and electrospray ionization-MS, leading to unavoidable ambiguity in the identification of the phosphonate moiety. A set of five 'V'-type agents, including O-ethyl S-(2-diisopropylamino)ethyl methylphosphonothiolate (VX), O-isobutyl S-(2-diethylamino)ethyl methylphosphonothiolate (RVX) and O-ethyl S-(2-diethylamino)ethyl methylphosphonothiolate (VM) were studied by liquid chromatography/electrospray ionization/MS, utilizing a QTRAP mass detector. MS/MS enhanced product ion scans and multistage MS(3) experiments were carried out. Based on the results, possible fragmentation pathways were proposed, and a method for the differentiation and identification of structural isomers and derivatives of 'V'-type chemical warfare agents was obtained. MS/MS enhanced product ion scans at various collision energies provided information-rich spectra, although many of the product ions obtained were at low abundance. Employing MS(3) experiments enhanced the selectivity for those low abundance product ions and provided spectra indicative of the different phosphonate groups. Study of the fragmentation pathways, revealing some less expected structures, was carried out and allowed the formulation of mechanistic rules and the determination of sets of ions typical of specific groups, for example, methylphosphonothiolates versus ethylphosphonothiolates. The new group-specific ions elucidated in this work are also useful for screening unknown 'V'-type agents and related

  9. 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.

  10. 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.

  11. A label-free internal standard method for the differential analysis of bioactive lupin proteins using nano HPLC-Chip coupled with Ion Trap mass spectrometry.

    Science.gov (United States)

    Brambilla, Francesca; Resta, Donatella; Isak, Ilena; Zanotti, Marco; Arnoldi, Anna

    2009-01-01

    Quantitative proteomics based on MS is useful for pointing out the differences in some food proteomes relevant to human nutrition. Stable isotope label-free (SIF) techniques are suitable for comparing an unlimited number of samples by the use of relatively simple experimental workflows. We have developed an internal standard label-free method based on the intensities of peptide precursor ions from MS/MS spectra, collected in data dependent runs, for the simultaneous qualitative characterization and relative quantification of storage proteins of Lupinus albus seeds in protein extracts of four lupin cultivars (cv Adam, Arés, Lucky, Multitalia). The use of an innovative microfluidic system, the HPLC-Chip, coupled with a classical IT mass spectrometer, has allowed a complete qualitative characterization of all proteins. In particular, the homology search mode has permitted to identify single amino acid substitutions in the sequences of vicilins (beta-conglutin precursor and vicilin-like protein). The MS/MS sequencing of substituted peptides confirms the high heterogeneity of vicilins according to the peculiar characteristics of the vicilin-encoding gene family. Two suitable bioinformatics parameters were optimized for the differential analyses of the main bioactive proteins: the "normalized protein average of common reproducible peptides" (N-ACRP) for gamma-conglutin, which is a homogeneous protein, and the "normalized protein mean peptide spectral intensity" (N-MEAN) for the highly heterogenous class of the vicilins.

  12. Differentiation and characterization of isotopically modified silver nanoparticles in aqueous media using asymmetric-flow field flow fractionation coupled to optical detection and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gigault, Julien [National Institute of Standards and Technology, Material Measurement Laboratory, 100 Bureau Drive Stop 8520, Gaithersburg, MD 20899-8520 (United States); Hackley, Vincent A., E-mail: vince.hackley@nist.gov [National Institute of Standards and Technology, Material Measurement Laboratory, 100 Bureau Drive Stop 8520, Gaithersburg, MD 20899-8520 (United States)

    2013-02-06

    Highlights: ► Isotopically modified and unmodified AgNPs characterization by A4F-DAD-MALS–DLS-ICP-MS. ► Size-resolved characterization and speciation in simple or complex media. ► Capacity to detect stable isotope enriched AgNPs in a standard estuarine sediment. ► New opportunities to monitor and study fate and transformations of AgNPs. -- Abstract: The principal objective of this work was to develop and demonstrate a new methodology for silver nanoparticle (AgNP) detection and characterization based on asymmetric-flow field flow fractionation (A4F) coupled on-line to multiple detectors and using stable isotopes of Ag. This analytical approach opens the door to address many relevant scientific challenges concerning the transport and fate of nanomaterials in natural systems. We show that A4F must be optimized in order to effectively fractionate AgNPs and larger colloidal Ag particles. With the optimized method one can accurately determine the size, stability and optical properties of AgNPs and their agglomerates under variable conditions. In this investigation, we couple A4F to optical absorbance (UV–vis spectrometer) and scattering detectors (static and dynamic) and to an inductively coupled plasma mass spectrometer. With this combination of detection modes it is possible to determine the mass isotopic signature of AgNPs as a function of their size and optical properties, providing specificity necessary for tracing and differentiating labeled AgNPs from their naturally occurring or anthropogenic analogs. The methodology was then applied to standard estuarine sediment by doping the suspension with a known quantity of isotopically enriched {sup 109}AgNPs stabilized by natural organic matter (standard humic and fulvic acids). The mass signature of the isotopically enriched AgNPs was recorded as a function of the measured particle size. We observed that AgNPs interact with different particulate components of the sediment, and also self-associate to form

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. [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.

  11. Maximizing Ion Transmission in Differential Mobility Spectrometry

    Science.gov (United States)

    Schneider, Bradley B.; Londry, Frank; Nazarov, Erkinjon G.; Kang, Yang; Covey, Thomas R.

    2017-10-01

    We provide modeling and experimental data describing the dominant ion-loss mechanisms for differential mobility spectrometry (DMS). Ion motion is considered from the inlet region of the mobility analyzer to the DMS exit, and losses resulting from diffusion to electrode surfaces, insufficient effective gap, ion fragmentation, and fringing field effects are considered for a commercial DMS system with 1-mm gap height. It is shown that losses due to diffusion and radial oscillations can be minimized with careful consideration of residence time, electrode spacing, gas flow rate, and waveform frequency. Fragmentation effects can be minimized by limitation of the separation field. When these parameters were optimized, fringing field effects at the DMS inlet contributed the most to signal reduction. We also describe a new DMS cell configuration that improves the gas dynamics at the mobility cell inlet. The new cell provides a gas jet that decreases the residence time for ions within the fringing field region, resulting in at least twofold increase in ion signal as determined by experimental data and simulations. [Figure not available: see fulltext.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.)

  17. 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...

  18. 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

  19. 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

  20. 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.

  1. [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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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)

  8. 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

  9. 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)

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Differential anatomical expression of ganglioside GM1 species containing d18:1 or d20:1 sphingosine detected by MALDI Imaging Mass Spectrometry in mature rat brain

    Directory of Open Access Journals (Sweden)

    Nina eWeishaupt

    2015-12-01

    Full Text Available GM1 ganglioside plays a role in essential neuronal processes, including differentiation, survival and signaling. Yet, little is known about GM1 species with different sphingosine bases, such as the most abundant species containing 18 carbon atoms in the sphingosine chain (GM1d18:1, and the less abundant containing 20 carbon atoms (GM1d20:1. While absent in the early fetal brain, GM1d20:1 continues to increase throughout pre- and postnatal development and into old age, raising questions about the functional relevance of the GM1d18:1 to GM1d20:1 ratio. Matrix-assisted laser desorption/ionization (MALDI Imaging Mass Spectrometry is a novel technology that allows differentiation between these two GM1 species and quantification of their expression within an anatomical context. Using this technology, we find GM1d18:1/d20:1 expression ratios are highly specific to defined anatomical brain regions in adult rats. Thus, the ratio was significantly different among different thalamic nuclei and between the corpus callosum and internal capsule. Differential GM1d18:1/GM1d20:1 ratios measured in hippocampal subregions in rat brain complement previous studies conducted in mice. Across layers of the sensory cortex, opposing expression gradients were found for GM1d18:1 and GM1d20:1. Superficial layers demonstrated lower GM1d18:1 and higher GM1d20:1 signal than other layers, while in deep layers GM1d18:1 expression was relatively high and GM1d20:1 expression low. By far the highest GM1d18:1/d20:1 ratio was found in the amygdala. Differential expression of GM1 with d18:1- or d20:1-sphingosine bases in the adult rat brain suggests tight regulation of expression and points toward a distinct functional relevance for each of these GM1 species in neuronal processes.

  15. Analysis of the differentially expressed low molecular weight peptides in human serum via an N-terminal isotope labeling technique combining nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Leng, Jiapeng; Zhu, Dong; Wu, Duojiao; Zhu, Tongyu; Zhao, Ningwei; Guo, Yinlong

    2012-11-15

    Peptidomics analysis of human serum is challenging due to the low abundance of serum peptides and interference from the complex matrix. This study analyzed the differentially expressed (DE) low molecular weight peptides in human serum integrating a DMPITC-based N-terminal isotope labeling technique with nano-liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry (nano-LC/MALDI-MS). The workflow introduced a [d(6)]-4,6-dimethoxypyrimidine-2-isothiocyanate (DMPITC)-labeled mixture of aliquots from test samples as the internal standard. The spiked [d(0)]-DMPITC-labeled samples were separated by nano-LC then spotted on the MALDI target. Both quantitative and qualitative studies for serum peptides were achieved based on the isotope-labeled peaks. The DMPITC labeling technique combined with nano-LC/MALDI-MS not only minimized the errors in peptide quantitation, but also allowed convenient recognition of the labeled peptides due to the 6 Da mass difference. The data showed that the entire research procedure as well as the subsequent data analysis method were effective, reproducible, and sensitive for the analysis of DE serum peptides. This study successfully established a research model for DE serum peptides using DMPITC-based N-terminal isotope labeling and nano-LC/MALDI-MS. Application of the DMPITC-based N-terminal labeling technique is expected to provide a promising tool for the investigation of peptides in vivo, especially for the analysis of DE peptides under different biological conditions. Copyright © 2012 John Wiley & Sons, Ltd.

  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. Analysis of hazardous biological material by MALDI mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    KL Wahl; KH Jarman; NB Valentine; MT Kingsley; CE Petersen; ST Cebula; AJ Saenz

    2000-03-21

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) has become a valuable tool for analyzing microorganisms. The speed with which data can be obtained from MALDI-MS makes this a potentially important tool for biological health hazard monitoring and forensic applications. The excitement in the mass spectrometry community in this potential field of application is evident by the expanding list of research laboratories pursuing development of MALDI-MS for bacterial identification. Numerous research groups have demonstrated the ability to obtain unique MALDI-MS spectra from intact bacterial cells and bacterial cell extracts. The ability to differentiate strains of the same species has been investigated. Reproducibility of MALDI-MS spectra from bacterial species under carefully controlled experimental conditions has also been demonstrated. Wang et al. have reported on interlaboratory reproducibility of the MALDI-MS analysis of several bacterial species. However, there are still issues that need to be addressed, including the careful control of experimental parameters for reproducible spectra and selection of optimal experimental parameters such as solvent and matrix.

  18. 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.

  19. 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

  20. 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)

  1. 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)

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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....

  7. 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

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

    DEFF Research Database (Denmark)

    Corr, J. J.; Larsen, Erik Huusfeldt

    1996-01-01

    Ionspray mass spectrometry, a well established organic analysis technique, has been coupled to high-performance liquid chromatography for speciation of organic arsenic compounds, The ionspray source and differentially pumped interface of the mass spectrometer were operated in dual modes...... fragmentation patterns showing molecular dissociation through an expected common product ion were obtained for the four arsenosugars, Molecular mode detection was utilized for qualitative verification of speciation analysis by high-performance liquid chromatography coupled to inductively coupled plasma mass...

  9. [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.

  10. 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.

  11. [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.

  12. Iodine-Containing Mass-Defect-Tuned Dendrimers for Use as Internal Mass Spectrometry Calibrants

    Science.gov (United States)

    Giesen, Joseph A.; Diament, Benjamin J.; Grayson, Scott M.

    2018-03-01

    Calibrants based on synthetic dendrimers have been recently proposed as a versatile alternative to peptides and proteins for both MALDI and ESI mass spectrometry calibration. Because of their modular synthetic platform, dendrimer calibrants are particularly amenable to tailoring for specific applications. Utilizing this versatility, a set of dendrimers has been designed as an internal calibrant with a tailored mass defect to differentiate them from the majority of natural peptide analytes. This was achieved by incorporating a tris-iodinated aromatic core as an initiator for the dendrimer synthesis, thereby affording multiple calibration points ( m/z range 600-2300) with an optimized mass-defect offset relative to all peptides composed of the 20 most common proteinogenic amino acids. [Figure not available: see fulltext.

  13. Serum Biomarker Identification by Mass Spectrometry in Acute Aortic Dissection

    Directory of Open Access Journals (Sweden)

    Yong Ren

    2017-12-01

    Full Text Available Background/Aims: Aortic dissection (AD is also known as intramural hematoma. This study aimed to screen peripheral blood biomarkers of small molecule metabolites for AD using high-performance liquid chromatography-mass spectrometry (HPLC-MS. Methods: Sera from 25 healthy subjects, 25 patients with well-established AD, and 25 patients with well-established hypertension were investigated by HPLC-MS to detect metabolites, screen differentially expressed metabolites, and analyze metabolic pathways. Results: Twenty-six and four metabolites were significantly up- and down-regulated in the hypertensive patients compared with the healthy subjects; 165 metabolites were significantly up-regulated and 109 significantly down-regulated in the AD patients compared with the hypertensive patients. Of these metabolites, 35 were up-regulated and 105 down-regulated only in AD patients. The metabolites that were differentially expressed in AD are mainly involved in tryptophan, histidine, glycerophospholipid, ether lipid, and choline metabolic pathways. As AD alters the peripheral blood metabolome, analysis of peripheral blood metabolites can be used in auxiliary diagnosis of AD. Conclusion: Eight metabolites are potential biomarkers for AD, 3 of which were differentially expressed and can be used for auxiliary diagnosis of AD and evaluation of treatment effectiveness.

  14. Serum Biomarker Identification by Mass Spectrometry in Acute Aortic Dissection.

    Science.gov (United States)

    Ren, Yong; Tang, Qizhu; Liu, Wenwei; Tang, Yongqian; Zhu, Rui; Li, Bin

    2017-01-01

    Aortic dissection (AD) is also known as intramural hematoma. This study aimed to screen peripheral blood biomarkers of small molecule metabolites for AD using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Sera from 25 healthy subjects, 25 patients with well-established AD, and 25 patients with well-established hypertension were investigated by HPLC-MS to detect metabolites, screen differentially expressed metabolites, and analyze metabolic pathways. Twenty-six and four metabolites were significantly up- and down-regulated in the hypertensive patients compared with the healthy subjects; 165 metabolites were significantly up-regulated and 109 significantly down-regulated in the AD patients compared with the hypertensive patients. Of these metabolites, 35 were up-regulated and 105 down-regulated only in AD patients. The metabolites that were differentially expressed in AD are mainly involved in tryptophan, histidine, glycerophospholipid, ether lipid, and choline metabolic pathways. As AD alters the peripheral blood metabolome, analysis of peripheral blood metabolites can be used in auxiliary diagnosis of AD. Eight metabolites are potential biomarkers for AD, 3 of which were differentially expressed and can be used for auxiliary diagnosis of AD and evaluation of treatment effectiveness. © 2017 The Author(s). Published by S. Karger AG, Basel.

  15. 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)

  16. 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 .

  17. 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

  18. 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

  19. Authentication of organically and conventionally grown basils by gas chromatograpy/mass spectrometry chemical profiles

    Science.gov (United States)

    Basil plants cultivated by organic and conventional farming practices were differentiated using gas chromatography/mass spectrometry (GC/MS) and chemometric methods. The two-way GC/MS data sets were baseline-corrected and retention time-aligned prior to data processing. Two self-devised fuzzy clas...

  20. 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

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. 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.)

  6. 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.)

  7. 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)

  8. 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.

  9. 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.

  10. 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

  11. 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.).

  12. 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 ...

  13. 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

  14. Fast atom bombardment tandem mass spectrometry of carotenoids

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-02-01

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

  15. 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.

  16. 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....

  17. 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

  18. 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

  19. Clinical review: improving the measurement of serum thyroglobulin with mass spectrometry.

    Science.gov (United States)

    Hoofnagle, Andrew N; Roth, Mara Y

    2013-04-01

    Serum thyroglobulin (Tg) measurements are central to the management of patients treated for differentiated thyroid carcinoma. For decades, Tg measurements have relied on methods that are subject to interference by commonly found substances in human serum and plasma, such as Tg autoantibodies. As a result, many patients need additional imaging studies to rule out cancer persistence or recurrence that could be avoided with more sensitive and specific testing methods. The aims of this review are to: 1) briefly review the interferences common to Tg immunoassays; 2) introduce readers to liquid chromatography-tandem mass spectrometry as a method for quantifying proteins in human serum/plasma; and 3) discuss the potential benefits and limitations of the method in the quantification of serum Tg. Mass spectrometric methods have traditionally lacked the sensitivity, robustness, and throughput to be useful clinical assays. These methods failed to meet the necessary clinical benchmarks due to the nature of the mass spectrometry workflow and instrumentation. Over the past few years, there have been major advances in reagents, automation, and instrumentation for the quantification of proteins using mass spectrometry. More recently, methods using mass spectrometry to detect and quantify Tg have been developed and are of sufficient quality to be used in the management of patients. Novel serum Tg assays that use mass spectrometry may avoid the issue of autoantibody interference and other problems with currently available immunoassays for Tg. Prospective studies are needed to fully understand the potential benefits of novel Tg assays to patients and care providers.

  20. 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.

  1. 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…

  2. 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.

  3. Study by mass spectrometry of the formation of cluster ions generated by laser ablation/ionization of inorganic compounds: application to the differentiation of trivalent and hexavalent chromium compounds

    International Nuclear Information System (INIS)

    Aubriet, Frederic

    1999-01-01

    The introduction of new ionization techniques allows a fast growth of mass spectrometry applications in an increasing number of fields. More particularly, the introduction of laser ablation/ionization process and the design of new instruments (laser microprobes), has been very important for a better knowledge of inorganic compound mass spectrometry. The purposes of this work were mainly focussed firstly in the understanding of cluster ions formation process by laser ablation/ionization and secondly in the development of a new mass spectrometry technique for the speciation between trivalent and hexavalent chromium compounds. We show that cluster ion formation are multiple. The difficulty to identify clearly the processes involved is due to the superposition of many mechanisms. Mostly, these processes are representative of the complexity of the gas-phase chemistry between the various species generated by laser ablation/ionization. Thus, four mechanisms for the cluster ion formation have been highlighted. The most frequently met correspond to aggregative processes of neutral molecules on precursor ions. The knowledge of the processes of cluster ion formation allows us to explain why it is possible to distinguish the oxidation number of chromium. The organigram of chromium valence speciation proposed is based on the calculation of the ratio of negative cluster ion intensities after systematic analysis of nearly twenty chromium reference compounds using the same instrumental conditions. The examination of mixtures between 1) calcium. silicon, trivalent iron or zinc oxides and 2) the standard chromium compound allows us to observe the influence of these oxides on the fingerprints of the pure chromium compounds and to determine up to which point and with which limitations, the methodology suggested, could be applied to the analysis of trivalent and hexavalent chromium compounds in complex and polyphasic matrices

  4. 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....

  5. 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 ...

  6. 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.

  7. 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)

  8. Adapting mass spectrometry-based platforms for clinical proteomics applications: The capillary electrophoresis coupled mass spectrometry paradigm

    Science.gov (United States)

    Metzger, Jochen; Luppa, Peter B.; Good, David M.; Mischak, Harald

    2018-01-01

    Single biomarker detection is common in clinical laboratories due to the currently available method spectrum. For various diseases, however, no specific single biomarker could be identified. A strategy to overcome this diagnostic void is to shift from single analyte detection to multiplexed biomarker profiling. Mass spectrometric methods were employed for biomarker discovery in body fluids. The enormous complexity of biofluidic proteome compartments implies upstream fractionation. For this reason, mass spectrometry (MS) was coupled to two-dimensional gel electrophoresis, liquid chromatography, surface-enhanced laser desorption/ionization, or capillary electrophoresis (CE). Differences in performance and operating characteristics make them differentially suited for routine laboratory applications. Progress in the field of clinical proteomics relies not only on the use of an adequate technological platform, but also on a fast and efficient proteomic workflow including standardized sample preparation, proteomic data processing, statistical validation of biomarker selection, and sample classification. Based on CE-MS analysis, we describe how proteomic technology can be implemented in a clinical laboratory environment. In the last part of this review, we give an overview of CE-MS-based clinical studies and present information on identity and biological significance of the identified peptide biomarkers providing evidence of disease-induced changes in proteolytic processing and posttranslational modification. PMID:19404829

  9. Temperature effects in differential mobility spectrometry

    Science.gov (United States)

    Krylov, Evgeny V.; Coy, Stephen L.; Nazarov, Erkinjon G.

    2009-01-01

    Drift gas temperature and pressure influence differential mobility spectrometer (DMS) performance, changing DMS peak positions, heights and widths. This study characterizes the effect of temperature on DMS peak positions. Positive ions of methyl salicylate, DMMP, and toluene, and negative ions of methyl salicylate and the reactant ion peaks were observed in purified nitrogen in the Sionex microDMx planar DMS. Measurements were made at ambient pressure (1 atm) at temperatures from 25 °C to 150 °C in a planar sensor with height 0.5 mm. Peak value of the separation voltage asymmetric waveform was scanned from 500 V to 1500 V. Compensation voltage (DMS peak position) showed a strong variation with temperature for all investigated ions. By generalizing the concept of effective ion temperature to include the effects of inelastic ion-molecular collisions, we have been able to condense peak position dependence on separation field and temperature to dependence on a redefined effective temperature including a smoothly varying inelasticity correction. It allows prediction and correction of the gas temperature effect on DMS peak positions.

  10. 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

  11. 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.

  12. 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

  13. 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...

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.)

  1. Structural analyses of sucrose laurate regioisomers by mass spectrometry techniques

    DEFF Research Database (Denmark)

    Lie, Aleksander; Stensballe, Allan; Pedersen, Lars Haastrup

    2015-01-01

    6- And 6′-O-lauroyl sucrose were isolated and analyzed by matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) mass spectrometry (MS), Orbitrap high-resolution (HR) MS, and electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). The analyses aimed to explore 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...

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

    International Nuclear Information System (INIS)

    Yu, Xiangying; Yao, Zhong-Ping

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-22

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

  4. 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)

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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...

  11. COPD Exacerbation Biomarkers Validated Using Multiple Reaction Monitoring Mass Spectrometry.

    Directory of Open Access Journals (Sweden)

    Janice M Leung

    Full Text Available Acute exacerbations of chronic obstructive pulmonary disease (AECOPD result in considerable morbidity and mortality. However, there are no objective biomarkers to diagnose AECOPD.We used multiple reaction monitoring mass spectrometry to quantify 129 distinct proteins in plasma samples from patients with COPD. This analytical approach was first performed in a biomarker cohort of patients hospitalized with AECOPD (Cohort A, n = 72. Proteins differentially expressed between AECOPD and convalescent states were chosen using a false discovery rate 1.2. Protein selection and classifier building were performed using an elastic net logistic regression model. The performance of the biomarker panel was then tested in two independent AECOPD cohorts (Cohort B, n = 37, and Cohort C, n = 109 using leave-pair-out cross-validation methods.Five proteins were identified distinguishing AECOPD and convalescent states in Cohort A. Biomarker scores derived from this model were significantly higher during AECOPD than in the convalescent state in the discovery cohort (p<0.001. The receiver operating characteristic cross-validation area under the curve (CV-AUC statistic was 0.73 in Cohort A, while in the replication cohorts the CV-AUC was 0.77 for Cohort B and 0.79 for Cohort C.A panel of five biomarkers shows promise in distinguishing AECOPD from convalescence and may provide the basis for a clinical blood test to diagnose AECOPD. Further validation in larger cohorts is necessary for future clinical translation.

  12. Mass Spectrometry Imaging, an Emerging Technology in Neuropsychopharmacology

    Science.gov (United States)

    Shariatgorji, Mohammadreza; Svenningsson, Per; Andrén, Per E

    2014-01-01

    Mass spectrometry imaging is a powerful tool for directly determining the distribution of proteins, peptides, lipids, neurotransmitters, metabolites and drugs in neural tissue sections in situ. Molecule-specific imaging can be achieved using various ionization techniques that are suited to different applications but which all yield data with high mass accuracies and spatial resolutions. The ability to simultaneously obtain images showing the distributions of chemical species ranging from metal ions to macromolecules makes it possible to explore the chemical organization of a sample and to correlate the results obtained with specific anatomical features. The imaging of biomolecules has provided new insights into multiple neurological diseases, including Parkinson's and Alzheimer's disease. Mass spectrometry imaging can also be used in conjunction with other imaging techniques in order to identify correlations between changes in the distribution of important chemical species and other changes in the properties of the tissue. Here we review the applications of mass spectrometry imaging in neuroscience research and discuss its potential. The results presented demonstrate that mass spectrometry imaging is a useful experimental method with diverse applications in neuroscience. PMID:23966069

  13. 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.

  14. 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

  15. 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

  16. 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)

  17. 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)

  18. Mass spectrometry based proteomics in cell biology and signaling research

    International Nuclear Information System (INIS)

    Mann, M.; Andersen, J.; Ishihama, Y.; Rappsilber, J.; Ong, S.; Foster, L.; Blagoev, B.; Kratchmarova, I.; Lasonder, E.

    2002-01-01

    Full text: Proteomics is one of the most powerful post-genomics technologies. Recently accomplishments include large scale protein-protein interaction mapping, large scale mapping of phosphorylation sites and the cloning of key signaling molecules. In this talk, current state of the art of the technology will be reviewed. Applications of proteomics to the mapping of multiprotein complexes will be illustrated with recent work on the spliceosome and the nucleolus. More than 300 proteins have been mapped to each of these complexes. Quantitative techniques are becoming more and more essential in proteomics. They are usually performed by the incorporation of stable isotopes - a light form in cell state 'A' and a heavy form in cell state 'E' - and subsequent comparison of mass spectrometric peak heights. A new technique called, SILAC for Stable isotope Incorporation by Amino acids in Cell culture, has been applied to studying cell differentiation and mapping secreted proteins from adipocytes. A number of known and novel proteins important in adipocyte differentiation have been identified by this technique. Some of these proved to be upregulated at the 1 mRNA level, too, whereas others appear to be regulated post-translationally. We have also applied the SILAC method to protein-protein interaction mapping. For example, we compared immunoprecipitates from stimulated and non-stimulated cells to find binding partners recruited to the bait due to the stimulus. Several novel substrates in the EGF pathway were found in this way. An important application of proteomics in the signaling field is the mapping of post-translational modifications. In particular, there are a number of techniques for phosphotyrosine phosphorylation mapping which have proven very useful. Making use of the mass deficiency of the phosphogroup, 'parent ion scans' con be performed, which selectively reveal phosphotyrosine peptides from complex peptides mixtures. This technique has been used to clone several

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. 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.)

  5. 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.)

  6. 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.

  7. 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

  8. Characterization of Seed Storage Proteins from Chickpea Using 2D Electrophoresis Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Singh

    2016-01-01

    Full Text Available Proteomic analysis was employed to map the seed storage protein network in landrace and cultivated chickpea accessions. Protein extracts were separated by two-dimensional gel electrophoresis (2D-GE across a broad range 3.0–10.0 immobilized pH gradient (IPG strips. Comparative elucidation of differentially expressed proteins between two diverse geographically originated chickpea accessions was carried out using 2D-GE coupled with mass spectrometry. A total of 600 protein spots were detected in these accessions. In-gel protein expression patterns revealed three protein spots as upregulated and three other as downregulated. Using trypsin in-gel digestion, these differentially expressed proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS which showed 45% amino acid homology of chickpea seed storage proteins with Arabidopsis thaliana.

  9. 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.

  10. 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.

  11. 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)

  12. 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)

  13. 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

  14. 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

  15. 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…

  16. 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.)

  17. 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)

  18. 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...

  19. 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

  20. 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

  1. 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

  2. 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...

  3. 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

  4. Yeast expression proteomics by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

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

    2010-01-01

    -translational controls contribute majorly to regulation of protein abundance, for example in heat shock stress response. The development of new sample preparation methods, high-resolution mass spectrometry and novel bioinfomatic tools close this gap and allow the global quantitation of the yeast proteome under different...

  5. 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…

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.)

  11. 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

  12. 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...

  13. 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

  14. 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)

  15. 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

  16. 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 ...

  17. 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

  18. 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

  19. 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....

  20. 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)

  1. 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...

  2. 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

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

    OpenAIRE

    Yoon, Hye-Ran

    2015-01-01

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

  5. Characterization of Seed Storage Proteins from Chickpea Using 2D Electrophoresis Coupled with Mass Spectrometry

    OpenAIRE

    Singh, Pramod Kumar; Shrivastava, Nidhi; Chaturvedi, Krishna; Sharma, Bechan; Bhagyawant, Sameer S.

    2016-01-01

    Proteomic analysis was employed to map the seed storage protein network in landrace and cultivated chickpea accessions. Protein extracts were separated by two-dimensional gel electrophoresis (2D-GE) across a broad range 3.0–10.0 immobilized pH gradient (IPG) strips. Comparative elucidation of differentially expressed proteins between two diverse geographically originated chickpea accessions was carried out using 2D-GE coupled with mass spectrometry. A total of 600 protein spots were detected ...

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Hands-on Electrospray Ionization-Mass Spectrometry for Upper-Level Undergraduate and Graduate Students

    Science.gov (United States)

    Stock, Naomi L.; March, Raymond E.

    2014-01-01

    Electrospray ionization-mass spectrometry (ESI-MS) is a powerful technique for the detection, identification, and quantification of organic compounds. As mass spectrometers have become more user-friendly and affordable, many students--often with little experience in mass spectrometry--find themselves needing to incorporate mass spectrometry into…

  12. 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

  13. 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...

  14. 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)

  15. 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.

  16. 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.

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

    Science.gov (United States)

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

    2010-11-01

    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.

  18. 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

  19. 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.

  20. 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.)

  1. 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.)

  2. 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.

  3. Characterization of phenolic amides from cortex lycii by ultra high-performance liquid chromatography coupled with LTQ-Orbitrap mass spectrometry

    Science.gov (United States)

    High performance liquid chromatography (UPLC) and flow injection electrospray ionization with ion trap mass spectrometry (FIMS) fingerprints combined with the principal component analysis (PCA) were examined for their potential in differentiating commercial organic and conventional sage samples. The...

  4. 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

  5. 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.

  6. 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.)

  7. Atmospheric pressure plasma analysis by modulated molecular beam mass spectrometry

    NARCIS (Netherlands)

    Aranda Gonzalvo, Y.; Whitmore, T.D.; Rees, J.A.; Seymour, D.L.; Stoffels - Adamowicz, E.

    2006-01-01

    Fractional no. d. measurements for a radiofrequency plasma needle operating at atm. pressure were obtained using a mol. beam mass spectrometer (MBMS) system designed for diagnostics of atm. plasmas. The MBMS system comprises three differentially pumped stages and a mass/energy analyzer and includes

  8. 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…

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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.)

  17. 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

  18. 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

  19. 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)

  20. 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

  1. Using Spores for Fusarium spp. Classification by MALDI-Based Intact Cell/Spore Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Wolfgang Winkler

    2012-01-01

    Full Text Available Fusarium is a widespread genus of filamentous fungi and a member of the soil microbial community. Certain subspecies are health threatening because of their mycotoxin production that affects the human and animal food chain. Thus, for early and effective pest control, species identification is of particular interest; however, differentiation on the subspecies level is challenging and time-consuming for this fungus. In the present study, we show the possibilities of intact cell mass spectrometry for spore analysis of 22 different Fusarium strains belonging to six Fusarium subspecies. We found that species differentiation is possible if mass spectrometric analyses are performed under well-defined conditions with fixed parameters. A critical point for analysis is a proper sample preparation of spores, which increases the quality of mass spectra with respect to signal intensity and m/z value variations. It was concluded that data acquistion has to be performed automatically; otherwise, user-specific variations are introduced generating data which cannot fit the existing datasets. Data that show clearly that matrix-assisted laser desorption ionization-based intact cell/intact spore mass spectrometry (IC/ISMS can be applied to differentiate closely related Fusarium spp. are presented. Results show a potential to build a database on Fusarium species for accurate species identification, for fast response in the case of infections in the cornfield. We furthermore demonstrate the high precision of our approach in classification of intact Fusarium species according to the location of their collection.

  2. 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)

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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...

  9. 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...

  10. 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

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. A method for differentiating between vinegar produced by fermentation and vinegar made from synthetic acetic acid based on determination of 13C/12C-isotope ratio by mass spectrometry

    International Nuclear Information System (INIS)

    Schmid, E.R.; Fogy, I.

    1978-01-01

    The 13 C/ 12 C-isotope ratio is characteristic for vinegar of fermentation and synthetic origin respectively and used for their differentiation. The acetic acid was isolated from the vinegar as calcium acetate, the calcium acetate was pyrolysed to CaCO 3 and the CO 2 was released from the CaCO 3 with H 3 PO 4 . The CO 2 was measured in a mass spectrometer with double collector. The difference in the 13 C- content between the two varieties of vinegar is 5 0 / 00 ; the accuracy of the measurement is between 0,5 0 / 00 and 1 0 / 00 . Therefore, addition of synthetic acetic acid in excess of 15-20% to fermentation vinegar can be detected by this method. (orig.) [de

  18. Method for differentiating between vinegar produced by fermentation and vinegar made from synthetic acetic acid based on determination of the /sup 13/C//sup 12/C-isotope ratio by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, E R; Fogy, I [Vienna Univ. (Austria). Inst. fuer Analytische Chemie; Schwartz, P [International Atomic Energy Agency, Vienna (Austria)

    1978-02-01

    The /sup 13/C//sup 12/C-isotope ratio is characteristic for vinegar of fermentation and synthetic origin respectively and used for their differentiation. The acetic acid was isolated from the vinegar as calcium acetate, the calcium acetate was pyrolysed to CaCO/sub 3/ and the CO/sub 2/ was released from the CaCO/sub 3/ with H/sub 3/PO/sub 4/. The CO/sub 2/ was measured in a mass spectrometer with double collector. The difference in the /sup 13/C- content between the two varieties of vinegar is 5/sup 0///sub 00/; the accuracy of the measurement is between 0,5/sup 0///sub 00/ and 1/sup 0///sub 00/. Therefore, addition of synthetic acetic acid in excess of 15 to 20% to fermentation vinegar can be detected by this method.

  19. 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...

  20. 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.

  1. 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.

  2. A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements

    Science.gov (United States)

    Identification and differentiation of anthocyanins and non-anthocyanin compounds in natural products can be very difficult by mass spectrometry. Using a ultra-violet/visible detector can be helpful, but not fool-proof, and it requires an additional detector. To solve the problem, a fast and reliab...

  3. Recent advances in applying mass spectrometry and systems biology to determine brain dynamics.

    Science.gov (United States)

    Scifo, Enzo; Calza, Giulio; Fuhrmann, Martin; Soliymani, Rabah; Baumann, Marc; Lalowski, Maciej

    2017-06-01

    Neurological disorders encompass various pathologies which disrupt normal brain physiology and function. Poor understanding of their underlying molecular mechanisms and their societal burden argues for the necessity of novel prevention strategies, early diagnostic techniques and alternative treatment options to reduce the scale of their expected increase. Areas covered: This review scrutinizes mass spectrometry based approaches used to investigate brain dynamics in various conditions, including neurodegenerative and neuropsychiatric disorders. Different proteomics workflows for isolation/enrichment of specific cell populations or brain regions, sample processing; mass spectrometry technologies, for differential proteome quantitation, analysis of post-translational modifications and imaging approaches in the brain are critically deliberated. Future directions, including analysis of cellular sub-compartments, targeted MS platforms (selected/parallel reaction monitoring) and use of mass cytometry are also discussed. Expert commentary: Here, we summarize and evaluate current mass spectrometry based approaches for determining brain dynamics in health and diseases states, with a focus on neurological disorders. Furthermore, we provide insight on current trends and new MS technologies with potential to improve this analysis.

  4. Cylinder with differential piston for mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bordeaşu, I.; Bălăşoiu, V. [Universitatea Politehnica din Timişoara, Timosoara (Romania); Hadă, A. [UniversitateaPolitehnicaBucureşti, Bucureşti (Romania); Popoviciu, M. [Academy of Romanian ScientistsTimişoara Branch (Romania)

    2007-07-01

    The paper presents a cylinder with differential piston, adapted for measuring the weight of fixed objects such as: fuel tanks (regardless of their capacity), bunkers and silos for all kind of materials, or mobile objects such as: automobiles, trucks, locomotives and railway cars. Although, the cylinder with differential piston is used on a large scale in hydraulic drive or hydraulic control circuits, till now it was not used as constituent part for weight measurements devices. The novelty of the present paper is precisely the use of the device for such purposes. Based on a computation algorithm, the paper presents the general design (assembly), of the device used for weighing important masses (1…. 100 tones). The fundamental idea consist in the fact that, a mass over 10 tones may be weighted with a helicoidally spring subjected to an axial force between 0 and 3000 N, with a deflection of about 30 mm. Simultaneously with the mechanical part, the electronic recording system is also described. The great advantage of the presented device consist in the fact that it can be used in heavy polluted atmosphere or difficult topographic conditions as a result of both the small dimensions and the protection systems adopted. Keywords: cylinder hydraulic with differential piston, hydrostatic pressure, measuring devices.

  5. 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'.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Hooked differential mobility spectrometry apparatus and method therefore

    Science.gov (United States)

    Shvartsburg, Alexandre A [Richland, WA; Tang, Keqi [Richland, WA; Ibrahim, Yehia M [Richland, WA; Smith, Richard D [Richland, WA

    2009-02-17

    Disclosed are a device and method for improved interfacing of differential mobility spectrometry (DMS) or field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of substantially planar geometry to subsequent or preceding instrument stages. Interfacing is achieved using curved DMS elements, where a thick ion beam emitted by planar DMS analyzers or injected into them for ion filtering is compressed to the gap median by DMS ion focusing effect in a spatially inhomogeneous electric field. Resulting thinner beams are more effectively transmitted through necessarily constrained conductance limit apertures to subsequent instrument stages operated at a pressure lower than DMS, and/or more effectively injected into planar DMS analyzers. The technology is synergetic with slit apertures, slit aperture/ion funnels, and high-pressure ion funnel interfaces known in the art which allow for increasing cross-sectional area of MS inlets. The invention may be used in integrated analytical platforms, including, e.g., DMS/MS, LC/DMS/MS, and DMS/IMS/MS that could replace and/or enhance current LC/MS methods, e.g., for proteomics research.

  11. 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)

  12. 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.

  13. Detection of biological particles in ambient air using Bio-Aerosol Mass Spectrometry

    International Nuclear Information System (INIS)

    McJimpsey, E L; Steele, P T; Coffee, K R; Fergenson, D P; Riot, V J; Woods, B W; Gard, E E; Frank, M; Tobias, H J; Lebrilla, C

    2006-01-01

    The Bio-Aerosol Mass Spectrometry (BAMS) system is an instrument used for the real time detection and identification of biological aerosols. Particles are drawn from the atmosphere directly into vacuum and tracked as they scatter light from several continuous wave lasers. After tracking, the fluorescence of individual particles is excited by a pulsed 266nm or 355nm laser. Molecules from those particles with appropriate fluorescence properties are subsequently desorbed and ionized using a pulsed 266nm laser. Resulting ions are analyzed in a dual polarity mass spectrometer. During two field deployments at the San Francisco International Airport, millions of ambient particles were analyzed and a small but significant fraction were found to have fluorescent properties similar to Bacillus spores and vegetative cells. Further separation of non-biological background particles from potential biological particles was accomplished using laser desorption/ionization mass spectrometry. This has been shown to enable some level of species differentiation in specific cases, but the creation and observation of higher mass ions is needed to enable a higher level of specificity across more species. A soft ionization technique, matrix-assisted laser desorption/ionization (MALDI) is being investigated for this purpose. MALDI is particularly well suited for mass analysis of biomolecules since it allows for the generation of molecular ions from large mass compounds that would fragment under normal irradiation. Some of the initial results from a modified BAMS system utilizing this technique are described

  14. Rapid species specific identification and subtyping of Yersinia enterocolitica by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Stephan, Roger; Cernela, Nicole; Ziegler, Dominik; Pflüger, Valentin; Tonolla, Mauro; Ravasi, Damiana; Fredriksson-Ahomaa, Maria; Hächler, Herbert

    2011-11-01

    Yersinia enterocolitica are Gram-negative pathogens and known as important causes of foodborne infections. Rapid and reliable identification of strains of the species Y. enterocolitica within the genus Yersinia and the differentiation of the pathogenic from the non-pathogenic biotypes has become increasingly important. We evaluated here the application of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid species identification and subtyping of Y. enterocolitica. To this end, we developed a reference MS database library including 19 Y. enterocolitica (non-pathogenic biotype 1A and pathogenic biotypes 2 and 4) as well as 24 non-Y. enterocolitica strains, belonging to eleven different other Yersinia spp. The strains provided reproducible and unique mass spectra profiles covering a wide molecular mass range (2000 to 30,000 Da). Species-specific and biotype-specific biomarker protein mass patterns were determined for Y. enterocolitica. The defined biomarker mass patterns (SARAMIS SuperSpectrum™) were validated using 117 strains from various Y. enterocolitica bioserotypes in a blind-test. All strains were correctly identified and for all strains the mass spectrometry-based identification scheme yielded identical results compared to a characterization by a combination of biotyping and serotyping. Our study demonstrates that MALDI-TOF-MS is a reliable and powerful tool for the rapid identification of Y. enterocolitica strains to the species level and allows subtyping of strains to the biotype level. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. 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

  16. 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…

  17. 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

  18. 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

  19. 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,

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

    International Nuclear Information System (INIS)

    Tanner, Scott D.; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I.

    2007-01-01

    Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration

  8. Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, Scott D. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)], E-mail: sd.tanner@utoronto.ca; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)

    2007-03-15

    Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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).

  15. 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.)

  16. 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

  17. 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.

  18. 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.

  19. 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.)

  20. 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.)

  1. 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

  2. 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.).

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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)

  14. 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

  15. Tracking juniper berry content in oils and distillates by spectral deconvolution of gas chromatography/mass spectrometry data.

    Science.gov (United States)

    Robbat, Albert; Kowalsick, Amanda; Howell, Jessalin

    2011-08-12

    The complex nature of botanicals and essential oils makes it difficult to identify all of the constituents by gas chromatography/mass spectrometry (GC/MS) alone. In this paper, automated sequential, multidimensional gas chromatography/mass spectrometry (GC-GC/MS) was used to obtain a matrix-specific, retention time/mass spectrometry library of 190 juniper berry oil compounds. GC/MS analysis on stationary phases with different polarities confirmed the identities of each compound when spectral deconvolution software was used to analyze the oil. Also analyzed were distillates of juniper berry and its oil as well as gin from four different manufacturers. Findings showed the chemical content of juniper berry can be traced from starting material to final product and can be used to authenticate and differentiate brands. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Urinary metabonomics study in a rat model in response to protein-energy malnutrition by using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Wu, Zeming; Li, Min; Zhao, Chunxia; Zhou, Jia; Chang, Yuwei; Li, Xiang; Gao, Peng; Lu, Xin; Li, Yousheng; Xu, Guowang

    2010-11-01

    Systematic studies were performed on the biological perturbations in metabolic phenotype responding to protein-energy malnutrition through global metabolic profiling analysis, in combination with pattern recognition. The malnutrition rat model was established through five weeks of strict diet restriction, and the metabonome data obtained from gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were integrated to approximate the comprehensive metabolic signature. Principal component analysis and orthogonal projection to latent structure analysis were used for the classification of metabolic phenotypes and discovery of differentiating metabolites. The perturbations in the urine profiles of malnourished rats were marked by higher levels of creatine, threitol, pyroglutamic acid, gluconic acid and kynurenic acid, as well as decreased levels of succinic acid, cis-aconitic acid, citric acid, isocitric acid, threonic acid, trimethylglycine, N-methylnicotinic acid and uric acid. The alterations in these metabolites were associated with perturbations in energy metabolism, carbohydrate, amino acid, and fatty acid metabolism, purine metabolism, cofactor and vitamin metabolism, in response to protein and energy malnutrition. Our findings show the integration of GC-MS and LC-MS techniques for untargeted metabolic profiling analysis was promising for nutriology.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Determination of plutonium in soils by mass spectrometry

    International Nuclear Information System (INIS)

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

    1974-01-01

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

  5. Origin of the chemical noise in ambient mass spectrometry

    International Nuclear Information System (INIS)

    Yang Shuiping; Zhu Zhiqiang; Huang Longzhu; Zhang Xinglei; Zhu Tenggao; Chen Huanwen

    2012-01-01

    The instrumental background of ambient mass spectrometry, (API-MS) is analyzed and the possible potential origins of the background noise is identified. According to the mass spectra obtained using the API-MS instruments by different manufacturers, the characteristic fragment ions all indicated that the background noise are resulted from the phthalates such as diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), bis (2-ethylhexyl) phthalate (DEHP), and silicones such as decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6). These chemicals are probably released from the polymeric materials used in the ionization sources, such as O-type sealing ring etc. In addition, the instrumental background has to be considered especially during the analysis of phthalate and peptide compounds. (authors)

  6. The quest for improved reproducibility in MALDI mass spectrometry.

    Science.gov (United States)

    O'Rourke, Matthew B; Djordjevic, Steven P; Padula, Matthew P

    2018-03-01

    Reproducibility has been one of the biggest hurdles faced when attempting to develop quantitative protocols for MALDI mass spectrometry. The heterogeneous nature of sample recrystallization has made automated sample acquisition somewhat "hit and miss" with manual intervention needed to ensure that all sample spots have been analyzed. In this review, we explore the last 30 years of literature and anecdotal evidence that has attempted to address and improve reproducibility in MALDI MS. Though many methods have been attempted, we have discovered a significant publication history surrounding the use of nitrocellulose as a substrate to improve homogeneity of crystal formation and therefore reproducibility. We therefore propose that this is the most promising avenue of research for developing a comprehensive and universal preparation protocol for quantitative MALDI MS analysis. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:217-228, 2018. © 2016 Wiley Periodicals, Inc.

  7. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

    Full Text Available The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc. on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed subjected to a wide range of conditions.

  8. Tyrosine residues modification studied by MALDI-TOF mass spectrometry

    International Nuclear Information System (INIS)

    Santrucek, Jiri; Strohalm, Martin; Kadlcik, Vojtech; Hynek, Radovan; Kodicek, Milan

    2004-01-01

    Amino acid residue-specific reactivity in proteins is of great current interest in structural biology as it provides information about solvent accessibility and reactivity of the residue and, consequently, about protein structure and possible interactions. In the work presented tyrosine residues of three model proteins with known spatial structure are modified with two tyrosine-specific reagents: tetranitromethane and iodine. Modified proteins were specifically digested by proteases and the mass of resulting peptide fragments was determined using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Our results show that there are only small differences in the extent of tyrosine residues modification by tetranitromethane and iodine. However, data dealing with accessibility of reactive residues obtained by chemical modifications are not completely identical with those obtained by nuclear magnetic resonance and X-ray crystallography. These interesting discrepancies can be caused by local molecular dynamics and/or by specific chemical structure of the residues surrounding

  9. Statistical analysis of proteomics, metabolomics, and lipidomics data using mass spectrometry

    CERN Document Server

    Mertens, Bart

    2017-01-01

    This book presents an overview of computational and statistical design and analysis of mass spectrometry-based proteomics, metabolomics, and lipidomics data. This contributed volume provides an introduction to the special aspects of statistical design and analysis with mass spectrometry data for the new omic sciences. The text discusses common aspects of design and analysis between and across all (or most) forms of mass spectrometry, while also providing special examples of application with the most common forms of mass spectrometry. Also covered are applications of computational mass spectrometry not only in clinical study but also in the interpretation of omics data in plant biology studies. Omics research fields are expected to revolutionize biomolecular research by the ability to simultaneously profile many compounds within either patient blood, urine, tissue, or other biological samples. Mass spectrometry is one of the key analytical techniques used in these new omic sciences. Liquid chromatography mass ...

  10. Hyperthermal surface ionization mass spectrometry of organic molecules: monoterpenes

    International Nuclear Information System (INIS)

    Kishi, Hiroshi; Fujii, Toshihiro.

    1997-01-01

    This paper describes an experimental study on the influence of kinetic energy of fast monoterpene molecules on the surface ionization efficiency and on the mass spectral patterns, using rhenium oxide (ReO 2 ) surface. Molecular kinetic energy, given to the molecules through the acceleration in the seeded supersonic molecular beam, ranged from 1 to 10 eV. Hyperthermal surface ionization mass spectra (HSIMS) were taken for various incident kinetic energies and surface temperatures. The observed mass spectra were interpreted in a purely empirical way, by means of evidence from the previous investigations, and they were compared with conventional EI techniques and with the thermal energy surface ionization technique (SIOMS; Surface Ionization Organic Mass Spectrometry). Ionization efficiency (β) was also studied. Under hyperthermal surface ionization (HSI) conditions, many kinds of fragment ions, including quite abundant odd electron ions (OE +· ) are observed. HSIMS patterns of monoterpenes are different among 6-isomers, contrary to those of SIOMS and EIMS, where very similar patterns for isomers are observed. HSIMS patterns are strongly dependent on the molecular kinetic energies. The surface temperature does not affect much the spectral patterns, but it controls the total amount of ion formation. We conclude from these mass spectral findings, HSI-mechanism contains an impulsive process of ion formation, followed by the fragmentation process as a results of the internal energies acquired through the collision processes. (author)

  11. Advances in ultrasensitive mass spectrometry of organic molecules.

    Science.gov (United States)

    Kandiah, Mathivathani; Urban, Pawel L

    2013-06-21

    Ultrasensitive mass spectrometric analysis of organic molecules is important for various branches of chemistry, and other fields including physics, earth and environmental sciences, archaeology, biomedicine, and materials science. It finds applications--as an enabling tool--in systems biology, biological imaging, clinical analysis, and forensics. Although there are a number of technical obstacles associated with the analysis of samples by mass spectrometry at ultratrace level (for example analyte losses during sample preparation, insufficient sensitivity, ion suppression), several noteworthy developments have been made over the years. They include: sensitive ion sources, loss-free interfaces, ion optics components, efficient mass analyzers and detectors, as well as "smart" sample preparation strategies. Some of the mass spectrometric methods published to date can achieve sensitivity which is by several orders of magnitude higher than that of alternative approaches. Femto- and attomole level limits of detection are nowadays common, while zepto- and yoctomole level limits of detection have also been reported. We envision that the ultrasensitive mass spectrometric assays will soon contribute to new discoveries in bioscience and other areas.

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

    Science.gov (United States)

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

    2016-02-01

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

  13. Quantitation of DNA adducts by stable isotope dilution mass spectrometry

    Science.gov (United States)

    Tretyakova, Natalia; Goggin, Melissa; Janis, Gregory

    2012-01-01

    Exposure to endogenous and exogenous chemicals can lead to the formation of structurally modified DNA bases (DNA adducts). If not repaired, these nucleobase lesions can cause polymerase errors during DNA replication, leading to heritable mutations potentially contributing to the development of cancer. Due to their critical role in cancer initiation, DNA adducts represent mechanism-based biomarkers of carcinogen exposure, and their quantitation is particularly useful for cancer risk assessment. DNA adducts are also valuable in mechanistic studies linking tumorigenic effects of environmental and industrial carcinogens to specific electrophilic species generated from their metabolism. While multiple experimental methodologies have been developed for DNA adduct analysis in biological samples – including immunoassay, HPLC, and 32P-postlabeling – isotope dilution high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) generally has superior selectivity, sensitivity, accuracy, and reproducibility. As typical DNA adducts concentrations in biological samples are between 0.01 – 10 adducts per 108 normal nucleotides, ultrasensitive HPLC-ESI-MS/MS methodologies are required for their analysis. Recent developments in analytical separations and biological mass spectrometry – especially nanoflow HPLC, nanospray ionization MS, chip-MS, and high resolution MS – have pushed the limits of analytical HPLC-ESI-MS/MS methodologies for DNA adducts, allowing researchers to accurately measure their concentrations in biological samples from patients treated with DNA alkylating drugs and in populations exposed to carcinogens from urban air, drinking water, cooked food, alcohol, and cigarette smoke. PMID:22827593

  14. Computational methods for protein identification from mass spectrometry data.

    Directory of Open Access Journals (Sweden)

    Leo McHugh

    2008-02-01

    Full Text Available Protein identification using mass spectrometry is an indispensable computational tool in the life sciences. A dramatic increase in the use of proteomic strategies to understand the biology of living systems generates an ongoing need for more effective, efficient, and accurate computational methods for protein identification. A wide range of computational methods, each with various implementations, are available to complement different proteomic approaches. A solid knowledge of the range of algorithms available and, more critically, the accuracy and effectiveness of these techniques is essential to ensure as many of the proteins as possible, within any particular experiment, are correctly identified. Here, we undertake a systematic review of the currently available methods and algorithms for interpreting, managing, and analyzing biological data associated with protein identification. We summarize the advances in computational solutions as they have responded to corresponding advances in mass spectrometry hardware. The evolution of scoring algorithms and metrics for automated protein identification are also discussed with a focus on the relative performance of different techniques. We also consider the relative advantages and limitations of different techniques in particular biological contexts. Finally, we present our perspective on future developments in the area of computational protein identification by considering the most recent literature on new and promising approaches to the problem as well as identifying areas yet to be explored and the potential application of methods from other areas of computational biology.

  15. Optimal selection of epitopes for TXP-immunoaffinity mass spectrometry

    Directory of Open Access Journals (Sweden)

    Joos Thomas

    2010-06-01

    Full Text Available Abstract Background Mass spectrometry (MS based protein profiling has become one of the key technologies in biomedical research and biomarker discovery. One bottleneck in MS-based protein analysis is sample preparation and an efficient fractionation step to reduce the complexity of the biological samples, which are too complex to be analyzed directly with MS. Sample preparation strategies that reduce the complexity of tryptic digests by using immunoaffinity based methods have shown to lead to a substantial increase in throughput and sensitivity in the proteomic mass spectrometry approach. The limitation of using such immunoaffinity-based approaches is the availability of the appropriate peptide specific capture antibodies. Recent developments in these approaches, where subsets of peptides with short identical terminal sequences can be enriched using antibodies directed against short terminal epitopes, promise a significant gain in efficiency. Results We show that the minimal set of terminal epitopes for the coverage of a target protein list can be found by the formulation as a set cover problem, preceded by a filtering pipeline for the exclusion of peptides and target epitopes with undesirable properties. Conclusions For small datasets (a few hundred proteins it is possible to solve the problem to optimality with moderate computational effort using commercial or free solvers. Larger datasets, like full proteomes require the use of heuristics.

  16. Optimal selection of epitopes for TXP-immunoaffinity mass spectrometry.

    Science.gov (United States)

    Planatscher, Hannes; Supper, Jochen; Poetz, Oliver; Stoll, Dieter; Joos, Thomas; Templin, Markus F; Zell, Andreas

    2010-06-25

    Mass spectrometry (MS) based protein profiling has become one of the key technologies in biomedical research and biomarker discovery. One bottleneck in MS-based protein analysis is sample preparation and an efficient fractionation step to reduce the complexity of the biological samples, which are too complex to be analyzed directly with MS. Sample preparation strategies that reduce the complexity of tryptic digests by using immunoaffinity based methods have shown to lead to a substantial increase in throughput and sensitivity in the proteomic mass spectrometry approach. The limitation of using such immunoaffinity-based approaches is the availability of the appropriate peptide specific capture antibodies. Recent developments in these approaches, where subsets of peptides with short identical terminal sequences can be enriched using antibodies directed against short terminal epitopes, promise a significant gain in efficiency. We show that the minimal set of terminal epitopes for the coverage of a target protein list can be found by the formulation as a set cover problem, preceded by a filtering pipeline for the exclusion of peptides and target epitopes with undesirable properties. For small datasets (a few hundred proteins) it is possible to solve the problem to optimality with moderate computational effort using commercial or free solvers. Larger datasets, like full proteomes require the use of heuristics.

  17. Mass Spectrometry Coupled Experiments and Protein Structure Modeling Methods

    Directory of Open Access Journals (Sweden)

    Lee Sael

    2013-10-01

    Full Text Available With the accumulation of next generation sequencing data, there is increasing interest in the study of intra-species difference in molecular biology, especially in relation to disease analysis. Furthermore, the dynamics of the protein is being identified as a critical factor in its function. Although accuracy of protein structure prediction methods is high, provided there are structural templates, most methods are still insensitive to amino-acid differences at critical points that may change the overall structure. Also, predicted structures are inherently static and do not provide information about structural change over time. It is challenging to address the sensitivity and the dynamics by computational structure predictions alone. However, with the fast development of diverse mass spectrometry coupled experiments, low-resolution but fast and sensitive structural information can be obtained. This information can then be integrated into the structure prediction process to further improve the sensitivity and address the dynamics of the protein structures. For this purpose, this article focuses on reviewing two aspects: the types of mass spectrometry coupled experiments and structural data that are obtainable through those experiments; and the structure prediction methods that can utilize these data as constraints. Also, short review of current efforts in integrating experimental data in the structural modeling is provided.

  18. Increasing Protein Charge State When Using Laser Electrospray Mass Spectrometry

    Science.gov (United States)

    Karki, Santosh; Flanigan, Paul M.; Perez, Johnny J.; Archer, Jieutonne J.; Levis, Robert J.

    2015-05-01

    Femtosecond (fs) laser vaporization is used to transfer cytochrome c, myoglobin, lysozyme, and ubiquitin from the condensed phase into an electrospray (ES) plume consisting of a mixture of a supercharging reagent, m-nitrobenzyl alcohol ( m-NBA), and trifluoroacetic acid (TFA), acetic acid (AA), or formic acid (FA). Interaction of acid-sensitive proteins like cytochrome c and myoglobin with the highly charged ES droplets resulted in a shift to higher charge states in comparison with acid-stable proteins like lysozyme and ubiquitin. Laser electrospray mass spectrometry (LEMS) measurements showed an increase in both the average charge states (Zavg) and the charge state with maximum intensity (Zmode) for acid-sensitive proteins compared with conventional electrospray ionization mass spectrometry (ESI-MS) under equivalent solvent conditions. A marked increase in ion abundance of higher charge states was observed for LEMS in comparison with conventional electrospray for cytochrome c (ranging from 19+ to 21+ versus 13+ to 16+) and myoglobin (ranging from 19+ to 26+ versus 18+ to 21+) using an ES solution containing m-NBA and TFA. LEMS measurements as a function of electrospray flow rate yielded increasing charge states with decreasing flow rates for cytochrome c and myoglobin.

  19. Expanded newborn screening by mass spectrometry: New tests, future perspectives.

    Science.gov (United States)

    Ombrone, Daniela; Giocaliere, Elisa; Forni, Giulia; Malvagia, Sabrina; la Marca, Giancarlo

    2016-01-01

    Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second-tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X-adrenoleucodistrophy (X-ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second-tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs. © 2015 Wiley Periodicals, Inc.

  20. Automated spike preparation system for Isotope Dilution Mass Spectrometry (IDMS)

    International Nuclear Information System (INIS)

    Maxwell, S.L. III; Clark, J.P.

    1990-01-01

    Isotope Dilution Mass Spectrometry (IDMS) is a method frequently employed to measure dissolved, irradiated nuclear materials. A known quantity of a unique isotope of the element to be measured (referred to as the ''spike'') is added to the solution containing the analyte. The resulting solution is chemically purified then analyzed by mass spectrometry. By measuring the magnitude of the response for each isotope and the response for the ''unique spike'' then relating this to the known quantity of the ''spike'', the quantity of the nuclear material can be determined. An automated spike preparation system was developed at the Savannah River Site (SRS) to dispense spikes for use in IDMS analytical methods. Prior to this development, technicians weighed each individual spike manually to achieve the accuracy required. This procedure was time-consuming and subjected the master stock solution to evaporation. The new system employs a high precision SMI Model 300 Unipump dispenser interfaced with an electronic balance and a portable Epson HX-20 notebook computer to automate spike preparation