Integrated Fourier transform infrared spectroscopy and gas chromatography tandem mass spectrometry for forensic engine lubricating oil and biodiesel analysis

International Nuclear Information System (INIS)

Shang, D.

2009-01-01

Gas chromatography/mass spectrometry(GC/MS) is commonly used for oil fingerprinting and provides investigators with good forensic data. However, new challenges face oil spill forensic chemistry with the growing use of biodiesel as well as the recycling and reprocessing of used oil, particularly lubricating oils. This paper demonstrated that Fourier transform infrared (FTIR) spectroscopy may be a fast, cost effective and complementary method for forensic analysis of biodiesels (fatty acid methyl esters) and lubricating oils. Attenuated total reflectance (ATR)-FTIR spectroscopy was shown to be an interesting analytic method because of its use in monitoring and quantifying minor chemical compounds in sample matrices and its ability to identify a broad range or organic compounds. Unlike chromatography, FTIR spectroscopy with ATR can provide results without compound separation or lengthy sample preparation steps. This study described the combined use of GC and ATR-FTIR in environmental oil spill identification through the matching of source lube oil samples with artificially weathered samples. Samples recovered from a biodiesel spill incident were also investigated. ATR-FTIR provided detailed spectral information for rapid lube oil differentiation. This study was part of a continuing effort to develop a methodology to deal with chemical spills of unknown origin, which is an important aspect in environmental protection and emergency preparedness. This method was only successfully applied to the short term artificially weathered and fresh lube oil characterization, and to limited cases of biodiesel spills. It was concluded that further validation tests are needed to determine if this method can be applied to real-world weather lube oil samples. 10 refs., 11 figs.

Atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry for complex thiophenic mixture analysis

KAUST Repository

Hourani, Nadim; Andersson, Jan T.; Mö ller, Isabelle; Amad, Maan H.; Witt, Matthí as; Sarathy, Mani

2013-01-01

oil (VGO) and injected using the same method. The samples were analyzed using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). RESULTS PASH model analytes were successfully ionized and mainly [M + H]+ ions were produced. The same

High-Throughput Screening Using Fourier-Transform Infrared Imaging

Directory of Open Access Journals (Sweden)

Erdem Sasmaz

2015-06-01

Full Text Available Efficient parallel screening of combinatorial libraries is one of the most challenging aspects of the high-throughput (HT heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass-spectrometry, and gas-chromatography techniques. Of these, rapid-scanning Fourier-transform infrared (FTIR imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16-channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/Al2O3 and cobalt oxide nanoparticles synthesized with different reducer-reductant molar ratios, surfactant types, metal and surfactant concentrations, synthesis temperatures, and ramp rates.

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)

Physicochemical properties determining the detection probability of tryptic peptides in Fourier transform mass spectrometry. A correlation study

DEFF Research Database (Denmark)

Nielsen, Michael L; Savitski, Mikhail M; Kjeldsen, Frank

2004-01-01

Sequence verification and mapping of posttranslational modifications require nearly 100% sequence coverage in the "bottom-up" protein analysis. Even in favorable cases, routine liquid chromatography-mass spectrometry detects from protein digests peptides covering 50-90% of the sequence. Here we...... investigated the reasons for limited peptide detection, considering various physicochemical aspects of peptide behavior in liquid chromatography-Fourier transform mass spectrometry (LC-FTMS). No overall correlation was found between the detection probability and peptide mass. In agreement with literature data...... between pI and signal response. An explanation of this paradoxal behavior was found through the observation that more acidic tryptic peptide lengths tend to be longer. Longer peptides tend to acquire higher average charge state in positive mode electrospray ionization than more basic but shorter...

Advances in data processing for open-path Fourier transform infrared spectrometry of greenhouse gases.

Science.gov (United States)

Shao, Limin; Griffiths, Peter R; Leytem, April B

2010-10-01

The automated quantification of three greenhouse gases, ammonia, methane, and nitrous oxide, in the vicinity of a large dairy farm by open-path Fourier transform infrared (OP/FT-IR) spectrometry at intervals of 5 min is demonstrated. Spectral pretreatment, including the automated detection and correction of the effect of interrupting the infrared beam, is by a moving object, and the automated correction for the nonlinear detector response is applied to the measured interferograms. Two ways of obtaining quantitative data from OP/FT-IR data are described. The first, which is installed in a recently acquired commercial OP/FT-IR spectrometer, is based on classical least-squares (CLS) regression, and the second is based on partial least-squares (PLS) regression. It is shown that CLS regression only gives accurate results if the absorption features of the analytes are located in very short spectral intervals where lines due to atmospheric water vapor are absent or very weak; of the three analytes examined, only ammonia fell into this category. On the other hand, PLS regression works allowed what appeared to be accurate results to be obtained for all three analytes.

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

NARCIS (Netherlands)

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

2007-01-01

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

Characterization of polyesters by matrix-assisted laser desorption/ionization and Fourier transform mass spectrometry.

Science.gov (United States)

Mize, Todd H; Simonsick, William J; Amster, I Jonathan

2003-01-01

Two homopolyesters, poly(neopentyl glycol-alt-isophthalic acid) and poly(hexanediol-alt-azelaic acid), and two copolyesters, poly(dipropoxylated bisphenol-A-alt-(isophthalic acid-co-adipic acid)) and poly(neopentyl glycol-alt-(adipic acid-co-isophthalic acid)) were analyzed by internal source matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS). The high resolution and high mass accuracy provided by FTMS greatly facilitate the characterization of the polyester and copolyester samples. Isobaric resolution allows the ion abundances of overlapping isotopic envelopes to be assessed. Repeat units were confirmed and end functionality assigned. Single shot mass spectra of the entire polymeric distribution demonstrate that the dynamic range of this internal MALDI source instrument and the analyzer cell exceeds performance of those previously reported for higher field instruments. Corrections of space charge mass shift effects are demonstrated for the analytes using an external calibrant and (subsequent to confirmation of structure) via internal calibration which removes ambiguity due to space charge differences in calibrant and analyte spectra. Capillary gel permeation chromatography was used to prepare low polydispersity samples from a high polydispersity polyester, improving the measurement of molecular weight distribution two-fold while retaining the benefits of high resolution mass spectrometry for elucidation of oligomer identity.

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

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) for Rapid Determination of Microbial Cell Lipid Content: Correlation with Gas Chromatography-Mass Spectrometry (GC-MS).

Science.gov (United States)

Millan-Oropeza, Aaron; Rebois, Rolando; David, Michelle; Moussa, Fathi; Dazzi, Alexandre; Bleton, Jean; Virolle, Marie-Joelle; Deniset-Besseau, Ariane

2017-10-01

There is a growing interest worldwide for the production of renewable oil without mobilizing agriculture lands; fast and reliable methods are needed to identify highly oleaginous microorganisms of potential industrial interest. The aim of this study was to demonstrate the relevance of attenuated total reflection (ATR) spectroscopy to achieve this goal. To do so, the total lipid content of lyophilized samples of five Streptomyces strains with varying lipid content was assessed with two classical quantitative but time-consuming methods, gas chromatography-mass spectrometry (GC-MS) and ATR Fourier transform infrared (ATR FT-IR) spectroscopy in transmission mode with KBr pellets and the fast ATR method, often questioned for its lack of reliability. A linear correlation between these three methods was demonstrated allowing the establishment of equations to convert ATR values expressed as CO/amide I ratio, into micrograms of lipid per milligram of biomass. The ATR method proved to be as reliable and quantitative as the classical GC-MS and FT-IR in transmission mode methods but faster and more reproducible than the latter since it involves far less manipulation for sample preparation than the two others. Attenuated total reflection could be regarded as an efficient fast screening method to identify natural or genetically modified oleaginous microorganisms by the scientific community working in the field of bio-lipids.

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.

Applications of Fourier Transform Ion Cyclotron Resonance (FT-ICR) and Orbitrap Based High Resolution Mass Spectrometry in Metabolomics and Lipidomics

Science.gov (United States)

Ghaste, Manoj; Mistrik, Robert; Shulaev, Vladimir

2016-01-01

Metabolomics, along with other “omics” approaches, is rapidly becoming one of the major approaches aimed at understanding the organization and dynamics of metabolic networks. Mass spectrometry is often a technique of choice for metabolomics studies due to its high sensitivity, reproducibility and wide dynamic range. High resolution mass spectrometry (HRMS) is a widely practiced technique in analytical and bioanalytical sciences. It offers exceptionally high resolution and the highest degree of structural confirmation. Many metabolomics studies have been conducted using HRMS over the past decade. In this review, we will explore the latest developments in Fourier transform mass spectrometry (FTMS) and Orbitrap based metabolomics technology, its advantages and drawbacks for using in metabolomics and lipidomics studies, and development of novel approaches for processing HRMS data. PMID:27231903

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.

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)

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.

Monitoring of an esterification reaction by on-line direct liquid sampling mass spectrometry and in-line mid infrared spectrometry with an attenuated total reflectance probe

International Nuclear Information System (INIS)

Owen, Andrew W.; McAulay, Edith A.J.; Nordon, Alison; Littlejohn, David; Lynch, Thomas P.; Lancaster, J. Steven; Wright, Robert G.

2014-01-01

Highlights: • High efficiency thermal vaporiser designed and used for on-line reaction monitoring. • Concentration profiles of all reactants and products obtained from mass spectra. • By-product formed from the presence of an impurity detected by MS but not MIR. • Mass spectrometry can detect trace and bulk components unlike molecular spectrometry. - Abstract: A specially designed thermal vaporiser was used with a process mass spectrometer designed for gas analysis to monitor the esterification of butan-1-ol and acetic anhydride. The reaction was conducted at two scales: in a 150 mL flask and a 1 L jacketed batch reactor, with liquid delivery flow rates to the vaporiser of 0.1 and 1.0 mL min −1 , respectively. Mass spectrometry measurements were made at selected ion masses, and classical least squares multivariate linear regression was used to produce concentration profiles for the reactants, products and catalyst. The extent of reaction was obtained from the butyl acetate profile and found to be 83% and 76% at 40 °C and 20 °C, respectively, at the 1 L scale. Reactions in the 1 L reactor were also monitored by in-line mid-infrared (MIR) spectrometry; off-line gas chromatography (GC) was used as a reference technique when building partial least squares (PLS) multivariate calibration models for prediction of butyl acetate concentrations from the MIR spectra. In validation experiments, good agreement was achieved between the concentration of butyl acetate obtained from in-line MIR spectra and off-line GC. In the initial few minutes of the reaction the profiles for butyl acetate derived from on-line direct liquid sampling mass spectrometry (DLSMS) differed from those of in-line MIR spectrometry owing to the 2 min transfer time between the reactor and mass spectrometer. As the reaction proceeded, however, the difference between the concentration profiles became less noticeable. DLSMS had advantages over in-line MIR spectrometry as it was easier to generate

Application of Tandem Two-Dimensional Mass Spectrometry for Top-Down Deep Sequencing of Calmodulin.

Science.gov (United States)

Floris, Federico; Chiron, Lionel; Lynch, Alice M; Barrow, Mark P; Delsuc, Marc-André; O'Connor, Peter B

2018-06-04

Two-dimensional mass spectrometry (2DMS) involves simultaneous acquisition of the fragmentation patterns of all the analytes in a mixture by correlating their precursor and fragment ions by modulating precursor ions systematically through a fragmentation zone. Tandem two-dimensional mass spectrometry (MS/2DMS) unites the ultra-high accuracy of Fourier transform ion cyclotron resonance (FT-ICR) MS/MS and the simultaneous data-independent fragmentation of 2DMS to achieve extensive inter-residue fragmentation of entire proteins. 2DMS was recently developed for top-down proteomics (TDP), and applied to the analysis of calmodulin (CaM), reporting a cleavage coverage of about ~23% using infrared multiphoton dissociation (IRMPD) as fragmentation technique. The goal of this work is to expand the utility of top-down protein analysis using MS/2DMS in order to extend the cleavage coverage in top-down proteomics further into the interior regions of the protein. In this case, using MS/2DMS, the cleavage coverage of CaM increased from ~23% to ~42%. Graphical Abstract Two-dimensional mass spectrometry, when applied to primary fragment ions from the source, allows deep-sequencing of the protein calmodulin.

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.

Gas phase ion/molecule reactions as studied by Fourier Transform Ion Cyclotron Resonance mass spectrometry

International Nuclear Information System (INIS)

Joergensen, S.I.

1985-01-01

The subject of this thesis is gas phase ion/molecule reactions as studied by Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry (chapter 2 contains a short description of this method). Three chapters are mainly concerned with mechanistic aspects of gas phase ion/molecule reactions. An equally important aspect of the thesis is the stability and reactivity of α-thio carbanions, dipole stabilized carbanions and homoenolate anions, dealt with in the other four chapters. (Auth.)

The characterisation of molecular boric acid by mass spectrometry and matrix isolation-infrared spectroscopy

International Nuclear Information System (INIS)

Ogden, J.S.; Young, N.A.; Bowsher, B.R.

1987-10-01

Boric acid (H 3 BO 3 ) is used as a soluble neutron absorber in the coolant of pressurised water reactors and will be an important species in defining the fission product chemistry of severe reactor accidents. Mass spectrometry and matrix isolation-infrared spectroscopy have been used to characterise boric acid in the vapour phase and hence assess the implications of any chemical interactions. Crystalline orthoboric acid vaporises to yield molecular H 3 BO 3 when heated in vacuum to approximately 40 0 C. The infrared spectrum of the vapour species isolated in low-temperature nitrogen matrices shows characteristic absorptions at 3668.5 (E'), 1426.2 (E'), 1009.9 (E'), 675.0 (A''), 513.8 (A'') and 448.9 (E') cm -1 , consistent with C 3h symmetry. These spectral assignments are supported by extensive isotope labelling, and by a partial normal co-ordinate analysis. These data will be used to quantify specific thermodynamic functions and hence assist in determining the magnitude of reactions such as boric acid with caesium iodide. (author)

Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.

Science.gov (United States)

Nagornov, Konstantin O; Kozhinov, Anton N; Tsybin, Yury O

2017-04-01

The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω + ), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω + quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω + frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω + frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.

Dioxin analysis by gas chromatography-Fourier transform ion cyclotron resonance mass spectrometry (GC-FTICRMS).

Science.gov (United States)

Taguchi, Vince Y; Nieckarz, Robert J; Clement, Ray E; Krolik, Stefan; Williams, Robert

2010-11-01

The feasibility of utilizing a gas chromatograph-tandem quadrupole-Fourier transform ion cyclotron resonance mass spectrometer (GC-MS/MS-FTICRMS) to analyze chlorinated-dioxins/furans (CDDs/CDFs) and mixed halogenated dioxins/furans (HDDs/HDFs) was investigated by operating the system in the GC-FTICRMS mode. CDDs/CDFs and mixed HDDs/HDFs could be analyzed at 50,000 to 100,000 resolving power (RP) on the capillary gas chromatographic time scale. Initial experiments demonstrated that 1 pg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 5 pg of 2-bromo-3,7,8-trichlorodibenzo-p-dioxin (BTrCDD) could be detected. The feasibility of utilizing an FTICRMS for screening of CDDs/CDFs, HDDs/HDFs and related compounds was also investigated by analyzing an extract from vegetation exposed to fall-out from an industrial fire. CDDs/CDFs, chlorinated pyrenes and chlorinated tetracenes could be detected from a Kendrick plot analysis of the ultrahigh resolution mass spectra. Mass accuracies were of the order of 0.5 ppm on standards with external mass calibration and 1 ppm on a sample with internal mass calibration. Copyright © 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

Benefits of 2.94 μm infrared matrix-assisted laser desorption/ionization for analysis of labile molecules by Fourier transform mass spectrometry

DEFF Research Database (Denmark)

Budnik, Bogdan A.; Jensen, Kenneth Bendix; Jørgensen, Thomas J. D.

2000-01-01

A 2.94 microm Er:YAG laser was used together with a commercial Fourier transform mass spectrometer to study labile biomolecules. The combination has shown superior performance over conventional 337 nm ultraviolet matrix-assisted laser desorption/ionization (UV-MALDI) Fourier transform mass...

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

Fourier Transforms Simplified: Computing an Infrared Spectrum from an Interferogram

Science.gov (United States)

Hanley, Quentin S.

2012-01-01

Fourier transforms are used widely in chemistry and allied sciences. Examples include infrared, nuclear magnetic resonance, and mass spectroscopies. A thorough understanding of Fourier methods assists the understanding of microscopy, X-ray diffraction, and diffraction gratings. The theory of Fourier transforms has been presented in this "Journal",…

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

Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Marto, J A; White, F M; Seldomridge, S; Marshall, A G

1995-11-01

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode.

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.

Making Mass Spectrometry See the Light: The Promises and Challenges of Cryogenic Infrared Ion Spectroscopy as a Bioanalytical Technique.

Science.gov (United States)

Cismesia, Adam P; Bailey, Laura S; Bell, Matthew R; Tesler, Larry F; Polfer, Nicolas C

2016-05-01

The detailed chemical information contained in the vibrational spectrum of a cryogenically cooled analyte ion would, in principle, make infrared (IR) ion spectroscopy a gold standard technique for molecular identification in mass spectrometry. Despite this immense potential, there are considerable challenges in both instrumentation and methodology to overcome before the technique is analytically useful. Here, we discuss the promise of IR ion spectroscopy for small molecule analysis in the context of metabolite identification. Experimental strategies to address sensitivity constraints, poor overall duty cycle, and speed of the experiment are intimately tied to the development of a mass-selective cryogenic trap. Therefore, the most likely avenues for success, in the authors' opinion, are presented here, alongside alternative approaches and some thoughts on data interpretation.

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.

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.

The Role of Ultrahigh Resolution Fourier Transform Mass Spectrometry (FT-MS) in Astrobiology-Related Research: Analysis of Meteorites and Tholins.

Science.gov (United States)

Somogyi, Árpád; Thissen, Roland; Orthous-Daunay, Francois-Régis; Vuitton, Véronique

2016-03-24

It is an important but also a challenging analytical problem to understand the chemical composition and structure of prebiotic organic matter that is present in extraterrestrial materials. Its formation, evolution and content in the building blocks ("seeds") for more complex molecules, such as proteins and DNA, are key questions in the field of exobiology. Ultrahigh resolution mass spectrometry is one of the best analytical techniques that can be applied because it provides reliable information on the chemical composition and structure of individual components of complex organic mixtures. Prebiotic organic material is delivered to Earth by meteorites or generated in laboratories in simulation (model) experiments that mimic space or atmospheric conditions. Recent representative examples for ultrahigh resolution mass spectrometry studies using Fourier-transform (FT) mass spectrometers such as Orbitrap and ion cyclotron resonance (ICR) mass spectrometers are shown and discussed in the present article, including: (i) the analysis of organic matter of meteorites; (ii) modeling atmospheric processes in ICR cells; and (iii) the structural analysis of laboratory made tholins that might be present in the atmosphere and surface of Saturn's largest moon, Titan.

Technology of the Gramophone Records of the Music Museum by Fourier Transform Infrared Spectrometry (FTIR Method

Directory of Open Access Journals (Sweden)

Seyedeh Zeinab Afzali

2017-02-01

Full Text Available Music is one of the branches of the art whose helpful role and usefulness in the human’s mind and soul is undeniable. It is the only art which in the philosophers’ divisions is directly linked with the human spirit and immediate overflows the ears of his soul. The sound, as a psychological phenomenon is associated with the emotion and excitement so that sometimes calms and sometimes confuses the human. This study aims to examine the technology of the gramophone records in the Music Museum by Fourier transform infrared spectrometry (FTIR. The method of this research is experimental and the data are collected by documentation, library, and using FTIR tests. Some records of the Music Museum were studied including four samples of 78 rpm platter (stone platter, one sample of 45 rpm, and one sample of 33 rpm (vinyl platter. The results of the FTIR test indicated that the materials of the records were vinyl and shellac and in their raw material, some of the softening additives (phthalates and fillers (silica and calcium carbonate compounds had been used.

Silicon oxide particle formation in RF plasmas investigated by infrared absorption spectroscopy and mass spectrometry

NARCIS (Netherlands)

Hollenstein, Ch.; Howling, A.A.; Courteille, C.; Magni, D.; Scholz, S.M.; Kroesen, G.M.W.; Simons, N.; de Zeeuw, W.; Schwarzenbach, W.

1998-01-01

In situ Fourier transform infrared absorption spectroscopy has been used to study the composition of particles formed and suspended in radio-frequency discharges of silane - oxygen-argon gas mixtures. The silane gas consumption was observed by infrared absorption. The stoichiometry of the produced

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.

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.)

Determination of Oxidized Phosphatidylcholines by Hydrophilic Interaction Liquid Chromatography Coupled to Fourier Transform Mass Spectrometry

Directory of Open Access Journals (Sweden)

Pia Sala

2015-04-01

Full Text Available A novel liquid chromatography-mass spectrometry (LC-MS approach for analysis of oxidized phosphatidylcholines by an Orbitrap Fourier Transform mass spectrometer in positive electrospray ionization (ESI coupled to hydrophilic interaction liquid chromatography (HILIC was developed. This method depends on three selectivity criteria for separation and identification: retention time, exact mass at a resolution of 100,000 and collision induced dissociation (CID fragment spectra in a linear ion trap. The process of chromatography development showed the best separation properties with a silica-based Kinetex column. This type of chromatography was able to separate all major lipid classes expected in mammalian samples, yielding increased sensitivity of oxidized phosphatidylcholines over reversed phase chromatography. Identification of molecular species was achieved by exact mass on intact molecular ions and CID tandem mass spectra containing characteristic fragments. Due to a lack of commercially available standards, method development was performed with copper induced oxidation products of palmitoyl-arachidonoyl-phosphatidylcholine, which resulted in a plethora of lipid species oxidized at the arachidonoyl moiety. Validation of the method was done with copper oxidized human low-density lipoprotein (LDL prepared by ultracentrifugation. In these LDL samples we could identify 46 oxidized molecular phosphatidylcholine species out of 99 possible candidates.

Application of Fourier-transform ion cyclotron resonance mass spectrometry to metabolic profiling and metabolite identification.

Science.gov (United States)

Ohta, Daisaku; Kanaya, Shigehiko; Suzuki, Hideyuki

2010-02-01

Metabolomics, as an essential part of genomics studies, intends holistic understanding of metabolic networks through simultaneous analysis of a myriad of both known and unknown metabolites occurring in living organisms. The initial stage of metabolomics was designed for the reproducible analyses of known metabolites based on their comparison to available authentic compounds. Such metabolomics platforms were mostly based on mass spectrometry (MS) technologies enabled by a combination of different ionization methods together with a variety of separation steps including LC, GC, and CE. Among these, Fourier-transform ion cyclotron resonance MS (FT-ICR/MS) is distinguished from other MS technologies by its ultrahigh resolution power in mass to charge ratio (m/z). The potential of FT-ICR/MS as a distinctive metabolomics tool has been demonstrated in nontargeted metabolic profiling and functional characterization of novel genes. Here, we discuss both the advantages and difficulties encountered in the FT-ICR/MS metabolomics studies.

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)

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

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.)

The Role of Ultrahigh Resolution Fourier Transform Mass Spectrometry (FT-MS in Astrobiology-Related Research: Analysis of Meteorites and Tholins

Directory of Open Access Journals (Sweden)

Árpád Somogyi

2016-03-01

Full Text Available It is an important but also a challenging analytical problem to understand the chemical composition and structure of prebiotic organic matter that is present in extraterrestrial materials. Its formation, evolution and content in the building blocks (“seeds” for more complex molecules, such as proteins and DNA, are key questions in the field of exobiology. Ultrahigh resolution mass spectrometry is one of the best analytical techniques that can be applied because it provides reliable information on the chemical composition and structure of individual components of complex organic mixtures. Prebiotic organic material is delivered to Earth by meteorites or generated in laboratories in simulation (model experiments that mimic space or atmospheric conditions. Recent representative examples for ultrahigh resolution mass spectrometry studies using Fourier-transform (FT mass spectrometers such as Orbitrap and ion cyclotron resonance (ICR mass spectrometers are shown and discussed in the present article, including: (i the analysis of organic matter of meteorites; (ii modeling atmospheric processes in ICR cells; and (iii the structural analysis of laboratory made tholins that might be present in the atmosphere and surface of Saturn’s largest moon, Titan.

The Role of Ultrahigh Resolution Fourier Transform Mass Spectrometry (FT-MS) in Astrobiology-Related Research: Analysis of Meteorites and Tholins

Science.gov (United States)

Somogyi, Árpád; Thissen, Roland; Orthous-Daunay, Francois-Régis; Vuitton, Véronique

2016-01-01

It is an important but also a challenging analytical problem to understand the chemical composition and structure of prebiotic organic matter that is present in extraterrestrial materials. Its formation, evolution and content in the building blocks (“seeds”) for more complex molecules, such as proteins and DNA, are key questions in the field of exobiology. Ultrahigh resolution mass spectrometry is one of the best analytical techniques that can be applied because it provides reliable information on the chemical composition and structure of individual components of complex organic mixtures. Prebiotic organic material is delivered to Earth by meteorites or generated in laboratories in simulation (model) experiments that mimic space or atmospheric conditions. Recent representative examples for ultrahigh resolution mass spectrometry studies using Fourier-transform (FT) mass spectrometers such as Orbitrap and ion cyclotron resonance (ICR) mass spectrometers are shown and discussed in the present article, including: (i) the analysis of organic matter of meteorites; (ii) modeling atmospheric processes in ICR cells; and (iii) the structural analysis of laboratory made tholins that might be present in the atmosphere and surface of Saturn’s largest moon, Titan. PMID:27023520

Yersinia enterocolitica in Diagnostic Fecal Samples from European Dogs and Cats: Identification by Fourier Transform Infrared Spectroscopy and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Science.gov (United States)

Stamm, Ivonne; Hailer, Mandy; Depner, Barbara; Kopp, Peter A.

2013-01-01

Yersinia enterocolitica is the main cause of yersiniosis in Europe, one of the five main bacterial gastrointestinal diseases of humans. Beside pigs, companion animals, especially dogs and cats, were repeatedly discussed in the past as a possible source of pathogenic Y. enterocolitica. To investigate the presence and types of Y. enterocolitica in companion animals, a total of 4,325 diagnostic fecal samples from dogs and 2,624 samples from cats were tested. The isolates obtained were differentiated by using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). Isolated Y. enterocolitica strains were bioserotyped. The detection of the ail gene by PCR and confirmation by FT-IR were used as a pathogenicity marker. Y. enterocolitica strains were isolated from 198 (4.6%) of the dog and 8 (0.3%) of the cat fecal samples investigated. One hundred seventy-nine isolates from dogs were analyzed in detail. The virulence factor Ail was detected in 91.6% of isolates. Isolates of biotype 4 (54.7%) and, to a lesser extent, biotypes 2 (23.5%), 3 (11.2%), and 5 (2.2%) were detected. The remaining 8.4% of strains belonged to the ail-negative biotype 1A. All 7 isolates from cats that were investigated in detail were ail positive. These results indicate that companion animals could be a relevant reservoir for a broad range of presumptively human-pathogenic Y. enterocolitica types. MALDI-TOF MS and FT-IR proved to be valuable methods for the rapid identification of Y. enterocolitica, especially in regard to the large number of samples that were investigated in a short time frame. PMID:23284028

Yersinia enterocolitica in diagnostic fecal samples from European dogs and cats: identification by fourier transform infrared spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Science.gov (United States)

Stamm, Ivonne; Hailer, Mandy; Depner, Barbara; Kopp, Peter A; Rau, Jörg

2013-03-01

Yersinia enterocolitica is the main cause of yersiniosis in Europe, one of the five main bacterial gastrointestinal diseases of humans. Beside pigs, companion animals, especially dogs and cats, were repeatedly discussed in the past as a possible source of pathogenic Y. enterocolitica. To investigate the presence and types of Y. enterocolitica in companion animals, a total of 4,325 diagnostic fecal samples from dogs and 2,624 samples from cats were tested. The isolates obtained were differentiated by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared spectroscopy (FT-IR). Isolated Y. enterocolitica strains were bioserotyped. The detection of the ail gene by PCR and confirmation by FT-IR were used as a pathogenicity marker. Y. enterocolitica strains were isolated from 198 (4.6%) of the dog and 8 (0.3%) of the cat fecal samples investigated. One hundred seventy-nine isolates from dogs were analyzed in detail. The virulence factor Ail was detected in 91.6% of isolates. Isolates of biotype 4 (54.7%) and, to a lesser extent, biotypes 2 (23.5%), 3 (11.2%), and 5 (2.2%) were detected. The remaining 8.4% of strains belonged to the ail-negative biotype 1A. All 7 isolates from cats that were investigated in detail were ail positive. These results indicate that companion animals could be a relevant reservoir for a broad range of presumptively human-pathogenic Y. enterocolitica types. MALDI-TOF MS and FT-IR proved to be valuable methods for the rapid identification of Y. enterocolitica, especially in regard to the large number of samples that were investigated in a short time frame.

Electrochemistry-High Resolution Mass Spectrometry to Study Oxidation Products of Trimethoprim

Directory of Open Access Journals (Sweden)

Marc-André Lecours

2018-01-01

Full Text Available The study of the fate of emerging organic contaminants (EOCs, especially the identification of transformation products, after water treatment or in the aquatic environment, is a topic of growing interest. In recent years, electrochemistry coupled to mass spectrometry has attracted a lot of attention as an alternative technique to investigate oxidation metabolites of organic compounds. The present study used different electrochemical approaches, such as cyclic voltammetry, electrolysis, electro-assisted Fenton reaction coupled offline to high resolution mass spectrometry and thin-layer flow cell coupled online to high resolution mass spectrometry, to study oxidation products of the anti-infective trimethoprim, a contaminant of emerging concern frequently reported in wastewaters and surface waters. Results showed that mono- and di-hydroxylated derivatives of trimethoprim were generated in electrochemically and possibly tri-hydroxylated derivatives as well. Those compounds have been previously reported as mammalian and bacterial metabolites as well as transformation products of advance oxidation processes applied to waters containing trimethoprim. Therefore, this study confirmed that electrochemical techniques are relevant not only to mimic specific biotransformation reactions of organic contaminants, as it has been suggested previously, but also to study the oxidation reactions of organic contaminants of interest in water treatment. The key role that redox reactions play in the environment make electrochemistry-high resolution mass spectrometry a sensitive and simple technique to improve our understanding of the fate of organic contaminants in the environment.

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

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

Characterization and classification of uranium ore concentrates (yellow cakes) using infrared spectrometry

Energy Technology Data Exchange (ETDEWEB)

Varga, Z.; Oeztuerk, B.; Mayer, K.; Wallenius, M.; Apostolidis, C. [Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; Meppen, M. [Carl Friedrich von Weizsaecker-Zentrum fuer Naturwissenschaft und Friedensforschung, Hamburg (Germany)

2011-07-01

In this work the applicability of Fourier-transform infrared spectrometry (FTIR) for nuclear forensic studies of uranium ore concentrates (UOC) are investigated. The technique was used for the identification of the type of uranium compound and various process-related impurities, which can give information on the production method of the material. The measured spectra were evaluated also by statistical means, using the soft independent modelling of class analogy (SIMCA) technique to reveal less apparent similarities between the measured UOC samples.

Fourier Transform Infrared (FT-IR) and Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) Imaging of Cerebral Ischemia: Combined Analysis of Rat Brain Thin Cuts Toward Improved Tissue Classification.

Science.gov (United States)

Balbekova, Anna; Lohninger, Hans; van Tilborg, Geralda A F; Dijkhuizen, Rick M; Bonta, Maximilian; Limbeck, Andreas; Lendl, Bernhard; Al-Saad, Khalid A; Ali, Mohamed; Celikic, Minja; Ofner, Johannes

2018-02-01

Microspectroscopic techniques are widely used to complement histological studies. Due to recent developments in the field of chemical imaging, combined chemical analysis has become attractive. This technique facilitates a deepened analysis compared to single techniques or side-by-side analysis. In this study, rat brains harvested one week after induction of photothrombotic stroke were investigated. Adjacent thin cuts from rats' brains were imaged using Fourier transform infrared (FT-IR) microspectroscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The LA-ICP-MS data were normalized using an internal standard (a thin gold layer). The acquired hyperspectral data cubes were fused and subjected to multivariate analysis. Brain regions affected by stroke as well as unaffected gray and white matter were identified and classified using a model based on either partial least squares discriminant analysis (PLS-DA) or random decision forest (RDF) algorithms. The RDF algorithm demonstrated the best results for classification. Improved classification was observed in the case of fused data in comparison to individual data sets (either FT-IR or LA-ICP-MS). Variable importance analysis demonstrated that both molecular and elemental content contribute to the improved RDF classification. Univariate spectral analysis identified biochemical properties of the assigned tissue types. Classification of multisensor hyperspectral data sets using an RDF algorithm allows access to a novel and in-depth understanding of biochemical processes and solid chemical allocation of different brain regions.

Salmon Muscle Adherence to Polymer Coatings and Determination of Antibiotic Residues by Reversed-Phase High-Performance Liquid Chromatography Coupled to Selected Reaction Monitoring Mass Spectrometry, Atomic Force Microscopy, and Fourier Transform Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

E. Zumelzu

2015-01-01

Full Text Available The persistent adhesion of salmon muscle to food container walls after treatment with urea solution was observed. This work evaluated the diffusion of antibiotics from the salmon muscle to the polyethylene terephthalate (PET coating protecting the electrolytic chromium coated steel (ECCS plates. New aquaculture production systems employ antibiotics such as florfenicol, florfenicol amine, oxytetracycline, and erythromycin to control diseases. The introduction of antibiotics is a matter of concern regarding the effects on human health and biodiversity. It is important to determine their impact on the adhesion of postmortem salmon muscle to can walls and the surface and structural changes affecting the functionality of multilayers. This work characterized the changes occurring in the multilayer PET polymer and steel of containers by electron microscopy, 3D atomic force microscopy (3D-AFM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectroscopy (FT-IR analyses. A robust mass spectrometry methodology was employed to determine the presence of antibiotic residues. No evidence of antibiotics was observed on the protective coating in the range between 0.001 and 2.0 ng/mL; however, the presence of proteins, cholesterol, and alpha-carotene was detected. This in-depth profiling of the matrix-level elements is relevant for the use of adequate materials in the canning export industry.

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

Science.gov (United States)

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

2016-06-28

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

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

Directory of Open Access Journals (Sweden)

Charles W. Ross

2016-06-01

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

Identification of new natural sweet compounds in wine using centrifugal partition chromatography-gustatometry and Fourier transform mass spectrometry.

Science.gov (United States)

Marchal, Axel; Waffo-Téguo, Pierre; Génin, Eric; Mérillon, Jean-Michel; Dubourdieu, Denis

2011-12-15

Sweetness contributes notably to the taste-balance of dry wines and increases during oak-barrel aging owing to the release of natural sweeteners from wood. The search for such taste-active molecules, which are sometimes present at very low concentrations in wine or other complex matrixes, requires both reliable purification tools and powerful identification techniques. Here, we report the development of an original inductive method using centrifugal partition chromatography (CPC) and sensorial analysis. This method, called CPC-gustatometry, was implemented to isolate a sweet fraction with only four compounds from a complex oak wood extract. The recently developed Fourier transform mass spectrometry (FT-MS, Orbitrap analyzer) was used jointly with two-dimensional nuclear magnetic resonance (2D (1)H and (13)C NMR) to obtain the structural elucidation of the purified compounds. The tandem mass spectrometry (MS/MS) spectra obtained with resonant and nonresonant fragmentation modes were compared, thus providing complementary information about the molecular structure. Two oleanane-type triterpenoids substituted with galloyl and glucosyl moieties were identified, one of which exhibits sweet properties. We term these compounds which have never been reported, Quercotriterpenoside I and II.

Fourier transform infrared spectroscopy in physics laboratory courses

International Nuclear Information System (INIS)

Möllmann, K-P; Vollmer, M

2013-01-01

Infrared spectrometry is one of the most important tools in the field of spectroscopic analysis. This is due to the high information content of spectra in the so-called spectroscopic fingerprint region, which enables measurement not only of gases, but also of liquids and solids. Today, infrared spectroscopy is almost completely dominated by Fourier transform infrared (FTIR) spectroscopy. FTIR spectroscopy is able to detect minute quantities in the ppm and ppb ranges, and the respective analyses are now standard tools in science as well as industry. Therefore FTIR spectroscopy should be taught within the standard curriculum at university to physicists and engineers. Here we present respective undergraduate laboratory experiments designed for students at the end of their third year. Experiments deal first with understanding the spectrometer and second with recording and analysing spectra. On the one hand, transmission spectra of gases are treated which relate to environmental analytics (being probably the most prominent and well-known examples), and on the other hand, the focus is on the transmission and reflection spectra of solids. In particular, silicon wafers are studied—as is regularly done in the microelectronics industry—in order to characterize their thickness, oxygen content and phonon modes. (paper)

Mass measurement errors of Fourier-transform mass spectrometry (FTMS): distribution, recalibration, and application.

Science.gov (United States)

Zhang, Jiyang; Ma, Jie; Dou, Lei; Wu, Songfeng; Qian, Xiaohong; Xie, Hongwei; Zhu, Yunping; He, Fuchu

2009-02-01

The hybrid linear trap quadrupole Fourier-transform (LTQ-FT) ion cyclotron resonance mass spectrometer, an instrument with high accuracy and resolution, is widely used in the identification and quantification of peptides and proteins. However, time-dependent errors in the system may lead to deterioration of the accuracy of these instruments, negatively influencing the determination of the mass error tolerance (MET) in database searches. Here, a comprehensive discussion of LTQ/FT precursor ion mass error is provided. On the basis of an investigation of the mass error distribution, we propose an improved recalibration formula and introduce a new tool, FTDR (Fourier-transform data recalibration), that employs a graphic user interface (GUI) for automatic calibration. It was found that the calibration could adjust the mass error distribution to more closely approximate a normal distribution and reduce the standard deviation (SD). Consequently, we present a new strategy, LDSF (Large MET database search and small MET filtration), for database search MET specification and validation of database search results. As the name implies, a large-MET database search is conducted and the search results are then filtered using the statistical MET estimated from high-confidence results. By applying this strategy to a standard protein data set and a complex data set, we demonstrate the LDSF can significantly improve the sensitivity of the result validation procedure.

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...

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.

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)

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.

Matrix-assisted laser-desorption-ionization mass spectrometry of proteins using a free-electron laser

International Nuclear Information System (INIS)

Cramer, R.; Hillenkamp, F.; Haglund, R.

1995-01-01

Matrix-assisted laser desorption-ionization (MALDI) mass spectrometry (MS) is one of the most promising techniques for spectral fingerprinting large molecules, such as proteins, oligonucleotides and carbohydrates. In the usual implementation of this technique, the analyte molecule is dissolved in an aromatic liquid matrix material which resonantly absorbs ultraviolet laser light. Resonant absorption by π-π* transitions volatilizes the matrix and initiates subsequent charge transfer to the analyte molecules, which are detected by time-of-flight mass spectrometry. Recent MALDI-MS studies with Er:YAG (2.94 μm) and CO 2 4 (9.4-10.6 μm) lasers suggest that them is significant unexplored potential for mass spectrometry of macromolecules, including oligonucleotide, in the mid-infrared. Preliminary experiments show that it is possible to capitalize on the rich rovibronic absorption spectrum of virtually all organics to initiate resonant desorption in matrix material over the entire range of pH values. However, the mechanism of charge transfer is particularly problematic for infrared MALDI because of the low photon energy. In this paper, we report the results of MALI-MS studies on small proteins using the Vanderbilt FEL and several matrix materials. Proteins with masses up to roughly 6,000 amu were detected with high resolution in a linear time-of-flight mass spectrometer. By varying the pulse duration using a broadband Pockels cell, we have been able to compare the results of relatively long (5 μs) and short (0.1 μs) irradiation on the desorption and ionization processes. Compared to uv-MALDI spectra of identical analytes obtained with a nitrogen laser (337 nm) in the same time-of-flight spectrometer, the infrared results appear to show that the desorption and ionization process goes on over a somewhat longer time scale

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

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 ...

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.

Rapid characterisation of Klebsiella oxytoca isolates from contaminated liquid hand soap using mass spectrometry, FTIR and Raman spectroscopy.

Science.gov (United States)

Dieckmann, Ralf; Hammerl, Jens Andre; Hahmann, Hartmut; Wicke, Amal; Kleta, Sylvia; Dabrowski, Piotr Wojciech; Nitsche, Andreas; Stämmler, Maren; Al Dahouk, Sascha; Lasch, Peter

2016-06-23

Microbiological monitoring of consumer products and the efficiency of early warning systems and outbreak investigations depend on the rapid identification and strain characterisation of pathogens posing risks to the health and safety of consumers. This study evaluates the potential of three rapid analytical techniques for identification and subtyping of bacterial isolates obtained from a liquid hand soap product, which has been recalled and reported through the EU RAPEX system due to its severe bacterial contamination. Ten isolates recovered from two bottles of the product were identified as Klebsiella oxytoca and subtyped using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI TOF MS), near-infrared Fourier transform (NIR FT) Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Comparison of the classification results obtained by these phenotype-based techniques with outcomes of the DNA-based methods pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis of whole-genome sequencing (WGS) data revealed a high level of concordance. In conclusion, a set of analytical techniques might be useful for rapid, reliable and cost-effective microbial typing to ensure safe consumer products and allow source tracking.

Bioconversion of red ginseng saponins in the gastro-intestinal tract in vitro model studied by high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry

NARCIS (Netherlands)

Kong, H.; Wang, M.; Venema, K.; Maathuis, A.; Heijden, R. van der; Greef, J. van der; Xu, G.; Hankemeier, T.

2009-01-01

A high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) method was developed to investigate the metabolism of ginsenosides in in vitro models of the gastro-intestinal tract. The metabolites were identified by

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

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

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

Characterization of non-polar aromatic hydrocarbons in crude oil using atmospheric pressure laser ionization and Fourier transform ion cyclotron resonance mass spectrometry (APLI FT-ICR MS).

Science.gov (United States)

Schrader, Wolfgang; Panda, Saroj K; Brockmann, Klaus J; Benter, Thorsten

2008-07-01

We report on the successful application of the recently introduced atmospheric pressure laser ionization (APLI) method as a novel tool for the analysis of crude oil and its components. Using Fourier transform ion cyclotron resonance mass spectrometry, unambiguous determination of key compounds in this complex matrix with unprecedented sensitivity is presented.

Collision-induced dissociation with Fourier transform mass spectrometry

International Nuclear Information System (INIS)

Cody, R.B.; Burnier, R.C.; Freiser, B.S.

1982-01-01

Collision-induced dissociations (CID) is demonstrated on a number of primary and secondary ions using a Nicolet prototype Fourier transform mass spectrometer (FT-MS). Like the triple quadrupole technique, CID using FT-MS is a relatively low energy and efficient process. The ability to study a wide range of ion-molecule reaction products is exemplified by results on proton-bound dimers and transition metal containing ionic species. Variation of collision energy by varying the RF irradiation level can provide information about product distributions as a function of energy as well as yield ion structural information. Like the triple quadrupole technique, no slits are employed and virtually all of the fragment ions formed by the CID process may be detected. Unlike all previous mass spectrometric techniques for studying CID, a tandem instrument is not required, and different experiments are performed by making software modifications rather than hardware modifications

Fourier–transform infrared spectroscopic characterization of natu ...

Indian Academy of Sciences (India)

We present here the characterization of the fulgurites by Fourier transform infrared (FTIR) absorption, X-ray diffraction and X-ray fluorescence methods. The amorphous nature of the substance has been confirmed by Fourier transform infrared spectra of the fulgurites, which exhibit prominent absorption band in the region ...

Chlorococcalean microalgae Ankistrodesmus convolutes biodiesel characterization with Fourier transform-infrared spectroscopy and gas chromatography mass spectroscopy techniques

Directory of Open Access Journals (Sweden)

Swati SONAWANE

2015-12-01

Full Text Available The Chlorococcalean microalgae Ankistrodesmus convolutes was found in fresh water Godawari reservoir, Ahmednagar district of Maharashtra State, India. Microalgae are modern biomass for the production of liquid biofuel due to its high solar cultivation efficiency. The collection, harvesting and drying processes were play vital role in converting algal biomass into energy liquid fuel. The oil extraction was the important step for the biodiesel synthesis. The fatty acid methyl ester (FAME synthesis was carried through base catalyzed transesterification method. The product was analyzed by using the hyphened techniques like Fourier Transform-Infrared spectroscopy (FT-IR and Gas Chromatography Mass Spectroscopy (GCMS. FT-IR Spectroscopy was results the ester as functional group of obtained product while the Gas Chromatography Mass Spectroscopy was results the six type of fatty acid methyl ester with different concentration. Ankistrodesmus convolutes biodiesel consist of 46.5% saturated and 49.14% unsaturated FAME.

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

Application of point-to-point matching algorithms for background correction in on-line liquid chromatography-Fourier transform infrared spectrometry (LC-FTIR).

Science.gov (United States)

Kuligowski, J; Quintás, G; Garrigues, S; de la Guardia, M

2010-03-15

A new background correction method for the on-line coupling of gradient liquid chromatography and Fourier transform infrared spectrometry has been developed. It is based on the use of a point-to-point matching algorithm that compares the absorption spectra of the sample data set with those of a previously recorded reference data set in order to select an appropriate reference spectrum. The spectral range used for the point-to-point comparison is selected with minimal user-interaction, thus facilitating considerably the application of the whole method. The background correction method has been successfully tested on a chromatographic separation of four nitrophenols running acetonitrile (0.08%, v/v TFA):water (0.08%, v/v TFA) gradients with compositions ranging from 35 to 85% (v/v) acetonitrile, giving accurate results for both, baseline resolved and overlapped peaks. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Comparison of Pyrolysis Mass Spectrometry and Near Infrared Spectroscopy for Genetic Analysis of Lignocellulose Chemical Composition in Populus

Directory of Open Access Journals (Sweden)

Jianxing Zhang

2014-03-01

Full Text Available Genetic analysis of wood chemical composition is often limited by the cost and throughput of direct analytical methods. The speed and low cost of Fourier transform near infrared (FT-NIR overcomes many of these limitations, but it is an indirect method relying on calibration models that are typically developed and validated with small sample sets. In this study, we used >1500 young greenhouse grown trees from a clonally propagated single Populus family, grown at low and high nitrogen, and compared FT-NIR calibration sample sizes of 150, 250, 500 and 750 on calibration and prediction model statistics, and heritability estimates developed with pyrolysis molecular beam mass spectrometry (pyMBMS wood chemical composition. As calibration sample size increased from 150 to 750, predictive model statistics improved slightly. Overall, stronger calibration and prediction statistics were obtained with lignin, S-lignin, S/G ratio, and m/z 144 (an ion from cellulose, than with C5 and C6 carbohydrates, and m/z 114 (an ion from xylan. Although small differences in model statistics were observed between the 250 and 500 sample calibration sets, when predicted values were used for calculating genetic control, the 500 sample set gave substantially more similar results to those obtained with the pyMBMS data. With the 500 sample calibration models, genetic correlations obtained with FT-NIR and pyMBMS methods were similar. Quantitative trait loci (QTL analysis with pyMBMS and FT-NIR predictions identified only three common loci for lignin traits. FT-NIR identified four QTLs that were not found with pyMBMS data, and these QTLs were for the less well predicted carbohydrate traits.

Electrospray and MALDI mass spectrometry in the identification of spermicides in criminal investigations.

Science.gov (United States)

Hollenbeck, T P; Siuzdak, G; Blackledge, R D

1999-07-01

Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry have been used to examine evidence in a sexual assault investigation. Because condoms are being used increasingly by sexual assailants and some condom brands include the spermicide nonoxynol-9 (nonylphenoxy polyethoxyethanol) in the lubricant formulation, the recovery, and identification of nonoxynol-9 from evidence items may assist in proving corpus delicti. A method was developed for the recovery of nonoxynol-9 from internal vaginal swabs and for its identification by reverse phase liquid chromatography/electrospray ionization mass spectrometry (LC ESI-MS), nanoelectrospray ionization (nanoESI) mass spectrometry, and high resolution MALDI Fourier transform mass spectrometry (MALDI-FTMS). The method was tested on extracts from precoitus, immediate postcoitus, and four-hours postcoitus vaginal swabs provided by a volunteer whose partner does not normally use condoms, but for this trial used a condom having a water-soluble gel-type lubricant that includes 5% nonoxynol-9 in its formulation. Subsequently, LC ESI-MS was used to identify traces of nonoxynol-9 from the internal vaginal swab of a victim of a sexual assault.

Rapid characterization of the chemical constituents of Sijunzi decoction by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Guan, Zhibo; Wang, Miao; Cai, Yi; Yang, Hongmei; Zhao, Min; Zhao, Chunjie

2018-06-01

Sijunzi decoction, a renowned Chinese prescription has long been utilized to treat gastrointestinal problems. In the context of this research work, the use of Ultra high performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry was made to separate and characterize the components of Sijunzi decoction. The performance of Liquid chromatography was carried out on a C8 column (150 mm × 2.1 mm, 1.8 μm); moreover, the mobile phase were consisted of 0.2% formic acid (A) and acetonitrile (B). In accordance with the findings, characterization of 120 chemical compounds was performed by liquid chromatography with mass spectrometry. The key constituents among them included ginsenosides (in Radix Ginseng), 16 triterpene carboxylic acids (in Poria), sesquiterpenes (in Rhizoma Atractylodis Macrocephalae), triterpenesaponins (in Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle) as well as flavonoids (in Glycyrrhizae Radix et Rhizoma Praeparata Cum Melle) in Sijunzi decoction. This research developed the bases for prospective research associated with Sijunzi decoction, together with being expected to be useful to rapidly extract and characterize the constituents in other Traditional Chinese herbal formulations. Copyright © 2018 Elsevier B.V. All rights reserved.

APPLICATION OF STANDARDIZED QUALITY CONTROL PROCEDURES TO OPEN-PATH FOURIER TRANSFORM INFRARED DATA COLLECTED AT A CONCENTRATED SWINE PRODUCTION FACILITY

Science.gov (United States)

Open-path Fourier transform infrared (OP/FT-IR) spectrometry was used to measure the concentrations of ammonia, methane, and other atmospheric eases at a concentrated swine production facility. A total of 2200 OP/FT-IR spectra were acquired along nine different monitoring paths d...

Investigation of the metabolism of ergot alkaloids in cell culture by fourier transformation mass spectrometry.

Science.gov (United States)

Mulac, Dennis; Grote, Anna-Karina; Kleigrewe, Karin; Humpf, Hans-Ulrich

2011-07-27

Ergot alkaloids are known toxic secondary metabolites of the fungus Claviceps purpurea occurring in various grains, especially rye products. The liver is responsible for converting the ergot alkaloids into metabolites; however, the toxic impact of these end products of metabolism is still unknown. The aim of this study was to analyze the metabolism of ergot alkaloids in colon and liver cell lines (HT-29, HepG2), as well as in human primary renal cells (RPTEC). It was shown that cells in vitro are able to metabolize ergot alkaloids, forming a variety of metabolic compounds. Significant differences between the used cell types could be identified, and a suitable model system was established using HT-29 cells, performing an intensive metabolism to hydroxylated metabolites. The formed substances were analyzed by coupling of high-performance liquid chromatography with fluorescence detection and Fourier transformation mass spectrometry (HPLC-FLD-FTMS) as a powerful tool to identify known and unknown metabolites.

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

Source brightness fluctuation correction of solar absorption fourier transform mid infrared spectra

Directory of Open Access Journals (Sweden)

T. Ridder

2011-06-01

Full Text Available The precision and accuracy of trace gas observations using solar absorption Fourier Transform infrared spectrometry depend on the stability of the light source. Fluctuations in the source brightness, however, cannot always be avoided. Current correction schemes, which calculate a corrected interferogram as the ratio of the raw DC interferogram and a smoothed DC interferogram, are applicable only to near infrared measurements. Spectra in the mid infrared spectral region below 2000 cm⁻¹ are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents the established source brightness fluctuation correction. This problem can be overcome by a determination of the offset using the modulation efficiency of the instrument. With known modulation efficiency the offset can be calculated, and the source brightness correction can be performed on the basis of offset-corrected interferograms. We present a source brightness fluctuation correction method which performs the smoothing of the raw DC interferogram in the interferogram domain by an application of a running mean instead of high-pass filtering the corresponding spectrum after Fourier transformation of the raw DC interferogram. This smoothing can be performed with the onboard software of commercial instruments. The improvement of MCT spectra and subsequent ozone profile and total column retrievals is demonstrated. Application to InSb interferograms in the near infrared spectral region proves the equivalence with the established correction scheme.

TG/DTG, FT-ICR Mass Spectrometry, and NMR Spectroscopy Study of Heavy Fuel Oil

KAUST Repository

Elbaz, Ayman M.; Abdul Jameel, Abdul Gani; Hourani, Nadim; Emwas, Abdul-Hamid M.; Sarathy, Mani; Roberts, William L.

2015-01-01

infusion atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry (APCI-FTICR MS), high resolution 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear multiple bond correlation (HMBC

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.

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

Direct-on-Filter α-Quartz Estimation in Respirable Coal Mine Dust Using Transmission Fourier Transform Infrared Spectrometry and Partial Least Squares Regression.

Science.gov (United States)

Miller, Arthur L; Weakley, Andrew Todd; Griffiths, Peter R; Cauda, Emanuele G; Bayman, Sean

2017-05-01

In order to help reduce silicosis in miners, the National Institute for Occupational Health and Safety (NIOSH) is developing field-portable methods for measuring airborne respirable crystalline silica (RCS), specifically the polymorph α-quartz, in mine dusts. In this study we demonstrate the feasibility of end-of-shift measurement of α-quartz using a direct-on-filter (DoF) method to analyze coal mine dust samples deposited onto polyvinyl chloride filters. The DoF method is potentially amenable for on-site analyses, but deviates from the current regulatory determination of RCS for coal mines by eliminating two sample preparation steps: ashing the sampling filter and redepositing the ash prior to quantification by Fourier transform infrared (FT-IR) spectrometry. In this study, the FT-IR spectra of 66 coal dust samples from active mines were used, and the RCS was quantified by using: (1) an ordinary least squares (OLS) calibration approach that utilizes standard silica material as done in the Mine Safety and Health Administration's P7 method; and (2) a partial least squares (PLS) regression approach. Both were capable of accounting for kaolinite, which can confound the IR analysis of silica. The OLS method utilized analytical standards for silica calibration and kaolin correction, resulting in a good linear correlation with P7 results and minimal bias but with the accuracy limited by the presence of kaolinite. The PLS approach also produced predictions well-correlated to the P7 method, as well as better accuracy in RCS prediction, and no bias due to variable kaolinite mass. Besides decreased sensitivity to mineral or substrate confounders, PLS has the advantage that the analyst is not required to correct for the presence of kaolinite or background interferences related to the substrate, making the method potentially viable for automated RCS prediction in the field. This study demonstrated the efficacy of FT-IR transmission spectrometry for silica determination in

Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

Directory of Open Access Journals (Sweden)

Prabhakar Sripadi

Full Text Available BACKGROUND: Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. METHODS AND PRINCIPAL FINDINGS: Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3 transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI mass spectrometry (MS. Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1 and PC(O-34:1 plasmalogens were displaced by PC(30:0 and PC(32:0 species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. CONCLUSIONS AND SIGNIFICANCE: We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3

Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

Science.gov (United States)

Sripadi, Prabhakar; Shrestha, Bindesh; Easley, Rebecca L; Carpio, Lawrence; Kehn-Hall, Kylene; Chevalier, Sebastien; Mahieux, Renaud; Kashanchi, Fatah; Vertes, Akos

2010-09-07

Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3) transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC) lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1) and PC(O-34:1) plasmalogens were displaced by PC(30:0) and PC(32:0) species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3), expression-specific (Tax1 vs. Tax3) and cell-type-specific (T lymphocytes vs. kidney

Ultra High-Mass Resolution Paper Spray by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Directory of Open Access Journals (Sweden)

Kevin D. Quinn

2012-01-01

Full Text Available Paper Spray Ionization is an atmospheric pressure ionization technique that utilizes an offline electro-osmotic flow to generate ions off a paper medium. This technique can be performed on a Bruker SolariX Fourier transform ion cyclotron resonance mass spectrometer by modifying the existing nanospray source. High-resolution paper spray spectra were obtained for both organic and biological samples to demonstrate the benefit of linking the technique with a high-resolution mass analyzer. Error values in the range 0.23 to 2.14 ppm were obtained for calf lung surfactant extract with broadband mass resolving power (m/Δm50% above 60,000 utilizing an external calibration standard.

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.

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...

Gold nanoparticles bridging infra-red spectroscopy and laser desorption/ionization mass spectrometry for direct analysis of over-the-counter drug and botanical medicines.

Science.gov (United States)

Chau, Siu-Leung; Tang, Ho-Wai; Ng, Kwan-Ming

2016-05-05

With a coating of gold nanoparticles (AuNPs), over-the-counter (OTC) drugs and Chinese herbal medicine granules in KBr pellets could be analyzed by Fourier Transform Infra-red (FT-IR) spectroscopy and Surface-assisted Laser Desorption/Ionization mass spectrometry (SALDI-MS). FT-IR spectroscopy allows fast detection of major active ingredient (e.g., acetaminophen) in OTC drugs in KBr pellets. Upon coating a thin layer of AuNPs on the KBr pellet, minor active ingredients (e.g., noscapine and loratadine) in OTC drugs, which were not revealed by FT-IR, could be detected unambiguously using AuNPs-assisted LDI-MS. Moreover, phytochemical markers of Coptidis Rhizoma (i.e. berberine, palmatine and coptisine) could be quantified in the concentrated Chinese medicine (CCM) granules by the SALDI-MS using standard addition method. The quantitative results matched with those determined by high-performance liquid chromatography with ultraviolet detection. Being strongly absorbing in UV yet transparent to IR, AuNPs successfully bridged FT-IR and SALDI-MS for direct analysis of active ingredients in the same solid sample. FT-IR allowed the fast analysis of major active ingredient in drugs, while SALDI-MS allowed the detection of minor active ingredient in the presence of excipient, and also quantitation of phytochemicals in herbal granules. Copyright © 2016 Elsevier B.V. All rights reserved.

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

[A study of Boletus bicolor from different areas using Fourier transform infrared spectrometry].

Science.gov (United States)

Zhou, Zai-Jin; Liu, Gang; Ren, Xian-Pei

2010-04-01

It is hard to differentiate the same species of wild growing mushrooms from different areas by macromorphological features. In this paper, Fourier transform infrared (FTIR) spectroscopy combined with principal component analysis was used to identify 58 samples of boletus bicolor from five different areas. Based on the fingerprint infrared spectrum of boletus bicolor samples, principal component analysis was conducted on 58 boletus bicolor spectra in the range of 1 350-750 cm(-1) using the statistical software SPSS 13.0. According to the result, the accumulated contributing ratio of the first three principal components accounts for 88.87%. They included almost all the information of samples. The two-dimensional projection plot using first and second principal component is a satisfactory clustering effect for the classification and discrimination of boletus bicolor. All boletus bicolor samples were divided into five groups with a classification accuracy of 98.3%. The study demonstrated that wild growing boletus bicolor at species level from different areas can be identified by FTIR spectra combined with principal components analysis.

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.

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.)

Physicochemical effects of cosmic rays in solids: analyses by mass spectrometry and by infrared spectroscopy

International Nuclear Information System (INIS)

Silveira, Enio F. da

2012-01-01

Full text: Cosmic Rays (CR) are studied since their discovery by Victor Hess in the years 1911-1913. Interestingly, the beginning of research in Physics in Brazil started with experiments on CR. B. Gross (INT/ Rio), G. Wataghin and G. Occhialini (USP) started their investigation on CR in 1934. F.X. Roser, the founder of the Physics Institute of PUC-Rio, worked with Hess when he got the Nobel Prize in 1936. C. Lattes got in 1947 the experimental data in Chacaltaya that conducted to the discovery of the meson pi (C. Powell, Nobel Prize in 1950). Nowadays, the Auger Project deals with extremely high energy extragalactic particles. Except for these ones, the origin, the energy and mass distributions of CR constituents and their capability of producing elementary particles are well known. Nevertheless, there is an enormous lack of information on the effects caused by the CR on inorganic and biological materials. This motivates measurements of relevant physicochemical data, such as sputtering yields, cross sections for inducing chemical reactions and crystalline structure parameters. A fascinating question about CR is if they are/were the responsible for the transformation of inorganic into organic material, synthesizing therefore pre-biotic molecules in whole Universe. Nuclear Physics instrumentation is well suited to answer this question, providing ion sources and ion accelerators from keV to GeV. Time-of-flight mass spectrometry and FTIR infrared spectroscopy are techniques able to monitor the physicochemical modifications induced by the RC beam analogs. Data obtained in the GANIL (France) and Van de Graaff (PUC-Rio) accelerators are presented. Abundant inorganic molecular species in space, such as H 2 O, CO, CO 2 and NH 3 , are condensed in laboratory and bombarded by H to Fe ions, from 10 -3 to 10 3 MeV/u, covering the CR range. New chemical species are identified; sputtering yields (Y), formation (σf ) and destruction (σd) cross sections are measured. An

Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

Science.gov (United States)

Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

1997-06-01

The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

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...

Attempt of absolute analysis with spark source mass spectrometry; Essai d'analyse absolue par spectrometrie de masse a etincelles

Energy Technology Data Exchange (ETDEWEB)

Desjardins, M [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-10-01

By means of a graphical method developed in our laboratory, we have studied the linearity of the response of the MS-7 mass spectrometer for impurity determinations over a concentration range of 1 to 1000 ppm (parts per million of atoms). This method consist in transforming optical density measurements into 'true intensities', which are plotted on a logarithm-scale paper against the exposures. A moving transparent ruler graduated at the inverse scale of the exposures allows us to determine directly on the graph, the concentration of impurities in ppm. We have used this method for the determination of sensitivity coefficients in standard samples such as Al, Fe, Cu, Ni, Zr, and non conducting powders like SiO{sub 2} and Al{sub 2}O{sub 3}. This study shows that, for the samples studied, the sensitivity coefficients are practically independent of the matrix and the concentration. Moreover the results show the possibility of obtaining an absolute analysis by spark source mass spectrometry. (author) [French] Au moyen d'une methode graphique developpee ou laboratoire, nous avons etudie la linearite des determinations d'impuretes au spectrometre de masse, type MS-7, dans un domaine de concentration allont de 1 a 1000 ppm. Cette methode consiste en la transformation des mesures de densite optique en 'intensite vraie'. Ces dernieres mesures sont portees sur un graphique logarithmique et une reglette transparente graduee a l'inverse de l'echelle des expositions nous permet de determiner directement la teneur des impuretes en ppm (partie par million d'atomes). Nous avons utilise cette methode pour la determination des coefficients de sensibilite dans des echantillons etalons tels que Al, Fe, Cu, Ni, Zr, et des poudres non conductrices genre SiO{sub 2}, Al{sub 2}O{sub 3}. Cette etude a montre que, pour les echantillons etudies, les coefficients de sensibilite sont pratiquement independants de la matrice et de la concentration. De plus, les resultats obtenus montrent la

Fourier transform ion cyclotron resonance mass spectrometry: the analytical tool for heavy oil and bitumen characterization

Energy Technology Data Exchange (ETDEWEB)

Oldenburg, Thomas B.P; Brown, Melisa; Hsieh, Ben; Larter, Steve [Petroleum Reservoir Group (prg), Department of Geoscience, University of Calgary, Alberta (Canada)

2011-07-01

The Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICRMS), developed in the 1970's by Marshall and Comisarow at the University of British Columbia, has become a commercially available tool capable of analyzing several hundred thousand components in a petroleum mixture at once. This analytical technology will probably usher a dramatic revolution in geochemical capability, equal to or greater than the molecular revolution that occurred when GCMS technologies became cheaply available. The molecular resolution and information content given by the FTICRMS petroleum analysis can be compared to the information in the human genome. With current GCMS-based petroleum geochemical protocols perhaps a few hundred components can be quantitatively determined, but with FTICRMS, 1000 times this number of components could possibly be resolved. However, fluid and other properties depend on interaction of this multitude of hydrocarbon and non-hydrocarbon components, not the components themselves, and access to the full potential of this new petroleomics will depend on the definition of this interactome.

Multivariate analysis of the volatile components in tobacco based on infrared-assisted extraction coupled to headspace solid-phase microextraction and gas chromatography-mass spectrometry.

Science.gov (United States)

Yang, Yanqin; Pan, Yuanjiang; Zhou, Guojun; Chu, Guohai; Jiang, Jian; Yuan, Kailong; Xia, Qian; Cheng, Changhe

2016-11-01

A novel infrared-assisted extraction coupled to headspace solid-phase microextraction followed by gas chromatography with mass spectrometry method has been developed for the rapid determination of the volatile components in tobacco. The optimal extraction conditions for maximizing the extraction efficiency were as follows: 65 μm polydimethylsiloxane-divinylbenzene fiber, extraction time of 20 min, infrared power of 175 W, and distance between the infrared lamp and the headspace vial of 2 cm. Under the optimum conditions, 50 components were found to exist in all ten tobacco samples from different geographical origins. Compared with conventional water-bath heating and nonheating extraction methods, the extraction efficiency of infrared-assisted extraction was greatly improved. Furthermore, multivariate analysis including principal component analysis, hierarchical cluster analysis, and similarity analysis were performed to evaluate the chemical information of these samples and divided them into three classifications, including rich, moderate, and fresh flavors. The above-mentioned classification results were consistent with the sensory evaluation, which was pivotal and meaningful for tobacco discrimination. As a simple, fast, cost-effective, and highly efficient method, the infrared-assisted extraction coupled to headspace solid-phase microextraction technique is powerful and promising for distinguishing the geographical origins of the tobacco samples coupled to suitable chemometrics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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

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

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...

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

NARCIS (Netherlands)

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

2010-01-01

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

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

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.

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

Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry.

Science.gov (United States)

Duemichen, E; Braun, U; Senz, R; Fabian, G; Sturm, H

2014-08-08

For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS-GC-MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA-FTIR and TGA-MS. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry for complex thiophenic mixture analysis

KAUST Repository

Hourani, Nadim

2013-10-01

Rationale Polycyclic aromatic sulfur heterocycles (PASHs) are detrimental species for refining processes in petroleum industry. Current mass spectrometric Methods that determine their composition are often preceded by derivatization and dopant addition approaches. Different ionization Methods have different impact on the molecular assignment of complex PASHs. The analysis of such species under atmospheric pressure chemical ionization (APCI) is still considered limited due to uncontrolled ion generation with low- and high-mass PASHs. Methods The ionization behavior of a model mixture of five selected PASH standards was investigated using an APCI source with nitrogen as the reagent gas. A complex thiophenic fraction was separated from a vacuum gas oil (VGO) and injected using the same method. The samples were analyzed using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). RESULTS PASH model analytes were successfully ionized and mainly [M + H]+ ions were produced. The same ionization pattern was observed for the real thiophenic sample. It was found that S1 class species were the major sulfur-containing species found in the VGO sample. These species indicated the presence of alkylated benzothiophenic (BT), dibenzothiophenic (DBT) and benzonaphthothiophenic (BNT) series that were detected by APCI-FTICR MS. CONCLUSIONS This study provides an established APCI-FTICR MS method for the analysis of complex PASHs. PASHs were detected without using any derivatization and without fragmentation. The method can be used for the analysis of S-containing crude oil samples. © 2013 John Wiley & Sons, Ltd.

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.

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

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

Boosting Sensitivity in Liquid Chromatography–Fourier Transform Ion Cyclotron Resonance–Tandem Mass Spectrometry for Product Ion Analysis of Monoterpene Indole Alkaloids

Directory of Open Access Journals (Sweden)

Ryo eNakabayashi

2015-12-01

Full Text Available In metabolomics, the analysis of product ions in tandem mass spectrometry (MS/MS is noteworthy to chemically assign structural information. However, the development of relevant analytical methods are less advanced. Here, we developed a method to boost sensitivity in liquid chromatography–Fourier transform ion cyclotron resonance–tandem mass spectrometry analysis (MS/MS boost analysis. To verify the MS/MS boost analysis, both quercetin and uniformly labeled 13C quercetin were analyzed, revealing that the origin of the product ions is not the instrument, but the analyzed compounds resulting in sensitive product ions. Next, we applied this method to the analysis of monoterpene indole alkaloids (MIAs. The comparative analyses of MIAs having indole basic skeleton (ajmalicine, catharanthine, hirsuteine, and hirsutine and oxindole skeleton (formosanine, isoformosanine, pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, and mitraphylline identified 86 and 73 common monoisotopic ions, respectively. The comparative analyses of the three pairs of stereoisomers showed more than 170 common monoisotopic ions in each pair. This method was also applied to the targeted analysis of MIAs in Catharanthus roseus and Uncaria rhynchophylla to profile indole and oxindole compounds using the product ions. This analysis is suitable for chemically assigning features of the metabolite groups, which contributes to targeted metabolome analysis.

Boosting Sensitivity in Liquid Chromatography–Fourier Transform Ion Cyclotron Resonance–Tandem Mass Spectrometry for Product Ion Analysis of Monoterpene Indole Alkaloids

Science.gov (United States)

Nakabayashi, Ryo; Tsugawa, Hiroshi; Kitajima, Mariko; Takayama, Hiromitsu; Saito, Kazuki

2015-01-01

In metabolomics, the analysis of product ions in tandem mass spectrometry (MS/MS) is noteworthy to chemically assign structural information. However, the development of relevant analytical methods are less advanced. Here, we developed a method to boost sensitivity in liquid chromatography–Fourier transform ion cyclotron resonance–tandem mass spectrometry analysis (MS/MS boost analysis). To verify the MS/MS boost analysis, both quercetin and uniformly labeled 13C quercetin were analyzed, revealing that the origin of the product ions is not the instrument, but the analyzed compounds resulting in sensitive product ions. Next, we applied this method to the analysis of monoterpene indole alkaloids (MIAs). The comparative analyses of MIAs having indole basic skeleton (ajmalicine, catharanthine, hirsuteine, and hirsutine) and oxindole skeleton (formosanine, isoformosanine, pteropodine, isopteropodine, rhynchophylline, isorhynchophylline, and mitraphylline) identified 86 and 73 common monoisotopic ions, respectively. The comparative analyses of the three pairs of stereoisomers showed more than 170 common monoisotopic ions in each pair. This method was also applied to the targeted analysis of MIAs in Catharanthus roseus and Uncaria rhynchophylla to profile indole and oxindole compounds using the product ions. This analysis is suitable for chemically assigning features of the metabolite groups, which contributes to targeted metabolome analysis. PMID:26734034

Non-destructive grading of peaches by near-infrared spectrometry

Science.gov (United States)

Carlomagno, G.; Capozzo, L.; Attolico, G.; Distante, A.

2004-12-01

This paper describes an experimental study on non-destructive methods for sorting peaches according to their degree of ripeness. The method is based on near-infrared (NIR) transmittance spectrometry in the region between 730 and 900 nm. It estimates the ripeness in terms of internal sugar content and firmness. A station for acquiring the NIR signal has been designed and realized, carefully choosing between several options for each component. Four different stations have been realized and compared during the experimental phase. The signals acquired by the station have been pre-processed using a noise-reducing method based on a packets-wavelet transform. In addition, an outlier detection technique has been applied for identifying irregular behaviors inside each of the considered classes. Finally, a minimum distance classifier estimates the grade of each experimental data. The results obtained in classification show that this early version of the station enables the correct discrimination of peaches with a percentage of 82.5%.

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.)

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

Introduction to body composition assessment using the deuterium dilution technique with analysis of saliva samples by fourier transform infrared spectrometry

International Nuclear Information System (INIS)

2010-01-01

For many years, the IAEA has fostered the more widespread use of stable isotope techniques to assess body composition in different population groups to address priority areas in public health nutrition in Member States. The objective is to support national and regional nutrition projects through both the IAEA's technical cooperation programme and its coordinated research projects. In particular, during the last few years, the increased access to analyses of deuterium enrichment by Fourier transform infrared (FTIR) spectrometry has increased the application of this technique in Africa, Asia and Latin America. This publication was developed by an international group of experts to provide practical, hands-on guidance in the use of this technique in settings where the analysis of deuterium enrichment in saliva samples will be made by FTIR. It is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical application of state of the art methodologies to monitor changes in body composition can be found in an IAEA publication entitled Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques (IAEA Human Health Series No. 3)

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-03-01

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

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

Science.gov (United States)

Arjomand, Ali

2010-03-01

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

COMPARISON OF AN INNOVATIVE NONLINEAR ALGORITHM TO CLASSICAL LEAST SQUARES FOR ANALYZING OPEN-PATH FOURIER TRANSFORM INFRARED SPECTRA COLLECTED AT A CONCENTRATED SWINE PRODUCTION FACILITY

Science.gov (United States)

Open-path Fourier transform infrared (OP/FTIR) spectrometry was used to measure the concentrations of ammonia, methane, and other atmospheric gases at an integrated swine production facility. The concentration-pathlength products of the target gases at this site often exceeded th...

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.)

Matrix isolation-infrared and mass spectrometric studies of high-temperature molecules

International Nuclear Information System (INIS)

Dickinson, S.

1987-08-01

Matrix isolation-infrared spectroscopy and mass spectrometry have been developed at AEE Winfrith to study the high-temperature vapour species which could be generated during a hypothetical severe reactor accident. The principles of the techniques and the instruments are described in detail, and examples of their application to specific systems discussed. Although these examples refer to high-temperature chemical species which are relevant to reactor safety assessments, the techniques are equally applicable to other processes where the characterisation of transient vapour-phase species is required. (author)

Collisional Activation of Peptide Ions in FT-ICR Mass Spectrometry

International Nuclear Information System (INIS)

Laskin, Julia; Futrell, Jean H.

2003-01-01

In the last decade characterization of complex molecules, particularly biomolecules became a focus of both fundamental and applied research in mass spectrometry. Most of these studies utilize tandem mass spectrometry (MS/MS) for obtaining structural information for complex molecules. . Tandem mass spectrometry (MS/MS) typically involves the mass selection of a primary ion, its activation by collision or photon excitation, unimolecular decay into fragment ions characteristic of the ion structure and its internal excitation, and mass analysis of the fragment ions. Although the fundamental principles of tandem mass spectrometry of relatively small molecules are fairly well understood, our understanding of the activation and fragmentation of large molecules is much more primitive. For small ions a single energetic collision is sufficient to dissociate the ion but this is not the case for complex molecules. For large ions two fundamental limits severely constrain fragmentation in tandem mass spectrometry. First the center-of-mass collision energy?the absolute upper limit of energy transfer in a collision process?decreases with increasing mass of the projectile ion for fixed ion kinetic energy and neutral mass. Secondly, the dramatic increase in density of states with increasing internal degrees of freedom of the ion decreases the rate of dissociation by many orders of magnitude at a given internal energy. Consequently most practical MS/MS experiments with complex ions involve multiple collision activation (MCA-CID), multi-photon activation or surface-induced dissociation (SID). This review is focused on what has been learned in recent research studies concerned with fundamental aspects of MCA-CID and SID of model peptides with emphasis on experiments carried out using Fourier transform ion cyclotron resonance mass spectrometers (FT-ICR MS). These studies provide the first quantitative comparison of gas-phase multiple-collision activation and SID of peptide ions

'Collisional Activation of Peptide Ions in FT-ICR Mass Spectrometry'

International Nuclear Information System (INIS)

Laskin, Julia; Futrell, Jean H.

2003-01-01

In the last decade characterization of complex molecules, particularly biomolecules became a focus of both fundamental and applied research in mass spectrometry. Most of these studies utilize tandem mass spectrometry (MS/MS) for obtaining structural information for complex molecules. . Tandem mass spectrometry (MS/MS) typically involves the mass selection of a primary ion, its activation by collision or photon excitation, unimolecular decay into fragment ions characteristic of the ion structure and its internal excitation, and mass analysis of the fragment ions. Although the fundamental principles of tandem mass spectrometry of relatively small molecules are fairly well understood, our understanding of the activation and fragmentation of large molecules is much more primitive. For small ions a single energetic collision is sufficient to dissociate the ion but this is not the case for complex molecules. For large ions two fundamental limits severely constrain fragmentation in tandem mass spectrometry. First the center-of-mass collision energy?the absolute upper limit of energy transfer in a collision process?decreases with increasing mass of the projectile ion for fixed ion kinetic energy and neutral mass. Secondly, the dramatic increase in density of states with increasing internal degrees of freedom of the ion decreases the rate of dissociation by many orders of magnitude at a given internal energy. Consequently most practical MS/MS experiments with complex ions involve multiple collision activation (MCA-CID), multi-photon activation or surface-induced dissociation (SID). This review is focused on what has been learned in recent research studies concerned with fundamental aspects of MCA-CID and SID of model peptides with emphasis on experiments carried out using Fourier transform ion cyclotron resonance mass spectrometers (FT-ICR MS). These studies provide the first quantitative comparison of gas-phase multiple-collision activation and SID of peptide ions

Hadamard Transform Time-of-Flight Mass Spectrometry

Science.gov (United States)

2004-11-30

computer. This rather slow process -. 12 allowed us to evaluate different methods of -M processing the data prior to performing the 4- - inverse transform . The...DSK6713 is capable of • o , , performing the inverse transform and this would 0 & 10 Time (ms,)’ 5 20 25 be the preferred mode of operation since...treating the raw data prior to performing the -20"d Loutled patern inverse transform . We expected that noise associated 0-with the pulsing of the Bradbury

Combination of liquid chromatography-Fourier transform ion cyclotron resonance-mass spectrometry with 13C-labeling for chemical assignment of sulfur-containing metabolites in onion bulbs.

Science.gov (United States)

Nakabayashi, Ryo; Sawada, Yuji; Yamada, Yutaka; Suzuki, Makoto; Hirai, Masami Yokota; Sakurai, Tetsuya; Saito, Kazuki

2013-02-05

Phytochemicals containing heteroatoms (N, O, S, and halogens) often have biological activities that are beneficial to humans. Although targeted profiling methods for such phytochemicals are expected to contribute to rapid chemical assignments, thus making phytochemical genomics and crop breeding much more efficient, there are few profiling methods for the metabolites. Here, as an ultrahigh performance approach, we propose a practical profiling method for S-containing metabolites (S-omics) using onions (Allium cepa) as a representative species and (12)C- and (13)C-based mass spectrometry (MS) and tandem mass spectrometry (MS/MS) analyses by liquid chromatography-Fourier transform ion cyclotron resonance-mass spectrometry (LC-FTICR-MS). Use of the ultrahigh quality data from FTICR-MS enabled simplifying the previous methods to determine specific elemental compositions. MS analysis with a resolution of >250,000 full width at half-maximum and a mass accuracy of ions from other ions on the basis of the natural abundance of (32)S and (34)S and the mass differences among the S isotopes. Comprehensive peak picking using the theoretical mass difference (1.99579 Da) between (32)S-containing monoisotopic ions and their (34)S-substituted counterparts led to the assignment of 67 S-containing monoisotopic ions from the (12)C-based MS spectra, which contained 4693 chromatographic ions. The unambiguous elemental composition of 22 ions was identified through comparative analysis of the (12)C- and (13)C-based MS spectra. Finally, of these, six ions were found to be derived from S-alk(en)ylcysteine sulfoxides and glutathione derivatives. This S-atom-driven approach afforded an efficient chemical assignment of S-containing metabolites, suggesting its potential application for screening not only S but also other heteroatom-containing metabolites in MS-based metabolomics.

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.

Weathering trend characterization of medium-molecular weight polycyclic aromatic disulfur heterocycles by Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Hegazi, Abdelrahman H; Fathalla, Eiman M; Andersson, Jan T

2014-09-01

Different weathering factors act to change petroleum composition once it is spilled into the environment. n-Alkanes, biomarkers, low-molecular weight polyaromatic hydrocarbons and sulfur heterocycles compositional changing in the environment have been extensively studied by different researchers and many parameters have been used for oil source identification and monitoring of weathering and biological degradation processes. In this work, we studied the fate of medium-molecular weight polycyclic aromatic disulfur heterocycles (PAS2Hs), up to ca. 900Da, of artificially weathered Flotta North Sea crude oil by ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry. It was found that PAS2Hs in studied crude oil having double bond equivalents (DBE) from 5 to 8 with a mass range from ca 316 to 582Da were less influenced even after six months artificial weathering experiment. However, compounds having DBEs 12, 11 and 10 were depleted after two, four and six months weathering, respectively. In addition, DBE 9 series was more susceptible to weathering than those of DBE 7 and 8. Copyright © 2014 Elsevier Ltd. All rights reserved.

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...

Early stages of methanol radiolysis from data of photoelectron spectroscopy and mass spectrometry

International Nuclear Information System (INIS)

Kalyazin, E.P.; Kovalev, G.V.

1982-01-01

Comparison of data on photoelectron spectroscopy and mass spectrometry permits to conclude that 4 types of molecular ions CH 3 O + H, H + CH 2 OH, H 3 C + OH and CH 3 O + H are initial products of methanol radiolysis. They start four parallel lines of methanol transformations. Mass spectrum of methanol can be evaluated according to the structural formula of methanol molecule. Composition of radiolysis products of gaseous methanol correlate satisfactorily with its mass spectrum. Reasons for the difference in compositions of radiolysis products of liquid and gaseous methanol are discussed

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.

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.

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

The mass spectral density in quantitative time-of-flight mass spectrometry of polymers

Science.gov (United States)

Tate, Ranjeet S.; Ebeling, Dan; Smith, Lloyd M.

2001-03-01

Time-of-flight mass spectrometry (TOF-MS) is being increasingly used for the study of polymers, for example to obtain the distribution of molecular masses for polymer samples. Serious efforts have also been underway to use TOF-MS for DNA sequencing. In TOF-MS the data is obtained in the form of a time-series that represents the distribution in arrival times of ions of various m/z ratios. This time-series data is then converted to a "mass-spectrum" via a coordinate transformation from the arrival time (t) to the corresponding mass-to-charge ratio (m/z = const. t^2). In this transformation, it is important to keep in mind that spectra are distributions, or densities of weight +1, and thus do not transform as functions. To obtain the mass-spectral density, it is necessary to include a multiplicative factor of √m/z. Common commercial instruments do not take this factor into account. Dropping this factor has no effect on qualitative analysis (detection) or local quantitative measurements, since S/N or signal-to-baseline ratios are unaffected for peaks with small dispersions. However, there are serious consequences for general quantitative analyses. In DNA sequencing applications, loss of signal intensity is in part attributed to multiple charging; however, since the √m/z factor is not taken into account, this conclusion is based on an overestimate (by a factor of √z) of the relative amount of the multiply charged species. In the study of polymers, the normalized dispersion is underestimated by approximately (M_w/Mn -1)/2. In terms of M_w/Mn itself, for example, a M_w/M_n=1.5 calculated without the √m factor corresponds in fact to a M_w/M_n=1.88.

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...

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

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.

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

Science.gov (United States)

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

2017-12-01

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

Online quench-flow electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry for elucidating kinetic and chemical enzymatic reaction mechanisms.

Science.gov (United States)

Clarke, David J; Stokes, Adam A; Langridge-Smith, Pat; Mackay, C Logan

2010-03-01

We have developed an automated quench-flow microreactor which interfaces directly to an electrospray ionization (ESI) mass spectrometer. We have used this device in conjunction with ESI Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) to demonstrate the potential of this approach for studying the mechanistic details of enzyme reactions. For the model system chosen to test this device, namely, the pre-steady-state hydrolysis of p-nitrophenyl acetate by the enzyme chymotrypsin, the kinetic parameters obtained are in good agreement with those in the literature. To our knowledge, this is the first reported use of online quench-flow coupled with FTICR MS. Furthermore, we have exploited the power of FTICR MS to interrogate the quenched covalently bound enzyme intermediate using top-down fragmentation. The accurate mass capabilities of FTICR MS permitted the nature of the intermediate to be assigned with high confidence. Electron capture dissociation (ECD) fragmentation allowed us to locate the intermediate to a five amino acid section of the protein--which includes the known catalytic residue, Ser(195). This experimental approach, which uniquely can provide both kinetic and chemical details of enzyme mechanisms, is a potentially powerful tool for studies of enzyme catalysis.

Current use of high-resolution mass spectrometry in drug screening relevant to clinical and forensic toxicology and doping control.

Science.gov (United States)

Ojanperä, Ilkka; Kolmonen, Marjo; Pelander, Anna

2012-05-01

Clinical and forensic toxicology and doping control deal with hundreds or thousands of drugs that may cause poisoning or are abused, are illicit, or are prohibited in sports. Rapid and reliable screening for all these compounds of different chemical and pharmaceutical nature, preferably in a single analytical method, is a substantial effort for analytical toxicologists. Combined chromatography-mass spectrometry techniques with standardised reference libraries have been most commonly used for the purpose. In the last ten years, the focus has shifted from gas chromatography-mass spectrometry to liquid chromatography-mass spectrometry, because of progress in instrument technology and partly because of the polarity and low volatility of many new relevant substances. High-resolution mass spectrometry (HRMS), which enables accurate mass measurement at high resolving power, has recently evolved to the stage that is rapidly causing a shift from unit-resolution, quadrupole-dominated instrumentation. The main HRMS techniques today are time-of-flight mass spectrometry and Orbitrap Fourier-transform mass spectrometry. Both techniques enable a range of different drug-screening strategies that essentially rely on measuring a compound's or a fragment's mass with sufficiently high accuracy that its elemental composition can be determined directly. Accurate mass and isotopic pattern acts as a filter for confirming the identity of a compound or even identification of an unknown. High mass resolution is essential for improving confidence in accurate mass results in the analysis of complex biological samples. This review discusses recent applications of HRMS in analytical toxicology.

Fourier transform infrared spectra applications to chemical systems

CERN Document Server

Ferraro, John R

1978-01-01

Fourier Transform Infrared Spectroscopy: Applications to Chemical Systems presents the chemical applications of the Fourier transform interferometry (FT-IR).The book contains discussions on the applications of FT-IR in the fields of chromatography FT-IR, polymers and biological macromolecules, emission spectroscopy, matrix isolation, high-pressure interferometry, and far infrared interferometry. The final chapter is devoted to the presentation of the use of FT-IR in solving national technical problems such as air pollution, space exploration, and energy related subjects.Researc

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.

Identification of Organic Iodine Compounds and Their Transformation Products in Edible Iodized Salt Using Liquid Chromatography-High Resolution Mass Spectrometry.

Science.gov (United States)

Yun, Lifen; Peng, Yue'e; Chang, Qing; Zhu, Qingxin; Guo, Wei; Wang, Yanxin

2017-07-05

The consumption of edible iodized salt is a key strategy to control and eliminate iodine deficiency disorders worldwide. We herein report the identification of the organic iodine compounds present in different edible iodized salt products using liquid chromatography combined with high resolution mass spectrometry. A total of 38 organic iodine compounds and their transformation products (TPs) were identified in seaweed iodine salt from China. Our experiments confirmed that the TPs were generated by the replacement of I atoms from organic iodine compounds with Cl atoms. Furthermore, the organic iodine compound contents in 4 seaweed iodine salt samples obtained from different manufacturers were measured, with significant differences in content being observed. We expect that the identification of organic iodine compounds in salt will be important for estimating the validity and safety of edible iodized salt products.

Internal calibration on adjacent samples (InCAS) with Fourier transform mass spectrometry.

Science.gov (United States)

O'Connor, P B; Costello, C E

2000-12-15

Using matrix-assisted laser desorption/ionization (MAL DI) on a trapped ion mass spectrometer such as a Fourier transform mass spectrometer (FTMS) allows accumulation of ions in the cell from multiple laser shots prior to detection. If ions from separate MALDI samples are accumulated simultaneously in the cell, ions from one sample can be used to calibrate ions from the other sample. Since the ions are detected simultaneously in the cell, this is, in effect, internal calibration, but there are no selective desorption effects in the MALDI source. This method of internal calibration with adjacent samples is demonstrated here on cesium iodide clusters, peptides, oligosaccharides, poly(propylene glycol), and fullerenes and provides typical FTMS internal calibration mass accuracy of < 1 ppm.

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.

Magnetic solid phase extraction and static headspace gas chromatography-mass spectrometry method for the analysis of polycyclic aromatic hydrocarbons.

Science.gov (United States)

Cai, Ying; Yan, Zhihong; Wang, Lijia; NguyenVan, Manh; Cai, Qingyun

2016-01-15

A magnetic solid phase extraction (MSPE) protocol combining a static headspace gas chromatography coupled to mass spectrometry (HS-GC-MS) method has been developed for extraction, and determination of 16 polycyclic aromatic hydrocarbons (PAHs) in drinking water samples. Magnetic nanoparticles (MNPs) were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection (S/N=3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained (RSDs ≤ 9.9%). The proposed method was successfully applied to drinking water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

[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.

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.)

Analysis of Nitro-aromatic and Nitramine Explosives by Atmospheric Pressure Chemical Ionization / High Performance Liquid Chromatography / Mass Spectrometry / Mass Spectrometry

International Nuclear Information System (INIS)

Hicks, B.J.; Han, W.; Robben, J.R.

2009-01-01

This procedure is capable of separating and quantifying twenty-nine high explosives and internal surrogates with a single injection. After the initial preparation step, the sample is introduced to the high performance liquid chromatograph for target separation, ionized by atmospheric pressure chemical ionization and the explosives of interest are isolated / quantified by mass spectrometry / mass spectrometry. Concentrations of the target explosives are measured relative to the response of both internal and external standard concentrations. A C-18 reverse phase high performance liquid chromatograph column is used for separation. Ionization is performed using both positive and negative atmospheric pressure chemical ionization resulting in a molecular ion with little fragmentation. These ions are isolated at the first quadrupole of the mass spectrometer, dissociated by collision with argon in the collision cell and the resulting daughter ions are isolated at the second quadrupole. These daughter ions then reach the detector where they are quantified. To date this procedure represents the most thorough high performance liquid chromatography / mass spectrometry / mass spectrometry explosives analysis available in the environmental chemistry market. (authors)

Structure of [M + H − H2O]+ from Protonated Tetraglycine Revealed by Tandem Mass Spectrometry and IRMPD Spectroscopy

NARCIS (Netherlands)

Bythell, B. J.; Dain, Ryan P.; Curtice, Stephanie S.; Oomens, Jos; Steill, Jeffrey D.; Groenewold, Gary S.; la Paizs, Bé; van Stipdonk, M. J.

2010-01-01

Multiple-stage tandem mass spectrometry and collision-induced dissociation were used to investigate loss of H2O or CH3OH from protonated versions of GGGX (where X = G, A, and V), GGGGG, and the methyl esters of these peptides. In addition, wavelength-selective infrared multiple photon dissociation

[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.

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.

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...

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

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

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

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.

Quantitative analysis of red wine tannins using Fourier-transform mid-infrared spectrometry.

Science.gov (United States)

Fernandez, Katherina; Agosin, Eduardo

2007-09-05

Tannin content and composition are critical quality components of red wines. No spectroscopic method assessing these phenols in wine has been described so far. We report here a new method using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometric techniques for the quantitative analysis of red wine tannins. Calibration models were developed using protein precipitation and phloroglucinolysis as analytical reference methods. After spectra preprocessing, six different predictive partial least-squares (PLS) models were evaluated, including the use of interval selection procedures such as iPLS and CSMWPLS. PLS regression with full-range (650-4000 cm(-1)), second derivative of the spectra and phloroglucinolysis as the reference method gave the most accurate determination for tannin concentration (RMSEC = 2.6%, RMSEP = 9.4%, r = 0.995). The prediction of the mean degree of polymerization (mDP) of the tannins also gave a reasonable prediction (RMSEC = 6.7%, RMSEP = 10.3%, r = 0.958). These results represent the first step in the development of a spectroscopic methodology for the quantification of several phenolic compounds that are critical for wine quality.

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.

Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Saliva Samples by Fourier Transform Infrared Spectrometry (Spanish Edition)

International Nuclear Information System (INIS)

2013-01-01

For many years, the IAEA has fostered the more widespread use of stable isotope techniques to assess body composition in different population groups to address priority areas in public health nutrition in Member States. The objective is to support national and regional nutrition projects through both the IAEA's technical cooperation programme and its coordinated research projects. In particular, during the last few years, the increased access to analyses of deuterium enrichment by Fourier transform infrared (FTIR) spectrometry has increased the application of this technique in Africa, Asia and Latin America. This publication was developed by an international group of experts to provide practical, hands-on guidance in the use of this technique in settings where the analysis of deuterium enrichment in saliva samples will be made by FTIR. It is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical application of state of the art methodologies to monitor changes in body composition can be found in an IAEA publication entitled Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques (IAEA Human Health Series No. 3)

Introduction to Body Composition Assessment Using the Deuterium Dilution Technique with Analysis of Saliva Samples by Fourier Transform Infrared Spectrometry (French Edition)

International Nuclear Information System (INIS)

2013-01-01

For many years, the IAEA has fostered the more widespread use of stable isotope techniques to assess body composition in different population groups to address priority areas in public health nutrition in Member States. The objective is to support national and regional nutrition projects through both the IAEA's technical cooperation programme and its coordinated research projects. In particular, during the last few years, the increased access to analyses of deuterium enrichment by Fourier transform infrared (FTIR) spectrometry has increased the application of this technique in Africa, Asia and Latin America. This publication was developed by an international group of experts to provide practical, hands-on guidance in the use of this technique in settings where the analysis of deuterium enrichment in saliva samples will be made by FTIR. It is targeted at new users of this technique, for example nutritionists, analytical chemists and other professionals. More detailed information on the theoretical background and the practical application of state of the art methodologies to monitor changes in body composition can be found in an IAEA publication entitled Assessment of Body Composition and Total Energy Expenditure in Humans by Stable Isotope Techniques (IAEA Human Health Series No. 3)

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

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.

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

A low noise single-transistor transimpedance preamplifier for Fourier-transform mass spectrometry using a T feedback network.

Science.gov (United States)

Lin, Tzu-Yung; Green, Roger J; O'Connor, Peter B

2012-09-01

A novel single-transistor transimpedance preamplifier has been introduced for improving performance in Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry. A low noise junction field-effect transistor (JFET), BF862, is used as the main amplification stage of this trans-impedance preamplifier, and a T-shaped feedback network is introduced as both the feedback and the gate biasing solutions. The T feedback network has been studied using an operational amplifier (Op Amp), AD8099. Such a feedback system allows ~100-fold less feedback resistance at a given transimpedance, hence preserving bandwidth, which is beneficial to applications demanding high gain. The single-transistor preamplifier yields a tested transimpedance of ~10(4) Ω (80 dBΩ) in the frequency range between 1 kHz and 1 MHz (mass-to-charge ratio, m/z, of around 180-180k for a 12-T FT-ICR system), with a low power consumption of ~6 mW, which implies that this preamplifier is well suited to a 12-T FT-ICR mass spectrometer. In trading noise performance for higher trans-impedance, an alternative preamplifier design, an AD8099 preamplifier with the T feedback network, has also been studied with a capability of ~10(6) Ω (120 dBΩ) transimpedance in the same frequency range. The resistive components in the T feedback network reported here can be replaced by complex impedances, which allows adaptation of this feedback system to other frequency, transimpedance, and noise characteristics for applications not only in other mass spectrometers, such as Orbitrap, time-of-flight (TOF), and ion trap systems, but also in other charge/current detecting systems such as spectroscopy systems, microscopy systems, optical communication systems, or charge-coupled devices (CCDs).

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...

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.

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 ...

Infrared Image Segmentation by Combining Fractal Geometry with Wavelet Transformation

Directory of Open Access Journals (Sweden)

Xionggang Tu

2014-11-01

Full Text Available An infrared image is decomposed into three levels by discrete stationary wavelet transform (DSWT. Noise is reduced by wiener filter in the high resolution levels in the DSWT domain. Nonlinear gray transformation operation is used to enhance details in the low resolution levels in the DSWT domain. Enhanced infrared image is obtained by inverse DSWT. The enhanced infrared image is divided into many small blocks. The fractal dimensions of all the blocks are computed. Region of interest (ROI is extracted by combining all the blocks, which have similar fractal dimensions. ROI is segmented by global threshold method. The man-made objects are efficiently separated from the infrared image by the proposed method.

Progress in static fourier transform infrared spectroscopy: assessment of sifti preliminary performances

Science.gov (United States)

Hébert, Philippe; Pierangelo, Clémence; Rosak, Alain; Cansot, Elodie; Bernard, Frédéric; Camy-Peyret, Claude

2017-11-01

The concept of static Fourier transform interferometry at thermal infrared wavelengths is well suited in the case of narrow spectral bands that are looked at for targeted molecular species as CO and O3 for pollution and air quality monitoring, or H20 and CO2 for weather forecast, down to the troposphere. It permits a high spectral resolution and a very good radiometric performance, with the advantage of a static interferometer, including no moving part. Along with other molecules sounded in the UV-VIS domain, as for instance in the TRAQ mission, SIFTI will provide scientists with a complete set for pollution measurements and air quality survey. Our paper presents the principles of static Fourier transform spectrometry, the work led on the instrument performance model and our study of the SIFTI instrument. We describe the instrument, its main dimensions and characteristics, and its architecture and major subsystems. We eventually make a preliminary survey of the SIFTI performance budget items. As a conclusion, we introduce the future CNES phase A study of this instrument that is started in 2006

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.

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.

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.

Comparative study of wine tannin classification using Fourier transform mid-infrared spectrometry and sensory analysis.

Science.gov (United States)

Fernández, Katherina; Labarca, Ximena; Bordeu, Edmundo; Guesalaga, Andrés; Agosin, Eduardo

2007-11-01

Wine tannins are fundamental to the determination of wine quality. However, the chemical and sensorial analysis of these compounds is not straightforward and a simple and rapid technique is necessary. We analyzed the mid-infrared spectra of white, red, and model wines spiked with known amounts of skin or seed tannins, collected using Fourier transform mid-infrared (FT-MIR) transmission spectroscopy (400-4000 cm(-1)). The spectral data were classified according to their tannin source, skin or seed, and tannin concentration by means of discriminant analysis (DA) and soft independent modeling of class analogy (SIMCA) to obtain a probabilistic classification. Wines were also classified sensorially by a trained panel and compared with FT-MIR. SIMCA models gave the most accurate classification (over 97%) and prediction (over 60%) among the wine samples. The prediction was increased (over 73%) using the leave-one-out cross-validation technique. Sensory classification of the wines was less accurate than that obtained with FT-MIR and SIMCA. Overall, these results show the potential of FT-MIR spectroscopy, in combination with adequate statistical tools, to discriminate wines with different tannin levels.

Quantitative Thin-Layer Chromatography/Mass Spectrometry Analysis of Caffeine Using a Surface Sampling Probe Electrospray Ionization Tandem Mass Spectrometry System

Energy Technology Data Exchange (ETDEWEB)

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

2005-01-01

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

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.

Proceedings of the twelfth ISMAS triennial international conference on mass spectrometry

International Nuclear Information System (INIS)

Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.

2013-03-01

These Workshops are aimed at introducing the subject of Mass Spectrometry to novices, updating the Mass Spectrometrists with the latest developments in the field, exposing the participants to innumerable applications of Mass Spectrometry and providing a common forum for discussing the day-to-day problems when working with a Mass Spectrometer. The programme of these Workshops consists of Tutorials, Panel Discussions, Research Scholars' Presentations, Poster Presentations and Invited Lectures. The lectures include fundamentals of Mass Spectrometry, qualitative and quantitative aspects and data interpretation, maintenance of Mass Spectrometers, selection of a mass spectrometer, applications in various branches of science as well as recent advances in Mass Spectrometry. Papers relevant to INIS are indexed separately

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

Molecular Characterization of Thiols in Fossil Fuels by Michael Addition Reaction Derivatization and Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Science.gov (United States)

Wang, Meng; Zhao, Suoqi; Liu, Xuxia; Shi, Quan

2016-10-04

Thiols widely occur in sediments and fossil fuels. However, the molecular composition of these compounds is unclear due to the lack of appropriate analytical methods. In this work, a characterization method for thiols in fossil fuels was developed on the basis of Michael addition reaction derivatization followed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Model thiol compound studies showed that thiols were selectively reacted with phenylvinylsulfone and transformed to sulfones with greater than 98% conversions. This method was applied to a coker naphtha, light and heavy gas oils, and crude oils from various geological sources. The results showed that long alkyl chain thiols are readily present in petroleum, which have up to 30 carbon atoms. Large DBE dispersity of thiols indicates that naphthenic and aromatic thiols are also present in the petroleum. This method is capable of detecting thiol compounds in the part per million range by weight. This method allows characterization of thiols in a complex hydrocarbon matrix, which is complementary to the comprehensive analysis of sulfur compounds in fossil fuels.

Fourier Transfrom Ion Cyclotron Resonance Mass Spectrometry at High Magnetic Field

Science.gov (United States)

Marshall, Alan G.

1998-03-01

At high magnetic field (9.4 tesla at NHMFL), Fourier transform ion cyclotron resonance mass spectrometry performance improves dramatically: mass resolving power, axialization efficiency, and scan speed (each proportional to B), maximum ion mass, dynamic range, ion trapping period, kinetic energy, and electron self-cooling rate for sympathetic cooling (each proportional to B^2), and ion coalescence tendency (proportional 1/B^2). These advantages may apply singly (e.g., unit mass resolution for proteins of >100,000 Da), or compound (e.g., 10-fold improvement in S/N ratio for 9.4 T vs. 6 T at the same resolving power). Examples range from direct determination of molecular formulas of diesel fuel components by accurate mass measurement (=B10.1 ppm) to protein structure and dynamics probed by H/D exchange. This work was supported by N.S.F. (CHE-93-22824; CHE-94-13008), N.I.H. (GM-31683), Florida State University, and the National High Magnetic Field Laboratory in Tallahassee, FL.

Recent applications of gas chromatography with high-resolution mass spectrometry.

Science.gov (United States)

Špánik, Ivan; Machyňáková, Andrea

2018-01-01

Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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

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,

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.

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....

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.)

Comparison of photoacoustic radiometry to gas chromatography/mass spectrometry methods for monitoring chlorinated hydrocarbons

International Nuclear Information System (INIS)

Sollid, J.E.; Trujillo, V.L.; Limback, S.P.; Woloshun, K.A.

1996-01-01

A comparison of two methods of gas chromatography mass spectrometry (GCMS) and a nondispersive infrared technique, photoacoustic radiometry (PAR), is presented in the context of field monitoring a disposal site. First is presented an historical account describing the site and early monitoring to provide an overview. The intent and nature of the monitoring program changed when it was proposed to expand the Radiological Waste Site close to the Hazardous Waste Site. Both the sampling methods and analysis techniques were refined in the course of this exercise

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-12

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

[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.

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…

Atmospheric pressure chemical ionization of fluorinated phenols in atmospheric pressure chemical ionization mass spectrometry, tandem mass spectrometry, and ion mobility spectrometry

Science.gov (United States)

Eiceman, G. A.; Bergloff, J. F.; Rodriguez, J. E.; Munro, W.; Karpas, Z.

1999-01-01

Atmospheric pressure chemical ionization (APCI)-mass spectrometry (MS) for fluorinated phenols (C6H5-xFxOH Where x = 0-5) in nitrogen with Cl- as the reagent ion yielded product ions of M Cl- through ion associations or (M-H)- through proton abstractions. Proton abstraction was controllable by potentials on the orifice and first lens, suggesting that some proton abstraction occurs through collision induced dissociation (CID) in the interface region. This was proven using CID of adduct ions (M Cl-) with Q2 studies where adduct ions were dissociated to Cl- or proton abstracted to (M-H)-. The extent of proton abstraction depended upon ion energy and structure in order of calculated acidities: pentafluorophenol > tetrafluorophenol > trifluorophenol > difluorophenol. Little or no proton abstraction occurred for fluorophenol, phenol, or benzyl alcohol analogs. Ion mobility spectrometry was used to determine if proton abstraction reactions passed through an adduct intermediate with thermalized ions and mobility spectra for all chemicals were obtained from 25 to 200 degrees C. Proton abstraction from M Cl- was not observed at any temperature for phenol, monofluorophenol, or difluorophenol. Mobility spectra for trifluorophenol revealed the kinetic transformations to (M-H)- either from M Cl- or from M2 Cl- directly. Proton abstraction was the predominant reaction for tetra- and penta-fluorophenols. Consequently, the evidence suggests that proton abstraction occurs from an adduct ion where the reaction barrier is reduced with increasing acidity of the O-H bond in C6H5-xFxOH.

Utility of Higher Harmonics in Electrospray Ionization Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometry.

Science.gov (United States)

Dziekonski, Eric T; Johnson, Joshua T; McLuckey, Scott A

2017-04-18

Mass resolution (M/ΔM fwhm) is observed to linearly increase with harmonic order in a Fourier transform electrostatic linear ion trap (ELIT) mass spectrometer. This behavior was predicted by Grosshans and Marshall for frequency-multiple detection in a Fourier transform ion cyclotron resonance mass spectrometer only for situations when the prominent mechanism for signal decay is ion ejection from the trap. As the analyzer pressure in our ELIT chamber is relatively high, such that collisional scattering and collision-induced dissociation are expected to underlie much of the ion loss, we sought to explore the relationship between harmonic order and mass resolution. Mass resolutions of 36 900 (fundamental), 75 850 (2nd harmonic), and 108 200 (3rd harmonic) were obtained for GdO + (avg. m/z 173.919) with a transient length of 300 ms. To demonstrate that the mass resolution was truly increasing with harmonic order, the unresolved isotopes at the fundamental distribution of cytochrome c +8 (m/z ∼ 1549) were nearly baseline, resolved at the third harmonic (mass resolution ≈ 23 000) with a transient length of only 200 ms. This experiment demonstrates that, when the ion density is sufficiently low, ions with frequency differences of less than 4 Hz remain uncoalesced. Higher harmonics can be used to increase the effective mass resolution for a fixed transient length and thereby may enable the resolution of closely spaced masses, determination of a protein ion's charge state, and study of the onset of peak coalescence when the resolution at the fundamental frequency is insufficient.

DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY – HIGH RESOLUTION MASS SPECTROMETRY

Science.gov (United States)

Nikcevic, Irena; Wyrzykiewicz, Tadeusz K.; Limbach, Patrick A.

2010-01-01

Summary An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described. Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3′-terminal phosphate monoester and 3′-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N3 (2-cyanoethyl) adducts

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...

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

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

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'.

Capsule Typing of Haemophilus influenzae by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

Science.gov (United States)

Månsson, Viktor; Gilsdorf, Janet R; Kahlmeter, Gunnar; Kilian, Mogens; Kroll, J Simon; Riesbeck, Kristian; Resman, Fredrik

2018-03-01

Encapsulated Haemophilus influenzae strains belong to type-specific genetic lineages. Reliable capsule typing requires PCR, but a more efficient method would be useful. We evaluated capsule typing by using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Isolates of all capsule types (a-f and nontypeable; n = 258) and isogenic capsule transformants (types a-d) were investigated. Principal component and biomarker analyses of mass spectra showed clustering, and mass peaks correlated with capsule type-specific genetic lineages. We used 31 selected isolates to construct a capsule typing database. Validation with the remaining isolates (n = 227) showed 100% sensitivity and 92.2% specificity for encapsulated strains (a-f; n = 61). Blinded validation of a supplemented database (n = 50) using clinical isolates (n = 126) showed 100% sensitivity and 100% specificity for encapsulated strains (b, e, and f; n = 28). MALDI-TOF mass spectrometry is an accurate method for capsule typing of H. influenzae.

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...

Determination of phospholipid regiochemistry by Ag(I) adduction and tandem mass spectrometry.

Science.gov (United States)

Yoo, Hyun Ju; Håkansson, Kristina

2011-02-15

Collision-activated dissociation (CAD) and infrared multiphoton dissociation (IRMPD) of Ag-adducted phospholipids were investigated as structural tools. Previously, determination of the acyl chains at the two phospholipid esterification sites has been performed based on the R(1)COO(-)/R(2)COO(-) ratio in negative ion mode CAD tandem mass spectrometry. However, the observed product ion ratio is dependent on the extent of unsaturation of the fatty acyl group at sn-2 as well as on the total chain length. Similarly, in positive ion mode CAD with/without alkaline or alkaline earth metal adduction, the ratio of product ions resulting from either R(1)COOH or R(2)COOH neutral losses is dependent on the nature of the phospholipid polar headgroup. Ag(+) ion chromatography, in which silver ions are part of the stationary phase, can provide information on double bond number/distribution as well as double bond configuration (cis/trans) because of interaction between Ag(+) ions and olefinic π electrons of fatty acids and lipids. We hypothesized that interactions between double bonds and Ag(+) may be utilized to also reveal phospholipid esterification site information in tandem mass spectrometry. CAD and IRMPD of Ag-adducted phospholipids with unsaturated fatty acids (R(x)COOH, x = 1 or 2) provided characteristic product ions, [R(x)COOH + Ag](+), and their neutral losses. The characteristic product ions and their abundances do not depend on the type of polar headgroup or the number of double bonds of unsaturated acyl chains. Tandem mass spectrometry of Cu-adducted phospholipids was also performed for comparison based on the Lewis acid and base properties of Cu(+) and phospholipid double bonds, respectively.

Thermal transformation of bioactive caffeic acid on fumed silica seen by UV-Vis spectroscopy, thermogravimetric analysis, temperature programmed desorption mass spectrometry and quantum chemical methods.

Science.gov (United States)

Kulik, Tetiana V; Lipkovska, Natalia O; Barvinchenko, Valentyna M; Palyanytsya, Borys B; Kazakova, Olga A; Dudik, Olesia O; Menyhárd, Alfréd; László, Krisztina

2016-05-15

Thermochemical studies of hydroxycinnamic acid derivatives and their surface complexes are important for the pharmaceutical industry, medicine and for the development of technologies of heterogeneous biomass pyrolysis. In this study, structural and thermal transformations of caffeic acid complexes on silica surfaces were studied by UV-Vis spectroscopy, thermogravimetric analysis, temperature programmed desorption mass spectrometry (TPD MS) and quantum chemical methods. Two types of caffeic acid surface complexes are found to form through phenolic or carboxyl groups. The kinetic parameters of the chemical reactions of caffeic acid on silica surface are calculated. The mechanisms of thermal transformations of the caffeic chemisorbed surface complexes are proposed. Thermal decomposition of caffeic acid complex chemisorbed through grafted ester group proceeds via three parallel reactions, producing ketene, vinyl and acetylene derivatives of 1,2-dihydroxybenzene. Immobilization of phenolic acids on the silica surface improves greatly their thermal stability. Copyright © 2016 Elsevier Inc. All rights reserved.

Comprehensive determination of macrolide antibiotics, their synthesis intermediates and transformation products in wastewater effluents and ambient waters by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Senta, Ivan; Krizman-Matasic, Ivona; Terzic, Senka; Ahel, Marijan

2017-08-04

Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis intermediates, byproducts, metabolites and transformation products in wastewater and surface water was developed and validated. Samples were enriched using solid-phase extraction on Oasis HLB cartridges and analyzed by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The target macrolide compounds were separated on an ACE C18 PFP column and detected using multiple reaction monitoring in positive ionization polarity. The optimized method, which included an additional extract clean-up on strong anion-exchange cartridges (SAX), resulted in high recoveries and accuracies, low matrix effects and improved chromatographic separation of the target compounds, even in highly complex matrices, such as raw wastewater. The developed method was applied to the analysis of macrolide compounds in wastewater and river water samples from Croatia. In addition to parent antibiotics, several previously unreported macrolide transformation products and/or synthesis intermediates were detected in municipal wastewater, some of them reaching μg/L levels. Moreover, extremely high concentrations of macrolides up to mg/L level were found in pharmaceutical industry effluents, indicating possible importance of this source to the total loads into ambient waters. The results revealed a significant contribution of synthesis intermediates and transformation products to the overall mass balance of macrolides in the aquatic environment. Copyright © 2017. Published by Elsevier B.V.

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

Novel method for measurement of glutathione kinetics in neonates using liquid chromatography coupled to isotope ratio mass spectrometry

NARCIS (Netherlands)

Schierbeek, Henk; te Braake, Frans; Godin, Jean-Philippe; Fay, Laurent-Bernard; van Goudoever, Johannes B.

2007-01-01

A novel analytical method using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS) was developed for measuring the fractional synthesis rate (FSR) of glutathione (GSH) in neonates after infusion of [1-(13)C]-glycine as a tracer. After transformation of GSH into GSSG, its

[Continuum based fast Fourier transform processing of infrared spectrum].

Science.gov (United States)

Liu, Qing-Jie; Lin, Qi-Zhong; Wang, Qin-Jun; Li, Hui; Li, Shuai

2009-12-01

To recognize ground objects with infrared spectrum, high frequency noise removing is one of the most important phases in spectrum feature analysis and extraction. A new method for infrared spectrum preprocessing was given combining spectrum continuum processing and Fast Fourier Transform (CFFT). Continuum was firstly removed from the noise polluted infrared spectrum to standardize hyper-spectra. Then the spectrum was transformed into frequency domain (FD) with fast Fourier transform (FFT), separating noise information from target information After noise eliminating from useful information with a low-pass filter, the filtered FD spectrum was transformed into time domain (TD) with fast Fourier inverse transform. Finally the continuum was recovered to the spectrum, and the filtered infrared spectrum was achieved. Experiment was performed for chlorite spectrum in USGS polluted with two kinds of simulated white noise to validate the filtering ability of CFFT by contrast with cubic function of five point (CFFP) in time domain and traditional FFT in frequency domain. A circle of CFFP has limited filtering effect, so it should work much with more circles and consume more time to achieve better filtering result. As for conventional FFT, Gibbs phenomenon has great effect on preprocessing result at edge bands because of special character of rock or mineral spectra, while works well at middle bands. Mean squared error of CFFT is 0. 000 012 336 with cut-off frequency of 150, while that of FFT and CFFP is 0. 000 061 074 with cut-off frequency of 150 and 0.000 022 963 with 150 working circles respectively. Besides the filtering result of CFFT can be improved by adjusting the filter cut-off frequency, and has little effect on working time. The CFFT method overcomes the Gibbs problem of FFT in spectrum filtering, and can be more convenient, dependable, and effective than traditional TD filter methods.

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

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)

Glycine Identification in Natural Jarosites Using Laser-Desorption Fourier Transform Mass Spectrometry: Implications for the search for life on Mars

Energy Technology Data Exchange (ETDEWEB)

J. Michelle Kotler; Nancy W. Hinman; Beizhan Yan; Daphne L. Stoner; Jill R. Scott

2008-04-01

The jarosite group minerals have received increasing attention since the discovery of jarosite by the Mars Exploration Rover-Opportunity on the Martian surface. The mineral group has the ability to incorporate foreign ions in its structure leading to investigations regarding its use as an indicator of aqueous and/or biological activity on Earth and Mars. The use of laser desorption Fourier transform mass spectrometry has revealed the presence of organic matter in several jarosite samples from various worldwide locations. One of the organic cluster ions has been attributed to glycine based on results from combinations of glycine with synthetic jarosite and K2SO4. The ability to observe these organic signatures in jarosite samples with an “in situ” instrumental technique, such as employed in this study, furthers the goals of planetary geologists to determine whether signs of life (e.g., the presence of biomolecules or biomolecule precursors) can be detected in the rock record of terrestrial and extraterrestrial samples.

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

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...

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

New experiments in organic, fast-atom-bomdardment, and secondary-ion mass spectrometry

International Nuclear Information System (INIS)

DiDonato, G.C.

1987-01-01

The goal of research presented in this dissertation is the creative use of new ionization and instrumental techniques in mass spectrometry. This goal manifests itself in three areas of mass spectrometry. In the first portion, modern, state-of-the-art instrumentation and new experiments were used to re-examine the mass spectra of transition-metal acetates and acetylacetonates. High resolution, chemical ionization, negative chemical ionization, and extended-mass-range mass spectrometry uncovered a wealth of new gas-phase ionic species. Energy-resolved mass spectrometry/mass spectrometry was applied to the characterization of molecular and fragment ion first-row transition-metal acetylacetonates, and comprises the second portion of the thesis. Studies in fast-atom-bombardment mass spectrometry are the subject of the third portion of the dissertation. Since fast-atom bombardment samples a liquid matrix, absolute and relative abundances of sputtered secondary ions are influenced by solution chemistry. The design and construction of an imaging secondary-ion mass spectrometer is the subject of the final portion of the thesis. This instrument provides for direct mass-spectrometric analysis of thin-layer and paper chromatograms and electrophoretograms

Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

Energy Technology Data Exchange (ETDEWEB)

Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.; Wolff, Jeremy J.; Somogyi, Árpád; Pedder, Randall E.; Quintyn, Royston S.; Morrison, Lindsay J.; Easterling, Michael L.; Paša-Tolić, Ljiljana; Wysocki, Vicki H.

2017-01-03

Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on non-covalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. In this study, an SID device was designed and successfully installed in a hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 kDa to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.

Applications of mass spectrometry in the trace element analysis of biological materials

International Nuclear Information System (INIS)

Moens, L.

1997-01-01

The importance of mass spectrometry for the analysis of biological material is illustrated by reviewing the different mass spectrometric methods applied and describing some typical applications published recently. Though atomic absorption spectrometry is used in the majority of analyses of biological material, most mass spectrometric methods have been used to some extent for trace element determination in biomedical research. The relative importance of the different methods is estimated by reviewing recent research papers. It is striking that especially inductively coupled plasma mass spectrometry is increasingly being applied, partly because the method can be used on-line after chromatographic separation, in speciation studies. Mass spectrometric methods prove to offer unique possibilities in stable isotope tracer studies and for this purpose also experimentally demanding methods such as thermal ionization mass spectrometry and accelerator mass spectrometry are frequently used. (orig.)

Pathway confirmation and flux analysis of central metabolic pathways in Desulfovibrio vulgaris Hildenborough using Gas Chromatography-Mass Spectrometry and Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry

International Nuclear Information System (INIS)

Tang, Yinjie; Pingitore, Francesco; Mukhopadhyay, Aindrila; Phan, Richard; Hazen, Terry C.; Keasling, Jay D.

2007-01-01

Flux distribution in central metabolic pathways of Desulfovibrio vulgaris Hildenborough was examined using 13C tracer experiments. Consistent with the current genome annotation and independent evidence from enzyme activity assays, the isotopomer results from both GC-MS and Fourier Transform-Ion Cyclotron Resonance mass spectrometry (FT-ICR MS) indicate the lack of oxidatively functional TCA cycle and an incomplete pentose phosphate pathway. Results from this study suggest that fluxes through both pathways are limited to biosynthesis. The data also indicate that >80 percent of the lactate was converted to acetate and the reactions involved are the primary route of energy production (NAD(P)H and ATP production). Independent of the TCA cycle, direct cleavage of acetyl-CoA to CO and 5,10-methyl-THF also leads to production of NADH and ATP. Although the genome annotation implicates a ferredoxin-dependent oxoglutarate synthase, isotopic evidence does not support flux through this reaction in either the oxidative or reductive mode; therefore, the TCA cycle is incomplete. FT-ICR MS was used to locate the labeled carbon distribution in aspartate and glutamate and confirmed the presence of an atypical enzyme for citrate formation suggested in previous reports (the citrate synthesized by this enzyme is the isotopic antipode of the citrate synthesized by the (S)-citrate synthase). These findings enable a better understanding of the relation between genome annotation and actual metabolic pathways in D. vulgaris, and also demonstrate FT-ICR MS as a powerful tool for isotopomer analysis, overcoming problems in both GC-MS and NMR spectroscopy

Analysis of O-glycan heterogeneity in IgA1 myeloma proteins by Fourier transform ion cyclotron resonance mass spectrometry: implications for IgA nephropathy

DEFF Research Database (Denmark)

Renfrow, MB; Mackay, CL; Chalmers, MJ

2007-01-01

deficiency in IgA1 proteins occurs randomly or preferentially at specific sites. We have previously demonstrated the first direct localization of multiple O-glycosylation sites on a single IgA1 myeloma protein by use of activated ion-electron capture dissociation (AI-ECD) Fourier transform ion cyclotron...... resonance (FT-ICR) tandem mass spectrometry. Here, we report the analysis of IgA1 O-glycan heterogeneity by use of FT-ICR MS and liquid chromatography FT-ICR MS to obtain unbiased accurate mass profiles of IgA1 HR glycopeptides from three different IgA1 myeloma proteins. Additionally, we report the first AI......-ECD fragmentation on an individual IgA1 O-glycopeptide from an IgA1 HR preparation that is reproducible for each IgA1 myeloma protein. These results suggest that future analysis of IgA1 HR from IgAN patients and normal healthy controls should be feasible....

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

International Nuclear Information System (INIS)

Nataraju, V.

2007-01-01

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

Characterization of anti-theft devices directly from the surface of banknotes via easy ambient sonic spray ionization mass spectrometry.

Science.gov (United States)

Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Cuelbas, Claudio José; Zacca, Jorge Jardim; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Sawaya, Alexandra Christine Helena Frankland; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

2015-09-01

Using Brazilian banknotes as a test case, forensic examination and identification of Rhodamine B dye anti-theft device (ATD) staining on banknotes were performed. Easy ambient sonic spray ionization mass spectrometry (EASI-MS) was used since it allows fast and simple analysis with no sample preparation providing molecular screening of the surface with direct desorption and ionization of the security dye. For a more accurate molecular characterization of the ATD dye, Q Exactive Orbitrap™ Fourier transform (tandem) mass spectrometry using eletrospray ionization (ESI-HRMS/MS) was also applied. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Metabolic profile of Kudiezi injection in rats by UHPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Zhang, Jingdan; Zhang, Xiaoxue; Zhao, Yangyang; Song, Aihua; Sun, Wei; Yin, Ran

2018-02-01

In this study, a reliable and sensitive ultra-high performance liquid chromatography coupled with fourier transform ion cyclotron resonance mass spectrometry method was developed for the systematic study of the metabolic profile of Kudiezi injection in rat plasma, bile, urine, and feces after intravenous administration of a single dose. The chromatographic separation was performed on an Agilent Eclipse Plus C 18 column (4.6 mm × 50 mm, 1.8 μm) and the identification of prototype components and metabolites was achieved on a Bruker Solarix 7.0 T ultra-high resolution spectrometer in negative ion mode. Results indicated that a total of 76 constituents including 29 prototype compounds and 47 metabolites (10 phase I metabolites and 37 phase II metabolites) were tentatively identified. And the metabolic pathways of these prototype compounds including hydroxylation, dehydrogenation, glucuronidation, and sulfate conjugation. In conclusion, the developed method with high resolution and sensitivity was effective for screening and identification of prototypes and metabolites of Kudiezi injection in vivo. Moreover, these results would provide significant information for further pharmacokinetic and pharmacological research of Kudiezi injection in vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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...

Prognostic Metabolite Biomarkers for Soft Tissue Sarcomas Discovered by Mass Spectrometry Imaging

Science.gov (United States)

Lou, Sha; Balluff, Benjamin; Cleven, Arjen H. G.; Bovée, Judith V. M. G.; McDonnell, Liam A.

2017-02-01

Metabolites can be an important read-out of disease. The identification and validation of biomarkers in the cancer metabolome that can stratify high-risk patients is one of the main current research aspects. Mass spectrometry has become the technique of choice for metabolomics studies, and mass spectrometry imaging (MSI) enables their visualization in patient tissues. In this study, we used MSI to identify prognostic metabolite biomarkers in high grade sarcomas; 33 high grade sarcoma patients, comprising osteosarcoma, leiomyosarcoma, myxofibrosarcoma, and undifferentiated pleomorphic sarcoma were analyzed. Metabolite MSI data were obtained from sections of fresh frozen tissue specimens with matrix-assisted laser/desorption ionization (MALDI) MSI in negative polarity using 9-aminoarcridine as matrix. Subsequent annotation of tumor regions by expert pathologists resulted in tumor-specific metabolite signatures, which were then tested for association with patient survival. Metabolite signals with significant clinical value were further validated and identified by high mass resolution Fourier transform ion cyclotron resonance (FTICR) MSI. Three metabolite signals were found to correlate with overall survival ( m/z 180.9436 and 241.0118) and metastasis-free survival ( m/z 160.8417). FTICR-MSI identified m/z 241.0118 as inositol cyclic phosphate and m/z 160.8417 as carnitine.

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

Gas Measurement Using Static Fourier Transform Infrared Spectrometers.

Science.gov (United States)

Köhler, Michael H; Schardt, Michael; Rauscher, Markus S; Koch, Alexander W

2017-11-13

Online monitoring of gases in industrial processes is an ambitious task due to adverse conditions such as mechanical vibrations and temperature fluctuations. Whereas conventional Fourier transform infrared (FTIR) spectrometers use rather complex optical and mechanical designs to ensure stable operation, static FTIR spectrometers do not require moving parts and thus offer inherent stability at comparatively low costs. Therefore, we present a novel, compact gas measurement system using a static single-mirror Fourier transform spectrometer (sSMFTS). The system works in the mid-infrared range from 650 cm - 1 to 1250 cm - 1 and can be operated with a customized White cell, yielding optical path lengths of up to 120 cm for highly sensitive quantification of gas concentrations. To validate the system, we measure different concentrations of 1,1,1,2-Tetrafluoroethane (R134a) and perform a PLS regression analysis of the acquired infrared spectra. Thereby, the measured absorption spectra show good agreement with reference data. Since the system additionally permits measurement rates of up to 200 Hz and high signal-to-noise ratios, an application in process analysis appears promising.

Theory of peak coalescence in Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Boldin, Ivan A; Nikolaev, Eugene N

2009-10-01

Peak coalescence, i.e. the merging of two close peaks in a Fourier transform ion cyclotron resonance (FTICR) mass spectrum at a high number of ions, plays an important role in various FTICR experiments. In order to describe the coalescence phenomenon we would like to propose a new theory of motion for ion clouds with close mass-to-charge ratios, driven by a uniform magnetic field and Coulomb interactions between the clouds. We describe the motion of the ion clouds in terms of their averaged drift motion in crossed magnetic and electric fields. The ion clouds are considered to be of constant size and their motion is studied in two dimensions. The theory deals with the first-order approximation of the equations of motion in relation to dm/m, where dm is the mass difference and m is the mass of a single ion. The analysis was done for an arbitrary inter-cloud interaction potential, which makes it possible to analyze finite-size ion clouds of any shape. The final analytical expression for the condition of the onset of coalescence is found for the case of uniformly charged spheres. An algorithm for finding this condition for an arbitrary interaction potential is proposed. The critical number of ions for the peak coalescence to take place is shown to depend quadratically on the magnetic field strength and to be proportional to the cyclotron radius and inversely proportional to the ion masses. Copyright (c) 2009 John Wiley & Sons, Ltd.

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

Chemical modification of DNA: Molecular specificity studied by tandem mass spectrometry and liquid chromatography

International Nuclear Information System (INIS)

Chang, Ching-jer; Cooks, R.G.; Chae, Whi-Gun; Wood, J.M.

1989-01-01

Chemical modifications of DNA in vitro could be directly studied by C-13 NMR and P-31 NMR, which eliminated all degradation and separation processes. The prospects of utilized the NMR method in the in vitro experiments are limited because of the inherent low sensitivity of NMR and low level of DNA modification. We have developed a reverse-phase ion-paired HPLC method to study DNA modifications by methylating agents. The structural specificity of HPLC is significantly enhanced by conjunction with the specificity of enzymic transformations. The HPLC studies have also revealed the limitation of HPLC method for simultaneous determination of many minor modified nucleosides. This problem has been overcome by tandem mass spectrometry. In conjunction with the resolving power of HPLC in separating isomers, desorption chemical ionization tandem mass spectrometry has been utilized in the determination of the modified nucleosides at the picomole level using stable-isotope labeled compounds as internal references

Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry

Science.gov (United States)

Mahmoodani, Fatemeh; Perera, Conrad O.; Abernethy, Grant; Fedrizzi, Bruno; Greenwood, David; Chen, Hong

2018-03-01

In a successful fortification program, the stability of micronutrients added to the food is one of the most important factors. The added vitamin D3 is known to sometimes decline during storage of fortified milks, and oxidation through fatty acid lipoxidation could be suspected as the likely cause. Identification of vitamin D3 oxidation products (VDOPs) in natural foods is a challenge due to the low amount of their contents and their possible transformation to other compounds during analysis. The main objective of this study was to find a method to extract VDOPs in simulated whole milk powder and to identify these products using LTQ-ion trap, Q-Exactive Orbitrap and triple quadrupole mass spectrometry. The multistage mass spectrometry (MSn) spectra can help to propose plausible schemes for unknown compounds and their fragmentations. With the growth of combinatorial libraries, mass spectrometry (MS) has become an important analytical technique because of its speed of analysis, sensitivity, and accuracy. This study was focused on identifying the fragmentation rules for some VDOPs by incorporating MS data with in silico calculated MS fragmentation pathways. Diels-Alder derivatization was used to enhance the sensitivity and selectivity for the VDOPs' identification. Finally, the confirmed PTAD-derivatized target compounds were separated and analyzed using ESI(+)-UHPLC-MS/MS in multiple reaction monitoring (MRM) mode. [Figure not available: see fulltext.

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.

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

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.

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.

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...

Mass Spectrometric Fingerprinting of Tank Waste Using Tunable, Ultrafast Infrared Lasers

International Nuclear Information System (INIS)

Richard Haglund Jr.

2002-01-01

The principal scientific thrust of this project was to demonstrate a novel method for precision matrix-assisted laser desorption-ionization (MALDI) mass spectrometry (MS) of model tank-waste materials using, using the sodium nitrate component of the tank waste both as the matrix and as an internal calibration standard. Conventional nanosecond and femtosecond single-frequency lasers and a tunable, mid-infrared free-electron laser were used in the development of the MS protocols and in measurements of the MALDI dynamics. In addition to developing a model of the processes which lead to efficient desorption and ionization of organic molecules (e.g., toluene, benzene, chelators, various organic acids, crown ethers) from sodium nitrate, we developed protocols for quantitative analysis based on the use of the sodium nitrate in tank waste as an internal standard. Comparisons of MALDI-MS using nanosecond and picosecond lasers, and of infrared and ultraviolet lasers, have been especially instructive, and demonstrate the superior potential of IR-MALDI for this purpose, as well as for a number of related analytical and thin-film applications

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.)

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.)

[Research on Application of Fourier Transform Infrared Spectrometry in the Diagnosis of Lymph Node Metastasis in Gastric Cancer].

Science.gov (United States)

Bai, Yue-kui; Yu, Li-wei; Zhang, Le; Fu, Jing; Leng, Hui; Yang, Xiao-jun; Ma, Jun-qiang; Li, Xiao-juan; Li, Xiu-juan; Zhu, Qing; Zhang, Yuan-fu; Ling, Xiao-feng; Cao, Wen-lan

2015-03-01

To explore the feasibility of quick intraoperative in situ and noninvasive diagnosis of lymph node metastasis in gastric cancer by Fourier transform infrared (FTIR) spectrometry. FTIR spectra of surgically removed fresh lymph nodes were measured by FTIR via probe of attenuated total reflection (ATR). For each spectrum, 13 bands were indentified and assigned between 3 000 and 1 000 cm(-1). Peaks in the spectra were measured and relative intensity ratios were calculated and compared between the spectra of Metastatic lymph nodes (MLN) and Non-metastatic lymph nodes (NMLN). Standard statistic analysis was performed. 720 lymph nodes were measured in 38 gastric cancer patients. Results show that there were significant differences between the FTIR of 540 MLN and 180 NMLN. (1) For the band related to nucleic acid: The ratios of I1240/I1460 (p = 0.015) and I1080/I1460 (p = 0.034) increased in MLN, which shows that the relative quantity of nucleic acid was more in MLN than that in NMLN. (2) For the bands related to protein: The ratios of I1640 /I1460 (p = 0.001) and I146/I1460 (p = 0.027) increased in MLN, which shows that the relative quantity of protein was more in MLN. (3) For the bands related to lipid: The ratio of I2855/I460 and I1740/I1460 decreased in MLN FTIR spectrum, indicating the lower relative quantity of lipid in MLN. (4) For the bands related to carbohydrate: The ratio of I1160/I1460 (p = 0.023) decreased in MLN FTIR spectrum, indicating the lower relative quantity of carbohydrate in MLN. The results demonstrate that the FTIR spectroscopy technique maybe develop into a promising method for in situ and quick intraoperative differential diagnosis of lymph node metastasis in gastric cancer.

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…

Application of phase correction to improve the interpretation of crude oil spectra obtained using 7 T Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Cho, Yunju; Qi, Yulin; O'Connor, Peter B; Barrow, Mark P; Kim, Sunghwan

2014-01-01

In this study, a phase-correction technique was applied to the study of crude oil spectra obtained using a 7 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). 7 T FT-ICR MS had not been widely used for oil analysis due to the lower resolving power compared with high field FT-ICR MS. For low field instruments, usage of data that has not been phase-corrected results in an inability to resolve critical mass splits of C3 and SH4 (3.4 mDa), and (13)C and CH (4.5 mDa). This results in incorrect assignments of molecular formulae, and discontinuous double bond equivalents (DBE) and carbon number distributions of S1, S2, and hydrocarbon classes are obtained. Application of phase correction to the same data, however, improves the reliability of assignments and produces continuous DBE and carbon number distributions. Therefore, this study clearly demonstrates that phase correction improves data analysis and the reliability of assignments of molecular formulae in crude oil anlayses.

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.

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

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...

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.

Investigation of bio-oil produced by hydrothermal liquefaction of food waste using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Kostyukevich, Yury; Vlaskin, Mikhail; Borisova, Ludmila; Zherebker, Alexander; Perminova, Irina; Kononikhin, Alexey; Popov, Igor; Nikolaev, Eugene

2018-02-01

Recent research has revealed that more than 1.3 billion tons of food is wasted globally every year. The disposal of such huge biomass has become a challenge. In the present paper, we report the production of the bio-oil by hydrothermal liquefaction of three classes of food waste: meat, cheese and fruits. The highest yield of the bio-oil was observed for meat (∼60%) and cheese (∼75%), while for fruits, it was considerably low (∼10%). The molecular composition of the obtained bio-oil was investigated using ultrahigh resolution Fourier Transform Ion Cyclotron Resonance mass spectrometry and was found to be similar to that obtained from algae. Several thousand heteroatom compounds (N, N 2 , ON 2 , etc. classes) were reliably identified from each sample. It was found that bio-oils produced from meat and cheese have many compounds (∼90%) with common molecular formulas, while bio-oil produced from fruits differs considerably (∼30% of compounds are unique).

Applications of Hadamard transform-gas chromatography/mass spectrometry to the detection of acetone in healthy human and diabetes mellitus patient breath.

Science.gov (United States)

Fan, Gang-Ting; Yang, Chien-Lin; Lin, Cheng-Huang; Chen, Chien-Chung; Shih, Chung-Hung

2014-03-01

The Hadamard transform-gas chromatography/mass spectrometry (HT-GC/MS) technique was successfully employed to detect acetone, a biomarker for diabetes mellitus (DM) prediction, in human breath. Samples of exhaled breath were collected from four DM patients (one type-I and three type-II) and eight volunteers (nondiabetic healthy subjects), respectively. The gas samples, without any pretreatment, were simultaneously injected into a GC column through a Hadamard-injector based on Hadamard codes. Under optimized conditions, when cyclic S-matrix orders of 255, 1023 and 2047 were used, the S/N ratios of the acetone signals were substantially improved by 8.0-, 16.0- and 22.6-fold, respectively; these improvements are in good agreement with theoretically calculated values. We found that the breath acetone concentration levels in the four DM patients and the eight volunteers ranged from 1 to 10 ppmv and 0.1 to 1 ppmv, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Quantitation of Acrylamide in Foods by High-Resolution Mass Spectrometry

NARCIS (Netherlands)

Troise, A.D.; Fogliano, Vincenzo

2016-01-01

The use of liquid chromatography high-resolution mass spectrometry (LC-HRMS) and direct analysis real-time high-resolution mass spectrometry (DART-HRMS) defines a new scenario in the analysis of thermal-induced toxicants, such as acrylamide. Several factors contribute to the definition of the

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.

Mass spectrometry in grape and wine chemistry. Part II: The consumer protection.

Science.gov (United States)

Flamini, Riccardo; Panighel, Annarita

2006-01-01

Controls in food industry are fundamental to protect the consumer health. For products of high quality, warranty of origin and identity is required and analytical control is very important to prevent frauds. In this article, the "state of art" of mass spectrometry in enological chemistry as a consumer safety contribute is reported. Gas chromatography-mass spectrometry (GC/MS) and liquid-chromatography-mass spectrometry (LC/MS) methods have been developed to determine pesticides, ethyl carbamate, and compounds from the yeast and bacterial metabolism in wine. The presence of pesticides in wine is mainly linked to the use of dicarboxyimide fungicides on vineyard shortly before the harvest to prevent the Botrytis cinerea attack of grape. Pesticide residues are regulated at maximum residue limits in grape of low ppm levels, but significantly lower levels in wine have to be detected, and mass spectrometry offers effective and sensitive methods. Moreover, mass spectrometry represent an advantageous alternative to the radioactive-source-containing electron capture detector commonly used in GC analysis of pesticides. Analysis of ochratoxin A (OTA) in wine by LC/MS and multiple mass spectrometry (MS/MS) permits to confirm the toxin presence without the use of expensive immunoaffinity columns, or time and solvent consuming sample derivatization procedures. Inductively coupled plasma-mass spectrometry (ICP/MS) is used to control heavy metals contamination in wine, and to verify the wine origin and authenticity. Isotopic ratio-mass spectrometry (IRMS) is applied to reveal wine watering and sugar additions, and to determine the product origin and traceability.

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

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

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....

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.

Detection of sputtered molecular doubly charged anions: a comparison of secondary-ion mass spectrometry (SIMS) and accelerator mass spectrometry (AMS)

International Nuclear Information System (INIS)

Gnaser, Hubert; Golser, Robin; Kutschera, Walter; Priller, Alfred; Steier, Peter; Vockenhuber, Christof

2004-01-01

The detection of small molecular dianions by secondary-ion mass spectrometry (SIMS) and by accelerator mass spectrometry (AMS) is compared. In SIMS, the existence of these dianions can be identified safely if the total mass number of the molecule is odd and the dianion is hence detected at a half-integral mass number. The occurrence of fragmentation processes which may interfere with this scheme, is illustrated by means of the energy spectra of singly and doubly charged negative cluster ions. As compared to SIMS, AMS can rely, in addition, on the break-up of molecular species in the stripping process: this allows to monitor the simultaneous arrival of several atomic constituents with a clear energetic pattern in coincidence at the detector. This feature is exemplified for the C 10 2- dianion

Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra

International Nuclear Information System (INIS)

Persaud, K.

1965-01-01

We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [fr

Automated mass correction and data interpretation for protein open-access liquid chromatography-mass spectrometry.

Science.gov (United States)

Wagner, Craig D; Hall, John T; White, Wendy L; Miller, Luke A D; Williams, Jon D

2007-02-01

Characterization of recombinant protein purification fractions and final products by liquid chromatography-mass spectrometry (LC/MS) are requested more frequently each year. A protein open-access (OA) LC/MS system was developed in our laboratory to meet this demand. This paper compares the system that we originally implemented in our facilities in 2003 to the one now in use, and discusses, in more detail, recent enhancements that have improved its robustness, reliability, and data reporting capabilities. The system utilizes instruments equipped with reversed-phase chromatography and an orthogonal accelerated time-of-flight mass spectrometer fitted with an electrospray source. Sample analysis requests are accomplished using a simple form on a web-enabled laboratory information management system (LIMS). This distributed form is accessible from any intranet-connected company desktop computer. Automated data acquisition and processing are performed using a combination of in-house (OA-Self Service, OA-Monitor, and OA-Analysis Engine) and vendor-supplied programs (AutoLynx, and OpenLynx) located on acquisition computers and off-line processing workstations. Analysis results are then reported via the same web-based LIMS. Also presented are solutions to problems not addressed on commercially available, small-molecule OA-LC/MS systems. These include automated transforming of mass-to-charge (m/z) spectra to mass spectra and automated data interpretation that considers minor variants to the protein sequence-such as common post-translational modifications (PTMs). Currently, our protein OA-LC/MS platform runs on five LC/MS instruments located in three separate GlaxoSmithKline R&D sites in the US and UK. To date, more than 8000 protein OA-LC/MS samples have been analyzed. With these user friendly and highly automated OA systems in place, mass spectrometry plays a key role in assessing the quality of recombinant proteins, either produced at our facilities or bought from external

Rapid comparison of diacetylmorphine on banknotes by tandem mass spectrometry.

Science.gov (United States)

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

2005-01-01

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

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.

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/.

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

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.

Qualitative metabolome analysis of human cerebrospinal fluid by 13C-/12C-isotope dansylation labeling combined with liquid chromatography Fourier transform ion cyclotron resonance mass spectrometry.

Science.gov (United States)

Guo, Kevin; Bamforth, Fiona; Li, Liang

2011-02-01

Metabolome analysis of human cerebrospinal fluid (CSF) is challenging because of low abundance of metabolites present in a small volume of sample. We describe and apply a sensitive isotope labeling LC-MS technique for qualitative analysis of the CSF metabolome. After a CSF sample is divided into two aliquots, they are labeled by (13)C-dansyl and (12)C-dansyl chloride, respectively. The differentially labeled aliquots are then mixed and subjected to LC-MS using Fourier-transform ion cyclotron resonance mass spectrometry (FTICR MS). Dansylation offers significant improvement in the performance of chromatography separation and detection sensitivity. Moreover, peaks detected in the mass spectra can be readily analyzed for ion pair recognition and database search based on accurate mass and/or retention time information. It is shown that about 14,000 features can be detected in a 25-min LC-FTICR MS run of a dansyl-labeled CSF sample, from which about 500 metabolites can be profiled. Results from four CSF samples are compared to gauge the detectability of metabolites by this method. About 261 metabolites are commonly detected in replicate runs of four samples. In total, 1132 unique metabolite ion pairs are detected and 347 pairs (31%) matched with at least one metabolite in the Human Metabolome Database. We also report a dansylation library of 220 standard compounds and, using this library, about 85 metabolites can be positively identified. Among them, 21 metabolites have never been reported to be associated with CSF. These results illustrate that the dansylation LC-FTICR MS method can be used to analyze the CSF metabolome in a more comprehensive manner. © American Society for Mass Spectrometry, 2011

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)

Quantitative correlations between collision induced dissociation mass spectrometry coupled with electrospray ionization or atmospheric pressure chemical ionization mass spectrometry - Experiment and theory

Science.gov (United States)

Ivanova, Bojidarka; Spiteller, Michael

2018-04-01

The problematic that we consider in this paper treats the quantitative correlation model equations between experimental kinetic and thermodynamic parameters of coupled electrospray ionization (ESI) mass spectrometry (MS) or atmospheric pressure chemical ionization (APCI) mass spectrometry with collision induced dissociation mass spectrometry, accounting for the fact that the physical phenomena and mechanisms of ESI- and APCI-ion formation are completely different. There are described forty two fragment reactions of three analytes under independent ESI- and APCI-measurements. The developed new quantitative models allow us to study correlatively the reaction kinetics and thermodynamics using the methods of mass spectrometry, which complementary application with the methods of the quantum chemistry provide 3D structural information of the analytes. Both static and dynamic quantum chemical computations are carried out. The object of analyses are [2,3-dimethyl-4-(4-methyl-benzoyl)-2,3-di-p-tolyl-cyclobutyl]-p-tolyl-methanone (1) and the polycyclic aromatic hydrocarbons derivatives of dibenzoperylen (2) and tetrabenzo [a,c,fg,op]naphthacene (3), respectively. As far as (1) is known to be a product of [2π+2π] cycloaddition reactions of chalcone (1,3-di-p-tolyl-propenone), however producing cyclic derivatives with different stereo selectivity, so that the study provide crucial data about the capability of mass spectrometry to provide determine the stereo selectivity of the analytes. This work also first provides quantitative treatment of the relations '3D molecular/electronic structures'-'quantum chemical diffusion coefficient'-'mass spectrometric diffusion coefficient', thus extending the capability of the mass spectrometry for determination of the exact 3D structure of the analytes using independent measurements and computations of the diffusion coefficients. The determination of the experimental diffusion parameters is carried out within the 'current monitoring method

Glycine identification in natural jarosites using laser desorption Fourier transform mass spectrometry: implications for the search for life on Mars.

Science.gov (United States)

Kotler, J Michelle; Hinman, Nancy W; Yan, Beizhan; Stoner, Daphne L; Scott, Jill R

2008-04-01

The jarosite group minerals have received increasing attention since the discovery of jarosite on the martian surface by the Mars Exploration Rover Opportunity. Given that jarosite can incorporate foreign ions within its structure, we have investigated the use of jarosite as an indicator of aqueous and biological processes on Earth and Mars. The use of laser desorption Fourier transform mass spectrometry has revealed the presence of organic matter in several jarosite samples from various locations worldwide. One of the ions from the natural jarosites has been attributed to glycine because it was systematically observed in combinations of glycine with synthetic ammonium and potassium jarosites, Na(2)SO(4) and K(2)SO(4). The ability to observe these organic signatures in jarosite samples with an in situ instrumental technique, such as the one employed in this study, furthers the goals of planetary geologists to determine whether signs of life (e.g., the presence of biomolecules or biomolecule precursors) can be detected in the rock record of terrestrial and extraterrestrial samples.

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

The DENIS & 2MASS Near Infrared Surveys

OpenAIRE

Mamon, Gary

1996-01-01

The DENIS and 2MASS near infrared surveys are presented. Their applications in extragalactic astronomy and cosmology are listed. The prospects for a rapid spectroscopic followup survey of a near infrared selected sample of nearly $10^5$ galaxies are illustrated with Monte-Carlo simulations.

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.)

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

Comprehensive characterization of natural organic matter by MALDI- and ESI-Fourier transform ion cyclotron resonance mass spectrometry

International Nuclear Information System (INIS)

Cao, Dong; Huang, Huogao; Hu, Ming; Cui, Lin; Geng, Fanglan; Rao, Ziyu; Niu, Hongyun; Cai, Yaqi; Kang, Yuehui

2015-01-01

Highlights: • MALDI-FT-ICR-MS was firstly employed for molecular characterization of NOM. • 1,8-Bis(dimethyl-amino)-naphthalene (DMAN) was used as matrix. • Mass spectra of NOM generated by MALDI and ESI methods were compared. • Complementary molecular information of NOM was provided by MALDI. - Abstract: Natural organic matter (NOM) is a complex and non-uniform mixture of organic compounds which plays an important role in environmental processes. Due to the complexity, it is challenging to obtain fully detailed structural information about NOM. Although Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) has been demonstrated to be a powerful tool for providing molecular information about NOM, multiple ionization methods are needed for comprehensive characterization of NOM at the molecular level considering the ionizing selectivity of different ionization methods. This paper reports the first use of matrix assisted laser desorption/ionization (MALDI) method coupled with FT-ICR-MS for molecular characterization of NOM within a mass range of 200–800 Da. The mass spectral data obtained by MALDI were systematically compared with data generated by electrospray ionization (ESI). It showed that complementary molecular information about NOM which could not be detected by ESI, were provided by MALDI. More unsaturated and aromatic constituents of NOM with lower O/C ratio (O/C ratio < 0.5) were preferentially ionized in MALDI negative mode, whereas more polar constituents of NOM with higher O/C ratio were preferentially ionized in ESI negative mode. Molecular anions of NOM appearing at even m/z in MALDI negative ion mode were detected. The results show that NOM molecules with aromatic structures, moderate O/C ratio (0.7 > O/C ratio > 0.25) and lower H/C ratio were liable to form molecular anions at even m/z, whereas those with higher H/C ratio are more likely to form deprotonated ions at odd m/z. It is speculated that almost half of the NOM

Identification of keratinocyte specific markers using phage display and mass spectrometry

DEFF Research Database (Denmark)

Jensen, K.B.; Jensen, O.N.; Ravn, P.

2003-01-01

and mass spectrometry that allows identification of cell type-specific protein markers. The most important features of the method are (i) reduction of experimental noise originating from background binding of phage particles and (ii) isolation of affinity binders after a single round of selection, which...... antigens were subsequently identified by mass spectrometry as laminin-5, plectin, and fibronectin. The combination of phage display technology with mass spectrometry methods for protein identification is a general and promising approach for proteomic analysis of cell surface complexity....

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.)

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.

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

Science.gov (United States)

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

2018-06-02

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

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

Fourier transform infrared spectrometery: an undergraduate experiment

International Nuclear Information System (INIS)

Lerner, L

2016-01-01

Simple apparatus is developed, providing undergraduate students with a solid understanding of Fourier transform (FT) infrared (IR) spectroscopy in a hands on experiment. Apart from its application to measuring the mid-IR spectra of organic molecules, the experiment introduces several techniques with wide applicability in physics, including interferometry, the FT, digital data analysis, and control theory. (paper)

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).

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....

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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)

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.

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

3D spectral imaging with synchrotron Fourier transform infrared spectro-microtomography

Science.gov (United States)

Michael C. Martin; Charlotte Dabat-Blondeau; Miriam Unger; Julia Sedlmair; Dilworth Y. Parkinson; Hans A. Bechtel; Barbara Illman; Jonathan M. Castro; Marco Keiluweit; David Buschke; Brenda Ogle; Michael J. Nasse; Carol J. Hirschmugl

2013-01-01

We report Fourier transform infrared spectro-microtomography, a nondestructive three-dimensional imaging approach that reveals the distribution of distinctive chemical compositions throughout an intact biological or materials sample. The method combines mid-infrared absorption contrast with computed tomographic data acquisition and reconstruction to enhance chemical...

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

Fourier transform infrared spectrophotometry and X-ray powder ...

African Journals Online (AJOL)

This study aimed at demonstrating complementary roles offered by both Fourier transform infrared (FTIR) spectrophotometry and x-ray powder diffraction (XRPD) techniques in characterizing clay size fraction of kaolins. The clay size fraction of kaolin samples obtained from Kgwakgwe, Makoro, Lobatse and Serule kaolin ...

Fourier transform infrared (FTIR) spectroscopy for identification of ...

African Journals Online (AJOL)

Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chlorella vulgaris Beijerinck 1890 and Scenedesmus obliquus (Turpin) Kützing 1833. Two cultures were grown in a chemically-defined media under photoautotrophic culture conditions isolated from eutrophic ...

Transformation optics and metamaterials at infrared wavelength: engineering of permittivity and permeability

Science.gov (United States)

Ghasemi, Rasta; Degiron, Aloyse; Leroux, Xavier; Lupu, Anatole; de Lustrac, André

2013-05-01

The transformation optics was introduced by J. Pendry and U. Leonhardt in 2006 [1,2]. In this method an initial space is transformed into a new space and this transformed space can be materialized by a material, which the electromagnetic parameters can be deduced from the metric of the transformed space. In the general case the electromagnetic parameters are anisotropic tensors. At microwave frequencies these materials can be realized using classical metamaterials like SRR form J. Pendry or ELC from D. Smith [3]. At infrared wavelengths this realization is a challenge because the dimensions of the metamaterials are much smaller than the wavelength and become nanometric. Then the design of these metamaterials must be simplified and original methods must be developed to allow the realization of these metamaterials with controlled electromagnetic properties. In this paper we describe the realization of a multilayer metamaterial working at infrared wavelength, which the permittivity and the permeability can be adjusted separately. We give some examples of realized multilayer materials operating around 150THz, with a comparison between the results of full wave simulations of these materials and their characterizations using a Fourier Transform Infrared Spectrometer.

Fourier transform infrared spectra applications to chemical systems

CERN Document Server

Ferraro, John R

1985-01-01

The final and largest volume to complete this four-volume treatise is published in response to the intense commercial and research interest in Fourier Transform Interferometry.Presenting current information from leading experts in the field, Volume 4 introduces new information on, for example, applications of Diffuse Reflectance Spectroscopy in the Far-Infrared Region. The editors place emphasis on surface studies and address advances in Capillary Gas Chromatography - Fourier Transform Interferometry.Volume 4 especially benefits spectroscopists and physicists, as well as researchers

Detection of Nonvolatile Inorganic Oxidizer-Based Explosives from Wipe Collections by Infrared Thermal Desorption-Direct Analysis in Real Time Mass Spectrometry.

Science.gov (United States)

Forbes, Thomas P; Sisco, Edward; Staymates, Matthew

2018-05-07

Infrared thermal desorption (IRTD) was coupled with direct analysis in real time mass spectrometry (DART-MS) for the detection of both inorganic and organic explosives from wipe collected samples. This platform generated discrete and rapid heating rates that allowed volatile and semivolatile organic explosives to thermally desorb at relatively lower temperatures, while still achieving elevated temperatures required to desorb nonvolatile inorganic oxidizer-based explosives. IRTD-DART-MS demonstrated the thermal desorption and detection of refractory potassium chlorate and potassium perchlorate oxidizers, compounds difficult to desorb with traditional moderate-temperature resistance-based thermal desorbers. Nanogram to sub-nanogram sensitivities were established for analysis of a range of organic and inorganic oxidizer-based explosive compounds, with further enhancement limited by the thermal properties of the most common commercial wipe materials. Detailed investigations and high-speed visualization revealed conduction from the heated glass-mica base plate as the dominant process for heating of the wipe and analyte materials, resulting in thermal desorption through boiling, aerosolization, and vaporization of samples. The thermal desorption and ionization characteristics of the IRTD-DART technique resulted in optimal sensitivity for the formation of nitrate adducts with both organic and inorganic species. The IRTD-DART-MS coupling and IRTD in general offer promising explosive detection capabilities to the defense, security, and law enforcement arenas.

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…

Tensor Fukunaga-Koontz transform for small target detection in infrared images

Science.gov (United States)

Liu, Ruiming; Wang, Jingzhuo; Yang, Huizhen; Gong, Chenglong; Zhou, Yuanshen; Liu, Lipeng; Zhang, Zhen; Shen, Shuli

2016-09-01

Infrared small targets detection plays a crucial role in warning and tracking systems. Some novel methods based on pattern recognition technology catch much attention from researchers. However, those classic methods must reshape images into vectors with the high dimensionality. Moreover, vectorizing breaks the natural structure and correlations in the image data. Image representation based on tensor treats images as matrices and can hold the natural structure and correlation information. So tensor algorithms have better classification performance than vector algorithms. Fukunaga-Koontz transform is one of classification algorithms and it is a vector version method with the disadvantage of all vector algorithms. In this paper, we first extended the Fukunaga-Koontz transform into its tensor version, tensor Fukunaga-Koontz transform. Then we designed a method based on tensor Fukunaga-Koontz transform for detecting targets and used it to detect small targets in infrared images. The experimental results, comparison through signal-to-clutter, signal-to-clutter gain and background suppression factor, have validated the advantage of the target detection based on the tensor Fukunaga-Koontz transform over that based on the Fukunaga-Koontz transform.

Multidimensional chromatography coupled to mass spectrometry in analysing complex proteomics samples

NARCIS (Netherlands)

Horvatovich, Peter; Hoekman, Berend; Govorukhina, Natalia; Bischoff, Rainer

Multidimensional chromatography coupled to mass spectrometry (LC(n)-MS) provides more separation power and an extended measured dynamic concentration range to analyse complex proteomics samples than one dimensional liquid chromatography coupled to mass spectrometry (1D-LC-MS). This review gives an

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.

Determination of iprodione in agrochemicals by infrared and Raman spectrometry.

Science.gov (United States)

Armenta, Sergio; Garrigues, Salvador; de la Guardia, Miguel

2007-04-01

Two methodologies based on vibrational spectrometry--making use of Fourier transform infrared absorption (FTIR) and Raman spectrometry--were developed for iprodione determination in solid pesticide formulations. The FTIR procedure involved the extraction of iprodione by CHCl(3), and the latter determination involved measuring the peak area between 1450 and 1440 cm(-1), corrected using a horizontal baseline defined at 1481 cm(-1). FT-Raman determination was performed directly on the powdered solid products, using standard chromatography glass vials as sample cells and measuring the Raman intensity between 1003 and 993 cm(-1), with a two-point baseline correction established between 1012 and 981 cm(-1). The sensitivities obtained were 0.319 area values g mg(-1) for FTIR determination and 5.58 area values g g(-1) for FT-Raman. The repeatabilities, taken to be the relative standard deviation of five independent measurements at 1.51 mg g(-1) and 10.98% w/w concentration levels, were equal to 0.16% and 0.9% for FTIR and FT-Raman, respectively, and the limits of detection were 0.3 and 0.2% w/w (higher than those obtained for HPLC, 0.016% w/w). FTIR determination provided a sample frequency of 60 h(-1), higher than those obtained for the Raman and reference chromatography methods (25 and 8.6 h(-1), respectively). On the other hand, the new FT-Raman method eliminates reagent consumption and waste generation, and reduces the need for sample handling and the contact of operator with the pesticide. In spite of their lack of sensitivity, vibrational procedures can therefore provide viable environmentally friendly alternatives to laborious, time- and solvent-consuming reference chromatography methods for quality control in commercially available pesticide formulations.

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…

Laser microprobe mass spectrometry: Potential and limitations for inorganic and organic micro-analysis. Pt. 1

International Nuclear Information System (INIS)

Vaeck, I. van; Gijbels, R.

1990-01-01

Laser microprobe mass spectrometry (LMMS) employs a highly focused UV laser beam to ionise a microvolume in the order of 1 μm 3 . The ions produced are then mass-separated in a time-of-flight (TOF) or a Fourier Transform (FT) mass spectrometer. TOF LMMS allows element localisation, detailed speciation of inorganic substances and structural information of organic molecules. Quantitation is difficult. This paper focuses on instrumental aspects and inorganic analysis. Organic applications are treated in part II of this series. Selected examples illustrate that TOF LMMS is a valuable tool for the qualitative characterisation of micro-samples. Also, the applicability to the analysis with high spatial resolution is shown. The current technology and the prospects from the recent FTMS development are discussed. (orig.)

Symposium on fast atom and ion induced mass spectrometry of nonvolatile organic solids

International Nuclear Information System (INIS)

McNeal, C.J.

1982-01-01

The mechanisms of molecular and fragment ion production and the various parameters affecting ion yields were discussed by 6 invited speakers from Europe, Canada, and the US at this symposium. The work reported was almost equally divided between that using low-energy (keV) primary ion (or atom) beams, e.g. fast atom bombardment mass spectrometry (FABMS) and secondary ion mass spectrometry (SIMS) and that using high energy (MeV) particles, e.g. heavy ion induced mass spectrometry (HIIDMS) and 252 Cf-plasma desorption mass spectrometry ( 252 Cf-PDMS). Both theoretical foundations and observed experimental results for both techniques are included

Technical and economical aspects of mass spectrometry in food and agricultural industries

International Nuclear Information System (INIS)

Cornu, Ayme

1975-01-01

Mass spectrometry proved to be very useful for solving analytical problems in food and agricultural industries. Its essential properties are: high resolution mass spectrometry allows to find the molecular structure of an isolated compound, even with a very small sample; associated with on line gas chromatographic separation, it gives the possibility to identify a great number of components in a small complex extract; isotope determinations by mass spectrometry give an essential contribution to follow kinetic mechanisms of formation of natural molecules in plant-growing, photosynthesis, fertilization, ..., leading to identification of the origin of foods and beverages. The economical aspect of mass spectrometry is characterized by the cost of investment in instrumentation and the necessary high level of competence of the technicians [fr

Mass spectrometry in identification of ecotoxicants including chemical and biological warfare agents

International Nuclear Information System (INIS)

Lebedev, Albert T.

2005-01-01

Mass spectrometry is a unique tool to detect and identify trace levels of organic and bioorganic compounds as well as microorganisms in the environment. The range of potential chemical warfare (CW) and biological warfare (BW) agents is very broad. An important advantage of mass spectrometry over other techniques involves potential for full spectrum detection of chemical and biological agents including mid-spectrum materials (i.e. bioactive peptides, toxins, etc.) for which biological approaches are inadequate. Being very fast (seconds and minutes), extremely sensitive (zeptomoles 10 -21 ), and informative (detailed qualitative and quantitative composition of mixtures containing hundreds of chemicals), mass spectrometry is a principal analytical tool at the sites of destruction of CW. Due to its unique features, mass spectrometry is applied not only for the detection of CW agents, but for the analysis of products of metabolism and degradation of these agents in organisms or environment as well. The present paper deals with some examples of successful application of mass spectrometry for the analyses of ecotoxicants, chemical warfare agents, explosives, and microorganisms including biology warfare agents

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....

Fast and easy extraction combined with high resolution-mass spectrometry for residue analysis of two anticonvulsants and their transformation products in marine mussels.

Science.gov (United States)

Martínez Bueno, M J; Boillot, C; Fenet, H; Chiron, S; Casellas, C; Gómez, E

2013-08-30

Environmental field studies have shown that carbamazepine (Cbz) is one of the most frequently detected human pharmaceuticals in different aquatic compartments. However, little data is available on the detection of this substance and its transformation products in aquatic organisms. This study was thus mainly carried out to optimize and validate a simple and sensitive analytical methodology for the detection, characterization and quantification of Cbz and oxcarbazepine (Ox), two anticonvulsants, and six of their main transformation products in marine mussels (Mytilus galloprovincialis). A modified QuEChERS extraction method followed by analysis with liquid chromatography coupled to high resolution mass spectrometry (HRMS) was used. The analyses were performed using two-stage fragmentation to reveal the different fragmentation pathways that are highly useful for the identification of isomeric compounds, a common problem when several transformation products are analyzed. The developed analytical method allowed determination of the target analytes in the lower ng/g concentration levels. The mean recovery ranged from 67 to 110%. The relative standard deviation was under 11% in the intra-day and 18% in the inter-day analyses, respectively. Finally, the method was applied to marine mussel samples collected from Mediterranean Sea cultures in southeastern France. Residues of the psychiatric drug Cbz were occasionally found at levels up to 3.5ng/g dw. Lastly, in this study, other non-target compounds, such as caffeine, metoprolol, cotinine and ketoprofen, were identified in the real samples analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

QUANTITATIVE FOURIER TRANSFORM INFRARED SPECTROSCOPIC INVESTIGATION OF HUMIC SUBSTANCE FUNCTIONAL GROUP COMPOSITION

Science.gov (United States)

Infrared (IR) spectroscopy has been widely used for the structural investigation of humic substances. Although Fourier Transform Infrared (FTIR) instrumentation has been available for sometime, relatively little work with these instruments has been reported for humic substances,...

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.

Voltammetry coupled to mass spectrometry in the presence of isotope {sup 18}O labeled water for the prediction of oxidative transformation pathways of activated aromatic ethers: Acebutolol

Energy Technology Data Exchange (ETDEWEB)

Bussy, Ugo; Tea, Illa [LUNAM Université de Nantes, CNRS, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM), UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3 (France); Ferchaud-Roucher, Véronique; Krempf, Michel [Université de Nantes, Plateforme Spectrométrie de Masse, CRNH, SFR Santé F. Bonamy, Institut du Thorax, UMR S1087, IRT-UN, BP 70721, 8 Quai Moncousu, 44007 Nantes cedex 1 (France); Silvestre, Virginie; Galland, Nicolas [LUNAM Université de Nantes, CNRS, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM), UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3 (France); Jacquemin, Denis [LUNAM Université de Nantes, CNRS, Chimie et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM), UMR 6230, 2 rue de la Houssinière, BP 92208, F-44322 Nantes cedex 3 (France); Institut Universitaire de France, 103, Boulevard Saint-Michel, 75005 Cedex 5 France (France); Andresen-Bergström, Moa; Jurva, Ulrik [CVGI iMed DMPK, AstraZeneca R and D Mölndal, Mölndal (Sweden); and others

2013-01-31

Highlights: ► Voltammetry coupled to mass spectrometry method as a useful tool for on-line predictions of electrochemical transformations. ► Evidence of the O-dealkoxylation reaction pathway of acebutolol in the presence of labeled water. ► New approach for on line EC-MS applications. -- Abstract: The coupling between an electrochemical cell (EC) and a mass spectrometer (MS) is a useful screening tool (EC-MS) to study the oxidative transformation pathways of various electroactive species. For that purpose, we showed that the EC-MS method, carried out in the presence and absence of isotope {sup 18}O labeled water leads not only to a fast identification of oxidation products but also leads to a fast elucidation of the mechanism pathway reaction. We examined herein the case of the electrochemical hydrolysis of activated aromatic ether. Acebutolol (β-blockers) was selected herein as model of activated aromatic ether, and its electrochemical oxidation was examined in both the presence and absence of isotope {sup 18}O labeled water. To elucidate electrochemical hydrolysis pathway reaction: O-dealkylation or O-dealkoxylation, our approach was used to prove its applicability. The electrochemical oxidation mechanism was then elucidated showing an O-dealkoxylation reaction. In addition, density functional theory (DFT) calculations fully support the experimental conclusions.

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)

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

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...

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.

ISMAS international discussion meet on elemental mass spectrometry in health and environmental sciences

International Nuclear Information System (INIS)

Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.

2011-04-01

Mass spectrometry is an indispensable analytical tool associated with almost all branches of science including biology, chemistry, earth sciences, nuclear science, physics, etc. The technique holds tremendous potential owing to its high sensitivity, selectivity and its ability to measure small changes in the isotopic abundances of different elements. Innovations in mass spectrometry instrumentation are further widening the scope by making it possible to handle very large bio-molecules and polymers. New techniques for mass analysis, novel designs for ionization and developments in electronic accessories have contributed to elevate mass spectrometry to a position of prime importance in research. Development in mass spectrometry has revolutionized the study of micro-nutrient metabolism, of biologically active compounds and for drug discovery in pharmaceutical research. Elemental mass spectrometry is making major contributions to food toxicology, food forensics, and study of metabolism of nutrient minerals including Fe, Zn, Ca, Cu and Se. The area of speciation analysis using hyphenated techniques as well as electro-spray ionization have undergone a phenomenal evolution and development in the recent past. Impressive progress in mass spectrometry towards lower detection limits, higher resolution and molecule-specific detection at trace levels in complex matrices allows new frontiers to be crossed. Papers relevant to INIS are indexed separately

Mass Spectrometry Market: Value chain and stakeholder analysis up to 2024

OpenAIRE

Smita Deshmukh

2016-01-01

Transparency Market Research Reports incorporated a definite business overview and investigation inclines on "Mass Spectrometry Market". This report likewise incorporates more illumination about fundamental review of the business including definitions, requisitions and worldwide business sector industry structure. Read Full Report: http://www.transparencymarketresearch.com/mass-spectrometry-market.html

Mass Spectrometry-Based Proteomics for Pre-Eclampsia and Preterm Birth

Directory of Open Access Journals (Sweden)

Kai P. Law

2015-05-01

Full Text Available Pregnancy-related complications such as pre-eclampsia and preterm birth now represent a notable burden of adverse health. Pre-eclampsia is a hypertensive disorder unique to pregnancy. It is an important cause of maternal death worldwide and a leading cause of fetal growth restriction and iatrogenic prematurity. Fifteen million infants are born preterm each year globally, but more than one million of those do not survive their first month of life. Currently there are no predictive tests available for diagnosis of these pregnancy-related complications and the biological mechanisms of the diseases have not been fully elucidated. Mass spectrometry-based proteomics have all the necessary attributes to provide the needed breakthrough in understanding the pathophysiology of complex human diseases thorough the discovery of biomarkers. The mass spectrometry methodologies employed in the studies for pregnancy-related complications are evaluated in this article. Top-down proteomic and peptidomic profiling by laser mass spectrometry, liquid chromatography or capillary electrophoresis coupled to mass spectrometry, and bottom-up quantitative proteomics and targeted proteomics by liquid chromatography mass spectrometry have been applied to elucidate protein biomarkers and biological mechanism of pregnancy-related complications. The proteomes of serum, urine, amniotic fluid, cervical-vaginal fluid, placental tissue, and cytotrophoblastic cells have all been investigated. Numerous biomarkers or biomarker candidates that could distinguish complicated pregnancies from healthy controls have been proposed. Nevertheless, questions as to the clinically utility and the capacity to elucidate the pathogenesis of the pre-eclampsia and preterm birth remain to be answered.

Mass Spectrometry-Based Proteomics for Pre-Eclampsia and Preterm Birth

Science.gov (United States)

Law, Kai P.; Han, Ting-Li; Tong, Chao; Baker, Philip N.

2015-01-01

Pregnancy-related complications such as pre-eclampsia and preterm birth now represent a notable burden of adverse health. Pre-eclampsia is a hypertensive disorder unique to pregnancy. It is an important cause of maternal death worldwide and a leading cause of fetal growth restriction and iatrogenic prematurity. Fifteen million infants are born preterm each year globally, but more than one million of those do not survive their first month of life. Currently there are no predictive tests available for diagnosis of these pregnancy-related complications and the biological mechanisms of the diseases have not been fully elucidated. Mass spectrometry-based proteomics have all the necessary attributes to provide the needed breakthrough in understanding the pathophysiology of complex human diseases thorough the discovery of biomarkers. The mass spectrometry methodologies employed in the studies for pregnancy-related complications are evaluated in this article. Top-down proteomic and peptidomic profiling by laser mass spectrometry, liquid chromatography or capillary electrophoresis coupled to mass spectrometry, and bottom-up quantitative proteomics and targeted proteomics by liquid chromatography mass spectrometry have been applied to elucidate protein biomarkers and biological mechanism of pregnancy-related complications. The proteomes of serum, urine, amniotic fluid, cervical-vaginal fluid, placental tissue, and cytotrophoblastic cells have all been investigated. Numerous biomarkers or biomarker candidates that could distinguish complicated pregnancies from healthy controls have been proposed. Nevertheless, questions as to the clinically utility and the capacity to elucidate the pathogenesis of the pre-eclampsia and preterm birth remain to be answered. PMID:26006232

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....

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.

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)

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

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.

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.

Laser microprobe mass spectrometry: Potential and limitations for inorganic and organic micro-analysis. Pt. 2

International Nuclear Information System (INIS)

Vaeck, I. van; Gijbels, R.

1990-01-01

Laser microprobe mass spectrometry (LMMS) employs a highly focused UV laser beam to ionise a microvolume in the order of 1 μm 3 . The produced ions are then mass-separated in a time-of-flight (TOF) or a Fourier Transform (FT) mass spectrometer. The technique allows element localisation, detailed speciation of inorganic substances and structural information of organic molecules. Inorganic applications are treated in the preceding part. This paper will focus on the organic aspects. Selected examples illustrate that TOF LMMS can achieve structural characterisation of molecules, untractable by conventional mass spectrometric techniques. Applicability to the analysis with high spatial resolution is shown and the need for surface availability of organic target molecules is discussed. The recently developed FT LMMS may fulfil the need for better mass resolution. However, the comparability of FT LMMS results with TOF LMMS data is not yet obvious. (orig.)

Helium-3 mass spectrometry for low-level tritium analysis of environmental samples

International Nuclear Information System (INIS)

Surano, K.A.; Hudson, G.B.; Failor, R.A.; Sims, J.M.; Holland, R.C.; MacLean, S.C.; Garrison, J.C.

1991-04-01

Helium-3 ( 3 He) mass spectrometry for the analysis of low-level tritium ( 3 H) concentrations in environmental sample matrices was compared with conventional low-level β-decay counting methods. The mass-spectrometry method compared favorably, equaling or surpassing conventional decay-counting methods with respect to most criteria. Additional research and method refinements may make 3 He mass spectrometry the method of choice for routine, low-level to very-low-level 3 H measurements in a wide variety of environmental samples in the future

Determination of 5-fluorouracil in plasma with HPLC-tandem mass spectrometry

NARCIS (Netherlands)

van Kuilenburg, A. B. P.; van Lenthe, H.; Maring, J. G.; van Gennip, A. H.

2006-01-01

In this article, we describe a fast and specific method to measure 5FU with HPLC tandem-mass spectrometry. Reversed-phase HPLC was combined with electrospray ionization tandem mass spectrometry and detection was performed by multiple-reaction monitoring. Stable-isotope-labeled 5FU (1,3-15N2-5FU) was

Preparation of small uranium hexafluoride samples in view of mass spectrometry analysis; Preparation de petits echantillons d'hexafluorure d'uranium en vue d'analyse spectrometrique de masse

Energy Technology Data Exchange (ETDEWEB)

Severin, Michel

1958-07-01

We have studied the preparation of uranium hexafluoride for the determination of the isotopic ratio {sup 235}U/{sup 238}U by means of a mass spectrometer. UF{sub 6} should be produced from an amount of raw material (metallic uranium or oxide) that should not exceed 0,1 g. Our method has a good yield (we have studied the rate of transformation) and gives samples which present a content of impurities (HF and SiF{sub 4}) low enough to enable correct isotopic measurements. The method which seemed the best uses the cobalt trifluoride as a fluorining agent. It is now in current use in the laboratories of mass spectrometry. (author) [French] Nous avons etudie la preparation de l'hexafluorure d'uranium en vue de la determination au spectrometre de masse du rapport isotopique {sup 235}U/{sup 238}U. L'hexafluorure d'uranium devait etre produit a partir d'une quantite de matiere premiere (uranium metallique ou oxyde) ne devant pas exceder 0,1 g. Nous avons mis au point une methode de preparation presentant un rendement eleve (etude du taux de transformation) et donnant des echantillons dont le taux d'impuretes (HF et SiF{sub 4}) est suffisamment faible pour permettre des mesures isotopiques correctes. La methode ayant donne le plus de satisfaction utilise le trifluorure de cobalt comme agent fluorant. Ce procede est maintenant couramment employe dans les laboratoires de spectrometrie de masse. (auteur)

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

Impact of comprehensive two-dimensional gas chromatography with mass spectrometry on food analysis.

Science.gov (United States)

Tranchida, Peter Q; Purcaro, Giorgia; Maimone, Mariarosa; Mondello, Luigi

2016-01-01

Comprehensive two-dimensional gas chromatography with mass spectrometry has been on the separation-science scene for about 15 years. This three-dimensional method has made a great positive impact on various fields of research, and among these that related to food analysis is certainly at the forefront. The present critical review is based on the use of comprehensive two-dimensional gas chromatography with mass spectrometry in the untargeted (general qualitative profiling and fingerprinting) and targeted analysis of food volatiles; attention is focused not only on its potential in such applications, but also on how recent advances in comprehensive two-dimensional gas chromatography with mass spectrometry will potentially be important for food analysis. Additionally, emphasis is devoted to the many instances in which straightforward gas chromatography with mass spectrometry is a sufficiently-powerful analytical tool. Finally, possible future scenarios in the comprehensive two-dimensional gas chromatography with mass spectrometry food analysis field are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

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.

A MASSive Laboratory Tour. An Interactive Mass Spectrometry Outreach Activity for Children

Science.gov (United States)

Jungmann, Julia H.; Mascini, Nadine E.; Kiss, Andras; Smith, Donald F.; Klinkert, Ivo; Eijkel, Gert B.; Duursma, Marc C.; Cillero Pastor, Berta; Chughtai, Kamila; Chughtai, Sanaullah; Heeren, Ron M. A.

2013-07-01

It is imperative to fascinate young children at an early stage in their education for the analytical sciences. The exposure of the public to mass spectrometry presently increases rapidly through the common media. Outreach activities can take advantage of this exposure and employ mass spectrometry as an exquisite example of an analytical science in which children can be fascinated. The presented teaching modules introduce children to mass spectrometry and give them the opportunity to experience a modern research laboratory. The modules are highly adaptable and can be applied to young children from the age of 6 to 14 y. In an interactive tour, the students explore three major scientific concepts related to mass spectrometry; the building blocks of matter, charged particle manipulation by electrostatic fields, and analyte identification by mass analysis. Also, the students carry out a mass spectrometry experiment and learn to interpret the resulting mass spectra. The multistage, inquiry-based tour contains flexible methods, which teach the students current-day research techniques and possible applications to real research topics. Besides the scientific concepts, laboratory safety and hygiene are stressed and the students are enthused for the analytical sciences by participating in "hands-on" work. The presented modules have repeatedly been successfully employed during laboratory open days. They are also found to be extremely suitable for (early) high school science classes during laboratory visit-focused field trips.

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

MALDI-TOF mass spectrometry imaging reveals molecular level changes in ultrahigh molecular weight polyethylene joint implants in correlation with lipid adsorption.

Science.gov (United States)

Fröhlich, Sophie M; Archodoulaki, Vasiliki-Maria; Allmaier, Günter; Marchetti-Deschmann, Martina

2014-10-07

Ultrahigh molecular weight polyethylene (PE-UHMW), a material with high biocompatibility and excellent mechanical properties, is among the most commonly used materials for acetabular cup replacement in artificial joint systems. It is assumed that the interaction with synovial fluid in the biocompartment leads to significant changes relevant to material failure. In addition to hyaluronic acid, lipids are particularly relevant for lubrication in an articulating process. This study investigates synovial lipid adsorption on two different PE-UHMW materials (GUR-1050 and vitamin E-doped) in an in vitro model system by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry imaging (MSI). Lipids were identified by high performance thin layer chromatography (HP-TLC) and tandem mass spectrometry (MS/MS) analysis, with an analytical focus on phospholipids and cholesterol, both being species of high importance for lubrication. Scanning electron microscopy (SEM) analysis was applied in the study to correlate molecular information with PE-UHMW material qualities. It is demonstrated that lipid adsorption preferentially occurs in rough or oxidized polymer regions. Polymer modifications were colocalized with adsorbed lipids and found with high density in regions identified by SEM. Explanted, the in vivo polymer material showed comparable and even more obvious polymer damage and lipid adsorption when compared with the static in vitro model. A three-dimensional reconstruction of MSI data from consecutive PE-UHMW slices reveals detailed information about the diffusion process of lipids in the acetabular cup and provides, for the first time, a promising starting point for future studies correlating molecular information with commonly used techniques for material analysis (e.g., Fourier-transform infrared spectroscopy, nanoindentation).

Fast DNA analysis by laser mass spectrometry for human genome analysis

International Nuclear Information System (INIS)

Tang, K.; Taranenko, N. I.; Allman, S. L.; Chang, L. Y.; Chen, C. H.

1995-01-01

Fast DNA sequencing by laser mass spectrometry is possible if the following 3 criteria are met: (1) Size of DNA fragment should be greater than 300 nucleotides. (2) Enough sensitivity to detect DNA produce from polymerases chain reactins (PCR). (3) Higher resolution of mass spectr. So far, the firt 2 criteria are met: If the resolution can be significantly improve, fast DNA sequencing by laser mass spectrometry weil be a reality in the near feature

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.

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.

Contribution of photoelectron spectrometry and infrared spectrometry to the study of various oxidised forms of chromium

International Nuclear Information System (INIS)

Feve, L.

1985-03-01

Securate knowledge of internal surface of primary coolant circuits of PWR is required for an estimation of dissolution of used materials and for estimation of decontamination efficiency. The binding energies of various electron levels of chromium were determined by photoelectron spectrometry (ESCA), both for the metal and for certain compounds. Because of the intensities of the signals obtained the 2 p 3/2 level alone can be used for analytical purposes. Owing to a possible interference between this level due to hexavalent chromium and a satellite peak caused by trivalent chromium the method is not able to show up small amounts of chromium VI in chromium III. Simultaneous detection of the hexavalent and trivalent forms was achieved by infrared spectrometry. The problem of revealing traces of chromium VI in surface layers of trivalent chromium oxide has thus been solved [fr

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.

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.

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.

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

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.

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

Science.gov (United States)

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

2013-11-01

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

New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry

International Nuclear Information System (INIS)

Montaser, A.

1993-01-01

In this research, new high-temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. During the period January 1993--December 1993, emphasis was placed on (a) analytical investigations of atmospheric-pressure helium inductively coupled plasma (He ICP) that are suitable for atomization, excitation, and ionization of elements possessing high excitation and ionization energies; (b) simulation and computer modeling of plasma sources to predict their structure and fundamental and analytical properties without incurring the enormous cost of experimental studies; (c) spectrosopic imaging and diagnostic studies of high-temperature plasmas; (d) fundamental studies of He ICP discharges and argon-nitrogen plasma by high-resolution Fourier transform spectrometry; and (e) fundamental and analytical investigation of new, low-cost devices as sample introduction systems for atomic spectrometry and examination of new diagnostic techniques for probing aerosols. Only the most important achievements are included in this report to illustrate progress and obstacles. Detailed descriptions of the authors' investigations are outlined in the reprints and preprints that accompany this report. The technical progress expected next year is briefly described at the end of this report

DIRECT-DEPOSITION INFRARED SPECTROMETRY WITH GAS AND SUPERCRITICAL FLUID CHROMATOGRAPHY

Science.gov (United States)

A direct-deposition Fourier transform infrared (FT-IR) system has been evaluated for applicability to gas chromatography (GC) and supercritical fluid chromatography (SFC) of environmental analytes. A 100-um i.d. fused-silica transfer line was used for GC, and a 50-um transfer lin...

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.

The future of the accelerator mass spectrometry of rare long-lived radioactive isotopes

International Nuclear Information System (INIS)

Litherland, A.E.

1990-01-01

Accelerators, originally designed for nuclear physics, can be added to mass spectrometric apparatus to increase the sensitivity so that isotope ratios in the range 10 -12 to 10 -15 can be measured routinely. This significant improvement of high-sensitivity mass spectrometry has been called Accelerator Mass Spectrometry. The present article addresses the basic principles of accelerator mass spectrometry and some recent applications which show its versatility. In particular, it is noted that accelerator mass spectrometry could play an increasing role in the measurement of the levels of long lived radioactivities in the environment, including the actinides, which result from human activities such as the use of nuclear power. To fulfill this promise, continued research and development is necessary to provide ion sources, various types of heavy ion accelerators and peripheral magnetic and electric analysers. (N.K.)

Molecular formulae of marine and terrigenous dissolved organic matter detected by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Science.gov (United States)

Koch, Boris P.; Witt, Matthias; Engbrodt, Ralph; Dittmar, Thorsten; Kattner, Gerhard

2005-07-01

The chemical structure of refractory marine dissolved organic matter (DOM) is still largely unknown. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) was used to resolve the complex mixtures of DOM and provide valuable information on elemental compositions on a molecular scale. We characterized and compared DOM from two sharply contrasting aquatic environments, algal-derived DOM from the Weddell Sea (Antarctica) and terrigenous DOM from pore water of a tropical mangrove area in northern Brazil. Several thousand molecular formulas in the mass range of 300-600 Da were identified and reproduced in element ratio plots. On the basis of molecular elemental composition and double-bond equivalents (DBE) we calculated an average composition for marine DOM. O/C ratios in the marine samples were lower (0.36 ± 0.01) than in the mangrove pore-water sample (0.42). A small proportion of chemical formulas with higher molecular mass in the marine samples were characterized by very low O/C and H/C ratios probably reflecting amphiphilic properties. The average number of unsaturations in the marine samples was surprisingly high (DBE = 9.9; mangrove pore water: DBE = 9.4) most likely due to a significant contribution of carbonyl carbon. There was no significant difference in elemental composition between surface and deep-water DOM in the Weddell Sea. Although there were some molecules with unique marine elemental composition, there was a conspicuous degree of similarity between the terrigenous and algal-derived end members. Approximately one third of the molecular formulas were present in all marine as well as in the mangrove samples. We infer that different forms of microbial degradation ultimately lead to similar structural features that are intrinsically refractory, independent of the source of the organic matter and the environmental conditions where degradation took place.

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.)

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

SU-8 as a material for lab-on-a-chip-based mass spectrometry.

Science.gov (United States)

Arscott, Steve

2014-10-07

This short review focuses on the application of SU-8 for the microchip-based approach to the miniaturization of mass spectrometry. Chip-based mass spectrometry will make the technology commonplace and bring benefits such as lower costs and autonomy. The chip-based miniaturization of mass spectrometry necessitates the use of new materials which are compatible with top-down fabrication involving both planar and non-planar processes. In this context, SU-8 is a very versatile epoxy-based, negative tone resist which is sensitive to ultraviolet radiation, X-rays and electron beam exposure. It has a very wide thickness range, from nanometres to millimetres, enabling the formation of mechanically rigid, very high aspect ratio, vertical, narrow width structures required to form microfluidic slots and channels for laboratory-on-a-chip design. It is also relatively chemically resistant and biologically compatible in terms of the liquid solutions used for mass spectrometry. This review looks at the impact and potential of SU-8 on the different parts of chip-based mass spectrometry - pre-treatment, ionization processes, and ion sorting and detection.

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.

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.

Kinetic study of olive oil degradation monitored by fourier transform infrared spectrometry. Application to oil characterization.

Science.gov (United States)

Román Falcó, Iván P; Grané Teruel, Nuria; Prats Moya, Soledad; Martín Carratalá, M Luisa

2012-11-28

A new approach for the determination of kinetic parameters of the cis/trans isomerization during the oxidation process of 24 virgin olive oils belonging to 8 different varieties is presented. The accelerated process of degradation at 100 °C was monitored by recording the Fourier transform infrared spectra. The parameters obtained confirm pseudo-first-order kinetics for the degradation of cis and the appearance of trans double bonds. The kinetic approach affords the induction time and the rate coefficient; these parameters are related to the fatty acid profile of the fresh olive oils. The data obtained were used to compare the oil stability of the samples with the help of multivariate statistical techniques. Fatty acid allowed a classification of the samples in five groups, one of them constituted by the cultivars with higher stability. Meanwhile, the kinetic parameters showed greater ability for the characterization of olive oils, allowing the classification in seven groups.

A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra

International Nuclear Information System (INIS)

Chen LiMei; Carpita, N.C.; Reiter, W.D.; Wilson, R.H.; Jeffries, C.; McCann, M.C.

1998-01-01

We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. (author)

Discrimination of organic coffee via Fourier transform infrared-photoacoustic spectroscopy.

Science.gov (United States)

Gordillo-Delgado, Fernando; Marín, Ernesto; Cortés-Hernández, Diego Mauricio; Mejía-Morales, Claudia; García-Salcedo, Angela Janet

2012-08-30

Procedures for the evaluation of the origin and quality of ground and roasted coffee are constantly needed for the associated industry due to complexity of the related market. Conventional Fourier transform infrared (FTIR) spectroscopy can be used for detecting changes in functional groups of compounds, such as coffee. However, dispersion, reflection and non-homogeneity of the sample matrix can cause problems resulting in low spectral quality. On the other hand, sample preparation frequently takes place in a destructive way. To overcome these difficulties, in this work a photoacoustic cell has been adapted as a detector in a FTIR spectrophotometer to perform a study of roasted and ground coffee from three varieties of Coffea arabica grown by organic and conventional methods. Comparison between spectra of coffee recorded by FTIR-photoacoustic spectrometry (PAS) and by FTIR spectrophotometry showed a better resolution of the former method, which, aided by principal components analysis, allowed the identification of some absorption bands that allow the discrimination between organic and conventional coffee. The results obtained provide information about the spectral behavior of coffee powder which can be useful for establishing discrimination criteria. It has been demonstrated that FTIR-PAS can be a useful experimental tool for the characterization of coffee. Copyright © 2012 Society of Chemical Industry.

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.)

Surface analysis of lipids by mass spectrometry: more than just imaging.

Science.gov (United States)

Ellis, Shane R; Brown, Simon H; In Het Panhuis, Marc; Blanksby, Stephen J; Mitchell, Todd W

2013-10-01

Mass spectrometry is now an indispensable tool for lipid analysis and is arguably the driving force in the renaissance of lipid research. In its various forms, mass spectrometry is uniquely capable of resolving the extensive compositional and structural diversity of lipids in biological systems. Furthermore, it provides the ability to accurately quantify molecular-level changes in lipid populations associated with changes in metabolism and environment; bringing lipid science to the "omics" age. The recent explosion of mass spectrometry-based surface analysis techniques is fuelling further expansion of the lipidomics field. This is evidenced by the numerous papers published on the subject of mass spectrometric imaging of lipids in recent years. While imaging mass spectrometry provides new and exciting possibilities, it is but one of the many opportunities direct surface analysis offers the lipid researcher. In this review we describe the current state-of-the-art in the direct surface analysis of lipids with a focus on tissue sections, intact cells and thin-layer chromatography substrates. The suitability of these different approaches towards analysis of the major lipid classes along with their current and potential applications in the field of lipid analysis are evaluated. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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...

Multi-Reflection Time-of-Flight Mass Separation and Spectrometry

CERN Document Server

Kreim, Susanne; Wolf, R N

2014-01-01

The mass of a nucleus is one of its most fundamental ground-state properties and reveals the strength of nuclear binding. Investigating the binding energy of nuclei with respect to the number of protons and neutrons in a nucleus is important for advancing nuclear theory and increases our understanding of nucleosynthesis in supernovae and neutron stars. Precision mass measurements on radioactive nuclides belong to the state-of-the-art techniques [1, 2]. Presently, four complementary techniques are applied: isochronous and Schottky mass spectrometry in storage rings (IMS and SMS, respectively), magnetic-rigidity time-of-flight (TOF-ρ) measurements, and Penning-trap mass spectrometry (PTMS). With measurement cycles in the sub-ms range, IMS and TOF-Bρ MS are well suited for very short-lived species while offering moderate relative precision on the level of 10−6. A higher precision is achieved by SMS but with the need for measurement times on the order of several seconds. As soon as masses with a relative prec...

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

Multi photon ionization mass spectrometry of carbamate pesticides, herbicides and fungicides

International Nuclear Information System (INIS)

Grun, Carsten; Koenig, Marcelle; Grotemeyer, Juergen

2001-01-01

Pesticides and herbicides are useful for a wide range of applications today. The determination of these substances either in the pure form or in complex matrices is of high analytical interest. Especially since these substances can by found in every day products. The combination of multi photon ionization (MUPI) and time of flight laser mass spectrometry may be a powerful tool for achieving fast well interpretable mass spectra for analytical purposes. In this paper we will discuss the mass spectra of several pesticides and herbicides accessed by MUPI-time-of-flight mass spectrometry. The influence of the laser pulse duration on the mass spectra are discussed

Current medical research with the application of coupled techniques with mass spectrometry

OpenAIRE

Ka?u?na-Czapli?ska, Joanna

2011-01-01

Summary The most effective methods of analysis of organic compounds in biological fluids are coupled chromatographic techniques. Capillary gas chromatography/mass spectrometry (GC-MS) allows the most efficient separation, identification and quantification of volatile metabolites in biological fluids. Liquid chromatography-mass spectrometry (LC-MS) is especially suitable for the analysis of non-volatile and/or thermally unstable compounds. A major drawback of liquid chromatography-mass spectro...

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...

Matrix-assisted laser desorption/ionization mass spectrometry for the structural characterization of modified oligonucleotides

International Nuclear Information System (INIS)

Hurst, G.B.; Hettich, R.L.; Buchanan, M.V.; Stemmler, E.A.

1993-01-01

Matrix-assisted laser desorption ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry (FTMS) and MALDI time-of-flight mass spectrometry (TOFMS) are being used to characterize conditions for the efficient desorption and ionization of normal and modified nucleic acid components. Basic and acidic matrix materials have been evaluated on the components. Basic and acidic matrix materials have been evaluated on the FTMS and TOFMS. Using MALDI-FTMS at 355 nm, less fragmentation has been observed using 2,5-dihydroxybenzoic acid, while more extensive fragmentation is observed for basic matrices, such as 1,5-diaminonaphthalene and 9-aminophenanthrene. Elevation of the cell pressure by the addition of Ar or CO 2 provides collisional cooling of desorbed ions, resulting in an enhancement of [M--H] - and structurally significant high-mass fragment ions. Using MALDI-TOFMS at 337 nm, fragmentation is significantly reduced relative to that observed on the FTMS, perhaps as a consequence of the longer times required for FTMS detection. On the FTMS and TOFMS, cluster ions have been observed in the negative ion mode when metal ions are present in the 2,5-dihydroxybenzoic acid matrix. Metal ion additions and clusters with matrix salts have also been observed for dinucleotides. Applications of MALDI-FTMS and MALDI-TOF to the detection of hydroxylated PAH nucleoside adducts are presented

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.

Renal geology (quantitative renal stone analysis) by 'Fourier transform infrared spectroscopy'.

Science.gov (United States)

Singh, Iqbal

2008-01-01

To prospectively determine the precise stone composition (quantitative analysis) by using infrared spectroscopy in patients with urinary stone disease presenting to our clinic. To determine an ideal method for stone analysis suitable for use in a clinical setting. After routine and a detailed metabolic workup of all patients of urolithiasis, stone samples of 50 patients of urolithiasis satisfying the entry criteria were subjected to the Fourier transform infrared spectroscopic analysis after adequate sample homogenization at a single testing center. Calcium oxalate monohydrate and dihydrate stone mixture was most commonly encountered in 35 (71%) followed by calcium phosphate, carbonate apatite, magnesium ammonium hexahydrate and xanthine stones. Fourier transform infrared spectroscopy allows an accurate, reliable quantitative method of stone analysis. It also helps in maintaining a computerized large reference library. Knowledge of precise stone composition may allow the institution of appropriate prophylactic therapy despite the absence of any detectable metabolic abnormalities. This may prevent and or delay stone recurrence.

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

Mass spectrometry in structural biology and biophysics architecture, dynamics, and interaction of biomolecules

CERN Document Server

Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M

2012-01-01

The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol

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 .

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.

Optimization of biodiesel production from rice bran oil via ...

African Journals Online (AJOL)

... 9,12-octadecadienoic and 9-octadecadienoic acid. The fourier transform infrared spectrum of biodiesel also showed the characteristic bands of C=O, O-C-O, C=C and –(CH2)n-. Key words: Rice bran oil, biodiesel, response surface methodology, gas chromatography mass spectrometry, fourier transform infrared spectrum ...

[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.

Principle and analysis of a rotational motion Fourier transform infrared spectrometer

Science.gov (United States)

Cai, Qisheng; Min, Huang; Han, Wei; Liu, Yixuan; Qian, Lulu; Lu, Xiangning

2017-09-01

Fourier transform infrared spectroscopy is an important technique in studying molecular energy levels, analyzing material compositions, and environmental pollutants detection. A novel rotational motion Fourier transform infrared spectrometer with high stability and ultra-rapid scanning characteristics is proposed in this paper. The basic principle, the optical path difference (OPD) calculations, and some tolerance analysis are elaborated. The OPD of this spectrometer is obtained by the continuously rotational motion of a pair of parallel mirrors instead of the translational motion in traditional Michelson interferometer. Because of the rotational motion, it avoids the tilt problems occurred in the translational motion Michelson interferometer. There is a cosine function relationship between the OPD and the rotating angle of the parallel mirrors. An optical model is setup in non-sequential mode of the ZEMAX software, and the interferogram of a monochromatic light is simulated using ray tracing method. The simulated interferogram is consistent with the theoretically calculated interferogram. As the rotating mirrors are the only moving elements in this spectrometer, the parallelism of the rotating mirrors and the vibration during the scan are analyzed. The vibration of the parallel mirrors is the main error during the rotation. This high stability and ultra-rapid scanning Fourier transform infrared spectrometer is a suitable candidate for airborne and space-borne remote sensing spectrometer.

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

Science.gov (United States)

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

2012-01-01

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

Mapping posttranscriptional modifications in 5S ribosomal RNA by MALDI mass spectrometry.

OpenAIRE

Kirpekar, F; Douthwaite, S; Roepstorff, P

2000-01-01

We present a method to screen RNA for posttranscriptional modifications based on Matrix Assisted Laser Desorption/Ionization mass spectrometry (MALDI-MS). After the RNA is digested to completion with a nucleotide-specific RNase, the fragments are analyzed by mass spectrometry. A comparison of the observed mass data with the data predicted from the gene sequence identifies fragments harboring modified nucleotides. Fragments larger than dinucleotides were valuable for the identification of post...

Direct Analysis of Large Living Organism by Megavolt Electrostatic Ionization Mass Spectrometry

Science.gov (United States)

Ng, Kwan-Ming; Tang, Ho-Wai; Man, Sin-Heng; Mak, Pui-Yuk; Choi, Yi-Ching; Wong, Melody Yee-Man

2014-09-01

A new ambient ionization method allowing the direct chemical analysis of living human body by mass spectrometry (MS) was developed. This MS method, namely Megavolt Electrostatic Ionization Mass Spectrometry, is based on electrostatic charging of a living individual to megavolt (MV) potential, illicit drugs, and explosives on skin/glove, flammable solvent on cloth/tissue paper, and volatile food substances in breath were readily ionized and detected by a mass spectrometer.

Mass Spectrometry Parameters Optimization for the 46 Multiclass Pesticides Determination in Strawberries with Gas Chromatography Ion-Trap Tandem Mass Spectrometry

Science.gov (United States)

Fernandes, Virgínia C.; Vera, Jose L.; Domingues, Valentina F.; Silva, Luís M. S.; Mateus, Nuno; Delerue-Matos, Cristina

2012-12-01

Multiclass analysis method was optimized in order to analyze pesticides traces by gas chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry (IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time (ET), maximum excitation energy or " q" value (q), and isolation mass window (IMW) were numerically tested in order to maximize the instrument analytical signal response. For this, multiple linear regression was used in data analysis to evaluate the influence of the five parameters on the analytical response in the ion trap mass spectrometer and to predict its response. The assessment of the five parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a strong influence on both signal response and detection limit. Using the optimized method, a multiclass pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit established for strawberries by the European Union were found in some samples.

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)

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

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

The Means: Cytometry and Mass Spectrometry Converge in a Single Cell Deep Profiling Platform

Science.gov (United States)

Weis-Garcia, Frances; Bandura, Dmitry; Baranov, Vladimir; Ornatsky, Olga; Tanner, Scott

2013-01-01

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a distinct flavor of mass spectrometry that has had little association with cell biology: it remains the state of the art for the determination of the atomic composition of materials. Unrelatedly, flow cytometry is the superior method for distinguishing the heterogeneity of cells through the determination of antigen signatures using tagged antibodies. Simply replacing fluorophore tags with stable isotopes of the heavy metals, and measuring these cell-by-cell with ICP-MS, dramatically increases the number of probes that can be simultaneously measured in cytometry and enables a transformative increase in the resolution of rare cell populations in complex biological samples. While this can be thought of as a novel incarnation of single-cell targeted proteomics, the metal-labeling reagents, ICP-MS of single cells, and accompanying informatics comprise a new field of technology termed Mass Cytometry. While the conception of mass cytometry is simple the embodiment to address the issues of multi-parameter flow cytometry has been far more challenging. There are many elements, and many more stable isotopes of those elements, that might be used as distinct reporter tags. Still, there are many approaches to conjugating metals to antibodies (or other affinity reagents) and work in this area along with developing new applications is ongoing. The mass resolution and linear (quantitative) dynamic range of ICP-MS allows those many stable isotopes to be measured simultaneously and without the spectral overlap issues that limit fluorescence assay. However, the adaptation of ICP-MS to allow high-speed simultaneous measurement with single cell distinction at high throughput required innovation of the cell introduction system, ion optics (sampling, transmission and beam-shaping), mass analysis, and signal handling and processing. An overview of “the nuts and bolts” of Mass Cytometry is presented.

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.

Laser mass spectrometry of chemical warfare agents using ultrashort laser pulses

International Nuclear Information System (INIS)

Weickhardt, C.; Grun, C.; Grotemeyer, J.

1998-01-01

Fast relaxation processes in excited molecules such as IC, ISC, and fragmentation are observed in many environmentally and technically relevant substances. They cause severe problems to resonance ionization mass spectrometry because they reduce the ionization yield and lead to mass spectra which do not allow the identification of the compound. By the use of ultrashort laser pulses these problems can be overcome and the advantages of REMPI over conventional ionization techniques in mass spectrometry can be regained. This is demonstrated using soil samples contaminated with a chemical warfare agent

Mass spectrometry in nuclear technology - a review of application of thermal ionization mass spectrometry in fuel reprocessing plants. PD-7-1