3,366 results match your criteria Journal of Mass Spectrometry[Journal]


Acid-based Approach for Separation of Peptide Epimers using IM-MS.

J Mass Spectrom 2019 Apr 25. Epub 2019 Apr 25.

Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.

Chiral molecules frequently remain undistinguishable using ion mobility mass spectrometry (IM-MS), due to insufficient differences of their collision cross sections at the available mobility resolution of the ion mobility drift tubes. The influence of the complexation with organic acids on the ion mobility separation of peptide epimers is evaluated using traveling-wave ion mobility (TWIMS). The examined epimeric tripeptides containing Arg residue with the sequence: Ac-Phe-Arg-Trp-NH formed stable complexes in the gas phase, and under the increased pressure in ion mobility drift tube, noncovalent associates formed with carboxylic or sulfonic mono- and diacids with chiral variation of certain acids. Read More

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http://dx.doi.org/10.1002/jms.4362DOI Listing

An approach for visualizing the spatial metabolome of an entire plant root system inspired by the Swiss-rolling technique.

J Mass Spectrom 2019 Apr 24. Epub 2019 Apr 24.

Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, 99352.

The spatial configuration and morphology of roots are commonly monitored for a better understanding of plant health and development. However, this approach provides minimal details about the biochemistry regulating the observable traits. Therefore, the ability to metabolically map the entire root structure would be of major value. Read More

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http://dx.doi.org/10.1002/jms.4363DOI Listing

A Comparative Study of The Electrospray Ionization Response of β-O-4' Lignin Model Compounds.

J Mass Spectrom 2019 Apr 22. Epub 2019 Apr 22.

Department of Chemistry, University of Kentucky, Lexington, KY, 40506.

Electrospray ionization mass spectrometry has recently become the technique of choice for rapid characterization of lignin degradation products. However, the fundamental question of the relationship between lignin structure and ionization efficiency has not been explored. In this work, we studied the electrospray ionization response of five structurally similar β-O-4' model lignin compounds using lithium cationization in the positive electrospray ionization mode. Read More

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http://dx.doi.org/10.1002/jms.4365DOI Listing

Top-down Mass Spectrometry of Intact Phosphorylated β-casein: Correlation between The Precursor Charge State and Internal Fragments.

J Mass Spectrom 2019 Apr 17. Epub 2019 Apr 17.

Mass Spectrometry and Proteomics Facility, The Ohio State University, Columbus, OH, 43210, USA.

Phosphorylated proteins play essential roles in many cellular processes, and identification and characterization of the relevant phosphoproteins can help to understand underlying mechanisms. Herein, we report a collision-induced dissociation top-down approach for characterizing phosphoproteins on a quadrupole time-of-flight mass spectrometer. β-casein, a protein with two major isoforms and five phosphorylatable serine residues, was used as a model. Read More

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http://doi.wiley.com/10.1002/jms.4364
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http://dx.doi.org/10.1002/jms.4364DOI Listing
April 2019
1 Read

Electric Modeling and Characterization of Pulsed High Voltage Nano-Electrospray Ionization Sources by a Miniature Ion Trap Mass Spectrometer.

J Mass Spectrom 2019 Apr 15. Epub 2019 Apr 15.

School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.

A better understanding of nano-electrospray ionization (nano-ESI) would be beneficial in further improving the performances of nano-ESI. In this work, the pulsed high voltage (HV) nano-ESI has been electrically modeled and then systematically characterized by both voltage-current and mass spectrometry measurements. First the equivalent resistance of a nano-ESI source changes with respect to both emitter tip diameter and the HV applied. Read More

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http://dx.doi.org/10.1002/jms.4361DOI Listing

Gas-phase functionalized carbon-carbon coupling reactions catalyzed by Ni (II) complexes.

J Mass Spectrom 2019 Apr 15. Epub 2019 Apr 15.

Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA.

Gas-phase C-C coupling reactions mediated by Ni (II) complexes were studied using a linear quadrupole ion trap mass spectrometer. Ternary nickel cationic carboxylate complexes, [(phen)Ni (OOCR )] (where phen = 1,10-phenanthroline) were formed by electrospray ionization. Upon collision-induced dissociation (CID), they extrude CO forming the organometallic cation [(phen)Ni(R )] , which undergoes gas-phase ion-molecule reactions (IMR) with acetate esters CH COOR to yield the acetate complex [(phen)Ni (OOCCH )] and a C-C coupling product R -R . Read More

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http://dx.doi.org/10.1002/jms.4360DOI Listing

Assigning the ESI Mass Spectra of Organometallic and Coordination Compounds.

J Mass Spectrom 2019 Apr 13. Epub 2019 Apr 13.

Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Ave, San Francisco, CA, 94132, USA.

ESI mass spectrometry is a useful technique for solving organometallic and coordination chemistry characterization problems that are difficult to address using traditional methods. However, assigning the ESI mass spectra of organometallic compounds can be challenging and the considerations involved in doing so are quite different from assigning the mass spectrum of a purely organic sample. This is a tutorial article for organometallic/coordination chemists using ESI-MS to analyze pure compounds or reaction mixtures. Read More

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http://dx.doi.org/10.1002/jms.4359DOI Listing

Thermodynamic properties of gaseous cerium phosphate studied by Knudsen effusion mass spectrometry.

J Mass Spectrom 2019 Apr 3. Epub 2019 Apr 3.

Institute of Chemistry, St. Petersburg State University, Universitetskii pr. 26, 198504, Saint Petersburg, Russia.

Gaseous CePO has been identified by Knudsen effusion mass spectrometry during vaporization of CeO and magnesium diphosphate from tungsten double two-temperature effusion cell. Structure and molecular parameters of gaseous cerium phosphate under study were determined using quantum chemical calculations. On the basis of equilibrium constants measured for gas-phase reaction, standard formation enthalpy of CePO was determined to be -508±41 kJ⋅mol at the temperature 298 K. Read More

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http://doi.wiley.com/10.1002/jms.4358
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http://dx.doi.org/10.1002/jms.4358DOI Listing
April 2019
3 Reads

The unusual fragmentation of long-chain feruloyl esters under negative ion electrospray conditions.

J Mass Spectrom 2019 Mar 26. Epub 2019 Mar 26.

Department of Bioorganic Chemistry, Institute of Plant Biochemistry, Weinberg 3, D-06120, Halle/S, Germany.

Long-chain ferulic acid esters, such as eicosyl ferulate (1), show a complex and analytically valuable fragmentation behavior under negative-ion electrospay collision-induced dissociation ((-)-ESI-CID) mass spectrometry, as studied by use of a high-resolution (Orbitrap) mass spectrometer. In a strong contrast to the very simple fragmentation of the [M + H] ion, which is discussed briefly, the deprotonated molecule, [M - H] , exhibits a rich secondary fragmentation chemistry. It first loses a methyl radical (MS ) and the ortho-quinoid [M - H - Me] radical anion thus formed then dissociates by loss of an extended series of neutral radicals, C H (n = 0-16) from the long alkyl chain, in competition with the expulsion of CO and CO (MS ). Read More

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http://dx.doi.org/10.1002/jms.4357DOI Listing
March 2019
4 Reads

Development and Comparison of Liquid-liquid Extraction and Accelerated Solvent Extraction Methods for Quantitative Analysis of Chloramphenicol, Thiamphenicol, Florfenicol and Florfenicol Amine in Poultry Eggs.

J Mass Spectrom 2019 Mar 25. Epub 2019 Mar 25.

College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.

Accelerated solvent extraction was investigated as a novel alternative technology for the separation and quantitative analysis of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine from poultry eggs, and the results were compared with the results of liquid-liquid extraction. Rapid quantification of the target compounds was carried out by ultra-performance liquid chromatography-electrospray ionization tandem triple quadrupole mass spectrometry. This optimized method was validated according to the requirements defined by the European Union and the United States Food and Drug Administration. Read More

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http://doi.wiley.com/10.1002/jms.4355
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http://dx.doi.org/10.1002/jms.4355DOI Listing
March 2019
5 Reads

Detection and assignment of inorganic aqueous polymers relevant to environmental nanogeoscience by direct infusion electrospray ionization mass spectrometry.

J Mass Spectrom 2019 Mar 25. Epub 2019 Mar 25.

Department of Mining Engineering, University of Chile, Av. Tupper 2069, 8370451, Santiago, Chile.

Inorganic polymers in aqueous solutions are being proposed as essential components in new theories concerning non-classical nucleation and growth of nanominerals relevant to environmental nanogeosciences. The study of those complex natural processes requires multi-technique analytical approaches able to characterize the solutions and their constituents (solutes, oligomers, polymers, clusters and nanominerals) from atomic to micrometric scales. A novel analytical approach involving an electrospray ionization source (ESI) coupled to time-of-flight mass spectrometry (TOF/MS) was developed to identify inorganic polymers in aqueous solution. Read More

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http://dx.doi.org/10.1002/jms.4356DOI Listing

Dempster's Descendants - The Core of the Development of Mass Spectrometry.

Authors:
Keith A Nier

J Mass Spectrom 2019 Mar 22. Epub 2019 Mar 22.

Independent. No department, Madison, New Jersey, United States.

The work of Arthur Dempster generally has been considered significant but of less importance in the growth of mass spectrometry than that of Francis Aston, and as essentially limited to the pre-WW II era. The development of mass spectrometry, however, as distinct from nuclear science, was shaped far more by Dempster than by Aston. This influence is seen in several aspects of instrument design and practice and it has continued into the twenty-first century. Read More

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http://dx.doi.org/10.1002/jms.4353DOI Listing
March 2019
6 Reads

Theoretical chemical ionization rate constants of the concurrent reactions of hydronium ions (H O ) and oxygen ions (O ) with selected organic iodides.

J Mass Spectrom 2019 Mar 18. Epub 2019 Mar 18.

Aix-Marseille Univ, CNRS, LCE, Marseille, France.

Short chain volatile iodinated organic compounds (VIOCs) are of great importance in many fields that include atmospheric chemistry, agriculture and environmental chemistry related to nuclear power plant safety. Proton-transfer-reaction mass spectrometry (PTR-MS) allows for fast, sensitive and on-line quantification of VIOCs if the chemical ionization (CI) reaction rate constants are known. In this work, the theoretical CI collision rates for the reactions of hydronium ions (H O ) and oxygen ions ( ) with selected atmospherically relevant short chain VIOCs are calculated. Read More

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http://dx.doi.org/10.1002/jms.4349DOI Listing

An efficient solution for resolving iTRAQ and TMT channel crosstalk.

J Mass Spectrom 2019 Mar 18. Epub 2019 Mar 18.

Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States.

Isobaric tagging reagents such as iTRAQ and TMT typically have isotopic impurities that cause significant crosstalk between channels. Here we present an efficient solution to compensate for channel crosstalk using linear algebra and find that it is between 20x and 120x faster than previous methods. We also find that the effects of channel crosstalk are as important to manage as the effects of ratio compression due to precursor impurities, and we have released an open-source tool to perform both types of calculations. Read More

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http://doi.wiley.com/10.1002/jms.4354
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http://dx.doi.org/10.1002/jms.4354DOI Listing
March 2019
4 Reads

Dipolar DC Induced Collisional Activation of Non-Dissociated Electron-Transfer Products.

J Mass Spectrom 2019 Mar 14. Epub 2019 Mar 14.

Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.

The application of electron transfer and dipolar direct current induced collisional activation (ET-DDC) for enhanced sequence coverage of peptide/protein cations is described. A DDC potential is applied across one pair of opposing rods in the high-pressure collision cell of a hybrid quadrupole/time-of-flight tandem mass spectrometer (QqTOF) to induce collisional activation, in conjunction with electron transfer reactions. As a broadband technique, DDC can be employed for the simultaneous collisional activation of all the first-generation charge reduced precursor ions (e. Read More

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http://dx.doi.org/10.1002/jms.4352DOI Listing
March 2019
1 Read

Formation of Multimeric Steroid Metal Adducts and Implications for Isomer Mixture Separation by Traveling Wave Ion Mobility Spectrometry.

J Mass Spectrom 2019 Mar 12. Epub 2019 Mar 12.

Department of Chemistry, University of Nebraska - Lincoln, Lincoln, NE, 68588-0304, USA.

Steroid analysis is essential to the fields of medicine and forensics, but such analyses can present some complex analytical challenges. While chromatographic methods require long acquisition times and often provide incomplete separation, ion mobility spectrometry (IMS) as coupled to mass spectrometry (MS) has demonstrated significant promise for the separation of steroids, particularly in concert with metal adduction and multimerization. In this study, traveling wave ion mobility spectrometry (TWIMS) was employed to separate multimer steroid metal adducts of isomers in mixtures. Read More

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http://dx.doi.org/10.1002/jms.4350DOI Listing

Mechanistic insights into intramolecular phosphate group transfer during collision induced dissociation of phosphopeptides.

J Mass Spectrom 2019 Mar 12. Epub 2019 Mar 12.

Department of Chemistry, University of Florida, P.O. Box 7200, Gainesville, FL, 32611-7200, United States.

We report on the rearrangement chemistry of model phosphorylated peptides during collision-induced dissociation (CID), where intramolecular phosphate group transfers are observed from donor to acceptor residues. Such "scrambling" could result in inaccurate modification localization, potentially leading to misidentifications. Systematic studies presented herein provide mechanistic insights for the unusually high phosphate group rearrangements presented some time ago by Reid and co-workers (Proteomics 2013, 13 (6), 964-973). Read More

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http://dx.doi.org/10.1002/jms.4351DOI Listing
March 2019
1 Read

Influence of the amino acid composition on the ionization efficiencies of small peptides.

J Mass Spectrom 2019 Mar 8. Epub 2019 Mar 8.

Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, 50411, Tartu, Estonia.

Electrospray ionization is widely used to generate gas phase ions from a variety of molecules ranging from small ions to large proteins, while the ionization mechanism is claimed to depend on the size of the molecule. For small molecules, the ionization efficiency, the amount of gas phase ions produced in the electrospray process, depends on the properties of the compound. Here we show that the amino acid composition also influences the ionization efficiency of the oligopeptide. Read More

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http://dx.doi.org/10.1002/jms.4348DOI Listing

Are formalin-fixed and paraffin-embedded tissues fit for proteomic analysis?

J Mass Spectrom 2019 Mar 3. Epub 2019 Mar 3.

Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Münster, Germany.

Formalin-fixed and paraffin-embedded (FFPE)-tissue archives are potential treasure troves in the search for clinically interesting specimens. However, while the FFPE-treatment provides excellent conservation of the three-dimensional structure of the tissue and prevents degradation over decades, it also introduces numerous nonspecific and irreversible protein modifications. In this study, we have evaluated several published workflows for FFPE-tissue by fit-for-purpose proteomics technologies. Read More

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http://dx.doi.org/10.1002/jms.4347DOI Listing
March 2019
3 Reads

Direct flow injection profiling of acyl glycerols from food products using isopropanol as solvent.

J Mass Spectrom 2019 Feb 28. Epub 2019 Feb 28.

Faculty of Science and Technology, Free University of Bolzano, Piazza Università 1, 39100, Bolzano, Italy.

This work proposes a novel method for the direct flow injection profiling of acyl glycerols in edible oils and fats without preliminary extraction and consequent reconstitution in the injection solvent. The work exploits the outstanding performance of high-resolution mass spectrometry to target unique elemental compositions even in the most complex matrices. The performance of isopropanol as the unique solvent for both the solubilization and analysis of acyl glycerols was investigated in comparison with other classical methods involving preliminary extractions, sample recovery and analysis. Read More

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http://dx.doi.org/10.1002/jms.4346DOI Listing
February 2019
2.379 Impact Factor

Investigation of activation energies for dissociation of host-guest complexes in the gas phase using low-energy collision induced dissociation.

J Mass Spectrom 2019 Feb 23. Epub 2019 Feb 23.

Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, CNRS, 75005, Paris, France.

A low-energy collision induced dissociation CID (low-energy CID) approach that can determine both activation energy and activation entropy has been used to evaluate gas-phase binding energies of host-guest (H-G) complexes of a heteroditopic hemicryptophane cage host (Zn (II)@1) with a series of biologically-relevant guests. In order to use this approach, preliminary calibration of the effective temperature of ions undergoing resonance excitation is required. This was accomplished by employing blackbody infrared radiative dissociation (BIRD) which allows direct measurement of activation parameters. Read More

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http://dx.doi.org/10.1002/jms.4345DOI Listing
February 2019
1 Read

Comparison of the fragmentation behavior of DNA and LNA single strands and duplexes.

J Mass Spectrom 2019 Feb 16. Epub 2019 Feb 16.

Department of Chemistry, Humboldt-Universitaet zu Berlin, Berlin, Germany.

DNA and locked nucleic acid (LNA) were characterized as single strands, as well as double stranded DNA-DNA duplexes and DNA-LNA hybrids using tandem mass spectrometry with collision-induced dissociation. Additionally, ion mobility spectrometry was carried out on selected species. Oligonucleotide duplexes of different sequences - bearing mismatch positions and abasic sites of complementary DNA 15-mers - were investigated to unravel general trends in their stability in the gas phase. Read More

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http://doi.wiley.com/10.1002/jms.4344
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http://dx.doi.org/10.1002/jms.4344DOI Listing
February 2019
4 Reads

Reactivity of 4-thiothymidine with Fenton's reagent investigated by UV-Visible Spectroscopy and ElectroSpray Ionization Mass Spectrometry.

J Mass Spectrom 2019 Feb 15. Epub 2019 Feb 15.

Dipartimento di Chimica, Università degli Studi di Bari "Aldo Moro", Via Orabona, 4-70126, Bari, Italy.

The reactivity of the sulfur-containing nucleoside 4-thio-(2'-deoxy)-thymidine (S -TdR) under Fenton conditions, i.e. in the presence of H O and catalytic amounts of Fe (II), was investigated by UV-Vis spectroscopy and ElectroSpray Ionization Single and Tandem Mass Spectrometry (ESI-MS and MS/MS). Read More

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http://dx.doi.org/10.1002/jms.4343DOI Listing
February 2019
7 Reads

Fabrication of homogenous three-dimensional biomimetic tissue for mass spectrometry imaging.

J Mass Spectrom 2019 Feb 11. Epub 2019 Feb 11.

State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050, China.

Reference samples are essential for mass spectrometric method optimization, data quality control, and target analyte quantitation. However, it is highly challenging to prepare an ideal homogeneous, standard-spiked tissue sample for mass spectrometry imaging (MSI) research. Herein, we present a standard-spiked 3D biomimetic tissue model fabricated with native cells, homogenate matrix, and biocompatible polymer. Read More

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http://dx.doi.org/10.1002/jms.4342DOI Listing
February 2019
1 Read

Effects of aprotic solvents on the stability of metal-free superoxide dismutase probed by native electrospray ionization-ion mobility-mass spectrometry.

J Mass Spectrom 2019 Apr;54(4):351-358

National Center of Mass Spectrometry in Changchun & Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.

Considering that aprotic solvents are often used as cosolvents in investigating the interactions between small molecules and proteins, we assessed the effects of five aprotic solvents represented by dimethylformamide (DMF) on the structure stabilities of metal-free SOD1 (apo-SOD1) by native electrospray ionization-ion mobility-mass spectrometry (ESI-IM-MS). These aprotic solvents include DMF, 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl sulfoxide (DMSO), acetonitrile (ACN), and tetrahydrofuran (THF). Results indicated that DMI, DMSO, and DMF at low percentage concentration could reduce the average charge and the dimer dissociation of apo-SOD1. Read More

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http://dx.doi.org/10.1002/jms.4341DOI Listing
April 2019
1 Read

The pre-separation of oxygen containing compounds in oxidised heavy paraffinic fractions and their identification by GC-MS with supersonic molecular beams.

J Mass Spectrom 2019 Apr;54(4):328-341

School of Chemistry, Tel Aviv University, Tel Aviv, Israel.

The heavy petroleum fractions produced during refining processes need to be upgraded to useable products to increase their value. Hydrogenated heavy paraffinic fractions can be oxidised to produce high value products that contain a variety of oxygenates. These heavy oxygenated paraffinic fractions need to be characterised to enable the control of oxidation processes and to understand product properties. Read More

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http://dx.doi.org/10.1002/jms.4340DOI Listing
April 2019
1 Read

Top-down characterization of mouse core histones.

J Mass Spectrom 2019 Mar;54(3):258-265

School of Chemical Science and Engineering and Shanghai Key Laboratory of Chemical Assessment and Sustainability, Tongji University, Shanghai, 200092, China.

Histone post-translational modifications (PTMs) play various roles in chromatin-related cellular processes, and comprehensive analysis of these combinatorial PTMs at the intact protein level by top-down proteomics is the method of choice to reveal their crosstalk and biological functions. Here, we report our top-down characterization of the core histones from mouse fibroblasts cells NIH/3T3, which is a classic model used in many kinds of research. With nanoRPLC-MS/MS analysis and ProteinGoggle database search, 547 protein species were identified with spectrum-level FDR ≤ 1%, where PTMs in 51 protein species were unambiguously localized with PTM scores ≥1. Read More

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http://dx.doi.org/10.1002/jms.4339DOI Listing

Intellectual property-The Foundation of Innovation: A scientist's guide to intellectual property.

J Mass Spectrom 2019 Mar;54(3):288-300

Target Discovery, Inc., 4030 Fabian Way, Palo Alto, CA, 94303-4607.

Increasingly, the activities of the practicing scientist inextricably intersect with the business world. Science is central to the development and delivery of many goods or services, and scientific discovery can directly, or indirectly, lead to substantial revenue generation. Scientists, however, have little training in the complex issues of intellectual property (IP), and often little understanding of their rights and obligations. Read More

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http://dx.doi.org/10.1002/jms.4331DOI Listing
March 2019
2 Reads

Deep-ultraviolet laser ablation electrospray ionization mass spectrometry.

J Mass Spectrom 2019 Mar;54(3):281-287

Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana, USA.

A 193-nm wavelength deep ultraviolet laser was used for ambient laser ablation electrospray ionization mass spectrometry of biological samples. A pulsed ArF excimer laser was used to ablate solid samples, and the resulting plume of the desorbed material merged with charged electrospray droplets to form ions that were detected with a quadrupole time-of-flight mass spectrometer. Solutions containing peptide and protein standards up to 66-kDa molecular weight were deposited on a metal target, dried, and analyzed. Read More

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http://doi.wiley.com/10.1002/jms.4338
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http://dx.doi.org/10.1002/jms.4338DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422691PMC
March 2019
3 Reads

Is the placental proteome impaired in well-controlled gestational diabetes?

J Mass Spectrom 2019 Apr;54(4):359-365

Department of Medicine - DIMED, University of Padova, Padova, Italy.

In pregnancy complicated by gestational diabetes mellitus (GDM), the human placenta shows several pathological functional and structural changes, but the extent to which maternal glycemic control contributes to placental abnormalities remains unclear. The aim of this study was to profile and compare the proteome of placentas from healthy pregnant women and those with GDM, to investigate the placenta-specific protein composition and possible changes of its function in presence of GDM. Quantitative proteomic analysis, based on LC-MS approach, revealed that higher (approximately 15% increase) levels of galectin 1 and collagen alpha-1 XIV chain (although the difference regarding the latter was at the limit of significance) were present in GDM samples, while heat shock 70 kDa protein 1A/1B was less abundant in GDM placental tissue. Read More

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http://dx.doi.org/10.1002/jms.4336DOI Listing
April 2019
2 Reads

Comparison of ESI-MS/MS and APCI-MS methods for the quantification of folic acid analogs in C. elegans.

J Mass Spectrom 2019 Apr;54(4):316-327

Max Planck Institute for Biology of Ageing, Cologne, Germany.

Folic acid (FA) plays a vital role in central metabolism, including the one carbon cycle, nucleotide, and amino acid biosynthesis. The development of sensitive, accurate analytical methods to measure FA intermediates in tissues is critical to understand their biological roles in diverse physiological and pathological contexts. Here, we developed a highly sensitive method for the simultaneous quantification of FA intermediates in the nematode Caenorhabditis elegans as a model to dissect metabolic networks. Read More

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http://doi.wiley.com/10.1002/jms.4337
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http://dx.doi.org/10.1002/jms.4337DOI Listing
April 2019
13 Reads

Combining MALDI-2 and transmission geometry laser optics to achieve high sensitivity for ultra-high spatial resolution surface analysis.

J Mass Spectrom 2019 Apr;54(4):366-370

Mass Spectrometry Research Center, Vanderbilt University, Nashville, Tennessee, USA.

A transmission geometry optical configuration allows for smaller laser spot size to facilitate high-resolution matrix-assisted laser/desorption ionization (MALDI) mass spectrometry. This increase in spatial resolution (ie, smaller laser spot size) is often associated with a decrease in analyte signal. MALDI-2 is a post-ionization technique, which irradiates ions and neutrals generated in the initial MALDI plume with a second orthogonal laser pulse, and has been shown to improve sensitivity. Read More

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http://doi.wiley.com/10.1002/jms.4335
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http://dx.doi.org/10.1002/jms.4335DOI Listing
April 2019
9 Reads

Quantification of enantiomers by mass spectrometry based on chemical derivatization and spectral shape deformation quantitative theory.

J Mass Spectrom 2019 Mar;54(3):250-257

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, China.

A facile mass spectrometric kinetic method for quantitative analysis of chiral compounds was developed by integrating mass spectrometry based on chemical derivatization and the spectral shape deformation quantitative theory. Chemical derivatization was employed to introduce diastereomeric environments to the chiral compounds of interest, resulting in different abundance distribution patterns of fragment ions of the derivatization products of enantiomers in mass spectrometry. The quantitative information of the chiral compounds of interest was extracted from complex mass spectral data by an advanced calibration model derived based on the spectral shape deformation quantitative theory. Read More

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http://dx.doi.org/10.1002/jms.4334DOI Listing
March 2019
2 Reads
2.379 Impact Factor

Ion manipulation and enrichment mass spectrometer for cleavage of disulfide bond via ion/ion reaction.

J Mass Spectrom 2019 Apr;54(4):311-315

Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing, 100029, PR China.

A novel mass spectrometer with the capability of ion manipulation and enrichment was developed to perform gas-phase ion/ion reactions followed by product ions accumulation. The development of this apparatus opens opportunities for more complex sequences of ion manipulations, thus offers the potential on extensive application involving ion/ion reaction. Here, cleavage of disulfide bond in peptide was demonstrated based upon this ion manipulation and enrichment mass spectrometer. Read More

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http://doi.wiley.com/10.1002/jms.4333
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http://dx.doi.org/10.1002/jms.4333DOI Listing
April 2019
11 Reads

Identification of G-nerve agents at picogram levels from complex organic samples containing hydrocarbon interferences by aqueous extraction, followed by derivatization and liquid chromatography-mass spectrometry analysis.

J Mass Spectrom 2019 Mar;54(3):274-280

Department of Analytical Chemistry, Israel Institute for Biological Research (IIBR) P.O.B. 19, Ness Ziona, Israel.

The chromatograms obtained from the gas chromatography-electron ionization mass spectrometric (GC-EI-MS) analysis of extracts containing G-nerve agents in the presence of diesel, gasoline, etc., are dominated by hydrocarbon backgrounds that "mask" the G-nerve agents, leading to severe difficulties in identification. This paper presents a practical solution for this challenge by transferring the G-nerve agents from the organic phase into the aqueous phase using liquid-liquid extraction (LLE), followed by derivatization with 2-[(dimethylamino)methyl]phenol (2-DMAMP), allowing ultrasensitive LC-ESI-MS/MS analysis of the G-derivatives. Read More

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http://dx.doi.org/10.1002/jms.4332DOI Listing
March 2019
1 Read

Hydralazine derivative of aldehyde: A new type of [M - H] ion formed in electrospray ionization mass spectrometry.

J Mass Spectrom 2019 Mar;54(3):239-249

Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, 430072, People's Republic of China.

Hydralazine has been widely employed in the development of drugs, derivatization reagents, and ligands. In the present work, we reported a new type of dehydrogenated ion [M - H] that was produced from the hydralazine derivative of hexanal in electrospray ionization mass spectrometry (ESI-MS). The formation of [M - H] ions in the ESI-MS was found to be independent on the mobile phase composition of the liquid chromatography and ESI source parameters. Read More

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http://dx.doi.org/10.1002/jms.4330DOI Listing
March 2019
2 Reads
2.379 Impact Factor

Dissociation pathways of protic ionic liquid clusters: Alkylammonium nitrates.

J Mass Spectrom 2019 Jan 16. Epub 2019 Jan 16.

Space Vehicles Directorate, Air Force Research Laboratory, Kirtland AFB, New Mexico, United States, 87117.

Protic ionic liquids are promising candidates for many applications, including as spacecraft propellants. For both fundamental interest and understanding clustering and dissociation during electrospray-based propulsion, it is useful to explore the dissociation pathways of protic ionic liquid clusters, as well as the factors affecting the relative contributions of each pathway to the observed MS/MS spectra. With that said, most of the published reports on ionic liquid cluster dissociation have focused on aprotic ionic liquids. Read More

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http://dx.doi.org/10.1002/jms.4329DOI Listing
January 2019
2 Reads

Improved online hydrogen isotope analysis of halite aqueous inclusions.

J Mass Spectrom 2019 Apr;54(4):342-350

Stable Isotope Department, Elementar Analysensysteme GmbH, Langenselbold, Germany.

We demonstrate an improved method based on continuous-flow elemental analyser pyrolysis isotopic ratio mass spectrometry (CF-EA-PY-IRMS) to measure the H/ H ratios of water trapped in halite crystals. Two challenges to overcome are the low hydrogen concentration of samples (10-50 μmol H ·g ) and the high chloride concentration released when reacting halite in an elemental analyser. We describe an optimization procedure for determining the H/ H ratio of this trapped water with an acceptable accuracy. Read More

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http://dx.doi.org/10.1002/jms.4323DOI Listing
April 2019
4 Reads

Study of the cyanoacrylate fuming mechanism by matrix-assisted laser desorption/ionization mass spectrometry.

J Mass Spectrom 2019 Mar;54(3):222-226

Department of Chemistry, Iowa State University, Ames, IA, 50011.

Despite cyanoacrylate fuming being widely used in the forensic science field, its mechanism is not well understood. In this study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is used to study latent fingerprints that have been cyanoacrylate fumed in an attempt to gain insight into the fuming mechanism. In the negative mode mass spectrometry data, four compounds related to the polymerization of cyanoacrylate are identified and their structures are determined from accurate mass and MS/MS. Read More

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http://dx.doi.org/10.1002/jms.4325DOI Listing
March 2019
3 Reads

Signal enhancement in laser diode thermal desorption-triple quadrupole mass spectrometry analysis using microwell surface coatings.

J Mass Spectrom 2019 Feb;54(2):167-177

Department of Chemistry, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada.

Laser-diode thermal desorption (LDTD) is an ionization source usually coupled to triple quadrupole mass spectrometry (QqQMS) and specifically designed for laboratories requiring high-throughput analysis. It has been observed that surface coatings on LDTD microwell plates can improve the sensitivity of the analysis of small polar molecules. The objective of the present study is to understand and quantify the effect of microwell surface coatings on signal intensity of small organic molecules of clinical, environmental, and forensic interest. Read More

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http://dx.doi.org/10.1002/jms.4328DOI Listing
February 2019
3 Reads

High-throughput polymer tip-electrospray ionization mass spectrometry for enhanced detection of neopterin and biopterin in clinical urine samples.

J Mass Spectrom 2019 Feb;54(2):189-194

Neonatal Disease Screening Center, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, 330006, China.

Urinary biopterin (Bio) and neopterin (Neo) are important markers for clinical diagnosis of hyperphenylalaninemia. Herein, we developed a high-throughput analysis method based on electrospray ionization mass spectrometry (ESI-MS) with polymer tips for the rapid quantitative detection of Bio and Neo in clinical urine samples. Different polymer tips were investigated. Read More

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http://doi.wiley.com/10.1002/jms.4322
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http://dx.doi.org/10.1002/jms.4322DOI Listing
February 2019
27 Reads

Challenges in the identification process of phenidate analogues in LC-ESI-MS/MS analysis: Information enhancement by derivatization with isobutyl chloroformate.

J Mass Spectrom 2019 Mar;54(3):266-273

Department of Analytical Chemistry, Israel Institute for Biological Research (IIBR), P.O.B. 19, Ness Ziona, Israel.

A new analytical technique for the structural elucidation of four representative phenidate analogues possessing a secondary amine residue, which leads to a major/single amine-representative fragment/product ion at m/z 84 both in their GC-EI-MS and LC-ESI-MS/MS spectra, making their identification ambiguous, was developed. The method is based on "in vial" chemical derivatization with isobutyl chloroformate in both aqueous and organic solutions, followed by liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS/MS). The resulting carbamate derivatives promote rich fragmentation patterns with full coverage of all substructures of the molecule, enabling detailed structural elucidation and unambiguous identification of the original compounds at low ng/mL levels. Read More

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http://doi.wiley.com/10.1002/jms.4327
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http://dx.doi.org/10.1002/jms.4327DOI Listing
March 2019
4 Reads

Electrospray multistage mass spectrometry in the negative ion mode for the unambiguous molecular and structural characterization of acidic hydrolysates from 4-O-methylglucuronoxylan generated by endoxylanases.

J Mass Spectrom 2019 Mar;54(3):213-221

Bioconversion Group, Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, Japan.

A rapid analytical methodology is proposed to answer the two questions about the molecular and structural features of the acidic xylo-oligosaccharides (XOSs) formed upon the enzymatic hydrolysis of 4-O-methylglucuronoxylan. The shortest acidic XOSs carrying a methylglucuronic acid moiety and the possible distribution of larger products (molecular feature) are instantly found by electrospray ionization mass spectrometry (ESI-MS) in the negative ion mode, which filters the unwanted neutral XOS. The acidic moiety is then unambiguously localized along the xylose backbone (structural feature) by ESI-MS in the negative ion mode via the selection/activation/dissociation of the product ions formed upon the one-way and stepwise glycosidic bond cleavage at the reducing end. Read More

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http://dx.doi.org/10.1002/jms.4321DOI Listing
March 2019
4 Reads

LC-DAD-ESI-MS/MS-based phenolic profiling and antioxidant activity in Turkish cv. Nizip Yaglik olive oils from different maturity olives.

J Mass Spectrom 2019 Mar;54(3):227-238

Department of Biotechnology, Institute of Natural and Applied Sciences, Cukurova University, Adana, Turkey.

The current study was designed to find out how olive maturity indices (2.5, 3.5, and 4. Read More

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http://doi.wiley.com/10.1002/jms.4326
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http://dx.doi.org/10.1002/jms.4326DOI Listing
March 2019
21 Reads
2.379 Impact Factor

MALDI- and LDI-MS saponin fingerprint of leaves and stick components of commercial yerba mate (Ilex paraguariensis).

J Mass Spectrom 2019 Feb;54(2):195-203

Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica, Universidad de Buenos Aires, Buenos Aires, Argentina.

Yerba mate (YM) is massively produced and consumed as an infusion in South America and spreading all over the world. This product is obtained from dried leaves of Ilex paraguariensis Saint Hilaire, mixed with fragments of dried branches (sticks). For its commercialization, YM must have a minimum percentage of leaves because its presence determines YM quality and price. Read More

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http://doi.wiley.com/10.1002/jms.4324
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http://dx.doi.org/10.1002/jms.4324DOI Listing
February 2019
13 Reads

A high-throughput glutathione trapping assay with combined high sensitivity and specificity in high-resolution mass spectrometry by applying product ion extraction and data-dependent neutral loss.

J Mass Spectrom 2019 Feb;54(2):158-166

Department of Drug Metabolism and Pharmacokinetics, Sanofi, Waltham, Massachusetts.

Reactive metabolites are thought to play a pivotal role in the pathogenesis of some drug-induced liver injury (DILI) and idiosyncratic adverse drug reactions (IADRs), which is of concern to patient safety and has been a cause of drugs being withdrawn from the market place. To identify drugs with a lower propensity for causing DILI and/or IADRs, high-throughput assays to capture reactive metabolites are required in pharmaceutical industry for early drug discovery risk assessment. We describe the development of an assay to detect glutathione adducts with combined high sensitivity, enhanced specificity, and rapid data analysis. Read More

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http://dx.doi.org/10.1002/jms.4320DOI Listing
February 2019
17 Reads

Compositional elucidation of heavy petroleum base oil by GC × GC-EI/PI/CI/FI-TOFMS.

J Mass Spectrom 2019 Feb;54(2):148-157

Department of Chemistry, Organic & Biological Analytical Chemistry Group, University of Liège, Allée du 6 aout, B6c, Liège (Sart Tilman), B-4000, Belgium.

Comprehensive two-dimensional gas chromatography (GC × GC) coupled to time-of-flight mass spectrometry is a powerful separation tool for complex petroleum product analysis. However, the most commonly used electron ionization (EI) technique often makes the identification of the majority of hydrocarbons impossible due to the exhaustive fragmentation and lack of molecular ion preservation, prompting the need of soft-ionization energies. In this study, three different soft-ionization techniques including photo ionization (PI), chemical ionization (CI), and field ionization (FI) were compared against EI to elucidate their relative capabilities to reveal different base oil hydrocarbon classes. Read More

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http://dx.doi.org/10.1002/jms.4319DOI Listing
February 2019
4 Reads

Reagent-free and pH-independent degradation of N-nitrosamines using electrons generated via corona discharge at ambient pressure.

J Mass Spectrom 2019 Feb;54(2):141-147

Hefei National Laboratory for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China (USTC), Hefei, 230026, PR China.

Traditional degradation methods for N-nitrosamines are either confined with acid solution or required for additional chemical reagents to guarantee high reaction efficiency. Herein, we demonstrate a facile and effective way for reagent-free and pH-independent degradation of N-nitrosamines, which was induced by free electrons generated via corona discharge at ambient pressure. The highly reactive free electron is produced in situ and responsible for degradation of three N-nitrosamines, which was also theoretically confirmed. Read More

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http://dx.doi.org/10.1002/jms.4318DOI Listing
February 2019
3 Reads

How to avoid interfering electrochemical reactions in ESI-MS analysis.

J Mass Spectrom 2019 Apr;54(4):301-310

FAU Erlangen-Nuremberg, Institute of Particle Technology, Erlangen, Germany.

The presence of electrochemical reactions occurring in an electrospray processes at the point where the current enters the liquid is discussed since the early 1990's. This current transfer to the liquid results in oxidation or reduction of either electrolyte species in the liquid sprayed or of the electrode material in contact with the liquid. As a result, new chemical species are generated. Read More

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http://doi.wiley.com/10.1002/jms.4315
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http://dx.doi.org/10.1002/jms.4315DOI Listing
April 2019
13 Reads

Volatile compounds profiling by using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS). The case study of dark chocolates organoleptic differences.

J Mass Spectrom 2019 Jan;54(1):92-119

Centre des Sciences du Goût et de l'Alimentation (CSGA), AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France.

Direct-injection mass spectrometry (DIMS) techniques have evolved into powerful methods to analyse volatile organic compounds (VOCs) without the need of chromatographic separation. Combined to chemometrics, they have been used in many domains to solve sample categorization issues based on volatilome determination. In this paper, different DIMS methods that have largely outperformed conventional electronic noses (e-noses) in classification tasks are briefly reviewed, with an emphasis on food-related applications. Read More

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http://dx.doi.org/10.1002/jms.4317DOI Listing
January 2019
8 Reads