Journal of the Mass Spectrometry Society of Japan
Online ISSN : 1880-4225
Print ISSN : 1340-8097
ISSN-L : 1340-8097
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Volume 55, Issue 4
Displaying 1-7 of 7 articles from this issue
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INTEGRATED PAPER
  • Structural Characterization of Polymeric Materials by Mass Spectrometry
    Hiroaki SATO
    2007 Volume 55 Issue 4 Pages 261-270
    Published: 2007
    Released on J-STAGE: August 15, 2007
    DOIhttps://doi.org/10.5702/massspec.55.261
    JOURNAL FREE ACCESS
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    The development of new polymer characterization techniques is constantly required to understand the various properties of polymers and create new functional polymers. In this study, two mass spectrometry (MS) approaches have been investigated: temperature programmed pyrolysis-mass spectrometry (TPPy-MS) and soft laser desorption/ionization-mass spectrometry (SLD-MS). The study can be summarized as follows:
    1) A TPPy-MS system was developed to overcome the limitations of conventional evolved gas analysis (EGA) systems such as thermogravimetry/MS (TG/MS). The TPPy-MS system was used to investigate the mechanisms of thermal degradation of an engineering polymer with a brominated flame-retardant, and the intermolecular interaction mechanisms of miscible polymer blends and polymer/clay hybrids.
    2) Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was employed to characterize the chemical structure of each polymer chain. A new data processing method for size exclusion chromatography (SEC)/MALDI-MS was proposed to determine the accurate molecular weight distribution of polymers based on individual oligomer compositions. MALDI-MS was also used to investigate the biodegradation behavior of polymers. Based on the structural changes in each polymer chain, enzymatic degradation mechanisms of a biodegradable polyester and bacterial degradation of surfactants have been proposed.
    3) To avoid the use of matrix reagents that frequently interfere with the mass spectra of oligomer and polymer additives, novel ionization platforms for matrix-free SLD-MS were investigated. The etching conditions of porous silicon spots for desorption/ionization on porous silicon-mass spectrometry (DIOS-MS) were optimized to determine the accurate molecular weight distribution of a certified reference polystyrene. Finally, two ionization platforms were developed using a pyroelectric ceramic plate and germanium nanodot deposited on a silicon wafer. The latter method was preferred for characterization of brominated flame-retardants.
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REGULAR PAPERS
  • Unimolecular Decomposition of N-Ethoxycarbonyl Heptafluorobutyl Ester Derivatives of Amino Acids upon Electron Ionization
    Masaaki UBUKATA, Akihiko KUSAI, Toshinori TANIUCHI, Takeo KANEKO, Kens ...
    2007 Volume 55 Issue 4 Pages 271-277
    Published: 2007
    Released on J-STAGE: August 15, 2007
    DOIhttps://doi.org/10.5702/massspec.55.271
    JOURNAL FREE ACCESS
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    The fragmentation pathways of N-(ethoxycarbonyl)glycine-2,2,3,3,4,4,4-heptafluorobutyl ester (glycine derivative) (1) and N-(ethoxycarbonyl)alanine-2,2,3,3,4,4,4-heptafluorobutyl ester (alanine derivative) (2) upon electron ionization were investigated using a gas chromatograph/double-focusing mass spectrometer and time-of-flight mass spectrometer. To estimate the fragmentation pathways, the B/E-linked scan mass spectra of 13C-labeled derivatives (1-13C2 and 2-13C3) were compared with those of non-labeled derivatives. An elemental composition of each of the precursor ions was estimated by accurate mass measurements.
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  • Factors Governing Peptide Backbone Cleavages in Electron Capture Dissociation of Triantennary Complex-type N-Glycosylated Peptide
    Yayoi HONGO, Akihiro SATO, Takemichi NAKAMURA
    2007 Volume 55 Issue 4 Pages 279-285
    Published: 2007
    Released on J-STAGE: August 15, 2007
    DOIhttps://doi.org/10.5702/massspec.55.279
    JOURNAL FREE ACCESS
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    We investigated the factors governing peptide backbone cleavages in electron capture dissociation (ECD) of some glycopeptides. ECD with infrared laser irradiation (activated ion ECD; AI ECD) and ECD with hot electron (<10 eV) irradiation (H ECD) were applied to two triantennary complex-type N-glycopeptides from bovine fetuin and their derivatives. The glycopeptides are those that did not show extensive backbone cleavage in conventional ECD [Hongo et al., J. Mass Spectrom. Soc. Jpn., 55, 77 (2007)]. Similar to the conventional ECD case, AI ECD on the glycopeptides only gave glycan fragmentation and radical losses. On the other hand, AI ECD on de-NeuNAc derivatives gave a mixed result; various c-type ions were generated from only one glycopeptide. H ECD on two deglycosylated peptides gave b-, y-, and a few w-type ions. The data indicated that the ECD backbone cleavage of these peptides was governed by multiple factors including the availability of the radical localizing site and the amount of protonation in the precursor ions.
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TECHNICAL REPORT
Message from the President
Letters from the Editor-in-Chief
  • Benefits of Contributing to the JMSSJ
    Ken-ichi YOSHINO
    2007 Volume 55 Issue 4 Pages 294-297
    Published: 2007
    Released on J-STAGE: August 15, 2007
    DOIhttps://doi.org/10.5702/massspec.55.294
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  • Comments on Usage of the Abbreviation “MS” and the Japanese Abbreviation “Masu”
    Ken-ichi YOSHINO
    2007 Volume 55 Issue 4 Pages 298-309
    Published: 2007
    Released on J-STAGE: August 15, 2007
    DOIhttps://doi.org/10.5702/massspec.55.298
    JOURNAL FREE ACCESS
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    The term “mass spectrometry” is usually abbreviated as “MS.” It is confusing that “MS” is also used as an abbreviation for “mass spectrometer,” “mass spectroscopy,” “mass spectrograph,” “mass spectrum (spectra),” and “mass separation.” “Masu” in Japanese is an ambiguous word and originates from “mass” in English or “Mass” in German. In addition to the meaning of mass, however, “masu” is used as an abbreviation for “mass spectrometry,” “mass spectrometer,” “unified atomic mass unit,” and “a quantity of m/z= 1” by Japanese mass spectrometrists. Because of the ambiguity in the usage of “MS” and “masu,” some inappropriate terms, such as “peptide MS fingerprinting” for “peptide mass fingerprinting” and “TOF-mass” for “time-of-flight mass spectrometer,” were used by Japanese mass spectrometrists.
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