著者
平田 利美 前川 麻弥 能美 隆
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.46, no.4, pp.259-274, 1998 (Released:2007-07-20)
被引用文献数
14 13

Mechanisms of pyrolysis of cellulose which have been presented are reviewed in terms of pathways of the reaction, production of levoglucosan, carbonization and pyrolysis of levoglucosan, and kinetics. In addition measurements with machines are discussed in relation to the pyrolysis. In the section of reaction pathways five models given in diagrams are introduced and indicated lack of clear chemical definition of them, and in the levoglucosan formation six principal models are briefly described, and a proposal of an ion mechanism against a radical mechanism, and different interpretations of effects of fine structures on the reaction and the chain length are pointed out to make important controversial points. In the third section changes in residue structure through carbonization are discussed, and courses of levoglucosan pyrolysis full of variety are shown and significance of researches on the pyrolysis in air is emphasized from viewpoint of fire science. In the fifth section an enormous number of kinetic data presented with different orders of reaction are shown and a kinetics is systematically developed to explain the different reaction orders. In the sixth section, the dependency of data on individual instruments are revealed in the measurement with instruments problems involved in analytical pyrolysis. Understanding of the implication and reasonable choice of the data is shown to be important.
著者
脇坂 昭弘 古賀 健司 竹尾 陽敏
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.45, no.2, pp.125-136, 1997 (Released:2007-07-20)

Clusters, ensemble of atoms and/or molecules with less number enough to form stable bulk, are thought to play important roles in various phenomena such as, crystallization, phase separation, chemical reactions, etc. Several techniques to produce clusters have been developed and studies in this field are becoming active. Two new methods to produce clusters and the investigations on their characteristics are described in this paper. One is the characteristics of clusters formed from liquid (solution), and the other is the formation and the stabilization of clusters on the surface and their structural investigation.
著者
吉野 健一
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.62, no.5, pp.61-64, 2014-10-01 (Released:2014-10-15)
参考文献数
7

IUPAC (International Union of Pure and Applied Chemistry) recommends that a hyphen, or, alternatively, a slash, should be used to indicate a combination of two analytical techniques such as liquid chromatography separation combined with mass spectrometry detection, in the last definitions of terms relating to mass spectrometry. Thus, such combined methods can be written as liquid chromatography-mass spectrometry or alternatively liquid chromatography/mass spectrometry. The corresponding abbreviations are LC-MS or LC/MS.
著者
吉野 健一
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.56, no.4, pp.209-213, 2008-08-01 (Released:2008-08-15)
参考文献数
6
被引用文献数
1 1

Mass spectrometers separate ions according to each mass/charge value, which is not a dimensionless quantity. However, the m/z value indicated in the abscissa of mass spectra is defined as a dimensionless quantity and not a numerical value the same as the mass/charge value in kilograms/coulombs (kg/C) or in unified atomic mass units/coulombs (u/C). The numerical value of m/z converted from the mass/charge value depends on the unified atomic mass unit and the physical constant “elementary charge,” e that is also the atomic unit of charge. This conversion confuses many mass spectrometrists with regard to the abscissa labeling of mass spectra, e.g. the symbol “m/z” is considered as an abbreviation of the term “mass-to-charge ratio.”
著者
荒川 隆一
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.46, no.3, pp.219-227, 1998 (Released:2007-07-20)
被引用文献数
1 1

A number of polynuclear ruthenium(II), rhodium(III), and cobalt(III) bipyridine complexes have been examined by electrospray ionization mass spectrometry (ESI-MS). ESI-MS is shown to be a powerful tool for the identification of polymetallic complexes and for detecting the contamination, because ESI mass spectra for the complexes showed a simple enough mass pattern for easy structural assignment. Multiply charged ions with the charge state from 8+ to 3+ were observed in the full scan ESI mass spectra of star-burst type tetranuclear complexes denoted by [Met(II)(bpy)2B]3RuX8 (Met=Ru, Os, and bpy=2,2′-bipyridine, B=bridging ligands, X=ClO4-). Different charged ions were found to be generated by the combination of counterion loss and protonation/deprotonation at the proton site of the bridging ligand B. These ion intensities are qualitatively explained in terms of acidity of metal complexes depending upon bridging ligand structures and the charge of metal ions. Ions produced by a removal of ligands were not observed in the ESI spectra unlike the FAB spectra. For tetranuclear complexes, collision-induced dissociation (CID) of the multiply charged ions has made it clear that loss of one or more HX neutral is a major process for lower charge states, while complete fragmentation takes place for higher charge states and the fragments are based on a subunit group of [Met(II)(bpy)2B]2+. Insertion of formal O2- produced from ClO4- counterion was observed for the complexes without active protons even if low energy CID experiments, but not for the complexes with active protons. Advantages of ESI mass spectrometry are demonstrated for these polynuclear compounds and CID chemistry of the investigated ions will be discussed.
著者
中川 秀樹
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.44, no.3, pp.415-429, 1996 (Released:2007-07-20)
被引用文献数
1 1

Both MALDI and ESI are well-known ionization method which have been worthy of remark among mass spectrometrists. FTMS is a mass analyzer which can be used for each ionization method with very high mass resolving power and mass accuracy. Here we introduce some MALDI/FTMS and ESI/FTMS spectra with the new topics among the FTMS users. The new topics include SORI (Sustained Off-Resonance Irradiation) and QE (Quadrupolar Excitation) techniques.
著者
鳥越 大平 髙橋 政友 中尾 素直 相馬 悠希 池田 和輝 中谷 航太 馬場 健史 和泉 自泰
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.70, no.4, pp.245-247, 2022-12-01 (Released:2022-12-15)
参考文献数
4

Epimetabolite is defined as analogues of known metabolites with different substructures. The rapid development of high-resolution mass spectrometry (HRMS) and some data mining tools has contributed to detecting and identifying a few epimetabolites that could play an important role as biological functions. However, almost all epimetabolites have not been identified because a generally applicable method for the comprehensive annotation of epimetabolites had not been developed. In the present study, we have proposed an advanced methodology for comprehensive structural elucidation of unidentified hydrophilic metabolites by a combination of stable isotope labeling, unified-HILIC/AEX/HRMS/MS analysis, data mining techniques, and metabolite annotation using in silico epimetabolite database (IEMDB). In fact, we successfully annotated 444 novel epimetabolite candidates in E. coli. Our method has several advantages over conventional techniques and represents a potentially useful tool for structural elucidation of comprehensive epimetabolites.
著者
和田 芳直
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.51, no.2, pp.368-373, 2003 (Released:2007-10-16)
参考文献数
26
被引用文献数
2 1

Mass spectrometry (MS) is proud of its high-throughput and sensitivity in the proteomic studies. However, the measurement of DNA by MS has not been in practice mainly due to its inherently large molecular size, though various applications of genetic analysis have been proposed so far. Now in the post-genome era, one of the highest demands on the genome analysis is the single nucleotide polymorphism genotyping, which is, in principle, the determination of single nucleotide substitutions at specific sites. A number of different methods using MS have been developed for this purpose, and some of those enabling multiplex analysis have advantages over other gel- or hybridization-based methods.
著者
近藤 文雄 鈴木 匡弘
出版者
一般社団法人 日本質量分析学会
雑誌
Journal of the Mass Spectrometry Society of Japan (ISSN:13408097)
巻号頁・発行日
vol.51, no.1, pp.114-118, 2003 (Released:2007-10-16)
参考文献数
19
被引用文献数
5 3

During the past 20 years, outbreaks of enterohemorrhagic Escherichia coli (EHEC) have been increasing worldwide and have been recognized as a potential health concern. Vero toxins produced by EHEC seem to be the most common cause of hemolytic uremic syndrome. Rapid diagnosis of EHEC infection is important to prevent the expansion of infection. Diagnosis is carried out by both isolation of EHEC and detection of Vero toxins in fecal extracts or fecal cultures. This review describes briefly about the current knowledge of the EHEC and Vero toxins, and about the determination methods for Vero toxins. The attempt to identify Vero toxins by electrospray ionization-liquid chromatography/mass spectrometry is also discussed.
著者
中山 充 江口 鎮子 松尾 昭彦 林 修一 菱田 真三郎 加藤 義昭
出版者
一般社団法人 日本質量分析学会
雑誌
質量分析 (ISSN:13408097)
巻号頁・発行日
vol.20, no.3, pp.239-247, 1972
被引用文献数
1

Mass spectra of pterocarpan derivatives (I∼VII) are recorded in Figs. 1∼5 and Tables 1∼6. The major fragmentation pathways of these compounds are shown in Scheme1. The results illustrate that the observed fragmentation patterns are of considerable utility in the application of mass spectro metry to structure elucidation in this series.