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Volume 51 (2003)
- Issue 6 Pages 563-
- Issue 5 Pages 492-
- Issue 4 Pages 439-
- Issue 3 Pages 391-
- Issue 2 Pages 349-
- Issue 1 Pages 36-
Volume 51, Issue 4
Displaying 1-5 of 5 articles from this issue
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REVIEW
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Noriyasu NIIMURA, Tetsuo MIYAKOSHI2003 Volume 51 Issue 4 Pages 439-457
Published: 2003
Released on J-STAGE: October 16, 2007
JOURNAL FREE ACCESSTypical Japanese natural resin films, i.e., oriental lacquer films, cashew resin films, and drying oil polymers were characterized, and also an ancient coating was identified using two-stage pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Urushiol, laccol, and thitsiol components, which are the main constituents of the respective oriental lacquers, were detected by the pyrolysis at 400°C. Additionally, the pyrolysis products, which reflect the structure of the urushiol, laccol, and thitsiol polymers, were detected by pyrolysis at 500°C after pyrolysis at 400°C. All the results have shown a significant progress occurring in the side chain-side chain C-C coupling and aromatic nucleus-side chain C-O coupling of urushiol, laccol, and thitsiol concurrently with the formation of the respective lacquer films. The cashew resin film was found to be terminated with saturated cardols and cardanols by the pyrolysis at 400°C. Furthermore, pyrolysis at 500°C revealed that the autoxidative side chain-side chain C-C coupling accelerated the cross-linking of trienyl- and dienylcardanols during the polymerization. The C4-C18 free fatty acids were detected by the pyrolysis of the drying oil polymers. These pyrolysis products are significant markers for a drying oil polymer. The drying oil polymer is terminated with saturated fatty acids, especially with hexadecanoic acid and octadecanoic acid. Based on these results, the ancient coating sample obtained from the surface of a wooden dish excavated at Tobarikyu, Kyoto prefecture, Japan was identified as Rhus vernicifera lacquer combined with an drying oil, presumably added as the solvent. Py-GC/MS was proved to be effective for the characterization of natural resin films and identification of organic coatings of historic artifacts.View full abstractDownload PDF (630K)
REGULAR PAPERS
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Yasuhide NAITO, Rie SASAKI, Manabu HEYA, Kunio AWAZU2003 Volume 51 Issue 4 Pages 458-465
Published: 2003
Released on J-STAGE: October 16, 2007
JOURNAL FREE ACCESSA time-of-flight mass spectrometric apparatus was built for infrared matrix-assisted laser desorption/ionization (IR-MALDI) experiments using a free-electron laser (FEL). Preliminary experiments were carried out with a CO2 laser at 9.5 μm and a FEL at 10.6 μm. These mid-IR wavelengths were shown to produce light atomic ions from solid samples. The detected ion peaks were broadened by the FEL macropulse with 15 μs width. Applying a delayed extraction pulse to FEL-generated ions brought about a small improvement on the mass resolution. By chopping a flux of ions at exit of the ion source region, the ion peak width became narrower by a factor of more than 10.View full abstractDownload PDF (320K) -
Susumu TAJIMA, Yuko HIROI, Satoshi NAKAJIMA, Nico. M. M. NIBBERING2003 Volume 51 Issue 4 Pages 466-471
Published: 2003
Released on J-STAGE: October 16, 2007
JOURNAL FREE ACCESSThe unimolecular metastable decompositions of ethoxytrimethylsilane ((CH3)3SiOCH2CH3; 1, MW: 118) and its fluorine analogue, 2,2,2-trifluoroethoxytrimethylsilane ((CH3)3SiOCH2CF3, 2; MW: 172) induced by electron ionization, have been investigated by use of mass-analyzed ion kinetic energy (MIKE) spectrometry and D-labeling. Both molecular ions are formed in low abundance. The fragmentation of 1+ · is different from that of 2+ · , except for the loss of CH3 from the corresponding molecular ions. The MIKE spectra of the [M - CH3]+ ions from 1+ · and 2+ · gave five and three fragment ions, respectively. Two of the five reactions for 1 leading to the formation of the ion at m/z 101, (CH3)2Si+OCH = CH2, and m/z 61, CH3Si+HOH, concern new mechanistic pathways, which were not described in previous reports. Skeletal rearrangement by among others F and CF3 migrations, occurs during the fragmentation of the [M - CH3]+ ions from 2+ · . The m/z 61 ions from 2+ · are both CH2OCF+ (or CH2FCO+ etc.) and CH3Si+HOH.View full abstractDownload PDF (197K) -
Shoji OKUNO, Akito SHIOKAWA, Kimiya OGAWA, Hidenobu IRIE, Masayoshi OH ...2003 Volume 51 Issue 4 Pages 472-476
Published: 2003
Released on J-STAGE: October 16, 2007
JOURNAL FREE ACCESSMethoxymethylbenzoguanamine resins were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and electrospray ionization mass spectrometry (ESI-MS). In the case of MALDI-TOF-MS measurements, they could not be characterized because fragmentation occurred considerably. On the ESI-MS measurement, optimization of needle voltage, cone voltage, and cationizing agent made their molecular-related ions intense with little fragmentation. Cluster ions were formed owing to hydrogen bond among their complex components. Gel permeation chromatography (GPC) was used to fractionate the resins. As a result, different oligomer components could be characterized in detail.View full abstractDownload PDF (200K)
TECHNICAL REPORT
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Ryuichi ARAKAWA, Seiji UEMURA, Toshio ICHIHARA, Itsuo KATAKUSE2003 Volume 51 Issue 4 Pages 477-480
Published: 2003
Released on J-STAGE: October 16, 2007
JOURNAL FREE ACCESSA handy electrospray ion source that made use of commercially available spray device for cosmetic foundation was designed and manufactured. The performance of the handy ion-source for electrospray ionization mass spectrometry (ESI-MS) was evaluated with a triple-stage quadrupole mass spectrometer. The ion intensities and distribution of multiply charged ions obtained in positive ion mass spectra of cytochrome c and polyethyleneglycol (PEG) showed that the handy ESI source exhibited the same performance as the existing ESI source.View full abstractDownload PDF (176K)
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