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Volume 29 (1981)
- Issue 4 Pages 345-
- Issue 3 Pages 221-
- Issue 2 Pages 161-
- Issue 1 Pages 51-
Volume 29, Issue 4
Displaying 1-5 of 5 articles from this issue
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ORIGINAL PAPERS
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Michio Yamawaki, Masaru Yasumoto, Chuichiro Nakano, Masayoshi Kanno1981 Volume 29 Issue 4 Pages 345-353
Published: 1981
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA new method to precisely measure ion counting efficiencies of electron multipliers (SEM) has been developed in order to improve the accuracy of the pulse counting vapor pressure measurement over the ultra low vapor pressure range. This method combines the pulse counting as well as the SEM output current measurement by use of a pulse height analyser with the SEM multiplication factor measurement by use of a Faraday cup system. By using the proposed method, the ion counting efficiencies of SEM for the ions except H2+ have been determined to be 1.0 for ion energies higher than a threshold value close to 7 keV. While, that of H2+ was 1.1. Further, a new method to precisely measure SEM multiplication factors using PHA has also been presented.View full abstractDownload PDF (646K) -
Yoshiaki Hidaka, Hiroyuki Kawano, Masao Suga1981 Volume 29 Issue 4 Pages 355-364
Published: 1981
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSIn order to examine the performance of the apparatus of a shock tube connected to a quadrupole mass spectrometer, the temporal variation of the O2 concentration in the oxidation of H2 was studied over the temperature range of 1300 — 2000 K, and the relationships between the induction period and reciprocal temperature were determined. The induction period and the temporal variation observed with O2 were compared with those calculated theoretically. The temperature of the gas molecules sampled under our experimental condition was found to be slightly lower than that calculated from the incident shock velocity. The cooling of the sample gas molecules by the boundary layer at the end wall of the shock tube was found to have little effect on the time history curves for O2 up to about 1 msec after heating by reflected shock waves.View full abstractDownload PDF (555K) -
Susumu Tajima, Tadashige Azami, Hisanobu Hashimoto, Yoshikazu Hasegawa ...1981 Volume 29 Issue 4 Pages 365-370
Published: 1981
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe formation of an [M+1]+ ion and the fragmentation of isopropyl o-toluate have been further investigated by measuring the mass spectrum of CD3C6H4COOC3H7(d3). The hydrogen atom, which is involved in the [M+1]+ ion formation, originates mainly from the three methyl groups in the molecule, in contrast to the previous conclusions.
In the intermediate ion at m/z 136, [C8H8O2]+, almost complete scrambling of the hydroxyl hydrogen atom with the methyl hydrogen atoms in tolyl group, not with the hydrogen atoms in benzene ring, takes place prior to the elimination of a water molecule from this m/z 136 ion. However, any hydrogen exchange reaction does not occur prior to the elimination of a hydroxy radical, which is a competing reaction with water loss, from the m/z 136 ion.
Furthermore, it is shown that the metastable decomposing [C7H7]+ ion at m/z 91 isomerizes to tropylium ion prior to the decomposition of this ion into the [C5H5]+ ion at m/z 65.View full abstractDownload PDF (334K) -
Masayo Murozumi, Seiji Nakamura, Kazuya Suga1981 Volume 29 Issue 4 Pages 371-379
Published: 1981
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSMinute amounts of silver, copper, cadmium, lead and thallium in whole blood can be determined simultaneously by isotope dilution surface ionization mass spectrometry using 107Ag, 65Cu, 116Cd, 206Pb and 203Tl as spikes. A whole blood sample weighing 2~4 g is treated with a mixture of nitric and perchloric acids and evaporated to form a white residue. The residue is dissolved in a dilute nitric acid and spiked with 10-10 mol of the spikes. Metal components are separated from foreign elements by being shaked with a dithizone chloroform solution from which they are back extracted into a nitric acid solution. An aliquot of the solution is loaded onto the center of a rhenium single filament, ionization unit of a Hitachi RMU-6 type mass spectrometer. The present method can detect the presence of 10-15 mol of thallium and 10-14 mol of the other metals in the sample. Their concentrations can be measured with the relative error better than several percent, the best in comparison with those by the methods applied to blood samples during the past ten years.View full abstractDownload PDF (546K) -
Mitsutoshi Ueda, Shigeru Yamashita, Teruo Hayakawa1981 Volume 29 Issue 4 Pages 381-387
Published: 1981
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSAge estmate for the biotite samples contained in six granitic rocks, three of which were from Kitakami massif and the other three were from Abukuma massif, was carried out by Rb-Sr method. After dissolving each biotite sample in 3N-HC1 solution, Rb and Sr were separated by an ion-exchange column. Quantitative analyses of Rb and Sr were carried out by isotope dilution method using 87Rb- and 86Sr-spikes, respectively.
Isotopic abundance ratio was mearsured using a modified Hitachi RMU-6 mass spectrometer with a triple-filament type surface ionization ion source. The initial ratio (87Sr/86Sr)0 was obtained from the provisional isochron, and the ages for each three biotite samples of Kitakami and Abukuma massifs were estimated to be 121×106 yr and 105×106 yr, respectively.View full abstractDownload PDF (456K)
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