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Volume 40, Issue 1
Displaying 1-9 of 9 articles from this issue
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REGULAR PAPERS
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Hiroshi MIMA1992 Volume 40 Issue 1 Pages 1-7
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSA new mass spectrometer of non-magnetic type which was proposed previously by the author (ref. 1), was examined experimentally. One of the anticipation in the preceding article is that the resolving power of the mass spectrometer increases in proportion to the transit time of the detecting ions in the rf field. To confirm this property experimentally, two types of the mass spectrometer tube were prepared. The first tube was prepared to examine the property that the resolving power is proportional to the recoiling number N of the motion of ions. The case of N=1 to 3 was studied with a demountable ion collector. The other test tube (N=2) was designed to have the large electrode gap of d2 (>d1). With the second tube, a factor of 1.5 increase in the resolving power over the conventional tube (d1=d2) will be obtained. The resolving power obtained with two types of the mass spectrometer showed good agreement with theoretically estimated values, respectively.
This mass spectrometer is able to operate with frequency sweep method, and the relative transmission probability (relative ion current vs. mass to charge ratio) will be independent of the ion's mass. The result obtained showed constant ion transmission probability in the mass range larger than m/z=40, but it was decreased in the smaller mass range. The reduction is caused by the large rise time of the rf pulse used here. It was also confirmed experimentally that the resolving power does not be affected by the velocity distribution of beam ions.View full abstractDownload PDF (535K) -
Mitsuru ASANO, Yoshinari KATO, Toshio HARADA, Yasuo MIZUTANI1992 Volume 40 Issue 1 Pages 9-15
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSAlkali metaborate monomer and dimer vapors have been studied thermodynamically, and these results have been compared with those for alkali halides. The ratios of mean dissociation energies for one M-BO2 bond in the M2(BO2)2(g) dimers to dissociation energies for one M-BO2 bond in the MBO2(g) monomers are almost constant for all the alkali metals (M) and an average value is 0.63±0.01. This value is just equal to the corresponding ratios for halides. For the dimerization reactions of MBO2(g), both free energies and enthalpies decrease in going from M=Li to M=Cs, while entropies are almost constant. A similar tendency can be seen in chlorides. For the alkali-alkali exchange reactions in the dimers, free energies, enthalpies, and entropies are very small for both metaborates and chlorides. Excess stabilities in the alkali-alkali mixed-dimer formations are explained from the correlation with the increases in the alkali cation-cation repulsion energies.View full abstractDownload PDF (480K) -
Koichi OGURA, Takashi ARISAWA, Takemasa SHIBATA1992 Volume 40 Issue 1 Pages 17-23
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSThe metastable gadolinium atoms at 533 cm-1 were photoionized by pulsed laser beams after decreasing the population of 160Gd at 533 cm-1 by optical pumping using a continuous wave ring dye laser. Mass spectra of the ionized gadolinium atoms showed that an abundance ratio of 160Gd decreased from natural isotope abundance of 21.8% to 1%. This result demonstrates the isotope separation by photoionization of the atoms after decreasing of the photoionized level population of selected isotope using optical pumping.View full abstractDownload PDF (367K) -
Kazuo TSUJIMOTO, Mamoru OHASHI, Terumitsu HORI, Masakatsu WATANABE1992 Volume 40 Issue 1 Pages 25-31
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSCarotenes extracted from a green alga, Bryopsis maxima, were determined to consist of α-carotene as a major fraction of more than 99% by means of B/E constant linked scanning, HPLC with a Ca(OH)2 column and the absorption spectrum. The linked scanning showed the fragmentation characteristic of α-carotene, whose reaction has been well-documented as retro Diels-Alder fragmentation.View full abstractDownload PDF (396K) -
Masao MINAGAWA, Saho EGAWA, Yuko KABAYA, Kyoko KARASAWA-TSURU1992 Volume 40 Issue 1 Pages 47-56
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSEvaluation was made for carbon and nitrogen stable isotope analyses of amino acids which were hydrolyzed from biological samples. Alteration of isotopic compositions during chemical preparations was studied in incorporation with organic solvent, acid hydrolysis, and ion-exchange chromatography. Based on such assessment, analyses of isotope compositions of single amino acids were made for collagen and plant protein. The carbon isotope composition of soybean protein showed consistent pattern with algal amino acids. Similarity was also found in the intermolecular relationship of δ13C and δ15N between collagen and soybean protein.View full abstractDownload PDF (672K)
TECHNICAL REPORTS
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Naoki OGURI, Akira ONISHI, Sigeki UCHINO, Keiji HASHIMOTO, Xigao JIN1992 Volume 40 Issue 1 Pages 33-39
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSA multi-function Curie-point direct injection probe to be coupled to a mass spectrometer was developed. The probe can be used for pyrolysis, chemical reactions and trap-and-purge analysis. In this paper, two injection methods are described, one involves methylation and the other involves trap-and-purge in the probe.
Terephthalate was methylated by tetramethylammonium hydroxide and injected simultaneously by Curie-point heating at 500°C for 3 sec.
The trap-and-purge method was used to inject a low molecular weight substances, such as HPLC fractions and concentrated atmospheric hydrocarbons. This probe provided a new way to identify polar, volatile, and HPLC samples without pretreatment.View full abstractDownload PDF (378K) -
Naoki OGURI, Akira ONISHI, Sigeki UCHINO, Keiji HASHIMOTO, Xigao JIN1992 Volume 40 Issue 1 Pages 41-46
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSA Curie-point direct injection probe to be coupled to a mass spectrometer was developed. Its flash heating, wide range temperatures (160~1,040°C), reproducible temperature (±1°C) and direct connection to the ion source of a mass spectrometer were effectively applied to the polymer analysis. Pyrolysis-mass spectrometry by use of this device enabled the discrimination between a copolymer and the corresponding blended polymer of {poly(styrene) and poly(fluorostyrene)}, because of the decreased secondary reactions among the pyrolyzates, when compared with pyrolysis gas chromatography (Py-GC). As compared with Py-GC, the new technique can elute larger pyrolyzates, only within a few minutes, which provide compositional and structural information of the polymer samples. The rapid analysis of an additive in a polymer is also reported in this paper.View full abstractDownload PDF (365K) -
Hiroshi MIZUTANI, Donald A. McFARLANE, Yuko KABAYA1992 Volume 40 Issue 1 Pages 57-65
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSNitrogen and carbon isotope ratios were studied in a stratified deposit of guano of Mexican Free-tailed bats in Eagle Creek Cave, Arizona, U.S.A. Little diagenetic change was observed over the 25-year time span of the guano deposit. High aridity and reduced circulation of air in the cave are hypothesized to have slowed the normally rapid decomposition of the excreta and the subsequent escape of resultant ammonia. The results suggest the high dependency of the speed of diagenetic change on specific physical and other conditions of the caves and indicate that great care need be exercised in the interpretation of the isotopic ecogeochemistry of old guano. Relative contribution of C3 photosynthesis to the food chain leading to the bats was estimated to be more than C4 photosynthesis.View full abstractDownload PDF (620K) -
Hiroshi MIZUTANI, Donald A. McFARLANE, Yuko KABAYA1992 Volume 40 Issue 1 Pages 67-82
Published: 1992
Released on J-STAGE: July 20, 2007
JOURNAL FREE ACCESSCarbon and nitrogen isotope ratios were measured for various ecogeochemical samples relevant to bat guano ecosystems. In particular, ca. 800-year-old subfossil guano from Jackson's Bay Cave Compex, Jamaica, yielded ratios similar to the modern guano from other Jamaican bat caves but quite different from modern guano of the same area. Diagenetic change and differences in bat food habits were unlikely explanations for the observation. Instead, insects that feed on C4 and CAM plants were the main prey for the bats in present Jackson's Bay area, while the ultimate source of organic matter for bats in other Jamaican caves and for the bats that deposited guano in Jackson's Bay Great Cave ca. 800 years ago were C3 photosynthesis. We suggest that the isotopic data indicate that the surrounding environment experienced a significant mesic episode in the recent past. This mesic climate would have supported a large population of bats, which in turn would have accumulated significant quantities of guano. The subsequent return to the more xeric conditions prevailing today would have caused a drastic reduction in bat population size and effectively ended significant guano accumulation. Fossil guano from Carlsbad Caverns, New Mexico, U.S.A., suggested that native C3 plants might have been more abundant in Wisconsinan than today. Isotope analyses of old guanos from Bat Cave in Grand Canyon National Park, Arizona, U. S. A., found a possible implication that C4 photosynthesis might have had contributed a little more to the bats' diet in the cave before the construction of Glen Canyon Dam.View full abstractDownload PDF (1222K)
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