1998 Fiscal Year Final Research Report Summary
NITROGEN ISOTOPE GEOCHEMSITRY AT NANO-MOLE LEVEL
| Project/Area Number |
08404036
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
地球化学
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
SANO Yuji HIROSHIMA UNIV., FACULTY OF SCI., PROF., 理学部, 教授 (50162524)
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| Co-Investigator(Kenkyū-buntansha) |
TERADA Kentaro HIROSHIMA UNIV., FACULTY OF SCI., RES.ASSOC., 理学部, 助手 (20263668)
HIDAKA Hiroshi HIROSHIMA UNIV., FACULTY OF SCI., ASSOC.PROF., 理学部, 助教授 (10208770)
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| Project Period (FY) |
1996 – 1998
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| Keywords | NITROGEN / ISOTOPE / GEOCHEMISTRY / ARGON / HELIUM / CARBON / VOLCANIC GAS / GROUNDWATER |
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| Research Abstract |
We have improved noble gas mass spectrometer for nitrogen isotope measurement at sub-nano mole level. Low background high vacuume line was constracted for separation and purification of nitrogen and argon from rock and gas samples. In 1996, we started basic experiment of nitrogen isotope measurements using noble gas mass spectrometer. We also adjuested helium isotope mass spectrometer already installed at Hiroshima University for groundwaater and volcanic gas research. Separation of carbon dioxide from the samples was conducted using another vacuum line. In 1997, we succeeded in nitrogen isotope measurements at*O.3% using sub-namo mole sample. This is the best analytical system in the world at the time. Helium isotope and tritium analysis of groundwater samples were made at the same time using another vacuum line and mass spectrometer. These data are important for origin and evolution of groundwater in sedimentary basin. In 1998, we have developed argon measurement system using QMS.Bayed on the system, we could analyze argon isotopes and helium abundances in volcanic gas samples in addition to nitrogen and helium isotopes. We also improved gas extraction system from rock samples using a high vacuum ball mil. This is good for oceanic-basalt glass samples with low nitrogen abundances. Several important results were obtained by the system and they were published in international journals.
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