1999 Fiscal Year Final Research Report Summary
A New Gas Chromatography Mass Spectrometer Equipped with a Hyperthermal Surface Ionization as a Ion Source
| Project/Area Number |
09554052
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
分離・精製・検出法
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| Research Institution | Oyama National College of Technology |
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Principal Investigator |
KISHI Hiroshi Oyama National College of Technology, Department of Materials Chemistry and Bioengineering, Professor, 物質工学科, 教授 (60042529)
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| Co-Investigator(Kenkyū-buntansha) |
永柳 衍 島津製作所(株), 第一分析事業部, 部長
FUJII Toshihiro National Institute for Environmental Studies, Department of Chemical Environment, Deputy Director, 化学環境部, 上席研究官 (60109907)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Surface Ionization / Aerodynamical Acceleration of Molecules / GC / MS / Kinetic Energy / Detector |
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| Research Abstract |
A new gas chromatography-mass spectrometer system equipped with a hyperthermal surface ionization (HSI) system as an ion source is described. The HSI is a combination of molecular acceleration in supersonic molecular beam (SMB) and surface ionization (SI). To examine the effect of various parameters on operational characteristics of this system, ionization mechanism of HSI was studied.
In the article No.1, we defined the "γ-factor" as the fraction of the kinetic energy used for ionization, and was estimated from two unique Ek and Ts correlation with measured ion current, where, Ek is the molecular kinetic energy and Ts is the surface temperature. The γ values estimated from the two independent methods agreed fairly well. Deduced conclusions are : (1) the kinetic energy is partially used for ionization, (2) the efficiency of energy conversion (γ value) varies from molecule to molecule, (3) the energy required for surface ionization is associated with the energy gap due to the difference in ionization energy (IE) and the surface work function (ψ).
In the article No.2, a method to estimate the conversion rate of the molecular kinetic energy used for the excitation of the vibrational degrees in the molecule is described. The experimental results obtained by this method led to the following conclusions : (1) The kinetic energy is partially used for excitation of the vibrational degree, and the conversion rate amount to some 30 %. (2) The total rate amounts to some 50 % of the initial kinetic energy converted to the internal energy of the molecule. (3) There is only a very small probability of surface thermal energy being transferred to the internal energy of the molecule.
The article No.3 summarizes the recent development in surface ionization (SI) of organics. This includes (1) basic principles, (2) instrumentation, (3) response characteristics, and (4) applications.
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