An Attempt for Mineral Identification by Means of Secondary Ion Mass Spectrometry

二次离子质谱法矿物鉴定的尝试

• 批准号: 07504007
• 负责人: NISHIMURA Hiroshi
• 金额: $ 4.74万
• 依托单位: Naruto University of Education
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07504007/
• 关键词: Direct sample loading surface ionaization ion source; Mass spectrometry; Isotopic analysis; Mineral identification; Secondary ion mass spectrometry; 直接塗布型表面電離イオン源; 同位体比; SIMS; 軽元素同位体比

During this project, we first tried to find the grouping of mass spectral patterns to take a simultaneous characterization for rock-forming minerals during isotopic analysis by means of secondary ion mass spectrometry (SIMS). It is necessary to polish and wash the sample surfaces before mounting it in SIMS.Any terrestrial contamination could not be avoided through these processes. Especially, mass spectral peaks corresponding to alkaline elements were observed. These elements could not be stoichiometrically present, but might be originated from polishing powder or washing water. Such a contamination is not so troublesome for the isotopic analysis of terrestrial rock or mineral samples, because mass spectrometer can separate this kind of isotpic contamination with usual mass resolving power. However, in case of mineral identification, the reproduction of mass spectral peak patterns for the stoichiometrical compositions of minerls is needed. Furthermore, this kind of contamination causes … More serious problems for the analysis of the extraterrestrial matter, for example meteorite.For the purpose of corss-checking of mass spectrum, we have attempted to construct a new mass spectrometer with a direct sample loading surface ionization ion source. We named this new type of mass spectrometer "Direct sample Loding surface ionization ion source Mass Spectrometer (DLMS)." It is free from terrestrial contamination. For this ion source, a small portion (about 1mg weight) of fresh broken sample is picked out, and is directly loaded on a boat filament of tantalum for evaporation. Then, evaporated atoms are ionized on the surface of rhenium flament by surface ionization. Here the surface contamination from terrestrial environment during sample loading can happen. But this contamination is surfacial as compared to the polished sample in SIMS,and it can be removed by preheating the sample in vacuum for a few hours.With DLMS,rock-forming minerals containing Li, B,Mg, Si, Ti etc.were isotopically analyzed and checked for characteristic mass spectral patterns. We have preliminarily obtained the possible positive correlations between mass spectral patterns of the minerals and their chemical compositions. Less

在这个项目中，我们首先尝试通过二次离子质谱法（SIMS）在同位素分析过程中找到质谱模式的分组，以同时表征形成岩石的矿物。在将样品安装到SIMS中之前，有必要对样品表面进行抛光和清洗。任何陆地污染都不能通过这些过程来避免。尤其是碱性元素的质谱峰。这些元素不可能在化学计量上存在，但可能来自抛光粉或洗涤水。这种污染对于陆地岩石或矿物样品的同位素分析来说不是那么麻烦，因为质谱仪可以用通常的质量分辨能力分离这种同位素污染。然而，在矿物鉴定的情况下，需要再现矿物的化学计量成分的质谱峰模式。此外，这种污染会给分析地外物质带来更严重的问题，比如陨石。为了对质谱进行交叉检查，我们尝试构建了一种具有直接载样表面电离离子源的新型质谱仪。我们将这种新型质谱仪命名为“直接载样表面电离离子源质谱仪（DLMS）”。它不受陆地污染。对于这种离子源，挑选出一小部分（约1mg重量）新鲜破碎的样品，并直接装载在钽的船丝上进行蒸发。然后，蒸发的原子通过表面电离在铼火焰表面电离。在这里，在样品加载过程中可能会发生来自陆地环境的表面污染。但是，与SIMS中的抛光样品相比，这种污染是表面的，可以通过在真空中预热样品几个小时来去除。利用DLMS对含Li， B,Mg, Si， Ti等的造岩矿物进行了同位素分析，并对其特征质谱图进行了检查。初步得出了矿物的质谱模式与其化学成分之间可能存在的正相关关系。少

项目成果

Mamoru Murata: "X-Ray Fluorescence(XRF)Analysis of Refractories" Taikabutsu Overseas. 16巻・4号. 6-12 (1996)

Mamoru Murata：“耐火材料的 X 射线荧光（XRF）分析”Taikabutsu 海外，第 16 卷，第 4. 6-12 期（1996 年）。

西村 宏 他: "隕石中のリチウム同位体比" J.Mass Spectrom.Soc.Jpn.44. 1-11 (1996)

Hiroshi Nishimura 等人：“陨石中的锂同位素比率”J.Mass Spectrom.Soc.Jpn.44 (1996)。

Hiroshi Nishimura, Kumiko Kishi, Hiroaki Ozawa, and Mamoru Murata: "Lithium Isotope Ratios in Meteorites" J.Mass Spectrom.Soc.Jpn.44. 1-11 (1996)

Hiroshi Nishimura、Kumiko Kishi、Hiroaki Ozawa 和 Mamoru Murata：“陨石中的锂同位素比率”J.Mass Spectrom.Soc.Jpn.44。

西村宏他: "隕石中のリチウム同位体比" J.Mass Spectrom.Soc.Jpn.44巻・1号. 1-11 (1996)

Hiroshi Nishimura 等人：“陨石中的锂同位素比率”J.Mass Spectrom.Soc.Jpn.44，No.1-11 (1996)。