PGE (PLATINUM GROUP ELEMENTS) COSMOCHEMISTRY FOR METALLIC METEORITIES

PGE（铂族元素）金属流星的宇宙化学

• 批准号: 07554023
• 负责人: HIRATA Takafumi
• 金额: $ 10.43万
• 依托单位: TOKYO INSTITUTE OF TECHNOROGY
• 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 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07554023/
• 关键词: ICP MASS SPECTROMETRY; AMI ION DETECTOR; MULTIPUL COLLECTION; ISOTOPE GEOCHRONOLOGY; METEORITE FORMATION; 質量分析法; ファラデー検出器; 高精度同位体分析; 高感度イオン検出器; AMI検出器; 次世代検出器; 高感度検出器; イオン検出器; マルチコネクション

Mass spectrometer using inductively coupled plasma (ICP) as an ion source (ICPMS) is now accepted as a versatile analytical technique for elemental and isotopic analysis. However ICPMS had been most frequently utilised as a tool for the sensitive elemental analysis, and examples for isotopic anaylsis are not many. This is mainly because that the precision of isotopic abundance ratio achieved by present quadrupole analyzer based-ICPMS (ICP-QMS) is not always sufficient for the purchases of geological dating and nuclear industries. It has been suggested that the precision and accuracy of the isotopic measurement achieved by the ICP-QMSare severely restricted from the low performance of detector, high background contribution and/or large mass discrimination effect. Recently the measurement of isotopic ratios by multiple collector-ICP massspectrometry (MC-ICPMS) has been described. Multiple collectors allow eachisotope to be monitored simultaneously, and thus removing signal instability as … More a limitation on analytical precision. Furthermore, the analogue detector mode using Faraday cups as ion detector can offer better dynamic rangs and analytical precision compared with the detection system applied to most ICP-QMS instrument (high gain pulse counting mode). Relative standard deviations of 0.005-0.01% (s-sigma) could be typically achieved by the MC-ICPMS.Levels of analytical precision and accuracy achieved by the MC-ICPMS was comparable to those exhibited by thermal ionisation mass spectrometry (TIMS). However, enhancement of elemental sensitivity of the instrument is strongly required for the further progress of isotope geosciences using a MC-ICPMS.Recently, novel ion detector capable of directly detecting and digitizing on images were described by Matsumoto et al. (1993). This two dimensional ion detector which composed of 250,000 pixels, is a stacked photodiode type Amplified MOS Intelligent Imager (AMI) and was first applied to the secondary ion mass spectrometry (SIMS). Operational principles of AMI was based on the storage and detection of electrons in silicon photodiode generated by ion bombardments having kiloelectronvolt energy. The system applied to a MC-ICPMS instrument succeeded in directly detecting secondary ions with an excellent linearity and a wide dynamic range of four orders of magnitude for each pixel. The unique features shown in the MC-ICPMS analysis clearly demonstrate the AMI ion detector enables us to detect multiple isotopes which can improve the analytical precision of the isotope measurement. Moreover, sensitivity of AMI detector demonstrated by the ICPMS measurement were found to be at least 5 times higher than those of the Faraday detectors. This indicates that the AMI ion detector is suitable to most powerful high gain ion detector for the multiple collection of isotopes. Less

电感耦合等离子体（ICP）质谱仪作为一种多功能的元素和同位素分析技术已被广泛接受。然而，ICPMS最常用作灵敏元素分析的工具，同位素分析的例子并不多。这主要是因为目前基于四极杆分析仪的ICP-QMS（ICP-QMS）所获得的同位素丰度比的精度不足以满足地质定年和核工业的需求。ICP-QMS同位素测量的精密度和准确度受到探测器性能低、背景贡献大和质量分辨效应大的限制。近年来，多收集器-ICP质谱法（MC-ICPMS）测量同位素比值已被描述。多个收集器允许同时监测每个同位素，从而消除信号不稳定性， ...更多信息 对分析精度的限制。与大多数ICP-QMS仪器采用的检测系统（高增益脉冲计数模式）相比，采用法拉第杯作为离子检测器的模拟检测器模式具有更好的动态范围和分析精度。MC-ICPMS的分析精密度和准确度水平与热电离质谱（TIMS）相当。然而，提高仪器的元素灵敏度是利用MC-ICPMS进行同位素地球科学研究的进一步发展所迫切需要的。该二维离子探测器由25万像素组成，是一种叠层光电二极管型放大MOS智能成像器（AMI），并首次应用于二次离子质谱（西姆斯）。AMI的操作原理是基于存储和检测由具有千电子伏能量的离子轰击产生的硅光电二极管中的电子。该系统应用于MC-ICPMS仪器成功地直接检测二次离子具有良好的线性和宽的动态范围的四个数量级的每个像素。MC-ICPMS分析中显示的独特功能清楚地表明，AMI离子检测器使我们能够检测多种同位素，这可以提高同位素测量的分析精度。此外，由ICPMS测量表明的AMI探测器的灵敏度被发现比法拉第探测器的灵敏度高至少5倍。这表明AMI离子探测器适用于大功率高增益离子探测器的同位素多次采集。少

项目成果

平田岳史: "ICP質量分析計による微量元素同位体分析〜Rolling stone gathers no moss〜" 地球化学.

Takeshi Hirata：“使用ICP质谱仪进行微量元素同位素分析~滚石不生苔~”地球化学。

Barrat, J.A., Keller, F., Amosse J., Taylor, R.N., Nesbitt, R.W.and Hirata, T.: "Determination of rare earth elements in sixteen silicate reference samples by ICP-MS after Tm addition and ion-exchange separation" Geostandards Newsletter. 20. 133-139 (1996

Barrat, J.A.、Keller, F.、Amosse J.、Taylor, R.N.、Nesbitt, R.W. 和 Hirata, T.：“在添加 Tm 和离子交换分离后，通过 ICP-MS 测定 16 个硅酸盐参考样品中的稀土元素”

Takafumi Hirata,R.W.Nesbitt: "U-Pb Isotope Geochronology of Zircon:Evaluation of the Laser Probe-Induotively Coupled Plasma Mass Spectrometry Technique" Geochim.Cosmochim.Acta.59. 2491-2500 (1995)

Takafumi Hirata，R.W.Nesbitt：“锆石的 U-Pb 同位素地质年代学：激光探针耦合等离子体质谱技术的评估”Geochim.Cosmochim.Acta.59。

Takafumi Hirata: "Lead Isotopic Analysis using Multiple Collector-Inductively Coupled Plasma Mass Spectrometry coupled with Modified External Correction Method for Mass Discrimination Effect" Analyst. 121. 1407-1411 (1996)

Takafumi Hirata：“使用多收集器感应耦合等离子体质谱法结合改进的质量辨别效应外部校正方法进行铅同位素分析”分析师。

Takafumi Hirata,Robert W.Nesbitt: "U-Pb Isotope Geochronology of Zircon : Evaluation of the Laser Probe-Inductively Coupled Plasma Mass Spectrometry Technique" Geochim.Cosmochim.Acta.59. 2491-2500 (1995)

Takafumi Hirata，Robert W.Nesbitt：“锆石的 U-Pb 同位素地质年代学：激光探针感应耦合等离子体质谱技术的评估”Geochim.Cosmochim.Acta.59。