Development of mass spectrometry for nano-area

微量分析的最新发展已应用于测量小颗粒和矿物之间的晶界的地球化学和年代学数据。利用这些数据，我们可以阐明太阳系早期行星物质的演化过程。其中，微量同位素分析是其中最有力的技术。这些技术极大地改变了我们对地球科学的看法(Yurimoto，Kagaku，67,1997)。在微量同位素测量技术中，二次离子质谱仪(SIMS)是最引人注目的技术。然而，目前的SIMS方法仅限于离子微探针。因此，精确的同位素比值成像是困难的。在这项研究中，我们为SIM开发了新的固态离子成像器。我们证明了将SIMS与新开发的固态离子成像器相结合的离子显微镜的精度和空间分辨率可以扩展到具有Permil精度的二维同位素比成像。氧的同位素图谱清楚地揭示了黄长石中嵌有的尖晶石颗粒中的4%-160的分布，这些尖晶石颗粒来自碳质球粒陨石中的富钙铝包裹体。因此，这种表征技术为在微观尺度上观察同位素丰度的微小不均一性提供了“眼睛”。它很可能在地球、材料和生命科学研究中得到广泛的应用。

Recent development of microanalysis becomes applied to measure geochemical and chronological data from small particles and from grain boundary among minerals. Using these data, we can clarify evolution process of planetary materials at early solar system. Especially, micro-isotope analysis is the most powerful technique among them. Our earth science view is drastically changing by these techniques(Yurimoto, Kagaku 67, 1997). Among the micro-isotope measurement technique, secondary ion mass spectrometry(SIMS)is most impressive. However, present SIMS method is restricted to ion microprobe. Therefore, precise isotope-ratio imaging is difficult. In this study we develop new solid-state ion imager for SIMS.We demonstrate that the precision and spatial resolution of an ion microscope using SIMS coupled with a newly developed solid-state ion imager can be extended to two-dimensional isotope ratio imaging with permil precision. An isotopic map for oxygen clearly reveals the distribution of 4%-enrichment of 160 in spinel particles embedded in melilite from a Ca-Al-rich inclusion of a carbonaceous chondrite. This characterization technique thus provides the "eyes" to e small heterogeneity of isotope abundance in micro scale. It is likely to find broad application in earth, material, and life science research.