UT

Measure what is measurable, and make measurable what is not so.       - Galileo Galilei

Software for Imaging

基盤研究(A)研究業績

News 1 : Setup LAMIS Technique

Simultaneous detection of 206Pb and 207Pb has been made by dual-Daly ion counters equipped on multiple collector-ICP-mass spectrometer (MC-ICPMS).  Long term stability, evaluated by the relative changes in the measured signal intensity for over the 10 hours period, was better than 0.4%, which was significantly smaller than that achieved by the conventional ion counting technique using the electron multipliers.  The resulting higher gain stability could be due to clear difference in the peak heights between the noise components and the signals from collectors.  After the correction for the counting loss due to the collector dead time, the Daly ion counter is capable to accept the signal intensities as high as 107 cps.  This indicates that the crossover of the measurable range can exceed at least three orders of magnitude between the Daly ion counters (100 – 107 cps) and the Faraday collectors (103 – 1010 cps), suggestive of easier cross calibration between the collectors.  With the present dual-Daly ion counters, in-situ 207Pb/206Pb ratio measurements have been made on glass standards (NIST SRM 614)  by means of the laser ablation sampling technique.

Imaging for U-Th-Pb isotopes were measured by ArF Excimer laser ablation (ESI, NWR193) coupled with quadrupole-based ICP-mass spectrometer (Thermo Fisher Scientific,  iCAPQc).  Images were obtained by the repeated analysis of line profiling, and the resulting signal intensity profile were vidualised by iQuant2 software, specially designed for the LA-ICPMS by the imaging team at TITech and Kyoto University.  This software is available on request.  Please contact any contributors of this presentation.  Several unique features can be derived with the latest version (iQuant2+), such as chemical analysis, bird-view monitoring, as well as user friendly interface.

iQuant2 software is free of charge : contact Tak Hirata for further information.

基盤研究(A)研究業績

Seminar / Presentation

・日本地球惑星科学連合大会(5月、JpGU)

・日本質量分析学会討論会(5月、つくば)

・大阪工研記念講演会(5月、大阪)

・日本地球化学会年会(9月、東京工業大学)

・日本分析化学会(9月、東京理科大学)

・レーザーアブレーションワークショップ(9月、幕張)

iQuant2+

will be coming soon (January, 2017 launching)

Journal of the Mass Spectrometry Society of Japan Vol. 63 (2015) No. 6

無機質量分析計を用いた元素イメージング

平田 岳史1), 坂田 周平1), 槇納 好岐1), 小原 聖也1), 向山 翔1), 服部 健太郎1), 杉浦 悠毅2,3), Thomas WALCZYK4), 昆 慶明5), 折橋 裕二6), 鈴木 敏弘7)

International Conference

Asia Pacific Winter Conference at Matsue-city (November, 2017)

Post Conference of the APWC2017 at UTokyo

Simultaneous detection of 206Pb and 207Pb ions has been made by multiple-ion counting ICP-mass spectrometry using two Daly detectors (MC-ICPMS).  To evaluate the long-term gain stability of the detectors, the 135Ba/138Ba and 136Ba/138Ba ratios have been measured by combination of Daly and Faraday detectors (135Ba(D)/138Ba(F)) and electron multiplier and Faraday detectors (136Ba(EM)/138Ba(F)).  The measured 136Ba(EM)/138Ba(F) ratio changed 2% through the 10-hours analysis, whereas the 135Ba(D)/138Ba(F) showed smaller changes (<0.5%) over the 10-hours period, demonstrating that the Daly detector could provide better gain stability against conventional electron multipliers.  After the correction for the counting loss due to dead time, the Daly detector is capable to accept the signal intensities as high as 107 cps.  This indicates that the overlap of the analysis range, between the Daly detector (100 – 107 cps) and the Faraday detector (104 – 1010 cps), would be at least two orders of magnitude, suggestive of easier cross calibration of the collector gain between the detectors.  With the present two Daly detectors, in-situ 207Pb/206Pb ratio measurements have been made on Nancy 91500 zircon standard through the sample introduction technique using laser ablation.  The overall analytical precisions and the relative deviation from the literature value was 5.1% and 0.04%, respectively.  The data obtained here demonstrate clearly that the LA-MC-ICPMS technique equipped with the Daly detectors would become a major analytical tool for the in-situ U-Pb geochronology.

News 3 : 日本質量分析学会2017論文賞をいただきました(5月18日)

News 4 : Springer Nature社から「Metallomics」

            (編集:小椋康光・平田岳史)が発刊されました。

Variety of noble metals or transition metals are increasingly used in many industries, resulting in their invasion to our life area. Semimetals/metalloids are frequently used around us because of their unique physico-chemical properties. However, their biological, physiological and toxicological impact are not fully understood yet. For instance, although arsenic is well known as a historical toxic substance, the molecular mechanism underlying the arsenic toxicity is still unclear.  Selenium acts as an essential element for animals in spite of its higher toxicity than arsenic.  The metabolic pathway of selenium is one of puzzles. Tellurium, antimony, tin, germanium, indium and other semimetals/metalloids can also have unique toxic and physiological effects. Further, the recent developments in analytical techniques for monitoring these semimetals/metalloids seems to be also attractive topic. We have reached to the conclusion that the themed issue of "Metallomics" is good timing to focus on biological effect of semimetals/metalloids.

Guest Editors : Professor Yasumitsu Ogra and Professor Takafumi Hirata

Obayashi et al. (2017) published in JAAS.

Move on the NPs
Earth Metallomics

Revised October 2017, hrt1

Research Highlight (LPS Report 2017)

(Click picture to download posters : approximate file size 1 MB)

Chronology

Metalloics

NanoParticles

Imaging

Analytical Techniques

・プラズマ分光分析研究会(9月、幕張)

・質量分析学会同位体比部会(11月、伊東)

・Asia Pacific Winter Conference on Spectrochemistry (11月、松江)

・APWCポストカンファレンス(11月、東京)

Award

News 3 : 山下君が日本分析化学会若手ポスター賞を受賞しました(9月12日)

News 2 : Imaging of Nanoparticles

UTokyo

Award

Nanoparticles are the particles between 1 and 100 nanometers (nm) in size with a surrounding interfacial layer.  A bulk material should have constant physical properties regardless of its size, but at the nano-scale size-dependent properties are often observed.  For the unique physicochemical features, nanoparticles are of great scientific interest.


The nanoparticles have been widely used in the various research fields, such environmental, clinical, medical or material sciences.  However, the nanoparticles present possible dangers, both medically and environmentally.  Most of these are due to the high surface to volume ratio, which can make the particles very reactive or cataytic (Ying and Jackie, 2001).  They are also able to pass through a cell membranes in organisms, and their interactions with biological systems are poorly unveiled.  There are great concerns that the nanoparticles can be enriched in the creatures through a bioconcentration.  To investigate the behavior of the nanoparticles within the plants and animals, new analytical technique with high sensitivity and high analysis throughout for the nanoparticles of various types is desired.

With the combination of high sensitivity sector-based ICPMS system and in-house software for the automated detection of very transient signals obtained from single NP grain, we can now detect the Au NPs with the size of 5 nm, which was significantly smaller than the reported detection limits of the NPs (i.e., 10 nm)3.

The LAMIS

Program by Yoshikuni, Obayashi, Yamashita et al. (2017)

Since the born of our University at 13.8 Gyr ago, almost all the heavy elements have been episodically produced through the various nucleosynthetic processes such as e- (equilibrium), s- (slow) or r- (rapid) processes.  Both the origin and transport mechanism of the source materials of the solar system are still unknown.  We are going to unveil the evolution history BEFORE the Solar System Formation.


Brick walls are there for a reason: they let us prove how badly we want things

--- Randy Pausch