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 Single Particle-ICPMS using Nu AttoM017

News 2 : Age Cytometry to decode the evolutional

                 sequence of the Earth

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

ICP-mass spectrometry (ICP-MS) can provide key information concerning the characterization and quantification of metallic nanoparticles.  To obtain quantitative information from very transient signals ((200400 ms) generated by single nano-particle, time slice (dwell times) of the measurements should be 50100 µs.  However, with the analaysis using such short dwell time, limited sensitivity and linearlity of the quadrupole based-ICPMS system make analysis of particles below 10 nm diameter difficult.  To overcome this, we are using high-sensitivity sector-based ICPMS (Nu AttoM) to determine the size of the NPs.  Dwell times can be minimised down to 10 µs, and the system has an ability to measure fast transient signals with count rates being >30 Mcps. With the present SP-ICPMS system, Au NPs <10 nm can be monitored.  Newly developed software (nQuant) for size distribution analysis for the NPs will be launched shortly.

Moreover, the analysis time for U-Th-Pb age determinations can be significantly reduced by a multiple ion counting system setup to 1 - 10 sec/spot with shorter analysis time enabling to obtain an age distribution of the zircons collected from a sample. This analytical approach allows to decipher the contribution of multiple geological events or multiple sources of the zircons.  The “age distribution” is a useful and conventional approach to understand the geological sequence underlying the sample formation.  Advantage of the age distribution analysis can be well demonstrated by the growth rate of the continental crust based on the U-Pb ages and Lu-Hf isotope systematics derived from >500 - 20,000 zircon grains [Rino et sl., 2004; Iizuka et al., 2006, 2007].

Obayashi et al. (2017) published in JAAS.

Move on the NPs
Age Cytometry
For Earth Metallomics

Poster Presentation

at MSSJ2017

Revised June 2017, hrt1

Research Highlight (LPS Report 2017)

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

Chronology

Metalloics

NanoParticles

Imaging

Analytical Techniques

Further enquiry : contact hirata (hrt1(at) eqchem.s.u-tokyo.ac.jp

Laser Ablation Workshop 2017 (@JASIS)

・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

ICPMS Seminar 2017

終了しました。多数の参加、有り難うございました。

Tokyo International Conference (@JASIS)

Royal Society of Chemistry (UK)

日本分析化学会(@東京理科大学)

日本地球化学会(@東京工業大学)

プラズマ分光分析研究会第100回講演会(@JASIS)

宇宙化学研究会(東工大、京大、東大合同シンポジウム)

学会シーズン到来