1
|
Kavasi N, Sahoo SK. Measurement of 90Sr and 87Sr/ 86Sr isotope ratio in Japanese cow milk sample using thermal ionization mass spectrometry. Food Chem 2024; 434:137421. [PMID: 37713756 DOI: 10.1016/j.foodchem.2023.137421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/17/2023] [Accepted: 09/04/2023] [Indexed: 09/17/2023]
Abstract
The pure beta emitter 90Sr (T1/2 = 28.8y) is a typical contaminant released by nuclear accidents and nuclear explosions. In the event of a nuclear disaster, it is crucial to identify radioactive pollutants quickly, to expedite the public's awareness of radiation exposure. In this work, a rapid 90Sr analysis protocol using thermal ionization mass spectrometry (TIMS) was developed for milk samples. With the improved sample preparation, Sr separation, and a newly developed TIMS method, 18 milk samples can be analyzed in less than 30 h and only 1 mL of cow milk is required for the complete analysis. The minimum detectable activity concentration of 90Sr is affected by the stable Sr concentration therefore, it is around 500 mBq·kg-1 (∼100ag·g-1). Additionally, 87Sr/86Sr isotope ratios (0.71518(9)-0.74132(4)) were determined for the first time in Japanese cow milk samples.
Collapse
Affiliation(s)
- Norbert Kavasi
- Fukushima Environmental Research Project, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology (QST), 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Environmental Sciences, Jožef Stefan Institute, 39 Jamova, Ljubljana 1000, Slovenia
| | - Sarata K Sahoo
- Fukushima Environmental Research Project, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology (QST), 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
| |
Collapse
|
2
|
Aoki J, Wakaki S, Ishiniwa H, Kawakami T, Miyazaki T, Suzuki K, Takagai Y. Direct Quantification of Attogram Levels of Strontium-90 in Microscale Biosamples Using Isotope Dilution-Thermal Ionization Mass Spectrometry Assisted by Quadrupole Energy Filtering. Anal Chem 2023; 95:4932-4939. [PMID: 36906855 DOI: 10.1021/acs.analchem.2c04844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
Although thermal ionization mass spectrometry (TIMS) has been employed for the high-precision analysis of isotope ratios, direct quantification of artificial mono-nuclide in the environment is difficult by even using isotope dilution (ID) due to the coexistence of the great magnitude of natural stable nuclides or isobars. In traditional TIMS and ID-TIMS, a sufficient amount of stable Sr doped on a filament is required to realize a stable and adequate ion-beam intensity (i.e., thermally ionized beams). However, the background noise (BGN) at m/z 90, detected by an electron multiplier, disturbs 90Sr analysis at low concentration levels due to peak tailing of a significant 88Sr ion beam dependent on the 88Sr-doping amount. Here, TIMS assisted by quadruple energy filtering was successfully employed for the direct quantification of attogram levels of an artificial monoisotopic radionuclide strontium-90 (90Sr) in microscale biosamples. Direct quantification was achieved by integrating the ID quantification of natural Sr and simultaneous 90Sr/86Sr isotope ratio analysis. Additionally, the measurement amount calculated by the combination of the ID and intercalibration was corrected for the net result amount of 90Sr by subtracting dark noise and the detected amount derived from the survived 88Sr, which are equivalent with the BGN intensity at m/z 90. Background correction revealed that the detection limits were in the range of 6.15 × 10-2-3.90 × 10-1 ag (0.31-1.95 μBq), depending on the concentration of natural Sr in a 1 μL sample, and the quantification of 0.98 ag (5.0 μBq) of 90Sr in 0-300 mg/L of natural Sr was successful. This method could analyze small sample quantities (1 μL), and the quantitative results were verified against authorized radiometric analysis techniques. Furthermore, the amount of 90Sr in actual teeth was successfully quantified. This method will be a powerful tool for measuring 90Sr in the measurement of micro-samples, which are required to assess and understand the degree of internal radiation exposure.
Collapse
Affiliation(s)
- Jo Aoki
- Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
| | - Shigeyuki Wakaki
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 200 Monobe Otsu, Nankoku, Kochi 783-8502, Japan
| | - Hiroko Ishiniwa
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 Japan
| | | | - Takashi Miyazaki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natushima, Yokosuka, Kanagawa 237-0061, Japan
| | - Katsuhiko Suzuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natushima, Yokosuka, Kanagawa 237-0061, Japan
| | - Yoshitaka Takagai
- Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima 960-1296 Japan
| |
Collapse
|
3
|
Honda M, Martschini M, Marchhart O, Priller A, Steier P, Golser R, Sato TK, Kazuaki T, Sakaguch A. Novel 90Sr analysis of environmental samples by Ion-Laser InterAction Mass Spectrometry. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:2732-2738. [PMID: 35789229 DOI: 10.1039/d2ay00604a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The sensitive analysis of 90Sr with accelerator mass spectrometry (AMS) was developed to advance environmental radiology. One advantage of AMS is the ability to analyze environmental samples with 90Sr/88Sr atomic ratios of 10-14 in following a simple chemical separation. Three different IAEA samples with known 90Sr concentrations (moss-soil, animal bone, Syrian soil: 1 g each) were analyzed to assess the validity of the chemical separation and the AMS measurement. The 90Sr measurements were conducted on the AMS system VERA combined with the Ion Laser InterAction Mass Spectrometry (ILIAMS) setup at the University of Vienna, which has excellent isobaric separation performance. The isobaric interference of 90Zr in the 90Sr AMS was first largely removed by chemical separation. The separation factor of Zr in two-step column chromatography with Sr resin and anion exchange resin was 106. The 90Zr remaining in the sample was effectively suppressed by ILIAMS. This procedure achieved a limit of detection <0.1 mBq in the 90Sr AMS, which is lower than typical β-ray detection. The agreement between AMS measurements and nominal values for the 90Sr concentrations of IAEA samples indicated that the new highly-sensitive 90Sr analysis in the environmental samples with AMS is reliable.
Collapse
Affiliation(s)
- Maki Honda
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
| | - Martin Martschini
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
| | - Oscar Marchhart
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
| | - Alfred Priller
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
| | - Peter Steier
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
| | - Robin Golser
- Faculty of Physics, Isotope Physics, University of Vienna, Währinger Strasse 17, Vienna 1090, Austria.
| | - Tetsuya K Sato
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
| | - Tsukada Kazuaki
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan
| | - Aya Sakaguch
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| |
Collapse
|
4
|
A part per trillion isotope ratio analysis of 90Sr/ 88Sr using energy-filtered thermal ionization mass spectrometry. Sci Rep 2022; 12:1151. [PMID: 35064171 PMCID: PMC8783016 DOI: 10.1038/s41598-022-05048-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 01/06/2022] [Indexed: 11/28/2022] Open
Abstract
Strontium-90 is a major radioactive nuclide released by nuclear accidents and discharge waste. Input of such radioactive nuclide into earth surface environment causes potential threat of long-term internal exposure when taken up by organism. Rapid and precise measurement of 90Sr in variety of environmental sample is important to understand the distribution and dynamics of 90Sr in the local environment after the accident and to assess the effect of radioactive nuclide inputs on bodies. However, previous 90Sr measurement techniques have drawbacks such as long measurement times for radiometry and high detection limits for mass spectrometry. Here we present a technique to accurately measure a significantly small amount of 90Sr in natural environmental samples using an energy-filtered thermal ionization mass spectrometry. Our technique achieved a 90Sr detection limit of 0.23 ag, which corresponds to a 90Sr activity of 1.2 µBq. The detection limit was lowered by two orders of magnitude compared with the previous mass spectrometric 90Sr analyses. The ability of our technique will expand the applicability of mass spectrometric 90Sr survey not only to the rapid 90Sr survey upon nuclear accidents but also to study a long-term environmental diffusion of radioactive materials using size-limited environmental and biological samples.
Collapse
|
5
|
Froidevaux P, Pittet PA, Bühlmann D, Bochud F, Straub M. Ion-imprinted resin for use in an automated solid phase extraction system for determining 90Sr in environmental and human samples. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07974-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractIn 90Sr analysis, determining its daughter 90Y improves the sensitivity of the radiometric methods. We found that to imprint a cavity made of [Y(6-(4-Vinylphenylcarbamoyl)pyridine-2-carboxylate)3] into a polystyrene skeleton yields a solid phase extraction resin with high selectivity for Y and Ln(III) over transition metals, alkaline, and alkaline-earth cations. We used this resin in an automated chromatography system to extract 90Y from milk, grass, vegetables, soil, sediments, water, human bones, and milk teeth samples. We found that the ion-imprinted resin could be used to separate light Ln(III) using a pH gradient, favoring the targeting of molecules used in nuclear medicine.
Collapse
|
6
|
Firouzabadi M, Jahromi HJ, Ardakani HA. Determination of 90Sr in sea shell: environmental monitoring. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07871-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
7
|
Kavasi N, Sahoo SK, Aono T. Analytical procedure using DGA-normal resin developed for separation of 90Sr from radiocaesium and other elements. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07662-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
8
|
Ito C, Shimode R, Miyazaki T, Wakaki S, Suzuki K, Takagai Y. Isotope Dilution-Total Evaporation-Thermal Ionization Mass Spectrometric Direct Determination of Radioactive Strontium-90 in Microdrop Samples. Anal Chem 2020; 92:16058-16065. [PMID: 33172270 DOI: 10.1021/acs.analchem.0c03673] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermal ionization mass spectrometry (TIMS) was used to directly quantify an ultratrace of radioactive 90Sr in microliter droplet samples. No chemical separation was required in removing isobaric interferences on M = 90 such as 90Zr and organic molecules in the mass spectrum because the difference in evaporation and ionization (emission) temperature among organic molecules, Zr and Sr, allows us to control the emission manner and significantly suppress the isobaric interferences. Direct quantification was achieved by improving the intercalibration of Faraday cups and ion counting in an isotope dilution (ID) method. Furthermore, the use of a total evaporation method (TE) enhanced the detection efficiency by the complete collection of the 90Sr ion beam from the samples and minimized the complexity of the fractionation effect in the isotope ratio calculation. In this study, 1 fg of 90Sr (equal to activity of 5 millibecquerel (mBq)) in a very low-volume sample with 108 times greater isobaric interference from 90Zr was successfully measured using the proposed ID-TE-TIMS method. The limit of detection was 0.029 fg (equal to 0.15 mBq) without any preconcentration. To demonstrate the wide usability of this method, low-volume samples of tears, eyelashes, saliva, environmental standards, and water samples (i.e., seawater and ground water) were analyzed within 1 h. The relationship of the measured values between this ID-TE-TIMS method and a radiometric analysis was shown to have good linearity.
Collapse
Affiliation(s)
- Chihiro Ito
- Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
| | - Ryoya Shimode
- Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
| | - Takashi Miyazaki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natushima, Yokosuka, Kanagawa 237-0061, Japan
| | - Shigeyuki Wakaki
- Kochi Institute for Core Sample Research, JAMSTEC, 200 Monobe Otsu, Nankoku, Kochi 783-8502, Japan
| | - Katsuhiko Suzuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natushima, Yokosuka, Kanagawa 237-0061, Japan
| | - Yoshitaka Takagai
- Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan.,Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
| |
Collapse
|
9
|
Accurate and precise determination of 90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry. Sci Rep 2019; 9:16532. [PMID: 31712653 PMCID: PMC6848187 DOI: 10.1038/s41598-019-52890-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/24/2019] [Indexed: 11/08/2022] Open
Abstract
A novel method for the determination of ultra-trace level 90Sr has been recently developed applying thermal ionization mass spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of 90Zr) from the samples followed by determination of 90Sr/88Sr abundance sensitivity (2.1 × 10−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For 90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg−1 (2.2 ± 0.1 fg g−1) and 99.9 ± 5.0 Bq kg−1 (19.5 ± 1.0 fg g−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g−1 and 2.5 ± 0.1 µg g−1 while the 90Sr/88Sr isotope ratios were 6.47 ± 0.17 × 10−8 and 9.04 ± 0.45 × 10−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of inorganic mass-spectrometry, 90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.
Collapse
|