Production and purification of molecular 225Ac at CERN-ISOLDE
The radioactive nuclide <sup>225</sup>Ac is one of the few promising candidates for cancer treatment by targeted- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math> -therapy, but worldwide production of <sup>225</sup>Ac faces significant limitations. In this work, the Isotope Separation On-Line method was used to produce actinium by irradiating targets made of uranium carbide and thorium carbide with 1.4-GeV protons. Actinium fluoride molecules were formed, ionized through electron impact, then extracted and mass-separated as a beam of molecular ions. The composition of the mass-selected ion beam was verified using time-of-flight mass spectrometry, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>α</mml:mi></mml:math> - and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> -ray decay spectrometry. Extracted quantities of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mmultiscripts><mml:mrow></mml:mrow> <mml:mrow></mml:mrow> <mml:mn>225</mml:mn></mml:mmultiscripts> <mml:msup><mml:mtext>Ac</mml:mtext> <mml:mn>19</mml:mn></mml:msup> <mml:msubsup><mml:mtext>F</mml:mtext> <mml:mn>2</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> </mml:math> particles per <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>μ</mml:mi></mml:math> C of incident protons were <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>3.9</mml:mn> <mml:mrow><mml:mo>(</mml:mo> <mml:mn>3</mml:mn> <mml:mo>)</mml:mo></mml:mrow> <mml:mo>×</mml:mo> <mml:msup><mml:mn>10</mml:mn> <mml:mn>7</mml:mn></mml:msup> </mml:mrow> </mml:math> from a uranium carbide target and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>4.3</mml:mn> <mml:mrow><mml:mo>(</mml:mo> <mml:mn>4</mml:mn> <mml:mo>)</mml:mo></mml:mrow> <mml:mo>×</mml:mo> <mml:msup><mml:mn>10</mml:mn> <mml:mn>7</mml:mn></mml:msup> </mml:mrow> </mml:math> for a thorium carbide target. Using a magnetic mass separator, the long-lived contamination <sup>227</sup> Ac is suppressed to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo><</mml:mo> <mml:mn>5.47</mml:mn> <mml:mo>×</mml:mo> <mml:msup><mml:mn>10</mml:mn> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>7</mml:mn></mml:mrow> </mml:msup> </mml:mrow> </mml:math> (95% confidence interval) with respect to <sup>225</sup>Ac by activity. Measured rates scale to collections of 108 kBq <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>μ</mml:mi></mml:math> A <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mrow></mml:mrow> <mml:mrow></mml:mrow> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:mmultiscripts> </mml:math> h <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mrow></mml:mrow> <mml:mrow></mml:mrow> <mml:mrow><mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:mmultiscripts> </mml:math> of directly produced <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:mmultiscripts><mml:mrow></mml:mrow> <mml:mrow></mml:mrow> <mml:mn>225</mml:mn></mml:mmultiscripts> <mml:msup><mml:mtext>Ac</mml:mtext> <mml:mn>19</mml:mn></mml:msup> <mml:msubsup><mml:mtext>F</mml:mtext> <mml:mn>2</mml:mn> <mml:mo>+</mml:mo></mml:msubsup> </mml:mrow> </mml:math> .
Authors
- M. Schlaich (ORCID: https://orcid.org/0000-0002-3807-6655)
- Paul F. Giesel
- Ch. E. Düllmann (ORCID: https://orcid.org/0000-0002-1194-0423)
- M. Mougeot (ORCID: https://orcid.org/0000-0003-1372-1205)
- Christoph Schweiger (ORCID: https://orcid.org/0000-0002-7039-1989)
- Paul Fischer (ORCID: https://orcid.org/0000-0002-1985-313X)
- T. E. Cocolios (ORCID: https://orcid.org/0000-0002-0456-7878)
- S. Rothe (ORCID: https://orcid.org/0000-0001-5727-7754)
- J. D. Johnson (ORCID: https://orcid.org/0000-0003-4397-5732)
- M. Au (ORCID: https://orcid.org/0000-0002-8358-7235)
- L. Nies (ORCID: https://orcid.org/0000-0003-2448-3775)
- J.J. Reilly (ORCID: https://orcid.org/0000-0003-4753-781X)
- Daniel Lange (ORCID: https://orcid.org/0000-0002-4559-6739)
- L. Schweikhard (ORCID: https://orcid.org/0009-0002-8272-0388)
- U. Köster (ORCID: https://orcid.org/0000-0001-5701-3249)
- M. Athanasakis-Kaklamanakis (ORCID: https://orcid.org/0000-0003-0336-5980)
- W. Wojtaczka (ORCID: https://orcid.org/0000-0002-2476-6962)
- F. Wienholtz
- S. Stegemann
Institutions
- GSI Helmholtz Centre for Heavy Ion Research (DE)
- Johannes Gutenberg University Mainz (DE)
- University of Manchester (GB)
- Technische Universität Darmstadt (DE)
- Universität Greifswald (DE)
- Helmholtz Institute Mainz (DE)
- Institut Laue-Langevin (FR)
- Max Planck Institute for Nuclear Physics (DE)
- Imperial College London (GB)
- European Organization for Nuclear Research (CH)
- University of Jyväskylä (FI)
- KU Leuven (BE)
Publication Details
- Journal
- Journal of Radioanalytical and Nuclear Chemistry
- Published
- 2024-11-15
- DOI
- https://doi.org/10.1007/s10967-024-09811-0
- Citations
- 5
- Primary Topic
- Radiopharmaceutical Chemistry and Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.02
Funders
- CERN
- Bundesministerium für Bildung und Forschung
- Max-Planck-Gesellschaft
- European Research Council
- H2020 Marie Skłodowska-Curie Actions