Book/Dissertation / PhD Thesis

FZJ-2020-05316

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Radiochemische Separation von $^{45}$Ti und $^{52}$gMn zur Herstellung radiomarkierter Komplexe

Giesen, K. (Corresponding author)FZJ*

2020
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/27206

Report No.: Jül-4426

Abstract: With regard to special diagnostic applications, non-standard radionuclides often represent suitable alternatives to standard radionuclides like $\textit{11}$C and $\textit{18}$F due to their physical decay characteristics such as half-life (t$_{1/2}$) and decay modes. Furthermore, non-standard positron emission tomography (PET) nuclides enable a novel design and synthesis of specific PET tracers to study a variety of biological processes. However, their clinical application in diagnostics is hampered by their limited availability owing to the lack of suitable radiochemical separation techniques. The positron emitter $^{45}$Ti (t$_{½}$: 3.1 h, I$_{β+}$ = 84.8 %, E$_{β+max}$ = 439 keV) is of high importance for imaging studies since Ti-complexes have shown therapeutic efficacy in cancertreatment as cytostatic agents. $^{45}$Ti can be easily produced at a small cyclotron by proton bombardment of a Sc target via the $^{45}$Sc(p,n)$^{45}$Ti nuclear reaction. Unfortunately, efficient separation methods to isolate $^{45}$Ti from the irradiated targetare still missing. Therefore, this work aimed to develop a novel separation technique to obtain $^{45}$Ti in high purity and radiochemical yield. The separation method was based on a thermochromatographic approach via the formation of volatile [$^{45}$Ti]TiCl$_{4}$ in a chlorine gas stream, enabling the separation from low volatile ScCl$_{3}$. The separation apparatus and the individual steps were adjusted to enable trapping of [$^{45}$Ti]Cl$_{4}$ for further chemical conversions. The most relevant separation parameters like reaction temperature, volume flow, separation time, and chlorine concentration in the carrier gas were optimized to achieve efficient formation and trapping of [$^{45}$Ti]TiCl$_{4}$ in high separation yields. Finally, [$^{45}$Ti]TiCl$_{4}$ was obtained with a recovery yield of 76% ± 5%(n=5) (n.d.c. 48% ± 3% (n=5)) and a radionuclidic purity of >99%, facilitating subsequent labeling steps. To this end, [$^{45}$Ti]TiCl$_{4}$ was reacted with the complex ligand H$_{4}$(2,4-salan) [6,6'- ((ethane-1,2-diylbis((2-hydroxyethyl)azanediyl))-bis(methylene))-bis(2,4-dimethylphenol)] or with H$_{4}$(3,4-salane) [6,6'-((ethane-1,2-diylbis((2-ydroxyethyl)azanediyl))- bis(methylene))bis(3,4-dimethyl-phenol)] in THF to form the corresponding $^{45}$Ti complexes. Thus, [$^{45}$Ti][Ti(2,4-salan)] and [$^{45}$Ti][Ti(3,4-salan)] were afforded in radiochemical yields of 15% ± 7% (n=7) and 13% ± 6% (n=3), respectively. Furthermore, [$^{45}$Ti][Ti(HBED)] was obtained from [$^{45}$Ti]TiCl$_{4}$ by reaction with the chelator N,N-bis(2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid (HBED). [...]

Note: Universität Köln, Diss., 2020

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Contributing Institute(s):

1. Nuklearchemie (INM-5)

Research Program(s):

1. 573 - Neuroimaging (POF3-573) (POF3-573)

Appears in the scientific report 2021

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Database coverage:
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