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@PHDTHESIS{Giesen:888911,
author = {Giesen, Kai},
title = {{R}adiochemische {S}eparation von $^{45}${T}i und
$^{52}$g{M}n zur {H}erstellung radiomarkierter {K}omplexe},
volume = {4426},
school = {Universität Köln},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2020-05316, Jül-4426},
series = {Berichte des Forschungszentrums Jülich},
pages = {IX, 166 S.},
year = {2020},
note = {Universität Köln, Diss., 2020},
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). [...]},
cin = {INM-5},
cid = {I:(DE-Juel1)INM-5-20090406},
pnm = {573 - Neuroimaging (POF3-573)},
pid = {G:(DE-HGF)POF3-573},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
url = {https://juser.fz-juelich.de/record/888911},
}