Membrane-based microfluidic solvent extraction of Ga-68 from aqueous Zn solutions

Membrane-based microfluidic solvent extraction of Ga-68 from aqueous Zn solutions: towards an automated cyclotron production loop

Trapp, S. (TU Delft RST/Applied Radiation & Isotopes)
Lammers, Tom (Student TU Delft)
Engudar, Gokce (TRIUMF)
Hoehr, Cornelia (TRIUMF)
Denkova, A.G. (TU Delft RST/Applied Radiation & Isotopes)
Paulssen, E. (TU Delft RST/Applied Radiation & Isotopes; FH Aachen University of Applied Sciences)
de Kruijff, R.M. (TU Delft RST/Applied Radiation & Isotopes)

2023

Background: The radionuclide Ga-68 is commonly used in nuclear medicine, specifically in positron emission tomography (PET). Recently, the interest in producing Ga-68 by cyclotron irradiation of [⁶⁸Zn]Zn nitrate liquid targets is increasing. However, current purification methods of Ga-68 from the target solution consist of multi-step procedures, thus, leading to a significant loss of activity through natural decay. Additionally, several processing steps are needed to recycle the costly, enriched target material. Results: To eventually allow switching from batch to continuous production, conventional batch extraction and membrane-based microfluidic extraction were compared. In both approaches, Ga-68 was extracted using N-benzoyl-N-phenylhydroxylamine in chloroform as the organic extracting phase. Extraction efficiencies of up to 99.5% ± 0.6% were achieved within 10 min, using the batch approach. Back-extraction of Ga-68 into 2 M HCl was accomplished within 1 min with efficiencies of up to 94.5% ± 0.6%. Membrane-based microfluidic extraction achieved 99.2% ± 0.3% extraction efficiency and 95.8% ± 0.8% back-extraction efficiency into 6 M HCl. When executed on a solution irradiated with a 13 MeV cyclotron at TRIUMF, Canada, comparable efficiencies of 97.0% ± 0.4% were achieved. Zn contamination in the back-extracted Ga-68 solution was found to be below 3 ppm. Conclusions: Microfluidic solvent extraction is a promising method in the production of Ga-68 achieving high efficiencies in a short amount of time, potentially allowing for direct target recycling. Graphical Abstract: [Figure not available: see fulltext.].

Cyclotron production
Ga-68
Medical radionuclide production
Metal contaminants
Microfluidic solvent extraction
Zinc nitrate liquid target
OA-Fund TU Delft

http://resolver.tudelft.nl/uuid:6008b62d-3b6d-48e0-b4c6-9c749ecbb98c

https://doi.org/10.1186/s41181-023-00195-2

2365-421X

EJNMMI Radiopharmacy and Chemistry, 8 (1)

Institutional Repository

journal article

© 2023 S. Trapp, Tom Lammers, Gokce Engudar, Cornelia Hoehr, A.G. Denkova, E. Paulssen, R.M. de Kruijff