Development of the Purification Process of Gallium-68 Eluted from Germanium-68/Gallium-68 Generator


  • Tossaporn Sriprapa Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
  • Thanete Doungta Thailand Institute of Nuclear Technology, Nakhon Nayok Province 26120, Thailand
  • Napamon Sritongkul Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
  • Malulee Tantawiroon Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand



68Ge/68Ga generator, purification, radiolabeling, ion exchange purification, PET


Objective: 68Ga has a half-life of 68 minutes, with 89% of its decay is through positron emission. It is available from generator systems and possesses suitable property for labeling radioligands. These aspects make 68Ga a promising tracer for positron emission tomography (PET) imaging. This study aims to develop the purification process of the 68Ga eluates from 68Ge/68Ga generator after its recommended shelf-life and ensuring the quality through the radiolabeling process.

Materials and Methods: In this study, we explored the development of a purification method for 68Ga eluted from a
68Ge/68Ga generator before radiolabeling was investigated. Cation and anion exchange chromatography techniques were combined to remove trace amounts of competing metal ion impurities. Post-purification, the eluate’s metal contents were analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Breakthrough of 68Ge was measured using a multi-channel analyzer (MCA) spectrometer with high-purity germanium (HPGe) radiation detectors. Additionally, the radiochemical purity of 68Ga-NOTA-RGD was analyzed by high-performance liquid chromatography (HPLC).

Results: Metal impurities including Fe(II), Zn(II) and Al(III) were reduced by 61%, 38% and 44% respectively. The 68Ge breakthrough was approximately ~10–3%. The labeling efficiency with NOTA-RGD, a tracer for angiogenesis imaging, resulted in an average yield of 68Ga-NOTA-RGD (not corrected for decay) of around 50%, with a
radiochemical purity by HPLC of approximately 98%–99%.

Conclusion: Cation exchange in combination with anion exchange chromatography was thus proven to be an efficient method for purification of the 68Ga eluate from a 68Ge/68Ga generator prior to labeling the 68Ga PET radiotracer.


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How to Cite

Sriprapa, T., Doungta, T., Sritongkul, N., & Tantawiroon, M. (2024). Development of the Purification Process of Gallium-68 Eluted from Germanium-68/Gallium-68 Generator. Siriraj Medical Journal, 76(2), 90–96.



Original Article