Production scale purification of Ge-68 and Zn-65 from irradiated gallium metal

Germanium-68 (Ge-68) is produced by proton irradiation of a gallium metal target, purified by organic extraction and used in a medical isotope generator to produce Gallium-68 PET imaging agents. The purpose of this work was to implement a production scale separation of Ge-68 and Zn-65 that does not use organic solvents and uses a limited number of columns. The current separation approach was modified to use AG1 resin and/or Sephadex^© G25 with zinc spikes to purify Ge-68 with near quantitative recovery. The purified Ge-68 meets DOE specifications. Methods utilizing zinc spikes resulted in the purist Ge-68 produced at Brookhaven National Lab with no other impurities by ICP-OES. During process optimization approximately 2.5 Ci of Ge-68 was purified utilizing the different processing methods, and the material was sold to the Nuclear Medicine community between 2012–2013. - Highlights: • The processing method is scalable for optimized purification of Ge-68 and Zn-65. • The purified Ge-68 meet DOE specifications and recoveries were >90%. • The processing methods were used to purify ~2.5 Ci of Ge-68 at BNL in 2012–2013. • New processing methods minimize potential of Ge-68/Ga-68 volatility. • The processing methods do not use toxic organic solvents and are FDA compliant