Development of the Australian Standard for Germanium-68 by two Liquid Scintillation Counting methods

In response to the increasing application of ⁶⁸Ge/⁶⁸Ga and ⁶⁸Ga in nuclear medicine, an international comparison of activity measurement of ⁶⁸Ge in equilibrium with ⁶⁸Ga was organised. ANSTO standardised the comparison solution by the 4π(LS)β⁺-γ coincidence extrapolation and TDCR efficiency calculation methods, with excellent agreement between the two results. The primary standard was transferred to the ANSTO Secondary Standard Ionisation Chamber. Internationally traceable Australian Certified Reference Materials (ACRMs) of ⁶⁸Ge/⁶⁸Ga can now be prepared in various measurement geometries applied in nuclear medicine.