Determination of Radionuclide Impurities in Tc-99m: A Rapid Pulse Height Analysis Technique

Abstract

We have developed a simple and rapid procedure for determining levels of multiple radionuclide impurities in Tc-99m generator eluates before use in patients. The technique combines the use of a low gamma energy filter comprised of layers of lead, cadmium, and copper to reduce the radiation from Tc-99m—with pulse height analysis of the transmitted high energy photons from common impurities such as Ru-103, I-131, and Mo-99. The procedure, which employs a multichannel analyzer and subsequent calculations, can be performed in almost the same time required for the current technique using isotope calibrators.