The decomposition yields for crystalline alkali metal oxalates and some oxalates by γ-ray irradiation in the presence of air at room temperature were determined by UV and IR spectro-photometry. A logarithmic plot of the yields for alkali metal oxalates against metal-oxygen bond energy gave a good correlation, except for rubidium oxalate.
The additional absorbed radiation doses to total body from radioactive impurities in radiopharmaceuticals were estimated for a total of 10 samples (i.e., 99mTc generator eluates, 99mTc solutions, 67Ga, 81mKr generator eluates, 111In, 123I, 201Tl, 75Se, 197Hg, 198Au) selected from commonly used radiopharmaceuticals. The radioactive impurities in radiopharmaceuticals used in this estimation were previoulsy identified. The radiation doses were calculated according to the MIRD procedures, assuming each radionuclide to be uniformly distributed throughout the body. In the case of the cyclotron-produced radioisotopes and198Au, the additional total body absorbed doses from impurities were found to be rather high: 280% for123I, 55% for81mKr, 5% for198Au, 4% for111In and 2% for201Tl. The absorbed doses due to impurities in the other radioisotopes were less than 1%.