Variations have been found in the specific activity of ignited radioactive-labeled rare earth oxide samples. The variations appear to depend on the precipitating agents and temperatures. Using various precipitating agents and different ignition temperatures, samples of /sup 88/Y-, /sup 168/Tm-, and /sup 173/ /sup 174/Lu-labeled oxides were produced from stock solutions. Observed specific activities were compared to the known specific activities of the starting solutions. At 800/sup 0/C ignition temperatures, errors of 6% to 7% can be obtained for yttrium precipitated with 8-hydroxyquinoline or ammonia. Thulium and lutetium quinolates and cupferrates ignited at 800/sup 0/C are in error by 3 to 5%. Results show that temperatures in excess of 1000/sup 0/C are required for complete ignition of rare earth quinolates, cupferrates, hydroxides, and chlorides
