Radiochemical determination of technetium-99

A radiochemical method has been developed for determination of 99Tc by which both the chemical yield and the yield-corrected amount of 99Tc in a sample may be determined. The chemical yield estimation is based upon counting of low-energy internal-conversion electrons from the added isotopic tracer /sup 97m/Tc. Uncertainties in the 99Tc and yield estimates depend on the amount of /sup 97m/Tc tracer used, the amount of 99Tc in the sample, the fraction of time spent in counting with an added absorber, and the total counting period. For a 2000 min total counting period with 50% of it spent in counting with added absorber, with 20 counts min-1 of /sup 97m/Tc tracer added originally to the sample, and with 50% chemical yield the chemical yield uncertainty (relative standard deviation) is 2.3% and the detection limit is approximately 44 mBq of 99Tc. 7 references, 6 figures, 2 tables