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 97Tc. Uncertainties in the 99Tc and yield estimates depend on the amount of 97Tc 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. of 97Tc 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 44mBQ of 99Tc