Determination of 99Mo contamination in 99mTc elute obtained from 99Mo / 99mTc- generator

Background: 99mTc is a widely used radioisotope in nuclear medicine centers which is obtained by elution from Mo-99/Tc-99m generators. Usually the generators are either supplied by the Iran Atomic Energy Agency or by private companies from foreign countries. In this study we have measured 99Mo contamination in 99mTc elute from different generators in a period of one year. Materials and Methods: The radionuclide impurity of the 99mTc elute were studied in two types of radionuclide generators (A: produced in Iran and B: Imported from other country). In-vitro measurements were performed using dose calibrator. Direct measurements were made, using a standard canister at the time of milking of the generators and also in subsequent hours after milking. Results: The results showed a mean of 99Mo impurity in generators A and B to be 0.00932±0.0043 and 0.0170±0.0127 respectively. Although the results showed that the 99Mo contamination in 99mTc elute was lesser than the maximum accepted activity limit of 0.015%, the difference in these two types may reflect different methods of productions of generator, as well as the quality control procedures. Conclusion: The mean of 99Mo contamination in generators produced in Iran Atomic Energy Organization was lesser than generators imported from foreign origin.