The transition from technegas to pertechnegas.

UNLABELLED

We set out to determine the oxygen concentration of the argon-oxygen mixture in the technegas generator where technegas-like behavior changes to pertechnegas-like behavior which allows [99mTc]pertechnetate to enter the solution.

METHODS

We prepared radioaerosols analogous to technegas and pertechnegas, with oxygen concentrations between 0% and 5%. They then were examined by thin-layer chromatography using saline as a solvent to measure the amount of [99mTc]pertechnetate moving with the solvent front as a function of oxygen concentration.

RESULTS

The amount of mobile pertechnetate markedly increased when the radioaerosols were created in an atmosphere containing between 0.1% and 0.2% oxygen. The transition from technegas-like to pertechnegas-like behavior occurs when the oxygen-argon gas mixture contains lower concentrations of oxygen than those used in the preparation of pertechnegas.

CONCLUSION

Argon intended for the preparation of technegas should contain no more than 0.1% oxygen.