Development of a method for the determination of low levels of technetium-99

A radiochemical separation scheme for technetium is being developed in which rhenium is to be used as a yield monitor; those procedures which are most prone to technetium losses are to be avoided, and the final, purified material is to be capable of analysis by either radiometric or non-radiometric methods. A detailed investigation of the behaviour of technetium and other important elements (rhenium, as a yield monitor, and ruthenium, as a potential interference) in the proposed scheme has been undertaken and their behaviour in the individual stages of the procedure is described. These experiments show that rhenium can be used as a yield monitor; that the behaviour of ruthenium is complex, but that good decontamination is possible, and that high recoveries of technetium are possible from each stage of the procedure.