Technetium-99m generator

[5] While Richards was in charge of the radioisotope production at the Hot Lab Division of the Brookhaven National Laboratory, Walter Tucker and Margaret Greene were working on how to improve the separation process purity of the short-lived eluted daughter product iodine-132 from tellurium-132, its 3.2-days parent, produced in the Brookhaven Graphite Research Reactor.

[6] They detected a trace contaminant which proved to be 99mTc, which was coming from 99Mo and was following tellurium in the chemistry of the separation process for other fission products.

Transport of 99mTc from the limited number of production sites to radiopharmacies (for manufacture of specific radiopharmaceuticals) and other end users would be complicated by the need to significantly overproduce to have sufficient remaining activity after long journeys.

Instead, the longer-lived parent nuclide 99Mo can be supplied to radiopharmacies in a generator, after its extraction from the neutron-irradiated uranium targets and its purification in dedicated processing facilities.

[13] Radiopharmacies may be hospital-based or stand-alone facilities, and in many cases will subsequently distribute 99mTc radiopharmaceuticals to regional nuclear medicine departments.

Both isomers are carried out by the elution process and react equally well with the ligand, but the 99Tc is an impurity useless to imaging (and cannot be separated).