Sodium sulfate as an eluant for concentrated solution of pertechnetate

Fission molybdenum-99 based technetium-99m chromatography generators are the most widely employed generator systems in the field of diagnostic nuclear medicine. In the first week these generators provide high specific volume activity Na99mTcO4, but in the second week the radioactive concentration of the eluate (99mTc) becomes ⩽17% of that at the beginning of the first week. Low specific volume activity limits the clinical procedures (e.g. 99mTc-DTPA for lung ventilation scanning, 99mTc-sestamibi for myocardial perfusion studies, 99mTc-ECD for brain imaging and 99mTc-red cells for testicles) that can be performed at the beginning of the second week. To overcome such limitations sodium sulfate was used as an eluant, which provides >80% of 99mTc radioactivity in 2 ml solution, while 0.9% NaCl provides only 40-45% 99mTc in first 2 ml solution.