Molybdenum-99/ Technetium-99m Generator Based on Alumina Gel

Abstract

Technetium-99m is called the work horse, for many reasons, in nuclear medicine diagnostic purposes. It is produced as the β- decay of 99Mo radionuclide. Molybdenum-99 gel type generators are considered as suitable alternatives of the conventional chromatographic alumina columns loaded fission molybdenum-99. 99Mo solutions are cross-contaminated with 95Zr, 95Nb, 103Ru, 124Sb, 125Sb,125Sn..etc. Except for 103Ru, the detected radiocontaminants are common from activation 99Mo and fission 99Mo products. To prevent contamination of the eluted 99mTc, sequential purification and Al99Mo precipitation methods were conducted. After complete dissolution of thin Al foil and MoO3 powder ( tagged with 99Mo) in presence of Fe(III) with 5M NaOH solution, hydrogen peroxide was added to precipitate of Fe(OH)3 with partial elimination of radiocontaminants, 95Zr, 95Nb, 103Ru, 124Sb, 125Sb and 125Sn from the molybdate solute. The elimination % were gradually increased with increasing the total amount of fed iron dose in the system. Highly pure Alulinate/ molybdate-99Mo mixture solution was acidified with concentrated HNO3 to precipitate Al99Mo gel matrix at pH 5.5. The formed precipitate was washed and dried, then packed in the form of a chromatographic column. The generated 99mTc was eluted with 0.9% NaCl solution and exhibited high radionuclidic, radiochemical and chemical purity suitable for use in medical purposes.