99Mo/99mTc radioisotope generator based on adsorption of 99Mo (VI) on cerium (IV) molybdate column matrix

Based on neutron activated 99Mo, a procedure for preparation of 99Mo/99mTc radioisotope generator was developed. Batch equilibration method was used to investigate the sorption behavior of Mo (VI) (10−4 M) in chloride and nitrate solutions on cerium (IV) molybdate gel matrix using 99Mo radiotracer. The breakthrough sorption capacity of cerium molybdate gel matrix for 99Mo (VI) (3×10−2 M) were found to be 0.54 mmol/g of the sorbent [1 g column (0.6 cm i.d.)]. Elution performance of the generated 99mTc from cerium molybdate-99Mo chromatographic column was investigated as a function of inside diameter of the column, amount of the bed matrix and flow rate of the eluent. Based on the obtained results, 99Mo/99mTc radioisotope generator was prepared based on adsorption of neutron activated 99Mo (VI) of low specific activity onto chromatographic columns packed with 5 g cerium molybdate gel matrix. The radioactivity of 99mTc is periodically eluted with 10 mL 0.9% NaCl solution at a flow rate of 1 mL/min. Elution yield of 78±5% was obtained with high chemical, radionuclidic (99Mo breakthrough 1×10−3±0.3×10−3%) and radiochemical purity (97±2%).