Neutron irradiated 12-molybdocerate(IV) is evaluated as a column matrix for use in preparation of small chromatographic column type99mTc generators. Greater than 87% of the generated99mTc activity is immediately and reproducibly eluted with passing 10 cm3 of saline or chromated saline solutions through 3.0 g of molybdocerate column bed at flow rates of about 1.0 cm3/min. The elution performance of99mTc does not drastically change with increasing the drying temperature and/or the particles sixe of the column matrix in the range investigated. Saline eluent containing 5·10–5M CrO
increases the radiochemical purity of the eluate to >98% TcO
. Radionuclidic and chemical purities of the eluates satisfy the specifications for use in nuclear medicine.
The preparation of insoluble 12-molybdocerate(IV) from99Mo of low specific activity, produced by thermal neutron irradiation of MoO3, is described. Samples of the material are dried at 50, 100 and 200°C and used as column matrices from which the generated99mTc activity is periodically eluted with saline solution or saline solution containing 5·10–5M K2CrO4 as an oxidant. The elution yields of99mTc are high and reproducible (95–81%) with radionuclidic purity 99.98%. Both chemical and radiochemical purity (as TcO
) of the eluates decrease with increasing drying temperature of the column matrix. Using chromated saline solution as eluent improves the radiochemical purity of the99mTc eluate.