Isotope exchange between 12-molybdocerate(IV) and sodium molybdate-99Mo in aqueous media

⁹⁹Mo/^99mTc-¹¹³Sn/^113mIn Dual Radioisotope Generator Based on 6-Tungstocerate(IV) Column Matrix

“…K d of technetium increases with decreasing pH nearly parallel to that of molybdenum but with much less values; it increases gradually from 25±2 to 37±2 mL/g with decreasing pH from 12.4 to 2.4 and then increases abruptly to 67±2 mL g at pH 1. Along the studied pH range (1 20,36,38 6-WCe was prepared and characterized before as a cation exchanger 28,30 and therefore the uptake of 99 Mo cannot be interpreted by ion-exchange mechanism. Since 12tungstocerate(IV), 12-WCe, and 12-molybdocerate, 12-MoCe, could be prepared and characterized, 30,38 44,46 The higher K d -values of molybdenum compared to those of technetium at the corresponding pH values supports the possibility of the formation of 6-WCe-6-MoCe mixed heteropolyacid.…”

Synthesis of alumina 99Mo-molybdate(VI) gel matrices and evaluation of 99mTc elution performance

“…Neutron irradiation of the molybdate gels resulted in 99 Mo cross contaminants such as 95 Zr/ 95 Nb, 92m Nb, 51 Cr, 141 Ce, 60 Co, 124 Sb, 65 Zn and 134 Cs. Their elution in the 99m Tc eluates needs the use of purification filters which increases the problem of storage of the exhausted generators [4,16,19,25,30,31]. Radiation degradation of the molybdate(VI) gel [25] and release of MoO 3 particulates deposited onto acidic alumina loaded 99 Mo from HNO 3 solution (pH 2-6) at 100 ∘ C [21] have consequent low 99m Tc elution yield with improper chemical, radionuclidic and/or radiochemical purity.…”

“…tions of neutron irradiated MoO 3 and Zr [19,20], Ti [21], Sn [22], Ce [16,23] and Mg [24] precipitated the corresponding molybdate(VI) gels on acidification at pH 1-6. Although ZrMo gels are the most accepted matrices for preparation of 99 Mo/ 99m Tc gel type generator, the elution performance of 99m Tc was seriously influenced by the pre-and post preparation conditions [4,17,19,20].…”

Preparation and performance of 99Mo/99mTc chromatographic column generator based on zirconium molybdosilicate

“…Although ( , ) 99 Mo has a lower specific activity (< 10 Ci/g) [8], it has many advantages where simple equipment is needed for processing, radionuclidic contamination is limited by the target purity (especially for 98 Mo enriched targets) and the produced radioactive waste is minimal. [4] or secondly by incorporation of Mo into gel materials [e. g., 12-molybdocerate, 6-tungstocerate, stannic molybdate, titanium molybdate, zirconium molybdate, zirconium molybdophosphate, alumina molybdate, cerium(IV) molybdate, cerium(IV) tellurium molybdate] via precipitation reactions using the post-irradiation method or the less-common pre-irradiation method [9][10][11][12][13][14][15][16][17], (ii) Extraction generators including solvent extraction (conventional or aqueous biphasic system), solid phase extraction generators, extraction chromatographic generators and supported liquid membrane generators (as a modified version of extraction chromatography) (iii) sublimation and thermochromatographic generators and (iv) electrochemical generators [4].…”