Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

Abstract

99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.<br>O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio

Preparation of 99Mo from the 100Mo(γ, n) reaction and chemical separation of 99mTc

“…High power electron accelerators can serve as an attractive option for producing 99 Mo on a larger scale, and thus reduce the dependence of nuclear medicine community on 99 Mo production from the neutron irradiation of HEU targets. The feasibility of the present work can give a guide line for the photon irradiations of molybdate gels made with cerium (IV), titanium and mixture of MoO 3 -V 2 O 5 -SiC [49].…”

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

“…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].…”