Preparation and characterization of iron(III) 99Mo-molybdate(VI) gels for the assessment of 99mTc elution performance

Abstract

Abstract New iron(III) 99Mo-molybdate(VI) gels (Fe99Mo) of high Mo content were prepared by the precipitation/filtration method. 99Mo–MoO3 dissolved in NaOH was added to aqueous solutions of Fe(NO3)3 at Mo/Fe mole fractions ~2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe99Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe99Mo containing ≥800 mg Mo tagged with 740 MBq 99Mo were eluted with 5 mL saline solution. Highly reproducible 99mTc elution indices suitable for preparation of 99Mo/99mTc generators were achieved from generator supported with 0.5 g Al2O3 filter. Elution performance of 99mTc radionuclide was highly dependent on the gel structural properties.