Ammonium molybdophosphate impregnated alumina microspheres as a new generation sorbent for chromatographic 137Cs/137mBa generator

Barium-137m availed from a 137Cs/137mBa generator is an attractive industrial radiotracer for liquid flow rate measurement owing to its short half-life (T1/2 = 2.5 min) and emission of highly energetic gamma radiation (Eγ = 661.7 keV). Ammonium molybdophosphate (AMP) impregnated alumina microspheres (AMP-Al2O3), an engineered form of sorbent material was synthesized by Gel Entrapment Technique (GET). The utility of the material in the preparation of 137Cs/137mBa generator was evaluated. Various experimental parameters were optimized for efficient retention of 137Cs and selective elution of 137mBa. A chromatographic 0.74 GBq (20 mCi) 137Cs/137mBa generator was developed using this material and its performance was evaluated for 6 months. Barium-137m could be eluted from the generator using 0.1 M NH4NO3 + 0.5 M HNO3 solution with >80% yield and with acceptable radionuclidic purity suitable for industrial radiotracer investigations.