Solid state synthesis of mesoporous alumina: A viable strategy for preparation of an advanced nanosorbent for 99Mo/99mTc generator technology

Solid state reactions are becoming increasingly relevant as a technique for clean and efficient synthesis of advanced materials of immense technological relevance. Adsorption based column chromatographic processes are among of the most viable routes for radiochemical separation of medically important radioisotopes for clinical benefits. The fundamental and great challenge in this regard lies in development of highly efficient sorbent materials. Owing to their intrinsically high surface area and large pore volume, ordered mesoporous metal oxides may be the answer in the future for column chromatographic radiochemical separations. This work reports the synthesis of mesoporous alumina with greatly enhanced textural characteristics through solid state reaction of aluminium isopropoxide with glucose, followed by high temperature calcination. The nanostructured material (2-4 nm crystallite size) could be synthesized with large surface area (287 +/- 16 m(2)/g) and narrow pore size distribution with mean pore radius of 1.8 +/- 0.3 nm. When evaluated as Mo adsorbent for use in preparation of Mo-99/Tc-99(m) generator, mesoporous alumina displayed > 10 times higher sorption capacity compared to conventionally used bulk alumina. A clinical-scale Mo-99/Tc-99(m) generator (similar to 20.4 GBq) was developed using this sorbent material. Technetium-99 m could be regularly eluted from this generator over a prolonged period of 2 weeks with > 80% elution yield and it met all the requirements for clinical use. Overall, this study is expected provide inspiration to explore the relatively new terrain of solid state synthesis for large-scale preparation of 'next generation' sorbent materials for widespread utilization in radionuclide generator technology.