1. Production of tin-117m with high specific activity by recoil By Kefilwe Thoane North west university Energy Postgraduate Conference 2013

2. Contents Introduction Aim Method Results and discussion Conclusion Reference

3. Introduction The radionuclide 117m Sn can be produced in a nuclear reactor or an accelerator. 117m Sn has a half-life of 13,60 days and gamma energy of 159 KeV (86%). The radionuclide emits low energy conversion electrons with intensities of 127 keV (65%), 129 keV (12%) and 152 keV (26%).

4. Aim Obtain 117m Sn with high specific activity (Ci/g) Adapting Szilard-Chalmers reaction. The high specific activity means Higher signal to mass Less chemical toxicity Administer less but still have sufficient therapeutic effect.

5. Method

6. Method conti... Targets were weighed accurately and irradiated for 24 hours. Radiochemical separation was performed using sulphuric acid and nitric acid as aqua regia. ICP analysis Activated carbon Graphite Tin oxide Specific activity = Amount of activity/ mass

7. Results

8. Discussion Four recoil capture media used. Graphite flake pellet > graphite flake powder > graphite> activated carbon granules. The graphite flake pellet is the best recoil capture medium because of the physical properties graphite possess. Layers make it possible to trap recoil atoms. Occurs as isolated, flat, plate like particles, hexagonal.

9. Conclusion The radionuclide 117m Sn was captured by the recoil medium during the irradiation process. Future work will be to optimise the conditions with the best recoil capture medium, namely graphite flake pellets.

10. Reference Kyu, K. D., Abramov, A. A., Volkova, S.V., Dubovaya, D. V., Lofa, B. Z., Seropegina, E. N.1999. Extraction of tin-117m from antimonic target irradiated by protons. Srivastava, S.C., The role of electron-emitting radiopharmaceuticals in the palliative treatment of metastatic bone palliation for radiosynovectomy: applications of conversion electron emitter tin- 117m 2007. Braz. arch. Boil. Bechno; 50: 49-72. Jansen, D.R. An in vitro approach to evaluate and develop potential 117m Sn based bone-seeking radiopharmaceuticals. 2010., Dissertation. Delft University of technology.

11. Acknowledgements Prof Jan Rijn Zeevaart Dr David Jansen Dr Hester Oosthuizen Financial support Necsa National Research Foundation (NRF) of South Africa