Introduction: Sodium Iodide-123 is well known as a radioisotope that is used for studies of the thyroid and its metastases. 123 I labeled compounds are used for kidney, heart and brain studies.
Experimental: For 123 I production, a home made target was designed. The main part of the target contained; conical target vessel that was mounted in an aluminum cylinder of length 30 cm and diameter 8.5 cm for water cooling during bombardment. Front and rear target windows made by titanium foil and cooling system. In addition, some other part such as a cold finger, decay vessel, vacuum pump and four fingers also designed and installed on the system. 123 I was produced from the reaction of 28 Mev protons with 99.99% enriched 124 Xe [1] with IBA Cyclone-30. Bombarded xenon was transferred to the vessel and stored there up to about 6 hours to allow 123 Cs decay to 123 I with the maximum efficiency. The remaining xenon gas was then transferred into the reservoir capsule using a cryogenic technique. The produced, 123 I is deposited on the wall of the decay vessel, was rinsed out by dissolution in 0.05 ฮผs water at 80ยฐC. Nitrogen gas pressure was used to transfer the 123 I solution to the chemical hot lab. The pH, and adjusted with sodium hydroxide.
Results and Discussion: A sample of production was sent to quality control. Quality control results were in good accordance with the United States Pharmacopoeia [2]. QC results and production parameters are shown in table 1 and 2 respectively. For detection of chemical impurity which might be leached from target body, produced solution was also analyzed for determination of its chemical impurity, using Atomic Absorption and ICP (table 3). Table 1 Produced Na 123 I USP 2005 Clear solution Clear solution pH = 7.7 pH = 7.5-9
Conclusion: Using this system with the above specification, the production yield could be increased by increasing the current. The results show no chemical or radionuclide impurity.