Radiochemical studies on the separation of iodine-131 and radioiodination of some organic compounds

This thesis is constituted of three chapters:Chapter I: It deals with the theoretical consideration of the subject. The chapter deals with the importance of radioisotopes in medical applications, and the physical and biological properties of these isotopes. Also, this part deals with the chemical and physical properties of both tellurium and iodine and the methods of the production of radioiodine from tellurium targets especially dry distillation method and ion exchange method. It deals with general methods of labeling, chemistry of iodine especially the most frequently used in nuclear medicine, their methods of production and applications. It includes also the techniques used for the preparation of the radioiodinated compounds, especially the electrophilic technique or the oxidative radioiodination technique. In this technique, oxidizing agents are used to oxidize iodide ions to iodonium ions capable of electrophilic attack on the aryl group of the organic compound. This chapter deals also with the receptor tracers, their types and the effects that can occur due to the binding of these receptors to the cell membrane. Since these radiopharmaceuticals are used for diagnosis and therapeutic treatment of human diseases, quality control tests such as chemical purity, radionuclidic purity, radiochemical purity, sterility, apyrogenicity and biodistribution are performed to ensure the purity, the safety and efficiency of these products for the intended nuclear medicine application.Chapter II:It contains detailed information concerning the chemicals, reagents, the radionuclides, the equipment and the counting systems used in the study. It describes production technique of iodine-131 using dry distillation method. It describes also the electrophilic radioiodination for each of Y-indole and epidepride. Analysis of the labeled products was performed using two chromatographic techniques. The first technique is thin layer chromatography in which the compound was identified by its retardation factor (Rf). The second technique is the purification of the labeled compounds by means of high pressure liquid chromatography (HPLC). On the reverse phase RP-18, column eluted with an appropriate solvent where each compound is identified by its retention time (Rt).Chapter III :It deals with the idea of separation of iodine-131 from tellurium targets using the dry distillation method. The factors affecting the production and separation of 131I were studied such as the oven temperature; the distillation time and the sodium hydroxide concentration, the following flow sheet summarizes the production process. The quality control tests were carried out on the final product (Na131I). They were 99.9%, 98.7% for radionuclidic purity and radiochemical purity, respectively and the chemical purity of Te in the final radioiodine was 0.8μg/ml.