Dosimetric investigation of radiaton damage centers induced by gamma radiaton in some antibiotic drugs and foods using EPR technique

This thesis consists of two parts. In the first part; the behaviour of the free radicals induced by gamma irradiation in three different antibiotic drugs studied by Electron Paramagnetic Resonance Spectroscopy (EPR) to characterize the amounts and stability of these radicals, on the absorbed dose. Samples of drugs were irradiated by gamma rays at room temperature in the dose range of 0-20 kGy. While the EPR (Electron Paramagnetic Resonance) spectra of unirradiated drug samples show no signal, signals dependent on the irradiation dose observed with irradiated samples. Firstly microwave saturation of the irradiated samples was studied at room temperature. Several mathematical functions were tried to describe the dose-response curves obtained for irradiated samples and best functions describing the curves were determined. Correlation coefficients between absorbed doses and their corresponding EPR signals were identified from EPR signals. Storage at room temperature over 8 months was performed. The evolutions of the percentage of signal intensities were calculated. In the second part; dosimetric properties of unirradiated and irradiated olive seeds cultivated in Turkey were investigated through Electron Paramagnetic Resonance (EPR) technique. In unirradiated samples singlet EPR signals which are results of polyphenol oxidation in plants were obtained. Two satellite peaks on the sides of the central singlet signal attributed to cellulose radicals were observed after the samples were irradiated up to 7 kGy. In order to describe the variation of EPR signal intensity with absorbed radiation dose, several mathematical equations were tried. Correlation coefficients between the absorbed doses and their corresponding EPR signals were identified from EPR signals. Moreover time dependency of the intensity of the central EPR signal of the irradiated sample was analyzed to study the stability of the free radicals. Based on the results of the study, it can be concluded that EPR technique can be used to identify unirradiated and irradiated olive seeds even after two months. Keywords: Electron Paramagnetic Resonance(EPR), Free radical, Drug, Food irradiation.