An EPR study of gamma irradiated mixed materials based on sucrose for dosimetric purposes

Abstract

Since the recent past it was known that sucrose showed some good results as dosimeter using Electron Paramagnetic Resonance (EPR) technique. However there is still considerable interest in improving its accuracy and precision as well as in developing new systems with improved characteristics. In view of this fact, materials consisting of mixture at two different ratios (70:30 and 50:50%) between sucrose and ascorbic acid, sucrose and cysteine and sucrose and diphenylamine were studied by EPR spectroscopy. The obtained new materials were irradiated by γ-rays having doses varying from 0.5 up to 20 kGy. Before irradiation no EPR spectra were recorded. After irradiation complex EPR spectra with dominants of the sucrose spectrum in them were observed. The influence of the instrumental settings on the EPR signal intensity was reported. It was found out that the dose response of sucrose has linear dependence up to 20 kGy. The dose response of the new materials is compared with those in case of sucrose. The results showed that the addition of ascorbic acid, cysteine and diphenylamine to sucrose were leading to decrease in its sensitivity, but the EPR dose response remains unchanged. It was supposed that the decrease in the sensitivity was probably due to the antiradical activity of the added substances. To check this assumption the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity (FRSA) of the used substances was studied. It was concluded that these mixed materials can be used for dosimetric purposes, however they have lower sensitivity compared to sucrose.