Identification of fish irradiation by EPR spectrometry: Signal intensity and stability

Abstract

In this work, the application of electron paramagnetic resonance spectroscopy for assessing the irradiation of fish is described. Pink salmon was chosen as the research object and irradiated at 3 and 6 kGy doses. A linear correlation was observed between the increase in EPR signal intensity and the radiation dose. It was demonstrated that the fish used in this study had previously been irradiated by the supplier for microbiological sterilization. To assess the signal decay kinetics, repeat spectroscopy of samples was conducted over the course of a year after irradiation. A decrease in EPR signal intensity is observed initially after irradiation, attributed to the decay of short-lived radicals. The results indicate that EPR spectroscopy is an accurate and sensitive way to determine whether fish has been irradiated.