Improvement of the EPR detection of irradiated dry plants using microwave saturation and thermal treatment

The reported EPR studies on the dependence of the microwave saturation behavior as a function of temperature (up to 60 °C) and heating time of some dry plants demonstrate the possibility to distinguish naturally present from radiation induced EPR signals independently of the fact that they have equal g-factors in X- and Q-band spectra. Using these properties of the dry plants a new approach for identification of their previous radiation processing is considered. It is based on the fact that the intensity of the EPR line appearing after irradiation increases at high microwave power (for example 100 mW) and decreases at low microwave power (for example 1 mW) when the irradiated sample is recorded after thermal treatment (up to 60 °C, 60 min). The intensity of the naturally present EPR signal observed in non-irradiated samples remains, meanwhile, unchanged.