Electron Paramagnetic Resonance (EPR) spectroscopy—also known as Electron Spin Resonance (ESR)—is a method that provides information on the structure and properties of systems containing unpaired electrons (paramagnetic systems). Unpaired electrons often play a key role in the catalytic, magnetic, chemical, and physical properties of substances. EPR spectroscopy enables the determination of the local environment of unpaired electrons within materials. EPR is used to study free radicals and defects induced in substances by external factors (such as ionizing radiation, thermal treatment, etc.), paramagnetic transition metal ions, stable radicals in chemistry and biology, short-lived radicals, and more. The scope of EPR spectroscopy is extensive, encompassing the study of solids, liquids, and gases. It is characterized by high sensitivity, allowing for the detection of paramagnetic species at concentrations as low as 10???–10??? M. The method is non-destructive. EPR spectroscopy is also employed for quantitative measurements in dosimetry and dating applications. In our group, in addition to characterizing catalytic materials, we use EPR spectroscopy to identify irradiated food products, determine the antioxidant properties of natural products, and perform dosimetry.
