Detection of free radicals in gamma-irradiated seasnail hard tissues by electron paramagnetic resonance.

Gamma-irradiated seasnail (from family of Helix lukortium) hard tissues (CaCO3) were investigated by electron paramagnetic resonance (EPR) at room temperature. The radicals produced by gamma-irradiation in seasnail were attributed to orthorhombic C*O2-, freely rotating C*O2-, orthorhombic C*O3-, axial C*O3-, and axial C*O3(3-) free radicals. Unirradiated seasnail hard tissues also feature Mn2+ ions in their EPR spectra. The hyperfine values were determined for the 13C nucleus in the orthorhombic C*O2- and axial C*O3(3-) free radicals and for the manganese impurity ions. The g values of all the free radicals have been measured. The results were compared with the literature data for similar defects.