Multifrequency EPR Study of Carbonate- and Sulfate-Derived Radicals Produced by Radiation in Shells and Corallite

Strzelczak, G., Vanhaelewyn, G., Stachowicz, W., Goovaerts, E., Callens, F. and Michalik, J. Multifrequency EPR Study of Carbonate- and Sulfate-Derived Radicals Produced by Radiation in Shells and Corallite. Shells of two sea mollusks (Venus sp.), pearl oyster (Meleagrina vulgaris) and corallite (white coral) were exposed to ionizing radiation (γ and X rays) and then examined by EPR spectroscopy in X, Q and W band. The resulting spectra were analyzed and the g values of the EPR lines in the multicomponent spectra were determined. The increased resolution in Q- and W-band spectra allowed us to assign the observed lines to CO2– ion radicals (isotropic and orthorhombic), SO2– isotropic, SO3– (isotropic and axial), and Mn2+ species. The assignments were confirmed by simulations of the spectra. Practical implications for the use of Q and/or W band in low-dose quantitative EPR measurements for dating and for accidental dose estimation are discussed.