EPR of carbonate derived radicals: Applications in dosimetry, dating and detection of irradiated food

Multifrequency EPR study on radiation induced centers in calcium carbonates labeled with 13C

“…1e). Based on literature data [1], the signal is assigned to CO 3 -radical anion located in calcite crystalline lattice. In the POCH sample, other less intense signals were recorded.…”

“…The EPR studies of the irradiated carbonates showed the different spectra for the natural and synthetic samples and for the synthetic samples of different origin [3][4][5].…”

“…Radical species like CO 3 -, CO 3 3-, and CO 3 -can be generated in calcium carbonates by -or UV-radiation. In calcite and aragonite exposed to ionizing radiation, different paramagnetic centers are formed.…”

Ionizing Radiation Induced Radicals

“…The identification of radicals was based on EPR and ENDOR (Electron Nuclear Double Resonance) measurements of irradiated synthetic hydroxyapatite doped with 13 C (Callens, F., et al, 1998). Not all radiation-induced radicals are thermally stable, e.g., the CO3 -radical, with g-value of the EPR signal ranging from 2.0060 to 2.0122, decays completely at room temperature during the first two weeks after irradiation (Callens, F., et al, 1998, Cevc, P., et al, 1972, Romanyukha, A., et al, 1996. For dose reconstruction the asymmetric EPR signal with g ┴ =2.0018 and g||=1.9971 (signal maximum at g=2.0032 and minimum at g=1.9971) is used.…”

Effect of CO2 Ion Doping on Characteristics of Nanostructure Hydroxyapatite

“…In this method, high-energy ions produced by an ion implantation device with perfect vacuum penetrate into the substrate material. Planted ions may lead to three processes within the material that are: scission of primary bond and replacement of network atoms, entering the channel (space between the structure), and locating the position of network defects [9,10].…”