NUKLEONIKA 2013, 58(4):505-509

 


EPR STUDY OF GAMMA-IRRADIATED KERATIN AND HUMAN FINGERNAILS CONCERNING RETROSPECTIVE DOSE ASSESSMENT



Grażyna Strzelczak1, Marcin Sterniczuk1, Jarosław Sadło1, Maria Kowalska2,
Jacek Michalik1

1 Institute of Nuclear Chemistry and Technology,
16 Dorodna Str., 03-195 Warsaw, Poland
2 Central Laboratory for Radiological Protection,
7 Konwaliowa Str., 03-194 Warsaw, Poland

In this paper we report the results of comparative EPR studies on free radicals generated in gamma-irradiated powder samples of feather keratin powder and human fingernails. In degassed samples of both materials irradiated at 77 K the major component of EPR spectrum represents sulphur-centred radicals in cysteine residues. It quickly decays after air admission at room temperature while a singlet assigned to semiquinone melanin radicals remains the only one seen. The singlet recorded with fingernails decays slowly at room temperature and might be potentially useful for dose assessment by EPR. The advantages and limitations of fingernails EPR dosimetry are discussed.

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