Comparative EPR study CO2− radicals in modern and fossil tooth enamel

Comparative EPR study CO2− radicals in modern and fossil tooth enamel

Comparative EPR investigation of CO2− radicals in modern (γ-irradiated) and fossil samples of tooth enamel was performed. The samples studied were the enamel powders and plates, the latter demonstrating an orientation dependence of EPR spectra in an external magnetic field. It was found that the rat...

Full description

Saved in:
Bibliographic Details
Published in:Radiation measurements Vol. 78; pp. 53 - 57
Main Authors: Nosenko, V.V., Vorona, I.P., Baran, N.P., Ishchenko, S.S., Vysotskyi, B.V., Krakhmalnaya, T.V., Semenov, Yu.A.
Format: Journal Article
Language:English
Published: Elsevier Ltd 01-07-2015
Subjects:
CO2− radicals
Dating
EPR
Fossil enamel
Fossil enamel
Dating
EPR
CO2− radicals
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Comparative EPR investigation of CO2− radicals in modern (γ-irradiated) and fossil samples of tooth enamel was performed. The samples studied were the enamel powders and plates, the latter demonstrating an orientation dependence of EPR spectra in an external magnetic field. It was found that the ratio between the axial and orthorhombic CO2− centers amounts appears to be different for modern and fossil enamels. This ratio can be estimated by modeling of EPR spectra lineshape of powders or, in the case of plates, from the orientation dependence of EPR spectra in an external magnetic field. It was assumed that the difference between modern and fossil enamels is caused by the transformation, in the course of time, of orthorhombic CO2− centers into axial ones. The equations that describe this process were deduced. Their solutions show that the ratio between the amounts of the axial and orthorhombic centers does not depend on the dose rate. This finding can be used for the development of the method to determine the fossil enamel age avoiding the determination of the annual dose. •Ratio CO2−(axial)/CO2−(orthorhombic) is different for modern and fossil enamels.•Difference is caused by the transformation CO2−(or) → CO2− (ax), during lifetime.•Ratio CO2− (ax)/CO2− (or) does not depend on the dose rate.•Opportunity of enamel age determination avoiding annual dose estimation is discussed.
ISSN:1350-4487
1879-0925
DOI:10.1016/j.radmeas.2014.09.004