Antonio Biagio Carbonaro, Department of Chemical Sciences, University of Catania.

ISOTOPIC FRACTIONATION OF OLD EGYPTIAN FABRIC DUE TO NATURAL AGING.

Stable isotopes analysis of light elements (H, C, O, N, S) are employed in a multitude of fields, with their most prevalent utilisation being in the field of archaeology. This is exemplified by their use in investigating changes in habitat, food sources, animal herding practices, dietary tendencies and migration patterns of humans. Among the light elements, carbon has the most significant impact on modern archaeological science. Nitrogen isotopes are useful in the field to establish a probable diet pattern, and oxygen, that is mainly integrated in humans through ingestion of water, may thus be used to verify the hypothetical geographic origin. Organic carbon is isotopically "light" (i.e., with a comparatively large proportion of 12C) with strongly negative δ13C values. The study of the fractionation of the stable carbon isotopes 13C and 12C through the δ13C value finds applications in various fields of science, from quality control in agribusiness to the study of the geographical origin of materials. At the plant level, this information is useful to prove which photosynthetic cycle a particular plant belongs to: C3, C4 or Crassulacean Acid Metabolism. Here, with a brief introduction about the role of stable isotopic analysis in Archaeochemistry, we will shed light about the degradation due to aging of an ancient linen textile of Egyptian origins, in order to see whether degradation phenomena change the content of stable carbon isotopes, over time. For this purpose, the δ13C values of the ancient sample were compared with contemporary Egyptian and French flax fibers samples. For the first time, it was observed that, contrary to what might have been expected, material degradation due to natural aging contributes to the phenomenon of the isotopic fractionation, due to the increasing in measured δ13C values from contemporary to ancient samples.