Abstract |
The present M.Sc. thesis reports the application of Nuclear Magnetic
Resonance spectroscopy, NMR to the study of archaeological ceramic
vessels found in two storage rooms of a Minoan palace, in Archanes,
Heraklion Crete. Eight ceramic vessels and their subsamples, including the
inner’/outer surface ceramic pores, crusts and topsoils, as well as five soil
samples, found in contact with the ceramics during excavation, were
analyzed.
Molecular markers are compounds identified in archaeological materials that
provide information about human activity in the past. The identification of
chemical compounds in organic residues, the observation of their distribution
within the subsamples of each ceramic vessel and the discrimination of
molecular markers of various food types from compounds due to microbial or
modern chemical contamination, were the main objectives of the present
study.
Water:methanol solutions in a ratio of 4:1 and chloroform were the solvent
systems used for the extraction of the organic residues from the ceramic
vessels. Small organic acids, saccharides, alcohols and fatty acids, were
identified in the organic residues with the aid of one and two dimensional
NMR spectroscopy. The analytical results showed that acetic acid, glycolic,
lactic, propionic, hydroxy-propionic, succinic acid as well as saturated fatty
acids and the disaccharide trehalose, are more or less associated with
microbial contamination, since they were identified in almost all samples. By
contrast, the monosaccharides glucose and fructose were only identified in
one particular sample, and they are well known as the main sugars in honey.
The identification of the monounsaturated fatty acid oleic acid in two specific
vessels was used as evidence of olive oil storage, probably scented, while the
compounds 2,3-butanediol and acetoin were proposed as wine markers in
one ceramic vessel, based mainly on the stereochemistry of butanediol
obtained from NMR analysis. On the contrary tartaric acid, which is the most
common marker used for wine identification in ceramic vessels, was only
found in minor quantities, on soil and crust samples. Finally, butyric acid
identified in one ceramic sample, might be related to foods of animal origin or
dairy products, although at present a possible microbial origin cannot be excluded.
|