Characterisation of organic residues in pottery vessels of the Roman age from Antinoe (Egypt)

In the framework of a study on the Egyptian ceramic vessels belonging to the archaeological collection of the Istituto Papirologico Vitelli (Florence), the characterisation of organic residues from three findings of the 5th-7th centuries AD has been performed. The materials were identified by two analytical procedures based on Fourier transformed infrared spectroscopy (FT-IR) and on gas chromatography coupled with mass spectrometry (GC-MS), respectively. The first procedure is suitable for detecting the functional groups of organic substances and thus for distinguish them; the second permits the simultaneous analysis of several natural substances such as vegetable resins and oils, bitumen, tar and pitch, and waxes. The presence of monocarboxylic acids, ,-dicarboxylic acids, long chain dihydroxylated acids and terpenic species, highlights that although the organic residues showed a high heterogeneity in composition, they mainly consisted of materials of vegetable origin. In particular, the presence of oxidation products of characteristic unsaturated fatty acids suggests the occurrence of oil produced from plant seeds of the Cruciferae family, some of which are reported to have been used in ancient Egypt to produce oil. Moreover, the presence of characteristic diterpenic biomarkers in two of the three pieces of pottery enables us to assess the use of both pine resin and pine pitch.