Analysis of organic residues from the Châteaumeillant oppidum (Cher, France) using GC–MS

Scientific analysis has provided new evidence in historical and archaeological studies in recent years. Archaeological samples are frequently contaminated because of conservation conditions and/or cleaning before restoration. Roman amphora, made of a material of great interest, is no exception. This study develops the chemical analysis of Dressel I amphorae coming from the Châteaumeillant oppidum in France, dating from the 2nd century-1st century BC. Traces of organic matter located on the internal surface of the amphorae were identified using a gas chromatography-mass spectrometry (GC–MS). This analytical technique notably allows markers of resinous matter (pitch) and wine to be detected. Analytical results showing the presence of syringic acid, along with other wine acids (benzoic, succinic and vanillic acids) in certain amphorae in the archaeological context, demonstrated that the vessels had contained wine. Moreover, two families of resins (Pinaceae and Cupressaceae) were observed. They were used for waterproofing or as an additive to resinated wine. In particular, the observation of sandarac resin (Cupressaceae) is rare in wine amphorae.