Aromatic and therapeutic substances from the prehistoric site of Pyrgos - Mavrorachi, archaeometric studies

The areas, investigated in eight years of excavations, concern an oil-mill with store for the jars, a workshop for the production of perfumes-medicinal substances and a room for wine-making. Archaeometric investigation (begun during the 2004-2009 archaeological excavations) aimed to separate out certain apparently organic-resinous sediments. These sediments (Stratigraphic Units G7L5, J5L8, J7L2, J7L6, F8L4, G7, G7L3, G7/8, G9, G9L4 Palette H1044) implied particular preservation conditions; in fact, they were found in sealed levels composed mainly of sand and fine mud. The investigation used several colour-test methods generally reported in the chemical-toxicological literature (the Halphen-Grimaldi method, the Bloor mixture, the Liebermann method, Marquis, Bellier, Chen, Vitali, Bechi and McNally reactions and toxicological tests). These methods are based on dissolving residues extracted from archaeological sediments in acidified or alkalinised solvents, in order to trigger, with an appropriate reagent, the development of a specific colour that narrows the analytic field; in the end, the unknown substance can be identified by a specific reaction. In certain circumstances, we used chloroform acidified with HCl to extract alkaloids that had been salified in the chloroform phase. The extreme sensitivity of these reactions makes it possible to work with very small quantities of archaeological sediments. Samples of different organic residues were taken inside pottery of different typology; the analyses result in the identification of substances obtained from officinal plants of the Mediterranean area