Multi elemental analysis of roman pottery from northeastern Italy by inductively coupled plasma - optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS)

Chemical characterization has been carried out on 200 ceramic samples belonging to different classes of pottery (grey, coarse and semidepurata; I century B.C.–II century A.D.) coming from two archaeological sites in the area of Millepertiche (Veneto, Italy). The aims of the present study are to evaluate the differences in the pattern distribution of the sherds between the two sites and to better understand the ceramic typology for classification studies(1, 2). The archaeological interest of the study is related to the sites location since they are situated on the historical Via Annia. The Via Annia was an important vector for the circulation of material of different provenance, as it was built in the Roman period to connect northeastern Italy with Rome and the rest of the road system in the peninsula. For these purposes multielemental analysis has been carried out. After sample digestion in a microwave oven, the ceramic chemical composition in terms of major (Na, Mg, Al, Si, K, Ca and Fe) and minor elements (Sc, V, Cr, Mn, Co, Ni, Cu, Zn and Pb) was determined by means of inductively coupled plasma optical emission spectroscopy (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) (3, 4, 5). The most interesting major elements are Si, Ca and Fe, with concentrations that ranged respectively from 11·10^4 to 40·10^4 ppm, from 3·10^3 to 11·10^4 ppm, and from 4·10^3 to 11·10^4 ppm. Chemometric techniques such as principal component analysis (PCA) and cluster analysis have been applied to the complex dataset for extracting useful information in order to identify similarities and differences among ceramic samples. The results demonstrate that the different chemical compositions could be related both to the provenance from the two sites and to different pottery typology and fabrication.