Quantitative non-destructive determination of trace elements in archaeological pottery using a portable beam stability-controlled XRF spectrometer

A portable beam stability-controlled XRF spectrometer developed at the LNS/INFN laboratories at Catania (Italy) was used for the non-destructive determination of some trace elements (Rb, Sr, Y, Zr and Nb) in fine pottery artefacts. The XRF system and the method developed to control the energy and intensity stability of the excitation beam are briefly discussed. Concentrations of Rb, Sr, Y, Zr and Nb were determined in 50 fine potsherds from the votive deposit of San Francesco in Catania by using a multi-linear regression method. Additionally, in order to test the homogeneity of the material composing the fine pottery samples, a small portion of a few potsherds was powdered and analysed using the XRF system and the multilinear regression method. A comparison between non-destructive and destructive approaches is presented and discussed. Finally, quantitative XRF data were compared with those obtained by chemical analysis of the powdered samples. The results allowed the testing of a non-destructive methodology to be used for the identification and grouping of the different typological classes of fine pottery mainly represented in the San Francesco sanctuary.