Lead isotopic and elemental analysis of copper alloy statuettes by double focusing sector field ICP mass spectrometry

Lead isotopic analysis may be of great interest for provenance determinatio n of ancient bronze artefacts. Traditionally, thermal ionization mass spect rometry (TIMS) is used for this purpose, because of its superiority in term s of isotope ratio precision (RSD values typically < 0.05%). However, TIMS analysis is quite time-consuming, especially since the analyte of interest has to be isolated from the matrix. Quadrupole-based ICP-MS can be used as an alternative, but its application range is limited because of the rather poor isotope ratio precision (RSD values typically 0.1-0.5%). Hence, in thi s study, double focusing sector field ICP mass spectrometry was examined fo r use in provenance studies. Twenty-six statuettes representing Roman Gods, most of them said to be found during dredging-operations in the rivers Sch eldt and Durme around Hamme (Belgium), were selected for this study. The RS D values obtained for Pb-204/Pb-206, Pb-207/Pb-206 and Pb-208/Pb-206 were 0 .1-0.4%, 0.05-0.15% and 0.05-0.15%, respectively. Using simple bivariate pl ots, the lead used for the production of these statuettes was localized as originating from the British Islands or from the South of Europe (Cyprus, G reece and Italy). Also the elemental composition (Cu, Sn, Pb, Zn, Ni, Fe an d Sb content) of the alloys was determined in order to date the statuettes approximately.