Comparison of analytical techniques for analysis of archaeological bronze

Abstract

While many analyses of archaeological bronzes have been reported in the literature, in practice it is very difficult to compare them. To assess the present status of the chemical analysis of bronze two ancient objects—a flat axe (arsenic bronze) and a sickle (tin bronze)—were cut into pieces weighing about 2 g each and were distributed to 11 laboratories. The participants used the following methods for analysis: INAA, ED–XRF, PIXE, TRXRF, FAAS, ICP–AES, ICP–MS, SEM–EDS, LA–ICP–MS and PGAA. The samples were analysed in at least quadruplicate. Dixon's and Iglewicz and Hoaglin's tests were used to detect outliers. The majority of methods provided comparable results, especially for macroelements, independent of the technique and standards used. The number of determined elements depended on the method and, naturally, on the concentration level. Therefore an important recommendation that can be made is to supply, with each archaeometric investigation, data from the analysis of appropriate Certified Reference Materials (CRMs) used in the study.