Effects of sample processing on XRF results from archeological pottery

The aim of this paper is to present the results of XRF analysis of archeological samples in two different states of preservation: intact vessel surfaces and transformed into powder. To investigate the effect of sample processing for XRF analysis, a handheld spectrometer was used. In total, 41 pottery samples were measured. The samples were extracted from Late Bronze Age and Early Iron Age ceramic vessels of two different technological traditions: local (hand-made pottery) and exogenous (wheel-thrown pottery) from the archeological site of Setefilla (western Andalusia, Spain). Multiple statistical tests were used to examine the effect of sample processing on the semi-quantitative outcome of XRF analysis of pottery. The results obtained from intact samples are considerably different from the results obtained from pulverized samples. The analyses revealed that levels of Co, Sb, Sn, Al, Si, Ca, Fe, S, K, Sr and Nb were higher in the group of intact samples. This study underlines the need to evaluate sample preparation when designing archeometric research programs.