Multivariate comparison of ICP-OES and PIXE/PIGE analysis of east Asian storage jars

Abstract

In this paper we compare the results of proton-induced X-ray and gamma-ray emission (PIXE/PIGE) and simultaneous inductively coupled plasma–optical emission spectrometry (ICP-OES) using a multivariate modeling approach. Paired samples from 17th century east Asian stoneware jars recovered from dated shipwrecks provide the test population. The comparison highlights similar elemental behaviors irrespective of technique but shows that the additional elements available through ICP-OES provide identification of subgroups not evident in the PIXE/PIGE dataset. This study concludes that high dimensional datasets, such as those provided by ICP-OES, are preferable for modeling compositional groups where the archaeological samples are of unknown compositional range. It also highlights the power of multivariate approaches in assessing the quality of data generated by different techniques.