Is there a minimum physical sample size for XRF analysis?
Yes. Extensive experimentation in our laboratory has demonstrated that the absolute minimum size requirements for accurate trace element determinations of most samples is at least 1 cm in (minimum) diameter and 1 mm in thickness. Slightly larger samples will yield more robust trace elemt values and we prefer to analyze specimens at least 1.5 cm in diameter and 2 mm in thickness whenever possible. In any case, we do not recommend the use of small samples in complex source areas or regions where the source universe is poorly understood. • Will dirt or painted sample numbers on the artifacts affect the analysis? They often can. What we’re actually analyzing is the surface layer of the artifact – if there’s dirt, patina, or some encrustation present, the analysis will reflect the trace element composition of that material as well as the artifact. Because of this, the surface of the items to be analyzed should be clean and preferably free from labels or residues. A simple wash with tap wate
