Confocal micro-X-ray fluorescence analysis for difference identification of ceramic samples

A nondestructive analytical method for difference identification is required in the research fields such as forensic science or archeology. An X-ray fluorescence (XRF) analysis is one of feasible techniques for this purpose. Micro-XRF using an X-ray micro-beam gives elemental distributions by scanning the samples. A confocal micro-XRF (CM-XRF) technique is a unique analytical technique to analyze limited volume. CM-XRF enables elemental depth imaging and elemental profiling in depth nondestructively. Therefore, CM-XRF has been applied for various samples such as industrial samples, paintings, forensic samples, food materials, and human hairs. CM-XRF technique would be a suitable method for difference identification because the CM-XRF gives detailed information on elemental distribution not only on the surface of the sample but also in depth. We developed CM-XRF instrument in the laboratory and applied to two very similar ceramics samples. It showed differences in the intensity profiles of Fe and Mn for blue paintings on the ceramics. In addition, depth elemental analysis revealed different depth profiles especially of Co and Zn for both samples. These results suggest that CM-XRF provides useful information for the identification of ceramic samples.