An evaluation of inter-laboratory reproducibility for quantitative XRF of historic copper alloys PTISRC= METAL 2010, Proceedings of the Interim Meeting of the ICOM-CC Metal Working Group, Charleston, South Carolina 11-15 October 2010

This paper reports the results of a study conducted to evaluate the current state of inter-laboratory reproducibility when conducting quantitative XRF analysis of historic copper alloys. Fourteen institutions, primarily from the museum community, participated in the study, using a total of 19 X-ray fluorescence instruments. The design of the study was based largely on ASTM standard E1601, Standard Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method. In addition to addressing overall inter-laboratory reproducibility, we also attempt to evaluate the accuracy of individual laboratories. By determining correlations between accurate results and experimental methods and procedures, we are able to propose recommendations regarding best practice and ways in which reproducibility might be improved.