In July 2006 the GCI hosted a meeting entitled "Quantitative X-ray Fluorescence Analysis Using Handheld Instrumentation." Organized by the Institute's Museum Research Laboratory, this two-day event was the third in a series of informal workshops on the use of X-ray fluorescence (XRF) spectroscopy in the analysis of works of art. Over thirty conservation scientists and conservators, representing over twenty different cultural, industrial, and research institutions, attended the meeting.

XRF is widely used in cultural institutions because it can quickly yield information about the elemental composition of an object in a noninvasive and nondestructive manner. However, because works of art are frequently complex or composite structures, special consideration must be given to the interpretation of these results. The purpose of these meetings is to bring together users of XRF within the museum field to discuss optimizing and standardizing the use of this important analytical technique.

The previous meetings, held at the Detroit Institute of Arts in 2002 and 2004, focused on the use of XRF for the examination of photographs. The 2006 meeting focused on obtaining quantitative results, with particular emphasis on metal alloys, and on the use of handheld instruments, which has dramatically increased in recent years.

	XRF workshop participants from the Museum of Modern Art and Smithsonian Institution examining data obtained from a handheld XRF spectrometer. Photo: Dusan Stulik.

The first day of the meeting consisted of a series of presentations and lectures. Following a welcome by GCI Chief Scientist Giacomo Chiari, Karen Trentelman, head of the Museum Research Laboratory, began the sessions by providing an overview of the previous meetings and outlining the goals of the 2006 meeting. GCI Senior Scientist Dusan Stulik presented work on the use of XRF to study baryta layers in photographs, and Jennifer Giaccai of the Walters Art Museum presented work on the Archimedes Palimpsest, which uses a synchrotron radiation source to perform XRF imaging of the overlapping text. Lisha Glinsman, of the National Gallery of Art in Washington DC, explored the relative merits of different XRF spectrometers, while Aaron Shugar of Buffalo State College discussed the pitfalls of performing quantitative analysis on unprepared samples. Andy Drews of the Ford Motor Company Research Laboratories gave a tutorial on the principles of quantitative XRF spectroscopy, and George Havrilla of Los Alamos National Laboratories described recent advances in XRF spectroscopy, in particular the development of confocal micro-XRF that can enable three-dimensional nondestructive elemental imaging.

On the second day, participants used handheld XRF spectrometers to carry out a series of experiments designed to highlight instrumental characteristics and to explore functionalities. Prior to the meeting, eighteen institutions participated in a round-robin analysis of copper and aluminum alloys, the results of which were discussed at the workshop. Although the results provided by the various participants were generally in agreement, it was apparent that a more standardized approach to quantification should be developed. The participants agreed to the creation of a set of common reference materials that could be shared among cultural institutions. The ideas generated by the participants during the meeting will help shape the way this important technique is applied to the study of works of art, in order to ensure its maximum effectiveness.

The next meeting has been tentatively scheduled for 2008 in conjunction with the Denver X-ray Conference, a leading forum for scientists working in the field of X-ray analysis. For further information, please contact Karen Trentelman at ktrentelman@getty.edu.