XRF is a proven technique for the chemical analysis of materials. Industries such as mining and cement manufacturing often analyze samples in-house for exploration and quality control. However, academic institutions, governmental agencies, museums, consultants, and non-profit entities rely on outside labs like Hamilton’s to meet their need for this kind of chemical data. Professors, as well as students, use XRF for their research projects, as in a recent study that analyzed the composition of gravestones on a remote Irish island to establish the extent of early Christian trading networks through the movement of gravestone raw materials.
At Hamilton, students from a variety of majors – including environmental sciences, archaeology, biology, chemistry, physics and geosciences – may utilize the lab for class and senior research projects. Students will be able to learn the basics of XRF spectrometry while they grind, weigh and fuse their samples to prepare them for analysis.
According to Professor of Geosciences Dave Bailey, who oversees the lab with Associate Professor of Anthropology Nathan Goodale, “The x-ray machine can be considered a kind of chemical ruler.” Fluorescence is the atomic phenomenon that allows the “ruler” to work. Fluorescence is produced when atoms give off energy (in the form of visible light or x-rays) when stimulated by light or x-rays of a shorter (i.e. more powerful) wavelength. Perhaps you’ve seen an exhibit of rocks that glow brightly under UV light? Those brilliant colors are due to fluorescence. In an XRF spectrometer, high-energy x-rays, instead of UV light, are used to excite the atoms within a sample causing those atoms to emit x-rays of their own. These fluorescent x-rays are characteristic of each element, such as iron, sodium or copper, present in the sample. The x-ray photons emitted by each element are counted by the instrument’s detectors. The number of photons per unit of time determines the intensity of the signal which is then converted to element concentrations via a computer algorithm.
In July 2015, Richard Conrey and Laureen Wagoner, the college’s XRF technicians, arrived to set up the lab. Both technicians had worked with members of Hamilton’s geoscience faculty in prior years when they ran a similar lab in the state of Washington, serving hundreds of clients from more than 40 states and 20 countries. Conrey, the lab’s senior technician, earned his Ph.D. in geology from Washington State University while Wagoner has a master’s degree, also in geology, from the same institution. They enjoy the challenge of working with unusual materials and providing high caliber data for a wide variety of research projects.
The laboratory is accepting clients, making Hamilton one of very few small colleges in the nation to offer highly precise XRF data to the general scientific community. Interested individuals and organizations should contact the lab at 315-8594590 or visit the website at www.hamilton.edu/analytical-lab.