John Chiment
Simple Interest
Abstract:
Trace elements are those
found in things in the parts-per-thousand to parts-per-trillion range. They
contrast with major elements found in parts-per-hundred (percent). Several
techniques measure trace elements: x-ray fluorescence (XRF), neutron
activation analysis (NAA), inductively-coupled plasma/mass spectroscopy (ICP/MS),
particle-induced x-ray emission (PIXE), ion-pair chromatography (IPC), high
performance liquid chromatography (HPLC), and multi-axis differential
optical absorption spectroscopy (MAX-DOAS) being some of the most popular.
Using the XRF system at CHESS I've been interrogating medieval manuscripts about their place of origin--looking for the signature trace elements from soils where their sheep grazed and their ink was grown; prehistoric trees from the eastern Mediterranean--looking for the volcanic gases in the atmosphere around them and the metals they absorbed to make antioxidant enzymes; and Paleozoic trilobites--looking for changes in ancient ocean chemistry.
XRF is a fast, accurate measure of the medium-weight and heavier elements. Coupled with NAA, it may provide solutions to long-standing problems in paleobiology and paleography.
2008 Run
Nov 19th - Dec 22nd
