Shading in TXRF: calculations and experimental validation using a color X-ray camera

Autor: Uwe Reinholz, Christina Streli, Velma Lopez, George J. Havrilla, Stanisław H. Nowak, Günter Buzanich, Peter Hischenhuber, Ursula E. A. Fittschen, Oliver Scharf, Martin Radtke, Andreas Meyer, Kathryn G. McIntosh, Magnus Menzel
Rok vydání: 2015
Předmět:
Zdroj: JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
ISSN: 1364-5544
0267-9477
DOI: 10.1039/c5ja00127g
Popis: Absorption effects in total reflection X-ray fluorescence (TXRF) analysis are important to consider, especially if external calibration is to be applied. With a color X-ray camera (CXC), that enables spatially and energy resolved XRF analysis, the absorption of the primary beam was directly visualized for μL-droplets and an array of pL-droplets printed on a Si-wafer with drop-on-demand technology. As expected, deposits that are hit by the primary beam first shade subsequent droplets, leading to a diminished XRF signal. This shading effect was quantified with enhanced precision making use of sub-pixel analysis that improves the spatial resolution of the camera. The measured absorption was compared to simulated results using three different model calculations. It was found they match very well (average deviation < 10%). Thus errors in quantification due to absorption effects can be accounted for in a more accurate manner.
Databáze: OpenAIRE