Comparison of excitation mode in synchrotron X-ray fluorescence of environmental samples

Professor T. M. Cahill (Arizona State University) and his colleagues have recently compared the performance of the different excitation modes of synchrotron radiation X-ray fluorescence. The research team evaluated four different beamline configurations for the analysis of three representative environmental samples; a thin aerosol sample, an intermediate thickness biological sample, and a thick rare earth mineral specimen. They found that white beam excitation is optimal for the analysis of thin samples with little mass, and that filtered white beam excitation (removing lower energy X-rays by absorber) gives better sensitivity for elements emitting more energetic X-rays. In their study, monochromatic excitation, which tends to be the standard mode of operation, did not give good results in terms of sensitivity. For more information, see the paper, "Evaluation of Different Synchrotron Beamline Configurations for X.ray Fluorescence Analysis of Environmental Samples", S. R. Barberie et al., Anal. Chem., 86, 8253 (2014).