Detection limits evaluation of a portable energy dispersive X-ray fluorescence setup using different filter combinations

In this paper, we study the performance of a portable energy dispersive X-ray fluorescence spectrometer by making use of different filter configurations at the X-ray tube output. To fulfill this purpose, we systematically investigated how the detection limits (DL) can be improved by applying three different combinations of filters (Al, Cu and Al + Cu) between the X-ray tube and standard reference materials of different average-Z matrices. The obtained results were compared with the DL obtained with a benchtop system with triaxial geometry, considered the benchmark in detection of trace elements in a variety of sample matrices. The major differences occurred for the low-Z matrices, reflecting the increase of DL for elements with emission energies between 5 and 15 keV using filters. Regarding the high-Z matrices, the use of filters did not render an effective improvement in the DL but had a positive effect in diminishing sum peaks that could hinder the evaluation of some elements.