Eva Marguí is an Associate Professor in the Department of Chemistry of the University of Girona. She is a researcher in the Analytical and Environmental Chemistry Unit of the same University. Her research interests are focussed on the development of analytical methodologies based on XRF for the determination of elements in environmental and industrial samples. She is the author of more than thirty publications on XRF in high-level journals and has participated in different conferences in the field as an invited lecturer. She is the secretary of the European X-ray Spectrometry Association. René Van Grieken is a Professor in the Department of Chemistry of the University of Antwerp in Belgium, where he teaches instrumental analysis and environmental chemistry and is the Director of the Environmental Analysis Group within the Micro- and Trace Analysis Center. He is active with major European scientific organizations and has delivered 270 invited lectures at international scientific conferences. He has authored or co-authored over 700 publications with leading scientific journals, book publishers, and institutes in 51 countries. These publications have been cited over 11,000 times.