1. “Method for the determination of Pd-catalyst residues in active pharmaceutical ingredients by means of high-energy polarized-beam energy dispersive X-ray fluorescence”. Marguí E, van Meel K, Van Grieken R, Buendía A, Fontás C, Hidalgo M, Queralt I, Analytical chemistry 81, 1404 (2009).   http://doi.org/10.1021/AC8021373