Portable EDXRF and principal component analysis for inorganic element determination and provenance of eye shadows

Nowadays cosmetic products play an important role in the life of almost all people. Men and women devote much time, resources and efforts to cultivate personal hygiene and the best possible look along their lives. One of the most widely used kind of cosmetics is eye shadow. X-ray fluorescence (XRF) is a well-established technique, known for its ability to identify and quantify inorganic species in a simple, fast and non-destructive way, however, it is not extensively used in cosmetic analysis. In order to show the potentiality of the technique, portable energy-dispersive X-ray fluorescence spectrometry has been employed in the quantification of inorganic elements in 40 Brazilian eye shadows. It was possible to identify and quantify the elements Cl, K, Ca, Ti, Cr, Mn, Fe, Cu, Zn and Bi. Using principal component analysis, specific manufacturers could be distinguished. The X-ray fluorescence methodology associated with principal component analysis proved to be a valuable tool for the discrimination and characterization of cosmetics. (author)