Essential and toxic elements in clays for pharmaceutical and cosmetic use

Essential and toxic elements (Al, Si, P, S, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Ba, Cd, Ce, Nd, Pb, U, Th and La) were determined by Energy Dispersive Polarised X-Rays Fluorescence Spectrometry (EDPXRF) in 15 samples of clay materials for pharmaceutical and cosmetic use. The investigated samples were grouped according to their mineralogical composition determined by X-ray powder diffraction (XRPD). Samples made up of smectites showed the lowest content of K, Zn, La, Ce, Nd, Pb, Ti and Th and the highest content of Sr, Br and U. The sample containing smectite and kaolinite displayed the lowest content of Ca, Fe, Mn, Cu, Ni, Sr and the highest amount of Al, Si, Ba, Zn, As, La, Ce, Pb and Th. Samples composed of illite demonstrated minimal amounts of Br and the maximal content of K, Rb, Ti and Fe. In all samples analyzed, Cd and Hg were below 2.0 mgkg-1.