Trace element analysis of sediments by HR-ICP-MS using low and medium resolution and different acid digestions

Abstract

For the multielement analysis of sediments (Li, Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Mo, Cd, Sn, Sb, Cs, Ba, lanthanides, Hf, Tl, Pb, Bi, Th, U) a dissolution with a hydrofluoric - sulfuric - nitric acid mixture, subsequent evaporation of the acids, dissolution of the residue by HCl, evaporation of the acid and redissolution of the residue by HNO₃ is a useful procedure which allows the dissolution of a wide range of mineral mixtures. An ICP-MS was used for the determination of the elements. For Cr, Ni, Cu and Zn the analysis may be complicated by the interferences of sulfur or chlorine species, which remain in the solution during dissolution. The best analytical results for these elements can be achieved in the medium resolution mode of a HR-ICP-MS. In the low resolution mode (quadrupole instrument characteristics) the determination of these elements should be performed by the isotopes of ⁵²Cr, ⁶²Ni, ⁶³Cu, ⁶⁸Zn as it was found that interferences from remaining acids are of minor importance.