Elemental speciation of lead, zinc and copper in sedimented dust and soil using a capacitively coupled plasma atomic emission spectrometer as detector

Abstract

A radiofrequency (r.f.) capacitively coupled plasma of low to medium power was used to analyse Pb, Cu and Zn for the speciation of these elements in sedimented dust and soil from a heavily polluted area. The torch was operated at 27.12 MHz, 185 W and 1.01 min^–1 argon flow. The speciation is based on the selective dissolution of the samples in acids and ammonium salts. The analysed species were sulfates, oxides and carbonates, silicates and sulfides, regardless of the oxidation state of the element. The speciation indicates that in the sedimented dust, Pb and Zn occur mainly as sulfides and sulfates and Cu as sulfides and oxides. The soil speciation shows a residual pollution with sulfides.