A method for total analysis of minor and trace elements in the soil clay fraction to atmospheric aerosols.

Abstract

Several methods recommended for soil analysis using acid digestion were tested for the total analysis of minor and trace elements of the clay fraction. The proposed method using mixtures of HClO4/HF was adequate to dissolve clay. The recovery results ranged from 84-116% for Cr and Zn respectively. The clay fraction fron four sites located in an area surrounding a copper minefield (VI Región, Chile) was analyzed for the elements Mg, Ca, Cr, Mn, Fe, Co, Ni Cu, Zn,Cd and Pb, using atomic absorption spectrometry, Na and K were determined by flame photometry. The origin of the trace elements occurring in the atmospheric aerosols, is redetermined using the results obtained by the modified method of analysis proposed in this paper. The use of the enrichment factors (EF)calculated from the composition of the local clay and the coefficients of variation are proposed as a better criterion than the EF calculated from the composition of terrestrial crust. An actual atmospheric contamination with Cu, Zn and Pb was found in this studied area.