Sedimentation Field-Flow Fractionation Coupled Online to Inductively Coupled Plasma Mass SpectrometryNew Possibilities for Studies of Trace Metal Adsorption onto Natural Colloids

Abstract

This work presents a new approach for studies of trace metal adsorption processes onto natural particles by coupling of a sedimentation field-flow fractionation system on-line to an inductively coupled plasma mass spectrometer (ICPMS). This enables size dependent separation of clay sediment particles with continuous determination of elemental composition in the different size fractions. Major elements Al, Si, Fe, and Mn were determined simultaneously together with the trace elements Cs, Cd, Cu, Pb, Zn, and La. Adsorption experiments where different metal loadings have been added to the particle populations under different pH conditions are also presented. The aim of these experiments was to distinguish between weaker and stronger binding sites as well as between surface complexation adsorption and ion-exchange mechanisms.