Size-elemental characterization of suspended particle matter by split-flowthin cell fractionation and slurry analysis-electrothermal atomic absorption spectrometry

An analytical methodology is presented for characterizing SPM (suspended pa rticle matter) from natural waters by using the coupling between the SPLITT (split-flow thin) cell separation and elemental spectroscopic identificati on. The results of a systematic study validating direct slurry elemental an alysis by ETAAS (electrothermal atomic absorption spectrometry) are reporte d for the determination of Al and Fe in mineral particulates, considered re presentative models of real SPM. Slurry analysis of clay-like particle mate rials was accurate in the particle size range up to 25 mu m, provided that slurry concentrations met quantitative sampling conditions. The coupled SPL ITT-ETAAS technique was then evaluated for the dimensional and elemental ch aracterization of the same samples. The developed procedure was applied to a real SPM sample from the Po river, where trace elements of environmental interest were determined for the whole fraction in the 0.2-25 mu m dimensio nal range as well as for some sub-fractions obtained by SPLITT fractionatio n.