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

An analytical methodology is presented for characterizing SPM (suspended particle matter) from natural waters by using the coupling between the SPLITT (split-flow thin) cell separation and elemental spectroscopic identification. The results of a systematic study validating direct slurry elemental analysis by ETAAS (electrothermal atomic absorption spectrometry) are reported for the determination of Al and Fe in mineral particulates, considered representative models of real SPM. Slurry analysis of clay-like particle materials was accurate in the particle size range up to 25 mu m, provided that slurry concentrations met quantitative sampling conditions. The coupled SPLITT-ETAAS technique was then evaluated for the dimensional and elemental characterization 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 dimensional range as well as for some sub-fractions obtained by SPLITT fractionation.