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

An analytical methodology 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, is presented. The results of a systematic study about the validation of the direct slurry elemental analysis by ETAAS (Electrothermal Absorption Atomic Spectroscopy), are reported for Al and Fe determination in mineral particulates, considered as representative models of the real SPM. Slurry determination of like-clay particle materials results to be accurate in the particle size range up to 25 m, provided that slurry concentrations satisfies conditions for quantitative sampling. The evaluation of the coupled SPLITT-ETAAS technique is then considered for the dimensional and elemental characterization of the same samples. The developed procedure has been applied to a real sample of SPM from Po river, where trace elements of environmental interest have been determined for the whole fraction in the dimensional range 0.2 - 25 m, and for some sub-fractions obtained by SPLITT fractionation