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

Abstract

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 mm, 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 mm dimensional range as well as for some sub-fractions obtained by SPLITT fractionation.

Particulate Phases Possibly Conveyed from Nuclear Waste Repositories by Groundwater

“…The direct determination method consists in separating the suspensions on filtering membranes of various porosities, followed by subsequent digestion and quantitative assessment of the contaminants from the separated material, by means of an adequate spectrometric technique (Blo et al, 2000;Nordstrom et al, 1999;Ödman et al, 1999;Ollivier et al, 2011;Yeager et al, 2005). Through the indirect method, both the filtered and the unfiltered water samples are analyzed in parallel, and the resulting concentration difference is considered to represent the concentration of the element bound on the SPM (Cidu & Frau, 2009;Cortecci et al, 2009;Gammons et al, 2005;Pokrovsky & Schott, 2002).…”

Quantitative Splitt Fractionation of Lagoon Sediments

“…Detailed description of this unit can be found in previous papers 9,11,19,22,23 . One Minipuls3 peristaltic pump (Gilson, Middleton, WI, USA) was employed to provide flow streams for sample A'.…”

“…Particle matter size distribution and surface characteristics are important properties affecting the mobility, role and fate of the aquatic solid phases, both sediments and SPM [4][5][6] . In recent years, classical grain size analysis has been complemented by instrumental approaches such as the Split Flow Thin Cell (SPLITT) Fractionation [7][8][9][10][11] and Field-Flow Fractionation (FFF) technique [12][13][14][15][16] . The advantage of these two methods is that they separate particles according to buoyancy mass by size and density, without perturbing their surface properties, thus allowing dimensional characterization of different size fractions.…”

Metal Content in River Suspended Particulate Matter: Data on Po River

“…River water is generally collected with sampling bottles at depths of 0.5 -2 m below the surface. [10][11][12][13][16][17][18][19][20] Principal sampling areas have been Pontelagoscuro (Ferrara), 60 km from the mouth and 600 km from the source, [10][11][12][13][16][17][18][19][20] the Po di Pila channel and, in the delta area, in the river freshwater plume on the sea surface. [18][19][20] Samples are generally stored in polyethylene bottles or tanks, previously soaked with diluted HNO 3 and rinsed with ultrapure water.…”

“…[9][10][11][12][13][14] (and references therein) A significant work in dimensional and elemental SPM characterization has been performed coupling specific techniques, Ultrafiltration (UF) and Splitt-Flow Thin Cell Fractionation (SPLITT) to set up handling procedures for sample preconcentration and prefractionation, coupled with spectroscopic techniques, Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), for elemental determination as a function of SPM size. [10][11][12][13] The first section of this paper summarizes application to the Po river samples and discusses the data with reference to last 10 years studies dealing with the distribution of heavy metals in the Po River. The importance of evaluating the metal load in the dimensionally different SPM fractions, obtained by the SPLITT fractionation procedure, is also underlined with respect to the soluble fraction.…”