Colloidal Particles in Sediment Pore Waters: Particle Size Distributions and Associated Element Size Distribution in Anoxic and Re‐oxidized Samples, Obtained by FFF‐ICP‐MS Coupling

Abstract

Pore water samples from sediment cores of the rivers Saale and Elbe were examined for variations of colloidal heavy metal associations during transition from anoxic to oxic conditions. Asymmetric flow-field flow fractionation coupled to ICP-MS was used to collect size distributions and element-size distributions simultaneously. The data obtained reveal an increasing amount of colloidal bound main and trace elements in the pore waters during oxidation. Although there was a significant trend to increasing colloid concentrations and colloidal bound heavy metals over the observed 48 hour period of oxidation, differences between both samples were obvious. Values for molecular mass are approximated, since the spatial extension of macromolecules (humic substance) is depending on molecular structure and surrounding conditions. Operationally defined cut-offs are given for classical laboratory filtration (0.45 µm) and settling (2 µm).Größenbereiche natürlicher kolloidaler Partikel in nm und kDa. Die Molekülmassen sind Näherungswerte, da die Raumausdehnung von Makromolekülen (Huminstoffe) von der Molekülstruktur und den Umgebungsbedingungen abhängt. Die Werte für 0.45 µm (Filtration) und 2 µm (Sedimentation) sind als operationell definierte Trenngrenzen angegeben.

A Review of the Properties and Processes Determining the Fate of Engineered Nanomaterials in the Aquatic Environment

“…Because of their importance for environmental processes, natural iron oxide colloids and IONM have been investigated intensively (Banfield and Zhang, 2001). Due to their relatively straightforward synthesis (although receiving a certain property in a reproducible way can become an art) and widely available synthesis protocols (Schwertman and Cornell, 2000) they have been used as model colloids/NMs to understand aggregation processes (Hunter et al, 1997;Mylon et al, 2004;Baalousha et al, 2008) and colloidal/nanoparticulate transport Grolimund et al, 1998;Kuhnen et al, 2000) and contaminant cotransport in freshwaters, soil porewaters (Von der Kammer et al, 2004), and groundwaters (Forstner et al, 2001).…”

Analysis of engineered nanomaterials in complex matrices (environment and biota): General considerations and conceptual case studies

“…31,2012fresh water sediments. An individual porewater subsample would be beneficial to determine the pore water dispersed fraction [67]. Porewater extraction, however, must consider the selective separation or loss of nanoparticles during centrifugation or porewater extraction/filtration.…”

Detection and characterization of engineered nanoparticles in food and the environment

“…FFF coupling techniques have been successfully applied in geochemistry and natural colloid research as well as studies into the behaviour of engineered nanoparticles. Applications range from colloids in fresh and marine water to size separation of soil suspensions (Ranville et al 1999;Hassello¨v et al 1999a,b;Chen and Beckett 2001;Lyven et al 2003;Siepmann et al 2004;von der Kammer et al 2004von der Kammer et al , 2005aStolpe et al 2005;Baalousha et al 2005a;Graff and Frazier 2006;Lead and Wilkinson 2006;Gimbert et al 2006;Peng et al 2006;Baalousha et al 2006a,b;Baalousha and Lead 2007). Also, singlewalled carbon nanotubes have been length-separated by dielectrophoresis FFF (Peng et al 2006) and many engineered nanoparticles, such as SiO 2 , metals, metal oxides, carbon black, etc.…”

“…An increasingly popular combination in this respect is FFF-ICP-MS, which allows the size separation of the sample with quantitative and elemental analysis of the obtained size fractions. This development is highly promising for nanoparticle analysis, as particles can be simultaneously sized and analyzed in their original environment (Ranville et al 1999;Hassello¨v et al 1999a,b;Lyven et al 2003;von der Kammer et al 2004;Bolea et al 2006;Baalousha et al 2006a).…”