Size fractionation and characterization of natural colloids by flow-field flow fractionation coupled to multi-angle laser light scattering

Using FlFFF and aTEM to determine trace metal–nanoparticle associations in riverbed sediment

“…Information about the shape of the particles, or in a first instance, the deviation from an ideal homogeneous sphere, can then be obtained by taking the ratio of these two values (r g /r h ). [40,41] Homogeneous spherical particles would have a value of 0.775 and values above this indicate an increasingly higher aspect ratio or a non-homogeneous distribution of mass (e.g. hollow spheres).…”

“…This combination of FlFFF and aTEM, therefore, gives a comprehensive picture of trace metal-nanoparticle associations. While various studies have utilised FFF coupled to light scattering, [34][35][36][37][38][39][40][41][42][43][44][45] ICPMS, [7,[46][47][48][49][50][51][52] TEM [33,[53][54][55] or some combination thereof, many of these studies focussed on organic matter, synthetic nanoparticles, or uncontaminated river water. This study uses the above mentioned techniques to provide a first look at the direct associations between mineral nanoparticles and toxic trace metals in contaminated sediment.…”

Combining asymmetrical flow field-flow fractionation with light-scattering and inductively coupled plasma mass spectrometric detection for characterization of nanoclay used in biopolymer nanocomposites

“…The theory and application of field-flow fractionation was originally developed by Giddings (Giddings 1966) and is today widely used with MALS detection for particle characterization in environmental analysis. Furthermore, coupling the non destructive technique AF 4 -MALS to inductively coupled plasma mass spectrometry (ICP-MS) gives an additional detection and quantisation possibility of a wide range of elements contained in the separated nanoparticles such as nanoclay platelets (Baalousha et al 2006;Beckett 1990;Hassellöv et al 1999;Kammer 2005).…”

Size fractionation and characterization of nanocolloidal particles in soils

“…Natural colloids are mixed complexes of silicates, inorganic oxides and humic substances (Doucet et al 2004(Doucet et al , 2005 with a broad particle size distribution and diversity of shapes (Baalousha et al 2006). Colloids in soil and water are involved in the adsorption, transport, and transformation of heavy metals, organic pollutants, and nutrients (Means and Wijayaratne 1982;McCarthy and Zachara 1989;Orlandini et al 1990; Ledin et al 1995;Lead et al 1997Lead et al , 1999Doucet et al 2001).…”

“…The primary requirements for sampling and fractionation of colloids are reliability, lack of bias, and minimum perturbation of their native forms (Baalousha et al 2005). A wide variety of techniques have been applied to fractionate colloids, including split-thin flow fractionation (SPLIFF) (Contado et al 2003), flow field-flow fractionation (FIFFF) (Benedetti et al 2002;Lyvén et al 2003;Baalousha et al 2005Baalousha et al , 2006, sedimentation field-flow fractionation (SdFFF) (Ranville et al 1999;Ran et al 2000), and cross-flow filtration (CFF, also called tangential flow filtration (TFF)) (Guo et al 2000;Hoffmann et al 2000;Wilding et al 2004;Doucet et al 2004Doucet et al , 2005. Among these fractionation techniques cross-flow filtration has perhaps been the most widely used (Powell et al 1996;Stordal et al 1996;Benoit and Rozan 1999;Guéguen et al 2002).…”