- Thursday, March 16, 2006
- Size fractionation and characterization of natural colloids by flow-field flow fractionation coupled to multi-angle laser light scattering
- Published at:Not Found
Journal of Chromatography A, 1104(2006)272-281
M. Baalousha, F.V.D. Kammer, M. Motelica-Heino, H. S. Hilal and P. Le Coustumer. .
Flow-field flow fractionation (FlFFF) coupled to multi-angle laser light scattering (MALLS) was evaluated for size and shape determination of
standard spherical and arbitrarily shaped natural colloids. Different fitting methods for light scattering data retrieved from MALLS were evaluated
to determine the particle size of spherical standards and natural colloids. In addition, FlFFF was optimized for best fractionation in connection
to MALLS, minimal colloids-membrane interaction, and minimal sample losses. FlFFF, calibrated with standard particles, was used to determine
hydrodynamic diameter, or radius (
Dh or Rh), of the fractionated colloids, whereas the MALLS was used to determine root mean square radius of
Rg) for fractionated colloids. Combining both results, by calculating the Rg/Rh ratio, allows an estimation of colloid deviation from the
shape of homogeneous sphere. Accordingly, this study demonstrates that, FlFFF–MALLS is a valuable technique for characterizing heterogeneous
and arbitrarily shaped natural colloidal particles in terms of size and shape. To check the usefulness of FlFFF–MALLS in natural colloid studies,
the technique was used to investigate the sedimentation behavior of extracted soil colloidal particles. Results illustrate that, in a silty till sample,
carbonates function as cement between the colloidal particles, and consequently, change their sedimentation behavior. On the other hand, carbonate
dissolution generates a more homogeneous colloidal sample.
© 2005 Published by Elsevier B.V.