Scientific Article
previous document  unige:18002  next document
add to browser collection

Quantifying Pb and Cd complexation by alginates and the role of metal binding on macromolecular aggregation

Lamelas, Cristina
Avaltroni, F
Benedetti, Marc
Wilkinson, Kevin J
Published in Biomacromolecules. 2005, vol. 6, no. 5, p. 2756-2764
Abstract The Pb and Cd binding capacity of alginates were quantified by the determination of their complex stability constants and the concentration of complexing sites using H+, Pb2+, or Cd2+ selective electrodes in both static and dynamic titrations. Centrifugation filter devices (30 kDa filter cutoff), followed by inductively coupled plasma mass spectrometry (ICP-MS) measurements of lead or cadmium in the filtrates, were used to validate the results. The influence of ionic strength, pH, and the metal-to-alginate ratio was determined for a wide range of metal concentrations. Because of their polyelectrolytic properties, alginates may adopt different conformations depending on the physicochemistry of the medium, including the presence of metals. Therefore, molecular diffusion coefficients of the alginate were determined by fluorescence correlation spectroscopy under the same conditions of pH, ionic strength, and metal-to-alginate ratios that were used for the metal binding studies. The complexation and conformational properties of the alginate were related within the framework of the nonideal competitive adsorption isotherm (NICA) combined with a Donnan approach to account for both intrinsic and electrostatic contributions.
Full text
(ISO format)
LAMELAS, Cristina et al. Quantifying Pb and Cd complexation by alginates and the role of metal binding on macromolecular aggregation. In: Biomacromolecules, 2005, vol. 6, n° 5, p. 2756-2764.

246 hits



Deposited on : 2012-01-04

Export document
Format :
Citation style :