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; Slaveykova, Vera

doi:10.1021/bm050252y

Scientific article

English

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

Contributors

Lamelas, Cristina; Avaltroni, F; Benedetti, Marc; Wilkinson, Kevin J; Slaveykova, Vera

Published in

Biomacromolecules, vol. 6, no. 5, p. 2756-2764

Publication date

2005

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.

UNIGE affiliation entities

Not a UNIGE publication

Citation (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. doi: 10.1021/bm050252y

Article (Published version)

Identifiers

PID : unige:18002
DOI : 10.1021/bm050252y

Journal ISSN

1525-7797

648views

954downloads

Creation

04/01/2012 14:19:17

First validation

04/01/2012 14:19:17

Update

14/03/2023 17:06:33

Status update

14/03/2023 17:06:33

Last indexation

29/10/2024 18:48:36

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

Contributors

Published in

Publication date

Abstract

UNIGE affiliation entities

Citation (ISO format)

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Identifiers

Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation