Gibbs-Donnan and specific ion interaction theory descriptions of the effect of ionic strength on proton dissociation of alginic acid

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2004Suggested citation
Rey Castro, Carlos;
Herrero, Roberto;
Sastre de Vicente, Manuel E.;
.
(2004)
.
Gibbs-Donnan and specific ion interaction theory descriptions of the effect of ionic strength on proton dissociation of alginic acid.
Journal of Electroanalytical Chemistry, 2004, vol. 564, p. 223-230.
https://doi.org/10.1016/j.jelechem.2003.10.023.
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The apparent proton dissociation constants of a commercial alginic acid have been
obtained in KNO3 and NaCl at concentrations ranging between 0.01 and 2 mol·L-1. An
analysis of the dependence on the ionic strength at a constant value of the dissociation
degree was done by means of empirical functions derived from the Gibbs-Donnan
formalism for polyelectrolytes and a specific ion interaction theory (SIT). Both functions
were able to fit the experimental data, although SIT yielded rather high errors in the fitted
parameters due to a problem of multicollinearity, in contrast to the function derived from
the Gibbs-Donnan approach.