An accurate model for the determination of the kinetic coefficients of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium

Talanta. 2009 Dec 15;80(2):1034-8. doi: 10.1016/j.talanta.2009.08.030. Epub 2009 Aug 28.

Abstract

The reaction rate of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium is first order in copper and oxygen concentrations, Michaelis-Menten in pH and a complex, asymmetrical bell shaped function in iodide concentrations. A theoretical, multivariate reaction rate equation was proposed which enabled to optimise the various kinetic coefficients. During the parameter optimisation, the experiments were weighted taking into account all measurement uncertainties, i.e. both on the reaction rate (output) and on the reactants' concentrations (inputs). This has two important advantages: (1) the model can be statistically checked to be acceptable for the description of the available measurements, and (2) the parameter uncertainties can be estimated accurately. In this case study, the model was indeed validated to be acceptable and the kinetic parameters could be estimated with a standard deviation between 5% (minimum) and 16% (maximum). As an application of this model, copper concentrations can be determined.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / chemistry*
  • Algorithms
  • Catalysis
  • Copper / analysis
  • Copper / chemistry*
  • Hydrogen-Ion Concentration
  • Iodides / chemistry*
  • Kinetics
  • Models, Chemical*
  • Oxidation-Reduction
  • Oxygen / chemistry*
  • Reproducibility of Results
  • Water / chemistry

Substances

  • Acids
  • Iodides
  • Water
  • Copper
  • Oxygen