Collect. Czech. Chem. Commun. 1987, 52, 582-586

Simple model of equilibration dynamics of a membrane electrode for determination of CO2

Karel Lívanský

Institute of Microbiology, Czechoslovak Academy of Sciences, 379 81 Třeboň


A differential equation is derived describing the course of pH measured by a membrane electrode after a stepwise change in the concentration of CO2 in the measured solution on the assumption that a chemical equilibrium exists between the concentration of CO2 and pH in the solution of hydrogen carbonate forming the inner electrolyte of the membrane electrode. The equation involves chemical equilibrium constants and an adjustable parameter. Calculations were carried out for selected literature data.