Analysis of chemically reacting systems by sedimentation-diffusion equilibrium

A novel procedure to evaluate equilibrium constants from sedimentation-diffusion equilibrium data of analytical ultracentrifuge runs is proposed. It is shown that, by comparison of a reacting mixture at chemical equilibrium with a non-reacting but equally composed one, the sum of the mean concentrations of the reaction products can immediately be taken from optical absorption or from interferometric measurements. In most but not in all cases the use of stacked double-sector centerpieces is required.