Quaternary diffusion coefficients for the sucrose-NaCl-KCl-water system at 25 °C

Transport properties of saccharide-salt aqueous mixtures are important for basic research and applications in the biochemical and biotechnological fields. We have experimentally determined the nine multicomponent diffusion coefficients for the sucrose (0.25 M) + NaCl (0.50 M) + KCl (0.50 M) + H2O quaternary system at 25 degrees C. Our results are compared with those previously obtained for all the corresponding ternary systems and binary systems. A simple excluded-volume model can be used to successfully predict the effect of sucrose on salt cross-term diffusion coefficients for ternary and quaternary systems. We have found that the ternary cross-term diffusion coefficients can be used to make reasonable estimates of the corresponding quaternary coefficients. These estimates can replace the corresponding experimental data when they cannot be measured with satisfactory precision. (C) 2010 Elsevier By. All rights reserved.