The interaction of simultaneous diffusion and adsorption of pure gases and gas mixtures in a Vycor glass membrane has been studied under transient conditions in a modified Wicke-Kallenbach cell. A lumped two parameter approach was developed in order to analyse all the observed pressure responses in a unified manner. This approach was found to be capable to fit well almost all the observations made for different types of gases and at different temperatures with sufficient or excellent accuracy. (c) 2006 Elsevier B.V. All rights reserved.