Specific ion effects in colloidal and biological systems

During the last ten years significant progress has been made in the understanding of specific ion effects. On the one hand new ideas about the origin of these effects came up, and on the other hand new experimental techniques were developed so that now even the ion concentration profile near surfaces can be measured with some confidence. In the present review some of the most important new progresses are summarised and critically discussed, especially in the context of colloidal and biological systems.