Getting Specific About Specific Ion Effects

Science

DJ Tobias，JC Hemminger

Have you noticed that "lite" salt, which is a mixture of KCl and NaCl, tastes slightly different from ordinary table salt, which is essentially pure NaCl? If so, then you have experienced a specific ion effect. Such effects are ubiquitous in chemical and biochemical processes involving salt solutions and have traditionally been attributed to the influence of the salt ions on the structure of water. Yet, a surge of recent research has provided compelling evidence that we should instead think about these phenomena in terms of specific ion interactions with surfaces and influences on hydrophobic interactions (1-5).