A method and composition for removing perchlorate from a highly selective ion exchange resin is disclosed. The disclosed approach comprises treating the resin in a solution of super critical or liquid carbon dioxide and one or more quaternary ammonium chloride surfactant compounds.
 The United States Government has rights in this invention pursuant to Contract No. AC04-94AL-85000 between the United States Department of Energy and the Sandia Corporation for operation of the Sandia National Laboratories and Contract No. DE-AC05-90OR22464 between the U.S. Department of Energy and Lockheed Martin Energy Research Corporation for operation of the Oak Ridge National Laboratory.