A membrane selectively extracted a radioactive analyte from a sample solution. The membrane was prepared as thin film, and includes a soluble extractant and a collodion matrix that disperse the extractant homogeneously throughout the membrane. A membrane was formed by applying a solution including collodion, an extractant, and an organic solvent onto a surface of an aqueous solution containing a radioactive analyte. After the membrane formed on the surface, it was removed and then analyzed. The analysis proved that the membrane extracted radioactive analyte from the solution in far greater amounts compared to a control membrane prepared without the extractant.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. DE-AC52-06NA25396 awarded by the U.S. Department of Energy. The government has certain rights in the invention.