The symposium which provided the incentive for this volume was conducted in San th Diego, California as a part of the 207 National Meeting of the American Chemical Society, March 13-17, 1994. It was conceived partly to continue an informal decennial sequence of sym- posia dedicated to the topic off element separations. A lot has changed in the world of f ele- ments over the last ten years, precipitating a change in emphasis which should be evident to most practitioners in the field. Production and reprocessing of nuclear fuels are no longer the principal drivers of f element separation...