From summary: "The concentration of plutonium by cation exchange was significantly improved by using a solution of ammonium lactate and sulfamate as the elutriant instead of nitric and sulfamic acids. The new elutriant permitted essentially complete elution of the plutonium and also avoided formation of gases in the resin bed during elution. At 45ºC, 2.8M ammonium lactate plus 0.15M ammonium sulfamate eluted 99.3 per cent of the total plutonium at an average concentration of 43.8 grams per liter. It was found necessary to elute hydrogen and hydroxylammonium ions from the resin beds before elution of plutonium. The hydroxylammonium ions decompose to form gases in the resin bed at the desired temperature for plutonium elution. The hydrogen ions exchange with ammonium ions of the elutriant and decrease the concentration of plutonium in the eluate."