Combined solvent extraction-liquid scintillation methods for radioassay of alpha emitters

Alpha emitting nuclides frequently can be separated from one another and from interfering ions by solvent extraction procedures. If the last step of such a scheme automatically incorporates the nuclide of interest in a liquid scintillator (containing an extractant), a simple procedure for radioassay of the nuclide results. It is shovwn that correct choices of scintillators and detector systems produce further advantages. Quenching is minimized and held constant, so that the pulse height obtained from a given alpha energy is reproducible, and the energy resolution is improved over that obtainable with conventional liquid scintillation methods, so that alpha peak widths are decreased from around 1 MeV to 0.2 to 0.3 MeV at half maximum. Compatibility of several extractants with scintillator solutions is described. Procedures are described for separation and analysis of several nuclides (e.g., plutonium, uranium, and tnivalent actinides), including a specific application to the assay of plutonium in enviromnental samples. (auth