Implementation of a radiochemical procedure for the analysis of isotopes of Pu, Am and Cm in food and environmental samples.

A radiochemical procedure for the analysis of isotopes of Pu, Am and Cm was implemented during an expert mission to Thailand sponsored by the International Atomic Energy Agency. This method was to be used for the analysis of food and environmental samples, particularly those of marine origin. The project was initiated by evaluating a procedure which had recently been published by the IAEA. This procedure could not handle the wide range of matrix materials used in the testing and a program was undertaken to develop a modified procedure. Plutonium was radiochemically separated using an anion exchange procedure which gives clean separations from the matrix. Americium and curium came off the column unseparated from most of the other elements in the matrix and they were separated by using a number of steps, which were selected to handle the specific chemical and radiochemical interferences in a particular matrix material. Sources were prepared for alpha spectrometry by coprecipitation with CeF3. The procedure was tested with a wide variety of sample types and good chemical yields and separations were obtained in most cases.