PRECONCENTRATION AND SEPARATION OF THORIUM, URANIUM, PLUTONIUM AND AMERICIUM IN HUMAN SOFT-TISSUES BY EXTRACTION CHROMATOGRAPHY

An extraction chromatographic method is described for the pre-concentr ation and separation of thorium, uranium, plutonium end americium in h uman soft tissues. Tissues such as lung and liver are oven dried at 12 0 degrees C, ashed at 450 degrees C and the ashed sample is alternatel y wet (HNO3/H2O2) and dry ashed, and then dissolved in 8M HCl. Because of the complex matrix and large sample samples (up to 1500 g), the ac tinides were pre concentrated from the tissue solution using the TRU(T M) resin (EIChroM) prior to elemental separation by extraction chromat ography and determination of americium, plutonium, uranium and thorium by alpha spectrometry. The actinides were eluted from the preconcentr ation column and each actinide was individually eluted on TEVA(TM) and TRU(TM) resin columns in a tandem configuration. Actinide activities were; then determined by alpha spectrometry after electrodeposition fr om a sulfate medium. The method was validated by analyzing human tissu e samples previously analyzed for americium, plutonium, uranium and th orium in the United States Transuranium and Uranium Registries (USTUR) . Two National Institute of Standards and Technology (NIST) Standard R eference Materials, SRM 4351-Human Lung and SRM 4352-Human Liver were also analyzed.