A RAPID DISSOLUTION TECHNIQUE FOR TISSUE SAMPLE ANALYSIS OF TRANSURANIUMS K. D. Lee, W. J. Major, and R. A. Wessman LFE Environmental Analysis Laboratory Richmond, California ABSTRACT A rapid dissolution technique for the analysis of transuraniums in soft animal tissue samples has been developed. The sample is dissolved, tracer-free, in HNO3 in the presence of HF while being warmed on a boiling water bath in a disposable plastic bottle. After the tissue is solubilized, boric acid is added to boil off fluoride ion. Fat separates on cooling and is filtered off, ashed, dissolved, and combined with the original sample. The solubilized tissue sample may then be aliquoted for transuranium analysis. The aliquot is equilibrated with tracer by boiling in HNO3 with added H)0>. If Pu is being analyzed, the sample is cooled and NaNO» added so that the final solution is 6-8N HNO3 and ready for an anion column separation of Pu and Np from Am and Cm. The analyses are then completed by the appropriate method. The method is most suitable for samples in the 250-g size category. Larger samples can be done in increments. The dissolution is accomplished in about one hour. The method is particularly suited to the analysis of samples from injection or uptake by animals. The dissolution puts the sample into a soluble form which is most useful for obtaining a uniform counting geometry for instrumental techniques or taking a small aliquot for subsequent isotope dilution analysis. INTRODUCTION In recent years, a number of methods have been devised for ashing and dissolving large tissue samples for analysis of Pu, Am, and other nuclides. Two obvious methods are furance ashing plus acid treatment of the ash and direct wet ashing of the sample. Presently, many tissue samples at our laboratory are processed by a previously reported procedure (Major et al., 1975) in which the 277