VEGETATION BIOLOGICAL The dissolution and concentration of vegetation samples presents far less problems than soil. Most studies of the actinides in vegetation have been for the purpose of the determination of their partition between soil and plant. Fallout under natural and greenhouse conditions and uptake of solutions of the actinides has been studied. Due to the extremely small uptake, approximately 107" to 1078, large volumes of plant material are required. The usual procedure in working with vegetation involves washing, drying, grinding, and dry ashing, after which the residues are treated according to many of the techniques described in soil. Jacobson and Overstreet (1948) studied uptake of Pu in plants using tracer-free techniques and dry ashing. Olafson (1945) processed plant samples by wet ashing using tracer-free methods. Neubould and Mercer (1962) studied the uptake of 73%pu by ryegrass in which the plant samples were wet ashed in HNO, and HC10, and any silica residues were washed. Concéntration was by coprecipitation as the fluoride with neodymium carrier. Talvitie (1971) ashed 1l-g samples of vegetation and filters in a muffle furnace, pulverized the ash, added 36 py tracer, and dissolved in HC1. Price (1972) studies the uptake of 237Np, 23%pu, 24lam, and 2*4cm by tumbleweed and cheatgrass, He pre-ashed the plant tissue with H250, before dry ashing and then pulverized the sulfated ash. Major et al. (1974) carbonized up to 500 g of dry vegetation at 250° C then ashed at 600° C. An acid dissolution, including the use of HF, was performed on the ash to solubilize actinide-containing residues. Butler (1965) and Major (1968) determined 241am in urine using 244om tracer by FILTERS Filters employed for the collection of atmospheric dust are either inorganic, such as glass fiber and ACC Type V asbestos paper, or organic, such as plastic or natural fibers. In some cases, the matrix mass is small, but for composited filter samples of 10° cubic meters of air or ultrahigh-volume air samplers with large sized (1 m@ IPC filter), the inorganic sample mass may be several grams. The inorganic filters are amenable to HF and acid dissolutions. Early procedures, Beaufait (1952), were developed for the effective dissolution of the Type V filters employed in sampling close-in and long-range fallout. Since these procedures were lengthy, organic filters having the desirable filtration and particle retention properties such as IPC and polyfiber were developed. Hunt et al. (1968) used an HNO3, HC10,, and HF procedure for Am and Cm, subsequently precipitating on La(OH),. Major and Wessman (1964), in Operation Roller Coaster, used acid dissolution on Casella and Andersen impactor discs and a f-HNO3 and HC10, boil down on sticky film samples from the Nevada Safety Tests. Talvitie (1971) ashed and dissolved in 1 N HC1. Khandekar (1976) obtained high-altitude dust samples by swiping aircraft with cotton wool soaked with white petrol, and acid leaching with better than 50% yield of Np, Pu, Am, and Cm. For microsorban (polystyrene) filters, up to Z nm’, Tracerlab (LFE) (1965) pyrolysed the sample up to a maximum of 525° C until black carbon is decomposed; the residue is treated by the soil HF dissolution procedure. $52 Biological samples, which include a variety of tissues, bone, urine, and feces, in most cases require high sample mass to obtain the necessary sensitivity for the actinides. Dehydration and decarbonization of the samples are the initial necessary steps. Special problems are fatty tissues and calcium and phosphates in bone. After such preparatory steps are complete, the procedures are those indicated for inorganic ash. Major et al. (1965) wet ashed animal samples up to 3 1b. from the Roller Coaster tests, with f-HNO;, H2S0,, HC10,. Greater than 3 1b. samples employed a Hg catalyst, K,S0,, an antifoam agent, and H2S0,. Pu was separated from the salts with a cupferron-CHCly extraction . Bone was dry ashed, dissolved in HCl, and the Pu extracted. Metabolic samples were dried, boiled to low volume with f-HNO3, ignited, and then extracted, as with the small animal samples. Sansoni and Kracke (1971) used an iron catalyzed H20) procedure for rapidly wet ashing organic matrices. For Pu and Am Major et al. (1975) cut up bovine bone and meat into small sections, added 150, and slowly ashed at 200° C then at 520° C in a muffle furnace to a white ash, and dissolved in HCl. Any residue was dissolved in HNO3, HF, H3B03, added, combined and HF and Y added. The Pu and Am are carried on the CaFo-YF3 precipitate. Crawley and Goddard (1976) studied 2%Jam and 24%cm in rats, drying, ashing at 300° C, and dissolving in HNO; with ultimate recovery of 55-65%. Shipman and Weiss (1960) isolated Pu in urine by cocrystallization with potassium rhodizon-~ ate, Bokowski (1964) determined Am in urine in the presence of Pu, coprecipitating the Pu with BiPO,, wet ashing, and counting the LaF3 slurry. , wet ashing with HNO, and HC10, and concentrating by an HDEHP extraction and coprecipitation with Fe(OH)3. Lee et al. (1975) used HNO3, HF to rapidly dissolve soft tissue samples up to 1 Kg. Undissolved fat found to be free of activity is filtered off. The method is particularly suited to the analysis of samples from injection or uptake by animals. AQUEOUS Techniques suitable for aqueous volume reduction, depending on salt content are evaporation, coprecipitation, extraction, and ton exchange. Scheidhauer et al. (1953) separated Pu from 3-liter water samples quantitati vely by chemisorption on solid CaFo. Seawater samples suitable for Pu and Am measurement require at least 60 liters for Pu and 100 for Am, according to Murray and Kautsky (1975). Pillai et al. (1964) reduced the Plutonium and then coprecipitated with Bi3(P0,)2 from 45 liters of seawater. Bowen et al. (1971) acidified the seawater, added tracer and H202, and carried the plutonium on Fe(OH) 3. Noshkin (1972) lists numerous analytical references. Miyake and Sugimura (1975) used the Fe(OH), Procedure to determine the plutonium content in Pacific Ocean waters. Murray and Kautsky (1975), after an Fe(OH) 3 step, used an HDEHP extraction to separate Pu from Am. Livingston et al. (1975) have published a review of analytical procedures for the tranguranium elements in seawater and marine sediments. 553