[en] Personnel conducted testing to determine the apparent solubility of benzene in potassium tetraphenylborate (KTPB) slurries. The lack of benzene vapor pressure suppression in these tests indicate that for a 6.5 wt percent solids KTPB slurry in 4.65 M Na+ salt solution at approximately 25 degrees Celsius, no significant difference exists between the solubility of benzene in the slurry and the solubility of benzene in salt solution without KTPB solids. The work showed similar results in slurry with 6,000 mg/L sludge and 2,000 mg/L monosodium titanate added. Slurries containing tetraphenylborate decomposition intermediates (i.e., 4,200 mg/L triphenylboron (3PB), 510 mg/L diphenylborinic acid (2PB) and 1,500 mg/L phenylboric acid (1PB) or 100 mg/L tri-n-butylphosphate (TBP)) also showed no significant difference in benzene solubility form filtrate containing no KTPB solids. Slurry containing 2,000 mg/L Surfynol 420 did exhibit significant additional benzene solubility, as did irradiated slurries. The vapor pressure depression in the irradiated slurries presumably results from dissolution of biphenyl and other tetraphenylborate irradiation products in the benzene

[en] Speciation refers to the use of different fractionation techniques by which information on radionuclide species can be obtained. Techniques fractionating species according to size and charge properties allows information on size classes and reactivity classes to be obtained. Fractionation of radionuclides should take place in situ, at site or shortly after sampling. There are some few in situ size fractionation techniques for radionuclides in waters. In sea water large capacity (tangential flow systems) is needed, while hollow fibre systems can often be applied for rivers and lakes. By interphasing chromatographic systems (ion exchange columns) with hollow fibres, in situ sampling, size and charge fractionation can be performed simultaneously. For small volume soil waters in situ suction techniques may suffer from methodological effects. Structural information on radioactive particles or colloids can be attained by using different electron microscopy techniques. Separation of radionuclide species in solid samples is still an analytical challenge. Grain size analysis and determination of radionuclides associated with the sand, silt, clay and colloidal fractions should be combined with sensitive surface analytical techniques. Reactivity studies using extraction reagents can be useful for distinguishing between reversible and irreversible (or slow reversible) kinetics processes. Repeated extractions with inert electrolytes (or by lowering pH gradually) should reflect if reversible processes (e.g. physical, electrochemical sorption) take place. In contrast, information on irreversible processes (e.g chemisorption) is obtained if strong red/ox agents are needed for dissolution of species (binding rupture). The paper will focus on available size or charge fractionation techniques which should be useful within radioecology

[en] This developed spectrophotometric method is helpful to determine and control the total aromatic contents in kerosene, during the treatment process of kerosene with conc. H sup 2 SO sup 4 and P sup 2 O sup 5 to remove aromatics, which have negative effect on the solvent extraction coefficient KD of uranium from the Syrian phosphoric acid, where kerosene is used as diluent. this method is rapid according to others, and simply, using the standard curve prepared by the separated aromatics from the Syrian kerosene, A =f (C) at 272 nm, we can calculate the aromatic contents in the known samples. (author). 24 Refs., 5 Figs

[en] The analytical method was elaborated with the purpose to increase detection limit and radiation safety of labelled iodide determination. The method includes oxidation of iodide by iodate in diluted sulphur acid solution with molar concentration 0,03-0,04/moles/litre at molar ratio of iodide to iodate I^-:IO^-₃ 1:12,5. The extraction of I₂ produced is done by toluene. (author)

[en] Extraction of Pr(III), Ho(III) and Er(III) has been studied in the pH range of 1-10 with N-benzoyl-N-phenylhydroxylamine (BPHA) in benzene. The separation was found to be quantitative in borate media from pH 7 to 10, at an ionic strength of 0.1M (H⁺, BO^3-₃). The stoichiometric composition of the complexes under the optimal conditions of shaking time, pH and reagent concentration was formulated using slope analysis and found to be M(BPHA)₃, where M = Pr(III), Ho(III) and Er(III). The effect of various masking agents shows that citrate, ascorbate, EDTA, oxalate, fluoride and phosphate from stable complexes with these rare earths as compared to BPHA. The decontamination factors for different cations with respect to these rare earths under the optimum conditions have been evaluated. (author). 13 refs., 3 figs., 4 tabs

[en] Short communication

[en] Short communication

[en] During the isotopic separation processes steps by laser of an atomic vapor (the Silva process which is an uranium enrichment technology), the uranium atoms, introduced initially in the separator into a solid form, is transformed successively into a liquid and a vapor phase. The vapor phase is then partially ionized and forms thus a plasma before condensing again. The study of the Silva process is then a unique exploration field of the uranium different states which are detailed in this work. (O.L.). 5 figs

[en] A method for selectively removing yttrium-90 from its parent strontium-90 contained in an environmental sample includes loading the sample onto a column containing a chelating ion-exchange resin capable of retaining yttrium-90; washing the column with a solution capable of removing strontium, calcium, and other contaminants from the yttrium-90 fraction retained on the column; removing excess acetate salts from the column; eluting yttrium-90 solution from the column and adjusting the pH of this solution to about 2.7; filtering the yttrium-90 solution and weighing this solution for gravimetric yield; and, counting the yttrium-90 containing solution with a radiological counter for a time sufficient to achieve the statistical accuracy desired. It is preferred that the chelating ion-exchange resin is a ligand having the chemical name iminodiacetic acid mounted on a divinyl benzene substrate, converted from sodium form to ammonia form

[en] The possibility of application of chelating resin with amidoxime functional group for isolation and concentration of metal ions from aqueous solutions at trace levels was investigated. The resin was prepared by aminolysis of acrylonitrile-divinylbenzene copolymer with hydroxylamine. Optimum conditions of sorption and elution of Fe, Mn an Mo ions were determined. A number of determinations of Fe(III), Mn(II) and Mo(VI) ions in samples of natural waters of various chemical composition have been performed to collect documentary data on quantitative isolation and determination of trace amounts of metal on amidoxime resin. (author). 9 refs, 2 figs, 3 tabs