Extraction of yttrium and some of the lanthanoids by diisodecylphosphoric acid (DIDPA) has been studied as a function of nitric acid concentration in the aqueous phase and concentration of the DIDPA in n-dodecane. The distribution ratio of yttrium was found to increase with the second power of concentration of the extractant and decrease with the third power of concentration of nitric acid. As the concentration of yttrium in the organic phase increased, an amorphous solid was found to precipitate and the composition of the solid was determined to be Y(DIDP)3. To dissolve Y(DIDP)3 into n-dodecane, a 14-fold molar excess of DIDPA was required over Y(DIDP)3. The distribution ratio of yttrium was found to be too high to back-extract this element by nitric acid of medium concentration.
Distribution coefficients of fission products on a cation exchanger in 1M nitirc acid were measured as a function of the pressure by means of the column method. The distribution coefficients were found to decrease with the pressure, and this became more pronounced with increasing charge of the ions. The distribution coefficients of yttrium and RuNO3+ decreased with the pressure to a relatively greter extent than lighter lanthanides, and RuNO3+ appeared at a separate peak from europium in the elution chromatogram as the pressure was increased up to 900 kg/cm2.
The results for the extractions of divalent (manganese, cobalt, zinc and cadmium) and trivalent (gallium and indium) metals and hexavalent uranium from aqueous solutions by various extractants such as organophosphorus compounds (tributyl phosphate, trioctylphosphine oxide, di-(2-ethylhexyl)phosphoric acid and 2-ethylhexyl 2-ethylhexylphosphonic acid), sulfur-containing compound (dihexyl sulfoxide), high-molecular weight amines (trioctylamine and trioctylmethylammonium chloride) and 7-alkylated hydroxyquinoline (7-(5,5,7,7-tetramethyl-1-octen-3-yl)-8-hydroxyquinoline are discussed in the viewpoint of separation chemistry.
It was found that the reaction of sodium nitrite with ruthenium trichloride proceeds at room temperature even without hydrochloric acid, giving disodium hydroxotetranitronitrosylruthenate /Na2RuNO/NO2/4OH/. No appreciable amount of nitrogen oxide evolved in the reaction.
The variations in concentrations of 12 elements (Na, Mg, Cl, K, Fe, Co, Zn, Se, Br, Rb, I and Cs) were investigated by thermal neutron activation analysis. Variation patterns were given in their concentration with the progression of lactation day: (1) a constant level without significant variations in time; (2) a progressive depletion throughout lactation; (3) a rapid decrease in the early stage of lactation, which does not continue significantly during late lactation; (4) an initial increase in the early stage of lactation followed by decrease in concentration levels. The behaviours in concentrations of Mg, Fe, Co, Zn, Se, I and Cs are similar in both rat and mouse milks. Different patterns between both milks were observed in the concentrations of Na, Cl, K, Br and Rb, and those of these elements including Mg and I seemed to be influenced by maternal dietary intakes.
The distribution coefficient of silver for a strongly acidic cation exchanger of the sulfonic acid type was measured as a
function of time, pH, the concentration of silver and of the bulk electrolyte. At lower pH, the distribution coefficient increases
with increasing pH, with a slope of +1. The distribution coefficient then decreases with increasing pH with a slope between
−0.2 and −0.3. The tendency was the same for four brands of exchanger. The distribution coefficient decreases with decreasing
concentration of silver. The phenomena cannot be attributed to silver hydrolysis or silver radiocolloid formation but should
be ascribed to the substance released from the exchange resin itself.
Non-destructive photon activation analysis with 30-MeV bremsstrahlung has been applied for the determination of zirconium in biological materials. The materials investigated were the NBS SRMs Orchard Leaves and Bovine Liver, and various tissues of rats. The detection limits of this method for a 2 h irradiation are 0.1 g for Orchard Leaves, 0.04 g for Bovine Liver and animal tissues. The zirconium contents of animal tissues obtained in this work appear to be significantly lower than the values reported earlier. New data on zirconium in the NBS SRMs are presented.
The complexes of molybdenum(VI) with trioctylamine (TOA, R3N) and trioctyl methylammonium chloride (TOMAC, R3R'NCl) were prepared by drying in vacuo the organic solutions for the extraction of molybdenum(VI) from hydrochloric acid solutions at low and higher acidities, respectively, by TOA and TOMAC in benzene. The resulting complexes were examined by thermal analysis (TG and DTA) in air and under the atmosphere of nitrogen, and their thermally decomposed products such as volatile matters and residues by gas chlomatography, X-ray diffraction study and infrared spectrophotometry. It was found that their complexes decompose thermally to MoO3 by cracking of alkyl groups combined with molybdenum(VI) ion. Accordingly the thermal decomposition process of those complexes is discussed and the probable structure of the complexes is proposed on the basis of the results obtained.
Rutnenium volatilized from boiling nitric acid with an induction period, which depended on both the concentrations of nitric acid and ruthenium in the solution. The lower the nitric acid concentration, the longer the induction period. A high ruthenium concentration brought about a reduction of the induction period. The rate of volatilization of ruthenium did not directly depend on the concentration of nitric acid. The addition of 0.1M ferric ion to the ruthenium solution retarded volatilization rate of ruthenium to one twentieth under boiling of the solution.
Volatilization behaviour of ruthenium from boiling solutions has been studied using106Ru-labeled (Na2 RuNO(NO2)4OH). The volatilization rate of ruthenium was measured at a constant concentration of nitrate in various acidities using a mixture of nitric acid and sodium nitrate. Volatilization of ruthenium was found to accur after a certain induction period depending on the acidity. However, the volatilization rate was constant at acidities greater than 3M in the presence of 10M nitrate. Ruthenium volatilized from a mixture of nitric acid and sulfuric acid, but the volatilization rate and induction period were independent of the mixing ratio of both acids.