Extraction Of Sr Research Articles

COMPLEXATION OF STRONTIUM IN THE SYNERGISTIC EXTRACTION SYSTEM DICYCLOHEXANO-18-CROWN-6, VERSATIC ACID, CARBON TETRACHLORIDE

ABSTRACT The synergism in the extraction of Sr⊃ +⊃ from 0.5M Sr(NO⊂3⊂) ⊂2⊂ by 0.05M dicyclohexano-18-crown-6 (DC18C6) + 0.1M Versatic 1519 (abbreviated v-acid or RCOOH, a neo carboxylic acid) in CCl⊂4⊂ has been found to stem from a strong 1:1 interaction between DC18C6 and Sr⊃2+ ⊃ However, both nitrate and carboxylate can function as the anion for the (DC18C6)Sr⊃2+⊃ moiety. At aqueous conditions corresponding to less than complete loading (i.e., [Sr⊃2+⊃[ org < 0.05M for pH < 11.7), (DC18C6)Sr(NO⊂3;)⊂2⊂ precipitates as a solid. As the pH is raised in the interval 7 < pH < 11.7 to deprotonate the V-acid, the precipitate (DC18C6)Sr(NO⊂3⊂) ⊂2⊂ becomes solubilized first with probable formation of a mixed-anion complex and finally with quantitative (0.05M) formation of the monoraeric complex (DC18C6)Sr(OOCR) ⊂2⊂ H⊂2⊂O at pH = 11.7 as confirmed by viscometric titration of 0.05M DC18C6 in wet CCl⊂4⊂ with Sr(OOCR) ⊂2⊂, Karl-Fischer titrations, vapor-phase osmometry, and IR spectrophotometry.

Solvent extraction of calcium(II) and strontium(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone

The extraction of calcium and strontium from aqueous solution with 1-phenyl-3-methyl-4-acyl-5-pyrazolone (C n) in MIBK and benzyl alcohol has been studied. In the extraction of Sr with 4-acyl derivatives-MIBK systems, the pH 1/2 values change with increasing the length of acyl chain in the derivatives. The reagent C 3 is more suitable than the other reagents for the separation of Ca and Sr, using MIBK as solvent.

87 Sr/ 86 Sr ratio measurements on sulfides, carbonates, and fluid inclusions from Pine Point, Northwest Territories, Canada; an 87 Sr/ 86 Sr ratio increase accompanying the mineralizing process

Crystallization of fine-grained, early diagenetic dolomite and later coarse dolomite has occurred in Sr isotope equilibrium with Devonian sea water ( 87 Sr/ 86 Sr = 0.7082). Extraction of radiogenic Sr from silicates in the metal source sediments by mineralizing brines.--Modified journal abstract.

Separation of137Cs and90Sr from mineralizates of biological materials by dicarbolide of cobalt

The distribution of some radionuclides in the course of137Cs and90Sr extraction and scrubbing between organic and water phase was determined.137Cs and90Sr were isolated from the mixture of radionuclides in mineralized biological materials. Dicarbolide of cobalt i. e. 3,3′-commo-bis[undecahydro-1,2-dicarbo-3-closo-dodecaborate] was used as an extracting agent. Quantities of the extracted radionuclides were determined by gamma spectrometric technique. Single and repeated extraction of90Sr with 0.01M resp. 0.1M dicarbolide of cobalt in nitrobenzene and scrubbing of coextracted radionuclides by 0.5M HNO3 were studied. The extraction of90Sr was investigated from solutions of a hydrofobizing agent in the same way. Finally, the quantitative extraction of137Cs followed by the extraction of90Sr from mixtures of radionuclides in a mineralized biological material was studied. Extraction yields from dry and wet mineralizates of biological tissues, from urine and milk were compared. Suitable working conditions for the separation procedures were selected.

Variation with Flow Rate of the Extraction of Sr 85 by Bone from Blood in the Dog

Variation with Flow Rate of the Extraction of Sr 85 by Bone from Blood in the Dog

Solvent Extraction of Alkaline Earths with 1-Phenyl -3-Methyl 4 Stearoylpyrazol - 5 - One and Topo

Abstract The synergic extraction of Ca, Sr, and Ba ions from aqueous solutions into cyclohexane or benzene containing 1- pheny 1 - 3 - methyl - 4 - stearoylpyrazol - 5 - one (HPMSP) and TOPO has been studied. Quantitative extraction (log D>2) was attained at pH>5.4 for Ca, pH>6.5 for Sr, and pH>7.3 for Ba when cyclohexane containing 0.05 M HPMSP and 0.01 M TOPO was used, and the corresoponding values for benzene were 6.5, 7.8, and 8.4. Extracted species were M(PMSP)2(TOPO)3 (M=Ca, Sr, Ba) for cyclohexane and Ca(PMSP)2(TOPO)3 and Sr (or Ba) (PMSP)2(TOPO)2 for benzene.

Extraction of alkaline earth cations from aqueous solutions by crown ether carboxylic acids

Solvent extraction of Mg, Ca, Sr, and Ba cations from aqueous solutions by sym-dibenzo-16-crown-5-oxyacetic acid (1), sym-dibenzo-13-crown-4-oxyacetic acid (2), and sym-dibenzo-19-crown-6-oxyacetic acid (3) in chloroform has been investigated. Influences of pH and metal ion concentration in the aqueous phase upon the concentrations of metal(s) and complexing agent in the organic phase are assessed for single ion (with 1) and competitive (with 1, 2, or 3) extractions. Marked differences in the efficiency and selectivity order for single ion and competitive extractions using 1 are noted. Although chloroform phase extraction complexes of MA/sub 2/ are indicated for each crown ether carboxylic acid, 1 surpasses 2 and 3 in extraction efficiency and selectivity. The crown ether carboxylic acids 1, 2, and 3 are superior extraction agents to closely related neutral crown ethers and to phenoxyacetic acid.

Extraction of americium, lanthanides and some fission product elements by bidentate phosphonates

The extraction of Am, Eu, Ce(III), Zr(IV), and Sr from aqueous nitric acid— nitrate media by dibutyl N,N-diethylcarbamylphosphonate and dibutyl N,N-diethylcar-bamylmethylenephosphonate dissolved in carbon tetrachloride was studied. The trivalent actinide and lanthanide elements may be separated in certain aqueous phase acidity regions from Fe(III), Zr(IV), and Sr, whereas the separation of actinide elements from the lanthanide elements is poor. The extractant to metal ratio in the extracted complexes of Am, Eu, and Ce(III) is 3. The interferences in the extraction due to acidic impurities in the extracting agent are discussed.

Extraction of Lanthanoids (III) with Di-isodecyl Phosphoric Acid from Nitric Acid Solution

The extraction of Nd(III) with di-isodecylphosphoric acid was studied and compared with that by di(2-ethylhexyl) phosphoric acid. DIDPA possesses higher Df values in a strong acid medium but poorer separation factors against lanthanoids(III) than that of DEHPA. Mono (2-ethylhexyl) phosphoric acid increased extraction of Nd(III) with DIDPA in a similar manner as in the case of DEHPA, by a factor of Df of 103. The extraction of Sr(II) was also investigated with DIDPA, which showed a maximum of Df at pH 5.0. Results showed that DIDPA is a promising extractant for the partitioning of the high level liquid waste.

Effects of radiolysis of di(2-ethylhexyl)phosphoric acid upon the extraction of strontium(II)

The radiolysis of di(2-ethylhexyl)phosphoric acid causes deterioration of the extraction of Sr(II) at about pH 5. This effect is attributed to the main radiolysis product, mono(2-ethylhexyl)phosphoric acid. However, MEHPA shows an ability of extracting Sr(II) in an acid medium. The presence of TBP prevents MEHPA from extracting Sr(II) in acidic solutions. The decrease of Df due to γ-irradiation is almost consistent with that estimated from the G values for the decomposition of DEHPA and formation of MEHPA. The diluent effect of radiolysis on the extraction was also determined.

Extraction of Lanthanoids (III) with Di-isodecyl Phosphoric Acid from Nitric Acid Solution

The extraction of Nd(III) with di-isodecylphosphoric acid was studied and compared with that by di(2-ethylhexyl) phosphoric acid. DIDPA possesses higher Df values in a strong acid medium but poorer separation factors against lanthanoids(III) than that of DEHPA. Mono (2-ethylhexyl) phosphoric acid increased extraction of Nd(III) with DIDPA in a similar manner as in the case of DEHPA, by a factor of Df of 103. The extraction of Sr(II) was also investigated with DIDPA, which showed a maximum of Df at pH 5.0. Results showed that DIDPA is a promising extractant for the partitioning of the high level liquid waste.

Extraction of cesium and strontium into nitrobenzene in the presence of arsenic acid—catechol complex

The extraction of Cs and Sr into nitrobenzene in the presence of complex of arsenic acid and catechol is described. The dependence of distribution ratio of Cs and Sr on the concentration of HNO3, NH4NO3, NaNO3, and the reagent concentration were determined. On the basis of these results a probable mechanism of Cs and Sr extraction was suggested.

Acidic organophosphorus extractants—XVI Effect of tri- n-butyl phosphate on the extraction of some metals by di-(2-ethylhexyl) phosphoric acid in n-hexane

Tri- n-butyl phosphate (TBP) causes only an antagonistic effect on the extraction of Eu(III), Am(III), Zr(IV) and Nb(V) by di(2-ethylhexyl) phosphoric acid (HDEHP) in n-hexane from aqueous solutions containing perchlorate, citrate and nitrilotriacetate at log [H +] = −2·87 and in extracting Eu(III) from a perchlorate solution at log [H +] = −0·70. A weak synergic effect occurs in the extraction of Sr(II) from solutions containing perchlorate and citrate at log [H +] = −2·87. The complexes Eu A 3 . H A . yB (with A, H A and B denoting the anion of HDEHP, the molecule of HDEHP and the molecule of TBP respectively), Eu A 3 . yB and possibly also Eu A 2(ClO 4) . yB are extracted from 0·2 M HClO 4 + 0·8 M NaClO 4. With 0·10 M citric acid +0·15 M monosodium citrate +0·85 M NaClO 4 as the aqueous phase, the complexes Eu A 3 . 3H A, Am A 3 . 3H A′, Sr A 2 . 2H A. B and Sr A 2 . 2H A . 2 B prevail in the organic phase at the TBP concentration 0·08−0·1 F, while the complexes Eu A 3 . H A . yB, Am A 3 . H A. yB, Sr A 2 . yB, Sr A 2 . H A. yB and probably also Sr A 2 . 2H A . yB are formed at 1·0 F TBP. The value of y in the above complexes could not be determined.

The Determination of Trace Elements in Brine by Atomic Absorption

A method for the determination of Mn, Fe, Co, Ni, Cu, Zn, and Pb in oil field brines is described. The elements are concentrated by passing 200 ml of the brine through a column of Dowex A-1 chelating resin. The pH of the resin is adjusted to 4.5 with ammonium chloride. At this pH, the trace metals are retained on the resin and the sodium and other alkali metals allowed to pass through. The metals are then eluted with 1 N HCl to a final volume of 50 ml and the concentration of the elements determined by atomic absorption. The method is compared with the standard additions method and coefficients of variation calculated for both methods. The advantages and disadvantages of both methods are discussed. A similar method is described for the extraction and analysis of Ca, Mg, and Sr. Six oil field brines were analyzed using the described method and the results tabulated.

Bestimmung von90Sr auf der Ionex-Säule in Milch und Knochen Unter Berücksichtigung der Komplexen Eigenschaften Einiger Reagenzien

The determination of90Sr is extremely difficult in biological materials by chemical meth ods owing to the quantity of calcium associated. The problem consists of the quantitative removal of calcium and of the selective extraction of90Sr using strontium carrier. It can be solved by precipitation and extraction methods, or by ion exchange chromatography. Following our previous works, experimental evidence is presented using ion exchange technique for these purposees, where complex compounds are used as eluents for calcium removal. For the determination of90Sr in milk and bones, calcium was removed with 1,2-diamino-cyclohexane-N,N,N′,N′-tetraacetic acid (CyDTA) eluent from Amberlite IR-120 column. Our results show that compounds of chelatone type used as eluents with a strong acidic cation exchanger column are the most convenient, for they prefer to compound with ligands of weaker or mean complexibility (hydrochloric acid, citric acid and lactic acid).

Acidic organophosphorus extractants—VI: Extraction of calcium and strontium by dioctyl phosphoric acids in various diluents

The solvent extraction of Ca(II) and Sr(II) by di- n-octyl and di-(2-ethyl hexyl) phosphoric acids has been studied radiometrically. n-Heptane, cyclohexane, butyl ether, carbon tetrachloride and toluene were used as diluents. The effect of extractant structure and diluent nature on the composition of Ca(II) and Sr(II) complexes in the organic phase as well as on the efficiency of Ca(II) and Sr(II) extraction and separation is discussed.

A new method for the carrier-free production of 90y from 90sr- 90y mixture and 89sr from neutron-irradiated y 2o 3

The extraction of strontium(II) and yttrium(III) ions from aqueous solutions at various pH values into methyl isobutyl ketone containing I-phenyl-3-methyl-4-caprylpyrazolone-5 is described. Quantitative extraction of Sr and Y at pH 8.6–10 and pH 2.8–5.4 respectively is utilized for the carrier-free production of 90Y from 90Sr– 90Y mixtures and 89Sr from neutron-irradiated yttrium oxide. A clean separation of these elements from each other and more than 95% calculated activities were recovered

Extraction of Ca(II), Sr(II) and Ba(II) by acidic esters of phosphorus oxy acids

The extraction of Ca(II), Sr(II) and Ba(II) from aqueous mineral acid, in the presence and absence of the corresponding sodium salt, into xylene solutions of (GO) 2PO(OH), G = 2-ethyl hexyl and para (1,1,3,3 tetramethyl butyl) phenyl, and of (GO)G′PO(OH), G = n-octyl and G′ = phenyl and chloro methyl, has been investigated radiometrically. The distribution ratio, K, has been found to be inversely second-power dependent upon the hydrogen ion concentration in the equilibrated aqueous phase. The dependency of K upon the concentration of extractant in the equilibrated xylene phase was found to be 2·5-power for Ca and Sr and 3·0-power for Ba in systems involving bis [para (1,1,3,3 tetramethyl butyl) phenyl] phosphoric acid or n-octyl hydrogen chloromethyl phosphonate; 3·0-power for Ca, Sr and Ba in systems involving n-octyl hydrogen phenyl phosphonate; and 3·0-power for Ca (Sr and Ba not proved) in systems involving bis(2-ethyl hexyl) phosphoric acid. The effect of structural differences in the extractants is discussed, and the extraction of alkaline earths (II) is compared with that of Pm(III) and Cm(III).