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1.
D. R. Ghadse D. M. Noronha I. C. Pius M. M. Charyulu A. R. Joshi C. K. Sivaramakrishnan 《Journal of Radioanalytical and Nuclear Chemistry》1996,213(3):225-232
Sorption of Pu(IV) from hydrochloric acid-oxalic acid solutions has been investigated using different anion exchangers, viz., Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) for the recovery of plutonium from plutonium oxalate solutions. Distribution ratios of Pu(IV) for its sorption on these anion exchangers have been determined. The sorption of Pu(IV) from hydrochloric acid solutions decreases drastically in the presence of oxalic acid. However, addition of aluminium chloride enhances the sorption of plutonium in the presence of oxalic acid, indicating the feasibility of recovery of plutonium. Pu(IV) breakthrough capacities have been determined with a 10 ml resin bed of each of these anion exchangers at a flow rate of 60 ml per hour using a solution of Pu(IV) with the composition: 6M HCl+0.05M HNO3+0.1M H2C2O4+0.5M AlCl3+100 mg.l–1 Pu(IV). The 10% Pu(IV) breakthrough capacities for Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) are 15.0, 8.9 and 6.2 g of Pu(IV) l–1 of resin respectively. 相似文献
2.
S. C. Gupta B. B. Tak N. K. Mathur C. K. Narang 《Journal of Radioanalytical and Nuclear Chemistry》1993,170(1):3-8
Polyamino group-containing resins act both as chelating ion exchangers and weakly basic anion exchangers depending upon the species in contact in the solution. In the present work, ion exchangers based on polyamine incorporated polysaccharides (cellulose and galactomannan or guaran) have been used for removal of radioisotopes of185W as WO
4
2–
,99Mo as MoO
4
2–
and125Sb as Sb3+ from their separate aqueous solutions. These chelating anion exchangers have been synthesized by reaction of polysaccharides with epichlorohydrin followed by the respective polyamines as nucleophiles in a strongly alkaline medium. WO
4
2–
and MoO
4
2–
are adsorbed from their aqueous solutions through anion exchange process by chloride form of cellulose-triethylenetetraamine (cellulose-trien), cellulose-tetraethylenepentaamine (cellulose-tetren), guaran-triethylenetetraamine (guar-trien) and guar-tetraethylenepentaamine (guar-tetren) weakly basic anion exchangers. Guar-tetren chelating polymer has been found to be highly selective for125Sb isotopes presumably due to the presence of chelating cis-hydroxy and tetren groups in the galactomannan matrix. 相似文献
3.
Summary A cellulose collector with immobilized triethylenetetraminepentaacetic acid (TETPA) groups has been developed for multielement preconcentration (e.g., Al, Be, Bi, Cd, Co, Cu, Fe(III), In, Mn, Ni, Pb, Tl(III), U(VI), V(IV), Zn) using a low-pressure flow system. Analyte distribution coefficients Kd of the order of 104–105 ml/g (0.5 mol/l NaCl, pH 3–8) and fast exchange kinetics enable effective trace/matrix separations by means of small TETPA-filled (75 mg) columns even at high flow rates (contact time<1 s). Accordingly, recovery rates ranging from 88 (Tl(III)) to 99.5% (Ni), relative standard deviations sr mostly between 1.5 and 4.0% (off-line determined by flame AAS) and blank levels (e.g., Cu, Fe, Zn) in the lower ng range (quantified by ETAAS) can be achieved. Metal-complexing dissolved organic substances (e.g. humic substances), however, considerably lower the recovery rates of some analytes (e.g., Cu, Fe, Ni). A series of water analyses (e.g., river, sea, bog water) prove the reliability of the developed flow-preconcentration system.Dedicated to Prof. Dr. V. Krivan on the occasion of his 60th birthday 相似文献
4.
Z. Grahek I. Eškinja K. Košutić S. Lulić K. Kvastek 《Journal of Radioanalytical and Nuclear Chemistry》1999,241(3):617-626
A procedure for semi-automatic isolation and determination of radioactive strontium from natural samples was developed. The
method was tested by the determination of90Sr in soil samples and the results obtained were compared to those obtained by the standard procedure. The procedure consists
of leaching of strontium (and other cations as well) from soil samples with a water suspension of the cation exchanger Amberlite
IR-20, the separation of strontium from other cations, e.g., potassium, calcium, sodium, barium by the anion exchangers Amberlite
CG-400 or Dowex Ag 1×8 with 0.25M HNO3 in ethanol-methanol mixture as eluent in the apparatus specially constructed for this purpose. Determination of90Sr was done on the low-level gas-flow β-counter and by Cherenkow counting on the liquid-scintillation counter few hours after
the separation. It was shown that this procedure might be successfully applied for rapid determination of90Sr in soil samples and other natural samples in a timesaving manner. 相似文献
5.
Summary Highly sensitive and selective test for vanadium(V) detection, with desferrioxamine B, is proposed. The method is based on reddish-violet complex fixation on cation-exchange resin. Detection limit of 1.01×10–10 g V(V)-ion is achieved by application of Dowex HCR(NH4
+) resin. Among 89 foreign substances investigated (diverse ions, complexing, oxidizing and reducing agents), Fe(II/III)-(under atmospheric conditions) and Co(II)-ion are the only interfering species.
Presented at 9th International Symposium on Microchemical Techniques, Amsterdam, August 28–September 2, 1983. 相似文献
Mikronachweis von Vanadin(V) mit Desferrioxamin B mit Hilfe der Harz-Tüpfeltechnik
Zusammenfassung Eine hochempfindliche und selektive Reaktion für den Nachweis von V(V) mit Desferrioxamin B wurde vorgeschlagen. Der dabei entstehende rot-violette Komplex wird an ein Kationenaustauscher-Harz gebunden. Die Nachweisgrenze 1,01×10–10 g V(V) wird mit Dowex HCR(NH4 +)-Harz erreicht. Unter 89 geprüften Fremdsubstanzen (div. Ionen, Komplexbildner, Oxydations- und Reduktionsmittel) sind Fe(II, III) und Co(II) die einzigen störenden Substanzen.
Presented at 9th International Symposium on Microchemical Techniques, Amsterdam, August 28–September 2, 1983. 相似文献
6.
The sorption of 1,8-dihydroxy-2-(pyrazol-5-ylazo)-naphthalene-3,6-disulfonic acid onto the anion exchange resins Dowex 1-X8 and Dowex 2-X8 from aqueous solutions of between pH 1 and 10 was studied spectrophotometrically. Conditions for obtaining modified sorbents with a given capacity for the azo compound were investigated. The absorption and reflectance spectra of the sorbed dye were traced. The immobilized reagent retained chromic characteristics similar to those it had in solution. The mechanism of sorption was investigated under static conditions in the temperature range of 0 to 25°C by following the amount of sorbed dye as a function of contact time. The sorption was a first-order process in all cases. Pore diffusion was found to be the rate-limiting step in the sorption process. Diffusion coefficient values of from 6.0 × 10–7 to 7.4 × 10–7 cm2/s were calculated from the experimental results. The values of the activation energy of PACA sorption were found to be –8.56 and –8.05 kJ/mol for Dowex 1-X8 and Dowex 2-X8, respectively. 相似文献
7.
The possibility of the determination of sulfate ions with the use of fibrous materials filled with ion exchangers on the basis of color reactions of barium with the organic reagents Arsenazo III, Orthanilic B, and Orthanilic K on a solid phase was examined. A polyacrylonitrile fiber filled the cation exchanger KU-2; anion exchangers AB-17, A-5, ANKF-211, and EDE-10p; and polyampholyte ANKB-50 (PANV-ANKB-50) was used as the support. The study of the different techniques of the sorption of the reaction components demonstrated the efficiency of the two systems involving PANV-ANKB-50. The determination of sulfates is possible because of the sorption of the excess barium remaining after the reaction with sulfate ions in the solution and its detection on the solid phase with a solution of Arsenazo III or the detection of the excess barium remaining after the interaction with the solution of sulfate ions on the solid phase with a solution of Orthanilic K. The calibration plots are linear in the concentration range of sulfate ions 10?4–10?5 M. 相似文献
8.
A radiochemical neutron activation analysis method for the determination of 34 elements in titanium dioxide has been developed. For the assay of indicator radionuclides with short and with long half-lives, the radiochemical separation was performed by anion exchange on a Dowex 1 × 8 column and by combination of cation and anion exchange on a Dowex 50W × 8 and a Dowex 1 × 8 column from HF- and HF/NH4F-medium, respectively. With both separation modes, a selective removal of the matrix-produced radionuclides 46Sc, 47Sc and 48Sc was achieved. A selective extraction of copper with dithizone from 15 mol/L HF enabled counting the intensive but unspecific 511-keV rays of 64Cu for the determination of Cu. The limits of detection achieved were between 0.004 ng/g for Sm and 0.8 μg/g for Sn (via 125Sb). The elements La, Mn and Th were determined by instrumental neutron activation analysis only. These techniques were applied to the analysis of two titanium dioxide samples of different purity grade. The results and limits of detection are compared with those of other methods. 相似文献
9.
The effect of arsenate and phosphate ions on the adsorption and color reaction of uranium(VI) with Arsenazo III on the solid phase of a fibrous material filled with the EDE-10p anion exchanger was studied in different adsorption processes. We selected the optimum conditions for the system of U(VI)-AsO 4 3? (H2PO 4 ? )-PANV-EDE-10p-Arsenazo III and used this system for the adsorption-spectrophotometric determination of (0.03–0.3) 10?3 M arsenate, (0.004–0.06) 10?3 M phosphate, and 0.01–0.1 μg/mL uranyl ions. 相似文献
10.
M. Griesbach und K. H. Lieser 《Fresenius' Journal of Analytical Chemistry》1980,302(2):109-114
Zusammenfassung Selektive Chelataustauscher auf der Basis von Polystyrol mit folgenden Ankergruppen werden durch Kapazitätsbestimmung, Messung der Austauschgeschwindigkeit und Bestimmung der Verteilungskoeffizienten charakterisiert: 4,5-Dihydroxynaphthalindisulfonsäure-(2,7) (Chromotropsäure), Alizarin, 1,2,5,8-Tetrahydroxyanthrachinon (Chinalizarin), Morin, 1,5-Diphenylthiocarbazon (Dithizon), 1,5-Diphenylcarbazid, Glyoxal-bis(2-hydroxyanil), 1-[Thenoyl-(2)]-3,3,3-trifluoraceton (TTA), 5-(4-Di-methylaminobenzyliden)-rhodanin (DMABR), Ethylendiamin-N,N-bis-(o-hydroxyphenylessigsäure) (Chel I), 1,2,3-Trihydroxybenzol (Pyrogallol), 4-Methoxy-2-[thiazolyl-(2)-azo]-phenol (TAM), Bis-(salicyliden)-1,2-diaminoethan (Salen), 8-Hydroxychinolin, Brenzcatechindisulfonsäure(3,5) (Tiron) Die Werte für die Kapazität der chelatbildenden Polystyrolaustauscher mit einer Korngröße von 0,1–0,2 mm variieren zwischen 0,4 und 1,5 mmol/g. Es ist zu erwarten, daß diese Austauscher teilweise wesentlich bessere Trenneigenschaften aufweisen als der handelsübliche Austauscher Dowex A-1.
Properties of chelating ion-exchangers on the basis of polystyrene
Summary Selective chelating exchangers on the basis of polystyrene with the following anchor groups are characterized by capacity, determination of exchange rates and of distribution coefficients: 4,5-dihydroxynaphthalenedisulphonic acid-(2,7) (chromotropic acid), alizarin, 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin), morin, 1,5-diphenylthiocarbazone (dithizone), 1,5-diphenyl-carbazide, glyoxalbis(2-hydroxyanil), 1-[thenoyl-(2)]-3,3,3-trifluoroacetone (TTA), 5-(4-dimethylaminobenzylidene)-rhodanine (DMABR), ethylenediamine-N,N-bis-(o-hydroxyphenylacetic acid) (Chel I), 1,2,3-trihydroxybenzene (pyrogallol), 4-methoxy-2-[thiazolyl-(2)-azo]-phenol (TAM), bis-salicylidene)-1,2-diaminoethane (Salen), 8-hydroxyquinoline, pyrocatecholdisulphonic acid-(3,5) (Tiron). The capacity values of the chelating polystyrene exchangers with grain sizes of 0.1–0.2 mm vary between 0.4 and 1.5 mmol/g. It can be expected that these exchangers will have more favourable separation properties than the commercially available exchanger Dowex A-1.相似文献
11.
R. Naumann und W. Schmidt 《Fresenius' Journal of Analytical Chemistry》1968,234(4):248-251
Zusammenfassung Eine Methode zur kathodenstrahlpolarographischen Bestimmung von Spuren Kobalt und Zink in Nickel und Nickelsalzen wird beschrieben. Die Spuren werden untereinander und von der Matrix über den Anionenaustauscher Dowex 1X8 getrennt. Die Nachweisgrenzen betragen für Kobalt 5·10–4% und für Zink 4·10–4%.
Summary A method is described for the cathode-ray polarographic determination of cobalt and zinc traces in nickel and nickel salts after separation by the anionexchange resin Dowex 1X8. Traces are detectable as low as 5·10–4% and 4·10–4%, respectively.相似文献
12.
Summary: Three pyridine strong base anion exchangers as beads were obtained by quaternization reactions of a 4-vinylpyridine : 8% divinylbenzene copolymer of gel type. These resins possess methyl / ethyl / butyl radicals as substituents on N+ atoms and have exchange capacities of 4.80 mEq/g and 2.10 mEq/mL. For pyridine strong base anion exchangers, the behaviours in the retention processes of Cr(VI) as oxyanions and Ga(III) as [GaCl4]− complex anion were evaluated with the bath method. All the resins exhibited retention properties, but the retained amounts of the metal cations are different as a function of the alkyl length as substituent on N+ atoms and the complex anion nature. Thus, Cr(VI) oxyanions are best retained by the resin with CH3 as substituent on N+ atoms while [GaCl4]− complex anion by the resin with C4H9 as substituent on N+ atoms. By aminolysis reaction of an ethylacrylate : acrylonitrile : divinylbenzene copolymer as beads of macroporous type with NH2OH · HCl in the presence of C2H5OH a new chelating ion exchanger was performed which contains both amidoxime and hydroxamic acid functional groups. This ion exchanger has the retention property for different metal cations but its retention capacities values are strongly dependent of the nature of metal cation and the counterion as well as pH of the solution. Thus, in the static conditions Zn(II) cation with NOequation/tex2gif-stack-1.gif anion as counterion is retained with the best result at pH = 5. As an example, for the aqueous metal cation solution of 10−2 M concentration for Zn(NO3)2 the resin possess at equilibrium a retention capacity of 6.70 mmol Zn/g dry resin and for Cu(II) from Cu(NO3)2 solution of same concentration, the retention capacity is 0.22 mmol Cu/g dry resin and Fe(III) from Fe(NO3)3 solution is not retained. 相似文献
13.
Maria Domenica Grillone 《Transition Metal Chemistry》1981,6(2):93-96
Summary [Cr2(CO)10(-H)]– undergoes ready hydride substitution on reaction with HgX2 (X = Cl, Br, I or SCN) or with iodine in acetone, yielding [Cr2(CO)10(-X)]– complex species which can be converted quantitatively into [Cr(CO)5X]– anions by reactions conducted in the presence of an excess of X–.LCr(CO)5 and (L-L)Cr(CO)4 complexes (L = pyridine; L-L = 1,10-phenanthroline or 2,2-bipyridine) are easily prepared by reactions performed in the presence of the L or L-L ligand, respectively. 相似文献
14.
N. I. Buryak V. A. Bandur V. N. Zavadovskaya D. F. Stepanishcheva 《Theoretical and Experimental Chemistry》1990,25(5):560-564
The structure of Ti(III) coordination polyhedrons in both individual NaPO3 and 70 mole % NaPO3-30 mole % NanX mixtures (X=PO3
3–, P2O7
4–, F–, Cl–) in the molten and solid states has been investigated on the basis of data from electronic absorption and ESR spectra. The formation of tetragonally distorted Ti(III) coordination polyhedrons with D4h symmetry coordinated only by (PO3
–)n chains with the following values of the spectroscopic parameters for the molten (and solid) states has been established in all the phosphate systems investigated: 10Dq=17,300 (18,000) cm–1 (Ds=50 cm–1, Dt=5600, g=1.959, g1=1.930, =93. cm–1). It has been shown that the greater is the extent of depolymerization of the phosphate chains in the melt, the stronger is the Ti(III) coordination polyhedron formed; the following relative series of the depolymerizing strength of the anions has accordingly been established: PO4
3–
2O7
4–
15.
1. | The reaction of 2,6-dinitro-4R-anisoles (R=OCH3, Cl, H, COO–) with potassium methoxide has been found to result in the formation of the anion radicals of these compounds; the anion radicals of the anionic complexes, i.e., the potassium 1,1-dimethoxy-3,6-dinitro-4R-cyclohexadienates (R=Cl, OCH3, H); the anion radicals of the 2-nitroso-4R-6-nitroanisoles (R=OCH3, Cl, H, COO–); and the anion radicals of the 2-nitroso-3-methoxy-4R-6-nitroanisoles (R=Cl, OCH3). |
2. | The structures have been established and mechanisms have been proposed for the formation of these anion radicals. |
16.
An extraction and spectrophotometric method for determination of trace amounts of uranium in phosphate fertilizers is described. It is based on the extraction of uranium with trioctylphosphine oxide in benzene and the spectrophotometric determination of uranium with Arsenazo III in buffer-alcoholic medium. The maximum absorbance occurs at 655 nm with a molar absorptivity of 1.2·104 l·mol–1·cm–1. Beer's law is obeyed over the range 0.6–15.0 g·ml–1 of uranium(VI). The proposed method has been applied successfully to the analysis of phosphate fertilizers with phosphate concentrations of 45% P2O5. 相似文献
17.
S. V. Konovalikhin G. V. Shilov O. A. D'yachenko M. Z. Aldoshina R. N. Lyubovskaya R. B. Lyubovskii 《Russian Chemical Bulletin》1992,41(10):1819-1826
The compositions and structures of two new organic metals based on ET [where ET = bis(ethylenedithio)tetrathiafulvalene], viz., (ET)2[Hg(SCN)Cl2], with a metal-dielectric transition temperature (Tm-d) of 35°K, and (ET)2[Hg(SCN)2Br], with Tm-d = 140°K, were established by x-ray diffraction analysis. The crystal structures of the investigated compounds are similar to the structure of the previously studied organic metal (ET)2[Hg(SCN)2Cl] with Tm-d = 50°K. The principal crystallographic data for (ET)2[Hg(SCN)Cl2] are as follows: a = 36.64(1), b = 8.300(4), c = 11.798(1) Å, = 89.91(3)°, V = 3588.1(9) Å3, space group Cc, Z = 4, dcalc = 2.05 g/cm3. The principal crystallographic data for (ET)2[Hg(SCN)2Br] are as follows: a = 37.088(14), b = 8.338(3), c = 11.738(5) Å, = 89.71(3)°, V = 3629.6(8) Å3, space group C2/c, Z = 8, dcalc = 2.15 g/cm3. A characteristic feature of the crystal structure of the investigated compounds is alternation of the anion and cation layers along the a axis of the crystal. In the cation layer of the k type the ET are interconnected by shortened S...S intermolecular contacts (3.39–3.58 Å). The [Hg(SCN)3–nXn]– anions (X = Cl, Br; n = 1, 2) form polymeric chains with one or two bridged SCN groups. A tendency for a decrease in the metal-dielectric transition temperature with a decrease in the volume of the anion is detected in the (ET)2[Hg(SCN)3–nXn] salts, where X = Cl and Br, and n = 1 and 2.Institute of Chemical Physics, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2323–2331, October, 1992. 相似文献
18.
Summary A rigorous analysis of the effect of various concentrations (0.02–1.60M) of ammonium acetate on the distribution coefficients (K) of a number of metal ions using cation exchanger Dowex 50W-X8 (100–200 mesh NH4
+-form) has been made. On account of the low affinity of U(VI) for resin in 0.20M NH4OAc it can be separated from all other metal ions. HighK values of Sr(II), Ba(II) and Hg(II) at higher 0.50M NH4OAc are responsible for their separation from others. The abnormal column Chromatographic behaviour of Al(III) permits its separation from other metal ions including U(VI), Sr(II), Ba(II), Hg(II). A number of binary and ternary separations have been achieved. 相似文献
19.
A radiochemical neutron activation analysis method for the determination of 22 elements in high-purity tungsten has been developed. For the assay of indicator radionuclides with long half-lives, the radiochemical separation was performed from HF/H2O2, HF/NH4F and HCl/H2SO4 media by a combination of cation and anion exchange on a Dowex 50 W × 8 and Dowex 1 × 8 column. An effective removal of the matrix-produced radionuclides of W and Re was achieved. U was determined via 140La, the daughter nuclide of the fission product 140Ba. Limits of detection of 2 ng/g for U and 0.02 ng/g for Th can be achieved. For the other elements, the limits of detection are between 0.004 ng/g (Sc) and 200 ng/g (Sr). The elements Hf, Ta and Sb could be determined by instrumental neutron activation analysis. This method was applied to the analysis of two tungsten powder samples of different purity grade. The results and limits of detection are compared with those of other methods. 相似文献
20.
K. P. Balashev A. M. Zimnyakov S. A. Vinogradov 《Theoretical and Experimental Chemistry》1991,26(4):431-438
The kinetics of some outer-sphere electron-transfer reactions with the participation of the complexes [Pt(NH3)nX6–n]2 (n=6–0, X=Cl–, Br–) and dipyridyl complexes of Os(II), Ru(II), Ir(III), and Cr(II) have been investigated by means of luminescence-quenching measurements and flash photolysis. Estimates of the values of the Pt(IV)/Pt(III) one-electron potential and the change in the free energy of activation of electron self-exchange processes of the type Pt(IV) Pt(III) have been obtained on the basis of an analysis of the dependence of the rate constant on the change in the free energy accompanying the electrontransfer process.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 4, pp. 455–462, July–August, 1990. 相似文献