共查询到20条相似文献,搜索用时 15 毫秒
1.
H. J. Ding Y. N. Niu Y. B. Xu W. F. Yang S. G. Yuan Z. Qin X. L. Wu 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(2):263-266
Solvent extraction of protactinium with tri-iso-octyl-amine (TIOA) in xylene, benzene, carbon tetrachloride and chloroform
from HCl, HF, HNO3, HClO4 and H2SO4 media was studied using 233Pa as a radiotracer. The extraction efficiencies of protactinium were determined as a function of shaking time, concentrations
of mineral acids in aqueous phase, extractant concentrations and diluents in organic phase. The extraction mechanism was discussed.
The results show that the extracted species in the organic phase is [(R3N−H)nPa(OH)xCl
y
5−x−y
]. 相似文献
2.
Solvent extraction of Zn(II) by 2-hexylpyridine (HPy) in benzene has been studied from aqueous mineral acid—thiocyanate media.
The extraction, though dependent on the acidity of the aqueous phase, is poor from mineral acids (HCl, HNO3 or H2SO4). Addition of 0.02M KSCN to the aqueous phase enhances the distribution ratio by a factor of almost one thousand. The stoichiometry
of the extracted complex established by the usual slope analysis method indicates that an ionic type complex, e.g. Zn(SCN)4·(HPyH)2, is responsible for extraction. Complexing anions like acetate, oxalate or citrate at 1 M concentration mask the extraction
of Zn(II) almost completely. Separation factors determined at optimal conditions (0.1M HPy in benzene −0.05M H2SO4+0.2M SCN−) indicate that Zn(II), along with Hg(II), can be separated in a single extraction from a number of metals, e.g. Cs(I), Sr(II),
Ln(III), Y(III), Cr(III) and (VI). Other metals of interest like Cu(II), Co(II), Fe(III), Mo(VI), U(VI) and Tc(VII) are coextracted
but the separation factors are large enough to allow separation in a multistage extraction process. 相似文献
3.
(Extraction of alkali on alkaline earth metal ions with (sym-dibenzo-14-crown-4-oxy)- and (sym-dibenzo-16-crown-5-oxy)-carboxylic acids.)The extraction of lithium, sodium, potassium, calcium and some other metal ions with dibenzo-4-crown-4-oxy- and dibenzo-16-crown-5-oxycarboxylic acids containing the groups -CH2COOH, -(CH2)2COOH, -(CH2)3COOH, -CH(C2H5)COOH and -CH(C4H9)COOH was studied. The extraction increases as a function of the lipophilic character of the carboxylic acid group. Calcium, barium and strontium ions are better extracted than Li+, Na+ and K+; there are only small differences among the alkaline earth metal ions. Evaluated from the extraction data, the composition of the extracted species was 1:1 (metal/ligand) for Li+, and 1:2 for CaCa2+; Na+ and K+ favour the formation of 1:2 complexes with dibenzo-14-crown-4-derivatives bbut 1:1 complexes with dibenzo-16-crown-5-oxy-carboxylic acids. The dependence of the distribution ratio on pH does not provide unequivocal evidence for the composition of the extracted compounds. 相似文献
4.
A. A. Voshkin V. V. Belova Yu. A. Zakhodyaeva 《Russian Journal of Inorganic Chemistry》2018,63(3):387-390
Iron(III) extraction with trioctylmethylammonium di(2-ethylhexyl)dithiophosphate and di(2- ethylhexyl)dithiophosphoric acid was studied. It was shown that di(2-ethylhexyl)dithiophosphoric acid extracts iron in the form of the complex FeA2, regardless of the oxidation state of iron in the initial aqueous solution. It was also shown that the iron(III) extraction with trioctylmethylammonium di(2-ethylhexyl)dithiophosphate over a wide acidity range occurs primarily to produce extractable substance (R4N)FeCl4; and at pH > 1, iron(II) dialkyldithiophosphate is also extracted into the organic phase. It was established that, in a system with a binary extractant, iron can be efficiently stripped from the organic phase with water or diluted solutions of mineral acids. 相似文献
5.
R. Kopunec F. N. Abudeab S. Skraŝková 《Journal of Radioanalytical and Nuclear Chemistry》1998,230(1-2):51-61
Solvent extraction of pertechnetate anions from aqueous solutions of some mineral acids (HCl, HNO3, HClO4, H2SO4), (NaCl, NaNO3, NaClO4, K2CrO4, NaCO3), NaOH and NH4OH by tetraphenylphosphonium chloride in chloroform and nitrobenzene was studied. The results are presented in the form of
the dependencies of extraction characteristics of TcO
4
−
(distribution ratio, percentage of extraction) on the (C6H5)4PCl, H+ and competitive anion concentrations. The solvent extraction of sub-and super-stoichiometric ratio of TcO
4
−
: (C6H5)4P+ was performed. The extraction constant values of ion pairs TcO
4
−
−Cl−, TcO
4
−
−NO
3
−
, TcO
4
−
−ClO
4
−
and of individual anions TcO
4
−
, Cl−, NO
3
−
, ClO
4
−
were calculated. 相似文献
6.
A. N. Turanov V. K. Karandashev N. A. Bondarenko 《Russian Journal of Inorganic Chemistry》2013,58(5):590-595
Interfacial distribution of trace amounts of ReO 4 ? ions between aqueous solutions of mineral acids and solutions of diphosphoryl-substituted aza podand [Ph2P(O)CH2CH2OCH2CH2]2NBu (I) in dichloroethane was studied. The stoichiometry of extracted complexes was determined, the influence of HClO4, HNO3, HCl, and H2SO4 concentration in aqueous phase and the nature of organic solvent on the efficiency of transition of ReO 4 ? ions into organic phase was considered. Aza podand I shows larger extraction ability toward Re(VII) than monophosphorylated amines. The possibility of selective extraction and preconcentration of ReO 4 ? ions by a complex-forming sorbent obtained by the noncovalent binding of compound I on the surface of carbon nanotubes was shown. 相似文献
7.
J. M. Navarrete V. M. Urbina T. Martínez L. Cabrera 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(2):311-314
Among humic substances formed by organic matter decomposition process, fulvic acids have been extensively studied because
their solubility and soil fertilizer properties. This paper describes how some mineral nutrient elements are absorbed by the
root as well as the foliage of bean plants and how they move in both directions depending on their association to fulvic acids.
In this study, radiotracers of phosphate and iron have been used (H2
32PO4
-, 59Fe2+). The results obtained are quantitative by instrumental detection and qualitative by autoradiography of the radiotracers.
A very clear effect has been found about motion and fixation of phosphate and iron ions in bean plants brought about by fulvic
acids commercially produced in Mexico by organic synthesis. This effect seems to be the more homogeneous distribution in the
vegetable tissues of the mineral ions absorbed from the soil.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
P. K. Mohapatra R. Veeraraghavan V. K. Manchanda 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(1):31-38
The extraction behavior of Th(IV) from dilute nitric as well as perchloric acid medium using 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone
(PMBP) and its mixture with tri-n-octyl phosphine oxide (TOPO) was investigated. The species of the type Th(X)(PMBP)3·(HPMBP) and Th(X)(PMBP)3·(TOPO) were extracted for the binary and ternary extraction systems, respectively, where X=NO3− or ClO4−. The presence of 1.25·10−5M Th carrier in the aqueous phase resulted in the extracted species of the type of Th(PMBP)4 and Th(PMBP)4·(TOPO), respectively. The extraction constant (logk
ex
) for the binary species Th(PMBP)4 was found to be 6.89±0.01 while the overall extraction constant (logK) for the ternary species Th(PMBP)4·(TOPO) was calculated to be 13.17±0.06. 相似文献
9.
《Journal of Inorganic and Nuclear Chemistry》1978,40(2):325-329
The extraction of phosphoric acid from its aqueous solutions containing various proportions of potassium hydrogen phosphates with the long-chain tertiary amine Alamine 336 in toluene was studied at 25°C. Also measured was the exchange of phosphate anions with the anions of strong mineral acids (chloride, bromide and sulfate) between aqueous acid solutions and those of Alamine 336 in toluene at 25 and 40°C. The extraction of phosphoric acid was previously found to increase with the activity of undissociated acid aH3PO4. It therefore decreased on replacement of H3PO4 with KH2PO4 due to reversal of the acid dissociation and to formation of the dimeric species H5P2O8− in the aqueous phase, and conforms to the previously proposed model with the inclusion of this aqueous species. The relative affinities of the anions for the tertiary substituted ammonium cation increase in the order: H2PO4−<HSO4−<Cl−<Br−. 相似文献
10.
H. B. Maghrawy C. Girgis A. S. Abdel-Gawad 《Journal of Radioanalytical and Nuclear Chemistry》1984,81(1):5-13
The extraction of Pa(V) from strongly acidic solutions of mineral acids is carried out with benzene solution of thenoyltrifluoroacetone. To interpret the data obtained, two extraction mechanisms representing the descending and ascending parts of the extraction curves are suggested. At lower acidity, the formation of PaO(TTA)3·HTTA species predominates. In going to higher acidity, an ion-pair formation between anionic protactiniuminorganic complex species and H2 TTA+ cation is assumed. 相似文献
11.
A systematic study is presented on Pu IV extraction with tri-n-butyl phosphate and trilaurylamine from binary mixtures of H2SO4 with HCl and HBr. The addition of sulfuric acid to the mentioned mineral acid solutions, was found to affect appreciably DPu, which recommended some useful purification procedures. The effect of water-miscible alcohols on the extraction of plutonium from HCl and HNO3 solutions was also investigated. 相似文献
12.
A systematic study on the extraction of99Mo and its daughter99mTc by pure organic diluents and dinonylnaphthalinesulfonic acid (DNNS) is described. The aqueous phases used are H2SO4, HCl, KI and their binary mixture solutions. The effect of alcohols on the distribution coefficient has been investigated.
As a result of the study, a simple and rapid generator is built for the production of pure99mTc from99Mo. 相似文献
13.
P. D. Mithapara V. K. Manchanda P. R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》1984,83(2):301-307
Octylphenyl acid phosphate, the commercially available mixture of monooctylphenylphosphoric acid (MOPPA) and dioctylphenylphosphoric acid (DOPPA) in xylene medium has been employed as an extractant for distribution studies on Pu(IV) in different mineral acids including phosphoric acid. It was found possible to extract Pu quantitatively from an acid mixture comprising 2.5M H3PO4, 0.75M H2SO4 and 0.5M HNO3. Quantitative stripping was observed with a mixture of 0.25M oxalic acid and 0.2M ammonium oxalate.Parts of this work have been reported at symposie (Refs1,2) 相似文献
14.
A systematic study is presented on the extraction of Zr(IV) by tri-n-butylphosphate from H2SO4, HNO3, HCl and HBr solutions as well from binary mixtures of H2SO4 and halogen acids. It has been found that Zr(IV) extraction is appreciably increased by addition of halogen acid to sulphuric
acid solutions. On the other hand, the presence of water-miscible alcohols and acetone was found to enhance Zr(IV) extraction
from HCl and HNO3 solutions. An investigation of extracted Zr complexes from pure acids and mixed aqueous media enabled an explanation of the
observed enhancements. In the light of the obtained results, an extraction mechanism is suggested. 相似文献
15.
The distribution behaviour of ion association of Pdl2?4 with ten quaternary ammonium cations between chloroform and an aqueous phase was examined and extraction constants (log Kex) were determined. Linear relationships between log Kex and the number of methylene groups in the quaternary ammonium ions were observed. Quantitative extraction of palladium was achieved with Zeph+ or TBA+; the molar absorptivity was 2.5 × 104 l mol?1 cm?1 at 344 nm. The effect of other ions on the spectrophotometric determination of palladium, based on their extraction, is reported. 相似文献
16.
B. F. Myasoedov M. K. Chmutova M. N. Litvina Yu. M. Kulyako 《Russian Chemical Bulletin》1998,47(9):1690-1696
The possibility of changing the aggregate state of several solid mono- and bidentate neutral organophosphorus compounds in
contact with various mineral acids was demonstrated. The formation of the liquid phase immiscible with water was observed.
The, phase exhibits a high extraction capability with respect to actinides in various oxidation states. The diphenyl(dibutylcarbamoylmethyl)phosphine
oxide-NHO3 extraction system was studied in detail. The composition of the liquid phase was shown to the Ph2P(O)CH2C(O)NBu2·HNO3·nH2O (n=2 or 3). The kinetics of formation of this phase and extraction of Amiii from solutions of nitric acid and its salts was studied. The organic phase exhibits redox properties, due to which some actinides
change the oxidation state during extraction. The “aryl strengthening effect” was suggested to exist for extraction of AmIII in the absence of a solvent.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1739–1745, September, 1998. 相似文献
17.
A. M. Radalla 《Journal of solution chemistry》2010,39(9):1394-1407
The binary and ternary complexes of Cu2+, Ni2+, Co2+ and Zn2+ metal ions with resorcinol (R) as primary ligand and some biologically important aliphatic dicarboxylic acids (adipic, succinic,
malic, malonic, maleic, tartaric and oxalic acids) as secondary ligands were studied in aqueous solution at 25 °C and I=0.1 mol⋅dm−3 NaNO3 using the potentiometric technique. The formation of different 1:1 and 1:2 binary complexes and 1:1:1 ternary complexes is
inferred from the corresponding potentiometric pH-titration curves. The ternary complex formation was found to take place
in a stepwise manner. The protonation constants of the ligands were determined and used for determining the stability constants
of the different complexes formed in aqueous solutions. The lower stability of the 1:2 binary complexes compared to the corresponding
1:1 systems of all ligands studied were in accordance with statistical considerations. The order of stability of the complexes
formed in solution was investigated in terms of the nature of the resorcinol, carboxylic acid, and metal ion used. The values
of Δlog 10
K, percentage of relative stabilization (% R.S.), and log 10
X for mixed-ligand complexes studied have been evaluated and discussed. The concentration distribution of the various species
formed in solution was evaluated. The mode of chelation of the ternary complexes was ascertained by conductivity measurements. 相似文献
18.
Yang Yonghui Sun Sixiu Xue Shuyun Yang Yanzhao Bao Borong 《Journal of Radioanalytical and Nuclear Chemistry》1998,237(1-2):171-173
The extraction of uranium(VI) from sulfuric acid medium with tri-octylphosphine oxide (TOPO) in n-heptane was studied. Accompanied
with the increase in the concentration of H2SO4, the distribution coefficient of uranium(VI) increased in the region of dilute sulfuric acid. When the concentration of H2SO4 surpassed 3.5 mol·dm−3, the distribution coefficient of uranium(VI) was at maximum. This result was due to the competition extraction between uranium(VI)
and H2SO4. From the data, the composition of extracted species and the equilibrium constant of extraction reaction have been evaluated,
which were (TOPOH)2UO2(SO4)2 (TOPO) and 107.6±0.15, respectively. 相似文献
19.
A method for the selective extraction of mercury has been developed. The extraction of Hg(II) by 2-benzylpyridine (BPy) in benzene from dilute mineral acid solution containing iodide ions has been investigated, and variables such as concentration of acids, iodide and the extractant have been optimized. The optimum conditions for the extraction of Hg(II) by 0.1M BPy/benzene are: 0.01M (HCl, HNO3, H2SO4)+0.01M KI. The distribution coefficients and separation factors of 19 elements relative to Hg(II), have been reported. Effect of anions such as ascorbate, acetate, citrate, oxalate and thiosulfate has also been studied. The method developed could find useful applications in selective extraction of small amounts of mercury from environmental samples. 相似文献
20.
N. R. Das B. Nandi S. N. Bhattacharyya 《Journal of Radioanalytical and Nuclear Chemistry》1981,62(1-2):53-60
A simple solvent extraction procedure for the efficient separation of the radioactive tracers95Nb and182Ta from each other in a mixture using di-(2-ethylhexyl)phosphoric acid (HDEHP) as extractant is described. Tantalum was found to be quantitatively extracted from an aqueous madium, which is 1.6N in HCl and 10?2 M in oxalic acid, with a HDEHP solution of 0.1 M concentration. Extractabilities of both niobium and tantalum in mineral acids like HCl, H2SO4 and HNO3 and in some organic acids like oxalic, citric, etc., in HDEHP under the experimental conditions were also studied. The reliability of the separation procedure was verified further by γ-ray spectrometry. 相似文献