Separation of antimony from uranium using zirconium phosphate

Summary The distribution behaviour of antimony and uranium between zirconium phosphate and hydrochloric acid solutions of different concentrations has been determined. The effect of organic solvent addition to the aqueous phase on the distribution data has been investigated. In all cases, the separation factors are evaluated and discussed. The best separation factor was achieved using 1M HCl over all organic-aqueous solvent mixtures. Based on these findings, a procedure has been developed for the separation of antimony from uranium using a Chromatographic column loaded with zirconium phosphate and 1M HCl as eluant.

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Zusammenfassung Das Verteilungsverhalten von Antimon und Uran zwischen Zirkonium-phosphat und Salzsäure verschiedener Konzentration wurde bestimmt. Der Einfluß zugesetzten organischen Lösungsmittels auf die Verteilungsdaten wurde untersucht. Die besten Trennungsergebnisse wurden mit 1-n Salzsäure ohne jeden organischen Zusatz erzielt. Auf dieser Grundlage wurde ein Verfahren ausgearbeitet, um mit Hilfe einer mit Zirkoniumphosphat beladenen chromatographischen Säule und mit 1-n Salzsäure als Elutionsmittel Antimon von Uran zu trennen.

     

Separation and preconcentration of the rare-earth elements and yttrium from geological materials by ion-exchange and sequential acid elution

The abundance of rare-earth elements (REE) and yttrium in geological materials is generally low, and most samples contain elements that interfere in the determination of the REE and Y, so a separation and/or preconcentration step is often necessary. This is often achieved by ion-exchange chromatography with either nitric or hydrochloric acid. It is advantageous, however, to use both acids sequentially. The final solution thus obtained contains only the REE and Y, with minor amounts of Al, Ba, Ca, Sc, Sr and Ti. Elements that potentially interfere, such as Be, Co, Cr, Fe, Mn, Th, U, V and Zr, are virtually eliminated. Inductively-coupled argon plasma atomic-emission spectroscopy can then be used for a final precise and accurate measurement. The method can also be used with other instrumental methods of analysis.     

Separation of uranium from molybdenum using a diamine functional group bonded to controlled-pore glass

A method for selective extraction of uranium from carbonate solutions containing molybdate is reported. A liquid chromatography column, packed with N-β-aminoethyl-γ-ammopropyltrimethoxysilane immobilized on a glass substrate, was utilized in a continuous How system. The selective retention of the uranyl carbonate species [UO₂(CO₃)₂? 2H₂O]^2- and UO₂(CO₃)^4- on protonated immobilized diamine is the basis for this separation Recoveries of uranium and molybdenum from synthetic samples ranged from 96.7 to 113.4% for uranium and from 96.7 to 110.5% for molybdate for a range of recommended conditions.     

Separation of thorium from uranium ore

Thorium-230 has many research applications, but there is not a commercial source of this isotope. However, since ²³⁰Th is part of the ²³⁸U decay chain, it can be separated from naturally occurring uranium. In this work, a novel procedure was developed to separate thorium from uranium ore, consisting of leaching, liquid–liquid extraction, precipitations and ion exchange chromatography. The final product was 91.32?±?0.77 mg of thorium with a purity of 99.5?±?1.2 wt%. Of that, 7.65?±?0.10 mg was ²³⁰Th and the remainder ²³²Th. The total yield of ²³⁰Th was 71.1?±?5.4%. Ways to improve the yield by further processing the back-extraction solution are suggested.

     

Separation of tanshinones from Salvia miltiorrhiza Bunge by high-speed counter-current chromatography using stepwise elution

High-speed counter-current chromatography (HSCCC) was successfully used for isolation and purification of tanshinones from the roots of Salvia miltiorrhiza Bunge by stepwise elution. A set of three solvent systems and other experimental conditions were determined by analytical HSCCC. Using the optimized conditions, the preparative HSCCC separation was performed on 50 mg of crude light petroleum extract yielding pure tanshinones of tanshinone HA (7 mg), tanshinone I (3 mg) and cryptotanshinone (4 mg) all at purities of over 95% in a single run.     

Purification of DNA-derived deoxynucleotides from leukocytes involving nuclease elution of an ion-exchange column

A method has been developed in which the DNA of leukocytes (as the buffy coat from blood) is isolated in the form of its constituent deoxynucleotides. The steps in this method are as follows: (1) lyse the leukocytes with sodium dodecyl sulfate (SDS) and enzymatically digest the proteins and RNA, (2) remove the SDS on a non-polar adsorbent (Bio-Beads SM-4) and then trap the DNA on a quaternary amine silica cartridge, (3) wash the column with 1 M NaCl-buffer, (4) digest the DNA on the column with staphylococcal nuclease and (5) elute the digested DNA with 0.5 M NaCl-buffer and digest it further with bovine spleen phosphodiesterase II to deoxynucleotide-3′-monophosphates. From a 40-μl sample of butty coat was obtained 126 ± 14 μg (two experiments, eight sample total) of deoxynucleotides. Reversed-phase high-performance liquid chromatography, which removed the added enzymes, showed only peaks for deoxynucleotides. For comparison, the amount of deoxynucleotides obtained from the leukocytes by an automated phenol extraction procedure was 101 ± 5.4 μg (one experiment in triplicate).     

Separation of abietane-type diterpenoids from Clerodendrum kaichianum Hsu by high-speed counter-current chromatography using stepwise elution

High-speed counter-current chromatography (HSCCC) was successfully used for the separation of abietane-type diterpenoids from the medicinal plant C. kaichianum, which were not separated in our previous study using preparative HPLC. The HSCCC separation employed the lower phases of n-hexane–ethyl acetate–methanol–water (HEMW) 4:5:4:5 and HEMW 4:5:5:4 as the mobile phase for stepwise elution while the upper phase of HEMW 4:5:4:5 was used as the stationary phase. HSCCC separation yielded 90.5 mg of compound 1(kaichianone A), 137.7 mg of compound 2 (kaichianone B), 125.0 mg of compound 3 (teuvincenone E), and 227.6 mg of compound 4 (taxusabietane A) with purities of 95.3%, 97.2%, 97.8%, and 98.6%, respectively, as determined by HPLC. Compounds 1–2 are two new abietane-type diterpenoids while Compounds 3–4 are known abietane-type diterpenoids, analyzed by ESIMS and NMR data. The results demonstrated that HSCCC can be an excellent alternative for other separation methods. The two new compounds showed significant cytotoxicity against ileocecal carcinoma HCT-8 and breast adenocarcinoma MCF-7 cells.     

Separation of structurally related estrogens using isocratic elution pressurized capillary electrochromatography

In this paper, the pressurized capillary electrochromatography (pCEC) with UV detection was utilized for the separation and determination of three structurally related estrogens, such as diethylstilbestrol (DES), hexestrol (HEX) and dienestrol (DE), which were difficult to be separated by capillary electrophoresis (CE) and HPLC due to their similarity in the structure and charge-to-mass ratios. Experiments were carried out in a commercially available pCEC instrument using a capillary column packed with 3 microm octadecyl silica (ODS). Surfactant sodium dodecyl sulfate (SDS) was introduced in the mobile phase to enhance the speed of analysis. The effective factors on the retention time and separation resolution, such as the applied voltage, supplementary pressure, the pH and the concentration of the buffer solution, the concentration of SDS, and the content of acetonitrile in the mobile phase, were evaluated. Based on the investigation, 31% (v/v) acetonitrile and 69% (v/v) of 10 mmol/L phosphate buffer (pH 6.5) containing 1.0 mmol/L SDS at an applied voltage of -12 kV and a supplementary pressure of 1000 psi were found to be the optimal conditions for pCEC to separate the three estrogens. The method also had been applied to the analysis of fish muscle samples spiked with estrogens.     

Separation of different oligomers by supercritical fluid chromatography using gradient elution

Summary In supercritical fluid chromatography (SFC), the solubilizing nature of the mobile phase enables the use of composition gradients (gradient elution) like in liquid chromatography. With this gradient technique, oligomer separations have been achieved over wide molecular weight ranges. For separating oligomers which absorb only at low wavelengths, a carbon dioxide/acetonitrile mobile phase was used which allows UV detection down to 200 nm. As an ideally suited detection assembly for the chromatography of oligomers, a combination of mass-sensitive and evaporative light-scattering detection is suggested.

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Trennung von verschiedenen Oligomeren durch Chromatographie mit überkritischen fluiden Phasen unter Verwendung der Gradientenelution

     

Separation of uranium from iron in ground water samples using ion exchange resins

Uranium determination in environmental samples is faced with problems due to presence of iron and other major elements. Iron is also used many a times for pre-concentration of uranium and actinides. Separation of milligram quantity of Fe from microgram quantity of uranium becomes essential during the estimation step. A simple two step procedure has been standardized for separating uranium and iron using anion exchange in 0.025 M H₂SO₄. Quantitative recovery of uranium was obtained as well as good separation from iron. This method was applied for estimation of uranium in water samples.     

Separation of uranium from soils for its determination

A method has been developed for the determination of microamounts of uranium in soils, which is based on application of the rapid and effective removing of luminescence quenchers from liquid preparations with subsequent uranium determination by laser-induced luminescence registration of its polysilicate complexes. To remove the luminescence quenchers, they were precipitated in strongly basic carbonate medium in the presence of activated charcoal (as a collector of the precipitate).     

Separation of cerium,uranium and plutonium using sephadex gel

Adsorption of some fission product elements on sephadex was attained at pH 5.5±0.2. Individual separation of adsorbed radioactive cerium, uranium and plutonium on sephadex was performed using 25 ml of 10^–4M triethylenetetraaminehexaacetic acid (TTHA) at different pH values.     

Amino acid analysis by ion-exchange chromatography using a lithium elution gradient. Influence of methanol concentration and sample pH.

The separation of amino acids has been achieved on a short column of Chromo-Beads C2 resin, with a lithium gradient-elution system. The analysis took 8 h. The separation of asparagine and glutamine from glutamic acid was highly dependent on the sample pH and on the methanol concentration in the first buffer of the gradient. The method has been applied to analysis of human plasma and granulocytes for amino acids.     

Separation of beryllium and aluminium from other elements using an ion-exchange resin with N-benzoylphenylhydroxylamine as a functional group

A chelating polystyrene-divinylbenzene-based resin containing N-benzoylphenylhydroxylamine as the chelating group was synthesized and characterized through its water regain capacity (0.56 g g^?1) and stability towards acids, alkalis, heat and γ-radiation. The effective pH for use of the resin was 1.0–7.0 for beryllium, 2.5 for aluminium and 6.5 for coppjt]Analyst     

Separation of uranium from different uranium oxide matrices employing supercritical carbon dioxide extraction

Uranium from different uranium oxide matrices was extracted with tri-n-butyl phosphate–nitric acid (TBP–HNO₃) adduct using supercritical carbon dioxide (SC CO₂). While 30 min dissolution time at 323 K was sufficient for U₃O₈ and UO₂ powder, UO₂ granule (at 333 K) and crushed green pellet (at 353 K) required 40 min. Crushed sintered pellet required 60 min at 353 K for complete dissolution. Influence of various experimental parameters such as temperature, pressure, volume of TBP–HNO₃ adduct, acidity of nitric acid used for preparing TBP–HNO₃ adduct and extraction time on uranium extraction efficiency was also investigated. For UO₂ powder, temperature of 323 K, pressure of 15.2 MPa, 1 mL TBP–HNO₃ adduct, 10 M nitric acid and 30 min extraction time was found to be optimum. ~70% uranium extraction efficiency was obtained on extraction with SC CO₂ alone which increased to 90% with the addition of 2.5% TBP in SC CO₂ stream. Extraction efficiency was found to vary linearly with TBP percentage and nearly complete uranium extraction (~99%) was observed with 20% TBP. Nearly complete extraction was also achieved with addition of 2.5% thenoyltrifluoroacetylacetone (TTA) in methanol. The optimized procedure was extended to remove uranium from simulated tissue paper waste matrix smeared with uranium oxide solids.