Carrier-free separation of 22Na from magnesium by chromatographic techniques

Carrier-free ²²Na was separated from bulk quantities of magnesium by both ion exchange and extraction chromatographic techniques. An extraction chromatographic procedure based on di-(2-ethylhexyl) phosphoric acid (HDEHP) coated on to an inert support (Amberlite XAD-7) was developed for the first time for separation of sodium from magnesium. The sorption behavior for sodium and magnesium was studied as a function of percentage of HDEHP loaded on to the inert support as well as pH of aqueous phase. These data were used to arrive at the optimum conditions of separation. In addition, carrier free ²²Na was also separated from magnesium using ion exchange chromatographic technique.     

Europium isotope separation in the HCl/HDEHP extraction system

The^153/151Eu isotope separation factor (q) for the Eu(II)/Eu(III) chemical exchange in the liquid-liquid extraction system, containing Eu (III) in di (2-ethylhexyl) phosphoric acid (HDEHP) and Eu(II) in water acidified with hydrochloric acid, was found to be 0.9993±0.0002 (2) for the single stage. Some theoretical aspects of separation of the Eu isotopes are discussed. The decisive role of the electron exchange reaction and complexation by the counter-ion in the aqueous phase is emphasized.     

The separation of micro-amounts of indium from zinc by liquid-liquid extraction

Summary The study of a method for the determination of indium in zinc by radioactivation created the necessity for the isolation of indium after irradiation. The separation procedure based on the extractability of InBr3 into diethylether is not achievable in the presence of zinc. The distribution coefficients as determined by the use of radioactive⁶⁵Zn for awide range of hydrobromic acid concentrations and metal ion concentrations are relatively high, corresponding to a 9% extraction.Further experiments showed the possibility of such a separation when ethylether was replaced by isopropylether. The extractability of ZnBr₂ in this solvent is negligible in the acidity range 0.5 to 6 M HBr.The results of the distribution of indium tribromide obtained from the activity measurements when radioactive¹¹⁴In has been used as tracer, have demonstrated quantitative recovery of indium in a single extraction from 6 M HBr.The volume changes of the two phases are very small in comparison to those arising when diethylether is used as solvent.Because of its simplicity and efficiency, this separation method could prove very convenient in the analysis of metallic zinc and zinc concentrates in which indium is to be determined.

---

Zusammenfassung Die Ausarbeitung einer Methode zur Bestimmung von Indium in Zink auf radioaktivem Wege ergab die Notwendigkeit, das Indium nach der Bestrahlung zu isolieren. Die Trennung durch Extraktion des InBr₃ mit Diäthyläther ist bei Gegenwart von Zink nicht durchführbar. Die unter Verwendung von radioaktivem⁶⁵Zn innerhalb weiter Konzentrationsbereiche an Bromwasserstoffsäure und Metallion bestimmten Verteilungskoeffizienten sind relativ groß und entsprechen einer 9%igen Extraktion. Weitere Versuche ergaben die Möglichkeit einer Trennung bei Verwendung von Isopropyläther an Stelle von Diäthyläther. Aus 0,5- bis 6-m Bromwasserstoffsäure ist ZnBr₂ durch Isopropyläther kaum zu extrahieren. Die bei Verwendung von radioaktivem¹¹⁴In als Indikator durchgeführten Untersuchungen der Verteilung von Indiumtribromid durch Aktivitätsmessung ergaben, daß Indium bei einer einzigen Extraktion aus 6-m HBr quantitativ wiedergefunden wird. Die Volumveränderungen der beiden Phasen sind sehr klein gegen die bei Verwendung von Äthyläther.Wegen seiner Einfachheit und großen Wirksamkeit könnte sich dieses Trennungsverfahren gut für die Bestimmung von Indium in metallischem Zink oder Zinkkonzentraten bewähren.

---

Résumé L'étude d'une méthode de dosage de 1'indium dans le zinc par radioactivation a nécessité son isolement après irradiation. La technique de séparation qui est basée sur la possibilité d'extraire InBr₃ dans l'éther diéthylique n'est pas applicable en présence du zinc. L'emploi de zinc radioactif⁶⁵Zn dans un vaste domaine de concentrations de l'acide bromhydrique et de l'ion métallique permet de déterminer les coefficients de distribution; ils sont relativement élevés et correspondent à une extraction de 9%. De nouvelles expériences ont montré la possibilité d'effectuer la séparation lorsqu'on remplace l'éther éthylique par l'éther isopropylique. Le pouvoir d'extraction de ce solvant pour ZnBr₂ est négligeable lorsque la concentration en acide bromhydrique est comprise entre 0,5 et 6 M. Lorsqu'on emploie¹¹⁴In comme traceur, les mesures d'activité ont montré, par étude de la distribution du tribromure d'indium que la récupération de 1'indium était quantitative après une seule extraction dans l'acide bromhydrique 6 M. Les variations de volumes des deux phases sont très faibles comparativement à celles qui se produisaient avec l'éther diéthylique comme solvant. Cette méthode de séparation simple et efficace aurait un emploi des plus appropriés pour l'analyse du zinc métallique ou des solutions concentrées de zinc dans lesquelles on doit doser l'indium.

---

---

L. Kosta, on leave from the Institute J. Stefan, Ljubljana, Yugoslavia, expresses his indebtedness to Prof.J. Gillis, Rector of the University of Ghent, for the permission to work in his laboratory and to the Institute J. Stefan for the financial support during this investigation.     

Perfluorocarbon-based liquid-liquid extraction for separation of transition metal ions.

We report a liquid-liquid extraction system based on perfluorocarbon (fluorous-solvent extraction) that allows selective extraction of metal ions from aqueous and organic phases to a perfluorocarbon phase (FC-72) with perfluorinated beta-diketone (1,1,1,5,5,6,6,6-octafluoro-2,4-hexanedione), which can be followed by backward extraction using 1 M nitric acid.     

Separation of transplutonium and rare-earth elements by extraction with HDEHP from DTPA solutions

The extraction behaviour of Am, Cm, Bk, Cf, Es, La, Ce, Pr, Pm, Sm, Eu, Gd, Ho, Yb and Lu in the system HDEHP—DTPA in lactic acid has been studied from the point of view of group separation of the transplutonium and rare-earth elements. Optimum separation conditions have been found on the basis of the results obtained. Some test separations of transplutonium elements from rare-earth fission products have been carried out in real solutions by extraction chromatography. It has been shown that this method can be used successfully for the analytical determination of transplutonium elements as well as for recovery of the latter from irradiated samples.     

Carrier-free separation of (115m)In from irradiated Cd by solvent extraction with 1-phenyl-3-methyl-4-caproylpyrazolone-5

A method is presented for the routine milking of the 41 2 -hr half-life nuclide (115m)In from its 2.3 day half-life parent (115m)Cd. The method utilizes the extraction of In and Cd from aqueous solution at various pH values, 1-phenyl-3-methyl-4-caproylpyrazolone-5 in isobutyl methyl ketone being used as extracting agent. A good decontamination factor was obtained and the yield of (115m)In from residual cadmium activity was 85-90%.     

Separation of rhodium from ruthenium and iridium by fast solvent extraction with HDEHP

Solvent extraction of rhodium, ruthenium and iridium with di(2-ethylhexyl)phosphoric acid (HDEHP) has been investigated. Under the conditions [Cl^–1]=0.20M, [(HDEHP)₂]=0.30M, pH 4.05, phase contact time 1 minutes, Rh(III) is extracted 90.7%, Ru(III) and Ir(III) 20.0% and 11.5%, respectively, at phase ratio 11. The distribution ratio of rhodium is proportional to [(HDEHP)₂]³ for a freshly prepared aqueous phase with low chloride concentration but might drop to [(HDEHP)₂]^1to2 for an aqueous phase high in chloride concentration and after standing. The spectroscopic studies indicate that the extracted compound of rhodium is Rh(H₂O)_6–x Cl _x [H(DEHP)₂]_3–x (x=0, 1, 2).     

Removal of organic dyes from water by liquid-liquid extraction using reverse micelles

In the present work, solvent extraction using reverse micelles is proposed for the removal of organic dyes from water. In this approach, the dye is solubilized in the aqueous core of the reverse micelles, which are present in the organic phase. The organic phase is subsequently separated from the aqueous phase leading to signifi-cant removal of dye. Experimental results reveal that the electrostatic interaction between the oppositely charged surfactant head group present in the reverse micelles and the dye molecule plays a key role in the separation. The removal of the anionic methyl orange dye from water is carried out in the presence of cationic hexadecyltrimethyl ammonium bromide surfactant, whereas the removal of the cationic methylene blue dye is carried out in the presence of anionic sodium dodecylbenzene sulfonate surfactant. Amyl alcohol is used as the solvent. The influence of parameters such as dye concentrations, surfactant concentrations, pH, and KCl and NaBr concentrations on the percentage removal of dye was studied. The percentage removal of dye is decreased with the increase in dye concentration in the feed. The increase in surfactant concentration resulted in higher dye removal, because more reverse micelles could be hosted in the organic phase. The increase in aqueous phase pH resulted in enhanced removal of methyl orange from water, while in the case of methylene blue the percentage removal decreased. The increase in KCl and NaBr concentrations resulted in decreased percentage removal of methylene blue, whereas the percentage removal of methyl orange was increased. The effect of pH and salt concentration is explained based on charge transfer mechanism and electrostatic interactions and dye-surfactant complex formation.     

表面活性剂对HDEHP萃取动力学的影响

用上升液滴法测定二(2-乙基己基)磷酸(HDEHP)从硫酸盐介质中萃取Co^2^+的速率。研究体系中加入不同表面活性剂所引起萃取速率的不同改变: 三辛基氧化膦(TOPO)因与HDEHP形成可萃取的Co^2^+活性分子缔合物, 降低了萃取过程活化能而使反应加速; 十二烷基磺酸钠(SDS)和十六烷基三甲基溴化铵(CTMAB)因占据发生萃取反应的界面区, 减小了HDEHP与Co^2^+反应的机会而使反应减速; SDS还因其在界面形成较强的负电场(层), 造成Co^2^+的附加势能而使萃取速率有更大幅度的降低。     

Ultrasound-assisted continuous liquid-liquid extraction without phase separation and hydrolysis of paracetamol in suppositories

An automated flow injection (FI) manifold based on iterative change of the flow direction has been designed to carry out continuous liquid-liquid extraction without phase separation and hydrolysis both with ultrasound-assistance. The dynamic approach has been applied to suppositories from which paracetamol has been extracted in this way into an aqueous phase and hydrolysed prior to reaction with o-cresol in the alkaline medium used as extractant. The three linked reactions, extraction-hydrolysis-derivatisation, cause displacement of the balance to completeness. The strategic location of the photometric flow-cell in the flow-injection manifold enables monitoring of the overall process and the obtaining of a characteristic multipeak recording. The influence of ultrasounds on the different steps was investigated. The indophenol blue dye formed was monitored at 620 nm. The limits of detection (LOD) and quantification (LOQ) of the method are 0.38 and 0.64 μg ml⁻¹, respectively, with a linear range from 0.64 to 50 μg ml⁻¹; a within-laboratory reproducibility between 2.07 and 4.66% and repeatability from 2.01 to 4.63%, both expressed as relative standard deviation. The results obtained with the proposed method are in excellent agreement with those provided by the official method, but with a shorter analysis time, lower sample and reagent consumption and less analyst involvement.     

搅拌对三氯乙烯及糠醛水溶液液-液分层的影响

糠醛是用玉米芯、麦杆等农林植物纤维废料生产的重要的有机溶剂和原料。用于生产糠醇,石油化工中润滑油精制及C4、C5馏分的分离纯化。传统的糠醛精致方法是将水解后的糠醛稀溶液多次蒸馏,能耗高,作者采用液-液萃取法分离糠醛,工艺简单,能耗低。本文选择三氯乙烯为萃取剂,考察了萃取分离糠醛水溶液体系的影响因素,为进一步中试及工业放大提供参考。     

Some aspects of the separation of nuclear fission products by liquid-liquid extraction

The technique for and methods of separation of products of nuclear fission play a major role in many stages of the nuclear fuel cycle. The extraction of these products from effluent solution after the processing of the burnt-up nuclear fuel is receiving considerable attention. Trivalent lanthanoides are usualy extracted together with Am(III) and their mutual separation is rather difficult.^1–4 The extraction of lanthanoides with tertiary amines or quaternary ammonium salts involving the benzyl group as one of substituents has been studied in order to find the influence of the alkyl chain length on the extraction selectivity and capacity.^3–5 Suitable extractants for the separation of Am(III) and Ln(III) from the acidic nitrate solutions were recommended. Using vapour phase osmometry and cryoscopy the association of these compounds was measured at 5.25 and 50°C allowing a rough estimation of medium association degree for the formation of the aggregates. The method of apparent molar volumes, supplemented by the spectrophotometric method, was used for identification of the chemical composition of the aqueous phase.     

Extraction and separation of141Ce and153Gd with HDEHP

Studies on liquid-liquid extraction of trace level cerium and gadolinium,¹⁴¹Ce and¹⁵³Gd, from HCl and HNO₃ media with liquid cation exchanger, HDEHP reveal that a quantitative separation of the elements from an admixture of the two radioisotopes can be achieved with 0.1% HDEHP and 0.01N HCl. The condition is also valid for separation of trace amount of¹⁵³Gd from bulk or macro quantity of cerium.     

The separation of In,Sn, and Sb by liquid-liquid extraction

Summary The extraction behaviour of In, Sn and Sb in HI and HCl media has been investigated and several separation procedures have been developed. Removal of Sb(V) from Sn(IV) is accomplished by extraction of Sb(V) from 7M HCl solution with isoamylacetate. Selective removal of Sn(IV) or In(III), or both, from Sb(V) is effected by extraction with benzene or isopropylether from HI solutions. The extractions are quite simple, rapid and efficient and therefore useful in the study of short-lived fission products.

---

Zusammenfassung Das Verhalten von In, Sn und Sb bei Extraktion aus Jodwasserstoffsaurem bzw. salzsaurem Milieu wurde untersucht und einzelne Trennungsverfahren ausgearbeitet. Die Trennung von Sb(V) und Sn(IV) erfolgt durch Extraktion des Antimons aus 7-m Salzsäure mit Isoamylacetat. Die selektive oder gemeinsame Trennung der Ionen Sn(IV) und In(III) von Sb(V) gelingt durch Extraktion mit Benzol oder Isopropyläther aus jodwasserstoffsaurer Lösung. Diese Extraktionen sind einfach, rasch durchführbar und wirksam und daher geeignet für die Untersuchung kurzlebiger Spaltprodukte.

---

Résumé On a étudié le comportement vis-à-vis de l'extraction de In, Sn et Sb dans les milieux HI et HCl et l'on a développé plusieurs procédés de séparation. On a réalisé la séparation de Sb(V) d'avec Sn(IV) par extraction de Sb(V) par l'acétate d'isoamyle à partir d'une solution HCl 7M. On a effectué la séparation sélective de Sn(IV) ou de In(III), ou des deux, d'avec Sb(V), par extraction par le benzène ou l'éther isopropylique à partir des solutions HI. Les extractions sont très simples, rapides et efficaces, et par conséquent d'une grande utilité dans l'étude des produits de fission à courte durée de vie.

---

---

On leave from Natron Maglaj-Yugoslavia. This author wishes to acknowledge his gratitude to the C. E. N., Mol-Donk, for having made possible this radiochemical study.     

Assessment of matrix effects and determination of niacin in human plasma using liquid-liquid extraction and liquid chromatography-tandem mass spectrometry

A simple, sensitive and rapid liquid-liquid extraction method for the analysis of nicotinic acid (niacin) and its labeled internal standard nicotinic acid-d4 (niacin-d4) in human plasma was developed and validated. The analyte and its internal standard were isolated from acidified plasma using a single liquid-liquid extraction procedure with methyl-t-butyl ether. The extracted samples were analyzed by liquid chromatography-tandem mass spectrometry in positive electrospray ionization mode with multiple reaction monitoring. The calibration curves were linear in the measured range between 5 and 1000 ng/mL and the limit of detection was calculated as 122 pg/mL. The method required 250 microL of human plasma and the total run time between injections was 3.5 min. Matrix effects were assessed by post-column infusion experiments, phospholipids monitoring and post-extraction addition experiments. The extraction of phospholipids and niacin from plasma was studied under acidic, neutral and basic conditions. Acidic conditions were optimal for both the recovery of niacin and the removal of phospholipids; the degree of matrix effects for niacin was determined to be 2.5%. It was concluded that effective removal of matrix components can overcome low recovery issues associated with liquid-liquid extractions of polar analytes.     

Selective adsorptive separation of cyclohexane over benzene using thienothiophene cages

The selective separation of benzene (Bz) and cyclohexane (Cy) is one of the most challenging chemical separations in the petrochemical and oil industries. In this work, we report an environmentally friendly and energy saving approach to separate Cy over Bz using thienothiophene cages (ThT-cages) with adaptive porosity. Interestingly, cyclohexane was readily captured selectively from an equimolar benzene/cyclohexane mixture with a purity of 94%. This high selectivity arises from the C–H⋯S, C–H⋯π and C–H⋯N interactions between Cy and the thienothiophene ligand. Reversible transformation between the nonporous guest-free structure and the host–guest assembly, endows this system with excellent recyclability with minimal energy requirements.

Selective adsorptive separation of cyclohexane was realized from an equimolar benzene and cyclohexane mixture via crystalline thienothiophene cages with a selectivity of 94%.