Anionenaustauschtrennungen der mit Tributylphosphat extrahierbaren Elemente. II

Zusammenfassung Eine sehr empfindliche und selektive Methode zur spektrophotometrischen Bestimmung des Germaniums unter Verwendung von Brenzcatechinviolett wurde beschrieben. Vor der Bestimmung wird das Germanium zunächst durch Extraktion mit Tributylphosphat (TBP) und Kerosin angereichert und dann mit dem stark basischen Anionenaustauscher Dowex 1, X 8 in einer Mischung aus 30 Vol. %> TBP, 60 Vol. % Methylglykol und 10 Vol. % 12-n Salzsäure von den mitextrahierten, die Bestimmung störenden Elementen abgetrennt. Weiters wird gezeigt, daß sich diese Mischung gut eignet, um Uran quantitativ vom Germanium zu trennen. Die spektrophotometrische Bestimmung des Germaniums wird von V(V), Mo(VI), Ga(III), Tl(III), Sb(III), Sn(II) und Fe(III) gestört. Die Störung durch Eisen kann durch Zugabe von Natrium-Kaliumtartrat ausgeschaltet werden.

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Anionic exchange separations of the elements that can be extracted with tributyl phosphat. II

Summary A very sensitive and selective method for the spectrophotometric determination of germanium has been described employing pyrocatechol violet. Prior to the determination, the germanium is first accumulated by extraction with tributyl phosphate (TBP) and kerosene and then separated from the co-extracted elements, that interfere with the determination, by means of the strongly basic anion-exchanger Dowex 1, X8 in a mixture consisting of 30 vol. % TBP, 60 vol. % methylglycol and 10 vol. % 12N hydrochloric acid. In addition it was shown that this mixture is well suited to separate uranium quantitatively from germanium. The spectrophotometric determination of germanium is interfered with by V(V), Mo(VI), Ga(III), Tl(III), Sb(III), Sn(II) and Fe(III). The interference by iron can be averted by adding sodium-potassium tartrate.

     

Reversed Phase Extraction Chromatographic Separation of Manganese(II) with Tributyl Phosphate

Abstract

The extraction chromatography of manganese(II) was developed using tributyl phosphate as extractant from thiocyanate media with silica gel as the stationary phase. Manganese was extracted from 1.5 M ammonium thiocyanate, stripped with mineral acids and determined spectrophotometrically at 450 nm. It was separated from alkali metals, Mo(VI), nickel, silver and lead by selective extraction, and from iron(III), zinc, cobalt by selective stripping. The method was extended for the analysis of manganese in samples of soil and minerals.     

Synergic liquid-liquid extraction studies of neodymium and praseodymium with mixtures of tributyl phosphate and Aliquat-336 in nitrate media

Extraction studies of neodymium and praseodymium with mixtures of tributyl phosphate and Aliquat-336 in xylene have been carried out. From 3.0M aqueous ammonium nitrate solutions, negatively charged complexes of neodymium and praseodymium were extracted with Aliquat-336 in the presence of tributyl phosphate into the organic phase. The synergic extracted species observed was M(NO₃) ₄ ^– L⁺·TBP. The synergic extraction of lanthanide elements in nitrate media increases from lanthanum to lutetium.     

A Novel Room Temperature Ionic Liquid Extraction Spectrophotometric Determination of Trace Germanium in Natural Water with Methybenzeneazosalicylfluorone

Abstract

This paper describes a highly sensitive and selective extraction spectrophotometric method for determination of trace germanium in natural water with new a chromogenic reagent methybenzeneazosalicylfluorone abbreviated as MBASF, in which a typical room temperature ionic liquid, 1‐butyl‐3‐methylimidazolium hexafluorophosphate abbreviated as [C₄mim][PF₆] was used as novel medium for liquid/liquid extraction of germanium(IV). In the presence of TritonX‐100, MBASF reacted with germanium(IV) to form a red complex rapidly, the complex was then extracted into the [C₄mim][PF₆] phase, the absorbance of the complex in ionic liquid at 496 nm was recorded and used to determine trace germanium(IV). The apparent molar absorptivity of the complex and the detection limit for the real sample were found to be 3.12×10⁶ L mol^?1 cm^?1 and 0.2 ng mL^?1, respectively. The absorbance of the complex at 496 nm increases linearly with the concentration up to 4 µg of germanium (IV) in 250 mL of aqueous solution. The interference study show the determination of germanium is free from the interference of almost all positive and negative ions found in the natural water samples. The determination of germanium in natural water was carried out by the present method and electrothermal atomic absorption spectrometry (AAS). The results were satisfactorily comparable so that the applicability of the proposed method was confirmed using the real samples. Moreover, the extraction mechanism with the ionic liquid system was also investigated. We think the extraction performance of the ionic liquid system is a combination of ion‐pairing effect between imidazolium cation and basic solute in the aqueous phase with the dissolution of polar molecule in ionic liquid phase. A wise choice of the appropriate combination of anion with imidazolium cation hydrophobicity allows playing with solute selectivity.     

Radiochemical analysis of90Sr in milk,soil and plants by solvent extraction

A universal and fast method of⁹⁰Sr determination in environmental matrices (raw and dried milk, plants, soils) has been elaborated. Solvent extraction method of daughter⁹⁰Y by tributyl phosphate was used. The method of strontium determination is compatible with determination of other transuranic elements (americium, plutonium) and there is no need to check the chemical yield of strontium.     

Extraction - Spectrophotometric Determination of Phosphate Using N-Phenylbenzohydroxamic Acid

Abstract

A simple solvent extraction and spectrophotometric method for the determination of micro amount of phosphate (PO₄) is described. Phosphate is selectively separated from associated elements by reacting it with calcium and extracting excess calcium with N-phenylbenzohydroxamic acid (PBHA) at pH 11.3. The excess calcium was determined in ultra-violet and visible region and hence the phosphate content was calculated. The Beer's law is obeyed in the range 0.5 ? 10.0 ppm at 340 nm and 0.25 - 8.0 ppm at 560 nm of phosphate for a fixed amount of calcium (20.0 ppm). These results are also compared with those obtained by atomic absorption spectrophotometry. The method has been applied for the determination of phosphate in pharmaceutical and other samples.     

Liquid-liquid extraction of arsenic(III) with diluted tributyl phosphate

A 40% tributyl phosphate solution in xylene was used for the quantitative extraction of arsenic(III) from 4M hydrochloric acid/2M lithium chloride. It was stripped from the organic phase with water and determined volumetrically with potassium bromate. The period of equilibration was 3 min. Arsenic was extracted in presence of copper, cobalt, nickel, tin, bismuth, iron, cadmium and other elements which are usually associated with it in sulphide minerals and alloys.     

Solvent extraction of neodymium,europium and thulium by di-(2-ethylhexyl)phosphoric acid

The extraction of Na³⁺, Eu³⁺ and Tm³⁺ by di-(2-ethylhexyl)phosphoric acid, HDEHP has been studied from various aqueous acidic solutions. The extraction of these elements is inversely proportional to the third power of the hydrogen ion concentration. Antagonistic effects were observed when the extraction was studied by mixtures of HDEHP and tributyl phosphate, TBP, or trioctylphosphine oxide, TOPO. The presence of water-miscible alcohols and acetone generally increases the extraction of these three elements from HCl solutions. Reaction mechanisms have been suggested and discussed in the light of the data obtained.     

Solvent Extraction Separation of Germanium(IV) with N-<Emphasis Type="Italic">n</Emphasis>-Octylaniline As an Extractant

The extraction behavior of germanium(IV) from aqueous hydrochloric acid solution with N-n-octylaniline in xylene was investigated. Hydrochloric acid concentration higher than 9 M remained effective for quantitative extraction of germanium(IV). Phenylfluorone ion as a counter anion was used. More than 2% N-n-octylaniline provided quantitative extraction at 1 min equilibrium time and germanium(IV) was back extracted by 7 M ammonia. The method was free from the interference of a large number of metal ions and anions, except for Te(IV) and Sn(IV); this was avoided using the masking effect. Germanium(IV) was separated from associated elements in its binary mixture with Si(IV), Te(IV), Sb(III), Bi(III), Au(III), Cu(II), Zn(II), and its ternary mixture with Se(IV), Te(IV); Sb(III), Bi(III); and Au(III), Cu(II). The proposed method was applied to a synthetic sample containing associated metal ions. The results indicated that trace amounts of germanium(IV) could be separated effectively from higher amounts of other elements.__________From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 5, 2005, pp. 463–467.Original English Text Copyright © 2005 by Sargar, Anuse.This article was submitted by the authors in English.     

Rapid Synergistic Extraction And Atomic Absorption Spectrometric Determination Of Iron In Environmental Samples Using Tributyl Phosphate And N-Phenyl-2-Furylacrylohydoroxamic Acid

Abstract

Iron (III) was rapidly extracted as its ternary complex with tributyl phosphate and N-phenly1-2-furylacrylohydroxamic acid (PFHA) from weakly acidic (pH 1.0-1.5) solutions into isobutyl methyl ketone and was determined atomic absorption spectrometrically. The method tolerated the presences of a large number of anions and cations commonly associated with iron, and was successfully tested with certified samples of coal fly ash, alloys, and plant tissues. It was also applied to the analysis of animal tissues, natural waters, and wastewaters; validating it by standard addition technique. PFHA was selected from nine new hydroxamic acids.     

Studies on extraction of indium by tributyl phosphate from thiocyanate solutions

Indium can be quantitatively separated from a large number of elements which are usually associated with it, by extraction with 15% tributyl phosphate solution in kerosene from hydrochloric acid (pH 1)/0.5M potassium thiocyanate medium and stripping with 6M nitric acid. The equilibration takes 20 min.     

Extraction of antimony and tantalum from aqueous fluoride solutions by n-octanol and tributyl phosphate

¹⁹F and ²¹Sb NMR spectroscopy and chemical analysis were used to study the composition and structure of fluoride complexes of antimony(V) and tantalum(V) in organic and aqueous phases in extraction by tributyl phosphate (TBP) and n-octanol. It is found that extraction from solutions containing a single element or both elements occurs via the hydrate-solvate mechanism. The possibility of separating tantalum(V) and antimony(V) by extraction from fluoride solutions is shown. The efficiency of tantalum(V) and antimony(V) separation by extraction from fluoride solutions is enhanced at a transition from TBP to n-octanol.     

The Effect of the Anion of the Salt Background of the Aqueous Phase on the Extraction of Germanium (IV) 8-Hydroxyquinolinate

Abstract

The effect of the anion of the salt background of the aqueous phase on the extraction of the 8-oxyquinolinate of germanium has been investigated The anion effect is associated with the change in ionization constants and distribution of 8-oxyquinoline The degree of anion influence depends on the reagent concentration.     

Separation of gram quantities of uranium from fission products by extraction chromatography

The separation of gram quantities of uranium from fission products has been investigated by extraction chromatography. The separation which is based on the difference in distribution coefficients between uranium and the fission products on a tributyl phosphate (TBP) resin in nitric acid medium, was carried out by means of high acidity feed and stepwise elution on a TBP chromatography column. The results show that this technique is capable to separate 5 g of uranium from a large quantity of fission products. The recovery of uranium is more than 99%. The decontamination factors of g- and b-activities were 2.1^.10³ and 2.3^.10³, respectively.     

Determination of rare earth elements in geological samples by inductively coupled plasma atomic emission spectrometry with flow injection liquid-liquid extraction.

A direct sampling with organic solvent extracts for simultaneous multi-element determination implemented with inductively coupled plasma atomic emission spectrometry (ICP-AES) associated with a flow injection liquid-liquid extraction (FI-LLE) sample preconcentration method was studied. The "robustness" of the plasma discharge with tributyl phosphate (TBP) loading was diagnosed by using the Mg II 279.55 nm and Mg I 285.21 nm lines intensity ratio. A FI-LLE preconcentration system for rare earth elements (REEs)-nitrate-TBP was established by using a laboratory-designed phase separator. For these elements, an average sensitivity enhancement factor of 64 was obtained with respect to ICP-AES sampling with aqueous solutions. The precision of the method was characterized by a relative standard deviation (%RSD) of 1.8 - 5.2%. A throughput of 27 samples per hour can be achieved with an organic solvent consumption of less than 200 microl per determination. Good results were obtained for the analysis of standard reference materials.     

Extraction and Flameless AAS Determination of Germanium in Lignite Fly Ash

Abstract

The use of dicyclohexyl-18-crown-6 methyl isobutyl ketone solution in extraction and flamelessatomic absorption spectrophotometry (AAS) determination of germanium in lignite fly ashes have been studied.

Germanium is usually determined in lignites after the carbonaceous part of the sample has been burnt by a dry or wet ashing method. However, methods are described for direct determination of germanium.

In the present paper a wet ashing method is reported for the determination of germanium in lignite fly ashes by flameless AAS after extraction into dicyclohexyl-18-crown-6 methyl isobutyl ketone (MIBK) solution. Solvent extraction is a known hydrometallurgical method that could be applied in germanium recovery.     

Synergistic extraction and spectrophotometric determination of plutonium(VI)

A rapid method for the synergistic extraction and spectrophotometric determination of plutonium(VI) in milligram amounts using a mixture of thenoyltrifluoroacetone (TTA) and tributyl phosphate (TBP) in benzene has been developed. Quantitative extraction is obtained from aqueous solutions of pH=2 affording separation from many commonly occurring impurities, viz., thorium, fission products and cladding materials. The precision and accuracy of the method has been found to be∼1%. The study of the solid product isolated from the extraction system indicates the stoichiometry of the extracted species as PuO₂(TTA)₂ TBP.     

The Gas Chromatographic Determination of the Decomposition Products of Tributyl Phosphate

Abstract

The products formed from tributyl phosphate in different diluents have been quantitatively analyzed for components by gas chromatography. Methylation yields and limits of detection of di butyl phosphate are given.     

Seperation of neptunium from irradiated uranium targets

A new chemical method based in two separation steps was developed to isolate²³⁵Np from uranium targets irradiated with charged particles. Neptunium and plutonium are separated from uranium and most of the fission products by ion exchange. Then, neptunium is isolated from plutonium and remaining contaminants by extraction chromatography with tributyl phosphate in hydrochloric acid solution. High decontamination was achieved.     

In situ electro-oxidation and liquid-liquid extraction of cerium(IV) from nitric acid medium using tributyl phosphate and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate

The process of in situ electro-oxidation of Ce(III) to Ce(IV) followed by its extraction into the organic phase has been investigated for its applicability in the separation of Ce from nitrate medium. Solvent extraction of cerium from nitric acid after its electro-oxidation to fourth valency state was carried out using tributyl phosphate (TBP) and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (KSM-17, equivalent to PC-88A). The efficiency of the extractants at different aqueous phase nitric acid concentrations and different electrode potentials were determined. Various reducing agents such as hydroxylamine hydrochloride, sodium nitrite, ferrous sulphate as well as complexing agents like EDTA, oxalic acid etc, were studied as strippants for the back extraction of cerium from the loaded organic phase. The method developed for the extraction of cerium was further extended to the partitioning of cerium from Ce-Am mixture obtained during the KSM-17 based extraction chromatographic elemental fractionation of PUREX High Activity Waste (HAW) solutions. Recovery of Ce obtained in the extraction experiments by batch as well as by continuous flow organic phase was >95% with good radiochemical purity.