Quantitative separation of gallium from zinc, copper, indium, iron(III) and other elements by cation-exchange chromatography in hydrobromic acid-acetone medium

Gallium can be separated from Zn, Cu(II), In, Cd, Pb(II), Bi(III), Au(III), Pt(IV), Pd(II), Tl(III), Sn(IV) and Fe(III) by elution of these elements with 0.50M hydrobromic acid in 80% acetone medium, from a column of AG50W-X4 cation-exchange resin. Gallium is retained and can be eluted with 3M hydrochloric acid. Separations are sharp and quantitative except for iron(III) which shows extensive tailing. With 0.20M hydrobromic acid in 80% acetone as eluting agent, all the species above except iron(III) and copper(II) can be separated from gallium with very large separation factors. Only a 1-g resin column and small elution volumes are required to separate trace amounts and up to 0.5 mmole of gallium from more than 1 g of zinc or the other elements. Hg(II), Rh(III), Ir(IV), Se(IV), Ge(IV), As(III) and Sb(III) have not been investigated, but should be separated together with zinc according to their known distribution coefficients. Relevant elution curves, results for the analysis of synthetic mixtures and for amounts of some elements remaining in the gallium fraction are presented.     

Studies on extraction of Cu(II), Ga(III), In(III) and Tl(III) with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one Separation and spectrophotometric determination of copper and gallium

The extraction of Cu(II), Ga(III), In(III) and Tl(III) with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HPMBzP) from aqueous solutions has been investigated. The mechanism of extraction and the composition of the species extracted has been determined. The effect of equilibration time, various organic solvents and salting-out agents on the extraction of copper and gallium has also been investigated. The green Cu(PMBzP)₂ chelate has absorption maxima at 298 and 670 nm, and PMBzP has maximum absorbance at 290 nm. A new and sensitive spectrophotometric method for copper has been devised, based on the absorbance at 670 nm. The presence of excess of reagent does not interfere and no special treatment is necessary to destroy it. The proposed method has some advantages and has been applied for the determination of copper in various soil samples. Gallium has been separated from indium, thallium, copper, iron and many other elements. The recovery of gallium and copper was 100 ± 0.2%.     

Analytical applications of a liquid anion-exchanger for the separation of uranium(IV) in malonate solution

Uranium was quantitatively extracted with 4% Amberlite LA-1 in xylene at pH 2.5-4.0 from 0.001 M malonic acid. It was stripped from the organic phase with 0.01 M sodium hydroxide and determined spectrophotometrically at 530 nm as its complex with 4-(2-pyridylazo) resorcinol. Of various liquid anion-exchangers tested, Amberlite LA-1 was found to be best. Uranium was separated from alkali and alkaline earth metal ions, thallium(I), iron(II), silver, arsenic(III) and tin(IV) by selective extraction, and from zinc, cadmium, nickel, copper(II), cobalt(II), chromium(III), aluminium, iron(III), lead, bismuth, antimony(III) and yttrium by selective stripping. The separation from scandium, zirconium, thorium and vanadium(V) was done by exploiting differences in the stability of chloro-complexes.     

Extraction and separation of gallium, indium and thallium with several carboxylic acids from chloride media

A method is proposed for the extraction and individual separation of trivalent gallium, indium and thallium with sec-octylphenoxy acetic acid (CA-12), sec-nonylphenoxy acetic acid (CA-100) and naphthenic acid (NA) from chloride media. The distribution equilibria of gallium (III), indium (III), thallium (III) and thallium (I) between carboxylic acids (CA-12, CA-100 and NA) dissolved in kerosene and acidic aqueous chloride media has been investigated as a function of the concentration of extractants and the concentration of hydrogen ion in aqueous phase. A possible mechanism of the extraction is discussed. The method permits rapid and precise individual separation of gallium (III), indium (III) and thallium (III), and is applicable to the analysis of alloy samples.     

Vanadium(III) as an analytical reagent: The titrimetric determination of iron, copper, thallium, molybdenum, uranium, vanadium, chromium and manganese

Vanadium(III) solutions can be used in direct titrations of iron(III), copper(II), thallium(III), molybdenum(VI), uranium(VI), vanadium(V), chromium(VI) and manganese(VII) in milligram amounts. The titrations are done at 70-80 degrees for iron(III), copper(II), thallium(III), molybdenum(VI) and at room temperature for vanadium(V), chromium(VI) and manganese(VII). Uranium(VI) is titrated at 70-80 degrees in presence of iron(II). The vanadium(III) solution is prepared by reduction of vanadium(V) to vanadium(IV) with sulphur dioxide, followed by addition of phosphoric acid and reduction with iodide, and is reasonably stable.     

Solvent extraction of scandium from malonic acid with high molecular-weight amines

Scandium is quantitatively extracted with 4% Amberlite LA-1 or Amberlite LA-2 in xylene at pH 2.5-5.5 from 0.1M malonic acid. Scandium is stripped from the organic phase with 0.5M hydrochloric acid and determined spectrophotometrically at 525 nm, as its complex with Alizarin Red S. Primene JM-T, tri-iso-octylamine, tributylamine and tribenzylamine have also been studied as extractants, but found to be unsatisfactory for various reasons. Xylene, toluene, benzene, chloroform, carbon tetrachloride, hexane, cyclohexane and kerosene have been studied as diluents. Xylene is found to be the most efficient. Scandium can be separated from most metals by selective extraction, and from gallium, thallium(III), bismuth, antimony(III), chromium(III), copper(II), iron(III), uranium(VI), cerium, zirconium, indium, thorium and titanium by selective stripping, in some cases combined with use of suitable complexing media to retain the other metals in the organic phase.     

Niobium(III) as an analytical reagent. : Part I. The titrimetric determination of iron,copper, thallium,molybdenum, uranium and vanadium

Niobium(III) solutions can be used in direct titrations of copper(II), iron(III), thallium(III), moIybdenum(VI), vanadium(V) and uranium(VI) in milligram amounts. Phenosafranine is generally satisfactory as the indicator, but potentiometric end-points can also be used. Copper and iron can be determined successively when a mixed indicator containing phenosafranine and méthylene blue is used. Thallium(I) and thallium (III) can be determined in mixtures. The niobium (III) solutions are stable for several days under a carbon dioxide atmosphere.     

Solvent extraction and separation of gallium, indium and thallium with N-benzylaniline

A simple and rapid method is proposed for the separation of tervalent gallium, indium and thallium by solvent extraction with N-benzylaniline in chloroform from different concentrations of hydrochloric acid. Thallium and gallium are extracted from 1M and 7.0-7.5M hydrochloric acid respectively. Indium is finally extracted from hydriodic acid. These metals in the final extracts are determined complexometrically. Interference from some cations can easily be eliminated by reduction with sulphite, followed by selective oxidation of thallium(I) to thallium(III) with saturated bromine water, and from others by the use of thioglycollic acid as a masking agent in the extraction of gallium and indium. Most common anions cause no interference. Log-log plots of distribution coefficients vs. concentration of amine for gallium, indium and thallium indicate a 2:1 limiting mole ratio of amine to these metals.     

Extraction of chloride acido complexes of triply charged metal cations in water–oxyethylated nonylphenol–salting-out agent systems

The characteristic features of extraction of chloride acido complexes of iron(III), thallium(III), indium, and gallium in water–oxyethylated nonylphenol (neonol AF-9-12)–salting-out agent systems are studied. The role of temperature, nature of the salting-out agent, and its salting-out ability is shown.     

Quantitative separation of traces of lead,cadmium and many other elements from gram amounts of thallium by cation-exchange chromatography

Traces of lead and minor amounts up to 20 mg, can be separated from gram amounts of thallium by cation-exchange chromatography on a column containing only 2 g of AG50W-X4 resin. Thallium passes through the column in 0.1 M HCl in 40% acetone. The retained lead can be eluted with 3 M HCl or HNO₃. Other elements, including Cd, Zn, In, Ga, Cu(II), Fe(III). Mn(II), Co(II). Ni(II), U(VI) and Al, are retained quantitatively with lead. Only Hg(II), Au(III), the platinum metals, bismuth and elements forming oxyanions accompanying thallium. Results for the determination of trace elements in 99.999% pure thallium are presented.     

Solvent extraction and separation of gallium(III), indium(III), and thallium(III) with tributylphosphate

A systematic study has been made of the solvent extraction behaviour of milligram amounts of gallium(III), indium(III), and thallium(III) with TBP from hydrochloric acid, and of thallium(III) from nitric acid, sulphuric acid and buffer solutions of different pH. The effect of the metal ion concentration, acid concentration, reagent concentration, salting-out agent, and diverse ions have been critically examined. A scheme for separation of gallium(III), indium(III), and thallium(III) from each other and for their determination is proposed.     

Redoxkinetik von Metallkomplexen in nichtwäßrigen Lösungen,XI. Die Reduktion von Thallium(III)oxinat mit Eisen(II) in schwach koordinierenden Lösungsmitteln

The kinetics of the iron(II) reduction of thallium(III) oxinate does not differ essentially from that of the oxinate-transfer from thallium(III)-oxinate to iron(III), described before: formation of a binuclear intermediate, rearrangements within, and subsequent reaction with the excess reactant to the final products. As for the redox process, these intermediates are binuclear Tl(II)-Fe(III) complexes which, with initial reactants, form further complexes in which the second electron is transferred. In the cases of excess Tl(ox)₃ and of equimolar reactants, disproportionations are likely involved.     

Photometric determination of gallium with rhodamine b

Gallium is extractable as rhodamine B chlorogallate with benzene from 6M hydrochloric acid, and can be determined absorptiometrically or fluorimetrically in the extract. The interference of iron(III) is avoided by first separating gallium by extraction with isopropyl ether from hydrochloric acid solution containing titanous chloride. Traces of gallium can be determined in the presence of aluminium, indium, zinc, antimony, thallium, tungsten and other elements.     

Cation Exchange Separation of Thallium (I) From Other Elements In Mixed Solvents

Abstract

The cation exchange chromatographic behaviour of thallium (I) on Dowex 50W-X8 was carried out in mixed solvents. Nitric, sulphuric, perchloric acid and their salts, as well as in mixtures of 2 M nitric acid with methanol, ethanol, acetone, dioxane and titrahydrofuran, were studied as the eluants. In comparison with other elements, since thallium was weakly sorbed, it was first eluted, while strongly bound elements like manganese, magnesium, cobalt, indium, gallium, zinc, iron, scandium, yttrium, aluminium, calcium, strontium, and barium were subsequently eluted. The best separations were possible from nitric acid in the presence of non-aqueous solvents such as methanol and ethanol.     

The polarographic determination of thallium

A polarographic method is described for the determination of thallium in sodium triphosphate supporting electrolyte. The incorporation of 0.1% camphor in the electrolyte displaces the cathodic steps of many interfering ions, e.g., lead(II), copper(II), iron(III) and bismuth(III) to a more negative potential (1?.0 V), well away from the thallium step which remains unaffected.     

Determination of trace elements in manganese metal and compounds by ion-exchange chromatography and atomic absorption spectrometry : part 2. Determination of Bi,Cd, In,Zn, Pb,Fe(III), Ga,Cu(II), Co and U(VI)

Traces of the specified elements are separated from 1 g of manganese (II), using a 30- g column of AG50W-X8 cation-exchange resin and mixtures of hydrochloric acid and acetone as eluents. The trace elements are separated into three groups and are determined by atomic absorption spectrometry, except uranium for which spectrophotometry is used. Recoveries for 10 μg amounts (20 μg for gallium) vary between 94% (for gallium) and 103% (for uranium). A combined elution curve, results for the analysis of synthetic mixtures and for the determination of ten trace elements in samples of manganese metal, chloride and dioxide are presented.     

Separation gallium-fer en presence d'edta

Macro- or microquantities of gallium can be separated from iron by precipitating the latter with sodium hydroxide in the presence of EDTA. Nearly all the gallium remains in solution. After the separation of iron, gallium is extracted with tributylphosphate from 3 N hydrochloric acid medium, and then re-extracted into water. Gallium is finally determined by precipitation with cupferron and ignition to the oxide, or for trace amounts of gallium, by colorimetric determination with rhodamine B. The method was checked with radioactive gallium and iron.     

Solvent extraction separation of gallium with 18crown6 from chloride media

Gallium was quantitatively extracted with 0.02M 18crown6 in methylene chloride from 6M hydrochloric acid, then stripped with 1M acetic acid and determined with 2-(pyridylazo)naphthol with measurement at 545 nm. Gallium was separated from indium, thallium, lead, aluminium and bismuth. The method was applied to determination of gallium in bauxite.     

Separation of gallium, indium and thallium by extraction with n-octylaniline in chloroform

Extraction of gallium(III), indium(III) and thallium(III) with n-octylaniline in chloroform at various concentrations of hydrogen halide acids (HCl, HBr, HI) has been studied and a scheme for their separation proposed. The procedure can be successfully applied to the separation and determination of gallium in presence of mercury, bismuth, manganese, zinc and lead; indium in presence of bismuth, antimony, lead, mercury, cadmium and zinc; and thallium in presence of mercury, cadmium, manganese, aluminium, tin and antimony. The advantage of the method is that the reagent can be recovered for reuse. The method is simple, rapid, and effects clear-cut separation.     

An extraction study of gallium, indium and thallium using TPASO as an extractant

A method is proposed for the extraction and individual separation of trivalent gallium, indium and thallium from salicylate media using triphenylarsine oxide dissolved in toluene as an extractant. The optimum extraction conditions are evaluated and described. The extracted metal ions are stripped and estimated spectrophotometrically following complexation with 4-(2-pyridylazo) resorcinol. A possible mechanism of the extraction is discussed. The method permits rapid and precise individual separation of gallium (III), indium (III) and thallium (III) and is applicable to the analysis of alloy samples.