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 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.     

Sensitive spectrophotometric determination of gallium with bromopyrogallol red in the presence of surfactants

Gallium in the presence of surfactants (NTGE and CTA) forms with BPR a violet ternary complexes with λ_max at 615 and 625 nm, respectively, with molar absorptivities of 7.0 × 10⁴ and 1.3 × 10⁵ liters mol^?1 cm^?1. These complexes can be advantageously used for the determination of gallium. The molar ratio of gallium to BPR, which is 1:1 in the binary complex, increases to 1:3 in the ternary complex. The presence of surfactants changes the number of BPR molecules bonded to gallium. This is the main factor in the increase in color intensity. Numerous metals interfere. Gallium can be separated by extraction of gallium from 7 M hydrochloric acid with diisopropyl ether.     

Gallium(III) Extraction from Hydrochloric Acid Solutions with Diacylated Diethylenetriamine Hydrochloride

Extraction of gallium(III) from hydrochloric acid solutions with hydrochloride of diethylenetriamine [N-(2-aminoethyl)ethane-1,2-diamine] N,N'-diacylated with neodecanoic acid was studied using chloroform as diluent. Gallium(III) can be effectively recovered from 6–10 M HCl solutions and selectively separated from indium(III), aluminum(III), and zinc(II). The concentration constant and thermodynamic parameters of the anion-exchange extraction of gallium(III) from 6 M HCl solutions were evaluated.     

Determination of Gallium By Liquid-Liquid Extraction-Flame Atomic Absorption Spectrometry In Bayer Process Aluminate Solutions

Abstract

The described flame-atomic absorption determination of gallium involves the extraction of 8-hydroxyauinoline-Ga complex and the extraction of galhum as an ion association complex from strong hydrochloric acid into Methyl Isobutyl Ketone (MIBK). Both of the examined extraction systems were found to be workable for gallium determination in aqueous solutions. A comparison of mentioned extraction systems showed that only the second one can be applied for gallium determination in low concentration in aluminate solutions (strong alkaline). Finally, an analytical scheme for gallium determination in aluminate solutions is recommended (extraction of Ga from hydrochloric acid solutions, 3.0-50M, through matrix matched calibration curve). the proposed procedure was found to be simple, selective and accurate.     

Dosage colorimetrique du zinc dans le gallium de haute purete

A method for the determination of traces of zinc in high-purity gallium is proposed. The sample is dissolved in hydrochloric acid, the reaction being catalysed by platinum, and gallium is extracted as its chloro complex with ether; losses of zinc during this operation are determined radiochemically with ⁶⁵Zn as tracer. Zinc is then separated from other impurities in gallium by two extractions with dithizone, and determined colorimetrically as the dithizonate after excess of reagent has been removed. The limit of sensitivity of the method is 0.04 p.p.m.     

Spectrophotometric determination of the pH scale in ethane-1,2-diol

A highly selective method is described for the determination of gallium at the ppm-level in manganese nodules and geological reference samples. After dissolution of the sample, gallium is adsorbed on Dowex 1 (chloride form) from hydrochloric acid solution containing titanium trichloride, which reduces iron(III) so that it is not adsorbed. After elution with dilute nitric acid and evaporation, gallium is determined by atomic-absorption spectrometry with an air-acetylene flame.     

Spectrophotometric determination of aluminium and gallium with pyrogallol red and cetyltrimethylammonium ions

Spectrophotometric methods are described for the determination of microgram amounts of aluminium and gallium based on the formation of a ternary complex between the metal, pyrogallol red, and cetyltrimethylammonium bromide. The complexes have absorbance maxima at 610 and 615 nm, respectively, with molar absorptivities of 4.8 × 10⁴(Al)and 1.0 × 10⁵ liter mol^?1 cm^?1 (Ga). Numerous metals interfere. Gallium can be separated by extraction of gallium from 7 M hydrochloric acid with di-isopropyl ether. However, aluminium can be separated by extraction of interfering ions with cupferron.     

Fluorimetric determination of gallium in a nickel alloy and aluminium with N-oxalylamine(salicylaldehyde hydrazone)

A fluorimetric determination of gallium, based on the formation of the fluorescent chelate with N-oxalylamine(salicylaldehyde hydrazone) (OSH)-Ga(III), is proposed. The complex has excitation and emission maxima at 395 and 475 nm, respectively. The detection limit is 3 ng/ml and Ga can be determined up to 277 ng/ml. The method has been applied to the determination of gallium in a nickel alloy and aluminium. Extraction with n-butyl acetate from 6M hydrochloric acid medium has been used to separate Ga from the interfering elements in the alloys.     

Determination of manganese in uranium by ion exchange and square-wave polarography

Traces of manganese in uranium and its compounds can be determined by ion-exchange separation and square-wave polarography. When a 9 M hydrochloric acid solution of the sample is introduced into a column of strongly basic anion-exchange resin, manganese can be quantitatively separated from uranium by cluting with 9 M hydrochloric acid. The determination of the separated manganese by square-wave polarography is performed in 1 M potassium hydroxide-0.4 M triethanolamine solution with an excellent sensitivity. The lower limit of the method is 0.5 p.p.m. of manganese.     

Extraction of gallium from mixed acid solutions by tributyl phosphate and its application to activation analysis

The extraction of gallium from chloride-containing solutions was investigated in detail. In the main, mixtures of hydrochloric acid and sulfuric acid were used as the aqueous phase, and the optimum extraction conditions have been established. Other acids and neutral salts increase the extraction rate very effectively, but nitric acid exhibits a detrimental effect. The extraction method has been applied successfully to the neutron activation determination of traces of gallium in insoluble aluminium oxide, which can be decomposed only by fusion with sodium pyrosulphate.     

Extraction of gallium(III) by 1-{[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl}-1H-1,2,4-triazole from hydrochloric acid solutions

The extraction of gallium(III) with 1-{[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2- yl]methyl}-1H-1,2,4-triazole from hydrochloric acid solutions into toluene was studied. It was found that gallium( III) was efficiently extracted from 5–10 M solutions of HCl by the anion-exchange mechanism. The following metal extraction order was determined in the above aqueous phase acidity range: Ga(III) > In(III) > Al(III). The concentration constants and the thermodynamic parameters of the reaction of gallium(III) extraction from 6 M solutions of HCl at 25 °C were calculated.     

Quantitative separation of the alkali metals by cation-exchange chkomatography with bio-rex 40 resin : Application to silicate analysis

The application of BIO-REX 40, a phenolformaldehyde resin, to the quantitative separation of Li, Na, K, Rb and Cs is described. All five elements can be separated in a single procedure by using a 25-g (62-ml) resin column and eluting lithium with 500 ml of 1.00 M hydrochloric acid in 80% ethanol, sodium with 500 ml of 0.20 M hydrochloric acid, potassium with 250 ml of 0.70 M hydrochloric acid, rubidium with another 450 ml of 0.70 M hydrochloric acid and cesium with 500 ml of 4.0 M hydrochloric acid. Procedures are described for the accurate determination of alkali metals in silicate minerals, plant material and water. Al, Fe, Ti, Zr, V, Mo and some other elements are first separated by absorption as oxalato complexes on a column of AG1-X8 resin. The alkali metals are finally determined by gravimetry or atomic absorption spectrometry. Tables of distribution coefficients and quantitative results of analyses of synthetic mixture and standard silicate samples are presented together with typical elution curves.     

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.     

Determination of gallium in an iron-aluminium matrix by solvent extraction and flame emission spectroscopy

Solvent extraction of gallium(III) into methyl isobutyl ketone from hydrochloric acid solutions containing titanium (III) sulphate provides a rapid method for separation of gallium from an iron/aluminium matrix and may be employed to eliminate the interference of these elements in the flame emission spectrometric determination of gallium.     

Quantitative extraktive abtrennung von zirkon und titan mit hilfe von n-heptylarsonsäure

Zirconium and titanium can be easily and quickly extracted from ca. 0.5 M hydrochloric, nitric or sulphuric acid by means of n-heptylarsonic acid in chloroform. The metal can be determined gravimetrically, or after some pretreatment, titrimetrically or photometrically. The extraction allows a quantitative separation from a large number of elements. The results obtained for technical products such as alloys and glass are compared with results of standard methods.     

The micro-determination of gold with p-dimethyl-aminobenzylidenerhodanine

Gold can be determined in the range 4–14 μg within 2% by a simple extraction of chlorauric acid in 0.12 N hydrochloric acid with a solution of p-dimethylaminobenzylidenerhodanine in iso-amyl acetate A 1:1 complex is formed with maximum absorption at 515 mμ.     

N503萃取镓及其机理的研究

镓的提取过去多采用中和、置换等老力法,其流程长,收率又低。近年来,溶剂萃取法显示出极大的优越性,因此,在镓的萃取分离方面国内外也给予了极大的重视,并已有综述^[1-3]。目前,从盐酸体系中萃取镓常用的工业萃取剂有:甲基异丁基酮(MIBK)^[4-7]、磷酸三丁酯(TBP)^[8-12]、三辛胺(TOA)^[13-17]等。但由于MIBK水溶性大、易挥发、TBP对聚氯乙烯萃取设备有严重的溶胀性、TOA的萃取选择性较     

A scheme for the analysis of monazite and monazite concentrates

A scheme using ion-exchange methods is described for the analysis of monazites and monazite concentrates. The sample is opened up with concentrated sulphuric acid, and the resultant solution is applied to a column of Zeocarb 225 resin. After phosphate has been washed out, lead, aluminium, titanium, iron, uranium, calcium and magnesium are eluted with N hydrochloric acid and determined by specific, mainly spectrophotometric, methods. Rare earth elements are eluted with 3 N hydrochloric acid. Cerium is separated from the other rare earths by solvent extraction of its nitrate with methyl iso-butyl ketone; both groups are determined gravimetrically. Thorium is eluted from the ion-exchange resin with 3.6 N sulphuric acid and determined spectrophotometrically with thorin.The sulphuric acid-insoluble minerals are brought into solution by a double fusion method, and the determinations are carried out by a combination of ion-exchange and photometric procedures. Silica, phosphorus pentoxide, tin and chromium are determined by photometric methods, using separate portions of the sample.Lanthanum, yttrium and ytterbium are determined in a 1 M perchloric acid solution of the mixed rare earth oxides (less cerium) using flame photometry. Samarium, praseodymium and neodymium are determined by spectrophotometry.     

The quantitative separation of calcium from magnesium,aluminium and other elements by cation-exchange chromatography in ethanol-hydrochloric acid

Magnesium can be separated from calcium by elution with 3.0 M hydrochloric acid containing 60% ethanol from a column of AG₅₀W-X8 cation-exchange resin. Calcium is retained and can be eluted with 3.0 M hydrochloric acid or 2.0 M nitric acid. The separation factor of (α_Mg^ca=5.6 is considerably higher than that in aqueous hydrochloric acid and comparable to those obtained with organic complexing reagents. Separations are sharp and quantitative; up to 10 mmol of magnesium can be separated from 0.01 mmol of calcium and vice versa on a 60-ml column. Al, Fe(III), Mn, Ni(II), Co(II), Zn, Cd, Cu(II), Pb(II), U(VI), Be, Ga, Ti(IV) in the presence of H₂O₂ and many other elements accompany magnesium and can be separated from calcium quantitatively. Sr, Ba, Zr, Hf, Th, Sc, La and the rare earths are retained together with Ca, but can be separated by other methods.