5-Methyl-7-nitroso-8-hydroxyquinoline and its sensitivity and selectivity towards certain metallic ions

5-Methyl-7-nitroso-8-hydroxyquinoline (5-methyl-7-nitroso-oxine), hitherto undescribed, has been prepared and tested for its sensitivity and selectivity towards various metallic ions at differing pH's. The metals tested include cadmium, ferrous and ferric iron, mercurous and mercuric mercury, lead, nickel, cobalt, thallous thallium, cerous and cerie cerium, copper, chromium, aluminium, zinc, magnesium, vanadium (as vanadate) and gallium. This reagent is comparatively “unsclective” in that it chelates with all the above metals under the conditions employed, and therefore closely follows the behaviour of the parent compound, 8-hydroxyquinoline (oxine). Its average sensitivity is somewhat greater than that of the parent compound, and it shows its greatest sensitivity with. divalent mercury.     

Analytic aspects of the chemical behaviour of 8-hydroxyquinoline (oxine)

As a result of the study of the chemical behaviour of some metallo-oxinates it is shown that : 1. A fluorescence test can be used to detect the presence of calcium, magnesium and aluminium in paper. The test is made by spotting the paper or its ash with a solution of oxine and examining tlie spot in the ultraviolet light. 2. A test for a fluoridc can be based on the inability of a qualitative filter paper which has been exposed to hydrogen fluoride to form fluorescent oxinate by spotting with oxine. 3. A test for a cyanide can be based on the liberation of oxine from coppcr(II)oxinate and the detection of the oxine by the formation of fluorescent aluminium oxinate. 4. Some non-fluorescent oxinates are able to quench the fluorescence of aluminium oxinate dissolved in chloroform. 5. The oxinates of aluminium, gallium, and iron(III) have a remarkable resistance to the action of 3N hydrochloric acid, whereas all other oxinates dissolve immediately. An explanation for this behaviour is proposed.     

1-Hydroxy-ethylidene-1,1-diphosphonic acid as a titrimetric agent

1-Hydroxy-ethylidene-1,1-diphosphonic acid (HEDPHA) has been proposed as a highly selective titrimetric reagent for thorium. In the presence of 1,2-diaminocyelohexanetetra-acetic acid (DCTA) a soluble binuclear ternary complex, Th(2)(DCTA)(2)(HEDPHA), is formed. The determination of thorium is carried out in a slightly acidic medium, buffered with urotropine, with 0.025M HEDPHA, and Xylenol Orange as indicator. DCTA masks all bivalent metals, rare earths, scandium, yttrium, bismuth, iron, gallium and indium. Only zirconium, titanium, aluminium and large amounts of thallium(III) interfere.     

Studies on oxine and its derivatives : The sensitivity and selectivity of some 7-substituted 8-hydroxyquinoline-5-sulphonic acids and some 2-substituted 8-hydroxyquinoline-4-carboxylic acids towards certain metals

A number of new derivatives of 8-hydroxyquinoline containing both solubilising groups and groups which might sterically hinder chelation have been prepared, viz. 8-hydroxy-7-morpholino-methylquinoline-5-sulphonic acid, 8-hydroxy-7-piperidinomethylquinoline-5-sulphonic acid, 8-hydroxy-2-(3,4-dimethoxyphenyl)-quinoline-4-carboxylic acid, 8-hydroxy-2-n-hexylquinoline-4-carboxylic acid and 8-hydroxy-2-(i-ethylpropyl)-quinoline-4-carboxylic acid. The limiting sensitivities of the reactions of these reagents towards copper, nickel, aluminium, zinc, magnesium, gallium, indium, thallium, yttrium, cadmium, cobalt and iron have been investigated     

Metal and metalloid indicator electrodes for the non-aqueous potentiometric titration of weak acids: comparative evaluation of group III, IV and V main-group elements

Indicator electrodes constructed from aluminium, gallium, indium, thallium, carbon, silicon, germanium, tin, lead, arsenic, antimony and bismuth have been evaluated for the potentiometric titration of solutions of benzoic acid in dimethylformamide and 4-methyl-2-pentanone. The aluminium, gallium, silicon and arsenic electrodes have also been evaluated for the determination of 3,5-xylenol in the same two solvents. Aluminium, gallium, indium, silicon, germanium, antimony and bismuth electrodes are superior to, or compare favourably with, a glass electrode for the determination of benzoic acid, when the criterion of efficiency is the sharpness of the end-point inflexion. In non-aqueous titrations of 3,5-xylenol, aluminium and gallium electrodes are similar in efficiency to the glass electrode for determinations in dimethylformamide solution, while the gallium electrode is superior to the glass electrode when 4-methyl-2-pentanone is the solvent. Possible relationships between the properties of the electrode element and the end-point sharpness when it is used as an indicator electrode are briefly considered.     

Propriétés des oxinates d'aluminium,de gallium et d'Indium.: Séparation du gallium par extraction par le chloroforme

A study has been made of the solubility in water as a function of pH of oxine and of the oxinatus of aluminium, gallium and indium, as well as their solubility in chloroform.The curves showing the partition between chloroform and water as a function of pu have been established.Gallium can be separated, from aluminium by extraction of the oxinate al pH₂O. It is possible by this means to separate one part of gallium from 10¹ parts of aluminium. The formation of the oxinates serves as a basis of an acidimetric determination of the ions Al⁺³, Ga⁺³ and In⁺³.     

Tris(2-ethylhexyl)phosphate as an extractant for trivalent gallium, indium and thallium

A systematic study of solvent extraction behaviour of gallium(III), indium(III) and thallium(III) with tris(2-ethylhexyl)phosphate from salicylate media has been undertaken and a scheme for their separation is proposed. The optimum extraction conditions are evaluated and described. The method is applicable to the analysis of standard aluminium and aluminium alloys samples. The results obtained are reproducible and accurate.     

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.     

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%.     

The fluorescence properties of metal complexes of alkyl derivatives of aromatic schiff bases

Seventeen alkylated salicylidene-o-aminophenol derivatives were tested as fluorimetric reagents for aluminium, gallium, indium, scandium and beryllium. The aluminium, gallium and beryllium complexes are intensely fluorescent, and the scandium and indium complexes weakly fluorescent. The fluorescence properties of the aluminium, gallium and beryllium complexes were studied and conditions for the fluorimetric determination of these metals were established. 2-Hydroxy-4-methylaniline-N-2-hydroxy-4-methyl-benzylidene is a good reagent because of the reproducibility and sensitivity of the fluorescence. The optimal ranges for determination are 0.005–3 mg Al/25 ml, 0.1–7 μg Ga/25 ml and 0.02–7 μg Be/25 ml. In all cases, 1:1 metal—ligand complexes are formed. Optimal reaction conditions and interference studies are reported.     

Reversed Phase Extraction Chromatographic Separation Of Scandium With Amberlite LA-1 From Malonate Solutions

Abstract

Scandium was extracted at pH 5.0 from 0.01 M malonic acid on silica gel column impregnated with Amberlite LA-1. Nickel, zinc, cadmium, mercury, lead, tin, aluminium, and lanthanum in binary mixtures because they could not form malonato complexes. It was separated by the process of selective elution from elements such as zirconium, thorium, uranium, iron(III), gallium, indium, cerium(III), litanium by exploiting difference in stability of malonato complexes. Scandium was separated from multicomponent mixture containing yttrium, titanium, zironium, thorium, uranium and aluminium by a process of selective sorbtion and selective elution.     

A simple oxidation procedure for biological material prior to analysis for mercury

The stability constants of aluminium(III), gallium(III), indium(III) and scandium(III) with 8-hydroxyquinoline and its 2-methyl derivative have been determined by potentiometric titration, with computation by the SCOGS program. In contrast to previous work, the results show that protonated species occur in several of the equilibria. The constants are discussed in terms of the nature of metal-to-ligand bonding in the complexes. X-ray photoelectron spectroscopy of the ligand coordinating atoms in the solid complexes confirms the significantly increased covalency of the gallium—oxygen bond compared to the same bond in the aluminium complex.     

Solvent extraction of some trace metals and iron with <Emphasis Type="Italic">N</Emphasis>-Octyl-<Emphasis Type="Italic">N,N</Emphasis>-bis(dihexylphosphinylmethyl)amine

The processes were studied of the solvent extraction of the ions of triply-charged trace elements including scandium, indium, gallium, and yttrium, as well as iron, with N-octyl-N,N-bis(dihexylphosphinylmethyl) amine solution in toluene, chloroform or methylene chloride from hydrochloric, nitric or perchloric acids aqueous solutions. The metals extraction dependence on the acid concentration showed that the best results were reached using perchloric acid. The calculation of partition coefficients of metals allowed us to reveal a high selectivity of the scandium extraction. The prospects of using the investigated bisphosphinylamine in the technology of extraction, concentration and separation of the trace metals ions was concluded.     

Micelle-stabilized liquid room-temperature phosphorimetry for metals: The micellar reaction of gallium with 7-iodo-hydroxyquinoline-5-sulfonic acid and its application to the metal determination

The Ga(III)-7-iodo-8-hydroxyquinoline-5-sulfonic acid complex in the presence of suitable micelles and with sodium sulfite as oxygen scavenger exhibited strong phosphorescence at room temperature in aqueous solutions. This micellar reaction provides the basis for a convenient phosphorimetric determination of traces of gallium. Different types of micelles showed their maximum enhancing effects at different pH ranges, affording greater convenience for various analytical purposes. A phosphorimetric procedure with surfactant cetyltrimethylammonium bromide as enhancing agent is proposed. The detection limit for gallium was 5 ng/ml and the calibration graph was rectilinear in the range of 5 to 600 ng/ml. The relative standard deviation was 4% at 50 ng/ml level. The applicability of this room-temperature phosphorimetric procedure to multi-component analyses for the group III elements, Al(III), Ga(III), and In(III), was demonstrated. Kalman filtering was used to deconvolute the phosphorescence spectra of mixtures of aluminium and gallium allowing the simultaneous determination of both metals with satisfactory results.     

Chlorometallate(III) ionic liquids as Lewis acidic catalysts--a quantitative study of acceptor properties

The Gutmann Acceptor Number (AN), which is a quantitative measure of Lewis acidity, has been estimated using the (31)P NMR chemical shift of a probe molecule, triethylphosphine oxide, for a range of chlorometallate(III) ionic liquids, based on Group 13 metals (aluminium(III), gallium(III) and indium(III)) and the 1-octyl-3-methylimidazolium cation, at different compositions. The results were interpreted in terms of extant speciation studies of chlorometallate(III) ionic liquids, and compared with a range of standard molecular solvents and acids. The value of these data were illustrated in terms of the selection of appropriate ionic liquids for specific applications.     

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.     

Spectrophotometric determination of traces of gallium and indium with 1-(2-pyridylazo)-2-naphthol

1-(2-Pyridylazo)-2-naphthol (PAN) reacts with either gallium or indium at pH 5–6 giving a red complex in an aqueous medium in the presence of N.N-dimethyl-formamide. The maximum absorption of both PAN complexes of gallium and indium in an aqueous solution is at 545 mμ. The gallium-PAN complex shows a characteristic enhancement of color by addition of small amounts of ethers. Based on this selective enhancement reaction, gallium can be determined in the presence of other metals without separation. The results of determining gallium and indium in the presence of each other are reported. Both gallium and indium form M₂(PAN)₃; but in the presence of certain organic solvents, a different gallium complex, Ga(PAN)₅, and the same indium complex, In₂(PAN)₃, are formed. The reaction of PAN with cadmium can be masked by iodide; an example of determining indium in the presence of cadmium is given. The PAN method has a sensitivity of 0.003 μg/cm² for gallium and 0.005μg/cm² for indium and an absorptivity of 24,900 for the Ga-PAN complex and of 24,500 for the In-PAN complex, respectively. The methods have been successfully applied to the determination of both gallium and indium in germanium thin films.     

The use of Oxine in the analysis of commercial aluminium sulphate - a statistical approach

The analysis of commercial aluminium sulphate by precipitation of the aluminium and iron with 8-hydroxyquinoline (oxine) has been investigated. Factorial experiments were used to determine what control of experimental conditions was required for accurate results. The oxine method way compared with other methods and found to be considerably more accurate and precise, provided that correct conditions of precipitation were rigidly adhered to.     

3,5,7,4'-Tetrahydroxyflavone (kaempferol) as a chromogenic reagent for gallium and indium

3,5,7,4'-Tetrahydroxyflavone (kaempferol) forms yellow chelates with indium and gallium. Based on this reaction, a sensitive spectrophotometric method for the determination of gallium and indium alone and in presence of other metals and alloys has been developed. Beer's law is obeyed up to 2.8 and 1.44 ppm for indium and gallium respectively.     

Sorption of M(III) with KFP-12 Phosphonic Cation Exchanger from Chloride Solutions

Sorption by KFP-12 phosphonic anion exchanger of ions of triply charged metals, such as indium, gallium, yttrium, and iron, from chloride solutions was studied. The nature of bonding between sorbed cations and functional groups of the cation exchanger and the mechanism of the ion exchange reaction were elucidated.