Simultaneous Preconcentration of Copper,Nickel and Cobalt In Water By Coprecipitation-Flotation For Electrothermal Atomic Absorption Spectrometry

Abstract

A method is described for the simultaneous flotation separation and determination of μg-levels of copper (II), nickel (II) and cobalt (II) in water. Copper, nickel and cobalt in a 1000-ml sample of water are coprecipitated with hydrated zirconium oxide at pH 9.1±0.1. The precipitate is floated with the aid of a surfactant solution and small air bubbles, separated and dissolved in dilute hydrochloric acid. The contents of these elements are determined by electrothermal atomic absorption spectrophotometry. The method is applied to the determination of low μg/1 levels of copper, nickel and cobalt in fresh water.     

Assessment of differential-pulse adsorption voltammetry for the simultaneous determination of nickel and cobalt in biological materials

An assessment of the voltammetric method based on chelate adsorption at the hanging mercury drop electrode is described for the simultaneous determination of nickel and cobalt in biological materials. The interfacial accumulation of the elements as metal dimethylglyoximates during the adsorption step, and the use of differential-pulse voltammetry during the reduction step, provide substantial gains in the sensitivity of their voltammetric responses. The decomposition of the sample material by direct dry ashing provides a blank-free approach for the accurate determination of the elements. Application of the method to the available certified biological reference materials for cobalt and nickel was successful. The limits of detection obtained under the conditions of this study were 0.01 μg g^?1 and 0.02 μg g^?1 for cobalt and nickel, respectively, in bovine liver.     

Simultaneous Trace Determination of Nickel and Cobalt in Natural Waters by Differential Pulse Polarography

Abstract

A differential pulse polarographic method has been developed for the simultaneous low level determination of nickel and cobalt in the presence of furildioxime in natural waters. The nature of the electrode processes was studied with cyclic voltammetry. Limits of determination of 0.4 μg/L and 0.15 μg/L were achieved for nickel and cobalt respectively     

Determination of Gold and Palladium in Manganese and Nickel Compounds by Atomic Absorption Spectrometry After Separation by Use of Amberlite XAD-7 Resin

Abstract

A method for preconcentration and determination of traces of Au and Pd from manganese, nickel and their compounds is described. The trace elements are preconcentrated at a small column filled with Amberlite XAD-7 resin. After their eluation the elements are determined by flame AAS. The relative standard deviations (N=10) were found to be lower than 5%; the detection limit (3s, N=20) for Au and Pd in metal samples is 0.07 μg/g.     

Extraction-spectrophotometric determination of nickel as Ni-(PAR)2-(CTAB)2 complex in polymetallic sea-bed nodules and steels

A red, water-soluble complex of nickel with PAR can be extracted into chloroform with CTAB at pH 7.0. The system obeys Beer's law upto 0.5 μg/ml with a molar absorptivity of 45 200 L·mol^?1·cm^?1 at 540 nm. Job's method of continuous variations revealed that the composition of the extracting species is 1:2:2 for nickel:PAR:CTAB. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of nickel in polymetallic sea-bed nodules and in steels, after prior separation of iron and manganese, was developed. The standard deviation was 0.04–0.127 μg for 5–25 μg of nickel.     

Simultaneous First-Derivative Spectrophotometric Determination of Nickel and Manganese Complexes with 2-(2-Pyridylmethyleneamino)phenol

Abstract

A method is proposed for the simultaneous determination of nickel and manganese by first-derivative spectrophotometry based on their reactions with 2-(2-pyridylmethyleneamino)phenol (PMAP) Schiff base. The method allows the determination of Ni and Mn in the concentration range 0.3–3.0 μg ml^?1 in mixtures with their ten-fold concentration ratio. The method has been applied for Ni and Mn determination in bronzes. To optimize the experimental conditions for spectrophotometric determination of Mn with PMAP stability constants at different pH values have been determined. A critical evaluation of the proposed method was performed by statistical analysis of the experimental data.     

Synthesis and structural characterization of new trinuclear cobalt(II) and nickel(II) complexes possessing five- and six-coordinated geometry

Tri-nuclear cobalt and nickel complexes ([(CoL)₂(OAc)₂Co]?·?THF (I) and [(NiL)₂(OAc)₂(THF)₂Ni]?·?THF (II)) have been synthesized by reaction of a new Salen-type bisoxime chelating ligand of 2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol(H₂L) with cobalt(II) acetate tetrahydrate or nickel(II) acetate tetrahydrate, respectively. Complexes I and II were characterized by elemental analyses, IR, TG-DTA and ¹H-NMR etc. The X-ray crystal structures of I and II reveal that two acetate ions coordinate to three cobalt or nickel ions through M–O–C–O–M (M?=?Co or Ni) bridges and four μ-naphthoxo oxygen atoms from two [ML] units also coordinate to cobalt(II) or nickel(II). Complex I has two distorted square-pyramidal coordination spheres and an octahedral geometry around Co1. In complex II all three nickel ions are six-coordinate.     

Neutron activation analysis of high purity nickel by solvent extraction using 2-benzylpyridin/benzene

A radiochemical neutron activation analysis using solvent extraction has been applied for the determination of trace impurities in high purity nickel. Because of the high activity of⁵⁸Co produced by the nuclear reaction,⁵⁸Ni(n,p)⁵⁸Co, cobalt should be separated from the impurities. Removal of cobalt from the other trace elements in the aqueous acidic solution containing 1M thiocyanate ion (KSCN) was achieved by extraction with 1M2-benzylpyridin (BPy) in benzene. From the result of tracer experiments, cobalt was completely separated from most other elements except Fe, Mo and Zn. To determine the experimental accuracy, NIST SRM 673 nickel oxide was analyzed and the results agreed well within 10% deviation. This established radiochemical method was applied to the analysis of high purity nickel samples.     

The determination of metals at ppb levels by thin-film x-ray fluorescence spectrometry after coprecipitation with a molybdenum carrier complex

A method is described for the determination of iron, cobalt, nickel, copper, zinc, cadmium and lead in water at μg 1^-1 levels, in which the metals are coprecipitated with a molybdenum—pyrrolidinedithiocarbamate carrier complex. The precipitate is collected as a thin film on a membrane filter (0.4-μm pore-size) and analysed directly by x-ray fluorescence spectrometry. Detection limits, for 100-ml water samples and counting times of 200 s per element, are 1 μg metal l^-1 or lower. Total dissolved metal concentrations are obtained without boiling or u.v. irradiation of the water sample. The method is applicable to river and estuarine waters and is not affected by dissolved organic matter.     

Flow-injection spectrophotometric determination of cobalt by extraction as tetrathiocyanatocobaltate(II) with the ethylenebis(triphenylphosphoniu) cation

Cobalt (0–10 μg) may be determined spectrophotometrically at 625 nm after flow-injection extraction into chloroform of the ion associate ethylenebis(triphenylphosphonium) tetrathiocyanatocobaltate(II). The carrier stream contained 10% (w/v) ammonium fluoride and the reagent stream contained 0.5% (w/v) ethylenebis (triphenylphosphonium) bromide and 5% (w/v) ammonium thiocyanate. The injection rate was 20 h^?1. The calibration graph is linear up to 20 μg ml^?1 and detection limit is 0.23 μg ml^?1 cobalt, based on injection volumes of 500 μl. The system has been applied to the determination of cobalt in a range of tool steels.     

Synthesis and properties of transition and lanthanide complexes with benzyl monohydrazone-3-hydrazine- 4-benzyl-6-phenyl pyridazine ligand (BHP)

Synthesis and characterization of benzyl-monohydrazone-3-hydrazino-4-benzyl-6-phenyl pyridazine (BHP) and its complexes with copper(II), nickel(II), cobalt(II), zinc(II), manganese(II), cadmium(II), thorium(IV), dioxyuranium(VI), samarium(III) and erbium(III) are presented. The protonation equilibrium of BHP ion and complex formation equilibrium with the metal ions have been studied by potentiometry in 75% (v/v) dioxane-water and 0.10M KNO₃ at different temperatures (10, 20, 30 and 40°C). A series of mononuclear complexes [ML _n ]^{(1? z )+} (L^? =?BHP and n =?1 ??z) were found in solution and their formation constants, enthalpies and entropies were determined.

The solid metal complexes and corresponding thermal products were elucidated by elemental analysis, conductance, IR and electronic spectra, magnetic moments, ¹H NMR and TG-DSC measurements as well as by mass spectroscopy. The use of BHP as analytical reagents for the determination of copper(II), nickel(II) and cobalt(II) as well as extracting agents for these metal ions are discussed.     

Indirekte inversvoltammetrische Bestimmung von Elementen unter Anwendung von Verdr?ngungsreaktionen

Zusammenfassung Zur indirekten inversvoltammetrischen Bestimmung von Kobalt und Nickel wurde die Verdrängung des Cadmiums aus seinen Nitrilotriessigsäure- bzw. Äthylendiamintetraessigsäure-Komplexen durch die genannten Elemente untersucht.Sowohl Einzelbestimmungen als auch Summenbestimmungen sind unter Anwendung von NTE als Komplexbildner im Konzentrationsbereich von 5 · 10^–7 bis 1 · 10^–5 M/l möglich. Der Variationskoeffizient beträgt für Co 4%, für Ni 12,5% und für die Summenbestimmung 9%.Der Einzelbestimmung in Co-Ni-Gemischen über den Cd-ÄDTE-Komplex ist nur Kobalt nach Oxydation zu Co (III) zugänglich, wenn die Bestimmung im alkalischen Milieu durchgeführt wird. Die Nickelkonzentration wird anschließend aus der Differenz der Konzentration beider Ionen und der Co-Konzentration berechnet.Der Cd-Oxin-5-sulfonsäure-Komplex eignet sich in wäßriger Lösung nicht zur Austauschbestimmung. Indirekte inversvoltammetrische Bestimmungen von Kobalt und Nickel sind jedoch in Gegenwart von 50 Vol-% Dioxan entweder in neutraler Lösung durch Ermittlung der freigesetzten Cd-Menge oder in Boratpuffer durch Bestimmung des verbleibenden Cd-Oxin-5-sulfonsäure-Komplexes möglich.

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Indirect determination of elements by inverse voltammetry using exchange reactionsII. Determination of cobalt and nickel

Indirect determinations of cobalt and nickel by inverse voltammetry are possible by displacement reaction of cadmium from its complexes with EDTA or NTA. The sum of cobalt and nickel and the single metals can be determined in the concentration range from 5×10^–7 to 1×10^–5 M. The coefficient of variation is for cobalt 4%, for nickel 12.5% and for the sum of both metals 9%. In solutions with both metals only cobalt can be determined by displacement reaction with Cd-EDTA after oxidation in alkaline medium. The concentration of nickel can be calculated from the difference between the concentration of the sum of both elements and the concentration of cobalt. The Cd-complex with oxine-5-sulphonic acid cannot be used for exchange determination in aqueous solution. However, in 50 vol.-% dioxane—water cobalt and nickel can be determined by measurement of liberated cadmium in neutral solutions or of remaining Cd-complex in borate buffer.

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I. Mitteilung: diese Z. 231, 11 (1967).     

The simultaneous determination of vanadium,chromium, manganese,iron, cobalt,nickel, copper and zinc in sea water by x-ray fluorescence sectrometry

A procedure is described for the determination of microgram quantities of the elements vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc in sea water. Separation and concentration of these elements from a large salt matrix, in order to prevent interferences in the subsequent X-ray fluorescence spectrometry, is achieved by continuous solvent extraction. Ammonium pyrrolidine dithiocarbamate is used as a chelating agent, and the chelated trace elements are quantitatively extracted at a pH of ca. 2.5 into methyl isobutyl ketone. Detection limits of 0.14 μg or better are obtained when a 600-sec counting period is used for X-ray fluorescence spectrometry.     

Determination of riboflavin in pharmaceutical products by automatic discrete-sample analysis

A procedure for the determination of iron, copper, nickel, cobalt, manganese and chromium down to 0.01 μg g^-1 in sodium calcium silicate glass, sodium borosilicate glass, sodium carbonate and calcium carbonate is described. The analytical procedure depends on the separation at pH 6 of the metal diethyldithiocarbamates into isobutyl methyl ketone, and their determination by flameless atomic absorption spectrometry, with a Massmann-type graphite furnace. The limiting factors on the detection limits attainable are discussed and related to the purity of the acids used for sample solution, sample contamination during chemical separation and the sensitivity of the analytical technique.     

(Series Editor) Transform Techniques in Chemistry,P.R. Griffiths,D. Hercules (Eds.), in: Modern Analytical Chemistry Series,Plenum, New York,NY (1978), 385 pp. $47.40

Concentration potentials in zinc sulphate, copper sulphate, nickel sulphate and cobalt sulphate solutions across liquid membranes based on myristates and laurates of zinc, copper, nickel and cobalt and caprate and caprylate of copper have been studied in concentration cells in which the liquid membrane separates the two solutions of the same electrolyte. The behaviour of the cell with heavy metal soap liquid ion-exchange membranes becomes more and more nernstian as the number of carbon atoms in the hydrocarbon chain of the fatty acid soap increases. Concentration potential values with copper, zinc, nickel or cobalt soap follow the order of their insolubility in water. The failure to record the theoretical potentials as calculated by Nernst's equation has been explained by considering the transport of water across organic phase by hydrated ions and the dissolution of heavy metal soaps in aqueous solutions. Liquid membranes based on heavy metal myristate soaps when used in concentration cells could measure the activities of zinc, copper, nickel and cobalt ions in the concentration range of 10^?4–10^?1M.     

Electrothermal Atomic Absorption Spectrometric Determination of Cobalt,Copper and Nickel in Fresh Water After Their Preconcentration by Precipitate Flotation

Abstract

A method is developed for simultaneous separation and determination of μg/L levels of Co(II), Cu(II) and Ni(II) in fresh water by precipitate flotation. The optimal conditions of the experimental procedure with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors were investigated. The pH interval of the working medium, within which Co(II), Cu(II) and Ni(II) can be successfully separated, was determined from the aspect of collectors and surfactant stability. The amounts of the elements investigated were determined by electrothermal atomic absorption spectrometry. The detection limit of the method is 0.15 μg/L for cobalt, 0.03 μg/L for copper and 0.79 μg/L for nickel.     

Liquid Anion Exchange Studies and Separation of Mercury

Abstract

A new method is developed for the extractive separation of mercury from associated elements. Mercury is quantitatively extracted from 0.5 M acetic acid solution by aliquat 336 S, which acts as a liquid anion exchanger. The metal ion from the organic phase is stripped with sodium hydroxide solution and determined in the aqueous phase complexometrically. The extracted species is [2(R₄N⁺), Hg(OAc)₄ ^?2]. A working procedure for the selective separation of mercury from zinc, cadmium, nickel, cobalt, copper, bismuth and manganese is described.     

Determination of tin in indium by neutron activation with pre-irradiation separation

A method has been developed for chemical control of a short-lived radiopharmaceutical,⁵²Fe. The optimum conditions have been investigated for the simultaneous determination of microgram amounts of nickel, iron and chromium in an admixture. The method developed is applicable for the determination of 0.01 to 20 μg·ml^?1 of nickel, 0.01 to 50 μg·ml^?1 of iron and 0.05 to 50 μg·ml^?1 of chromium. A study has been made of the mutual interference of these elements at different concentrations, and also of the interference by various other cations and anions. A list has been given of the other elements that can be analysed using the supporting electrolyte. A method of routine analysis is described.     

Determining of trace metals in nuclear-grade uranium dioxide by x-ray fluorescence spectrometry

A method is described for the simultaneous determination of low concentration of Ca, Cr, Cu, Fe, Mn and Ni in nuclear-grade uranium dioxide by x-ray fluroescence spectrometry, without the use of chemical treatment. The lower limits of detection range from 2 μg g^?1 for nickel and manganese to 5 μg g^?1 for copper. Samples are prepared in the form of double-layer pellets with boric acid as a binding agent. Standards are prepared in a U₃O₈ matrix, which is more chemically stable than UO₂ and has similar matrix behaviour. The correlation coefficients for calibration curves are better than 0.999. Errors range from 2.4% for chromium to 6.8% for nickel.     

Simultaneous extraction of trace amounts of cobalt, nickel and copper ions using magnetic iron oxide nanoparticles without chelating agent

The present study investigates the application of Fe₃O₄ nanoparticles as an adsorbent for solid phase extraction and their subsequent determination of trace amounts of cobalt, nickel and copper from environmental water samples using flame atomic absorption spectrometry. The analyte ions were adsorbed on magnetic nanoparticles in the pH range of 10–12 and then, Fe₃O₄ nanoparticles were easily separated from the aqueous solution by applying an external magnetic field and decantation. Hence, no filtration or centrifugation was needed. After extraction and collection of magnetic nanoparticles, the analyte ions were desorbed using 1.0 M HNO₃. Several factors that may affect the preconcentration and extraction process, including pH, type and volume of eluent, sample volume, salt effect and matrix effect were optimized. Under the optimized conditions, linearity was maintained from 0.005–3.0 μg/mL for cobalt and nickel and 0.001 to 1.25 μg/mL for copper in the initial solution. The detection limits of this method for cobalt, nickel and copper ions were 0.9, 0.7 and 0.3 ng/mL, respectively. Finally, the method was successfully applied to the extraction and determination of the analyte ions in natural waters and reference plant samples.