Extractive separation of Cu<Superscript>2+</Superscript>–Co<Superscript>2+</Superscript> and Ni<Superscript>2+</Superscript>–Co<Superscript>2+</Superscript> mixtures using <Emphasis Type="Italic">N</Emphasis>-salicylideneaniline

A study on the extraction of copper(II), cobalt(II), and nickel(II) from solutions containing ions of both metals with N-salicylideneaniline(SAN) in chloroform has been realized. Distribution of the metal ions in wide range of pH has been studied. Extraction of copper(II) was always favored over that of cobalt(II). Extraction of copper(II) from binary metal solution is selective and it can be quantitatively separated from cobalt(II). The equilibrium constant of the extraction of cobalt and nickel from an aqueous solution containing both metals using SAN were evaluated. The separation factors for cobalt and nickel were expressed as a function of the distribution of nickel and cobalt. From these results, salicylideneaniline is an adequate extractant for extractive separation of such mixtures.     

Simultaneous spectrophotometric determination of traces of cobalt,nickel and copper with n,n'-bis(3-dimethylaminopropyl)dithio-oxamide

The cobalt, nickel and copper complexes of N,N'-bis(3-dimethylaminopropyl)dithio-oxamide have been characterized in terms of color, effect of pH, rate of color formation, structure in solution, order of addition of reagents, adherence to Beer's law, and sensitivity. The reactivity of the reagent to other ions has been reported. A method for the simultaneous spectrophotometric determination of cobalt, nickel and copper has been developed. The results of the application of this procedure to synthetic samples and to several National Bureau of Standards samples are given.     

(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.     

Thermal and structural studies of the chloro complexes of cobalt,nickel and copper with 3-phenylpyridine

The chloro complexes of cobalt, nickel and copper with 3-phenylpyridine were prepared in ethanolic solution from which solid compounds were isolated. The cobalt and copper complexes have stoichiometry M₂LCl₄ while the nickel complex has stoichiometry NiLCl₂. The suggested structure for the cobalt and copper complexes is tetrahedral, while for the nickel complex it is octahedral. Thermal analysis studies show that the cobalt and copper complexes form intermediate complexes before their metal oxides are produced. The nickel complex also forms an intermediate complex and then nickel chloride before the nickel oxide is obtained.     

Organic complexation and total dissolved trace metal analysis in estuarine waters: comparison of solvent-extraction graphite furnace atomic absorption spectrometric and chelating resin flow injection inductively coupled plasma-mass spectrometric analysis

The measured concentrations of cadmium, cobalt, copper, nickel, lead, zinc, and manganese in acidified (pH<2) estuarine water samples analyzed for total dissolved trace metal concentrations using on-line chelating resin column partitioning with inductively coupled plasma-mass spectrometry (CRCP-ICP-MS) were compared to those analyzed by graphite furnace atomic absorption spectrometry (GFAAS) after liquid-liquid extraction using a combination of 1-pyrrolidinedithiocarbamate/diethyldithiocarbamate (PDC/DDC). Although there was good agreement between the two sets of analyses for cadmium, lead, manganese, and zinc concentrations, those of cobalt, copper, and nickel determined by CRCP-ICP-MS were found to be 10-20% lower than those determined by solvent-extraction GFAAS. The different yields were positively correlated (R>0.961, simple linear regression) to the dissolved organic carbon (DOC) concentration of the samples. Good agreement between the two methods for cobalt and copper was achieved after ultraviolet (UV) digestion of the acidified samples. Samples collected from the South Bay of the San Francisco Estuary with high DOC showed the greatest difference for cobalt, copper, and nickel which is tentatively attributed to complexation with humic material for copper and cobalt and strong synthetic chelating agents such as ethylenediaminetetraacetic acid (EDTA) for nickel. This is consistent with previous studies on copper, nickel and cobalt complexation in this region. We recommend UV digestion of acidified estuarine samples prior to multi-element analysis by chelating resin flow injection ICP-MS methods.     

Thermodynamics of ion association XXV. Transition metal complexes of proline and hydroxyproline

Calorimetric and potentiometric measurements have been made at 25°C of the formation of the mono- and bis-hydroxyproline complexes of cobalt(II), nickel(II), copper(II) and zinc(II) and the proline complexes of copper(II) and nickel(II). The data have been used to calculate ΔG, ΔH and ΔS values for both protonation and metal complexation and these are discussed in terms of the nature of the metal—ligand binding.     

The chromatographic properties of transition metal complexes of pyridine-2-aldehyde-2-quinolylhydrazone

A scheme has been devised whereby PAQH complexes of iron, nickel, copper and cobalt can be separated chromatographically and determined semiquantitatively in presence of up to tenfold excesses of interfering metal ions. The visual detection limits for iron, nickel and copper were found to be 0.01 μg and for cobalt 0.007 μg per spot. Interesting relationships were observed between R_F values, decomposition temperatures and position of the absorption maxima of the adsorbed complexes.     

Spectrophotometric simultaneous determination of cobalt, copper and nickel using nitroso-R-salt in alloys by partial least squares

Partial least squares modeling as a powerful multivariate statistical tool applied to spectrophotometric simultaneous determination of cobalt, copper, and nickel in aqueous solutions. The concentration range for cobalt, copper and nickel were 0.4-2.6, 0.6-3.4, 0.5-5.5 ppm, respectively. The experimental calibration set was composed with 36 sample solutions using a mixture design for three component mixtures. The absorption spectra were recorded from 470 to 600 nm. The effect of pH on the sensitivity and selectivity was studied according to net analyte signal (NAS). The values of root mean square difference (RMSD) for cobalt, copper and nickel using partial least squares (PLS) were 0.0192, 0.0263 and 0.0446 ppm, respectively. The effects of various cations and anions were investigated. The method was used to determination of cobalt, copper and nickel in two sample alloys based on copper, nickel and cobalt (known as cunico) and based on cobalt, nickel and iron (known as conife).     

Derivate von salicylketonen1: Mitt. schiffsche basen aromatischer o-aminoketone mit ǎthylendiamin und ihre analytische anwendung zur nickelbestimmung

Schiff bases from ethylenediamine with o-aminoacetophenone or o-aminoben-zophenone were prepared, and their chelating properties towards copper, nickel, cobalt, iron, palladium and platinum were studied. The use of the ligands for the photometric determination of metals was tested. A method for the determination of nickel with N,N'-bis(o-aminoacetophenone)-ethylenediimine was developed. Masking agents prevent the interference of iron and copper; a 25-fold amount of palladium and a 10-fold amount of cobalt can be tolerated.     

Colloid and nanosized catalysts in organic synthesis: IV. Reduction of nitroarenes with hydrazine hydrate catalyzed with metal nanoparticles

Reduction of a series of nitroarenes with hydrazine hydrate catalyzed with colloid iron, cobalt, nickel, and copper particles has been studied. High catalytic activity of nickel and iron nanoparticles has been demonstrated. Special features of nitrobenzene reduction in the presence of cobalt particles have been revealed.     

Determination of Ephedrine via the Formation of Metal Complexes

Abstract

The reaction of ephedrine with carbon disulphide and metals'reagents (nickel, copper and cobalt has been studied. Various methods are accordingly introduced for the determination of ephedrine in pure form and in pharmaceutical formulations. Direct spectrophotometric method determines 0.24-1.21, 0.61-5.45 and 6.05-60.5 μ moles. of epherdrine with a mean accuracy (P'=0.05) of 100.24± 1.48%,99.65±1.68% and 99.73±0.59% using nickel, copper and cobalt respectively. Indirect determinations- through the metals' content- include atomic absorption method, which is suitable for the determination of 0.73-8.5, 1.82-6.66 and 3.63-24.2 μ moles. of ephedrine with a mean accuracy of 99.49±1.18%, 100.13±1.65% and 99.68±0.63% on using nickel, copper and cobalt respectively. The corresponding data on determining the metals by the oxalyldrazide method are : 1.45-16.94, 0.61-1.57 and 0.73-17.54 μ moles. of epherdrine, 99.13±0.6%, 99.35±0.71% and 99.54±0.73% on using nickel, copper and cobalt respectively.     

Omega chrome black blue G as a colorimetric reagent for the microdetermination of various cations

Summary Omega Chrome Black Blue G has been found to be a suitable colorimetric reagent for the detection of cobalt and for the determination of copper, cobalt, cadmium, lead and magnesium. The effects of time, p_H, temperature, and foreign ions on the absorbancy are investigated. The reagent is practically suitable for the determination of microgram amounts of cobalt in presence of nickel and other ions which evoke a red colour.The reagent is not suitable for the determination of nickel, calcium, strontium, and zinc.     

Syntheses,Characterization and Anti-inflammatory Activity of a Benzamide Derivative and its Metal Chelates

N-Phenylbenzamide-2,2′-dicarboxylic acid (PBDA) and its copper(II), nickel(II), cobalt (II), zinc(II) and manganese(II) chelates have been synthesized and characterized by their physical measurements, infrared and electronic spectra and magnetic moment data. In an acute anti-inflammatory test, the cobalt chelate was most active (31.1% inhibition) followed by the zinc and copper chelates, whereas the copper chelate (22.3% inhibition) was most active in an adjuvant arthritis test. Again the cobalt chelate was most active in the cotton-wad granuloma test. Gastric irritancy was markedly reduced after chelation by copper, followed in order by zinc, cobalt, manganese and nickel chelates. © 1997 John Wiley & Sons, Ltd.     

Liquid chromatography of palladium and non-ferrous metal chelates with 1-(2-pyridylazo)-2-naphthol

1-(2-Pyridylazo)-2-naphthol has been used for extraction concentration of palladium, copper, cobalt and nickel from aqueous solutions and subsequent separation of the chelates obtained, by means of high-pressure liquid chromatography. A technique for determining microamounts of palladium in aqueous solutions in the presence of 100-fold ratio of copper and 80-fold ratio of cobalt has been developed.     

Synthesis,spectroscopic, and antimicrobial studies of the bivalent cobalt,nickel, and copper complexes of thioacetamide

A series of metal complexes of cobalt(II), nickel(II), and copper(II) having the general composition [M(L)₂X₂] with thioacetamide have been prepared and characterized by elemental chemical analysis, molar conductance, magnetic susceptibility measurements, mass, IR, EPR, and electronic spectral studies. The IR spectral data suggests the involvement of sulfur and amino nitrogen in coordination to central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for the cobalt(II) and nickel(II) complexes whereas tetragonal geometry for copper(II) complexes. Thioacetamide and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.     

Iron(II), cobalt(III), nickel(II) and copper(II) chelates of furan and thiophene azo-oximes

Summary Complexes of furan and thiophene azo-oximes with iron(II), cobalt(III), nickel(II) and copper(II) have been prepared and characterised. Iron(II), cobalt(III) and copper(II) complexes are diamagnetic in the solid state. The diamagnetism of the copper(II) chelates is suggestive of antiferromagnetic interaction between two copper centres.¹H n.m.r. spectral data suggest atrans-octahedral geometry for the tris-chelates of cobalt(III). Nickel(II) complexes are paramagnetic, in contrast to the diamagnetism of the analogous complexes of arylazooximes. The electronic spectra are suggestive of octahedral geometry for the iron(II), cobalt(III) and nickel(II) complexes, andD _4h -symmetry for copper(II). Infrared data indicate N-bonding of the oximino-group to the metal ions.     

Ligand trans-effect in octahedral complexes of 3d metals and its manifestation in the synthesis of metalloporphyrins in solution

We study features of the indicator kinetic reaction of meso(tetraphenyl)tetrabenzoporhine with cobalt(II), nickel(II), and manganese(II) acetates in electron-donating organic solvents (N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and pyridine (Py)) and in their binary mixtures at temperatures in the range 348–368 K. Specific features of the trans-effect of solvent molecules on the rate and activation parameters of formation of manganese(II), cobalt(II), nickel(II), and copper(II) complexes with porphyrin are noted.     

The formation of metal—carbon bonds via insertion reactions in gaseous negative ion/molecule reactions

The negative ion mass spectra under chemical ionization conditions for a series of copper(II), nickel(II), and cobalt(II) Schiff base complexes have been measured. Reagent gases employed include methane, isobutane, and methane-d₄. For all complexes, molecular negative ions were produced with all three reagent gases via secondary electron capture processes. Ion/molecule reactions between the molecular negative ion and the neutral reactant gas appear to be the dominant processes for the formation of secondary ions. The secondary reactions lead to the incorporation of the CH₂ moiety into the nickel(II) complexes and the CH₃ group into the cobalt(II) compounds.     

Coprecipitation with yttrium phosphate as a separation technique for iron(III), lead, and bismuth from cobalt, nickel, and copper matrices

The coprecipitation behavior of 44 elements (47 ions because of chromium(III,VI), arsenic(III,V), and antimony(III,V)) with yttrium phosphate was investigated at various pHs. Yttrium phosphate could quantitatively coprecipitate iron(III), lead, bismuth, and indium over a wide pH range; however, 18 ions, including alkali metals and oxo anions, such as vanadium(V), chromium(VI), molybdenum(VI), tungsten(VI), germanium(IV), arsenic(III,V), selenium(IV), and tellurium(VI), were scarcely collected. In addition, 19 ions, including cobalt, nickel, and copper(II), were hardly coprecipitated at pHs below about 3. Based on these results, the separation of iron(III), lead, and bismuth from cobalt, nickel, and copper(II) matrices was investigated. Iron(III), lead, and bismuth ranging from 0.5 to 25 μg could be separated effectively from a solution containing 0.5 g of cobalt, nickel, or copper at pH 3.0. The separated iron(III), lead, and bismuth could be determined by inductively coupled plasma atomic emission spectrometry using internal standardization. The detection limits (3σ, n = 7) of iron(III), lead, and bismuth were 0.008, 0.137, and 0.073 μg, respectively. The proposed method was applied to the analyses of metals and chlorides of cobalt, nickel, and copper.     

The photometric determination of cobalt by extraction with b -nitroso-a-naphthol

An improved procedure has been described for the photometric determination of cobalt by extraction of the β-mtroso-α-naphthol complex with chloroform. This procedure can be applied in the presence of large amounts of foreign elements. Interfering elements are: gold, palladium, platinum and copper (above 25 mg).The method has been applied to the determination of cobalt in steels, non-ferrous alloys and nickel.