Spectrophotometric determination of nickel after separation by adsorption of its α-furildioxime complex on naphthalene

A new method is proposed for collecting traces of nickel from aqueous solution by precipitation as the α-furildioxime complex and adsorption of this onto microcrystalline naphthalene. The precipitate is collected, dried, and dissolved in chloroform, and the nickel is determined spectrophotometrically at 438 nm. The linear calibration range is 2–35 μg/10 ml. The molar absorptivity is 1.6 × 10⁴ l. mole⁻¹. cm⁻¹. The main advantage is that the nickel is collected quantitatively after only a few seconds'shaking. The effect of varying pH, amount of reagent, naphthalene or buffer, shaking and standing time, and interferences have been investigated.     

Analysis of metals by solid-liquid separation after liquid-liquid extraction spectrophotometric determination of palladium(II) by extraction of palladium dimethylglyoximate with melted naphthalene

A method of liquid-liquid extraction of palladium di-methylglyoximate with molten naphthalene followed by solid-liquid separation is successfully applied to palladium. The complex between palladium and dimethylglyoxime is easily extracted into molten naphthalene. After extraction, the very fine solidified naphthalene crystals are dissolved in chloroform, and the absorbance of the resultant solution is measured at 370 nm against a reagent blank. Beer's law is obeyed for 30-370 mug of palladium in 10 ml of chloroform, and the molar absorptivity is calculated to be 1.72 x 10(4) l.mole.(-1)mm(-1). Various alkali metal salts and metal ions do not interfere. The interference of nickel(II) is overcome by the extraction at pH 2, and that of iron(III) by masking with EDTA or by reduction to iron(II). The method is rapid and accurate.     

A Study on the Color Reaction of Nickel with a New Chromogenic Reagent 1- (5-Nitro-2-Pyridylazo) - 2.7 - Dihydroxy - naphthalene and its Application

There has been study on heterocyclicazo reagent for the determination of microamount of nickel,but no study on the color reactron of nickel with a new chromogenic reagent 1- (5 -nitro - 2 - pyridylazo) - 2.7 - dihydroxy - naphthalene (5- NO₂ - PADN). So, here is a systematic study on condition under which the color reaction takes place. It proved that within PH 5.5~6.5,the maximnm absotption of the reagent lies at 460nm, that of the 2:1 turquoise chelate by 5 - NO₂ - PADN with nickel (Ⅱ) together is 650nm, and the apparent absorptivity is 1.02×10⁵ L · mol^-1 · cm^-1. The proposed method can be applied in the standard steel and the determination of microamounts of nickel in ore with satisfactory results.     

Preconcentration of trace nickel with the ion pair of disodium 1-nitroso-2-naphthol-3,6-disulfonate and tetradecyldimethylbenzylammonium chloride on microcrystalline naphthalene or by the column method and determination by third derivative spectrophotometry

Nickel is quantitatively retained by disodium 1-nitroso-2-naphthol-3,6-disulfonate (nitroso-R salt) and tetradecyldimethylbenzylammonium chloride (TDBA(+)Cl(-)) on microcrystalline naphthalene in the pH range 5.4-12.1 from large volumes of aqueous solutions of various alloys and biological samples. After filtration, the solid mass consisting of the nickel complex and naphthalene was dissolved with 5 ml of dimethylformamide (DMF) and the metal was determined by third derivative spectrophotometry. Nickel complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 10 ppb (signal to noise ratio 2) and the calibration curve is linear from 30 to 5.4x10(3) ppb in dimethylformamide solution with a correlation coefficient of 0.9997 by measuring the distance d(3)A/dlambda(3) between lambda(1) (537 nm) and lambda(2) (507 nm). Eight replicated determinations of 2.5 mug of nickel in 5 ml of dimethylformamide solution gave a mean intensity (peak-to-peak signal between lambda(1) and lambda(2)) of 0.339 with a relative standard deviation of +/-0.87%. The sensitivity of the method is 0.677 ml/mug found from the slope (d(3)A/dnm(3)) of the calibration curve. Various parameters such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of nickel has been studied in detail to optimize the conditions for nickel determination in various alloys and biological samples.     

Atomic absorption spectrometric determination of trace amounts of nickel after preconcentration with [1-(2-Pyridylazo)-2-Naphthol]-Naphthalene adsorbent or after adsorption of its complex on microcrystalline naphthalene

An atomic absorption spectrometric method for the determination of trace amounts of nickel after adsorption of its 1 -(2-pyridylazo)-2-naphthol complex on microcrystalline naphthalene has been developed. This complex is adsorbed on microcrystalline naphthalene in the pH range 4.5-7.8 from large volumes of aque ous solutions of various alloys and biological and environmental samples containing nickel. After filtration, the solid mass consisting of nickel complex and naphthalene was dissolved in 5 mL of dimethylformamide, and the metal was determined using a flame atomic absorption spectrometer at a wavelength of 232 nm. Alternatively, nickel can be quantitatively adsorbed on [l-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent packed in a column and determined similarly. The calibration curve is linear over the concentration range 2.0-100 Μg of nickel in 5 mL of the final dimethylformamide solution. Eight replicate determinations of 20 Μg of nickel give a mean absorbance of 0.072 with a relative standard deviation of 1.3%. The sensitivity for 1% absorption is 0.24 Μg/mL. Various parameters such as the effect of pH, the volume of the aqueous phase, and the interference of a large number of metal ions with the determination of nickel have been studied in detail to optimize the conditions for its determination in various standard alloys and biological and environmental samples. This article was submitted by the authors in English.     

Trace Analysis of Nickel by Extraction-Atomic Absorption Spectrophotometry Determination of its Acenaphthenequinone Dioxime Complex in Molten Naphthalene

A procedure is described for the trace analysis of nickel using the liquid-liquid extraction of nickel acenaphthenequinone dioxime complex with molten naphthalene followed by solid-liquid separation. Nickel complex cannot be extracted into any non-aqueous organic solvents, but can be quantitatively extracted into molten naphthalene. It is very stable at high temperature and is dissolved in the mixed solvent (HNO₃-DMF). The absorbance of the solution was measured at 231.5 nm against a reagent blank. Beer's law is followed in the concentration range of 5–100 μg of nickel in 10 ml of the final solution. The sensitivity for 1% absorption is 0.155 μg/ml nickel. The relative standard deviation is 1.0% for ten replicate determinations of 60 μg of nickel. The interference of various ions has been studied and the method has been applied to the determination of nickel in aluminium alloys.     

Rapid X-ray fluorescence analysis of trace metals collected by using naphthalene powder doped with 1-(2-thiazolylazo)-2-naphthol

Naphthalene powder doped with 1-(2-thiazolylazo)-2-naphthol is used as collector for traces of metals, which are then determined by X-ray fluorescence analysis of the naphthalene. The method is used for traces of nickel.     

Determination of a cationic surfactant with naphthalene black 12B by the resonance light scattering technique

A new determination method for a cationic surfactant, zephiramine (Zeph), was developed with resonance light scattering (RLS) technique, based on the interaction of naphthalene black 12B with Zeph. The resonance light scattering (RLS) and UV characteristics of interaction between naphthalene black 12B and Zeph were studied. The RLS intensity of naphthalene black 12B at 363 nm was greatly enhanced in the presence of Zeph at pH 6.0. The enhanced RLS is proportional to the concentration of Zeph in the range of 3.20 x 10(-7) - 1.44 x 10(-5) mol L(-1). The limit of detection was 8.8 x 10(-8) mol L(-1). The proposed method was applied to the determination of Zeph in synthetic and spiked water samples with the recovery of 96.2-104% and RSD of 1.1-2.5%.     

Spectrophotometric determination of nickel in vegetable oil with ammonium 2-amino-1-cyclohexene-1-dithiocarboate

The reaction between nickel and ammonium 2-amino-1-cyclohexene-1-dithiocarboate in aqueous acetone medium at pH 3.0-8.0 results in a stable dark red complex. The ratio of reagent to nickel in the complex is 2:1 and the formation constant is 7.38 +/- 0.12 x 10(10). Beer's law is obeyed up to 4 microg/ml nickel at the absorption maximum at 535 nm. The apparent molar absorptivity is 2.8 x 10(4) l.mole(-1). cm(-1), and the detection limit is 10 ng/ml nickel. The method is applied to the determination of nickel in vegetable oil.     

Column chromatographic preconcentration of palladium in alloys with 9,10 phenanthrenequinonemonoxime-naphthalene

A solid chelating compound phenanthrenequinonemonoxime (PQM) supported on naphthalene provides a rapid, sensitive and economical means of preconcentration and separation of palladium from standard solutions and from synthetic samples. Palladium forms a complex with PQM supported on naphthalene in a column at pH 2.2-5.4 with a flow-rate of 1 ml/min. The metal complex and naphthalene are dissolved out from the column with 5 ml of CHCl(3) and the absorbance is measured at 430 nm or 500 nm against a reagent blank. Beers law is obeyed in the concentration range 3.0-56.0 mug and 6.0-42.0 mug at 430 nm and 500 nm respectively. The molar absorptivities are 2.10 x 10(4) and 1.69 x 10(4) 1.mole(-1).cm(-1) at 430 and 500 nm respectively.     

Spectrophotometric determination of cobalt in a vitamin, alloys and an ore by extraction of its 3-hydroxy-2-methyl-1,4-naphthoquinone 4-oxime complex into molten naphthalene

A selective spectrophotometric method has been developed for the determination of cobalt after extraction of its 3-hydroxy-2-methyl-1,4-naphthoquinone 4-oxime (HMNQM) complex into molten naphthalene. The optimum pH range for the extraction is 5.0-7.5. The solidified naphthalene, containing the cobalt-HMNQM complex, is separated by filtration and dissolved in N,N-dimethylformamide. The absorbance is measured at 430 nm against a reagent blank. Beer's law is obeyed up to 1.90 ppm cobalt. The molar absorptivity is 2.09 x 10(4) l.mole(-1).cm(-1).     

Naphthalene and anthracene cobaltates(1-): useful storable sources of an atomic cobalt anion

Reductions of CoBr(2) or cobaltocene by 3 equiv of potassium anthracene radical anion in tetrahydrofuran (THF) afford 60-80% yields of bis(anthracene)cobaltate(1-) (1), of interest as a readily accessible and quite labile source of spin-paired atomic Co(-). Although the unsolvated potassium salt of 1 is thermally unstable at 20 °C, the [K(18-crown-6)(THF)(2)](+) salt of 1 functions as a useful storable crystalline reagent for Co(-) in several reactions. Previously known classic cobaltates, [CoL(4)](-), for L = 1/2 (1,3-butadiene) (2), PF(3) (3), and P(OiPr)(3) (5), were obtained directly from 1 and structurally characterized for the first time. Anion 3 is noteworthy because it appears to possess the shortest known Co-P distance, av = 2.012(4) ?. Although the naphthalene analogue of 1 is not yet available as a pure substance, low-temperature reductions of CoBr(2) or cobaltocene by naphthalene radical anion in the presence of 1,5-cyclooctadiene (COD) afford variable yields (80-90% from CoCp(2)) of (naphthalene)(COD)cobaltate(1-) (10). Ready displacement of naphthalene in 10 by L = 1,3-butadiene, 2,2'-bipyridine, and COD occurs to give good yields of the respective [Co(L)(COD)](-), all of which have been structurally characterized. Both ligands in 10 are displaced by tert-butylisocyanide to afford [Co(CNtBu)(4)](-) (16), the first isolable and structurally characterized homoleptic alkylisocyanometalate. The molecular structure of 16 shows unprecedented bending of the isocyanides, av C-N-C = 137(2)°, for homoleptic isocyanide complexes.     

Spectrophotometric determination of osmium with 1-phenyl-4,4,6-trimethyl-(1H,4H)-2-pyrimidinethiol and extraction into molten naphthalene

Conditions have been developed for the spectrophotometric determination of osmium with 1-phenyl-4,4,6-trimethyl-(1H,4H)-2-pyrimidinethiol after extraction of the complex into molten naphthalene. Beer's law holds for the concentration range of 4-77 mug of osmium in 10 ml of the final solution. The molar absorptivity is 1.33 x 10(4) l.mole(-1).cm(-1). The reagent is highly selective for osmium.     

Determination of serum nickel by graphite furnace atomic absorption spectrometry with Zeeman-effect background correction: values in a normal population and a population undergoing dialysis

An atomic absorption spectrometric method with Zeeman-effect background correction for the determination of nickel, which requires only serum dilution with an aqueous surfactant, is described. The average nickel concentration in sera collected from 38 healthy adult volunteers was 0.14 +/- 0.09 micrograms l-1 of Ni, which is approximately four times lower than normals reported previously (0.65 +/- 0.35 or 0.46 +/- 0.26 microgram l-1 of Ni). The procedure yielded accurate results for the analysis of three different reference serum pools. A comparison of the average nickel concentrations from a patient population undergoing regular haemodialysis with our normal population showed that the average concentration of serum nickel in the dialysis patient group (n = 27 patients) was 46 times higher than normal (6.38 +/- 3.36 micrograms l-1 of Ni; n = 40 specimens).     

Significantly enhanced reactivities of the nucleophilic substitution reactions in ionic liquid

We have investigated the reactivities of various metal fluorides in the nucleophilic fluorination of 2-(3-methanesulfonyloxypropyl)naphthalene (1) as a model compound in the presence of 1-n-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)]). The higher periodic alkali metal fluorides demonstrate greater reactivity. The fluorination using CsF among the alkali metal fluorides was completed in 20 min, affording the desired product 2-(3-fluoropropyl)naphthalene (2a, 95%) without any byproducts. However, the fluorinations using alkali earth, transition, and low periodic alkali metal fluorides under the same conditions occurred rarely or not at all. We have also carried out the various facile nucleophilic substitutions such as halogenations, acetoxylation, nitrilation, and alkoxylations of mesyloxyalkane 1 and 2-(3-bromopropyl)naphthalene (6) at the primary aliphatic position using the potassium halides, acetate, cyanide, and alkoxides, respectively, in the presence of ionic liquids. These reactions provided the desired products, such as 2-(3-halopropyl)naphthalenes 5-7 (95% for Cl, 96% for Br, and 93% for I), 2-(3-acetoxypropyl)naphthalene (8, 95%), 2-(3-cyanopropyl)naphthalene (9, 93%), and 2-(3-methoxypropyl)naphthalene (10, 92%).     

Column preconcentration of titanium in aluminium and zinc alloys with oxalic acid-ascorbic acid and the ion-pair of sodium 1,2-dihydroxybenzene-3,5-disulphonic acid and tetradecyldimethylbenzylammonium chloride supported on naphthalene using spectrometry

A solid ion-pair compound produced from sodium 1,2-dihydroxybenzene-3,5-disulphonic acid (Tiron) and tetradecyldimethylbenzylammonium chloride(TDBA) supported on naphthalene in a simple glass-tipped funnel tube provides a simple adsorbent system for preconcentrating titanium from some alloys. Titanium reacts with Tiron to form a water-soluble coloured chelate anion which in turn forms a water-insoluble stable titanium/Tiron/TDBA complex with the ion-pair on the surface of naphthalene packed in a column. Titanium is quantitatively retained on the naphthalene in the presence of L-ascorbic acid and oxalic acid in the pH range 3.0-4.5 and at a flow-rate of 1 mil/min. The metal complex and naphthalene were dissolved from the column with 5 ml of dimethylformamide(DMF), and the absorbance of the solution was measured at 398 nm. A calibration graph was linear over the range 1-18 mug of titanium in 5 ml of the final DMF solution. The complex has a molar absorptivity of 1.39 x 10(4) l.mole(-1).cm(-1) and a sensitivity of 3.44 x 10(-3) mug/cm(2) for 0.001 absorbance. Eight replicate determinations for a sample containing 12 mug of titanium gave a mean absorbance of 0.697 with a relative standard deviation of 0.82%. The interference of various ions was studied and optimum conditions were developed for the determination of titanium in various aluminium and zinc alloys.     

Simultaneous spectrophotometric determination of nickel and iron in copper-base alloy with bromo-PADAP

The reaction of nickel (II) with Br-PADAP, in the presence of tergitol NPX surfactant, forms a complex with absorption peaks at 520 and 560 nm. The iron(II)-Br-PADAP system at the same conditions forms a chelate with absorption peaks at 560 and 748 nm. This allows the simultaneous spectrophotometric determination of nickel and iron by measuring the absorbance at 560 and 748 nm. The proposed method, at ph 4.0-5.7, shows a molar absorptivity of 1.22 x 10(5)l . mole(-1) . cm(-1) for nickel at 560 nm and 8.20 x 10(4)l . mole(-1) . cm(-1) at 560 nm and 3.35 x 10(4)l . mole(-1) . cm(-1) at 748 nm for iron(II). Beer's law is obeyed up to 0.40 mu/ml of nickel(II) and up to 0.65 mu/ml of iron(II). Thiosulphate as masking agent allows the simultaneous determination of iron and nickel in the presence of high concentrations of copper. The ethylene glycol 2-(2-amino-ethyl) tetracetic acid provides the elimination of many other interferences. The method has been applied successfully to the simultaneous determination of nickel and iron in reference samples.     

Column preconcentration and FAAS determination of copper,iron, nickel and zinc using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol-tetraphenylborate-naphthalene adsorbent

A solid co-precipitated material obtained from an ion-pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) and tetraphenylborate (TPB), and microcrystals of naphthalene has been tried as an adsorbent for the column preconcentration of copper(I), iron(II), nickel(II) and Zn(II). The retention of the metal ions was found to be maximum and constant in the pH range 3.0-8.0 for Cu, 3.8-7.5 for Fe, 4.5-7.5 for Ni and 8.5-11.0 for Zn. The elements were determined by FAAS after dissolving the metal along with the adsorbent in an organic solvent (10 mL of DMF). The characteristic concentration for 1% absorption was found to be 0.0332, 0.0536, 0.0537 and 0.0142 (aqueous medium 0.0512, 0.0638, 0.1294 and 0.0216) microg mL(-1) for Cu, Fe, Ni and Zn, respectively. The calibration plot was linear in the range 1.5-20.0, 2.0-38.0, 2.5-25.0 and 0.5-15.0 micro g in the final 10 mL of DMF solution for Cu, Fe, Ni and Zn, respectively. Various parameters such as pH, volume of buffer, amount of adsorbent, flow rate, preconcentration factor and effect of diverse salts and cations were studied. The optimised conditions were utilized for the determination of Cu, Fe, Ni and Zn in various water, beverage and human hair samples.     

Determination of nickel with 2-(2-quinolylazo)-5-diethylaminoaniline as a chromogenic reagent.

A sensitive, selective and rapid method for the determination of nickel based on a rapid reaction of nickel(II) with 2-(2-quinolylazo)-5-diethylaminoaniline (QADEAA) has been developed. In the presence of pH = 6.0 ammonia-ammonium chloride buffer solution and sodium dodecyl sulfonate (SDS) medium, QADEAA reacts with nickel to form a violet complex having a molar ratio of 1:2 (nickel to QADEAA). The molar absorptivity of the complex is 1.38 x 10(5) l mol(-1) cm(-1) at 595 nm. Beer's law is obeyed in the range of 0.01-0.4 microg/ml. This method had been applied to the determination of nickel with good results.     

Synthese und Struktur porphinoider Nickel-Komplexe mit axial orientierten Seitenketten

Synthesis and Structure of Porphine-type Nickel Complexes Containing Axially Oriented Sidechains The structure of (±)-[1, 11-dimethoxy-10 H-HDP (2-)]nickel ( 3 ), the product of the thermodynamically controlled addition of methanol to [6 H-HDP]nickel-bis-(tetrafluoroborate) ( 1 ), was determined by X-ray analysis. The two methoxy groups in 3 are cis-oriented. The syntheses and spectroscopic properties of [1, 11-diethoxy-10 H-HDP (2-)]nickel ( 5 ), [1, 11-dineopentyloxy-10 H-HDP (2-)]nickel ( 6 ) as well as the bridged complexes [1, 11-pentamethylenedioxy-10 H-HDP (2-)]nickel ( 4 ) and [1, 11-(E)-2,3-(dimethyl-2-butenylenedioxy)-10 H-HDP (2-)]nickel ( 7 ) are described. Reaction of 1 with bromide ions or 4-methylpyridine leads to the formation of the corresponding hexacoordinated, paramagnetic complexes dibromo [6 H-HDP]-nickel (II) ( 8 ) and bis (4-methylpyridine)[6 H-HDP]nickel-bis (tetrafluoroborate) ( 9 ).