A spectrophotometric method for the determination of nickel

A photometric method for the determination of nickel using versene is described. Up to 20 mg of nickel can be determined with a maximum deviation of ± 0.10 mg. The effect of interfering elements, concentrations, accuracy and limitations of the method are discussed.     

A spectrophotometric method for the determination of plutonium in fuel solutions

A spectrophotometric method is described in which microgram amounts of plutonium can be determined in the presence of uranium, thorium, fission products and cladding materials. Plutonium is extracted with TTA in xylene and reextracted into a solution of Arsenazo III. Zirconium is masked by a Fe(III)-EDTA mixture, fluoride ions by Al(III). 2 to 40 μg of plutonium are required for one analysis. The standard deviation is 1.3% at 15 μg plutonium.     

A spectrophotometric method for the determination of neptunium and plutonium in process solutions

A method is described for the determination of neptunium and plutonium in process solutions. This involves the separation of these elements followed by their spectrophotometric determination as Arsenazo III complexes. Neptunium(IV) and plutonium(IV) are separated using TTA extraction method and the separated Np(IV) and Pu(IV) are then determined as their Arzenazo III complexes in 5M HNO₃. A few solutions obtained by dissolving irradiated fuels were analysed for plutonium and neptunium using this method and the results were compared with those obtained by other methods. An attempt was made to use Arsenazo III to determine uranium in the plant solutions.     

A simple stopped-flow method with continuous pumping for the spectrophotometric flow-injection determination of boron in plants

An alternative way of stopping a processed sample inside a flow-through detector is proposed. A commutating device permits the peristaltic pump to operate continuously, thus avoiding problems associated with the pump inertia often found in analyzers requiring pump stoppage. The feasibility of the approach is demonstrated by improving the spectrophotometric determination of boron in plants, which is based on a relatively slow reaction. Effects of commutating times, flow rates, manifold dimensions and reagent concentrations are studied. With the same analytical frequency (60 h^?1) and azomethine-H consumption (2.1 mg per sample) of the original procedure, the proposed system provides better sensitivity because of a three-fold increase in the sample-processing time and the absence of significant sample dispersion. Reproducible results (r.s.d. for typical samples usually less than 1%) are in agreement with those obtained with the original procedure.     

A spectrophotometric method for uranium determination

A very sensitive extraction spectrophotometric method for the analysis of uranium based on the extraction of a uranium—benzoate—crystal violet complex by a mixture of xylene and benzene is described. The absorbance maximum is at 606 nm and molar absorptivity is 4.28·10⁴ l·mol⁻¹·cm⁻¹. The interference due to a number of anions and cations studied without any pre-extraction was found to be within permissible limits. The method has been used for determining uranium in a synthetic solution, i.e., uranium in the presence of various other ions. The interference due to some cations was eliminated by the use of a masking agent (boric acid).     

A spectrophotometric method for the determination of nitrite

Nitrite reacts with dichromate quantitatively under suitable conditions of temperature and acid concentration. A linear relationship was found to exist between nitrite concentration and the absorbance at 580 nm of the chromium (III) species produced. This was used to determine the nitrite. The influence of a number of ions on the determination of nitrite was investigated; up to 100-fold excess nitrate has no influence on the determination of nitrite.     

Rapid spectrophotometric determination of boron in steel

A rapid spectrophotometric method is presented for the determination of boron in steel by use of the fluoborate-Methylene Blue complex. The method is in principle similar to that of Rosotte, but modifications simplify the operation, obviate contamination and avoid problems with emulsion formation. Up to 20% Cr, 10% Ni, and 1% each of V, Mo and W present either individually or collectively do not interfere in the determination, making it applicable to alloy steels. The determination limit of the method has been lowered from 5 to 0.2 ppm boron. Samples are dissolved at room temperature in polythene bottles, solubilizing all forms of boron including boron nitride, and avoiding loss of relatively volatile boron compounds. The precision of the method is good. Six samples can be analysed in less than 2 hr.     

Rapid and selective method for the spectrophotometric determination of nickel naphthenate in gasoline in a microemulsion

A new method for the spectrophotometric determination of nickel naphthenate in gasoline in a microemulsion was developed. PAN reacts with nickel(II) forming a red complex with composition 1:2 (metal to ligand) nickel(II)-PAN and absorption maximum at 568 nm. Nickel naphthenate in gasoline can be determined with PAN in a microemulsion, in the pH range 3.0 approximately 10.0 with a molar absorptivity of 4.8x10(4) l mol(-1) cm(-1). Beer's law was obeyed up to 0.8 mg l(-1) of nickel(II) in the microemulsion system. The interference of Cu(2+), Fe(3+), Mn(2+), Pb(2+) and Zn(2+) can be eliminated by adding 0.5 ml of a mixed masking agent. The method is rapid, simple and highly selective.     

A simple spectrophotometric method for the determination of minoxidil

A simple and sensitive method for the determination of minoxidil using 3-methyl-2-benzothiazolinone hydrazone (MBTH) and Fe(III) as the coloring agent is described. The method is sensitive to permit the determination of 0.5–4.5 μg ml⁻¹ of minoxidil at 500 nm. The accuracy and precision of the method were checked by high-performance liquid chromatography.     

A spectrophotometric method for the determination of nitric oxide

In dimethylsulfoxide, nitric oxide reduces copper(II) to copper(I) in the presence of p-chloroaniline. The resulting copper(I) is determined spectrophotometrically with 2,2′-biquinoline. The reactions are reproducible and the absorbance is proportional to the concentration of nitric oxide over the range 1.8–108 ppm (mg dm^?3. Most other atmospheric contaminants are without effect.     

A solid-phase spectrophotometric method for the determination of sulphathiazole

A spectrophotometric method for the determination of sulphathiazole (ST) has been developed, based on solid-phase spectrophotometry. The influence of experimental variables on fixation on Sephadex SP C-25 is discussed. The applicable concentration range is 0.10-10.00 mg/l., with a relative standard deviation of 0.62% and a detection limit of 0.02 mg/l. The accuracy and precision of the method are reported. The proposed method has been satisfactorily applied to the determination of sulphathiazole in pharmaceuticals.     

A new spectrophotometric method for the determination of nadolol

A new spectrophotometric method has been developed for the assay of nadolol in pure form and in tablets. The assay procedure is based on a derivatization methodology employing 4-carboxyl-2,6-dinitrobenzene diazonium ion (CDNBD) as a diazo coupling reagent. The azo dye formed between nadolol and CDNBD absorbed visible light at the wavelength maximum of 416 nm (λ_max) demonstrating a bathochromic shift from the absorption maximum of nadolol. Optimization studies established an optimal reaction time of 10 min at 60 °C. The assays were linear over 1.25–10 μg ml^?1 of nadolol, and the reaction occurred by a 3:1 reagent/drug stoichiometric ratio. The method is found to be selective and has a lower detection limit of 0.29 μg ml^?1. Recovery studies over three days gave mean recovery of 101.4% (RSD 3.0%). This new method has been successfully applied in the determination of nadolol and nadolol/bendroflumethiazide tablets with accuracy and precision similar to the official (USP) HPLC procedure (p > 0.05). The new procedure has the advantages of high sensitivity, lower limit of detection and could find application as an in-process quality control method for nadolol.     

Direct spectrophotometric method for determination of traces of boron in iron, steels and other compounds

For the determination of traces of boron in iron, low- and high-alloy steels and other materials a direct spectrophotometric method was developed. In this method the absorbance of the boron-Curcumin complex formed in the sample solution is compared with the absorbance of another aliquot of sample solution wherein the boron is rendered inactive with fluoride before the Curcumin is added.     

A facile spectrophotometric method for cobalt determination using alpha-benzilmonoxime in sodium dodecylsulfate micellar solutions.

Alpha-benzilmonoxime in sodium dodecylsulfate micellar media has been used for the spectrophotometric determination of cobalt at pH 9.0. The linear range of calibration is 0.05-1.50 microg cm(-3) of cobalt at 380 nm with molar absorptivity of 3.72 x 10(4) dm3 mol(-1) cm(-1), which is about 1.5-times greater than that of the alpha-benzilmonoxime extraction based method. The relative standard deviations, recoveries, detection limit and effects of diverse ions on the determination of cobalt were studied. These analytical results were satisfactory. The method was successfully applied to the determination of cobalt in the various samples.     

A rapid spectrophotometric method for determination of piperazine

A spectrophotometric method has been developed for the determination of piperazine and its salts (citrate, phosphate, and tartrate) without prior separation, based on the interaction of piperazine or any of its salts with phenothiazine and N-bromosuccinimide in aqueous methanol. The products exhibit absorption maxima at 448, 595 and 645 nm. Measurements are made at 595 nm. Beer's law is obeyed in the concentration range 0.5-5 mug/ml for piperazine salts and 0.5-3 mug/ml for piperazine hexahydrate. The method is rapid, simple and successful for analysis of some pharmaceutical preparations.     

Modified spectrophotometric method for the determination of traces of boron using quinalizarin in a sulfuric-acetic acid medium

Summary A modified spectrophotometric method for the determination of boron with quinalizarin in a sulfuric-acetic acid medium is proposed. The sensitivity of the method is 0.00037g/cm². The optimum concentration range is 0.06 to 0.25 ppm of boron.

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Zusammenfassung Eine modifizierte spektrophotometrische Bestimmungsmethode für Bor mit Chinalizarin in schwefelsaurer-essigsaurer Lösung wurde vorgeschlagen. Deren Empfindlichkeit beträgt 0,00037g/cm². Das optimale Konzentrationsbereich liegt zwischen 0,01 und 0,25 ppm Bor.

     

Automated method for the determination of boron in water by flow-injection analysis with in-line preconcentration and spectrophotometric detection

A sensitive, automated method for the determination of boron in water samples is described, involving flow injection with on-line ion-exchange preconcentration and spectrophotometric detection of the azomethine-H—boron complex. The method is applicable to various water samples and is free from interferences, even in coloured samples. Detection limits of 5 μg l^?1 at 20 samples h^?1 and 1 μg l^?1 at 10 samples h^?1 with relative standard deviations of < 10% at 1–10 μg l^?1 and < 5%at 10–200 μg l^?1 levels of boron were achieved. The recoveries for spiked natural water samples ranged from 96 to 101%. The method compares favourably with inductively coupled plasma atomic emission spectrometry.