Determination of copper by radiochemical displacement

5–25 g of copper has been determined by exchange with zinc-65 labelled zinc sulphide. The effect of diverse ions on the determination has also been reported.     

Determination of chromium by radiochemical displacement

A rapid and sensitive method has been developed for the determination of microgram amounts of chromium based on the radiochemical displacement of⁶⁵Zn from labeled Zn-[1-(2-pyridylazo-2-naphthol]₂ complex by chromium. The effect of pH on the displacement of⁶⁵Zn was studied. 5–65 g of chromium could be determined with great accuracy. The effect of various ions on the displacement of⁶⁵Zn by chromium was investigated and the method developed was utilized for the determination of chromium content present in geological water samples. The results were compared with values obtained by Atomic Absorption Spectrophotometry.     

Determination of mercury by radiochemical displacement

2–15 g of mercury has been determined by exchange with zinc in⁶⁵Zn labelled zinc sulphide. The influence of various ions which are likely to interfere in the determination of mercury has also been studied.     

Determination of cadmium by radiochemical displacement

Determination of cadmium by radiochemical displacement of zinc from a labelled ZnPAN complex has been studied. pH 5.5 in borate buffer was suitable for quantitative displacement. The effects of diverse ions on the displacement reaction are also reported.     

Determination of manganese by radiochemical displacement

The possibility of determination of 10–80 g of manganese by radiochemical displacement of zinc from a labelled zinc-PAN complex has been demonstrated. pH 6 borate buffer was suitable for quantitative displacement. The effect of diverse ions on the displacement reaction is also reported.     

Determination of mercury by radiochemical displacement method

A radiochemical displacement method for the determination of micro amounts of Hg(II) has been developed. 65Zn was displaced from the Zn-1-(2-pyridylazo-2-naphthol) complex at pH 5 in borate buffers by Hg (II). 10-80 micrograms of mercury could be determined. Interference of various metal ions and methods for suppression have also been carried out.     

Determination of copper by a radiochemical displacement method

Determination of copper/II/ by radiochemical displacement of labelled cobalt from cobalt-o-hydroxybenzaldehyde isonicotinoyl hydrazone /Co-BIH/ complex has been studied. Borate buffer of pH 5 was found to be a suitable medium for quantitative displacement. 10–70 g of copper could be determined. The effect of various foreign metal ions on the determination has also been studied.     

Analysis by radiochemical displacement: Determination of EDTA

A new radiochemical displacement method has been developed for the determination of EDTA /ethylene diamine-tetraacetic acid/. The displacement of labelled zinc from Zn:PAN complex by EDTA at pH 5.5 in borate buffers can be conveniently utilized for the determination of 50–150 g of EDTA. Effects of diverse ions on the determination have also been tested.     

Determination of micro amounts of copper by radiochemical displacement

A radiochemical displacement method for the determination of microgram quantities of copper has been developed. The method consists of the displacement of labelled zinc from its complex with PAN. 5–60 g of copper can be determined at pH 5. Effect of various ions on the method has also been studied.     

Determination of trace amounts of palladium by radiochemical displacement

A method has been developed for the determination of trace amounts of palladium using radioactive mercury dithizonate as the reagent. Experimental conditions for the quantitative displacement of mercury from the reagent, calibration graph and the interfering effects of various ions have been studied. The method is sensitive down to 2 g of palladium present in 10 ml of the aqueous solution.     

Trace analysis of mercury by a radiochemical displacement method using cobalt(III) diethyldithiocarbamate

A radiochemical displacement method was utilized for the determination of traces of mercury in water taking advantage of its ability to displace cobalt from cobalt(III) diethyldithiocarbamate tagged with⁶⁰Co. The method is found to be applicable in the concentration range of 50–200 g/ml mercury. The interfernces from various cations like Fe(III), Co(II), Cu(II), Pb(II) and Ag(I) ions were studied.     

Trace determination of nickel (and cobalt) in biological reference materials by radiochemical neutron activation analysis

Summary Very few biological reference materials are certified for nickel below 1 mg · kg^–1. Neutron activation analysis was only rarely considered as a possible approach; reported sensitivities were usually not very good, unless preconcentration was applied.In the present work, the relatively high fast neutron flux of our TRIGA reactor was used to induce the ⁵⁸Ni(n, p)⁵⁸Co reaction, and ⁵⁸Co (E =811 keV) was radiochemically separated from other radionuclides by classical anion-exchange chromatography in hydrochloric acid. ⁵⁷Co was added to the irradiated sample before decomposition as a radioisotopic yield monitor. By concentrating the final sample fraction and measurement in a well-type HP Ge detector, Ni concentrations down to the 10-g · kg^–1 level could be determined for samples irradiated for 1 day. ⁶⁰Co, produced by neutron capture on ⁵⁹Co, is also coseparated and quantified from the gamma spectrum, so that both elements Ni and Co are determined. Results are reported for a series of NBS and other biological reference materials in the concentration range 10 g-10 mg · kg^–1. Possibilities for further increases in sensitivity are discussed.

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Spurenbestimmung von Nickel (und Cobalt) in biologischen Referenzmaterialien durch radiochemische Neutronenaktivierungsanalyse

     

Determination of iron and antimony by radiochemical displacement of60Co from cobalt-o-hydroxybenzaldehyde isonicotinoyl hydrazone

A radiochemical displacement method has been developed for the determination of 10 g amounts of iron and antimony. The effect of pH and various foreign ions on the displacement of tracer⁶⁰Co from labeled Co-o-Hydroxybenzaldehyde isonicotinoyl hydrazone (BIH) complex in isoamyl alcohol by iron and antimony was studied.     

Determination of chromium, iron and cobalt in high-purity niobium by radiochemical neutron activation analysis

Summary Chromium, iron and cobalt were determined in niobium by radiochemical neutron activation analysis. The main steps of the technique involved the irradiation of the samples in a medium or high-flux reactor, the post-irradiation decontamination of the sample surface, a two-step separation procedure based on anion-exchange from HF and HCl medium, and counting the separated indicator radionuclides with a well-type NaI-detector. For a 42-day irradiation at a thermal neutron flux of 8×10¹³ n cm^–2 s^–1 and a sample weight of 100 mg, the limits of detection are: 10 ppt for chromium, 1.5 ppb for iron and 4 ppt for cobalt. The results obtained by this technique are compared with data obtained by radiochemical proton activation analysis and atomic absorption spectrometry.

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Bestimmung von Chrom, Eisen und Cobalt in hochreinem Niob durch radiochemische Neutronenaktivierungsanalyse

Zusammenfassung Die Hauptschritte der Methode sind die Bestrahlung der Probe in einem Mittel- oder Hochflußreaktor, eine anschließende Oberflächendekontamination und die spezifische Abtrennung der Indicatorradionuklide mittels Anionaustausch aus Flußsäure- und Salzsäure-Medium, sowie die Messung der Radionuklid-Fraktionen mit einem Natriumjodid-Detektor.Für eine 42tägige Bestrahlung mit Reaktorneutronen bei einem thermischen Fluß von 8×10¹³ n cm^–2 s^–1 konnte bei einem Probengewicht von 100 mg für Chrom eine Nachweisgrenze von 10 ppt, für Eisen von 1,5 ppb und für Cobalt von 4 ppt erreicht werden.Die mit dem Verfahren erhaltenen Ergebnisse werden mit denen der radiochemischen Protonenaktivierungsanalyse und der Atomabsorptions-Spektrometrie verglichen.

     

Determination of copper,cobalt and nickel by circular thin-layer chromatography

Summary A method for the microdetermination of copper, cobalt and nickel from a mixture containing 40 metal ions by circular thin-layer Chromatographic technique is described. The procedure is simple; the chromatoplate takes about 2 minutes for its development and other metal ions do not interfere with the determination. The recovery of copper, cobalt and nickel is better than 98%. The apparatus for the concentration of test solution before TLC analysis is also described.

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Zusammenfassung Die Mikrobestimmung von Kupfer, Kobalt und Nickel in Gemischen von 40 verschiedenen Metallionen im Wege der zirkulären Dünnschichtchromatographie wurde beschrieben. Die Vorgangsweise ist einfach; die Entwicklung der Chromatogramme erfordert 2 Minuten, fremde Metallionen stören nicht. Die Ausbeute an Kupfer, Kobalt und Nickel ist besser als 98%. Ein Gerät für das Einengen der Probelösung vor der DC-Analyse wurde gleichfalls beschrieben.

     

Substoichiometric masking-II Determination of traces of cobalt in nickel salts and metallic nickel

Cobalt is determined in the presence of large amounts of nickel by masking the latter substoichiometrically by addition of xxx 98% of the theoretically required amount of EDTA. The "free nickel" :cobalt ratio is thereby decreased below the critical value and the cobalt is extracted as the green cobalt(III)-PAN complex into chloroform. Small amounts of nickel-PAN formed are destroyed by a subsequent EDTA-hydrochloric acid treatment. The absorbance of the treated extract is measured at 635 mmu. Copper, zinc, cadmium and iron do not interfere in ratios (to cobalt) of 500:1, 100:1, 100:1 and 10:1, respectively.     

Determination of copper impurities in nickel and cobalt salts by atomic absorption spectroscopy

Summary A method is described for the rapid determination of traces of copper in the ppm range in cobalt and nickel salts. The % standard deviation for the analysis is reported as 3.4 to 3.7 for aequous solutions and 4.8 to 5.0 for carbon tetrachloride sprayed directly into the flame after extraction.

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Zusammenfassung Ein Verfahren zur raschen Bestimmung von Kupferspuren im ppm-Bereich in Kobalt- und Nickelsalzen wurde beschrieben. Die Standardabweichung in wäßrigen Lösungen beträgt 3,4 bis 3,7%, bei unmittelbarem Versprühen der Tetrachlorkohlenstoffextrakte in die Flamme 4,8 bis 5,0%.

     

Sorption of nickel and cobalt ions onto cobalt and nickel ferrites

The corrosion of the metal parts in the primary circuit of pressurized water reactors leads to the release of colloidal particles (NiFe(2)O(4), CoFe(2)O(4), NiO, Ni...) and ionic species (Co, Ni, Cr...). Particles can interact with ionic species in the primary medium, contributing to their transport and to their deposition onto surfaces outside the neutron flux generating radioactive contamination. Sorption and zetametry experiments at 25 °C were performed on the Ni(2+)/CoFe(2)O(4) and Co(2+)/NiFe(2)O(4) systems in order to determine the behaviour of corrosion products in the fluid of the primary circuit. Sorption appears as surface complexation starting from pH 6 and is followed by precipitation of hydroxide above pH 7.5. Complexation and solubility constants were obtained from the modelling of sorption curves. The two oxide systems present a very similar sorption behaviour, but some differences, due to their different isoelectric points, could be observed on zetametric measurements.