Cupferron Complex Research Articles

Precipitation of metal-cupferron complexes from homogeneous solution—I

The cupferron complex of copper has been precipitated from homogeneous solution by the addition of phenylhydroxylamine and sodium nitrite to a cold, acidic solution containing copper(II) ions. The precipitate can be dried at 90 +/- 5 degrees and weighed without ignition to the oxide. Less than 3 mg of copper can be determined. A fairly high concentration of acetic acid is tolerable. Separation from large quantities of zinc, nickel and silver has been achieved.

Precipitation of metal-cupferron complexes from homogeneous solution—II

The cupferron complex of titanium has been precipitated by the addition of phenylhydroxylamine and sodium nitrite to a cold acidic solution of the metal. Details of the method are given. Separation of titanium from aluminium, borate, phosphate and vanadate is described.

Extraction of the cupferron complex of niobium

The precipitation of the cupferron complex of niobium is well known, but the literature states that the extraction of the complex with an organic solvent is either not quantitative or suitable for separating only milligram amounts of niobium. The present work shows that under suitable conditions in sulphuric acid solution, chloroform extraction of the cupferron complex of niobium can be made quantitative. Less than 0.05% of the niobium remains in the acid layer. Non-extracted elements may be determined by any standard method.

The Determination of Iron in Terphenyl by X-Ray Emission Spectroscopy

A rapid, simple method using x-ray emission spectroscopy has been developed for the determination of iron in terphenyl with a limit of detection of 2 μg Fe/g of terphenyl. Terphenyl is an organic compound being considered for use in nuclear reactors. In the pure state it is solid at room temperature. Samples as received for analysis usually contain tars with the result that the sample is a very viscous liquid at room temperature. Chemical analysis involves careful ashing of large amounts of sample requiring several hrs. The major problem in developing an x-ray method was the preparation of satisfactory, homogeneous standards to be used in producing a calibration curve. This was solved by dissolving the cupferron complex of iron in the terphenyl and then determining the iron in the solution by x-ray spectroscopy.

Isolation of carrier-free 233Pa from irradiated thorium nitrate

A method is given for the isolation of carrier-free 233Pa from thorium nitrate irradiated with slow neutrons. It consists of isolating 233Pa from the thorium nitrate solution by sorption on a MnO 2 precipitate; extracting the cupferron complex of protactinium with amyl acetate; re-extracting the protactinium into aqueous citric acid; and decomposing the citrate complex by oxidation with nitric acid. Good separation from α- and β-emitters was achieved. The isolated radioisotope was identified by its half-life period. The method will be found useful for obtaining carrier-free 233pa, which can be employed as a tracer in chemical studies on protactinium, and in investigations of the extraction of protactinium from natural raw materials and of the separation of 233Pa from thorium during the preparation of 233U.

The separation of Pa233 without a carrier from thorium nitrate preparations irradiated by slow neutrons

The article gives a method for the separation of Pa233 without a carrier from thorium nitrate irradiated by slow neutrons. Pa233 was extracted from a thorium nitrate solution by absorption on a precipitate of MnO2, amyl acetate extraction of the cupferron complex of protactinium with subsequent re-extraction by a citric acid solution and, finally, decomposition of the citric acid complex by oxidation with concentrated nitric acid. During this process satisfactory removal of α-and-β-radiation was achieved. The separated radioisotope was identified by determination of its half-life. The method developed is important for obtaining the radioactive isotope Pa233, without a carrier which can be used as an indicator for studying the chemistry of protactinium and also for solving problems of the extraction of protactinium from naturally occurring raw material and the separation of Pa233 from thorium during the preparation of U233.

36—The Determination of Traces of Manganese in Textiles by means of Formaldoxime

The possibility of employing the formaldoxime method for the colorimetric determination of manganese in textile materials has been investigated with special reference to the possible interferences that may be encountered. It has been found necessary to provide for the separation of iron from the solution, and the procedure adopted, extraction of the Cupferron complex with methylene chloride, removes also certain other interfering metals. The remaining foreign ions that react with formaldoxime may be masked by means of cyanide. A few ions require separation for incidental reasons. The method is not as simple as those based upon oxidation of the manganese to permanganic acid, but is equally widely applicable and is about five times more sensitive.