Rechercher

Conversion of iron contained in a test sample to sulphate by treatment with hot sulphuric acid. Oxidation of the iron present in the solution by hydrogen peroxide and subsequently reduction of the iron(III) by hydroxylammonium chloride. Formation of the coloured complex iron(II)-2,2'bipyridyl in a buffered medium. Photometric measurement of the coloured complex at a wavelength of about 510…

The sample is dried at 105 to 110 °C in a stream of nitrogen and then pyrolysed under conditions in which the organic matter leaves an oxygen-free char. The volatile products, containing the organically bound oxygen and also water and carbon dioxide from any mineral matter, are decomposed with either pure carbon or platinized carbon to convert the oxygen to carbon monoxide. The carbon monoxide is…

The method is applicable to products having sulphate contents equal to or greater than 0,1 % (m/m). The principle consists in precipitation of the sulphates contained in a test portion as barium sulphate in diluted hydrochloric acid medium. Separation of the precipitate obtained and ignition of the residue in an electric furnace, amintained at (800 +- 25 ) °C, and weighing. Replaces ISO…

The method is applicable to unalloyed coppers not containing elements providing insoluble residues in the electrolytic solution. Annex A gives test portions of test sample and of copper precipitate. Annex B describes a spectrophotometric method for the determination of residual copper in the electrolytic solution after deposition of copper on the cathode.

Applicable to products having Cl- contents, expressed as chlorine, equal to or more than 0.001 % (m/m). The lower limit can be extended downwards by using weaker standard reference and volumetric solutions. Describes potentiometric titration of the ions with silver nitrate solution in a nitric acid-acetone-water medium using a silver measurement electrode and a calomel reference electrode.

Applicable to products having a content, expressed as N, equal to or more than 0.2 mg/kg. Consists in oxidation of nitrous nitrogen to nitric nitrogen by potassium permanganate and reaction of nitrogen(V) with 3,4-xylenol under specified conditions to form a nitrate derivative. Subsequent destillation of the nitrate derivative and absorption in sodium hydroxide solution. Spectrophotometric…

Applicable to products whether or not they are homogeneous and whether or not they contain polyphosphoric acids. Specifies preliminary hydrolysis of the polyphosphoric acids by boiling in the presence of hydrochloric acid. The precipitation of the phosphoric acid is carried out in the form of quinoline phosphomolybdate in the presence of acetone. Filtration by a filter crucible, washing, drying…

Applicable to products having contents of more than 2.5 mg Ca/kg and 0.5 mg Mg/kg if an acetylene-air flame is used or 0.6 mg Ca/kg and 1.0 mg Mg/kg if an acetylen-dinitrogen monoxide flame is used. The principle consists in the acidification of a test portion with hydrochloric acid, aspiration of the solution into an acetylene-dinitrogen monoxide flame or acetylene-air flame. In the latter case…

The method is applicable to the determination of nickel contents up to 2.5 % (m/m). Covers principle, reagents, apparatus, sampling, procedure, expression of results, and test report.

Defines carburization and specifies three methods of measuring the depth of decarburization of non-alloy and low-alloy steels (micrographic method, method of measuring the micro-hardness and methods of determination of carbon content).