Animal and vegetable fats and oils — Determination of residual technical hexane content
The method is based on desorption of volatile hydrocarbons by heating at 80 °C in a closed vessel after addition of an internal standard and determination of the particular volatile hydrocarbons content of the headspace by gas chromatography using packed or capillary columns.
Iron ores — Determination of calcium content — Flame atomic absorption spectrometric method
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for calcium with those obtained from…
Iron ores — Determination of magnesium content — Flame atomic absorption spectrometric method
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for magnesium with those obtained from…
Iron ores — Determination of aluminium content — Part 1: Flame atomic absorption spectrometric metho...
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for aluminium with those obtained from…
Iron ores — Determination of silicon content — Part 1: Gravimetric methods
The method is based on decomposition of the test portion by 1) sintering with sodium peroxide and treatment with hydrochloric and perchloric acids and treatment with dilute nitric acid, or 2) treatment with hydrochloric, nitric and perchloric acids, evaporation, filtration of silica with any residue, fusion with sodium carbonate and dissolution in hydrochloric and perchloric acids, in both cases…
Iron ores — Determination of silicon content — Part 2: Reduced molybdosilicate spectrophotometric me...
The method is based on decomposition of the test portion by fusion with sodium tetraborate and treatment with dilute nitric acid, addition of ammonium molybdate to convert silicate into a molybdatosilicate complex, reduction to molybdenum blue with ascorbic acid, and spectrophotometric measurement of the absorbance of the molybdenum blue complex at a wavelength of approximately 600 nm. Applies to…
Direct reduced iron — Determination of carbon and/or sulfur content — High frequency combustion meth...
The method is based on combustion of the test portion in a refractory crucible in a flow of oxygen in the presence of an accelerator, conversion of the carbon present into carbon dioxide and the sulfur present into sulfur dioxide, and measurement of each gas by infrared absorption. Applies to carbon contents between 0,05 % and 2,5 % and/or sulfur contents between 0,001 % and 0,05 % in direct…
Acid-grade and ceramic-grade fluorspar — Determination of loss in mass at 105 degrees C
The method is based on drying a test portion at 105 °C and determination of the loss in mass, which corresponds to the content of water and other components volatile at that temperature. Applies to fluorspars, which may be dried material containing not less than 0,02 % (m/m) of components volatile at 105 °C, or filter cake.
Acid-grade and ceramic-grade fluorspar — Determination of barium sulfate content — Gravimetric metho...
The method is based on evaporation to dryness of a test portion in the presence of hydrofluoric acid and concentrated sulfuric acid, extraction of the soluble salts from the mixture, filtration, drying and weighing of the residual barium sulfate. Applies to products having barium sulfate contents equal to or greater than 0,1 % (m/m).
