Rechercher

Method I is applicable to manganese ores having chromium contents less than 0.1 % (m/m), method II is applicable to manganese ores having chromium contents greater than 0.1 % (m/m). This second edition cancels and replaces the first edition (i.e. ISO 619-1975). Should be read in conjunction with ISO 4297.

The sample is oxidized by nitric and sulphuric acids or by the use of Eschka mixture. Then, using the method specified in ISO 2590, the arsenic is reduced by zinc in sulphuric acid or hydrochloric acid medium. The arsine formed is absorbed in a solution of silver diethyldithiocarbamate in pyridine. The purplish-red colour produced by the colloidally dispersed silver is measured photometrically at…

Describes three methods: methods I and II are gravimetric methods which are applicable to maganese ores having sulphur contents greater than 0.01 % (m/m), and method III is a titrimetric method. Should be read in conjunction with ISO 4297. Specifies principle, reagents, apparatus, sample, procedure and expression of results. A figure illustrates the apparatus for determination of sulphur content…

The method is applicable to products having esters contents in the range 0.005 % (m/m) to 0.15 % (m/m). The principle consists in the saponification of esters present in a test portion by boiling with excess standard volumetric sodium hydroxide solution; determination of the residual sodium hydroxide, and hence the amount used for saponification, by titration with standard volumetric hydrochloric…

The method is applicable to products having carbonyl compounds contents between 0.00025 % (m/m) and 0.01 % (m/m). The principle is based on reaction in acid medium of the carbonyl compounds in a test portion with 2,4-dinitrophenylhydrazine. Formation of the corresponding 2,4-dinitrophenylhydrazones which, after making the solution alkaline, take on a red coloration. Photometric measurement of…

The method is applicable to products having carbonyl compounds contents equal to or greater than 0.01 % (m/m). The method only allows determination of those carbonyl compounds which react under the specified conditions. The principle is based on the reaction of hydroxylammonium chloride with the carbonyl compounds in a test portion and titration of the hydrochloric acid formed with standard…

The method is applicable to products having aldehyde contents in the range 0.00025 % (m/m) to 0.00125 % (m/m). The principle is based on the reaction of the aldehydes present in a test portion with Schiff reagent. Visual comparison of the colour obtained with the colours of standard colorimetric solutions containing known quantities of acetaldehyde. - International Standards ISO 1388/1 to ISO…

Provides rules for the presentation and the position of the contents list of periodicals (see also ISO 8). Cancels and replaces ISO Recommendation R 18-1956, of which it constitutes a technical revision.

Specifies a conventional gravimetric method for the determination. A test portion ist reated with quinoline in a beaker at 70 to 80 °C for 15 to 20 min. Then the dissolved test portion and the residue are brought to a Hartley funnel fitted with a filter pad, and are filtered. The washed and dried residue on the filter pad is weighed.

Specifies a method based on the depolymerization of any polymerized silica by treatment with sodium fluoride in the presence of hydrochloride acid resulting in the formation of the oxidized molycdosilicate, followed by the selective reduction of this complex in the presence of oxalic acid and in a sulphuric acid medium, and spectrophotometric measurement of the blue-coloured complex at the…