Sodium carbonate for industrial use — Determination of sulphur compounds content — Method by reducti...
Applicable to products having a S compounds content, expressed as sulphate, of equal to or more than 5 mg/kg. Bases of progressive neutralization, with evolution of carbon dioxide, by adding slowly a mixture of hydriodic acid and hypophosphoruos acid. Reduction of the compounds to hydrogen sulphide by heating. Distilation of the hydrogen sulfide, entrainment in a flow of oxygen-free nitrogen and…
Sulphuric acid for industrial use — Evaluation of sulphuric acid concentration by measurement of den...
The principle consists in the determination of density at 20 °C by means of a hydrometer. Evaluation of the corresponding sulphuric acid concentration by means of the table. - Replaces ISO Recommendation R 911-1968.
Sulphuric acid and oleum for industrial use — Determination of ash — Gravimetric method
Based on evaporation of a test portion in a platinum dish, followed by ignition in an electric furnace, controlled at (850 50) °C, and weighing. - Replaces ISO Recommendation R 913-1968.
Sulphuric acid and oleum for industrial use — Determination of total nitrogen content — Titrimetric ...
The method is applicable to products having a total nitrogen content equal to or greater than 0.05 % (m/m). The principle consists in the conversion of the nitrogen present in a test portion to ammonia by means of nascent hydrogen. Distillation and absorption of the ammonia in an excess of standard volumetric sulphuric acid solution, and back-titration with a standard volumetric sodium hydroxide…
Nitric acid for industrial use — Determination of sulphated ash — Gravimetric method
The principle of the method consists inevaporation of a test portion in a platinum dish, conversion of the residue to sulphates by treatment with sulphuric acid; ignition in an electric furnace, controlled at (800 +- 25) °C, and weighing. Replaces ISO Recommendation R 1983-1971.
Nitric acid for industrial use — Determination of nitrous compounds — Titrimetric method
Two cases are considered: content of nitrous compounds, expressed as HNO2, equal to or greater than 0,01 % (m/m) and content of nitrous compounds, expressed as HNO2, less than 0,01 % (m/m). The principle consists in oxidatiuon of the compounds present in a test portion by an excess of standard volumetric potassium permanganate solution. Addition of an excess of a standard volumetric iron(II)…
Urea for industrial use — Determination of nitrogen content — Titrimetric method after distillation
The procedure is based on the catalytic conversion of nitrogen present in a test portion to ammonia by heating in concentrated sulphuric acid solution. Distillation and absorption of the ammonia in an excess of standard volumetric sulphuric acid solution and back-titration with standard volumetric sodium hydroxide solution in the presence of an indicator. - Replaces ISO Recommendation R 1592-1970.
Urea for industrial use — Determination of alkalinity — Titrimetric method
The principle consists in titration of the alkalinity of a test portion with a standard volumetric hydrochloric acid solution in the presence of an indicator. - Replaces ISO Recommendation R 1593-1970.
The procedure consists in the ignition of a test portion in a platinum dish at (800 25) °C to constant mass. - Replaces ISO Recommendation R 1594-1970.
