Sodium sulphate for industrial use — Determination of sodium sulphate content — Gravimetric method
Applicable to products in which not all impurities are known or determined. The methods specified in ISO 3237 cannot be applied. The principle consists in dissolution of a test portion, removal of insoluble matter, iron, aluminium and calcium from the solution and evaporation to dryness in the presence of sulphuric acid. Heating and weighing of the total amount. Calculation of the sodium sulphate…
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…
Leather — Determination of sulphated total ash and sulphated water-insoluble ash
To determine the total mineral content, for example within the framework of a complete leather analysis, the inorganic substances can be ascertained by calculation or determined separately. The principle consists of the carbonization of the leather followed by treatment with sulphuric acid and ashing in an open crucible. The method is applicable to all types of leather.
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…
Surface active agents — Technical sodium primary alkylsulphates — Methods of analysis
Specifies the following methods of analysis for the substances to be tested: measurement of pH, determination of water content, determination of free alkalinity or free acidity, determination of total alkalinity, determination of matter extractable by light petroleum, determination of matter extractable by diethyl ether after acid hydrolysis (combined technical fatty alcohols), determination of…
Surface active agents — Technical sodium secondary alkylsulphates — Methods of analysis
Specifies the following methods of analysis for the substances to be tested: measurement of pH, determination of water content, determination of free alkalinity or free acidity, determination of total alkalinity, determination of matter extractable by light petroleum, determinition of the sodium alkylsulphates content, determination of sodium sulphate content, determination of sodium chloride…
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.
Specifies the following determinations for the substances to be tested: Measurement of pH, determination of water content, determination of free alkalinity or free acidity, determination of matter extractable by light petroleum, determination of sodium alkylarylsulphonates content, determination of sodium sulphite content, determination of sodium sulphate content, determination of sodium chloride…
Butter — Determination of water, solids-not-fat and fat contents on the same test portion (Reference...
Depending on the content to be estimated the method described uses three different steps for determination, i.e. drying of a known mass of butter at 102 +/- 2 degrees centigrade and weighing to determination the loss of mass, extraction of the fat from the dried butter with light petroleum or n-hexane and weighing of the residue, and calculation of the fat content by difference.
