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.
Ammonium hydrogen carbonate for industrial use (including foodstuffs) — Determination of arsenic con...
Applicable to products having As contents more than 0.2 mg/kg. The principle consists in reduction of the element to arsine in a solution of silver diethyldithiocarbamate in pyridine. Photometric measurement of the purplish- red colour produced by the colloidally dispersed silver, at the maximum of the absorption curve (wavelength approximately 540 nm).
Bases for the design of structures — Deformations of buildings at the serviceability limit states
Establishes the basic principles that should be adopted when setting up national standards, regulations and recommendations for the deformation of buildings at the limit states of serviceability. Refers to the deformations at the serviceability limit states of buildings such as dwellings, offices, public buildings, and factories. Does not refer to the deformations of bridges, roads, masts,…
Sodium fluoride for industrial use — Determination of carbonate content — Gravimetric method
Applicable to products having contents, expressed as Na2 CO3 , more than 0.02 % (m/m). Describes the release of the carbon dioxide from a test portion by acidification and heating. Entrainment of the carbon dioxide in a flow of air and absorption in weighed absorption tubes containing soda asbestos. Specifies the weighing of the absorption tubes to determine the quantity released.
Aluminium fluoride for industrial use — Determination of sodium content — Flame emission spectrophot...
Applicable to products having Na contents, expressed as Na2 O, of equal to or more than 0.05 % (m/m). The principle bases on fusion, at a controlled temperature, of a test portion with a mixture of lithium carbonate and boric oxide or with a mixture of lithium carbonate and lithium tetraborate in a platinum or platinum-gold alloy crucible. Extraction of the fused mass with hydeochloric acid…
Cryolite, natural and artificial, and aluminium fluoride for industrial use — Determination of sulph...
Applicable to products having a content, expressed as sulphur trioxide, equal to or more than 0.1 % (m/m). Bases on alkaline fusion of a test portion with a mixture of sodium carbonate and boric acid. Extraction of the fused mass with perchloric acid solution and precipitation of the sulphate ions with barium chloride in an acidified medium. Filtration on a fine-texture, ashless filter paper (…