Potassium sulphate for industrial use — Determination of sulphate content — Barium sulphate gravimet...
The principle consists in dissolution of a test portion and precipitation of the sulphate ions by barium chloride in boiling acid medium. Filtration, washing and ignition of the precipitate. Weighing the barium sulphate.
Potassium sulphate for industrial use — Determination of chloride content — Mercurimetric method
The principle of the analysis consists in dissolution of a test portion and addition, in a dilute acid medium, of mercuric salts which, with the chloride ions, form soluble and only slightly ionized mercury(II) chloride. Indication of the completion of the reaction by the appearance of a violet coloration due to the reaction between the excess of mercury(II) ions and the diphenylcarbazone used as…
Potassium sulphate for industrial use — Determination of acidity to methyl orange
The principle of the analysis consists in dissolution of the test solution in water and titration of the acidity, in presence of methyl orange, using standard volumetric sodium hydroxide solution. If the solution is coloured yellow the product is not acid with respect to methyl orange.
Ammonium hydrogen carbonate for industrial use (including foodstuffs) — Determination of ammoniacal ...
Specifies a titrimetric method consisting in distillation of the ammonia after displacement by an alkaline solution; absorption in an excess of standard volumetric sulphuric acid solution and back-titration with standard volumetric sodium hydroxide solution in the presence of an indicator. The absorption of the ammonia may also be carried out in an excess of boric acid solution. The titration, in…
Ammonium hydrogen carbonate for industrial use (including foodstuffs) — Determination of total alkal...
The principle of the analysis consists in acidification of a test solution by addition of an excess of standard volumetric sulphuric acid solution and back-titration with standard volumetric sodium hydroxide solution in the presence of methyl red- methylene blue mixed indicator.
Potassium hydroxide for industrial use — Determination of iron content — 1,10- Phenanthroline photom...
Describes a method that is more sensitive and more widely used than the 2,2'-bipyridyl method. It is applicable to products having iron contents equal to or greater than 0.3 mg/kg. The principle is based on the reduction of iron(III) by hydroxylammonium chloride, formation of a iron(II)/1,10-phenanthroline complex in a buffered system. Photometric measurement of the coloured complex at a…
Potassium hydroxide for industrial use — Method of assay
Method for determination of the titre, conventionally expressed as percentages by mass of KOH. There are three ways: a) total alkalinity, b) caustic alkalinity corresponding to the total alkalinity less the alkalinity due to carbonates and c) actual potassium hydroxide corresponding to the total alkalinity less the alkalinity due to carbonates and any hydroxide which may be present. The principle…
Sodium hydrogen carbonate for industrial use — Determination of iron content — 1,10- Phenanthroline ...
The method is applicable to products having a content equal to or greater than 0,1 mg/kg. The principle concists in reduction of the iron(III) by hydroxylammoniumchloride. Formation of a iron(II)-1,10-phennanthroline complex in a buffered solution. Photometric measurement of the coloured complex at a wavelength of about 510 nm.
