Potassium hydroxide for industrial use — Determination of sulphur compounds — Method by reduction an...
Applicable to products the content of which, expressed as sulphate, is equal or more than 5 mg/kg. The principle consists in the reduction of the sulphur compounds to hydrogen sulphide by heating with a mixture of hydriodic acid and hypophosphorous acid. Distillation of the hydrogen sulphide by a current of purified oxygen-free nitrogen in a mixture of sodium hydroxide and acetone. Titration of…
Universal System for Designating Linear Density (Tex System)
Gives the principles and recommended units of the Tex System for
the expression of linear density and includes in Appendix A
conversion tables for calculating the tex values of numbers or
counts in other systems together with in Appendix B a statement
of the procedure for the implementation of the Tex System in
trade and industry.
Système universel de désignation de la masse linéique (système Tex)
Présente les principes et les unités recommandées du système Tex
relatifs à l'expression de la masse linéique, et donne à l'annexe
A des tables de conversion pour calculer les valeurs en Tex des
titres et numéros exprimés dans d'autres systèmes, et à l'annexe
B un exposé sur la marche à suivre pour la mise en application du
système Tex dans le commerce et l'industrie.
Sodium sulphate for industrial use — Determination of loss in mass at 110 degrees C
Applicable to anhydrous products. Heating of a test portion, spread in a thin layer, to constant mass in an oven the temperature of which is controlled at (110 2) 0C. In the special case of the decahydrate, progressive heating of a test portion, spread in a thin layer, to constant mass by means of a hot-plate and a radiator.
Sodium sulphate for industrial use — Determination of acid-insoluble matter
Applicable to anhydrous and hydrated products. The principle consists in dissolution of a test portion in water, subsequent addition of hydrochloric acid. Heating on a boiling wather bath for 30 min, filtration, drying and weighing of the residue.
Sodium sulphate for industrial use — Determination of chlorides content — Mercurimetric method
Applicable to products the content of which expressed as chlorine exceeds 0.005 % (m/m). If the analyst can easily detect the indicator's colour change using a 0.02 N standard volumetric mercury(II) nitrate solution the method can, subjected to agreement, be extended to products the content of which exceeds 0.001 % (m/m). The titration of the chloride ions (Cl- ) is carried out with a 0.1 N…
Sodium sulphate for industrial use — Determination of sulphates content — Calculation method and bar...
Applicable to the analysis of products manufactured by traditional methods provided that the impurities other than sulphates are well known. The gravimetric method shall be applied only in the case of doubt as to the accuracy of the calculated result. Principle of calculation: subtraction of the loss in mass at 110 °C, acid-insoluble matter, chlorides content (as NaCl), alkalinity (as Na2 CO3 )…
