International Organization for Standardization (ISO)
Status
2002-05
Latest
ISO 3200:1975
Scope
Applicable to the analysis of products having contents either above 0.1 % (m/m) or above 0.25 % (m/m) according to whether the product is readily or sparingly soluble in water. The principle consists in dissolution of a test portion either directly or after alkaline fusion. Separation of the insoluble matter. Precipitation, while boiling, of the sulphate ions in an acid medium. Filtration, washing and calcination of the precipitate. Weighing of the barium sulphate after treatment with hydrofluoric acid in order to remove any silica which may be present. Has also been approved by the IUPAC.
ISO 3200:1975 history
1975ISO 3200:1975 Sodium and potassium silicates for industrial use; Determination of sulphates content; Barium sulphate gravimetric method