ISO 995:1975 PDF
Potassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric method
Open preview (PDF)Potassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric methodPotassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric method
- Document status:
- Withdrawn
- Format:
- Electronic (PDF)
- Number of pages:
- 3
- Publication date:
- September 1, 1975
- Edition:
- ISO IS 995 edition 1 version 1
- ICS:
- 71.060.40
The method is applicable to products having silica contents exceeding 10 mg/kg. The principle is based on the formation of yellow oxidized silico-molybdic complex in a strongly acid medium, in the presence of boric acid to suppress interference by fluorides. Selective reduction of this complex with a mixture of aminonaphtholsulphonic acid (4-amino-3-hydroxynaphthalene-1-sulphonic acid), sodium metabisulphite and sodium sulphite, in the presence of oxalic acid and in a strongly acid medium so as to suppress interference by phosphates. Photometric measurement of the blue-coloured complex at a wavelength of about 795 nm.
Technical details
- Technical committee
- ISO/TC 47 - Chemistry
- SKU
- ISO 995:1975
