ISO 995:1975 PDF
Potassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric method
Potassium hydroxide for industrial use — Determination of silica content — Reduced molybdosilicate photometric method
- Статус документа:
- Отменён
- Формат:
- Электронный (PDF)
- Количество страниц:
- 3
- Дата публикации:
- 1 сентября 1975 г.
- Издание:
- 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.
Технические детали
- Технический комитет
- ISO/TC 47 - Chemistry
- SKU
- ISO 995:1975