Reference number
ISO 2362:1972
ISO 2362:1972
© ISO 2025
ISO 2362:1972
Aluminium fluoride for industrial use — Determination of fluorine content — Modified Willard-Winter method
Edition 1
1972-12
1972-12
Withdrawn
Abstract
The principle of the method consists in fusion of a test portion with sodium carbonate. Separation of fluorine by distillation with sulphuric acid. Titration with thorium nitrate solution using sodium alizarinsulphonate-methylene blue as indicator. Alternatively, the thorium nitrate titration may be made using only sodium alizarinsulphonate; the end-point being spectrophotometrically determined at 525 nm.