Reference number
ISO 1391-3:1976
ISO 1391-3:1976
© ISO 2025
ISO 1391-3:1976
Paraformaldehyde for industrial use — Methods of test — Part 3: Determination of iron content — 2,2'- Bipyridyl photometric method
Edition 1
1976-12
1976-12
Withdrawn
Abstract
Conversion of iron contained in a test sample to sulphate by treatment with hot sulphuric acid. Oxidation of the iron present in the solution by hydrogen peroxide and subsequently reduction of the iron(III) by hydroxylammonium chloride. Formation of the coloured complex iron(II)-2,2'bipyridyl in a buffered medium. Photometric measurement of the coloured complex at a wavelength of about 510 nm. - ISO 1391, Parts 1 to 4, replace ISO Recommendation R 1391-1970.