Reference number
ISO 2214:1972
ISO 2214:1972
© ISO 2025
ISO 2214:1972
Boric acid, boric oxide and Disodium tetraborates for industrial use — Determination of manganese content — Formaldehyde oxime photometric method
Edition 1
1972-07
1972-07
Withdrawn
Abstract
The principle consists in removal of the boron by evaporation with methanol and separation of manganese and other metals from the residue, by extraction with chloroform, as their diethyldithiocarbamates. Wet destruction of the diethyldithiocarbamates with a sulphuric acid/ hydrogen peroxide mixture. Removal of any interfering iron by extraction as the thiocyanate. Formation of the coloured manganese formaldoxime complex in alkaline solution and photometric measurement at a wavelength of approximately 450 nm.