ISO 5934:1980

Crude sodium borates for industrial use — Determination of alkali-soluble copper and manganese contents — Zinc bis(dibenzyldithiocarbamate) and formaldehyde oxime photometric methods

Describes a method applicable to products in which the alkalisoluble copper and manganese contents excess 0,25 and 0,5 mg/kg, respectively. The principle consists in successively determining the manganese and copper contents of the two coloured complexes obtained during the analysis, followed by photometric measurements at wavelengths of about 435 nm and 450 nm, respectively.