ISO 5992:1979

Sodium hydroxide for industrial use — Determination of mercury content — Dithizone photometric method ISO 5992:1979

Publication date:   Sep 1, 1979

Scope

Covers a method applicable to liquid or solid products having mercury contents greater than 0,05 mg/kg. The principle of determination is based on oxidation of the mercury contained in a test portion to mercury(II) ions by potassium permanganate in the presence of sulphuric acid, reduction of the excess oxidant, extraction in chloroform of the complex formed, and photometric measurement of the complex at a wavelength of about 490 nm.