ISO 5793:1978

Sulphur for industrial use — Determination of chloride content — Photometric method

Is applicable to products having chloride contents, expressed as chlorine, greater than 2 mg/kg. The principle of determination consists in extracting the chlorides by boilling a test portion in aqueous 2-propanol, followed by a quantitative displacement of the thiocyanate ions of mercury(II) thiocynate by the chloride ions contained in an aliquot portion of the extraction solution, and reaction of the thiocyanate ions with iron(III) nitrate to form iron(III) thiocyanate.