ISO 2482:1973

Sodium chloride for industrial use — Determination of calcium and magnesium contents — EDTA complexometric methods

The method is applicable to water-soluble salts for contents greater than 0,001 % (m/m). In a special case, the determination of ions in a principal solution prepared in an acid medium is pooible. The principle consists in dissolution of a test portion and separation of insoluble matter. Titration of the filtrate obtained according to ISO 2479 using disodium ethylendiamintetraacetate (EDTA) in the presence of glyoxal-bis-(2-hydroxyanil) (GBHA) and mordant black 11 (Cl 14645) respectively as indicators.