Abstract / scope
The principle consists in titration of a test portion with standard volumetric sodium hydroxide solution, using phenolphthalein as indicator. Calculation of the acid content, making allowance for any formic acid present, determined separately (see ISO 753/3). This International Standard has also been approved by the International Union of Pure and Applied Chemistry (IUPAC). International Standards ISO 753/1 to ISO 753/11 cancel and replace ISO Recommendation R 753-1968.