ISO 2888:1973

Furfural for industrial use — Determination of acidity to phenolphthalein — Volumetric method

Pretreatment of the water used, freshly boiled and cooled, by neutralization by addition of the standard volumetric sodium hydroxide solution or sulphuric acid solution as required. Addition of the test portion and titration with the standard volumetric sodium hydroxide solution in presence of phenolphthalein as indicator until the apperance of a pale pink colour.