Numéro de référence
ISO 2999:1974
ISO 2999:1974
© ISO 2024
ISO 2999:1974
Pyrophosphate de sodium à usage industriel — Évaluation de la teneur en pyrophosphate — Méthode potentiométrique
Edition 1
1974-12
1974-12
Annulée
Résumé
Applicable to products containing at least 90 % (m/m) of tetrasodium pyrophosphate and in the absence of more condensed forms of phosphates. The reaction based on conversion of tetrasodium pyrophosphate to disodium dihydrogenpyrophosphate by addition of hydrochloric acid. Introduction of zinc sulfate in solution for precipitation of zinc pyrophosphate and formation of sulphuric acid. Potentiometric titration of the sulphuric acid formed with standard volumetric sodium hydroxide solution. Has also been approved by the IUPAC.