ISO 3357:1975Published

Sodium tripolyphosphate and sodium pyrophosphate for industrial use — Determination of total phosphorus(V) oxide content — Quinoline phosphomolybdate gravimetric method

Tripolyphosphate et pyrophosphate de sodium à usage industriel — Dosage de l'oxyde de phosphore(V) total — Méthode gravimétrique au phosphomolybdate de quinolèine

Abstract / scope

Based on hydrolysis of a test portion by prolonged boiling in the presence of hydrochloric acid. Precipitation of the phosphate ions in the form of quinoline phosphomolybdate in the presence of acetone. Filtration by means of a filter crucible, washing, drying and weighing of the precipitate.