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

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.