适用于产品，无论其是否均匀，是否含有多磷酸。规定了在盐酸存在下通过沸腾对多磷酸进行初步水解。在丙酮存在下，以喹啉磷钼酸盐的形式进行磷酸沉淀。通过过滤坩埚过滤，洗涤、干燥和称量沉淀物。

Applicable to products whether or not they are homogeneous and whether or not they contain polyphosphoric acids. Specifies preliminary hydrolysis of the polyphosphoric acids by boiling in the presence of hydrochloric acid. The precipitation of the phosphoric acid is carried out in the form of quinoline phosphomolybdate in the presence of acetone. Filtration by a filter crucible, washing, drying and weighing of the precipitate.