Paragraph 3 PRINCIPLE

After hydrolysis, phosphorus is precipitated in an acidic solution in the form of quinoline phosphomolybdate. The precipitate is collected, washed, dried at 250°C and weighed.

In the above conditions, compounds likely to be found in the solution (mineral and organic acids, ammonium ions, soluble silicates, etc…) will not interfere provided that a reagent based on sodium molybdate or ammonium molybdate is used in the precipitation.