ISO 5314:1981

Fertilizers — Determination of ammoniacal nitrogen content — Titrimetric method after distillation

The method consists in distilling of the ammonia from an alkaline solution, absorbing in an excess of standard volumetric sulphuric acid solution and back-titrating with standard volumetric sodium hydroxide solution. It is applicable only in the absence of urea or its derivatives, of cyanamide and of organic nitrogenous compounds.