This standard BS 5551-4.1.4:1984 Fertilizers. Chemical analysis. Determination of nitrogen is classified in these ICS categories:
- 65.080 Fertilizers
Specifies reagents, apparatus, procedure and reporting of results.
https://www.en-standard.eu/bs-5551-4-1-4-1984-fertilizers-chemical-analysis-determination-of-nitrogen-method-for-determination-of-ammoniacal-nitrogen-content-in-the-presence-of-other-substances-which-release-ammonia-when-treated-with-sodium-hydroxide-titrimetric-method/