This standard BS 5551-4.1.2:1982 Fertilizers. Chemical analysis. Determination of nitrogen is classified in these ICS categories:
- 65.080 Fertilizers
https://www.en-standard.eu/bs-5551-4-1-2-1982-fertilizers-chemical-analysis-determination-of-nitrogen-determination-of-ammoniacal-nitrogen-titrimetric-method-after-distillation/