This standard specifies the method for the determination of total nitrogen content in compound fertilizers. This standard does not apply to compound fertilizers containing more than 7% organic matter (except urea and cyanamide compounds).
GB/T 8572-2001 history
2010GB/T 8572-2010 Determination of total nitrogen content for compound fertilizers titrimetric method after distillation
1987GB 8572-1988 Determination of total nitrogen content in compound fertilizer