GB/T 8572-2010 uses the Titrimetric method after distillation to determine the total nitrogen content in compound fertilizers, which is suitable for all kinds of compound fertilizer products. First, the compound fertilizer sample is heated with alkali solution, and the nitrogen is converted into ammonia distillation, absorbed with acid solution, and then the remaining acid is titrated with alkali standard solution. The standard specifies the requirements of distillingapparatus, Burette and other instruments, and specifies the preparation and calibration of reagents. Detailed description of Sample Handling steps, such as sample weighing, grinding and distillation conditions settings. Standardized titration operation process, including titration speed control and end point judgment. According to this standard, the total nitrogen content can be accurately determined, providing key data for mass control of compound fertilizers and agricultural production applications.