GB/T 16484.13-2009 Part 13 Determination of ammonium chloride in rare earth chloride and carbonic acid light rare earth by distillation-Titrimetric method. Applicable to related rare earth products. The ammonium chloride in the sample is first distilled, and then the distillate is titrated with a suitable standard solution. The standard specifies the requirements of distillingapparatus, Burette and other instruments, and specifies the preparation of reagents. Detailed description of Sample Handling, covering sample weighing and distillation conditions. Standardize titration operation, including titration speed, indicator use and end point judgment. According to this standard, the amount of ammonium chloride can be accurately determined, providing key data for the quality control of rare earth products and production process optimization, and ensuring the mass production of rare earth industry.