This standard specifies a specific method for the determination of tin content in sodium stannate using the potassium iodate Titrimetric method. This method is suitable for the determination of tin content in sodium stannate samples, and the determination range is 35.00%~ 44.00%. After the sample is dissolved by muriatic acid, tin (IV) is reduced to tin (II) using iron powder and metallic aluminum, and titrated with potassium iodate standard solution. Starch is used as an indicator to detect the titration endpoint. The reagent formulation and calibration steps are described in detail in the standard, which ensures the accuracy and Repeatability of the determination.