This standard specifies a method for the determination of fluorine in solid waste by alkali fusion - Ion selective electrode method. Suitable for the determination of fluorine content in solid waste. When the sample is solid or dryable semi-solid, the sampling amount is 0.25g, the detection limit is 0.03 g/kg, and the lower limit of determination is 0.12 g/kg; When the sample is liquid or semi-solid without drying, the sampling amount is 10g, the detection limit is 0.5 mg/kg, and the lower limit of determination is 2.0 mg/kg. During operation, the muriatic acid used is highly volatile and corrosive, the sample pretreatment process should be carried out in the fume cupboard, and protective equipment should be worn during operation to avoid direct contact with skin and clothing.