The SN/T 5052-2018 standard specifies a method for the determination of fluoride, chloride, sulfate and nitrate ions in water-soluble carbonic acid salts using Ion chromatography. It is suitable for the determination of fluoride (F), chloride (Cl), sulfate (SO4 ^ 2-) and nitrate (NO3 ^ -) in sodium carbonate, potassium carbonic acid and sodium hydrogen carbonic acid, with lower limits of 4.0 mg/kg, 4.0 mg/kg, 5.0 mg/kg and 5.0 mg/kg, respectively. The standard describes the pretreatment of the sample in detail, including the dissolving and pH value adjustment of the carbonic acid salt sample to 4.5~ 5.5, the infusion after filtration, and the determination using Ion Chromatography. All reagents used must meet the analytical purity requirements of national or professional standards, and the water is first-class water in accordance with GB/T 6682.