Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and their salts have various toxicities such as reproductive toxicity, mutagenic toxicity, and developmental toxicity. They are also among the most difficult - to - degrade persistent organic pollutants currently. The unique water - and oil - repellent properties of perchlorinated compounds have led to their wide application in industries such as textiles, leather, and papermaking. PFOS, PFOA, and their salts have unknowingly entered our food through food packaging materials, affecting food safety and threatening people's health. Research on their analysis and detection technologies and methods has received increasing attention.