This standard specifies the determination method of fluorine in grains, vegetables, fruits, beans and their products, meat, fish, eggs and other foods. This standard applies to the determination of fluorine in food. The fluoride ion selective electrode method is not suitable for samples with high fat content and no ashing (such as peanuts, fat meat, etc.). The detection limit of this method: the first method is 0.10mg/kg, and the second method is 1.25mg/kg.