Determination of Fluoride in Various Samples and Some Infusions Using a Fluoride Selective Electrode

Introduction Fluoride (F−) is an important anion, present in various environmental, clinical and food samples. Small amounts of fluoride are vital for the human organism, but it is toxic in larger amounts. For adults the lethal dose is 0.20–0.35 g F− per kg body weight. Fluoride is widely used in various branches of industry and some fluoride compounds are formed as by-products in certain processes. Excessive amounts of fluoride in the form of different compounds can enter the human body by means of polluted air, water and the food chain. An additional source of fluoride for humans is toothpastes containing ca. 0.1% fluoride (NaF, SnF2, Na2PO3F) and water fluoridation (adding fluoride in the form of NaF to drinking water). A small amount of fluoride is beneficial in the prevention of dental caries. Fluoride has also been used to treat osteoporosis . It is very characteristic that fluoride prevents tooth decay at about 1 mg L−1 but causes mottled teeth ∗Corresponding author