Abstract
A method is described for the specific determination of trace quantities of fluoride. The procedure depends upon the solvent extraction and subsequent colorimetric measurement of the blue complex formed between fluoride and the cerous-alizarin complexan chelate. Concentrations of 0.25 to 7 μg. of fluoride in 150 ml. of water can be determined. The method has been shown to be applicable to distillates from strong acid and has been used for solid samples of low fluoride content.