Determination of Fluoride Ion by a Flow Injection Analysis Based on the Formation of a Fluorescent Aluminium-Schiff Base Complex.

In the presence of fluoride ions, aluminium reacts with N-salicylideneethylenediamine to form fluorescent Schiff base complexes. A flow-injection analysis system based on this reaction has been developed for a determination of the fluoride ions at the ppm level. By measuring the fluorescence intensities, the number of fluoride ions could be selectively determined over the range 0.15–10 ppm; 40 samples could be analyzed per hour. The proposed system was applied to an analysis of the fluoried ion in river water.