Flow injection spectrofluorimetric determination of fluoride or phosphate based on their inhibitory effect on the photo-oxidation of acridine catalysed by iron(III)

An automated procedure for the photochemical determination of fluoride or phosphate has been developed, based on the inhibitory effect of these anions on the photo-oxidation of acridine in the presence of iron(III). The development of the photochemical reaction was monitored by making use of the fluorescence of acridine. Linear calibration graphs mere obtained over the ranges 0.76-9.5 mu g ml(-1) for fluoride and 0.95-9.5 mu g ml(-1) for phosphate, The method was applied to the determination of fluoride and phosphate in waters.