Spectrofluorimetric determination of trace amounts of aluminium with salicylaldehyde salicyloylhydrazone

Abstract

A new fluorescent reagent, salicylaldehyde salicyloylhydrazone (SASH), was synthesized and its ionization constants were established spectrophotometrically. The fluorescent reaction of this reagent with aluminium was studied. Based on this chelation reaction, a spectrofluorimetric method was developed for the determination of aluminium in a water–ethanol (3 + 2, v/v) medium at pH 3.4. Under these conditions, the Al–SASH complex has excitation and emission maxima at 375 and 450 nm, respectively. The linear range of the method is from 0.0 to 140 ppb and the detection limit is 1.2 ppb of aluminium when a standard additions method is used in the assay. The molar ratio of aluminium to the reagent is 1 : 3. Interferences of other ions were studied. The method has been successfully applied to the determination of aluminium in injection glucosi (glucose injection) and common beverages.