Abstract: A new fluorescent reagent, salicylaldehyde 5 bromo salicyloylhydrazone(SABSH), was synthesized and the fluorigenic reaction of this reagent with zinc was studied in detail. Based on this chelation reaction, a spectrofluorimetric method was developed for the determination of zinc in a 2-propanol-water(1: 1, V/V)medium at pH 7 9. Under these conditions the Zn SABSH complex has excitation and emission maxima at 393 nm and 465 nm, respectively. The linear range of the method is from 0 to 400 μg/L, the relative standard deviation of the method is 1.2% and the detection limit is 1.3 μg/L of zinc when a standard addition method is used in the assay. The molar ratio of zinc to reagent is 1: 2. Interferences of thirty six other ions were studied. The method has been successfully applied to the determination of trace zinc in wheat flour, rice, human urine and mineral spring water samples.

Key words: zinc, salicylaldehyde-5-bromo salicyloylhydrazone, spectrofluorimetry