Abstract: The fluorescent reagent salicylaldehyde benzoylhydrazone(SABH) was synthesized and its ionization constants were estimated spectrophotometrically. The fluorescent reaction of this reagent with gallium was studied. Based on this chelation reaction, a spectrofluorimetric method was developed for the determination of gallium in a water medium at pH 3.2. Under these conditions, the Ga-SABH complex has excitation and emission maxima at 372 and 455 nm, respectively. The linear range of the method was 0～150 μg/L and the detection limit was 0.36 μg/L of gallium when a standard addition method was used in the assay. The molar ratio of gallium to the reagent was 1∶3. The interference of other ions was studied. The extraction with n-butyl acetate from a 6 mol/L hydrochloric acid medium was used to separate Ga from the interfering elements in semiconductor silicon and geological samples, and themethod has been successfully applied to the determination of gallium in these samples.

Key words: Salicylaldehyde benzoylhydrazone, Gallium determination, Spectrofluorimetry