Determination of antimony(III) in environmental water samples in microemulsion system by the fluorescence quenching method

A novel highly sensitive and selective fluorescent reagent, 2,6,7-trihydroxy-9-(3,5-dibromo-4-hydroxyphenyl)fluorone (DBH-PF) has been studied for the spectrofluorimetic determination of antimony(III) in cetyltrimethylammonium bromide (CTMAB) microemulsion media. DBH-PF reacts with antimony(III) forming a complex with 1:2 (metal to ligand) antimony–DBH-PF in the system of HAc–NaAc buffer solution at pH 5.33. The maximum excitation and emission wavelengths are at 522 and 556 nm, respectively. The linear range of the method is 0.05∼1.50 μg 10 ml−1 and the detection limit is 0.015 μg 10 ml−1. Foreign ions are eliminated by preconcentration and separation with sulfhydryl dextrose gel (SDG) at pH 1.0. The proposed method has been applied to the determination of antimony(III) in industrial waste water samples with satisfactory results.