ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 43, Number 4
JKCSEZ 43(4)
August 20, 1999 

A spectrofluorimetric method for the determination of Fe(IIl) in aqueous solution with 4,5-dihydroxy-1,3-benzenedisulfonic acid(Tiron) as a fluorimetric reporter was developed. Tiron, which is very soluble in water,is a good fluorimentric reagent However, when Tiron was complexed with Fe(III), the fluorescent intensity was decreased proportionally with the concentration of Fe(III) by a quenching effect. The excitation and fluorescene wavelength of Tiron showing the quenching effect by Fe(III) at pH 4.5 were 312nm and 341nm, respectively. The highest sensitivities were shown at Tiron concentration of l.0 × 10-2M. To enhance the quenching effect, the Fe(III)-Tiron complex solution was heated to 80℃ for 90 minutes. As for Fe(III), the most interfering ion was Cu(II). The interference effects could be mostly eliminated by pH adjustment or by adding EDTA. The concentration ranges showing the linear response to Fe(III) was from 5.0× 10-7M to 6.0 × 10-5M With this proposed method, the detection limits of Fe(III) was 2.8 × 10-6M. Recovery of Fe(lII) in a synthetic sample was almost quantitative. Based on experimental results,lt is proposed that the above technique can be applied to the practical determination of Fe(III).