Micelle-mediated extraction for speciation and spectrophotometric determination of iron using a newly synthesized salicylic acid derivative

Abstract

A sensitive and selective method for speciation and determination of iron was developed using cloud point extraction combined with spectrophotometry. The method depends on formation of complex between Fe3+ and a newly synthesized reagent, 4-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxybenzoic acid (DOPHHBA), and its extraction into Triton X-114 rich phase prior to spectrophotometric determination at 438 nm. Total Fe was determined as Fe3+ by the same methodology after oxidation of Fe2+. The method exhibited dynamic linear range from 4.0 to 500 µg L-1 with limit of detection and enrichment factor of 1.2 µg L-1 and 95.2, respectively. The accuracy of the method was tested by analysis of certified reference materials and spiked samples. The method was applied for speciation of Fe in natural water samples and determination of Fe in food samples with satisfying results. The analytical results are statistically comparable with those obtained by a standard ICP-OES method.