Speciation, Preconcentration and Determination of Iron in Legumes Sample Based on a Novel Magnetic Mixed Hemimicell Solid Phase Extraction Technique

A novel magnetic mixed hemimicell solid phase extraction (MMHSPE) technique for speciation analysis of soluble, ferrous and ferric iron in legumes sample by flame atomic absorption spectrometry analysis (FAAS) was developed. MMHSPE system consisting of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3NPs) modified by sodium dodecylsulfate-1-(2-pyridylazo)-2-naphthol (SDS-PAN) have been successfully synthesized as an extracting agent. The procedure is based on complexation of Fe(II) with PAN that immobilized on the SDS-coated Fe3O4/Al2O3 NPs. Total iron is subjected to a similar extraction procedure after reduction. Then Fe(III) has been calculated by subtracting Fe(ΙI) from the total iron. The new and rapid method of analyses (MMHSPE technique) has been successfully applied for the determination of iron ions in certified reference materials (NCS DC 73349—bush, branches and leaves; and TM-23.2—fortified water) and legumes samples with high efficiency. Under the optimum conditions of parameters, the recoveries of Fe(ΙI) by analyzing the seven spiked some legumes samples were between 96.0% and 103.6% and detection limits of Fe(ΙI) were between 1.7 and 3.1 ng mg−1. The results have been also indicated that Fe3+ concentrations obtained are always higher than the Fe2+ contents in legumes sample and Soy bean snack and Peanut have the maximum content of Fe2+.