Detection of Fe(III)EDTA by using photoluminescent carbon dot with the aid of F- ion.

Iron(III) ethylenediaminetetraacetate (Fe(III)EDTA) is widely used in iron fortification for reducing iron deficiency, and its determination is urgently needed. The present work developed a fluorescent method to straightforwardly determine Fe(III)EDTA by using photoluminescent carbon dots (C-dots) with the aid of F- ions as the masking agent of free Fe3+ ions. In the presence of F- ions, only Fe(III)EDTA selectively quenched the photoluminescence of C-dots, and both Fe3+ and Fe2+ as well as other carboxylic acids have no effect on the emission of C-dots. The sensing mechanism was attributed to the ligand-tailored electron transfer process from C-dots to Fe3+. Under optimum conditions, this method showed a linear calibration plot over the Fe(III)EDTA range of 1.0-200 μmol L-1 and a detection limit of 0.4 μmol L-1. The proposed method was successfully applied to determine Fe(III)EDTA in real samples with acceptable recoveries of spikes (95%-110%) and repeatability (RSD, 4.2%-9.5%).