Optimization of a methodology for determination of iron concentration in aqueous samples using a newly synthesized chelating agent in dispersive liquid-liquid microextraction

The aim of this study was to establish a new dispersive liquid-liquid microextraction (DLLME) technique for the determination of iron concentration in aqueous solutions and fruit juices based on the reaction between iron and 3-hydroxy-1-(3-hydroxyphenyl)-2-methylpyridin-4(1H)-one (3-OH-PMPO) as a chelating agent. A central composite design (CCD) was applied to optimize the effects of independent parameters (pH, volume of disperser solvent and extractant solvent and chelating agent concentration) on extraction efficiency. Under the optimized conditions, the analytical curve is linear in a concentration range of 10-750 μgL−1 with a detection limit of 5 μgL−1. The relative standard deviation (RSD) for ten repeated determinations of iron concentrations at 40 and 200 μgL−1 was calculated to be 4.2% and 1.2%, respectively. Relative recovery of iron in several water samples was investigated and the average was obtained in the range of 91-108%.