Development of a dispersive liquid-liquid microextraction method for iron speciation and determination in different water samples.

A novel, simple and efficient method for the iron (Fe) speciation and determination in different water samples was developed using dispersive liquid-liquid microextraction (DLLME) technique followed by spectrophotometric analysis. The procedure is based on complexation of Fe(II) with O-phenanthroline (O-Phen), the subsequent ion-association formation with picrate anion, then extraction of the complex using DLLME technique. Some important parameters such as the type and volume of extraction and dispersive solvents as well as the extraction time were investigated and optimized in detail. Under the optimum conditions, the calibration graphs were linear over the range of 0.025-1.0 μg mL(-1) with limit of detection of 7.5 μg L(-1). Relative standard deviation for five replicate determinations of Fe at 0.2 μg mL(-1) concentration level was calculated to be 1.2%. Average recoveries for spiked samples were determined to be between 90% and 108%. The method was applied to water samples and parenteral solutions and the amounts of Fe found in these samples using the proposed method were similar with those obtained by a standard method.