Determination of Iron by Dispersive Liquid-Liquid Microextraction Procedure in Environmental Samples

A greener analytical procedure based on dispersive liquid-liquid microextraction (DLLME) coupled to flame atomic absorption spectrometry (FAAS) detection was developed. Various influencing factors on the separation and preconcentration of iron, such as the acidity of the aqueous solution, extraction and disperser solvent type and their volume have been investigated systematically, and the optimized operation conditions were established. Under the optimum conditions i.e., pH 4.0, [DPTH] = 5x10-3%, a preconcentration factor of 45 was reached. The lower limit of detection (LOD) obtained under the optimal conditions was 9 μg L-1. The precision for 8 replicate determinations at 50 and 100 μg L-1 of Fe were 1.8 % and 4.4 % relative standard deviation (R.S.D.), respectively. The calibration graph using the preconcentration method was linear from 10 to 5000 μg L-1, with a correlation coefficient of 0.9904. The proposed method was successfully applied to the preconcentration and determination of iron in food, vegetation, soil and water samples.