Abstrato

Determination of Total Iron in Corn and Wheat Samples by Electrothermal Atomic Absorption Spectrometry after Solid Phase Preconcentration

Alireza P and Mohsen S

A novel, simple, selective and sensitive solid phase extraction method for determination of total iron in wheat and corn samples was described. Fumaric acid (trans-butenedioic acid) was used as complexing agent and the silica gel and was used as solid phase extractor. Iron was complexed by fumaric acid and was adsorbed on the silicagel. Adsorbed complex were eluted with 20 mL of 1 M HCl and elutes were analyzed by electro thermal atomic absorption spectrometry. Effects of parameters such as pH, sample volume, type of eluent and sample flow rate were optimized by a Plackett-Burman design. The effect of foreign ions on preconcentration was also studied. Under the optimum conditions, the enrichment factor 25 was obtained. The calibration graph was linear in the rage of 2 ng L-1 to 100 ng L-1 of iron with detection limit of 0.5 ng L-1. The relative standard deviation (R.S.D) for ten replicate measurements of 10 ng L-1 of iron was 4.8%. Accuracy of method was confirmed by the analysis of corn and wheat certified reference materials.