A rapid method for iron determination in fortified foods

The objective of this study was to develop and evaluate a rapid method for iron determination in fortified and unfortified foods. Method: samples were mixed with an iron-extracting solution (1.2 M HCl, 0.6 M trichloroacetic acid, and 0.7 M hydroxylamine hydrochloride) and heated in a boiling water bath for 15 min. The mixtures were cooled and filtered. The filtrate was mixed with a chromogen reagent (0.03% bathophenanthroline disulfonic acid in 3 M sodium acetate). Iron concentration was determined by measuring absorbance at 535 nm. The accuracy of the rapid method was validated by comparing results to a standard laboratory method for iron determination. Results: the rapid method produced accurate results for the majority of the food samples tested, including wheat flour fortified with FeSO4, electrolytic iron, NaFeEDTA, Ferrochel® or ferrous fumarate; powdered drink mixes, and enriched rice. However, results obtained using the rapid method were significantly lower than results obtained using the standard method for the enriched cornmeal (30.04 vs. 33.16 μg Fe/g; P=0.0118) and the enriched flour (41.90 vs. 47.28 μg Fe/g; P<0.0001). Conclusion: The rapid method is simple, inexpensive, and suitable for monitoring iron concentrations in fortified foods.