Determination of total iron in foods by isotope dilution fast atom bombardment mass spectrometry

A method employing isotope dilution fast atom bombardment mass spectrometry has been developed for the quantitative determination of iron in foods. Samples were spiked with an enriched source of 54Fe, digested with concentrated HNO3/H2SO4 and the iron extracted from 6 M HCl into diethyl ether. Bracketing procedures gave precisions ranging from 1.30-4.49% relative standard deviation (RSD) for isotope ratio measurements and 1.26-6.44% RSD for iron measurements.