Development of techniques for the isolation of iron from biological material for measurement of isotope ratios by fast atom bombardment mass spectrometry

Abstract

Stable isotopes have gained prominence in nutrition and trace element research. Fast atom bombardment mass spectrometry (FAB-MS) measurement of iron isotope ratios has an accuracy of > or equal to 99.7% with the stable isotopes (54)Fe, (56)Fe, and (58)Fe with relative standard deviations (RSDs) of < or equal to 0.9%. The isolation of iron from biological matrices can be accomplished in 4 h with almost total removal of isobaric interferences caused by (39)KOH, (39)K.H2O, (40)CaOH, and/or (40)Ca.H2O. FAB-MS isotope enrichment measurements from this method compare favorably to predicted absorption/enrichment levels.