DEVELOPMENT OF TECHNIQUES FOR THE ISOLATION OF IRON FROM BIOLOGICAL-MATERIAL FOR MEASUREMENT OF ISOTOPE RATIOS BY FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY

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 greater than or equal to 99.7% with the stable isotopes Fe-54, Fe-56, and Fe-58 with relative standard deviations (RSDs) of less than 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 (KOH)-K-39, K-39.H2O, 40CaOH, and/or Ca-40.H2O. FAB-MS isotope enrichment measurements from this method compare favorably to predicted absorption/enrichment levels.