Comparison of fast atom bombardment mass spectrometry and thermal ionization quadrupole mass spectrometry for the measurement of zinc absorption in human nutrition studies.

A method is described for the measurement of apparent zinc absorption in human nutrition studies. An enriched source of the stable isotope 67Zn was given to adult subjects together with a wheat cereal and the unabsorbed 67Zn measured in the feces. After drying, subsamples of the homogenized fecal material were ashed at 480 degrees C, purified for analysis by ion exchange chromatography, and the 64Zn/67Zn ratios determined by both fast atom bombardment mass spectrometry and thermal ionization quadrupole mass spectrometry. Good agreement was found between the two sets of results with mean precisions of approximately 0.5% for both techniques.