The geometry of the equipment contains a fixed magnetic field and ion collectors which allows an extreme accurate determination of these ratios compare to the conventional types of mass spectrometers. The difference has only to be 0.1% in the relative amount of 13C or 15N to make a significant differences between the ratios in samples.
Product authenticity and traceability: atmospheric differences in the stable isotope ratio and therefore in the products can be detected to determine their geographic origin. Although these differences are very small, the high accuracy of the IRMS enables researchers to discriminate between olive oil from Spain and Greece.
Physiological research: labelled chemical components are used to identify specific biochemistry pathways or digestion processes. The advantage is that the components labelled with stable isotopes are not dangerous to use and will behave comparable to those with a normal isotope ratio. For these studies, highly enriched components are infused and their disappearance or the appearance in breakdown products is estimated by using the IRMS mostly in combination with the gas chromatograph. At this moment, methods are available for the measurement of this ratio in individual amino acids, alkanes and urea. In the future further applications will be developed.