The authenticity of natural flavor compounds is an important topic for the flavor industry. Over the last decade stable isotope analysis has become the most important tool for authenticity testing of non-chiral flavor compounds like vanillin and benzaldehyde. Our work deals with multielement isotope ratio mass spectrometry using a new online IRMS-technique in combination with 2H-NMR.
The origin of organic molecules can be determined by the examination of their stable isotope ratios. Isotope ratio mass spectrometry (IRMS) is well established for analysis of the isotope ratios of H, C, N, O, and S. Additionally, 2H-NMR, also called SNIF-NMR (Site-Specific Natural Isotope Fractionation - Nuclear Magnetic Resonance), is used for the evaluation of site-specific hydrogen isotope ratios in a molecule. IRMS, as well as 2H-NMR, can be used to determine the authenticity of flavor and fragrance compounds.
Most common is the analysis of the stable isotope ratio of 13C/12C by IRMS. The measured ratio is expressed as δ-value, which is defined as follows:
