Isotopic analysis by nuclear magnetic resonance

Isotopic analysis by nuclear magnetic resonance refers to overarching set of methodologies to precisely quantify differences in isotopic content at each atom of a molecule, and thus to measure the specific natural isotope fractionation for each site of the molecule. One such method, SNIF-NMR—the corresponding English of the original French acronym, which abbreviates site-specific natural isotopic fractionation nuclear magnetic resonance—is an analytical method developed to detect over-sugaring of wine and enrichment of grape musts. As of this date, its main use has been to check the authenticity of foodstuffs such as wines, spirits, fruit juice, honey, sugar, and vinegar, and to control the naturality of flavorant and odorant molecules such as vanillin, benzaldehyde, raspberry ketone, and anethole. The SNIF-NMR method in particular has been adopted by the International Organisation of Vine and Wine (OIV) and the European Union as an official method for wine analysis, by the Association of Official Agricultural Chemists (AOAC) as an official method for analysis of fruit juices, maple syrup, vanillin, and by the European Committee for Standardization (CEN) for analysis of vinegar.