A new method to perform position-specific 2H and 13C isotope NMR analyses on the same sample

Stable isotope analysis has been proven to be a highly valuable method for detecting a range of sophisticated food product counterfeits. This is especially true when position-specific isotope analysis (PSIA) is used, as it provides the isotopic distribution within a given molecule. 13 C-NMR is very efficient but does not replace 2 H-NMR, always used in official methods and providing complementary data. Obtaining both types of information is therefore essential, but the experimental conditions currently used routinely are very different. In this work, we show that – thanks to a new methodology - a single sample can be used for PSIA for both 2 H and 13 C NMR. The amount of material required for 2 H analysis is reduced. Furthermore, experimental time was significantly reduced compared to reference methods - with the same quantity of material. Preliminary results were obtained - using an average magnetic field and a room temperature probe - on two molecules of particular interest to the food industry: ethanol and vanillin. Significant potential was also demonstrated regarding the authentication capacity of this methodology. Furthermore, this approach can be easily extended to other molecules or other fields. • A single sample can be used for PSIA using 2 H and 13 C NMR. • The R 2 D 3 methodology is used for the reduction of the experimental time. • The amount of material required for 2 H analysis is reduced. • Efficiency was demonstrated for the authentication of ethanol and vanillin.