The Application of Site-Specific Natural Isotope Fractionation-Nuclear Magnetic Resonance (SNIF-NMR) to the Analysis of Alcoholic Beverages

Comparison of quantitative NMR and IRMS for the authentication of ‘Polish Vodka’

“…Due to the fact that our spectrometer was not fitted with a specific 'deuterium' probe having a field frequency stabilization channel at the fluorine frequency, in this study we used the second method, which required shimming on the proton free induction decay, which yields a reasonable signal‐to‐noise ratio in one pulse. To obtain reproducible data the greatest signal‐to‐noise ratio (S/N) in as short time as possible is required …”

“…To obtain reproducible data the greatest signal-to-noise ratio (S/N) in as short time as possible is required. 12 All quantitative 2 H NMR spectra were recorded using a Bruker Avance II Plus 16.4 T spectrometer (Bruker BioSpin, Germany) operating at the 1 H frequency 700.08 MHz and at 107.46 MHz for 2 H. The instrument was equipped with a 5 mm broadband inverse (BBI) probe carefully tuned to the recording frequency of 107.46 MHz. 2 H NMR spectra were acquired using pulse width of 47 μs (90 ∘ ) with 16K data points, WALTZ decoupling and including a relaxation delay of 8 s, which was calculated as 7T 1 of the longest relaxation time to ensure complete magnetization recovery.…”

“…Apart from D/H ratios, the R value is used for discrimination of geographical origin of ethanol. Parameter R is defined as the ratio between intensities of methyl and methylene signals in the deuterium spectra: …”

Synthesis, Structure and Conformation of Partially‐Modified Retro‐ and Retro‐Inverso ψ[NHCH(CF3)]Gly Peptides

“…The isotopic content in molecules is not statistically distributed, but depends on the molecule's precursor and on the physical–chemical processes that are involved 1. Although this interesting and useful characteristic was first described as an effective tool in heavy element geochemistry,2 isotopic studies applied to light nuclei in food science such as hydrogen,3 carbon,4 nitrogen5 and oxygen6 revealed the high potential of the technique in origin discrimination.…”

Procedures of Food Quality Control: Analysis Methods, Sampling and Sample Pretreatment

“…The relative deuterium concentration and specific deuterium-site locations in a molecule can be determined using SNIFNMR (Site-Specific Natural Isotope Fractionation-Nuclear Magnetic Resonance). This can provide information about the chemical pathway of formation and, in some cases, information about the geographic origin of a sample can also be discerned (Cross et al, 1998). In this context, food products such as olive oil, dairy milk and cheese have been tested (Bescia et al, 2005;D'Imperio et al, 2007;Karoui & Baerdemaeker, 2007).…”