Quantification of manganous ions in wine by NMR relaxometry

Philippe Bodart (1) , Adam Rachocki (2) , Jadwiga Tritt-Goc (2) , Bernhard Michalke (3) , Philippe Schmitt-Kopplin (4) , Thomas Karbowiak (5) , Régis Gougeon (6, 1)

1 PAM - Procédés Alimentaires et Microbiologiques [Dijon]
2 Institute of Physics, Polish Academy of Sciences
3 BGC - Research Unit Analytical BioGeoChemistry
4 Chair of Analytical Food Chemistry
5 PCAV - Physico-Chimie de l'Aliment et du Vin
6 IUVV Jules Guyot - Institut Universitaire de la Vigne et du Vin "Jules Guyot"

Proton relaxation in model and real wines is investigated for the first time by fast field cycling NMR relaxometry. The relaxation mechanism unambiguously originates form proton interaction with paramagnetic ions naturally present in wines. Profiles of a white Chardonnay wine from Burgundy, a red Medoc, and model wines are well reproduced by Solomon-Bloembergen-Morgan equations. Relaxation is primarily governed by interactions with Mn2+. A straightforward model-independent quantification of the manganese ion concentration (down to few tens of mu g/L) is proposed.

Mots clés: FFC NMR relaxometry; Chardonnay wine; Paramagnetic ions; Manganese

Domaines: Alimentation et Nutrition; Biochimie, Biologie Moléculaire

Philippe Bodart, Adam Rachocki, Jadwiga Tritt-Goc, Bernhard Michalke, Philippe Schmitt-Kopplin, et al.. Quantification of manganous ions in wine by NMR relaxometry. Talanta, 2020, 209, pp.120561. ⟨10.1016/j.talanta.2019.120561⟩. ⟨hal-02499122⟩