Rapid Quantification of Alcohol Content in Intact Bottles of Wine Using Scalar-Coupled Spectroscopy at Low Field

Abstract

Direct spectroscopic quantification of small molecules using low cost, low field (< 0.1 T) large bore portable magnets is not possible using conventional techniques due the presence of strong homonuclear coupling which results in complicated spectral patterns with resonances separated by much less than the achievable spectral linewidth. In contrast, a method using the signals from a Carr–Purcell–Meiboom–Gill (CPMG) train, in which the data are Fourier transformed in this indirect dimension, can produce so-called J-spectra in which several distinct spectral features can be distinguished. In this work, we evaluate this technique to quantify the amount of alcohol (ethanol) in intact bottles of wines or spirits.