1H NMR spectroscopy of strongly J-coupled alcohols acquired at 50 mT (2 MHz) using a Carr-Purcell-Meiboom-Gill echo technique

Abstract

We have investigated an approach for obtaining H-1 NMR spectra of different alcohols on a large-bore (27 cm diameter), B (0) = 0.05 T (f (0) = 2 MHz) portable MRI scanner. We used a Carr-Purcell-Meiboom-Gill (CPMG) sequence to acquire multiecho data from solutions of different alcohols, focusing on ethanol, a molecule of relevance to many applications in the food and beverage industry. Our results show that the Fourier transformed J-spectra at different echo spacings fit well with simulations of the evolution of the echo train signal with excellent signal to noise ratio (SNR) for concentrations of similar to 10 % within a few minutes. Spectra were also obtained from intact bottles of whiskey and wine. Finally, we show that different alcohols with similar chemical structures can be differentiated using this approach.