Wine Analysis by NMR

Brief Overview of Wine Analysis by 1H and 13C NMR Wine analysis by 1H or 13C NMR can be used to follow acid content during maturation. Lactic, succininc and acetic acid can be followed readily by both techniques and presence of sugar, glycerol, and methanol can be observed. Chemometric approaches are starting bear fruit with respect to quantitative analysis:

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NMR Without Solvents – Biodiesel Production Process – FAME, Glycerol, FFA, and Methanol

1H and 13C NMR NMR is typically obtained using deuterated NMR solvents to lock the field during acquisition. In some cases the use of these solvents is problematic as it prevents observation of solublized phases present in the sample. As an example we show here the NMR data obtained on a biodiesel production process. One of the major issues with the FAME product is the presence of glycerol in the product. NMR analysis is usually performed by dissolving the FAME in CDCl3 in which glycerol is completely insoluble. Thus NMR analysis performed in this way does not allow analysis of residual glycerol content. However, if the FAME is run neat this issue does not arise. Another analysis of enormous interest from the process control standpoint is the analysis of the glycerol/methanol phase. This phase contains considerable free fatty acids as well as the glycerol by product and excess methanol from the transesterification process. The three components are readily observed by 1H and 13C NMR, and 23Na can be used to observe NaOH content in the phase. Finally the shift and shape of the observed OH resonance can yield information on the pH of the glycerol phase. Typically this analysis is…

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