Chemical shift change in 1 H NMR spectroscopy was used to determine water content in bioethanol. As water content in ethanol is increased, the proton peaks shifted to down-field due to the change in the microstructure of the water-ethanol mixture. The linear correlation between water content and chemical shift change enables the evaluation of water content in bioethanol. Because the same relationship between chemical shift change and the water content is obtained for both ethanol and bioethanol, water content in bioethanol can be determined using the calibration curve obtained with anhydrous ethanol. The developed method was validated by comparison to the results of Karl Fischer titration and was applied to commercially available bioethanols.

Fumonisin B 1 (FB 1 ) a mycotoxin that contaminates grains and is related with liver and renal diseases. Although FB 1 levels in food are currently regulated, FB 1 's quantitation is complicated because of its lack of volatility and UV absorbance, preventing mass balance method from being employed for purity assessment of high-purity standard. This study used quantitative nuclear magnetic resonance (qNMR) spectroscopy to assess the purity of FB 1 . Unlike mass balance method, qNMR is a universal and simple quantification method. Using benzoic acid as an internal standard, the purity of FB 1 was determined. The measurement parameters were optimized to obtain accurate results, and 1 H NMR peak homogeneity was confirmed by analyzing impurities separated using liquid chromatography. The purity of the FB 1 was 993 mg/g and expanded uncertainty (k = 2.74) was 32 mg/g (3.2%). This result will be used to the development of the certified reference material for the FB 1 analysis in maize flour.