Quantitative determination of the ethanol content of alcoholic beverages using proton NMR

CHED 288

Julie Wagner, Donald E. Mencer, mencer@wilkes.edu, Kenneth L. Green, chemistry@wilkes.edu, Lauren Macri, Brynn Beaver, Faith Wydra, and Adam Butler. Department of Chemistry, Wilkes University, 84 West South Street, Wilkes-Barre, PA 18766
1H FT-NMR (EM360A) was employed for the determination of the ethanol content present in several brands of gin, scotch, whiskey, vodka, rum, and tequila. The ethanol content of pharmaceutical ethanol (70% by volume) was also determined experimentally to validate the method. Compared to the value specified on the product label, the ethanol content of alcoholic beverages were generally in agreement with the label values. However, the alcohol content of all three brands of gin was found to be higher than expected. Of the three brands of vodka that were used, one was found to be significantly lower than the ethanol content than indicated on the label. The experimentally determined results were also validated using GC-MS.