Rapid Determination of Total Thujone in Absinthe Using1H NMR Spectroscopy

摘要

1H NMR spectroscopy is utilized to quantify total thujone (sum ofα- andβ-isomers) in absinthe. For sample preparation, a simple dilution with buffer is required. Thujone produces a distinct peak of the CH2group in the cyclopentanone moiety in the 2.13–2.11 ppm range. No overlap with other typical constituents such as anethole or fenchone occurs. The detection limit of 0.3 mg/L is adequate to control the EU maximum limit. The relative standard deviation was 6%, and linearity was observed from 1 to 100 mg/L. Applicability was proven by analysis of 69 authentic absinthes. The correlation between NMR and our previous method consisting of liquid-liquid extraction followed by GC/MS was significant (P<0.0001,R=0.93). The simple and cheap NMR method can be used for rapid screening of absinthes for total thujone content while chromatographic techniques are recommended for more specific (α- andβ-thujone isomers) analysis if required.