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International Journal of Spectroscopy
Volume 2011, Article ID 171684, 5 pages
http://dx.doi.org/10.1155/2011/171684
Research Article

Rapid Determination of Total Thujone in Absinthe Using 1H NMR Spectroscopy

1Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, 76187 Karlsruhe, Germany
2Department of Chemistry, Saratov State University, Astrakhanskaya Street 83, Saratov 410012, Russia

Received 31 May 2011; Revised 11 July 2011; Accepted 19 July 2011

Academic Editor: Karol Jackowski

Copyright © 2011 Yulia B. Monakhova et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

1H NMR spectroscopy is utilized to quantify total thujone (sum of - and -isomers) in absinthe. For sample preparation, a simple dilution with buffer is required. Thujone produces a distinct peak of the CH2 group 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 ( ). 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 ( - and -thujone isomers) analysis if required.