Determination of thujone by derivatization with dansylhydrazine and liquid chromatography

The reaction of alpha- and beta-thujones with dansylhydrazine (DNSH) was studied using reversed phase liquid chromatography (LC) with fluorescence detection. The derivatization procedure, although slow, was applied for determination of alpha-thujone in white vermouth at concentrations 0.45-4.5 mug/L using a C-18 solid phase extraction column for cleanup; recoveries of added a-thujone were in the range 60-77%. Separation of dansyl alpha- and beta-thujones was achieved by LC and their identity confirmed by LC-tandem mass spectrometry (MS/MS).