Facile gas chromatography-tandem mass spectrometry stable isotope dilution method for the quantification of sesquiterpenes in grape.

Sesquiterpenes are a widespread class of compounds of increasing interest found in grapes and wines, amongst many other natural sources. Due to a lack of standards and the complexity of the mass spectra fragmentation, accurate quantification of these low concentration compounds had not previously been accomplished. The current paper presents a new method for the concurrent quantification of several sesquiterpenes.

Ethyl propiolate derivatisation for the analysis of varietal thiols in wine.

Varietal thiols [3-mercaptohexan-1-ol (3MH), 3-mercaptohexyl acetate (3MHA) and 4-mercapto-4-methylpentan-2-one (4MMP)] have been extensively studied in the recent literature. Nonetheless the hardest obstacle for research focussing on this class of compounds is the lack of quick, user-friendly and sensitive analytical methods. The current paper presents the use of ethyl propriolate (ETP) as a novel derivatising agent to quantify varietal thiols and the first time quantification of the thiol-ETP adducts via gas chromatography-mass spectrometry.