Quantitative analysis of β-d-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid, a potential precursor to cis-oak lactone, in oak extracts using liquid chromatography–tandem mass spectrometry based stable isotope dilution analysis

The β-D-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid (glucoside), exists in oak wood and is a potential precursor to cis-oak lactone. A method for the quantification of the glucoside in extracts of oak wood using liquid chromatography–tandem mass spectrometry was developed. The [2H4]-labeled analogue of the glucoside was synthesized and used as internal standard for the method which was subsequently applied to the analysis of extracts of both American and French oak woods. The concentration of the glucoside in the extracts varied widely from less than 0.1 up to approximately 50 μg/g-oak wood. The method allowed for the quantification of the glucoside as a potential oak lactone precursor in oak woods for the first time.