Determination of 13 Volatile Aldehyde Compounds in Wine by GC-QQQ-MS: p-Benzoquinone to Dissociate Hydrogen Sulfite Addition Products

Abstract

This study validates a new methodology which allows the direct quantification of 13 volatile aldehyde compounds related to oxidative off-flavours in wine. The compounds investigated were four (E)-2-alkenals ((E)-2-heptenal, (E)-2-hexenal, (E)-2-octenal and (E)-2-nonenal), four Strecker aldehydes (2-methylpropanal, 3-methylbutanal, methional and 2-phenylacetaldehyde) and five general aldehydes (hexanal, furfural, 5-methylfurfural, benzaldehyde and nonanal). This methodology involved the addition of p-benzoquinone to release the aldehydes bound to hydrogen sulfite, collection via solid phase extraction, derivatisation by o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride and quantification by gas chromatography triple-quadrupole mass spectrometer in multiple reaction monitoring mode. Overall, the limit of detection, limit of quantification, accuracy (recovery, 98–103%) and precision (repeatability and reproducibility, RSD ≤ 15%) are sufficient to enable routine measurement of the 13 aldehyde compounds in wine. Sixteen commercial white and red wines of varied varieties and vintages were analysed with this methodology. White wines trended to have higher concentrations of the aldehyde compounds in comparison with the red wines.