Identification of hydroxycinnamic acid–tartaric acid esters in wine by HPLC–tandem mass spectrometry

In this work hydroxycinnamic acid esters of tartaric acid (mono-p-coumaroyl tartaric acid, monocaffeoyl tartaric acid, monoferuloyl tartaric acid esters) were separated, identified and quantified in several red wines by high performance liquid chromatography coupled with tandem mass spectrometry. The method features direct analysis of wines with no preparation and analysis of grape juice with minimum sample manipulation. For the identification was used both a triple quadrupole and a quadrupole–Tof, while for the quantification a triple quadrupole.At the same time two impurities, due to interfering substances coming from methanol (stored in bottles with polypropylene tops without Teflon protection), were characterised. These impurities had the same molecular weight as the investigated compounds.