Rapid MALDI-TOF-MS Detection of Anthocyanins in Wine and Grape Using Different Matrices

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) as a new valuable technique has been used for qualitative screening of anthocyanins in wine and grape samples from Vranec and Merlot variety. For that purpose, different MALDI matrices have been tested, such as alpha-cyano-4-hydroxycinnamic acid, sinapic acid, 2,5-dihydroxybenzoic acid (2,5-DHB), and C-70 fullerene. It was observed that 2,5-DHB was superior with respect to all the matrices used in the study. Furthermore, fullerene was, for the first time, tested and used as a possible matrix for MALDI-TOF-MS identification of anthocyanins in wine and grape samples. The results obtained showed identification of aglycone forms of anthocyanins only, since the higher laser energy applied for ionization of the fullerene molecules led to great deal of fragmentation of the sugar moiety from glucosides, acetylglucoside, and p-coumaroylglucoside groups from the corresponding anthocyanin molecules. Additionally, liquid chromatography/electrospray ionization mass spectrometry has also been applied for anthocyanin characterization.