Reversed-Phase Ion-Pair Chromatography of Anthocyanins in Red Wines

Abstract

A reversed-phase ion-pair chromatographic method has been developed for the separation of anthocyanins from red wines. Separation of anthocyanin monoglucosides can be achieved with a gradient mode elution using tetrabutylammonium hydrogen sulfate as a counter-ion, phosphoric acid, and methanol-acetonitrile-water in the mobile phase (pH = 2). This technique allows a relatively fast separation and identification of different anthocyanins in one run without prior treatment of the wine or derivatization of the compounds; it also avoids both the use of low pH (below 2) and, consequently, the degradation of the column. The order of elution of anthocyanin monoglucosides does not change in this mode of chromatography; they elute in the order of their polarity, as is typical in reversed-phase chromatography (delphinidin, cyanidin, petunidin, peonidin, and malvidin monoglucoside). Therefore, this characteristic profile is useful for the identification of anthocyanins of Vitis vinifera in red wines.