Improved method for the extraction and chromatographic analysis on a fused-core column of ellagitannins found in oak-aged wine

- 10 wine ellagitannins, gallic and ellagic acids are simultaneously analyzed.
- Quantitative extraction of ellagitannins from low volume sample in a single step.
- Improved HPLC separation using fused-core C18 columns.
- Wine ellagitannins quantification can be performed by only DAD detectors.

A new method for the analysis of ellagitannins observed in oak-aged wine is proposed, exhibiting interesting advantages with regard to previously reported analytical methods. The necessary extraction of ellagitannins from wine was simplified to a single step of solid phase extraction (SPE) using size exclusion chromatography with Sephadex LH-20 without the need for any previous SPE of phenolic compounds using reversed-phase materials. The quantitative recovery of wine ellagitannins requires a combined elution with methanol and ethyl acetate, especially for increasing the recovery of the less polar acutissimins. The chromatographic method was performed using a fused-core C18 column, thereby avoiding the coelution of main ellagitannins, such as vescalagin and roburin E. However, the very polar ellagitannins, namely, the roburins A, B and C, still partially coeluted, and their quantification was assisted by the MS detector. This methodology also enabled the analysis of free gallic and ellagic acids in the same chromatographic run.