Use of solid-supported liquid-liquid extraction in the analysis of polyphenols in wine.

Solid-supported liquid-liquid extraction (SS-LLE) was compared to liquid-liquid extraction (LLE) for the analysis of phenolic compounds in wine. Diatomaceous earth commercial cartridges were evaluated together with "in-house" made cartridges for the wine phenolic extraction. Statistical treatment, analysis of variance ANOVA-single factor, was used to compare the extraction yields obtained by these methods, and for the majority of the studied compounds, significantly higher yields were obtained by the SS-LLE methodology using the "in-house" prepared cartridges. This is an environmentally friendly low-cost sample preparation method which proved to be reproducible (RSD<5% for the most compounds) and yielding high recoveries (80-100%) for the compounds studied.