Comparison of Different Extraction Methods Applied to Volatile Compounds in Wine Samples Previous to the Determination by Gas Chromatography

Abstract

This paper describes the optimization and comparison of discontinuous liquid–liquid extraction, continuous liquid–liquid extraction and solid‐phase extraction as methods for separating and concentrating volatile compounds from wine. The study has been applied to 11 compounds present in wine: 3‐methyl‐butyl acetate, 3‐methyl‐1‐butanol, ethyl hexanoate, 1‐hexanol, ethyl octanoate, diethyl succinate, 2‐phenyl‐ethyl acetate, hexanoic acid, 2‐phenyl‐ethanol, octanoic acid, and decanoic acid. These compounds were selected from those identified by gas chromatography‐mass spectrometry (GC‐MS) analysis of a natural wine sample. Factors such as the sample volume, the extraction time, and the solvent volume were considered. In all cases, the determination was performed by gas chromatography, using a flame ionization detector and the internal standard method (3‐octanol) as the quantification procedure. The optimization study was performed with synthetic wine samples containing all the volatile compounds under study. The solid‐phase extraction was subsequently applied to samples of red wines from La Rioja.

Keywords:

• Wine
• Volatile compounds
• Extraction
• Gas chromatography

Acknowledgments

This work was supported by the University of La Rioja, projects API‐99/A17 and API‐00/A28.