Detection of Cork Taint in Wine Using Automated Solid-Phase MicroExtraction in Combination with GC/MS-SIM

Cork taint is a musty/moldy off-odor in wine. It is related to the cork stopper, a wine bottle closure made from the bark of the cork oak (Quercus suber). In a correlation between sensory evaluation and chemical analysis, 2,4,6-trichloroanisole (TCA) has been identified as a major impact component. In sensitivity tests of a group of trained wine judges, a geometric mean of the minimum detectable concentrations of TCA has been determined at 4.6 ng/L. Solid Phase MicroExtraction (SPME) is a solvent-free sample preparation method based on the adsorption of analytes directiy from an aqueous sample onto a coated fused-silica fiber. Headspace SPME was used in combination with gas chromatography-mass spectrometry/ selective ion monitoring (GC/MS-SIM) to analyze for TCA in wine. Wines were spiked with TCA, and its deuterated stable isotope, 2H5-TCA, was used as an internal standard. The extraction fiber of the SPME, coated with polymethylsiloxane, was exposed for 25 minutes in the headspace of the sample vial, and then injected into the injection port of the GC-MS by a Varian 8200 CX autosampler. Limit of quantification of this method was 5 ng/L. The method was linear from 5 to 250 ng/L with an overall coefficient of variation for replicate analyses of less than 13%.