Determination of 2,4,6-Trichloroanisole in Wine

Analysis of TCA and 2,4,6-trichlorophenol (TCP) in wines can be performed by SPE sample preparation using a C18 cartridge followed by GC/MS. The cartridge (e.g. 500 mg) is conditioned by three consecutive passages of ethyl acetate, ethanol, and 10% ethanol aqueous solution. A volume of 50 mL of wine is passed through the cartridge, then the stationary phase is dried. TCA and TCP are recovered with 0.5 mL of dichloromethane. The first 200 jlL of eluate containing TCA and TCP is mixed with 200 jlL of acetonitrile in order to achieve a final sample 125-fold concentrated. Recoveries between 86-102% for TCA, and 82-103% for TCP, limits of detection (LOD) of O.lng/L and of quantification (LOQ) 2ng/L for TCA, and 0.7 and 4ng/L for TCP, are achieved (Soleas et al., 2002). 

A fast and sensitive method for determination of TCA in wine is to perform solid phase-microextraction (SPME) and GC/MS analysis. Extraction is performed on 10-mL sample headspace added of 2g NaCl in a 20-mL vial. A 100- xm polydimethylsiloxane (PDMS) 

1-cm length fiber, is used. After complete dissolution of the salt, the sample extraction is performed for 20 min at 30-35 °C. The fiber is then desorbed in the injector port of the GC/MS system at 250 °C for 3 min. 

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Riu, M., Mestres, M., Busto, O. and J. and Guasch, J. (2002) Determination of 2,4,6-trichloroanisole in wine by headspace solid-phase microextraction and gas chromatography-electron-capture detection,/. Chromatogr. A, 977(1), 1-8. 

Fontana, R, Patd, S., Banerjee, K., Altamirano, J. (2010). Ultrasound-Assisted Emulsification Microextraction for Determination of 2,4,6-Trichloroanisole in Wine Samples by Gas Chromatography Tandem Mass Spectrometry. /. Agric. Food Chem., Vol.58, N°8, pp. 4576-4578, ISSN 15205118. 

Alzaga, R., Ortiz, L., Sanchez-Baeza, E, Pilar, M., Bayona, XM. (2003) Accurate determination of 2,4,6-trichloroanisole in wines at low parts per trUhon by solid-phase microextraction followed by GC-FCD. Journal of Agricultural and Food Chemistry, 51,35Q9- 551A. 

Snow, M.S. The determination of 2,4,6-trichloroanisole in wine using headspace trap with GC/MS. http //las.perkinelmer.com/content/Application Notes/246trichloroanisoleinwi-... 

Jonsson, S. Hagberg, J. van Bavel, B. (2008). Determination of 2,4,6-Trichloroanisole and 2,4,6-Tribromoanisole in Wine Using Microextraction in Packed Syringe and Gas Chromatography-Mass Spectrometry. Journal of Agricultural and Food Chemistry 56, 4962-4967... 

However, is not the analysis of minor wine volatiles that still presents difficulties. With the level of sensitivity and automation of the analytical techniques, the determination of many odorants at /rg/L level is a simple analysis. The difficulties come when the analytes of interest cannot be easily determined using a single non-selective-preconcentration step. This will happen when the analytes are difficult to extract because they are very polar and/or not very volatile or when they are present at very low levels. The concentration level at which the analysis of an aroma compound becomes difficult is related to its polarity and to the quality of its mass spectrum. Eor instance, the analysis of 2,4,6-trichloroanisol (TCA) at, let s say, 20 ng/L is not a very difficult analysis, because this molecule is quite nonpolar (easily extractable, relative volatile) and has a mass spectrum with abundant high mass ions.In contrast, the analysis of methional or of sotolon at 1 /rg/L is quite difficult because these compounds are very polar (difficult to extract, not very volatile) and their mass spectra lack powerful ions. For these difficult analytes, some of which are very important wine impact aromas, specific strategies must be developed ... 

Cork taint is a musty/moldy off-odor in wine. It is related to the cork stopper, a wine botde closure made from the bark of the cork oak (Quercus suher). In a correlation between sensory evaluation and chemical analysis, 2,4,6-trichloroanisole (TCA) has b n 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. 

Mass spectrometry is also applied in the control of pesticides and other contaminants (e.g., 2,4,6-trichloroanisole), detection of compounds formed by yeast and bacteria, determination of illegal additions to the wine. Liquid chromatography/mass spectroscopy (LC/MS) methods for determination of toxins in the wine (e.g., ochratoxin A) have been proposed (Zollner et al., 2000 Flamini and Panighel, 2006 Flamini et al., 2007). 

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