2,3,6-Trichloroanisole

MHz H NMR spectrum of 2 3 4 trichloroanisole show mg the splitting of the ring protons into a pair of dou bletsthat lean toward each other... 

NP NPEC OC OP OPEC PCB PCDBT PCDD PCDF PCP PFB RA TCA TCDD TCF TCMTB TOC VSC VOC Nonylphenol Nonylphenol ethoxycarboxylate Organo chlorine Octylphenol Octylphenol ethoxycarboxylate Polychloroinated biphenyls Polychlorinated dibenzothiophene Polychlorin ated dib enzo-p - dioxins Polychlorinated dibenzo-p-furans Pentachlorophenol Pentafluorobenzyl Resin acids 2,4,6-Trichloroanisole Tetrachloro dibenzo dioxin Totally chlorine- free 2-(Thiocyanomethylthio)-benzothiazole Total organic carbon Volatile sulphur compounds Volatile organic compounds... 

Other compounds, such as 2,4,6-trichloroanisole (TCA), 2-isopropyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine, were found downstream of a pulp mill effluent, and were considered as off-flavours. These compounds are by-products of chlorination, or can be produced by actinomycetes or other biota [74]. 

Soil 2,4,5-Trichlorophenol and 2,4,5-trichloroanisole were formed when 2,4,5-T was incubated in soil at 25 °C under aerobic conditions. The half-life under these conditions was 14 d (McCall et al, 1981). When 2,4,5-T (10 pg), in unsterilized tropical clay and silty clay soils, was incubated for 4 months, 5 to 35% degradation yields were observed (Rosenberg and Alexander, 1980). Hydrolyzes in soil to 2,4,5-trichlorophenol (Somasundaram et al., 1989,1991) and 2,4,5-trichloroanisole (Somasundaram et al, 1989). The rate of 2,4,5-T degradation in soil remained unchanged in a soil pretreated with its hydrolysis metabolite (2,4,5-trichlorophenol) (Somasundaram et al., 1989). 

Evans, T.J., C.E. Butzke, and S.E. Ebeler. 1999. Analysis of 2,4,6-trichloroanisole in wines using solid-phase microextraction coupled to gas chromatography mass spectrometry. J. Chromatogr. A 786 293-298. 

Geosmin, 2-isopropyl, 3-methyox pyrazine, 2-isobutyl-3-methoxy-pyrazine, 2-methyl isobomeol, 2,3, 6 trichloroanisole ... 

Dichloroanisole 2.3.6- Trichloroanisole 2.4.6- Trichloroanisole 2.3.4.6- Tetrachloroanisole Pentachloroanisole 2.4.6- Tribromoanisole Geosmin 2-Methylisoborneol l-Octene-3-ol Octa-1,3-diene a-Terpineol 4.4.6- Tri methyl-1,3-dioxane... 

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 flavor, or the olfactory defect caused by moulds, is the commonest of the undesirable flavors found in wine. In most cases, the cork is responsible for tainting wine with 2,4,6-trichloroanisol (TCA) (Tanner et al. 1981). However, barrelled wine may also be contaminated with 2,3,4,6-tetrachloroanisol (TeCA) that can be present in the damp atmosphere of wine cellars in the presence of woods treated by polychlorophenols. TCA has a slightly different aroma than TeCA but the two contaminants are often confused. Another possibility is that the cork itself may be contaminated by other corks (TCA) or by TeCA. 

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