顶空固相微萃取联合气相色谱-质谱检测葡萄酒中2,4,6-三氯苯甲醚

利用响应面法优化采用顶空固相微萃取联合气相色谱-质谱技术检测葡萄酒中2,4,6-三氯苯甲醚（2,4,6-trichloroanisole,TCA）。对萃取头进行了选择,并优化固相微萃取参数：样品体积、萃取温度、平衡时间和萃取时间等对TCA萃取效果的影响。结果表明,用聚二甲基硅氧烷/二乙烯基苯（65 μm）萃取头进行TCA萃取的最佳条件：样品9.8 mL、2 g NaCl、33 ℃平衡10 min、萃取90 min进行气相色谱-质谱分析,以TCA-d5为内标物进行定量。该方法的相关系数R2为0.999 9,重复性的相对标准偏差为1.03%,加标回收率范围在95.7%～106.1%之间,检出限和定量限分别为0.3 ng/L和1 ng/L。检测7 种市售葡萄酒产品的TCA含量在0～7.6 ng/L之间,干白葡萄酒中TCA含量低于干红葡萄酒。该方法操作简单、可靠,适用于葡萄酒中TCA的测定。     

固相微萃取-气相色谱法测定葡萄酒及软木塞中2，4，6-三氯苯甲醚（TCA）

采用固相微萃取-气相色谱法测定葡萄酒及软木塞中的TCA含量,样品试液经固相微萃取装置萃取、富集后,直接无分流进样,经毛细管柱DB-5分离后,用ECD检测器检测。结果表明,该方法检出限为0.1 ng/L,回收率在90%～106%之间,相对标准偏差(n=5)小于5%。     

超声波辅助-顶空固相微萃取-气相色谱法测定软木塞中痕量2,4,6-三氯苯甲醚

通过对软木塞样品提取过程的优化,建立了超声波法辅助顶空固相微萃取-气相色谱仪检测软木塞中痕量2,4,6-三氯苯甲醚(TCA)的方法。试验结果表明,该方法的线性范围0.5 ng/L~80.0 ng/L,R2为0.999 8,线性关系良好。方法检出限为0.2 ng/g,方法定量限为0.5 ng/g,精密度(RSD)在1.35%~5.47%之间,加标回收率为81.5%~97.8%。该方法操作简便、快速、易操作、准确度高、重现性好,适用于普通实验室对软木塞中痕量2,4,6-三氯苯甲醚残留的检测。     

顶空固相微萃取与气相色谱-电子捕获技术联用检测软木塞中2,4,6-三氯苯甲醚

建立利用顶空固相微萃取与气相色谱电子捕获技术联用分析检测葡萄酒软木塞中2,4,6-三氯苯甲醚含量的方法。该方法测定软木塞中2,4,6-三氯苯甲醚的相关系数（R²）为0.999 9,精密度好（相对标准偏差不大于5.6%）,回收率为101%～108%,检出限为0.20 pg/L、定量限为0.66 pg/L。利用该方法测定了11 种不同类型的软木塞中2,4,6-三氯苯甲醚的含量,证实了所建方法适用于葡萄酒软木塞中痕量2,4,6-三氯苯甲醚含量的测定。     

葡萄酒中2,4,6-三氯苯甲醚(TCA)检测新技术的研究进展

2,4,6-三氯苯甲醚(TCA)是危害葡萄酒感官品质的一种物质,通常来自于葡萄酒封装所用的软木塞,也可能来自葡萄原料或酿酒过程中的污染,它的存在使葡萄酒产生不良气味和口感。简介了最近十几年来检测葡萄酒中TCA的新方法和新仪器,包括葡萄酒中TCA的萃取技术和检测技术。并对这些新技术的特点、原理及应用优势进行了阐述。目的是为对葡萄酒中的TCA做到精确、低检出限和高灵敏性的定性及定量测定提供参考,从而对葡萄酒中的TCA进行准确的监测,最终提高葡萄酒的品质。     

顶空-固相微萃取/气相色谱串联质谱法测定葡萄酒中多种氯酚及氯代茴香醚

样品中氯酚经乙酰化生成乙酰氯酚后,通过优化萃取头、离子强度、温度、时间等固相微萃取条件后,建立顶空-固相微萃取-气相色谱串联质谱法同时测定测定葡萄酒中的3种氯酚2,4,6-三氯酚(TCP)、2,3,4,6-四氯酚(TeCP)、五氯酚(PCP)以及两种氯代茴香醚2,4,6-三氯苯甲醚(TCA)、五氯苯甲醚(PCA)含量的方法。结果表明：该方法检出限为0.1ng/L,回收率为86.0%～105.9%,相对标准偏差小于16.5%。该方法前处理简单、高效、检测灵敏度高,可应用于进出口葡萄酒中木塞污染物的监控。     

不同软木塞中2,4,6-三氯苯甲醚迁移量的检测和评价分析

本文在建立了稳定的2,4,6-三氯苯甲醚(TCA)检测方法基础上,对不同类别的软木塞进行了TCA迁移量的检测,并对检测结果进行分析评价。结果表明,DIAM塞为TCA"零污染",天然塞和微颗粒塞次之,风险程度较低;1+1塞有较高的检出率,但TCA迁移量均在2 ng/L以下的可控范围内;而聚合塞不仅检出率高、合格率低,而且TCA检出值范围较宽,最大值达5.76 ng/L,对葡萄酒的污染风险程度最高。该研究为酿酒师木塞的选用提供数据支撑和指导作用。     

葡萄酒及软木塞中TCA的检测分析方法研究现状及应用前景

<正>随着生活水平的提升,人们对食品质量安全要求逐渐提升,在葡萄酒领域,葡萄酒及软木塞污染的问题越来越受到关注,其中TCA是主要污染物质。对葡萄酒及软木塞中TCA检测技术和方法的研究起始于二十世纪七十年代,近年来TCA检测领域有了较大进展,各种检测分析方法层出不穷,在我国葡萄酒行业不断发展的背景下,有必要总结和对比TCA检测分析方法,并展望其未来发展趋势,以此来为相关葡萄酒及软木塞中TCA检测分析实践提供参考,从而促进我国葡萄酒行     

气相色谱电子捕获技术分析检测葡萄酒及软木塞中TCA的研究进展

软木塞污染影响葡萄酒感官质量已成为葡萄酒行业最为关注的问题之一,主要原因在于软木塞中存在2,4,6-三氯苯甲醚(TCA).介绍了利用气相色谱电子捕获技术(GC-ECD)检测葡萄酒及软木塞中TCA的研究进展,同时对GC-ECD的工作原理及应用进行了阐述,为有效分析检测和控制葡萄酒及软木塞中的TCA含量提供参考.     

葡萄酒和软木塞中2,4,6-三氯苯甲醚检测方法的研究进展

本文介绍了葡萄酒和软木塞中2,4,6-三氯苯甲醚（2,4,6-trichloroanisole,TCA）的来源及影响,分析了2,4,6-三氯苯甲醚的检测难点,总结了目前检测2,4,6-三氯苯甲醚方法的总体趋势及现状。按照前处理方法的原理分类,介绍了前处理方法的定义、特点,并概述和讨论了前处理方法在萃取葡萄酒和软木塞中2,4,6-三氯苯甲醚中的应用;根据仪器检测方法的不同特点,总结和讨论了仪器检测方法在分析检测葡萄酒和软木塞中2,4,6-三氯苯甲醚的应用。前处理方法和仪器检测方法相结合,达到了浓缩和检测葡萄酒和软木塞中2,4,6-三氯苯甲醚的目的。     

Estimating a “consumer rejection threshold” for cork taint in white wine

Cork taint in wine produced by 2,4,6-trichloroanisole (TCA) is characterised by generally unacceptable musty or earthy odours. Estimates of TCA threshold in wine have been reported in the low parts per trillion (ppt) range, although it is not clear at what levels TCA begins to render a wine unacceptable. We conducted two studies to address this question by using a method that combined a paired preference test with a method of constant stimuli threshold procedure. The aim was to determine the point at which wine consumers would begin to reject a wine containing TCA, which we termed the consumer rejection threshold (CRT). Regular white wine consumers (Ss) received pairs of samples of white wine––one spiked with TCA in eight ascending concentrations––and were asked to indicate which of the samples was preferred. Detection thresholds (DT) for TCA in wine were also determined using triangle tests. The CRT and DT were 3.1 and 2.1 ppt, respectively. CRT and DT were significantly positively correlated with one another, and negatively correlated with TCA knowledge. A replication provided a similar CRT value, and suggested that a percentage of consumers are either highly insensitive to TCA or do not find it objectionable. These results suggest that the use of this method may provide a rational basis on which to assess the real impact of TCA in white wine.     

Absorption of chloroanisoles from wine by corks and by other materials

Sixty 750 mL bottles of a white wine were each spiked with deuterium-labelled 2,4,6-trichloroanisole (d₅ TCA) and then sealed with a variety of wine corks. Thirty months later, approximately half of the d_5-TCA had been absorbed by each of the corks, regardless of supplier, bleaching treatment or whether the corks were natural or agglomerate. In addition to the added labelled TCA, every one of these corks also contained endogenous (i.e. unlabelled) TCA. Fifteen of the corks, mostly agglomerates, imparted some of their endogenous TCA into the wines. There was no direct relationship between the amount of endogenous TCA in the corks and that found in wines. The high variability in the distribution of endogenous TCA between wine and cork contrasts with the relatively uniform distribution of the d₅-_-TCA. This contrasting behaviour distinguishes between wines tainted prior to closure and wine tainted by corks. Natural bark corks in wine bottles can also absorb 2,3,4,6-tetrachloroanisole (TeCA) and pentachloro-anisole (PCA) from bottled wine. Bottle storage of commercial wines that had become tainted with TeCA and PCA during production resulted in the corks absorbing most of these two compounds, so that the wines were no longer tainted to a significant extent. Soaking whole corks in wine spiked with chloroanisoles, under conditions typically employed in the wine industry to test batches of corks for possible taint, resulted in most of the TCA in the wine being absorbed by the corks. Thus, if five corks are being soaked in wine in order to test for taint, four sound corks could reabsorb TCA that had leached into the surrounding wine from a single contaminated cork, reducing the concentration of TCA to a point where it escapes detection. Soaking corks singly rather than in groups of five will therefore be a more sensitive method of screening batches of corks for taint than soaking them in groups of five. Plastic materials such as the lids of glass containers used to store wine samples were also able to absorb chloroanisoles via both direct liquid contact and the vapour phase. Wine cask bladders and polyethylene film were particularly effective in removing TCA from wine.     

Effect of wine style on the perception of 2,4,6-trichloroanisole,a compound related to cork taint in wine

2,4,6-Trichloroanisole (TCA) is a fungal metabolite that can contaminate cork stoppers and wines producing a very unpleasant mouldy odour (cork taint). Sensory control is very widely used for the detection of possible TCA presence in corks and wine, but the correct identification of TCA, especially at low concentrations, can be difficult. The aim of this study was to show how wine styles can affect the ability of the same panel to perceive TCA. For this purpose, a panel was selected, according to the panelists’ sensitivity to the TCA stimulus. The triangle test, a sensory difference test, was carried out by the panel with both white and red wines, using samples both free from TCA and spiked with known quantities of this contaminant. The results showed that the panelists identified the difference caused by the added TCA at different significance levels, depending on the wine style, so TCA detection was influenced by wine style for the selected panel.     

The analysis of 2,4,6-trichloroanisole and other chloroanisoles in tainted wines and corks

A new method has been developed for the analysis, by gas chromatography/mass spectrometry, of 2,4,6-trichloroanisole (TCA) and other chloroanisoles in cork-tainted wines, using a polydeuterated form of TCA as an internal standard. In a survey of wines presented at a wine assessment course, 4.8% (i.e. 18 bottles out of 374) were assessed by at least 20% of the participants as being affected by cork taint. TCA was present in each of these 18 wines at a concentration close to, or above the sensory detection threshold. All cases of taint seen by the participants could therefore be attributed, at least in part, to the presence of TCA, and this in turn could be attributed to the cork, since variation in apparent taint between bottles of the same wine was observed in every case. TCA was also found in the corks from the wines. Randomly selected bottles of wines considered to be affected by a high proportion of cork taint, and the corks from those bottles, were also analysed. There was considerable variation in the distribution of TCA and other chloroanisoles between wine and cork. In many cases, chloroanisoles were found only in the cork. TCA in corks was accompanied by varying amounts of 2,4– or 2,6-dichloroanisoles, 2,3,4,6-tetrachloroanisole and pentachloroanisole, indicating more than one origin for chloroanisoles in corks. No chloroanisoles, other than those derived by methylation of products formed by non-enzymatic chlorination of phenol, were detected in any of the samples.     

Quantitative determination of wine polysaccharides by gas chromatography-mass spectrometry (GC-MS) and size exclusion chromatography (SEC)

Wine polysaccharides play an important role on a number of technological and quality properties of wines and thus several methods have been proposed for their quantification. The present study evaluates the suitability of gas chromatography with mass spectrometry detector (GC-MS) for determining the content of wine monosaccharides and thus polysaccharide families. Factors affecting the yield of polysaccharide precipitation were firstly evaluated and the GC-MS method was characterised and compared with the previously reported GC-FID method. Repeatability and reproducibility values were similar in both methods, with values ranging from 1% to 14%. LODs obtained by MS were below 1.0 μg for all monosaccharides and LOQs were below 1.8 μg. Moreover, a recovery study of the whole method was carried out and it provided absolute recoveries between 81% and 116% for different wine samples, very good values taking into account the multi-step procedure. Both GC-MS and GC-FID were applied to determine the content of wine polysaccharide families in three wine samples and no significant differences were observed. Finally, high-resolution size exclusion chromatography with refractive index detector (HRSEC-RID) was applied to obtain the molecular weight distributions of the wine polysaccharides and to estimate their global content. The correlation observed between the polysaccharide values obtained with the GC method and the HRSEC-RID method (r = 0.746, p < 0.05) indicated that the latter could serve as a rapid and simple method to give an estimation of total wine polysaccharides although it can not be used to quantify in a precise way.