Establishment Of Detection Methods And Research Of The Migration Regularity For TCA In Wine Corks

The quality of wine depends largely on its unique flavor,the wine industry suffers severe losses because of the contamination of 2,4,6-trichloroanisole,TCA,which affect the tast of wine.However,most of TCA in wine is caused by the TCA of the wine cork migration into wine.So,establishing a rapid and effective method for detecting levels and analysing the migration law of TCA in corks,can be an effective evaluation for contamination of TCA,which can effectively control the wine in every link in the process of prodution and storage,so as to ahieve the aim of controlling pollution levels.TCA was the object of study.Firstly,a method for determination of levels of TCA in wine corks has been established by using headspace solid-phase microextraction?HS-SPME?and gas chromatography with electron-capture detection?GC-ECD?and extraction conditions were optimized.In addition,the treatment of cork samples was improved.Then,levels of TCA in production process of synthetic and natural stoppers were detected.Finally,during six months of soaking for three kinds of corks,timing sampling was carried out to detect content of TCA,analysis the leaching rule and judge the time for TCA maximum value,providing reference for the choice of the type of wine and bottle storage time,when this kind of wine corks was used to package.The results are as follows:In this paper,a method for determination of levels of 2,4,6-trichloroanisole?TCA?in wine corks has been presented by using HS-SPME and GC-ECD.There is a good correlation coefficient?R2=0.9999?,high recovery?101%to 108%?,good precision?RSD?5.6%?for the method.The limit of detection and limit of quantification were 0.20pg/L,0.66 pg/L,respectively.The optimum conditions were obtained as follows:polydimethylsiloxane-divinylbenzene?PDMS/DVB?as the extraction fiber,volume of extraction liquid 10 mL,equilibrium time 20 min,extraction time 35 min,sodium chloride concentration 30%,extraction temperature 30?and magnetic stirring 40 r/s.Compared the gas chromatographic electron capture technology?GC-ECD?and gas chromatography mass spectrometry?GC-MS?by the optimal extraction method,both of methods could satisfy the requirements of analysis.The sensitivity of the GC-ECD was higher,nonetheless,the quantification of GC-MS was more accurate.The study improved the treatment of cork samples and leaching amount of TCA in corks have been on an upward trend within 24 hours.When the radio of corks to oaking liquid was confirmed,TCA extraction amount almost unchanged and will not be affected by the weight of the cork.The optimum simulated wine sample component were obtained as follows:ethanol?12%?,SO₂?100 mg/L?,glucose?24 g/L?,pH?adjusted to 3.5 by tartaric acid?.Finally,to verify the methods of processing method of cork samples,TCA was detected with three kinds of wine corks.The results shows that the method can be applied to the detection the TCA for a variety of corks.In this paper,we tested the levels of TCA in the process of its production through the sythetic and natural corks.By examining each stage levels of TCA in corks,for natural corks,the fumigation process leads to TCA increase;For two kinds of corks,levels of TCA show opposite result after rinsing process.In this work,the results showed three kinds of corks TCA migration patterns:the migration quantity of TCA increase from synthetic plug to simulate liquor,as the extension of soaking time,and the peak is at 15 days.Subsequently it tends to reduce and minimize at 30 days.Then as the soaking time extends,TCA levels in soaking liquid continue to rise,until 18 days at maximum.Natural plug TCA levels in soaking liquid presented a first rise in almost 180 days after the change trend of decline.When the soaking time is 90 days,soaking liquid TCA levels is in maximum,and then begin to decline.in 180 days,TCA levels in soaking liquid is almost zero;In 180 days,the change of TCA levels in filling plug soaking liquid is to present a downward trend after rising first,when the soaking time for 30 days,TCA content is the highest,after 90 days,TCA levels almost keep stable.To sum up,this study establishes a rapid and effective method of detection TCA in cork,determines the cork TCA contamination during the production of the main ways,summes up the half a year the migration law of TCA in cork,norms and constraints of wine cork processing production and use,to form local or national standards theoretical and data basis.