固相微萃取在烏龍茶湯揮發性成份分析之應用

Application of Solid Phase Microextraction (SPME) Analysis for Headspace Volatile Compounds of Oolong Tea Infusion

本研究以青心烏龍所製成之烏龍茶茶湯為材料，進行固相微萃取分析法（solid phase microextraction，SPME）之效能試驗，以期判定此法於茶湯上部空間揮發性成分分析上之可行性。茶湯以polydimethylsiloxane／divinylbenzene微萃取纖維萃取茶湯上部空間之香氣成份，萃取溫度為30、40、50、與60℃，萃取時間為5、7.5、10、12.5、與15分鐘，以氣相層析質譜儀（GC／MS）分析，結果顯示50℃下10分鐘之萃取條件最適合烏龍茶湯上部空間揮發性成份之分析。共19種化合物被確認為烏龍茶湯上部空間之揮發性成份，以linalool、indole、hexanal與decanal等主要成份，分析在0.5ppm濃度下，4重覆試驗中其各成份之CV值約在10%左右，另於不同之濃度範圍分析所得之回收率分別為110.39%、105.49%、100.30%與74.50%。 The headspace solid phase micro-extraction (SPME) for volatile compounds in oolong tea infusion were studied. The solid phase microextraction (SPME) technique using a 100 mm polydimethylsiloxane / divinylbenzene coated fiber was examined for target chemicals. The combination of gas chromatograph with mass selective detector and with the headspace SPME method makes it possible to determine the volatile compounds in oolong tea infusion. The optimum conditions were 50℃ and 10 min for extraction. 0.5ppm of each major volatile compound, linalool, indole, hexanel and decanal added in 5ml oolong tea infusion sample would be determined by SPME methods for four replicates. The reproducibility of this technique was around 10% CV. Different recoveries for the the major volatile compounds determined by the method are 110.39% for linalool,105.49% for indole,100.30% for hexanal, and 74.50% for decanal at different ranges.