气相色谱-四极杆/飞行时间质谱法同时测定茶叶中10种香料化合物

Simultaneous determination of 10 kinds of fragrance compounds in tea by gas chromatography-high resolution quadrupole time-of-flight mass spectrometry

中文关键词:  气相色谱-四极杆/飞行时间质谱法  茶叶  香料

英文关键词:gas chromatography-high resolution quadrupole time-of-flight mass spectrometry  tea  flavorings

中文摘要:

      目的 考察3种前处理方法的提取效果, 建立结合气相色谱-四极杆/飞行时间质谱法(gas chromatography-high resolution quadrupole time-of-flight mass spectrometry, GC-Q-TOF/MS)同时测定茶叶中10种香料[1,8-桉叶素、(+)-异薄荷酮、胡椒酚甲醚、茴香烯、甲基丁香酚、反式肉桂醛、香豆素、樟脑、反式-甲基异丁香酚、顺式-甲基异丁香油酚]的分析方法。方法 样品经乙酸乙酯提取, 加入无水硫酸镁和氯化钠, 涡旋离心后取上清液过滤膜。采用GC-Q-TOF/MS仪, 目标化合物以全扫描模式测定, 以基质匹配标准曲线法进行定量。优化色谱及质谱条件后, 从操作步骤、加标回收率等方面考察3种前处理方法对目标化合物的提取效果。结果 直接提取法最为适用于同时提取茶叶中10种香料化合物。茴香烯在10.0~1000.0 μg/L范围内, 1,8-桉叶素和反式肉桂醛在30.0~2000.0 μg/L范围内, 其余7种香料化合物在15.0~1000.0 μg/L范围内呈良好线性关系, 相关系数r均大于0.9991, 平均回收率为85.3%~108.7%, 检出限为0.03~0.10 mg/kg, 定量限为0.10~0.30 mg/kg, 日内、日间精密度(n=6)分别小于11%和13%。结论 该方法准确、灵敏、回收率高, 适用于茶叶中10种香料的批量检测。

英文摘要:

      Objective To investigate the extraction effects of 3 kinds of pretreatment methods, and establish a method for the simultaneous determination of 10 kinds of fragrance compounds [1,8-cineole, (+)-isomenthone, 4-allylanisole, trans-anethole, methyl eugenol, trans-cinnamaldehyde, coumarin, camphor, trans-methyl isoeugenol, cis-methyl isoeugenol] in tea by gas chromatography-high resolution quadrupole time-of-flight mass spectrometry (GC-Q-TOF/MS). Methods The samples were extracted with ethyl acetate, following which anhydrous magnesium sulfate and sodium chloride were added to the extracting solution, after vortex and centrifugation, the supernatant was filtered over a membrane. The target compounds were determined in full scan mode by using GC-Q-TOF/MS, quantified by matrix-matched standard curve method. After the chromatographic and mass spectrometric conditions were optimized, the extraction effects of 3 kinds of pretreatment methods on the target flavorings were investigated from the aspects of operation steps and spiked recovery rates. Results Direct extraction method was most suitable for the simultaneous determination of 10 kinds of fragrance compounds in tea. In the range of 10.0?1000.0 μg/L, 30.0?2000.0 μg/L and 15.0?1000.0 μg/L, trans-anethole, 1,8-cineole and trans-cinnamaldehyde, as well as other 7 target flavorings had good relationships, respectively, the correlation coefficients were more than 0.9991, and the average recoveries were 85.3% to 108.7%. Further, the limits of detection were 0.03?0.10 mg/kg, the limits of quantification were 0.10?0.30 mg/kg, and the intra-day and inter-day relative standard deviations (n=6) were less than 11% and 13%, respectively. Conclusion This method is accurate, sensitive with high recovery rate, it is suitable for the batch detection of 10 kinds of fragrance compounds in tea.