Optimization of Headspace Solid-Phase Microextraction Coupled with Gas Chromatography鈥揗ass Spectrometry for Detecting Methoxyphenolic Compounds in Pu-erh Tea
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- 作者：Liping Du ; Chao Wang ; Jianxun Li ; Dongguang Xiao ; Changwen Li ; Yongquan Xu
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2013
- 出版时间：January 23, 2013
- 年：2013
- 卷：61
- 期：3
- 页码：561-568
- 全文大小：373K
- 年卷期：v.61,no.3(January 23, 2013)
- ISSN：1520-5118
文摘
A method based on headspace solid-phase microextraction coupled with gas chromatography鈥搈ass spectrometry was developed for the analysis of volatile methoxyphenolic compounds in pu-erh tea. Six fibers with different polarities were initially evaluated. The 75 渭m carboxen/polydimethylsiloxane fiber exhibited the highest extraction efficiency and was selected for further optimization. A Plackett鈥揃urman design was used to screen for the brewing proportion of tea and water, amount of pu-erh tea, ionic strength, extraction time, extraction temperature, desorption time, rate of agitation, and equilibrium time. A Box鈥揃ehnken design was then applied to optimize the significant factors. Under optimal conditions, the proposed method affords a wide range of linearity, high linear regression coefficients (0.996鈥?.999), less than 9.0% repeatability of relative standard deviation, and limits of detection ranging from 2.31 to 21.80 ng/g. The proposed method has satisfactory accuracy, with recoveries of 79.08鈥?13.9%. This method was successfully applied for the analysis of pu-erh tea samples.