Optimization of headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry for detecting methoxyphenolic compounds in pu-erh tea

J Agric Food Chem. 2013 Jan 23;61(3):561-8. doi: 10.1021/jf304470k. Epub 2013 Jan 9.

Abstract

A method based on headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry was developed for the analysis of volatile methoxyphenolic compounds in pu-erh tea. Six fibers with different polarities were initially evaluated. The 75 μm carboxen/polydimethylsiloxane fiber exhibited the highest extraction efficiency and was selected for further optimization. A Plackett-Burman 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-Behnken 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 (0.996-0.999), 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 79.08-113.9%. This method was successfully applied for the analysis of pu-erh tea samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dimethylpolysiloxanes / chemistry
  • Gas Chromatography-Mass Spectrometry / methods*
  • Phenyl Ethers / chemistry*
  • Reproducibility of Results
  • Solid Phase Microextraction / methods*
  • Tea / chemistry*
  • Temperature
  • Water / chemistry

Substances

  • Dimethylpolysiloxanes
  • Phenyl Ethers
  • Tea
  • Water
  • baysilon