Application of head-space solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the determination of multiple pesticide residues in tea samples

Anal Chim Acta. 2008 Mar 24;611(2):163-72. doi: 10.1016/j.aca.2008.01.007. Epub 2008 Jan 15.

Abstract

A new method has been developed to detect 36 pesticides that may contaminate tea samples (green, black and fruit tea). The hyphenation of solid-phase microextraction in head-space mode with a comprehensive two-dimensional gas chromatography coupled with high-speed time-of-flight mass spectrometry (HS-SPME-GCxGC/TOF MS) proved to be a quick alternative to conventional GC/MS methodology which employs solvent-based extraction. The key parameters for controlling HS-SPME performance were optimized, including fiber coating type, temperature and absorption time settings and tea matrix modification by adding water. Quantification was carried out using matrix-matched calibration. The repeatability of measurements, expressed as relative standard deviation (R.S.D.), was less than 24% for all analytes. The limits of quantification ranged from 1 to 28 microgkg(-1). The optimized method was applied to analyze real life samples obtained from a retail market. Results generated by the new SPME procedure and those obtained by using a conventional one involving ethyl acetate extraction and high-performance gel permeation chromatography (HPGPC) clean up agreed with each other for positive (containing residue) samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gas Chromatography-Mass Spectrometry / methods*
  • Pesticide Residues / analysis*
  • Tea / chemistry*

Substances

  • Pesticide Residues
  • Tea