Graphene as dispersive solidphase extraction materials for pesticides LC-MS/MS multi-residue analysis in leek, onion and garlic

Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2014;31(2):250-61. doi: 10.1080/19440049.2013.865278. Epub 2014 Jan 22.

Abstract

A multi-residue analytical method was validated for 24 representative pesticides residues in onion, garlic and leek. The method is based on modified QuEChERS sample preparation with a mixture of graphene, primary secondary amine (PSA), and graphitised carbon black (GCB) as reversed-dispersive solid-phase extraction (r-DSPE) material and LC-MS/MS. Graphene was first used as an r-DSPE clean-up sorbent in onion, garlic and leek. The results first show that the mixed sorbent of graphene, PSA and GCB has a remarkable ability to clean-up interfering substances in the r-DSPE procedure when compared with the mixture of PSA and GCB. Use of matrix-matched standards provided acceptable results for tested pesticides with overall average recoveries between 70.1% and 109.7% and consistent RSDs <15.6%. In any case, this method still meets the 1-10 μg kg(-1) detection limit needed for pesticide testing and may be used for qualitative screening applications in which any identified pesticides can be quantified and confirmed by a more intensive method that achieves >70% recovery.

MeSH terms

  • Allium / chemistry*
  • Chromatography, Liquid / methods*
  • Graphite / chemistry*
  • Pesticide Residues / chemistry
  • Pesticides / chemistry*
  • Solid Phase Extraction / methods*
  • Tandem Mass Spectrometry / methods*

Substances

  • Pesticide Residues
  • Pesticides
  • Graphite