Gas chromatographic determination of pesticide residues in malt, spent grains, wort, and beer with electron capture detection and mass spectrometry

J AOAC Int. 2007 Mar-Apr;90(2):544-9.

Abstract

A method for the simultaneous determination of 9 pesticides (dinitroanilines, organophosphorus, triazoles, and pyrimidines) in several products (malt, spent grains, wort, and beer) of the beer industry is reported. Solid samples (malt and spent grains) are extracted by homogenization with a water-hexane mixture, and the pesticides are partitioned with dichloromethane. Liquid samples (wort and beer) are extracted by sonication with a hexane-dichloromethane mixture. Determination of pesticide residues was made by capillary gas chromatography with an electron capture detector (ECD). Confirmation of the compounds was performed by gas chromatography/ion trap mass spectrometry in the selected ion monitoring mode. Detection limits for GC-ECD varied from 0.2 to 5.5 pg for trifluralin and malathion, respectively. Recoveries of the pesticides from spiked samples ranged from 81.2 to 113.7% with a relative standard deviation between 3.4-7.5%. The method presents good linearity over the studied range (0.005-2 microg/mL). The proposed method is rapid and reliable and can be useful for routine monitoring during brewing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Beer
  • Chromatography, Gas / methods*
  • Edible Grain / chemistry
  • Electrons
  • Hexanes / chemistry
  • Malathion / chemistry
  • Mass Spectrometry / methods*
  • Methylene Chloride / chemistry
  • Models, Chemical
  • Pesticide Residues / analysis*
  • Pesticide Residues / chemistry
  • Pesticides / chemistry*
  • Reproducibility of Results
  • Solvents
  • Trifluralin / chemistry

Substances

  • Hexanes
  • Pesticide Residues
  • Pesticides
  • Solvents
  • Methylene Chloride
  • Trifluralin
  • Malathion