Multi-residue determination method of pesticides in leek by gel permeation chromatography and solid phase extraction followed by gas chromatography with mass spectrometric detector

The paper describes a multi-residue determination method for 102 pesticides in leek. The preparation of samples included extraction by acetone and dichloromethane and cleaned up by gel permeation chromatography and solid phase extraction (SPE) tube. The target analytes were determined by gas chromatography-mass spectrometric detector with selected ions mode (GC-MS/SIM). The method was validated by fortified at the level 0.02-0.20 mg/kg in leek. The average recoveries of all analytes were between 70% and 113%, and standard deviations were below 13%. The limit of quantitation (LOQ) for most analytes was below 0.01 mg/kg. The method was used for other vegetables like spinach, cereal, capsicum, cucumber, tomato, eggplants, etc. For those matrixes, the same concentrations were fortified and got accepted recoveries and LOQ. (c) 2006 Elsevier Ltd. All rights reserved.