Optimization of the multiresidue method for the determination of pesticide residues in root vegetables

摘要

The aim of this study was to develop the multiresidue method for the determination of 426 pesticide residues in root vegetables (beetroot, carrot, parsnip, parsley, radish and celery) based on QuEChERS method extraction. Optimization of the method included selection of the parameters such as a sample weight, extracting solvent and sorbent in a clean-up step. The optimum parameter was the application of 10 g sample weight/10 ml 1% formic acid in acetonitrile/clean-up 150 mg MgS04 + 25 mg primary secondary amine + 2.5 mg graphitized carbon black. Active substances were determined by gas chromatography and liquid chromatography coupled with tandem quadrupole mass spectrometry (GC-MS/MS and LC-MS/MS). The average recoveries for most compounds were in the range 72.3-119.4% and the relative standard deviations were 0.3-16.2%. The developed method allowing the determination of very low concentration levels (0.005 mg/kg) has been adapted for routine tests defining the pesticide residues in root vegetables.The obtained results were highly satisfactory and demonstrated their compliance with the criteria recommended by the European Union document SANTE/11945/2015.