Update: 29 September, 2023
This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) AOAC sample preparation approach for the extraction and cleanup of 13 pesticide residues representing various pesticide classes in spinach. The method involves initial extraction in a buffered aqueous/acetonitrile system, an extraction/partitioning step after the addition of salt, and a cleanup step using dispersive solid-phase extraction (dispersive SPE). A modified method with the addition of toluene was employed to address the significant loss of planar pesticides caused by graphitized carbon black (GCB) in dispersive SPE. The presence of the target pesticides in the spinach extracts were then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The method was validated in terms of recovery and reproducibility for all of the analytes of interest, with a 5 ng/g limit of quantitation (LOQ) for pesticides in spinach. The mean recoveries ranged between 64% and 108% (average of 91.9%), with RSD.
File format: PDF
Size: -
MD5 Checksum: 7CDC407DAA8AFDE33DED037B119A5C22
Publication date: 11 June, 2012
Downloads: -