Dynamic MRM/Scan Mode: Adding More Confidence to Sensitive Quantitation in Complex Foods by Triple Quadrupole GC/MS (GC/TQ)

Abstract This application note describes the use of the novel simultaneous dynamic multiple reaction monitoring (dMRM) and scan (dMRM/scan) data acquisition mode for triple quadrupole gas chromatography mass spectrometry (GC/TQ) analysis of pesticides in challenging food matrices. The simultaneous dMRM/scan capability enables identification of the unknown compounds and retrospective analysis, while maintaining sensitivity and dynamic range of the method comparable to a conventional dMRM analysis. Additionally, scan data enables more confidence in compound identification by library spectrum matching. Finally, the full scan data allow the analyst to evaluate the sample matrix to ensure the most efficient performance of the GC/TQ system. This work demonstrates the application of dMRM/scan to the analysis of extracts, using Agilent QuEChERS sample preparation, of spinach, walnut, and cayenne pepper spiked with over 200 pesticides. The calibration results and method sensitivity for 203 evaluated compounds were comparable to results observed with conventional dMRM data acquisition mode with the Agilent 8890/7000E GC/TQ and the Agilent 8890/7010C GC/TQ. The unknown identification workflow based on the spectral library matching using a retention time locked library was carried out with Agilent MassHunter Unknowns Analysis. Many of the compounds with the established maximum residue limits (MRLs) were identified with full scan data at concentrations below their MRLs even in the challenging cayenne pepper extract