Optimization and validation of a multi-residue LC-MS/MS method for pesticides in spinach and cabbage by using Thermo Scientific Vanquish UHPLC and TSQ Quantis mass spectrometer. Sample preparation was performed using QuEChERS method that provided high recoveries for an extensive scope of pesticides in several simple steps. Data acquisition and processing were carried out using Thermo Scientific TraceFinder software. The optimized method was validated as per the SANTE guideline and applied to real samples demonstrating that the workflow is fit for purpose.
Multi-residue instrumental method that can be applied for high-throughput quantitation of pesticide residues in garlic and cumin at or below the current legislative requirements. The Thermo Scientific Orbitrap Exploris 120 mass spectrometer was operated in two different workflows: using full-scan Data-Independent Acquisition for quantitation and confirmation and using Thermo Scientific AcquireX intelligent data acquisition background exclusion workflow for full spectrum filtering, retrospective analysis, and multi-parameter-based compound identification.
We present a multi-residue instrumental method that can be applied for high-throughput screening and semi-quantitation of pesticide residues in food matrices at or below the current legislative requirements. A high-resolution, accurate-mass mass spectrometer operated in Full Scan – Variable Data-Independent Analysis (FS-vDIA)* mode provided an option for full spectrum filtering, retrospective analysis, and multi-parameter-based compound identification. The method was validated for 328 target pesticides, with an option for the future extension to a larger number. (*vDIA not available in US.)
Many pesticide analyses are based on the QuEChERS extraction method, which uses acetonitrile (ACN) in the final extraction step. This approach can cause peak shape problems (splitting or broadening) especially for the early eluting analytes. The common practice of exchanging the final extraction solvent step for one similar to the mobile phase is laborious and can lead to analyte losses. We demonstrate the ability to override the solvent effects from a sample extract using gradient solvents with HPLC. Additionally, to increase injection volume without overloading the column.
European Regulation 396/2005 sets maximum residue levels of pesticides in different products of plant and animal origin. These regulations present a significant analytical challenge with respect to LOQs required for some specified food matrices such as baby food. The multi-residue pesticide method described can be applied to fruits, cereals and composite baby foods at LODs in the range of 0.8–10.3 µg/kg - below respective EU maximum residue limits (MRLs). The method is validated for 48 pesticides from different classes, but can be readily extended to a larger number of residues.
