Validation of Multi-Residue GC-MS/MS and LC-MS/MS Methods for the Analysis of Pesticide Residues in Botanicals

Botanical food supplements are increasingly consumed worldwide. As finished products, they may be contaminated with pesticide residues, which can potentially become concentrated relative to the raw botanical materials during processing steps. In this study, analytical methods were developed for the quantification of 252 pesticide residues in botanical food supplements using LC-MS/MS and GC-MS/MS, with both techniques employing a common sample preparation procedure. Sample extraction and clean-up were performed using a QuEChERS-based approach combined with dispersive solid-phase clean-up step using graphitized carbon black (GCB) and primary–secondary amine (PSA) sorbents followed by Oasis® WAX cartridge purification. Method validation was performed in accordance with the EU guidance document SANTE/11312/2021. The validated methods were subsequently applied to ten plant extract samples to assess their applicability to different botanical food supplement matrices. Multiple pesticide residues were detected in three samples, with concentrations ranging from 0.01 to 0.19 mg/kg. The application of the methods to real samples confirmed suitability for the analysis of diverse botanical matrices and underscored the need for robust analytical approaches to support the routine monitoring of pesticide residues in botanical food supplements and ensure consumer safety.