Automation in food safety: Pressurized liquid extraction for pesticide analysis in coffee

This study presents the development and validation of an automated pressurized liquid extraction (PLE) method using the EXTREVA ASE system for the determination of 233 pesticide residues in coffee, a matrix considered challenging due to its complex composition. The method was evaluated at three fortification levels (10, 20, and 50 μg/kg), with nine replicates per level distributed over three days to assess inter-day reproducibility. At 20 and 50 μg/kg, all compounds met the established performance criteria of 70-120 % recovery and relative standard deviations (RSDs) below 20 %. At the 10 μg/kg level, only 12 compounds (5.2 %) were outside these criteria, primarily due to known issues such as co-elution with matrix components or the acidic nature of certain analytes. All analytes exhibited excellent linearity (R² ≥ 0.99) across a five-point procedural calibration from 0.005 to 0.1 mg/L (0.005, 0.01, 0.02, 0.05, 0.1 mg/L), confirming the method's suitability for quantitative analysis. Matrix effect evaluation showed that 44 % of analytes experienced low or negligible effects, 42 % moderate effects, and only 14 % were strongly affected. Real sample analysis confirmed the method's applicability for routine monitoring, while participation in the EUPT-FV-SC07 proficiency test for coffee demonstrated high analytical performance, with z-scores ranging from -0.7 to 0.3 and RSDs below 20 % for all compounds. Overall, this work provides a validated, reproducible and automation-ready solution for multiresidue pesticide control in complex matrices such as coffee, meeting regulatory standards and suited for high-throughput laboratories.