High throughput analysis of multiclass pesticide residues in human blood using low-volume QuEChERS-Fe 3 O 4 magnetic nanoparticle d-SPE coupled with GC-MS/MS

Accurate quantification of multi-class pesticide residues in human blood is vital for reliable exposure assessment and policy development. However, developing the cost-effective, robust and high-throughput method for pesticide residues analysis in biological matrices remains challenging. Hence, this study focuses on to develop and optimise a low-volume QuEChERS-d-SPE method incorporating Fe3O4 MNPs magnetic nanoparticles (MNPs) to analysed the 200 multiclass pesticide residues in human blood. The optimisation was performed using central composite design (CCD), where increased sample weight and sorbent minimisation significantly enhance analyte recovery, while effectively mitigating the matrix interference. Quantitative analysis and validation studies were carried out using gas chromatography tandem mass spectrometry (GC-MS/MS) in multiple reaction monitoring (MRM) mode. The method demonstrated excellent linearity (r2 > 0.99), with back-calculated concentrations were ≤±20% across the linear range. Ion ratios were within the acceptable threshold of ±30% for all analytes. Recoveries at 2.5 ng/mL ranged within 60–120%, and a LOQ of 2.5 ng/mL was achieved for all the target analytes. The optimised protocol provided rapid, robust, cost-effective, and sustainable extraction of multi-pesticide residues with effective matrix cleanup, signifying the excellent suitability for trace-level pesticide quantification in human biomonitoring studies.