Modified QuEChERS strategy based on dynamic in-situ assembly of aminated single-walled carbon nanotubes and magnetic Fe3O4 nanoparticles for pesticide residue analysis in Rhizoma Polygonati

Accurate quantification of pesticide residues is critical to ensure the quality and safety of Rhizoma Polygonati , a well-recognized medicine-food homologous herb widely applied in functional food development. Strong matrix interference in gas chromatography-tandem mass spectrometry (GC-MS) detection and notable quantitative bias are frequently induced by the abundant pigments, polysaccharides, saponins and endogenous components in the herbal matrix. Conventional PSA and C 18 adsorbents in standard QuEChERS protocols exhibit restricted purification capacity for this complex matrix, while most documented magnetic carbon-based adsorbents demand tedious pre-synthesis procedures that may block the active adsorption sites of nanomaterials. A modified QuEChERS-GC-MS method coupled with dynamic in-situ assembly strategy was established for 12 pesticide residues in Rhizoma Polygonati . Without pre-synthesis of any composites, in-situ functional synergy between NH 2 -SWCNTs and magnetic Fe 3 O 4 nanoparticles was achieved during the dispersive solid-phase extraction (d-SPE) step. Superior purification performance to conventional adsorbents was obtained by this system, with the matrix effect range of target pesticides narrowed from -31.4%−64.3% to -25.3%−36.7%. Favorable linearity ( R  ≥ 0.9990), acceptable spiked recoveries (86.2%–106.5%) and stable precision (RSD ≤ 15.20%) were validated through systematic method validation, providing a feasible and robust analytical protocol for pesticide residue monitoring in Rhizoma Polygonati and other complex herbal matrices. Graphical abstract