One-step purification using MWCNTs@chitosan composite adsorbents for effective matrix interference removal in determination of 49 Pesticides in aquatic products.

Multi-walled carbon nanotubes (MWCNTs) are known for their excellent purification properties in QuEChERS-based pesticide analysis, but their potential release and non-recyclability pose environmental and economic challenges. In this study, a novel strategy is proposed to immobilize MWCNTs with chitosan, forming the MWCNTs@chitosan composite, which enables the recyclability of MWCNTs. This composite was employed in a one-step pressure filtration purification method to simultaneously purify extracts of 49 pesticides from aquatic products. Coupled with HPLC-MS/MS, an optimized QuEChERS method was successfully validated for the determination of 49 pesticides. The MWCNTs@chitosan composite demonstrated excellent clean-up capability, effectively removing interfering substances from crude extracts while maintaining recoveries of 71.2-119.4 % and relative standard deviations (RSDs) below 20.0 %. These results demonstrate the composite's suitability as a QuEChERS cleanup material, with potential applications in other complex matrices.