Carbon nanotubes stabilized in chitosan sponge (CNT-CS) as a new alternative clean-up sorbent for pesticide multiresidue determination in eggplants using QuEChERS and UHPLC-MS/MS

The continuous development and application of pesticides in agriculture require robust multiresidue detection methods to guarantee food safety. This study introduces a novel method for multiresidue determination of pesticides in eggplants using the QuEChERS procedure, incorporating a clean-up step using carbon nanotubes stabilized in chitosan sponge (CNT-CS) and ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) for analysis. Upon identifying the optimal extraction conditions, various sorbents were assessed for their efficacy in the dispersive solid-phase extraction (d-SPE). Among these, the biosorbent CNT-CS emerged as the most efficient and cost-effective material, showing the best recovery results from spiked blank samples. The validation demonstrated that the method was adequate for analyzing 111 pesticides in eggplant samples with practical method quantification limits from 5 to 25 µg kg^-1. When applied to commercial eggplant samples, 27 pesticides were detected, demonstrating the importance of the proposed method. It is noteworthy that the conducted work represents the first report on the use of the biosorbent CNT-CS in the clean-up step of the QuEChERS method. The results obtained in the validation and application steps demonstrate that the proposed method is an excellent alternative for monitoring programs.