Determination of 70 pesticide residues in tobacco leaves based on EMR-Lipid dispersive solid-phase extraction combined with gas chromatography-tandem mass spectrometry.

Abstract

The objective of this study was to establish an effective sample preparation protocol for the determination of pesticide residues in tobacco. Two distinct cleanup approaches were evaluated: the classical QuEChERS method and a protocol utilizing EMR-Lipid. All prepared samples were analyzed via gas chromatography-tandem mass spectrometry (GC-MS/MS), and the optimally selected approach was subjected to method validation. This is the first study to use EMR-Lipid as a dispersive solid-phase extraction (d-SPE) sorbent for pesticide detection in tobacco. Compared with the conventional PSA-based cleanup approach, the EMR-Lipid method substantially alleviated matrix interference, reducing the number of pesticides exhibiting high matrix effects from 30 to 11. It also improved recovery performance, with 94% of the target pesticides showing recoveries within 70-110% at the 0.5 mg kg-1 spiking level. Validation experiments for the EMR-Lipid method showed good linearity, with coefficients of determination (R2 > 0.99). The limits of quantification (LOQs) ranged from 2.0 to 10.0 µg kg-1. The RSDs for all selected pesticides ranged from 0.7% to 15.9%. This method was applied for the first time to determine pesticide residues in tobacco samples from Jiangxi Province, China. The methodology demonstrated acceptable accuracy and precision for multi-residue analysis.