A novel carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) dispersive solid phase extraction (d-SPE) method combined with gas chromatography (GC) with an electron capture detector (ECD) was developed for the determination of seven pyrethroid pesticides in cucumber, spinach, eggplant, tomato and carrot. We optimised d-SPE conditions including the type and volume of the extractant, the type and amount of the sorbent, and shaking time. Under the optimal conditions, the linear range was from 2.0 to 2000 μg kg-1. The recoveries were from 88.5% to 108.2%, with the corresponding RSDs <6%, correlation coefficients 0.9987-0.9998, LOD 0.5-2.9 μg kg-1 and LOQ 1.5-9.7 μg kg-1. The proposed method is simple, fast, and safe, with high recovery and sensitivity, and is applicable to analysis of pyrethroid pesticides in vegetable samples.
Keywords: GC; MWCNTs-COOH; d-SPE; pyrethroid pesticides; vegetables.