Simultaneous determination of four neonicotinoid insecticides residues in cereals, vegetables and fruits using ultra-performance liquid chromatography/tandem mass spectrometry

Abstract

A rapid multi-residue analytical method was developed for the determination of four nicotinoid insecticides (thiacloprid, thiamethoxam, clothianidin, and dinotefuran) in cereals, vegetables and fruits using QuEChERS method and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples were extracted by acetonitrile and subsequently cleaned up using primary secondary amine (PSA) and graphitized carbon black (GCB) prior to UPLC-MS/MS analysis. The determination of the target compounds was achieved in less than 2.5 min using an electrospray ionization source in positive ion mode (ESI⁺). The method showed good linearity in the concentration range of 0.01–1 mg L⁻¹ with correlation coefficients >0.999. Recovery studies were performed at three fortification levels of 0.01, 0.05, and 0.5 mg kg⁻¹ in blank rice, wheat, cucumber, tomato, cabbage, apple, and peach samples. The overall average recoveries ranged from 82.7% to 103.4% with intra-day relative standard deviations (RSD_r) which ranged between 1.3% and 7.9% and inter-day RSD (RSD_R) from 3.9% to 11.6%, respectively. The limits of detection (LOD) were below 0.68 μg kg⁻¹, while the limits of quantification (LOQ) were 0.71–2.26 μg kg⁻¹. The developed analytical method provides a basis for monitoring neonicotinoid insecticide residues in cereals, vegetables and fruits.