Rapid screening of 42 pesticides in rice and rice stems by QuEChERS-UPLC-MS/MS

A method for the analysis of 42 pesticide residues in rice and rice stems was developed using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with QuEChERS pretreatment technology. The sample was extracted with acetonitrile vortex extraction, purified by QuEChERS purification tube and separated by C₁₈ ultra-high performance liquid chromatography column. 42 analytes were measured under multiple reaction monitoring (MRM) using the electrospray positive ionization mode (ESI⁺). Quantification determination was performed by peak area external standard methods using matrix-matched calibration, which were linear in the range of 0.01-0.2 mg/L with good linear relationships. The determination coefficients (R²) were all above 0.99. The limits of detection (LOD) were lower than 0.002 mg/kg. The average recoveries of 42 pesticides in rice and rice stems all ranged from 70%-117%, and the relative standard deviations were in the range of 1.5%-15% in rice, and 0.9%-15% in rice stems, at the spiked levels of 0.01, 0.02, 0.05, 0.1 and 0.2 mg/kg. This method is simple, rapid, sensitivite, accuracy, which can be used in the simple and rapid screening of pesticide multi-residues in rice and rice stems.