Comparison of matrix solid-phase dispersion and modified QuEChERS methods for extraction of pesticide residues from onion

Abstract

Matrix solid-phase dispersion (MSPD) and modified QuEChERS methods were compared for the extraction of pesticide residues from onion followed by determination by liquid chromatography with electrospray ionization tandem mass spectrometry. The efficiency of the methods was statistically compared using recovery and precision data, matrix effects and other extraction characteristics such as the sample mass, solvent volume, extraction time and limits of detection and quantification (LOQ). In general, faster extractions and lower LOQ values (0.0005 to 0.05 mg kg⁻¹) were achieved with QuEChERS, whereas greater ruggedness and lower matrix effects were obtained with MSPD. For both methods, high extraction yields were achieved (61.8–120%) with relative standard deviations lower than 20%. Matrix effects were observed for both methods, and were compensated by using matrix-matched calibration.