Determination of 214 pesticide residues in green vegetables using QuEChERS-ultra high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry

Abstract

Objective A method for the determination of 214 pesticide residues in green vegetables by QuEChERS using ultra high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry was established. Methods After extracted by acetonitrile, the green vegetables were cleaned-up by a mixed sorbent with primary secondary amine (PSA), C18, Na2SO4 and graphitized carbon black (GCB). The target compounds were separated by Waters ACQUITY UPLC BEH C18 column (2.1 mm×100 mm, 1.7 μm) using 5 mmol/L ammonium formate solution (0.1% formic acid) and acetonitrile as mobile phase by gradient elution, and analyzed in positive electrospray ionization mode by time of flight mass spectrometry scan-information dependent acquisition (IDA) -product ion scan. Results All the 214 pesticides showed good linear relationships in the range of 4-1 000 ng/L, and the correlation coefficients (r2) were higher than 0.99. The recoveries at three different spiked levels for all target compounds in blank matrices were 41.9%-128.5%, and the relative standard deviations (RSD) were 0.4%-14.3% (n=6). The limits of detection and quantitation of the method were 0.004-5.443 and 0.206-18.125 μg/kg, respectively. Eight pesticide residues were detected in the real samples. Conclusion The method was suitable for rapid screening and analysis of pesticide residues in green vegetables with the advantages of accuracy, rapidity, simplicity, high sensitivity and high throughput