Rapid Screening of 145 Pesticide Residues in Limnetic Products by Gas Chromatography-Quadrupole Time of Flight Mass Spectrometry and QuEChERS with Multi-walled Carbon Nanotubes

KeyWord:gas chromatography-quadrupole time of flight mass spectrometry£¨GC-QTOF/MS£©  multi-walled carbon nanotubes£¨MWCNTs£©  pesticide multi-residues  limnetic product

Abstract:

      A modified QuEChERS£¨quick£¬easy,cheap,effective,rugged,safe£© method based on multi-walled carbon nanotubes£¨MWCNTs£© was established for the simultaneous determination of 145 pesticide residues in limnetic products by gas chromatography- quadrupole time of flight mass spectrometry£¨GC-QTOF/MS£©.The samples were extracted with water and acetonitrile£¬purified by QuEChERS with MWCNTs£¬determined by GC-QTOF/MS.The quantification analysis was performed with the external standard calibration.The extraction conditions£¬type and amount of adsorbents£¬acquisition rate and extraction window of GC-QTOF/MS were optimized.Under the optimal conditions£¬the results indicated that the calibration curves were linear£¨r2>0.98£© in the range of 5-200¦Ìg/kg.The recoveries for 145 pesticides were in the range of 69.4%-114.2% at three spiked levels of 10£¬20£¬100¦Ìg/kg£¬with relative standard deviations£¨RSD£¬n=6£© of 2.2%-13.8%.The limits of quantitation were in the range of 1.1-40.0¦Ìg/kg. Compared to the original QuEChERS method£¬the proposed method was rapid and accurate,and could significantly reduce matrix interference.