Abstract: A method by using a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS) was established to analyze 88 pesticide residues in cranberry plant extract. The sample was extracted with acetone-hexane (1:1, v/v) containing 1% acetic acid, then cleaned-up by ethylenediamine-N-propyl silyl (PSA) and graphite carbon (GCB). The extract was determined by GC-MS/MS in multi-reaction monitoring (MRM) mode, and external standard method was applied to quantified the pesticides. All the 88 pesticides showed good linearity in the range of 0.001~0.2 mg/L, and the limits of quantification (LOQs, S/N≥10) were all less than 31.5 μg/kg. The average recoveries of all the pesticides were in the range of 71.4% to 116.6% at three spiked levels of 5, 25 and 50 μg/kg in cranberry plant extract, with the relative standard deviations (RSDs) of 2.4%~16.9%. The results demonstrated that this method is simple, rapid and suitable for the determination of 88 pesticide residues in cranberry plant extract. The analytical sensitivity and accuracy can meet the requirements of multiple pesticide residue analysis.

Key words: cranberry plant extract, pesticide residues, QuEChERS, gas chromatography-triple quadrupole tandem mass spectrometry (GC-MS/MS)