Simultaneous Determination of 46 Pesticide Residues in Lycium barbarum by QuEChERS Method Combined with Gas Chromatography-Triple Quadrupole Mass Spectrometry

A method for simultaneous determination of 46 pesticide residues in Lycium barbarum by QuEChERS method combined with gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS)was established. The samples were extracted with acetonitrile,then purified by anhydrous magnesium sulfate and N-propyl ethylenediamine(PSA). The target pesticides were separated by HP-5MS column,tested by GC-MS/MS with multiple reaction monitoring mode(MRM),and quantified by external standard method considering matrix effects. The correlation coefficients were higher than 0.99,which indicated that the linear dependence of the 46 pesticide residues were good in the range of 0.01~0.20 μg/mL. The limits of detection(S/N=3)were in the range of 0.02~3.90 μg/kg,and the limits of quantitation(S/N=10)were in the range of 0.05~12.99 μg/kg. The average recoveries were 71.5%~99.8% with the relative standard deviations of 0.7%~8.9% at the spiked levels of 10,50 and 100 μg/kg. Pesticide residues were detected in 4 of the 10 batches of Lycium barbarum samples,the content ranged from 19.4 to 262 μg/kg. The method is rapid,sensitive and accurate,which is suitable for the detection of multi-pesticide residues in Lycium barbarum.