[Determination of pesticide residues in wolfberry using QuEChERS-gas chromatography-tandem mass spectrometry].

A method based on QuEChERS-gas chromatography-tandem mass spectrometry (GC-MS/MS) was established for the determination of 20 pesticide residues in wolfberry. The samples were extracted with acetonitrile. The extract was purified with PSA (primary secondary amine), GCB (graphite carbon black) and C18 to suppress the matrix in wolfberry. The analytical results showed that the calibration curves for the 20 pesticides obtained by GC-MS/MS were linear in the range of 5-500 μg/L, with the correlation coefficients higher than 0.99. The recoveries ranged from 70.02% to 110.78% with relative standard deviations (RSDs) ranging from 2.05% to 9.53%. This method has the advantages of being time-saving, convenient and sensitive. The proposed method can simultaneously detect organic phosphorus and organic chlorine pesticides residues with a good performance in terms of qualitative and quantitative detection.