关键词: QuEChERS, 气相色谱-质谱联用法, 灵芝, 农药

Abstract: In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample pretreatment method coupled with gas chromatography-mass spectrometry (GC-MS) was established to determine 17 pesticide residues in Ganoderma tsugae. A total of 1.0 g of dry G. tsugae powder was mixed with 10 mL of water, and then extracted by homogenization with aceonitrile. The extract was cleaned up with n-propyl ethylenediamine (PSA) and MgSO4 to remove the interferences from co-extractives. The separation was accomplished on an HP-5 capillary column and programmed heating was carried out. The target compounds were detected by electron impact ionization in the single ion monitoring (SIM) mode. Under the optimum conditions, the method showed a good linear relationship for all these pesticides in certain concentration ranges, with correlation coefficients greater than 0.98. Moreover, the limits of detection (LODs) (RSN = 3) were 0.002–0.022 mg/kg, the limits of quantitation (LOQs) (RSN =10) were 0.007–0.072 mg/kg. The average recoveries of this method were in the range of 71.10%–119.55% with relative standard deviations (RSDs) between 0.47% and 20.05%. In comparison with previous methods, the new procedure has the characteristics of simple sample preparation and higher sensitivity.

Key words: QuEChERS, gas chromatography-mass spectrometry, Ganoderma tsugae, pesticides