Simultaneous Determination of 68 Pesticide Residues in Chrysanthemum Morifolium by GC-MS/MS

OBJECTIVE To establish a multi-residue analytical method for the determination of 68 pesticides in Chrysanthemum morifolium by GC-triple quadrupole mass spectrometry (GC-MS/MS). METHODS Samples were treated with QuEChERS pretreatment method. They were extracted with acetonitrile after soaking in 1% acetic acid for 30 min, and then purified by dispersed solid-phase extraction and purification tubes containing 900 mg of anhydrous magnesium sulfate, 300 mg of PSA, 300 mg of octadecyl-bonded silica, 300 mg of silica gel and 90 mg of graphitized carbon black. The GC-MS/MS dynamic multiple reaction monitoring (dMRM) mode was used for the qualitative and quantitative analysis. RESULTS The linear relationship of each pesticide residue was good (r>0.993) in their respective concentration range. The recoveries of most pesticides were between 70.0% and 120.0% at 3 spiked levels of 20, 100, 200 μg·kg^-1, with the relative standard deviations (RSD) from 0.4% to 13.9%, except hexachlorobenzene, methyl-pentachlorophenyl sulfide, dichlofluanid, DDE-p,p' and cyhalothrin. The limits of detection (LOD) were 0.2-25.6 μg·kg^-1, and the limits of quantification (LOQ) were 0.8-85.5 μg·kg^-1. CONCLUSION The method is simple, rapid, efficient and sensitive, which can be used for the simultaneous anlysis and screening of pesticide multiresidues in Chrysanthemum morifolium.