Multiresidue Determination of Six Pesticide Adjuvants in Characteristic Minor Crops Using QuEChERS Method and Gas Chromatography-Mass Spectrometry

A new multiresidue analysis method using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure for the determination of 6 pesticide adjuvants (toluene, p-xylene, o-xylene, m-xylene, N, N-dimethylformamide (DMF) and dimethyl sulphoxide (DMSO) in characteristic minor crops was developed via gas chromatography-mass spectrometry (GC-MS). Matrices, including lily bulb, millet, and Chinese yam, were extracted with CH3CN/CH3CN-H2O and then cleaned up by primary secondary amine (PSA), followed by GC-MS analysis with selected ion monitoring (SIM) mode. Under the optimal conditions, the established QuEChERS-GC/MS method showed good linearity (r>0.998) for all targets with limits of detection of 0.001-0.005 mg kg(-1) for benzene compounds, 0.012-0.022 mg kg(-1) for DMF, and 0.012-0.024 mg kg(-1) for DMSO, respectively. The average recoveries in the three characteristic minor crop samples ranged from 72.9% to 94.9% with relative standard deviations from 2.4% to 9.9%. The method is demonstrated to be accurate, sensitive, and convenient and thus could be applied for routinely monitoring multiresidues of pesticide adjuvants in agro-products.