Determination of ten pesticide residues in cucumber using QuEChERS-gas chromatography-tandem mass spectrometry

A multiresidue analytical method for the determination of 10 pesticide (flonicamid、fenpropimorph、fluopyram、sulfoxaflor、fenhexamid、fluopicolide、ametoctradin、flumorph、enestroburin and fenaminstrobin) residues in cucumber was developed using QuEChERS-gas chromatography-tandem mass spectrometry (GC-MS/MS).The target compound were extracted with acetonitrile by QuEChERS method. After salting out of anhydrous magnesium sulfate (MgSO₄) and sodium chloride (NaCl), 5 mL extraction solvent was cleaned up and purified by a mixed sorbent of 125 mg PSA, 900 mg MgSO₄ and 25 mg GCB. The samples was then separated on an Agilent HP-5 MS Ultra Inert column and wsa detected by GC-MS/MS system with the external standard method using matrix matched calibration curves. Results showed that linear relationships between peak area and mass concentration of 10 pesticides were achieved with a determination coefficient of 0.99. The recoveries ranged from 76% to 105% at four spiked levels in cucumber and the relative standard deviations (RSDs) ranged from 4.0% to 12%. The limits of quantification (LOQs) of the method were from 0.001 mg/kg to 0.05 mg/kg. This new method is suitable for the rapid and accurate determination of the 10 pesticide residues in cucumber.