Determination of Fipronil and Its Metabolites Residues in Vegetative Foods by High Performance Liquid Chromatography-tandem Mass Spectrometry

A methods was developed for the simultaneous determination of fipronil and its metabolites residues in various vegetative foods (such as spinach, apple, banana, rice, soybean and tea) by HPLC-MS/MS. The sample was extracted with acetronitrile by QuEChERS extraction tube (CEN EN-15662), cleaned-up with an dSPE or GCB/PSA solid phase extraction cartridge prior to separate on a Thermo Accucore aQ (2.6 μm, 2.1×150 mm), detected by HPLC-MS/MS with multiple reaction monitoring mode. The analyte was quantified by matrix-matched external standard method for fipronil and its metabolites. The results showed that good linearity was obtained when the concentration of the method was within 0.1~5 μg/L. The correlation coefficients (R²) were greater than 0.999. The average recoveries ranged from 91.5%~101.5% with the relative standard deviations of 0.47%~3.88% at the spiked levels of 1, 2, 4 μg/kg for fipronil and its metabolites. The limites of quantitation (LOQ) were 0.1 μg/kg. The methods were simple, sensitive and reliable, and had been applied successfully for the residue determination of fipronil in the real samples.