Abstract:A food analytical method that combines QuEChERS pretreatment assay with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the detection of eight phenylpyrazole residues in food; ethiprole, flufiprole, pyraflufen-ethyl, fipronil-desulfinyl, fipronil, fipronil-sulfone, fipronil-sulfide, and fipronil-detrifluoromethyl sulfoxide. Different food matrices were directly measured by salting-out and QuEChERS purification using 1% acetonitrile acetate and water as extraction solvents. Gradient elution was conducted using methanol and water as the mobile phase and scanning in the multiple reaction monitoring (MRM) mode was performed simultaneously in the positive and negative ion ESI modes. Matrix-matched standard solutions were used for quantitative analysis. The peak shape of phenylpyrazoles was sharp and symmetrical, showing good separation effects, good linearity within the 1~800 μg/L range, and correlation coefficients greater than 0.99. The detection limit of this method for eggs, poultry meat, milk, dates, Chinese cabbage, tea, and rice matrices ranged between 0.01~0.53 μg/kg, with the quantitation limit at 0.04~1.75 μg/kg, the standard recovery rates at 70.12~119.87%, and the relative standard deviation (RSD) from 1.01~9.91% (n=6). The developed QuEChERS-UHPLC-MS/MS method can be considered effective, accurate, and versatile, and it can be successfully applied for the simultaneous detection and analysis of different phenylpyrazole residues in food.
