Determination of fipronil and its metabolites in eggs using dispersive- solid phase extraction and gas chromatography-tandem mass spectrometry

Abstract

To develop a method for determination of fipronil and its metabolites in eggs by gas chromatography-tandem mass spectrometry(GC-MS/MS)cleaned with dispersive-solid phase extraction(D-SPE). Orthogonal array design with OA16(4~4) matrices was used to optimize the efficiency of D-SPE. The targets were extracted from samples with acetonitrile, and followed by D-SPE cleanup. The extracts were analyzed by GC-MS/MS, and quantified by internal standard method with matrix correction. The calibration curves showed good linearity in the range of 1.0-250.0 μg/L. The correlation coefficients were larger than 0.99.The average recoveries spiked in eggs at the levels of 2 μg/kg, 4 μg/kg and 20 μg/kg were between 87.1% and 125.0%(n=6), and the relative standard deviations were less than 10%. The limits of determination were between 0.1 and 0.4 μg/kg, and the limits of quantitation were between 0.3 and 1.2 μg/kg. The method possesses low background, high sensitivity. It can be applied to determine the residues of fipronil and its metabolites in eggs.