Analytical method for determination of fipronil and its metabolites in vegetables using the QuEChERS method and gas chromatography/mass spectrometry.

An easy, simple, and efficient analytical method was validated for the determination of residues of fipronil and its metabolites in different vegetables comprising brinjal, cabbage, capsicum, cauliflower, okra, and tomato. The Quick, Easy, Cheap, Rugged and Safe method was used for the extraction and cleanup of fipronil and its metabolites on these vegetables. Final clear extracts of ethyl acetate were concentrated under vacuum and reconstituted into acetone, and residues were determined by GC/MS with an Rtx-5 capillary column. The retention times of desulfinyl, sulfide, fipronil, sulfone, and amide were 11.8, 15.8, 16.4, 19.7, and 24.1 min, respectively. The average recoveries obtained for fipronil and its metabolites at different spiking levels were determined to be above 85% in all samples. The repeatability and reproducibility in different matrixes ranged from 1.36 to 5.42 and 1.75 to 4.53%, respectively, for fipronil and its metabolites. The LOQ of this method was 0.01 mg/kg and LOD was 0.003 mg/kg.