A modified method for the simultaneous determination of fluindapyr and its metabolites residues in vegetables and fruits by SPE and UHPLCMS/MS

A sensitive and reliable method for the determination of fluindapyr residue and its five metabolites is necessary in its registration, application and dissipation researches. Two typical national standard multi-residue analytical methods that involved fluindapyr was validated in this study, and the results found that both the methods gave low recoveries for one or more analytes and were not satisfied for detecting the residues of fluindapyr and its metabolites simultaneously. With comprehensive optimization, a simple and efficient method was established using mixed solution extraction with acetonitrile and water and cleaning-up by a modified SPE procedure with mixed-mode cation exchange cartridges, followed by ultrahigh-performance liquid chromatographytandem mass spectrometry (UHPLCMS/MS) detection for the simultaneous determination of fluindapyr and its five metabolites in vegetables and fruits. Method validation in nine vegetables and fruits was performed by analyzing the linearity (0.001–0.5 mg/L, and R² ≥ 0.99), matrix effects (−95 %–80 %), fortified recoveries (71 %–118 %), relative standard deviations (0.2 %–16 %), limits of detection (0.0001–0.0002 mg/L), limits of quantification (0.0003–0.0006 mg/L) and the method limits of quantification (0.001 mg/kg). The proposed method was highly sensitive and reliable, and provides beneficial supplement to the two national standards in China in the simultaneously analysis of fluindapyr and its five metabolites in vegetables and fruits, and this study also provides reference for the method establishment for highly water-soluble analytes.