Simultaneous determination of fluopyram and its metabolite in vegetables using gas chromatography-tandem mass spectrometry

A method was developed for simultaneous determination of fluopyram and its metabolite residues in vegetables by gas chromatography-tandem mass spectrometry (GC-MS/MS). Samples were extracted with acetonitrile, and salted-out by magnesium sulfate and sodium chloride. After clean up with PSA, the analyte was subjected to determination using GC-MS/MS. The results showed that the average recoveries varied from 80% to 108% at the spiked concentrations of 0.01, 0.1 and 1 mg/kg, with the relative standard deviation (RSD) varied from 1.5% to 8.4%. The limits of detection (LOD, S/N=3) varied from 2.17 μg/kg to 3.13 μg/kg for fluopyram in different vegetable samples, while the LOD of fluopyram metabolite varied from 1.22 μg/kg to 2.04 μg/kg. For both fluopyram and its metabolite, the limit of quantification (LOQ) (based on the recovery test) was 0.01 mg/kg. Hence, the method developed in this work is convenient, rapid, reliable, and, more importantly, applicable for qualitative and quantitative analyses of residues of fluopyram and its metabolite in the majority of vegetables.