Residue dynamics of pyraclostrobin in peanut and field soil by QuEChERS and LC–MS/MS

A modified QuEChERS–LC–MS/MS (acronym of quick, easy, cheap, effective, rugged and safe-liquid chromatography tandem mass spectrometry) method for the analysis of pyraclostrobin residue in peanut and soil was developed and validated. Pyraclostrobin residue dynamics and final residues in supervised field trials at Good Agricultural Practice (GAP) conditions in peanut and soil were studied. The limits of quantitation (LOQs) for pyraclostrobin in soil, plant, shell and peanut samples were 0.00057, 0.00026, 0.003 and 0.0037mgkg−1, respectively. At fortification levels of 0.005, 0.05 and 0.5mgkg−1 in all samples, it was shown that recoveries ranged from 80.3% to 109.4% with relative standard deviations of 1.1–8.2% (n=5). The dissipation experiments showed the half-lives (T1/2) of pyraclostrobin in soil and plants were 13.1–16.5 days and 10.3–11.2 days, respectively. At pre-harvest intervals (PHI) of 14, 21 and 28 days, pyraclostrobin residue were 0.005–0.20mgkg−1 in soil, 0.006–0.27mgkg−1 in plants, below 0.053mgkg−1 in shells and not detectable in peanuts. ► A method was developed to determine pyraclostrobin residue in peanut and soil. ► The results showed perfect linearity and precision. ► The procedure was efficient, and the retention time was not more than 2min. ► The dissipation and residue of pyraclostrobin were studied under field condition.