Dissipation and residue of flonicamid in cucumber, apple and soil under field conditions

A method based on QuEChERS-like extraction and UPLC-ESI-MS/MS for the analysis of flonicamid was established. The samples were extracted by acetonitrile-methanol mixture and were purified using PSA. At fortification levels of 0.01, 0.1 and 0.5mg/kg in cucumber, apple and soil, recoveries ranged from 71.5 to 106.0% with relative standard deviation (RSD) of 2.6-9.9%. The limit of quantification (LOQ) was 0.003mg/kg for cucumber, apple and soil. This study also investigates the dissipation of flonicamid in cucumber, apple and soil. The dissipation half-lives of flonicamid in cucumber, apple and soil were 3.0-4.9days, 5.1-6.1days and 10.3-14.2days, respectively. The final residues of flonicamid ranged from 0.029 to 0.295mg/kg in cucumbers, <0.01-0.174mg/kg in apples and <0.01-0.172mg/kg in soil, respectively. The observed low residual levels of flonicamid suggest that the cucumber and apple are safe when applied at the recommended dosage.