Method validation, dissipation and residue status of fluopicolide and fosetyl‐aluminium in citrus using a rapid extraction method coupled with ultra‐performance liquid chromatography–tandem mass spectrometry

Abstract The dissipation and residue status of a combination of fluopicolide and fosetyl‐aluminium (fosetyl‐Al) in citrus were evaluated in an experimental field. An efficient and sensitive liquid chromatography–tandem mass spectrometry, with rapid extraction, was carried out according to the SANTE guidelines. During the method validation, the recovery was within the range of 106.1–117.5, 94.4–115 and 85.4–109.5%, for fluopicolide, its metabolite 2,6‐dichlorobenzamide and fosetyl‐Al, respectively, with a relative standard deviation (RSD) of 0.3–10.6%. As a result, accuracy and precision at the spiking concentrations of 0.01, 0.05 and 0.10 mg/kg in citrus were within the acceptable range of 70–120% with an RSD of 20%. The amount of the deposits of fluopicolide, 2,6‐dichlorobenzamide and fosetyl‐Al was less than the limit of quantification (LOQ) at 0.01 mg/kg at 0 day, adhering to the application in standard [1.77 + 2.66 g of active ingredient (a.i.)/L] and double (3.54 + 5.32 g a.i./L) doses. The present study proposes that the utilisation of fluopicolide and fosetyl‐Al in citrus and the soil may not pose a health or environmental hazard provided that good agricultural practices are followed.