Pesticides and VDs were extracted from feed using an extraction method based on the procedure previously described by Gómez-Pérez et al. [35]. Briefly, 2.5 g of feed was weighed into a 50-mL propylene tube and 2.5 mL of water (LC–MS grade) was added. The mixture was shaken in a vortex. Then 7.5 mL of acetonitrile (1 % formic acid, v/v) was added, and the sample was put into a rotary agitator and extracted by endover-end shaking for 1 h at 50 rpm. After that, the mixture was centrifuged for 10 min at 4,500 rpm (2,264×g), and 1 mL of the supernatant was passed through a Florisil cartridge. The final extract was transferred to a vial and injected into the chromatographic system.