OTA standard obtained from Acros Organics (Geel, Belgium) was
used both for the animal treatment (in a crystalline form) and for
sample fortification (within the frame of the validation process).
Standard solutions used for the validation of the applied methodology
were prepared in the form of an aqueous stock and working solution,
in concentrations of 10,000 ng/mL and 20 ng/mL, respectively, and
were stored at +4 °C until analyses