*4.2. Mixed Working Solution*

A mixed working solution (MIX6) was prepared in ACN from the individual stock of six mycotoxins at a concentration of 9 µg/mL for DON and NIV and 1 µg/mL for 3Ac-DON, 15Ac-DON, DON-3Glc and FUS-X. The internal standards solution (MIX IS) was mixed in ACN to achieve concentrations of 1 µg/mL and 0.5 µg/mL for DON IS and DON-3Glc IS, respectively. All working standard solutions were stored at 2–8 ◦C.
