Quechers

LC–MS grade methanol, formic acid and QuEChERS [41 (link)] kit were purchased from Sigma Aldrich. Deionised water, water purified through Milli-Q system (Millipore) was used to prepare the standard solutions and for LC/MS analysis. The following mycotoxin standards were used: aflatoxins mix of AFG1, AFB1, AFG2, AFB2 (10 mg / L), ochratoxin A (OTA, 10 mg / L), ochratoxin B (OTB, 10 mg / L) fumonisin B1 (FB1, 50 mg / L), fumonisin B2 (FB2, 50 mg / L) were procured from Sigma Aldrich.

The analytical standards of ZEN, α-ZOL, and β-ZOL, used for both in vitro and the animal experiment, was obtained from Sigma-Aldrich, CA, USA. Standards were diluted in acetonitrile to obtain working solutions of ZEN, α-ZOL, and β-ZOL for assays with High Performance Liquid Chromatography (HPLC) and Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC). All analytical standards were stored at ≤−15 °C. The internal standard (IS) --¹³C₁₈-ZEN, enzyme of β-glucuronidase used for hydrolysis of the conjugate, and QuECHERs used for impurities were purchased from Sigma, CA, USA. Chemicals of chloroform and ethyl acetate, used for ZEN extraction, were purchased from Sinopharm Chemical Reagent, Shanghai, China.

PZQ (2-cyclohexylcarbonyl-1,2,3,6,7-11b-hexahydro-4H-pyrazino[2,1-a]isoquinolin-4-one), PZQ-D11 (2-cyclohexyl-d11-carbonyl-1,2,3,6,7-11b-hexahydro-4H-pyrazino[2,1-a]isoquinolin-4-one) and QuEChERS tubes were purchased from Sigma Aldrich (Milano, Italy). Stock standards solutions (1 mg/mL) of PZQ and IS were prepared in methanol and stored at +4 °C. All proper dilutions were made in mobile phase when needed. All solvents used were of the highest commercial quality and were obtained from Fluka (Buchs, Switzerland). Ultrapure water was obtained using a Milli-Q water system (Millipore, Billerica, MA, USA).