Ethyl acetate etoac hplc grade

Standards of mycotoxins (four aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), beauvericin (BEA), four enniatins (ENA, ENA1, ENB, and ENB1), zearalenone (ZEN), α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), alternariol (AOH), tentoxin (TENT), T-2, and HT-2 toxins) were purchased from Sigma Aldrich (St. Louis, MO, USA). Individual stock solutions containing a concentration of 1000 µg/mL were prepared in methanol. Working solutions were prepared starting from the appropriate individual stock solutions. All solutions were prepared and stored in the dark at −20 °C. Methanol and acetonitrile (≥ 99.9% purity) liquid chromatography tandem mass spectrometry grades (LC-MS/MS) were supplied by VWR international Eurolab (Barcelona, Spain). Formic acid (≥ 98%) was obtained from Sigma Aldrich (St. Louis, MO, USA ). Ammonium formate (≥ 99.995%) and chloroform (CHCl₃) (99%) were obtained from Merck KGaA (Darmstadt, Germany). Ethyl acetate (EtOAc) (HPLC-grade, > 99.5%) was purchased from Alfa Aesar (Karlsruhe, Germany). The water used was purified (≤ 10 MΩ cm⁻¹ resistivity) in the laboratory using a Milli-Q SP^® Reagent water system (Millipore, Bedford, MA, USA).

Chloroform (CHCl₃), acetonitrile (ACN), and methanol (MeOH) solvents (99% grade) were provided by Merck (Darmstadt, Germany). Ethyl acetate (EtOAc) (HPLC grade) was supplied from Alfa Aesar (Karlsruhe, Germany). The deionized water with resistivity >18 MΩ cm⁻¹ used to prepare the mobile phase was obtained through Milli-Q SP^® Reagent Water System (Millipore Corporation, Bedford, MA, USA). In advance of the use, all mobile phase solvents were filtered through a 0.45-µm cellulose filter acquired by Scharlau (Barcelona, Spain). Sodium chloride (NaCl) was bought from VWR Chemicals (Leuven, Belgium), ammonium formate (99%) was purchased from Panreac Quimica S.A.U. (Barcelona, Spain), and formic acid (reagent grade 95%) was obtained from Sigma-Aldrich (St. Louis, MO, USA). Before injection, all samples were filtered through a 13 mm/0.22 µm nylon filter supplied by Membrane Solutions (Plano, TX, USA). OTA and ENNs (Enniatin B (ENNB) and Enniatin B1(ENNB1)) standards were supplied by Sigma and were prepared in methanol at a concentration of 1000 mg/L. Afterwards, working solutions were elaborated from the stock solutions. All solutions were saved at 20 °C.