Hplc grade methyl tert butyl ether

HPLC grade water, acetonitrile (ACN), and methanol (MeOH) were purchased from Thomas Scientific (Swedesboro, NJ, USA) and Sigma-Aldrich (St. Louis, MO, USA). Water from a Milli-Q® water purification system (MilliporeSigma, Burlington, MA, USA) was also used. HPLC grade methyl tert-butyl ether (MTBE) was purchased from VWR (Radner, PA, USA). Sodium acetate buffer (pH 4.65, 0.2 M) was obtained from Fluka (Honeywell Products, Charlotte, NC, USA). β-Glucuronidase from Helix pomatia (type HP-2, >100000 units/mL) was purchased from Sigma-Aldrich. ZEN, ZER, α-ZOL, β-ZOL, β-ZAL, ZAN standards were all purchased from Sigma-Aldrich. Internal standards Rac-Zearalenone-d₆ (ZEN-d₆; used for ZAN and ZEN) and α-Zearalenol-d₇ (α-ZOL-d₇; used for the other compounds) were obtained from Toronto Research Chemicals (North York, ON, Canada). Chem Elut supported liquid extraction (SLE) columns (3 mL, unbuffered) were from Agilent (Santa Clara, CA, USA); Discovery DSC-NH2 solid-phase extraction tubes (1 mL/100 mg) were from Supelco (Bellefonte, PA, USA); Sep-Pak silica cartridges (3 cc/500 mg) were from Waters (Milford, MA, USA).

Reference standards of Zen (≥ 99%), Zer (≥ 98%, HPLC grade), zearalanone (Zan; ≥ 98%), β-zearalanol (bZal; ≥ 96%, HPLC grade), α-zearalenol (aZol; ≥ 98%), and β-zearalenol (bZol; ≥ 97%) were obtained from Sigma-Aldrich. The internal standards Rac-Zearalenone-d₆ (Zen-d₆; ≥ 96.9%) and α-zearalenol-d₇ (aZol-d₇; ≥ 98%) were obtained from Toronto Research Chemicals. Sodium acetate buffer solution (pH = 4.65, 0.2 M) was purchased from Honeywell Fluka. The enzyme β-glucuronidase from Helix pomatia (type HP-2, > 100,000 units/mL, sulfatase activity < 7500 units/mL) was obtained from Sigma-Aldrich. HPLC-grade methyl tert-butyl ether (MTBE) and methanol (MeOH) were purchased from VWR. HPLC-grade acetonitrile (ACN) was purchased from Honeywell. Water was obtained from a Milli-Q water purification system (Millipore).