13c34 fb1

Acetonitrile, methanol, and formic acid were of LC/MS grade (Fisher Scientific, Loughborough, UK). All other chemicals were of analytical grade or better. Deionized water (18.2 MΩ cm) was collected from a Milli-Q system (Millipore Corp., Bedford, MA, USA). Oasis MAX 3cc 60 mg cartridges and Oasis HLB 3cc 60 mg cartridges were purchased from Waters (Milford, MA, USA). Standard solutions of mixed FB1, FB2, and FB3 with certified concentrations of each analyte were purchased from Biopure (Tulln, Austria). [¹³C₃₄]-FB1, [¹³C₃₄]-FB2, and [¹³C₃₄]-FB3 standard solutions with certified concentrations were also purchased from Biopure (Tulln, Austria).

The standards of FB1, FB2 and FB3 were obtained from Fermentek Ltd (Jerusalem, Israel) and stored at 2–8 °C. The internal standard (IS), ¹³C₃₄-FB1 was purchased as a 25 µg/mL solution in acetonitrile/water (50/50, v/v) from Biopure (Tulln, Austria) and stored at 2–8 °C. A standard mixture containing FB1 (2.9 µg/mL), HFB1 (5.0 µg/mL), pHFB1a (8.3 µg/mL) and pHFB1b (14.5 µg/mL) was prepared by Biomin according to the procedure described by Hahn et al. [2 (link)]. This standard mixture was stored at ≤−15 °C.
The solvents and reagents that were used for the preparation of the UPLC mobile phase (water, ACN, FA, NH₄FA) were of UPLC-MS grade and were obtained from Biosolve (Valkenswaard, The Netherlands). All other solvents and reagents were of HPLC grade (water, ACN, diethylether, EtOAc; Filterservice, Eupen, Belgium) or analytical grade (FA, hydrochloric acid; VWR, Leuven, Belgium).
Oasis^® Ostro^TM protein precipitation & phospholipid removal 96-well plates (25 mg) were obtained from Waters (Zellik, Belgium).

HPLC grade MeOH, ACN, ammonium formate, FA, and AA were obtained from Thermo Fisher Scientific (Waltham, MA, USA). Deionized water was prepared using a Milli-Q system (Millipore Corporation, Bedford, MA, USA). The MycoSpin^TM 400 SPE cartridge was purchased from Romer Labs (Tulln, Austria). Certified standard solutions of AFB₁ (25 μg mL⁻¹), AFB₂ (25 μg mL⁻¹), AFM₁ (10 μg mL⁻¹), AFM₂ (10 μg mL⁻¹), AFG₁ (25 μg mL⁻¹), AFG₂ (25 μg mL⁻¹), 15-AcDON (100 μg mL⁻¹), 3-AcDON (100 μg mL⁻¹), DAS (, 100 μg mL⁻¹), HT-2 (100 μg mL⁻¹), T-2 (100 μg mL⁻¹), DOM-1 (50 μg mL⁻¹), DON (50 μg mL⁻¹), NEO (100 μg mL⁻¹), ZEN (25 μg mL⁻¹), ST (50 μg mL⁻¹), OTA (10 μg mL⁻¹), OTB (10 μg mL⁻¹), OTC (10 μg mL⁻¹), FB₁ (50 μg mL⁻¹), FB₂ (FB₂, 50 μg mL⁻¹),FB₃ (FB₃, 50 μg mL⁻¹), [¹³C₁₇]-AFB₁ (0.5 μg mL⁻¹), [¹³C₂₀]-OTA (10 μg mL⁻¹), and [¹³C₃₄]-FB₁ (25 μg mL⁻¹) were acquired from Romer Labs (Butzbach, Germany) with purities above 98%.