13c34 fb2

All reagents were purchased from Sharlab (Sharlab S.L., Sentmenat, Spain), Fluka (Fluka, Buchs, Switzerland) and Sigma (Sigma Chemical Co, Saint Quentin Fallavier, France). Pure water, methanol, formic acid, and acetic acid were of LC-MS grade; all other reagents were of HPLC analytical grade. Standard solutions of FB1, FB2, FB3, [¹³C₃₄]-FB1, [¹³C₃₄]-FB2 and [¹³C₃₄]-FB3 with certified concentrations of each analyte and all other mycotoxins dosed in feed and reported in Table S2 were purchased from Biopure (Romer Labs, 3131 Getzersdorf, Austria) and Sigma (Sigma Chemical Co, Saint Quentin Fallavier, France). Immunoaffinity FUMONIPREP columns were purchased from R-Biopharm (R-Biopharm Rhone LTD, Glasgow, Scotland). Sphinganine, sphingosine, and C20 sphinganine were purchased from Bertin (Bertin Technologies, Montigny le Bretonneux, France). Algo clay (Batch number R174P1E22) was provided by Olmix (Olmix S.A, 56580 Bréhan, France).

LC grade acetonitrile, methanol, and water were purchased from Thermo Fisher Scientific (Waltham, MA, USA). Mycotoxin stock solutions I, II, and III were obtained from Romer Labs (Union, MO, USA). Solution I contained 10 μg/mL each of aflatoxin B₁ (AFB1), aflatoxin B₂ (AFB2), aflatoxin G₁ (AFG1), aflatoxin G₂ (AFG2), and ochratoxin A (OTA) in methanol; Solution II contained 100 μg/mL each of fumonisin B₁ (FB1), fumonisin B₂ (FB2), and fumonisin B₃ (FB3) in acetonitrile–water (1 + 1, v/v); Solution III contained 100 μg/mL each of deoxynivalenol (DON), HT-2 toxin (HT-2), T-2 toxin (T-2), and zearalenone (ZON) in acetonitrile. The following carbon-13 (¹³C)-IS stock solutions were purchased from Romer Labs: ¹³C₁₇-AFB1 + B2 + G1 + G2 (0.5 μg/mL), ¹³C₂₀-OTA (10 μg/mL), ¹³C₃₄-FB1 (25 μg/mL), ¹³C₃₄-FB2 (10 μg/mL), ¹³C₃₄-FB3 (10 μg/mL), ¹³C₁₅-DON (25 μg/mL), ¹³C₂₂-HT-2 (25 μg/mL), ¹³C₂₄-T-2 (25 μg/mL), and ¹³C₁₈-ZON (25 μg/mL).Spiking solutions of ¹³C-IS and calibration standards were prepared according to a previously described protocol [22 (link)].