Trifluoroacetic acid

Commercially available materials and solvents were purchased from Aldrich Chemical Co (St. Louis, MO, USA). Aceanthrenequinone was recrystallized from 1, 2-dichlorobenzene using charcoal. biphenyl was used without further purification. Trifluoromethanesulfonic acid (98%, TFSA), trifluoroacetic acid (≥99%, TFA), methanol (technical grade, MeOH), methylene chloride (CH₂Cl₂), and 1-methyl-2-pyrrolidone (NMP) were provided by Aldrich Chemical Co. All solvents and superacids were distilled prior to use [17 (link)].
Polymer Synthesis: A solution was prepared by combining 0.4591 g (2.52 mmol) of acenaphthenequinone, 0.2775 g (1.8 mmol) of biphenyl, 0.7 mL of methylene chloride, and 1 mL of TFA in a 5 mL Erlenmeyer flask under a nitrogen atmosphere. Subsequently, the reaction mixture was placed into an ice bath and 1.28 mL of triflic acid (TFSA) was added. Following a five-minute period, the ice bath was removed, and the stirring continued at room temperature for six hours. After this time, 2 mL of TFA:CH₂Cl₂ in a 1:1 ratio was added as a solvent to obtain a homogeneous mixture before precipitation. The polymer was precipitated into methanol, filtered, washed with hot methanol, and dried. The resulting polymer (0.5927 g, 99%) exhibited an inherent viscosity of 1.09 dL g⁻¹ in NMP.

Sodium acetate, sodium phosphate dibasic, sodium carbonate, sodium bicarbonate, H₂O₂, and trifluoroacetic acid were sourced from Sigma-Aldrich (St. Louis, MO, USA). Glacial acetic acid was purchased from VWR. Citric acid (10% solution) was purchased from RICCA. 1-hydroxybenzotriazole monohydrate was purchased from TCI (Tokyo Chemical Industry Co., Ltd.). Aspergillus sp. laccase (cat. # SAE0050-50mL), Trametes versicolor laccase (cat. # 38429-1G), Agaricus bisporus laccase (cat. # 40452-100MG) and five horseradish peroxidases (P8125, P8250, P6782, P8375, and P8415) were purchased from Sigma-Aldrich. “Aspergillus sp. laccase” contains a Myceliophthora thermophila laccase that is expressed in Aspergillus oryzae^{35 (link)}. Metzyme bacterial laccases L111 and L371^{13 (link)} were provided by MetGen Oy (Kaarina, Finland, www.metgen.com). Metzyme L371 is engineered to be alkaliphilic. NIMS-tagged substrates (Fig. 2) were synthesized and purified in house. Details about the synthetic scheme and characterization of new compounds can be found in Supplementary Figure S1 and the Supplementary Methods.

Standard solutions of DON, DOM1, ZEN, α-ZOL, β-ZOL, α-ZAL, β-ZAL, T2, HT2, and OTA, along with internal isotope-labeled standards U-[¹³C₁₅]-DON, U-[¹³C₁₈]-ZEN, U-[¹³C₂₄]-T-2, U-[¹³C₂₂]-HT-2 and U-[¹³C₂₀]-OTA, were acquired from Romer Labs Diagnostic (Tulln, Austria). The creatinine standard and trifluoroacetic acid were obtained from Sigma–Aldrich (Darmstadt, Germany). Acetonitrile (gradient grade), methanol (LC–MS grade), ammonium acetate, and acetic acid were purchased from Merck (Darmstadt, Germany). Immunoaffinity columns Ochraprep® and DZT MS-PREP®, along with phosphate-buffered saline tablets, were provided by R-Biopharm Rhone (Glasgow, UK). A β-glucuronidase/arylsulfatase solution derived from Helix pomatia (with specific activities of 5.5 U/ml and 2.6 U/ml at +38°C, respectively) and potassium acetate hydrolysis buffer (pH 5) was purchased from Sigma-Aldrich (Darmstadt, Germany). Deionized water was purified using a Simplicity UV water purification system (Millipore, USA).