Disodium hydrogenphosphate anhydrous

Acetonitrile (ACN, HPLC-MS grade) and methanol (MeOH, HPLC grade) were purchased from CARLO ERBA Reagents S.r.l. (Milano, Italy). Acetic acid (CH3COOH, pur. ≥ 99.8%), ammonium formate (HPLC grade), sodium hydroxide (NaOH, for analysis grade), and periodic acid (for analysis grade) were obtained from Sigma-Aldrich (Steinheim, Germany). Disodium hydrogenphosphate anhydrous (analysis grade) was obtained from CHEM-LAB NV (Zedelgem, Belgium). Ultrapure water (0.054 µS at 25 °C) was obtained from a MilliQ water purification system (Millipore Ltd., Bedford, MA, USA). STX, GTX1,4, C1,2, dcSTX, dcNEO, GTX2,3, GTX5, NEO, GTX6, and dcGTX2,3 certified solutions were purchased from CIFGA (Lugo, Spain). Stock PSTs standard solutions were prepared in 0.03 M acetic acid. C18-SPE cartridges (Supelclean 3 mL, 500 mg) were purchased from SUPELCO—Sigma-Aldrich (Steinheim, Germany). Hydrogen peroxide (analysis grade) and ammonium acetate (analysis grade) were obtained from VWR International S.r.l. (Milano, Italy). Potassium hydroxide (analysis grade) was purchased from ACROS ORGANICS- Thermo Fisher Scientific (Geel, Belgium). COOH-SPE cartridges (3 mL, 500 mg) were purchased from J.T.BAKER-Thermo Fisher Scientific (Geel, Belgium).

Pectinase from Aspergillus aculeatus (Pectinex® Ultra Clear, a blend of pectinases, hemicellulases and arabinases with activity of 8600 PGNU/g) and (Pectinex® Ultra SP-L, a blend of pectinases, hemicellulases and beta-glucanases with activity of 3300 PGNU/g), cellulase from Trichoderma reesei (Celluclast® 1.5L, a cellulase aqueous solution with activity of ≥700 units/g) were obtained from Sigma Aldrich (Darmstadt, Germany). Information about the optimal conditions of these enzymes as declared by the producer can be found in Table 1. Microcrystalline cellulose Avicel® PH-101, pectin from citrus peel, 3,5-dinitro salicylic acid, D-(+)-galacturonic acid monohydrate and D-(+)-glucose were purchased from Sigma Aldrich (Darmstadt, Germany). Sodium carbonate anhydrous, citric acid, sodium hydroxide, and L (+)-potassium sodium tartrate tetrahydrate were purchased from VWR Chemicals (Leuven, Belgium), while di-sodium hydrogen phosphate anhydrous, sodium acetate trihydrate, and acetic acid 99–100 % were obtained from Chem-Lab (Zedelgem, Belgium).Table 1

Conditions range of activity of the used enzymes as declared by the producer.

Enzyme	pH range of activity	Temperature range of activity
Pectinex® Ultra Clear	1.8–3.0	25–40 °C
Pectinex® Ultra SP-L	2.8–6.5	15–55 °C
Celluclast® 1.5L	4.0–6.0	50–60 °C