Carbopac sa10g guard column

Acid hydrolysis and neutral monosaccharide determinations were performed as previously described [60 (link)], on non-pretreated, WRF-treated (30-day incubation with P. ostreatus) and mild alkali-treated (ALK and WRF-ALK) AIR samples. Briefly, 10 mg of each sample was weighed into 10 mL Pyrex glass tubes, and 100 μL H₂SO₄ (72% w/w) was added. Sealed tubes were left at 30 °C for 1 h. Samples were diluted to 4% H₂SO₄ (w/w) and autoclaved at 121 °C for 1 h. Once at room temperature, hydrolysates were neutralised using CaCO₃, and the tubes were centrifuged (2000× g for 10 min) to obtain a clear supernatant. Carbohydrate separation and detection were achieved using high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The ICS-5000 ion chromatography system (Dionex, Sunnyvale, CA, USA) was operated at 45 °C using a CarboPac SA10 column with a CarboPac SA10G guard column. An eluent generator prepared 1 mM KOH for 14 min isocratic elution at 1.5 mL min⁻¹. Calibration standards (glucose, xylose and arabinose) were used for monosaccharide identification and quantitation.

Acid hydrolysis was performed as described in Sluiter et al. (2012): 10 mg of CWM were weighed into 10 ml Pyrex glass tubes and 100 μl H₂SO₄ (72% w/w) was added. Sealed tubes were left at 30°C for 1 h. Samples were diluted to 4% H₂SO₄ (w/w) and autoclaved at 121°C for 1 h. Once at room temperature, tubes were centrifuged to produce a supernatant; 400 μl of diluted (1 : 200) samples was transferred to filter vials (0.45 μm nylon filter; Thomson Instrument Company, Oceanside, CA, USA). Carbohydrate separation was by high‐performance anion‐exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) using a gold working electrode and Ag/AgCl reference electrode. The ICS‐5000 ion chromatography system (Dionex, Sunnyvale, CA, USA) was operated at 45°C using a CarboPac SA10 column with a CarboPac SA10G guard column. An eluent generator prepared 0.001 M KOH for 14 min isocratic elution at 1.5 ml min⁻¹. Calibration standards were used for monosaccharide identification and quantitation. In order to resolve galactose (Gal) which coelutes with rhamnose at 45°C, the HPAEC‐PAD method was adapted by reducing the flow rate to 1.2 ml min⁻¹ and temperature to 30°C.