Rezex rhm monosaccharide h 8

Carbohydrates were measured on a Dionex (Sunnyvale, CA, USA) HPLC (ICS-3000) system equipped with an autosampler, electrochemical detector, dual pumps, and anion exchange column (Dionex, CarboPac PA1). Deionized water at 1 ml/min was used as an eluent, and post-column addition of 0.2 M NaOH at a flow rate of 0.5 ml/min ensured optimization of baseline stability and detector sensitivity. After each analysis, the column was reconditioned with 0.25 M NaOH. Twenty microliters of each sample were injected after filtration through a 0.22-µm syringe filter (Restek Corp., Bellefonte, PA, USA). Samples were measured against standards consisting of arabinose, galactose, glucose, xylose, and mannose. In addition, fucose was used as an internal standard.
Acetic acid, furfural, and HMF were measured using refractive index detection on a Shimadzu Prominence LC. Separation of these compounds was achieved by an anion exchange column [REZEX RHM-Mono-saccharide H⁺ (8 %), Phenomenex, Inc., Torrance, CA, USA] with an isocratic mobile phase that of 5 mM H₂SO₄ at a flow rate of 0.6 ml/min. The column oven temperature was maintained at 63 °C. Twenty microliters of each sample were injected after being appropriately diluted in deionized water and filtered through a 0.22-µm syringe filter (Restek Corp., Bellefonte, PA, USA). Standards were prepared and used to quantify the unknown samples.

Monomeric/oligomeric soluble carbohydrates and degradation products were determined using NREL LAP TP-510-42623 [28 ]. Briefly, 0.7 ml of 72% H₂SO₄ was added to 15 ml of the liquid samples, and the volume made up to 20 ml with water. Samples were autoclaved at 121 °C for 60 min. The samples were then analyzed by a Dionex (Sunnyvale, CA) HPLC (ICS-3000) system equipped with an anion exchange column (Dionex, CarboPac PA1) and an electrochemical detector using deionized water at a flow rate of 1 ml/min as an eluent [29 ]. Oligomeric sugar was calculated by subtracting monomeric sugar content from total sugar content determined after acid hydrolysis.
Degradation products, such as acetic acid, furfural, and HMF, were determined using a Shimadzu Prominence LC equipped with an anion exchange column (Rezex RHM Monosaccharide H⁺ (8%) Phenomenex, Inc., Torrance, CA) using 5 mM H₂SO₄ at 0.6 ml/min [29 ]. Phenolic concentration in the WSF was assayed by the Folin Ciocalteu method [30 (link)] using a spectrophotometer (Shimadzu, Tokyo, Japan) at 765 nm. Gallic acid was used as calibration standard.

The concentration of monomeric sugars from chemical composition analyses and enzymatic hydrolysis was determined with a Dionex (Sunnyvale, CA) HPLC (ICS-3000) system equipped with an autosampler, dual pumps, an anion-exchange column (Dionex, CarboPac PA1), and an electrochemical detector (Dionex disposable gold electrode) [15 (link)]. DI water at 1 mL/min was used as an eluent, and postcolumn addition of 0.2 M NaOH at a flow rate of 0.5 mL/min ensured optimization of baseline stability and detector sensitivity. Acetic acid, furfural, HMF, and ethanol were measured using refractive index detection on a Shimadzu Prominence LC. Separation of these compounds was achieved by an anion-exchange column (Rezex RHM Monosaccharide H⁺ (8%), Phenomenex, Inc., Torrance, CA) with an isocratic mobile phase that consisted of 5 mM H₂SO₄ at a flow rate of 0.6 mL/min [15 (link)].