HPLC Analysis of Sugars and Byproducts

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)].