Analysis of biomass sugars and galacturonic acid by gradient anion exchange chromatography and pulsed amperometric detection without post-column addition.

While the most accurate method for analysis of sugars in biomass is based on gas chromatography of trimethylsilane or alditol acetate derivatives of sugars, the derivation method is time consuming and laborious. In comparison, sample preparation for sugar analysis of hydrolyzed biomass samples using liquid chromatography is a simple dilution procedure with water. A gradient HPLC method using a anion-exchange column and pulsed-amperometric detection modified to reduce analysis time from 75 to 40 min was further improved. The new method no longer requires post-column addition to stablilize the baseline using a pulsed-amperometric detector with the mobile phase gradient. The method provides good resolution of arabinose, rhamnose, galactose, xylose, glucose, fructose, sucrose, cellobiose, and galacturonic acid in both standards and hydrolyzed citrus waste materials. By changing the waveform used with the PAD detector, the requirement for post-column addition was eliminated while maintaining a stable baseline.