Investigation of the sugar content in wood hydrolysates with iodometric titration and UPLC-ELSD

Autohydrolysis of birch wood is a mild pretreatment process, which gives a notable yield of sugars -monosaccharides and oligosaccharides -in the aqueous hydrolysate, while a solid lignocellulose fraction can be further processed into other valuable products within a biorefinery concept. In this work two analytical methods -iodometric titration and ultra-high performance liquid chromatography with evaporative light scattering detection (UPLC-ELSD) -have been optimized and compared for the determination of the sugar content in series of birch wood hydrolysates. The results of both methods were consistent and showed that the highest yield of sugars, mostly xylose, was obtained by hydrolysis at 180 °C after 75 min.