Hydrophilic interaction/weak cation-exchange mixed-mode chromatography for chitooligosaccharides separation

► A HILIC/WCX chromatography method was used for chitooligosaccharides (COS) separation. ► Low level of organic solvent was employed compared with HILIC method. ► Mild elution conditions instead of drastic elution conditions as reported before. ► Economical elution conditions are potential for large-scale COS preparation.