Diboronic acid assisted labeling and separation for highly efficient analysis of saccharides

In this study, a diboronic acid assisted labeling and separation strategy was proposed for the efficient analysis of saccharides in real samples. The diboronic acid was first synthesized and characterized and then used as chemical labels for saccharides through boronate affinity. After labeling, the product was direct submitted to chromatographic analysis. The whole labeling procedure was organic solvent-free and could be accomplished within 1 h. Furthermore, the separation could be realized on the most commonly used chromatographic techniques (RPLC-UV). Taking glucose as an example, the established strategy provided broad linear dynamics ranges (25-5000 ng/mL) with acceptable correlation coefficients (R²>0.98), substantial sensitivity (LOD: 5 ng/mL), high reproducibility (RSD<6.7%) and excellent accuracy (Recovery: 98.2-99.8%). Finally, different saccharides were successfully analyzed in various complex samples, from tryptic glycans of glycoproteins to monosaccharides in traditional Chinese medicine.