Application of online preconcentration affinity capillary electrophoresis method to glycans labeled with 8-aminonaphthalene-1,3,6-trisulfonic acid using blue light emitting diode-induced fluorescence detection.

An online preconcentration technique, large volume sample stacking with an electroosmotic flow pump, was combined with partial filling affinity capillary electrophoresis (PFACE) to create a highly sensitive analysis of the interaction of glycoprotein-derived oligosaccharides with plant lectins. Oligosaccharides were derivatized with 8-aminonaphthalene-1,3,6-trisulfonic acid (ANTS) for use in a blue light emitting diode-induced fluorescence detection capillary electrophoresis system. ANTS-labeled oligosaccharides were delivered to an entire neutrally coated capillary, and lectin solution was then hydrodynamically introduced from the outlet of the capillary as a short plug. When negative voltage was then applied, a low concentration sample solution caused a significant flow by electroosmosis from anode to cathode and the ANTS-labeled oligosaccharides moved quickly towards the anode and concentrated in the lectin phase. Finally, when the electroosmotic flow became negligible, ANTS-labeled saccharides passed through the lectin plug and were detected at the anodic end. The sensitivity was enhanced by a factor of roughly 200 compared to typical hydrodynamic injection (13.8 kPa, 5 s).