Highly sensitive oligosaccharide analysis in capillary electrophoresis using large-volume sample stacking with an...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) offers high resolution but often lacks sensitivity for oligosaccharide analysis.
• Achieving high sensitivity typically requires complex procedures or compromises resolution.

Purpose of the Study:

• To investigate large-volume sample stacking with an electroosmotic flow pump (LVSEP) for sensitive and high-resolution oligosaccharide analysis.
• To assess the applicability of LVSEP for real-world samples, including those with salts and complex biological matrices.

Main Methods:

• LVSEP coupled with capillary zone electrophoresis (CZE) was employed.
• The effect of sample solution conductivity on LVSEP performance was examined.
• Analysis of glucose oligomers, maltoheptaose, and N-linked glycans from glycoproteins was performed.

Main Results:

• LVSEP successfully handled sample solutions with high ionic strength and conductivity ratios.
• Effective separation of glucose oligomers was achieved with minimal loss of resolution.
• A 500-fold improvement in the limit of detection for maltoheptaose was observed (2 pM).
• N-linked glycans from glycoproteins were concentrated and separated with up to a 770-fold sensitivity increase.
• Good run-to-run repeatabilities were obtained for migration time, peak height, and peak area.

Conclusions:

• LVSEP is a robust and effective technique for enhancing oligosaccharide sensitivity in CE without sacrificing resolution.
• The method demonstrates broad applicability for analyzing complex biological samples, simplifying sample preparation.
• LVSEP offers a significant advancement for sensitive glycan analysis in various scientific fields.