Chromatographic separation of glucose oligomers in size exclusion mode

Significance of the Topic

Size exclusion chromatography of sugars is crucial for quality control and research in food science, biotechnology and polymer analysis. The ability to separate and characterize glucose oligomers enables precise monitoring of carbohydrate mixtures, optimization of enzymatic processes and verification of product purity.

Objectives and Overview of the Study

This work demonstrates the performance of the Shim-pack SUR-Na column operated in size exclusion and sodium-based ligand exchange mode for the separation of glucose oligomers ranging from disaccharides to high-molecular-weight pullulan.

Used Instrumentation

• Chromatograph: Nexera lite
• Column: Shim-pack SUR-Na, 250 mm x 7.8 mm I.D., 8 μm, with a guard column (50 mm x 7.8 mm I.D., 8 μm)
• Detector: Refractive index detector (RID)

Methodology

The separation employed water as the mobile phase at a flow rate of 0.5 mL/min and a column temperature of 60 °C. A 10 μL sample injection was used to analyze a standard mixture including acetic acid, pullulan standards (MW ~6,200 and 12,200) and maltooligosaccharides (DP4 to DP7). Retention times were monitored over a 30-minute run and recorded in μV (×10,000) by the RID.

Main Results and Discussion

The chromatogram revealed clear baseline separation of glucose oligomers with retention times increasing from maltose (DP2) to pullulan (DP~120). Key observations include:

• Maltose (MW 342.30) eluted earliest, followed by maltotriose, maltotetraose, maltopentaose, maltohexaose and maltoheptaose.
• Pullulan standards exhibited distinct peaks corresponding to approximate molecular weights of 6,200 and 12,200.
• The sodium-based ligand exchange in conjunction with size exclusion principles provided consistent retention indices correlating linearly with oligomer length.

These results confirm the column’s capability for reliable molecular-weight discrimination in carbohydrate analysis.

Benefits and Practical Application

• Rapid, reproducible analysis of maltooligosaccharides and polysaccharides for food quality assurance.
• Non-derivatized sugar analysis using water as the mobile phase simplifies sample preparation.
• High thermal stability at 60 °C reduces peak broadening and improves resolution.

Future Trends and Opportunities

Advances may include coupling size exclusion with mass spectrometry for structural elucidation, expanding applications to complex glycan profiling in biopharmaceuticals, and integrating high-throughput configurations for industrial process monitoring.

Conclusion

The Shim-pack SUR-Na column operated in size exclusion and sodium-based ligand exchange mode provides effective separation of glucose oligomers across a broad molecular weight range. The methodology offers a straightforward, robust approach for carbohydrate characterization in research and quality control laboratories.

References

No external references were provided in the original document.