Analysis of Four Sugar Alcohols

Significance of the Topic

Sugar alcohols serve as low-calorie sweeteners in food and pharmaceutical formulations, offering reduced glycemic response compared to sucrose. Accurate quantification of these polyols is critical for quality control, nutritional labeling, and compliance with regulatory standards.

Aims and Overview of the Study

This application note demonstrates a straightforward high-temperature, isocratic liquid chromatography method using size-exclusion/ligand-exchange separation to resolve four common sugar alcohols: isomalt, maltitol, mannitol, and sorbitol. The goal is to achieve baseline separation with minimal sample preparation and a simple mobile phase.

Methodology and Instrumentation

A Shimadzu Prominence HPLC system equipped with a Shim-pack SCR-101C column (300 mm × 7.9 mm I.D., 10 µm particle size) was employed. Key parameters:

• Mobile phase: Water
• Flow rate: 0.5 mL/min
• Column temperature: 85 °C
• Injection volume: 20 µL
• Detection: Refractive index (RID-20A)

Analyte concentrations:

1. Isomalt A: 1 g/L
2. Maltitol: 1 g/L
3. Isomalt B: 1 g/L
4. Mannitol: 25 g/L
5. Sorbitol: 25 g/L

Main Results and Discussion

The chromatogram displayed five distinct peaks corresponding to the two isomalt fractions, maltitol, mannitol, and sorbitol. Separation is driven by differences in molecular size and hydroxyl group interactions with the ligand-exchange resin. Elevated temperature (85 °C) minimized mobile phase viscosity, improving peak shape and resolution.

Benefits and Practical Applications

The method offers:

• Simple isocratic operation with pure water
• No need for buffer preparation
• High reproducibility and short analysis time (~25 min)
• Robust detection of low-level sugar alcohols

It is ideally suited for routine QA/QC in food and beverage manufacturing, pharmaceutical excipient testing, and nutritional analysis.

Future Trends and Potential Applications

Emerging directions include:

• Integration with mass spectrometry for structural confirmation
• Use of sub-2 µm or core-shell columns to reduce analysis time
• Expansion to other polyols and oligosaccharides
• Online process monitoring (PAT) in sugar reduction and fermentation processes

Conclusion

The Shim-pack SCR-101C column combined with RI detection provides a reliable, easy-to-implement method for the separation and quantification of key sugar alcohols, enhancing analytical efficiency in industrial and research laboratories.

Reference

Shimadzu Corporation. Application Note ERAS-1000-0102, First Edition December 2021.