Sugar Analysis: An aqueous alternative to the use of amino-bonded HPLC columns with acetonitrile eluents

Significance of the Topic

The accurate and cost-effective analysis of simple sugars and sugar alcohols is vital for quality control, product development and regulatory compliance in the food and beverage industry. Traditional amino-bonded HPLC methods rely heavily on acetonitrile, whose supply volatility and rising cost motivate alternative approaches. Ligand exchange chromatography on Hi-Plex ion-exchange columns offers a water-only eluent option, improved resolution for complex sugar mixtures and reduced solvent costs, addressing both economic and sustainability concerns.

Objectives and Study Overview

This work compares the performance of an amino-bonded silica column (Polaris NH2) operated with 80:20 acetonitrile/water and a Hi-Plex Ca ligand exchange column running on water alone. Three example applications are presented: separation of mixed mono-, di-, tri- and tetrasaccharides; differentiation of similar sugar structures; and analysis of multiple sugar alcohols. The aim is to evaluate resolution, run times, solvent requirements and applicability to routine food analysis.

Methodology and Instrumentation

Two stationary phases were tested:

• Polaris NH2 (aminopropyl-silane on silica, 100 Å, 5 µm, 150 × 2.1 mm)
• Hi-Plex Ca (sulphonic acid cation exchanger, monodispersed styrene/divinylbenzene, 8 µm, 300 × 7.7 mm)

The mobile phase for the amino column was 80:20 acetonitrile/water at 0.2 mL/min and 40 °C nebulizer/60 °C evaporator temperatures. Hi-Plex Ca runs isocratically with water at 0.5–0.6 mL/min and 85–90 °C. Detection employed evaporative light scattering (Varian 385-LC ELS) for the amino column and refractive index detection (Varian 356-LC RI) for the Hi-Plex Ca.

Main Results and Discussion

Example 1 (8-component sugar mix) showed poor resolution on the amino column, with co-elution of monosaccharides and late elution of larger saccharides. Hi-Plex Ca reversed elution order (large oligomers elute first) and achieved baseline separation within 25 minutes using only water.

Example 2 (fruit wine): the Hi-Plex Ca column cleanly resolved seven compounds (sugars, sugar alcohols, ethanol) in under 30 minutes. Amino phase retained larger sugars longer and co-eluted similar molecular weight analytes.

Example 3 (7 sugar alcohols): the amino column separated alcohols by polarity but failed to resolve isobaric pairs. Hi-Plex Ca combined ligand exchange and size exclusion to baseline‐separate all seven alcohols in a single run without organic solvents.

Benefits and Practical Applications

• Eliminates dependence on acetonitrile, reducing operating costs and environmental impact.
• Improves resolution of complex sugar and sugar alcohol mixtures in food, beverage and fermentation analysis.
• Extends column lifetime and stability due to monodisperse particle technology.
• Simplifies method development with isocratic water elution.

Future Trends and Opportunities

Advances in ligand exchange media may enable coupling with mass spectrometry for structural elucidation of sugars, high-throughput screening in quality assurance, and online process monitoring. Further reduction in particle size and optimization of counter-ion chemistry could enhance speed and resolution. Integration with green analytical chemistry initiatives will drive broader adoption in food, pharmaceutical and bioprocess industries.

Conclusion

Ligand exchange chromatography on Hi-Plex Ca columns offers a robust, solvent-free alternative to amino-bonded silica methods for sugar and sugar alcohol analysis. It delivers superior resolution, reduced costs and greener operation, making it well suited for routine laboratory and industrial applications.

Reference Language and Target

This summary was produced based on English source material and is provided in English.