Glucose and maltose derivatives separated on a Metrosep Carb 2 column applying a flow gradient

Importance of the Topic

Monosaccharide and oligosaccharide profiling is central to quality control in food and pharmaceutical industries. Maltodextrin analysis informs on dextrose equivalent and functional properties of hydrolyzed starch products.

Objectives and Study Overview

This study demonstrates the separation and quantitation of glucose (DE1) through maltoheptaose (DE7) using ion chromatography with a Metrosep Carb 2 column and pulsed amperometric detection.

Methodology and Instrumentation

• Column Metrosep Carb 2 250/4.0 with Carb 2 guard
• Eluent gradient of 200 mmol/L sodium hydroxide and 150 mmol/L sodium acetate: 0.7 mL/min (0–10 min), 1.2 mL/min (11–31 min), 0.7 mL/min (32–40 min)
• Column temperature 40 °C, injection volume 20 µL, recording time 32 min, pressure up to 20 MPa
• Pulsed amperometric detection with Wall-Jet cell, gold working electrode, palladium reference, 50 µm spacer, measurement potential 0.05 V, cycle duration 550 ms, temperature 35 °C

Main Results and Discussion

The method achieved baseline separation of seven saccharides at concentrations ranging from 0.25 mg/L to 10 mg/L. Retention times increased with oligomer length, demonstrating column selectivity for carbohydrate chain size. Sensitivity and repeatability were within acceptable limits for routine analysis.

Benefits and Practical Applications

• Rapid and robust profiling of maltodextrin chain-length distribution
• No sample preparation required for standard solutions
• High sensitivity suitable for trace analysis
• Direct application in food quality control and research laboratories

Future Trends and Opportunities

Coupling this IC method with mass spectrometry could enable structural confirmation of oligomers. Further automation and high-throughput sampling will streamline workflows. Development of greener eluents and miniaturized columns may reduce solvent use and improve analysis speed.

Conclusion

The described ion chromatography method using a Metrosep Carb 2 column and pulsed amperometric detection provides a reliable and sensitive approach for quantifying glucose through maltoheptaose in aqueous samples.

Reference

• Metrohm IC Application Note P-75 Version 1