ALEXYS™ Carbohydrate Analyzer

Importance of the Topic

Carbohydrate profiling is essential across food science, biotechnology and glycomics. Reliable quantification of mono-, oligo- and polysaccharides supports quality control, nutritional evaluation and fundamental research in plant, microbial and clinical matrices.

Objectives and Study Overview

This study presents the ALEXYS Carbohydrate Analyzer, a fully dedicated high-performance anion-exchange chromatography system with pulsed amperometric detection (HPAEC-PAD). The aim is to demonstrate its precision, sensitivity and reproducibility for direct, derivatization-free carbohydrate analysis in routine and R&D applications.

Methodology and Instrumentation

The ALEXYS system integrates the following modules:

• Eluent Bottle Tray ET210: inert blanketing of mobile phases to exclude CO2/O2, ensuring stable high-pH eluents.
• Quaternary HPLC Pump P6.1L: dual-piston design for minimal pulsation, flow rates from tens of µL/min up to 10 mL/min, pressures to 400 bar, automated piston wash.
• Inert Autosampler AS6.1L: dual needle, headspace pressure, sample volumes down to 100 nL, temperature control (4–40 °C), rapid cycle times under 30 s.
• Column Thermostat CT2.1: Peltier-controlled oven (5–85 °C) with ±0.1 °C stability and leak shutdown.
• Electrochemical Detector DECADE Elite: Faraday-shielded, temperature-stabilized flow cell compartment, advanced digital filter, programmable 4-step PAD waveform.
• Flow Cells: FlexCell thin-layer design for routine use with replaceable gold electrode; SenCell wall-jet cell with adjustable spacing technology for maximum sensitivity.

Main Results and Discussion

Pump flow accuracy tests at 0.05, 0.2, 1.0 and 5.0 mL/min showed errors ≤0.6 % and RSD ≤0.19 %. Ten consecutive injections of a ten-sugar mixture yielded retention time RSD 0.11–0.21 % and peak area RSD 0.20–0.59 %. Sensitivity assessments revealed limits of detection ≤0.055 ppm and quantitation ≤0.185 ppm for trisaccharides, with even lower values for mono- and disaccharides. Representative chromatograms illustrate baseline separation of sugars in standards, honey, lactose-free milk, N-glycan mixtures and inulin extracts.

Practical Benefits and Applications

The system enables:

• Direct analysis of mono- to pentasaccharides, oligosaccharides and polysaccharides including prebiotics (TGOS, FOS), sugar acids, sugar alcohols, phosphates and nucleotides.
• Routine quality control in food and beverage industries, dairy and meat products, honey authenticity, lactose intolerance screening.
• Glycan profiling in biopharmaceutical and clinical research.
• High-throughput screening with robust carry-over control and minimal maintenance.

Future Trends and Potential Applications

Integration with mass spectrometry for structural elucidation, miniaturized and multiplexed HPAEC-PAD designs, advanced automation workflows and coupling with microfluidic sampling are emerging directions. Enhanced data processing algorithms and online monitoring of fermentation or bioprocess streams will further expand the utility of dedicated carbohydrate analyzers.

Conclusion

The ALEXYS Carbohydrate Analyzer offers a turnkey solution for precise, sensitive and reproducible carbohydrate analysis without derivatization. Its dedicated configuration, modular instrumentation and advanced detection capabilities make it a versatile platform for both routine and research-grade workflows.

References