Agilent Hi-Plex Ligand-Exchange HPLC Columns

Significance of the Topic

The accurate profiling of carbohydrates, sugar alcohols and organic acids is essential for product quality assurance, regulatory compliance and process monitoring across food, beverage and pharmaceutical industries.

Objectives and Study Overview

This study presents the design and performance of Agilent Hi-Plex ligand-exchange HPLC columns, focusing on their capacity to simplify mobile phases, reduce operating pressure and meet USP requirements for carbohydrate and organic acid analysis.

Methodology and Instrumentation

Agilent Hi-Plex columns use monodisperse sulfonated styrene-divinylbenzene particles in various counter-ion forms (H+, Ca2+, Pb2+, Na+, K+) and controlled crosslinking to tune pore size and size-exclusion properties. Isocratic separations with water or dilute acid eluent at elevated temperatures (40–90 °C) serve as the primary method. Detection modes include refractive index (RID), evaporative light scattering (ELSD) and pulsed amperometric detection (PAD) when using sodium hydroxide eluent.

Used Instrumentation

• Agilent 1260 Infinity LC system with high-pressure capability up to 600 bar
• Agilent 1260 Infinity Refractive Index Detector for non-UV active analytes
• Agilent 385-ELSD for thermally labile compounds
• Hi-Plex H, Ca, Pb, Na and K columns in dimensions specified by USP methods

Main Results and Discussion

Hi-Plex columns demonstrated:

• Stable, low-pressure operation thanks to monodisperse particles
• High selectivity and resolution of mono-, di- and oligosaccharides and sugar alcohols using different counter ions
• Efficient separation of organic acids on H-form columns with dilute acid eluent
• Excellent batch-to-batch reproducibility supporting reliable QA/QC

Representative chromatograms showed baseline separation of glucose, fructose, sucrose, mannitol, sorbitol, raffinose and stachyose under optimized conditions.

Benefits and Practical Applications

• Simple isocratic methods eliminate gradient complexity
• Water or dilute acid eluents reduce reliance on hazardous solvents
• Compatibility with USP L17, L19, L34 and L58 media types ensures regulatory compliance
• Wide application range including food adulteration detection, fermentation monitoring and pharmaceutical carbohydrate testing

Future Trends and Opportunities

Developments may include further miniaturization for UHPLC and microflow systems, integration with high-resolution mass spectrometry, advanced multivariate data analysis for complex matrices and continued expansion of detector options for improved sensitivity and specificity.

Conclusion

Agilent Hi-Plex ligand-exchange columns deliver robust, reproducible and user-friendly solutions for routine carbohydrate, sugar alcohol and organic acid analysis, combining low-pressure operation, simple mobile phases and compliance with pharmacopeial methods.

Reference

No literature references were provided in the original document.