Comparison of the Chromatographic Resolution of Solid Core 4 μm and Fully Porous 3 μm and 5 μm Columns

Importance of the Topic

High-resolution chromatographic separation is essential for reliable analysis of complex mixtures. Selecting columns with optimized particle architecture improves peak efficiency, resolution, and productivity, facilitating robust methods in pharmaceutical, food, environmental, and regulated laboratories.

Objectives and Study Overview

The work compares chromatographic performance of 4 μm solid core (Accucore XL) columns against fully porous 3 μm and 5 μm counterparts under isocratic and gradient conditions. It aims to demonstrate efficiency and resolution gains achievable on conventional HPLC systems without altering method parameters or requiring full revalidation.

Methodology and Instrumentation

• Columns: 150 × 4.6 mm Accucore XL C18 4 μm solid core; fully porous C18 5 μm and 3 μm; Accucore XL C8 4 μm and fully porous C8 5 μm for catechin analysis.
• Mobile phases: acetonitrile/methanol blends for fat-soluble vitamins; water and acetonitrile (with 0.1% formic acid) for herbicides and catechins.
• Operating conditions: flow rates 1.0–1.3 mL/min; temperatures 25–30 °C; UV detection at 247–280 nm; injection volume 5 μL.
• Core Enhanced Technology™ solid core particles to sharpen peaks and reduce column void volume.

Main Results and Discussion

• Isocratic vitamins: Accucore XL 4 μm doubled plate counts versus 5 μm porous columns, boosting critical pair resolution from 1.92 to 2.50 under identical conditions.
• Gradient herbicides: Solid core 4 μm columns delivered 27% and 11% higher critical-pair resolution over 5 μm and 3 μm porous columns, with peak capacity improvements of 66% and 44%, respectively.
• Catechins on C8 phase: Resolution of the key pair rose from 1.17 on 5 μm porous to 2.68 on 4 μm solid core, with average peak-width reduction of 34%.
• Productivity: Flat van Deemter behavior enabled gradient and flow rate optimization, halving run times to ~4 min while maintaining resolution >3 for critical analytes.

Benefits and Practical Applications

• Enhanced resolution on existing HPLC platforms with no method revalidation, ideal for regulated environments.
• Lower solvent consumption and faster analyses due to reduced column volume and higher optimal velocities.
• Sharper peaks and increased peak capacity support accurate quantitation in quality control and research.

Future Trends and Potential Applications

• Broader use of solid core columns in routine and high-throughput laboratories balancing efficiency and pressure constraints.
• Coupling with mass spectrometry to exploit improved peak shapes for trace-level detection.
• Development of novel stationary phases combining superficial porosity with advanced chemistries targeting polar, chiral, and biomolecule separations.

Conclusion

Accucore XL 4 μm solid core columns offer significant gains in chromatographic efficiency and resolution over fully porous 3 μm and 5 μm columns. These improvements translate into faster, more productive methods on standard HPLC systems without altering established protocols.

Reference

1. Thermo Scientific Technical Note 20641 Solid Core 4 μm HPLC Column Comparison to Fully Porous 3 μm and 5 μm Columns: Efficiency and Pressure.