Waters Cortecs 2.7 μm columns

Importance of Solid-Core 2.7 μm Columns

Objectives and Overview

Methodology and Instrumentation

• Solid-core theory: Short diffusion paths reduce van Deemter A, B and C terms via uniform packing, lower porosity and improved thermal conductivity.
• Manufacturing controls: In-house synthesis of silica/hybrid particles ensures consistent quality and minimal batch variation.
• Acid stability testing: 21-hour exposure to 0.5% TFA at 60 °C to assess bonded phase retention of a neutral marker.
• Instrumentation used:
  
  • Waters ACQUITY UPLC H-Class System with PDA and QDa detectors
  • Waters Alliance HPLC with PDA detection

Key Results and Discussion

• Efficiency: CORTECS 2.7 μm phases outperform comparable fully-porous and competitive solid-core columns, delivering up to 50% higher plate counts at equivalent flow rates.
• Reproducibility: Four different production batches exhibit virtually identical retention and resolution profiles for test mixtures of acids, bases and neutrals.
• Acid tolerance: Minimal retention loss of methyl paraben under harsh low-pH conditions suggests robust bonding and endcapping strategies.
• C18+ performance: Positively charged surface modification yields narrower peaks and up to 60% S/N enhancement for basic analytes without ion-pair reagents.
• C18 performance: Balanced retention and high peak capacity for complex mixtures of acidic, basic and neutral compounds.
• HILIC performance: Effective retention of highly polar morphine metabolites via acetonitrile-rich mobile phases, enabling direct analysis from SPE, LLE or PPT extracts.
• Backpressure advantage: 25% lower operating pressure than competitive 2.6 μm solid-core columns, permitting longer columns or faster flow rates for increased resolution and throughput.
• Method transfer: Scaling from 5 μm to 2.7 μm and to 1.6 μm formats accelerates run times up to 9× and cuts solvent consumption up to 12× while preserving selectivity.
• Guard column protection: VanGuard cartridges extend analytical column life with negligible impact on chromatographic performance.

Benefits and Practical Applications

• High efficiency and resolution at HPLC/UHPLC pressures
• Versatile selectivity across C18+, C18 and HILIC phases
• Enhanced sensitivity in LC-MS workflows, especially for basic and polar compounds
• Robust performance under extreme pH and temperature conditions
• Seamless method transfer across multiple LC platforms
• Reduced analysis times and solvent usage for higher throughput
• Extended column lifetime through VanGuard protection

Future Trends and Opportunities

• Integration with advanced high-resolution mass spectrometry and data-driven workflows
• Novel surface chemistries for challenging analytes and biotherapeutics
• Digital QCRM implementation for real-time system suitability and method validation
• Global method standardization across multi-site and contract laboratories
• Further optimization of particle morphology for ultra-high throughput at moderate pressures

Conclusion

Reference

• G. Guiochon and F. Gritti, Journal of Chromatography A, 1218, 2011, 1915–1938.