HPLC, LC/MS Columns Inertsil Hybrid-C18

Importance of the Topic

Modern pharmaceutical, environmental and biochemical analyses demand chromatographic columns that maintain performance under a wide range of pH conditions. The ability to operate reliably at both acidic and basic pH expands method flexibility, reduces equilibration time, and minimizes column replacement costs. Inertsil Hybrid-C18 addresses these needs by combining hybrid organic–inorganic silica bonding technology with robust manufacturing control, delivering stable, reproducible separations from pH 1 to 12.

Objectives and Study Overview

This report introduces the key features, performance characteristics and application examples of the Inertsil Hybrid-C18 column. It aims to demonstrate:

• pH tolerance and chemical stability under extreme mobile phase conditions
• batch-to-batch reproducibility
• chromatographic performance across diverse analyte classes
• practical application in pharmaceutical assay and dissolution testing

Methodology and Instrumentation

The column is based on hybrid silica particles with a C18 bonded phase, available in 1.7, 3.5 and 5 µm sizes, pore size 165 Å and carbon load 15%. It supports temperatures up to 80 °C (pH 1–10) and 60 °C (pH 1–12) and pressures to 18 000 psi. Testing employed high-pressure LC systems, LC/MS and LC/MS/MS instrumentation with both stainless steel and bio-inert PEEK hardware. Durability studies used pH 11.5 phosphate buffer/ACN and monitored retention and plate count stability at 40 °C, 0.2 mL/min flow, detection at 254 nm.

Main Results and Discussion

• pH Impact on Selectivity: Mobile phase pH shifts from 4.8 to 9.8 altered retention of acidic (COOH) and basic (pKa≈9) compounds predictably, without loss of efficiency. Peak resolution remained high across the range.
• Alkali Resistance: After prolonged exposure to pH 11.5, Inertsil Hybrid-C18 retained theoretical plates and peak shape, confirming superior silica stability over conventional columns.
• Batch Reproducibility: Three production lots exhibited nearly identical retention times and peak shapes for test compounds, ensuring method transfer without revalidation.
• Analyte Scope: The column delivered sharp, symmetric peaks for basic (berberine, dextromethorphan), acidic (Blue FCF, salicylic acid), and metal-coordinating (8-quinolinol, piroctone olamine) analytes, outperforming a leading competitor in peak tailing factor.
• Application Examples: Assay and dissolution of azithromycin tablets under USP conditions, analysis of guanine and nucleoside antiviral agents, antihistamines and antidepressants all achieved tailing factors <1.5 and RSD <0.2%.

Benefits and Practical Applications

Inertsil Hybrid-C18 offers:

• Wide pH range compatibility to simplify method development and reduce column inventory
• High chemical and thermal stability for extended lifetime in alkaline conditions
• Consistent performance across production lots for reliable QA/QC workflows
• Flexible hardware options (SS and PEEK) suitable for routine LC, LC/MS and bioanalytical assays
• Custom dimensions available for preparative scale or specialized configurations

Future Trends and Potential Applications

Advances in hybrid silica technology are expected to extend pH stability further and enable sub-2 µm particles for UHPLC applications. Emerging fields such as proteomics, metabolomics and green analytical chemistry will benefit from columns that endure aggressive cleaning and rapid pH cycling. Integration with automated method scouting platforms and direct coupling to high-resolution mass spectrometers offers potential for high-throughput screening and multi-omics workflows.

Conclusion

Inertsil Hybrid-C18 represents a versatile, high-performance reversed-phase column that excels under both acidic and basic mobile phase conditions. Its robust hybrid silica bonding, excellent lot-to-lot consistency and broad compatibility with modern LC and LC/MS systems make it a valuable tool for pharmaceutical, environmental and biological laboratories seeking reliable, long-lifetime chromatographic solutions.

Reference

No formal literature citations were included in the source document; performance data and specifications are provided by GL Sciences Inc.