Transferring HPLC Gradient Methods Using CORTECS Solid-Core Particle Columns

Significance of the Topic

Efficient method transfer in high-performance liquid chromatography (HPLC) is critical for modern analytical laboratories seeking to improve throughput, reduce solvent and sample consumption, and lower operational costs. Solid-core particle columns, such as CORTECS® 2.7 µm, offer high efficiency comparable to larger fully porous particles but enable significant reductions in analysis time and resource usage while maintaining chromatographic performance.

Objectives and Study Overview

This study demonstrates the transfer of a gradient HPLC method for the analysis of abacavir and its four related substances from a conventional fully porous C18, 5 µm (4.6 × 150 mm) column to a shorter CORTECS C18, 2.7 µm (4.6 × 75 mm) column. Objectives include:

• Calculating appropriate column dimensions, flow rate, injection volume, and gradient time to preserve separation selectivity and resolution.
• Comparing analytical performance, run time, solvent consumption, and backpressure between the original and transferred methods.

Methodology and Instrumentation

The original and transferred methods were performed on a Waters Alliance® HPLC system with a 2489 TUV detector, controlled by Empower® 3 software. Key parameters:

• Mobile Phase A: 0.1 % trifluoroacetic acid in water
• Mobile Phase B: 85 % methanol in water
• Detection: UV at 254 nm
• Original Column: Fully porous C18, 5 µm, 4.6 × 150 mm
• Transferred Column: CORTECS C18, 2.7 µm, 4.6 × 75 mm
• Scaled Flow Rate: from 1.0 mL/min to 1.85 mL/min to maintain linear velocity
• Adjusted Injection Volume: from 8 µL to 4 µL
• Gradient times adjusted to preserve equivalent column volumes

Instrumentation Used

• Alliance HPLC System with 2489 TUV detector
• CORTECS® 2.7 µm C18 solid-core columns
• Fully porous C18, 5 µm columns
• Empower® 3 Chromatography Data Software

Key Results and Discussion

The transferred method on the CORTECS C18, 2.7 µm column achieved equivalent selectivity and maintained critical resolution values (USP resolution of 2.7 and 4.1 for key peak pairs) compared to the original:

• Analysis time reduced from 50 min to 15 min (~4× faster)
• Solvent consumption halved (from ~20.8 mL to ~10.5 mL MeCN per run)
• Backpressure increased from 1,800 psi to 4,400 psi, remaining below the 5,000 psi instrument limit

The study confirmed that proper scaling equations for column length, flow rate, injection volume, and gradient duration ensure preservation of chromatographic efficiency when transitioning to solid-core particles.

Benefits and Practical Applications

This method transfer approach enables laboratories in pharmaceutical quality control, research and development, and industrial analytics to:

• Increase sample throughput and reduce run times without sacrificing resolution
• Lower solvent and sample use, supporting cost savings and greener operations
• Maintain existing HPLC hardware by operating within standard pressure limits

Future Trends and Potential Applications

Emerging directions in HPLC method transfer include:

• Broader adoption of solid-core and sub-2 µm particles for ultra-high performance applications
• Integration of automated scaling tools and predictive software to streamline method translation
• Expansion of green analytical chemistry practices through reduced solvent footprints
• Use in regulated environments (pharmaceuticals, environmental, food safety) to meet evolving throughput and sustainability demands

Conclusion

The transfer of an abacavir impurity gradient method from a fully porous 5 µm column to a CORTECS C18 2.7 µm solid-core column successfully demonstrated a four-fold increase in throughput and a two-fold reduction in solvent usage without compromising chromatographic performance. Adherence to scaling equations for column dimensions, flow rate, injection volume, and gradient time ensures robust method equivalence and leverages cost and efficiency benefits for routine HPLC analysis.