All About LC Connections –What to Do to Make A Great One - HPLC educational webinar: Becoming a better chromatographer

Importance of the Topic

High-performance liquid chromatography (HPLC) performance and reproducibility depend critically on minimizing extracolumn dispersion, avoiding leaks, and maintaining zero-dead-volume connections. Inadequate tubing and improper fittings can compromise peak shape, resolution, and analytical accuracy, leading to wasted time and resources in research and quality control laboratories.

Objectives and Overview of the Study

This educational webinar by Golnar Javadi reviews best practices for LC connections, identifies common sources of chromatographic band broadening due to extracolumn volume, compares different fitting types, and introduces Agilent InfinityLab Quick Connect and Quick Turn fittings as solutions for reliable, user-friendly, zero-dead-volume connections.

Methodology and Instrumentation

Key methodological elements include:

• Assessment of dispersion via the Aris-Taylor equation and experimental peak width measurements.
• Comparison of extracolumn volumes using flow cells, heat exchangers, valves, and connecting capillaries of varying lengths and inner diameters.
• Evaluation of stainless steel, PEEK, and polyketone fittings across pressures up to 600–1300 bar.
• Test columns: StableBond SB-C18 (4.6×30 mm, 3.5 μm) and Eclipse Plus C18 (3×100 mm, 1.8 μm) under standard mobile phases (water/TFA and acetonitrile or methanol mix).

Main Results and Discussion

• Extracolumn volume as small as 10–50 μL markedly broadens peaks and reduces resolution, especially with UHPLC columns (1.8 μm particle size).
• Shorter, narrower (0.12 mm id vs. 0.17 mm) capillaries cut dispersion by over 50%, improving resolution from ~0.96 to ~1.9 and halving peak widths.
• Traditional Swagelok, Parker, and Waters fittings vary in ferrule design and nut length; mismatches cause leaks, mixing chambers, and distorted peak shapes.
• Agilent InfinityLab Quick Connect (finger-tight to 1300 bar) and Quick Turn (tool-assist to 1300 bar) fittings maintain zero dead volume, show consistent chromatograms after 200 reconnections, and allow user-replaceable capillaries and ferrules.

Benefits and Practical Applications

• Reduced troubleshooting time and maintenance costs by eliminating leaks and column damage from overtightening.
• Fast and reproducible column changes, supporting high-throughput labs and users with varying experience levels.
• Compatibility with Agilent 1290, 1260, 1200, 1100 and Waters Alliance systems, as well as various column brands.
• Enhanced chromatographic reproducibility, peak shape, and resolution across routine and UHPLC applications.

Future Trends and Applications

Advances are expected in:

• Further miniaturization of flow paths and integration of zero-dead-volume modules (heat exchangers, valves).
• Wider adoption of bioinert and hybrid materials to prevent sample adsorption.
• Smart fittings with embedded sensors for pressure and leak detection.
• Standardization of universal connectors across manufacturers to simplify method transfer.

Conclusion

Proper LC connections are as critical as column selection and mobile-phase preparation for achieving optimal chromatographic results. Minimizing extracolumn dispersion through correctly sized tubing and zero-dead-volume fittings significantly improves peak shape and resolution. Agilent InfinityLab Quick Connect and Quick Turn fittings offer an effective, user-friendly solution for reliable, high-pressure connections and reproducible performance in HPLC and UHPLC workflows.

Reference

No external literature references were cited in the source material.