Agilent Poroshell 120 columns – Now with 4 μm particle size

Significance of the Topic

The introduction of Agilent Poroshell 120 columns with 4 µm superficially porous particles addresses a critical need for high-efficiency separations on standard HPLC systems. By delivering near sub-2 µm performance at lower backpressures, these columns enable laboratories to increase throughput, improve resolution, and extend column lifetime, all without major hardware upgrades.

Objectives and Overview of the Article

This application note aims to present the enhanced performance characteristics of the new Poroshell 120, 4 µm columns, compare them to existing Poroshell 2.7 µm and conventional 5 µm columns, and demonstrate their benefits through benchmark analyte separations. It outlines column families, particle sizes, and phase chemistries, and illustrates how the columns solve common resolution and throughput challenges.

Used Instrumentation

• HPLC/UHPLC systems compatible with standard 400 bar pumps
• Agilent Poroshell 120 columns: 4 µm and 2.7 µm particle sizes in various chemistries (EC-C18, EC-C8, PFP, Phenyl-Hexyl, HILIC, SB-Aq, Bonus-RP, SB-C18/C8, HPH series)
• Mobile phases: mixtures of acetonitrile or methanol with water and acetic acid modifiers
• Flow rates: 1.2–2 mL/min for 4.6 mm ID columns; standard guard cartridges for sample protection
• Detection: UV absorbance at wavelengths appropriate for analytes (e.g., 220 nm for steroids)

Methodology

Analyses were conducted under isocratic and gradient conditions. Naproxen and butyrophenone mixtures compared performance between Poroshell 120, 4 µm and 5 µm reference columns using a 50:40:1 methanol:water:acetic acid mobile phase at 1.2 mL/min. Positional isomer separations employed PFP, C18, Phenyl-Hexyl, and C8 chemistries to highlight selectivity differences. Steroid mixtures were separated on EC-C18 and Phenyl-Hexyl columns using 36% organic in water with 0.1% acetic acid, at 1.2 mL/min and 25 °C.

Main Results and Discussion

• The Poroshell 120, 4 µm columns achieved nearly double the number of theoretical plates versus conventional 5 µm columns, with only ~100 bar backpressure.
• In naproxen separations, a 79% increase in efficiency was observed for a 150 mm, 4 µm column at equivalent run times; a 24% efficiency gain was seen with a 40% shorter 100 mm run.
• PFP phase provided superior resolution of 15 positional isomers compared with C18, Phenyl-Hexyl, and C8.
• Phenyl-Hexyl packing enhanced pi-pi interactions, yielding clearer steroid separations than EC-C18.

Benefits and Practical Applications

• Drop-in replacement for 5 µm methods with minimal method adjustment
• Sub-2 µm-like performance on conventional HPLC, saving time and solvent usage
• Robust frit design (2 µm frits) improves tolerance for dirty samples
• Wide phase selection (up to 12 chemistries) supports comprehensive method development, including high and low pH screening
• Compatible with standard UHPLC guard cartridges to prolong column life

Future Trends and Opportunities

Given ongoing demands for higher throughput and greener chromatography, superficially porous particle technology will likely expand into even lower backpressure designs and broader pH stability ranges. Integration with automated method scouting, novel stationary phase chemistries (ionic, mixed-mode), and coupling with high-resolution mass spectrometry will further extend application reach in pharmaceutical, environmental, and food analysis.

Conclusion

Agilent’s Poroshell 120 4 µm columns deliver a compelling balance of efficiency, speed, and robustness for both HPLC and UHPLC systems. By offering near sub-2 µm performance at accessible pressures, extensive phase options, and easy integration into existing workflows, these columns represent a versatile solution for modern chromatographic challenges.