Achieve Ultrafast Separations with Agilent InfinityLab Poroshell 120 EC-C18, 1.9 μm Columns

Significance of the Topic

Superficially porous particle columns have transformed high-performance liquid chromatography by combining high efficiency with reduced pressure demands. Reducing particle size further enhances resolution and sensitivity, enabling faster analyses and resource savings in applications such as agricultural, food testing, and pharmaceutical small-molecule separations.

Objectives and Study Overview

This study compares the chromatographic performance of a conventional 5 µm Agilent ZORBAX Eclipse Plus C18 column with Agilent InfinityLab Poroshell 120 EC-C18 columns packed with 1.9 µm superficially porous particles. Ten alkylphenone analytes, including a thiourea void marker, were separated under three conditions: the original 5 µm method, a scaled 1.9 µm method, and an ultrafast high-pressure 1.9 µm method.

Methodology

The 5 µm method used a 4.6 × 250 mm ZORBAX Eclipse Plus C18 column with a 35–95 % acetonitrile gradient over 36 minutes at 1 mL/min. The 1.9 µm method was geometrically scaled to a 2.1 × 50 mm Poroshell column, a 35–95 % gradient in 3 minutes at 0.5 mL/min. The ultrafast run employed the same 2.1 × 50 mm column at 60 °C, 2.3 mL/min, and a 50–100 % gradient in 0.3 minutes. All mobile phases were water and acetonitrile; sample concentration was 1 mg/mL with 0.1 mL of thiourea.

Instrumentation

An Agilent 1290 Infinity LC system configured for ultralow dispersion, including a binary pump, high-performance autosampler, thermostatted column compartment, and diode array detector, was used. Columns evaluated were Agilent ZORBAX Eclipse Plus C18 (4.6 × 250 mm, 5 µm) and Agilent InfinityLab Poroshell 120 EC-C18 (2.1 × 50 mm, 1.9 µm). Data were acquired with Agilent OpenLAB CDS ChemStation.

Main Results and Discussion

– The original 5 µm method achieved baseline separation of 10 compounds in 36 minutes with minimum resolution of 6.1.
– The scaled 1.9 µm method completed separation in 3 minutes with minimum resolution of 5.5, using 96 % less solvent and 95 % less sample.
– The ultrafast 1.9 µm method at 1,150 bar and 60 °C separated all analytes in 0.3 minutes with minimum resolution of 2.2, saving 98 % of mobile phase and achieving a 120-fold acceleration.

Benefits and Practical Applications

• Rapid method transfer between ZORBAX and Poroshell columns due to similar stationary phases
• Dramatic reduction in analysis time, solvent consumption, and sample usage
• Enhanced throughput for QA/QC and high-volume laboratories without extensive method redevelopment

Future Trends and Potential Applications

Further reductions in particle size and optimization of system dispersion are expected to push analysis speeds even further. High-pressure and high-temperature operation of superficially porous columns will expand ultrafast separations to complex matrices, real-time monitoring, and coupling with mass spectrometry for trace-level quantitation.

Conclusion

Agilent InfinityLab Poroshell 120 EC-C18 columns packed with 1.9 µm superficially porous particles enable seamless transfer of existing C18 methods and offer dramatic improvements in speed, efficiency, and resource savings. When system pressure limits permit, ultrafast separations can be achieved without compromising resolution, making these columns an attractive choice for modern analytical laboratories.

Reference

• Gratzfeld-Hugsen A, Naegele E. Maximizing efficiency using Agilent Poroshell 120 Columns. Agilent Technologies Application Note 5990-5602EN; 2016.
• Meyer VR. Practical High Performance Liquid Chromatography. 4th ed. Wiley; 2004.
• Agilent Technologies. Transfer of Methods between Poroshell 120 EC-C18 and ZORBAX Eclipse Plus C18 Columns. Application Note 5990-6588EN; 2011.