Modernizing HPLC Methods with Agilent InfinityLab Poroshell 120 Columns

Significance of the topic

Carbonyl compounds are ubiquitous environmental pollutants with significant health and regulatory importance. Their analysis often relies on derivatization with dinitrophenylhydrazine (DNPH) to stabilize volatile species for HPLC detection. Efficient, high-throughput methods are essential for routine monitoring in air, soil and industrial settings.

Objectives and study overview

This study aimed to modernize an established DNPH-HPLC method by transferring and scaling it from a conventional 5 µm ZORBAX StableBond C18 column to Agilent InfinityLab Poroshell 120 SB-C18 columns with superficially porous particles of 4, 2.7 and 1.9 µm. The goal was to maintain chromatographic resolution while reducing analysis time and solvent consumption.

Methodology and instrumentation

Gradient separations were performed using an Agilent 1290 Infinity II UHPLC system equipped with a high speed pump, multisampler, multicolumn thermostat and diode array detector (DAD). Three Poroshell 120 SB-C18 columns (4.6×250 mm, 4 µm; 4.6×150 mm, 2.7 µm; 3.0×100 mm, 1.9 µm) and the original ZORBAX C18 column (4.6×250 mm, 5 µm) were evaluated. Mobile phase A was water and B was acetonitrile, with stepwise gradients increasing acetonitrile content. Flow rates ranged from 1.5 mL/min on larger columns to 0.64 mL/min on the 1.9 µm column. Detection was at 360 nm.

Main results and discussion

The 4 µm Poroshell column delivered comparable selectivity to the 5 µm ZORBAX column, reducing run time from 14 to 17 minutes while doubling efficiency. Scaling to the 2.7 µm column cut analysis time by 41% (10 min) and solvent use by 41% (15 mL). The 1.9 µm column achieved a 61% faster run (6.7 min) and an 83% reduction in mobile phase (4.3 mL) without loss of resolution. These gains reflect the L/dp ratio and the superficially porous particle design offering high efficiency at lower backpressure.

Benefits and practical applications

• Enhanced throughput accelerates sample turnaround in environmental and QA/QC labs.
• Substantial solvent savings lower operational costs and environmental impact.
• Straightforward method transfer preserves existing calibration and selectivity.

Future trends and potential applications

The use of superficially porous particles is expected to expand in UHPLC, enabling faster separations and greener analyses. Integration with mass spectrometry detection and microflow systems will further enhance sensitivity and robustness. Ongoing developments in column technology and automated workflows will support high-throughput screening and real-time environmental monitoring.

Conclusion

Scaling a DNPH-based HPLC method to Poroshell 120 SB-C18 superficially porous columns achieves tripled throughput and dramatic solvent reductions while maintaining resolution. This approach offers an effective path for modernizing routine carbonyl compound analysis.

Reference

1. EPA Method 8315a, Determination of Carbonyl Compounds by HPLC, U.S. Environmental Protection Agency, 1996.
2. HJ 997-2018, Soil and Sediment — Determination of Carbonyl Compounds — HPLC, Standards of Environmental Protection, China, 2018.