Fast Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) for Food and Environmental Samples

Significance of PAH Analysis in Food and Environment

Polycyclic aromatic hydrocarbons (PAHs) pose health and environmental risks due to their carcinogenic and mutagenic properties. Regulatory bodies such as the EPA and various food safety agencies mandate monitoring of PAH levels in water, soil, and food. Rapid and reliable quantification of PAHs supports compliance, risk assessment, and protection of public health.

Study Objectives and Overview

This work compares conventional HPLC methods with modern sub-2 µm particle columns for both environmental and food PAH analyses. Key aims include:

• Demonstrating fast screening of six PAHs in food matrices in less than 2 minutes.
• Achieving comprehensive analysis of 16 EPA priority PAHs in environmental samples within 5–13 minutes.
• Comparing column performance for different particle sizes and dimensions to balance resolution, speed, and pressure.

Methodology and Used Instrumentation

High-performance liquid chromatography was conducted on an Agilent 1200SL system equipped with diode array detection (DAD) at 220.4 nm and optional fluorescence detection (FLD). Eclipse Plus PAH columns with varied geometries were evaluated:

• Sub-2 µm RRHT columns (1.8 µm) for ultra-fast screening (2–7 min).
• Rapid Resolution columns (3.5 µm) for mid‐range speed and high resolution (11–19 min).
• Conventional 5 µm columns for routine analyses (20–30 min).

Mobile phases consisted of water (A) and acetonitrile (B) with simple gradient elution. Flow rates ranged from 0.42 to 3.0 mL/min depending on column diameter.

Main Results and Discussion

Use of sub-2 µm columns yielded:

• Screening of six PAHs in food in under 2 minutes with resolution ≥ 1.9.
• Complete separation of 16 environmental PAHs in 5 minutes (2.1 × 50 mm column) to 13 minutes (4.6 × 100 mm column), maintaining resolution Rs ≥ 1.7.
• Enhanced plate counts (N up to 32,500) and selectivity across critical PAH pairs.
• Reduced analysis time by up to 80% compared to 150 mm, 5 µm columns.

Comparative data underscore that shorter, narrow-bore columns conserve solvent (up to 50%) and reduce run times without sacrificing resolution.

Benefits and Practical Applications

• High throughput for environmental monitoring and food safety screening.
• Solvent savings and reduced operating costs with narrow-bore formats.
• Scalable column geometries to meet varying regulatory and laboratory throughput needs.
• Compatibility with existing HPLC systems and detection modes.

Future Trends and Potential Applications

Emerging directions include coupling sub-2 µm PAH columns with mass spectrometry for enhanced sensitivity and selectivity; development of green chromatography with aqueous or low-toxicity media; and integration into automated, high-throughput workflows for large-scale environmental surveys and food industry quality control.

Conclusion

Sub-2 µm RRHT and Rapid Resolution PAH columns markedly accelerate PAH analysis while preserving or improving chromatographic resolution. These advances enable laboratories to meet stringent regulatory demands with greater efficiency, lower solvent consumption, and flexibility across diverse sample types.

Reference

Faizy Ahmed, Maureen J. Joseph, John W. Henderson Jr. "Fast Analysis of Polycyclic Aromatic Hydrocarbons (PAHs) for Food and Environmental Samples," Agilent Technologies, 2008