Polyaromatic hydrocarbons - PAHS analyzed according to EPA 610

Significance of the topic

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants formed during incomplete combustion of organic matter. Many PAHs are classified as toxic, mutagenic or carcinogenic, making their reliable detection and quantification critical for environmental monitoring, food safety and regulatory compliance. The U.S. EPA Method 610 defines a standard protocol for separating and measuring 16 priority PAHs using gas chromatography with flame ionization detection (GC-FID).

Objectives and overview of the study

This application note demonstrates a fast, robust GC-FID method for analyzing the full suite of EPA-610 PAHs in under one hour. Using an Agilent CP-Sil PAH CB UltiMetal capillary column, the study aims to achieve baseline resolution of all 16 compounds with high sensitivity, reproducibility and minimal carryover.

Methodology

The analytical procedure employs capillary GC with a temperature gradient to separate PAHs based on volatility and molecular structure. Key method parameters include:

• Temperature program: 70 °C initial hold, ramp at 3 °C/min to 300 °C
• Carrier gas: hydrogen at 100 kPa (flow ~30 cm/s)
• Injection: split mode (100 mL/min) at 325 °C
• Detection: flame ionization detector (FID) at 350 °C
• Sample: 0.5 µL of 100 ppm PAH standard in methanol

Used instrumentation

• Agilent gas chromatograph with split/splitless injector and flame ionization detector
• CP-Sil PAH CB UltiMetal column, 0.25 mm ID × 25 m length, 0.12 µm film thickness (Part No. CP7440)
• Hydrogen supply (carrier gas) and high-purity air for FID

Main results and discussion

The developed method achieved complete separation of all 16 EPA-610 PAHs within 58 minutes. Each analyte produced sharp, well-resolved peaks, enabling reliable identification and quantification. The column’s stable metal deactivation layer ensured low bleed and high inertness, preserving peak shape for early-eluting compounds such as naphthalene and late-eluting heavy PAHs like benzo[g,h,i]perylene. Reproducibility tests showed retention time variation below 0.2% and consistent peak areas across multiple injections.

Benefits and practical applications of the method

• Comprehensive coverage of 16 priority PAHs in a single run
• Fast analysis time (<60 min) increases laboratory throughput
• High sensitivity and reproducibility suitable for trace-level environmental samples
• Compatible with routine monitoring of air, water, soil and food matrices

Future trends and possibilities

• Integration with automated sample preparation (e.g., solid-phase extraction) for high-volume testing
• Adaptation to tandem MS detection for enhanced selectivity and lower detection limits
• Development of faster temperature programs and narrow-bore columns to reduce analysis time further
• Application of multivariate data analysis and machine learning for pattern recognition in complex environmental samples

Conclusion

This application note validates a robust GC-FID approach for rapid, accurate analysis of 16 EPA-610 PAHs using an Agilent CP-Sil PAH CB UltiMetal column. The method combines excellent separation, reproducibility and ease of use, supporting environmental and regulatory laboratories in meeting stringent monitoring requirements.

References

• EPA Method 610: Polyaromatic Hydrocarbons (PAHs) by Capillary Gas Chromatography with Flame Ionization Detection
• Agilent Technologies, Application Note A00586, October 2011