Common Dibenzo Pyrenes and Coronene on Rxi®-PAH (60 m x 0.25 mm x 0.10)

Importance of the Topic

The analysis of high molecular weight polycyclic aromatic hydrocarbons (PAHs) such as dibenzo pyrenes and coronene is critical for environmental monitoring, food safety, and industrial quality control. These compounds are potent environmental contaminants with carcinogenic potential, requiring sensitive and selective analytical techniques for reliable detection and quantification.

Study Objectives and Overview

This application note presents a gas chromatography–mass spectrometry (GC-MS) method optimized for the separation and quantitation of common dibenzo pyrene isomers and coronene using an Rxi®-PAH capillary column. The study aims to achieve baseline resolution of structurally similar PAHs and demonstrate linearity across a concentration range of 0.71 to 10 µg/mL.

Methodology and Instrumentation

A split injection (10:1) of 1 µL sample was introduced into an Agilent 7890B GC equipped with a 60 m × 0.25 mm ID × 0.10 µm Rxi®-PAH column. The oven temperature was programmed from 110 °C (1.6 min hold) to 175 °C at 30 °C/min, then to 265 °C at 1.6 °C/min, and finally to 350 °C at 4 °C/min (15 min hold). Helium was used as the carrier gas at 1.0 mL/min. Detection was performed on an Agilent 5977A MSD in single ion monitoring (SIM) mode. Key ions (m/z 300, 302) were monitored for quantitation of the target analytes.

Main Results and Discussion

The method provided excellent chromatographic resolution of six target compounds:

• Dibenzo[b,k]fluoranthene (tR 82.23 min, 0.71 µg/mL)
• Dibenzo[a,l]pyrene (tR 82.51 min, 4.4 µg/mL)
• Dibenzo[a,e]pyrene (tR 84.18 min, 5.3 µg/mL)
• Coronene (tR 84.51 min, 0.98 µg/mL)
• Dibenzo[a,i]pyrene (tR 85.15 min, 4.4 µg/mL)
• Dibenzo[a,h]pyrene (tR 85.66 min, 4.4 µg/mL)

The SIM approach enhanced sensitivity and selectivity, yielding sharp peaks and consistent retention times. Linear calibration curves demonstrated reliable quantitation across the tested concentration range.

Benefits and Practical Applications

This rapid and robust GC-MS method enables environmental laboratories and industrial QA/QC facilities to:

• Accurately profile high-molecular-weight PAHs in complex matrices
• Ensure regulatory compliance for carcinogenic contaminants
• Support research on PAH fate and transport in the environment

Future Trends and Opportunities

Advancements in GC column technology, high‐resolution mass spectrometry, and automated data processing are expected to further improve PAH analysis by reducing run times, increasing throughput, and enhancing detection limits. Green analytical methods using alternative carrier gases and reduced solvent consumption will gain importance.

Conclusion

The optimized Rxi®-PAH GC-MS method provides high resolution and sensitivity for dibenzo pyrenes and coronene. Its reproducibility and linear performance make it suitable for routine analysis of trace-level PAHs in environmental and industrial samples.

References

Application Note: Common Dibenzo Pyrenes and Coronene on Rxi®-PAH, Restek Corporation, 2023.