GC/MS analysis of 16 EPA and (15+1) EU PAHs in salmon using a Agilent J&W Select PAH GC column

Significance of the Topic

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants with known carcinogenic and mutagenic properties. Their monitoring in foodstuffs such as fish is critical for consumer safety and regulatory compliance. Recent revisions in EU and EPA priority lists have increased the demand for reliable analytical methods capable of resolving complex PAH isomer mixtures at trace levels.

Objectives and Study Overview

This application study evaluates a new Agilent J&W Select PAH capillary column for the simultaneous GC/MS determination of 16 US EPA and 15+1 EU priority PAHs in a salmon matrix. The goal is to achieve complete separation of critical isomer pairs in a single 30-minute run using selected ion monitoring (SIM), thereby improving identification confidence and quantification accuracy.

Methodology and Instrumentation

Sample preparation involved saponification of 2 g homogenized salmon with methanolic KOH followed by cyclohexane extraction. The extract underwent automated gel permeation chromatography (GPC) clean-up coupled directly to an evaporation unit. The final concentrated fraction was analyzed by GC/MS in SIM mode.

Used Instrumentation

• Gas Chromatograph: Agilent GC with PTV large-volume injector
• Column: Select PAH, 15 m × 0.15 mm ID, 0.10 µm film
• Mass Spectrometer: MSD in EI (70 eV) SIM mode
• Carrier Gas: Helium, constant flow 1.2 mL/min
• Temperature Program: 70 °C to 350 °C with stepped ramps and holds

Main Results and Discussion

The Select PAH column achieved baseline or >50% valley separation for all critical isomer pairs, including chrysene/triphenylene, benzo[b/k/j]fluoranthene isomers, and high-molecular-weight dibenzopyrenes. Calibration over 1–400 ng/mL showed R2 ≥ 0.995. Limits of quantification were 0.5–1 ppb in salmon, with repeatability relative standard deviations < 15% and trueness between 74% and 117%.

Benefits and Practical Applications

• Comprehensive single-column separation reduces analysis complexity and false positives.
• High thermal stability (up to 350 °C) ensures sharp peaks for high-boiling PAHs.
• Low bleed improves signal-to-noise for trace-level detection.
• Automated GPC clean-up minimizes matrix interference and extends column lifetime.

Future Trends and Applications

Further developments may integrate high-resolution MS detection or multiplexed sample preparation for lower limits of detection and broader food matrices. Adoption of fast GC temperature programming and tandem mass spectrometry can expedite throughput while maintaining robustness. Compliance with evolving regulations may drive standardization of multi-responsibility analytical platforms.

Conclusion

The Agilent Select PAH column in combination with SIM-based GC/MS provides a reliable, accurate, and efficient solution for the determination of priority PAHs in salmon. Its unique selectivity for critical isomers and excellent thermal stability address current regulatory and analytical challenges in food safety testing.

References

• EFSA Journal 2008;724: Scientific Opinion on PAHs in Food
• Gomez-Ruiz & Wenzl, Anal Bioanal Chem 2009, 393:1697–1707
• Wenzl et al., Trends Anal Chem 2006, 25(7)
• Lerda, JRC Factsheet 2009
• Bordajandi et al., J Sep Sci 2008, 31:1769–1778
• Ziegenhals et al., J Sep Sci 2008, 31:1779–1786