Determination of 19 Polycyclic Aromatic Hydrocarbon Compounds in Salmon and Beef

Importance of the Topic

Polycyclic aromatic hydrocarbons (PAHs) are persistent, bioaccumulative, and potentially carcinogenic compounds that can contaminate fatty foods such as fish and meat during processing or environmental exposure. Regulatory bodies, including the U.S. FDA and the European Commission, set strict limits on heavy PAHs in seafood and meat to levels below 1 µg/kg. Reliable analytical methods are essential to monitor PAH residues at low part-per-billion concentrations in complex lipid-rich matrices.

Objectives and Study Overview

This work describes the development and validation of a robust multiresidue method for the determination of 19 PAH compounds in salmon and beef. The protocol integrates solid/liquid extraction (SoLE), Agilent Captiva EMR–Lipid cleanup, and GC/MS/MS analysis. Key goals include achieving high PAH recoveries, low detection limits, efficient removal of lipid co-extractives, and compliance with European Commission performance criteria.

Methodology and Instrumentation

Sample preparation comprises:

• Two-step SoLE using 20:80 ethyl acetate/acetonitrile with ceramic homogenizers and 10 min shaking per step.
• Cleanup by gravity elution through a 3 mL Captiva EMR–Lipid cartridge, followed by a supplementary elution with 16:64:20 EtOAc/ACN/water to maximize recovery.
• Water removal and solvent exchange via back-extraction into isooctane (1:1, v/v) to produce a GC-amenable extract.

Used Instrumentation

• Agilent 7890B gas chromatograph with electronic pneumatic control (EPC), multimode inlet (MMI), and backflush capability.
• Agilent 7000D triple quadrupole mass spectrometer operated in dynamic MRM mode.
• Agilent 7693A autosampler and positive pressure manifold (PPM-48) for cartridge processing.
• Captiva EMR–Lipid cartridges (3 mL, 300 mg) and associated ceramic homogenizers.

Main Results and Discussion

Validation in salmon and beef matrices showed:

• Calibration linearity (1–500 ng/g) with R² > 0.99 for all analytes.
• Mean recoveries between 50 % and 120 % and RSD < 20 % at spiking levels of 1, 10, and 100 ng/g.
• LOQ established at 1 ng/g for most PAHs; critical heavy PAHs (benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, chrysene) are reliably detected at 1 ng/g with S/N > 10.
• Matrix co-extractive removal of 60 % in salmon and 92 % in beef, significantly reducing lipid interference.

Benefits and Practical Applications

The optimized workflow delivers a streamlined, reproducible approach for routine monitoring of PAHs in high-fat foods. It simplifies cleanup, reduces solvent use, and enables quantitation at regulatory levels without extensive user intervention. Laboratories can adapt this method for quality control, food safety testing, and regulatory compliance.

Future Trends and Potential Applications

Opportunities for further advancement include:

• Extension to other lipid-rich matrices (dairy, oils, processed foods).
• Automation and miniaturization of the sample preparation steps.
• Integration with high-resolution mass spectrometry for non-target screening.
• Continuous refinement of lower detection limits to meet emerging regulatory standards.

Conclusion

An efficient multiresidue GC/MS/MS method combining SoLE, Captiva EMR–Lipid cleanup, and isooctane back-extraction has been established for reliable determination of 19 PAHs in salmon and beef. The method meets stringent recovery, precision, and sensitivity requirements, offering a powerful tool for food safety laboratories.

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