Determination of 14 Polycyclic Aromatic Hydrocarbon Compounds in Edible Oil

Significance of the Topic

Edible oils can accumulate toxic heavy polycyclic aromatic hydrocarbons during high-temperature processing. These compounds pose carcinogenic risks and are regulated by EU limits requiring quantitation at sub-ppb levels. Reliable analysis is essential for food safety and regulatory compliance.

Objectives and Study Overview

• Develop and validate a multiresidue method for 14 heavy PAHs in five edible oils
• Achieve efficient oil matrix removal and selective cleanup
• Meet EU LOQ requirements of 0.9 to 2 ng per gram
• Demonstrate hybrid EMR-Lipid and PSA cleanup followed by GC/MS/MS analysis

Methodology and Instrumentation

• Sample oils: pumpkin seed, olive, avocado, almond, and grape seed oil
• Extraction: two-step liquid-liquid extraction with ethyl acetate/acetonitrile (20:80 v/v)
• Cleanup: Captiva EMR-Lipid 6 mL cartridge hyphenated with Bond Elut Jr PSA 500 mg cartridge
• Back-extraction: isooctane to remove water
• Detection: large volume injection GC/MS/MS in dynamic MRM mode

Used Instrumentation

• Agilent 7890B gas chromatograph with multimode inlet and backflush system
• Agilent 7000D triple quadrupole mass spectrometer
• Captiva EMR-Lipid and Bond Elut Jr PSA cartridges
• MassHunter software for data acquisition

Main Results and Discussion

Efficient matrix removal of more than 95% was achieved in all five oils, with significantly cleaner chromatographic backgrounds. The method reached LOQs between 0.9 and 2 ng/g, with accuracy ranging from 87 to 114% and RSDs below 15% across spiking levels. Recoveries were high for neutral PAHs; extraction efficiency decreased for the most hydrophobic analytes. Large volume injection enhanced sensitivity while maintaining reproducibility.

Benefits and Practical Applications

• Meets stringent regulatory requirements for heavy PAHs in edible oils
• Hybrid cleanup workflow reduces sample preparation time and solvent use
• Provides a clean extract for reliable quantitation via GC/MS/MS
• Applicable to quality control in food safety laboratories

Future Trends and Potential Applications

Further optimization may include alternative solvents or sonication to improve extraction of highly hydrophobic PAHs. Automating the cleanup workflow and expanding to other lipid-rich matrices such as dairy or biofuels could enhance throughput. Integration with high-resolution mass spectrometry may enable broader contaminant screening.

Conclusion

The method offers a robust, sensitive, and efficient approach for determining 14 heavy PAHs in edible oils. Combining Captiva EMR-Lipid with PSA cleanup on a GC/MS/MS platform yields reliable quantitation at sub-ppb levels, ensuring EU compliance and supporting food safety testing.

References

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