Determination of 24 Polycyclic Aromatic Hydrocarbons in Smoked Meat by ASE Extraction-GPC Purification Coupled with GC/MS

Importance of the topic

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants formed during incomplete combustion of organic materials. Their known mutagenic, teratogenic and carcinogenic properties make them a critical target for food safety monitoring. Smoked meats are particularly prone to PAH contamination, and regulatory bodies have set strict limits (e.g., EU limits: 2 µg/kg benzo(a)pyrene, 12 µg/kg sum of PAH4) to protect consumer health.

Objectives and overview of the study

This application note presents a validated analytical workflow for simultaneous determination of 24 PAHs in smoked meat products. The aims were to develop a robust sample preparation protocol combining accelerated solvent extraction (ASE), gel permeation chromatography (GPC) and solid phase extraction (SPE), coupled with gas chromatography–mass spectrometry (GC/MS), and to demonstrate performance metrics including sensitivity, accuracy, precision and applicability to real samples.

Methodology and used instrumentation

Sample preparation:

• Homogenize 1 g of smoked meat with diatomaceous earth and spike with 50 µL internal standard (16-isotope PAHs).
• ASE extraction: ethyl acetate/cyclohexane (1:1), 120 °C, 1500 psi, 3 × 6 min cycles; extract concentration to 10 mL and filtration.
• GPC cleanup: Bio-Beads S-X3 column, ethyl acetate/cyclohexane (50:50), collect fraction 8–24 min, concentrate and redissolve in n-hexane.
• SPE cleanup: deactivated silica cartridge, wash with n-hexane/dichloromethane (8:2), concentrate and reconstitute in acetonitrile.

Instrumentation:

• ASE system: Dionex ASE Prep DE.
• GPC system: column 25 × 400 mm packed with Bio-Beads S-X3.
• SPE cartridges: deactivated silica gel (100–200 mesh).
• GC/MS: PerkinElmer Clarus SQ8 with Agilent J&W DB-EUPAH (20 m × 0.18 mm × 0.14 µm) capillary column; splitless injection, helium carrier, oven program 80 °C–315 °C, MS operated in SIFI mode.

Main results and discussion

Calibration and performance:

• Calibration linear over 1–600 µg/L for most PAHs; correlation coefficients r² > 0.997.
• Method detection limits (MDLs) ranged from 0.4 to 5.0 µg/kg.
• Recoveries: 70–118%; intra-day precision (RSD): 5–10% across three spike levels (10, 50, 100 µL).

Real sample analysis:

• 100 smoked meat samples analyzed; benzo(a)pyrene detected in 76% of samples, PAH4 sum exceeded regulatory limits in 33% of cases.
• Individual PAH concentrations spanned from sub-µg/kg to several thousand µg/kg for low-molecular-weight PAHs like phenanthrene.

Benefits and practical applications

The combined ASE–GPC–SPE–GC/MS workflow delivers high throughput, minimized solvent usage, and effective removal of matrix interferences. It meets regulatory requirements for ultra-trace PAH quantification in complex food matrices, supporting quality control in food safety laboratories and industry.

Future trends and potential applications

Emerging directions include integration of high-resolution mass spectrometry for enhanced selectivity, miniaturized extraction techniques to further reduce solvent consumption, automation of sample cleanup steps, deployment of green solvents, and coupling with ambient ionization methods for rapid on-site screening of PAHs in food and environmental samples.

Conclusion

The validated method achieves reliable quantification of 24 PAHs in smoked meats with excellent sensitivity, accuracy and precision. Its applicability to real samples and compliance with EU limits demonstrate its suitability for routine food safety monitoring.

References

• Rey-Salgueiro L, García-Falcón MS, Martínez-Carballo E, et al. Effects of toasting procedures on PAH levels in toasted bread. Food Chemistry. 2008.
• IARC Monographs. Latest classification of carcinogenic hazards. 2023.
• Farhadian A, Jinap S, Hanifah HN, et al. Effects of meat preheating on PAHs in charcoal-grilled meat. Food Chemistry. 2011.
• Martí-Cid R, Llobet JM, Castell V. Evolution of dietary exposure to PAHs in Catalonia. Food & Chemical Toxicology. 2008.
• Hokkanen M, Luhtasela U, Kostamo P, et al. Critical effects of smoking parameters on PAH levels in traditional smoked fish and meats. Journal of Chemistry. 2018.
• Commission Regulation (EU) No 835/2011 amending Reg. (EC) No 1881/2006 on maximum PAH levels in foodstuffs.