Ultra-Sensitive Detection of PCBs and PAHs in seafood by GC-MS/MS following the European Union regulations

Importance of the Topic

Persistent organic pollutants such as non-dioxin-like polychlorinated biphenyls (NDL-PCBs) and polycyclic aromatic hydrocarbons (PAHs) pose serious health risks when accumulated in seafood. Regulatory bodies in the European Union have set stringent maximum levels and method performance criteria to protect consumers from endocrine disruption, carcinogenicity and other toxic effects. Reliable, ultra-sensitive analytical techniques are essential for routine monitoring, food safety and compliance.

Study Objectives and Overview

The presented work aims to develop and validate a simultaneous gas chromatography-tandem mass spectrometry (GC-MS/MS) method for the quantitation of six marker NDL-PCBs and sixteen PAHs in bivalve mollusks and other seafood. The method follows EU Regulations 252/2012, 1259/2011, 589/2014, 835/2011 and 836/2011, ensuring detection limits and performance meet or exceed legal requirements.

Methodology and Used Instrumentation

Sample Preparation:

• Eight-gram seafood homogenates were alkaline hydrolyzed (KOH/MeOH), filtered and extracted with n-hexane.
• Extracts underwent solid-phase cleanup on alumina-florisil cartridges, solvent evaporation under nitrogen and reconstitution in cyclohexane:toluene (9:1).

Chromatography and Detection:

• Instrument: Bruker EVOQ GC-TQ Premium triple quadrupole MS.
• Gas chromatograph: Bruker 436 GC with 40 m × 0.18 mm, 0.18 µm BR-PCB column.
• Injection: 1 µL splitless on Bruker 1177 injector; He carrier gas at 0.8 mL/min; oven ramp from 70 °C to 320 °C in 50 min.
• Mass spectrometry: Electron ionization (70 eV), MRM mode with up to three transitions per analyte; argon CID gas at 2.0 mTorr.
• Software: Bruker MSWS 8.2.1 and TASQ 1.4 for data processing.

Main Results and Discussion

The method achieved limits of detection below 0.1 µg/kg and limits of quantitation at 0.5 µg/kg for each target PCB and PAH. Calibration curves were linear across 0.5–100 ppb (R² > 0.995; RSD < 15%). Repeatability at 0.8 µg/kg spike showed RSD < 4% for all analytes. Excellent chromatographic separation resolved critical co-eluting pairs (e.g., PCB 28/31, B(b)F/B(k)F, B(a)A/Chrysene). Robust ion-ratio stability and retention time precision met EU tolerances (±20% ion ratio; ±0.25% retention shift). Dilution of extracts by two-fold maintained detection criteria, reducing matrix effects and extending instrument uptime.

Benefits and Practical Applications

High sensitivity and selectivity allow routine 24/7 monitoring of trace levels in seafood with minimal sample injection volume (1 µL). The method’s robustness under diluted conditions decreases maintenance frequency and extends column life. Rapid run time and reliable quantitation support quality assurance in research, regulatory control and industrial testing laboratories.

Future Trends and Applications

Advances may include expanded analyte panels covering dioxin-like PCBs and emerging contaminants, integration of high-resolution MS for non-target screening, automated sample preparation workflows and AI-driven data interpretation. Portable or miniaturized GC-MS/MS systems could enable on-site seafood safety testing at aquaculture or processing facilities.

Conclusion

An optimized GC-MS/MS protocol using the Bruker EVOQ GC-TQ Premium system provides ultra-sensitive, accurate and robust detection of NDL-PCBs and PAHs in seafood. The approach complies with EU regulatory demands, offers efficient throughput and extends instrument maintenance intervals, making it suitable for routine food safety surveillance.

Reference

• Commission Regulation (EU) No 252/2012 on methods of sampling and analysis for dioxins and PCBs in food.
• Commission Regulation (EU) No 1259/2011 amending maximum levels for PCBs in food.
• EFSA Scientific Report, Monitoring of non-dioxin-like PCBs in food and feed, EFSA Journal 2010;8(7):1071.
• Commission Regulation (EU) No 835/2011 on maximum levels for PAHs in foodstuffs.
• Commission Regulation (EU) No 836/2011 on sampling and analysis methods for PAHs in food.
• NOAA Technical Memorandum NMFS-NWFSC-59, Extraction and GC/MS analysis of sediments and tissues, 2004.