EU Compliant Routine Quantitative Dioxin, Dioxin-like PCB and Marker PCB Analysis by GC-MS/MS Using an Advanced Electron Ionization Source

Significance of the Topic

The routine quantification of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), dioxin-like PCBs, and indicator PCBs in food and feed is critical for consumer safety and regulatory compliance within the European Union. High sensitivity and reliable confirmation of trace-level contaminants support risk assessment and quality control efforts in laboratories across different geographic regions.

Objectives and Study Overview

This study assesses the performance of two Thermo Scientific TSQ 9000 AEI triple quadrupole GC-MS/MS systems, located in the UK and the USA, for compliance with EU regulations (Regulations 2017/644 and 771/2017). Key goals included demonstrating method sensitivity to one-fifth of the maximum levels, validating limits of quantitation (LOQs), precision, accuracy, and cross-laboratory reproducibility using solvent standards, proficiency test samples, and certified reference materials.

Methodology

Sample Preparation:

• 2 g fat aliquots from food/feed matrices or certified test materials.
• Extraction via Twisselmann hot extraction or pressurized liquid extraction.
• Automated clean-up using multistage acidic silica, alumina, and carbon columns on a DEXTech™ Plus system.

Analytical Approach:

• GC-MS/MS analysis in timed-SRM mode with advanced electron ionization (AEI) source.
• Chromatographic separation on TG-Dioxin capillary column (P/N 26066-1540).
• Calibration-based LOQ determination following EURL guidance to ensure continual performance monitoring.
• Data acquisition, processing, and reporting via Thermo Scientific Chromeleon™ 7.2 software.

Instrument Used

• Thermo Scientific TSQ 9000 AEI triple quadrupole GC-MS/MS.
• Advanced Electron Ionization (AEI) source.
• TG-Dioxin capillary GC column for optimal congener separation.
• DEXTech™ Plus automated clean-up system (LCTech GmbH).
• Chromeleon™ Chromatography Data System version 7.2.

Main Results and Discussion

The TG-Dioxin column achieved baseline separation of tetra- and penta-substituted congeners. Calibration-based LOQs reached as low as 0.15 pg on-column for upper bound WHO-PCDD/F-TEQs in 2 g samples, fulfilling the EU requirement of one-fifth of ML. Inter-run ion ratio deviations remained within ±15% for confirmation ions, and response factor deviations were below 30%. Proficiency test sample (QK1) and certified reference material (WMF-01) analyses across two laboratories showed deviations under 6% from reference values and LOQ repeatability deviations under 1.2% (well below the 20% acceptance criterion).

Benefits and Practical Applications

• Robust cross-laboratory performance ensures consistent regulatory compliance.
• High sensitivity enables reliable detection and quantification at sub-picogram levels.
• Integrated software platform streamlines method setup, data acquisition, processing, and reporting in regulated environments.
• Applicable to routine monitoring in food safety, feed analysis, and quality assurance.

Future Trends and Potential Applications

Advancements may include enhanced ionization sources for further sensitivity gains, expanded compound libraries for broader contaminant profiling, automation of sample preparation workflows, and integration with AI-driven data analytics. Such developments will support high-throughput screening and real-time decision-making in environmental, clinical, and forensic laboratories.

Conclusion

Validation on two TSQ 9000 AEI systems in distinct geographies demonstrated reliable quantitation of PCDD/Fs and PCBs in compliance with EU regulations. The method offers high sensitivity, reproducibility, and streamlined data management, making it suitable for routine monitoring and regulatory support in food and feed laboratories.

References

1. European Commission Regulation (EU) 2017/644, Official Journal of the European Union L 92, 2017.
2. European Commission Regulation (EU) 2017/771, Official Journal of the European Union L 115, 2017.
3. Thermo Fisher Scientific Application Note AN-10590: Low level quantification of PCDD/Fs in animal feed using TSQ 9000 with AEI source, 2019.
4. Guidance Document on the Estimation of LOD and LOQ for Measurements in the Field of Contaminants in Feed and Food, European Commission, 2019.
5. Directive 2002/32/EC on undesirable substances in animal feed, Official Journal L 140, 2002 (amended 2015).