Trace analysis of polychlorinated dibenzo-p-dioxins/ dibenzofurans using GC-MS/MS in accordance with EU Regulations 2017/644 and 2017/771 for food and feed

Significance of the Topic

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are persistent, fat-soluble pollutants regulated under EU 2017/644 and 2017/771 due to their high toxicity and bioaccumulation risks in food and feed. Accurate trace-level analysis is essential to ensure compliance with tightening limits and protect public health.

Objectives and Study Overview

This study evaluates the performance of the Thermo Scientific TSQ 9610 triple quadrupole GC-MS/MS system, equipped with the NeverVent AEI source and controlled by Chromeleon CDS 7.3 using the Dioxin Analyzer eWorkflow, for the quantification of PCDD/Fs in various food and feed matrices. Samples with known concentrations from EURL POPs and Wageningen Food Safety Research were analyzed to verify sensitivity, accuracy, and regulatory compliance.

Methodology

Sample Preparation:

• Food samples (animal fats, oils, baby food, herbs) and feed fats extracted via accelerated solvent extraction or hot extraction.
• Cleansing using sulfuric acid treatment, liquid-liquid extraction, and automated multi-layer column clean-up on DEXTech Plus.
• Spiking with 13C-labelled dioxin standards for isotopic dilution quantification.

Instrumental Setup

GC-MS/MS Configuration:

• TRACE 1610 GC with iConnect PTV injector and TriPlus RSH SMART autosampler.
• TRACE TG-Dioxin capillary column (60 m×0.25 mm×0.25 µm).
• TSQ 9610 triple quadrupole mass spectrometer with NeverVent AEI source and XLXR detector.
• Chromeleon CDS 7.3 control with eWorkflow for automated method setup, data acquisition, isotopic dilution quantification, and compliance reporting.

Main Results and Discussion

Sensitivity and Linearity:

• Femtogram-level detection: 10 fg on-column for 1,3,6,8-TCDD with <11% RSD over ten injections.
• Linear dynamic range for tetra- to octa-substituted congeners (R2>0.990) across pg·µL-1 concentrations.
• Calibration response factors within <10% RSD over six points, meeting EU ±30% criteria.

Check Standards and Regulatory Compliance:

• LOQ/2 and LOQ/4 check standards passed ion ratio and quantitation thresholds at 12.5–25 fg on-column.
• Quantification of EURL and Wageningen proficiency samples yielded results closely matching reference HRMS values and below current maximum levels and action thresholds.

Workflow Efficiency:

• Integrated data processing in Chromeleon CDS eliminated external spreadsheet use and reduced transcription errors.
• NeverVent source technology enabled maintenance without venting, saving instrument downtime.

Benefits and Practical Applications

• High sensitivity and reproducibility facilitate reliable routine monitoring of PCDD/Fs in food/feed at regulatory limits.
• Automated eWorkflow simplifies method execution, quality control, and compliance reporting under EU regulations and FDA Title 21 CFR Part 11.
• Rapid instrument maintenance reduces downtime, increasing laboratory throughput.

Future Trends and Applications

Anticipated lower maximum levels for certain feedstuffs in 2024 will demand further sensitivity improvements. Integration with advanced data analytics and linking real-time results to risk assessment frameworks will enhance food safety monitoring. Emerging miniaturized and high-throughput GC-MS/MS systems may further streamline dioxin testing workflows.

Conclusion

The TSQ 9610 GC-MS/MS system with NeverVent AEI source and Chromeleon CDS eWorkflow demonstrates the capability to meet stringent EU regulations for dioxin analysis in food and feed. It provides femtogram-level sensitivity, regulatory compliance, and operational efficiency, making it a robust solution for routine and proficiency testing laboratories.

References

1. Commission Regulation (EU) 2017/644 on methods for dioxins and PCBs in food/feed.
2. Commission Regulation (EU) 2017/771 amending method standards for dioxins and PCBs.
3. EU 2023/915 on maximum levels of contaminants in food.
4. EPA Method 1613B for PCDD/F analysis in environmental samples.