Determination of Polychlorinated Dibenzo-p-dioxins (PCDD) and Polychlorinated Dibenzofurans (PCDF) in Foodstuffs and Animal Feed using the Agilent 7000 Triple Quadrupole GC/MS System

Significance of the Topic

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) are persistent organic pollutants with high toxicity, bioaccumulation potential, and significant human health impacts. Most human exposure originates in animal-derived foods. Regulatory bodies in the EU and US require reliable quantitation at pg-level equivalents (pg TEQ/g fat). A robust, sensitive, and high-throughput screening method is therefore essential to protect public health and ensure compliance with food safety standards.

Study Objectives and Overview

This application note presents the development and validation of an isotope-dilution GC/MS/MS method using the Agilent 7000 Triple Quadrupole system. The goals were:

• To achieve linear response across the regulatory concentration range down to low pg TEQ/g fat
• To demonstrate repeatability and sensitivity suitable for EU maximum and action levels
• To compare results against traditional GC/HRMS analyses

Methodology and Instrumentation

Sample preparation combined fat extraction by Soxhlet or accelerated solvent extraction, fortified with 13C-labelled PCDD/PCDF internal standards, followed by multi-stage cleanup using sulphuric acid-silica, florisil, and activated carbon columns. Target fractions (dioxins/furans and PCBs) were eluted sequentially and reconstituted in toluene for analysis.

Instruments Used

• Agilent 7000 Triple Quadrupole GC/MS/MS
• Agilent 7890 GC with carbon dioxide-cooled Multi-Mode Inlet
• 2 m deactivated precolumn and 60 m Agilent J&W DB-5ms UI capillary column
• Pressure-Controlled Tee and Capillary Flow Technology for concurrent backflush
• Agilent 7693 Autosampler with cooled tray

Main Results and Discussion

The method delivered excellent linearity (R2>0.999 for most congeners) over 0.05–5 pg on-column. Repeatability tests (n=15) showed peak area RSDs <10% for all but one congener. Lower-level calibration points (100 fg) produced clear MRM signals. Screening of real food and feed samples (n=50) yielded pg TEQ/g values in close agreement (±10–20%) with GC/HRMS data. Deviations >20% occurred only at very low levels (<0.2 pg TEQ/g) near detection limits.

Benefits and Practical Applications

This triple-quadrupole approach offers:

• Rapid, high-throughput screening compliant with EU and US regulations
• Sensitivity and repeatability comparable to HRMS at reduced cost and instrument complexity
• Individual congener quantitation enabling source identification

Future Trends and Applications

Ongoing advances in multimode inlets, ultra-inert precolumns, and automated cleanup will further enhance robustness. Integration with bioassay-guided fractionation and advanced data analytics may support broader screening of emerging POPs and dioxin-like compounds in complex matrices.

Conclusion

The Agilent 7000 Triple Quadrupole GC/MS/MS meets the stringent requirements for PCDD/PCDF screening in foodstuffs and animal feed. It combines sensitivity, reproducibility, and regulatory compliance, providing an efficient alternative to high-resolution MS methods.

Reference

1. UK Food Standards Agency Ref 74/2008 "Emerging incident involving presence of dioxins in Irish pork meat"
2. US EPA Method 1613B
3. EC Regulation 1883/2006 and EC Regulation 152/2009, Annex V, Part B