A Confirmatory Method for PCDDs and PCDFs in Compliance with EU Regulation 589/2014/EU Using Atmospheric Pressure Gas Chromatography (APGC) with Xevo TQ-S

Importance of the Topic

Exposure to dioxins (PCDDs and PCDFs) in food and feed poses significant health risks due to their toxicity and persistence. Regulation 589/2014/EU mandates robust confirmatory methods to monitor these persistent pollutants and ensure consumer safety.

Objectives and Study Overview

This study presents a confirmatory analytical approach using Atmospheric Pressure Gas Chromatography (APGC) coupled to a Waters Xevo TQ-S triple quadrupole mass spectrometer. The method is evaluated for compliance with EU Regulation 589/2014/EU and compared to traditional GC-HRMS performance.

Methodology and Instrumentation

The GC system comprised an Agilent 7890A with a DB-5MS UI column (60 m × 0.25 mm × 0.25 µm) operated in pulsed splitless mode. APGC ionization (API+) interfaced to a Xevo TQ-S mass spectrometer running in Multiple Reaction Monitoring (MRM) with unit mass resolution. Data acquisition and processing were performed using MassLynx and TargetLynx. Calibration standards (EPA-1613 CSL–CS5) and 13C-labeled analogues were used, and sample cleanup followed EC Methods 252/2012 and 152/2009.

Key Results and Discussion

• Selectivity: Two MRM transitions per congener and unit mass resolving power delivered clear chromatographic and spectral separation of all 17 PCDD/F congeners.
• Sensitivity: Limits of quantification reached low femtogram levels (10 fg on column) with S/N>49, meeting the one-fifth maximum limit criterion.
• Ion Ratios: Measured ion intensity ratios stayed within ±15% tolerance, with automated flagging via TargetLynx ensuring regulatory compliance.
• Linearity and Response: Calibration over 0.01–40 pg/µL achieved R²>0.999; relative response factors met EU (≤30% RSD) and EPA criteria.
• Comparison to GC-HRMS: TEQ results for mixed animal fat matched GC-HRMS outputs below the 2 pg/g regulatory limit.
• Carryover and Maintenance: Low-volume (1 µL) injections and optimized cleaning reduced carryover by 20%, prolonging instrument and consumable life.

Benefits and Practical Applications

• Fully compliant confirmatory method for PCDD/Fs under EU Regulation 589/2014/EU.
• Sensitivity and selectivity comparable to high-resolution MS with simplified operation.
• Improved throughput and reduced maintenance demands support routine food safety and environmental monitoring.

Future Trends and Applications

• Extension of APGC-MS/MS to other persistent organic pollutants requiring ultratrace detection.
• Automation of sample preparation and data workflows to boost laboratory efficiency.
• Enhanced software algorithms for faster data processing and improved selectivity.
• Global harmonization of confirmatory methods leveraging tandem MS technology.

Conclusion

APGC coupled with the Xevo TQ-S triple quadrupole mass spectrometer offers a sensitive, specific, and regulation-compliant confirmatory method for dioxin analysis. It meets or exceeds EU requirements while reducing operational complexity compared to GC-HRMS.

References

1. United Nations Treaty, Stockholm Convention of Persistent Organic Pollutants, 2001.
2. WHO 2005 Re-evaluation of Human and Mammalian Toxic Equivalency Factors for Dioxins.
3. European Commission Regulation No. 589/2014/EU.
4. European Commission Regulation No. 1881/2006/EC.
5. Commission Regulation (EU) No. 252/2012.
6. Commission Regulation (EU) No. 152/2009.
7. Portoles T. et al., Journal of Chromatography A, 1260, 2012.
8. Ladak A. et al., Waters Technology Brief No. 720004964EN, 2014.