DIOXIN: Low level quantification of PCDD/Fs in animal feedstuffs using the Thermo Scientific TSQ 9000 GC-MS/MS system with AEI source

Significance of the Topic

Polychlorinated dibenzo p dioxins and related furans are persistent organic pollutants that accumulate in animal feed and the food chain. Their high toxicity, including endocrine disruption, immunotoxicity and carcinogenic effects, makes trace level monitoring essential to ensure food safety and regulatory compliance.

Study Objectives and Overview

This work evaluates the Thermo Scientific TSQ 9000 triple quadrupole GC MS MS system equipped with an Advanced Electron Ionization source for confirmatory analysis of PCDD Fs in animal feedstuffs. Key goals include demonstrating sensitivity at ppt levels, selectivity via SRM transitions, robustness over extended sequences and suitability for routine regulatory testing under EU requirements.

Methodology and Used Instrumentation

Feed samples such as alfalfa, premixes and pork fat were prepared following European standard EN 1948. An aliquot was injected by a TriPlus RSH autosampler into a TRACE 1310 GC fitted with a 60 m TG Dioxin column. The TSQ 9000 MS with AEI source operated in timed SRM mode using two transitions per congener and argon collision gas. Calibration utilized EN 1948 solutions, and LOQs were defined from the lowest calibration level meeting recovery and repeatability criteria.

Main Results and Discussion

The system delivered instrument detection limits at the attogram level and on column LOQs from 0.02 pg to 0.32 pg per congener. Calibration linearity extended from 0.01 pg to over 320 pg per microlitre, with response factor RSDs below 7 %. Ion ratio measurements stayed within ±15 % of theoretical values throughout multi day sequences, confirming robustness. Matrix LOQs expressed as TEQs were well below one fifth of EU maximum levels across all sample types.

Benefits and Practical Applications

This validated method fulfills official confirmatory criteria for dioxin analysis in feed at extremely low levels with minimal sample intake. Laboratories benefit from high throughput, reliable quantification, and seamless integration with chromatography data systems and LIMS for streamlined workflows and reporting.

Future Trends and Opportunities

Emerging developments in ionization technology and automation are poised to further lower detection limits and improve specificity. Enhanced digital integration and real time data handling will expand capabilities to other persistent organic pollutants and novel contaminants, fostering more comprehensive environmental and food safety monitoring.

Conclusion

The TSQ 9000 GC MS MS system with AEI source provides a sensitive, selective and robust platform for ultra trace dioxin quantification in animal feed, fully compliant with current EU regulations and adaptable to routine laboratory operations.

References

• Commission Regulation EU 2017 644 of 5 April 2017
• Commission Regulation EU 2017 771 of 3 May 2017
• European standard EN 1948 method
• Guidance document on estimation of LOD and LOQ for contaminants in feed and food