APGC Advances Ultra-Trace Toxins Analysis in Feed and Food

Significance of the Topic

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are persistent organic pollutants that bioaccumulate in the food chain, posing serious health risks such as cancer, immune dysfunction and developmental disorders. Monitoring ultra-trace levels of these toxins in feed and food is essential to ensure regulatory compliance under frameworks like the Stockholm Convention and EU directives. Improved analytical methods help laboratories worldwide detect and quantify dioxins with higher sensitivity and reliability, safeguarding animal and human health.

Objectives and Study Overview

This study at the Institute of Quality Standard and Testing Technology for Agro Products (IQSTAP) in Beijing aimed to evaluate Atmospheric Pressure Gas Chromatography coupled with tandem Mass Spectrometry (APGC-MS/MS) for ultra-trace analysis of 17 priority PCDDs and PCDFs in feed and food matrices. The goals were to enhance detection limits, reduce matrix interferences, streamline workflows, and compare APGC performance with conventional high-resolution GC–MS methods.

Methodology and Instrumentation Used

IQSTAP researchers implemented APGC-MS/MS using a Waters atmospheric pressure GC source interfaced to a triple quadrupole MS. Key methodological features included:

• Soft ionization via atmospheric pressure chemical ionization (APCI) to minimize fragmentation and improve selectivity.
• Reduced injection volumes to limit matrix contamination and extend instrument uptime.
• Seamless switching between liquid chromatography and gas chromatography modes to maximize laboratory throughput.
• Use of isotope dilution for quantitative accuracy and trace-level confirmation.

Main Results and Discussion

Adoption of APGC-MS/MS delivered several important advances:

• Significantly improved sensitivity allowed reliable quantification of PCDDs/PCDFs at or below current regulatory limits.
• Enhanced selectivity arising from soft ionization led to clearer precursor and product ion selection in MS/MS, overcoming limitations of traditional electron ionization (EI).
• Lower sample matrix loads reduced the need for extensive clean-up steps and decreased consumable usage by approximately 50 %, cutting operational costs.
• Quick equilibration between LC and GC modes enabled flexible scheduling of diverse analyses without long downtime.

Overall, APGC-MS/MS demonstrated robust performance for complex feed and food matrices and aligned well with the laboratory’s accreditation requirements.

Benefits and Practical Applications

The APGC approach offers multiple practical advantages for routine dioxin testing:

• Faster turnaround times for regulatory and QA/QC laboratories.
• Cost savings through reduced solvent and sorbent consumption.
• Greater instrument uptime and simplified maintenance due to lower contamination risk.
• Enhanced confidence in ultra-trace measurements supporting food safety decision-making.

Future Trends and Applications

Future developments may include:

• Expansion of APGC-MS/MS workflows to other persistent organic pollutants and emerging contaminants.
• Integration with high-throughput screening platforms for broad-spectrum monitoring.
• Continuous refinement of ionization parameters to further boost selectivity and sensitivity.
• Collaboration on interlaboratory studies to standardize APGC methods under international guidelines.

Conclusion

Atmospheric pressure GC coupled with MS/MS represents a valuable alternative to conventional high-resolution techniques for trace dioxin analysis in feed and food. By delivering greater sensitivity, selectivity and operational efficiency, APGC-MS/MS helps laboratories comply with stringent safety regulations while reducing costs and sample-preparation complexity. Ongoing method optimization and wider adoption promise to advance global monitoring of these critical contaminants.

Reference

• Waters Corporation. APGC Advances Ultra-Trace Toxins Analysis in Feed and Food. 2018.