Analysis of Dioxins in Foods and Feeds Using GC-MS/MS

Importance of the Topic

Quantification of dioxins in foods and feeds is critical due to their extreme persistence and toxicity even at femtogram levels. Regulatory bodies such as the European Union mandate very low maximum limits and rigorous analytical performance criteria to protect public health and ensure compliance in agricultural and food processing industries.

Objectives and Study Overview

This study aimed to evaluate the performance of a modern triple-quadrupole GC-MS/MS system (Shimadzu GCMS-TQ8050) combined with an EU-compliant method package for dioxin analysis, and to compare its quantitative capability with that of traditional high-resolution magnetic sector GC-HRMS. A total of 201 samples covering 44 food and feed matrices were analyzed to assess method accuracy, sensitivity, and regulatory compliance.

Methodology and Instrumentation

Sample pretreatment involved automated extraction (SpeedExtractor) and cleanup (GO-xHT) with nonane as the final solvent. Calibration standards covered six concentration levels down to 0.025 pg/µL. Instrumental analysis used predefined transitions and collision energies for all 17 dioxin congeners and their 13C12-labeled analogues. Data acquisition and retention time alignment were automated via the GCMSsolution and LabSolutions Insight software, including an automatic report creation tool tailored to EU 589/2014 and 644/2017 regulatory requirements.

Main Results and Discussion

• Method validation demonstrated that at the limit of quantitation (LOQ, 0.060 pg/µL for key congeners), signal-to-noise ratios exceeded 3:1 and calibration curve response factor deviations remained within ±30 %.
• Comparison of total toxic equivalents (TEQ) between GC-MS/MS and GC-HRMS showed nearly identical results for samples with TEQ ≥ 0.060 pg/µL, with 98 % of ratios within 50–200 %.
• For samples below this TEQ threshold, measurement variability increased, largely driven by concentrations near or below the quantitation limits, underscoring the importance of system sensitivity checks.
• Linear regression of TEQ values yielded a slope of 1.049 (95 % CI 1.046–1.051) and intercept –0.005 (95 % CI –0.008 to –0.002), confirming statistical equivalence between the two techniques at regulatory concentration levels.

Benefits and Practical Applications of the Method

• GC-MS/MS offers lower capital and operational costs compared to GC-HRMS while achieving equivalent quantitative accuracy at required concentration ranges.
• Pre-registered method files and automated retention time adjustment accelerate method transfer and reduce development time.
• Integrated report generation ensures that outputs meet EU regulatory formatting and calculation requirements, streamlining laboratory workflows in food quality control and regulatory testing.

Future Trends and Possibilities for Application

• Continued refinement of triple-quadrupole technology and software algorithms will further lower detection limits and improve robustness at ultra-trace levels.
• Expansion of automated sample preparation modules could shorten turnaround times and reduce analyst variability.
• Integration with laboratory information management systems (LIMS) and cloud-based data analytics may facilitate real-time global monitoring of dioxin contamination trends.

Conclusion

The GCMS-TQ8050 in combination with the EU-compliant GC-MS/MS method package delivers quantitation performance on par with GC-HRMS for dioxin analysis in foods and feeds at regulatory concentration levels. Laboratories can adopt this cost-effective, fully automated workflow to meet stringent EU requirements, while remaining mindful of increased variability when measuring at concentrations below the LOQ.

Used Instrumentation

• Extraction: SpeedExtractor (BUCHI)
• Cleanup: GO-xHT (Miura Co., Ltd.)
• GC-MS/MS: Shimadzu GCMS-TQ8050 with SH-Rxi™-5Sil MS column
• Autosampler: AOC-20i/s
• Software: GCMSsolution™ Ver.4.45 SP1, LabSolutions Insight™ Ver.3.2 SP1

References

• Takakura M., Lehardy T., Marchand P. Technical Report C146-E376: Analysis of Dioxins in Foods and Feeds Using GC-MS/MS. Shimadzu Corporation, 2018.
• European Commission Regulation (EU) No 589/2014 on method performance for dioxins.
• European Commission Regulation (EU) No 644/2017 authorizing GC-MS/MS for dioxin analysis in foods and feeds.