Fast and Flexible Automated Sample extraction of PCDD/Fs and PCBs with X-TRACTION for environmental samples

Importance of the topic

Persistent organic pollutants such as polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are highly toxic, bioaccumulative and subject to strict global regulation. Efficient, standardized and cost-effective extraction methods are essential to meet growing sample throughput and regulatory demands in environmental, food and feed analysis.

Objective and Overview

This application note presents the development and evaluation of a low-pressure fluid extraction system (X-TRACTION) for automated, rapid and reproducible isolation of PCDD/Fs and PCBs from environmental matrices. The study uses certified reference materials (CRM BCR-536 for PCBs in harbour sediment and BCR-677 for PCDD/Fs in sewage sludge) following US EPA Method 3545A.

Methods and Instrumentation

Sample preparation involved homogenisation of 1–2 g dry sample (<1 mm) mixed with sodium polyacrylate to ensure free-flowing conditions. Extraction employed the X-TRACTION system (75 mL cells) under low pressure (≤17 bar) and elevated temperature, using multiple cycles of picograde hexane/toluene/dichloromethane. Clean-up and fractionation were performed on acidic silica, alumina and carbon columns using the DEXTech platform. Concentrated extracts were evaporated with the D-EVA system and analyzed by high-resolution GC-MS (DFS HRMS) with both SSL and PTV injectors.

Key instrument components:

• X-TRACTION low-pressure fluid extractor with magnetic cell lids and glass fiber filters
• DEXTech purification columns (silica, alumina, carbon)
• D-EVA automated evaporation unit
• Thermo Fisher DFS HRMS with Trajan and Restek capillary columns

Key Results and Discussion

Four replicates of PCB extraction from BCR-536 yielded recoveries between 85 % and 113 %, demonstrating strong accuracy and precision across 12 congeners. Five replicates of PCDD/F extraction from BCR-677 achieved recoveries from 74 % to 131 %, covering 17 dioxin and furan congeners. These results confirm that low-pressure extraction matches performance of conventional high-pressure techniques while reducing solvent use and instrument wear.

Benefits and Practical Applications

The X-TRACTION workflow offers:

• Short extraction cycles and reduced solvent consumption
• High reproducibility with no cross-contamination
• Scalability from single to six parallel extraction cells with independent protocols
• Intuitive handling via a magnetic lid locking system

This approach is directly applicable to routine QA/QC, environmental monitoring and screening for a range of persistent organic pollutants.

Future Trends and Applications

Integration of low-pressure fluid extraction with automated clean-up and evaporation can be extended to other POP classes (e.g., PBDEs, PCNs, PFAS). Further method development may optimize cycle parameters for diverse matrices. Multi-unit configurations support high-throughput laboratories and evolving regulatory requirements.

Conclusion

The X-TRACTION LPFE system provides a fast, flexible and reliable solution for extracting PCDD/Fs and PCBs in environmental samples. It delivers accuracy comparable to established methods while enhancing instrument longevity, safety and operational efficiency.

Reference

• Bernsmann T, Albrecht M, Fürst P (2016) Organohalogen Compounds Vol. 78, 797–799
• Calaprice C, Calvano CD, Zambonin C, Focant JF (2015) Organohalogen Compounds Vol. 77, 733–735
• Bernsmann T, Albrecht M, Fürst P (2014) Organohalogen Compounds Vol. 76, 1281–1284