Determination of PCDD/Fs in Environmental Samples using Accelerated Solvent Extraction (ASE) and GC-MS/MS

Importance of the topic

The accurate measurement of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) at ultra-trace levels is critical due to their high toxicity and persistence in the environment. Regulatory agencies require reliable data on PCDD/F contamination in soils, sediments, and incinerator residues to protect human health and wildlife.

Objectives and overview of the study

This study evaluates an accelerated solvent extraction (ASE) method combined with a triple-quadrupole GC-MS/MS system (Thermo Scientific TSQ Quantum XLS Ultra) for PCDD/F analysis. Performance metrics, including limits of detection (LODs), precision, and agreement with high-resolution GC-HRMS (“gold standard”), are compared across reference materials and real samples.

Methodology

Sample preparation follows accredited procedures: an in-house ISO 17025 variation of EPA 1613B for soils and sediments and an EN 1948-based protocol for incinerator fly ash. ASE with toluene at 1,500 psi and 175 °C streamlines extraction. Cleanup steps adhere to established ion-ratio and recovery criteria. Quantitation employs isotope dilution and selected reaction monitoring (SRM) transitions under optimized collision energy (22 eV).

Instrumentation used

• Thermo Scientific Dionex ASE accelerated solvent extractor
• Thermo Scientific TRACE GC Ultra gas chromatograph
• Thermo Scientific TSQ Quantum XLS Ultra triple-quadrupole mass spectrometer
• Thermo Scientific TargetQuan 3 data processing software

Main results and discussion

Instrumental LODs for key congeners ranged from 0.01 pg/μL to 0.09 pg/μL at 99% confidence, with RSDs below 12%. SRM chromatograms demonstrated clear quantifier and qualifier transitions for 2,3,7,8-TCDD and other congeners at low fg levels. Certified reference materials (CRM 490 fly ash, SETOC 738 sediment) showed excellent agreement between GC-MS/MS and GC-HRMS, within QC criteria. Routine environmental samples produced comparable results; in some low-level soils, GC-MS/MS outperformed the HRMS system used, confirming additional detections.

Benefits and practical applications

The combined ASE and GC-MS/MS workflow offers high sensitivity and selectivity comparable to GC-HRMS, while reducing solvent use and enabling automation. Full isotope-dilution quantitation and robust QC compliance make it well suited for environmental monitoring, regulatory testing, and industrial quality control laboratories.

Future trends and potential applications

Advances in triple-quadrupole sensitivity and data-processing algorithms will further close the gap with ultrahigh-resolution systems. Integration with smaller-scale or portable GC-MS platforms could expand in-field analysis. Broader application to food safety, biota, and atmospheric particulates is anticipated as extraction and cleanup methods evolve.

Conclusion

The Thermo Scientific TSQ Quantum XLS Ultra GC-MS/MS, when paired with ASE extraction, delivers detection limits, precision, and quantitative accuracy on par with GC-HRMS for PCDD/F analysis across diverse environmental matrices. This approach provides a cost-effective, high-throughput alternative for routine trace dioxin monitoring.

References

• Ingelido A.M., Brambilla G., Abballe A., et al. Rapid Commun. Mass Spectrom. 2012, 26(3), 236–242.
• Kotz A., Malisch R., Wahl K., et al. Organohalogen Compd. 2011, 73, 688–691.
• Silcock P., Krumwiede D., de Dobbeleer I., et al. Thermo Scientific Application Note 52266, 2011.