EAS: Recent advances in sample preparation for POPs

Significance of the Topic

Analytical determination of persistent organic pollutants requires reliable sample preparation to isolate target compounds from complex matrices and protect chromatographic and MS systems from contamination and signal suppression. Effective extraction and cleanup enhance reproducibility, sensitivity and data quality in routine and regulated analyses.

Objectives and Study Overview

This work introduces the Thermo Scientific EXTREVA ASE system as the first fully automated accelerated solvent extractor offering integrated cleanup, concentration and solvent evaporation in a walk-away workflow. The study compares its performance against the ASE 350 system for extraction of organochlorine pesticides and polycyclic aromatic hydrocarbons in soil.

Methodology and Instrumentation

The method uses accelerated solvent extraction with patented gas-assisted delivery to process up to 16 samples in parallel. Automated in-cell cleanup and moisture removal, 2D barcode tracking and machine-learning-based endpoint detection enable true unattended operation. Extracts are delivered to vials via independent channels and concentrated under N₂ with individual heating and vacuum control. Instruments included the EXTREVA ASE system, TRACE 1310 GC with electron capture detector and ISQ 7000 single quadrupole mass spectrometer for PAH analysis.

Main Results and Discussion

Compared to the ASE 350 system, the EXTREVA ASE achieved 48 sample extractions in 24 hours versus 36. Extraction of OCPs yielded recoveries of 82–106% with RSDs below 10%, within EPA criteria. Carryover tests showed negligible residual contamination and thermal degradation remained under 15%. PAH analysis delivered RSDs below 7% in certified reference soils and minimal blank carryover after high spike samples. Solvent usage and manual labor requirements were reduced significantly.

Benefits and Practical Applications of the Method

• Enhanced throughput via parallel processing and walk-away automation.
• Reduced solvent consumption and lower operating costs through gas-assisted extraction.
• Improved data integrity by 2D barcode sample tracking and consistent endpoint detection.
• High reproducibility and low carryover support regulatory compliance.

Applications include routine extraction of PAHs, PCBs and OCPs from environmental matrices and extractables/leachables in food contact materials.

Future Trends and Potential Applications

Automation trends will focus on expanded analyte classes, integration with advanced LC-MS workflows, greener solvent alternatives and seamless LIMS connectivity. Further enhancements in AI-driven process control may optimize method development and ensure robust performance across diverse sample types.

Conclusion

The EXTREVA ASE system streamlines POP analysis by fully automating extraction, cleanup and concentration with reliable recoveries, minimal carryover and high throughput. Its deployment can enhance laboratory efficiency, data quality and operational sustainability.

References

• Application Note AN001054. Organochlorine pesticide extraction performance.
• Application Note AN001106. Polycyclic aromatic hydrocarbon analysis in soil.