Investigation of carryover or cross-contamination in the EXTREVA ASE Accelerated Solvent Extractor

Importance of the Topic

The increasing need for rapid, reproducible, and low-solvent analytical workflows in environmental and industrial laboratories drives the development of advanced accelerated solvent extraction technologies. Assessing potential carryover and cross-contamination is essential when processing multiple samples in parallel to ensure data integrity and method robustness.

Objectives and Study Overview

This study evaluates the Thermo Scientific EXTREVA ASE Accelerated Solvent Extractor for carryover and cross-contamination during parallel extraction of heavily spiked soil samples. Two applications were tested: polyaromatic hydrocarbons (PAHs) at 12 500 µg/kg and organochlorine pesticides (OCPs) at 250 µg/kg, following optimized methods and assessing blank extractions immediately thereafter.

Methodology and Instrumentation

• Sample Preparation: Soil was mixed with diatomaceous earth dispersant and spiked with target analytes. Two cellulose filters confined each 10 mL stainless-steel extraction cell.
• Extraction Conditions: 100 °C, 200 psi, dichloromethane-acetone (1:1 v/v) solvent, 10 mL pre-rinse per pathway, four cells extracted in parallel.
• Evaporation and Concentration: Nitrogen gas at 50 mL/min under 0.55 bar vacuum, 40 °C to 1 mL final volume; level sensing by AI machine vision.
• Analysis: PAHs by GC-MS, OCPs by GC-ECD.

Main Results and Discussion

• PAH Recoveries ranged from 78 % to 104 % with RSD ≤ 3.2 %, and carryover below 0.5 % for all compounds.
• OCP Recoveries ranged from 82 % to 102 % with RSD ≤ 7.9 %, and carryover below 0.5 % for all pesticides.
• Pre- and post-rinse steps effectively removed residual contaminants; rinse volumes can be adjusted to accommodate diverse sample loads and concentrations.

Benefits and Practical Applications

• Fully automated parallel extraction and evaporation frees analyst time for other tasks.
• Reduced solvent usage and rapid cycle times improve laboratory throughput and sustainability.
• High reproducibility and negligible cross-contamination support compliance in environmental monitoring, QA/QC, and industrial analysis.

Future Trends and Opportunities

• Integration of advanced AI-driven controls for dynamic method adjustments based on real-time monitoring.
• Expansion to additional matrices and higher throughput configurations for large-scale environmental screening.
• Coupling with high-resolution mass spectrometry and automated data processing for comprehensive target and non-target analysis.

Conclusion

The EXTREVA ASE system delivers exhaustive extractions with minimal solvent consumption and carryover below 0.5 %, even when processing high-concentration samples in parallel. Its automation and reproducibility make it a robust solution for routine environmental and industrial applications.

Reference

• Thermo Fisher Scientific. White paper WP001431-EN Investigation of carryover or cross-contamination in the EXTREVA ASE Accelerated Solvent Extractor.
• Thermo Fisher Scientific. PAH Application Note AN001106.
• Thermo Fisher Scientific. OCP Application Note AN001054.