Accelerated Solvent Extraction

Importance of the Topic

Accelerated solvent extraction (ASE) has emerged as a pivotal technique in environmental and industrial laboratories for isolating trace organic and inorganic analytes from solid and semi‐solid matrices. By applying elevated temperature and pressure to common solvents, ASE significantly speeds up extraction kinetics, reduces solvent consumption, and delivers more reproducible data compared to conventional methods such as Soxhlet extraction. This approach supports timely decision making in environmental monitoring, quality control, and regulatory compliance.

Study Objectives and Overview

The technical resource guide presents ASE as a universal platform for extracting a wide range of compounds—polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), persistent organic pollutants (POPs), dioxins/furans, pesticides, polybrominated diphenyl ethers (PBDEs), and trivalent/hexavalent chromium—from diverse matrices including soil, sludge, fly ash, mussel tissue, household dust, and consumer materials. The objective is to demonstrate ASE’s compatibility with U.S. EPA and CLP reference methods, and to illustrate simultaneous multi‐analyte workflows with integrated cleanup steps.

Instrumentation

• Thermo Scientific Dionex ASE 150/350 Accelerated Solvent Extractor systems
• In‐cell sorbents: alumina, Dionex ASE Prep MAP polymer, silica cartridges
• Thermo Scientific Rocket Evaporator for concentrate
• Thermo Scientific AutoTrace 280 SPE for aqueous cleanup
• Thermo Scientific TRACE 1300 GC and TSQ Quantum XLS Ultra GC‐MS/MS for PAHs, PCBs, PBDEs, dioxins/furans
• Thermo Scientific Dionium extraction cells coupled to ion chromatography for Cr(III)/Cr(VI)

Methodology and Instrumentation

ASE operates by heating a solvent–sample mixture above the solvent’s boiling point under high pressure (up to 1500 psi), enhancing solvating power, diffusion rates, and matrix disruption. Typical PAH extraction uses dichloromethane/acetone (1:1 v/v) at 100 °C, two static cycles of 5 min each, a 60% purge, and 40 mL total solvent per 10 g soil in a 34 mL cell. Pesticides employ hexane/acetone (1:1) under similar conditions with three static cycles. PBDEs in dust are extracted at 100 °C and 6.8 MPa with dichloromethane and in‐cell silica cleanup. Trivalent and hexavalent chromium are extracted with an aqueous PDCA/KI/NH4Ac/LiOH mixture at 100 °C for 2 cycles, followed by direct ion chromatography quantification.

Main Results and Discussion

PAH recoveries from soil ranged from 86.7% to 116.2% with relative standard deviations below 5%. Combined PAH/PCB extraction from mussel tissue and soil achieved recoveries of 72–115% for PAHs and 85–95% for PCB congeners. ASE provided 90% recovery for Aroclor 1248 in ambient air cartridges, comparable to 96% by Soxhlet, while consuming 550 mL vs. 1.5–2 L of solvent and completing in 3 h vs. 20–32 h. Dioxins/furans in sediments, soils, and fly ash met target congener concentration ranges when analyzed by GC-MS/MS or GC-HRMS. Extraction of organochlorine pesticides from oyster tissue using Prep MAP polymer yielded recoveries around 101% versus 71% with sodium sulfate. PBDE analysis in house dust achieved low‐ppb detection limits. Cr(III) was quantified in soils, solid waste, textiles, and leather at µg/g levels; Cr(VI) remained below detection limits in all matrices except leather.

Benefits and Practical Applications

• Substantial reductions in solvent usage and extraction time.
• In‐cell cleanup simplifies workflows and minimizes post‐extraction handling.
• Wide compatibility with regulatory methods (EPA SW-846 3545A/6860, CLP OLM 04.2A).
• Single‐instrument multi‐analyte capability supports environmental monitoring and QA/QC testing.
• Improved data consistency and laboratory throughput.

Future Trends and Opportunities

Advances in ASE may include further miniaturization, online coupling with UHPLC and high-resolution MS, novel sorbents for selective in-cell cleanup, in-cell derivatization strategies, and remote process control via laboratory information management systems. Green chemistry initiatives will drive interest in bio-based solvents and solvent‐free extraction technologies. Integration of ASE data with machine learning platforms may optimize method development and predictive maintenance.

Conclusion

Accelerated solvent extraction stands as a versatile, efficient, and environmentally considerate sample preparation technique. Its proven performance across multiple analyte classes and matrices, combined with simplified cleanup and regulatory acceptance, positions ASE as an essential tool for modern analytical and environmental laboratories.

References

• U.S. EPA Method SW-846 3545A, 6860
• CLP OLM 04.2A
• Thermo Scientific Application Note 313, 1025, 71064, 10336, 152, 52294, 1079