Extraction of Contaminants, Pollutants, and Poisons from Animal Tissue Using Accelerated Solvent Extraction (ASE)

Importance of Topic

Accelerated Solvent Extraction (ASE) addresses the demand for rapid and solvent-efficient techniques to isolate trace organic contaminants from complex animal tissues. Traditional methods like Soxhlet or methanol solvent extraction often require large solvent volumes and extended run times, limiting throughput and increasing environmental footprint.

Objectives and Study Overview

This application note explores ASE performance for extracting six classes of analytes—dioxins/furans, polybrominated flame retardants (PBDEs), polychlorinated biphenyls (PCBs), pesticides, polycyclic aromatic hydrocarbons (PAHs), and organotins—from various animal tissue matrices. Comparative assessments versus conventional techniques examine recovery, extraction time, and solvent usage.

Methodology

Sample matrices included fish, mussels, clams, oysters, beef kidney, and certified reference materials. Tissue homogenates were mixed with ASE prep material and loaded into stainless steel cells featuring in-cell sorbents or cellulose filters. Key ASE parameters were optimized per analyte class:

• Pressure range: 735–2000 psi
• Temperatures: 40–175 °C
• Solvents: toluene; acetone/DCM; DCM/pentane; ethanol/water
• Static cycles: 1–4 with 5–10 min per cycle
• Flush volumes and purge times tailored for each protocol

Post-extraction cleanup combined in-cell sorbents (e.g., florisil) or offline purification (gel permeation chromatography, acid silica, alumina) before analysis by GC/MS, GC/ECD, GC-FPD, or HPLC-Fl.

Used Instrumentation

• Dionex ASE 200 Accelerated Solvent Extractor with ASE Solvent Controller
• 11 mL, 22 mL, and 33 mL stainless steel extraction cells; cellulose filters
• Dionex SE 500 Solvent Evaporation System
• Analytical balance, tissue homogenizer, freeze dryer, centrifuge, mechanical shaker
• Gas chromatography systems with MS, ECD or FPD detectors; HPLC with fluorescence detection

Results and Discussion

ASE delivered comparable or improved recoveries relative to traditional methods, with marked reductions in extraction time and solvent use:

• Dioxins/furans in fish: identical total TEQ (~21 ppt) using 30 min and 50 mL toluene versus 36 h and 300 mL for Soxhlet
• PBDEs in estuarine bivalves: 9–106 ppb (dry weight) with RSD <20%
• PCBs in bird eggs: average recovery 100% (range 87–113%) in 25 min and 40 mL solvent compared to 13 h and 150 mL for Soxhlet
• Pesticides in beef kidney: atrazine recoveries 90–115% using subcritical ethanol/water extraction and direct SPME sampling
• PAHs in mussels: 94–99% recoveries with 10 min and 25 mL solvent, achieving a 12× faster extraction than methanol solvent extraction
• Organotins in fish tissue: tributyltin quantification at 96% of certified value using acidified methanol extraction

Benefits and Practical Applications

ASE dramatically accelerates sample preparation, decreases solvent consumption by up to an order of magnitude, and integrates with automated workflows. These advantages support high-throughput environmental monitoring, food safety screening, toxicological research, and regulatory compliance.

Future Trends and Opportunities

Potential developments include:

• Expanded in-cell cleanup chemistries to eliminate offline purification steps
• Direct coupling of ASE with on-line detection for real-time analysis
• Adaptation to emerging contaminants and diverse biological matrices
• Use of greener solvents to further reduce environmental impact

Conclusion

Accelerated Solvent Extraction proves to be a robust alternative to classical extraction techniques for a wide range of organic contaminants in animal tissues. Its speed, solvent efficiency, and adaptability make it a valuable asset for modern analytical laboratories.

References

• Raccanelli S et al. Comparative PCDD/F Analysis by Pressurized Fluid Extraction vs Soxhlet. Organohalogen Compounds. 1999;40:239–242.
• Oros D et al. Levels and Distribution of PBDEs in Water, Sediments, and Bivalves from San Francisco Estuary. Environ Sci Technol. 2005;39:33–41.
• Gomez-Ariza JL et al. PCBs in Biota Using Simultaneous Pressurized Liquid Extraction and Purification. J Chromatogr A. 2002;946:209–219.
• Curren M, King J. Ethanol-Modified Subcritical Water Extraction Combined with SPME for Atrazine in Beef Kidney. J Agric Food Chem. 2001;49:2175–2180.
• Yusa V et al. ASE followed by GPC and HPLC-Fl for PAHs in Mussel Tissue. Food Addit Contam. 2005;22(5):482–489.
• Wasik A, Ciesielski T. Determination of Organotin Compounds in Biological Samples Using ASE, Ethylation, and GC-FPD. Anal Biochem. 2004;378:1357–1363.