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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Food Animal Metabolism Research » Research » Publications at this Location » Publication #134508
Title: COMPARISON OF SOXHLET AND ACCELERATED SOLVENT EXTRACTIONS IN THE ANALYSIS OF DIOXINS AND FURANS FROM LIVER SAMPLES

Author
item Huwe, Janice

Submitted to: Organohalogen Compounds
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2002
Publication Date: 1/1/2002
Citation: Huwe, J.K. 2002. Comparison of soxhlet and accelerated solvent extractions in the analysis of dioxins and furans from liver samples. Organohalogen Compounds. 58:229-232.

Interpretive Summary: Analysis of dioxin residues in food samples is time consuming and costly. The initial procedure in the analysis is often Soxhlet extraction of the dioxins from the food product which requires approximately 300 mL of organic solvent per sample and may take up to 20 hours to perform. In this study, we have explored an alternative to Soxhlet, accelerated solvent extraction (ASE), which has the potential to reduced solvent consumption and decrease extraction times. Beef livers containing dioxins were chosen as a representative food product. Five different ASE methods were evaluated and compared to the traditional Soxhlet method. Two of the ASE methods showed recoveries and quantitation of the dioxins equivalent to the Soxhlet method. Compared to Soxhlet extractions, these ASE methods decreased extractions times from 20 h to less than 30 min and reduced the amount of solvent by 100 ml per sample. Further optimization of the ASE methods may decrease solvent usage even further and ultimately shorten analysis time and decrease the cost.

Technical Abstract: Accelerated solvent extraction (ASE) has several benefits over conventional Soxhlet extraction including reduced solvent consumption and decreased extraction times. For these reasons, we have conducted a study to compare the use of ASE and Soxhlet extraction in the analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from beef liver. Beef livers with elevated PCDD/F levels from a dosing experiment were analyzed by conventional dioxin methods after extraction be Soxhlet or ASE. Five ASE methods employing different solvent mixtures were evaluated for the recovery of lipids and PCDD/Fs. Using methylene chloride/hexane (50:50) in the ASE, PCDD/Fs were recovered with good yield, but lipid amounts were approximately half of that recovered by Soxhlet. Toluene or a mixture of hexane/isopropanol (3:2) in the ASE showed poor average recoveries of PCDD/Fs (<35%). Mixtures of methylene chloride/isopropanol (3:2) or methylene chloride/hexane/isopropanol (1:1:1) in the ASE gave the best overall results. PCDD/F and lipid recoveries were as high as in the Soxhlet method, and total toxic equivalencies on a lipid or wet weight basis were equivalent to the Soxhlet method.