Reduction in acute toxicity of soils to terrestrial oligochaetes following the removal of bioavailable polycyclic aromatic hydrocarbons with mild supercritical carbon dioxide extraction.
Three soil samples contaminated with polycyclic aromatic hydrocarbons (PAHs) that caused 100% mortality to terrestrial oligochaetes were extracted with supercritical carbon dioxide to remove the bioavailable fraction of PAHs. Although the remaining PAH concentrations were high after supercritical fluid extraction (SFE), 650 to 8,000 mg/kg, acute toxicity to Eisenia fetida and Enchytraeus albidus essentially was eliminated. These results demonstrate that mild SFE with pure carbon dioxide preferentially extracts PAH molecules that are bioavailable toxicologically to the oligochaetes, although biologically unavailable PAHs are not extracted, suggesting that SFE could be used for the removal of toxicity due to hydrophobic organic chemicals in soils during toxicity identification evaluations.
Hawthorne
Steven B
SB
Energy and Environmental Research Center, University of North Dakota, Box 9018, Grand Forks, North Dakota 58202, USA. shawthorne@undeerc.org
Lanno
Roman
R
Kreitinger
Joseph P
JP
D000818:Animals; D001682:Biological Availability; D002245:Carbon Dioxide; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D009835:Oligochaeta / Q000187:drug effects*; D011083:Polycyclic Compounds / Q000302:isolation & purification* / Q000493:pharmacokinetics; D012987:Soil
D011083:Polycyclic Compounds; D012987:Soil; D002245:Carbon Dioxide