No abstract

Toxicity bioassays of solvent extracts of sediments are used to evaluate the toxicological effects of extracted hydrophobic organic contaminants. However, this type of bioassay assesses the toxicity of all extracted compounds, natural or anthropogenic. Sediment extracts are typically subjected to cleanup procedures before chemical analysis to remove interfering, coextracted substances. This study evaluated the effect of cleanup procedures on the toxicity of acetonitrile extracts of contaminated sediments by using the Microtox® bioluminescence bioassay. Extract cleanup significantly reduced toxicity of most extracts when copper powder was added to remove coextracted sulfur. Microtox was shown to be highly sensitive (EC50 of 24.7‐35.8 μg/L) to elemental sulfur dissolved in several organic solvents. Toxicity tests utilizing solvent extracts of sediments must take into account the toxic effects of coextracted sulfur on bioassay organisms to accurately assess the environmental impacts of extracted hydrophobic contaminants.