Comparison of sediment extract microtox� toxicity with semi-volatile organic priority pollutant concentrations

A total of 105 sediment samples were extracted with acetonitrile and subjected to cleanup with C-18 columns and copper powder. Extracts were analyzed for semi-volatile organic priority pollutants and for acute toxicity using the Microtox® bioassay. Polynuclear aromatic hydrocarbons (PAHs) accounted for 85% of all priority pollutant identifications. The results of statistical comparisons made between PAH concentrations and extract toxicity depended upon the correlation procedures used. Total PAHs were significantly correlated with toxicity using Spearman's correlation procedure, but not correlated using a linear correlation procedure. Many extracts with below or barely detectable levels of priority pollutants were highly toxic. On an individual extract basis, concentrations of priority pollutants were poor indicators of extract toxicity. Toxicity determinations were also made for commonly detected priority pollutants dissolved in dimethyl sulfoxide.