Polyacrylate coated SPME fibers as a tool to simulate body residues and target concentrations of complex organic mixtures for estimation of baseline toxicity

The acute toxicity of narcotic organic chemical mixtures is related to the total molar concentration within organisms. In this study, the use of polyacrylate SPME fibers is investigated for the purpose of biomimetic extractions, a procedure used to simulate bioconcentration and to estimate total concentrations in aquatic organisms. Experimental SPME-water partition coefficients correlate well with octanol-water and membrane-water partition coefficients, indicating that these passive sampling devices provide a good surrogate for lipid partitioning. On the basis of these relationships, the total internal concentration resulting from exposure to an aqueous sample can be estimated from the total moles of chemicals that sorb to the fiber. The aquatic toxicity of the sample is then predicted by comparison to critical internal concentrations that elicit adverse effects. This procedure offers a number of practical advantages over previous biomimetic extraction techniques (e.g., Empore disk) due to faster sorption kinetics, smaller sample volumes, and applicability to volatile compounds.