Toxicity of Reference Sediment Samples

This study was done to determine toxicity of certified reference sediment to be used for quality assurance in sediment toxicity testing program. Certified Reference Harbor Sediment (HS-4B for PAHs) and Estuarine Sediment (LGC-6137 for Trace Metals) were procured commercially from LGC Company, UK, and repeatedly analyzed against solid phase Microtox toxicity assay to determine EC₅₀ values. Both PAHs rich and trace metals rich sediments were very toxic to Microtox with EC₅₀ 405 mg L^-1 and 554 mg L^-1 respectively. Solvent extraction resulted in a drastic decrease in the toxicity of PAHs rich reference sediment sample but in trace metal rich sediment the decrease in the toxicity was marginal. The certified reference sediments with the availability of toxicity data can be incorporated for quality assurance as controls in Microtox toxicity determination of field samples of unknown toxicity.