Urease inhibition: a tool for toxicity identification in sediment elutriates

A method for the detection and confirmation of heavy metal toxicants in sed iment elutriates based on a urease inhibition assay, ICP-AES analysis and E DTA chelation in the frame of toxicity identification evaluation (TIE) is p resented. Zinc was identified as the major toxicant in pH(stat) elutriates of sediments of the river Saale (Germany). Implications of natural and anth ropogenic chelating agents, which are frequently present in environmental s amples, on toxicity confirmation of heavy metals based on the toxic unit ap proach are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.