Trace metal partitioning and concentration in sediment from the St. Clair Delta, Lake St. Clair and the Detroit River, Ontario, Canada

In this study, sediments were collected from the Detroit River - Lake Erie waterway and subjected to a sequential extraction procedure in order to evaluate the precision of the procedure and determine metal partitioning and concentrations of Pb, Zn, Ni, Cu and Cr. The samples were subjected to a three stage sequential extraction procedure. The three phases that were separated out were (1) carbonate, exchangeable and adsorbed (AEC) fraction; (2) organic material (ORG); and (3) Fe-Mn oxides (RED). Metal concentrations were determined by ICP-OES. The metal concentrations and distribution among three sediment fractions were scrutinised in the context of other sediment characteristics including grain-size, total carbon and total major element data.; Precision of certified reference materials indicated the sequential extraction procedure produced good to excellent results aside from zinc contamination within the procedure. The highest metal concentration of Pb, Cu, Zn and Cr were found in Lake St. Clair sediment at site LS17, adjacent to the shipping channels and in the deeper part of the Lake. Ni, Cu and Zn recorder higher concentrations than released in previous reports. The trace metals were primarily released from the less labile reducible step of the extraction excepting for lead which favoured the AEC step. Lower metal levels were recorded in Detroit River sediment but Detroit River sediment recorded higher proportions of the more labile metal forms.