Butyltin Species and Inorganic Tin in Water and Sediment of the Detroit and St. Clair Rivers

Abstract

Water and sediment samples from 29 locations in the Detroit and St. Clair rivers were analyzed for the highly toxic tri-n-butyltin (Bu 3Sn +) species and for the less toxic di-n-butyltin (Bu 2Sn 2+) and n-butyltin (BuSn 3+) species and inorganic tin. In general, locations sampled in the St. Clair River were less contaminated with butyltin species than those in the Detroit River. Inorganic tin and BuSn 3+ were detected in over 90% of all subsurface water samples, while Bu 2Sn 2+ and Bu 3Sn + were detected in 45 and 28% of the same samples, respectively. The highest concentration ofBu 3Sn + in subsurface water, 5.9 × 10 −10 mol Sn/L, was at the mouth of the Ecorse River, a tributary of the Detroit River. The three butyltin species and inorganic tin were also detected in 23–46% of all sediment samples. The highest concentrations of Bu 3Sn + in sediment were found close to the mouths of the River Rouge, another tributary of the Detroit River, and the Ecorse River, and were 6.2 × I0 –7 and 1.7 × I0 –7 mol Sn/kg dry weight, respectively, for the top 2 cm of sediment.