Tributyltin and total tin in marine sediments: Profiles and the apparent rate of TBT degradation

Abstract
Total tin and tributyltin (TBT) were measured in sediment cores collected from the Tamaki Estuary in Auckland. New Zealand. The total tin concentration ranged up to 6.2 μg g−1 and the TBT concentration ranged up to 0.759 μg TBT‐Sn g−1. While the maximum total tin values were observed adjacent to a storm water outfall, the highest surficial TBT levels were observed in the vicinity of boat washdown and painting yards. TBT concentrations decreased with depth in the sediments. The degradation rate for TBT in sediments exhibited first order kinetics, with a rate constant of 0.375 y−1. TBT had a half‐life of 1.85 years in the sediments.