Isotopic characteristics of antifouling paints and fractionation of Cu and Zn isotopes during dissolution by seawater and their adsorption to marine sediments.

The elemental and isotopic (δCu and δZn) characteristics of 34 AFP samples from 5 paint manufacturers, the isotopic fractionation during the dissolution of AFPs by seawater, and the subsequent adsorption of isotopes onto coastal fine-grained sediments were investigated to identify potential indicators (metal ratios and isotopes). The δCu and δZn values for 34 AFPs could be divided into 2 groups regardless of the type of paint or manufacturer. Dissolution by seawater induced substantial fractionation but δCu and δZn approached the bulk AFP values when the leached fraction increased. The adsorption of metals onto marine sediments resulted in substantial fractionation (ΔCu = 0.91 ± 0.30 ‰ and ΔZn = -0.14 ± 0.07 ‰), but the δCu values in sediments were similar to those in bulk AFP because almost all of the Cu adsorbed to marine sediments within 12 h.