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 (S65Cu and S 66 Zn) 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 S 65 Cu and S 66 Zn 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 S 65 Cu and S 66 Zn approached the bulk AFP values when the leached fraction increased. The adsorption of metals onto marine sediments resulted in substantial fractionation ( z 65 Cu soln-solid = 0.91 +/- 0.30 %o and z 66 Zn =-0.14 +/- 0.07 %o ), but the S 65 Cu values in sediments were similar to those in bulk AFP because almost all of the Cu adsorbed to marine sediments within 12 h.