Polarographic studies on tributyltin oxide in dichloromethane and tetrahydrofuran with application to antifouling paint

Abstract

In the presence of tributyltin oxide, (Bu 3Sn) 2O, an oxidation process is observed at mercury electrodes in non-aqueous solvents. On the polarographic time-scale, the oxidation involves the mercury electrode and is believed to occur according to the following reaction scheme: 2Bu 3SnOSnBu 3 + 2Hg⇌[Bu 3SnHgSnBu 3] 2+ + Hg (OSnBu 3) 2 + 2e − Hg(OSnBu 3) 2+2Hg⇌[BuSnHgSnBu 3] 2+ + 2HgO+2e − to give the overall process Bu 3SnOSnBu 3+2Hg⇌[Bu 3SnHgSnBu 3] 2+ + HgO+2e −. On the time scale of controlled-potential electrolysis, [Bu 3SnHgSnBu 3] 2+ is unstable and additional electron transfer occurs. The oxidation process forms the basis of a specific high-performance liquid chromatographic method for the determination of tributylin oxide in antifouling paint. A static mercury drop electrode in the hanging drop mode is used as an amperometric detector in a flow-cell configuration.