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

In the presence of tributyltin oxide, (Bu₃Sn)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: 2Bu₃SnOSnBu₃ + 2Hg?Bu₃SnHgSnBu₃]²⁺ + Hg (OSnBu₃)₂ + 2e^? Hg(OSnBu₃)₂+2Hg?BuSnHgSnBu₃]²⁺ + 2HgO+2e^? to give the overall process Bu₃SnOSnBu₃+2Hg?Bu₃SnHgSnBu₃]²⁺ + HgO+2e^?. On the time scale of controlled-potential electrolysis, Bu₃SnHgSnBu₃]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.