ELECTROCHEMICAL OXIDATION OF 8-HYDROXYQUINOLINE AND SELECTIVE DETERMINATION OF TIN(II) AT SOLID ELECTRODES

The electrochemical oxidation of 8-hydroxyquinoline and several struct urally related molecules has been investigated by cyclic voltammetry a t solid electrodes (GCE, CPE,Pt) as a Function of pH in aqueous acetat e media. Oxine showed one irreversible oxidation peak whose magnitude decreased in the presence of cations readily complexed by oxine and wi th concomitent formation of a new oxidation peak at more positive pote ntials. Tin(Ir) was found to exhibit a distinct behavior as its oxidat ion was catalyzed by the presence of oxine in the analyzed solution. T he tin(II)-oxine oxidation peak was found to be linearly related to in organic tin(II) concentration allowing its quantitative determination at micromolar levels.