EFFECT OF SURFACTANTS AND RELATED BIOLOGICAL ACTIVE SUBSTANCES ON THEO-2 H2O2 VOLTAMMETRY AND ITS UTILIZATION FOR DETERMINATION OF THE TOTAL SURFACTANT CONTENT/

The effect of surfactants on the second voltammetric reduction peak of air oxygen dissolved in aqueous electrolyte solutions is described. S odium dodecylbenzenesulfonate (DBSNa) was used as a model surfactant i n the concentration range 9 x 10(-8)-9 x 10(-7) molL(-1). With increas ing DBSNa concentration the second oxygen reduction peak increases and shifts to negative potentials. Measurements were carried out in pure 0.1 mol L-1 KCl as well as in freshly collected samples of seawater. B y means of calibration plots obtained with DBSNa we could determine th e total surfactant concentration in seawater, i.e., the voltammetric s urfactant background signal. Expressed in equivalent concentration of DBSNa this background amounted to 3 x 10(-7) mol L-1.