POLAROGRAPHIC STUDY OF ORGANOCHLORINE PESTICIDES IN MICELLAR SOLUTIONS

A polarographic study of the organochlorine pesticides dieldrin, endosulfan and endosulfan sulphate in micellar solutions is described. A mixture of two surfactants, Hyamine 2389 and Triton X-405, was found to be the medium giving the best analytical signal-to-noise ratio. The characteristics of the current controlling the reduction processes were examined at pH 6.0, diffusion-controlled limiting currents being obtained in all instances. The diffusion coefficients of the pesticides were calculated, in addition to the kinetic parameters alpha-n(a) and K(f)O. The polarographic reduction processes are irreversible and their mechanisms are proposed. Dieldrin, endosulfan and endosulfan sulphate can be determined in micellar solutions by differential-pulse polarography using a pulse amplitude, DELTA-E, of -50 mV, over the range 1.0 x 10(-6)-10.0 x 10(-5) mol l-1. Simultaneous analysis of binary mixtures of these pesticides was possible, based on hydrolysis of endosulfan and endosulfan sulphate in basic medium.