MODIFIED CARBON WAX COMPOSITE ELECTRODES

Chemically-modified carbon-wax composite electrodes were fabricated by incorporating appropriate quantities of model modifiers into melted w ax/graphite-powder mixtures prior to the solidification step. Such mel ting and solidification processes result in homogeneous dispersion of the modifier and mechanical rigidity of the surface. It also maintains the attractive features of analogous carbon paste electrodes, includi ng low background current, flexible modifier loading, surface renewal, speed and low cost. The compatibility of different modifiers with car bon-wax composites is illustrated in connection with preconcentrating/ voltammetric measurements of nickel and copper at DMG- and cation-exch anger resin containing surfaces, as well as electrocatalytic monitorin g of hydrazines, oxalic acid or butanone peroxide at cobalt-phthalocya nine and metalized carbon-based composites.