The concentration of of Sb(III) in zinc plant electrolyte is determined by adsorptive stripping voltammetry (AdSV) with chloranilic acid as complexing agent. In this method high copper concentrations do not interfere. An approx. 10-fold excess of lead interferes, since it shows a signal close to the antimony. With the parameters given below the working range of this method is 1 - 30 µg/L antimony(III) with respect to the concentration in the measuring vessel.