Abstract The application of differential pulse polarographic (DPP) experiments at low ligand concentration to the characterization of complexes has been investigated by studying three previously characterized copper(II)-polyamine systems. The DPP results were compared to cyclic voltammetry (CV) and cyclic differential pulse voltammetry (CDPV) measurements as well as to simulations. The Cu(II)-ethylene-diamine system at a 1:1 concentration exhibits three DPP peaks. This is shown to be due to direct reduction of the complexes. In the case of Cu(II)-triethylenetetramine, direct observation of two protonated complexes is possible at a 1:1 concentration upon titration with strong acid. The results for Cu(II)-diethylenetriamine appear consistent with values of log β 1=16 and log β 2 = 21, although detailed studies of this system were precluded by a polarographic maximum.