The adsorbed Ni–NN complex gives a well defined cathodic stripping peak current at −0.70 V,
which was used for the determination of nickel in the concentration range of 10.0–70.0 g L−1 (pH 7.5;
CNN 6.5 mol L−1 ; Eads −0.30 V; tads 60 s) with a detection limit of 0.1 g L−1 .