Complexation kinetics of 8-quinolinol (HQ) and 5-alkyloxymethyl-8-quinolinols (HC(n)Q; n = 1, 2, 3, 5, 8) with metal ions M2+ (M = Ni, Zn) at the 1,2-dichloroethane (DCE)-water interface is analyzed by dynamic interfacial tensiometry and electrolyte ascending electrode polarography. Polarographic measurements show that the chemical species formed at the interface is a cationic 1:1 complex (M(Q)(+) or M(C(n)Q)(+)). For Zn2+, the interfacial complexation is very fast, and its kinetics is controlled by the diffusion of ligands from the bulk DCE phase to the DCE-water interface. On the other hand, for Ni2+, the kinetics is interfacial reaction-controlled and is significantly affected by the alkyl chain length of the chelating reagents.