The adsorption behaviour of a dinitroaniline herbicide benfluralin was studied by means of electrochemical as well as scanning probe techniques. The double layer capacitance reflects very sensitively changes of the interfacial structure at the surfaces. This allows discrimination between a simple adsorption process and a slow transition of adsorbed film structure controlled by the mechanism of nucleation. The information about nucleation kinetics and growth mechanism of the film on the electrode was obtained from the time dependence of the double layer capacitance employing the mercury drop electrode. The phase transition may lead to the reorientation of the molecules within the adsorbed layer. These findings were supported by scanning tunneling microscopy. (C) 2013 Elsevier B.V. All rights reserved.