Copper foils with and without benzotriazole are exposed to reactive species generated in a low-temperature gliding arc plasma in humid air, which induces the oxidation of the copper surface. Copper foils immersed in a 0.1 M benzotriazole solution, and later exposed to a strongly oxidizing gliding arc plasma in humid air, yield oxide layers, the thickness and the nature of which differ from the unconditioned samples. The benzotriazole limits the oxidation process induced by the gaseous species. The organic layer remains active for at least 40 min. For longer exposures, the benzotriazole molecules, which form a film at the surface copper, begin to degrade to carbon dioxide or other volatile organic compounds. This study shows that the non-thermal gliding arc discharge can be used as a tool to study the efficiency of the organic inhibitors present at metallic surfaces. (C) 2004 Elsevier B.V. All rights reserved.