The present study explored various modes of FTIR analysis, including Surface Enhanced Infrared Spectroscopy (SEIRS), to characterize monolayers of lubricant oil residues which are retained on the surface of aluminum sheet after the rolling process. In this study, gold nano-particles have been deposited from aqueous suspensions to create plasmons on the surface in order to enhance the IR signal. The hydrocarbon peaks were enhanced by a factor of 3 indicating that not all mechanisms of enhancement were engaged. Organic films studied after thermal treatment did not demonstrate any enhancement of the IR signal. This is believed to be related to structural constrains imposed by the thermal treatment on the films and consequent restrictions on the mutual orientation of the plasmons and molecules embedded in the film. Only IR signals associated with organic film were enhanced. The IR signal related to the underlying aluminum oxide film was not enhanced indicating the likely presence of the continuous layer of organics on the surface. Variations in the incident angle of the variable angle attenuated total reflection mode of IR Spectroscopy allowed for accentuation of various parts of the IR spectrum. The FTIR work was supported by measuring absolute surface carbon content using direct combustion method and measurement of the wettability by water. As expected the thermal degradation of the residual rolling oil caused a decrease in the carbon content of the film and an increase in the wettability of surface. However, it was also found that there is a direct proportionality between the cosine of contact angle of water and the absolute amount of carbon on the surface in the process of thermal treatment. (C) 2007 Elsevier B.V. All rights reserved.