Inverse gas chromatography (IGC) is a powerful technique for characterizing the physicochemical properties of a wide variety of materials. The behaviour of minerals in the flotation process is directly related to their wettability, which can be described by surface free energy. In this work, the adsorption of copper and xanthate on hydrophilic pyrite, prepared under different conditions, was studied using X-ray photoelectron spectroscopy (XPS) and IGC. Microflotation experiments were also conducted to determine flotation recovery. The XPS analyses confirmed the presence of copper (I) and xanthate compounds on the surface of treated samples. The surface energy and work of adhesion to water decreased, while the flotation recovery increased due to treatment. IGC has been shown to have the capability of characterizing mineral surfaces, pre- and post-treatment. It enabled the observation of the changes in physicochemical properties of pyrite surface due to surface modification at different conditions. Moreover, combining the microflotation recovery of the samples with IGC results confirmed the correlation between surface energy and flotation response. (C) 2016 Elsevier Ltd. All rights reserved.