A spectroelectrochemical cell(1) has been developed to follow in situ the fate of surface reaction products of interest in flotation. The products of xanthate adsorption on a copper electrode were used to test the cell and procedure. Dixanthogen and copper xanthate were identified as the main surface products by both ex situ and in situ FT-IR spectroscopy. Over time, dixanthogen disappeared while the peaks for the copper xanthate intensified. The rare of dixanthogen disappearance was greater for the ex situ than for the in situ conditions.