A novel coupling between atomic emission spectroelectrochemistry (AESEC) and electrochemical impedance spectrometry (EIS) is demonstrated. In this way, it is possible to distinguish situations in which the oxidation of the metal leads directly to the formation of dissolved ions or passes through a slightly soluble film intermediate. It was found that Zn dissolution 0.1M NH4Cl occurs without any significant solid intermediate as evidenced by the excellent correlation between the AC components of the electrical current and the zinc dissolution rate. Analysis of the dissolution rate and total current transients as a function of potential directly yields the anodic and cathodic Tafel slopes for this system. In contrast, for Zn/0.5M NaCl, electrochemical oxidation leads directly to the formation of an intermediate corrosion product film with subsequent dissolution. (C) 2015 Elsevier Ltd. All rights reserved.