A fast and environment-friendly strategy for the determination of thiol content in fossil fuel by cyclic voltammetry (CV) method using an in situ Bismuth film electrode (BiFE) with an acetic acid-acetate/ methanol electrolyte is reported. An extra anodic peak in the CV curve appears, which is at a more positive potential than the oxidation of normal Bi atoms due to the oxidation of Bi adsorbed by thiol. In addition, the cathodic peak is positively shifted due to overlap of the reduction peaks of the Bi-III ons and the Bi-III/thiol complex, forming a Bi film. It is demonstrated that the intensity of the extra anodic peak at -0.45 V is proportional (R-2 >= 0.9990) to the thiol concentration in the electrolyte over the range of 0.10-1.00 mu g mL(-1) with a sensitivity of 121.35 mu A mu g(-1) mL. The proposed method has been successfully applied to the determination of thiol contents in fuel samples with satisfactory recoveries of 100.60-110.00%. (C) 2016 Elsevier Ltd. All rights reserved.