Deposition of electrolytic products and contamination may change the surface condition of a glassy carbon electrode, the working electrode in voltammetric measurements. A method for in situ auto-renewal of the surface was developed to obtain reproducible fresh surfaces. The analytical application of this method was verified by differential pulse voltammetric determination of Fe(II). The determination exhibited a reproducibility significantly better than that with un-renewed electrodes or those renewed manually. The results of the voltammetric determination correlated well with those found by a colorimetric method (r = 0.9989). The recovery of Fe(II) added to soil solution ranged from 98% to 104%. The method may find applications in the determination of reducing substances and studies on chemical reaction kinetics in closed systems. (C) 2003 Elsevier B.V. All rights reserved.