Several kinds of graphites (natural from Ceylon, highly oriented pyrolytic (HOPG), pyrolytic crystals) were cathodically charged in the presence of dimethylformamide containing 0.1 M tetraalkylammonium tetrafluoroborate. After uptake of different amounts of charge, the reduced materials were allowed to react with carbon dioxide in solution. Data on the rate of carboxylation are given and the analytical methods providing information on the modification of graphite on the surface and in the bulk. (C) 2003 Elsevier B.V. All rights reserved.