Interaction of certain organic compounds with activated carbon and its effect on the carbon open circuit potentials were studied. It was shown that shifts in open circuit potentials depended on the filling of the activated carbon surface. Whereas adsorption of the investigated compounds on the carbon led to positive potential shifts, their elimination (desorption) from carbon surface led to shifts in the opposite direction. It was also observed that the time dependence of potential shifts is similar for different carbon brands. The magnitude of shifts depended on adsorption activity and porometric characteristics of the carbon adsorbent, as well as the nature of the adsorbate.